3D–2D–0D Interface Profiling for Record Efficiency All‐Inorganic CsPbBrI2 Perovskite Solar Cells with Superior Stability

All‐inorganic CsPbBrI₂ perovskite has great advantages in terms of ambient phase stability and suitable band gap (1.91 eV) for photovoltaic applications. However, the typically used structure causes reduced device performance, primarily due to the large recombination at the interface between the perovskite, and the hole‐extraction layer (HEL). In this paper, an efficient CsPbBrI₂ perovskite solar cell (PSC) with a dimensionally graded heterojunction is reported, in which the CsPbBrI₂ material is distributed within bulk–nanosheet–quantum dots or 3D–2D–0D dimension‐profiled interface structure so that the energy alignment is optimized in between the valence and conduction bands of both CsPbBrI₂ and the HEL layers. Specifically, the valence‐/conduction‐band edge is leveraged to bend with synergistic advantages: the graded combination enhances the hole extraction and conduction efficiency with effectively decreased recombination loss during the hole‐transfer process, leading to an enhanced built‐in electric field, hence a high V_OC of as much as 1.19 V. The profiled structure induces continuously upshifted energy levels, resulting in a higher J_SC of as much as 12.93 mA cm^?2 and fill factor as high as 80.5%, and therefore record power conversion efficiency (PCE) of 12.39%. As far as it is known, this is the highest PCE for CsPbBrI₂ perovskite‐based PSC.     

全球陆地保护地60年增长情况分析和趋势预测

保护地建设已成为全球生物多样性保护的第一道防线。掌握其在不同尺度上的发展状况和变化趋势对保护地规划和建设有重要意义。针对已有研究在时间跨度、空间尺度以及结果对比方面的不足, 本文基于世界保护地数据库(World Database of Protected Areas, http://www.protectedplanet.net), 对全球、洲际、地区及国家尺度1950-2013年陆地保护地的增长情况进行描述和短期预测。结果发现: (1)全球保护地增长速率不断加快, 特别是在20世纪90年代以后。(2)洲际和地区保护地发展大致呈现3种增长趋势: 在美洲及大洋洲, 多数地区的保护地增长速率一直在加快; 在亚洲和欧洲, 多数地区的发展高峰出现在20世纪80、90年代; 在非洲, 多数地区的发展高峰为20世纪70年代及21世纪前10年。(3)各国保护地建设存在不平衡性, 仍有近一半国家的陆地保护地比例小于10%, 但这种差距随时间的推移有缩小的趋势。(4)绝大部分保护地增速均匀性低的国家分布在非洲。(5)虽然全球的《爱知生物多样性目标》在2020年预计不能完成, 但包括中国在内的22个国家有望如期达到目标。本文结果为未来保护地规划和建设工作的开展提供了参考依据。     

(Z)-3-Hexenol Induces Tea Defense against Ectropis grisescens in the Field

Russian Journal of Plant Physiology - The tea geometrid Ectropis grisescens is an important pest of tea plant (Camellia sinensis (L.) O. Kuntze). It feeds on the new leaves and tender...     

Binding of genistein to human serum albumin demonstrated using tryptophan fluorescence quenching

Genistein is an isoflavone and phytoestrogen that is a potent inhibitor of cell proliferation and angiogenesis. This study was designed to investigate the binding of genistein to human serum albumin (HSA) under physiological conditions with drug concentrations in the range of 6.7 × 10⁻⁶ to 2.0 × 10⁻⁵ mol L⁻¹ and HSA concentration at 1.5 × 10⁻⁶ mol L⁻¹. Fluorescence quenching methods in combination with Fourier transform infrared (FT-IR) spectroscopy and circular dichroism (CD) spectroscopy was used to determine the binding mode, the binding constant and the protein structure changes in the presence of genistein in aqueous solution. Changes in the CD spectra and FT-IR spectra were observed upon ligand binding, and the degree of tryptophan fluorescence quenching change did significantly in the complexes. These data have proved the change in protein secondary structure accompanying ligand binding. The change in tryptophan fluorescence intensity was used to determine the binding constants. The thermodynamic parameters, the enthalpy change (ΔH) and the entropy change (ΔS) were calculated to be −22.24 kJ mol⁻¹and 19.60 J mol⁻¹ K⁻¹ according to the van’t Hoff equation, which indicated that hydrophobic and electrostatic interactions play the main role in the binding of genistein to HSA.     

Biochar’s effect on crop productivity and the dependence on experimental conditions—a meta-analysis of literature data

Background and aims

For the last decade, there has been an increasing global interest in using biochar to mitigate climate change by storing carbon in soil. However, there is a lack of detailed knowledge on the impact of biochar on the crop productivity in different agricultural systems. The objective of this study was to quantify the effect of biochar soil amendment (BSA) on crop productivity and to analyze the dependence of responses on experimental conditions.

Methods

A weighted meta-analysis was conducted based on data from 103 studies published up to April, 2013. The effect of BSA on crop productivity was quantified by characterizing experimental conditions.

Results

In the published experiments, with biochar amendment rates generally <30 t ha^?1, BSA increased crop productivity by 11.0 % on average, while the responses varied with experimental conditions. Greater responses were found in pot experiments than in field, in acid than in neutral soils, in sandy textured than in loam and silt soils. Crop response in field experiments was greater for dry land crops (10.6 % on average) than for paddy rice (5.6 % on average). This result, associated with the higher response in acid and sandy textured soils, suggests both a liming and an aggregating/moistening effect of BSA.

Conclusions

The analysis suggests a promising role for BSA in improving crop productivity especially for dry land crops, and in acid, poor-structured soils though there was wide variation with soil, crop and biochar properties. Long-term field studies are needed to elucidate the persistence of BSA’s effect and the mechanisms for improving crop production in a wide range of agricultural conditions. At current prices and C-trading schemes, however, BSA would not be cost-effective unless persistent soil improvement and crop response can be demonstrated.     

Delineating spatiotemporal and hierarchical development of human fetal innate lymphoid cells

Whereas the critical roles of innate lymphoid cells (ILCs) in adult are increasingly appreciated, their developmental hierarchy in early human fetus remains largely elusive. In this study, we sorted human hematopoietic stem/progenitor cells, lymphoid progenitors, putative ILC progenitor/precursors and mature ILCs in the fetal hematopoietic, lymphoid and non-lymphoid tissues, from 8 to 12 post-conception weeks, for single-cell RNA-sequencing, followed by computational analysis and functional validation at bulk and single-cell levels. We delineated the early phase of ILC lineage commitment from hematopoietic stem/progenitor cells, which mainly occurred in fetal liver and intestine. We further unveiled interleukin-3 receptor as a surface marker for the lymphoid progenitors in fetal liver with T, B, ILC and myeloid potentials, while IL-3RA^– lymphoid progenitors were predominantly B-lineage committed. Notably, we determined the heterogeneity and tissue distribution of each ILC subpopulation, revealing the proliferating characteristics shared by the precursors of each ILC subtype. Additionally, a novel unconventional ILC2 subpopulation (CRTH2^– CCR9⁺ ILC2) was identified in fetal thymus. Taken together, our study illuminates the precise cellular and molecular features underlying the stepwise formation of human fetal ILC hierarchy with remarkable spatiotemporal heterogeneity.Subject terms: Innate immunity, Haematopoietic stem cells     

Ptk2b deletion improves mice folliculogenesis and fecundity via inhibiting follicle loss mediated by Erk pathway

Ptk2b has been found playing critical roles in oocyte maturation and subsequent fertilization in vitro. But what is the exact in vivo function in reproduction still elusive. Here, by constructing Ptk2b mutant mice, we found Ptk2b was not essential for mice fertility, unexpectedly, contrary to previously reported in vitro findings, we found Ptk2b ablation significantly improved female fecundity. Follicle counting indicated that the number of primordial follicles and growing follicles in matured mice was significantly increased in the absence of Ptk2b, whereas the primordial follicle formation showed no defects. We also found this regulation was in an autophosphorylation independent pathway, as autophosphorylation site mutant mice (PTK2B^Y402F) show no phenotype in female fertility. Further biochemistry studies revealed that Ptk2b ablation promotes folliculogenesis via Erk pathway mediate follicle survival. Together, we found a novel biological function of Ptk2b in folliculogenesis, which could be potentially used as a therapeutic target for corresponding infertility.