A novel integrated lateral flow immunoassay platform for the detection of cardiac troponin I using hierarchical dendritic copper-nickel nanostructures.

Cardiac troponin I (cTnI) is a critical biomarker for the diagnosis of acute myocardial infarction (AMI). Herein, we report a novel integrated lateral flow immunoassay (LFIA) platform for highly sensitive point-of-care testing (POCT) of cTnI using hierarchical dendritic copper-nickel (HD-nanoCu-Ni) nanostructures. The electrodeposited HD-nanoCu-Ni film (∼22 µm thick) on an ITO-coated glass substrate exhibits superior capillary action and structural integrity. These properties enable efficient sample transport and antibody immobilization, making it a compelling alternative to conventional multi-component paper-based LFIA test strips, which are often plagued by structural fragility and susceptibility to moisture damage. The biofunctionalized HD-nanoCu-Ni substrates were laser-etched with lateral flow channels, including a sample loading/conjugate release zone, a test zone, and a control zone. Numerical simulations were used to further optimize the design of these channels to achieve optimal fluid flow and target capture. The HD-nanoCu-Ni LFIA device utilizes a fluorescence quenching based sandwich immunoassay format using antibody-labeled gold nanoparticles (AuNPs) as quenchers. Two different fluorescent materials, fluorescein isothiocyanate (FITC) and CdSe@ZnS quantum dots (QDs), were used as background fluorophores in the device. Upon the formation of a sandwich immunocomplex with cTnI on the HD-nanoCu-Ni device, introduced AuNPs led to the fluorescence quenching of the background fluorophores. The total assay time was approximately 15 min, demonstrating the rapid and efficient nature of the HD-nanoCu-Ni LFIA platform. For FITC, both inner filter effect (IFE) and fluorescence resonance energy transfer (FRET) contributed to the AuNP-mediated quenching. In the case of CdSe@ZnS QDs, IFE dominated the AuNP-induced quenching. Calibration curves were established based on the relationship between the fluorescence quenching intensity and cTnI concentration in human serum samples, ranging from 0.5 to 128 ng/mL. The limits of detection (LODs) were determined to be 0.27 ng/mL and 0.40 ng/mL for FITC and CdSe@ZnS QDs, respectively. A method comparison study using Passing-Bablok regression analysis on varying cTnI concentrations in human serum samples confirmed the equivalence of the HD-nanoCu-Ni LFIA platform to a commercial fluorescence cTnI LFIA assay kit, with no significant systematic or proportional bias observed.

Effects of the elongated needling combined with routine acupuncture therapy in the patients with post-stroke hemiplegia and central pain： a randomized controlled trial. / èŠ’é’ˆé€åˆºè”åˆä½“é’ˆæ²»ç–—å¯¹ä¸­é£ŽåŽåç˜«ä¼´ä¸­æž¢æ€§ç–¼ç—›æ‚£è€ çš„ä¸´åºŠç–—æ•ˆè§‚å¯Ÿï¼šéšæœºå¯¹ç §è¯•éªŒ.

OBJECTIVES: To investigate the effects of the elongated needling at the points of hand and foot yang meridians and the Governor Vessel combined with the routine acupuncture therapy on pain, balance function and muscle strength of the patients with post-stroke hemiplegia and central post-stroke pain (CPSP), and to investigate whether its therapeutic mechanism is related to antioxidant damage. METHODS: Ninety-four patients with post-stroke hemiplegia and CPSP admitted from March 2020 to September 2021 were divided into a trial group (47 cases, 1 cases dropped out) and a control group (47 cases 3 cases dropped out). In the control group, the rehabilitation exercise combined with routine acupuncture therapy was used, and in the trial group, on the base of the treatment as the control group, the elongated needling at the points of hand and foot yang meridians and the Governor Vessel was supplemented. In the two groups, the treatment was given once daily, and 1 course of treatment was composed of 14 days, a total of 6 courses were required in the trial. Separately, before treatment, and 1, 2 and 3 months after treatment, between two groups, the score of visual analogue scale (VAS) and that of Berg balance scale (BBS), as well as muscle strength were compared；the neural function was evaluated using the national institutes of health stroke scale (NIHSS) and the serum contents of nitricoxide synthase (NOS), superoxide dismutase (SOD) and malondialdehyde (MDA) were detected by ELISA in the patients. RESULTS: Compared with those before treatment, VAS score and NIHSS score were all decreased (P<0.05) in the trial and the control group after 1 month, 2 months and 3 months of treatment, and BBS score was increased (P<0.05)；and the case proportion of muscle strength grade 4 and 5 was higher (P<0.05) in the trial group. In the control group, the proportion of grade 4 increased after treatment for 2 months (P<0.05), and that of grade 4 and 5 increased after treatment for 3 months (P<0.05). The serum contents of NOS and SOD were increased (P<0.05), and MDA was decreased (P<0.05) after 3 months of treatment in the two groups. In comparison with the control group at the same time point, VAS score and NIHSS score were lower (P<0.05), BBS score higher (P<0.05) and the muscle strength grade was improved (P<0.05, P<0.01) after 1, 2 and 3 months of treatment, respectively；and the serum contents of NOS and SOD increased (P<0.05), and MDA decreased (P<0.05) after 3 months of treatment in the trial group. CONCLUSIONS: The elongated needling at the points of hand and foot yang meridians and the Governor Vessel, combined with the routine acupuncture therapy alleviates CPSP, improves balance and muscle strength and promotes the recovery of neural function in the patients with post-stroke hemiplegia, the mechanism may be related to antioxidant damage.

Lateral Flow Biosensor for On-Site Multiplex Detection of Viruses Based on One-Step Reverse Transcription and Strand Displacement Amplification.

Respiratory pathogens pose a huge threat to public health, especially the highly mutant RNA viruses. Therefore, reliable, on-site, rapid diagnosis of such pathogens is an urgent need. Traditional assays such as nucleic acid amplification tests (NAATs) have good sensitivity and specificity, but these assays require complex sample pre-treatment and a long test time. Herein, we present an on-site biosensor for rapid and multiplex detection of RNA pathogens. Samples with viruses are first lysed in a lysis buffer containing carrier RNA to release the target RNAs. Then, the lysate is used for amplification by one-step reverse transcription and single-direction isothermal strand displacement amplification (SDA). The yield single-strand DNAs (ssDNAs) are visually detected by a lateral flow biosensor. With a secondary signal amplification system, as low as 20 copies/µL of virus can be detected in this study. This assay avoids the process of nucleic acid purification, making it equipment-independent and easier to operate, so it is more suitable for on-site molecular diagnostic applications.

Visible light-enabled synthesis of phosphorylated indolizine and pyridoindole derivatives via HAT-mediated radical cascade cyclization.

A visible light-enabled cascade cyclization strategy is disclosed with concomitant phosphorylation and heterocycle construction. It provides a novel and environmentally benign approach for accessing tetrahydroindolizine-containing phosphonates under metal-free conditions. Mechanistic studies revealed that phosphinoyl radicals were generated from H-phosphonates via a HAT process.

Constructing CoAl-LDO/MoO3-x S-scheme heterojunctions for enhanced photocatalytic CO2 reduction.

Converting CO2 into chemicals and fuels by solar energy can alleviate global warming and solve the energy crisis. In this work, CoAl-LDO/MoO3-x (LDO/MO) composites were successfully prepared and achieved efficient CO2 reduction under visible light. The CoAl-layered double oxides (CoAl-LDO) evolved from CoAl-layered double hydroxide (CoAl-LDH) exhibited a more robust structure, broader light absorption, and improved CO2 adsorption ability. The local surface plasmon resonance (LSPR) effect excited by nonstoichiometric MoO3-x broadened the photo-response range of CoAl-LDO/MoO3-x. In addition, constructing step-scheme (S-scheme) heterojunctions could simultaneously optimize the migration mechanism of photogenerated electrons and holes, and retain carriers with strong redox ability. Therefore, the production rates of CO and CH4 on the optimal LDO/MO composite were 7 and 9 times higher than the pristine CoAl-LDH, respectively. This work hybridizes oxidation photocatalysts and LDO-based materials to optimize the charge separation and migration mechanisms, which guides the modification of LDO-based materials.

Chiral separation of racemic closantel and ultratrace detection of its enantiomers in bacteria by enhanced liquid chromatography-tandem mass spectrometry combined with postcolumn infusion of ammonia.

Reliable analysis of ultratrace antibiotics in bacterial cells may become a new means to elucidate the antibacterial mechanism, drug resistance and environmental fate. In this work, an ultrahigh-sensitive, accurate and enhanced liquid chromatography-tandem mass spectrometric method was first developed for chiral separation and detection of racemic closantel, as an antibacterial adjuvant. Optimizing acetonitrile-water-formic acid system that is compatible with mass spectrometry as a mobile phase, the baseline separation of two enantiomers was achieved by using EnantioPak® Y1-R chiral column, and the resolution of the two analytes was more than 1.95. Further adopt the strategy of postcolumn infusion of ammonia, the mobile phase pH was reversed from acidic condition suitable for the optimal chromatographic separation of R- and S-closantel to alkaline, so that closantel could realize efficient electrospray ionization under the preferred negative ion mode. The bacterial cells were subjected to be frozen-cracked, and the analytes were extracted with acetonitrile after clipping the pointed bottom of the Eppendorf tube into a new tube. The method was linear over concentration ranges of 0.5-50 pg/mL (r2≥0.99) for R- and S-closantel. The detection limits of target analytes were all 0.15 pg/mL in bacterial cells. The average recoveries of two enantiomers ranged from 81.2% to 107.8% with relative standard deviations below 15%. The method proposed might be important support for the deep research of the stereoselectivity of biological activity, toxicity and metabolism of closantel enantiomers.

A novel function of the key nitrogen-fixation activator NifA in beta-rhizobia: Repression of bacterial auxin synthesis during symbiosis.

Rhizobia fix nitrogen within root nodules of host plants where nitrogenase expression is strictly controlled by its key regulator NifA. We recently discovered that in nodules infected by the beta-rhizobial strain Paraburkholderia phymatum STM815, NifA controls expression of two bacterial auxin synthesis genes. Both the iaaM and iaaH transcripts, as well as the metabolites indole-acetamide (IAM) and indole-3-acetic acid (IAA) showed increased abundance in nodules occupied by a nifA mutant compared to wild-type nodules. Here, we document the structural changes that a P. phymatum nifA mutant induces in common bean (Phaseolus vulgaris) nodules, eventually leading to hypernodulation. To investigate the role of the P. phymatum iaaMH genes during symbiosis, we monitored their expression in presence and absence of NifA over different stages of the symbiosis. The iaaMH genes were found to be under negative control of NifA in all symbiotic stages. While a P. phymatum iaaMH mutant produced the same number of nodules and nitrogenase activity as the wild-type strain, the nifA mutant produced more nodules than the wild-type that clustered into regularly-patterned root zones. Mutation of the iaaMH genes in a nifA mutant background reduced the presence of these nodule clusters on the root. We further show that the P. phymatum iaaMH genes are located in a region of the symbiotic plasmid with a significantly lower GC content and exhibit high similarity to two genes of the IAM pathway often used by bacterial phytopathogens to deploy IAA as a virulence factor. Overall, our data suggest that the increased abundance of rhizobial auxin in the non-fixing nifA mutant strain enables greater root infection rates and a role for bacterial auxin production in the control of early stage symbiotic interactions.

Heat stress in broilers of liver injury effects of heat stress on oxidative stress and autophagy in liver of broilers.

This study aimed to investigate the effect of chronic heat stress on oxidative stress in liver of broilers. In our study, chickens were randomly allocated to control 1 group (control 7 d), heat stress 1 group (HS1, 7 d), control 2 group (control 14 d) and heat stress 2 group (HS2, 14 d), with 30 replicates in each group. Broilers in heat stress groups exposed 8 h/day heat stress (35 ± 2°C) for 7 or 14 consecutive days, and the rest of time per day were kept at 23 ± 2℃ the same as control group broilers. Growth performance and the liver tissues were collected for histological observation and detection of organ index and liver redox status. The serum indicators (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) related to liver injury were determined. Moreover, Nrf2-related genes and protein expression levels in liver were measured. The results showed that in heat stress group broilers the body weight gain, feed conversion ratio, liver weight, and liver index were decreased, inflammatory cells infiltration in liver, and serum AST level was enhanced, compared with control group broilers. Moreover, the hepatic malondialdehyde (MDA) and superoxide dismutase (SOD) level were increased after 1 wk of heat stress. Nrf2, Sqstm1/p62, HO-1, and NQO1 mRNA expressions in the liver of broilers were decreased by heat stress. P62 and p-p62 protein expressions were significantly up-regulated, but Nrf2 and keap1 protein level was decreased in heat stress group broilers as compared to control group. The mRNA expression levels of Beclin1, LC3-I, LC3-II were down-regulated significantly with heat stress for 1 wk. The mRNA expression level of mTOR up-regulated after 2 wk of heat stress. In conclusion, heat stress induced liver injury of broilers by down-regulating Nrf2-keap1 signaling pathway and autophagy.

Chronic heat stress promotes liver inflammation in broilers via enhancing NF-κB and NLRP3 signaling pathway.

BACKGROUND: This study investigated the effects of chronic heat stress on liver inflammatory injury and its potential mechanisms in broilers. Chickens were randomly assigned to the 1-week control group (Control 1), 1-week heat stress group (HS1), 2-week control group (Control 2), and a 2-week heat stress group (HS2) with 15 replicates per group. Broilers in the heat stress groups were exposed to heat stress (35 ± 2 °C) for 8 h/d for 7 or 14 consecutive days, and the rest of 26 hours/day were kept at 23 ± 2 °C like control group broilers. Growth performance and liver inflammatory injury were examined for the analysis of liver injury. RESULTS: The results showed that heat stress for 2 weeks decreased the growth performance, reduced the liver weight (P < 0.05) and liver index (P < 0.05), induced obvious bleeding and necrosis points. Liver histological changes found that the heat stress induced the liver infiltration of neutrophils and lymphocytes in broilers. Serum levels of AST and SOD were enhanced in HS1 (P < 0.01, P < 0.05) and HS2 (P < 0.01, P < 0.05) group, compared with control 1 and 2 group broilers. The MDA content in HS1 group was higher than that of in control 1 group broilers (P < 0.05). Both the gene and protein expression levels of HSP70, TLR4 and NF-κB in the liver were significantly enhanced by heat stress. Furthermore, heat stress obviously enhanced the expression of IL-6, TNF-α, NF-κB P65, IκB and their phosphorylated proteins in the livers of broilers. In addition, heat stress promoted the activation of NLRP3 with increased NLRP3, caspase-1 and IL-1ß levels. CONCLUSIONS: These results suggested that heat stress can cause liver inflammation via activation of the TLR4-NF-κB and NLRP3 signaling pathways in broilers. With the extension of heat stress time, the effect of heat stress on the increase of NF-κB and NLRP3 signaling pathways tended to slow down.

Identification of Key Factors for Anoxic Survival of B. cenocepacia H111.

Burkholderia cenocepacia is an opportunistic pathogen that can lead to severe infections in patients suffering from cystic fibrosis (CF) and chronic granulomatous disease. Being an obligate aerobe, B. cenocepacia is unable to grow in the absence of oxygen. In this study, we show that the CF isolate B. cenocepacia H111 can survive in the absence of oxygen. Using a transposon sequencing (Tn-seq) approach, we identified 71 fitness determinants involved in anoxic survival, including a Crp-Fnr family transcriptional regulatory gene (anr2), genes coding for the sensor kinase RoxS and its response regulator RoxR, the sigma factor for flagella biosynthesis (FliA) and subunits of a cytochrome bd oxidase (CydA, CydB and the potentially novel subunit CydP). Individual knockouts of these fitness determinants significantly reduced anoxic survival, and inactivation of both anr copies is shown to be lethal under anoxic conditions. We also show that the two-component system RoxS/RoxR and FliA are important for virulence and swarming/swimming, respectively.

Metabolomics and Dual RNA-Sequencing on Root Nodules Revealed New Cellular Functions Controlled by Paraburkholderia phymatum NifA.

Paraburkholderia phymatum STM815 is a nitrogen-fixing endosymbiont that nodulate the agriculturally important Phaseolus vulgaris and several other host plants. We previously showed that the nodules induced by a STM815 mutant of the gene encoding the master regulator of nitrogen fixation NifA showed no nitrogenase activity (Fix-) and increased in number compared to P. vulgaris plants infected with the wild-type strain. To further investigate the role of NifA during symbiosis, nodules from P. phymatum wild-type and nifA mutants were collected and analyzed by metabolomics and dual RNA-Sequencing, allowing us to investigate both host and symbiont transcriptome. Using this approach, several metabolites' changes could be assigned to bacterial or plant responses. While the amount of the C4-dicarboxylic acid succinate and of several amino acids was lower in Fix- nodules, the level of indole-acetamide (IAM) and brassinosteroids increased. Transcriptome analysis identified P. phymatum genes involved in transport of C4-dicarboxylic acids, carbon metabolism, auxin metabolism and stress response to be differentially expressed in absence of NifA. Furthermore, P. vulgaris genes involved in autoregulation of nodulation (AON) are repressed in nodules in absence of NifA potentially explaining the hypernodulation phenotype of the nifA mutant. These results and additional validation experiments suggest that P. phymatum STM815 NifA is not only important to control expression of nitrogenase and related enzymes but is also involved in regulating its own auxin production and stress response. Finally, our data indicate that P. vulgaris does sanction the nifA nodules by depleting the local carbon allocation rather than by mounting a strong systemic immune response to the Fix- rhizobia.

Differential Expression of Paraburkholderia phymatum Type VI Secretion Systems (T6SS) Suggests a Role of T6SS-b in Early Symbiotic Interaction.

Paraburkholderia phymatum STM815, a rhizobial strain of the Burkholderiaceae family, is able to nodulate a broad range of legumes including the agriculturally important Phaseolus vulgaris (common bean). P. phymatum harbors two type VI Secretion Systems (T6SS-b and T6SS-3) in its genome that contribute to its high interbacterial competitiveness in vitro and in infecting the roots of several legumes. In this study, we show that P. phymatum T6SS-b is found in the genomes of several soil-dwelling plant symbionts and that its expression is induced by the presence of citrate and is higher at 20/28°C compared to 37°C. Conversely, T6SS-3 shows homologies to T6SS clusters found in several pathogenic Burkholderia strains, is more prominently expressed with succinate during stationary phase and at 37°C. In addition, T6SS-b expression was activated in the presence of germinated seeds as well as in P. vulgaris and Mimosa pudica root nodules. Phenotypic analysis of selected deletion mutant strains suggested a role of T6SS-b in motility but not at later stages of the interaction with legumes. In contrast, the T6SS-3 mutant was not affected in any of the free-living and symbiotic phenotypes examined. Thus, P. phymatum T6SS-b is potentially important for the early infection step in the symbiosis with legumes.

Chai Hu oral liquid enhances the immune functions of both spleen and bursa of Fabricius in heat-stressed broilers through strengthening TLR4-TBK1 signaling pathway.

Heat stress can affect the poultry production and immune status of broilers. Heat stress disrupts intestinal integrity and increases intestinal inflammation, which is related with body immune dysfunction. Chai Hu oral liquid used as an antipyretic and anti-inflammatory drug is widely used in exogenous fever of poultry, but its resistance to heat stress and the mechanism is still unclear. In this study, a chronic heat stressed broilers model was established to explore the mechanisms of broilers' immune function changes and the effects of Chai Hu oral liquid. In this study, a total of 480 broilers were randomly divided into 6 groups with 80 replicates. Heat stress (HS) group broilers were stressed at 35 ± 2°C for 5 or 10 consecutive d with 6 h/d. Heat stressed (for 5 or 10 d) broilers were given with Jieshu KangreSan (Positive), Chai Hu oral liquid high, middle and low dosage (CH-High, CH-Mid, CH-Low) by oral administration. Birds in control group were treated with the same volume of PBS only in 25 ± 2°C. All birds were sacrificed at last heat stress challenged day. Changes in immune function were assessed by immune organs index, serum IFN-γ level, gene and protein expressions of immune factors in spleen and bursa of Fabricius. Results from this experiment showed that heat stress enhanced the immune organs' edema by directly increased the organs indexes of spleen and bursa of Fabricius in broilers. Heat stress for 10 d also increased bursa of Fabricius HSP70 protein level and significantly lowered the spleen and bursa of Fabricius proteins expressions of IFN-α, IFN-ß, and IFN-γ in broilers. The IFN-ß and IFN-γ protein levels in spleen and bursa of Fabricius also decreased in heat stressed broilers for 5 d. The gene and protein expressions of TLR4 and TBK1 markedly decreased in spleen and bursa of Fabricius of broilers treated with chronic heat stress. Chai Hu oral liquid reduced edema of immune organs and elevated TLR4-TBK1 signaling pathway to release immune factors. Above results indicated that chronic heat stress induced impaired immune function by inhibiting TLR4-TBK1 signaling pathway, and Chai Hu oral liquid had effective protection of body's immune ability by enhancing this signaling pathway.

Heat stress inhibits TLR4-NF-κB and TLR4-TBK1 signaling pathways in broilers infected with Salmonella Typhimurium.

With the global warming, the harm of heat stress (HS) to the breeding industry has become more common, which causes the decline of animal production performance and low immunity. This study aimed to analyze the effect of HS on the intestinal immune function of Salmonella-infected chickens. Fourteen-day-old broilers were divided into the following four groups of eight replicates: control (Control), heat stress (HS), Salmonella Typhimurium (ST), and heat stress + Salmonella Typhimurium (HS+ST). The broilers were subjected to a heat stress of 35 °C from 15 to 28 days of age. Salmonella Typhimurium (ST, 14028, 109 cfu/mL) was inoculated, via oral administration at 29 days of age, into ST and HS+ST group birds. On the 4th day after Salmonella Typhimurium administration, an increase in jejunum IgA levels was observed in chickens infected with Salmonella Typhimurium. Mechanistic regulation of TLR4-NFκB-NLRP3 and TLR4-TBK1 signaling by heat stress was evaluated in Salmonella Typhimurium-infected broilers. Heat stress markedly inhibited the expression of cytokines including TNF-α, IL-6, IL-1ß, NLRP3, caspase-1, NF-κB-p65, and p-NF-κB-p65, and the TLR4-TBK1 cytokines IFN-α, IFN-γ, p-IRF3, and p-TBK1 in jejunum of broilers infected with Salmonella Typhimurium. Collectively, our results demonstrate that heat stress can inhibit intestinal immune response by downregulating the expression of TLR4-NFκB-NLRP3 and TLR4-TBK1 signaling pathways in broilers infected with Salmonella Typhimurium.

Heat stress inhibits expression of the cytokines, and NF-κB-NLRP3 signaling pathway in broiler chickens infected with salmonella typhimurium.

High ambient temperature has potential influence on oxidative stress, or systemic inflammation affecting poultry production and immune status of chickens. Heat stress (HS) induces intestinal inflammation and increases susceptibility of harmful pathogens, such as Salmonella and Escherichia coli. Intestinal inflammation is a common result of body immune dysfunction. Therefore, we designed an experiment to analyze the effects of 35 ± 2 °C HS on salmonella infection in chickens through regulation of the immune responses. 40 broiler chickens were randomly divided into 4 groups: control group, heat stress (HS) group, salmonella typhimurium (ST) group and model group (heat stress + salmonella typhimurium, HS + ST). Birds in HS and model group were treated with 35 ± 2 °C heat stress 6 h a day and for 14 continuous days. Then, ST and model group birds were orally administrated with 1 mL ST inoculum (109 cfu/mL). Chickens were sacrificed at the 4th day after ST administration and ileum tissues were measured. We observed that heat stress decreased ileum TNF-α and IL-1ß protein expressions. Concomitantly heat stress decreased NLRP3 and Caspase-1 protein levels. The protein expressions of p-NF-κB-p65 and p-IκB-α in ileum. Heat stress also inhibited IFN-α, p-IRF3 and p-TBK1, showing a deficiency in the HS + ST group birds. Together, the present data suggested that heat stress suppressed intestinal immune activity in chickens infected by salmonella typhimurium, as observed by the decrease of immune cytokines levels, which regulated by NF-κB-NLRP3 signaling pathway.

Paraburkholderia phymatum Homocitrate Synthase NifV Plays a Key Role for Nitrogenase Activity during Symbiosis with Papilionoids and in Free-Living Growth Conditions.

Homocitrate is an essential component of the iron-molybdenum cofactor of nitrogenase, the bacterial enzyme that catalyzes the reduction of dinitrogen (N2) to ammonia. In nitrogen-fixing and nodulating alpha-rhizobia, homocitrate is usually provided to bacteroids in root nodules by their plant host. In contrast, non-nodulating free-living diazotrophs encode the homocitrate synthase (NifV) and reduce N2 in nitrogen-limiting free-living conditions. Paraburkholderia phymatum STM815 is a beta-rhizobial strain, which can enter symbiosis with a broad range of legumes, including papilionoids and mimosoids. In contrast to most alpha-rhizobia, which lack nifV, P. phymatum harbors a copy of nifV on its symbiotic plasmid. We show here that P. phymatum nifV is essential for nitrogenase activity both in root nodules of papilionoid plants and in free-living growth conditions. Notably, nifV was dispensable in nodules of Mimosa pudica despite the fact that the gene was highly expressed during symbiosis with all tested papilionoid and mimosoid plants. A metabolome analysis of papilionoid and mimosoid root nodules infected with the P. phymatum wild-type strain revealed that among the approximately 400 measured metabolites, homocitrate and other metabolites involved in lysine biosynthesis and degradation have accumulated in all plant nodules compared to uninfected roots, suggesting an important role of these metabolites during symbiosis.

Comparison of the prognosis of four different treatment strategies for acute left malignant colonic obstruction: a systematic review and network meta-analysis.

BACKGROUND: There is controversy regarding the efficacy of different treatment strategies for acute left malignant colonic obstruction. This study investigated the 5-year overall survival (OS) and disease-free survival (DFS) of several treatment strategies for acute left malignant colonic obstruction. METHODS: We searched for articles published in PubMed, Embase (Ovid), MEDLINE (Ovid), Web of Science, and Cochrane Library between January 1, 2000, and July 1, 2020. We screened out the literature comparing different treatment strategies. Evaluate the primary and secondary outcomes of different treatment strategies. The network meta-analysis summarizes the hazard ratio, odds ratio, mean difference, and its 95% confidence interval. RESULTS: The network meta-analysis involved 48 articles, including 8 (randomized controlled trials) RCTs and 40 non-RCTs. Primary outcomes: the 5-year overall survival (OS) and disease-free survival (DFS) of the CS-BTS strategy and the DS-BTS strategy were significantly better than those of the ES strategy, and the 5-year OS of the DS-BTS strategy was significantly better than that of CS-BTS. The long-term survival of TCT-BTS was not significantly different from those of CS-BTS and ES. SECONDARY OUTCOMES: compared with emergency resection (ER) strategies, colonic stent-bridge to surgery (CS-BTS) and transanal colorectal tube-bridge to surgery (TCT-BTS) strategies can significantly increase the primary anastomosis rate, CS-BTS and decompressing stoma-bridge to surgery (DS-BTS) strategies can significantly reduce mortality, and CS-BTS strategies can significantly reduce the permanent stoma rate. The hospital stay of DS-BTS is significantly longer than that of other strategies. There was no significant difference in the anastomotic leakage levels of several treatment strategies. CONCLUSION: Comprehensive literature research, we find that CS-BTS and DS-BTS strategies can bring better 5-year OS and DFS than ER. DS-BTS strategies have a better 5-year OS than CS-BTS strategies. Without considering the hospital stays, DS-BTS strategy is the best choice.

Heat stress aggravates intestinal inflammation through TLR4-NF-κB signaling pathway in Ma chickens infected with Escherichia coli O157:H7.

Heat stress can decrease poultry performance indices, immune function, and intestinal development, which can reduce birds' innate protective mechanisms and may be more susceptible for pathogens. Ma chickens heat-stressed with 41°C for 12 h and recovered for 7 d had extremely low immunity. In this study, a susceptible chicken model induced by heat stress and then infected with Escherichia coli O157:H7 was established to explore the mechanisms of birds' intestinal immune function changes. Ma chickens in heat stress + E. coli (HS + E. coli) group were stressed at 41°C for 12 h and recovered for 7 d, then chickens in E. coli group and HS + E. coli group were orally administered with 1 mL E. coli O157:H7 (1 × 109 cfu/mL). Chickens were sacrificed at the fourth day after E. coli administration. Results showed that the HS + E. coli group had increased intestinal length and weight, had higher E. coli counts in cecum contents than the E. coli group. Heat stress also enhanced serum diamine oxidase and decreased IgA level in chickens infected by E. coli. Heat stress had protective effects in small intestinal morphology except for duodenum by using hematoxylin and eosin staining. Compared with the E. coli group birds, IL-1ß, TNF-α, and caspase-1 protein levels in the duodenum and ileum were significantly increased. Heat stress also can significantly enhance the gene and protein expression of Hsp70, TLR4, and NF-κB in the duodenum and ileum, respectively. The gene expression of Hsp70, TLR4, and NF-κB in the jejunum was not influenced, but the protein expression of Hsp70 and NF-κB was inhibited by heat stress. The results indicated heat stress can amplify the effect of E. coli on intestinal inflammatory injury of Ma chickens through increasing TLR4-NF-κB signaling pathway.

Regulation of ferroptosis by non­coding RNAs in the development and treatment of cancer (Review).

Ferroptosis, a relatively recently discovered type of cell death that is iron dependent and nonapoptotic, is involved in the accumulation of lipid reactive oxygen species (ROS), and has been shown to serve a vital role in various pathological processes, including those underlying neurodegeneration, ischemic reperfusion injury, acute organ injury, and in particular, tumor biology. Emerging evidence has highlighted the roles of ferroptosis in the development and resistance to chemoradiotherapy in cancer. Recently, an increasing number of studies have shown that non­coding RNAs modulate the process of ferroptotic cell death, and this has further highlighted the potential of regulation of ferroptosis as a means of cancer management. Although these studies have highlighted the critical role of ferroptosis in cancer therapeutics, the roles of ferroptosis induced by non­coding RNAs in cancer development remain unclear. Herein, the current body of knowledge of ferroptosis in cancer is summarized and an overview of the mechanisms of ferroptosis and the functions of non­coding RNAs in regulating ferroptotic cell death are discussed. The future status of ferroptosis in cancer management is deliberated and strategies for treatment of therapy­resistant cancers are discussed.