Effect of cytochrome P450 3A4 on tissue distribution of humantenmine, koumine, and gelsemine, three alkaloids from the toxic plant Gelsemium.

Humantenmine, koumine, and gelsemine are three indole alkaloids found in the highly toxic plant Gelsemium. Humantenmine was the most toxic, followed by gelsemine and koumine. The aim of this study was to investigate and analyze the effects of these three substances on tissue distribution and toxicity in mice pretreated with the Cytochrome P450 3A4 (CYP3A4) inducer ketoconazole and the inhibitor rifampicin. The in vivo test results showed that the three alkaloids were absorbed rapidly and had the ability to penetrate the blood-brain barrier. At 5 min after intraperitoneal injection, the three alkaloids were widely distributed in various tissues and organs, the spleen and pancreas were the most distributed, and the content of all tissues decreased significantly at 20 min. Induction or inhibition of CYP3A4 in vivo can regulate the distribution and elimination effects of the three alkaloids in various tissues and organs. Additionally, induction of CYP3A4 can reduce the toxicity of humantenmine, and vice versa. Changes in CYP3A4 levels may account for the difference in toxicity of humantenmine. These findings provide a reliable and detailed dataset for drug interactions, tissue distribution, and toxicity studies of Gelsemium alkaloids.

An efficient method for the preparative isolation and purification of alkaloids from Gelsemium by using high speed counter-current chromatography and preparative HPLC.

We established an efficient method using high-speed countercurrent chromatography (HSCCC) combined with preparative high-performance liquid chromatography (prep-HPLC) for isolating and purifying Gelsemium elegans (G. elegans) alkaloids. First, the two-phase solvent system composed of 1% triethylamine aqueous solution/n-hexane/ethyl acetate/ethanol (volume ratio 4:2:3:2) was employed to separate the crude extract (350 mg) using HSCCC. Subsequently, the mixture that resulted from HSCCC was further separated by Prep-HPLC, resulting in seven pure compounds including: 14-hydroxygelsenicine (1, 12.1 mg), sempervirine (2, 20.8 mg), 19-(R)-hydroxydihydrogelelsevirine (3, 10.1 mg), koumine (4, 50.5 mg), gelsemine (5, 32.2 mg), gelselvirine (6, 50.5 mg), and 11-hydroxyhumanmantenine (7, 12.5 mg). The purity of these seven compounds were 97.4, 98.9, 98.5, 99, 99.5, 96.8, and 85.5%, as determined by HPLC. The chemical structures of the seven compounds were analyzed and confirmed by electrospray ionization mass spectrometry (ESI-MS), 1H-nuclear magnetic resonance (1H NMR), and 13 C-nuclear magnetic resonance (13 C NMR) spectra. The results indicate that the HSCCC-prep-HPLC method can effectively separate the major alkaloids from the purified G. elegans, holding promising prospects for potential applications in the separation and identification of other traditional Chinese medicines.

Comparative Analysis of the Gelsemium Alkaloids Metabolism in Human, Pig, Goat, and Rat Liver Microsomes.

AIM: The aim of this study was to investigate the metabolism of Gelsemium elegans in human, pig, goat and rat liver microsomes and to elucidate the metabolic pathways and cleavage patterns of the Gelsemium alkaloids among different species. METHODS: A human, goat, pig and rat liver microparticles were incubated in vitro. After incubating at 37°C for 1 hour and centrifuging, the processed samples were detected by HPLC/Qq-TOFMS was used to detect alcohol extract of Gelsemium elegans and its metabolites. RESULTS: Forty-six natural products were characterized from alcohol extract of Gelsemium elegans and 13 metabolites were identified. These 13 metabolites belong to the gelsemine, koumine, gelsedine, humantenine, yohimbane, and sarpagine classes of alkaloids. The metabolic pathways included oxidation, demethylation and dehydrogenation. After preliminary identification, the metabolites detected in the four species were different. All 13 metabolites were detected in pig and rat microsomes, but no oxidative metabolites of Gelsedine-type alkaloids were detected in goat and human microsomes. CONCLUSION: In this study, Gelsemium elegans metabolic patterns in different species are clarified and the in vitro metabolism of Gelsemium elegans is investigated. It is of great significance for its clinical development and rational application.

Reference Genes Screening and Gene Expression Patterns Analysis Involved in Gelsenicine Biosynthesis under Different Hormone Treatments in Gelsemium elegans.

Reverse transcription quantitative polymerase chain reaction (RT-qPCR) is an accurate method for quantifying gene expression levels. Choosing appropriate reference genes to normalize the data is essential for reducing errors. Gelsemium elegans is a highly poisonous but important medicinal plant used for analgesic and anti-swelling purposes. Gelsenicine is one of the vital active ingredients, and its biosynthesis pathway remains to be determined. In this study, G. elegans leaf tissue with and without the application of one of four hormones (SA, MeJA, ETH, and ABA) known to affect gelsenicine synthesis, was analyzed using ten candidate reference genes. The gene stability was evaluated using GeNorm, NormFinder, BestKeeper, ∆CT, and RefFinder. The results showed that the optimal stable reference genes varied among the different treatments and that at least two reference genes were required for accurate quantification. The expression patterns of 15 genes related to the gelsenicine upstream biosynthesis pathway was determined by RT-qPCR using the relevant reference genes identified. Three genes 8-HGO, LAMT, and STR, were found to have a strong correlation with the amount of gelsenicine measured in the different samples. This research is the first study to examine the reference genes of G. elegans under different hormone treatments and will be useful for future molecular analyses of this medically important plant species.

China Medicinal Plants of the Ampelopsis grossedentata-A Review of Their Botanical Characteristics, Use, Phytochemistry, Active Pharmacological Components, and Toxicology.

Ampelopsis grossedentata (AG) is mainly distributed in Chinese provinces and areas south of the Yangtze River Basin. It is mostly concentrated or scattered in mountainous bushes or woods with high humidity. Approximately 57 chemical components of AG have been identified, including flavonoids, phenols, steroids and terpenoids, volatile components, and other chemical components. In vitro studies have shown that the flavone of AG has therapeutic properties such as anti-bacteria, anti-inflammation, anti-oxidation, enhancing immunity, regulating glucose and lipid metabolism, being hepatoprotective, and being anti-tumor with no toxicity. Through searching and combing the related literature, this paper comprehensively and systematically summarizes the research progress of AG, including morphology, traditional and modern uses, chemical composition and structure, and pharmacological and toxicological effects, with a view to providing references for AG-related research.

DNA-bridged double gold nanoparticles-based immunochromatography for dual-mode detection of ochratoxin A.

A novel immunochromatography strip (ICS) based on the DNA-bridged double gold nanoparticles was established and evaluated for the dual-mode detection of ochratoxin A (OTA). For this purpose, the streptavidin was coupled with the big size of gold nanoparticle (40 nm, AuNP), the OTA monoclonal antibody and biotinylated DNA-SH were simultaneously immobilized on the small size of AuNP (20 nm), and then the enhanced ICS was self-assembled and evaluated. The dual-mode detection of semi-quantification and quantification had been achieved and performed by the proposed ICS. The LOD for semi-quantification (semi-Q-LOD) was 0.06 ng/mL by the directly naked eye (eightfold enhanced than conventional ICS). By the on-site reader, the LOD for quantification (Q-LOD) was 0.03 ng/mL (threefold enhanced), with the detection range between 0.03 and 1.2 ng/mL. The specificity, reliability, and practicability had been well represented. Furthermore, the OTA-positive results of the enhanced ICS method correlated well with those obtained by the referenced HPLC-MS/MS for the market samples. This study provided a new ICS pattern of semi-quantification and quantification for OTA contamination, which could be used as a valuable reference for improving the ICS technology and enhancing the sensitivity.

Antinociceptive effect of gelsenicine, principal toxic alkaloids of gelsemium, on prostaglandin E2-induced hyperalgesia in mice: Comparison with gelsemine and koumine.

Gelsemium elegans (G.elegans) is a plant of the Loganiaceae family, known for its indole alkaloids, including gelsemine, koumine, and gelsenicine. Gelsemine and koumine are well-studied active alkaloids with low toxicity, valued for their anti-anxiety and analgesic properties. However, gelsenicine, another important alkaloid, remains underexplored due to its high toxicity. This study focuses on evaluating the analgesic properties of gelsenicine and comparing them with gelsemine and koumine. The results indicate that all three alkaloids exhibit robust analgesic properties, with gelsemine, koumine, and gelsenicine showing ED50 values of 0.82 mg/kg, 0.60 mg/kg, and 8.43 µg/kg, respectively, as assessed by the hot plate method. Notably, the therapeutic dose of gelsenicine was significantly lower than its toxic dose (LD50 = 0.185 mg/kg). The study also investigated the mechanism of action by analyzing the expression levels of GlyRα3 and Gephyrin. The PGE2 model group showed decreased expression levels of GlyRα3 and Gephyrin, while groups treated with gelsemine, koumine, and gelsenicine were able to reverse this decrease. These results suggest that gelsenicine effectively alleviates PGE2-induced hyperalgesia by upregulating the expression of GlyRα3 and Gephyrin, which are key targets of the Gly receptor pathway.

Effect of Dietary Gelsemium elegans Benth. Extract on the Growth, Slaughter Performance, Meat Quality, Intestinal Morphology, and Microflora of Yellow-Feathered Chickens.

The plant species Gelsemium elegans Benth. (GEB) promotes pig and sheep growth; however, little is known about its effects in chickens. In this study, a GEB extract (GEBE) was prepared, and its effects on the growth, slaughter, antioxidant performance, meat quality, serum biochemical indices, intestinal morphology, and microflora of yellow-feathered chickens were evaluated. In total, 600 chickens aged 15 days were randomly divided into four groups with five replicates each and fed a basal diet containing 0% (control), 0.25% (0.25 GEBE), 0.75% (0.75 GEBE), or 1.25% (1.25 GEBE) GEBE until 49 days of age. Chickens were then killed, and their meat, organs, and serum and cecal contents were collected. GEBE reduced the feed conversion ratio, particularly in the 0.75 and 1.25 GEBE groups. Furthermore, the GEBE diet improved meat tenderness and reduced the meat expressible moisture content and liver malondialdehyde content, indicating high meat quality. Whereas the 0.25 GEBE diet increased the level of Lactobacillus acidophilus in the cecum, the 0.75 GEBE diet decreased the Escherichia coli level therein. These findings demonstrate that GEBE may improve the meat quality and cecal microbiota of yellow-feathered chickens, providing a basis for identifying candidate alternatives to conventional antibiotics as growth promoting feed additives.

Room Temperature Anhydrous Suzuki-Miyaura Polymerization Enabled by C-S Bond Activation.

The Suzuki-Miyaura cross-coupling is one of the most important and powerful methods for constructing C-C bonds. However, the protodeboronation of arylboronic acids hinder the development of Suzuki-Miyaura coupling in the precise synthesis of conjugated polymers (CPs). Here, an anhydrous room temperature Suzuki-Miyaura cross-coupling reaction between (hetero)aryl boronic esters and aryl sulfides was explored, of which universality was exemplified by thirty small molecules and twelve CPs. Meanwhile, the mechanistic studies involving with capturing four coordinated borate intermediate revealed the direct transmetalation of boronic esters in the absence of H2 O suppressing the protodeboronation. Additionally, the room temperature reaction significantly reduced the homocoupling defects and enhanced the optoelectronic properties of the CPs. In all, this work provides a green protocol to synthesize alternating CPs.

Protocol to characterize target components of Gelsemium using an in-house herb database and high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

Currently, the identification of herb metabolites is challenging due to a lack of clear standards. Here, using Gelsemium as an example, we present a protocol for characterizing target components of herbs. This approach utilizes high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry guided by an in-house herb metabolite database based on reported studies and mass spectrometry. We describe steps for creating an in-house database, preparing and detecting samples, processing data, and characterizing compounds. This approach offers a reference for future research on the identification of herb metabolites. For complete details on the use and execution of this protocol, please refer to Liu et al. (2017).1.

A Novel Two-Dimensional Liquid Chromatography Combined with Ultraviolet Detection Method for Quantitative Determination of Pyridoxal 5'-Phosphate, 4-Pyridoxine Acid and Pyridoxal in Animal Plasma.

Vitamin B6 is an indispensable micronutrient in organisms and is widely distributed in blood, tissues, and organs. Changes in the content and ratio of vitamin B6 can affect the entire physiological condition of the body, so it becomes particularly important to reveal the relationship between changes in its content and disease by monitoring vitamin B6 levels in the organism. In this study, a two-dimensional liquid chromatography-UV detector (2D-LC-UV) was used to establish a method for the simultaneous detection of PLP, PA, and PL for the first time. First, PLP, PA, and PL were extracted with plasma: 0.6 M TCA: ultrapure water = 1:2:3 (v/v/v) and then derivatized. Enrichment and preliminary separation were performed on a one-dimensional column and automatically entered into a two-dimensional column for further separation. This method exhibited good selectivity, and the correlation coefficients for the analyte calibration curves were >0.99. The detection limits for PLP, PA, and PL were 0.1, 0.2, and 4 nmol/L, respectively. The results showed that the system has high loading capacity, excellent resolution, and a good peak shape. This method is expected to provide applicability for the determination of PLP, PA, and PL in pharmacological, pharmaceutical, and clinical research.

Long-term plant diversity increases soil extractable organic carbon and nitrogen contents in a subtropical forest.

Plant diversity is one of the various factors influencing ecosystem functions such as soil carbon (C) and nitrogen (N) stocks. Soil extractable organic carbon (EOC) and nitrogen (EON) contents are active fractions in soil organic matter, but little is known about the impact of variations in long-term plant diversity on soil EOC and EON contents in forest ecosystems. Utilizing the Biodiversity-Ecosystem Functioning Experiment China platform, we selected long-term plant diversity level treatments, distinguished the functional types of evergreen and deciduous plants, and explored their effects on soil EOC and EON contents. The results showed that soil EOC and EON contents increased significantly with greater plant diversity, which is mainly attributed to proportional increases in complementary effects. After distinguishing plant functional types, we did not find the strong complementary effects at the mixed planting of evergreen and deciduous tree species. Within two-species planting mixtures, evergreen tree species can increase soil EON compared to deciduous tree species. Cyclobalanopsis have a strong carbon and nitrogen storage capacity, suggesting that increasing the plant diversity and the proportion of Cyclobalanopsis planting in forest management will promote carbon and nitrogen accumulation in forest soil. These findings enhance our understanding of long-term forest C and N cycling processes and also provide theoretical support for managing forest soil C sinks.

Effect of different bone cement distributions in percutaneous kyphoplasty on clinical outcomes for osteoporotic vertebral compression fractures: A retrospective study.

Osteoporotic fractures and their complications are becoming increasingly harmful to the elderly. This study aimed to evaluate the clinical results of connected or unconnected bilateral cement after bilateral percutaneous kyphoplasty (PKP) in patients with osteoporotic vertebral compression fractures (OVCF). The clinical data of 217 patients with single-segment OVCF were retrospectively collected. Patients were allocated into 2 groups according to the bilateral bone cement in the vertebrae was connected or unconnected after surgery. The surgery-related indexes of the 2 groups were compared, including operation time; bone cement injection volume; contact situation between bone cement and the upper and lower endplates of the vertebral body; visual analogue scale (VAS) scores before surgery, 1 week and 1 year after surgery; Oswestry disability index (ODI) before surgery, 1 week and 1 year after surgery; local kyphosis angle (LKA) before surgery, 1 week and 1 year after surgery; postoperative vertebral body height at 1 week and 1 year after surgery; vertebral body height restoration rate (HRR) at 1 week and 1 year after surgery. The follow-up results of all patients were recorded. The postoperative VAS, ODI, vertebral body height, LKA and other indexes of the 2 groups were significantly improved compared with those before the operation (P < .05), and there was no significant difference between the 2 groups (P > .05). At the same time, there were no significant difference in vertebral body HRR and bone cement leakage rate between the 2 groups (P > .05). X-ray examination showed that 21 of 217 patients (21/217, 9.8%) had a refracture of the injured vertebral body, including 16 cases (16/121, 13.2%) in the unconnected group and 5 cases (5/96, 5.2%) in the connected group (P < .05). Adjacent vertebrae fractures occurred in 25 cases (25/217, 11.5%), while 19 cases (19/121, 15.7%) were in the unconnected group and 6 cases (6/96, 6.3%) were in the connected group (P < .05). PKP has a good therapeutic effect on OVCF no matter whether the bilateral bone cement is connected or not. However, if the bilateral cement inside the vertebra was connected, the risk of recollapse of the injured vertebrae and the new fracture of adjacent vertebrae could be reduced.

Network Pharmacology and Experimental Verification to Unveil the Mechanism of N-Methyl-D-Aspartic Acid Rescue Humantenirine-Induced Excitotoxicity.

Gelsemium is a medicinal plant that has been used to treat various diseases, but it is also well-known for its high toxicity. Complex alkaloids are considered the main poisonous components in Gelsemium. However, the toxic mechanism of Gelsemium remains ambiguous. In this work, network pharmacology and experimental verification were combined to systematically explore the specific mechanism of Gelsemium toxicity. The alkaloid compounds and candidate targets of Gelsemium, as well as related targets of excitotoxicity, were collected from public databases. The crucial targets were determined by constructing a protein-protein interaction (PPI) network. Subsequently, Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore the bioprocesses and signaling pathways involved in the excitotoxicity corresponding to alkaloids in Gelsemium. Then, the binding affinity between the main poisonous alkaloids and key targets was verified by molecular docking. Finally, animal experiments were conducted to further evaluate the potential mechanisms of Gelsemium toxicity. A total of 85 alkaloids in Gelsemium associated with 214 excitotoxicity-related targets were predicted by network pharmacology. Functional analysis showed that the toxicity of Gelsemium was mainly related to the protein phosphorylation reaction and plasma membrane function. There were also 164 pathways involved in the toxic mechanism, such as the calcium signaling pathway and MAPK signaling pathway. Molecular docking showed that alkaloids have high affinity with core targets, including MAPK3, SRC, MAPK1, NMDAR2B and NMDAR2A. In addition, the difference of binding affinity may be the basis of toxicity differences among different alkaloids. Humantenirine showed significant sex differences, and the LD50 values of female and male mice were 0.071 mg·kg-1 and 0.149 mg·kg-1, respectively. Furthermore, we found that N-methyl-D-aspartic acid (NMDA), a specific NMDA receptor agonist, could significantly increase the survival rate of acute humantenirine-poisoned mice. The results also show that humantenirine could upregulate the phosphorylation level of MAPK3/1 and decrease ATP content and mitochondrial membrane potential in hippocampal tissue, while NMDA could rescue humantenirine-induced excitotoxicity by restoring the function of mitochondria. This study revealed the toxic components and potential toxic mechanism of Gelsemium. These findings provide a theoretical basis for further study of the toxic mechanism of Gelsemium and potential therapeutic strategies for Gelsemium poisoning.

[Screening of housekeeping genes in Gelsemium elegans and expression patterns of genes involved in its alkaloid biosynthesis].

Gelsemium elegans is a traditional Chinese herb of medicinal importance, with indole terpene alkaloids as its main active components. To study the expression of the most suitable housekeeping reference genes in G. elegans, the root bark, stem segments, leaves and inflorescences of four different parts of G. elegans were used as materials in this study. The expression stability of 10 candidate housekeeping reference genes (18S, GAPDH, Actin, TUA, TUB, SAND, EF-1α, UBC, UBQ, and cdc25) was assessed through real-time fluorescence quantitative PCR, GeNorm, NormFinder, BestKeeper, ΔCT, and RefFinder. The results showed that EF-1α was stably expressed in all four parts of G. elegans and was the most suitable housekeeping gene. Based on the coexpression pattern of genome, full-length transcriptome and metabolome, the key candidate targets of 18 related genes (AS, AnPRT, PRAI, IGPS, TSA, TSB, TDC, GES, G8H, 8-HGO, IS, 7-DLS, 7-DLGT, 7-DLH, LAMT, SLS, STR, and SGD) involved in the Gelsemium alkaloid biosynthesis were obtained. The expression of 18 related enzyme genes were analyzed by qRT-PCR using the housekeeping gene EF-1α as a reference. The results showed that these genes' expression and gelsenicine content trends were correlated and were likely to be involved in the biosynthesis of the Gelsemium alkaloid, gelsenicine.

Genomic evidence supports the genetic convergence of a supergene controlling the distylous floral syndrome.

Heterostyly, a plant sexual polymorphism controlled by the S-locus supergene, has evolved numerous times among angiosperm lineages and represents a classic example of convergent evolution in form and function. Determining whether underlying molecular convergence occurs could provide insights on constraints to floral evolution. Here, we investigated S-locus genes in distylous Gelsemium (Gelsemiaceae) to determine whether there is evidence of molecular convergence with unrelated distylous species. We used several approaches, including anatomical measurements of sex-organ development and transcriptome and whole-genome sequencing, to identify components of the S-locus supergene. We also performed evolutionary analysis with candidate S-locus genes and compared them with those reported in Primula and Turnera. The candidate S-locus supergene of Gelsemium contained four genes, of which three appear to have originated from gene duplication events within Gelsemiaceae. The style-length genes GeCYP in Gelsemium and CYP734A50 in Primula likely arose from duplication of the same gene, CYP734A1. Three out of four S-locus genes in Gelsemium elegans were hemizygous, as previously reported in Primula and Turnera. We provide genomic evidence on the genetic convergence of the supergene underlying distyly among distantly related angiosperm lineages and help to illuminate the genetic architecture involved in the evolution of heterostyly.

Two-Dimensional Liquid Chromatography Method for the Determination of Gelsemium Alkaloids in Honey.

Toxic Chinese medicine residues in honey pose a serious threat to consumer health. Gelsemium is one of the nine ancient poisons, making the whole plant virulent. The residue of Gelsemium alkaloid in honey causes poisoning from time to time. Therefore, it is very important to establish a method for the detection of Gelsemium alkaloids in honey. In this study, a method of solid phase extraction (SPE) with two-dimensional liquid chromatography (2D-LC) was developed for the first time for the simultaneous determination of Gelsemium alkaloids in honey, including gelsemine, koumine and humantenmine. First, the honey samples were purified by a PRS cation exchange column and extracted with 5% ammoniated methanol. Then, we verified the methodological indicators, which were in line with the Codex Guideline requirements. The verification results are as follows: matrix-matched calibrations indicated that the correlation coefficients were higher than 0.998. The recovery was in the range of 81%-94.2% with an intraday precision (RSD) of ≤5.0% and interday RSD of ≤3.8%. The limit of detection for the three alkaloids was 2 ng/g. The limits of quantification for gelsemine and koumine were 5 ng/g, and humantenmine was 20 ng/g. This method can be applied to the monitoring of Gelsemium alkaloids in honey.

Thoughts on surgical excision of onychopapilloma.

Although onychopapilloma (OP) is a benign tumor of the nail bed and distal matrix, there is nevertheless a demand for treatment in some patients. Classical longitudinal excision (CLEx) with avulsion of the nail plate was the most suitable surgical procedure. However, there may be better ways to produce a pleasing esthetic effect. The aim of this study was to modify CLEx to render it more effective, reduce the rate of recurrence, and achieve better esthetic results. We identified 23 patients with OP in varying clinical manifestations that were treated with CLEx and modified CLEx with or without avulsion of the nail plate. With the procedure of modified CLEx without avulsion of the nail plate, there was no bleeding as a side effect and recovery was faster. The appearance of the nail was nearly unchanged and no patient complained about the cosmetic results. We modified CLEx to treat OP to improve the esthetic effect while maintaining surgical effectiveness.

Reducing plant-derived ethylene concentrations increases the resistance of temperate grassland to drought.

Model predictions indicate that extreme drought events will occur more frequently by the end of this century, with major implications for terrestrial ecosystem functions such as plant productivity and soil respiration. Previous studies have shown that drought-induced ethylene produced by plants is a key factor affecting plant growth and development, but the impact of drought-induced ethylene on ecosystem functions in natural settings has not yet been tested. Here, we reduced the amount of plant-derived ethylene concentrations by adding the ethylene inhibitor aminoethoxyvinylglycine (AVG), and investigated in situ plant productivity, soil respiration and ethylene concentrations for two years in a semi-arid temperate grassland in Inner Mongolia, China. Drought significantly reduced plant productivity and soil respiration, but the application of AVG reduced ethylene concentrations and significantly increased aboveground plant productivity and soil respiration, effectively enhancing resistance to drought. The reason for this could be that AVG application increased the activity of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and abundance of the acdS gene (the key gene for ACC deaminase), facilitating reduced ACC concentrations in the plant tissue and reduced in planta ethylene synthesis. In addition, there was a significant correlation between soil ACC deaminase activity and plant productivity. Given the global distribution of arid and semi-arid areas, and the expected increases in the frequency and intensity of drought stress, this is a significant concern. These results provide novel evidence of the impact of drought-induced plant ethylene production on ecosystem functions in semi-arid temperate grassland ecosystems.

Development and validation of the interpretability analysis system based on deep learning model for smart image follow-up of nail pigmentation.

Background: Nail pigmentation can be a clinical manifestation of malignant melanoma and a variety of benign diseases. Nail matrix biopsy for pathologic examination, the gold standard for diagnosis of subungual melanoma, is a painful procedure and may result in nail damage. Therefore, there is a great need for non-invasive methods and long-term follow-up for nail pigmentation. The objective of this study is to establish an intelligent precursor system to provide convenient monitoring for nail pigmentation, early warning subungual melanoma, and reduce nail biopsies to the minimum necessary. Methods: Dermoscopic images of nail lesions were obtained from outpatients between 2019 and 2020. The images were divided into the training set and the test set using k-fold cross validation at a ratio of 10:1. The deep learning model is developed based on the Pytorch framework. The model structure is optimized using the image segmentation model U-Net. An image segmentation module analyzed the contours of the whole nail plate and pigmented area according to the boundary features of the input images and a rule calculation module used the output information of the segmentation model to automatically analyze specific indicators referring to the "ABCDEF" rule. The model's results were compared with those of clinical experts. Results: From 550 dermoscopic images of nail lesions obtained, 500 were selected randomly as the training set, and the remaining 50 as the test set. Our image segmentation module realized automatic segmentation of the pigmented area and the whole nail plate with dice coefficient to be 0.8711 and 0.9652, respectively. Five qualitative indicators were selected in the interpretability analysis system and the models showed a certain degree of consistency with the evaluation by clinical experts, i.e., R2 for area ratio vs. breadth score was 0.8179 (P<0.001), for mean pixel value vs. pigment score was 0.7149 (P<0.001), for evenness vs. pigment score was 0.5247 (P<0.001). Conclusions: The proposed system made accurate segmentation of the nail plate and pigmented area and achieved medically interpretable index analysis. It is potentially a primer of an intelligent follow-up system that will enable convenient and spatially unaffected management and monitoring of nail pigmentation. It may provide clinicians with understandable auxiliary information for diagnosis.