最新刊期
卷 70 ， 期 5 ， 2024
- “据最新研究，重组蛋白疫苗在免疫原设计、蛋白表达纯化工艺等方面取得显著进展，具有广谱性、长效性等优势，为疫苗研发提供新思路。”摘要：Recombinant protein vaccines, obtained through gene engineering expression, offer strong immunogen design flexibility, single and controllable components, high biological safety, and mature large-scale amplification technology, making them the main type of new vaccines in recent years. In terms of immunogen design, technologies such as immunogen conjugation, engineering design, and immunogen reconstruction in recombinant protein vaccines can extend the vaccine’s broad-spectrum and long-lasting efficacy. Regarding expression and purification, various expression and purification processes can meet the requirements for immunogen modification, product yield, and quality in different recombinant protein vaccines. For large-scale production, multiple production processes such as cell reactors and cell factories have improved the yield of recombinant protein immunogens. This article reviews the types of recombinant protein vaccines, summarizes the progress in immunogen design, protein expression and purification processes, and highlights their advantages in terms of immunogenicity, protection, and safety. It also explores strategies and prospects for further optimization of recombinant protein vaccines, aiming to provide theoretical references for their future applications.关键词：viral infectious diseases;vaccine;recombinant protein vaccines;immunogen design;vaccines production technologies649|722|0更新时间：2024-10-11
- “杂交水稻育种技术取得重大进展，为粮食安全提供有力保障。”摘要：The invention of hybrid rice breeding technology is a significant milestone in the history of modern technology, making substantial contributions to global food security. This paper reviews the progress in hybrid rice breeding technology. It covers the first generation of hybrid rice using cytoplasmic male sterile lines, the second generation which employed environment-sensitive genic male sterile lines, then the third generation using genetically engineered male sterile lines, and the new generation that utilizes apomixis. The paper also discusses the application of different breeding technologies, analyzes the limitations of breeding work at this stage, and looks into the future direction of the exploitation of heterosis.关键词：hybrid rice;cytoplasmic male sterile lines;environment-sensitive genic male sterile lines;genetically engineered male sterile lines;apomixis1033|1762|0更新时间：2024-10-11
- “科技媒体新闻记者报道：研究人员合成了一种新型树形阳离子型铱（Ⅲ）配合物，具有高聚集诱导发光活性，成功用于潜指纹的可视化和检测。”摘要：Using 2-phenylpyridine (ppy) as main ligand and 4-(3,6-di-tert-butyl-9H-carbazol-9-yl)-N-(4-(3,6-di-tert-butyl- 9H-carbazol-9-yl)phenyl)-N-(4-(5-(pyridin-2-yl)-1,3,4-oxadiazol-2-yl)phenyl)aniline (CPPOA) as auxiliary ligand, a dendrimeric cationic iridium (Ⅲ) complex [(ppy)2Ir(CPPOA)]PF6 was synthesized. The complex showed high aggregation-induced emission (AIE) activity. The solutions of the complex in mixed solvents of CH3CN/H2O (1.0×10-5 mol/L) emitted orange-red light via photoluminescence (PL) when fw≥50% (fw: water fraction), and the PL intensities enhanced with the increasing of fw. Moreover, the quantum yields correspondingly increased from 2.6% (fw=50%) to 50.7% (fw=90%), and further increased to 54.7% in solid powders. It was successfully used for visualizing and detecting latent fingerprints via a simple powder dusting method, resultantly, the first, second, and third level fingerprint details all were clear and distinguishable.关键词：cationic iridium(Ⅲ) complex;latent fingerprint detection;aggregation-induced emission;photoluminescence530|331|0更新时间：2024-10-11
- “在柔性压电装置领域，研究人员通过优化静电纺丝工艺，制备出高β相含量的PVDF纳米纤维膜，显著提升了压电性能。”摘要：Polyvinylidene fluoride (PVDF) is an ideal material for the fabrication of flexible piezoelectric devices, and the preparation of PVDF nanofiber membranes with high β-phase content can significantly enhance their piezoelectric properties. This study focuses on the impact of the key electrospinning parameters on the morphology and piezoelectric performance of PVDF nanofiber membranes. The experimental findings reveal that the concentration of the polymer solution and the solvent composition significantly influence the rheological properties of the spinning solution. Furthermore, the electrospinning voltage, flow rate, and collection device dictate the morphological transformation and deposition process of the spinning solution within the electric field. Optimal fiber morphology and the highest β-phase content (63.65%), along with excellent piezoelectric performance characterized by an output voltage of 2.2 V, were achieved when utilizing a mixed solvent of DMF and acetone with a mass ratio of 6∶4, a 12% mass fraction of PVDF powder, an electrospinning voltage of 18 kV, a spinning solution flow rate of 0.4 mL/h, and a 5 cm diameter drum as the collection device. This research not only provides detailed parameter guidance for the preparation of PVDF nanofiber membranes but also furnishes significant scientific evidence and technical support for their application in high-performance piezoelectric devices.关键词：piezoelectric nanofiber membrane;polyvinylidene fluoride (PVDF);electrospinning1029|1659|0更新时间：2024-10-11
- “最新研究采用溶胶凝胶法制备富锂锰基正极材料，通过表面改性显著提升其电化学性能。”摘要：A lithium-rich manganese-based cathode material of Li1.2Mn0.54Co0.13Ni0.13O2 (LMO) was prepared by using sol-gel method. Subsequently, surface modification of LMO is achieved through S2- doping and Cu9S5 coating using thioacetamide and copper nitrate as raw materials, via a solvothermal process combined with high-temperature calcination. The results indicate that substituting O2- with S2-, which has a weaker electronegativity and larger ionic radius, can induce oxygen vacancies in the LMO structure and adjust the electronic cloud distribution of transition metal elements within the structure. The high electronic conductivity of the Cu9S5 coating layer effectively alleviates the issues caused by S2- doping and suppresses interfacial side reactions. After modification, the lithium-rich manganese-based cathode material with 1% Cu9S5 coating and S2- doping (1%CS@LMOS) exhibits the highest initial discharge specific capacity (290.6 mAh /g) and initial Coulombic efficiency (84.07%), excellent rate performance (151 mAh/g at 5 C) and cycling stability (92.76%, capacity retention after 100 cycles at 1 C). In addition, the apparent lithium ion diffusion rate of 1%CS@LMOS during charge and discharge processes is significantly higher than that of the unmodified material. This modification method effectively improves the electrochemical performance of lithium-rich manganese-based cathode materials.关键词：lithium ion batteries;manganese-based cathode material;electrochemical performance;coating;doping;modification638|246|0更新时间：2024-10-11
- “在氢气吸附存储领域，研究人员利用超声辅助磷酸活化技术制备了一种粘胶基磷氧共掺杂活性碳纤维，实现了氢气物理/化学协同吸附，质量储氢密度达到2.19%。”摘要：Based on the low-cost viscose fiber precursors produced in industrial production, a P, O co-doped viscose-based activated carbon fiber was prepared using ultrasonic-assisted phosphoric acid activation technology, which achieving synchronous construction of nanopores and surface chemical structure during the activation process. The specific surface area and total pore volume of activated carbon fibers treated by 15% phosphoric acid reached 1 184.51 m2/g and 0.60 cm3/g, respectively. The surface oxygen and phosphorus atom relative percentages reached 15.25% and 0.99%, respectively. The research results indicate that its coupling effect of rich nanopore structure and oxygen/phosphorus surface groups enable the physical/chemical synergistic adsorption of hydrogen gas. This material achieves a mass hydrogen storage density of 2.19% under ambient conditions of 77 K and 100 kPa. Hydrogen adsorption of this activated carbon fiber belongs to a typical Type Ⅰ adsorption, and the fitting analysis results prove that the Langmuir (N=3) model, which divides the nanopore interface into three categories of non-polar, weakly polar and strongly polar, has the best fitting effect on the hydrogen adsorption process under atmospheric pressure conditions.关键词：carbon materials;hydrogen storage technology;hydrogen energy;nanopore structure;surface chemical structure496|147|0更新时间：2024-10-11
- “最新研究揭示了生理环境下4-羟基脯氨酸与羟基自由基的反应机制，为消除自由基提供了新思路。”摘要：The reaction mechanism of 4-hydroxyproline (4-Hyp) and hydroxyl radical (OH·) was studied by using M06-2X and MN15 methods of density functional theory, combined with SMD model method to deal with aqueous solvent effect under physiological environment (310.15 K， 1.013×105 Pa， aqueous liquid phase). It is found that the reaction of OH· and 4-Hyp has three channels: H extraction, unsaturated C addition and single electron transfer. The theoretical calculation shows that the H extraction reaction has significant advantages. The H extraction energy barrier of OH· and 4-Hyp ranges from 5.3 to 36.0 kJ/mol, and the reaction is accompanied by exothermic effect (the process allowed by thermodynamics). The energy barrier of OH· addition to 4-Hyp unsaturated C is 77.7 kJ/mol, and the reaction is weakly endothermic. The energy barrier of 4-Hyp single electron transfer to OH· is 248.5 kJ/mol. The results show that 4-Hyp can easily eliminate OH· radical by providing H atom in physiological environment.关键词：hydroxyproline;hydroxyl radical;density functional theory (DFT);self-consistent reaction field theory;transition state;electron transfer;free energy barrier502|271|1更新时间：2024-10-11
- “全球变暖加剧水循环，未来洪水风险增加。专家预测，高排放路径下，全球近20%陆地将出现极端洪水，中值年份为2048年；低排放路径下，占比降至10.6%，中值年份为2067年。”摘要：Global warming induced by greenhouse gas emissions will lead to the intensification of the water cycle and the increase of flood risk. It is of great significance to quantify the differences in the evolution of future floods and the time of emergence (TOE) of extreme floods under different emission scenarios. Using the annual maximum daily runoff as the flood indicator, we investigated the changes in future floods under different Shared Socioeconomic Pathways (SSPs), predicted the TOE of extreme floods based on Bootstrap, and developed an attribution framework to explore the dominant factors of future flood changes. The results showed that under the high-emission fossil fuel development pathway (SSP5-8.5), 19.7% of the global landmass (except Antarctica, Greenland, and desert regions) would experience extreme floods, with a median TOE of 2048; while under the low-emission sustainable development pathway (SSP1-2.6), the share of the global region experiencing extreme floods would decrease to 10.6%, and the median TOE would be delayed to 2067. Extreme floods were likely to occur in northern North America, eastern Russia, the Qinghai-Xizang Plateau in China, etc. Rainfall played a dominant role in flood changes in most basins, with a predominantly positive contribution to flood changes. The results suggest that only by effectively controlling greenhouse gas emissions and delaying global warming can the emergence of extreme floods be reduced and delayed.关键词：extreme floods;water cycle;global warming;water resources;extreme weather;quantitative attribution;greenhouse gas334|376|0更新时间：2024-10-11
- “长江武汉段船舶大气污染物排放量研究显示，普通货船排放量最高，1月、8月和9月为高峰期。”摘要：This study took Wuhan section of the Yangtze River as the research area, and established the typical air pollutants emissions inventory of ships in 2019. Two methods were adopted for the calculation of emissions, which were based on automatic identification system （AIS） data and ship turnover amount respectively. It was found that the former estimation results were more in line with the real situation of Wuhan. The emissions of SO2, NOx, CO, PM10, PM2.5 and VOCs from ships are 183.0, 12 003.5, 1 727.0, 1 505.2, 1 442.0 and 359.6 t respectively. The proportion of pollutant emissions from ordinary cargo ships is the highest, with SO2, NOx, CO, PM10, PM2.5, and VOCs accounting for 92.9%, 90.8%，94.7%, 85.1%, 85.0%, and 87.6% of the total emissions from ships, respectively. January, August and September are the peak periods for ship pollutants emissions.关键词：ship pollution;Yangtze River;atmospheric pollutants;emission inventory125|616|1更新时间：2024-10-11
- “在农业废弃物处理领域，研究者利用玉米秸秆制备草木灰和生物炭，发现生物炭能显著提高土壤对草甘膦的吸附能力，为土壤修复提供新思路。”摘要：Corn straw ash (CSA) and corn straw biochar (CSB) were produced from agricultural waste corn straw through natural incineration and oxygen separation pyrolysis techniques. CSA and CSB were added to the soil (S) at a mass fraction of 1% to form S-CSA and S-CSB, respectively. A comprehensive investigation was conducted to analyze the adsorption performances and mechanisms of glyphosate by absorbents (S, S-CSA, S-CSB). The results show that the adsorption capacity of glyphosate by S-CSA decreases, while the adsorption capacity of glyphosate by S-CSB increases compared with S. Notably, the adsorption capacity of S-CSB is 15.22 times as higher as that of S-CSA by the same mass of corn straw, and the return of corn straw to the field in the form of biochar is more conducive to the adsorption of glyphosate by the soil. The adsorption processes of glyphosate by adsorbents conform to the quasi-second-order kinetic model and Langmuir monolayer chemisorption model, and the adsorption process is spontaneous and endothermic. The increase in glyphosate adsorption by S-CSB is due to the amplified specific surface area and oxygen-containing functional groups. In contrast, the decrease in glyphosate adsorption by S-CSA is attributed to the enhancement of electrostatic repulsion and phosphate competition.关键词：glyphosate;straw return;straw ash;biochar;adsorption133|211|0更新时间：2024-10-11
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Effect of Snailase on the Bioactivity of Ethanol Extracts from
Ziziphus jujuba var.spinosa Leaves AI导读“在食品科学领域，研究人员采用蜗牛酶对酸枣叶醇提物进行酶解，发现酶解后样品具有更好的抗氧化和神经保护活性。”摘要：The enzymatic hydrolysis of the ethanol extracts from Ziziphus jujuba var. spinosa leaves was carried out by snailase. In order to reveal the effect of snailase on the biological activity of the extracts, the differences of in vitro and in vivo activities of the samples before and after enzymatic hydrolysis were compared. And the composition changes were analyzed by ultra performance liquid chromatography-mass spectrometry (UPLC-MS). The results showed that the enzymatic hydrolyzed ethanol extracts of Ziziphus jujuba var. spinosa leaves had better antioxidant activity both in vitro and in vivo, and had significant neuroprotective effect. UPLC-MS analysis and Spearman correlation analysis showed that enzymatic hydrolysis mainly affected the content of flavonoids, organic acids, phenylpropanes, carbohydrates and other compounds. The biological activity was positively correlated with the content of flavonoid aglycones, dihydroxybenzoic acid, simple phenylpropanoids and saccharic acid. It is speculated that snailase can increase the content of active ingredients by breaking the glucoside bonds of compounds in Ziziphus jujuba var. spinosa leaves, so as to improve the biological activity.关键词：Ziziphus jujuba var. spinosa leaves;enzymatic hydrolysis;antioxidant activity;neuroprotection128|125|0更新时间：2024-10-11 - “最新研究发现，槟榔碱能显著提高小鼠运动耐力，降低代谢产物堆积，缓解肌糖原和肝糖原耗竭，增强血脑屏障通透性，发挥抗疲劳作用。”摘要：The animal behavioral sensitization model was constructed to analyze the effects of arecoline on exercise tolerance，metabolite accumulation, oxygen transport protein levels, liver glycogen, muscle glycogen, malondialdehyde (MDA) levels of muscles and liver tissues, the level of central neurotransmitters, and blood-brain barrier (BBB) permeability in swimming mice, and the synergistic effects of sensitization treatment and different administration routes (oral sustained-release and gavage) on the anti-fatigue activity of arecoline were explored. The results show that arecoline can prolong the exhaustive swimming time of mice, among which the group of oral sustained-release administration and behavioral sensitization was extremely significant longer than that of other groups (P<0.01). Arecoline exerts anti-fatigue effects by effectively reducing the accumulation of metabolite such as blood lactate, MDA and blood urea nitrogen in swimming mice, alleviating the decrease in hemoglobin (Hb) and dopamine (DA) levels, inhibiting the depletion of muscle glycogen and liver glycogen, hindering the increase in the ratio of 5-hydroxytryptamine (5-HT) to DA in the brain, enhancing the permeability of BBB, and reducing the inhibition of 5-HT on the excitatory of brain. The above indicators of the sensitized mice can be improved by oral sustained-release administration, indicating that chewing areca nut can better exert the anti-fatigue activity.关键词：arecoline;blood-brain barrier;fatigue;neurotransmitter;behavioral sensitization249|293|0更新时间：2024-10-11
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