Molecular Dynamics-Assisted Design of High Temperature-Resistant Polyacrylamide/Poloxamer Interpenetrating Network Hydrogels.

Polyacrylamide has promising applications in a wide variety of fields. However, conventional polyacrylamide is prone to hydrolysis and thermal degradation under high temperature conditions, resulting in a decrease in solution viscosity with increasing temperature, which limits its practical effect. Herein, combining molecular dynamics and practical experiments, we explored a facile and fast mixing strategy to enhance the thermal stability of polyacrylamide by adding common poloxamers to form the interpenetrating network hydrogel. The blending model of three synthetic polyacrylamides (cationic, anionic, and nonionic) and poloxamers was first established, and then the interaction process between them was simulated by all-atom molecular dynamics. In the results, it was found that the hydrogen bonding between the amide groups on all polymers and the oxygen-containing groups (ether and hydroxyl groups) on poloxamers is very strong, which may be the key to improve the high temperature resistance of the hydrogel. Subsequent rheological tests also showed that poloxamers can indeed significantly improve the stability and viscosity of nonionic polyacrylamide containing only amide groups at high temperatures and can maintain a high viscosity of 3550 mPa·S at 80 °C. Transmission electron microscopy further showed that the nonionic polyacrylamide/poloxamer mixture further formed an interpenetrating network structure. In addition, the Fourier transform infrared test also proved the existence of strong hydrogen bonding between the two polymers. This work provides a useful idea for improving the properties of polyacrylamide, especially for the design of high temperature materials for physical blending.

Development and Validation of a Clinical Prediction Model for Complicated Appendicitis in the Elderly.

Background: For elderly patients with mild clinical symptoms of uncomplicated appendicitis(UA), non-surgical treatment has been shown to be feasible, whereas emergency surgical treatment is recommended in elderly patients with complicated appendicitis(CA), but it is still challenging to accurately distinguish CA and UA before treatment. This study aimed to develop a predictive model to assist clinicians to quickly determine the type of acute appendicitis. Methods: We retrospectively studied the clinical data of elderly patients with acute appendicitis who visited the First Affiliated Hospital of Anhui University of Traditional Chinese Medicine from January 2012 to January 2022. The patients were divided into UA group and CA group, and the general conditions, medical history, physical examination, laboratory examination and imaging examination were compared between the two groups, and SPSS 26.0 and R 4.0.2 software were used to establish CA clinic. Predict the model, and validate it internally. Results: The clinical data of 441 elderly patients with acute appendicitis were collected, 119 patients were excluded due to incomplete clinical data or other diseases. Finally, 332 patients were included in the study and divided into UA group (n = 229) and CA group (n = 103). By analyzing the clinical data of the two groups of patients, the duration of abdominal pain [OR = 1.094, 95% CI (1.056-1.134)], peritonitis [OR = 8.486, 95% CI (2.017-35.703))] and total bilirubin [OR = 1.987, 95% CI (1.627-2.426)] were independent predictors of CA (all p < 0.01). The model's Area Under Curve(AUC) = 0.985 (95% CI, 0.975-0.994). After internal verification by Bootstrap method, the model still has high discriminative ability (AUC = 0.983), and its predicted CA curve is still in good agreement with the actual clinical CA curve. Conclusion: We found that a clinical prediction model based on abdominal pain duration, peritonitis, and total bilirubin can help clinicians quickly and effectively identify UA or CA before treatment of acute appendicitis in the elderly, so as to make more scientific clinical decisions.

Time lag effects of COVID-19 policies on transportation systems: A comparative study of New York City and Seattle.

The unprecedented challenges caused by the COVID-19 pandemic demand timely action. However, due to the complex nature of policy making, a lag may exist between the time a problem is recognized and the time a policy has its impact on a system. To understand this lag and to expedite decision making, this study proposes a change point detection framework using likelihood ratio, regression structure and a Bayesian change point detection method. The objective is to quantify the time lag effect reflected in transportation systems when authorities take action in response to the COVID-19 pandemic. Using travel patterns as an indicator of policy effectiveness, the length of policy lag and magnitude of policy impacts on the road system, mass transit, and micromobility are investigated through the case studies of New York City (NYC), and Seattle-two U.S. cities significantly affected by COVID-19. The quantitative findings show that the National declaration of emergency had no policy lag while stay-at-home and reopening policies had a lead effect on mobility. The magnitude of impact largely depended on the land use and sociodemographic characteristics of the area, as well as the type of transportation system.

The genotype distribution, infection stage and drug resistance mutation profile of human immunodeficiency virus-1 among the infected blood donors from five Chinese blood centers, 2014-2017.

Human immunodeficiency virus-1 (HIV-1) exhibits high diversity and complexity in China, challenging the disease surveillance and antiretroviral therapy. Between July 1, 2014 and January 30, 2017, we investigated the profiles of HIV-1 infection stages, genotype distribution and drug resistance mutations (DRMs) using plasma samples from HIV Western blot (WB) confirmed blood donors from five Chinese blood centers (Chongqing, Guangxi, Luoyang, Mianyang, and Urumqi). HIV pol regions consisted of whole protease and partial reverse transcriptase were genotyped and analyzed for DRMs. Lag-Avidity testing was performed to identify the infection stages. Of the 356 HIV-1 WB positive samples tested by Lag-avidity assay, 19.1% (68/356) were recent infections. Genotyping on 356 amplified sequences presented the subtype distributions as following: CRF07_BC (65.7%), CRF08_BC (7.3%), CRF01_AE (19.1%), B (4.2%), CRF55_01B (3.1%), CRF59_01B (0.3%) and CRF68_01B (0.3%). No significant difference in genotype distribution was observed between recent and long-term infections. 48 DRMs were identified from 43 samples, indicating a drug resistance prevalence of 12.1% (43/356), which include seven protease inhibitors (PIs) accessory DRMs (Q58E, L23I and I84M), two PIs major DRMs (M46I, M46L), seven nucleoside RT inhibitors DRMs (D67N, K70Q, K219R and M184L), and 32 non-nucleoside RT inhibitors DRMs (K103N, V179E, K238N, V179D, E138G, G190E, A98G, Y188D and E138A). In addition, we had also identified CRFs from the 01B subtype including CRF55_01B (3.1%), CRF59_01B (0.3%) and CRF68_01B (0.3%). As an important part of the continuous monitoring of HIV-1 circulating strains among blood donors, our findings were expected to contribute to the comprehensive AIDS control and development of proper diagnostics for HIV-1 in China.

Hepatitis C virus genotype/subtype distribution and evolution among Chinese blood donors: Revealing recent viral expansion.

Hepatitis C virus (HCV) genotype (GT) distribution in China shows significant geographical and demographic difference. As a routinely tested virus in Chinese blood bank systems, rare molecular epidemiology research in blood donors is reported. Our purpose is to investigate the HCV GT/subtypes distribution, phylogenetic analysis and population genetics in Chinese blood donors. Anti-HCV screen positive samples and donor demographics were collected. HCV Core and E1 gene fragments were amplified by RT-PCR, followed by sequencing and phylogenetic analysis to determine HCV GTs/subtypes using MEGA 7.0. The population genetics were performed using Arlequin v3.0 and Beast v1.10.4. SPSS Statistics 17.0 software was used to analyze the correlation between HCV GTs/subtypes distribution and demographic characteristics. 419 and 293 samples based on Core and E1 gene respectively were successfully amplified. HCV la, lb, 2a, 3a, 3b, 6a, 6e and 6n were found, and the corresponding proportions were 0.66% (3/455), 58.68% (267/455), 17.80% (81/455) and 5.05% (23/455), 3.52% (16/455), 12.31% (56/455), 0.88% (4/455) and 0.66% (3/455). Samples from Guangxi showed the most abundant genetic diversity with 8 subtypes were found. The number of haplotypes in HCV-1b is higher than 2a and 6a. The negative Tajima's D and Fu's Fs values of HCV-1b, 2a and 6a suggested the population expansion of those HCV subtypes. The distribution of HCV GT showed significant statistical difference by age and ethnicity. Conclusion: An abundance of HCV genetic diversity was found in Chinese blood donors with mainly 1b and then 2a subtype. There were significant geographical and demographic differences in HCV GTs/subtypes among Chinese blood donors. HCV subtype 1b has stronger viability and HCV subtype 6a has experienced significant expansion.

Current risk factors for HIV infection among blood donors in seven Chinese regions.

BACKGROUND: In China, there is a rising concern on the increasing trends of HIV infections in high-risk groups, who make blood donations that might potentially challenge the blood safety. Analyses on current risk factors for HIV infection among Chinese blood donors are urgently needed for developing effective strategies to defer high-risk donors and to warrant the safety of the blood supply. STUDY DESIGN AND METHODS: We recruited 313 HIV-positive and 762 HIV-negative donors from seven study sites in China and evaluated donor demographic characteristics, current medical and behavioral risk factors associated with HIV infection in a case-control survey. Univariable analyses examined the relationship between HIV infection and donor and donation characteristics, medical and behavioral risks, living conditions, and lifestyles. Multivariable logistic regression analyses evaluated the association between selected individual risks and HIV infection. Regression tree analysis was used to select covariates correlated with both HIV infection and individual risks and thus need to be controlled for in logistic regression models. RESULTS: Being a man who has sex with men was associated with the highest odds of HIV infection. Not using a condom, having sex with HIV-infected individuals, having sex partners with sexually transmitted diseases (STDs), having more than two concurrent sex partners, or having an STD were all associated with more than five times higher odds of having HIV. Having remunerated sex was associated with a 2.4 increased odds of having HIV infection. CONCLUSION: High-risk sexual behaviors were among the major risks for HIV infection among Chinese blood donors.

HIV prevalence and incidence estimates among blood donors in five regions in China.

BACKGROUND: Previous data, although scant, indicated that the incidence of HIV in China has increased over the past decade. There is a growing concern about the impact of the HIV epidemic on blood safety. METHODS AND MATERIALS: We used donation data from five geographically-disperse blood centers in 2013-2016 participating in the Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) China program to estimate HIV prevalence and incidence among blood donors. Multivariable logistic regression model was used to examine factors associated with HIV infection in Chinese blood donors. RESULTS: The overall HIV prevalence among first-time donors from 2013 through 2016 was 68.04 per 100,000 donors (95% CI 61.68-74.40). The HIV incidence rate was estimated to be 37.93 per 100,000 person-years (95% CI 30.62-46.97) among first-time donors and 20.55 per 100,000 person-years (95% CI 16.95-24.91) among repeat donors. There was substantial variation in HIV prevalence and incidence rates across blood centers. Multivariable logistic regression results showed that among first-time donors, being male, older than 25 years, minority ethnicity, less than college education, and certain occupations (commercial services, factory workers, retired, unemployed, or self-employed) were associated with positive HIV confirmatory testing results. CONCLUSION: HIV prevalence and incidence among blood donors remain low in the selected five regions in China; however, an increasing trend is observed at some blood centers. It is important to monitor HIV epidemiology in Chinese blood donors on a continuous basis, especially among populations and regions of higher risk.

Comparison study between mesoporous silica nanoscale microsphere and active carbon used as the matrix of shape-stabilized phase change material.

Mesoporous silica nanoscale microsphere (MSNM), with a special morphology, high porosity, large pore volume and specific surface area, was successfully prepared and used as the matrix material of lauric acid (LA) to prepare a favorable shape-stabilized phase change material (LA/MSNM). The porous network structure of MSNM is effective to prevent the leakage and enhance the thermal stability of LA/MSNM. For comparison, shape-stabilized phase change material of LA/AC, which contained commercially purchased active carbon (AC) and LA, was prepared by the same method. Characterizations of LA/MSNM and LA/AC, such as chemical properties, structure, thermal properties and crystallization properties were studied. The mechanisms of interaction between LA molecules and MSNM or AC were explicated. The results of TGA test showed that the LA/MSNM and LA/AC had superior thermal stability, and however, the melting and solidification enthalpies of LA/MSNM were much higher than that of LA/AC, which was attributed that the loading capacity of MSNM was better than that of LA/AC. All of the study results demonstrated that the mesoporous silica nanoscale microspheres of MSNM synthesized in this study possessed the potential for practical applications as a suitable supporter of organic phase change materials.

Hepatitis C virus prevalence and incidence estimates among Chinese blood donors.

BACKGROUND: Hepatitis C virus (HCV) is an important transfusion-transmitted virus with global significance. The objective of this study was to evaluate the HCV prevalence and incidence among Chinese blood donors from 2013 to 2016. STUDY DESIGN AND METHODS: Whole blood and apheresis platelet donations collected from five Chinese blood centers from June 1, 2013, to December 31, 2016, were screened in parallel by two different enzyme-linked immunosorbent assays for anti-HIV 1/2, hepatitis B surface antigen, anti-HCV, and syphilis. Screening-reactive samples were further confirmed by western blot. Confirmatory positive rates among first-time and repeat donors were used to estimate the prevalence and incidence rates. Multivariable logistic regression modeling was used to examine factors associated with HCV infection. RESULTS: A total of 1,276,544 donations were collected from five Chinese blood centers, of which an estimated 1203 were confirmed HCV positive. The overall HCV prevalence among first-time donors was 166.56 per 100,000 donors (95% confidence interval, 156.04-177.08). The HCV incidence rate was estimated to be 15.21 (95% confidence interval, 11.83-19.56) per 100,000 person-years among repeat donors. Multivariable logistic regression results showed that increased age, lower educational levels, ethnicity, and occupation were all important factors associated with HCV confirmatory status among first-time donors (p < 0.01). CONCLUSIONS: HCV infection is still an important concern for transfusion safety in China. Our findings indicate that continued strong efforts are needed to monitor and control the risk of transfusion-transmitted HCV infection in China. Moreover, to reduce unnecessary donor loss, HCV donor screening procedures should be improved by incorporating confirmatory testing into routine blood center operations.

Blood utilization in five Chinese hospitals shows low hemoglobin thresholds in medical patients.

BACKGROUND: The number of red blood cell units transfused per capita in China is lower than in western countries and the reason(s) for the difference is unknown. STUDY DESIGN AND METHODS: We randomly chose 5050 transfused patients from five Chinese hospitals. We compared transfused cases to nontransfused controls matched for the same underlying diagnosis. We assessed the pretransfusion hemoglobin (Hb) trigger and other clinical characteristics associated with transfusion. After stratifying by underlying disease, we compared pretransfusion Hb level in Chinese hospitals to 12 US hospitals. RESULTS: In 5050 patients who received transfusion, the pretransfusion Hb levels were lower in medical (6.3 g/dL) compared to surgical patients receiving transfusion postoperatively (8.1 g/dL). In patients with nonsurgical diagnoses, the pretransfusion Hb was much lower than that in the United States; the difference in mean Hb level varied by underlying diagnosis from 0.4 to 1.8 g/dL. In case-control analysis of cases (n = 1356) compared to controls (n = 1201), the pretransfusion Hb showed the strongest association with transfusion. Compared to 10 g/dL, the odds ratio (95% confidence interval) for pretransfusion Hb of 7 to 7.9 g/dL was 37.7 (24.8-57.4). CONCLUSION: Transfusion triggers in five Chinese hospitals appear comparable to those in the United States for surgical patients; however, medical patients have lower pretransfusion Hb levels (approx. 6 g/dL). Of the factors assessed, the pretransfusion Hb was most strongly associated with transfusion. The clinical impact of lower transfusion thresholds used in China is unknown.

Estimation of hepatitis B-positive rates in Chinese blood donors by combining predonation and postdonation screening results.

BACKGROUND: Chinese blood centers use Hepatitis B surface antigen (HBsAg) rapid test (RT) in pre-donation and two rounds of screening with different enzyme-linked immunosorbent assays in post-donation. Nucleic acid testing (NAT) on screening non-reactive (SC-) donations has been gradually implemented since 2010. Yet RT+ and SC-/NAT+ donors are seldom included in hepatitis B virus (HBV) positive rate estimates in Chinese blood donors. METHODS: We performed HBsAg neutralization test (NT) on whole blood (WB) with pre-donation RT+ results and post-donation screening reactive (SC+) samples from Mianyang and Chongqing in 2015. The annual totals of pre- and post-donation NT+ donors were combined with the annual totals of SC-/NAT+ donors to derive the estimated HBV positive rates. RESULT: In Mianyang and Chongqing, 59.4% and 68.2% of RT+ donors in Jan-Aug 2015 contributed for NT, 95.5% and 97.2% of which were NT+ respectively. In 2015, 422 and 667 donors from Mianyang and Chongqing respectively were HBsAg RT+, yielding estimated 403 and 648 pre-donation RT+/NT+ deferrals. 411 and 668 post-donation SC+ samples were NT tested from Mianyang and Chongqing, of which 249 and 323 were NT+ respectively. An estimated 63 donors in Mianyang and 88 donors in Chongqing were SC-/NAT+. The estimated HBV confirmed positive rate in blood donors are 1.59% in Mianyang and 1.01% in Chongqing. CONCLUSION: Pre-donation HBsAg RT effectively intercepts donations from HBV infected donors. Using NT confirmatory results from RT+, SC+ and SC-/NAT+ donors, this study provides a model for more accurate estimation for HBV positive rates in China.

Extracting Trips from Multi-Sourced Data for Mobility Pattern Analysis: An App-Based Data Example.

Passively-generated data, such as GPS data and cellular data, bring tremendous opportunities for human mobility analysis and transportation applications. Since their primary purposes are often non-transportation related, the passively-generated data need to be processed to extract trips. Most existing trip extraction methods rely on data that are generated via a single positioning technology such as GPS or triangulation through cellular towers (thereby called single-sourced data), and methods to extract trips from data generated via multiple positioning technologies (or, multi-sourced data) are absent. And yet, multi-sourced data are now increasingly common. Generated using multiple technologies (e.g., GPS, cellular network- and WiFi-based), multi-sourced data contain high variances in their temporal and spatial properties. In this study, we propose a "Divide, Conquer and Integrate" (DCI) framework to extract trips from multi-sourced data. We evaluate the proposed framework by applying it to an app-based data, which is multi-sourced and has high variances in both location accuracy and observation interval (i.e. time interval between two consecutive observations). On a manually labeled sample of the app-based data, the framework outperforms the state-of-the-art SVM model that is designed for GPS data. The effectiveness of the framework is also illustrated by consistent mobility patterns obtained from the app-based data and an externally collected household travel survey data for the same region and the same period.

The infection staging and profile of genotypic distribution and drug resistance mutation among the human immunodeficiency virus-1 infected blood donors from five Chinese blood centers, 2012-2014.

The increasing complexity and diversity of the human immunodeficiency virus-1 (HIV-1) infections challenge the disease control and anti-retrovirus treatment in China. The infection stages and molecular characteristics of HIV-1 from infected Chinese blood donors were examined to shed light on the HIV genotype distribution and the status of drug resistance mutations (DRMs) in the changing HIV epidemic in China. Western blot (WB) confirmed HIV-1 positive plasma samples were collected from blood donors at five Chinese blood centers from April 16, 2012, through June 30, 2014. The HIV infection stages were determined using the Lag-avidity assay. HIV Pol regions including whole protease and partial reverse transcriptase (RT) were amplified and sequenced to establish the profile of genotype distribution and drug resistance mutations (DRMs). Viral loads were determined using the ROCHE COBAS system. Of the 259 HIV-1 positive samples tested by the Lag-avidity assay, 23.6% (61/259) were identified as recent infections. A total of 205 amplified sequences displayed the following genotype distributions: circulating recombinant form (CRF) 07_BC (61.5%), CRF08_BC (8.3%), CRF01_AE (20%), B (6.3%), and 01B (3.9%). There was no significant difference in genotype distribution between recent and long-term infections. 31 DRMs were identified from 27 samples including four protease inhibitors (PIs) accessory DRMs, two PIs major DRMs (M46I), two nucleoside RT inhibitors DRMs (K219R and K70Q), and 23 nonnucleoside RT inhibitors DRMs. 27 samples had DRMs, yielding a drug resistance prevalence of 13.2% (27/205). Our findings provide important information for developing strategies for comprehensive HIV control and improving anti-retroviral treatment in China.

The association of elevated alanine aminotransferase levels with hepatitis E virus infections among blood donors in China.

BACKGROUND: Transfusion transmission of hepatitis E virus (HEV) is an emerging health risk, yet blood donors are rarely screened for this pathogen. Many blood centers instituted screening of blood donors for elevated levels of alanine aminotransferase (ALT) levels to prevent hepatitis C virus, which has continued in China. We evaluated whether elevated ALT levels were associated with HEV among blood donors in China. STUDY DESIGN AND METHODS: Blood samples were collected from 9069 qualified volunteer blood donors from four blood centers in China. A total of 5023 had elevated ALT levels, that is, more than 40 IU/L, and 4046 samples had normal ALT. We tested all the 9069 samples for anti-HEV immunoglobulin (Ig)M, anti-HEV IgG, and HEV antigen. Those who were positive for anti-HEV IgM or HEV antigen were tested individually for HEV RNA by polymerase chain reaction. RESULTS: The prevalence of anti-HEV IgG in donors with elevated ALT levels (33.3%) was higher than those with normal ALT (24.9%; p < 0.01). The prevalence of anti-HEV IgM was similar in donations with increased ALT (1.41%) and normal ALT (1.46%). More ALT-elevated donations were HEV antigen positive, 62 of 5023 (1.23%), than were ALT-normal donations, seven of 4046 (0.17%; p < 0.01). Six donors with elevated ALT levels and acute HEV infection markers (anti-HEV IgM or HEV antigen) were HEV RNA positive. CONCLUSION: Markers of active infection including HEV antigen and HEV RNA are significantly more common among donors with elevated ALT levels in China. These data support the fact that ALT testing of donors to HEV antigen or HEV RNA would have greater specificity and exclude fewer acceptable donors.

The characteristics of hepatitis B surface antigen (HBsAg)-negative hepatitis B virus (HBV) infection in Chinese blood donors: a follow-up study of donors tested negative for HBsAg and reactive for simultaneous nucleic acid testing of HBV, hepatitis C virus, and human immunodeficiency virus.

BACKGROUND: The real infection status of hepatitis B virus (HBV) of hepatitis B surface antigen (HBsAg)-negative yet nucleic acid test (NAT)-positive blood donors is difficult to clarify. Detailed follow-up study is needed for analyzing the infectivity of these blood donors. STUDY DESIGN AND METHODS: Blood donors who screened negative for HBsAg and reactive for simultaneous NAT of HBV, hepatitis C virus (HCV), and human immunodeficiency virus (HIV) were included in a follow-up epidemiologic questionnaire survey and contributed follow-up samples for further testing. The follow-up samples were tested repeatedly for the serologic markers and HBV DNA. The genotypes and sequence mutations of HBV infected by 11 HBV DNA-positive donors were analyzed through the amplification and sequencing of HBV S region. RESULTS: Of the 46 donors included in this study, 89.1% were infected with HBV (41/46), including one (2.2%) window period infection, three (6.5%) recovered infections, and 37 (80.4%) occult HBV infections (OBIs). The S region of HBV was successfully amplified and sequenced for seven donors, five infected with Genotype B (71.4%), one with Genotype C (14.3%), and one with Genotype D (14.3%). Mutations in the S region were detected in four donors (57.1%) CONCLUSIONS: This is the first detailed study with multiple follow-up testing of the HBV infection status among blood donors who were tested negative for HBsAg and reactive for simultaneous NAT of HBV, HCV, and HIV. Most of these donors were infected with HBV with very low viral load. Our findings indicate that it is important to improve the sensitivity of NAT so as to decrease the residual risk of transfusion-transmitted HBV infection.

The Impact of Emerging Infectious Diseases on Chinese Blood Safety.

Emerging infectious diseases (EIDs) have always been one of the major threats to public health. Although the implementation of mandatory testing for 4 classical transfusion-transmitted infectious-human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and syphilis-has reduced the transfusion risk of these pathogens, the potential threat of various EID agents and their constantly evolving variants to blood safety in China is not fully understood. This review presents 9 representative EID agents that are autochthonous and epidemic nationally or regionally in China. The epidemiologic status and distribution of these EID agents among donors and/or healthy populations are summarized. The potential risks of these EID agents to blood safety are discussed. The review also explores strategies to strengthen hemovigilance systems and studies to further evaluate the impact of EID agents on blood safety.

Development and validation of a real-time reverse transcriptase PCR assay for sensitive detection of SFTSV.

BACKGROUND: Severe fever with thrombocytopenia syndrome bunyavirus (sftsv) is an emerging tick-borne rna virus recently identified as the pathogen that causes severe fever with thrombocytopenia syndrome (sfts) in china. the existing commercial nucleic acid testing (comnat) assay with a relatively high claimed limit of quantitative detection (loqd) is not capable of sensitive detection and quantitation of sftsv. Thus, a new real-time reverse transcriptase (rt)-pcr assay with improved sensitivity is needed for clinical diagnosis; it could also be used to screen blood donors if necessary. MATERIALS AND METHODS: We developed a new sftsv rt-pcr nat assay (newnat). About 129 plasma samples from 93 suspected sfts patients with typical clinical symptoms were tested using an anti-sftsv total antibody elisa and both comnat and newnat. The test performance of the two nat assays was evaluated and compared. RESULTS: The newnat had a lower limit for quantitative testing compared to comnat. Twelve samples were comnat negative but newnat positive. Out of 35 suspected sfts patients who were comnat negative and anti-sftsv total antibody negative, four tested positive by the newnat assay and one of these four seroconverted within 2-4 days after testing newnat positive. A high correlation was observed between the cts of the newnat and comnat assays. CONCLUSION: The newnat assay was sensitive for quantitative detection of sftsv and may be applicable to clinical diagnosis and studies of the need for blood donor screening.

Development of High Hydrostatic Pressure Applied in Pathogen Inactivation for Plasma.

High hydrostatic pressure has been used to inactivate pathogens in foods for decades. There is a great potential to adapt this technology to inactivate pathogens in plasma and derivatives. To better evaluate the potential of this method, pathogen inoculated plasma samples were pressurized under different pressure application modes and temperatures. The inactivation efficacy of pathogens and activities of plasma proteins were monitored after treatment. The CFUs of E.coli was examined as the indicator of the inactivation efficiency. The factor V and VIII were chosen as the indicator of the plasma function. Preliminary experiments identified optimized treatment conditions: 200-250MPa, with 5×1 minute multi-pulsed high pressure at near 0°C (ice-water bath). Under this conditions, the inactivation efficacy of EMCV was >8.5log. The CFUs of E. coli were reduced by 7.5log, B. cereus were 8log. However, PPV and S. aureus cannot be inactivated efficiently. The activities of factor II, VII, IX, X, XI, XII, fibrinogen, IgG, IgM stayed over 95% compared to untreated. Factor V and VIII activity was maintained at 46-63% and 77-82%, respectively.

Risk factors for hepatitis B and C infection among blood donors in five Chinese blood centers.

BACKGROUND: Few studies were conducted on hepatitis B and C virus (HBV and HCV, respectively) risk factors among Chinese blood donors in recent years since voluntary donors replaced commercial donors. STUDY DESIGN AND METHODS: A case-control survey was conducted in HBV- or HCV-positive and -negative donors from five blood centers in China between September 2009 and April 2011. Case status was defined by having a reactive result on Monolisa HBsAg Ultra (Bio-Rad) for HBV and Ortho anti-HCV EIA 3.0 (Johnson & Johnson) for HCV. Controls were randomly selected qualified blood donors matched to cases by donation month and blood center. Specific test-seeking, medical-related, and behavioral risk factors were compared by HBV and HCV status using chi-square tests or Fisher's exact tests with Bonferroni correction. RESULTS: A total of 364 HBV cases, 174 HCV cases, and 689 controls completed the survey; response rates were 66.2, 47.3, and 82%, respectively. HCV-positive donors were significantly more likely to report having a blood transfusion history (23.4% vs. 3.0%, p < 0.0001) and ever living with a person with illegal drug injection (6.0% vs. 0.5%, p < 0.0001) than controls. Having intravenous and intramuscular injections in the past 12 months and ever having a tattoo are marginal risk factors for HCV (p values < 0.01). No specific risk factor for HBV was identified. CONCLUSION: History of previous transfusion and living with illegal drug users are risk factors for HCV infection among Chinese blood donors from five regions. Test-seeking behavior is not associated with HBV or HCV infections.

Blood transfusion practice: a survey in Sichuan, China.

OBJECTIVE: To get full knowledge of current conditions and development in the past seven years of clinical transfusion practice in Sichuan, China. STUDY DESIGN AND METHODS: This survey was performed by means of a questionnaire which consisted of three parts of questions including basic conditions of blood banks in the hospitals, procedures for clinical blood transfusion and the utilization of different types of blood products. Thirty-five representative hospitals from different geographic locations in Sichuan province participated in this survey. RESULTS: All of the 35 hospitals returned the questionnaires and 33 hospitals (94.3%) answered the questions completely. The blood bank information system began to be used by more hospitals from 2006 (21.21%, 7/33) to 2012 (48.48%, 16/33). Automated grouping and cross-matching systems have not been used in level 2 hospitals and only 3 level 3 hospitals used automated systems in 2012. Still less common were procedures for evaluation of blood order forms for appropriateness (2/33, 6.06%) and evaluation of appropriateness and effect of blood component transfusion (8/33, 24.2%), and all the hospitals having these procedures are level 3 hospitals. The percentage of whole blood usage in the volume of all types of blood products used decreased a lot from 7.45% in 2006 to 0.16% in 2010. Technological instruments for bedside checking are not used by any of the hospitals. CONCLUSIONS: The transfusion service degree of the hospitals in Sichuan, China, has developed a lot in the past seven years; however, there are still some problems including whole blood still being used, albeit decreasing; lack of independent blood banks within the hospitals; lack of dedicated personnel for the transfusion services; lack of education; lack of blood bank information systems and automation; lack of screening for appropriateness for blood orders. Thus, the quality control center of clinical blood transfusion (QCCCBT) of Sichuan province should help the transfusion departments to attract more investment in staffing, equipment and information system from the hospitals, enhance the training of transfusion department staffs, and emphasize the supervision of transfusion department's work on directing clinical blood utilization and evaluating clinical transfusion appropriateness.