BACKGROUND Acute appendicitis is the most common abdominal emergency.At present,the main treatments for periappendiceal abscess include antibiotics and surgery.However,the complications and mortality of emergency surg...BACKGROUND Acute appendicitis is the most common abdominal emergency.At present,the main treatments for periappendiceal abscess include antibiotics and surgery.However,the complications and mortality of emergency surgery are high.The preferred therapy is conservative treatment with antibiotics first,ultrasound-guided puncture drainage or surgical treatment is followed when necessary.Endoscopic retrograde appendicitis therapy(ERAT)for acute uncomplicated appendicitis have been proved clinically effective,but it is rarely used in periap-pendiceal abscess.CASE SUMMARY We report a patient admitted to hospital because of“right lower abdominal pain for six days”.The computerized tomography(CT)of patient showed that appendicitis with fecaliths and abscess in the pelvis.The patient was treated by CT-guided puncture and drainage of abdominal abscess combined with ERAT to remove appendiceal fecaliths,irrigation and stent placement.CONCLUSION The patient did not receive surgery because of impoverished family.Abdominal pain did not recur during the follow-up period.This case confirms the value of ERAT in the treatment of periappendiceal abscess.展开更多
The information transmission path optimization(ITPO) can often a ect the e ciency and accuracy of remanufactur?ing service. However, there is a greater degree of uncertainty and complexity in information transmission ...The information transmission path optimization(ITPO) can often a ect the e ciency and accuracy of remanufactur?ing service. However, there is a greater degree of uncertainty and complexity in information transmission of remanu?facturing service system, which leads to a critical need for designing planning models to deal with this added uncer?tainty and complexity. In this paper, a three?dimensional(3D) model of remanufacturing service information network for information transmission is developed, which combines the physic coordinate and the transmitted properties of all the devices in the remanufacturing service system. In order to solve the basic ITPO in the 3D model, an improved 3D ant colony algorithm(Improved AC) was put forward. Moreover, to further improve the operation e ciency of the algorithm, an improved ant colony?genetic algorithm(AC?GA) that combines the improved AC and genetic algorithm was developed. In addition, by taking the transmission of remanufacturing service demand information of certain roller as example, the e ectiveness of AC?GA algorithm was analyzed and compared with that of improved AC, and the results demonstrated that AC?GA algorithm was superior to AC algorithm in aspects of information transmission delay, information transmission cost, and rate of information loss.展开更多
A tissue engineering model of heart valve calcification induced in a bio-reactor was established to evaluate the calcification induced by abnormal mechanical stimulation and explore the underlying molecular mechanisms...A tissue engineering model of heart valve calcification induced in a bio-reactor was established to evaluate the calcification induced by abnormal mechanical stimulation and explore the underlying molecular mechanisms.Polyethylene glycol (PEG)-modified decellularized porcine aortic leaflets seeded with human valve interstitial cells (huVICs)were mounted on a Ti-Ni alloy frame to fabricate two-leaflet and three-leaflet tissue engineered valves.The two-leaflet model valves were exposed to abnormal pulsatile flow stimulation with null (group A),low (1000mL/min,group B),medium (2000mL/min,group C),and high velocity (3000mL/min,group D)for 14 days. Morphology and calcification were assessed by yon Kossa staining,alkaline phosphatase (ALP)content,and Runx2 immunostaining.Leaflet calcification and mRNA and protein expression of transforming growth factor (TGF)-β1,bone morphogenetic protein 2 (BMP2),Smadl,and MSX2 were measured at different time points.ALP content was examined in two-leaflet valves seeded with BMP2 shRNA plasmid-infected huVICs and exposed to the same stimulation conditions.The results showed that during 14 days of flow stimulation,huVICs on the leaflet surface proliferated to generate normal monolayer coverage in groups A,B,and C.Under mechanical stimulation,huVICs showed a parallel growth pattern in the direction of the fluid flow,but huVICs exhibited disordered growth in the high-velocity flow environment,yon Kossa staining,ALP measurement,and immunohistochemical staining for Runx2 confirmed the lack of obvious calcification in group A and significant calcification in group D.Expression levels of TGF-β1,BMP2, and MSX2 mRNA and protein were increased under fluid stimulation.ALP production by BMP2 shRNA plasmid-infected huVICs on model leaflets was significantly reduced.In conclusion,abnormal mechanical stimulation in a bioreactor induced calcification in the tissue engineering valve model.The extent of calcification correlated positively with the flow velocity,as did the mRNA and protein levels of TGF-β1,BMP2,and MSX2.These findings indicate that TGF-β1/BMP2 signaling is involved in valve calcification induced bv abnormal mechanical stimulation.展开更多
This study aims to evaluate the clinical outcomes of endoscopic vein harvesting (EVH) for coronary artery bypass grafting (CABG) in obese patients. Totally, 153 obese patients who underwent EVH (n=81) or standar...This study aims to evaluate the clinical outcomes of endoscopic vein harvesting (EVH) for coronary artery bypass grafting (CABG) in obese patients. Totally, 153 obese patients who underwent EVH (n=81) or standard bridging technique (SBT, n=72) in CABG surgery from May 2012 to October 2014 in our hospital were enrolled in this retrospective non-randomized controlled study. The general situation of operation, postoperative complications and short medium-term outcomes were analyzed. The baseline characteristics were similar between these two groups (P〉0.05). There were no statistical differences in total operation time (226±28 min vs. 224±30 min, P〉0.05), number of damaged vessels (0.12±0.05 vs. 0.16±0.06, P〉0.05) and short medium-term outcomes including revascularization rate (1.25% vs. 2.78%, P〉0.05), vessel dysfunction rate (11.25% vs. 11.11%, P〉0.05) and mortality (0.00% vs. 0.00%, P〉0.05). Use of EVH was associated with significant reduction of total harvesting time (41±6 min vs. 63±11 min, P〈0.05), incision length (4.4±1.1 cm vs. 18.2±4.5 cm, P〈0.05) and postoperative lower extremity complications (P〈0.05). EVH can reduce the risk of wound complications, whereas does not influence short- and medium-term outcomes in obese patients. It can be considered a reliable procedure of harvesting vessel conduits for obese patients undergoing CABG.展开更多
YbMnBi2 is a recently discovered time-reversal-symmetry breaking type-Ⅱ Weyl semimetal.However, as a representation of the new category of topological matters, the scanning tunneling microcopy(STM) results on such im...YbMnBi2 is a recently discovered time-reversal-symmetry breaking type-Ⅱ Weyl semimetal.However, as a representation of the new category of topological matters, the scanning tunneling microcopy(STM) results on such important material are still absent.Here, we report the STM investigations on the morphology of vacuum cleaved single crystalline YbMnBi2 samples.A hill and valley type of topography is observed on the YbMnBi2 surface, which is consistent with the non-layer nature of its crystal structure.Analysis of STM images yields the information of the index of the vicinal surface.Our results here lay a playground of future atomic scale research on YbMnBi2.展开更多
BACKGROUND Gastroesophageal varices are a rare complication of essential thrombocythemia(ET).ET is a chronic myeloproliferative neoplasm(MPN)characterized by an increased number of blood platelets.CASE SUMMARY A 46-ye...BACKGROUND Gastroesophageal varices are a rare complication of essential thrombocythemia(ET).ET is a chronic myeloproliferative neoplasm(MPN)characterized by an increased number of blood platelets.CASE SUMMARY A 46-year-old woman,who denied a history of liver disease,was admitted to our hospital on presentation of hematemesis.Laboratory examination revealed a hemoglobin level of 83 g/L,and a platelet count of 397×109/L.The appearance of gastric and esophageal varices with red colored signs as displayed by an urgent endoscopy was followed by endoscopic variceal ligation and endoscopic tissue adhesive.Abdominal computed tomography revealed cirrhosis,marked splenomegaly,portal vein thrombosis and portal hypertension.In addition,bone marrow biopsy and evidence of mutated Janus kinase 2,substantiated the onset of ET.The patient was asymptomatic with regular routine blood testing during the 6-mo follow-up period.Therefore,in this case,gastroesophageal varices were induced by ET.CONCLUSION MPN should be given considerable attention when performing differential diagnoses in patients with gastroesophageal varices.An integrated approach such as laboratory tests,radiological examination,and pathological biopsy,should be included to allow optimal decisions and management.展开更多
A large gate metal height technique is proposed to enhance breakdown voltage in GaN channel and AlGaN channel high-electron-mobility-transistors(HEMTs).For GaN channel HEMTs with gate-drain spacing LGD=2.5μm,the brea...A large gate metal height technique is proposed to enhance breakdown voltage in GaN channel and AlGaN channel high-electron-mobility-transistors(HEMTs).For GaN channel HEMTs with gate-drain spacing LGD=2.5μm,the breakdown voltage VBR increases from 518 V to 582 V by increasing gate metal height h from 0.2μm to 0.4μm.For GaN channel HEMTs with LGD=7μm,VBR increases from 953 V to 1310 V by increasing h from 0.8μm to 1.6μm.The breakdown voltage enhancement results from the increase of the gate sidewall capacitance and depletion region extension.For Al0.4Ga0.6N channel HEMT with LGD=7μm,VBR increases from 1535 V to 1763 V by increasing h from 0.8μm to 1.6μm,resulting in a high average breakdown electric field of 2.51 MV/cm.Simulation and analysis indicate that the high gate metal height is an effective method to enhance breakdown voltage in GaN-based HEMTs,and this method can be utilized in all the lateral semiconductor devices.展开更多
Objective: To determine the frequency of anti-HCV antibody positivity in patients with nonliver disease complaints, to explore whether anti-HCV positive patients had been properly advised and visited hepatologists for...Objective: To determine the frequency of anti-HCV antibody positivity in patients with nonliver disease complaints, to explore whether anti-HCV positive patients had been properly advised and visited hepatologists for further assessments, and to investigate their clinical characteristics as well as the HCV treatment status.Methods: A hospital based survey of nonliver disease patients with anti-HCV positive and their attending physicians was conducted to determine: 1.were the patients adequately advised of the implication of anti-HCV positive finding; 2.to what extent the patients were aware of potential chronic liver disease associated with HCV infection and whether they sought for further assessments and care of hepatologists.Results: A total of 295 294 non-liver disease patients were tested for anti-HCV antibody, and 2 778 of them were found to be positive(0.94%).However, only 45.10%(1 253/2 778) of the anti-HCV antibody(+) patients were referred to hepatologists and received HCV RNA test.In addition, 34.10%(312/915) and 1.42%(13/915) of them had already advanced to cirrhosis and hepatocellular carcinoma(HCC), respectively.Further analysis showed that the patients who declined antiviral therapy were older, with lower education and lower income, possessed poorer knowledge on the risk of chronic hepatitis C, and had more severe liver diseases.Surprisingly, 65% of the surveyed physicians did not know the genotype-guided treatment duration suggested by the guidelines.Alarmingly, 22% of the surveyed physicians did not know the standard assays for the diagnosis of HCV infection.Conclusions: Our findings highlight the challenge and hidden enormous burden of chronic HCV infection among patients with non-liver disease complaints in China.展开更多
AIM: To evaluate the efficacy and tolerability of low-dose standard or pegylated interferon (PEG-IFN) in hepatitis C virus (HCV)-positive hemodialysis patients.
BACKGROUND Ischemic gastritis is a clinically rare disease with high mortality that infrequently reported in the medical literature and under-recognized clinically and histopatho-logically.Early diagnosis and treatmen...BACKGROUND Ischemic gastritis is a clinically rare disease with high mortality that infrequently reported in the medical literature and under-recognized clinically and histopatho-logically.Early diagnosis and treatment can only be achieved through upper gastrointestinal endoscopy after symptoms appear.CASE SUMMARY A 68-year-old woman with a history of intracranial aneurysm developed dizziness,chest tightness and unconsciousness for 2 d.Computed tomography angiography showed diffuse coronary atherosclerosis,moderate to severe stenosis in the proximal end of the left anterior descending branch,multiple calcified plaques in the proximal end of the circumflex branch and right coronary artery,and mild to moderate stenosis.The patient also developed diffuse atherosclerosis in the splenic and mesenteric arteries,with mild lumen stenosis and athero-sclerosis in the abdominal aorta and its branches.Endoscopy showed submucosal congestion and damage of the entire gastric mucosa,of which the fundus and body of the stomach were most seriously affected.The mucosa was swollen,with a deep purple color,surface erosion and dark red oozing blood.Pathological examination showed bleeding and necrosis of the gastric mucosa,with residual contours of the gastric glands,consistent with ischemic gastritis.CONCLUSION Ischemic gastritis is a rare disease that may be difficult to diagnose as its symptoms may be similar to those of other gastrointestinal diseases.Diagnosis is usually based on endoscopic and pathological examinations,which show insufficient blood supply to the gastric mucosa leading to mucosal damage and necrosis.展开更多
A new stationary phase for iodide ion analysis has been developed. The cationic polymerepichlorohydrin-dimethylamine(PEPI-DMA) was served as modifier in synthesizing polyelectrolyte sorbents and the macroporous poly...A new stationary phase for iodide ion analysis has been developed. The cationic polymerepichlorohydrin-dimethylamine(PEPI-DMA) was served as modifier in synthesizing polyelectrolyte sorbents and the macroporous polystyrene-divinylbenzene(PS-DVB) resin was used as support. The positively charged polymer(PEPI-DMA) was electrostatically bonded to a negatively charged particle(PS-DVB sulfonated). The new stationary phase was characterized by scanning electron microscopy(SEM), Fourier transform infrared(FTIR), elemental analysis, chemical adsorption and desorption measurements. The chromatographic evaluation of the new stationary phase was performed using various anions with a conductivity detector. The new stationary phase was also applied to the determination of iodide directly with a DC amperometric detector using a platinum working electrode and an Ag/Ag Cl reference electrode. The chromatographic conditions were optimized and the eluent solution contained 5 mmol/L HNO3 and 15 mmol/L Na NO3 at a flow rate of 1.0 m L/min and column temperature of 30 8C. The applied voltage of the DC amperometric detector was 0.9 V. Under the optimum conditions, the linear range of the method was 0.2–50 mg/L for iodide ion with a correlation coefficient of 0.9990. The detection limit was 0.05 mg/L(calculated at S/N = 3) and the relative standard deviations(RSD, n = 6) were all less than 1% for retention time, peak area and peak height. This method was also utilized for the determination of iodide ions in samples of povidone iodine solution and kelp samples with satisfactory results.展开更多
To get a better understanding of the influence of rare-earth element doping,CaCu3Ti4O12(CCTO) samples with a partial substitution of Ca with Eu with different compensation mechanisms were designed and prepared by so...To get a better understanding of the influence of rare-earth element doping,CaCu3Ti4O12(CCTO) samples with a partial substitution of Ca with Eu with different compensation mechanisms were designed and prepared by solid-state reaction.All the ceramics were single phase,while the dielectric constants and thermally activated energy values for dielectric relaxation in Eu-doped ceramics were both lower than those of CCTO.Ca(0.875)Eu(0.1)Cu3Ti4O12(CECT1)exhibited a slight decrease in both the permittivity and electric resistance of grain boundaries compared with CCTO,while Ca(0.85)Eu(0.1)Cu3Ti4O12(CECT2) underwent a sharp decrease in permittivity associated with an abnormally large resistance.The different dielectric behavior indicates that the dielectric properties of CCTO are sensitive to the valence states of cations and defects.The variation of permittivity is related to the localization of carriers,which,according to the XPS results,should be caused by the presence of oxygen vacancies.The formation of defect complexes between cations and oxygen vacancies leads to the increase in resistance and prevents the hopping between Cu^+ and Cu^2+,which is an important source of the polarization in grain boundaries.展开更多
In recent years,computational intelligence has been widely used in many fields and achieved remarkable performance.Evolutionary computing and deep learning are important branches of computational intelligence.Many met...In recent years,computational intelligence has been widely used in many fields and achieved remarkable performance.Evolutionary computing and deep learning are important branches of computational intelligence.Many methods based on evolutionary computation and deep learning have achieved good performance in remote sensing image registration.This paper introduces the application of computational intelligence in remote sensing image registration from the two directions of evolutionary computing and deep learning.In the part of remote sensing image registration based on evolutionary calculation,the principles of evolutionary algorithms and swarm intelligence algorithms are elaborated and their application in remote sensing image registration is discussed.The application of deep learning in remote sensing image registration is also discussed.At the same time,the development status and future of remote sensing image registration are summarized and their prospects are examined.展开更多
Dysregulated HGF/c-Met signalling has been associated with many human cancers,poor clinical outcomes,and even resistance acquisition to some approved targeted therapies.As such,c-Met kinase has emerged as an attractiv...Dysregulated HGF/c-Met signalling has been associated with many human cancers,poor clinical outcomes,and even resistance acquisition to some approved targeted therapies.As such,c-Met kinase has emerged as an attractive target for anticancer drug discovery.展开更多
A rapid sample treatment procedure for the gas chromatography-tandem mass spectrometry (GC-MS) determination of 19-nortestosterone (19-NT) in animal tissues has been developed. In our optimized procedures, enzymat...A rapid sample treatment procedure for the gas chromatography-tandem mass spectrometry (GC-MS) determination of 19-nortestosterone (19-NT) in animal tissues has been developed. In our optimized procedures, enzymatic hydrolysis with β-glucuronidase from Escherichia coliwas performed in an acetate buffer (pH 5.2, 0.2 mol/L) Next, the homogenate was mixed with methanol and heated at 60℃ for 15 min, then placed in an ice-bath at -18℃ for 2 h. After liquid-liquid extraction with n-hexane, the analytes were subjected to a normal-phase solid phase ex- traction (SPE) C18 cartridge for clean-up. The dded organic extracts were derivatized with heptafluorobutydc anhydride (HFBA), and then the products were injected into GC-MS. Using electron impact mass spectrometry (El-MS) with positive chemical ionization (PCI), four diagnostic ions (mlz 666, 453, 318, and 306) were determined. A standard calibration curve over the concentration range of 1-20 ng/g was reached, with Y=467084X-68354 (R^2=0.9997) for 19-NT, and the detection limit was 0.3 ng. When applied to spiked samples collected from bovine and ovine, the recoveries ranged from 63% to 101% with relative standard deviation (RSD) between 2.7% and 8.9%. The procedure is a highly efficient, sensitive, and more economical method which offers considerable potential to resolve cases of suspected nandrolone doping in husbandry animals.展开更多
基金Supported by the Medical Health Science and Technology Project of Zhejiang Provincial Health Commission,No.2020KY1082 and No.2021KY1238.
文摘BACKGROUND Acute appendicitis is the most common abdominal emergency.At present,the main treatments for periappendiceal abscess include antibiotics and surgery.However,the complications and mortality of emergency surgery are high.The preferred therapy is conservative treatment with antibiotics first,ultrasound-guided puncture drainage or surgical treatment is followed when necessary.Endoscopic retrograde appendicitis therapy(ERAT)for acute uncomplicated appendicitis have been proved clinically effective,but it is rarely used in periap-pendiceal abscess.CASE SUMMARY We report a patient admitted to hospital because of“right lower abdominal pain for six days”.The computerized tomography(CT)of patient showed that appendicitis with fecaliths and abscess in the pelvis.The patient was treated by CT-guided puncture and drainage of abdominal abscess combined with ERAT to remove appendiceal fecaliths,irrigation and stent placement.CONCLUSION The patient did not receive surgery because of impoverished family.Abdominal pain did not recur during the follow-up period.This case confirms the value of ERAT in the treatment of periappendiceal abscess.
基金National Natural Science Foundation of China(Grant Nos.51805385,71471143)Hubei Provincial Natural Science Foundation of China(Grant No.2018CFB265)Center for Service Science and Engineering of Wuhan University of Science and Technology(Grant No.CSSE2017KA04)
文摘The information transmission path optimization(ITPO) can often a ect the e ciency and accuracy of remanufactur?ing service. However, there is a greater degree of uncertainty and complexity in information transmission of remanu?facturing service system, which leads to a critical need for designing planning models to deal with this added uncer?tainty and complexity. In this paper, a three?dimensional(3D) model of remanufacturing service information network for information transmission is developed, which combines the physic coordinate and the transmitted properties of all the devices in the remanufacturing service system. In order to solve the basic ITPO in the 3D model, an improved 3D ant colony algorithm(Improved AC) was put forward. Moreover, to further improve the operation e ciency of the algorithm, an improved ant colony?genetic algorithm(AC?GA) that combines the improved AC and genetic algorithm was developed. In addition, by taking the transmission of remanufacturing service demand information of certain roller as example, the e ectiveness of AC?GA algorithm was analyzed and compared with that of improved AC, and the results demonstrated that AC?GA algorithm was superior to AC algorithm in aspects of information transmission delay, information transmission cost, and rate of information loss.
基金This work was supported by the National Natural Science Foundation of China (No.81400290).
文摘A tissue engineering model of heart valve calcification induced in a bio-reactor was established to evaluate the calcification induced by abnormal mechanical stimulation and explore the underlying molecular mechanisms.Polyethylene glycol (PEG)-modified decellularized porcine aortic leaflets seeded with human valve interstitial cells (huVICs)were mounted on a Ti-Ni alloy frame to fabricate two-leaflet and three-leaflet tissue engineered valves.The two-leaflet model valves were exposed to abnormal pulsatile flow stimulation with null (group A),low (1000mL/min,group B),medium (2000mL/min,group C),and high velocity (3000mL/min,group D)for 14 days. Morphology and calcification were assessed by yon Kossa staining,alkaline phosphatase (ALP)content,and Runx2 immunostaining.Leaflet calcification and mRNA and protein expression of transforming growth factor (TGF)-β1,bone morphogenetic protein 2 (BMP2),Smadl,and MSX2 were measured at different time points.ALP content was examined in two-leaflet valves seeded with BMP2 shRNA plasmid-infected huVICs and exposed to the same stimulation conditions.The results showed that during 14 days of flow stimulation,huVICs on the leaflet surface proliferated to generate normal monolayer coverage in groups A,B,and C.Under mechanical stimulation,huVICs showed a parallel growth pattern in the direction of the fluid flow,but huVICs exhibited disordered growth in the high-velocity flow environment,yon Kossa staining,ALP measurement,and immunohistochemical staining for Runx2 confirmed the lack of obvious calcification in group A and significant calcification in group D.Expression levels of TGF-β1,BMP2, and MSX2 mRNA and protein were increased under fluid stimulation.ALP production by BMP2 shRNA plasmid-infected huVICs on model leaflets was significantly reduced.In conclusion,abnormal mechanical stimulation in a bioreactor induced calcification in the tissue engineering valve model.The extent of calcification correlated positively with the flow velocity,as did the mRNA and protein levels of TGF-β1,BMP2,and MSX2.These findings indicate that TGF-β1/BMP2 signaling is involved in valve calcification induced bv abnormal mechanical stimulation.
文摘This study aims to evaluate the clinical outcomes of endoscopic vein harvesting (EVH) for coronary artery bypass grafting (CABG) in obese patients. Totally, 153 obese patients who underwent EVH (n=81) or standard bridging technique (SBT, n=72) in CABG surgery from May 2012 to October 2014 in our hospital were enrolled in this retrospective non-randomized controlled study. The general situation of operation, postoperative complications and short medium-term outcomes were analyzed. The baseline characteristics were similar between these two groups (P〉0.05). There were no statistical differences in total operation time (226±28 min vs. 224±30 min, P〉0.05), number of damaged vessels (0.12±0.05 vs. 0.16±0.06, P〉0.05) and short medium-term outcomes including revascularization rate (1.25% vs. 2.78%, P〉0.05), vessel dysfunction rate (11.25% vs. 11.11%, P〉0.05) and mortality (0.00% vs. 0.00%, P〉0.05). Use of EVH was associated with significant reduction of total harvesting time (41±6 min vs. 63±11 min, P〈0.05), incision length (4.4±1.1 cm vs. 18.2±4.5 cm, P〈0.05) and postoperative lower extremity complications (P〈0.05). EVH can reduce the risk of wound complications, whereas does not influence short- and medium-term outcomes in obese patients. It can be considered a reliable procedure of harvesting vessel conduits for obese patients undergoing CABG.
基金Project supported by the “Shuguang Program” from Shanghai Education Development Foundation and Shanghai Municipal Education Commission,Ministry of Science and Technology of China(Grant Nos.2016YFA0301003 and 2016YFA0300403)the National Natural Science Foundation of China(Grant Nos.11521404,11634009,11874256,11574202,11874258,11790313,11674226,U1632102,11674222,and 11861161003)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB28000000)
文摘YbMnBi2 is a recently discovered time-reversal-symmetry breaking type-Ⅱ Weyl semimetal.However, as a representation of the new category of topological matters, the scanning tunneling microcopy(STM) results on such important material are still absent.Here, we report the STM investigations on the morphology of vacuum cleaved single crystalline YbMnBi2 samples.A hill and valley type of topography is observed on the YbMnBi2 surface, which is consistent with the non-layer nature of its crystal structure.Analysis of STM images yields the information of the index of the vicinal surface.Our results here lay a playground of future atomic scale research on YbMnBi2.
文摘BACKGROUND Gastroesophageal varices are a rare complication of essential thrombocythemia(ET).ET is a chronic myeloproliferative neoplasm(MPN)characterized by an increased number of blood platelets.CASE SUMMARY A 46-year-old woman,who denied a history of liver disease,was admitted to our hospital on presentation of hematemesis.Laboratory examination revealed a hemoglobin level of 83 g/L,and a platelet count of 397×109/L.The appearance of gastric and esophageal varices with red colored signs as displayed by an urgent endoscopy was followed by endoscopic variceal ligation and endoscopic tissue adhesive.Abdominal computed tomography revealed cirrhosis,marked splenomegaly,portal vein thrombosis and portal hypertension.In addition,bone marrow biopsy and evidence of mutated Janus kinase 2,substantiated the onset of ET.The patient was asymptomatic with regular routine blood testing during the 6-mo follow-up period.Therefore,in this case,gastroesophageal varices were induced by ET.CONCLUSION MPN should be given considerable attention when performing differential diagnoses in patients with gastroesophageal varices.An integrated approach such as laboratory tests,radiological examination,and pathological biopsy,should be included to allow optimal decisions and management.
基金Project supported by the National Key Science&Technology Special Project of China(Grant No.2017ZX01001301)the National Key Research and Development Program of China(Grant No.2016YFB0400100)the National Natural Science Foundation of China(Grant Nos.51777168 and 61801374).
文摘A large gate metal height technique is proposed to enhance breakdown voltage in GaN channel and AlGaN channel high-electron-mobility-transistors(HEMTs).For GaN channel HEMTs with gate-drain spacing LGD=2.5μm,the breakdown voltage VBR increases from 518 V to 582 V by increasing gate metal height h from 0.2μm to 0.4μm.For GaN channel HEMTs with LGD=7μm,VBR increases from 953 V to 1310 V by increasing h from 0.8μm to 1.6μm.The breakdown voltage enhancement results from the increase of the gate sidewall capacitance and depletion region extension.For Al0.4Ga0.6N channel HEMT with LGD=7μm,VBR increases from 1535 V to 1763 V by increasing h from 0.8μm to 1.6μm,resulting in a high average breakdown electric field of 2.51 MV/cm.Simulation and analysis indicate that the high gate metal height is an effective method to enhance breakdown voltage in GaN-based HEMTs,and this method can be utilized in all the lateral semiconductor devices.
基金partly supported by the grants from the National Natural Science Foundation of China(81470856,81772923,31470263 and 81360001)
文摘Objective: To determine the frequency of anti-HCV antibody positivity in patients with nonliver disease complaints, to explore whether anti-HCV positive patients had been properly advised and visited hepatologists for further assessments, and to investigate their clinical characteristics as well as the HCV treatment status.Methods: A hospital based survey of nonliver disease patients with anti-HCV positive and their attending physicians was conducted to determine: 1.were the patients adequately advised of the implication of anti-HCV positive finding; 2.to what extent the patients were aware of potential chronic liver disease associated with HCV infection and whether they sought for further assessments and care of hepatologists.Results: A total of 295 294 non-liver disease patients were tested for anti-HCV antibody, and 2 778 of them were found to be positive(0.94%).However, only 45.10%(1 253/2 778) of the anti-HCV antibody(+) patients were referred to hepatologists and received HCV RNA test.In addition, 34.10%(312/915) and 1.42%(13/915) of them had already advanced to cirrhosis and hepatocellular carcinoma(HCC), respectively.Further analysis showed that the patients who declined antiviral therapy were older, with lower education and lower income, possessed poorer knowledge on the risk of chronic hepatitis C, and had more severe liver diseases.Surprisingly, 65% of the surveyed physicians did not know the genotype-guided treatment duration suggested by the guidelines.Alarmingly, 22% of the surveyed physicians did not know the standard assays for the diagnosis of HCV infection.Conclusions: Our findings highlight the challenge and hidden enormous burden of chronic HCV infection among patients with non-liver disease complaints in China.
文摘AIM: To evaluate the efficacy and tolerability of low-dose standard or pegylated interferon (PEG-IFN) in hepatitis C virus (HCV)-positive hemodialysis patients.
文摘BACKGROUND Ischemic gastritis is a clinically rare disease with high mortality that infrequently reported in the medical literature and under-recognized clinically and histopatho-logically.Early diagnosis and treatment can only be achieved through upper gastrointestinal endoscopy after symptoms appear.CASE SUMMARY A 68-year-old woman with a history of intracranial aneurysm developed dizziness,chest tightness and unconsciousness for 2 d.Computed tomography angiography showed diffuse coronary atherosclerosis,moderate to severe stenosis in the proximal end of the left anterior descending branch,multiple calcified plaques in the proximal end of the circumflex branch and right coronary artery,and mild to moderate stenosis.The patient also developed diffuse atherosclerosis in the splenic and mesenteric arteries,with mild lumen stenosis and athero-sclerosis in the abdominal aorta and its branches.Endoscopy showed submucosal congestion and damage of the entire gastric mucosa,of which the fundus and body of the stomach were most seriously affected.The mucosa was swollen,with a deep purple color,surface erosion and dark red oozing blood.Pathological examination showed bleeding and necrosis of the gastric mucosa,with residual contours of the gastric glands,consistent with ischemic gastritis.CONCLUSION Ischemic gastritis is a rare disease that may be difficult to diagnose as its symptoms may be similar to those of other gastrointestinal diseases.Diagnosis is usually based on endoscopic and pathological examinations,which show insufficient blood supply to the gastric mucosa leading to mucosal damage and necrosis.
基金financially supported by Natural Science Foundation of Zhejiang Province(Nos.Y4110532,LQ13B050001,LY12B05003)Professional Development Program for Visiting Scholars from Colleges and Universities in Zhejiang Province(No.FX2013148)+1 种基金Major National Scientific Instrument and Equipment Development Special of China(No.2012YQ09022903)Key Laboratory of Health Risk Appraisal for Trace Toxic Chemicals of Zhejiang Province
文摘A new stationary phase for iodide ion analysis has been developed. The cationic polymerepichlorohydrin-dimethylamine(PEPI-DMA) was served as modifier in synthesizing polyelectrolyte sorbents and the macroporous polystyrene-divinylbenzene(PS-DVB) resin was used as support. The positively charged polymer(PEPI-DMA) was electrostatically bonded to a negatively charged particle(PS-DVB sulfonated). The new stationary phase was characterized by scanning electron microscopy(SEM), Fourier transform infrared(FTIR), elemental analysis, chemical adsorption and desorption measurements. The chromatographic evaluation of the new stationary phase was performed using various anions with a conductivity detector. The new stationary phase was also applied to the determination of iodide directly with a DC amperometric detector using a platinum working electrode and an Ag/Ag Cl reference electrode. The chromatographic conditions were optimized and the eluent solution contained 5 mmol/L HNO3 and 15 mmol/L Na NO3 at a flow rate of 1.0 m L/min and column temperature of 30 8C. The applied voltage of the DC amperometric detector was 0.9 V. Under the optimum conditions, the linear range of the method was 0.2–50 mg/L for iodide ion with a correlation coefficient of 0.9990. The detection limit was 0.05 mg/L(calculated at S/N = 3) and the relative standard deviations(RSD, n = 6) were all less than 1% for retention time, peak area and peak height. This method was also utilized for the determination of iodide ions in samples of povidone iodine solution and kelp samples with satisfactory results.
基金supported by the National Natural Science Foundations of China(Grant Nos.21271084 and11264024)the Open Project of State Key Laboratory of Superhard Materials(No.201608)
文摘To get a better understanding of the influence of rare-earth element doping,CaCu3Ti4O12(CCTO) samples with a partial substitution of Ca with Eu with different compensation mechanisms were designed and prepared by solid-state reaction.All the ceramics were single phase,while the dielectric constants and thermally activated energy values for dielectric relaxation in Eu-doped ceramics were both lower than those of CCTO.Ca(0.875)Eu(0.1)Cu3Ti4O12(CECT1)exhibited a slight decrease in both the permittivity and electric resistance of grain boundaries compared with CCTO,while Ca(0.85)Eu(0.1)Cu3Ti4O12(CECT2) underwent a sharp decrease in permittivity associated with an abnormally large resistance.The different dielectric behavior indicates that the dielectric properties of CCTO are sensitive to the valence states of cations and defects.The variation of permittivity is related to the localization of carriers,which,according to the XPS results,should be caused by the presence of oxygen vacancies.The formation of defect complexes between cations and oxygen vacancies leads to the increase in resistance and prevents the hopping between Cu^+ and Cu^2+,which is an important source of the polarization in grain boundaries.
基金National Natural Science Foundation of China(Nos.61702392 and 61772393)Key Research and Development Program of Shaanxi Province(Nos.2018ZDXM-GY-045 and 2019JQ-189).
文摘In recent years,computational intelligence has been widely used in many fields and achieved remarkable performance.Evolutionary computing and deep learning are important branches of computational intelligence.Many methods based on evolutionary computation and deep learning have achieved good performance in remote sensing image registration.This paper introduces the application of computational intelligence in remote sensing image registration from the two directions of evolutionary computing and deep learning.In the part of remote sensing image registration based on evolutionary calculation,the principles of evolutionary algorithms and swarm intelligence algorithms are elaborated and their application in remote sensing image registration is discussed.The application of deep learning in remote sensing image registration is also discussed.At the same time,the development status and future of remote sensing image registration are summarized and their prospects are examined.
基金This work was supported by the Fundamental Research Funds for the Central Universities(Nos.31920170193 and 31920200026).
文摘Dysregulated HGF/c-Met signalling has been associated with many human cancers,poor clinical outcomes,and even resistance acquisition to some approved targeted therapies.As such,c-Met kinase has emerged as an attractive target for anticancer drug discovery.
基金Project supported by the Eleventh Five-Year Plan for National Science and Technology of China (No.2006BAK02A21/1)the Henan Innovation Project for University Prominent Research Talents (No.2010HASTIT026),China
文摘A rapid sample treatment procedure for the gas chromatography-tandem mass spectrometry (GC-MS) determination of 19-nortestosterone (19-NT) in animal tissues has been developed. In our optimized procedures, enzymatic hydrolysis with β-glucuronidase from Escherichia coliwas performed in an acetate buffer (pH 5.2, 0.2 mol/L) Next, the homogenate was mixed with methanol and heated at 60℃ for 15 min, then placed in an ice-bath at -18℃ for 2 h. After liquid-liquid extraction with n-hexane, the analytes were subjected to a normal-phase solid phase ex- traction (SPE) C18 cartridge for clean-up. The dded organic extracts were derivatized with heptafluorobutydc anhydride (HFBA), and then the products were injected into GC-MS. Using electron impact mass spectrometry (El-MS) with positive chemical ionization (PCI), four diagnostic ions (mlz 666, 453, 318, and 306) were determined. A standard calibration curve over the concentration range of 1-20 ng/g was reached, with Y=467084X-68354 (R^2=0.9997) for 19-NT, and the detection limit was 0.3 ng. When applied to spiked samples collected from bovine and ovine, the recoveries ranged from 63% to 101% with relative standard deviation (RSD) between 2.7% and 8.9%. The procedure is a highly efficient, sensitive, and more economical method which offers considerable potential to resolve cases of suspected nandrolone doping in husbandry animals.