Dendrite-Free Zn Anode Endowed by Facile Al-Complex Coating for Long-Cycled Aqueous Zn-Ion Batteries.

Side reactions and dendrite growth on the zinc metal anode surface seriously damage the shelf life and calendar life of Zn-based batteries. Here, an Al-complexed artificial interfacial layer is constructed on the Zn surface (denoted as Al-complex@Zn) by a low-cost, facile, and scalable chemical method. The Al-complex interfacial layer improves the wettability of the electrolyte. Meanwhile, the Al-complex layer not only inhibits the side reaction by a physical barrier on the Zn surface but also regulates the zinc-ion flux to realize the uniform deposition of Zn2+. The Zn//Zn symmetric cell with an Al-complex layer has realized an ultralong cycle life of 2400 h and an extremely low polarization voltage of 20 mV (1 mA cm-2, 0.5 mAh cm-2), surpassing those reported in most literature. Furthermore, when an Al-complex@Zn//NaV3O8·1.5H2O (NVO) full cell is assembled, a high capacity retention of 92.5% is achieved over 1000 cycles at a current density of 4 A g-1. This work provides a facile and low-cost strategy on the modification of zinc anode to realize long-cycled aqueous Zn-ion batteries.

In situ space-confined growth of Co3O4 nanoparticles inside N-doped hollow porous carbon nanospheres as bifunctional oxygen electrocatalysts for high-performance rechargeable zinc-air batteries.

Developing high-performance and low-cost bifunctional oxygen electrocatalysts for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is of great significance for accelerating the commercialization of rechargeable zinc-air batteries (RZABs). Herein, in situ grown Co3O4 nanoparticle-embedded N-doped hollow porous carbon nanospheres (Co3O4@N-HPCNs) are synthesized via template-assisted pyrolysis as efficient bifunctional ORR/OER electrocatalysts. The N-HPCNs efficiently seize and confine Co3O4 nanoparticles to enhance electronic conductivity and structural stability, while the hollow porous architecture offers adequate mass diffusion pathways to improve the accessibility of reactants and electrolytes on active sites. Therefore, the as-obtained Co3O4-10%@N-HPCNs display outstanding activity and stability for the ORR and the OER, even outperforming commercial Pt/C and Ru/C catalysts. Liquid RZABs assembled with Co3O4-10%@N-HPCN cathodes exhibit a large specific capacity of 768.3 mA h g-1Zn, a high peak power density of 145.6 mW cm-2 and a long-term cycling stability for over 1000 h, demonstrating much-enhanced battery performance in comparison with that of Pt/C + Ru/C based RZABs. Also, flexible quasi-solid-state RZABs assembled with Co3O4-10%@N-HPCN cathodes exhibit a considerable power density of 132.0 mW cm-2 and a stable charge-discharge voltage for a long period even upon bending. This work provides a new approach for the development of catalysts with high activity, long-term stability and low cost.

Flexible All-Solid-State Direct Methanol Fuel Cells with High Specific Power Density.

It is vital to create flexible batteries as power sources to suit the needs of flexible electronic devices because they are widely employed in wearable and portable electronics. The direct methanol fuel cell (DMFC) is a desirable alternative portable energy source since it is a clean, safe, and high energy density cell. The traditional DMFC in mechanical assembly and its unbending property, however, prevent it from being employed in flexible electrical devices. In this study, the flexible membrane electrode assembly (MEA) with superior electrical conductivity and nanoscale TiC-modified carbon cloth (TiC/CC) is used as supporting layer. Additionally, solid methanol fuels used in the manufacturing of flexible all-solid-state DMFC have the advantages of being tiny, light, and having high energy density. Furthermore, the DMFC's placement and bending angle have little effect on its performance, suggesting that DMFC is appropriate for flexible portable energy. The flexible all-solid-state DMFC's power density can reach 14.06 mW cm-2 , and after 50 bends at 60°, its voltage loss can be disregarded. The flexible all-solid DMFC has an energy density that is 777.78 Wh Kg-1 higher than flexible lithium-ion batteries, which is advantageous for the commercialization of flexible electronic products.

A sensor of liquid methanol for direct methanol fuel cells.

The methanol sensors are of significance to maintain the efficient and stable operation of direct methanol fuel cells (DMFCs). The issues, including stability, the relationship between temperature, current density and concentration need, however, urgent attention. A novel electrochemical methanol sensor which is based on current output limited by methanol diffusion is developed. The stability of sensors was lifted steeply through introducing a reference electrode, narrowing the methanol flow channel, and adding a water container. The relationship between the temperature, response current and methanol concentration was determined with the help of theoretical derivation and the validity was verified by the fitting result. Other sensors can avail of this relationship to correct the temperature effect. Application test indicated that the sensor may be of great potential for the accurate monitoring of methanol concentration at the levels of DMFCs application.

An Artificial Polyacrylonitrile Coating Layer Confining Zinc Dendrite Growth for Highly Reversible Aqueous Zinc-Based Batteries.

Aqueous rechargeable zinc-metal-based batteries are an attractive alternative to lithium-ion batteries for grid-scale energy-storage systems because of their high specific capacity, low cost, eco-friendliness, and nonflammability. However, uncontrollable zinc dendrite growth limits the cycle life by piercing the separator, resulting in low zinc utilization in both alkaline and mild/neutral electrolytes. Herein, a polyacrylonitrile coating layer on a zinc anode produced by a simple drop coating approach to address the dendrite issue is reported. The coating layer not only improves the hydrophilicity of the zinc anode but also regulates zinc-ion transport, consequently facilitating the uniform deposition of zinc ions to avoid dendrite formation. A symmetrical cell with the polymer-coating-layer-modified Zn anode displays dendrite-free plating/stripping with a long cycle lifespan (>1100 h), much better than that of the bare Zn anode. The modified zinc anode coupled with a Mn-doped V2 O5 cathode forms a stable rechargeable full battery. This method is a facile and feasible way to solve the zinc dendrite problem for rechargeable aqueous zinc-metal batteries, providing a solid basis for application of aqueous rechargeable Zn batteries.

Co3O4@NiCo2O4 double-shelled nanocages with hierarchical hollow structure and oxygen vacancies as efficient bifunctional electrocatalysts for rechargeable Zn-air batteries.

Highly efficient bifunctional oxygen electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucially important for the rechargeable Zn-air battery, a potential power source for applications in electric vehicles and grid-scale stationary storage systems. Herein, Co3O4@NiCo2O4 double-shelled nanocages (Co3O4@NiCo2O4 DSNCs) with hierarchical hollow structure and oxygen vacancies were designed and synthesized via annealing metal-organic frameworks. Co3O4@NiCo2O4 DSNCs with large specific surface area and three-dimensional interconnected mesopores and cavity not only provide more reaction sites, but also offer an efficient transport environment for reactants. Moreover, oxygen vacancies on the surfaces improve the capture of oxygen species to enhance the reactivity of the catalyst. Consequently, Co3O4@NiCo2O4 DSNCs displayed excellent bifunctional electrocatalytic performance, with a positive half-wave potential of 0.81 V (vs. reversible hydrogen electrode, RHE) for ORR (approaching the potential of commercial Pt/C catalyst) and a low potential of 1.65 V at 10 mA cm-2 for OER (exceeding Pt/C). In a practical demonstration, the Zn-air battery using Co3O4@NiCo2O4 DSNCs as the cathode delivered a satisfactory power density of 102.1 mW cm-2, comparable to the Zn-air battery with a Pt/C cathode, and exhibited much longer cycling stability.

Molecular characteristics of Clostridium difficile in children with acute gastroenteritis from Zhejiang.

BACKGROUND: Clostridium difficile infection (CDI) has an increasing pediatric prevalence worldwide. However, molecular characteristics of C. difficile in Chinese children with acute gastroenteritis have not been reported. METHODS: A five-year cross-sectional study was conducted in a tertiary children's hospital in Zhejiang. Consecutive stool specimens from outpatient children with acute gastroenteritis were cultured for C. difficile, and isolates then were analyzed for toxin genes, multi-locus sequence type and antimicrobial resistance. Diarrhea-related viruses were detected, and demographic data were collected. RESULTS: A total of 115 CDI cases (14.3%), and 69 co-infected cases with both viruses and toxigenic C. difficile, were found in the 804 stool samples. The 186 C. difficile isolates included 6 of toxin A-positive/toxin B-positive/binary toxin-positive (A+B+CDT+), 139 of A+B+CDT-, 3 of A-B+CDT+, 36 of A-B+CDT- and 2 of A-B-CDT-. Sequence types 26 (17.7%), 35 (11.3%), 39 (12.4%), 54 (16.7%), and 152 (11.3%) were major genotypes with significant differences among different antimicrobial resistances (Fisher's exact test, P < 0.001). The A-B+ isolates had significantly higher resistance, compared to erythromycin, rifampin, moxifloxacin, and gatifloxacin, than that of the A+B+ (χ2 = 7.78 to 29.26, P < 0.01). The positive CDI rate in infants (16.2%) was significantly higher than that of children over 1 year old (10.8%) (χ2 = 4.39, P = 0.036). CONCLUSIONS: CDI has been revealed as a major cause of acute gastroenteritis in children with various genotypes. The role of toxigenic C. difficile and risk factors of CDI should be emphatically considered in subsequent diarrhea surveillance in children from China.

A high voltage aqueous zinc-manganese battery using a hybrid alkaline-mild electrolyte.

A high-voltage aqueous zinc-manganese battery using an alkaline-mild hybrid electrolyte is reported. The operation voltage of the battery can reach 2.2 V. The energy density is 487 W h kg-1 at 200 mA g-1, calculated based on the positive electrode material, higher than that of a Zn-MnO2 battery in mild electrolyte and those of other Zn-based aqueous batteries.

The impact of lack of disease awareness on the experience of primary varicose veins.

Symptoms are often one of the main reasons for patients with chronic diseases to seek medical care. However, the symptoms experienced by patients with primary varicose veins are not serious until late in the course, hence rarely drawing enough attention. A deep understanding of disease awareness and experiences of patients is particularly important in disease management. The aim of this study was to describe the awareness and experience of patients with primary varicose veins. This study used a descriptive design with a qualitative approach. Semistructured interviews were conducted with 12 patients with primary varicose veins at a general central county hospital in China. Colaizzi's 7-step analysis was used to analyze the interview text. Participants reported their lack knowledge of the disease, including etiology, symptoms, and complications. Three themes emerged concerning the experiences: "preoperative emotional responses," "lack of confidence in disease management," and "the need for family and social support." The findings suggested that the health care system in China needed to increase the awareness about the disease and pay more attention to the needs of patients, give better health education, and provide effective social support, so as to improve self-management among patients.

Synergy of Sulfur/Polyacrylonitrile Composite and Gel Polymer Electrolyte Promises Heat-Resistant Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries with high theoretical energy density attract great research attention. Although tremendous efforts have been made, heat tolerance capability of Li-S batteries is a topic rarely touched, although it is essential for practical application. At high temperatures, the dissolution of the polysulfides is aggravated, and the safety issue becomes severe. Herein, by using sulfur/polyacrylonitrile (SPAN) composites as positive electrode materials and a gel polymer membrane with carbonate electrolyte, we successfully realized a Li-S battery with remarkable heat-resistant performance at 50°C and 60°C. The SPAN-positive materials allow the Li-S battery operated in safer carbonate-containing electrolyte. The gel polymer electrolyte enhances the charge transfer, maintains the morphology of Li metal during cycling, and suppresses the migration of the soluble polysulfides, which is also observed when SPAN is used as positive electrode material. This contribution would bring new opportunity to extend the application of lithium batteries at high temperatures.

Understanding the Behavior and Mechanism of Oxygen-Deficient Anatase TiO2 toward Sodium Storage.

TiO2 has drawn increasing research attention as negative electrode material in sodium ion battery because of its natural abundance, low cost, nontoxicity, and facile preparation. Despite tremendous studies carried out, the sodium storage mechanism is still under discussion, and the electronic and local structures of TiO2 during sodiation/desodiation process are not well understood either. Herein, we reported a mechanism study of graphene-supported oxygen-deficient anatase TiO2 nanotubes (nanowires) as the negative electrode material for sodium ion batteries. Different from the previous reports, the insertion/extraction of Na+ ions leads to almost no changes of titanium valence state but there is a charge redistribution of O 2p orbitals which alters the hybridization between O 2p and Ti 3d states, suggested by the combined electrochemical and X-ray spectroscopic study. Both the electronic and local structures of TiO2 during the reversible sodiation/desodiation process are revealed from the Ti L-edge and O K-edge spectra. This detailed study would shed light on the material design and structural optimization of TiO2 as energy storage material in different systems.

CoS x /C hierarchical hollow nanocages from a metal-organic framework as a positive electrode with enhancing performance for aqueous supercapacitors.

Benefiting from abundant redox chemistry and high electrochemical properties, metal sulfides have been broadly employed as electrode materials in supercapacitor systems. However, the predominant limitation in their performance, which arises from indifferent electron and ion dynamics for transportation and a rapid slash in capacitance, is of particular concern. Herein, we portray the cobalt sulfides/carbon (CoS x /C) hierarchical hollow nanocages using ZIF-67 nanocrystals coated with carbon from resorcinol-formaldehyde (ZIF-67@RF) as a self-sacrificial template. The RF acted as a hard framework to prevent the hollow structure from breaking and was transformed to a carbon layer to enhance the charge transfer process. When used as positive electrodes in supercapacitor systems with aqueous electrolytes, the optimized CoS x /C hierarchic hollow nanocages exhibited a considerable specific capacitance (618 F g-1 at 2 A g-1), superior rate performance (83.6% capacitance retention of the initial capacity when the current density was amplified from 2 A g-1 to 50 A g-1) and an extraordinary cycle stationarity along with an undiminished specific capacitance after 10 000 cycles. In this study, the meticulously designed hierarchical hollow structure that we conceived not only provides an outstanding electrochemical performance but also provides options for other related materials, such as various MOFs.

Activation of the JAK-STAT3 pathway is associated with the growth of colorectal carcinoma cells.

Excessive activation of inflammatory signaling pathways facilitates colorectal carcinoma (CRC) malignancy. Continuous activation of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathway plays a central role in the development and progression of CRC. With the intent to explore whether attenuation of the JAK-STAT3 signaling axis inhibits cancer cell proliferation or induces apoptosis, a sophisticated oncolytic adenoviral vector, AdCN305, carrying the SOCS3 gene was used to treat CRC cells. Our data revealed that i) in CRC cells, STAT3 was continuously activated by phosphorylation, and SOCS3 was at a relative low expression level; and ii) AdCN305-cppSOCS3 inhibited the continuous activation of the JAK/STAT3 pathway, suppressed CRC cell growth and induced apoptosis, in vitro and in vivo. We proved that SOCS3, a negative regulator of the JAK-STAT3 pathway, efficiently inhibited the activation of the pathway and decreased levels of downstream factors which regulate cell proliferation and the cell cycle.

[Spatial organization of neurons, astrocytes and vessels in rat brain].

OBJECTIVE: To demonstrate the spatial organization of neurons, astrocytes and vessels in rat brain. METHODS: Cerebral vascular was shown by vivi-perfusion with ink. Glial fibrillary acidic protein (GFAP) immunohistochemistry and nissl's staining were performed on the serial sections of frozen brain tissues. RESULTS: Astracytes distributed along the branches of blood vessels, and neurons in the region of the relatively rich blood vessels. Neurons and astrocytes presented regional distribution. CONCLUSION: This method can well indicate the spatial organization of neurovascular unit, the regional differences in the distribution may be related to physical activities and the corresponding adjustment function.

Influence of gut microflora on mesenteric lymph cytokine production in rats with hemorrhagic shock.

OBJECTIVE: The aim of the present study was to test the hypothesis that the resident gut microflora play a role in modulating gut cytokine production under normal circumstances and in response to tissue injury with or without hemorrhagic shock. METHODS: The postnodal lymph was collected from the main mesenteric lymphatic channel 1 hour before, during (1.5 hours), and hourly for 6 hours after 90 minutes of sham or actual hemorrhagic shock (30 mm Hg) in the following three groups of rats, all of which had laparotomies and vascular instrumentation: rats with a normal gut flora (NF), rats whose gut flora had been decontaminated with oral antibiotics (AD), and rats with Escherichia coli C25 intestinal overgrowth (MA). Interleukin (IL)-6 and TNF levels in the mesenteric lymph were measured using cytokine-dependent cellular assays. Endotoxin levels and endotoxin-neutralizing capacity in the lymph were also measured. RESULTS: Mesenteric lymph IL-6 levels in the laparotomized MA-sham animals were significantly elevated compared with NF-sham animals at 2 to 4 hours (p < 0.05) and at 5 and 6 hours after sham shock (p < 0.01). Similarly, IL-6 levels in laparotomized AD-shock animals were increased when compared with NF-shock animals 3 hours after shock (p < 0.001). Lymph tumor necrosis factor bioactivity, although present in all surgically manipulated groups, was scarcely detectable in untouched animals. Endotoxin-neutralizing capacity was significantly impaired in shocked animals compared with untouched animals. CONCLUSION: Changes in the gut microflora modulate the gut cytokine production after tissue injury with or without hemorrhagic shock, with intestinal bacterial overgrowth leading to the greatest increase in mesenteric lymph IL-6 levels.