从祁连山圆柏（Sabina przewalskii Kom.）年轮的测定推论该地区气候和冰川变化的趋势

 本文的二份圆柏年轮标本,均采自祁连山。 根据圆柏年轮资料,分析了祁连山地区900年温度变化和近300年的降水量变化。 根据同一时期的温度和降水最组合状况,阐明祁连山地区近300年冰川有过二次前进和三次退缩。     

Irradiation of the bovine mitochondrial F1-ATPase previously inactivated with 5'-p-fluorosulfonylbenzoyl-8-azido-[3H]adenosine cross-links His-beta 427 to Tyr-beta 345 within the same beta subunit.

The bovine heart mitochondrial F1-ATPase (MF1) is inactivated by 5'-p'-fluorosulfonylbenzoyl-8-azidoadenosine (8-N3-FSBA) with an apparent Kd of 0.47 mM at pH 8.0 and 23 degrees C in the absence of light. Irradiation of dark-inactivated enzyme with long-wavelength UV light produced cross-linked dimers and, to a lesser extent, trimers made up of alpha and beta subunits. Two major radioactive peptides were resolved by high-performance liquid chromatography from tryptic digests of MF1 which had been inactivated with 8-N3-FSB[3H]A at pH 8.0 in the dark. Sequence analysis revealed that one contained Tyr-beta 368 and the other contained His-beta 427 which were labeled in the ratio of 18:15. Sequence analysis of radioactive tryptic peptides isolated from digests of irradiated MF1 derivatized with 8-N3-FSB[3H]A showed that photolysis induced cross-linking of His-427 to Tyr-345 within the same beta subunit in high yield. When MF1 derivatized with 8-N3-FSB[3H]A was irradiated in the presence of beta-mercaptoethanol, alpha-beta cross-links were eliminated, whereas those between His-beta 427 and Tyr-beta 345 were unaffected. Analysis of radioactive peptides in tryptic digests of MF1 derivatized with 8-N3-FSB[3H]A and then irradiated in the presence or absence of beta-mercaptoethanol showed that the nitrene generated from reagent attached to Tyr-beta 368 participates in formation of alpha-beta cross-links in the absence of beta-mercaptoethanol. Therefore, the nitrene generated from reagent tethered to His-beta 427 is shielded from solvent and reacts with the side chain of Tyr-beta 345. In contrast, the nitrene generated from reagent attached to Tyr-beta 368 is exposed to solvent, but in the absence of scavengers reacts with side chains present in the alpha subunit. Irradiation of MF1, partially inactivated with 8-N3-FSBA, led to loss of residual ATPase activity without affecting residual ITPase activity. The amount of photoinactivation was greater when partial dark inactivation was performed at pH 6.9, where modification of His-beta 427 predominates, than when performed at pH 8.0, where modification of Tyr-beta 368 predominates. This suggests that cross-linking of His-beta 427 to Tyr-beta 345, and not cross-linking of alpha and beta subunits, is responsible for the augmented inactivation induced by irradiation.     

FDPS promotes glioma growth and macrophage recruitment by regulating CCL20 via Wnt/β‐catenin signalling pathway

Glioma is one of the most lethal tumours and common malignant in the central nervous system (CNS), which exhibits diffuse invasion and aggressive growth. Several studies have reported the association of FDPS to tumour development and progression. However, the role of FDPS in progression of glioma and macrophage recruitment is not well‐elucidated. In the current study, a remarkable enhancement in FDPS level was observed in glioma tissues and associated with poor prognosis, contributed to tumour growth. FDPS was correlated with macrophage infiltration in glioma and pharmacological deletion of macrophages largely abrogated the oncogenic functions of FDPS in glioma. Mechanistically, FDPS activated Wnt/β‐catenin signalling pathway and ultimately facilitates macrophage infiltration by inducing CCL20 expression. In conclusion, overexpressed FDPS exhibits an immunomodulatory role in glioma. Therefore, targeting FDPS may be an effective therapeutic strategy for glioma.     

Association between METTL3 gene polymorphisms and neuroblastoma susceptibility: A nine‐centre case‐control study

Neuroblastoma ranks as the most commonly seen and deadly solid tumour in infancy. The aberrant activity of m⁶A‐RNA methyltransferase METTL3 is involved in human cancers. Therefore, functional genetic variants in the METTL3 gene may contribute to neuroblastoma risk. In the current nine‐centre case‐control study, we aimed to analyse the association between the METTL3 gene single nucleotide polymorphisms (SNPs) and neuroblastoma susceptibility. We genotyped four METTL3 gene SNPs (rs1061026 T>G, rs1061027 C>A, rs1139130 A>G, and rs1263801 G>C) in 968 neuroblastoma patients and 1814 controls in China. We found significant associations between these SNPs and neuroblastoma risk in neither single‐locus nor combined analyses. Interestingly, in the stratified analysis, we observed a significant risk association with rs1061027 AA in subgroups of children ≤ 18 months of age (adjusted OR = 1.87, 95% CI = 1.03‐3.41, P = .040) and females (adjusted OR = 1.86, 95% CI = 1.07‐3.24, P = .028). Overall, we identified a significant association between METTL3 gene rs1061027 C>A polymorphism and neuroblastoma risk in children ≤18 months of age and females. Our findings provide novel insights into the genetic determinants of neuroblastoma.     

Boosting Polysulfide Redox Kinetics by Graphene‐Supported Ni Nanoparticles with Carbon Coating

Lithium–sulfur batteries have attracted extensive attention because of their high energy density. However, their application is still impeded by the inherent sluggish kinetics and solubility of intermediate products (i.e., polysulfides) of the sulfur cathode. Herein, graphene‐supported Ni nanoparticles with a carbon coating are fabricated by directly carbonizing a metal–organic framework/graphene oxide composite, which is then dispersed on a commercial glass fiber membrane to form a separator with electrocatalytic activity. In situ analysis and electrochemical investigation demonstrate that this modified separator can effectively suppress the shuttle effect and regulate the catalytic conversion of intercepted polysulfides, which is also confirmed by density functional theory calculations. It is found that Ni–C sites can chemically interact with polysulfides and stabilize the radical S₃^?? through Ni? S bonds to enable fast dynamic equilibrium with S₆^2?, while Ni nanoparticles reduce the oxidation barrier of Li₂S and accelerate ion/electron transport. As a result, the corresponding lithium–sulfur battery shows a high cycle stability (88% capacity retention over 100 cycles) even with a high sulfur mass loading of 8 mg cm^?2 and lean electrolyte (6.25 µ L mg^?1). Surprisingly, benefitting from the improved kinetics, the battery can work well at ?50 °C, which is rarely achieved by conventional Li–S batteries.     

Conductive Hole‐Selective Passivating Contacts for Crystalline Silicon Solar Cells

Defect state passivation and conductivity of materials are always in opposition; thus, it is unlikely for one material to possess both excellent carrier transport and defect state passivation simultaneously. As a result, the use of partial passivation and local contact strategies are required for silicon solar cells, which leads to fabrication processes with technical complexities. Thus, one material that possesses both a good passivation and conductivity is highly desirable in silicon photovoltaic (PV) cells. In this work, a passivation‐conductivity phase‐like diagram is presented and a conductive‐passivating‐carrier‐selective contact is achieved using PEDOT:Nafion composite thin films. A power conversion efficiency of 18.8% is reported for an industrial multicrystalline silicon solar cell with a back PEDOT:Nafion contact, demonstrating a solution‐processed organic passivating contact concept. This concept has the potential advantages of omitting the use of conventional dielectric passivation materials deposited by costly high‐vacuum equipment, energy‐intensive high‐temperature processes, and complex laser opening steps. This work also contributes an effective back‐surface field scheme and a new hole‐selective contact for p‐type and n‐type silicon solar cells, respectively, both for research purposes and as a low‐cost surface engineering strategy for future Si‐based PV technologies.     

Rice stripe virus coat protein induces the accumulation of jasmonic acid,activating plant defence against the virus while also attracting its vector to feed

The jasmonic acid (JA) pathway plays crucial roles in plant defence against pathogens and herbivores. Rice stripe virus (RSV) is the type member of the genus Tenuivirus. It is transmitted by the small brown planthopper (SBPH) and causes damaging epidemics in East Asia. The role(s) that JA may play in the tripartite interaction against RSV, its host, and vector are poorly understood. Here, we found that the JA pathway was induced by RSV infection and played a defence role against RSV. The coat protein (CP) was the major viral component responsible for inducing the JA pathway. Methyl jasmonate treatment attracted SBPHs to feed on rice plants while a JA-deficient mutant was less attractive than wild-type rice. SBPHs showed an obvious preference for feeding on transgenic rice lines expressing RSV CP. Our results demonstrate that CP is an inducer of the JA pathway that activates plant defence against RSV while also attracting SBPHs to feed and benefitting viral transmission. This is the first report of the function of JA in the tripartite interaction between RSV, its host, and its vector.