Objective: To compare the stress distribution in the periodontal ligament under different orthodontic forces during canine distalization using long-arm brackets, and to determine the optimal force value for this devic...Objective: To compare the stress distribution in the periodontal ligament under different orthodontic forces during canine distalization using long-arm brackets, and to determine the optimal force value for this device in orthodontic treatment. Methods: A finite element model was constructed after extracting the mandibular first premolar, and a long-arm bracket with a traction height of 6 mm was placed on the labial side of the mandibular canine. Three working conditions of 50 g, 100 g, and 150 g were simulated, and the magnitude and distribution of von Mises stress in the periodontal ligament were compared for each condition. Results: The maximum von Mises stress in the periodontal ligament was 0.013281 MPa in the 50 g condition, 0.02536 MPa in the 100 g condition, and 0.035549 MPa in the 150 g condition. As the orthodontic force increased, the stress distribution area in the periodontal ligament also expanded. Conclusion: A 100 g orthodontic force is the most suitable when using long-arm brackets, providing a relatively uniform stress distribution in the periodontal ligament and keeping the stress within a reasonable range.展开更多
Background: The incidence of early-onset colorectal cancer (EOCRC), which exhibits differential clinical, patho- logical, and molecular features compared to late-onset CRC (LOCRC), is rising globally. The potential di...Background: The incidence of early-onset colorectal cancer (EOCRC), which exhibits differential clinical, patho- logical, and molecular features compared to late-onset CRC (LOCRC), is rising globally. The potential differential effects of blood glucose on EOCRC compared to LOCRC have not been investigated. Methods: This study analyzed 374,568 participants from the UK Biobank cohort and 172,809 participants from the Kailuan cohort. The linear associations between blood glucose and EOCRC/LOCRC were estimated using Cox regression models. Restricted cubic spline (RCS) analysis and non-linear Mendelian randomization (MR) analysis using a 70-SNPs genetic instrument for fasting glucose were used to explore the potential non-linear associations. Results: Participants in the highest quintile of blood glucose had higher overall CRC risk compared to the lowest quintile (HR = 1.10 in the UK Biobank cohort, 95% CI: 1.01-1.21, P -trend = 0.012;HR = 1.23 in the Kailuan cohort, 95% CI: 1.01-1.51, P -trend = 0.036). Elevated glucose ( > 7.0 mmol/L) was more strongly associated with increased risk of EOCRC (HR = 1.61, 95% CI: 1.07-2.44) than with LOCRC (HR = 1.14, 95% CI: 1.02-1.27) in the UK Biobank cohort ( P- heterogeneity = 0.014). Elevated glucose ( > 7.0 mmol/L) was associated with increased risk of LOCRC (HR = 1.25, 95% CI: 1.04-1.65) in the Kailuan cohort as well. There was no evidence for non-linear associations between blood glucose and risks of EOCRC/LOCRC. Conclusions: This study showed a positive association between blood glucose and CRC risk in a dose-response manner, particularly for EOCRC, suggesting that tighter glucose control should be a priority for younger age groups.展开更多
Background and Objective:iASPP, an inhibitory member of the apoptosis-stimulating proteins of p53 (ASPP) family, has been found to be up-regulated in various human tumor types.This study was to construct an efficient ...Background and Objective:iASPP, an inhibitory member of the apoptosis-stimulating proteins of p53 (ASPP) family, has been found to be up-regulated in various human tumor types.This study was to construct an efficient doxycycline-regulated, lentiviral vector-mediated knockdown system for iASPP that will allow for inducible down-regulation of iASPP gene expression and preliminary functional analysis.Methods:A pair of complementary oligos with hairpin structures targeting the iASPP gene and a negative control were synthesized, then ligated with pLVTHM vector and sequenced.The fragment containing the shRNA cassette was cloned to pLVCT-tTR-KRAB plasmid.The recombinant vectors were co-transfected with viral packaging mix into 293T cells, and viral supernatant was harvested to determine the titer.After treatment with or without doxycycline, HepG2 cells infected with virus were harvested and the expression of iASPP was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis.Its effects on tumor growth were characterized using MTS assay, soft agar colony formation, and flow cytometry analysis.Results:The lentiviral vector expressing shRNA that targets to the oncogene iASPP was constructed successfully.HepG2 infected with the lentivirus expressing shRNA against iASPP inhibited the expression of iASPP in the presence of doxycycline, which resulted in the repression of tumor cell proliferation and anchorage-independent growth potential.Conclusions:The lentiviral vector-mediated tet-on system demonstrates efficient and inducible knockdown of iASPP in hepatocellular carcinoma cells.iASPP gene may be involved in tumorigenesis and progression of human tumors.展开更多
BACKGROUND Time in range(TIR),as a novel metric for glycemic control,has robust relevance with diabetic complications.Diabetic peripheral neuropathy(DPN)is characterized by sudomotor dysfunction.AIM To explore the rel...BACKGROUND Time in range(TIR),as a novel metric for glycemic control,has robust relevance with diabetic complications.Diabetic peripheral neuropathy(DPN)is characterized by sudomotor dysfunction.AIM To explore the relationship between TIR obtained from continuous glucose monitoring(CGM)and sudomotor function detected by SUDOSCAN in subjects with type 2 diabetes.METHODS The research enrolled 466 inpatients with type 2 diabetes.All subjects underwent 3-d CGM and SUDOSCAN.SUDOSCAN was assessed with electrochemical skin conductance in hands(HESC)and feet(FESC).Average feet ESC<60μS was defined as sudomotor dysfunction(+),otherwise it was sudomotor dysfunction(-).TIR refers to the percentage of time when blood glucose is between 3.9-10 mmol/L during 1 d period.RESULTS Among the enrolled subjects,135(28.97%)presented with sudomotor dysfunction.Patients with sudomotor dysfunction(+)showed a decreased level of TIR(P<0.001).Compared to the lowest tertile of TIR,the middle and the highest tertiles of TIR was associated with an obviously lower prevalence of sudomotor dysfunction(20.51%and 21.94%vs 44.52%)(P<0.001).In addition,with the increase of TIR,HESC and FESC increased(P<0.001).Regression analysis demonstrated that TIR was inversely and independently linked with the prevalence of sudomotor dysfunction after adjusting for confounding values(odds ratio=0.979,95%CI:0.971-0.987,P<0.001).CONCLUSION The tight glycemic control assessed by TIR is of vitally protective value for sudomotor dysfunction in type 2 diabetes mellitus.展开更多
AIM:To evaluate the effect of reducing the use of antibiotics in the treatment of infant bacterial dacryocystitis after probing of the lacrimal duct.METHODS:A total of 542 cases of children under one year old and acce...AIM:To evaluate the effect of reducing the use of antibiotics in the treatment of infant bacterial dacryocystitis after probing of the lacrimal duct.METHODS:A total of 542 cases of children under one year old and accepting nasolacrimal duct probing treatment were divided into two groups, which were treated with topical and oral antibiotics, respectively.Conjunctival sac secretions were used as a control index of bacterial infection, whereas the disappearance of epiphora symptoms and lacrimal passage patency were used as cure indexes. The χ2test was used to compare enumeration and measurement data, and a statistical significance was set at P 【0.05. The therapeutic effect on the two groups of postoperative patients was investigated.RESULTS:In the two study groups, no significant differences in gender, age and postoperative control of lacrimal sac infection were observed. The cure rates after three probing operations also showed no significant difference.CONCLUSION:After probing of the lacrimal passage,results of this study confirmed that postoperative medication without oral antibiotics but an ophthalmic dosage of antibiotics was a simple and effective treatment method.展开更多
·AIM: To evaluate the difference in angle parameters and clinical outcome following phacoemulsification and combined phacotrabeculectomy in patients with acute primary angle closure(APAC) using ultrasound biomicr...·AIM: To evaluate the difference in angle parameters and clinical outcome following phacoemulsification and combined phacotrabeculectomy in patients with acute primary angle closure(APAC) using ultrasound biomicroscopy(UBM).·METHODS: Patients(n =23, 31 eyes) were randomized to receive phacoemulsification or combined phacotrabeculectomy(n =24, 31 eyes). Best-corrected visual acuity(BCVA), intraocular pressure(IOP), the main complications following surgery, and indentation gonioscopy and angle parameters measured using UBM were documented preoperatively and postoperatively.· RESULTS: The improvement in BCVA in the phacoemulsification group was significantly greater than in the combined group(P 【0.05). IOP in the phacoemulsification group was slightly higher than in the combined group following 1wk of follow-up(P 【0.05),whereas there was no significant difference between the two groups at the latter follow-up(P 】0.05).Phacoemulsification alone resulted in a slight increase in the trabecular ciliary processes distance compared with the combined surgery(P 【0.05), whereas the other angle parameters showed no significant difference between the groups. Complications in combined group were greater than phacoemulsification only group.·CONCLUSION: Both surgeries effectively opened the drainage angle and deepened the anterior chamber, and IOP was well controlled postoperatively. However,phacoemulsification showed better efficacy in improving visual function and showed reduced complications following surgery.展开更多
Published data on earthquake-associated peripheral nerve injury is very limited. Ultrasonography has been proven to be efficient in the clinic to diagnose peripheral nerve injury. The aim of this study was to assess t...Published data on earthquake-associated peripheral nerve injury is very limited. Ultrasonography has been proven to be efficient in the clinic to diagnose peripheral nerve injury. The aim of this study was to assess the role of ultrasound in the evaluation of persistent peripheral nerve injuries 1 year after the Wenchuan earthquake. Thirty-four patients with persistent clinical symptoms and neurologic signs of impaired nerve function were evaluated with sonography prior to surgi- cal repair. Among 34 patients, ultrasonography showed that 48 peripheral nerves were entrapped, and 11 peripheral nerves were disrupted. There was one case of misdiagnosis on ultrasonogra- phy. The concordance rate of ultrasonographic findings with those of surgical findings was 98%. A total of 48 involved nerves underwent neurolysis and the symptoms resolved. Only five nerves had scar tissue entrapment. Preoperative and postoperative clinical and ultrasonographic results were concordant, which verified that ultrasonography is useful for preoperative diagnosis and postoperative evaluation of injured peripheral nerves.展开更多
HSP90 AA1 is part of the heat shock protein 90 gene family and has important functions against heat stress. We report a case of molecular level parallel evolution of the HSP90 AA1 gene in high elevation amphibians. HS...HSP90 AA1 is part of the heat shock protein 90 gene family and has important functions against heat stress. We report a case of molecular level parallel evolution of the HSP90 AA1 gene in high elevation amphibians. HSP90 AA1 gene sequences of four high-elevation anurans, Bufo gargarizans, Nanorana parkeri, Rana kukunoris, and Scutiger boulengeri, were compared along with five of their low-elevation relatives. A total of 16 amino-acid sites were identified as parallel evolution between N. parkeri and R. kukunoris. We generated both model based（Zhang and Kumar＇s test） and empirical data based（parallel/divergence plotting） null distributions for non-parallel evolution, and both methods clearly determined that the observed number of parallel substitutions were significantly more than the null expectation. Furthermore, on the HSP90 AA1 gene tree, N. parkeri and R. kukunoris formed a strongly supported clade that was away from their respective relatives. This study provides a clear case of molecular parallel evolution, which may have significant implications in understanding the genetic mechanisms of high-elevation adaptation.展开更多
With the development and expansion of China's economy, people's artistic and cultural forms have also been significantly improved and developed. At the same time, the educational development of art design in c...With the development and expansion of China's economy, people's artistic and cultural forms have also been significantly improved and developed. At the same time, the educational development of art design in colleges and universities has also become a common trend, for the shaping of the Chinese women's top of the artistic design concept has laid a good cornerstone. At the same time, the Chinese nation after five thousand years of development, the formation of the vast treasures of art and culture, in the origins of circulation is still endless, to the later Chinese children to provide valuable artistic learning resources. The fusion of Chinese folk art culture in the art design education of colleges and universities has a crucial influence on broadening students 'artistic vision, cultivating students' artistic innovation thinking and inheriting Chinese traditional folk art culture. Through the combination of folk art and modern art, the art education of colleges and universities has very far-reaching foresight significance.展开更多
Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic aci...Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.展开更多
BACKGROUND Previous studies have demonstrated the benefits of ideal cardiovascular health(CVH) in reducing cardiovascular risk.However,its role in subclinical atherosclerosis(SA) progression remains unclear.We aim to ...BACKGROUND Previous studies have demonstrated the benefits of ideal cardiovascular health(CVH) in reducing cardiovascular risk.However,its role in subclinical atherosclerosis(SA) progression remains unclear.We aim to examine the association of CVH,estimated by the American Heart Association's new Life's Essential 8(LE8),with the progression of SA.METHODS This prospective cohort study was conducted among 972 asymptomatic Chinese participants and followed up for5.7 years.The LE8 score(range,0–100) consisted of blood pressure,lipids,glucose,body mass index,smoking status,diet health,physical activity and sleep health was evaluated in 1998 and 2008–2009.Progression of SA was determined by carotid plaque and coronary artery calcification(CAC) in 2008–2009 and 2013–2014.Log-binomial regression model was used to estimate the association of LE8 score with SA progression.RESULTS Each 10 points increment in LE8 score was associated with 15.2%(RR:0.848,95% CI:0.797–0.902),17.7%(RR:0.823,95% CI:0.766–0.884) and 12.0%(RR:0.880,95% CI:0.845–0.916) lower risks of carotid plaque,CAC and overall SA progression,respectively.Compared with participants with non-ideal CVH at both visits,the participants with ideal CVH at both visits had39.1%(RR:0.609,95% CI:0.494–0.752),41.0%(RR:0.590,95% CI:0.456–0.764) and 29.7%(RR:0.703,95% CI:0.598–0.825) lower risks of carotid plaque,CAC and overall SA progression,respectively.CONCLUSIONS Higher LE8 scores were associated with lower risks of SA progression.Besides,long-term maintenance of optimal CVH was more beneficial to prevent SA progression.展开更多
AIM： To observe the attenuation of ethanol extract of Herba Scutellaria barbata （SE） against diabetic retinopathy （DR） and its engaged mechanism. METHODS： C57BL/6J mice were intraperitoneally injected with stre...AIM： To observe the attenuation of ethanol extract of Herba Scutellaria barbata （SE） against diabetic retinopathy （DR） and its engaged mechanism. METHODS： C57BL/6J mice were intraperitoneally injected with streptozotocin （STZ, 55 mg/kg） for 5 consecutive days to induce diabetes, The diabetic mice were orally given with SE （100, 200 mg/kg） for lmo at lmo after STZ injection. Blood-retinal barrier （BRB） breakdown was detected by using Evans blue permeation assay. Real-time polymerase chain reaction （RT-PCR）, Western blot and immunofiuorescence staining were used to detect mRNA and protein expression. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum contents of tumor necrosis factor-e （TNF-a） and interleukin （IL）-II. RESULTS： SE （100, 200 mg/kg） reversed the breakdown of BRB in STZ-induced diabetic mice. The decreased expression of retinal claudin-1 and claudin-19, which are both tight junction （T J） proteins, was reversed by SE. SE decreased the increased serum contents and retinal mRNA expression of TNF-a and IL-113. SE also decreased the increased retinal expression of intercellular cell adhesion molecule-1 （ICAM-1）. SE reduced the increased phosphorylation of nuclear factor kappa B （NFKB） p65 and its subsequent nuclear translocation in retinas from STZ- induced diabetic mice. Results of Western blot and retinal immunofluorescence staining of ionized calcium-binding adapter molecule 1 （Ibal） demonstrated that SE abrogated the activation of microglia cells in STZ-induced diabetic mice. CONCLUSION： SE attenuates the development of DR by inhibiting retinal inflammation and restoring the decreased expression of TJ proteins including claudin-1 and claudin-19.展开更多
AIM:To compare postoperative complications and prognosis of esophageal squamous cell carcinoma patients treated with different routes of reconstruction. METHODS:After obtaining approval from the Medical Ethics Committ...AIM:To compare postoperative complications and prognosis of esophageal squamous cell carcinoma patients treated with different routes of reconstruction. METHODS:After obtaining approval from the Medical Ethics Committee of the Sun Yat-Sen University Cancer Center, we retrospectively reviewed data from 306 consecutive patients with histologically diagnosed esophageal squamous cell carcinoma who were treated between 2001 and 2011. All patients underwent radical McKeown-type esophagectomy with at least two-field lymphadenectomy. Regular follow-up was performed in our outpatient department. Postoperative complica-tions and long-term survival were analyzed by treatment modality, baseline patient characteristics, and operative procedure. Data from patients treated via the retrosternal and posterior mediastinal routes were compared. RESULTS:The posterior mediastinal and retrosternal reconstruction routes were employed in 120 and 186 patients, respectively. Pulmonary complications were the most common complications experienced during the postoperative period (46.1% of all patients; 141/306). Compared to the retrosternal route, the posterior mediastinal reconstruction route was associated with a lower incidence of anastomotic stricture (15.8% vs 27.4%, P = 0.018) and less surgical bleeding (242.8 ± 114.2 mL vs 308.2 ± 168.4 mL, P < 0.001). The median survival time was 26.8 mo (range:1.6-116.1 mo). Upon uni/multivariate analysis, a lower preoperative albumin level (P = 0.009) and a more advanced pathological stage (pT; P = 0.006; pN; P < 0.001) were identified as independent factors predicting poor prognosis. The reconstruction route did not influence prognosis (P = 0.477). CONCLUSION:The posterior mediastinal route of reconstruction reduces incidence of postoperative complications but does not affect survival. This route is recommended for resectable esophageal squamous cell carcinoma.展开更多
AIM To study the role of microbial metabolites in the modulation of biochemical and physiological processes in irritable bowel syndrome(IBS).METHODS In the current study, using a metabolomic approach, we analyzed the ...AIM To study the role of microbial metabolites in the modulation of biochemical and physiological processes in irritable bowel syndrome(IBS).METHODS In the current study, using a metabolomic approach, we analyzed the key metabolites differentially excreted in the feces of control mice and mice with IBS, with or without Clostridium butyricum(C. butyricum) treatment. C57 BL/6 mice were divided into control, IBS, and IBS + C. butyricum groups. In the IBS and IBS + C. butyricum groups, the mice were subjected to water avoidance stress(WAS) for 1 h/d for ten days. Gas chromatography/mass spectrometry(GC-MS) together with multivariate analysis was employed to compare the fecal samples between groups. RESULTS WAS exposure established an appropriate model of IBS in mice, with symptoms of visceral hyperalgesia and diarrhea. The differences in the metabolite profiles between the control group and IBS group significantly changed with the progression of IBS(days 0, 5, 10, and 17). A total of 14 differentially excreted metabolites were identified between the control and IBS groups, and phenylethylamine was a major metabolite induced by stress. In addition, phenylalanine metabolism was found to be the most relevant metabolic pathway. Between the IBS group and IBS + C. butyricum group, 10 differentially excreted metabolites were identified. Among these, pantothenate and coenzyme A(Co A) biosynthesis metabolites, as well as steroid hormone biosynthesis metabolites were identified as significantly relevant metabolic pathways.CONCLUSION The metabolic profile of IBS mice is significantly altered compared to control mice. Supplementation with C. butyricum to IBS mice may provide a considerable benefit by modulating host metabolism.展开更多
·AIM: To establishtherat model of streptozotocin (STZ)- induced diabetic retinopathy (DR), which is the most common cause of visual loss and blindness in patients with diabetes, and observe the gene expression of...·AIM: To establishtherat model of streptozotocin (STZ)- induced diabetic retinopathy (DR), which is the most common cause of visual loss and blindness in patients with diabetes, and observe the gene expression of vascular endothelial growth factor (VEGF) and its receptors during the development of DR. ·METHODS: A rat model of diabetes was established by intraperitoneal injection of STZ. The diabetic rats were housed for 2, 3 and 4 months after the development of diabetes. Retinal histopathological observation was performed. The retinal vessels were observed by immunofluorescence staining by CD31. The mRNA expression of VEGF, VEGF receptor 1 and 2 (VEGFR1/2) in rat retina was detected by reverse transcription - polymerase chain reaction (RT-PCR) analysis. · RESULTS: Retinal histopathological observation showed the morphological changes of inner nuclear layer (INL) and outer nuclear layer (ONL) at any time -point, and also demonstrated the increased new vessels at both 3, 4 months after the development of diabetes. The CD31 staining results showed that the number of vessels was increased in the retinas of diabetic rats at both 3 and 4 months after the development of diabetes. As compared to the normal rats, the mRNA expression of VEGF was increased in retinas of diabetic rats at 3 months after the development of diabetes, while VEGFR1 and VEGFR2 mRNA expression was increased at 2, 3 and 4 months after the development of diabetes.·CONCLUSION:Takentogether,ourresultsdemonstrated that DR was occurred at 3 months after the development of diabetes, and the mRNA expression of VEGF, VEGFR1 and VEGFR2 were increased in the process of DR. The present study further evidenced the involvement of VEGF and its receptors in the process of DR. ·展开更多
Background The incidence of coronary heart disease （CHD） is higher in Northern than that in Southern China, however differences in traditional CHD risk factors do not fully explain this. No study has examined the di...Background The incidence of coronary heart disease （CHD） is higher in Northern than that in Southern China, however differences in traditional CHD risk factors do not fully explain this. No study has examined the differences in subclinical atherosclerosis that may help explain the differences in incidence. This study examined these differences in subclinical atherosclerosis using coronary computed tomography （CT） for calcification between the Northern and Southern China. Methods We selected a random sample of participants in a large multi-center ongoing epidemiologic study for coronary calcium scanning in one northern city （North） （Beijing, n = 49） and in two southern cities （South） （Shanghai, n = 50, and Guangzhou, n = 50）. Participants from the three field centers （mean age 67 years） underwent coronary risk factor evaluation and cardiac CT scanning for coronary calcium measurement using the Multi-Ethnic Study of Atherosclerosis scanning protocol. Results Adjusted log-transformed coronary artery calcium score in North China （Beijing） was 3.1 ±0.4 and in South China （Shanghai and Guangzhou） was 2.2 ＋_ 0.3 （P = 0.04）. Mean calcium score for the northern city of Beijing was three times higher than that of the southern city of Guangzhou （P = 0.01） and 2.5 times higher than for the southern city of Shanghai （P = 0.03）. Conclusions The extent of subclinical atherosclerosis is significantly higher in the northern city of Beijing than that in the two southern cities of Guangzhou and Shanghai, even after adjusting for standard cardiac risk factors. This finding suggests that standard risk factors do not fully explain north south differences in clinical CHD incidence.展开更多
The synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide using potassium hydroxide as catalyst in the presence of CH3I and the effect of ionic liquid on the reaction were investigated. The results ...The synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide using potassium hydroxide as catalyst in the presence of CH3I and the effect of ionic liquid on the reaction were investigated. The results showed that KOH is an effective catalyst; the high selectivity and raised yield of DMC formation under mild conditions were achieved. However, the addition of the ionic liquid, l-ethyl-3-methylimidazolium bromide （emimBr）, can evidently accelerate the conversion of methanol and yield of the product.展开更多
Helicobacter pylori(H.pylori)infection is a major riskfactor for gastric cancer(GC)development,which isone of the most challenging malignant diseases worldwide with limited treatments.In the multistep pathogenesis of ...Helicobacter pylori(H.pylori)infection is a major riskfactor for gastric cancer(GC)development,which isone of the most challenging malignant diseases worldwide with limited treatments.In the multistep pathogenesis of GC,H.pylori infection slowly induces chronicactive gastritis,which progresses through the premalignant stages of atrophic gastritis,intestinal metaplasia,and dysplasia,and then finally to GC.Although eradication of H.pylori is a reasonable approach for the prevention of GC,there have been some contradictory reports,with only some long-term follow-up data showingefficacy of this approach.The inconsistencies are likely due to the insufficient number of participants,relatively short follow-up periods,poor quality of study designs,and the degree and extent of preneoplastic changes atthe time of H.pylori eradication.This review analyzesrecent high-quality studies to resolve the discrepancies regarding the eradication of H.pylori for GC prevention.The relationship between H.pylori eradication and GC/precancerous lesions/metachronous GC is examined,and the cost-effectiveness of this strategy in the prevention of GC is assessed.Although it is assumed that eradication of H.pylori has the potential to prevent GC,the feasibility and appropriate timing of this strategy for cancer prevention remain to be determined.As a result,additional well-designed trials with longer followup periods are needed to clarify this issue.展开更多
文摘Objective: To compare the stress distribution in the periodontal ligament under different orthodontic forces during canine distalization using long-arm brackets, and to determine the optimal force value for this device in orthodontic treatment. Methods: A finite element model was constructed after extracting the mandibular first premolar, and a long-arm bracket with a traction height of 6 mm was placed on the labial side of the mandibular canine. Three working conditions of 50 g, 100 g, and 150 g were simulated, and the magnitude and distribution of von Mises stress in the periodontal ligament were compared for each condition. Results: The maximum von Mises stress in the periodontal ligament was 0.013281 MPa in the 50 g condition, 0.02536 MPa in the 100 g condition, and 0.035549 MPa in the 150 g condition. As the orthodontic force increased, the stress distribution area in the periodontal ligament also expanded. Conclusion: A 100 g orthodontic force is the most suitable when using long-arm brackets, providing a relatively uniform stress distribution in the periodontal ligament and keeping the stress within a reasonable range.
基金funded by the Chinese Academy of Medical Science Innovation Fund for Medical Science(grant number:2022-I2M-1-0031)the National Natural Science Foundation of China(grant number:82173606)+1 种基金supported by the Beijing Nova Program of Science and Technology(grant number:20230484397)the Na-tional Natural Science Foundation of China(grant number:82273726).
文摘Background: The incidence of early-onset colorectal cancer (EOCRC), which exhibits differential clinical, patho- logical, and molecular features compared to late-onset CRC (LOCRC), is rising globally. The potential differential effects of blood glucose on EOCRC compared to LOCRC have not been investigated. Methods: This study analyzed 374,568 participants from the UK Biobank cohort and 172,809 participants from the Kailuan cohort. The linear associations between blood glucose and EOCRC/LOCRC were estimated using Cox regression models. Restricted cubic spline (RCS) analysis and non-linear Mendelian randomization (MR) analysis using a 70-SNPs genetic instrument for fasting glucose were used to explore the potential non-linear associations. Results: Participants in the highest quintile of blood glucose had higher overall CRC risk compared to the lowest quintile (HR = 1.10 in the UK Biobank cohort, 95% CI: 1.01-1.21, P -trend = 0.012;HR = 1.23 in the Kailuan cohort, 95% CI: 1.01-1.51, P -trend = 0.036). Elevated glucose ( > 7.0 mmol/L) was more strongly associated with increased risk of EOCRC (HR = 1.61, 95% CI: 1.07-2.44) than with LOCRC (HR = 1.14, 95% CI: 1.02-1.27) in the UK Biobank cohort ( P- heterogeneity = 0.014). Elevated glucose ( > 7.0 mmol/L) was associated with increased risk of LOCRC (HR = 1.25, 95% CI: 1.04-1.65) in the Kailuan cohort as well. There was no evidence for non-linear associations between blood glucose and risks of EOCRC/LOCRC. Conclusions: This study showed a positive association between blood glucose and CRC risk in a dose-response manner, particularly for EOCRC, suggesting that tighter glucose control should be a priority for younger age groups.
文摘Background and Objective:iASPP, an inhibitory member of the apoptosis-stimulating proteins of p53 (ASPP) family, has been found to be up-regulated in various human tumor types.This study was to construct an efficient doxycycline-regulated, lentiviral vector-mediated knockdown system for iASPP that will allow for inducible down-regulation of iASPP gene expression and preliminary functional analysis.Methods:A pair of complementary oligos with hairpin structures targeting the iASPP gene and a negative control were synthesized, then ligated with pLVTHM vector and sequenced.The fragment containing the shRNA cassette was cloned to pLVCT-tTR-KRAB plasmid.The recombinant vectors were co-transfected with viral packaging mix into 293T cells, and viral supernatant was harvested to determine the titer.After treatment with or without doxycycline, HepG2 cells infected with virus were harvested and the expression of iASPP was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis.Its effects on tumor growth were characterized using MTS assay, soft agar colony formation, and flow cytometry analysis.Results:The lentiviral vector expressing shRNA that targets to the oncogene iASPP was constructed successfully.HepG2 infected with the lentivirus expressing shRNA against iASPP inhibited the expression of iASPP in the presence of doxycycline, which resulted in the repression of tumor cell proliferation and anchorage-independent growth potential.Conclusions:The lentiviral vector-mediated tet-on system demonstrates efficient and inducible knockdown of iASPP in hepatocellular carcinoma cells.iASPP gene may be involved in tumorigenesis and progression of human tumors.
基金National Natural Science Foundation of China,No.81774134 and No.81873174Natural Science Foundation of Jiangsu Province of China,No.BK20150558 and No.BK20171331+2 种基金Postdoctoral Foundation of Jiangsu Province of China,No.1501120CJiangsu Province 333 Talent Funding Project,No.BRA2017595Young Medical Key Talents Project of Jiangsu Province,No.QNRC2016902.
文摘BACKGROUND Time in range(TIR),as a novel metric for glycemic control,has robust relevance with diabetic complications.Diabetic peripheral neuropathy(DPN)is characterized by sudomotor dysfunction.AIM To explore the relationship between TIR obtained from continuous glucose monitoring(CGM)and sudomotor function detected by SUDOSCAN in subjects with type 2 diabetes.METHODS The research enrolled 466 inpatients with type 2 diabetes.All subjects underwent 3-d CGM and SUDOSCAN.SUDOSCAN was assessed with electrochemical skin conductance in hands(HESC)and feet(FESC).Average feet ESC<60μS was defined as sudomotor dysfunction(+),otherwise it was sudomotor dysfunction(-).TIR refers to the percentage of time when blood glucose is between 3.9-10 mmol/L during 1 d period.RESULTS Among the enrolled subjects,135(28.97%)presented with sudomotor dysfunction.Patients with sudomotor dysfunction(+)showed a decreased level of TIR(P<0.001).Compared to the lowest tertile of TIR,the middle and the highest tertiles of TIR was associated with an obviously lower prevalence of sudomotor dysfunction(20.51%and 21.94%vs 44.52%)(P<0.001).In addition,with the increase of TIR,HESC and FESC increased(P<0.001).Regression analysis demonstrated that TIR was inversely and independently linked with the prevalence of sudomotor dysfunction after adjusting for confounding values(odds ratio=0.979,95%CI:0.971-0.987,P<0.001).CONCLUSION The tight glycemic control assessed by TIR is of vitally protective value for sudomotor dysfunction in type 2 diabetes mellitus.
文摘AIM:To evaluate the effect of reducing the use of antibiotics in the treatment of infant bacterial dacryocystitis after probing of the lacrimal duct.METHODS:A total of 542 cases of children under one year old and accepting nasolacrimal duct probing treatment were divided into two groups, which were treated with topical and oral antibiotics, respectively.Conjunctival sac secretions were used as a control index of bacterial infection, whereas the disappearance of epiphora symptoms and lacrimal passage patency were used as cure indexes. The χ2test was used to compare enumeration and measurement data, and a statistical significance was set at P 【0.05. The therapeutic effect on the two groups of postoperative patients was investigated.RESULTS:In the two study groups, no significant differences in gender, age and postoperative control of lacrimal sac infection were observed. The cure rates after three probing operations also showed no significant difference.CONCLUSION:After probing of the lacrimal passage,results of this study confirmed that postoperative medication without oral antibiotics but an ophthalmic dosage of antibiotics was a simple and effective treatment method.
文摘·AIM: To evaluate the difference in angle parameters and clinical outcome following phacoemulsification and combined phacotrabeculectomy in patients with acute primary angle closure(APAC) using ultrasound biomicroscopy(UBM).·METHODS: Patients(n =23, 31 eyes) were randomized to receive phacoemulsification or combined phacotrabeculectomy(n =24, 31 eyes). Best-corrected visual acuity(BCVA), intraocular pressure(IOP), the main complications following surgery, and indentation gonioscopy and angle parameters measured using UBM were documented preoperatively and postoperatively.· RESULTS: The improvement in BCVA in the phacoemulsification group was significantly greater than in the combined group(P 【0.05). IOP in the phacoemulsification group was slightly higher than in the combined group following 1wk of follow-up(P 【0.05),whereas there was no significant difference between the two groups at the latter follow-up(P 】0.05).Phacoemulsification alone resulted in a slight increase in the trabecular ciliary processes distance compared with the combined surgery(P 【0.05), whereas the other angle parameters showed no significant difference between the groups. Complications in combined group were greater than phacoemulsification only group.·CONCLUSION: Both surgeries effectively opened the drainage angle and deepened the anterior chamber, and IOP was well controlled postoperatively. However,phacoemulsification showed better efficacy in improving visual function and showed reduced complications following surgery.
基金supported by a grant from the National High Technology Research and Development Program of China(863 Program),No.2008AA022400a grant from the Sichuan Technology Department of Sichuan Province,No.2009Y0174a grant from the Chengdu Technology Department of Chengdu City,No.(2012)530021
文摘Published data on earthquake-associated peripheral nerve injury is very limited. Ultrasonography has been proven to be efficient in the clinic to diagnose peripheral nerve injury. The aim of this study was to assess the role of ultrasound in the evaluation of persistent peripheral nerve injuries 1 year after the Wenchuan earthquake. Thirty-four patients with persistent clinical symptoms and neurologic signs of impaired nerve function were evaluated with sonography prior to surgi- cal repair. Among 34 patients, ultrasonography showed that 48 peripheral nerves were entrapped, and 11 peripheral nerves were disrupted. There was one case of misdiagnosis on ultrasonogra- phy. The concordance rate of ultrasonographic findings with those of surgical findings was 98%. A total of 48 involved nerves underwent neurolysis and the symptoms resolved. Only five nerves had scar tissue entrapment. Preoperative and postoperative clinical and ultrasonographic results were concordant, which verified that ultrasonography is useful for preoperative diagnosis and postoperative evaluation of injured peripheral nerves.
基金supported by the National Nature Science Foundation of China (grant number 31328021 to Jinzhong FU)NSERC of Canada (a discovery grant to Jinzhong FU)
文摘HSP90 AA1 is part of the heat shock protein 90 gene family and has important functions against heat stress. We report a case of molecular level parallel evolution of the HSP90 AA1 gene in high elevation amphibians. HSP90 AA1 gene sequences of four high-elevation anurans, Bufo gargarizans, Nanorana parkeri, Rana kukunoris, and Scutiger boulengeri, were compared along with five of their low-elevation relatives. A total of 16 amino-acid sites were identified as parallel evolution between N. parkeri and R. kukunoris. We generated both model based（Zhang and Kumar＇s test） and empirical data based（parallel/divergence plotting） null distributions for non-parallel evolution, and both methods clearly determined that the observed number of parallel substitutions were significantly more than the null expectation. Furthermore, on the HSP90 AA1 gene tree, N. parkeri and R. kukunoris formed a strongly supported clade that was away from their respective relatives. This study provides a clear case of molecular parallel evolution, which may have significant implications in understanding the genetic mechanisms of high-elevation adaptation.
文摘With the development and expansion of China's economy, people's artistic and cultural forms have also been significantly improved and developed. At the same time, the educational development of art design in colleges and universities has also become a common trend, for the shaping of the Chinese women's top of the artistic design concept has laid a good cornerstone. At the same time, the Chinese nation after five thousand years of development, the formation of the vast treasures of art and culture, in the origins of circulation is still endless, to the later Chinese children to provide valuable artistic learning resources. The fusion of Chinese folk art culture in the art design education of colleges and universities has a crucial influence on broadening students 'artistic vision, cultivating students' artistic innovation thinking and inheriting Chinese traditional folk art culture. Through the combination of folk art and modern art, the art education of colleges and universities has very far-reaching foresight significance.
基金supported by the National Natural Science Foundation of China(32272654)the Natural Science Foundation of Hebei Province China(C2023204016)+2 种基金the Hebei Province Introduced Overseas-Scholar Fund China(C20220361)the S&T Program of Hebei China(20326330D)the Hebei Province Outstanding Youth Fund China(2016,2019)。
文摘Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.
基金funded by the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(2021-I2M-1-010,2019-I2M-2-003,and 2017-I2M-1-004)National Natural Science Foundation of China(82030102,12126602,82330106,82322059,and 91857118)+1 种基金National High Level Hospital Clinical Research Funding(2022-GSP-GG-1,and 2022-GSP-GG-2)National Key Research and Development Program of China(2021YFC2500500).
文摘BACKGROUND Previous studies have demonstrated the benefits of ideal cardiovascular health(CVH) in reducing cardiovascular risk.However,its role in subclinical atherosclerosis(SA) progression remains unclear.We aim to examine the association of CVH,estimated by the American Heart Association's new Life's Essential 8(LE8),with the progression of SA.METHODS This prospective cohort study was conducted among 972 asymptomatic Chinese participants and followed up for5.7 years.The LE8 score(range,0–100) consisted of blood pressure,lipids,glucose,body mass index,smoking status,diet health,physical activity and sleep health was evaluated in 1998 and 2008–2009.Progression of SA was determined by carotid plaque and coronary artery calcification(CAC) in 2008–2009 and 2013–2014.Log-binomial regression model was used to estimate the association of LE8 score with SA progression.RESULTS Each 10 points increment in LE8 score was associated with 15.2%(RR:0.848,95% CI:0.797–0.902),17.7%(RR:0.823,95% CI:0.766–0.884) and 12.0%(RR:0.880,95% CI:0.845–0.916) lower risks of carotid plaque,CAC and overall SA progression,respectively.Compared with participants with non-ideal CVH at both visits,the participants with ideal CVH at both visits had39.1%(RR:0.609,95% CI:0.494–0.752),41.0%(RR:0.590,95% CI:0.456–0.764) and 29.7%(RR:0.703,95% CI:0.598–0.825) lower risks of carotid plaque,CAC and overall SA progression,respectively.CONCLUSIONS Higher LE8 scores were associated with lower risks of SA progression.Besides,long-term maintenance of optimal CVH was more beneficial to prevent SA progression.
基金Supported by the National Natural Science Foundation of China(No.81173517No.81322053)
文摘AIM： To observe the attenuation of ethanol extract of Herba Scutellaria barbata （SE） against diabetic retinopathy （DR） and its engaged mechanism. METHODS： C57BL/6J mice were intraperitoneally injected with streptozotocin （STZ, 55 mg/kg） for 5 consecutive days to induce diabetes, The diabetic mice were orally given with SE （100, 200 mg/kg） for lmo at lmo after STZ injection. Blood-retinal barrier （BRB） breakdown was detected by using Evans blue permeation assay. Real-time polymerase chain reaction （RT-PCR）, Western blot and immunofiuorescence staining were used to detect mRNA and protein expression. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum contents of tumor necrosis factor-e （TNF-a） and interleukin （IL）-II. RESULTS： SE （100, 200 mg/kg） reversed the breakdown of BRB in STZ-induced diabetic mice. The decreased expression of retinal claudin-1 and claudin-19, which are both tight junction （T J） proteins, was reversed by SE. SE decreased the increased serum contents and retinal mRNA expression of TNF-a and IL-113. SE also decreased the increased retinal expression of intercellular cell adhesion molecule-1 （ICAM-1）. SE reduced the increased phosphorylation of nuclear factor kappa B （NFKB） p65 and its subsequent nuclear translocation in retinas from STZ- induced diabetic mice. Results of Western blot and retinal immunofluorescence staining of ionized calcium-binding adapter molecule 1 （Ibal） demonstrated that SE abrogated the activation of microglia cells in STZ-induced diabetic mice. CONCLUSION： SE attenuates the development of DR by inhibiting retinal inflammation and restoring the decreased expression of TJ proteins including claudin-1 and claudin-19.
基金Supported by Science and Technology Project of Guangdong Province, China, No. 2010B031600220 and 2008B030303008
文摘AIM:To compare postoperative complications and prognosis of esophageal squamous cell carcinoma patients treated with different routes of reconstruction. METHODS:After obtaining approval from the Medical Ethics Committee of the Sun Yat-Sen University Cancer Center, we retrospectively reviewed data from 306 consecutive patients with histologically diagnosed esophageal squamous cell carcinoma who were treated between 2001 and 2011. All patients underwent radical McKeown-type esophagectomy with at least two-field lymphadenectomy. Regular follow-up was performed in our outpatient department. Postoperative complica-tions and long-term survival were analyzed by treatment modality, baseline patient characteristics, and operative procedure. Data from patients treated via the retrosternal and posterior mediastinal routes were compared. RESULTS:The posterior mediastinal and retrosternal reconstruction routes were employed in 120 and 186 patients, respectively. Pulmonary complications were the most common complications experienced during the postoperative period (46.1% of all patients; 141/306). Compared to the retrosternal route, the posterior mediastinal reconstruction route was associated with a lower incidence of anastomotic stricture (15.8% vs 27.4%, P = 0.018) and less surgical bleeding (242.8 ± 114.2 mL vs 308.2 ± 168.4 mL, P < 0.001). The median survival time was 26.8 mo (range:1.6-116.1 mo). Upon uni/multivariate analysis, a lower preoperative albumin level (P = 0.009) and a more advanced pathological stage (pT; P = 0.006; pN; P < 0.001) were identified as independent factors predicting poor prognosis. The reconstruction route did not influence prognosis (P = 0.477). CONCLUSION:The posterior mediastinal route of reconstruction reduces incidence of postoperative complications but does not affect survival. This route is recommended for resectable esophageal squamous cell carcinoma.
基金Supported by the National Natural Science Foundation of China,No.81470814 and No.81400594Zhejiang Provincial Natural Science Foundation of China,No.LQ14H160014
文摘AIM To study the role of microbial metabolites in the modulation of biochemical and physiological processes in irritable bowel syndrome(IBS).METHODS In the current study, using a metabolomic approach, we analyzed the key metabolites differentially excreted in the feces of control mice and mice with IBS, with or without Clostridium butyricum(C. butyricum) treatment. C57 BL/6 mice were divided into control, IBS, and IBS + C. butyricum groups. In the IBS and IBS + C. butyricum groups, the mice were subjected to water avoidance stress(WAS) for 1 h/d for ten days. Gas chromatography/mass spectrometry(GC-MS) together with multivariate analysis was employed to compare the fecal samples between groups. RESULTS WAS exposure established an appropriate model of IBS in mice, with symptoms of visceral hyperalgesia and diarrhea. The differences in the metabolite profiles between the control group and IBS group significantly changed with the progression of IBS(days 0, 5, 10, and 17). A total of 14 differentially excreted metabolites were identified between the control and IBS groups, and phenylethylamine was a major metabolite induced by stress. In addition, phenylalanine metabolism was found to be the most relevant metabolic pathway. Between the IBS group and IBS + C. butyricum group, 10 differentially excreted metabolites were identified. Among these, pantothenate and coenzyme A(Co A) biosynthesis metabolites, as well as steroid hormone biosynthesis metabolites were identified as significantly relevant metabolic pathways.CONCLUSION The metabolic profile of IBS mice is significantly altered compared to control mice. Supplementation with C. butyricum to IBS mice may provide a considerable benefit by modulating host metabolism.
基金National Natural Science Foundation of China(No.81173517)
文摘·AIM: To establishtherat model of streptozotocin (STZ)- induced diabetic retinopathy (DR), which is the most common cause of visual loss and blindness in patients with diabetes, and observe the gene expression of vascular endothelial growth factor (VEGF) and its receptors during the development of DR. ·METHODS: A rat model of diabetes was established by intraperitoneal injection of STZ. The diabetic rats were housed for 2, 3 and 4 months after the development of diabetes. Retinal histopathological observation was performed. The retinal vessels were observed by immunofluorescence staining by CD31. The mRNA expression of VEGF, VEGF receptor 1 and 2 (VEGFR1/2) in rat retina was detected by reverse transcription - polymerase chain reaction (RT-PCR) analysis. · RESULTS: Retinal histopathological observation showed the morphological changes of inner nuclear layer (INL) and outer nuclear layer (ONL) at any time -point, and also demonstrated the increased new vessels at both 3, 4 months after the development of diabetes. The CD31 staining results showed that the number of vessels was increased in the retinas of diabetic rats at both 3 and 4 months after the development of diabetes. As compared to the normal rats, the mRNA expression of VEGF was increased in retinas of diabetic rats at 3 months after the development of diabetes, while VEGFR1 and VEGFR2 mRNA expression was increased at 2, 3 and 4 months after the development of diabetes.·CONCLUSION:Takentogether,ourresultsdemonstrated that DR was occurred at 3 months after the development of diabetes, and the mRNA expression of VEGF, VEGFR1 and VEGFR2 were increased in the process of DR. The present study further evidenced the involvement of VEGF and its receptors in the process of DR. ·
文摘Background The incidence of coronary heart disease （CHD） is higher in Northern than that in Southern China, however differences in traditional CHD risk factors do not fully explain this. No study has examined the differences in subclinical atherosclerosis that may help explain the differences in incidence. This study examined these differences in subclinical atherosclerosis using coronary computed tomography （CT） for calcification between the Northern and Southern China. Methods We selected a random sample of participants in a large multi-center ongoing epidemiologic study for coronary calcium scanning in one northern city （North） （Beijing, n = 49） and in two southern cities （South） （Shanghai, n = 50, and Guangzhou, n = 50）. Participants from the three field centers （mean age 67 years） underwent coronary risk factor evaluation and cardiac CT scanning for coronary calcium measurement using the Multi-Ethnic Study of Atherosclerosis scanning protocol. Results Adjusted log-transformed coronary artery calcium score in North China （Beijing） was 3.1 ±0.4 and in South China （Shanghai and Guangzhou） was 2.2 ＋_ 0.3 （P = 0.04）. Mean calcium score for the northern city of Beijing was three times higher than that of the southern city of Guangzhou （P = 0.01） and 2.5 times higher than for the southern city of Shanghai （P = 0.03）. Conclusions The extent of subclinical atherosclerosis is significantly higher in the northern city of Beijing than that in the two southern cities of Guangzhou and Shanghai, even after adjusting for standard cardiac risk factors. This finding suggests that standard risk factors do not fully explain north south differences in clinical CHD incidence.
文摘The synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide using potassium hydroxide as catalyst in the presence of CH3I and the effect of ionic liquid on the reaction were investigated. The results showed that KOH is an effective catalyst; the high selectivity and raised yield of DMC formation under mild conditions were achieved. However, the addition of the ionic liquid, l-ethyl-3-methylimidazolium bromide （emimBr）, can evidently accelerate the conversion of methanol and yield of the product.
文摘Helicobacter pylori(H.pylori)infection is a major riskfactor for gastric cancer(GC)development,which isone of the most challenging malignant diseases worldwide with limited treatments.In the multistep pathogenesis of GC,H.pylori infection slowly induces chronicactive gastritis,which progresses through the premalignant stages of atrophic gastritis,intestinal metaplasia,and dysplasia,and then finally to GC.Although eradication of H.pylori is a reasonable approach for the prevention of GC,there have been some contradictory reports,with only some long-term follow-up data showingefficacy of this approach.The inconsistencies are likely due to the insufficient number of participants,relatively short follow-up periods,poor quality of study designs,and the degree and extent of preneoplastic changes atthe time of H.pylori eradication.This review analyzesrecent high-quality studies to resolve the discrepancies regarding the eradication of H.pylori for GC prevention.The relationship between H.pylori eradication and GC/precancerous lesions/metachronous GC is examined,and the cost-effectiveness of this strategy in the prevention of GC is assessed.Although it is assumed that eradication of H.pylori has the potential to prevent GC,the feasibility and appropriate timing of this strategy for cancer prevention remain to be determined.As a result,additional well-designed trials with longer followup periods are needed to clarify this issue.
