A single stage ammonia-water absorption chiller with complete condensation is designed, built and tested. The apparatus is designed for a cooling capacity of 2814 W, which is obtained using electric heater as heating ...A single stage ammonia-water absorption chiller with complete condensation is designed, built and tested. The apparatus is designed for a cooling capacity of 2814 W, which is obtained using electric heater as heating source. The thermodynamic models have been derived using the First and Second Laws. Calculated results are compared with experimental data. The results show that the cooling capacity of experimental apparatus is found between 1900 and 2200 W with the actual coefficient of performance (COP) between 0.32 and 0.36. The contribution of the components to internal entropy production is analyzed. It shows that the larger irreversibility is caused by spanning the largest temperature and dissipated thermal energy by heat transfer losses at the generator and evaporator. In the experimentation, the low pressure is lower than the designed value. This is a consequence of a large capacity in the falling film absorber which performs as expected. This decreases the evaporation pressure, and the evaporating temperature could be reduced to the designed value.展开更多
This study was evaluated the antimicrobial activities of the crude extract,different fractions,and compounds from the plant of Lomatogonium carinthiacum.The fractions of chloroform and compounds 5,2 and 6 exhibited st...This study was evaluated the antimicrobial activities of the crude extract,different fractions,and compounds from the plant of Lomatogonium carinthiacum.The fractions of chloroform and compounds 5,2 and 6 exhibited stronger antimicrobial activities.Compound 5 was the most active while Staphylococcus aureus and Candida albicans were sensitive to all the tested compounds.The existence of a relationship between the xanthone structures and inhibition of microorganism activity.The antimicrobial activity of this plant was reported here firstly.The results provided evidence that the studied plant extract,fractions as well as some of the isolated compounds might be potential sources of new antimicrobial drug.展开更多
BACKGROUND Early recurrence(ER)is associated with dismal outcomes in patients undergoing radical resection for pancreatic ductal adenocarcinoma(PDAC).Approaches for predicting ER will help clinicians in implementing i...BACKGROUND Early recurrence(ER)is associated with dismal outcomes in patients undergoing radical resection for pancreatic ductal adenocarcinoma(PDAC).Approaches for predicting ER will help clinicians in implementing individualized adjuvant therapies.Postoperative serum tumor markers(STMs)are indicators of tumor progression and may improve current systems for predicting ER.AIM To establish an improved nomogram based on postoperative STMs to predict ER in PDAC.METHODS We retrospectively enrolled 282 patients who underwent radical resection for PDAC at our institute between 2019 and 2021.Univariate and multivariate Cox regression analyses of variables with or without postoperative STMs,were performed to identify independent risk factors for ER.A nomogram was constructed based on the independent postoperative STMs.Receiver operating characteristic curve analysis was used to evaluate the area under the curve(AUC)of the nomogram.Survival analysis was performed using Kaplan-Meier survival plot and log-rank test.RESULTS Postoperative carbohydrate antigen 19-9 and carcinoembryonic antigen levels,preoperative carbohydrate antigen 125 levels,perineural invasion,and pTNM stage III were independent risk factors for ER in PDAC.The postoperative STMs-based nomogram(AUC:0.774,95%CI:0.713-0.835)had superior accuracy in predicting ER compared with the nomogram without postoperative STMs(AUC:0.688,95%CI:0.625-0.750)(P=0.016).Patients with a recurrence nomogram score(RNS)>1.56 were at high risk for ER,and had significantly poorer recurrence-free survival[median:3.08 months,interquartile range(IQR):1.80-8.15]than those with RNS≤1.56(14.00 months,IQR:6.67-24.80),P<0.001).CONCLUSION The postoperative STMs-based nomogram improves the predictive accuracy of ER in PDAC,stratifies the risk of ER,and identifies patients at high risk of ER for tailored adjuvant therapies.展开更多
BACKGROUND Pancreatectomy with concomitant portomesenteric vein resection(PVR)enables patients with portomesenteric vein(PV)involvement to achieve radical resection of pancreatic ductal adenocarcinoma,however,early re...BACKGROUND Pancreatectomy with concomitant portomesenteric vein resection(PVR)enables patients with portomesenteric vein(PV)involvement to achieve radical resection of pancreatic ductal adenocarcinoma,however,early recurrence(ER)is frequently observed.AIM To predict ER and identify patients at high risk of ER for individualized therapy.METHODS Totally 238 patients undergoing pancreatectomy and PVR were retrospectively enrolled and were allocated to the training or validating cohort.Univariate Cox and LASSO regression analyses were performed to construct serum recurrence score(SRS)based on 26 serum-derived parameters.Uni-and multivariate Cox regression analyses of SRS and 18 clinicopathological variables were performed to establish a Nomogram.Receiver operating characteristic curve analysis was used to evaluate the predictive accuracy.Survival analysis was performed using Kaplan-Meier method and log-rank test.RESULTS Independent serum-derived recurrence-relevant factors of LASSO regression model,including postoperative carbohydrate antigen 19-9,postoperative carcinoembryonic antigen,postoperative carbohydrate antigen 125,preoperative albumin(ALB),preoperative platelet to ALB ratio,and postoperative platelets to lymphocytes ratio,were used to construct SRS[area under the curve(AUC):0.855,95%CI:0.786–0.924].Independent risk factors of recurrence,including SRS[hazard ratio(HR):1.688,95%CI:1.075-2.652],pain(HR:1.653,95%CI:1.052-2.598),perineural invasion(HR:2.070,95%CI:0.827-5.182),and PV invasion(HR:1.603,95%CI:1.063-2.417),were used to establish the recurrence nomogram(AUC:0.869,95%CI:0.803-0.934).Patients with either SRS>0.53 or recurrence nomogram score>4.23 were considered at high risk for ER,and had poor long-term outcomes.CONCLUSION The recurrence scoring system unique for pancreatectomy and PVR,will help clinicians in predicting recurrence efficiently and identifying patients at high risk of ER for individualized therapy.展开更多
In this study, novel Carbon aerogel (CA)/Co<sub>3</sub>O<sub>4</sub>/Carbon (C) composites with a double protective structure are synthesized through a solvothermal method and in-situ polymeriz...In this study, novel Carbon aerogel (CA)/Co<sub>3</sub>O<sub>4</sub>/Carbon (C) composites with a double protective structure are synthesized through a solvothermal method and in-situ polymerization. The morphology and structure are characterized by X-ray diffraction, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Fourier transform infrared spectroscopy (FTIR). The loading content of active anode material <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> in the composite is investigated by thermogravimetry, and the electrochemical properties of the composite are characterized by electrochemical impedance spectroscopy (EIS). The SEM results show that the nano-sized spherical <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> particle is adhered to the inner Carbon aerogel (CA). The HRTEM result indicates the thickness of the prepared Carbon (C) up to 40 nm. Nano-sheet is coated on the surface of the <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> particle. Compared with the pure <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> anode materials, the Carbon aerogel (CA)/<span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub>/Carbon (C) composites have better transport kinetics for both electron and lithium-ion in EIS testing results, which may contribute to its higher specific capacity and higher first coulomb efficiency. Due to the unique structure of the composite material with double protection against the volume expansion of <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> when charged, the Carbon aerogel (CA)/<span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub>/Carbon (C) composite material exhibits better cycle stability with a discharge capacity of 1180 mAh/g after 50 cycles. Therefore, the double protection strategy is verified as an effective method to improve the electrochemical performance of transition metal oxide with carbon composite as an anode material in lithium battery.展开更多
To enhance the accuracy of performance analysis of regional airline network,this study applies complex network theory and Density-Based Spatial Clustering of Applications with Noise(DBSCAN)algorithm to investigate the...To enhance the accuracy of performance analysis of regional airline network,this study applies complex network theory and Density-Based Spatial Clustering of Applications with Noise(DBSCAN)algorithm to investigate the topology of regional airline network,constructs node importance index system,and clusters 161 airport nodes of regional airline network.Besides,entropy power method and approximating ideal solution method(TOPSIS)is applied to comprehensively evaluate the importance of airport nodes and complete the classification of nodes and identification of key points;adopt network efficiency,maximum connectivity subgraph and network connectivity as vulnerability measurement indexes,and observe the changes of vulnerability indexes of key nodes under deliberate attacks and 137 nodes under random attacks.The results demonstrate that the decreasing trend of the maximum connectivity subgraph indicator is slower and the decreasing trend of the network efficiency and connectivity indicators is faster when the critical nodes of the regional airline network are deliberately attacked.Besides,the decreasing trend of the network efficiency indicator is faster and the decreasing trend of the maximum connectivity subgraph indicator is slower when the nodes of four different categories are randomly attacked.Finally,it is proposed to identify and focus on protecting critical nodes in order to better improve the security level of regional airline system.展开更多
TaMs1 encodes a non-specific lipid transfer protein(nsLTP) and is required for pollen development in wheat. Although MS1 is a Poaceae-specific gene, the roles of MS1 genes in other Poaceae plants are unknown, especial...TaMs1 encodes a non-specific lipid transfer protein(nsLTP) and is required for pollen development in wheat. Although MS1 is a Poaceae-specific gene, the roles of MS1 genes in other Poaceae plants are unknown, especially in rice and maize. Here, we identified one ortholog in rice(OsLTPg29) and two orthologs in maize(ZmLTPg11 and ZmLTPx2). Similar to TaMs1, both OsLTPg29 and ZmLTPg11 genes are specifically expressed in the microsporocytes, and both OsLTPg29 and ZmLTPg11 proteins showed lipid-binding ability to phosphatidic acid and several phosphoinositides. To determine their roles in pollen development, we created osltpg29 mutants and zmltpg11 zmltpx2 double mutants by CRISPR/Cas9.osltpg29, not zmltpg11 zmltpx2, is defective in pollen development, and only OsLTPg29, not ZmLTPg11,can rescue the male sterility of tams1 mutant. Our results demonstrate that the biological function of MS1 in pollen development differs in the evolution of Poaceae plants.展开更多
AIM To compare efficacy and safety of endoscopic ultrasound (EUS)-guided and surgical drainage in pancreatic fluid collection management.METHODS Data were obtained retrospectively from January 2012 to December 2016.Pa...AIM To compare efficacy and safety of endoscopic ultrasound (EUS)-guided and surgical drainage in pancreatic fluid collection management.METHODS Data were obtained retrospectively from January 2012 to December 2016.Patients with pancreatic fluid collection were performed EUS-guided or surgical procedure.Main outcome measures including clinical efficiency,complication,duration of procedures,hospital stay and cost were analyzed.RESULTS Thirty-six patients were enrolled into the study,including 14 in endoscopic group while 22 in the surgical group.Twelve (86%) patients were treated successfully by endoscopic approach while 21 (95%) patients benefited through surgical procedure.Endoscopic treatment had higher recurrence and complication rates than surgery,resulting in more re-interventions.Meanwhile,duration of procedure,hospital stay and cost were significantly lower in endoscopic group.CONCLUSION Both approaches were effective and safe.EUS-guided approach should be the first-line treatment in mild and simple cases,while surgical approach should be considered as priority in severe and complex cases.展开更多
With the increasing number of airports and the expansion of their scale,the aviation network has become complex and hierarchical.In order to investigate the complex network characteristics of aviation networks,this pa...With the increasing number of airports and the expansion of their scale,the aviation network has become complex and hierarchical.In order to investigate the complex network characteristics of aviation networks,this paper constructs a Chinese aviation network model and carries out related research based on complex network theory and K-means algorithm.Initially,the P-space model is employed to construct the Chinese aviation network model.Then,complex network indicators such as degree,clustering coefficient,average path length,betweenness and coreness are selected to investigate the complex characteristics and hierarchical features of aviation networks and explore their causes.Secondly,using K-means clustering algorithm,five values are obtained as the initial clustering parameter K values for each of the aviation network hierarchies classified according to five complex network indicators.Meanwhile,clustering simulation experiments are conducted to obtain the visual clustering results of Chinese aviation network nodes under different K values,as well as silhouette coefficients for evaluating the clustering effect of each indicator in order to obtain the hierarchical classification of aviation networks under different indicators.Finally,the silhouette coefficient is optimal when the K value is 4.Thus,the clustering results of the four layers of the aviation network can be obtained.According to the experimental results,the complex network association discovery method combined with K-means algorithm has better applicability and simplicity,while the accuracy is improved.展开更多
Thirteen xanthones were isolated from L.rotatum,which were established as l,8-dihydroxy-3,4,5-trimethoxyxanthone(1);l-hydroxy-3异,8-trimethoxyxanthone(2);8-hydroxy-l,3?5-trimethoxyxaiithone(3);l-hydroxy-3,4,5-trimetho...Thirteen xanthones were isolated from L.rotatum,which were established as l,8-dihydroxy-3,4,5-trimethoxyxanthone(1);l-hydroxy-3异,8-trimethoxyxanthone(2);8-hydroxy-l,3?5-trimethoxyxaiithone(3);l-hydroxy-3,4,5-trimethoxyxanthone(4);l-hydroxy-3,5,8-trimethoxyxanthone(5);l,4,8-trihydroxy-5,6-dimethoxyxanthone(6);l,3,8-trihydroxy-4,7-dimethoxyxanthone(;7)l,8-dihydroxy-3,7-dimethoxyxanthone(8);l-hydroxy-3,5-dimethoxyxanthone(9);l-hydroxy-2,3,4,5-tetramethoxyxanthone(;10)l-hydroxy-2,3,4,7-tetramethoxyxanthone(11);l,7-dihydroxy-3,8-dimethoxyxanthone(12);rel-l,3,5,8-tetrahydroxy-2,4,6,7-tetrahydroxanthen-9-one(13).Compounds 4,6,7,9,10,11,12 and 13 are reported for the first time from Lomatogonium.Furthermore,the activity of xanthones was assessed.展开更多
A six-color fluorescent multiplex amplification system for 31 Y-chromosomal short tandem repeats(Y-STRs)(DYS19,DYS390,DYS391,DYF399S1,DYF404S1,DYS439,DYS444,DYS449,DYS452,DYS456,DYS458,DYS460,DYS481,DYS508,DYS513,DYS5...A six-color fluorescent multiplex amplification system for 31 Y-chromosomal short tandem repeats(Y-STRs)(DYS19,DYS390,DYS391,DYF399S1,DYF404S1,DYS439,DYS444,DYS449,DYS452,DYS456,DYS458,DYS460,DYS481,DYS508,DYS513,DYS516,DYS518,DYS543,DYS547,DYS549,DYS552,DYS557,DYS570,DYS576,DYS612,DYS622,DYS626,DYS627,DYS630,DYS635,and Y-GATA-A10)was developed for investigating the mutation rates of 31 highly mutated Y-STR genes in the Han population of northern China.The mutation rates of the 31 highly mutated Y-STRs were calculated using the father-son pair study method after typing 526 Northern Han father-son pairs with this system.Statistically,148 Y-STR mutations were found,with mutation rates ranging from 0(95%confidence interval[CI]0 to 9.0×10^(−3),DYS622)to 7.0×10^(−2)(95%CI 5.1×10^(−2)to 9.7×10^(−2),DYF399S1).Out of these,126 father-son pairs were successfully identified,with a distinction rate of 24.0%(95%CI 20.4%-27.9%).The ability of the 31 highly mutated Y-STRs to distinguish closely related males from the same paternal lineage in the Northern Han population is extremely valuable for criminal investigations and other purposes.展开更多
Maize is a globally important crop that was a classic model plant for genetic studies. Here, we report a 2.2 Gb draft genome sequence of an elite maize line, HuangZaoSi (HZS). Hybrids bred from HZS-improved lines (HIL...Maize is a globally important crop that was a classic model plant for genetic studies. Here, we report a 2.2 Gb draft genome sequence of an elite maize line, HuangZaoSi (HZS). Hybrids bred from HZS-improved lines (HILs) are planted in more than 60% of maize fields in China. Proteome clustering of six completed sequeneed maize genomes show that 638 proteins fall into 264 HZS-specific gene families with the majority of contributions from tandem duplication events. Resequencing and comparative analysis of 40 HZSrelated lines reveals the breeding history of HILs. More than 60% of identified selective sweeps were clustered in identity.by.descent conserved regions, and yield-related genes/QTLs were enriched in HZS characteristic selected regions. Furthermore, we dem on strated that HZS-specific family genes were not uniformly distributed in the genome but enriched in improvement/function.related genomic regions. This study provides an important and novel resource for maize genome research and expands our knowledge on the breadth of genomic variation and improvement history of maize.展开更多
Photoperiodic flowering is one of the most important pathways to govern flowering in rice （Oryza sativa）, in which Heading date 1 （Hdl）, an ortholog of the Arabidopsis CONSTANS gene, encodes a pivotal regulator. H...Photoperiodic flowering is one of the most important pathways to govern flowering in rice （Oryza sativa）, in which Heading date 1 （Hdl）, an ortholog of the Arabidopsis CONSTANS gene, encodes a pivotal regulator. Hdl promotes flowering under short-day conditions （SD） but represses flowering under long-day conditions （LD） by regulating the expression of Heading date 3a （Hd3a）, the FLOWERING LOCUS T （FT） ortholog in rice. However, the molecular mechanism of how Hdl changes its regulatory activity in response to day length remains largely unknown. In this study, we demonstrated that the repression of flowering in LD by Hdl is dependent on the transcription factor DAYS TO HEADING 8 （DTHS）. Loss of DTH8 function results in the activation of Hd3a by Hdl, leading to early flowering. We found that Hdl directly interacts with DTH8 and that the formation of the DTH8-Hd1 complex is necessary for the transcriptional repression of Hd3a by Hdl in LD, implicating that the switch of Hdl function is mediated by DTH8 in LD rather than in SD. Furthermore, we revealed that DTH8 associates with the Hd3a promoter to modulate the level of H3K27 trimethylation （H3K27me3） at the Hd3a locus. In the presence of the DTH8-Hdl complex, the H3K27me3 level was increased at Hd3a, whereas loss of DTH8 function resulted in decreased H3K27me3 level at Hd3a. Taken together, our findings indicate that, in response to day length, DTH8 plays a critical role in mediating the transcriptional regulation of Hd3a by Hdl through the DTH8-Hd1 module to shape epigenetic modifications in photoperiodic flowering.展开更多
Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their development...Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their developmental patterns to optimally utilize light energy for photosynthesis. The mechanisms of light perception and signal transduction have been comprehensively studied in past decades, mostly in a few model plants, including Arabidopsis thaliana. However, systematic analyses of the origin and evolution of core components involved in light perception and signaling are still lacking. In this study, we took advantage of the recently sequenced genomes and transcriptomes covering all the main Archaeplastida clades in the public domain to identify orthologous genes of core components involved in light perception and signaling and to reconstruct their evolutionary history. Our analyses suggested that acclimation to different distribution of light quality in new environments led to the origination of specific light signaling pathways in plants. The UVR8 (UV Resistance Locus 8) signaling pathway originated during the movement of plants from the deeper sea to shallow water and enabled plants to deal with ultraviolet B light (UV-B). After acquisition of UV-B adaptation, origination of the phytochrome signaling pathway helped plants to colonize water surface where red light became the prominent light energy source. The seedling emergence pathway, which is mediated by a combination of light and phytohormone signals that orchestrate plant growth pattern transitions, originated before the emergence of seed plants. Although cryptochromes and some key components of E3 ubiquitin ligase systems already existed before the divergence of the plant and animal kingdoms, the coevolution and optimization of light perception and downstream signal transduction components, including key transcription factors and E3 ubiquitin ligase systems, are evident during plant terrestrialization.展开更多
Kiwifruit is a recently domesticated horticultural fruit crop with substantial economic and nutritional value,especially because of the high content of vitamin C in its fruit.In this study,we de novo assembled two tel...Kiwifruit is a recently domesticated horticultural fruit crop with substantial economic and nutritional value,especially because of the high content of vitamin C in its fruit.In this study,we de novo assembled two telomere-to-telomere kiwifruit genomes from Actinidia chinensis var.‘Donghong’(DH)and Actinidia latifolia‘Kuoye’(KY),with total lengths of 608327852 and 640561626 bp for 29 chromosomes,respectively.With a burst of structural variants involving inversion,translocations,and duplications within 8.39 million years,the metabolite content of DH and KY exhibited differences in saccharides,lignans,and vitamins.A regulatory ERF098 transcription factor family has expanded in KY and Actinidia eriantha,both of which have ultra-high vitamin C content.With each assembly phased into two complete haplotypes,we identified allelic variations between two sets of haplotypes,leading to protein sequence variations in 26494 and 27773 gene loci and allele-specific expression of 4687 and 12238 homozygous gene pairs.Synchronized metabolome and transcriptome changes during DH fruit development revealed the same dynamic patterns in expression levels and metabolite contents;free fatty acids and flavonols accumulated in the early stages,but sugar substances and amino acids accumulated in the late stages.The AcSWEET9b gene that exhibits allelic dominance was further identified to positively correlate with high sucrose content in fruit.Compared with wild varieties and other Actinidia species,AcSWEET9b promoters were selected in red-flesh kiwifruits that have increased fruit sucrose content,providing a possible explanation on why red-flesh kiwifruits are sweeter.Collectively,these two gap-free kiwifruit genomes provide a valuable genetic resource for investigating domestication mechanisms and genome-based breeding of kiwifruit.展开更多
Heterosis,one of the most important biological phenomena, refers to the phenotypic superiority of a hybrid over its genetically diverse parents with respect to many traits such as biomass,growth rate and yield.Despite...Heterosis,one of the most important biological phenomena, refers to the phenotypic superiority of a hybrid over its genetically diverse parents with respect to many traits such as biomass,growth rate and yield.Despite its successful application in breeding and agronomic production of many crop and animal varieties,the molecular basis of heterosis remains elusive.The classic genetic explanations for heterosis centered on three hypotheses：dominance（Davenport,1908;Bruce,展开更多
文摘A single stage ammonia-water absorption chiller with complete condensation is designed, built and tested. The apparatus is designed for a cooling capacity of 2814 W, which is obtained using electric heater as heating source. The thermodynamic models have been derived using the First and Second Laws. Calculated results are compared with experimental data. The results show that the cooling capacity of experimental apparatus is found between 1900 and 2200 W with the actual coefficient of performance (COP) between 0.32 and 0.36. The contribution of the components to internal entropy production is analyzed. It shows that the larger irreversibility is caused by spanning the largest temperature and dissipated thermal energy by heat transfer losses at the generator and evaporator. In the experimentation, the low pressure is lower than the designed value. This is a consequence of a large capacity in the falling film absorber which performs as expected. This decreases the evaporation pressure, and the evaporating temperature could be reduced to the designed value.
基金We thank the fourth national survey of traditional Chinese medicine resources(2018016)for funding this research.
文摘This study was evaluated the antimicrobial activities of the crude extract,different fractions,and compounds from the plant of Lomatogonium carinthiacum.The fractions of chloroform and compounds 5,2 and 6 exhibited stronger antimicrobial activities.Compound 5 was the most active while Staphylococcus aureus and Candida albicans were sensitive to all the tested compounds.The existence of a relationship between the xanthone structures and inhibition of microorganism activity.The antimicrobial activity of this plant was reported here firstly.The results provided evidence that the studied plant extract,fractions as well as some of the isolated compounds might be potential sources of new antimicrobial drug.
基金Supported by National Natural Science Foundation of China,No.82373012.
文摘BACKGROUND Early recurrence(ER)is associated with dismal outcomes in patients undergoing radical resection for pancreatic ductal adenocarcinoma(PDAC).Approaches for predicting ER will help clinicians in implementing individualized adjuvant therapies.Postoperative serum tumor markers(STMs)are indicators of tumor progression and may improve current systems for predicting ER.AIM To establish an improved nomogram based on postoperative STMs to predict ER in PDAC.METHODS We retrospectively enrolled 282 patients who underwent radical resection for PDAC at our institute between 2019 and 2021.Univariate and multivariate Cox regression analyses of variables with or without postoperative STMs,were performed to identify independent risk factors for ER.A nomogram was constructed based on the independent postoperative STMs.Receiver operating characteristic curve analysis was used to evaluate the area under the curve(AUC)of the nomogram.Survival analysis was performed using Kaplan-Meier survival plot and log-rank test.RESULTS Postoperative carbohydrate antigen 19-9 and carcinoembryonic antigen levels,preoperative carbohydrate antigen 125 levels,perineural invasion,and pTNM stage III were independent risk factors for ER in PDAC.The postoperative STMs-based nomogram(AUC:0.774,95%CI:0.713-0.835)had superior accuracy in predicting ER compared with the nomogram without postoperative STMs(AUC:0.688,95%CI:0.625-0.750)(P=0.016).Patients with a recurrence nomogram score(RNS)>1.56 were at high risk for ER,and had significantly poorer recurrence-free survival[median:3.08 months,interquartile range(IQR):1.80-8.15]than those with RNS≤1.56(14.00 months,IQR:6.67-24.80),P<0.001).CONCLUSION The postoperative STMs-based nomogram improves the predictive accuracy of ER in PDAC,stratifies the risk of ER,and identifies patients at high risk of ER for tailored adjuvant therapies.
基金Supported by National Natural Science Foundation of China,No.82373012.
文摘BACKGROUND Pancreatectomy with concomitant portomesenteric vein resection(PVR)enables patients with portomesenteric vein(PV)involvement to achieve radical resection of pancreatic ductal adenocarcinoma,however,early recurrence(ER)is frequently observed.AIM To predict ER and identify patients at high risk of ER for individualized therapy.METHODS Totally 238 patients undergoing pancreatectomy and PVR were retrospectively enrolled and were allocated to the training or validating cohort.Univariate Cox and LASSO regression analyses were performed to construct serum recurrence score(SRS)based on 26 serum-derived parameters.Uni-and multivariate Cox regression analyses of SRS and 18 clinicopathological variables were performed to establish a Nomogram.Receiver operating characteristic curve analysis was used to evaluate the predictive accuracy.Survival analysis was performed using Kaplan-Meier method and log-rank test.RESULTS Independent serum-derived recurrence-relevant factors of LASSO regression model,including postoperative carbohydrate antigen 19-9,postoperative carcinoembryonic antigen,postoperative carbohydrate antigen 125,preoperative albumin(ALB),preoperative platelet to ALB ratio,and postoperative platelets to lymphocytes ratio,were used to construct SRS[area under the curve(AUC):0.855,95%CI:0.786–0.924].Independent risk factors of recurrence,including SRS[hazard ratio(HR):1.688,95%CI:1.075-2.652],pain(HR:1.653,95%CI:1.052-2.598),perineural invasion(HR:2.070,95%CI:0.827-5.182),and PV invasion(HR:1.603,95%CI:1.063-2.417),were used to establish the recurrence nomogram(AUC:0.869,95%CI:0.803-0.934).Patients with either SRS>0.53 or recurrence nomogram score>4.23 were considered at high risk for ER,and had poor long-term outcomes.CONCLUSION The recurrence scoring system unique for pancreatectomy and PVR,will help clinicians in predicting recurrence efficiently and identifying patients at high risk of ER for individualized therapy.
文摘In this study, novel Carbon aerogel (CA)/Co<sub>3</sub>O<sub>4</sub>/Carbon (C) composites with a double protective structure are synthesized through a solvothermal method and in-situ polymerization. The morphology and structure are characterized by X-ray diffraction, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Fourier transform infrared spectroscopy (FTIR). The loading content of active anode material <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> in the composite is investigated by thermogravimetry, and the electrochemical properties of the composite are characterized by electrochemical impedance spectroscopy (EIS). The SEM results show that the nano-sized spherical <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> particle is adhered to the inner Carbon aerogel (CA). The HRTEM result indicates the thickness of the prepared Carbon (C) up to 40 nm. Nano-sheet is coated on the surface of the <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> particle. Compared with the pure <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> anode materials, the Carbon aerogel (CA)/<span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub>/Carbon (C) composites have better transport kinetics for both electron and lithium-ion in EIS testing results, which may contribute to its higher specific capacity and higher first coulomb efficiency. Due to the unique structure of the composite material with double protection against the volume expansion of <span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub> when charged, the Carbon aerogel (CA)/<span style="white-space:normal;">Co</span><sub style="white-space:normal;">3</sub><span style="white-space:normal;">O</span><sub style="white-space:normal;">4</sub>/Carbon (C) composite material exhibits better cycle stability with a discharge capacity of 1180 mAh/g after 50 cycles. Therefore, the double protection strategy is verified as an effective method to improve the electrochemical performance of transition metal oxide with carbon composite as an anode material in lithium battery.
文摘To enhance the accuracy of performance analysis of regional airline network,this study applies complex network theory and Density-Based Spatial Clustering of Applications with Noise(DBSCAN)algorithm to investigate the topology of regional airline network,constructs node importance index system,and clusters 161 airport nodes of regional airline network.Besides,entropy power method and approximating ideal solution method(TOPSIS)is applied to comprehensively evaluate the importance of airport nodes and complete the classification of nodes and identification of key points;adopt network efficiency,maximum connectivity subgraph and network connectivity as vulnerability measurement indexes,and observe the changes of vulnerability indexes of key nodes under deliberate attacks and 137 nodes under random attacks.The results demonstrate that the decreasing trend of the maximum connectivity subgraph indicator is slower and the decreasing trend of the network efficiency and connectivity indicators is faster when the critical nodes of the regional airline network are deliberately attacked.Besides,the decreasing trend of the network efficiency indicator is faster and the decreasing trend of the maximum connectivity subgraph indicator is slower when the nodes of four different categories are randomly attacked.Finally,it is proposed to identify and focus on protecting critical nodes in order to better improve the security level of regional airline system.
基金supported by Peking University Institute of Advanced Agricultural Sciences, and Beijing Municipal Government Science Foundation (IDHT20170513)。
文摘TaMs1 encodes a non-specific lipid transfer protein(nsLTP) and is required for pollen development in wheat. Although MS1 is a Poaceae-specific gene, the roles of MS1 genes in other Poaceae plants are unknown, especially in rice and maize. Here, we identified one ortholog in rice(OsLTPg29) and two orthologs in maize(ZmLTPg11 and ZmLTPx2). Similar to TaMs1, both OsLTPg29 and ZmLTPg11 genes are specifically expressed in the microsporocytes, and both OsLTPg29 and ZmLTPg11 proteins showed lipid-binding ability to phosphatidic acid and several phosphoinositides. To determine their roles in pollen development, we created osltpg29 mutants and zmltpg11 zmltpx2 double mutants by CRISPR/Cas9.osltpg29, not zmltpg11 zmltpx2, is defective in pollen development, and only OsLTPg29, not ZmLTPg11,can rescue the male sterility of tams1 mutant. Our results demonstrate that the biological function of MS1 in pollen development differs in the evolution of Poaceae plants.
文摘AIM To compare efficacy and safety of endoscopic ultrasound (EUS)-guided and surgical drainage in pancreatic fluid collection management.METHODS Data were obtained retrospectively from January 2012 to December 2016.Patients with pancreatic fluid collection were performed EUS-guided or surgical procedure.Main outcome measures including clinical efficiency,complication,duration of procedures,hospital stay and cost were analyzed.RESULTS Thirty-six patients were enrolled into the study,including 14 in endoscopic group while 22 in the surgical group.Twelve (86%) patients were treated successfully by endoscopic approach while 21 (95%) patients benefited through surgical procedure.Endoscopic treatment had higher recurrence and complication rates than surgery,resulting in more re-interventions.Meanwhile,duration of procedure,hospital stay and cost were significantly lower in endoscopic group.CONCLUSION Both approaches were effective and safe.EUS-guided approach should be the first-line treatment in mild and simple cases,while surgical approach should be considered as priority in severe and complex cases.
文摘With the increasing number of airports and the expansion of their scale,the aviation network has become complex and hierarchical.In order to investigate the complex network characteristics of aviation networks,this paper constructs a Chinese aviation network model and carries out related research based on complex network theory and K-means algorithm.Initially,the P-space model is employed to construct the Chinese aviation network model.Then,complex network indicators such as degree,clustering coefficient,average path length,betweenness and coreness are selected to investigate the complex characteristics and hierarchical features of aviation networks and explore their causes.Secondly,using K-means clustering algorithm,five values are obtained as the initial clustering parameter K values for each of the aviation network hierarchies classified according to five complex network indicators.Meanwhile,clustering simulation experiments are conducted to obtain the visual clustering results of Chinese aviation network nodes under different K values,as well as silhouette coefficients for evaluating the clustering effect of each indicator in order to obtain the hierarchical classification of aviation networks under different indicators.Finally,the silhouette coefficient is optimal when the K value is 4.Thus,the clustering results of the four layers of the aviation network can be obtained.According to the experimental results,the complex network association discovery method combined with K-means algorithm has better applicability and simplicity,while the accuracy is improved.
基金We thank the fourth national survey of traditional Chinese medicine resources(2018016)for funding this research.
文摘Thirteen xanthones were isolated from L.rotatum,which were established as l,8-dihydroxy-3,4,5-trimethoxyxanthone(1);l-hydroxy-3异,8-trimethoxyxanthone(2);8-hydroxy-l,3?5-trimethoxyxaiithone(3);l-hydroxy-3,4,5-trimethoxyxanthone(4);l-hydroxy-3,5,8-trimethoxyxanthone(5);l,4,8-trihydroxy-5,6-dimethoxyxanthone(6);l,3,8-trihydroxy-4,7-dimethoxyxanthone(;7)l,8-dihydroxy-3,7-dimethoxyxanthone(8);l-hydroxy-3,5-dimethoxyxanthone(9);l-hydroxy-2,3,4,5-tetramethoxyxanthone(;10)l-hydroxy-2,3,4,7-tetramethoxyxanthone(11);l,7-dihydroxy-3,8-dimethoxyxanthone(12);rel-l,3,5,8-tetrahydroxy-2,4,6,7-tetrahydroxanthen-9-one(13).Compounds 4,6,7,9,10,11,12 and 13 are reported for the first time from Lomatogonium.Furthermore,the activity of xanthones was assessed.
基金supported by the Fundamental Research Funds for the Central Universities.In addition,this study was also supported by opening research grants from Shanghai Key Lab of Forensic Medicine,Key Lab of Forensic Science,the Ministry of Justice,PR.China(Academy of Forensic Science)(No.KF202111).
文摘A six-color fluorescent multiplex amplification system for 31 Y-chromosomal short tandem repeats(Y-STRs)(DYS19,DYS390,DYS391,DYF399S1,DYF404S1,DYS439,DYS444,DYS449,DYS452,DYS456,DYS458,DYS460,DYS481,DYS508,DYS513,DYS516,DYS518,DYS543,DYS547,DYS549,DYS552,DYS557,DYS570,DYS576,DYS612,DYS622,DYS626,DYS627,DYS630,DYS635,and Y-GATA-A10)was developed for investigating the mutation rates of 31 highly mutated Y-STR genes in the Han population of northern China.The mutation rates of the 31 highly mutated Y-STRs were calculated using the father-son pair study method after typing 526 Northern Han father-son pairs with this system.Statistically,148 Y-STR mutations were found,with mutation rates ranging from 0(95%confidence interval[CI]0 to 9.0×10^(−3),DYS622)to 7.0×10^(−2)(95%CI 5.1×10^(−2)to 9.7×10^(−2),DYF399S1).Out of these,126 father-son pairs were successfully identified,with a distinction rate of 24.0%(95%CI 20.4%-27.9%).The ability of the 31 highly mutated Y-STRs to distinguish closely related males from the same paternal lineage in the Northern Han population is extremely valuable for criminal investigations and other purposes.
文摘Maize is a globally important crop that was a classic model plant for genetic studies. Here, we report a 2.2 Gb draft genome sequence of an elite maize line, HuangZaoSi (HZS). Hybrids bred from HZS-improved lines (HILs) are planted in more than 60% of maize fields in China. Proteome clustering of six completed sequeneed maize genomes show that 638 proteins fall into 264 HZS-specific gene families with the majority of contributions from tandem duplication events. Resequencing and comparative analysis of 40 HZSrelated lines reveals the breeding history of HILs. More than 60% of identified selective sweeps were clustered in identity.by.descent conserved regions, and yield-related genes/QTLs were enriched in HZS characteristic selected regions. Furthermore, we dem on strated that HZS-specific family genes were not uniformly distributed in the genome but enriched in improvement/function.related genomic regions. This study provides an important and novel resource for maize genome research and expands our knowledge on the breadth of genomic variation and improvement history of maize.
基金This work was supported by the National Natural Science Foundation （31501278, 31671378 to X.O.）, the National Key Research and Development Program of China （2017YFA0506100 to X.H.） and the Fundamental Research Funds for the Central Universities （20720170068 to X.O. and 20720150098 to X.H.）.
文摘Photoperiodic flowering is one of the most important pathways to govern flowering in rice （Oryza sativa）, in which Heading date 1 （Hdl）, an ortholog of the Arabidopsis CONSTANS gene, encodes a pivotal regulator. Hdl promotes flowering under short-day conditions （SD） but represses flowering under long-day conditions （LD） by regulating the expression of Heading date 3a （Hd3a）, the FLOWERING LOCUS T （FT） ortholog in rice. However, the molecular mechanism of how Hdl changes its regulatory activity in response to day length remains largely unknown. In this study, we demonstrated that the repression of flowering in LD by Hdl is dependent on the transcription factor DAYS TO HEADING 8 （DTHS）. Loss of DTH8 function results in the activation of Hd3a by Hdl, leading to early flowering. We found that Hdl directly interacts with DTH8 and that the formation of the DTH8-Hd1 complex is necessary for the transcriptional repression of Hd3a by Hdl in LD, implicating that the switch of Hdl function is mediated by DTH8 in LD rather than in SD. Furthermore, we revealed that DTH8 associates with the Hd3a promoter to modulate the level of H3K27 trimethylation （H3K27me3） at the Hd3a locus. In the presence of the DTH8-Hdl complex, the H3K27me3 level was increased at Hd3a, whereas loss of DTH8 function resulted in decreased H3K27me3 level at Hd3a. Taken together, our findings indicate that, in response to day length, DTH8 plays a critical role in mediating the transcriptional regulation of Hd3a by Hdl through the DTH8-Hd1 module to shape epigenetic modifications in photoperiodic flowering.
基金National Key R&D Program of China (2017YFA0503800)National Natural Science Foundation of China (31330048, 31621001 and 31570219)+3 种基金Peking-Tsinghua Center for Life Sciences, US NIH grant (GM-47850)the Jiangsu Province Key Project for Scientific Research (16KJA180002)the Young 日ite Scientists Sponsorship Program and Qing Lan project of Jiangsu Provincethe Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
文摘Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their developmental patterns to optimally utilize light energy for photosynthesis. The mechanisms of light perception and signal transduction have been comprehensively studied in past decades, mostly in a few model plants, including Arabidopsis thaliana. However, systematic analyses of the origin and evolution of core components involved in light perception and signaling are still lacking. In this study, we took advantage of the recently sequenced genomes and transcriptomes covering all the main Archaeplastida clades in the public domain to identify orthologous genes of core components involved in light perception and signaling and to reconstruct their evolutionary history. Our analyses suggested that acclimation to different distribution of light quality in new environments led to the origination of specific light signaling pathways in plants. The UVR8 (UV Resistance Locus 8) signaling pathway originated during the movement of plants from the deeper sea to shallow water and enabled plants to deal with ultraviolet B light (UV-B). After acquisition of UV-B adaptation, origination of the phytochrome signaling pathway helped plants to colonize water surface where red light became the prominent light energy source. The seedling emergence pathway, which is mediated by a combination of light and phytohormone signals that orchestrate plant growth pattern transitions, originated before the emergence of seed plants. Although cryptochromes and some key components of E3 ubiquitin ligase systems already existed before the divergence of the plant and animal kingdoms, the coevolution and optimization of light perception and downstream signal transduction components, including key transcription factors and E3 ubiquitin ligase systems, are evident during plant terrestrialization.
基金supported by the Provincial Technology Innovation Program of Shandongan award from the Natural Science Foundation of Shandong Province(ZR2021ZD30)+2 种基金the Director’s Award from the Peking University Institute of Advanced Agricultural Sciences,the National Top Young Talents Program of Chinathe Boya Postdoctoral Program of Peking University,the National Key R&D Program of China(2019YFD1000200)the Youth Innovation Promotion Association CAS(2018376).
文摘Kiwifruit is a recently domesticated horticultural fruit crop with substantial economic and nutritional value,especially because of the high content of vitamin C in its fruit.In this study,we de novo assembled two telomere-to-telomere kiwifruit genomes from Actinidia chinensis var.‘Donghong’(DH)and Actinidia latifolia‘Kuoye’(KY),with total lengths of 608327852 and 640561626 bp for 29 chromosomes,respectively.With a burst of structural variants involving inversion,translocations,and duplications within 8.39 million years,the metabolite content of DH and KY exhibited differences in saccharides,lignans,and vitamins.A regulatory ERF098 transcription factor family has expanded in KY and Actinidia eriantha,both of which have ultra-high vitamin C content.With each assembly phased into two complete haplotypes,we identified allelic variations between two sets of haplotypes,leading to protein sequence variations in 26494 and 27773 gene loci and allele-specific expression of 4687 and 12238 homozygous gene pairs.Synchronized metabolome and transcriptome changes during DH fruit development revealed the same dynamic patterns in expression levels and metabolite contents;free fatty acids and flavonols accumulated in the early stages,but sugar substances and amino acids accumulated in the late stages.The AcSWEET9b gene that exhibits allelic dominance was further identified to positively correlate with high sucrose content in fruit.Compared with wild varieties and other Actinidia species,AcSWEET9b promoters were selected in red-flesh kiwifruits that have increased fruit sucrose content,providing a possible explanation on why red-flesh kiwifruits are sweeter.Collectively,these two gap-free kiwifruit genomes provide a valuable genetic resource for investigating domestication mechanisms and genome-based breeding of kiwifruit.
基金supported by grants from the National Basic Research Program of China(973 Program) (No.2012CB910900)the National Program on Key Basic Research Project of China(No.2011CB 100101)+3 种基金the National High Technology Research and Development Program of China (863 Program)(No.2012AA10A304)the National Natural Science Foundation of China(No.U1031001)the Ministry of Agriculture of China(948 Program)(No.2011-G2B)the Peking-Tsinghua Center for Life Sciences
文摘Heterosis,one of the most important biological phenomena, refers to the phenotypic superiority of a hybrid over its genetically diverse parents with respect to many traits such as biomass,growth rate and yield.Despite its successful application in breeding and agronomic production of many crop and animal varieties,the molecular basis of heterosis remains elusive.The classic genetic explanations for heterosis centered on three hypotheses：dominance（Davenport,1908;Bruce,
