Tailored Catalysis Inducing Exceptionally Fire-Safe and Mechanically Reinforced Epoxy at An Ultralow Loading.

An unconventional P/N/Si-free fire safety of epoxy at an ultralow loading with a significantly improved mechanical robustness and toughness via a mere nanocomposite technique is a great challenge. To achieve the goal, a proof of concept is proposed associated with a hierarchical manipulation of catalysis-tailored FexSy ultrathin nanosheets on organic-layered double hydroxide (LDH-DBS@FexSy) toward the formation of porous piling structure via a self-sacrificing conversion of metal-organic framework. A sufficient characterization certified the targeted architecture and composition. A P/N/Si-free ultralow loading of 2 wt % LDH-DBS@FexSy (i.e., 0.6 wt % FexSy) imparted epoxy with UL-94 V-0 rating, a 36.1% reduction of peak heat release rate, as well as a pronounced fire-protection feature. A systematic contrastive investigation evidenced a time-dependent fire-shielding effect induced by a featured catalysis-tailored ultrafast charring behavior at the interface of epoxy and LDH nanosheets. Intriguingly, the tensile strength, impact strength, and flexural strength were simultaneously enhanced by 62.2, 185.4, and 62.9%, respectively, with a 0.6 wt % incorporation of FexSy hierarchy on the basis of a "root-soil"-inspired interfacial "interlocking" structure. In perspective, an integrated manipulation of an interface catalysis-tailored ultrafast charring and hierarchical "interlocking" construction offer an effective balance of the fire safety, mechanical robustness, and toughness of polymers.

A case report of encephalitis induced by SARS-CoV-2 confirmed by etiology: first case in Qingdao, China.

The neurological manifestations of SARS-CoV-2-infected patients are receiving increasing attention with the global spread of SARS-CoV-2. Here, we report the first case of SARS-CoV-2-induced encephalitis in Qingdao, China. We detected SARS-CoV-2 in nasopharyngeal swabs and cerebrospinal fluid from this 68-year-old female patient.

Basalt Fiber Modified Ethylene Vinyl Acetate/Magnesium Hydroxide Composites with Balanced Flame Retardancy and Improved Mechanical Properties.

In this study, we selected basalt fiber (BF) as a functional filler to improve the mechanical properties of ethylene vinyl acetate (EVA)-based flame retardant materials. Firstly, BF was modified by grafting γ-aminopropyl triethoxysilane (KH550). Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) were used to comprehensively prove the successful modification of the BF surface. Subsequently, the modified BF was introduced into the EVA/magnesium hydroxide (MH) composites by melt blending. The limiting oxygen index (LOI), UL-94, cone calorimeter test, tensile test, and non-notched impact test were utilized to characterize both the flame retardant properties and mechanical properties of the EVA/MH composites. It was found that the mechanical properties were significantly enhanced without reducing the flame retardant properties of the EVA/MH composites. Notably, the surface treatment with silane is a simple and low-cost method for BF surface modification and the pathway designed in this study can be both practical and effective for polymer performance enhancement.

Human papillomavirus infections among women with cervical lesions and cervical cancer in Eastern China: genotype-specific prevalence and attribution.

BACKGROUND: Cervical cancer and its precursor, high-grade cervical intraepithelial neoplasia (CIN2/3), are associated with persistent high-risk human papillomavirus (HPV) infection. HPV genotype prevalence varies with severity of cervical lesions, patient age and geographical location. The aim of this study was to investigate HPV genotypes prevalence and attribution according to the severity of cervical lesions among Chinese women. METHOD: A 4-year surveillance study was performed. A total of 1664 female patients were included and their cervical histological diagnosis consisted of cervical intraepithelial neoplasia grade 1 (CIN1, 376 cases), grade 2 (CIN2, 408 cases), grade 3 (CIN3, 336 cases) and invasive cervical cancers (ICC, 544 cases). HPV genotypes prevalence and attribution to cervical lesions were calculated and analyzed. The 95% confidence interval (CI) for proportion was also calculated. RESULTS: HPV positivity rates increased directly with cervical lesions severity (72.4% for CIN1, 81.4% for CIN2, 88.1% for CIN3 and 90.4% for ICC). Infections with multiple HPV types were inversely related to cervical lesions severity. HPV16, 52, 31, 33 and 58 were the most prevalent genotypes in ICC. 49.1% of squamous cell carcinoma, 65.1% of adenocarcinoma and 12.0-43.3% of cervical intraepithelial neoplasia could be attributed to vaccine-covered high-risk genotypes (HPV16/18). Inclusion of HPV52 and HPV31 in future vaccines would provide the highest marginal benefit in protection for individuals residing in this region. CONCLUSIONS: These findings provide information about HPV genotypes in this region which may be important to target with future vaccination and screening programs.

Human papillomavirus prevalence and genotypes distribution among female outpatients in Qingdao, East China.

Persistent infection with human papillomavirus, especially high risk ones, is a necessary cause of cervical cancer. This study aimed to investigate the distribution of HPV genotypes in female outpatients from Qingdao, East China. A total of 4,534 cervical swabs from women visiting this medical institution for gynecologic care were included. HPV genotypes were examined by a PCR-based hybridization gene chip assay and liquid-based cytology analysis was used to evaluate cervical cytology. The overall HPV prevalence in this study was 32.2% (1,459/4,534). A total of 23 HPV genotypes were identified and the five most prevalent ones were HPV16 (16.1%), HPV52 (8.9%), HPV58 (7.9%), HPV6 (7.0%), and HPV53 (6.5%). Age-specific prevalence of HPV exhibited one peak at the youngest age group and the HPV positive rate decreased gradually with age growth. But high risk HPV infections were more prevalent among aged women. Besides, association between cervical cytology and HPV infection was also determined, 27.2% (1124/4,126) of women with normal cytology were HPV positive while 82.1% (335/408) of women with abnormal cytology were HPV positive. These findings give new epidemiological data and may provide guidance for the vaccination program in this area.

Antithrombotic effects of a newly purified fibrinolytic protease from Urechis unicinctus.

INTRODUCTION: The prevalence of thromboembolic disease, one of the top 3 leading causes of mortality worldwide, is being reported continually. More effective and safer antithrombotic drugs may overcome the underlying problems in antithrombotic therapy. In the present work, antithrombotic effects of UFEIII, a newly purified fibrinolytic protease from Urechis unicinctus were evaluated. MATERIALS AND METHODS: UFEIII was purified from the marine invertebrate, Urechis unicinctus, using anion exchange and gel filtration chromatography. Molecular weight, fibrinolytic activity and fibrinogenolysis pattern of UFEIII were determined. Furthermore, antithrombotic effects of UFEIII in vivo were investigated through electrical induced carotid arterial thrombosis in rats, FeCl3 induced carotid arterial thrombus model in rabbits and stasis induced vena caval thrombus model in rats. RESULTS: SDS-PAGE of the purified enzyme showed a single polypeptide chain with molecular weight of 20.8kDa. In fibrin plate assays, UFEIII could not only directly degrade fibrin but also activate plasminogen. The fibrinogenolysis pattern of UFEIII was Aα-chains>Bß-chains>γ-chain. Moreover, UFEIII could effectively prolong the time to occlusion in electrical induced carotid arterial thrombosis. Besides, both in rabbits and rats, the administration of UFEIII not only prolonged the activated partial thromboplastin time (APTT) and thrombin time (TT) also decreased the fibrinogen (FIB) content. Further, the thrombus lysis was observed after administration of UFEIII both in rabbits and rats. CONCLUSION: UFEIII can possibly be a new potential source of fibrinolytic agent.

Purification and characterization of a new serine protease with fibrinolytic activity from the marine invertebrate, Urechis unicinctus.

A non-hemorrhagic, chymotrypsin-like serine protease, UFEII, was purified from the marine echiuroid worm, Urechis unicinctus, after a combination of chromatography steps. UFEII was monomeric, with an apparent molecular weight of 26.7 kDa via SDS-PAGE. The isoelectric point of UFEII was 4.03, and the maximum activity of the enzyme was observed at 50 °C and pH8.0. According to fibrin plate assays, UFEII could not only directly degrade fibrin and fibrinogen but also activate plasminogen. Further, UFEII preferentially hydrolyzed the fibrinogen γ-chain, followed by the Bß-chains and Aα-chains. Moreover, ufeII, full length of the gene encoding UFEII, was obtained by RT-PCR, degenerated PCR, and nested PCR. The ufeII was determined to be a 906-bp cDNA containing an open reading frame of 795 bp encoding a putative protein of 264 amino acids with a predicted molecular weight of 27.03 kDa. Besides, UFEII exhibited no hemorrhagic effect. Overall, U. unicinctus may represent a potential source of new therapeutic agents in thrombolytic therapy.

UFEIII, a fibrinolytic protease from the marine invertebrate, Urechis unicinctus.

A new serine protease with fibrinolytic activity from a marine invertebrate, Urechis unicinctus, was purified to electrophoretic homogeneity using column chromatography. SDS-PAGE of the purified enzyme showed a single polypeptide chain with MW ~20.8 kDa. Its N-terminal sequence was IIGGSQAAITSY. The purified enzyme, UFEIII, was stable at pH 6-10 below 60 °C with an optimum pH of 8.5 at approx. 55 °C. The enzyme activity was significantly inhibited by PMSF and SBTI suggesting that it was a serine protease. In fibrin plate assays, UFEIII was contained 1.46 × 10(3 )U (urokinase units) mg(-1) total fibrinolytic activity, which consisted of 692 U mg(-1) direct fibrinolytic activity and 769 U mg(-1) plasminogen-activator activity. Km and Vmax values for azocasein were 1 mg ml(-1) and 43 µg min(-1) ml(-1), respectively.

An in situ formed biodegradable hydrogel for reconstruction of the corneal endothelium.

Biodegradable hydrogels are important biomaterials for tissue engineering and drug delivery. For the purpose of corneal regenerative medicine, we describe an in situ formed hydrogel based on a water-soluble derivative of chitosan, hydroxypropyl chitosan (HPCTS), and sodium alginate dialdehyde (SAD). Periodate oxidized alginate rapidly cross-links HPCTS due to Schiff's base formation between the available aldehyde and amino groups. Hydrogel cytotoxicity, degradability and histocompatibility in vivo were examined. The potential of the composite hydrogel for corneal endothelium reconstruction was demonstrated by encapsulating corneal endothelial cells (CECs) to grow on Descemet's membranes. The results demonstrate that the composite hydrogel was both non-toxic and biodegradable and that CECs transplanted by the composite hydrogel could survive and retain normal morphology. These results provide an opportunity for corneal endothelium reconstruction based on tissue engineering by the in situ formed composite hydrogel.