Multicomponent Reductive Coupling for Selective Access to Functional γ-Lactams by a Single-Atom Cobalt Catalyst.

Despite their significant importance to numerous fields, the difficulties in direct and diverse synthesis of α-hydroxy-γ-lactams pose substantial obstacles to their practical applications. Here, we designed a nitrogen and TiO2 co-doped graphitic carbon-supported material with atomically dispersed cobalt sites (CoSA-N/NC-TiO2), which was successfully applied as a multifunctional catalyst to establish a general method for direct construction of α-hydroxy-γ-lactams from cheap and abundant nitro(hetero)arenes, aldehydes, and H2O with alkynoates. The striking features of operational simplicity, broad substrate and functionality compatibility (>100 examples), high step and atom efficiency, good selectivity, and exceptional catalyst reusability highlight the practicality of this new catalytic transformation. Mechanistic studies reveal that the active CoN4 species and the dopants exhibit a synergistic effect on the formation of key acid-masked nitrones; their subsequent nucleophilic addition to the alkynoates followed by successive reduction, alkenyl hydration, and intramolecular ester ammonolysis delivers the desired products. In this work, the concept of reduction interruption leading to new reaction route will open a door to further develop useful transformations by rational catalyst design.

Therapeutic challenges in peripheral T-cell lymphoma.

Peripheral T-cell lymphoma (PTCL) is a rare and heterogeneous group of hematological malignancies. Compared to our knowledge of B-cell tumors, our understanding of T-cell leukemia and lymphoma remains less advanced, and a significant number of patients are diagnosed with advanced stages of the disease. Unfortunately, the development of drug resistance in tumors leads to relapsed or refractory peripheral T-Cell Lymphomas (r/r PTCL), resulting in highly unsatisfactory treatment outcomes for these patients. This review provides an overview of potential mechanisms contributing to PTCL treatment resistance, encompassing aspects such as tumor heterogeneity, tumor microenvironment, and abnormal signaling pathways in PTCL development. The existing drugs aimed at overcoming PTCL resistance and their potential resistance mechanisms are also discussed. Furthermore, a summary of ongoing clinical trials related to PTCL is presented, with the aim of aiding clinicians in making informed treatment decisions.

Identification of genetic variants controlling diosgenin content in Dioscorea zingiberensis tuber by genome-wide association study.

BACKGROUND: Diosgenin is an important steroidal precursor renowned for its diverse medicinal uses. It is predominantly sourced from Dioscorea species, particularly Dioscorea zingiberensis. Dioscorea zingiberensis has an ability to accumulate 2-16% diosgenin in its rhizomes. In this study, a diverse population of 180 D. zingiberensis accessions was used to evaluate the genomic regions associated with diosgenin biosynthesis by the genome wide association study approach (GWAS). RESULTS: The whole population was characterized for diosgenin contents from tubers by gas chromatography mass spectrometry. The individuals were genotyped by the genotyping-by-sequencing approach and 10,000 high-quality SNP markers were extracted for the GWAS. The highest significant marker-trait-association was observed as an SNP transversion (G to T) on chromosome 10, with 64% phenotypic variance explained. The SNP was located in the promoter region of CYP94D144 which is a member of P450 gene family involved in the independent biosynthesis of diosgenin from cholesterol. The transcription factor (TF) binding site enrichment analysis of the promoter region of CYP94D144 revealed NAC TF as a potential regulator. The results were further validated through expression profiling by qRT-PCR, and the comparison of high and low diosgenin producing hybrids obtained from a bi-parental population. CONCLUSIONS: This study not only enhanced the understanding of the genetic basis of diosgenin biosynthesis but also serves as a valuable reference for future genomic investigations on CYP94D144, with the aim of augmenting diosgenin production in yam tubers.

Genome-wide association analysis and transgenic characterization for amylose content regulating gene in tuber of Dioscorea zingiberensis.

BACKGROUND: Amylose, a prebiotic found in yams is known to be beneficial for the gut microflora and is particularly advantageous for diabetic patients' diet. However, the genetic machinery underlying amylose production remains elusive. A comprehensive characterization of the genetic basis of amylose content in yam tubers is a prerequisite for accelerating the genetic engineering of yams with respect to amylose content variation. RESULTS: To uncover the genetic variants underlying variation in amylose content, we evaluated amylose content in freshly harvested tubers from 150 accessions of Dioscorea zingibensis. With 30,000 high-quality single nucleotide polymorphisms (SNP), we performed a genome-wide association analysis (GWAS). The population structure analysis classified the D. zingiberensis accessions into three groups. A total of 115 significant loci were detected on four chromosomes. Of these, 112 significant SNPs (log10(p) = 5, q-value < 0.004) were clustered in a narrow window on the chromosome 6 (chr6). The peak SNP at the position 75,609,202 on chr6 could explain 63.15% of amylose variation in the population and fell into the first exon of the ADP-glucose pyrophosphorylase (AGPase) small subunit gene, causing a non-synonymous modification of the resulting protein sequence. Allele segregation analysis showed that accessions with the rare G allele had a higher amylose content than those harboring the common A allele. However, AGPase, a key enzyme precursor of amylose biosynthesis, was not expressed differentially between accessions with A and G alleles. Overexpression of the two variants of AGPase in Arabidopsis thaliana resulted in a significantly higher amylose content in lines transformed with the AGPase-G allele. CONCLUSIONS: Overall, this study showed that a major genetic variant in AGPase probably enhances the enzyme activity leading to high amylose content in D. zingiberensis tuber. The results provide valuable insights for the development of amylose-enriched genotypes.

Efficient Exciton Dissociation on Ceria Chelated Cerium-Based MOF Isogenous S-Scheme Photocatalyst for Acetaldehyde Purification.

Long-term exposure to low concentration indoor VOCs of acetaldehyde (CH3CHO) is harmful to human health. Thus, a novel isogenous heterojunction CeO2/Ce-MOF photocatalyst is synthesized via a one-step hydrothermal method for the effective elimination of CH3CHO in this work. This CeO2/Ce-MOF photocatalyst performs well in CH3CHO removal and achieves an apparent quantum efficiency of 7.15% at 420 nm, which presents ≈6.7 and 3.4 times superior to those generated by CeO2 and Ce-MOF, respectively. The enhanced efficiency is due to two main aspects including i) an effective photocarrier separation ability and the prolonged reaction lifetime of excitons play crucial roles and ii) the formation of an internal electric field (IEF) is sufficient to overcome the considerable exciton binding energy, and increases the exciton dissociation efficiency by up to 50.4%. Moreover, the reasonable pathways and mechanisms of CH3CHO degradation are determined by in situ DRIFTS analysis and simulated DFT calculations. Those results demonstrated that S-scheme heterojunction successfully increases the efficiency of harmful volatile organic compounds elimination, and it offers essential guidance for designing rare earth-based MOF photocatalysts.

Fibrotic Matrix Induces Mesenchymal Transformation of Epithelial Cells in Oral Submucous Fibrosis.

Oral submucous fibrosis (OSF) is a potentially malignant disorder of the oral mucosa; however, whether and how the fibrotic matrix of OSF is involved in the malignant transformation of epithelial cells remains unknown. Herein, oral mucosa tissue from patients with OSF, OSF rat models, and their controls were used to observe the extracellular matrix changes and epithelial-mesenchymal transformation (EMT) in fibrotic lesions. Compared with controls, oral mucous tissues from patients with OSF showed an increased number of myofibroblasts, a decreased number of blood vessels, and increased type I and type III collagen levels. In addition, the oral mucous tissues from humans and OSF rats showed increased stiffness, accompanied by increased EMT activities of epithelial cells. The EMT activities of stiff construct-cultured epithelial cells were increased significantly by exogenous piezo-type mechanosensitive ion channel component 1 (Piezo1) activation, and decreased by yes-associated protein (YAP) inhibition. During ex vivo implantation, oral mucosal epithelial cells of the stiff group showed increased EMT activities and increased levels of Piezo1 and YAP compared with those in the sham and soft groups. These results indicate that increased stiffness of the fibrotic matrix in OSF led to increased proliferation and EMT of mucosal epithelial cells, in which the Piezo1-YAP signal transduction is important.

Reduction-Specified Coupling Reactions of Nitroarenes by Heterogeneous Cobalt Catalysis.

The in-depth study on reduction-specified coupling reactions of the nitroarenes by heterogeneous cobalt catalysis opens a door for diversified syntheses of functional N-containing molecules. Guided by the structure-function relationship of heterogeneous materials, rational design of nano-catalysts can effectively regulate the routes of organic reactions. Precise transformation of the intermediates generated during the nitroarene reduction with a suitable nano-catalyst is a promising way to develop new tandem reactions, and to synthesize structurally novel compounds that are of difficult access with the conventional approaches.

Peripheral blood eosinophils: an important reference for radiologists to distinguish between pulmonary paragonimiasis and tuberculous pleurisy in children.

OBJECTIVE: In this study, we examined the value of chest CT signs combined with peripheral blood eosinophil percentage in differentiating between pulmonary paragonimiasis and tuberculous pleurisy in children. METHODS: Patients with pulmonary paragonimiasis and tuberculous pleurisy were retrospectively enrolled from January 2019 to April 2023 at the Kunming Third People's Hospital and Lincang People's Hospital. There were 69 patients with pulmonary paragonimiasis (paragonimiasis group) and 89 patients with tuberculous pleurisy (tuberculosis group). Clinical symptoms, chest CT imaging findings, and laboratory test results were analyzed. Using binary logistic regression, an imaging model of CT signs and a combined model of CT signs and eosinophils were developed to calculate and compare the differential diagnostic performance of the two models. RESULTS: CT signs were used to establish the imaging model, and the receiver operating characteristic (ROC) curve was plotted. The area under the curve (AUC) was 0.856 (95% CI: 0.799-0.913), the sensitivity was 66.7%, and the specificity was 88.9%. The combined model was established using the CT signs and eosinophil percentage, and the ROC was plotted. The AUC curve was 0.950 (95% CI: 0.919-0.980), the sensitivity was 89.9%, and the specificity was 90.1%. The differential diagnostic efficiency of the combined model was higher than that of the imaging model, and the difference in AUC was statistically significant. CONCLUSION: The combined model has a higher differential diagnosis efficiency than the imaging model in the differentiation of pulmonary paragonimiasis and tuberculous pleurisy in children. The presence of a tunnel sign on chest CT, the absence of pulmonary nodules, and an elevated percentage of peripheral blood eosinophils are indicative of pulmonary paragonimiasis in children.

Epsin1-mediated exosomal sorting of Dll4 modulates the tubular-macrophage crosstalk in diabetic nephropathy.

Tubular epithelial cells (TECs) play critical roles in the development of diabetic nephropathy (DN), and can activate macrophages through the secretion of exosomes. However, the mechanism(s) of TEC-exosomes in macrophage activation under DN remains unknown. By mass spectrometry, 1,644 differentially expressed proteins, especially Dll4, were detected in the urine exosomes of DN patients compared with controls, which was confirmed by western blot assay. Elevated Epsin1 and Dll4/N1ICD expression was observed in kidney tissues in both DN patients and db/db mice and was positively associated with tubulointerstitial damage. Exosomes from high glucose (HG)-treated tubular cells (HK-2) with Epsin1 knockdown (KD) ameliorated macrophage activation, TNF-α, and IL-6 expression, and tubulointerstitial damage in C57BL/6 mice in vivo. In an in vitro study, enriched Dll4 was confirmed in HK-2 cells stimulated with HG, which was captured by THP-1 cells and promoted M1 macrophage activation. In addition, Epsin1 modulated the content of Dll4 in TEC-exosomes stimulated with HG. TEC-exosomes with Epsin1-KD significantly inhibited N1ICD activation and iNOS expression in THP-1 cells compared with incubation with HG alone. These findings suggested that Epsin1 could modulate tubular-macrophage crosstalk in DN by mediating exosomal sorting of Dll4 and Notch1 activation.

Characterization and Effect of a Nematophagous Fungus Talaromyces cystophila sp. nov. for the Biological Control of Corn Cyst Nematode.

The dynamic of plant-parasitic nematode populations in soil is closely related to soil microorganisms. Fungi from Heterodera zeae cysts were isolated to explore the phenomenon of decline in the H. zeae population in the soil. Phylogenetic study of partial ITS, BenA, CaM, and RPB2 gene sequences, in addition to morphological investigations, was utilized to identify a nematode-destroying fungus. The nematicidal activity of a novel strain GX1 against H. zeae was assessed in vitro and in the greenhouse. Our findings revealed that strain GX1 is a new species of Talaromyces, named Talaromyces cystophila. It has a strong parasitic and lethal effect on H. zeae cysts, with 91.11% parasitism on cysts at 3 days after treatment. The contents of second-stage juveniles (J2s) and eggs inside the cysts were degraded and formed dense vacuoles, and the damaged eggs could not hatch normally. The spore suspension exhibited high nematophagous activity against nematodes, and fermentation filtrate exhibited marked inhibition of egg hatching and nematicidal activities on J2s. The hatching inhibition rates of eggs exposed to 1 × 108 CFU/ml spore suspensions or 20% 1-week fermentation filtrate (1-WF) for 15 days were 98.56 and 100%, respectively. The mortality of J2s exposed to 1 × 108 CFU/ml spore suspension reached 100% at 24 h; exposure to 50% 2-WF was 98.65 and 100% at 24 and 48 h, respectively. Greenhouse experiments revealed that the spore suspension and fermentation broth considerably decreased H. zeae reproduction by 56.17 to 78.76%. T. cystophila is a potential biocontrol strain with nematophagous and nematicidal activity that deserves attention and application.

Case-controlled study of tuberculosis in in-vitro fertilisation-embryo transfer and natural pregnancy.

OBJECTIVE: To improve the understanding of the clinical features and imaging characteristics of pregnant women with and without in-vitro fertilisation-embryo transfer combined with pulmonary tuberculosis (TB). METHODS: A retrospective analysis was conducted involving 50 patients with pregnancy who had pulmonary TB and were admitted to the Third People's Hospital of Kunming (China) between 1 January 2017 and 31 December 2021. These patients were divided into an in-vitro fertilisation and embryo transfer (IVF-ET) conception group and a natural conception group according to the conception method. The clinical and imaging data were then collected and compared. RESULTS: The mean age of the IVF-ET group (n = 13, 31.85 ± 5.84 years) was higher than in the natural conception group (n = 37, 27.05 ± 5.5 years). The proportions of fever, haematogenous TB and extrapulmonary TB in the IVF-ET group (92.31%, 84.62% and 76.92%, respectively) were higher than those in the natural conception group (40.54%,16.22%,27.03%,respectively). The percentage of patients with pregnancy who had intracranial TB (76.9%) in the IVF-ET group was higher than in the natural conception group (10.8%). The percentage of pregnancy terminations in the IVF-ET conception group (84.62%) was higher than in the natural conception group (48.65%). All the above results had statistically significant differences (p < 0.05). CONCLUSION: Overall, IVF-ET conception combined with extensive pulmonary TB lesions lead to heavy systemic toxic symptoms, severe disease and poor pregnancy outcomes. Therefore, screening for TB prior to performing IVF-ET is recommended.

Association between postoperative changes in natremia and outcomes in patients undergoing elective craniotomy.

Postoperative dysnatremias, characterized by imbalances in serum sodium levels, have been linked to increased resource utilization and mortality in surgical and intensive care patients. The management of dysnatremias may involve medical interventions based on changes in sodium levels. In this study, we aimed to investigate the impact of postoperative changes in natremia on outcomes specifically in patients undergoing craniotomy.We conducted a retrospective analysis of patient records from the Department of Neurosurgery at West China Hospital, Sichuan University, covering the period from January 2011 to March 2021. We compared the highest and lowest sodium values in the first 14 postoperative days with the baseline values to define four categories for analysis: no change < 5 mmol/L; decrease > 5 mmol/L; increase > 5 mmol/L; both increase and decrease > 5 mmol/L. The primary outcome measure was 30-day mortality.A total of 12,713 patients were included in the study, and the overall postoperative mortality rate at 30 days was 2.1% (264 patients). The increase in sodium levels carried a particularly high risk, with a tenfold increase (OR 10.21; 95% CI 7.25-14.39) compared to patients with minimal or no change. Decreases in sodium levels were associated with an increase in mortality (OR 1.60; 95% CI 1.11-2.23).Moreover, the study revealed that postoperative sodium decrease was correlated with various complications, such as deep venous thrombosis, pneumonia, intracranial infection, urinary infection, seizures, myocardial infarction, and prolonged hospital length of stay. On the other hand, postoperative sodium increases were associated with acute kidney injury, deep venous thrombosis, pneumonia, intracranial infection, urinary infection, surgical site infection, seizures, myocardial infarction, and prolonged hospital length of stay.Changes in postoperative sodium levels were associated with increased complications, prolonged length of hospital stay, and 30-day mortality. Moreover, the severity of sodium change values correlated with higher mortality rates.

Association between elevated preoperative red cell distribution width and mortality after brain tumor craniotomy.

BACKGROUND: Red cell distribution width (RDW) has been recognized as a potential inflammatory biomarker, with elevated levels associated with adverse outcomes in various diseases. However, its role in predicting outcomes after brain tumor craniotomy remains unclear. We aimed to assess whether preoperative RDW influences mortality and postoperative complications in patients undergoing brain tumor craniotomy. METHODS: This retrospective cohort study analyzed serum RDW levels in patients undergoing brain tumor craniotomy at West China Hospital. RDW was evaluated in two forms: RDW-CV and RDW-SD, and was categorized into four quartiles for analysis by using logistic regression and multivariate analysis to adjust for confounding. RESULTS: The study encompassed 10,978 patients undergoing brain tumor craniotomy. our analysis revealed no significant difference in 30-day mortality across various RDW-CV levels. However, we observed a dose-response relationship with preoperative RDW-CV levels in assessing long-term mortality risks. Specifically, patients with RDW-CV levels of 12.6-13.2% (HR 1.04, 95% CI 1.01-1.18), 13.2-13.9% (HR 1.12, 95% CI 1.04-1.26), and > 13.9% (HR 1.34, 95% CI 1.18-1.51) exhibited a significantly higher hazard of long-term mortality compared to those with RDW-CV < 12.6%. When preoperative RDW-CV was analyzed as a continuous variable, for each 10% increase in RDW-CV, the adjusted OR of long-term mortality was 1.09 (95% CI 1.05-1.13). we also observed significant associations between preoperative higher RDW-CV levels and certain postoperative complications including acute kidney injury (OR 1.46, 95% CI: 1.10-1.94), pneumonia infection (OR 1.19 95% CI: 1.05-1.36), myocardial infarction (OR 1.32, 95% CI: 1.05-1.66), readmission (OR 1.15, 95% CI: 1.01-1.30), and a prolonged length of hospital stay (OR 1.11, 95% CI: 1.02-1.21). For RDW-SD levels, there was no significant correlation for short-term mortality, long-term mortality, and postoperative complications. CONCLUSIONS: Our study showed elevated preoperative RDW-CV is significantly associated with increased long-term mortality and multiple postoperative complications, but no such association is observed with RDW-SD. These findings show the prognostic importance of RDW-CV, reinforcing its potential as a valuable tool for risk stratification in the preoperative evaluation of brain tumor craniotomy patients.

Tooth intentional replantation from 1964 to 2023: A bibliometric analysis.

BACKGROUND/AIM: There is no thorough overview of intentional tooth replantation techniques. We performed a bibliometric analysis of the development of intentional tooth replantation. MATERIALS AND METHODS: A comprehensive search of the Web of Science and SCOPUS databases was conducted in February 2023. Original articles and reviews of human studies with "intentional replantation" or synonyms in the titles, abstracts, or keywords were included. A descriptive analysis of bibliographic data, co-occurrence analysis, and coupling of publications was performed. Multivariate analysis was used to explore the bibliometric parameters associated with the citation counts. RESULTS: The study included 171 papers, which were co-authored by 500 individuals affiliated with 217 institutions from 28 countries/regions. The USA contributed the greatest number of publications, followed by China, and Japan. The USA had 694 citations, followed by Japan (210), and Turkey (210). The Journal of Endodontics and Dental Traumatology contributed the most citations. Five directions for future research were identified based on the coupling relationships of publications, including "managing vertical root fractures with adhesive resin using the intentional replantation technique," "intentional replantation for periodontally hopeless or endodontically compromised teeth," "intentional replantation for treating abnormalities of morphological development," "outcomes and prognosis factors of intentional replantation," and "treating root replacement resorption by intentional replantation." Multivariate analysis showed that the publication year, Journal Citation Reports ranking of journals, study design, and disease type were predictors of citation counts. CONCLUSIONS: This bibliometric analysis provides a comprehensive description of the intentional replantation technique. The USA published the greatest volume of papers and generated the most citations. The Journal of Endodontics and Dental Traumatology are considered the most influential. The Journal Citation Reports journal ranking (Q1, Q2), study design (case reports, cohort studies), and disease type (crown root fractures) were associated with the citation counts.

Characterization of the complete mitochondrial genome of Ergasilus anchoratus Markevich, 1946 (Ergasilidae) and phylogeny of Copepoda.

The mitochondrial (mt) genome can provide data for phylogenetic analyses and evolutionary biology. Herein, we sequenced and annotated the complete mt genome of Ergasilus anchoratus. This mt genome was 13852 bp long and comprised 13 protein-coding genes (PCGs), 22 tRNAs and 2 rRNAs. All PCGs used the standard ATN start codons and complete TAA/TAG termination codons. A majority of tRNA genes exhibited standard cloverleaf secondary structures, with the exception of one tRNA that lacked the TψC arm (trnC), and three tRNAs that lacked the DHU arm (trnR, trnS1 and trnS2). Phylogenetic analyses conducted using Bayesian inference (BI) and maximum likelihood (ML) methods both supported Ergasilidae as a monophyletic family forming a sister group to Lernaea cyprinacea and Paracyclopina nana. It also supported the monophyly of orders Calanoida, Cyclopoida, and Siphonostomatoida; and the monophyly of families Harpacticidae, Ergasilidae, Diaptomidae, and Calanidae. The gene orders of E. anchoratus and Sinergasilus undulatus were identical, which represents the first instance of two identical gene orders in copepods. More mt genomes are needed to better understand the phylogenetic relationships within Copepoda in the future.

Environmental Impact Assessment for the Use of an Orally Aerosolized Adenovirus Type-5 Vector-Based COVID-19 Vaccine in Randomized Clinical Trials.

BACKGROUND: An orally aerosolized adenovirus type-5 vector-based coronavirus disease 2019 (COVID-19) vaccine (Ad5-nCoV) has recently been authorized for boosting immunization in China. Our study aims to assess the environmental impact of the use of aerosolized Ad5-nCoV. METHODS: We collected air samples from rooms, swabs from the desks on which the vaccine nebulizer was set, mask samples from participants, and blood samples of nurses who administered the inoculation in the clinical trials. The viral load of adenovirus type-5 vector in the samples and the antibody levels against the wild-type severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain in serum were detected. RESULTS: Only one (4.00%) air sample collected before initiation of vaccination was positive and most air samples collected during and after vaccination were positive (97.96%, 100%, respectively). All nurses in trial A showed at least 4-fold increase of the neutralizing antibody against SARS-CoV-2 after initiation of the study. In trial B, the proportion of positive mask samples was 72.97% at 30 minutes after vaccination, 8.11% at day 1, and 0% at days 3, 5, and 7. CONCLUSIONS: Vaccination with the orally aerosolized Ad5-nCoV could result in some spillage of the vaccine vector viral particles in the environment and cause human exposure. Clinical Trials Registration. NCT04840992 and NCT05303584.

CsbD, a Novel Group B Streptococcal Stress Response Factor That Contributes to Bacterial Resistance against Environmental Bile Salts.

Group B Streptococcus (GBS) can cause many serious infections and result in severe symptoms depending on the infected organs. To survive and initiate infection from the gastrointestinal tract, GBS must resist physiochemical factors, such as bile salts, a potent antibacterial compound in the intestine. We found that GBS isolated from diverse sources all possess the capability to defend bile salts and permit survival. By constructing the GBS A909 transposon mutant library (A909Tn), we identified several candidate genes that might participate in the bile salt resistance of GBS. The rodA and csbD genes were validated as relevant to bile salt resistance. The rodA gene was anticipated to be related to peptidoglycan synthesis and influence the bile salt resistance of GBS by cell wall construction. Notably, we found that the csbD gene worked as a bile salt resistance response factor and influenced several ABC transporter genes, specifically at the later growth period of GBS under bile salt stress. We further detected the marked intracellular bile salt accumulation in ΔcsbD by hydrophilic interaction chromatography-liquid chromatography/mass spectrometry (HILIC-LC/MS). Collectively, we showed a novel GBS stress response factor, csbD, contributes to bacterial survival in bile salts by sensing bile salt stress and subsequently induces transcription of transporter genes to excrete bile salts. IMPORTANCE GBS, a conditional pathogenetic colonizer of the human intestinal flora, can cause severe infectious diseases in immunocompromised patients. Therefore, it is critical to understand the factors that contribute to the resistance to bile salts, which are abundant in the intestine but harmful to bacteria. We identified rodA and csbD genes involved in bile salt resistance using a transposon insertion site sequencing (TIS-seq) based screen. The rodA gene products might be involved in peptidoglycan synthesis as important contributors to stress resistance including bile salts. However, the csbD gene conferred bile salt resistance by promoting transporter genes transcription at the later growth period of GBS in response to bile salts. These findings developed a better understanding of the stress response factor csbD on the bile salt resistance of GBS.

Reductive Coupling of Nitroarenes and HCHO for General Synthesis of Functional Ethane-1,2-diamines by a Cobalt Single-Atom Catalyst.

Despite the extensive applications, selective and diverse access to N,N'-diarylethane-1,2-diamines remains, to date, a challenge. Here, by developing a bifunctional cobalt single-atom catalyst (CoSA-N/NC), we present a general method for direct synthesis of such compounds via selective reductive coupling of cheap and abundant nitroarenes and formaldehyde, featuring good substrate and functionality compatibility, an easily accessible base metal catalyst with excellent reusability, and high step and atom efficiency. Mechanistic studies reveal that the N-anchored cobalt single atoms (CoN4) serve as the catalytically active sites for the reduction processes, the N-doped carbon support enriches the HCHO to timely trap the in situ formed hydroxyamines and affords the requisite nitrones under weak alkaline conditions, and the subsequent inverse electron demand 1,3-dipolar cycloaddition of the nitrones and imines followed by hydrodeoxygenation of the cycloadducts furnishes the products. In this work, the concept of catalyst-controlled nitroarene reduction to in situ create specific building blocks is anticipated to develop more useful chemical transformations.

The catalase-peroxidase PiCP1 plays a critical role in abiotic stress resistance, pathogenicity and asexual structure development in Phytophthora infestans.

Catalase-peroxidase is a heme oxidoreductase widely distributed in bacteria and lower eukaryotes. In this study, we identified a catalase-peroxidase PiCP1 (PITG_05579) in Phytophthora infestans. PiCP1 had catalase/peroxidase and secretion activities and was highly expressed in sporangia and upregulated in response to oxidative and heat stresses. Compared with wild type, PiCP1-silenced transformants (STs) had decreased catalase activity, reduced oxidant stress resistance and damped cell wall integrity. In contrast, PiCP1-overexpression transformants (OTs) demonstrated increased tolerance to abiotic stresses and induced the upregulation of PR genes in the host salicylic acid pathway. The high concentration of PiCP1 can also induced callose deposition in plant tissue. Importantly, both STs and OTs have severely reduced sporangia formation and zoospore releasing rate, but the sporangia germination rate and type varied depending on environmental conditions. Comparative sequence analyses show that catalase-peroxidases are broadly distributed and highly conserved among soil-borne plant parasitic oomycetes, but not in freshwater-inhabiting or strictly plants-inhabiting oomycetes. In addition, we found that silencing PiCP1 downregulated the expression of PiCAT2. These results revealed the important roles of PiCP1 in abiotic stress resistance, pathogenicity and in regulating asexual structure development in response to environmental change. Our findings provide new insights into catalase-peroxidase functions in eukaryotic pathogens.

Physiological and transcriptional mechanisms associated with cadmium stress tolerance in Hibiscus syriacus L.

BACKGROUND: Cadmium (Cd) pollution of soils is a global concern because its accumulation in plants generates severe growth retardation and health problems. Hibiscus syriacus is an ornamental plant that can tolerate various abiotic stresses, including Cd stress. Therefore, it is proposed as a plant material in Cd-polluted areas. However, the molecular mechanisms of H. syriacus tolerance to Cd are not yet understood. RESULTS: This study investigated the physiological and transcriptional response of "Hongxing", a Cd2+-tolerant H. syriacus variety, grown on a substrate containing higher concentration of Cd (400 mg/kg). The Cd treatment induced only 28% of plant mortality, but a significant decrease in the chlorophyll content was observed. Malondialdehyde content and activity of the antioxidant enzymes catalase, peroxidase, and superoxide dismutase were significantly increased under Cd stress. Transcriptome analysis identified 29,921 differentially expressed genes (DEGs), including 16,729 down-regulated and 13,192 up-regulated genes, under Cd stress. Functional enrichment analyses assigned the DEGs mainly to plant hormone signal transduction, transport, nucleosome and DNA processes, mitogen-activated protein kinase signaling pathway, antioxidant process, fatty acid metabolism, and biosynthesis of secondary metabolites. Many MYB, EP2/ERF, NAC, WRKY family genes, and genes containing metal binding domains were up-regulated, implying that they are essential for the Cd-stress response in H. syriacus. The most induced genes were filtered out, providing valuable resources for future studies. CONCLUSIONS: Our findings provide insights into the molecular responses to Cd stress in H. syriacus. Moreover, this study offers comprehensive and important resources for future studies toward improving the plant Cd tolerance and its valorization in phytoremediation.