The global escalation of soil salinization has led to increased water erosion, adversely impacting plant growth and development. Heat shock proteins (HSPs) are highly conserved proteins found across a wide range of organisms. When biological organisms are stimulated by the external environment, they will express themselves in large quantities. HSPs play a pivotal role in mediating plant responses to abiotic stress. This study identified 22 members of the PcHsp20 gene family with complete open reading frames (ORFs) through transcriptomic analysis conducted under Pugionium cornutum salt stress, and evaluated their expression levels. Notably, PcHsp18.1 was significantly upregulated in the leaves of Pugionium cornutum (L.) Gaertn. Based on this, we cloned the PcHsp18.1 gene and determined through subcellular localization that PcHsp18.1 is localized in both the cytoplasm and nuclear membrane. Subsequently, we transformed the PcHsp18.1 gene into Arabidopsis thaliana to investigate its involvement in the response to salt stress. The results indicated that the overexpressing (OE) plants exhibited improved growth conditions, higher seed germination rates, increased root lengths, a greater number of lateral roots, reduced relative conductivity, and elevated relative chlorophyll content compared to the wild-type (WT) plants. These findings suggesting that the transgenic line possesses enhanced salt tolerance. Moreover, the concentrations of malondialdehyde (MDA) and relative conductivity in the overexpressing (OE) plants were significantly lower than those observed in the wild-type (WT) plants, suggesting a reduced extent of damage to their cell membranes. In comparison to the wild type (WT), the transgenic line (OE) exhibited elevated activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), along with increased proline content, suggesting that the transgenic plants possess enhanced resistance to abiotic stress and a greater capacity for scavenging reactive oxygen species (ROS). Meanwhile, salt treatment resulted in the significant expression of stress-related genes in the transgenic plants. These results indicate that PcHsp18.1 positively regulates salt stress in Arabidopsis.

Under environment with various water contents, the variations in the mixing state and particle size of coated black carbon (BC) aerosols cause changes in optical and radiative effects. In this study, fractal models for thinly, partially, and thickly coated BC under six relative humidities (RHs 1/4 0-95%) are constructed and optically simulated at 1064 and 532 nm. Differential scattering cross-sections are selected to retrieve the mixing state (Dp/Dc) of BC to investigate the possible retrieval errors caused by the nonspherical morphology when using the single-particle soot photometer (SP2). Furthermore, the radiative forcing of BC aerosols at different RHs are analyzed. Results showed that the retrieval errors (REs) of Dp/Dc are negative for coated particles with BC volume fraction smaller than 0.10, indicating that the mixing states of coated fractal BC are underestimated during the hygroscopic growth. The partiallycoated BC has the best retrieval accuracy of the mixing state, followed by the closed-cell and coatedaggregate model, judging from averaged REs. Radiative forcing enhancements for partially-coated aerosols with different BC volume fractions exponentially increase to opposite values, resulting in a warming or cooling effect. This study helps understand the uncertainties in Dp/Dcof BC aerosols retrieved by SP2 and their radiative forcing at different RHs. (c) 2025 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

PurposeAcanthamoeba species are eucaryotic protozoa found predominantly in soil and water. They cause ulceration and vision loss in the cornea (Acanthamoeba keratitis) and central nervous system (CNS) infection involving the lungs (granulomatous amoebic encephalitis). Antiparasitic drugs currently used in the treatment of infections caused by Acanthamoeba species are not effective at the desired level in some anatomical regions such as the eye and CNS. The existence of an agent effective against both cysts and trophozoites has not yet been proven. Drugs used for treatment of Acanthamoeba infrections are still limited.MethodThe present study investigates amoebicidal activites of various concentrations of ethanolic fruit extract of E. umbellata (EU) (40, 20, 10, 5, 2.5, 1.25, 0.625 mM/mL), silver nanoparticles (AgNP) that are synthesized from EU and confirmed with characterization tests (20, 10, 5, 1, 0.5 mM/mL), and lauric acid (LA) in EU detected with gas chromatography-mass spectrometry (GC-MS) against A. castellanii trophozoites. In addition, DNA-preserving activities of EU, AgNP and LA were studied on pBR322 plasmid DNA, following damage induced with hydroxyl radical (-OH). Cytotoxicity of EU over HeLa cells was examined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Furthermore, the effects over the expression of SOD and CAT genes, which are coding oxidative stress enzymes in trophozoites, and expression of genes responsible for pseudocyst and cyst formation (CSII and CSP21, respectively) were investigated following methanol-induced stress, with reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR).ResultsAt highest concentrations, EU, AgNP and LA showed lethal effects against majority of trophozites at 24 th h and against all trophozoites at 48th hour. EU at 5 mg/mL concentration and LA at 1, 0.8, 0.6, 0.4 mM/mL concentrations prevented DNA damage. A dose-dependent decrease in cell viability was observed, EU was found to be non-cytotoxic for 53.82% of HeLa cells at 72 nd h even at 40 mg/mL concentration. Greatest inhibitory effects were found with EU, AgNP and LA on CSII, EU on CAT, LA on CSP21, and hydrogen peroxide (H2O2) on SOD genes.ConclusionThe findings of this study show that EU, LA and AgNPs can be used in a controlled manner to combat A. castellanii infections by reducing or blocking the activity of the parasite's antioxidant enzymes (SOD and CAT), without giving the parasite a chance to initiate the process of pseudocyst or proper cyst formation.

Ground vibrations caused by soil-structure (SSI) can be magnified or de-amplified, and estimating them is essential for seismic designs and fragility assessments. Field survey reports show that SSI is an important factor causing severe damage to structural elements, especially in soft soils that have been exposed to an earthquake. The soil-structure interaction (SSI) is widely ignored, or drastically simplified, in most conventional seismic fragility assessments of RC structures. This paper presents a probabilistic approach for assessing the effects of soilstructure interaction (SSI) on the seismic response of mid -rise (four story) RC frame structures, by seismic fragility curves. RC frame response is evaluated by Static Pushover 2 Incremental Dynamic Analysis (SPO2IDA). Two basic models of typical residential buildings are modeled, without SSI (fixed base) and with SSI, and an elastic model is used to simulate linear soil behavior. The ultimate displacement results demonstrate the contrast between two cases: one with a rigid base and no soil-structure interaction (SSI), and the other involving a structure with SSI, considering different soil types including S1 (rock), S2 (stiff), S3 (soft), and S4 (very soft). The ratio of ultimate displacement between a rigid base and a structure with SSI for soil types S1, S2, S3, and S4 is 4%, 19%, 25%, and 46%, respectively. The results also demonstrate that the design of short-period frame structures (rigid structures) founded on soft soils (S3 and S4), and not taking into account the effect of soil-structure interaction (SSI) when modeling and designing, leads to a greater probability of damage and makes the structure more vulnerable in the event of a large earthquake.

青藏高原冰川蕴含了丰富的历史环境变化信息。通过青藏高原冰芯钻取及环境指标分析，可在季节至万年时间尺度上重建高分辨率环境变化历史。黑碳气溶胶来源于生物和化石燃料燃烧排放，对光具有强烈的吸收作用，是气候环境变化的敏感因子之一。准确测量冰芯中的黑碳粒子浓度，是恢复其排放历史、评估其气候环境效应的必要手段。单颗粒黑碳光度计(Single Particle Soot Photometer, SP2)是近些年发展起来的用于雪冰样品中黑碳测量的主要方法之一，能够获得准确的黑碳浓度信息。近10年来，实验室开展了大量的冰芯黑碳样品测量，从野外冰芯钻取、样品前处理、仪器原理及测试、黑碳数据处理等全过程对SP2在青藏高原冰芯黑碳研究中的应用与问题进行了全面系统的阐述。同时，将SP2与热光学(Thermal-optical method)等测试方法进行对比，强调了SP2对冰芯黑碳样品研究的可靠性，并对未来黑碳研究的进一步发展作出了展望。

青藏高原冰川蕴含了丰富的历史环境变化信息。通过青藏高原冰芯钻取及环境指标分析，可在季节至万年时间尺度上重建高分辨率环境变化历史。黑碳气溶胶来源于生物和化石燃料燃烧排放，对光具有强烈的吸收作用，是气候环境变化的敏感因子之一。准确测量冰芯中的黑碳粒子浓度，是恢复其排放历史、评估其气候环境效应的必要手段。单颗粒黑碳光度计(Single Particle Soot Photometer, SP2)是近些年发展起来的用于雪冰样品中黑碳测量的主要方法之一，能够获得准确的黑碳浓度信息。近10年来，实验室开展了大量的冰芯黑碳样品测量，从野外冰芯钻取、样品前处理、仪器原理及测试、黑碳数据处理等全过程对SP2在青藏高原冰芯黑碳研究中的应用与问题进行了全面系统的阐述。同时，将SP2与热光学(Thermal-optical method)等测试方法进行对比，强调了SP2对冰芯黑碳样品研究的可靠性，并对未来黑碳研究的进一步发展作出了展望。

青藏高原冰川蕴含了丰富的历史环境变化信息。通过青藏高原冰芯钻取及环境指标分析，可在季节至万年时间尺度上重建高分辨率环境变化历史。黑碳气溶胶来源于生物和化石燃料燃烧排放，对光具有强烈的吸收作用，是气候环境变化的敏感因子之一。准确测量冰芯中的黑碳粒子浓度，是恢复其排放历史、评估其气候环境效应的必要手段。单颗粒黑碳光度计(Single Particle Soot Photometer, SP2)是近些年发展起来的用于雪冰样品中黑碳测量的主要方法之一，能够获得准确的黑碳浓度信息。近10年来，实验室开展了大量的冰芯黑碳样品测量，从野外冰芯钻取、样品前处理、仪器原理及测试、黑碳数据处理等全过程对SP2在青藏高原冰芯黑碳研究中的应用与问题进行了全面系统的阐述。同时，将SP2与热光学(Thermal-optical method)等测试方法进行对比，强调了SP2对冰芯黑碳样品研究的可靠性，并对未来黑碳研究的进一步发展作出了展望。