Because the wound is difficult to heal, repeated bacterial infection will lead to complex clinical problems. Therefore, it is necessary to find an effective method to strengthen the healing process ...and resist bacterial infection. Hydrogels have many advantages, such as injectability and self-healing under physiological conditions, so they have been widely studied in recent years. Hydrogels can keep the wound moist and promote the wound healing. In addition, the growth of bacteria can be obviously inhibited by hydrogels themself or by doping some antibacterial active substances. Based on this, herein, this review highlighted the preparation and properties of different polysaccharide-based injectable hydrogels, and discuss their biological applications in antibacterial therapy for wound healing in recent years.
The application of hydrogels with injectable and rapid self-healing has attracted increasing interest in recent years. In this review, enhancing the antibacterial potentials of polysaccharide-based injectable hydrogels for wound healing are highlighted. Display omitted
Despite rapid advances in modern medical technology and significant improvements in survival rates of many cancers, pancreatic cancer is still a highly lethal gastrointestinal cancer with a low ...5-year survival rate and difficulty in early detection. At present, the incidence and mortality of pancreatic cancer are increasing year by year worldwide, no matter in the United States, Europe, Japan, or China. Globally, the incidence of pancreatic cancer is projected to increase to 18.6 per 100000 in 2050, with the average annual growth of 1.1%, meaning that pancreatic cancer will pose a significant public health burden. Due to the special anatomical location of the pancreas, the development of pancreatic cancer is usually diagnosed at a late stage with obvious clinical symptoms. Therefore, a comprehensive understanding of the risk factors for pancreatic cancer is of great clinical significance for effective prevention of pancreatic cancer. In this paper, the epidemiological characteristics, developmental trends, and risk factors of pancreatic cancer are reviewed and analyzed in detail.
Wuhan was the first epicentre of COVID-19 in the world, accounting for 80% of cases in China during the first wave. We aimed to assess household transmissibility of severe acute respiratory syndrome ...coronavirus 2 (SARS-CoV-2) and risk factors associated with infectivity and susceptibility to infection in Wuhan.
This retrospective cohort study included the households of all laboratory-confirmed or clinically confirmed COVID-19 cases and laboratory-confirmed asymptomatic SARS-CoV-2 infections identified by the Wuhan Center for Disease Control and Prevention between Dec 2, 2019, and April 18, 2020. We defined households as groups of family members and close relatives who did not necessarily live at the same address and considered households that shared common contacts as epidemiologically linked. We used a statistical transmission model to estimate household secondary attack rates and to quantify risk factors associated with infectivity and susceptibility to infection, accounting for individual-level exposure history. We assessed how intervention policies affected the household reproductive number, defined as the mean number of household contacts a case can infect.
27 101 households with 29 578 primary cases and 57 581 household contacts were identified. The secondary attack rate estimated with the transmission model was 15·6% (95% CI 15·2–16·0), assuming a mean incubation period of 5 days and a maximum infectious period of 22 days. Individuals aged 60 years or older were at a higher risk of infection with SARS-CoV-2 than all other age groups. Infants aged 0–1 years were significantly more likely to be infected than children aged 2–5 years (odds ratio OR 2·20, 95% CI 1·40–3·44) and children aged 6–12 years (1·53, 1·01–2·34). Given the same exposure time, children and adolescents younger than 20 years of age were more likely to infect others than were adults aged 60 years or older (1·58, 1·28–1·95). Asymptomatic individuals were much less likely to infect others than were symptomatic cases (0·21, 0·14–0·31). Symptomatic cases were more likely to infect others before symptom onset than after (1·42, 1·30–1·55). After mass isolation of cases, quarantine of household contacts, and restriction of movement policies were implemented, household reproductive numbers declined by 52% among primary cases (from 0·25 95% CI 0·24–0·26 to 0·12 0·10–0·13) and by 63% among secondary cases (from 0·17 0·16–0·18 to 0·063 0·057–0·070).
Within households, children and adolescents were less susceptible to SARS-CoV-2 infection but were more infectious than older individuals. Presymptomatic cases were more infectious and individuals with asymptomatic infection less infectious than symptomatic cases. These findings have implications for devising interventions for blocking household transmission of SARS-CoV-2, such as timely vaccination of eligible children once resources become available.
National Natural Science Foundation of China, Fundamental Research Funds for the Central Universities, US National Institutes of Health, and US National Science Foundation.
The Majorana fermion, which is its own antiparticle and obeys non-Abelian statistics, plays a critical role in topological quantum computing. It can be realized as a bound state at zero energy, ...called a Majorana zero mode (MZM), in the vortex core of a topological superconductor, or at the ends of a nanowire when both superconductivity and strong spin orbital coupling are present. A MZM can be detected as a zero-bias conductance peak (ZBCP) in tunneling spectroscopy. However, in practice, clean and robust MZMs have not been realized in the vortices of a superconductor because of contamination from impurity states or other closely packed Caroli–de Gennes-Matricon (CdGM) states, which hampers further manipulations of MZMs. Here, using scanning tunneling spectroscopy, we show that a ZBCP well separated from the other discrete CdGM states exists ubiquitously in the cores of free vortices in the defect-free regions of(Li0.84Fe0.16)OHFeSe, which has a superconducting transition temperature of 42 K. Moreover, a Dirac-cone-type surface state is observed by angle-resolved photoemission spectroscopy, and its topological nature is confirmed by band calculations. The observed ZBCP can naturally be attributed to a MZM arising from the chiral topological surface state of a bulk superconductor. Thus,(Li0.84Fe0.16)OHFeSeprovides an ideal platform for studying MZMs and topological quantum computing.
Loess is typically a kind of soil with metastable structure, which makes loess sensitive to collapse and sliding upon wetting. Such structure has thus profound influence on loess's mechanical ...behavior. However, there have been arguments about how the metastable structure influences on loess's mechanical behavior and what the mechanism behind is. In this study, the influence of structure on shear characteristics of the unsaturated loess in Lanzhou city of China was investigated with comparison of variation of shear strength and its parameters between six pairs of the undisturbed and remolded samples. It is found that the peak shear strength and strength parameters of the loess significantly reduced once its structure was destroyed, while shear behavior of the loess showed little change. Strength parameter c was much more sensitive to structure of the loess than ϕ. Shear strength reduction of the loess due to change of structure should be largely attributed to breaking up of cementation bonds between particles, evidenced by the difference in pore size distribution and microstructure of soil fabrics between the undisturbed and remolded samples. The bonds provided by clays and carbonates contributed the most to structure of the loess with minor by soluble salts, while matric suction played little role in structure of the loess.
Representative results (sample XGY) showing sensitivity (St) of the loess' shear strength and the parameters c and ϕ to structure and matric suction ratio before and after destruction of the loess' fabric, as well as collapse of large size pores due to breaking up of interparticle bonds. Display omitted
•The loess’s shear strength reduced significantly once its structure was destroyed.•The loess’s strength parameter c was much more sensitive to structure than its ϕ.•Loss of shear strength and c was largely due to breaking up of interparticle bonds.•The interparticle bonds were provided by clay, carbonates and soluble salts.•Matric suction contributed little to structure of the loess.
Despite the extensive studies on rejection of large molecular dyes by nanofiltration (NF), their small molecular weight intermediates have got limited concern. Taking reactive black 5 (RB-5) as an ...example, the separation behaviors of the dye, the intermediate (H-acid) and salts (NaCl) were investigated by preparing two types of NF membranes featuring different charge and pore structural properties. It was found that optimum selectivity could be achieved by the combined effects between aperture sieving and Donnan repulsion. Both membranes possess reasonable long-term stability and more than 95% rejection of large molecular RB-5. But they feature complicated and different rejective behavior for H-acid with small Mw in different aqueous environment, such as different solute concentration and different pH value for feed solution. The results indicate that (1) small pore size of M-PEI may be the dominant factor for high retention of H-acid; (2) highly selective separation of dye intermediate and sodium chloride may be achieved at high pH with positively charged membranes. This study may provide insightful guidelines for developing next-generation NF membranes for treating textile wastewater with complex compositions.
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•The understanding of nanofiltration membranes for high removal of dye intermediate is expanded.•Optimum selectivity achieved by combined effects of aperture sieving and Donnan repulsion.•Small pore size may be the dominant factor for high retention of H-acid.•High selectivity of H-acid and NaCl may be achieved at high pH with positively charged membranes.
Background and purpose
The insidious onset of Parkinson's disease (PD) makes early diagnosis difficult. Notably, idiopathic rapid eye movement sleep behavior disorder (iRBD) was reported as a ...prodrome of PD, which may represent a breakthrough for the early diagnosis of PD. However, currently there is no reliable biomarker for PD diagnosis. Considering that α‐synuclein (α‐Syn) and neuroinflammation are known to develop prior to the onset of clinical symptoms in PD, it was hypothesized that plasma total exosomal α‐Syn (t‐exo α‐Syn), neural‐derived exosomal α‐Syn (n‐exo α‐Syn) and exosomal apoptosis‐associated speck‐like protein containing a caspase activation and recruitment domain (ASC) may be potential biomarkers of PD.
Methods
In this study, 78 PD patients, 153 probable iRBD patients (pRBD) and 63 healthy controls (HCs) were recruited. α‐Syn concentrations were measured using a one‐step paramagnetic particle‐based chemiluminescence immunoassay, and ASC levels were measured using the Ella system.
Results
It was found that t‐exo α‐Syn was significantly increased in the PD group compared to the pRBD and HC groups (p < 0.0001), whilst n‐exo α‐Syn levels were significantly increased in both the PD and pRBD groups compared to HCs (p < 0.0001). Furthermore, although no difference was found in ASC levels between the PD and pRBD groups, there was a positive correlation between ASC and α‐Syn in exosomes.
Conclusions
Our results suggest that both t‐exo α‐Syn and n‐exo α‐Syn were elevated in the PD group, whilst only n‐exo α‐Syn was elevated in the pRBD group. Additionally, the adaptor protein of inflammasome ASC is correlated with α‐Syn and may facilitate synucleinopathy.
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