Silk protein builds one of the strongest natural fibers based on its complex nanocomposite structures.However,the mechanical performance of silk protein,related to its molecular structure and packing is still elusive....Silk protein builds one of the strongest natural fibers based on its complex nanocomposite structures.However,the mechanical performance of silk protein,related to its molecular structure and packing is still elusive.In this study,we constructed an atomistic silk protein network model,which reproduces the extensive connection topology of silk protein with structure details of theβ-sheet crystallites and amorphous domains.With the silk protein network model,we investigated the structure evolution and stress distribution of silk protein under external loading.We found a pre-stretching treatment during the spinning process can improve the strength of silk protein.This treatment improves the properties of silk protein network,i.e.,increases the number of nodes and bridges,makes the nodes distributed homogeneously,and induces the bridges in the network well aligned to the loading direction,which is of great benefit to the mechanical performances of silk protein.Our study not only provides a realized atomistic model for silk protein network that well represents the structures and deformations of silk proteins under loading,but also gains deep insights into the mechanism how the pre-loading on silk proteins during spinning improves the mechanical properties of silk fibers.展开更多
Curvature is one of the most important features of lipid membranes in living cells,which significantly influences the structure of lipid membranes and their interaction with proteins.Taken the human islet amyloid poly...Curvature is one of the most important features of lipid membranes in living cells,which significantly influences the structure of lipid membranes and their interaction with proteins.Taken the human islet amyloid polypeptide(h IAPP),an important protein related to the pathogenesis of type II diabetes,as an example,we performed molecular dynamics(MD)simulations to study the interaction between the protein and the lipid structures with varied curvatures.We found that the lipids in the high curvature membrane pack loosely with high mobility.The h IAPP initially forms H-bonds with the membrane surface that anchored the protein,and then inserts into the membrane through the hydrophobic interactions between the residues and the hydrophobic tails of the lipids.h IAPP can insert into the membrane more deeply with a larger curvature and with a stronger binding strength.Our result provided important insights into the mechanism of the membrane curvature-dependent property of proteins with molecular details.展开更多
Background and Aims:Epidemiological data on bacterial infections in cirrhosis in China remain limited.Therefore,we aimed to conduct a multicenter study to investigate the characteristics and outcomes of patients with ...Background and Aims:Epidemiological data on bacterial infections in cirrhosis in China remain limited.Therefore,we aimed to conduct a multicenter study to investigate the characteristics and outcomes of patients with cirrhosis and bacterial infections in China.Methods:We retrospectively enrolled 1,438 hospitalized adult patients with cirrhosis and bacterial or fungal infections from 24 hospitals across China between January 2018 and September 2024.Data on demographics,clinical features,microbiology,treatment,and outcomes were collected.Results:A total of 1,783 infection episodes were recorded,including 1,668 first infections and 115 second infections.Most infections were community-acquired(86.6%).Pneumonia was the most common infection type(26.7%),followed by spontaneous bacterial peritonitis(19.5%)and spontaneous bacteremia(14.1%).Among 754 pathogens isolated from 620 patients,Klebsiella pneumoniae(20.1%)was nearly as common as Escherichia coli(21.7%).Multidrug-resistant(MDR)organisms accounted for 41.0%of(20.1%)was nearly as common as Escherichia coli(21.7%).Multidrug-resistant(MDR)organisms accounted for 41.0%of all isolates,with extended-spectrum p-lactamase-producing Escherichia coli being the most prevalent MDR strain(8.9%of patients).Adherence to empirical antibiotic treatment guidelines from the European Association for the Study of the Liver was significantly lower in this cohort compared to the global study(21.5%vs.61.2%,P<0.001),accompanied by a lower clinical resolution rate(63.5%vs.79.8%,P<0.001).Conclusions:The clinical and microbiological characteristics of bacterial infections in patients with cirrhosis in China differ substantially from those reported in other regions.These findings highlight the need for region-specific management and prevention strategies,particularly in light of the changing microbiological landscape,high MDR prevalence,and suboptimal antibiotic practices.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grants Nos.12122212,11932017,11772054,and 11772055).
文摘Silk protein builds one of the strongest natural fibers based on its complex nanocomposite structures.However,the mechanical performance of silk protein,related to its molecular structure and packing is still elusive.In this study,we constructed an atomistic silk protein network model,which reproduces the extensive connection topology of silk protein with structure details of theβ-sheet crystallites and amorphous domains.With the silk protein network model,we investigated the structure evolution and stress distribution of silk protein under external loading.We found a pre-stretching treatment during the spinning process can improve the strength of silk protein.This treatment improves the properties of silk protein network,i.e.,increases the number of nodes and bridges,makes the nodes distributed homogeneously,and induces the bridges in the network well aligned to the loading direction,which is of great benefit to the mechanical performances of silk protein.Our study not only provides a realized atomistic model for silk protein network that well represents the structures and deformations of silk proteins under loading,but also gains deep insights into the mechanism how the pre-loading on silk proteins during spinning improves the mechanical properties of silk fibers.
基金supported by funds from the National Natural Science Foundation of China(Grants 11932017,11772054,11772055,and 11532009)supported by the Fundamental Research Funds for the Central Universities(Grant 2019QNA4060)。
文摘Curvature is one of the most important features of lipid membranes in living cells,which significantly influences the structure of lipid membranes and their interaction with proteins.Taken the human islet amyloid polypeptide(h IAPP),an important protein related to the pathogenesis of type II diabetes,as an example,we performed molecular dynamics(MD)simulations to study the interaction between the protein and the lipid structures with varied curvatures.We found that the lipids in the high curvature membrane pack loosely with high mobility.The h IAPP initially forms H-bonds with the membrane surface that anchored the protein,and then inserts into the membrane through the hydrophobic interactions between the residues and the hydrophobic tails of the lipids.h IAPP can insert into the membrane more deeply with a larger curvature and with a stronger binding strength.Our result provided important insights into the mechanism of the membrane curvature-dependent property of proteins with molecular details.
基金supported by the National Key Research and Development Program of China(No.2022YFC2304500,No.2021YFC2301800)the National Natural Science Foundation of China(No.81870425)+1 种基金the Fundamental Research Funds for the Central Universities(2023QZJH50)the Medical and Health Research Project of Zhejiang Province(2022RC141).
文摘Background and Aims:Epidemiological data on bacterial infections in cirrhosis in China remain limited.Therefore,we aimed to conduct a multicenter study to investigate the characteristics and outcomes of patients with cirrhosis and bacterial infections in China.Methods:We retrospectively enrolled 1,438 hospitalized adult patients with cirrhosis and bacterial or fungal infections from 24 hospitals across China between January 2018 and September 2024.Data on demographics,clinical features,microbiology,treatment,and outcomes were collected.Results:A total of 1,783 infection episodes were recorded,including 1,668 first infections and 115 second infections.Most infections were community-acquired(86.6%).Pneumonia was the most common infection type(26.7%),followed by spontaneous bacterial peritonitis(19.5%)and spontaneous bacteremia(14.1%).Among 754 pathogens isolated from 620 patients,Klebsiella pneumoniae(20.1%)was nearly as common as Escherichia coli(21.7%).Multidrug-resistant(MDR)organisms accounted for 41.0%of(20.1%)was nearly as common as Escherichia coli(21.7%).Multidrug-resistant(MDR)organisms accounted for 41.0%of all isolates,with extended-spectrum p-lactamase-producing Escherichia coli being the most prevalent MDR strain(8.9%of patients).Adherence to empirical antibiotic treatment guidelines from the European Association for the Study of the Liver was significantly lower in this cohort compared to the global study(21.5%vs.61.2%,P<0.001),accompanied by a lower clinical resolution rate(63.5%vs.79.8%,P<0.001).Conclusions:The clinical and microbiological characteristics of bacterial infections in patients with cirrhosis in China differ substantially from those reported in other regions.These findings highlight the need for region-specific management and prevention strategies,particularly in light of the changing microbiological landscape,high MDR prevalence,and suboptimal antibiotic practices.
