The effect of Pluronic P123 on shape memory of cross-linked polyurethane/poly(l-lactide) biocomposite.

Polyurethane (PU) and poly(l-lactide) (PLLA) have attracted increasing attention in the development of shape memory polymers (SMPs) due to their good biocompatibility and degradability. Although Pluronic P123 can be used to tune polymeric surface hydrophilicity, its effect on SM performance is a mystery. In this study, a soluble cross-linked PU is synthesized as the switching phase and combined with PLLA and P123 to construct a hydrothermally responsive SM composite. The water contact angle of PU/PLLA/P123 decreases from 22.7° to 5.1° within 2 min. PU and P123 form the switching group, which enhances the SM behavior of the composite. The shape fixity (Rf) and shape recovery (Rr) of PU/PLLA/P123 are 94.4 % and 98 % in 55 °C water, respectively, and the shape recovery time is only 10 s. P123 plays the role of "turbine" in the SM process. PU/PLLA/P123 exhibits a balance between stiffness and elasticity, and good degradability. Furthermore, PU/PLLA/P123 is also biocompatible and beneficial to cell proliferation and growth. Therefore, it offers an alternative approach to developing hydrothermally responsive SM biocomposites based on P123, PU and PLLA for biomedical applications.

Short-Term Exposure to Ambient Air Pollution and Influenza: A Multicity Study in China.

BACKGROUND: Air pollution is a major risk factor for planetary health and has long been suspected of predisposing humans to respiratory diseases induced by pathogens like influenza viruses. However, epidemiological evidence remains elusive due to lack of longitudinal data from large cohorts. OBJECTIVE: Our aim is to quantify the short-term association of influenza incidence with exposure to ambient air pollutants in Chinese cities. METHODS: Based on air pollutant data and influenza surveillance data from 82 cities in China over a period of 5 years, we applied a two-stage time series analysis to assess the association of daily incidence of reported influenza cases with six common air pollutants [particulate matter with aerodynamic diameter ≤2.5µm (PM2.5), particulate matter with aerodynamic diameter ≤10µm (PM10), NO2, SO2, CO, and O3], while adjusting for potential confounders including temperature, relative humidity, seasonality, and holiday effects. We built a distributed lag Poisson model for one or multiple pollutants in each individual city in the first stage and conducted a meta-analysis to pool city-specific estimates in the second stage. RESULTS: A total of 3,735,934 influenza cases were reported in 82 cities from 2015 to 2019, accounting for 72.71% of the overall case number reported in the mainland of China. The time series models for each pollutant alone showed that the daily incidence of reported influenza cases was positively associated with almost all air pollutants except for ozone. The most prominent short-term associations were found for SO2 and NO2 with cumulative risk ratios of 1.094 [95% confidence interval (CI): 1.054, 1.136] and 1.093 (95% CI: 1.067, 1.119), respectively, for each 10 µg/m3 increase in the concentration at each of the lags of 1-7 d. Only NO2 showed a significant association with the daily incidence of influenza cases in the multipollutant model that adjusts all six air pollutants together. The impact of air pollutants on influenza was generally found to be greater in children, in subtropical cities, and during cold months. DISCUSSION: Increased exposure to ambient air pollutants, particularly NO2, is associated with a higher risk of influenza-associated illness. Policies on reducing air pollution levels may help alleviate the disease burden due to influenza infection. https://doi.org/10.1289/EHP12146.

A shape-memory poly(ε-caprolactone) hybridized TiO2/poly(l-lactide) composite with antibacterial properties.

Organic-inorganic composites as an efficient strategy to upgrade the structural and functional properties of synthetic polymers are attracting extensive attentions. However, there are few studies on the shape memory (SM) behavior of organic-inorganic composites. In the work, poly(ε-caprolactone) hybridized TiO2 nanomaterial (PCL-TiO2) is made as the switching phase and integrated into poly (l-lactide) (PLLA) to construct an SM composite. PCL-TiO2/PLLA shows "sea-island" structure and better interfacial adhesion than PCL/PLLA, which facilitates the transmission of elastic power between the switching phase and the fixing phase. PCL-TiO2 as switching phase exhibits lower enthalpy at 57 °C than PCL, and PCL-TiO2 also acts as "heat dispersion pump station", which builds a dynamically responsive system and initiates shape change. The shape fixing and recovery ratio of PCL-TiO2/PLLA are 93.9 % and 94.4 %, respectively, and go back to the original shape within 15 s at 57 °C. At the same time, PCL-TiO2 endows SMP with good antibacterial properties. Then this work provides a well-placed way for developing SM materials with structure-function integration.

Myofibroblasts: A New Factor Affecting the Hyperlipidemia-Induced Elastic Abnormality of Corpus Cavernosum in Rabbits Detected by 2-D Shear Wave Elastography.

OBJECTIVE: Two-dimensional shear wave elastography (2-D SWE) has been proven to detect hyperlipidemia-induced elastic abnormality in the corpus cavernosum. This study investigated cytological factors affecting the elasticity of the corpus cavernosum in rabbits with hyperlipidemia using single-cell RNA sequencing (scRNA-seq). METHODS: Male New Zealand white rabbits were randomly divided into a hyperlipidemia group (high-cholesterol diet) and a control group (standard diet). Penile 2-D SWE was performed to detect the elastic abnormality in the corpus cavernosum. ScRNA-seq was performed to observe cellular changes in the corpus cavernosum of rabbits with hyperlipidemia. Immunohistochemistry, immunofluorescence and histological examinations were conducted to verify the results of scRNA-seq. RESULTS: Two-dimensional SWE revealed that the Young's modulus of the corpus cavernosum was significantly greater in the hyperlipidemia group than that in the control group (p < 0.001). Histological findings revealed extracellular matrix accumulation within the corpus cavernosum, with stronger staining of collagen types I and Ⅲ. ScRNA-seq revealed that fibroblasts, smooth muscle cells, and endothelial cells were the major cell types in the corpus cavernosum. A novel subtype of fibroblasts (myofibroblast) was discovered in the hyperlipidemia group, which was verified by immunofluorescence staining and gene ontology analysis. Fibroblasts, smooth muscle cells and endothelial cells were three cellular sources for myofibroblasts. CONCLUSION: Myofibroblasts are activated and proliferate and secrete large amounts of collagen fibers in the corpus cavernosum during hyperlipidemia, leading to abnormal Young's modulus detected by 2-D SWE and their recognition as a new factor affecting the hyperlipidemia-induced elastic abnormality of the corpus cavernosum.

Hydroxyapatite cross-linked in situ polyvinyl alcohol hydrogel for bionic calcified cartilage layer.

Many tissue engineering constructs have been investigated for repairing the calcified cartilage layer in the recent years, but engineering a consistent and stable interface to facilitate a graft-to-bone fixation remains a concern. In the work, hydroxyapatite (HA) is modified by diisocyanate (HDI) and integrated with polyvinyl alcohol (PVA) to prepare the hydrogel. The IR shows that HDI is grafted onto HA and helps HA to cross-link in situ in the PVA gel network. When the mass ratio of HA/PVA is 3.5 wt%, the swelling rate in the PBS of different pH reduced with time prolong, and the hydrogel takes on good swelling resistance. The tensile strength and toughness are 1890 KPa and 264 KJ/m-3, respectively, while the compression strength reaches 1125 KPa at compressive strain of 60%. The hydrogel not only is well durable via continuous 100 rounds of compression-recovery, but also has excellent bioactivity. The work will provide a platform for developing multifunctional soft tissue scaffold.

Human infection with a reassortment avian influenza A H3N8 virus: an epidemiological investigation study.

A four-year-old boy developed recurrent fever and severe pneumonia in April, 2022. High-throughput sequencing revealed a reassortant avian influenza A-H3N8 virus (A/Henan/ZMD-22-2/2022(H3N8) with avian-origin HA and NA genes. The six internal genes were acquired from Eurasian lineage H9N2 viruses. Molecular substitutions analysis revealed the haemagglutin retained avian-like receptor binding specificity but that PB2 genes possessed sequence changes (E627K) associated with increased virulence and transmissibility in mammalian animal models. The patient developed respiratory failure, liver, renal, coagulation dysfunction and sepsis. Endotracheal intubation and extracorporeal membrane oxygenation were administered. H3N8 RNA was detected from nasopharyngeal swab of a dog, anal swab of a cat, and environmental samples collected in the patient's house. The full-length HA sequences from the dog and cat were identical to the sequence from the patient. No influenza-like illness was developed and no H3N8 RNA was identified in family members. Serological testing revealed neutralizing antibody response against ZMD-22-2 virus in the patient and three family members. Our results suggest that a triple reassortant H3N8 caused severe human disease. There is some evidence of mammalian adaptation, possible via an intermediary mammalian species, but no evidence of person-to-person transmission. The potential threat from avian influenza viruses warrants continuous evaluation and mitigation.

A medicated shape memory composite of grafting tannin/poly(l-lactide).

Establishing drug release from shape memory polymers (SMPs) for biomedical applications will broaden the horizon of SMP applications from commercial medical device to scientific drug delivery system. Therefore, a strategy combining degradable SMP with drug release is put forward. However, there are few reports about the relevance between them so far. In the work, incorporations of three grafting tannins (TA) as switching phase into poly (l-lactide)(PLLA) construct different thermoresponsive SM composites. TA-PCL-COOH/PLLA exhibites good shape fixation (Rf) and recovery rate (Rr) at 55 °C, and its recovery time is 75 s. After loading lipophilic drug, SM capability of medicated TA-PCL-COOH/PLLA enhances, the Rf and Rr are 97.8% and 97.2%, in particular, its recovery time decreases to 32 s. The effect of SM on drug release is explored. After the first round of SM, the drug release accelerates obviously at body temperature; for example, the release amount of drug increases from 46.5% to 66.1% at initial 12 h due to change of microstructure and improvement of wettability. The drug release rate climbs only slightly as the SM round increases.

Sensitive and Easy-Read CRISPR Strip for COVID-19 Rapid Point-of-Care Testing.

Rapid and clinically sensitive detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) play an important role in the contact tracing and containment of the COVID-19 pandemic. A recently developed field-deployable clustered regularly interspaced short palindromic repeats (CRISPR) detection assay with lateral flow strips shows promise for point-of-care detection of SARS-CoV-2. However, the limit of detection of paper strip-based assays (10-100 copies/µL) is much lower than that of fluorescence-based detection methods. In this study, we developed an easy-readout and sensitive enhanced (ERASE) strip to visualize the results of CRISPR detection and improve the sensitivity to 1 copy/µL with an unambiguous easy-read result. Using 649 clinical samples from blind specimens collected from patients in China, we validated our ERASE assay for SARS-CoV-2 RNA detection with 90.67% positive predictive agreement and 99.21% negative predictive agreement. In conclusion, our study provided a customized CRISPR strip for use in a simple, rapid, ultrasensitive, and highly specific assay for SARS-CoV-2 detection. (Clinical Trial Registration number: 2020-008-01; [2020]IEC(ZD01); PJ-NBEY-2020-009-01; 2020#34).

Vitamin D (1,25-(OH)2D3) regulates the gene expression through competing endogenous RNAs networks in high glucose-treated endothelial progenitor cells.

Vitamin D (vit-D) supplementation can improve endothelial cell function in type 2 diabetes mellitus patients with vit-D insufficiency or deficiency. In the present study, we aimed to compare the expression profiles of circRNAs, lncRNAs, miRNAs, and mRNAs between 1,25-(OH)2D3-treated endothelial progenitor cells (EPCs) and control cells, and to further construct the 1,25-(OH)2D3-regulated ceRNA networks in EPCs. RNA sequencing was performed on the 1,25-(OH)2D3-treated EPCs and control cells derived from the bone marrow (BM). Bioinformatics analyses were performed to identify differentially expressed (DE) microRNAs (miRNAs), circular RNAs (circRNAs), mRNAs, and long non-coding RNAs (lncRNAs). Then Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to predict the function of genes. Competing endogenous RNA (ceRNA) networks were constructed with Cytoscape software. 1,25-(OH)2D3 application induced changes in the expression profiles of 1791 mRNAs, 2726 lncRNAs, 205 circRNAs, and 45 miRNAs in EPCs treated with high levels of glucose. These DE RNAs were associated with MMP and GTPase activities, specific signaling pathways, and components of actin, extracellular matrix, or adherens junction. DE circRNAs, which functioned independently of their linear host genes, interacted with miRNAs to serve as miRNA sponges in complex ceRNA networks. The data indicated that circRNAs and lncRNAs comprised ceRNAs to sponge effects of miRNAs on the expressions of mRNAs following 1,25-(OH)2D3 application in EPCs. 1,25-(OH)2D3 improved the function of EPCs via associated ceRNA interaction networks in diabetes patients.

Curcumin Delays Retinal Degeneration by Regulating Microglia Activation in the Retina of rd1 Mice.

BACKGROUND/AIMS: Retinitis pigmentosa (RP) is characterized by degeneration of photoreceptors, and there are currently no effective treatments for this disease. However, curcumin has shown neuroprotectant efficacy in a RP rat and swine model, and thus, may have neuroprotective effects in this disease. METHODS: Immunofluorescence staining, electroretinogram recordings, and behavioral tests were used to analyze the effects of curcumin and the underlying mechanism in retinal degeneration 1 (rd1) mice. RESULTS: The number of apoptotic cells in the retina of rd1 mice at postnatal day 14 significantly decreased with curcumin treatment and visual function was improved. The activation of microglia and secretion of chemokines and matrix metalloproteinases in the retina were inhibited by curcumin. These effects were also observed in a co-culture of BV2 microglial cells and retina-derived 661W cells. CONCLUSIONS: Curcumin delayed retinal degeneration by suppressing microglia activation in the retina of rd1 mice. Thus, it may be an effective treatment for neurodegenerative disorders such as RP.

The 2007 Estimates for People at Risk for and Living With HIV in China: Progress and Challenges.

OBJECTIVE: To present the methods used for the 2007 estimates for the number of people at risk for and infected with HIV. DESIGN: : Estimation work took place throughout 2007, led by the National Center for AIDS and Sexually Transmitted Disease Control and Prevention in collaboration with United Nations AIDS and the World Health Organization. METHODS: The workbook method was used to process prefecture and county-level surveillance data to generate HIV prevalence by risk group for each prefecture, which was in turn imported into the spectrum model to generate estimates of new infections and HIV-related deaths. RESULTS: The working group estimated that as of 2007, there were 700,000 people living with HIV/AIDS in China, with 50,000 new infections and 20,000 HIV-related deaths in that year. Injection drug use and sexual contact are still primary modes of HIV transmission, with heterosexual contact quickly becoming the dominant route, making up 44.7% of new infections in 2007. The HIV/AIDS epidemic is still highly concentrated in certain areas, with wide variation in prevalence across regions. CONCLUSIONS: The 2007 estimates are based on the most accurate and local-level data available to date, including case reports, sentinel surveillance data, results from mass screening of key target groups, and special epidemiological studies.

[Retrospective research on proportion of HIV related death causes in nine counties in China].

OBJECTIVE: To investigate the proportion of HIV related death cause, and its years of potential life lost (YPLL) and work years of potential life lose (WYPLL) in project counties. METHOD: According to the protocol of the third national death causes surveillance and HIV related death causes surveillance, retrospective study was implemented including baseline investigation of deaths' name list, demography information, door-to-door interview and death causes deduction in Gejiu, Ruili and Longchuan county in Yunnan province, Yangdong county in Guangdong province, Luzhai county in Guangxi zhuang Autonomous Region, Weishi and Zhecheng county in Henan province, Xishui county in Hubei province and Gu'an county in Hebei province. RESULTS: The study was conducted among nine counties located in seven provinces. A total of 118 719 cases were included, raw mortality was 5.83 per thousand, 2002 death cases were related to HIV, which contributed 1.67% of total deaths. The average age of HIV death was 38.03 yearsow, which was earlier than the non-HIV-related life-span (63.10 years). The YPLL and WYPLL of HIV death was 33.80 years and 20.50 years, respectively, which had contributed the second highest average YPLL. CONCLUSION: HIV has an important proportion among all death causes, and has contributed severe average YPLL and WYPLL.

[Forecast about number of patients with pulmonary tuberculosis 2001 - 2010].

OBJECTIVE: To forecast the number of patients with pulmonary tuberculosis in 2010. METHODS: A mathematical model was established based on the nationwide epidemiological survey on tuberculosis conducted in 2000 so as to forecast the numbers of patients with pulmonary tuberculosis in 2000s. RESULTS: (1) The number of patients with pulmonary tuberculosis would be a little more than that in 2000, with the pulmonary tuberculosis case detection rate rho of 0.26 being adopted. (2) The number of patients with pulmonary tuberculosis would be smaller than that in 2000, with the pulmonary tuberculosis case detection rate rho of 0.30 being adopted. (3) If the current intervention strategy manages to keep the pulmonary tuberculosis case detection rate at the level of 0.35, the decline in number of patients with pulmonary tuberculosis will approach the goal set by the national program that the number of patients with pulmonary tuberculosis be decreased by 50%. CONCLUSION: The goal set by the national program can be achieved only when the pulmonary tuberculosis case detection rate reaches 0.35.