Linkages among stem xylem transport, biomechanics, and storage in lianas and trees across three contrasting environments.

PREMISE: Stem xylem transports water and nutrients, mechanically supports aboveground tissues, and stores water and nonstructural carbohydrates. These three functions are associated with three types of cells-vessel, fiber, and parenchyma, respectively. METHODS: We measured stem theoretical hydraulic conductivity (Kt), modulus of elasticity (MOE), tissue water content, starch, soluble sugars, cellulose, and xylem anatomical traits in 15 liana and 16 tree species across three contrasting sites in Southwest China. RESULTS: Lianas had higher hydraulic efficiency and tissue water content, but lower MOE and cellulose than trees. Storage traits (starch and soluble sugars) did not significantly differ between lianas and trees, and trait variation was explained mainly by site, highlighting how environment shapes plant storage strategies. Kt was significantly positively correlated with vessel diameter and vessel area fraction in lianas and all species combined. The MOE was significantly positively correlated with fiber area fraction, wood density, and cellulose in lianas and across all species. The tissue water content was significantly associated with parenchyma area fraction in lianas. Support function was strongly linked with transport and storage functions in lianas. In trees, transport and support functions were not correlated, while storage function was tightly linked with transport and support functions. CONCLUSIONS: These findings enhance our understanding of the relationship between stem xylem structure and function in lianas and trees, providing valuable insights into how plants adapt to environmental changes and the distinct ecological strategies employed by lianas and by trees to balance the demands of hydraulic transport, mechanical support, and storage.

PGC1α plays a pivotal role in renal fibrosis via regulation of fatty acid metabolism in renal tissue. / PGC1αé€šè¿‡è°ƒæŽ§è‚¾ç»„ç»‡è„‚è‚ªé ¸ä»£è°¢åœ¨è‚¾çº¤ç»´åŒ–ä¸­å‘æŒ¥æž¢çº½ä½œç”¨.

Renal fibrosis is a common and irreversible pathological feature of end-stage renal disease caused by multiple etiologies. The role of inflammation in renal fibrosis tissue has been generally accepted. The latest view is that fatty acid metabolism disorder contributes to renal fibrosis. peroxisome proliferator activated receptor-gamma coactivator 1α (PGC1α) plays a key role in fatty acid metabolism, regulating fatty acid uptake and oxidized protein synthesis, preventing the accumulation of lipid in the cytoplasm, and maintaining a dynamic balanced state of intracellular lipid. In multiple animal models of renal fibrosis caused by acute or chronic kidney disease, or even age-related kidney disease, almost all of the kidney specimens show the down-regulation of PGC1α. Upregulation of PGC1α can reduce the degree of renal fibrosis in animal models, and PGC1α knockout animals exhibit severe renal fibrosis. Studies have demonstrated that AMP-activated protein kinase (AMPK), MAPK, Notch, tumor necrosis factor-like weak inducer of apoptosis (TWEAK), epidermal growth factor receptor (EGFR), non-coding RNA (ncRNAs), liver kinase B1 (LKB1), hairy and enhancer of split 1 (Hes1), and other pathways regulate the expression of PGC1α and affect fatty acid metabolism. But some of these pathways interact with each other, and the effect of the integrated pathway on renal fibrosis is not clear.

Mechanism and influencing factors of crystal-cell interaction in the formation of calcium oxalate stones. / è‰é ¸é’™ç»“çŸ³å½¢æˆè¿‡ç¨‹ä¸­æ™¶ä½“-ç»†èƒžç›¸äº’ä½œç”¨çš„æœºåˆ¶åŠå½±å“å› ç´ .

Kidney stone is a disease with complex etiology and high incidence, and the most common chemical composition type of it is calcium oxalate stone. The formation of calcium oxalate stones includes crystal formation, crystal growth and aggregation, crystal interaction with renal tubular epithelial cells, and crystal invasion of renal interstitial extracellular matrix and so on. In these processes, crystal-cell interactions are essential for kidney crystal retention and kidney stone formation. Recently many studies have found that the interaction between crystal and renal tubular epithelial cells is closely related to various key binding molecules, endoplasmic reticulum stress of tubular cells, extracellular matrix proteins, and various lithotriptic drugs. Understanding the mechanism of crystal-cell interaction is of great significance for the prevention and early treatment of calcium oxalate stones.

The effect of working memory load on the SNARC effect: Maybe tasks have a word to say.

We investigated the effect of working memory load on the SNARC (spatial-numerical association of response codes) effect under different number judgment tasks (parity judgment and magnitude comparison), using a novel dual task. Instead of exerting load over the whole block of number judgment trials, in this dual task, number judgment trials were inserted into each interstimulus interval of an n-back task, which served as the working memory load. We varied both load type (verbal and spatial) and amount (1-load, 2-load, and 3-load). The results indicated that the SNARC effect disappeared even under the 1-load condition for a parity judgment, regardless of the type of load. However, during the magnitude comparison task, the SNARC effect increased with increasing load amounts under spatial load conditions; under verbal load conditions, the SNARC effect decreased with increasing amounts of load, and disappeared during the 3-load task. The difference between the parity and magnitude tasks was not attributable to the interval stimuli or task switching. These findings confirm that different spatial-numerical associations for comparing numerical magnitudes and judgments of parity have different needs with respect to working memory resources.

Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation.

Germination and thermoinhibition in lettuce (Lactuca sativa 'Jianyexianfeng No. 1') seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (P<0.05) in abundance in at least one germination treatment. Nineteen proteins increasing and one protein decreasing in abundance during germination had higher abundance in germinated 15°C, 15°C after imbibition at 25°C for 48 h, and 25°C in KNO3 seeds than in ungerminated 25°C seeds. Gene expression of 12 of those proteins correlated well with the protein accumulation. Methionine metabolism, ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition.

[Pharmacokinetic Effect of Acteoside in Blood Deficiency Rats].

Objective: To study the different pharmacokinetics effect of acteoside extracted from Rehmanniae Radix Preparata in normal and blood deficiency rats. Methods: Injected acetyl phenylhydrazine and cyclophosphamide to make blood deficiency rats models subcutaneously,and gave mice the ethand extracts of Rehmanniae Radix preparata by oral administration,the concentration of acteoside in rats at different time points were detected by HPLC method, pharmacokinetic parameters were calculated by 3p87 software. Results: The determination of acteoside in the linear range were 0. 2 ~ 80 µg / m L, the limit of detection and quantification was 0. 03 and 0. 12µg/m L,respectively. Compared with the normal group,the content of AUC0-tand AUC0-∞of corresponding dose in model group rats increased significantly, and the average dwell time and the elimination half-life prolong significantly. Conclusion: This method has high specificity,high sensitivity and simple operation, which can be used for the determination to pharmacokinetic process of acteoside in blood deficiency model.

[In vivo Pharmacokinetics of Notoginsenoside R1 in Ischemia Rats After Acute Myocardial Infarction].

OBJECTIVE: To establish an HPLC-UV method for determining pharmacokinetic difference of notoginsenoside R1 between normal rats and ischemic rats. METHODS: 48 male SD rats were randomly divided into normal group and acute myocardial ischemia( AMI) model group induced by pituitrin and each group was classified into high,middle and low-dose of groups with notoginsenoside R1 (200, 100 and 50 mg/kg) respectively. Blood samples were collected at different points in time after they were administered once by gavage and separated by Waters symmetry C18 column (250 mm x 4.6 mm, 5 µm) under the detective wavelength 203 nm, the mobile phase was acetonitrile-water with icariin as the internal standard and the pharmacokinetic parameters were calculated by DAS 2. 0. RESULTS: Notoginsenoside R1 had good linearity in the ranges of 0.2~125 µg/mL (R2 = 0.9997) with SNR 1:3 and the lowest detection limit was 0.053 µg/mL, the extraction rate, RSDs of within-day and between-day, specificity, accuracy and precision accorded with the require-ment of bio-sample pretreatment. Compared to the normal group, AUC0-t, and AUC0-∞ was significantly increased (P < 0.01) and the terminal half-life was prolonged markedly (P < 0.01) in AMI group. CONCLUSIONS: The method is simple, accurate and had high specificity and sensitivity, that could be applied in quantitative determination of notoginsenoside R1 and research of pharmacokinetics; the relative bioavailability of notoginsenoside R1 is increased significantly in AMI group,which indicates that notoginsenoside R1 has better effect in model rat.

The complete Chloroplast genome of Stachys geobombycis and comparative analysis with related Stachys species.

Herb genomics, at the forefront of traditional Chinese medicine research, combines genomics with traditional practices, facilitating the scientific validation of ancient remedies. This integration enhances public understanding of traditional Chinese medicine's efficacy and broadens its scope in modern healthcare. Stachys species encompass annual or perennial herbs or small shrubs, exhibiting simple petiolate or sessile leaves. Despite their wide-ranging applications across various fields, molecular data have been lacking, hindering the precise identification and taxonomic elucidation of Stachys species. To address this gap, we assembled the complete chloroplast (CP) genome of Stachys geobombycis and conducted reannotation and comparative analysis of seven additional species within the Stachys genus. The findings demonstrate that the CP genomes of these species exhibit quadripartite structures, with lengths ranging from 14,523 to 150,599 bp. Overall, the genome structure remains relatively conserved, hosting 131 annotated genes, including 87 protein coding genes, 36 tRNA genes, and 8 rRNA genes. Additionally, 78 to 98 SSRs and long repeat sequences were detected , and notably, 6 highly variable regions were identified as potential molecular markers in the CP genome through sequence alignment. Phylogenetic analysis based on Bayesian inference and maximum likelihood methods strongly supported the phylogenetic position of the genus Stachys as a member of Stachydeae tribe. Overall, this comprehensive bioinformatics study of Stachys CP genomes lays the groundwork for phylogenetic classification, plant identification, genetic engineering, evolutionary studies, and breeding research concerning medicinal plants within the Stachys genus.

The complete chloroplast genome sequence of Ampelopsis delavayana Planchon. ex Franch 1886 (Vitaceae).

Ampelopsis delavayana Planchon. ex Franch 1886 is a plant with significant pharmacological effects and ornamental importance. This research unveiled the complete chloroplast (cp) genome sequence of A. delavayana. The study highlights that the cp genome of A. delavayana possesses a distinct tetrameric structure spanning 162,497 base pairs, comprising a small single-copy (SSC) region of 18,902 base pairs, a large single-copy (LSC) region of 90,441 base pairs, and two inverted-repeat regions (IRs), each 26,577 base pairs in length. The GC content of the SSC, LSC, and IR regions of the genome was 31.80%, 35.16%, and 42.82%, respectively, culminating in an overall GC content of 37.27%. The genome comprised 130 genes, which included eight rRNAs, 36 tRNAs, and 86 protein-coding genes. Through phylogenetic analysis utilizing the maximum-likelihood method, it was established that A. delavayana was closely related to Ampelopsis glandulosa var. brevipedunculata, positioning it as a sister species. This report not only provides a scientific reference for understanding the phylogeny of the family Vitaceae but also enriches our genetic information of Ampelopsis.

Comparative analysis of codon usage bias in the chloroplast genomes of eighteen Ampelopsideae species (Vitaceae).

BACKGROUND: The tribe Ampelopsideae plants are important garden plants with both medicinal and ornamental values. The study of codon usage bias (CUB) facilitates a deeper comprehension of the molecular genetic evolution of species and their adaptive strategies. The joint analysis of CUB in chloroplast genomes (cpDNA) offers valuable insights for in-depth research on molecular genetic evolution, biological resource conservation, and elite breeding within this plant family. RESULTS: The base composition and codon usage preferences of the eighteen chloroplast genomes were highly similar, with the GC content of bases at all positions of their codons being less than 50%. This indicates that they preferred A/T bases. Their effective codon numbers were all in the range of 35-61, which indicates that the codon preferences of the chloroplast genomes of the 18 Ampelopsideae plants were relatively weak. A series of analyses indicated that the codon preference of the chloroplast genomes of the 18 Ampelopsideae plants was influenced by a combination of multiple factors, with natural selection being the primary influence. The clustering tree generated based on the relative usage of synonymous codons is consistent with some of the results obtained from the phylogenetic tree of chloroplast genomes, which indicates that the clustering tree based on the relative usage of synonymous codons can be an important supplement to the results of the sequence-based phylogenetic analysis. Eventually, 10 shared best codons were screened on the basis of the chloroplast genomes of 18 species. CONCLUSION: The codon preferences of the chloroplast genome in Ampelopsideae plants are relatively weak and are primarily influenced by natural selection. The codon composition of the chloroplast genomes of the eighteen Ampelopsideae plants and their usage preferences were sufficiently similar to demonstrate that the chloroplast genomes of Ampelopsideae plants are highly conserved. This study provides a scientific basis for the genetic evolution of chloroplast genes in Ampelopsideae species and their suitable strategies.

On-road evaluation and regulatory recommendations for NOx and particle number emissions of China VI heavy-duty diesel trucks: A case study in Shenzhen.

This research analyzed the real-world NOx and particle number (PN) emissions of 21 China VI heavy-duty diesel trucks (HDDTs). On-road emission conformity was first evaluated with portable emission measurement system (PEMS). Only 76.19 %, 71.43 % and 61.90 % of the vehicles passed the NOx test, PN test and both tests, respectively. The impacts of vehicle features including exhaust gas recirculation (EGR) equipment, mileage and tractive tonnage were then assessed. Results demonstrated that EGR helped reducing NOx emission factors (EFs) while increased PN EFs. Larger mileages and tractive tonnages corresponded to higher NOx and PN EFs, respectively. In-depth analyses regarding the influences of operating conditions on emissions were conducted with both numerical comparisons and statistical tests. Results proved that HDDTs generated higher NOx EFs under low speeds or large vehicle specific powers (VSPs), and higher PN EFs under high speeds or small VSPs in general. In addition, unqualified vehicles generated significantly higher NOx EFs than qualified vehicles on freeways or under speed≥40 km/h, while significant higher PN EFs were generated on suburban roads, freeways or under operating modes with positive VSPs by unqualified vehicles. The reliability and accuracy of on-board diagnostic (OBD) NOx data were finally investigated. Results revealed that 43 % of the test vehicles did not report reliable OBD data. Correlation analyses between OBD NOx and PEMS measurements further demonstrated that the consistency of instantaneous concentrations were generally low. However, sliding window averaged concentrations show better correlations, e.g., the Pearson correlation coefficients on 20s-window averaged concentrations exceeded 0.85 for most vehicles. The research results provide valuable insights into emission regulation, e.g., focusing more on medium- to high-speed operations to identify unqualified vehicles, setting higher standards to improve the quality of OBD data, and adopting window averaged OBD NOx concentrations in evaluating vehicle emission performance.

[Analysis of volatile composition of different specification of Panax notoginseng].

OBJECTIVE: To analyse the volatile compositions of different specification of Panax notoginseng. METHODS: Volatile compositions from different specification of Panax notoginseng were detected by Headspace Solid-Phase Micro-Extraction with GC/MS. RESULTS: Terpenoids were the main compositions in different specification of Panax Notoginseng, and a-guaiene was the fundamental ingredient. The type, content and quantity of the compounds were different in different type of Panax notoginseng. CONCLUSION: Terpenoids were the main pharmacodynamics of the volatile compositions of Panax notoginseng and worthy of further study.

Full-Length Transcriptome Sequencing Reveals the Molecular Mechanism of Metasequoia glyptostroboides Seed Responding to Aging.

Metasequoia glyptostroboides, Hu and W. C. Cheng, as the only surviving relict species of the Taxodiaceae Metasequoia genus, is a critically endangered and protected species in China. There is a risk of extinction due to the low vigor of M. glyptostroboides seeds, and the physiological mechanism of seed aging in M. glyptostroboides is not yet clear. In order to investigate the physiological and molecular mechanisms underlying the aging process of M. glyptostroboides seeds, we analyzed the antioxidant system and transcriptome at 0, 2, 4, 6, and 8 days after artificial accelerated aging treatment at 40 °C and 100% relative humidity. It was found that the germination percentage of fresh dried M. glyptostroboides seeds was 54 ± 5.29%, and significantly declined to 9.33 ± 1.88% after 6 days of aging, and then gradually decreased until the seed died on day 8. Superoxide dismutase (SOD) activity, ascorbic acid (AsA), glutathione (GSH) content and superoxide anion (O2·-) content and production rate significantly decreased, while malondialdehyde (MDA) and hydrogen peroxide (H2O2) content and glutathione peroxidase (GPX) and catalase (CAT) activity gradually increased during the aging process. A total of 42,189 unigenes were identified in the whole transcriptome, and 40,446 (95.86%) unigenes were annotated in at least one protein database. A total of 15,376 differentially expressed genes (DEGs) were obtained; KEGG enrichment analysis results revealed that seed aging may be mainly involved in the protein-processing pathways in endoplasmic reticulum, oxidative phosphorylation, and ascorbate and aldarate metabolism. Weighted gene co-expression network analysis (WGCNA) revealed that the dark magenta, orange, and medium purple modules were highly correlated with physiological indicators such as SOD, CAT, and GSH and further identified 40 hub genes such as Rboh, ACO, HSF, and CML as playing important roles in the antioxidant network of M. glyptostroboides seeds. These findings provide a broader perspective for studying the regulatory mechanism of seed aging and a large number of potential target genes for the breeding of other endangered gymnosperms.

Long non-coding RNA FABP5P3/miR-22 axis improves TGFß1-induced fatty acid oxidation deregulation and fibrotic changes in proximal tubular epithelial cells of renal fibrosis.

Severe hydronephrosis increases the risk of urinary tract infection and irretrievable renal fibrosis. While TGFß1-mediated fibrotic changes in proximal tubular epithelial cells and fatty acid oxidation (FAO) deregulation contribute to renal fibrosis and hydronephrosis. Firstly, a few elements were analyzed in this paper, including differentially-expressed long non-coding RNAs (lncRNAs), and miRNAs correlated to CPT1A, RXRA, and NCOA1. This paper investigated TGFß1 effects on lncRNA FABP5P3, CPT1A, RXRA, and NCOA1 expression and fibrotic changes in HK-2 cells and FABP5P3 overexpression effects on TGFß1-induced changes. Moreover, this paper predicted and proved that miR-22 binding to lncRNA FABP5P3, 3'UTR of CPT1A, RXRA, and NCOA1 was validated. The dynamic effects of the FABP5P3/miR-22 axis on TGFß1-induced changes were investigated. A Renal fibrosis model was established in unilateral ureteral obstruction (UUO) mice, and FABP5P3 effects were investigated. Eventually, this paper concluded that TGFß1 inhibited lncRNA FABP5P3, CPT1A, RXRA, and NCOA1 expression, induced fibrotic changes in HK-2 cells, and induced metabolic reprogramming within HK-2 cells, especially lower FAO. FABP5P3 overexpression partially reversed TGFß1-induced changes. miR-22 targeted lncRNA FABP5P3, CPT1A, RXRA, and NCOA1. LncRNA FABP5P3 counteracted miR-22 inhibition of CPT1A, NCOA1, and RXRA through competitive binding. TGFß1 stimulation induced the activation of TGFß/SMAD and JAG/Notch signaling pathways; Nocth2 knockdown reversed TGFß1 suppression on lncRNA FABP5P3. FABP5P3 overexpression attenuated renal fibrosis in unilateral ureteral obstruction mice. The LncRNA FABP5P3/miR-22 axis might be a potent target for improving the FAO deregulation and fibrotic changes in proximal TECs under TGFß1 stimulation.

iTRAQ-Based Proteomic and Physiological Analyses Reveal the Mechanisms of Dehydration and Cryopreservation Tolerance of Sophora tonkinensis Gagnep. Seeds.

Sophora tonkinensi is a shrub of the genus Sophora in the family Fabaceae with anti-inflammatory and pain-relieving effects. While the cultivation, chemical makeup, and medicinal properties of S. tonkinensis have been reported, the physiological mechanisms governing its dehydration and cryopreservation tolerance of seeds remain unclear. In this study, we investigated the morphological, physiological, biochemical, and protein expression characteristics of S. tonkinensis seeds subjected to dehydration and cryopreservation techniques via the observation of cell microstructure, determination of antioxidant enzyme activity, and iTRAQ-based proteomic analysis, respectively. The results of the study demonstrated that the seeds possessed a certain level of tolerance to dehydration. The highest germination percentage of 83.0% was observed after 2 h of dehydration (10.1% water content), which was identified as the optimal time point for cryopreservation. However, the germination percentage was reduced to only 30.5% when the water content reached 5.4%, indicating that S. tonkinensis seeds exhibit intermediate storage behavior. Further investigation revealed that during seed dehydration and cryopreservation treatment, liposomes were gradually and highly fused, whereas the activities of ROS scavenging and stress defense were significantly enhanced. During dehydration, the seed tissues formed a protective mechanism of stress resistance based on protein processing in the endoplasmic reticulum and antioxidant system, which was related to the dehydration tolerance. Moreover, only three differentially expressed LEA proteins were identified, and it is speculated that the strengthening of intracellular metabolism and the absence of specific LEA and dehydrins could be crucial factors for the reduced germination percentage after excessive dehydration and cryopreservation.

Hyperforin regulates renal fibrosis via targeting the PI3K-AKT/ICAM1 axis.

OBJECTIVE: To explore the role and mechanism of hyperforin (one of the active components of Sophora flavescens) in renal fibrosis. METHODS: The active compounds and target proteins of Sophora flavescens were first screened through TCMSP (https://tcmsp-e.com/). The renal fibrosis-related genes were analyzed through GeneCards (https://www.genecards.org/). The differentially expressed genes (DEGs) in renal fibrosis in GEO dataset GSE156181 were obtained. Metascape was applied for target protein enrichment analysis. TGF-ß1-stimulated renal tubular epithelial cells were used for renal fibrosis cell model establishment. The unilateral ureteral obstruction (UUO) mouse model was used for the renal fibrosis in vivo model. Cell viability was detected using an MTT assay. Immunofluorescence staining was employed to detect cell morphology changes and the expression of α-SMA and collagen I. Hematoxylin and eosin (H&E) and Masson staining were employed to determine the renal morphologic change. qRT-PCR or Western blotting was applied to determine the expression levels of the target proteins. RESULTS: After intersecting the analysis results of TCMSP, GeneCards, and dataset GSE156181, hyperforin targeting ICAM1 was identified. Metascape pathway enrichment analysis results revealed that the effective compounds of Sophora flavescens were tightly associated with extracellular matrix (ECM) remodeling and inflammatory response. MTT assay demonstrated that hyperforin had no toxic effect on cells. Immunofluorescence staining results evidenced that hyperforin could partially restore TGF-ß1-induced epithelial-mesenchymal transition (EMT), the PI3K/AKT pathway activation, and ICAM1 upregulation, and these effects of hyperforin could be reversed by ICAM1 overexpression. While the PI3K/AKT pathway activator IGF-1 effectively reversed the EMT inhibition effect of hyperforin on renal tubular epithelial cells. Moreover, the UUO mouse model further confirmed that hyperforin reduced renal fibrosis. CONCLUSION: Hyperforin inhibited renal fibrosis via the PI3K/AKT/ICAM1 axis.

The complete chloroplast genome and phylogenetic analysis of Cardamine circaeoides Hook. f. et Thoms., 1861 (Brassicaceae).

A species of Cardamine circaeoides Hook. f. et Thoms., 1861, which belongs to the Cardamine family (Brassicaceae), is an endemic species of the Wuling Mountains in Hunan and Hubei Provinces of China. Since there are many morphologically related species of C. circaeoides, the chloroplast (cp) genome characteristics of C. circaeoides were analyzed in order to explore the phylogenetic relationship between it and the closely related species. A cp genome totaling 154,838 base pairs exhibited a typical quadripartite structure with a pair of IRs (inverted repeats; 26,493 base pairs) separated by a small single-copy region of 17,938 base pairs and a large single-copy region of 83,914 base pairs. A total of 130 genes were found in the cp genome, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. There were 36.21%, 33.96%, 29.09%, and 42.35% GC content in the entire cp genome, LSC region, SSC region, and IR region, respectively. According to phylogenetic analysis, C. circaeoides is evolutionarily closer to Cardamine hupingshanensis.

A Bibliometric Study on Trends in Proton Exchange Membrane Fuel Cell Research during 1990-2022.

Proton exchange membrane fuel cell (PEMFC) with high density and safe reliability has been extensively studied in the world. With the circumstance of extensive PEMFC research, in this study we carried out a bibliometric analysis to understand the technological development. The information of 17,769 related publications from 1990 to 2022 was retrieved from the Web of Science Core Collection for bibliometric analysis based on the VOSviewer tool. The results show that the International Journal of Hydrogen Energy dominates among all of the source journals. The closest collaboration is between China and the USA, and publications from both of those account for 53.9% of the total. In terms of institutions, the Chinese Academy of Sciences has prolific publications, in which representative groups, such as Shao Zhigang's, have achieved many outputs in this field. The theme of PEMFC research can be divided into three aspects: "materials", "design" and "mechanisms". This study demonstrated overall mapping knowledge domain and systematic analysis, and contributed to making a guide for researchers on the progress and trends of PEMFC.

Experimental Investigation on the Anode Flow Field Design for an Air-Cooled Open-Cathode Proton Exchange Membrane Fuel Cell.

A flow channel structure design plays a significant role in an open-cathode proton exchange membrane fuel cell. The cell performance is sensitive to the structural parameters of the flow field, which mainly affects the heat and mass transfer between membrane electrode assembly and channel. This paper presents theoretical and experimental studies to investigate the impacts of anode flow field parameters (numbers of the serpentine channels, depths, and widths of the anode channel) on cell performance and temperature characteristics. The result indicates that the number of anode serpentine channels adjusts the pressure and flow rate of hydrogen in the anode flow channel effectively. The depth and width of the channel change the pressure, flow rate, and mass transfer capacity of hydrogen, especially under the high current density. There appears the best depth to achieve optimum cell performance. The velocity and concentration of hydrogen have important influences on the mass transfer which agrees with the anode channel structure design and performance changes based on the field synergy principle. This research has great significance for further understanding the relationship between anode flow field design and fuel cell performance in the open-cathode proton exchange membrane fuel cell stack.

The complete chloroplast genome sequence of Nekemias cantoniensis (Hook. et Arn.) Planch 1873 (Vitaceae).

Nekemias cantoniensis (Hook. et Arn.) Planch 1873 is a woody vine species native to South and Southwest China that is rich in flavonoids and also displays excellent pharmacological activities. The purpose of this study was to characterize the complete chloroplast (cp) genome of N. cantoniensis using Illumina pair-end sequencing data. In summary, the complete cp genome of N. cantoniensis exhibits a quadripartite structure with a length of 162,655 base pairs, including a large single-copy (LSC) region of 89,341 base pairs, a small single-copy (SSC) region of 19,076 base pairs, and two inverted repeats (IRs) regions of 27,119 base pairs. The overall GC content of the genome is 37.41%, while the corresponding values for the LSC, SSC, and IR regions are 34.75%, 32.89%, and 43.02%, respectively. The genome contains 137 genes, of which 87 are protein coding, 36 are tRNA coding, and eight are rRNA coding. Maximum-likelihood phylogenetic analyses revealed that N. cantoniensis was clustered with N. grossedentata.