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The utilization of methane, a potent greenhouse gas, is an important component of local and global carbon cycles that is characterized by tight linkages between methane-utilizing (methanotrophic) and nonmethanotrophic bacteria. It has been suggested that the methanotroph sustains these nonmethanotrophs by cross-feeding, because subsequent products of the methane oxidation pathway, such as methanol, represent alternative carbon sources. We established cocultures in a microcosm model system to determine the mechanism and substrate that underlay the observed cross-feeding in the environment. Lanthanum, a rare earth element, was applied because of its increasing importance in methylotrophy. We used co-occurring strains isolated from Lake Washington sediment that are involved in methane utilization: a methanotroph and two nonmethanotrophic methylotrophs. Gene-expression profiles and mutant analyses suggest that methanol is the dominant carbon and energy source the methanotroph provides to support growth of the nonmethanotrophs. However, in the presence of the nonmethanotroph, gene expression of the dominant methanol dehydrogenase (MDH) shifts from the lanthanide-dependent MDH (XoxF)-type, to the calcium-dependent MDH (MxaF)-type. Correspondingly, methanol is released into the medium only when the methanotroph expresses the MxaF-type MDH. These results suggest a cross-feeding mechanism in which the nonmethanotrophic partner induces a change in expression of methanotroph MDHs, resulting in release of methanol for its growth. This partner-induced change in gene expression that benefits the partner is a paradigm for microbial interactions that cannot be observed in studies of pure cultures, underscoring the importance of synthetic microbial community approaches to understand environmental microbiomes.

Methanotrophic metabolism has been under investigation for decades using biochemical and genetic approaches. Recently, a further step has been taken toward understanding methanotrophic metabolism in a quantitative manner by means of flux balance analysis (FBA), a mathematical approach that predicts fluxes constrained by mass balance and a few experimental measurements. However, no study has previously been undertaken to experimentally quantitate the complete methanotrophic central metabolism. The significance of this study is to fill such a gap by performing 13 C INST-MFA on a fast-growing methanotroph. Our quantitative insights into the methanotrophic carbon and energy metabolism will pave the way for future FBA studies and set the stage for rational design of methanotrophic strains for industrial applications. Further, the experimental strategies can be applied to other methane or methanol utilizers, and the results will offer a unique and quantitative perspective of diverse methylotrophic metabolism. Methanotrophic bacteria are a group of prokaryotes capable of using methane as their sole carbon and energy source. Although efforts have been made to simulate and elucidate their metabolism via computational approaches or 13 C tracer analysis, major gaps still exist in our understanding of methanotrophic metabolism at the systems level. Particularly, direct measurements of system-wide fluxes are required to understand metabolic network function. Here, we quantified the central metabolic fluxes of a type I methanotroph, “ Methylotuvimicrobium buryatense ” 5GB1C, formerly Methylomicrobium buryatense 5GB1C, via 13 C isotopically nonstationary metabolic flux analysis (INST-MFA). We performed labeling experiments on chemostat cultures by switching substrates from 12 C to 13 C input. Following the switch, we measured dynamic changes of labeling patterns and intracellular pool sizes of several intermediates, which were later used for data fitting and flux calculations. Through computational optimizations, we quantified methane and methanol metabolism at two growth rates (0.1 h −1 and 0.05 h −1 ). The resulting flux maps reveal a core consensus central metabolic flux phenotype across different growth conditions: a strong ribulose monophosphate cycle, a preference for the Embden-Meyerhof-Parnas pathway as the primary glycolytic pathway, and a tricarboxylic acid cycle showing small yet significant fluxes. This central metabolic consistency is further supported by a good linear correlation between fluxes at the two growth rates. Specific differences between methane and methanol growth observed previously are maintained under substrate limitation, albeit with smaller changes. The substrate oxidation and glycolysis pathways together contribute over 80% of total energy production, while other pathways play less important roles. IMPORTANCE Methanotrophic metabolism has been under investigation for decades using biochemical and genetic approaches. Recently, a further step has been taken toward understanding methanotrophic metabolism in a quantitative manner by means of flux balance analysis (FBA), a mathematical approach that predicts fluxes constrained by mass balance and a few experimental measurements. However, no study has previously been undertaken to experimentally quantitate the complete methanotrophic central metabolism. The significance of this study is to fill such a gap by performing 13 C INST-MFA on a fast-growing methanotroph. Our quantitative insights into the methanotrophic carbon and energy metabolism will pave the way for future FBA studies and set the stage for rational design of methanotrophic strains for industrial applications. Further, the experimental strategies can be applied to other methane or methanol utilizers, and the results will offer a unique and quantitative perspective of diverse methylotrophic metabolism.

The identification of subgroups of people living with HIV in China based on the severity of symptom clusters and individual symptoms is crucial to determine group-specific symptom management strategies. Participants reported 27 highly prevalent HIV/AIDS-related symptoms. Latent profile analysis based on symptom severity was used to identify person-centered subtypes of HIV/AIDS-related symptoms. Symptom networks were compared among subgroups identified by latent profile analysis. A total of 2927 eligible people living with HIV (PWH) were included in the analysis. Five profiles were identified: “Profile 1: all low symptom severity” (n 2  = 2094, 71.54%), “Profile 2: medium symptom severity with syndemic conditions” (n 3  = 109, 3.72%), “Profile 3: medium symptom severity with low functional status” (n 1  = 165, 5.64%), “Profile 4: medium symptom severity in transitional period” (n 4  = 448, 15.31%), and “Profile 5: all high symptom severity” (n 5  = 111, 3.79%). Except for Profile 1 and Profile 5, the symptom severity was similar among the other three profiles. Profiles 1 (2.09 ± 0.52) and 4 (2.44 ± 0.66) had the smallest ∑s values, and Profiles 2 (4.38 ± 1.40) and 5 (4.39 ± 1.22) had the largest ∑s values. Our study demonstrates the need for health care professionals to provide PWH with group-specific symptom management interventions based on five profiles to improve their physical and psychological well-being. Future studies should be conducted in different contexts using different symptom checklists to further validate our results.

Background The Knee Injury and Osteoarthritis Outcomes Score (KOOS) is a free clinical tool commonly used to evaluate the symptoms and functional status of patients with knee injury. For people who speak Chinese, the Hong Kong Chinese and Singapore Chinese versions are preferred. However, variations in the Chinese language and culture are influenced by the country’s geography. KOOS for Mainland China has not been reported. Therefore, the current study was to cross-culturally translate the original English version into a simplified Chinese version and to investigate its psychometric properties. Methods The simplified Chinese KOOS was obtained through forward-backward translation according to appropriate guidelines. A total of 158 individuals with knee osteoarthritis (KOA) were recruited from 13 hospitals in China to examine the psychometric properties. The test-retest questionnaire was performed at an interval of 5–7 days. Test-retest reliability and internal consistency were evaluated using the intraclass correlation coefficient (ICC) and Cronbach’s alpha, respectively. The data of the first test were used to analyse the construct validity of the simplified Chinese KOOS and Chinese SF-36 through convergent and discriminant validity using Spearman’s correlation coefficient. Results Cross-cultural translation exhibited minor cultural differences, and the questionnaire was well understood by the patients. The data from 128 patients, used for the test-retest reliability study, showed good to excellent reliability, with an ICC of 0.808–0.976 for all KOOS subscales. The Cronbach’s alpha for all subscales ranged from 0.757 to 0.970, indicating acceptable internal consistency. There was a low-to-high correlation between the five domains of the simplified Chinese version of the KOOS and all domains of the SF-36 in construct validity. Conclusion The simplified Chinese KOOS demonstrated acceptable reliability and validity. In clinical practice and research, this version can help provide valuable information on health-related quality of life for Chinese individuals with KOA in mainland China.

One-carbon compounds such as methane and methanol are of increasing interest as sustainable substrates for biological production of fuels and industrial chemicals. The bacteria that carry out these conversions have been studied for many decades, but gaps exist in our knowledge of their metabolic pathways. One such gap is the difference between growth on methane and growth on methanol. Understanding such metabolism is important, since each has advantages and disadvantages as a feedstock for production of chemicals and fuels. The significance of our research is in the demonstration that the metabolic network is substantially altered in each case and in the delineation of these changes. The resulting new insights into the core metabolism of this bacterium now provide an improved basis for future strain design. Methylomicrobium buryatense 5GB1 is an obligate methylotroph which grows on methane or methanol with similar growth rates. It has long been assumed that the core metabolic pathways must be similar on the two substrates, but recent studies of methane metabolism in this bacterium suggest that growth on methanol might have significant differences from growth on methane. In this study, both a targeted metabolomics approach and a 13 C tracer approach were taken to understand core carbon metabolism in M. buryatense 5GB1 during growth on methanol and to determine whether such differences occur. Our results suggest a systematic shift of active core metabolism in which increased flux occurred through both the Entner-Doudoroff (ED) pathway and the partial serine cycle, while the tricarboxylic acid (TCA) cycle was incomplete, in contrast to growth on methane. Using the experimental results as constraints, we applied flux balance analysis to determine the metabolic flux phenotype of M. buryatense 5GB1 growing on methanol, and the results are consistent with predictions based on ATP and NADH changes. Transcriptomics analysis suggested that the changes in fluxes and metabolite levels represented results of posttranscriptional regulation. The combination of flux balance analysis of the genome-scale model and the flux ratio from 13 C data changed the solution space for a better prediction of cell behavior and demonstrated the significant differences in physiology between growth on methane and growth on methanol. IMPORTANCE One-carbon compounds such as methane and methanol are of increasing interest as sustainable substrates for biological production of fuels and industrial chemicals. The bacteria that carry out these conversions have been studied for many decades, but gaps exist in our knowledge of their metabolic pathways. One such gap is the difference between growth on methane and growth on methanol. Understanding such metabolism is important, since each has advantages and disadvantages as a feedstock for production of chemicals and fuels. The significance of our research is in the demonstration that the metabolic network is substantially altered in each case and in the delineation of these changes. The resulting new insights into the core metabolism of this bacterium now provide an improved basis for future strain design.

The bacteria that grow on methane aerobically (methanotrophs) support populations of non-methanotrophs in the natural environment by excreting methane-derived carbon. One group of excreted compounds are short-chain organic acids, generated in highest abundance when cultures are grown under O 2 -starvation. We examined this O 2 -starvation condition in the methanotroph Methylomicrobium buryatense 5GB1. The M. buryatense 5GB1 genome contains homologs for all enzymes necessary for a fermentative metabolism, and we hypothesize that a metabolic switch to fermentation can be induced by low-O 2 conditions. Under prolonged O 2 -starvation in a closed vial, this methanotroph increases the amount of acetate excreted about 10-fold, but the formate, lactate, and succinate excreted do not respond to this culture condition. In bioreactor cultures, the amount of each excreted product is similar across a range of growth rates and limiting substrates, including O 2 -limitation. A set of mutants were generated in genes predicted to be involved in generating or regulating excretion of these compounds and tested for growth defects, and changes in excretion products. The phenotypes and associated metabolic flux modeling suggested that in M. buryatense 5GB1, formate and acetate are excreted in response to redox imbalance. Our results indicate that even under O 2 -starvation conditions, M. buryatense 5GB1 maintains a metabolic state representing a combination of fermentation and respiration metabolism.

Methane (CH 4 ) is a potent greenhouse gas that is released from fossil fuels and is also produced by microbial activity, with at least one billion tonnes of CH 4 being formed and consumed by microorganisms in a single year 1 . Complex methanogenesis pathways used by archaea are the main route for bioconversion of carbon dioxide (CO 2 ) to CH 4 in nature 2 – 4 . Here, we report that wild-type iron-iron (Fe-only) nitrogenase from the bacterium Rhodopseudomonas palustris reduces CO 2 simultaneously with nitrogen gas (N 2 ) and protons to yield CH 4 , ammonia (NH 3 ) and hydrogen gas (H 2 ) in a single enzymatic step. The amount of CH 4 produced by purified Fe-only nitrogenase was low compared to its other products, but CH 4 production by this enzyme in R. palustris was sufficient to support the growth of an obligate CH 4 -utilizing Methylomonas strain when the two microorganisms were grown in co-culture, with oxygen (O 2 ) added at intervals. Other nitrogen-fixing bacteria that we tested also formed CH 4 when expressing Fe-only nitrogenase, suggesting that this is a general property of this enzyme. The genomes of 9% of diverse nitrogen-fixing microorganisms from a range of environments encode Fe-only nitrogenase. Our data suggest that active Fe-only nitrogenase, present in diverse microorganisms, contributes CH 4 that could shape microbial community interactions. Here the authors show that a bacterial iron-only nitrogenase can generate CH 4 in a single step, which can consequently be used for growth by a CH 4 -utilizing Methylomonas strain.

Purpose The present study was conducted to determine the relationship between neurotic personality traits and symptoms of post-traumatic stress disorder (PTSD) in breast cancer patients, with the mediation of self-efficacy and negative coping. Methods A cross-sectional study design was used. A total of 328 breast cancer patients admitted to two tertiary hospitals in Dali, China, from July 2023 to January 2024 were included. Participants completed the General Information Questionnaire, the PTSD Inventory-Civilian Version, the Social Support Rating Scale, the Brief Coping Styles Questionnaire, the General Self-Efficacy Scale, and the Eysenck Personality Questionnaire-Revised, short Scale for Chinese-Neuroticism. Data were analyzed using SPSS 26.0 and Mplus 8.8 software, binary logistic regression analysis, and weighted least squares estimation. Data were analyzed by SPSS 26.0 and Mplus 8.8 software, using binary logistic regression analysis and weighted least squares estimation. Results Employment status, time since diagnosis, neurotic personality traits, negative coping, and self-efficacy were correlates of the development of PTSD symptoms in breast cancer patients ( P  < 0.05). Neurotic personality traits in breast cancer patients had significant direct and indirect effects on PTSD symptoms (total effect: 0.625), and self-efficacy and negative coping were also mediated independently or in combination. Conclusion We suggest that healthcare workers pay close attention to the personality traits of breast cancer patients in their daily work, and take a series of effective targeted measures promptly for patients with neurotic personality traits to help them enhance their sense of self-efficacy and reduce their negative coping styles, to effectively improve the mental health of patients.

As of the end of 2022, over 20 million women worldwide, aged 15 and above, are living with HIV. Stigma remains a formidable barrier for women living with HIV/AIDS, hindering their access to healthcare and exacerbating health disparities. Indeed, some women living with HIV/AIDS can successfully confront and overcome stigma. There remains a paucity of qualitative research exploring the stigma coping strategies of women living with HIV/AIDS in China. This study was aimed to gain the deeper understanding of stigma experienced by women living with HIV/AIDS and coping strategies. We recruited diverse participants using snowball sampling and purposive sampling. Semi-structured personal in-depth interviews were conducted with 30 women living with HIV/AIDS from December 2022 to June 2023. The samples were from four HIV/AIDS designated hospitals. The data were analyzed using the Colaizzi seven-step model. The experiences of stigma among women living with HIV/AIDS included family role (wife/mother/grandmother) collapse and disgusted by family, resignation in being shunned by others, helplessness due to social exclusion, grief at being devaluated, and resentment for experiencing injustice. The coping strategies used to deal with stigma included concealing their conditions, avoiding socialization, and attempting to retaliate against society. Healthcare professionals are recommended to offer women living with HIV/AIDS effective emotional support and guidance to cope with stigma. The study highlights the stigma they face, providing valuable evidence for policymakers. Recommendations emphasize the importance of developing services addressing both physical and psychological needs of women living with HIV/AIDS.

With Western Pacific Region reporting more imported cases, the World Health Organization (WHO) declared monkeypox a public health emergency of international concern in July. Currently, we are now at the beginning of forming stigmatization toward monkeypox. Based on the experience of combating HIV stigmatization for over 30 years, in this comment, we proposed measures based on the three stages of the stigma formation process. We believe the paper may be of particular interest to the readers of your journal as it offered implications for both healthcare professionals and researchers in Western Pacific Region. Keywords: infectious disease, stigmatization, global public health, measures