Publications by authors named "Wenjia Xiao"

15 Publications

  • Page 1 of 1

Prevalence of 16S rRNA Methylation Enzyme Gene in From Outpatients and Food.

Front Microbiol 2021 25;12:663210. Epub 2021 May 25.

State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.

is the primary cause of community-acquired foodborne infections, so its resistance to antimicrobials, such as aminoglycosides, is a public health issue. Of concern, aminoglycoside resistance in is increasing rapidly. Here, we performed a retrospective study evaluating the prevalence of harboring -mediated aminoglycoside resistance in community-acquired infections and in food or environmental sources. The prevalence rates of -harboring strains were 1.1/1,000 (13/12,095) and 8.7/1,000 (32/3,687) in outpatient and food/environmental isolates, respectively. All the -harboring strains were resistant to multiple drugs, including fluoroquinolone and/or extended-spectrum cephalosporins, and most (34/45) belonged to serovar Indiana. The gene of these strains were all carried on plasmids, which spanned five replicon types with IncHI2 being the dominant plasmid type. All the -carrying plasmids were transferable into and recipients. The conjugation experiment results revealed that the -harboring . Indiana strains had a relatively higher ability to acquire -carrying plasmids. The low similarity of their pulsed field gel electrophoresis patterns indicates that the -harboring strains were unlikely to have originated from a single epidemic clone, suggesting broad spread. Furthermore, the genetic backgrounds of -harboring strains isolated from outpatients exhibited higher similarity to those isolated from poultry than to those isolated from swine, suggesting that poultry consumption maybe an infection source. These findings highlight an urgent need to monitor the prevalence and transmission of -harboring , especially Indiana, to better understand the potential public health threat and prevent the further spread of these strains.
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http://dx.doi.org/10.3389/fmicb.2021.663210DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8186500PMC
May 2021

Epidemiological and clinical characteristics of 161 discharged cases with coronavirus disease 2019 in Shanghai, China.

BMC Infect Dis 2020 Oct 20;20(1):780. Epub 2020 Oct 20.

Shanghai Municipal Center for Disease Control and Prevention, No. 1380, West Zhongshan Road, Shanghai, 200336, China.

Background: In December 2019, the outbreak of coronavirus disease 2019 (COVID-19) began in Wuhan, China, and rapidly spread to other regions. We aimed to further describe the epidemiological and clinical characteristics of discharged COVID-19 cases and evaluate the public health interventions.

Methods: We collected epidemiological and clinical data of all discharged COVID-19 cases as of 17 February 2020 in Shanghai. The key epidemiological distributions were estimated and outcomes were also compared between patients whose illness were before 24 January and those whose illness were after 24 January.

Results: Of 161 discharged COVID-19 cases, the median age was 45 years, and 80 (49.7%) cases were male. All of the cases were categorized as clinical moderate type. The most common initial symptoms were fever (85.7%), cough (41.0%), fatigue (19.3%), muscle ache (17.4%), sputum production (14.9%), and there were six asymptomatic cases. 39 (24.2%) cases got infected in Shanghai, and three of them were second-generation cases of Shanghai native cases. The estimated median of the time from onset to first medical visit, admission, disease confirmation, and discharge for 161 cases was 1.0 day (95% CI, 0.6-1.2), 2.0 days (95% CI, 1.5-2.6), 5.2 days (95% CI, 4.6-5.7), 18.1 days (95% CI, 17.4-18.8), respectively. The estimated median of the time from admission to discharge was 14.0 days (95% CI, 13.3-14.6). The time from onset to first medical visit, admission and disease confirmation were all shortened after the Shanghai's first-level public health emergency response. In Cox regression model, the significant independent covariates for the duration of hospitalization were age, the time from onset to admission and the first-level public health emergency response.

Conclusions: Local transmission had occurred in Shanghai in late January 2020. The estimated median of the time from onset to discharge of moderate COVID-19 was 18.1 days in Shanghai. Time intervals from onset to first medical visit, admission and disease confirmation were all shortened after the Shanghai's first-level public health emergency response. Age, the first-level public health emergency response and the time from onset to admission were the impact factors for the duration of hospitalization.
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http://dx.doi.org/10.1186/s12879-020-05493-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7573864PMC
October 2020

Three infection clusters related with potential pre-symptomatic transmission of coronavirus disease (COVID-19), Shanghai, China, January to February 2020.

Euro Surveill 2020 08;25(33)

Department of Infectious Disease Control and Prevention, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.

We report three clusters related with potential pre-symptomatic transmission of coronavirus disease (COVID-19) between January and February 2020 in Shanghai, China. Investigators interviewed suspected COVID-19 cases to collect epidemiological information, including demographic characteristics, illness onset, hospital visits, close contacts, activities' trajectories between 14 days before illness onset and isolation, and exposure histories. Respiratory specimens of suspected cases were collected and tested for SARS-CoV-2 by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) assay. The interval between the onset of illness in the primary case and the last contact of the secondary case with the primary case in our report was 1 to 7 days. In Cluster 1 (five cases), illness onset in the five secondary cases was 2 to 5 days after the last contact with the primary case. In Cluster 2 (five cases) and Cluster 3 (four cases), the illness onset in secondary cases occurred prior to or on the same day as the onset in the primary cases. The study provides empirical evidence for transmission of COVID-19 during the incubation period and indicates that pre-symptomatic person-to-person transmission can occur following sufficient exposure to confirmed COVID-19 cases. The potential pre-symptomatic person-to-person transmission puts forward higher requirements for prevention and control measures.
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http://dx.doi.org/10.2807/1560-7917.ES.2020.25.33.2000228DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7441604PMC
August 2020

Clusters of 2019 coronavirus disease (COVID-19) cases in Chinese tour groups.

Transbound Emerg Dis 2021 Mar 27;68(2):684-691. Epub 2020 Jul 27.

Department of Acute Communicable Diseases Control and Prevention, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.

International travel may facilitate the spread of the novel coronavirus disease (COVID-19). The study describes clusters of COVID-19 cases within Chinese tour groups travelling in Europe January 16-28. We compared characteristics of cases and non-cases to determine transmission dynamics. The index case travelled from Wuhan, China, to Europe on 16 January 2020, and to Shanghai, China, on 27 January 2020, within a tour group (group A). Tour groups with the same outbound flight (group B) or the same tourism venue (group D) and all Chinese passengers on the inbound flight (group C) were investigated. The outbreak involved 11 confirmed cases, 10 suspected cases and six tourists who remained healthy. Group A, involving seven confirmed cases and six suspected cases, consisted of familial transmission followed by propagative transmission. There was less pathogenicity with propagative transmission than with familial transmission. Disease was transmitted in shared outbound flights, shopping venues within Europe and inbound flight back to China. The novel coronavirus caused clustered cases of COVID-19 in tour groups. When tourism and travel opens up, governments will need to improve screening at airports and consider increased surveillance of tour groups-particularly those with older tour members.
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http://dx.doi.org/10.1111/tbed.13729DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7404672PMC
March 2021

Pre-symptomatic transmission of novel coronavirus in community settings.

Influenza Other Respir Viruses 2020 11 19;14(6):610-614. Epub 2020 Jun 19.

Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.

We used contact tracing to document how COVID-19 was transmitted across 5 generations involving 10 cases, starting with an individual who became ill on January 27. We calculated the incubation period of the cases as the interval between infection and development of symptoms. The median incubation period was 6.0 days (interquartile range, 3.5-9.5 days). The last two generations were infected in public places, 3 and 4 days prior to the onset of illness in their infectors. Both had certain underlying conditions and comorbidity. Further identification of how individuals transmit prior to being symptomatic will have important consequences.
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http://dx.doi.org/10.1111/irv.12773DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7323319PMC
November 2020

Epidemiological and clinical characteristics of 333 confirmed cases with coronavirus disease 2019 in Shanghai, China.

Transbound Emerg Dis 2020 Jul 13;67(4):1697-1707. Epub 2020 May 13.

Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease first identified in Wuhan City, Hubei Province, China. As of 19 February 2020, there had been 333 confirmed cases reported in Shanghai, China. This study elaborates on the epidemiological and clinical characteristics of COVID-19 based on a descriptive study of the 333 patients infected with COVID-19 in Shanghai for the purpose of probing into this new disease and providing reference. Among the 333 confirmed cases in Shanghai, 172 (51.7%) were males and 161 (48.3%) were females, with a median age of 50 years. 299 (89.8%) cases presented mild symptoms. 139 (41.7%) and 111 (33.3%) cases were infected in Wuhan and Shanghai, respectively. 148 (44.4%) cases once had contact with confirmed cases before onset, while 103 (30.9%) cases had never contacted confirmed cases but they had a sojourn history in Wuhan. The onset date of the first case in Shanghai was 28 December, with the peak appearing on 27 January. The median incubation period of COVID-19 was estimated to be 7.2 days. 207 (62.2%) cases had fever symptoms at the onset, whereas 273 (82.0%) cases experienced fever before hospitalization. 56 (18.6%) adults experienced a decrease in white blood cell and 84 (42.9%) had increased C-reactive protein after onset. Elderly, male and heart disease history were risk factors for severe or critical pneumonia. These findings suggest that most cases experienced fever symptoms and had mild pneumonia. Strengthening the health management of elderly men, especially those with underlying diseases, may help reduce the incidence of severe and critical pneumonia. Time intervals from onset to visit, hospitalization and diagnosis confirmed were all shortened after Shanghai's first-level public health emergency response. Shanghai's experience proves that COVID-19 can be controlled well in megacities.
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http://dx.doi.org/10.1111/tbed.13604DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7267440PMC
July 2020

Epidemiologic and genomic insights on mcr-1-harbouring Salmonella from diarrhoeal outpatients in Shanghai, China, 2006-2016.

EBioMedicine 2019 Apr 21;42:133-144. Epub 2019 Mar 21.

State Key Laboratory of Infectious Disease Prevention and Control, Beijing, China; National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China; Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing, China. Electronic address:

Background: Colistin resistance mediated by mcr-1-harbouring plasmids is an emerging threat in Enterobacteriaceae, like Salmonella. Based on its major contribution to the diarrhoea burden, the epidemic state and threat of mcr-1-harbouring Salmonella in community-acquired infections should be estimated.

Methods: This retrospective study analysed the mcr-1 gene incidence in Salmonella strains collected from a surveillance on diarrhoeal outpatients in Shanghai Municipality, China, 2006-2016. Molecular characteristics of the mcr-1-positive strains and their plasmids were determined by genome sequencing. The transfer abilities of these plasmids were measured with various conjugation strains, species, and serotypes.

Findings: Among the 12,053 Salmonella isolates, 37 mcr-1-harbouring strains, in which 35 were serovar Typhimurium, were detected first in 2012 and with increasing frequency after 2015. Most patients infected with mcr-1-harbouring strains were aged <5 years. All strains, including fluoroquinolone-resistant and/or extended-spectrum β-lactamase-producing strains, were multi-drug resistant. S. Typhimurium had higher mcr-1 plasmid acquisition ability compared with other common serovars. Phylogeny based on the genomes combined with complete plasmid sequences revealed some clusters, suggesting the presence of mcr-1-harbouring Salmonella outbreaks in the community. Most mcr-1-positive strains were clustered together with the pork strains, strongly suggesting pork consumption as a main infection source.

Interpretation: The mcr-1-harbouring Salmonella prevalence in community-acquired diarrhoea displays a rapid increase trend, and the ESBL-mcr-1-harbouring Salmonella poses a threat for children. These findings highlight the necessary and significance of prohibiting colistin use in animals and continuous monitoring of mcr-1-harbouring Salmonella.
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http://dx.doi.org/10.1016/j.ebiom.2019.03.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6491383PMC
April 2019

[Epidemiology of confirmed and suspected norovirus outbreaks in Shanghai, 2010-2014].

Zhonghua Liu Xing Bing Xue Za Zhi 2015 Nov;36(11):1249-52

Department of Acute Infectious Disease, Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China; Email:

Objective: To understand the epidemiologic characteristics of confirmed and suspected norovirus outbreaks in Shanghai during 2010-2014.

Methods: The investigation reports of confirmed and suspected norovirus outbreaks in Shanghai from 2010 to 2014 were analyzed.

Results: A total of 80 norovirus outbreaks, involving 2 399 cases, were reported during this period, and the overall attack rate was 4.17%. The median of the outbreak duration was 4.5 days and the incidence peaked 2 days later averagely for an outbreak. The outbreaks mainly occurred in autumn and winter, 53 outbreaks occurred during October-February, accounting for 66.25%. Seventy five outbreaks occurred in schools, child care settings and nursing houses, accounting for 93.75%. The attack rates in hospitalized patients and the elders in nursing houses were higher than those in pre-school and school aged children, the differences were statistically significant (χ² =683.12, P<0.01). The attack rates in medical staff and nurses in hospitals and nursing houses or staff in pre-schools and schools were lower. Vomiting, the main clinical symptom, occurred in 1 900 cases (79.20%), diarrhea and fever developed in 694 cases (28.93% ) and 364 cases (15.17% ) respectively. The differences were statistically significant (χ² =2 251.48, P<0.01). The outbreaks were mainly caused by short common exposures and contact with cases.

Conclusion: The surveillance for norovirus infection should be strengthened in hospitals, schools and others with the crowed during autumn-winter. The protection of risk population should be enhanced.
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November 2015

Prevalence of antimicrobial resistance of non-typhoidal Salmonella serovars in retail aquaculture products.

Int J Food Microbiol 2015 Oct 16;210:47-52. Epub 2015 Apr 16.

Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China; Department of Food Science and Nutrition, University of Maryland, College Park, MD, USA. Electronic address:

Aquaculture products can become sources of Salmonella by exposure to contaminated water or through processing practices, thus representing a public health hazard. A study was conducted on Salmonella contamination in aquaculture products sampled from marketplaces and retailers in Shanghai, China. A total of 730 samples (including fish, shellfish, bullfrog, clam, shrimp and others) were obtained from 2006 to 2011. Among them, 217 (29.7%) were positive for Salmonella. Thirty-eight serovars were identified in the 217 Salmonella isolates. The most prevalent were Salmonella Aberdeen (18.4%), S. Wandsworth (12.0%), S. Thompson (9.2%), S. Singapore (5.5%), S. Stanley (4.6%), S. Schwarzengrund (4.6%), S. Hvittingfoss (4.1%) and S. Typhimurium (4.1%). Many resistant isolates were detected, with 69.6% resistant to at least one antimicrobial drug. We observed high resistance to sulfonamides (56.5%), tetracycline (34.1%), streptomycin (28.6%), ampicillin (23.5%) and nalidixic acid (21.2%). Lower levels of resistance were found for gentamicin (3.2%), ciprofloxacin (2.3%), ceftiofur (1.3%), cefotaxime (0.9%), ceftazidime (0.5%) and cefepime (0.5%). A total of 43.3% of the Salmonella isolates were multidrug-resistant and 44 different resistance patterns were found. This study provided data on the prevalence, serovars and antimicrobial resistance of Salmonella from retail aquaculture products in Shanghai, and indicated the need for monitoring programs for microbiologic safety in such projects and for more prudent drug use in aquaculture production in order to reduce the risk of development and spread of antimicrobial resistance.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2015.04.019DOI Listing
October 2015

Epidemiology of norovirus infections among diarrhea outpatients in a diarrhea surveillance system in Shanghai, China: a cross-sectional study.

BMC Infect Dis 2015 Apr 15;15:183. Epub 2015 Apr 15.

Department of Infectious Disease Control and Prevention, Shanghai Municipal Center for Disease Control and Prevention, No. 1380, West Zhongshan Road, Shanghai, 200336, China.

Background: Norovirus is an important cause of gastroenteritis both in children and adults. In China, few studies have been conducted on adult populations. This study aimed to determine the contribution of norovirus to gastroenteritis, characterize the features of norovirus infections, compare them with other pathogens, and test the effectiveness of the surveillance system.

Methods: A citywide surveillance network on diarrhea patients was established. Samples were collected with intervals from both children and adults among diarrhea outpatients in hospitals and tested for viruses using rRT-PCR and for bacteria in CDCs. Patient information was acquired through interviews and recorded into a dedicated online system. The Pearson χ2 test, multivariate logistic regression models and discriminant models were fitted into its comparisons with the non-norovirus group and other pathogens.

Results: Norovirus was detected in 22.91% of sampled diarrhea patients. The seasonal distribution of norovirus infections was different from non-norovirus patients (p<0.001), with a half-year peak. Higher proportions of males (p=0.001, OR=1.303, 95% CI=1.110-1.529), local citizens (p<0.001) and officials/clerks (p=0.001, OR=1.348, 95% CI=1.124-1.618) were affected with norovirus when compared with non-norovirus patients. Diarrhea patients affected with norovirus featured nausea (p<0.001, OR=1.418, 95% CI=1.176-1.709) and vomiting (p<0.001, OR=1.969, 95% CI=1.618-2.398), while fewer manifested fever (p=0.046, OR=0.758, 95% CI=0.577-0.996) and abdominal pain (p=0.018, OR=0.815, 95% CI=0.689-0.965). Children were more vulnerable to rotavirus (p=0.008, OR=1.637, 95% CI=1.136-2.358) and bacteria (p=0.027, OR=1.511, 95% CI=1.053-2.169) than norovirus. There was a seasonal difference between the GI and GII genotypes (p<0.001). Officials or clerks were more easily affected with GI than GII (p=0.006, OR=1.888, 95% CI=1.205-2.958).

Conclusions: This study was based on a citywide hospital-sentinel surveillance system with multiple enteric pathogens included. Norovirus was recognized as the most prevalent enteric pathogen in Shanghai. The seasonal peak was from October to April. Males had a higher prevalence than females. Local citizens and officials/clerks were more vulnerable to norovirus than other pathogens. Compared with rotavirus and bacteria, children were less frequently affected by norovirus. Nausea and vomiting were typical of norovirus, whereas fever and abdominal pain were uncommon symptoms of this pathogen. GI and GII infections were centered in different seasons. Officials and clerks were more easily affected by GI than GII.
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http://dx.doi.org/10.1186/s12879-015-0922-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4438334PMC
April 2015

Light-controlled tuning of the optical properties of nanoporous glass.

Opt Express 2014 Oct;22(21):25560-9

Materials having tunable optical properties are of great interest for photonic applications. Promising candidates in that context are transparent nanoporous media whose optical properties change after infiltration of a liquid into the pores. Herein we present an all-optical method to tune the light scattering properties of a nanoporous glass based on the light-induced phase change of the fluid filling the pores. The thermodynamic state of the gas inside the nanopores determines the light scattering, thereby the light transmission. The extent of capillary condensation inside the nanoscale pores is controlled by heat generated from light absorption inside the medium. The material can be configured in such a way that a laser beam of sufficient intensity either opens up or shuts down its own light path on a time scale of a few seconds. The scattering events inside the medium change the beam profile from Gaussian to super-Gaussian with a more homogeneous intensity distribution close to the beam axis. Our results demonstrate a new way of tuning the light transmission properties of nanoporous materials that could find various applications in integrated optical systems and optofluidic devices.
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http://dx.doi.org/10.1364/OE.22.025560DOI Listing
October 2014

[Study on the molecular epidemiology and antibiotic resistance of Salmonella enterica serovar Pomona].

Zhonghua Liu Xing Bing Xue Za Zhi 2014 Jul;35(7):842-7

Shanghai Municipal Center for Disease Control and Prevention. Email:

Objective: To study the epidemiological characteristics and antibiotic resistance of Salmonella enterica serovar Pomona (S. Pomona).

Methods: Antimicrobial susceptible testing (AST) and pulsed field gel electrophoresis (PFGE) methods were used to analyze on S. Pomona strains that were isolated from diarrhea cases through the diarrhea network monitoring program, environment and food samples in Shanghai as well as from reptiles in Guangxi Zhuang Autonomous Region.

Results: 4 553 clinic Salmonella (S.) strains were isolated from the Shanghai network laboratories from 2005 to 2012. The top 10 serotypes would include 20 serotypes all belonged to A-F groups, while S. Pomona was next to S. Wandsworth, according to the non- A-F groups. Young children seemed to be susceptible to S. Pomona, and might cause bloody stools and super-infection. The top 10 serotypes from 1 805 foodborne Salmonella strains were significantly more extensive than those from the human S. Pomona strains, followed by those rare serotypes which were mostly isolated from turtle, sea-shellfish and reptiles. Antibiotic resistance of S. Pomona strains from other sources were significantly more severe than those from human samples, and belonged to A and B clones by means of PFGE. Clone A strains were non-epidemic strains which showed multi-drug resistance (MDR) to antimicrobials. Clone B was the main epidemic-causing strain that not resistant to drugs, which consisting B- I from young-age-groups and B-II were from the seniors. B-I strains were homologous to those from shellfish, tortoises and lizards, while B-II strains only showing homology to those from shellfish. One S. Pomona strain-MDR, isolated from human was homologous to 8 antimicrobials.

Conclusion: S. Pomona was a quite common serotype among those rare serotypes, which showed higher pathogenicity to infants while genetic evolution might take place when comparing them with the strains isolated from the clinics in 2005. Surveillance programs should be intensified along with the early warnings systems on infections which were from seafood and reptiles.
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July 2014

Wetting transitions within membrane compartments.

Soft Matter 2014 Aug 19;10(29):5311-7. Epub 2014 Jun 19.

College of Materials Science and Engineering, Hunan University, Changsha, 410082, China.

A biomimetic membrane in contact with several aqueous phases is theoretically studied using a combination of Helfrich curvature elasticity theory for fluid membranes and self-consistent field theory for polymers in solutions. Two phases that are thermodynamically formed by phase separation of aqueous solutions, as well as stable and metastable shapes of fluid vesicles, have been observed. The wetting transitions from complete to partial wetting and to complete dewetting are identified within a membrane compartment. The dependences of wetting transitions on material parameters, such as the intrinsic contact angles θin, the interaction strengths between the polymers χαβ and between the membrane and the polymer ηp, and impermeability of the membrane to the enclosed polymers ζp, are investigated. For a given χαβ, impermeability ζp and affinity to the membrane ηp, θin is found to be a constant and independent of the reduced volume of vesicles and the volume fraction of two phases.
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http://dx.doi.org/10.1039/c4sm00515eDOI Listing
August 2014

Shapes of vesicles encapsulating two aqueous phases.

Soft Matter 2014 Apr;10(15):2539-49

College of Materials Science and Engineering, Hunan University, Changsha, 410082, China.

Motivated by recent experiments, vesicles encapsulating two aqueous phases are theoretically explored using a combination of Helfrich curvature elasticity theory for fluid membranes and self-consistent field theory for polymers. The spatial distributions of two polymers, α and β, have been obtained, and two thermodynamic phases occur, as expected. Stable or metastable shapes of fluid and closed vesicles have also been achieved. Due to the impenetrability of the membrane to polymer, the available spaces of polymers α and β are limited and the conformational entropies for the polymers are reduced. Different chain segments that possess different permeability to the membrane would induce different inhomogeneous entropic pressures on the membrane, thereby leading to shape transformations of the vesicles. In the present study, the typical shapes of vesicles encapsulating two phases are studied as functions of the concentrations of polymers α and β, and the interactions between the chain segments and the membrane. The two phases formed by polymers α and β are also found to be altered and have been discussed in detail. In addition, morphological phase diagrams are presented as a function of the reduced volume, v. The phase boundaries between oblates and prolates, and oblates and stomatocytes of vesicles encapsulating two phases are found to move toward the higher reduced volume, and oblates occupy a much wider range of the reduced volume compared with 'neat' vesicles.
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http://dx.doi.org/10.1039/c3sm52404cDOI Listing
April 2014

Polymerization of actin filaments coupled with adenosine triphosphate hydrolysis: Brownian dynamics and theoretical analysis.

J Chem Phys 2011 Sep;135(10):105101

College of Materials Science and Engineering, Hunan University, Changsha 410082, China.

Polymerization dynamics of single actin filaments coupled with adenosine triphosphate (ATP) hydrolysis is investigated via both theoretical analysis and Brownian dynamics simulations. Brownian dynamics simulations have been applied recently to study the growth behaviors of long filaments as a function of the free actin monomer concentrations, C(T), which is found to be in agreement with the associated experiments. In the present study, both ATP cap length and length diffusivity are studied as a function of the free ATP-actin monomer concentrations, C(T). The exact analytical expressions are found to be in perfect consistency with Brownian dynamics simulations. Likewise, we find that the length diffusion coefficient is peaked near the critical concentration, C(T,cr). It is, therefore, expected that the dependence of length diffusivity on ATP-actin monomer concentrations is utilized to analyze the surprising experiments on the length fluctuations of individual actin filaments.
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http://dx.doi.org/10.1063/1.3634006DOI Listing
September 2011
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