Assessment of the consumptive safety of mercury in fish from the surface waters of the Vologda region in northwestern Russia.

It is known that the consumption of fish is the main source of mercury intake in human beings. In this study, the concentration of mercury in the muscle tissue of fish from different reservoirs of northwestern Russia was found to be 0.01-1.68 µg/g wet weight. The features of mercury accumulation in the muscle tissue of fish, depending on their type, trophic specialization, body weight, length, and the type of water body, were also revealed. Of the fish studied, 7% had mercury concentrations above the regulatory levels of the Russian Federation. The proportion of examined fish, the consumption of which will lead to an excess of the permissible weekly intake of mercury in the individual, is 44% for preschool children (2-5 years old), 34% for children of primary school age (6-10 years old), and 17% for adults. Special attention is drawn to the fact that the mercury content in fish that does not exceed the sanitary and hygienic standards (normative levels) of the Russian Federation may still be unsafe for the health of the population, especially children.

Changes in therapeutic response, ocular manifestations of Graves' orbitopathy and quality of life during the first year after orbital radiotherapy.

PURPOSE: The aim of our study was to assess the changes in the therapeutic response, ocular manifestations of GO and quality of life during the first year after OR. METHODS: The study involved 26 consecutive patients with active moderate-to-severe GO indicated for OR, 18 females, mean age 57 ± 12.5. At baseline, all patients underwent comprehensive ocular examination and thyroid hormone and antibody testing. Then, OR was performed with a total dose of 20 Gy, divided into 10 sessions of 2 Gy each with concomitant oral intake of low-dose glucocorticoids. Therapeutic response and individual ocular manifestations were evaluated 1, 3, 6 and 12 months after OR, and QoL-at 3, 6 and 12 months by a disease-specific questionnaire. RESULTS: One month after OR, 61.6% of patients had a therapeutic response (full or partial). During the follow-up, the proportion of full-responders gradually increased up to 57.5% at 12 months, while that of non-responders gradually decreased, reaching 11.5% at 12 months. All individual ocular manifestations improved significantly 1-3 months after OR. QoL related to visual functioning increased significantly at 6 months, whereas QoL related to appearance improved significantly at 12 months. CONCLUSIONS: The vast majority of our patients with active moderate-to-severe GO exhibited full or partial therapeutic response after OR. The initial effect on the therapeutic response and individual ocular parameters was evident as soon as 1-3 months after the procedure. OR also has a beneficial effect on patients' QoL. TRIAL REGISTRATION NUMBER: NCT05775185/07.03.2023, retrospectively registered.

Synthesis of flexible Co nanowires from bulk precursors.

This work reports a method of producing flexible cobalt nanowires (NWs) directly from the chemical conversion of bulk precursors at room temperature. Chemical reduction of Li6CoCl8 produces a nanocomposite of Co and LiCl, of which the salt is subsequently removed. The dilute concentration of Co in the precursor combined with the anisotropic crystal structure of the hcp phase leads to 1D growth in the absence of any templates or additives. The Co NWs are shown to have high saturation magnetization (130.6 emu g-1). Our understanding of the NW formation mechanism points to new directions of scalable nanostructure generation.

Anisotropic nanoporous morphology of ZnO-supported Co that enhances catalytic activity.

A novel conversion reaction synthesis (CRS) method is used to synthesize ZnO-supported Co nanoporous metal hybrid structures from a co-precipitated nanocomposite precursor of ZnO and Co3O4. After removal of Li2O with water, the resulting material consists of ZnO-supported Co nanoparticles that are interconnected to form anisotropic micro-particles. Additionally, individual ZnO nanoparticles have an anisotropic morphology, as revealed by synchrotron XRD analysis. Microscopy and surface area studies show these materials have an average pore size of 10-30 nm and specific surface areas up to 28 m2 g-1. The hybrid structure also has increased heat resistance compared to that of pure nanoporous metals; the Co phase within the ZnO-Co hybrid exhibits much less coarsening than the analogous nanoporous metal without ZnO at temperatures of 400 °C and above. These ZnO-Co hybrid materials were tested as heterogeneous catalysts for the steam reformation of ethanol at 400 °C. The nanoporous ZnO-Co hybrid material exhibits complete conversion of ethanol and high hydrogen selectivity, producing H2 with a molar yield of approximately 70%.

Draining Over Blocking: Nano-Composite Janus Separators for Mitigating Internal Shorting of Lithium Batteries.

Catastrophic battery failure due to internal short is extremely difficult to detect and mitigate. In order to enable the next-generation lithium-metal batteries, a "fail safe" mechanism for internal short is highly desirable. Here, a novel separator design and approach is introduced to mitigate the effects of an internal short circuit by limiting the self-discharge current to prevent cell temperature rise. A nano-composite Janus separator-with a fully electronically insulating side contacting the anode and a partially electronically conductive (PEC) coating with tunable conductivity contacting the cathode-is implemented to intercept dendrites, control internal short circuit resistance, and slowly drain cell capacity. Galvanostatic cycling experiments demonstrate Li-metal batteries with the Janus separator perform normally before shorting, which then results in a gradual increase of internal self-discharge over >25 cycles due to PEC-mitigated shorting. This is contrasted by a sudden voltage drop and complete failure seen with a single layer separator. Potentiostatic charging abuse tests of Li-metal pouch cells result in dendrites completely penetrating the single-layer separator causing high short circuit current and large cell temperature increase; conversely, negligible current and temperature rise occurs with the Janus separator where post mortem electron microscopy shows the PEC layer successfully intercepts dendrites.

Achieving Fast and Durable Lithium Storage through Amorphous FeP Nanoparticles Encapsulated in Ultrathin 3D P-Doped Porous Carbon Nanosheets.

Conversion-type transition-metal phosphide anode materials with high theoretical capacity usually suffer from low-rate capability and severe capacity decay, which are mainly caused by their inferior electronic conductivities and large volumetric variations together with the poor reversibility of discharge product (Li3P), impeding their practical applications. Herein, guided by density functional theory calculations, these obstacles are simultaneously mitigated by confining amorphous FeP nanoparticles into ultrathin 3D interconnected P-doped porous carbon nanosheets (denoted as FeP@CNs) via a facile approach, forming an intriguing 3D flake-CNs-like configuration. As an anode for lithium-ion batteries (LIBs), the resulting FeP@CNs electrode not only reaches a high reversible capacity (837 mA h g-1 after 300 cycles at 0.2 A g-1) and an exceptional rate capability (403 mA h g-1 at 16 A g-1) but also exhibits extraordinary durability (2500 cycles, 563 mA h g-1 at 4 A g-1, 98% capacity retention). By combining DFT calculations, in situ transmission electron microscopy, and a suite of ex situ microscopic and spectroscopic techniques, we show that the superior performances of FeP@CNs anode originate from its prominent structural and compositional merits, which render fast electron/ion-transport kinetics and abundant active sites (amorphous FeP nanoparticles and structural defects in P-doped CNs) for charge storage, promote the reversibility of conversion reactions, and buffer the volume variations while preventing pulverization/aggregation of FeP during cycling, thus enabling a high rate and highly durable lithium storage. Furthermore, a full cell composed of the prelithiated FeP@CNs anode and commercial LiFePO4 cathode exhibits impressive rate performance while maintaining superior cycling stability. This work fundamentally and experimentally presents a facile and effective structural engineering strategy for markedly improving the performance of conversion-type anodes for advanced LIBs.

Hierarchical Design of Mn2P Nanoparticles Embedded in N,P-Codoped Porous Carbon Nanosheets Enables Highly Durable Lithium Storage.

Although transition metal phosphide anodes possess high theoretical capacities, their inferior electronic conductivities and drastic volume variations during cycling lead to poor rate capability and rapid capacity fading. To simultaneously overcome these issues, we report a hierarchical heterostructure consisting of isolated Mn2P nanoparticles embedded into nitrogen- and phosphorus-codoped porous carbon nanosheets (denoted as Mn2P@NPC) as a viable anode for lithium-ion batteries (LIBs). The resulting Mn2P@NPC design manifests outstanding electrochemical performances, namely, high reversible capacity (598 mA h g-1 after 300 cycles at 0.1 A g-1 ), exceptional rate capability (347 mA h g-1 at 4 A g-1), and excellent cycling stability (99% capacity retention at 4 A g-1 after 2000 cycles). The robust structure stability of Mn2P@NPC electrode during cycling has been revealed by the in situ and ex situ transmission electron microscopy (TEM) characterizations, giving rise to long-term cyclability. Using in situ selected area electron diffraction and ex situ high-resolution TEM studies, we have unraveled the dominant lithium storage mechanism and confirmed that the superior lithium storage performance of Mn2P@NPC originated from the reversible conversion reaction. Furthermore, the prelithiated Mn2P@NPC∥LiFePO4 full cell exhibits impressive rate capability and cycling stability. This work introduces the potential for engineering high-performance anodes for next-generation high-energy-density LIBs.

Dendrite Suppression Membranes for Rechargeable Zinc Batteries.

Aqueous batteries with zinc metal anodes are promising alternatives to Li-ion batteries for grid storage because of their abundance and benefits in cost, safety, and nontoxicity. However, short cyclability due to zinc dendrite growth remains a major obstacle. Here, we report a cross-linked polyacrylonitrile (PAN)-based cation exchange membrane that is low cost and mechanically robust. Li2S3 reacts with PAN, simultaneously leading to cross-linking and formation of sulfur-containing functional groups. Hydrolysis of the membrane results in the formation of a membrane that achieves preferred cation transport and homogeneous ionic flux distribution. The separator is thin (30 µm-thick), almost 9 times stronger than hydrated Nafion, and made of low-cost materials. The membrane separator enables exceptionally long cyclability (>350 cycles) of Zn/Zn symmetric cells with low polarization and effective dendrite suppression. Our work demonstrates that the design of new separators is a fruitful pathway to enhancing the cyclability of aqueous batteries.