Nanopatterning of beaded poly(lactic acid) nanofibers for highly electroactive, breathable, UV-shielding and antibacterial protective membranes.

Despite great potential in fabrication of biodegradable protective membranes by electrospinning of poly(lactic acid) (PLA) nanofibers, it is still thwarted by smooth surfaces and poor electroactivity that challenge the promotion of electret properties and long-term air filtration performance. Here, a microwave-assisted synthetic method was used to customize dielectric TiO2 nanocrystals of ultrasmall and uniform dimensions (∼30 nm), which were homogeneously embedded at beaded PLA nanofibers (PLA@TiO2, diameter of around 280 nm) by the combined "electrospinning-electrospray" approach. With small amounts of TiO2 (2, 4 and 6 wt%), the nanopatterned PLA@TiO2 nanofibrous membranes (NFMs) were characterized by largely increased dielectric constants (nearly 1.9), surface potential (up to 1.63 kV) and triboelectric properties (output voltage of 12.2 V). Arising from the improved electroactivity and self-charging mechanisms, the nanopatterned PLA@TiO2 NFMs exhibited remarkable PM0.3 filtration properties (97.9 %, 254.6 Pa) even at the highest airflow rate of 85 L/min, surpassing those of pure PLA membranes (86.2 %, 483.7 Pa). This was moreover accompanied by inhibition rates of 100 % against both E. coli and S. aureus, as well as excellent UV-blocking properties (UPF as high as 3.8, TUVA of 50.9 % and TUVB of 20.1 %). The breathable and electroactive nanopatterned PLA NFMs permit promising applications in multifunctional protective membranes toward excellent UV shielding and high-efficiency removal of both PMs and pathogens.

Self-Charging, Breathable, and Antibacterial Poly(lactic acid) Nanofibrous Air Filters by Surface Engineering of Ultrasmall Electroactive Nanohybrids.

Despite the great promise in the development of biodegradable and ecofriendly air filters by electrospinning of poly(lactic acid) (PLA) nanofibrous membranes (NFMs), the as-electrospun PLA nanofibers are generally characterized by poor electroactivity and smooth surface, challenging the exploitation of electrostatic adsorption and physical interception that are in need for efficient removal of pathogens and particulate matters (PMs). Herein, a combined "electrospinning-electrospray" strategy was disclosed to functionalize the PLA nanofibers by direct anchoring of highly dielectric BaTiO3@ZIF-8 nanohybrids (BTO@ZIF-8), conferring simultaneous promotion of surface roughness, electret properties (surface potential as high as 7.5 kV), and self-charging capability (∼190% increase in tribo-output voltage compared to that of pure PLA). Benefiting from the well-tailored morphology and increased electroactivity, the electrospun-electrosprayed PLA/BTO@ZIF-8 exhibited excellent PM-capturing performance (up to 96.54% for PM0.3 and 99.49% for PM2.5) while providing desirable air resistance (only 87 Pa at 32 L/min) due primarily to the slip flow of air molecules over the nanohybrid protrusions. This was accompanied by excellent antibacterial properties (99.9% inhibition against both Staphylococcus aureus and Escherichia coli), arising presumably from the synergistic effects of enhanced reactive oxygen species (ROS) generation, plentiful ion release, and surface charges. Our proposed strategy opens up pathways to afford exceptional combination of high-efficiency and low-resistance filtration, excellent antibacterial performance, and mechanical robustness without sacrificing the biodegradation profiles of PLA NFMs, holding potential implications for efficient and long-term healthcare.

Epidemiological characteristics and risk factors of syphilis among blood donors in Huzhou.

OBJECTIVE: To investigate the epidemiological characteristics and risk factors for syphilis in Huzhou City, and to provide data to support the design of more effective health counselling and screening measures for blood donors. METHODS: A retrospective study was conducted to analyse the demographic characteristics and seropositivity of syphilis among blood donors from 2019 to 2021. The differences in the serological status of syphilis among different populations under different demographic factors were compared, and conditional logistic regression analysis was used to identify the risk factors for syphilis. RESULTS: The seropositivity rate of syphilis among blood donors in Huzhou City was 133/100,000, which decreased year by year. There were significant differences in the syphilis seropositivity rate among different groups in terms of age, education level, occupation, household registration, marital status and blood donation history (P < 0.05). The multivariate logistic regression model showed that all six factors, including age, education level, occupation, household registration, marital status and blood donation history, had significant effects on syphilis infection (P < 0.01), with OR values and 95% CIs of 2. 387 (1.381-4.127), 3.607 (1.609-8.086), 2.784 (1.657-4.679), 5.074 (1.865-13.804), 11.177 (3.481-35.888), and 11.244 (3.940-32.091), respectively. CONCLUSION: There is room for improvement in pre-donation health counselling and screening of high-risk populations. Timely monitoring and updating of demographic data for specific high-risk populations is essential.

Electroactive, Antibacterial, and Biodegradable Poly(lactic acid) Nanofibrous Air Filters for Healthcare.

Poly(lactic acid) (PLA)-based nanofibrous membranes (NFMs) hold great potential in the field of biodegradable filters for air purification but are largely limited by the relatively low electret properties and high susceptibility to bacteria. Herein, we disclosed a facile approach to the fabrication of electroactive and antibacterial PLA NFMs impregnated with a highly dielectric photocatalyst. In particular, the microwave-assisted doping (MAD) protocol was employed to yield Zn-doped titanium dioxide (Zn-TIO), featuring the well-defined anatase phase, a uniform size of ∼65 nm, and decreased band gap (3.0 eV). The incorporation of Zn-TIO (2, 6, and 10 wt %) into PLA gave rise to a significant refinement of the electrospun nanofibers, decreasing from the highest diameter of 581 nm for pure PLA to the lowest value of 264 nm. More importantly, dramatical improvements in the dielectric constants, surface potential, and electret properties were simultaneously achieved for the composite NFMs, as exemplified by a nearly 94% increase in surface potential for 3-day-aged PLA/Zn-TIO (90/10) compared with that of pure PLA. The well regulation of morphological features and promotion of electroactivity contributed to a distinct increase in the air filtration performance, as demonstrated by 98.7% filtration of PM0.3 with the highest quality factor of 0.032 Pa-1 at the airflow velocity of 32 L/min for PLA/Zn-TIO (94/6), largely surpassing pure PLA (89.4%, 0.011 Pa-1). Benefiting from the effective generation of reactive radicals and gradual release of Zn2+ by Zn-TIO, the electroactive PLA NFMs were ready to profoundly inactivate Escherichia coli and Staphylococcus epidermidis. The exceptional combination of remarkable electret properties and excellent antibacterial performance makes the PLA membrane filters promising for healthcare.

Biomineralization of bone-like hydroxyapatite to upgrade the mechanical and osteoblastic performances of poly(lactic acid) scaffolds.

Biomimetic mineralization of high-strength apatite structure essentially relies on mimicking the inorganic building blocks of naturally occurring bones. However, conventional routes still have substantial function gaps in providing precision control over the geometrical dimensions and crystalline morphology of biomineralized apatite. Herein, we conceived the concept of microwave-assisted biomineralization (MAB) to customize 1D hydroxyapatite nanowhiskers (HANWs) at graphene templates, rendering the formation of graphene-hydroxyapatite (Gr-HA) nanohybrids. The HANWs essentially resembled bone apatite in elemental composition (Ca/P = 1.74), diameter (~20 nm), crystallinity (63 %), and rodlike geometry (aspect ratio of ~6). The Gr-HA nanohybrids were uniformly incorporated into poly(lactic acid) (PLA) microfibers (~1 µm) by electrospinning, engendering fibrous membranes with a set of Gr-HA loadings (10, 20 and 30 wt%). Intimate interactions were generated between Gr-HA and PLA matrix, contributing to significant promotion of the mechanical properties for PLA composite membranes. For example, the yield strength and elastic modulus of the PLA composite membranes loaded with 30 wt% Gr-HA achieved 5.4 and 66.4 MPa, increasing nearly 182 % and over 94 % compared to those of pure PLA, respectively. Moreover, the bone-like HANWs endowed PLA membranes with excellent cytocompatibility and good bioactivity, as demonstrated by over 38 % increase in cell viability and rapid apatite formation in mineral solution. The impressive combination of mechanical properties and biological characteristics make the PLA/Gr-HA scaffolds promising for guided tissue/bone regeneration therapy.

UV-protective and high-transparency poly(lactic acid) biocomposites for ecofriendly packaging of perishable fruits.

The past decades have witnessed the archetypal shift from petroleum-based to bioplastics including poly(lactic acid) (PLA) for multifunctional packaging. Here we disclose a microwave-assisted functionalization (MAF) approach to functionalize wood fibers (FWFs) at minute level and high yields (approaching 99 %), conferring high affinity to PLA matrix and significant promotion of mechanical properties. By incorporating of 10 wt% FWFs, the tensile strength and toughness of PLA composite films were elevated to 54.5 MPa and 1.6 MJ/m3, increasing nearly 28 % and over 45 % compared to those of the counterpart loaded pristine wood fibers (PWFs), respectively. It is of significance to note the FWF-enabled unique optical properties for PLA, as exemplified by approximately 100 % UV-blocking ratio (UVR) in the whole UV region with the addition of 20 wt% FWFs. By contrast, the UVR values of PWF-filled PLA (5 %-20 %) gradually decreased as the fiber contents increased, mainly ascribed to the UV reflection at the poorly bonded interfaces and relatively inferior functionality of PWFs. This distinction allowed us to fabricate UV-barrier packaging for preservation of fresh fruits, which were perishable under the UV light of sunshine. The impressive mechanical robustness and high UVR, may prompt affordable and ecofriendly PLA/FWF composites appropriate for packaging.

High-heat and UV-barrier poly(lactic acid) by microwave-assisted functionalization of waste natural fibers.

The application of poly(lactic acid) (PLA) in the packaging area is frequently dwarfed by the inadequate gas/water barrier properties, low heat resistance and high UV transmittance. Herein, an environmentally friendly and high-efficiency microwave-assisted functionalization (MAF) approach was proposed to aqueous grafting waste bamboo fibers with the bridging agent. It permitted significant promotion of interfacial interactions between the MAF bamboo fibers (MAFBs) and neighboring PLA chains, contributing to uniform dispersion and intimate interphase. Featuring the morphological features, the MAFB-reinforced (5, 10 and 20 wt%) PLA biocomposites achieved an unexpected combination of high mechanical properties, exceptional resistance to heat deflection and UV irradiation, and excellent water barrier performance. Upon addition of only 5 wt% MAFBs, the tensile strength and toughness of PLA composite films were increased to 46.5 MPa and 0.6 MJ/m3, increasing over 52 % and nearly 107 % compared to those of the counterpart loaded pristine bamboo fibers (PBFs), respectively. This was favorably accompanied by the remarkably reduced water vapor permeability, falling down to the lowest value of 3.5 × 10-11 g∙m/Pa∙s∙m2 for PLA/MAFB (80/20) with a decrease of nearly 79 % compared to the counterpart. It is of interest to note the MAFB-enabled nearly 100 % UV-blocking ratio for PLA loaded 10 and 20 wt% fibers, as well as excellent resistance to heat deflection even at high temperatures like 120 °C. This effort paves the way to multifunctional natural fibers with high affinity to PLA for elegant implementation of high-heat and UV-resistant packaging materials in an ecofriendly manner.

Pea pod-mimicking hydroxyapatite nanowhisker-reinforced poly(lactic acid) composites with bone-like strength.

The anisotropic hierarchical structures of naturally derived materials have offered useful design principles for the fabrication of high-strength and functional materials. Herein, we unraveled a structure-by-bionics approach to construction of pea pod-mimicking architecture for poly(lactic acid) (PLA) composites impregnated with hydroxyapatite nanowhiskers (HANWs). The HANWs (length of 80-120 nm, diameter of ~30 nm) were customized using microwave-assisted aqueous biomineralization at minute level, which were incorporated into PLA microfibers by electrospinning with filler loadings of 10-30 wt%. The membranes comprising HANW-modified PLA microfibers were stacked and structured into composite films, strategically involving high-pressure compression at a relatively low temperature to impart the confined structuring mechanisms. It thus allowed partial melting and thinning of PLA microfibers into nanofibers, onto which the discrete HANWs were tightly adhered and embedded, showing distinguished architectural configurations identical with pea pod. More importantly, the mechanical properties and bioactivity were remarkably promoted, as demonstrated by the increments of over 54 % and nearly 72 % for the yield strength and elastic modulus (71.6 and 2547 MPa) of the structured composite loaded 30 wt% HANWs compared to those of pure PLA (46.4 and 1484 MPa), as accompanied by significant improvements in the bioactivity to nucleate and create apatite entities in mineral solution. The unusual combination of excellent biological characteristics and bone-like mechanical elasticity and extensibility make the structured PLA composites promising for guided bone/tissue regeneration therapy.

Value of Acoustic Radiation Force Impulse Imaging in the Diagnosis of Early Non-alcoholic Steatohepatitis / 中国医学科学院学报

Objective To evaluate the value of acoustic radiation force impulse(ARFI)imaging in the diagnosis of early non-alcoholic steatohepatitis(NASH).Methods Totally 32 SD rats were randomly divided into high-fat diet group(n=24)and normal-diet group(n=8)by using the random number table. At the end of the 4,8,12,and 16week,six rats from the high-diet group and two rats from the normal-diet group were selected blindly for weighting,blood biochemical test,conventional ultrasound,and ARFI imaing. HE staining was used for pathological observation. Results None of the 32 rats developed liver fibrosis. Based on the pathological results,these rats were divided into M1 [mild-to-moderate simple fatty liver(SS)],M2(severe SS),M3(severe SS with early NASH),and C groups(normal control). Early NASH was seen only in the severe hepatic steatosis groups,and its distribution had a significant difference(P=0.006). The diagnostic accuracy of conventional ultrasound based on histological results was 34.4%(11/32). The ARFI value of M3 group was significantly lower than that of M2 group [(1.16±0.04)m/s vs.(1.22±0.05)m/s;t=2.301,P=0.04),and the low-density lipoprotein of M3 group was significantly higher than M2 group [(1.53±0.07)mmol/L vs.(1.21±0.22)mmol/L;t=3.075,P=0.01),while other clinical indicators had no statistical difference between these two groups. Conclusions The development of early NASH is associated with the severity of hepatic steatosis. ARFI value can provide important information to identify early NASH in patients with severe hepatic steatosis.

Research Advances in Clinical and Imaging Characteristics of Intraductal Papillary Mucinous Neoplasm of the Bile Duct / 中国医学科学院学报

Understanding on the intraductal papillary mucinous neoplasm of the pancreas (IPMN-P) has dramatically improved in the past three decades. A new disease named intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) reported in recent years shares several similar clinical features with IPMN-P. The clinical manifestations and imaging characteristics of IPMN-B have been gradually recognized. This review summarizes some of the typical cases reported since 2000 and find that clinical manifestations of IPMN-B include epigastric discomfort,biliary colic,jaundice,intermittent fever,sometimes without any symptoms; imaging triads for IPMN-B are mucobilia,dilated bile duct,and bile duct mural nodule.

Influence of single agent and combined medication chemotherapy in elderly patients with gastric cancer / 重庆医学

Objective To investigate the influence of single agent and combined medication chemotherapy on elderly patients with gastric cancer. Methods One hundred and twenty elderly inpatients with gastric cancer in the general surgery department of the Nanyang Municipal Central Hospital from January 2009 to October 2014 were divided into the single agent chemotherapy group (n=60) and combined medication chemotherapy group(n=60). The adverse reactions and survival time were compared between the two groups. Results The occurrence rates of nausea, vomiting, diarrhea, constipation, leukopenia, oral mucositis and peripheral neuropathy in the single agent group were lower than those in the combined chemotherapy group, the difference between the two groups was statistically significant (P<0.05) ; the occurrence rates of Hb decrease, thrombocytopenia and transaminase elevation in the single agent group were lower than those in the combined chemotherapy group,but the difference was not statistically significant(P>0. 05);the survival time in the combined chemotherapy group was longer than that in the single agent chemotherapy group,but the difference between them was not statistically significant(P>0.05). Conclusion Single agent chemotherapy may be considered as the first-line chemotherapy scheme for elderly patients with gastric cancer.

Value of Contrast-enhanced Ultrasound for Small Focal Liver Lesions / 中国医学科学院学报

Objective To explore the diagnostic value of contrast-enhanced ultrasound (CEUS)for small focal liver lesions (FLLs). Methods The clinical data,CEUS findings,and pathology of 69 patients with small FLLs were retrospectively analyzed. Patients were grouped according to size of FLLs and the performance of CEUS was compared. Results The accuracy,sensitivity,specificity,positive predictive value,and negative predictive value of CEUS for the 69 FLLs were 94.2%,95.2%,93.8%,87.0%,and 97.8%,respectively. Rate of fast wash-out in portal vein phase was lower in group of diameters ≤2 cm than that in group of diameters>2 cm (P<0.05). Conclusions CEUS has a high diagnostic value for small FLLs.However,the CEUS findings of malignant lesions smaller than 2 cm are not typical in the portal phase and therefore the diagnosis should also be based on clinical features.

Review of AIDS response in China by applying the indicators from "China Monitoring & Evaluation Plan of AIDS Response" / 中国艾滋病性病

Objective To review 2006-2007 AIDS response in China by applying the indicators of "Monitoring & Evaluation Plan of AIDS Response". Method Data from the national AIDS routine reporting system and special survey in line with the definitions of the indicators and standardized methods were summarized,classified and analyzed; mid-term targets or indicator value of 2005 were employed as comparison. Results The 2007 result of the national HIV sentinel surveillance showed that the HIV prevalence among female sex workers,injecting drug users,men who have sex with men and pregnant women was 0.0%,1.9%,3.1% and 0.0% respectively;the data from the national HIV comprehensive response information system showed that by the end of 2007,72.8% of the adults and children with advanced HIV infection had received antiretroviral therapy (ART) ,and 83.6% of the ART receivers survived after 12 month treatment. Conclusion Indicators of the "Monitoring & Evaluation Plan" are able to reflect the outcomes and achievements of 2006-2007 HIV/AIDS response in China,which has made good progress and has fulfilled the mid-term targets as defined by the Plan.

The mechanism research of inhibitory effects of FK228 on retinal neovascularization / 重庆医科大学学报

0.05);HIF-1?positive rate of control groups was higher than that in normal group and treatment group with significant difference among them(P0.05);VEGF positive rate in control groups was higher than that in normal group and treatment group with significant difference among them(P

Relation between intrauterine growth and carotid atherosclerosis in adult life by ultrasonography / 中华超声影像学杂志

Objective To investigate the relation between intrauterine growth and the development of carotid atherosclerosis in later life. Methods The intima-media thickness of carotid was measured with ultrasonography in 2036 people aged above fifty who had complete birth records, and divided into normal and abnormal group. They were asked to fill in the cardio-cerebrovascular questionnaire, and venous blood samples were taken and analysed for various biochemical parameters. The relation between carotid atherosclerosis and various parameters at birth and in adult life was assessed. Results The birthweight and head circumference in abnormal group were less than those in normal. The prevalence of carotid atherosclerosis was greatest in those weighed 2500g or less, whose risk of carotid atherosclerosis was greater than those weighed between 3000g and 3500g, after adjustment for cardiovascular risk factors. Conclusions Increased atherogenesis may be one independent mechanism mediating the epidemiological link between impaired fetal growth and vascular disease.