Accelerated Theta Burst Transcranial Magnetic Stimulation for Refractory Depression in Autism Spectrum Disorder.

PURPOSE: Major depressive disorder (MDD) disproportionately affects those living with autism spectrum disorder (ASD) and is associated with significant impairment and treatment recidivism. METHODS: We studied the use of accelerated theta burst stimulation (ATBS) for the treatment of refractory MDD in ASD (3 treatments daily x 10 days). This prospective open-label 12-week trial included 10 subjects with a mean age of 21.5 years, randomized to receive unilateral or bilateral stimulation of the dorsolateral prefrontal cortex. RESULTS: One participant dropped out of the study due to intolerability. In both treatment arms, depressive symptoms, scored on the Hamilton Depression Rating Scale scores, diminished substantially. At 12 weeks post-treatment, full remission was sustained in 5 subjects and partial remission in 3 subjects. Treatment with ATBS, regardless of the site of stimulation, was associated with a significant, substantial, and sustained improvement in depressive symptomatology via the primary outcome measure, the Hamilton Depression Rating Scale. Additional secondary measures, including self-report depression scales, fluid cognition, and sleep quality, also showed significant improvement. No serious adverse events occurred during the study. Mild transient headaches were infrequently reported, which are expected side effects of ATBS. CONCLUSION: Overall, ATBS treatment was highly effective and well-tolerated in individuals with ASD and co-occurring MDD. The findings support the need for a larger, sham-controlled randomized controlled trial to further evaluate efficacy of ATBS in this population.

Comparative metabolomics combined with genome sequencing provides insights into novel wolfberry-specific metabolites and their formation mechanisms.

Wolfberry (Lycium, of the family Solanaceae) has special nutritional benefits due to its valuable metabolites. Here, 16 wolfberry-specific metabolites were identified by comparing the metabolome of wolfberry with those of six species, including maize, rice, wheat, soybean, tomato and grape. The copy numbers of the riboflavin and phenyllactate degradation genes riboflavin kinase (RFK) and phenyllactate UDP-glycosyltransferase (UGT1) were lower in wolfberry than in other species, while the copy number of the phenyllactate synthesis gene hydroxyphenyl-pyruvate reductase (HPPR) was higher in wolfberry, suggesting that the copy number variation of these genes among species may be the main reason for the specific accumulation of riboflavin and phenyllactate in wolfberry. Moreover, the metabolome-based neighbor-joining tree revealed distinct clustering of monocots and dicots, suggesting that metabolites could reflect the evolutionary relationship among those species. Taken together, we identified 16 specific metabolites in wolfberry and provided new insight into the accumulation mechanism of species-specific metabolites at the genomic level.

Methane mitigation via the nitrite-DAMO process induced by nitrate dosing in sewers.

Nitrate or nitrite-dependent anaerobic methane oxidation (n-DAMO) is a microbial process that links carbon and nitrogen cycles as a methane sink in many natural environments. This study demonstrates, for the first time, that the nitrite-dependent anaerobic methane oxidation (nitrite-DAMO) process can be stimulated in sewer systems under continuous nitrate dosing for sulfide control. In a laboratory sewer system, continuous nitrate dosing not only achieved complete sulfide removal, but also significantly decreased dissolved methane concentration by ∼50 %. Independent batch tests confirmed the coupling of methane oxidation with nitrate and nitrite reduction, revealing similar methane oxidation rates of 3.68 ± 0.5 mg CH4 L-1 h-1 (with nitrate as electron acceptor) and 3.57 ± 0.4 mg CH4 L-1 h-1 (with nitrite as electron acceptor). Comprehensive microbial analysis unveiled the presence of a subgroup of the NC10 phylum, namely Candidatus Methylomirabilis (n-DAMO bacteria that couples nitrite reduction with methane oxidation), growing in sewer biofilms and surface sediments with relative abundances of 1.9 % and 1.6 %, respectively. In contrast, n-DAMO archaea that couple methane oxidation solely to nitrate reduction were not detected. Together these results indicated the successful enrichment of n-DAMO bacteria in sewerage systems, contributing to approx. 64 % of nitrite reduction and around 50 % of dissolved methane removal through the nitrite-DAMO process, as estimated by mass balance analysis. The occurrence of the nitrite-DAMO process in sewer systems opens a new path to sewer methane emissions.

Quantifying Methane Influx from Sewer into Wastewater Treatment Processes.

Wastewater treatment contributes substantially to methane (CH4) emissions, yet monitoring and tracing face challenges because the treatment processes are often treated as a "black box". Particularly, despite growing interest, the amount of CH4 carryover and influx from the sewer and its impacts on overall emissions remain unclear. This study quantified CH4 emissions from six wastewater treatment plants (WWTPs) across China, utilizing existing multizonal odor control systems, with a focus on Beijing and Guiyang WWTPs. In the Beijing WWTP, almost 90% of CH4 emissions from the wastewater treatment process were conveyed through sewer pipes, affecting emissions even in the aerobic zone of biological treatment. In the Guiyang WWTP, where most CH4 from the sewer was released at the inlet well, a 24 h online monitoring revealed CH4 fluctuations linked to neighborhood water consumption and a strong correlation to influent COD inputs. CH4 emission factors monitored in six WWTPs range from 1.5 to 13.4 gCH4/kgCODrem, higher than those observed in previous studies using A2O technology. This underscores the importance of considering CH4 influx from sewer systems to avoid underestimation. The odor control system in WWTPs demonstrates its potential as a cost-effective approach for tracing, monitoring, and mitigating CH4.

Dental caries status and related factors among 5-year-old children in Shanghai.

BACKGROUND: Dental caries in young children is a difficult global oral health problem. In the last decade, China has put a great deal of effort into reducing the prevalence of dental caries. This study, which is part of the China Population Chronic Disease and Nutrition Surveillance 2021, aimed to investigate the prevalence of dental caries among children aged 5 in Shanghai, China, and its associated factors. METHODS: A total of 1281 children aged 5 years from 6 districts in Shanghai were selected by a stratified sampling method. The survey consisted of an oral health questionnaire and an oral health examination. The questionnaire included questions on oral health knowledge, attitudes, and behaviours. The oral health examination used WHO standards. After screening, the data were input and analysed. Chi-square tests and logistic regression analyses were used to study the relevant factors affecting dental caries. RESULTS: The prevalence of dental caries among 1281 children was 51.0%, the dmft index score was 2.46, the Significant Caries Index (SiC) score was 6.39, and the SiC10 score was 10.35. Dental caries experience was related to the frequency of sweet drink consumption, the age of starting tooth brushing, eating habits after brushing, whether the children had received an oral examination provided by the government (p < 0.05), and the mother's education level but was not related to sex, the use of fluoride toothpaste, the frequency of brushing, whether the parents assisted brushing, or the frequency of flossing (p > 0.05). Logistic regression analysis showed that the region of residence, eating after brushing and the age of starting brushing were associated with dental caries. CONCLUSIONS: Dental caries remained prevalent among 5-year-old children in Shanghai, China. Prevention strategies that target the associated factors including region of residence, eating after brushing, and the age of starting brushing should be considered.

Development of a machine learning-based model for predicting individual responses to antihypertensive treatments.

BACKGROUND AND AIMS: Personalized antihypertensive drug selection is essential for optimizing hypertension management. The study aimed to develop a machine learning (ML) model to predict individual blood pressure (BP) responses to different antihypertensive medications. METHODS AND RESULTS: We used data from a pragmatic, cluster-randomized trial on hypertension management in China. Each patient's multiple visit records were included, and two consecutive visits were paired as the index and subsequent visits. The least absolute shrinkage and selection operator method was used to select index visit variables for predicting subsequent BP. The dataset was randomly divided into training and test sets in a 7:3 ratio. Model performance was evaluated using mean absolute error (MAE) and R-square in the test set. A total of 19,013 hypertension management visit records (6282 patients) were included. The mean age of the study population was 63.9 years, and 2657 (42.3%) were females. A total of 12 phenotypical features (age, sex, smoking within seven days, body mass index, waist circumference, index visit systolic BP, diastolic BP, heart rate, comorbidities of diabetes, dyslipidemia, coronary heart disease, and stroke), together with currently taking any prescribed antihypertensive medication regimens and visits time interval were selected to build the model. The Extreme Gradient Boost model performed best among all candidate algorithms, with an MAE of 8.57 mmHg and an R2 = 0.28 in the test set. CONCLUSION: The ML techniques exhibit significant potential for predicting individual responses to antihypertensive treatments, thereby aiding clinicians in achieving optimal BP control safely and efficiently. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03636334. Registered July 3, 2018, https://clinicaltrials.gov/study/NCT03636334.

Predicting the risk of 1-year mortality among patients hospitalized for acute heart failure in China.

BACKGROUND: We aimed to develop and validate a model to predict 1-year mortality risk among patients hospitalized for acute heart failure (AHF), build a risk score and interpret its application in clinical decision making. METHODS: By using data from China Patient-Centred Evaluative Assessment of Cardiac Events Prospective Heart Failure Study, which prospectively enrolled patients hospitalized for AHF in 52 hospitals across 20 provinces, we used multivariate Cox proportional hazard model to develop and validate a model to predict 1-year mortality. RESULTS: There were 4,875 patients included in the study, 857 (17.58%) of them died within 1-year following discharge of index hospitalization. A total of 13 predictors were selected to establish the prediction model, including age, medical history of chronic obstructive pulmonary disease and hypertension, systolic blood pressure, Kansas City Cardiomyopathy Questionnaire-12 score, angiotensin converting enzyme inhibitor or angiotensin receptor blocker at discharge, discharge symptom, N-terminal pro-brain natriuretic peptide, high-sensitivity troponin T, serum creatine, albumin, blood urea nitrogen, and highly sensitive C-reactive protein. The model showed a high performance on discrimination (C-index was 0.759 [95% confidence interval: 0.739, 0.778] in development cohort and 0.761 [95% confidence interval: 0.731, 0.791] in validation cohort), accuracy, calibration, and outperformed than several existed risk scores. A point-based risk score was built to stratify low- (0-12), intermediate- (13-16), and high-risk group (≥17) among patients. CONCLUSIONS: A prediction model using readily available predictors was developed and internal validated to predict 1-year mortality risk among patients hospitalized for AHF. It may serve as a useful tool for individual risk stratification and informing decision making to improve clinical care.

Clinical-grade human embryonic stem cell-derived mesenchymal stromal cells ameliorate diabetic retinopathy in db/db mice.

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) hold great promise in the treatment of diabetic retinopathy (DR), as evidenced by increasing preclinical and clinical studies. However, the absence of standardized and industrialized clinical-grade donor cells hampers the continued development and large-scale clinical application of MSCs-based therapies for DR. Previously, we have identified a unique population of MSCs generated from a clinical-grade human embryonic stem cell (hESC) line under Good Manufacturing Practice conditions that could be a potential source to address the issues. Here, we investigated the therapeutic potential of the clinical-grade hESC line-derived MSCs (hESC-MSCs) on db/db mice with DR. METHODS: hESC-MSCs were initially characterized by morphological assessment, flow cytometry analysis and trilineage differentiation assays. These cells (5 × 106 cells) were then transplanted intravenously into 12-week-old db/db mice via tail vein, with phosphate-buffered saline transplantation and untreated groups used as controls. The retinal alterations in neural functions and microvascular perfusions, and inflammatory responses in peripheral blood and retina were evaluated at 4 and 6 weeks after transplantation using electroretinography, optical coherence tomography angiography and flow cytometry, respectively. Body weight and fasting blood glucose (FBG) levels were also measured to investigate their systemic implications. RESULTS: Compared with controls, intravenous transplantation of hESC-MSCs could significantly: (i) enhance impaired retinal electroretinography functions (including amplitudes of a-, b-wave and oscillatory potentials) at 4 weeks after transplantation; (ii) alleviate microvascular dysfunctions, especially in the inner retina with significance (including reducing non-perfusion area and increasing vascular area density) at 4 weeks after transplantation; (iii) decrease FBG levels at 4 weeks after transplantation and induce weight loss up to 6 weeks after transplantation and (iv) increase both peripheral blood and retinal interleukin-10 levels at 4 weeks after transplantation and modulate peripheral blood inflammatory cytokines and chemokines levels, such as monocyte chemotactic protein-1, up to 6 weeks after transplantation. CONCLUSIONS: The findings of our study indicated that intravenous transplantation of hESC-MSCs ameliorated retinal neural and microvascular dysfunctions, regulated body weight and FBG and modulated peripheral blood and retinal inflammation responses in a mouse model of DR. These results suggest that hESC-MSCs could be a potentially effective clinical-grade cell source for the treatment of DR.

Global research trends and prospects of cellular metabolism in colorectal cancer.

BACKGROUND: An increasing number of studies have focused on the role of cellular metabolism in the development of colorectal cancer (CRC). However, no work is currently available to synthesize the field through bibliometrics. AIM: To analyze the development in the field of "glucose metabolism" (GM), "amino acid metabolism" (AM), "lipid metabolism" (LM), and "nucleotide metabolism" (NM) in CRC by visualization. METHODS: Articles within the abovementioned areas of GM, AM, LM and NM in CRC, which were published from January 1, 1991, to December 31, 2022, are retrieved from the Web of Science Core Collection and analyzed by CiteSpace 6.2.R4 and VOSviewer 1.6.19. RESULTS: The field of LM in CRC presented the largest number of annual publications and the fastest increase in the last decade compared with the other three fields. Meanwhile, China and the United States were two of the most prominent contributors in these four areas. In addition, Gang Wang, Wei Jia, Maria Notarnicola, and Cornelia Ulrich ranked first in publication numbers, while Jing-Yuan Fang, Senji Hirasawa, Wei Jia, and Charles Fuchs were the most cited authors on average in these four fields, respectively. "Gut microbiota" and "epithelial-mesenchymal transition" emerged as the newest burst words in GM, "gut microbiota" was the latest outburst word in AM, "metastasis", "tumor microenvironment", "fatty acid metabolism", and "metabolic reprogramming" were the up-to-date outbreaking words in LM, while "epithelial-mesenchymal transition" and "apoptosis" were the most recently occurring words in NM. CONCLUSION: Research in "cellular metabolism in CRC" is all the rage at the moment, and researchers are particularly interested in exploring the mechanism to explain the metabolic alterations in CRC. Targeting metabolic vulnerability appears to be a promising direction in CRC therapy.

Research on Multi-Hole Localization Tracking Based on a Combination of Machine Vision and Deep Learning.

In the process of industrial production, manual assembly of workpieces exists with low efficiency and high intensity, and some of the assembly process of the human body has a certain degree of danger. At the same time, traditional machine learning algorithms are difficult to adapt to the complexity of the current industrial field environment; the change in the environment will greatly affect the accuracy of the robot's work. Therefore, this paper proposes a method based on the combination of machine vision and the YOLOv5 deep learning model to obtain the disk porous localization information, after coordinate mapping by the ROS communication control robotic arm work, in order to improve the anti-interference ability of the environment and work efficiency but also reduce the danger to the human body. The system utilizes a camera to collect real-time images of targets in complex environments and, then, trains and processes them for recognition such that coordinate localization information can be obtained. This information is converted into coordinates under the robot coordinate system through hand-eye calibration, and the robot is then controlled to complete multi-hole localization and tracking by means of communication between the upper and lower computers. The results show that there is a high accuracy in the training and testing of the target object, and the control accuracy of the robotic arm is also relatively high. The method has strong anti-interference to the complex environment of industry and exhibits a certain feasibility and effectiveness. It lays a foundation for achieving the automated installation of docking disk workpieces in industrial production and also provides a more favorable choice for the production and installation of the process of screw positioning needs.

In-sewer stability assessment of 140 pharmaceuticals, personal care products, pesticides and their metabolites: Implications for wastewater-based epidemiology biomarker screening.

The monitoring of pharmaceuticals, personal care products (PCPs), pesticides, and their metabolites through wastewater-based epidemiology (WBE) provides timely information on pharmaceutical consumption patterns, chronic disease treatment rates, antibiotic usage, and exposure to harmful chemicals. However, before applying them for quantitative WBE back-estimation, it is necessary to understand their stability in the sewer system to screen suitable WBE biomarkers thereby reducing research uncertainty. This study investigated the in-sewer stability of 140 typical pharmaceuticals, PCPs, pesticides, and their metabolites across 15 subcategories, using a series of laboratory sewer sediment and biofilm reactors. For the first time, stability results for 89 of these compounds were reported. Among the 140 target compounds, 61 biomarkers demonstrated high stability in all sewer reactors, while 41 biomarkers were significantly removed merely by sediment processes. For biomarkers exhibiting notable attenuation, the influence of sediment processes was generally more pronounced than biofilm, due to its stronger microbial activities and more pronounced diffusion or adsorption processes. Adsorption emerged as the predominant factor causing biomarker removal compared to biodegradation and diffusion. Significantly different organic carbon-water partitioning coefficient (Koc) and distribution coefficient at pH = 7 (logD) values were observed between highly stable and unstable biomarkers, with most hydrophobic substances (Koc > 100 or logD > 2) displaying instability. In light of these findings, we introduced a primary biomarker screening process to efficiently exclude inappropriate candidates, achieving a commendable 77 % accuracy. Overall, this study represents the first comprehensive report on the in-sewer stability of 89 pharmaceuticals, PCPs, pesticides, and their metabolites, and provided crucial reference points for understanding the intricate sewer sediment processes.

Magnolol-driven microbiota modulation elicits changes in tryptophan metabolism resulting in reduced skatole formation in pigs.

Skatole of gut origin has garnered significant attention as a malodorous pollutant due to its escalating emissions, recalcitrance to biodegradation and harm to animal and human health. Magnolol is a health-promoting polyphenol with potential to considerably mitigate the skatole production in the intestines. To investigate the impact of magnolol and its underlying mechanism on the skatole formation, in vivo and in vitro experiments were conducted in pigs. Our results revealed that skatole concentrations in the cecum, colon, and faeces decreased by 58.24% (P = 0.088), 44.98% (P < 0.05) and 43.52% (P < 0.05), respectively, following magnolol supplementation. Magnolol supplementation significantly decreased the abundance of Lachnospira, Faecalibacterium, Paramuribaculum, Faecalimonas, Desulfovibrio, Bariatricus, and Mogibacterium within the colon (P < 0.05). Moreover, a strong positive correlation (P < 0.05) between skatole concentration and Desulfovibrio abundance was observed. Subsequent in silico studies showed that magnolol could dock well with indolepyruvate decarboxylase (IPDC) within Desulfovibrio. Further in vitro investigation unveiled that magnolol addition led to less indole-3-pyruvate diverted towards the oxidative skatole pathway by the potential docking of magnolol towards IPDC, thereby diminishing the conversion of substrate into skatole. Our findings offer novel targets and strategies for mitigating skatole emission from the source.

Clinical outcomes and medical resource utilization of toripalimab combination therapy versus bevacizumab plus chemotherapy in advanced non-squamous non-small cell lung cancer.

OBJECTIVE: This study aimed to evaluate the real-world clinical efficacy and safety, economic burdens and medical resource utilization (MRU) of toripalimab treatment patterns compared with bevacizumab plus chemotherapy (BCP) for patients with advanced non-squamous NSCLC in China. METHODS: Progression-free survival (PFS), adverse drug reactions (ADR) and the costs of drugs, laboratory testing, imageology examinations (including CT, B ultrasound, MRI), medical service, nursing, treatment, genetic test and medical disposable material were compared between two groups. A retrospective observational study was conducted with electronic medical records from Fudan University Huashan hospital. Data was obtained from established electronic medical records (EMRs) and patient surveys. Survival time from the study enrollment to disease progression or death plus from 1st progression disease (PD) in the maintenance phase to 2nd PD (PFS II), adverse events (AE), direct medical costs, MRU and AE-related costs were collected and compared between toripalimab group and BCP group. A total of 246 patients were enrolled. RESULTS: Toripalimab combination therapy has significantly prolonged PFS comparing with BCP (13.8 months vs. 6.2 months, p < .001). A statistically significant improvement in PFS was observed favoring all toripalimab regimen subgroups compared with the bevacizumab group. Patients in toripalimab group occupied more overall resource consumption, more direct medical costs ($47,056.9 vs. $29,951.0, p < .0001) and AE-related costs ($4,500.2 vs. $784.4, p < .0001) than BCP group. Although patients in the toripalimab group used more drugs to prevent AEs ($4,500.2 vs. $784.4, p < .0001), they still experienced more AEs than patients in BCP group (51.4% vs. 41.4%). CONCLUSION: Toripalimab combination therapy could significantly prolonged PFS for patients with advanced non-squamous NSCLC compared with BCP, but at the expense of more MRU, costs and AEs.

Associations of cumulative depressive symptoms within 1-year of discharge with subsequent mortality among patients hospitalized for acute heart failure: Findings from The China PEACE Prospective Heart Failure Study.

BACKGROUND: To examine the associations between cumulative depressive symptoms and subsequent mortality among patients hospitalized for acute hear failure (AHF). METHODS: By using data from a prospective cohort study of patients with HF, depressive symptoms were measured by using Patient Health Questionnaire-2 (PHQ-2) at admission, 1-and 12-month after discharge. Cumulative depressive symptoms were interpreted by cumulative PHQ-2 score and cumulative times of depressive symptoms. Outcomes included subsequent 3-year all-cause and cardiovascular mortality. RESULTS: We included 2347 patients with the median follow-up of 4.4 (interquartile range [IQR]: 4.0-5.0) years. Tertile 3 of cumulative PHQ-2 score had the highest risk of all-cause (hazard ratio [HR]: 1.47, 95 % confidence interval [CI]: 1.21-1.78) and cardiovascular mortality (HR: 1.51, 95 % CI: 1.21-1.89) compared with Tertile 1; patients with≥2 times of depressive symptoms had the highest risk of all-cause (HR: 1.62, 95 % CI: 1.31-2.00) and cardiovascular mortality (HR: 1.60, 95 % CI: 1.25-2.05) compared with patients without any depressive symptom. Cumulative PHQ-2 score provided the highest level of incremental prognostic ability in predicting the risk of all-cause (C-statistics: 0.64, 95 % CI: 0.62-0.66) and cardiovascular mortality (C-statistics: 0.65, 95 % CI: 0.62-0.67) on the basis of Get With The Guidelines-Heart Failure score. CONCLUSION: Cumulative depressive symptoms were associated with the increased risk of subsequent mortality and provided incremental prognostic ability for the outcomes among patients with HF. Repeated depressive symptom measurements could be helpful to monitor long-term depressive symptoms, identify targeted patients and perform psychological interventions and social support to improve clinical outcomes among patients with AHF.

Effects of Cumulative Cognitive Function Within 1 Year of Discharge on Subsequent Mortality Among Patients Hospitalized for Acute Heart Failure: A Nationwide Prospective Cohort Study.

BACKGROUND: To examine the association between cumulative cognitive function and subsequent mortality among patients hospitalized for acute heart failure (AHF). METHODS: Based on a prospective cohort of patients hospitalized for AHF, cognitive function was measured using Mini-Cog test at admission, 1- and 12-month following discharge. Cumulative cognitive function was interpreted by cumulative Mini-Cog score and cumulative times of cognitive impairment. Outcomes included subsequent all-cause and cardiovascular mortality. RESULTS: 1 454 patients hospitalized for AHF with median follow-up of 4.76 (interquartile range [IQR]: 4.18-5.07) years were included. Tertile 1 of cumulative Mini-Cog score had the highest risk of all-cause (hazard ratio [HR]: 1.52, 95% confidence interval [CI]: 1.14-2.03) and cardiovascular mortality (HR: 1.40, 95% CI: 1.02-1.93) compared with Tertile 3; patients with ≥2 times of cognitive impairment had the highest risk of all-cause (HR: 1.34, 95% CI: 1.03-1.73) and cardiovascular mortality (HR: 1.25, 95% CI: 0.93-1.67) compared with patients without any cognitive impairment. Cumulative Mini-Cog score provided the highest incremental prognostic ability in predicting all-cause (C-statistics: 0.64, 95% CI: 0.61-0.66) and cardiovascular mortality (C-statistics: 0.63, 95% CI: 0.60-0.67) risk on the basis of Get With The Guidelines-Heart Failure score. CONCLUSIONS: Poor cumulative cognitive function was associated with increased risk of subsequent mortality and provided incremental prognostic ability for the outcomes among patients with AHF. Longitudinal assessment and monitoring of cognitive function among patients with AHF would be of great importance in identifying patients at greater risk of self-care absence for optimizing personal disease management in clinical practice.

OsBCAT2, a gene responsible for the degradation of branched-chain amino acids, positively regulates salt tolerance by promoting the synthesis of vitamin B5.

Salt stress negatively affects rice growth, development and yield. Metabolic adjustments contribute to the adaptation of rice under salt stress. Branched-chain amino acids (BCAA) are three essential amino acids that cannot be synthesized by humans or animals. However, little is known about the role of BCAA in response to salt stress in plants. Here, we showed that BCAAs may function as scavengers of reactive oxygen species (ROS) to provide protection against damage caused by salinity. We determined that branched-chain aminotransferase 2 (OsBCAT2), a protein responsible for the degradation of BCAA, positively regulates salt tolerance. Salt significantly induces the expression of OsBCAT2 rather than BCAA synthesis genes, which indicated that salt mainly promotes BCAA degradation and not de novo synthesis. Metabolomics analysis revealed that vitamin B5 (VB5) biosynthesis pathway intermediates were higher in the OsBCAT2-overexpressing plants but lower in osbcat2 mutants under salt stress. The salt stress-sensitive phenotypes of the osbcat2 mutants are rescued by exogenous VB5, indicating that OsBCAT2 affects rice salt tolerance by regulating VB5 synthesis. Our work provides new insights into the enzymes involved in BCAAs degradation and VB5 biosynthesis and sheds light on the molecular mechanism of BCAAs in response to salt stress.

Nitrogen removal characteristics of novel bacterium Klebsiella sp. TSH15 by assimilatory/dissimilatory nitrate reduction and ammonia assimilation.

A novel strain with heterotrophic nitrification and aerobic denitrification was screened and identified as Klebsiella sp. TSH15 by 16S rRNA. The results demonstrated that the ammonia-N and nitrate-N removal rates were 2.99 mg/L/h and 2.53 mg/L/h under optimal conditions, respectively. The analysis of the whole genome indicated that strain TSH15 contained the key genes involved in assimilatory/dissimilatory nitrate reduction and ammonia assimilation, including nas, nar, nir, nor, glnA, gltB, gdhA, and amt. The relative expression levels of key nitrogen removal genes were further detected by RT-qPCR. The results indicated that the N metabolic pathways of strain TSH15 were the conversion of nitrate or nitrite to ammonia by assimilatory/dissimilatory nitrate reduction (NO3-→NO2-→NH4+) and further conversion of ammonia to glutamate (NH4+-N â†’ Glutamate) by ammonia assimilation. These results indicated that the strain TSH15 had the potential to be applied to practical sewage treatment in the future.

Potential stimulation of nitrifying bacteria activities and genera by landfill leachate.

With the increasing complexity of influent composition in wastewater treatment plants, the potential stimulating effects of refractory organic matter in wastewater on growth characteristics and genera conversion of nitrifying bacteria (ammonium-oxidizing bacteria [AOB] and nitrite-oxidizing bacteria [NOB]) need to be further investigated. In this study, domestic wastewater was co-treated with landfill leachate in the lab-scale reactor, and the competition and co-existence of NOB genera Nitrotoga and Nitrospira were observed. The results demonstrated that the addition of landfill leachate could induce the growth of Nitrotoga, whereas Nitrotoga populations remain less competitive in domestic wastewater operation. In addition, the refractory organic matter in the landfill leachate also would have a potential stimulating effect on the maximum specific growth rate of AOB genus Nitrosomonas (µmax, aob). The µmax, aob of Nitrosomonas in the control group was estimated to be 0.49 d-1 by fitting the ASM model, and the µmax, aob reached 0.66-0.71 d-1 after injection of refractory organic matter in the landfill leachate, while the maximum specific growth rate of NOB (µmax, nob) was always in the range of 1.05-1.13 d-1. These findings have positive significance for the understanding of potential stimulation on nitrification processes and the stable operation of innovative wastewater treatment process.

Dynamic Simulation of Nitrifying Microbial Communities for Establishing Acidic Partial Nitritation in Suspended Activated Sludge.

Acidic partial nitritation (PN) is a promising technology to achieve low-cost and energy-efficient shortcut nitrogen removal from wastewater. However, a comprehensive understanding of the acidic PN under dynamic changes of pH in a sequencing batch reactor (SBR) is still lacking. In this study, we successfully established acidic PN (NO2- accumulation ratio >80%) under dynamic pH variation from 7.0 to 4.5 in a lab-scale SBR. By accumulating in situ free nitrous acid (FNA) generation based on the dynamic pH change, acidic PN maintained stability even at a low NH4+ concentration of 100 mg N L-1. The microbial community analysis revealed that two ammonium-oxidizing bacteria (AOB) genera, Nitrosospira and Nitrosomonas, successfully coexisted and cooperated during acidic PN. None of the species of nitrite-oxidizing bacteria (NOB) showed adaptation to intermittent inhibition of in situ FNA even under high DO conditions (>4.0 mg O2 L-1). Furthermore, we innovatively incorporated the classic nitrification model with the growth and decay of different nitrifying bacterial species and their inhibition by pH, FNA, and free ammonia (FA) to predict the nitrifying microbial communities shifting for establishing acidic PN. The extended model was calibrated by using short-term batch experiments and was validated by using long-term dynamic data of the nitrifying microbial community during SBR operation. The validated model was further used to identify feasible influent conditions for the SBR PN process, including influent HCO3- concentration, NH4+ concentration and molar ratio (HCO3/NH4+). Outcomes from this study support the optimal design of acidic PN-based short-cut nitrogen removal processes for future application.

OsMDH12: A Peroxisomal Malate Dehydrogenase Regulating Tiller Number and Salt Tolerance in Rice.

Salinity is an important environmental factor influencing crop growth and yield. Malate dehydrogenase (MDH) catalyses the reversible conversion of oxaloacetate (OAA) to malate. While many MDHs have been identified in various plants, the biochemical function of MDH in rice remains uncharacterised, and its role in growth and salt stress response is largely unexplored. In this study, the biochemical function of OsMDH12 was determined, revealing its involvement in regulating tiller number and salt tolerance in rice. OsMDH12 localises in the peroxisome and is expressed across various organs. In vitro analysis confirmed that OsMDH12 converts OAA to malate. Seedlings of OsMDH12-overexpressing (OE) plants had shorter shoot lengths and lower fresh weights than wild-type (WT) plants, while osmdh12 mutants displayed the opposite. At maturity, OsMDH12-OE plants had fewer tillers than WT, whereas osmdh12 mutants had more, suggesting OsMDH12's role in tiller number regulation. Moreover, OsMDH12-OE plants were sensitive to salt stress, but osmdh12 mutants showed enhanced salt tolerance. The Na+/K+ content ratio increased in OsMDH12-OE plants and decreased in osmdh12 mutants, suggesting that OsMDH12 might negatively affect salt tolerance through influencing the Na+/K+ balance. These findings hint at OsMDH12's potential as a genetic tool to enhance rice growth and salt tolerance.