Mapping annual 10-m soybean cropland with spatiotemporal sample migration.

China, as the world's biggest soybean importer and fourth-largest producer, needs accurate mapping of its planting areas for global food supply stability. The challenge lies in gathering and collating ground survey data for different crops. We proposed a spatiotemporal migration method leveraging vegetation indices' temporal characteristics. This method uses a feature space of six integrals from the crops' phenological curves and a concavity-convexity index to distinguish soybean and non-soybean samples in cropland. Using a limited number of actual samples and our method, we extracted features from optical time-series images throughout the soybean growing season. The cloud and rain-affected data were supplemented with SAR data. We then used the random forest algorithm for classification. Consequently, we developed the 10-meter resolution ChinaSoybean10 maps for the ten primary soybean-producing provinces from 2019 to 2022. The map showed an overall accuracy of about 93%, aligning significantly with the statistical yearbook data, confirming its reliability. This research aids soybean growth monitoring, yield estimation, strategy development, resource management, and food scarcity mitigation, and promotes sustainable agriculture.

Superhardness in nanotwinned boron carbide: a molecular dynamics study.

Boron carbide ceramics are often considered ideal materials for lightweight bulletproof armor, but their anomalous brittle failure at hypervelocity impact limits their use. Recent experiments have reported that nanotwins are ubiquitous in boron carbide and that nanotwinned samples are harder than the twin-free boron carbide, but although the strengthening effect of nanotwins on metals and alloys is well-established, their role in boron carbide ceramics is not well understood. In this study, we used classical molecular dynamics simulations to investigate how nanoscale twins affect the mechanical properties of boron carbide ceramics. Our classical molecular dynamics results show that introducing nanotwins in boron carbide can increase the shear strength limit by 19.72%, reduce the number of amorphized atoms, and narrow the width of the amorphous shear band. Under indentation load, nanotwins can also increase the compressive shear strength limit of boron carbide by 15.97% and change the crystal formation direction and region of the amorphous shear band. These findings suggest that twin boundaries can hinder the expansion of the amorphous shear band and provide a new design idea for improving the impact resistance of boron carbide ceramics and avoiding their abnormal brittle failure.

Platelet-Membrane-Coated Polydopamine Nanoparticles for Neuroprotection by Reducing Oxidative Stress and Repairing Damaged Vessels in Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) has a high morbidity and mortality rate. Excessive reactive oxygen species (ROS) caused by primary and second brain injury can induce neuron death and inhibit neurological functional recovery after ICH. Therefore, exploring an effective way to noninvasively target hemorrhage sites to scavenge ROS is urgently needed. Inspired by the biological function of platelets to target injury vessel and repair injury blood vessels, platelet-membrane-modified polydopamine (Menp@PLT) nanoparticles are developed with targeting to hemorrhage sites of ICH. Results demonstrate that Menp@PLT nanoparticles can effectively achieve targeting to the location of intracranial hematoma. Furthermore, Menp@PLT with excellent anti-ROS properties can scavenge ROS and improve neuroinflammation microenvironment of ICH. In addition, Menp@PLT may play a role in decreasing hemorrhage volume by repairing injury blood vessels. Combining platelet membrane and anti-ROS nanoparticles for targeting brain hemorrhage sites provide a promising strategy for efficiently treating ICH.

Study on the mechanism of urban morphology on river cooling effect in severe cold regions.

In the context of global warming, urban climate problems such as heat waves, urban heat islands and air pollution are becoming increasingly prominent, and the cooling effect of rivers is an effective way to mitigate urban hot climate. This study investigates the surrounding urban area of the Hun River in Shenyang, a severe cold region of China, by calculating satellite inversion surface temperature and urban morphology data, and explores the cooling effect of rivers using linear regression models and spatial regression models. The results show that (1) water bodies have a cooling effect on the surrounding environment, with the farthest cooling distance being 4,000 m, but the optimal cooling distance being 2,500 m. (2) In the results of the spatial regression model analysis, the R 2 value stays above 0.7 in the range of 0-4,000 m, indicating that urban morphological factors are closely related to LST (land surface temperature). The negative correlation is most pronounced for NVDI (normalized vegetation index), with a peak of -14.8075 calculated by the regression model, and the positive correlation is most pronounced for BD (building density), with a peak of 8.5526. (3) The urban thermal environment can be improved and the heat island effect mitigated through measures such as increasing urban vegetation cover and reducing building density, and these findings can provide data references and case studies to support urban planning and development departments.

Spatial differences in thermal comfort in summer in coastal areas: A study on Dalian, China.

Thermal comfort is an important indicator for evaluating the environment of urban public space, and appropriate thermal comfort can effectively prolong the duration of outdoor activities. In the existing studies, there is a lack of thermal comfort comparison between hot spots and cold spots. In this study, we selected the coastal city of Dalian in China as our study area and conducted field investigations on the thermal comfort of two landmark resorts, namely, a downtown commercial street and coastal leisure park. The study was conducted on typical summer days and consisted of interviewing several residents to understand their thermal comfort requirements. We investigated the thermal expectations of the interviewees through meteorological measurements and questionnaires. The universal thermal climate index (UTCI) was used to determine the thermal benchmarks of the on-site subjects. The results indicated that (1) globe temperature and air temperature were the most important factors that affected thermal comfort, followed by relative humidity and wind speed in summer daytime. (2) Shaded spaces are more comfortable than open spaces, and tree shade is preferred over artificial shade in coastal park. (3) The neutral UTCI (NUTCI) of the respondents were 24.1°C (coastal park) and 26.0°C (commercial street); the neutral UTCI ranges (NUTCIR) were 20.8-27.4°C (coastal park) and 23.3-28.7°C (commercial street). (4) The upper thermal acceptable range limits of the coastal park and commercial street were 30.2 and 32.1°C, respectively, which were substantially higher than the upper NUTCIR limit, indicating that the residents in Dalian were well-adapted to hot weather. The results can provide a good reference for determining ideal design strategies to optimize the thermal environment of urban outdoor recreation spaces in summers and improve the quality of life in coastal cities.

High Emotional Similarity Will Enhance the Face Memory and Face-Context Associative Memory.

Previous research has explored how emotional valence (positive or negative) affected face-context associative memory, while little is known about how arousing stimuli that share the same valence but differ in emotionality are bound together and retained in memory. In this study, we manipulated the emotional similarity between the target face and the face associated with the context emotion (i.e., congruent, high similarity, and low similarity), and examined the effect of emotional similarity of negative emotion (i.e., disgust, anger, and fear) on face-context associative memory. Our results showed that the greater the emotional similarity between the faces, the better the face memory and face-context associative memory were. These findings suggest that the processing of facial expression and its associated context may benefit from taking into account the emotional similarity between the faces.

Optimization of green infrastructure networks based on potential green roof integration in a high-density urban area-A case study of Beijing, China.

Green infrastructure network (GIN) optimization is an effective measure to reduce the landscape fragmentation caused by rapid urbanization. However, there are few targeted and practical studies of GINs in high-density urban areas with a prominent contradiction between ecological construction and land scarcity, leading to insufficient feasibility of most optimization paths as they avoid practical contradictions (scarcity of land, high cost, etc.). As an effective way to economically increase green infrastructure, green roofs have been demonstrated to provide habitats and stepping stones to increase landscape connectivity for high-mobility organisms. However, few studies have applied green roofs to GIN optimization. To address this question, a new approach to optimize GINs was proposed from the perspective of integrating potential green roofs (PGRs). A complete and feasible workflow was also established to rapidly, accurately, and cost-effectively extract PGRs, scientifically evaluate the comprehensive landscape connectivity accounting for PGR isolation factors, and practically optimize GINs according to the spatial differentiation of PGRs with high landscape connectivity. This was done by integrating high-spatial-resolution remote sensing, machine learning, morphological spatial pattern analysis, landscape index method, and a minimum cumulative resistance model. A case study in a typical high-density urban area within the Beijing Fifth Ring Road, China demonstrated the applicability and implications of the workflow. The results clearly showed that the study area had a high potential for green roof retrofitting, PGRs with high landscape connectivity could effectively improve the GINs, and the spatial differentiation characteristics of the PGR network optimization benefits provided the scientific guidance for developing targeted ecological strategies. The new approach effectively improves the scientificity and implementability of GINs. It also provides a strong reference for landscape planning and ecological construction in other high-density urban areas facing the contradiction between ecological construction and land scarcity.

Entropy-Enthalpy Compensations Fold Proteins in Precise Ways.

Exploring the protein-folding problem has been a longstanding challenge in molecular biology and biophysics. Intramolecular hydrogen (H)-bonds play an extremely important role in stabilizing protein structures. To form these intramolecular H-bonds, nascent unfolded polypeptide chains need to escape from hydrogen bonding with surrounding polar water molecules under the solution conditions that require entropy-enthalpy compensations, according to the Gibbs free energy equation and the change in enthalpy. Here, by analyzing the spatial layout of the side-chains of amino acid residues in experimentally determined protein structures, we reveal a protein-folding mechanism based on the entropy-enthalpy compensations that initially driven by laterally hydrophobic collapse among the side-chains of adjacent residues in the sequences of unfolded protein chains. This hydrophobic collapse promotes the formation of the H-bonds within the polypeptide backbone structures through the entropy-enthalpy compensation mechanism, enabling secondary structures and tertiary structures to fold reproducibly following explicit physical folding codes and forces. The temperature dependence of protein folding is thus attributed to the environment dependence of the conformational Gibbs free energy equation. The folding codes and forces in the amino acid sequence that dictate the formation of ß-strands and α-helices can be deciphered with great accuracy through evaluation of the hydrophobic interactions among neighboring side-chains of an unfolded polypeptide from a ß-strand-like thermodynamic metastable state. The folding of protein quaternary structures is found to be guided by the entropy-enthalpy compensations in between the docking sites of protein subunits according to the Gibbs free energy equation that is verified by bioinformatics analyses of a dozen structures of dimers. Protein folding is therefore guided by multistage entropy-enthalpy compensations of the system of polypeptide chains and water molecules under the solution conditions.

Effects of graphene oxide on tomato growth in different stages.

The nano-carbon graphene has unique structural and physicochemical properties, which are conducive to various biomedical applications. We assessed the effect of graphene oxide (GO) on tomato plants at the seedling and mature stages in terms of morphological and biochemical indices. GO treatment significantly improved the shoot/stem growth of tomato in a dose-dependent manner by increasing the cortical cells number, cross-sectional area, diameter and vascular-column area. In addition, GO also promoted the morphological development of the root system and increased biomass accumulation. The surface area of root tips and hairs of tomato plants treated with 50 mg/L and 100 mg/L GO were significantly greater compared to the untreated control. At the molecular level, GO induced the expression of root development-related genes (SlExt1 and LeCTR1) and inhibited the auxin-responsive gene (SlIAA3). However, 50 mg/L and 100 mg/L GO significantly increased the root auxin content, which in turn increased the number of fruits and hastened fruit ripening compared to the control plants. Taken together, GO can improve the tomato growth when used at the appropriate concentration, and is a promising nano-carbon material for agricultural use.

A Hydrophobic-Interaction-Based Mechanism Triggers Docking between the SARS-CoV-2 Spike and Angiotensin-Converting Enzyme 2.

A recent experimental study found that the binding affinity between the cellular receptor human angiotensin-converting enzyme 2 (ACE2) and receptor-binding domain (RBD) in the spike (S) protein of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is more than tenfold higher than that of the original severe acute respiratory syndrome coronavirus (SARS-CoV). However, main chain structures of the SARS-CoV-2 RBD are almost the same with that of the SARS-CoV RBD. Understanding the physical mechanism responsible for the outstanding affinity between the SARS-CoV-2 S and ACE2 is an "urgent challenge" for developing blockers, vaccines, and therapeutic antibodies against the coronavirus disease 2019 (COVID-19) pandemic. Taking into account the mechanisms of hydrophobic interaction, hydration shell, surface tension, and the shielding effect of water molecules, this study reveals a hydrophobic-interaction-based mechanism by means of which SARS-CoV-2 S and ACE2 bind together in an aqueous environment. The hydrophobic interaction between the SARS-CoV-2 S and ACE2 protein is found to be significantly greater than that between SARS-CoV S and ACE2. At the docking site, the hydrophobic portions of the hydrophilic side chains of SARS-CoV-2 S are found to be involved in the hydrophobic interaction between SARS-CoV-2 S and ACE2.

C7-Prenylation of Tryptophan-Containing Cyclic Dipeptides by 7-Dimethylallyl Tryptophan Synthase Significantly Increases the Anticancer and Antimicrobial Activities.

Prenylated natural products have interesting pharmacological properties and prenylation reactions play crucial roles in controlling the activities of biomolecules. They are difficult to synthesize chemically, but enzymatic synthesis production is a desirable pathway. Cyclic dipeptide prenyltransferase catalyzes the regioselective Friedel-Crafts alkylation of tryptophan-containing cyclic dipeptides. This class of enzymes, which belongs to the dimethylallyl tryptophan synthase superfamily, is known to be flexible to aromatic prenyl receptors, while mostly retaining its typical regioselectivity. In this study, seven tryptophan-containing cyclic dipeptides 1a-7a were converted to their C7-regularly prenylated derivatives 1b-7b in the presence of dimethylallyl diphosphate (DMAPP) by using the purified 7-dimethylallyl tryptophan synthase (7-DMATS) as catalyst. The HPLC analysis of the incubation mixture and the NMR analysis of the separated products showed that the stereochemical structure of the substrate had a great influence on their acceptance by 7-DMATS. Determination of the kinetic parameters proved that cyclo-l-Trp-Gly (1a) consisting of a tryptophanyl and glycine was accepted as the best substrate with a KM value of 169.7 µM and a turnover number of 0.1307 s-1. Furthermore, docking studies simulated the prenyl transfer reaction of 7-DMATS and it could be concluded that the highest affinity between 7-DMATS and 1a. Preliminary results have been clearly shown that prenylation at C7 led to a significant increase of the anticancer and antimicrobial activities of the prenylated derivatives 1b-7b in all the activity test experiment, especially the prenylated product 4b.

Association and Genetic Identification of Loci for Four Fruit Traits in Tomato Using InDel Markers.

Tomato (Solanum lycopersicum) fruit weight (FW), soluble solid content (SSC), fruit shape and fruit color are crucial for yield, quality and consumer acceptability. In this study, a 192 accessions tomato association panel comprising a mixture of wild species, cherry tomato, landraces, and modern varieties collected worldwide was genotyped with 547 InDel markers evenly distributed on 12 chromosomes and scored for FW, SSC, fruit shape index (FSI), and color parameters over 2 years with three replications each year. The association panel was sorted into two subpopulations. Linkage disequilibrium ranged from 3.0 to 47.2 Mb across 12 chromosomes. A set of 102 markers significantly (p < 1.19-1.30 × 10-4) associated with SSC, FW, fruit shape, and fruit color was identified on 11 of the 12 chromosomes using a mixed linear model. The associations were compared with the known gene/QTLs for the same traits. Genetic analysis using F2 populations detected 14 and 4 markers significantly (p < 0.05) associated with SSC and FW, respectively. Some loci were commonly detected by both association and linkage analysis. Particularly, one novel locus for FW on chromosome 4 detected by association analysis was also identified in F2 populations. The results demonstrated that association mapping using limited number of InDel markers and a relatively small population could not only complement and enhance previous QTL information, but also identify novel loci for marker-assisted selection of fruit traits in tomato.

A new helvolic acid derivative from an endophytic Fusarium sp. of Ficus carica.

A new helvolic acid derivative named helvolic acid methyl ester (1), together with two known helvolic acid compounds, helvolic acid (2) and hydrohelvolic acid (3), were isolated from the fermentation of endophytic fungus Fusarium sp. in Ficus carica leaves. Their structures were elucidated and identified by spectroscopic methods. Compounds 1-3 showed potent antifungal and antibacterial activities.

Cytotoxic and Antibiotic Cyclic Pentapeptide from an Endophytic Aspergillus tamarii of Ficus carica.

A new cyclic pentapeptide, disulfide cyclo-(Leu-Val-Ile-Cys-Cys) (1), named malformin E, together with 13 known cyclic dipeptides, was isolated from the culture broth of endophytic fungus FR02 from the roots of Ficus carica. The strain FR02 was identified as Aspergillus tamarii on the basis of morphological characteristics and molecular analyses of internal transcribed spacer (ITS). Their structures were determined by the combination of 1D and 2D NMR spectroscopy, HRMS (ESI), UV, and Marfey's analysis. Compound 1 exhibited strong cytotoxic activities against human cancer cell strains MCF-7 and A549 with IC50 values of 0.65 and 2.42 µM, respectively. It also displayed remarkable antimicrobial activities against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Penicillium chrysogenum, Candida albicans, and Fusarium solani with MIC values of 0.91, 0.45, 1.82, 0.91, 3.62, 7.24, and 7.24 µM, respectively.

Synthesis and biological evaluation of apigenin derivatives as antibacterial and antiproliferative agents.

Two series of apigenin [5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-chromen-4-one] derivatives, 3a-3j and 4a-4j, were synthesized. The apigenin and alkyl amines moieties of these compounds were separated by C2 or C3 spacers, respectively. The chemical structures of the apigenin derivatives were confirmed using ¹H-NMR, ¹³C-NMR, and electrospray ionization mass spectroscopy. The in vitro antibacterial and antiproliferative activities of all synthesized compounds were determined. Among the tested compounds, 4a-4j displayed significant antibacterial activity against the tested strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa). Additionally, 4i showed the best inhibitory activity with minimum inhibitory concentrations of 1.95, 3.91, 3.91, and 3.91 µg/mL against S. aureus, B. subtilis, E. coli, and P. aeruginosa, respectively. The antiproliferative activity of the apigenin derivatives was evaluated by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. We determined that 4a-4j displayed better growth inhibition activity against four human cancer cell lines, namely, human lung (A549), human cervical (HeLa), human hepatocellular liver (HepG2), and human breast (MCF-7) cancer cells, than the parent apigenin. Compound 4j was found to be the most active antiproliferative compound against the selected cancer cells. Structure-activity relationships were also discussed based on the obtained experimental data.