Developing low‐cost and high‐activity pH‐universal hydrogen evolution reaction (HER) catalysts is very crucial to the industrialization of water electrolysis. However, the high price, low yield, and ...poor stability of current HER catalysts make them difficult to meet practical requirements. Herein, a plasma spraying technique is employed to prepare self‐supported Cu catalysts with tensile strain for the first time. The tensile strain upshifts the d‐band of Cu, improves the water dissociation and H* adsorption, eventually improves the intrinsic HER catalytic activity. As such, Cu electrode achieves overpotentials of 182 mV in 0.5 m H2SO4, 261 mV in 1 M PBS, and 121 mV in 1 M KOH at 10 mA cm–2. In addition, Cu electrode also performs well at high current densities, the overpotentials at 1 A cm–2 are much lower than those of Pt foil in acid, neutral, and alkaline solutions.
The Cu electrode prepared by plasma spraying exhibits an excellent pH‐universal HER catalytic activity, superb long‐term stability, and marvelous corrosion resistance. The superb HER activity is attributed to self‐supported porous structure, abundant active sites, tensile strain enhanced intrinsic catalytic activity, and small charge transfer resistance.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Designing highly conducting metal-organic frameworks (MOFs) is currently a subject of great interest for their potential applications in diverse areas encompassing energy storage and generation. ...Herein, a strategic design in which a metal-sulfur plane is integrated within a MOF to achieve high electrical conductivity, is successfully demonstrated. The MOF {Cu
(6-Hmna)(6-mn)·NH
}
(1, 6-Hmna = 6-mercaptonicotinic acid, 6-mn = 6-mercaptonicotinate), consisting of a two dimensional (-Cu-S-)
plane, is synthesized from the reaction of Cu(NO
)
, and 6,6'-dithiodinicotinic acid via the in situ cleavage of an S-S bond under hydrothermal conditions. A single crystal of the MOF is found to have a low activation energy (6 meV), small bandgap (1.34 eV) and a highest electrical conductivity (10.96 S cm
) among MOFs for single crystal measurements. This approach provides an ideal roadmap for producing highly conductive MOFs with great potential for applications in batteries, thermoelectric, supercapacitors and related areas.
Background
Hepatocellular carcinoma (HCC) is a prevalent malignancy with poor prognosis. As a cell adhesion molecule, poliovirus receptor (PVR/CD155) is abnormally overexpressed in tumour cells, and ...related to tumour proliferation and invasion. However, the potential role and mechanism of CD155 have not yet been elucidated in HCC.
Methods
Immunohistochemistry, RT‐PCR and Western blot assays were used to determine CD155 expression in HCC cell lines and tissues. Cell Counting Kit‐8 and colony formation assays were used to examine cell proliferation. Transwell and wound healing assays were used to evaluate cell migration and invasion. Cell apoptosis and cycle distribution were assessed by flow cytometry. Cox regression and Kaplan–Meier analyses were performed to explore the clinical significance of CD155. The role of CD155 in vivo was evaluated by establishing liver orthotropic xenograft mice model. RNA sequencing, bioinformatics analysis and co‐immunoprecipitation assay were used to explore the downstream signalling pathway of CD155.
Results
CD155 was upregulated in HCC tissues and represented a promising prognostic indicator for HCC patients (n = 189) undergoing curative resection. High CD155 expression enhanced cell proliferation, migration and invasion, and contributed to cell survival in HCC. CD155 overexpression also induced epithelial–mesenchymal transition in HCC cells. CD155 function in HCC involved SRC/p38 MAPK signalling pathway. CD155 interacted with SRC homology‐2 domain of SRC and promoted SRC activation, further inhibiting the downstream p38 MAPK signalling pathway in HCC.
Conclusions
CD155 promotes HCC progression via the SRC/p38 MAPK signalling pathway. CD155 may represent a predictor for poor postsurgery prognosis in HCC patients.
CD155 is highly expressed in hepatocellular carcinoma (HCC) tissues, and its overexpression predicts poor postsurgery prognosis in HCC patients.
CD155 promotes HCC progression via its cell‐intrinsic role in regulating cell proliferation, migration, invasion and epithelial–mesenchymal transition (EMT).
CD155 enhances SRC activation through interacting with SH2 domain of SRC, further inhibiting the downstream p38 MAPK signalling pathway in HCC.
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Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide because of rapid progression and high incidence of metastasis or recurrence. Accumulating evidence shows that ...CD73-expressing tumor cell is implicated in development of several types of cancer. However, the role of CD73 in HCC cell has not been systematically investigated and its underlying mechanism remains elusive.
CD73 expression in HCC cell was determined by RT-PCR, Western blot, and immunohistochemistry staining. Clinical significance of CD73 was evaluated by Cox regression analysis. Cell counting kit-8 and colony formation assays were used for proliferation evaluation. Transwell assays were used for motility evaluations. Co-immunoprecipitation, cytosolic and plasma membrane fractionation separation, and ELISA were applied for evaluating membrane localization of P110β and its catalytic activity. NOD/SCID/γc(null) (NOG) mice model was used to investigate the in vivo functions of CD73.
In the present study, we demonstrate that CD73 was crucial for epithelial-mesenchymal transition (EMT), progression and metastasis in HCC. CD73 expression is increased in HCC cells and correlated with aggressive clinicopathological characteristics. Clinically, CD73 is identified as an independent poor prognostic indicator for both time to recurrence and overall survival. CD73 knockdown dramatically inhibits HCC cells proliferation, migration, invasion, and EMT in vitro and hinders tumor growth and metastasis in vivo. Opposite results could be observed when CD73 is overexpressed. Mechanistically, adenosine produced by CD73 binds to adenosine A2A receptor (A2AR) and activates Rap1, which recruits P110β to the plasma membrane and triggers PIP3 production, thereby promoting AKT phosphorylation in HCC cells. Notably, a combination of anti-CD73 and anti-A2AR achieves synergistic depression effects on HCC growth and metastasis than single agent alone.
CD73 promotes progression and metastasis through activating PI3K/AKT signaling, indicating a novel prognostic biomarker for HCC. Our data demonstrate the importance of CD73 in HCC in addition to its immunosuppressive functions and revealed that co-targeting CD73 and A2AR strategy may be a promising novel therapeutic strategy for future HCC management.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The intracellular potassium (K+) homeostasis, which is crucial for plant survival in saline environments, is modulated by K+ channels and transporters. Some members of the high‐affinity K+ ...transporter (HAK) family are believed to function in the regulation of plant salt tolerance, but the physiological mechanisms remain unclear. Here, we report a significant inducement of OsHAK21 expression by high‐salinity treatment and provide genetic evidence of the involvement of OsHAK21 in rice salt tolerance. Disruption of OsHAK21 rendered plants sensitive to salt stress. Compared with the wild type, oshak21 accumulated less K+ and considerably more Na+ in both shoots and roots, and had a significantly lower K+ net uptake rate but higher Na+ uptake rate. Our analyses of subcellular localizations and expression patterns showed that OsHAK21 was localized in the plasma membrane and expressed in xylem parenchyma and individual endodermal cells (putative passage cells). Further functional characterizations of OsHAK21 in K+ uptake‐deficient yeast and Arabidopsis revealed that OsHAK21 possesses K+ transporter activity. These results demonstrate that OsHAK21 may mediate K+ absorption by the plasma membrane and play crucial roles in the maintenance of the Na+/K+ homeostasis in rice under salt stress.
We investigated a highly salt‐induced high‐affinity K+ transporter (HAK) gene, OsHAK21. OsHAK21 is localized in the plasma membrane, and expressed in xylem parenchyma and passage cells. Knockout of the OsHAK21 gene led to an increased Na+/K+ ratio and salt sensitivity. These results highlight the importance of OsHAK21‐mediated K+ acquisition for maintaining Na+/K+ homeostasis under salt stress.
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Lead (Pb) is known to impair children's cognitive function. It has been previously shown that developmental Pb exposure alters dendritic spine formation in hippocampal pyramidal neurons. However, the ...underlying mechanism has not yet been defined. In this study, a low-level gestational Pb exposure (GLE) rat model was employed to investigate the impact of Pb on the spine density of the hippocampal pyramidal neurons and its regulatory mechanism. Pb exposure resulted in impaired performance of the rats in the Morris water maze tasks, and in decreased EPSC amplitudes in hippocampal CA3-CA1 regions. With a 3D reconstruction by the Imaris software, the results from Golgi staining showed that the spine density in the CA1 region was reduced in the Pb-exposed rats in a dose-dependent manner. Decreased spine density was also observed in cultured hippocampal neurons following the Pb treatment. Furthermore, the expression level of NLGN1, a postsynaptic protein that mediates synaptogenesis, was significantly decreased following the Pb exposure both in vivo and in vitro. Up-regulation of NLGN1 in cultured primary neurons partially attenuated the impact of Pb on the spine density. Taken together, our resultssuggest that Pb exposure alters spine plasticity in the developing hippocampus by down-regulating NLGN1 protein levels.
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As an emerging nitrogen-rich 2D carbon material, graphitic carbon nitride (CN) has drawn much attention for applications ranging from photo-/electrocatalysts to biosensors. Interfacial modification ...of CN is fundamentally vital but is still in its infancy and remains challenging due to the low reactivity of CN. Here we report that, in conjunction with a π-π stacking interaction, bulk CN could be simultaneously exfoliated via facile mechanical grinding. The obtained CN nanosheets (m-CNNS) not only retained the pristine optoelectronic properties of bulk CN but also enriched a friendly interface for further coupling biomolecules with advanced properties, overcoming the deficiencies of CN in surface science. The m-CNNS were further covalently linked to a DNA probe, and the resultant electrochemiluminescent biosensor for the target DNA exhibited much enhanced sensitivity with respect to that obtained by direct physical absorption of the DNA probe on unmodified CNNS. This noncovalent exfoliation and interfacial modification should greatly expand the scope of potential applications of CN in areas such as biosensing and should also be applicable to other 2D materials in interface modulation.
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IJS, KILJ, NUK, PNG, UL, UM
High‐performance asymmetric super‐capacitors containing thick‐film electrodes (over 100 μm thick) made of CNT/V2O5 nanowire composite are designed. The excellent conductivity, high specific ...capacitance, and a large voltage window of the CNT/V2O5 nanocomposite enable the fabrication of devices with high energy and high power densities. Moreover, the resulting devices exhibit excellent cycling stability. This supercapacitor approach may be attractive for a wide range of device applications.
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Although numerous studies on the impacts of climate change on biodiversity have been published, only a handful are focused on the intraspecific level or consider population‐level models (separate ...models per population). We endeavored to fill this knowledge gap relative to the Qinghai‐Tibetan plateau (QTP) by combining species distribution modeling (SDMs) with population genetics (i.e., population‐level models) and phylogenetic methods (i.e., phylogenetic tree reconstruction and phylogenetic diversity analyses). We applied our models to 11 endemic and widely distributed herpetofauna species inhabiting high elevations in the QTP. We aimed to determine the influence of environmental heterogeneity on species’ responses to climate change, the magnitude of climate‐change impacts on intraspecific diversity, and the relationship between species range loss and intraspecific diversity losses under 2 shared socioeconomic pathways (SSP245 and SSP585) and 3 future periods (2050s, 2070s, and 2090s). The effects of global climatic change were more pronounced at the intraspecific level (22% of haplotypes lost and 36% of populations lost) than the morphospecies level in the SSP585 climate change scenario. Maintenance of genetic diversity was in general determined by a combination of factors including range changes, species genetic structure, and the part of the range predicted to be lost. This is owing to the fact that the loss and survival of populations were observed in species irrespective of the predicted range changes (contraction or expansion). In the southeast (mountainous regions), climate change had less of an effect on range size (>100% in 3 species) than in central and northern QTP plateau regions (range size <100% in all species). This may be attributed to environmental heterogeneity, which provided pockets of suitable climate in the southeast, whereas ecosystems in the north and central regions were homogeneous. Generally, our results imply that mountainous regions with high environmental heterogeneity and high genetic diversity may buffer the adverse impacts of climate change on species distribution and intraspecific diversity. Therefore, genetic structure and characteristics of the ecosystem may be crucial for conservation under climate change.
Impactos del cambio climático sobre la diversidad de herpetofauna en la meseta Qinghai‐Tíbet
Región
Aunque se han publicado numerosos estudios sobre los impactos del cambio climática en la biodiversidad, son muy pocos los que se enfocan en el nivel intraespecífico o que consideran modelos a nivel poblacional (modelos separados por población). Intentamos cerrar este vacío de conocimiento en relación con la meseta Qinghai‐Tíbet (MQT) con la combinación entre modelos de distribución de especies (MDE) y genética poblacional (modelos a nivel poblacional) y métodos filogenéticos (reconstrucción de árboles filogenéticos y análisis de diversidad filogenética). Aplicamos nuestros modelos a once especies endémicas de herpetofauna con distribución amplia en las elevaciones más altas de la MQT. Nos planteamos determinar la influencia de la heterogeneidad de las especies sobre la respuesta de las especies al cambio climático, la magnitud de los impactos del cambio climático sobre la diversidad intraespecífica y la relación entre la pérdida de distribución de la especie y las pérdidas de diversidad intraespecífica bajo dos vías socioeconómicas (SSP245 y SSP585) y tres periodos del futuro (2050s, 2070s y 2090s). Los efectos del cambio climático global fueron más pronunciados a nivel intraespecífico (22% de pérdida en los haplotipos y 36% en las poblaciones) que al nivel morfoespecie en el escenario de cambio climático SSP585. El mantenimiento de la diversidad genética casi siempre estuvo determinado por una combinación de factores que incluyen cambios en la distribución, estructura genética de las especies y la parte de la distribución que se pronosticó se perdería. Esto se debe a que observamos la pérdida y supervivencia de las poblaciones sin importar los cambios pronosticados en la distribución (contracción o expansión). En las regiones montañosas del sureste, el cambio climático tuvo un efecto menor sobre la distribución (>100% en tres especies) comparado con las regiones de la meseta central y del norte de la MQT (distribución <100% en todas las especies). Esto puede atribuirse a la heterogeneidad ambiental, la cual proporciona recovecos de clima adecuado en el sureste, mientras que los ecosistemas en las regiones central y norte fueron homogéneos. De manera general, nuestros resultados implican que las regiones montañosas con una elevada heterogeneidad ambiental y una gran diversidad genética podrían reducir los impactos adversos del cambio climático sobre la distribución de las especies y la diversidad intraespecífica. Por lo tanto, la estructura genética y las características del ecosistema pueden ser cruciales para conservar bajo el cambio climático.
【摘要】
尽管已有大量有关气候变化对生物多样性影响的研究发表, 但只有少数研究考虑种下或种群水平的模型。我们将物种分布模型(SDMs)与种群遗传学和系统发生学方法相结合, 填补青藏高原地区(QTP)在这一方面的研究空白。我们对11种栖息在青藏高原特有且分布广泛的两栖爬行动物进行了模型分析, 探究环境异质性对物种响应气候变化的影响、气候变化对种内多样性的影响程度、以及在SSP245和SSP585两种情景下, 未来(2050年、2070年和2090年)物种分布范围丧失与种内多样性丧失之间的关系。结果显示, 在SSP585气候变化情景中, 在种下有22%的单倍型和36%的种群将会丢失, 全球气候变化对种内多样性的影响比种间更为明显。遗传多样性是否能够维持一般由多种因素共同决定, 包括分布区的变化、物种遗传结构以及预测丢失的分布区。在青藏高原东南部山区, 气候变化对物种分布范围大小的影响(有3个物种的分布范围扩张)小于青藏高原北部和中部地区(所有物种的分布范围均缩小), 主要原因可能是东南部环境异质性更高, 物种可以选择较为合适的生境, 而北部和中部地区环境则趋于同质化。本研究结果表明, 环境异质性高、遗传多样性高的山区可以缓冲气候变化对物种分布和种内多样性的不利影响。因此, 生态系统的遗传结构和特征对于气候变化下的多样性保护至关重要。
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Ag nanoparticles with different sizes were produced by laser ablation in liquid (PLAL) through tuning laser energy. As the catalyst for hydrogen evolution reaction (HER) in acidic medium, Ag ...nanoparticles show strong size‐dependent activity, and the smallest Ag nanoparticles with average size of 3 nm display a low overpotential of 96 mV at 10 mA cm−2 and Tafel slope of 76.10 mV dec−1, being superior to Ag foil and commercial Ag powder. The excellent performance is attributed to the large exposed surface, low coordination number, moderate hydrogen adsorption energy, and low charge transfer resistance.
Electrocatalysis: An eco‐friendly technique, laser ablation in liquid, to prepare Ag nanocatalysts with ultrafine size (approx. 3 nm) and clean surface is presented. The Ag nanoparticles displays an overpotential of 96 mV at 10 mA cm−2 and Tafel slope of 76.10 mV dec−1 for HER in acid medium, overwhelming the commercial Ag powder. Experimental and theoretical investigations reveal that the excellent catalytic activity arises from large exposed surface, abundant active sites, moderate adsorption energy for hydrogen, and low charge transfer resistance.
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