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Stannous sulfate is commonly used as an additive in the positive lead pastes of lead-acid batteries, but its real function and mechanism are still vague and need further study. The present work investigates the intrinsic effects of tin additives on the positive electrode performance under well-controlled experimental conditions. The tin additives are added in three ways: the SnSO4 dissolved in 4.5 M H2SO4 electrolyte, the metal Sn melted in metal Pb substrate, and the SnSO4 mixed in homemade industrial lead pastes. A series of evolutions are clearly revealed in structure, composition, and redox activity of the positive active materials with the content of Sn. Both the SnSO4 in the electrolyte and in the positive lead pastes have a significant inhibiting effect on the transformation between PbSO4 and PbO2, leading to a decrease in the charge/discharge capacities with increasing content of SnSO4. A similar but weaker inhibiting effect was also found for the Sn melted in the Pb-Sn alloys. The SnSO4 has a significant enhancement effect on the grain size of PbSO4/PbO2, which increases the resistance of the solid-phase transformation deep inside the grains during the charge/discharge. All these results do not support the use of SnSO4 in the positive pastes of lead-acid batteries. [ABSTRACT FROM AUTHOR]

The aim of this study was to distinguish the characteristics of intervertebral disc degeneration (IVDD) originating from mechanics imbalance, biology disruption, and their communion, and to develop a composite IVDD model by ovariectomy combined with lumbar facetectomy for mimicking elderly IVDD with osteoporosis and lumbar spinal instability. Mice were randomly divided into four groups and subjected to sham surgery (CON), ovariectomy (OVX), facetectomy (mechanical instability, INS) or their combination (COM), respectively. Radiographical (n = 4) and histological changes (n = 8) of L4/5 spinal segments were analyzed. Tartrate-resistant acid phosphatase (TRAP) staining was conducted to detect osteoclasts, and expression of osterix (OSX), type I collagen (Col I), type II collagen (Col II) and vascular endothelial growth factor (VEGF) were evaluated by immunochemistry. OVX affected the body's metabolism but INS did not, as the body weight increased and uterus weight decreased in OVX and COM mice compared to CON and INS mice. OVX, INS, and COM caused IVDD in various degrees at 12 weeks after surgery. However, the major pathogeneses of OVX- and INS-induced IVDD were different, which focused on endplate (EP) remodeling and annulus fibrosus (AF) collapse, respectively. OVX induced osteopenia of vertebra. In contrast, INS promoted the stress-adaptive increase of subchondral bone trabeculae. The COM produced a reproducible severe IVDD model with characteristics of sparse vertebral trabeculae, cartilaginous EP ossification, subchondral bone sclerosis, fibrous matrix disorder, angiogenesis, disc stiffness, as well as space fusion. Additionally, all groups had elevated bone and cartilage turnover compared with CON group, as the quantity of trap + osteoclasts and the osteogenic OSX expression increased in these groups. Likewise, the VEGF expression levels were similar, accompanied by the altered matrix expression of disc, including the changed distribution and contents of Col II and Col I. The findings suggested that the composite mouse model to some extent could effectively mimic the interactions of biology and mechanics engaged in the onset and natural course of IVDD, which would be more compatible with the IVDD of elderly with vertebral osteoporosis and spinal instability and benefit to further clarify the complicated mechanobiological environment of elderly IVDD progression. [ABSTRACT FROM AUTHOR]

Developing atomically precise catalysts for hydrogen evolution reaction (HER) will help understand the catalytic reaction mechanisms for guiding the synthesis of new HER catalysts. A Cu-based metal-organic framework (CuII-MOF) consisting of trinuclear mixed-ligand units was prepared under hydrothermal conditions, and the structure, morphology, and elemental composition were characterized by (single crystal) XRD, TEM, SEM, XPS, BET, TGA and ATR-FTIR. Doping of 9.2 wt% CuII-MOF powder into the carbon paste electrode caused a roughly 440 mV positive shift of the HER potential at 10 mA cm−2 in 1.0 M H 2 SO 4. The CuII-MOF showed a high working stability due to the dual-ligand-protected Cu active centers. The intrinsic catalytic mechanism was investigated by Tafel slope analysis, solid state electrochemistry and electrochemical impedance spectroscopy. The CuII ions in the CuII-MOF are successively reduced through two single-electron steps over a potential range of 0.7 to 0.1 V vs. RHE to form single-atom Cu0 active centers, on which adsorbed H atoms can be generated with a positive onset potential of about 100 mV vs. RHE through a following chemical redox reaction. The mechanistic findings point out the necessity and feasibility of developing bicomponent or bifunctional MOF-based catalysts to efficiently accelerate both the first and second electron transfer steps of HER. Image 1 • A CuII-MOF single crystal as a new HER catalyst is synthesized and characterized. • The catalyst brings about a positive onset potential of 100 mV vs. RHE for the first electron transfer of HER. • The formation and spillover of adsorbed H atoms are investigated. • A new insight into the mechanism how the Cu active sites catalyze HER. [ABSTRACT FROM AUTHOR]

Bipolar electrochemistry is an unconventional but powerful technique in the fields of materials science and analytical chemistry. We report here the one-step cathodic deposition of Ni x Cu 1– x alloys with a composition gradient and a morphology evolution on a copper substrate, based on an in-plane potential gradient over the interface of a bipolar electrode (BPE) and an electrolytic solution. The alloy gradient was characterized using scanning and transmission electron microscopy techniques. As a result, the deposited alloy layer exhibits a composition gradient from 0 to ca. 89% Ni atoms corresponding to an abundant morphology evolution from pyramids to dendrites and to nano/microballs along the surface of the BPE. Electrochemical screenings were performed for the dissected alloy specimens as the electrocatalyst of hydrogen evolution reaction. The present work shows that bipolar electrochemistry can give access to the fabrication of alloys with abundant architectures as high throughput screening candidates. [ABSTRACT FROM AUTHOR]

The nickel-copper nanoalloys with tunable composition and morphology were prepared by galvanostatic deposition on copper substrate, in order to investigate the relationship between alloy composition and electrocatalytic activity. Both the composition and morphology of the Ni x Cu y nanoalloys are highly dependent on the applied current density. The atomic ratio of Ni to Cu in the alloys changes from 1:9 to 3:1, with the increase of current density from 10 to 100 mA cm − 2 . The difference in electrocatalytic activity among these nanoalloys was evaluated through the hydrogen evolution reaction (HER) in 1.0 M H 2 SO 4 and 1.0 M KOH. The composition-dependence of the electrocatalytic activity of the alloys is more pronounced in 1.0 M H 2 SO 4 than in 1.0 M KOH. By tuning the composition of Ni x Cu y alloys, 13.5 and 5.7 times increase in exchange current density of the HER was achieved in 1.0 M H 2 SO 4 and 1.0 M KOH, respectively. Meanwhile, 4.5 and 2.0 times decrease in charge transfer resistance was observed in the same two media. The best electrocatalytic activity to the HER was always achieved on the nanoalloy with a 1:1 atom ratio and a single crystal (111) plane. This favorable nanoalloy is composed of four-level dendritic nanochains. The results demonstrate that galvanostatic method can tune not only the composition but also the morphology of nanoalloys, both being important for nanoscale design of industrial electrocatalysts. [ABSTRACT FROM AUTHOR]

Diffusion restriction of precursor ions was applied using filter paper during platinum electrodeposition on a solid carbon paste substrate, in order to uniformize the growth of Pt catalyst particles. An additional 3D nucleation process was then observed in the initial deposition stage, and the growth rate of Pt particles kept constant over whole deposition time. The prepared particles showed a sunflower-head-like morphology with numerous nanoscale “seeds” on the surface. Both the “sunflower-heads” and the “seeds” become more uniform in size, shape and surface distribution due to diffusion restriction, leading to an increase in the electrochemical active area of Pt particles and an enhancement in methanol oxidation kinetics. The analysis of electrochemical impedance spectroscopy by equivalent circuit fitting yields potential-dependent charge-transfer resistances and inductances with the same sign (positive or negative), corresponding to the regeneration or passivation of surface active sites at different potentials. This study offers insight into the role of the diffusion-restricted electrodeposition in preparing the catalyst particles with high catalytic activity. [ABSTRACT FROM AUTHOR]

Abstract: A simple electrodeposition approach to grow multi-laminated copper particles on two conductive substrates is presented. Morphological and structural characterization was performed using SEM and XRD. The copper crystallites are preferentially oriented with {111} planes parallel to the substrate surfaces, providing an optimum interface for methanol oxidation. There are a large number of edges, corners, and atomic steps around individual multi-laminated nanostructured particles. The excellent electrocatalytic activity of the particles to methanol oxidation in alkaline solutions is demonstrated by cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. The presence of the conductive poly(2-amino-5-mercapto-1,3,4-thiadiazole) interlayer between the Cu particles and the carbon paste substrate results in larger specific surface areas of the particles and smaller charge-transfer resistances of methanol oxidation reaction in the lower potential range. Such an anisotropic laminated structure of non-noble metal nanomaterials deserves further investigation for finding a suitable alternative to noble metal-based anodic catalysts in fuel cells. [Copyright &y& Elsevier]

Lateral gradient coatings displaying various compositions and microstructures along a single surface are desirable for material screening. Here we report a successful application of bipolar electrochemistry to deposit lateral gradient polypyrrole films on a graphite strip substrate. The gradient film shows varying morphologies and a wettability gradient along the length of the bipolar electrode, with superabsorbent property in the middle portion of the film. The film was use as a catalyst matrix for ethanol oxidation in alkaline electrolyte. Aqueous Ni(NO 3) 2 solution as the catalyst precursor was absorbed into the film. Area-step cyclic voltammetry was used to evaluate the electrocatalytic activity of various local parts along the gradient film to ethanol oxidation. The local surface with the highest catalytic activity was screened out and the excellent catalytic activity is attributed to the outstanding properties of this zone in both water absorption and electrical conductivity. The nickel oxide catalyst can be highly dispersed in the nanoporous network polymer matrix, due to the uniform penetration of the aqueous precursor solution into the superabsorbent film. XPS and EIS analyses support the catalytic mechanism based on the redox transition between NiOOH and Ni(OH) 2. This work indicates that loading aqueous catalyst precursors into superabsorbent conducting polymer films may be a promising method for the preparation of electrocatalysts. [Display omitted] • Bipolar electrodeposition of conducting polymer films with a lateral gradient. • Area-step voltammetry for position-resolved characterization of gradient films. • A polypyrrole film with varying morphologies and a wettability gradient. • Superabsorbent part of the film suitable for loading aqueous catalyst precursors. [ABSTRACT FROM AUTHOR]

Background: The prognostic value of cytokeratin 19 fragment (CYFRA 21 - 1) and Ki67 in advanced non-small cell lung cancer (NSCLC) patients with wild-type epidermal growth factor receptor (EGFR) remains to be explored., Methods: In this study, 983 primary NSCLC patients from January 2016 to December 2019 were retrospectively reviewed. Finally, 117 advanced NSCLC patients with wild-type EGFR and 37 patients with EGFR mutation were included and prognostic value of CYFRA 21 - 1 and Ki67 were also identified., Results: The patients age, smoking history and the Eastern Corporative Oncology Group (ECOG) performance scores were significantly different between CYFRA21-1 positive and negative groups (p < 0.05), while no significant differences were found in Ki67 high and low groups. The results of over survival (OS) demonstrated that patients with CYFRA21-1 positive had markedly shorter survival time than CYFRA21-1 negative (p < 0.001, For whole cohorts; p = 0.002, For wild-type EGFR). Besides, patients with wild-type EGFR also had shorter survival times than Ki67 high group. Moreover, In CYFRA 21 - 1 positive group, patients with Ki67 high had obviously shorter survival time compared to patients with Ki67 low (median: 24vs23.5 months; p = 0.048). However, Ki67 could not be used as an adverse risk factor for patients with EGFR mutation. Multivariate cox analysis showed that age (HR, 1.031; 95%CI, 1.003 ~ 1.006; p = 0.028), Histopathology (HR, 1.760; 95%CI,1.152 ~ 2.690; p = 0.009), CYFRA 21 - 1 (HR, 2.304; 95%CI,1.224 ~ 4.335; p = 0.01) and Ki67 (HR, 2.130; 95%CI,1.242 ~ 3.652; p = 0.006) served as independent prognostic risk factor for advanced NSCLC patients., Conclusions: Our finding indicated that CYFRA 21 - 1 was an independent prognostic factor for advanced NSCLC patients and Ki67 status could be a risk stratification marker for CYFRA 21 - 1 positive NSCLC patients with wild-type EGFR., (© 2023. The Author(s).)

Maternal stress has been associated with poor birth outcomes, including preterm birth, infant mortality, and low birth weight. Bone development disorders in the embryo as a result of maternal stress are believed to be mediated through oxidative stress damage. Various species of free radicals, such as alkoxyl radicals, can be formed through endogenous redox response or exogenous stimuli in the womb and transmitted to embryos. Yet, whether these free radicals lead to abnormal fetal bone development is unclear. Here, we demonstrate prenatal bone growth retardation and ferroptosis-related signals of chondrocytes were induced by classic alkoxyl radical generators. We also show that alkoxyl radicals lead to significant accumulation of oxidized phospholipids in chondrocytes, through the iron-mediated Fenton reaction in embryos. We further demonstrate a role for the lipid peroxidation end product, 4-HNE, which forms adducts with the pivotal chondrogenesis transcription factor SOX9, leading to its degradation, therefore dampening chondrogenesis. Our data define a critical role for phospholipid peroxidation in alkoxyl radicals-evoked abnormal chondrogenesis, and pinpoint it being a precise target for treating oxidative stress-related bone development disorders., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Low-cost and efficient bifunctional catalysts are urgently needed for overall water splitting used in large-scale energy storage. In this study, we develop a nickel and iron (di)sulfide (Ni-Fe-S) composite catalyst that is in situ synthesized and fixed within the intergranular nanopores inside high pure polycrystalline graphite. Two precursor solutions (reactants) may permeate the graphite intergranular pores to a depth of more than 3.5 mm. The nanoscale pores serve as an array of nanoreactors for the synthesis of the Ni-Fe-S nanoparticles under conditions much milder than usual. The prepared catalyst efficiently catalyzes both the hydrogen and oxygen evolution reactions (HER and OER) in 1.0 M KOH. It delivers a current density of 400 mA cm -2 at a full cell voltage of around 2.3 V without considerable activity decay over 24 h electrolysis. The active species of the catalyst are different for the HER and OER and discussed accordingly. The synthesis strategy based on the nanopores in a monolithic conductive substrate proves to be a simple, efficient, and promising way to prepare electrocatalysts that are cheap, abundant, and industrially attractive., (© 2021 Wiley-VCH GmbH.)

Iron incorporation is essential for the record activity of NiFe-(oxy)hydroxides to oxygen evolution reaction (OER), but the details of how Fe affects catalysis remain under active investigation. In this work, we present a double thin-layer strategy for finding unique and solid evidence for the role of Fe in the OER mechanism. A thin-layer catalyst of a few nanometers of thickness was deposited on a Ni substrate and a thin-layer electrolyte of 0.1 mm thickness was created using a thin-layer spectroelectrochemical cell. The OER activity, the catalyst composition, and the electrolyte species were investigated together as a function of the Fe deposition time. The results show that trace Fe incorporation favors the formation of β-NiOOH in the thin-layer catalyst and effectively suppresses the dissolution of NiOOH into the electrolyte. The results of double-potential step chronoabsorptometry and cyclic voltabsorptometry demonstrate the potential-dependent formation of a Ni 3+ intermediate in the electrolyte and, more importantly, the dissolution suppression effect due to Fe incorporation. These findings link the role of Fe in OER catalysis to the increased insolubility of Ni 3+ active sites and highlight the importance of paying close attention to the active-site stability of an electrocatalyst impaired by the electrolyte at a reaction potential.

GATA binding protein 6 (GATA6) is a member of the GATA family of zinc-finger transcriptional regulators, whose names come from the conservative base sequence (G/A)GATA(A/T). The GATA families play key roles in cell fate determination, proliferation, migration, and organogenesis of endoderm- and mesoderm-derived organs in vertebrates. As a lineage-specific factor, a chromatin remodeling factor, a pluripotent factor and a pioneer factor, GATA6 is involved in various stages of liver development, including endoderm liver-lineage determination, liver specification, hepatic bud outgrowth and hepatoblast differentiation. In this review, we summarize recent progress in the roles and regulatory mechanisms of GATA6 in liver development.

Based on monthly in situ data collected at six sampling sites in Qiandaohu Lake between 2011 and 2012, the dynamic distributions of dissolved oxygen (DO) were analyzed and the relationships between DO and the environmental factors were investigated. The results showed that there were obviously vertical and temporal variations in the distributions of DO. In winter, the average values of DO were generally higher than those in other seasons, but no significant vertical distribution variation was found except Dabaqian. However, the vertical differences of DO in summer were larger than those in spring and autumn. Moreover, the maximum values of DO found in euphotic zone at the sites of Xiaojinshan, Santandao, Dabaqian in summer were 11.59, 12.52, 10.96 mg x L(-1), respectively. The maximum DO at surface layer was found in spring while the minimum value appeared in autumn. Seasonal differences in relationships between dissolved oxygen and water temperature, pH, and Chla concentration were discussed. In summer, highly significant linear correlation between DO and water temperature was found indicating that the temperature thermal stratification was the key factor to influence the vertical distribution of DO. The relative higher correlation coefficients between DO and pH, Chla concentration in spring and summer were due to the phytoplankton photosynthesis.

The interaction between umbelliferone (UMB) with tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe) was studied by using fluorescence (FS) and ultraviolet (UV) spectroscopy. The results show that UMB can strongly quench the fluorescence of the three aromatic amino acids with the maximum quenching wavelengths at 347, 303 and 282 nm, respectively. Data analyses based on the Stern-Volmer curve and the UV spectroscopy show that static quenching occurred through the formation of the complexes of UMB with each aromatic amino acid in a molar ratio of 1 : 1. The binding constant K(c) of UMB with Trp, Tyr and Phe is 2.993 x 10(6), 7.858 x 10(4) and 1.186 x 10(3) L x mol(-1) (298.15 K) and 2.702 x 10(4), 1.063 x 10(5) and 8.352 x 10(3) L x mol(-1) (310.15 K), respectively. The thermodynamic parameters indicate that UMB has a strong interaction with the three aromatic amino acids. Hydrogen bond and Van der Waals force may play a major role in the reaction of UMB with Trp, whereas hydrophobic interaction should be responsible for the binding of UMB with Tyr and Phe. In addition, the dipole-dipole interaction may be another factor in the reactions between UMB and the three aromatic aminoacids.

A population of F8 recombinant inbred lines (RILs), derived from a cross between IR26 (Oryza sativa L. spp. indica) and Jiucaiqing (japonica), were used to identify the quantitative trait loci (QTLs) for Cd2+ content in brown rice under 5 mg/kg Cd2+ stress. Two QTLs, qCCBR-11a and qCCBR-11b, associated with the Cd2+ content in brown rice, were detected on chromosome 11. qCCBR-11a was located at the position between markers RM6288 and RM6544, accounting for 11.17% of the phenotypic variance with an additive effect value of 0.089. qCCBR-11b at the interval between markers RM167 and RM5704 explained 7.66% of the phenotypic variance with an additive effect value of 0.075. In addition, the correlation coefficients between Cd2+ content of brown rice and plant height, spikelets per panicle, filled grains per panicle, seed setting rate, and 1 000-grain weight were not significant. This suggested that the Cd2+ content in brown rice under Cd2+ stress was an independent genetic trait.