Mouse circulating extracellular vesicles contain virus-derived siRNAs active in antiviral immunity.

Induction and suppression of antiviral RNA interference (RNAi) has been observed in mammals during infection with at least seven distinct RNA viruses, including some that are pathogenic in humans. However, while the cell-autonomous immune response mediated by antiviral RNAi is gradually being recognized, little is known about systemic antiviral RNAi in mammals. Furthermore, extracellular vesicles (EVs) also function in viral signal spreading and host immunity. Here, we show that upon antiviral RNAi activation, virus-derived small-interfering RNAs (vsiRNAs) from Nodamura virus (NoV), Sindbis virus (SINV), and Zika virus (ZIKV) enter the murine bloodstream via EVs for systemic circulation. vsiRNAs in the EVs are biologically active, since they confer RNA-RNA homology-dependent antiviral activity in both cultured cells and infant mice. Moreover, we demonstrate that vaccination with a live-attenuated virus, rendered deficient in RNAi suppression, induces production of stably maintained vsiRNAs and confers protective immunity against virus infection in mice. This suggests that vaccination with live-attenuated VSR (viral suppressor of RNAi)-deficient mutant viruses could be a new strategy to induce immunity.

LUSTR: a new customizable tool for calling genome-wide germline and somatic short tandem repeat variants.

BACKGROUND: Short tandem repeats (STRs) are widely distributed across the human genome and are associated with numerous neurological disorders. However, the extent that STRs contribute to disease is likely under-estimated because of the challenges calling these variants in short read next generation sequencing data. Several computational tools have been developed for STR variant calling, but none fully address all of the complexities associated with this variant class. RESULTS: Here we introduce LUSTR which is designed to address some of the challenges associated with STR variant calling by enabling more flexibility in defining STR loci, allowing for customizable modules to tailor analyses, and expanding the capability to call somatic and multiallelic STR variants. LUSTR is a user-friendly and easily customizable tool for targeted or unbiased genome-wide STR variant screening that can use either predefined or novel genome builds. Using both simulated and real data sets, we demonstrated that LUSTR accurately infers germline and somatic STR expansions in individuals with and without diseases. CONCLUSIONS: LUSTR offers a powerful and user-friendly approach that allows for the identification of STR variants and can facilitate more comprehensive studies evaluating the role of pathogenic STR variants across human diseases.

Efficient Dicer processing of virus-derived double-stranded RNAs and its modulation by RIG-I-like receptor LGP2.

The interferon-regulated antiviral responses are essential for the induction of both innate and adaptive immunity in mammals. Production of virus-derived small-interfering RNAs (vsiRNAs) to restrict virus infection by RNA interference (RNAi) is a recently identified mammalian immune response to several RNA viruses, which cause important human diseases such as influenza and Zika virus. However, little is known about Dicer processing of viral double-stranded RNA replicative intermediates (dsRNA-vRIs) in mammalian somatic cells. Here we show that infected somatic cells produced more influenza vsiRNAs than cellular microRNAs when both were produced by human Dicer expressed de novo, indicating that dsRNA-vRIs are not poor Dicer substrates as previously proposed according to in vitro Dicer processing of synthetic long dsRNA. We report the first evidence both for canonical vsiRNA production during wild-type Nodamura virus infection and direct vsiRNA sequestration by its RNAi suppressor protein B2 in two strains of suckling mice. Moreover, Sindbis virus (SINV) accumulation in vivo was decreased by prior production of SINV-targeting vsiRNAs triggered by infection and increased by heterologous expression of B2 in cis from SINV genome, indicating an antiviral function for the induced RNAi response. These findings reveal that unlike artificial long dsRNA, dsRNA-vRIs made during authentic infection of mature somatic cells are efficiently processed by Dicer into vsiRNAs to direct antiviral RNAi. Interestingly, Dicer processing of dsRNA-vRIs into vsiRNAs was inhibited by LGP2 (laboratory of genetics and physiology 2), which was encoded by an interferon-stimulated gene (ISG) shown recently to inhibit Dicer processing of artificial long dsRNA in cell culture. Our work thus further suggests negative modulation of antiviral RNAi by a known ISG from the interferon response.

Somatic variants in diverse genes leads to a spectrum of focal cortical malformations.

Post-zygotically acquired genetic variants, or somatic variants, that arise during cortical development have emerged as important causes of focal epilepsies, particularly those due to malformations of cortical development. Pathogenic somatic variants have been identified in many genes within the PI3K-AKT-mTOR-signalling pathway in individuals with hemimegalencephaly and focal cortical dysplasia (type II), and more recently in SLC35A2 in individuals with focal cortical dysplasia (type I) or non-dysplastic epileptic cortex. Given the expanding role of somatic variants across different brain malformations, we sought to delineate the landscape of somatic variants in a large cohort of patients who underwent epilepsy surgery with hemimegalencephaly or focal cortical dysplasia. We evaluated samples from 123 children with hemimegalencephaly (n = 16), focal cortical dysplasia type I and related phenotypes (n = 48), focal cortical dysplasia type II (n = 44), or focal cortical dysplasia type III (n = 15). We performed high-depth exome sequencing in brain tissue-derived DNA from each case and identified somatic single nucleotide, indel and large copy number variants. In 75% of individuals with hemimegalencephaly and 29% with focal cortical dysplasia type II, we identified pathogenic variants in PI3K-AKT-mTOR pathway genes. Four of 48 cases with focal cortical dysplasia type I (8%) had a likely pathogenic variant in SLC35A2. While no other gene had multiple disease-causing somatic variants across the focal cortical dysplasia type I cohort, four individuals in this group had a single pathogenic or likely pathogenic somatic variant in CASK, KRAS, NF1 and NIPBL, genes previously associated with neurodevelopmental disorders. No rare pathogenic or likely pathogenic somatic variants in any neurological disease genes like those identified in the focal cortical dysplasia type I cohort were found in 63 neurologically normal controls (P = 0.017), suggesting a role for these novel variants. We also identified a somatic loss-of-function variant in the known epilepsy gene, PCDH19, present in a small number of alleles in the dysplastic tissue from a female patient with focal cortical dysplasia IIIa with hippocampal sclerosis. In contrast to focal cortical dysplasia type II, neither focal cortical dysplasia type I nor III had somatic variants in genes that converge on a unifying biological pathway, suggesting greater genetic heterogeneity compared to type II. Importantly, we demonstrate that focal cortical dysplasia types I, II and III are associated with somatic gene variants across a broad range of genes, many associated with epilepsy in clinical syndromes caused by germline variants, as well as including some not previously associated with radiographically evident cortical brain malformations.

Effects of graphitic carbon nitride in the formation of disinfection byproducts.

Graphitic carbon nitride (CN) was a promising candidate for efficient environmental remediation in the advanced oxidation processes (AOPs). However, whether CN itself had some potential environmental risks, such as affecting the production of disinfection byproducts (DBPs) was still unknown. This study investigated the formation potential of DBPs in the presence of CN. The experimental data revealed that CN had a high potential to form DBPs, and dichloroacetonitrile (DCAN) was the most produced species during the chlorination and chloramination processes. Moreover, the effects of chlorine time, chlorine dosage, pH, and CN dosage during the chlorination process were evaluated to understand the formation pattern of DBPs. The possible mechanism of DBPs formation was deduced by analyzing the results of FTIR, Raman, and XPS before and after chlorination. Finally, the DBPs formation potential and cytotoxicity of the CN leaching solution were investigated, indicating CN could leach the precursors of DBPs and that the potential toxicity of the leaching solution increased with the extension of CN immersion time. In general, this research adds an understanding of the DBP formation of CN in water treatment systems and sheds light on CN's environmental potential risks.

WDR87 interacts with CFAP47 protein in the middle piece of spermatozoa flagella to participate in sperm tail assembly.

Spermatogenesis is a complex process that includes spermatogonia self-renewal, spermatocyte meiosis and spermatozoa assembly. Recent studies have revealed that WD40-repeat domain-containing (WDR) proteins play important roles in spermatocyte division, spermatozoa flagella assembly and head shaping. In this study, we investigated the expression pattern of WDR87 and found that it was highly expressed in the testis of both humans and mice. Immunofluorescence staining revealed that mouse WDR87 was distributed in the perinuclear cytoplasm of primary spermatocytes, secondary spermatocytes and round spermatids. In the spermiogenesis stage, with extension of the nucleus, WDR87 migrated to the manchette and finally localized to the middle piece of the spermatozoa tail. Furthermore, we identified a cilia- and flagella-associated protein, CFAP47, which interacted with WDR87 in the flagellar midpiece of the spermatozoa, suggesting that WDR87 may be associated with multiple morphological abnormalities of the flagella (MMAF). Subsequently, we screened gene mutations in seven MMAF individuals and found two novel mutations in CFAP47 (c.706G>A, Val236Met; c.1337C>T, Thr446Met) in one case. Immunoblotting and immunofluorescence revealed that CFAP47 was dramatically reduced in spermatozoa from the CFAP47-mutated man. Meanwhile, the expression of WDR87 was also significantly decreased, and weak signals were detected adjacent to the spermatozoa nuclei, indicating that CFAP47 was necessary for WDR87 transportation during spermatozoa flagella biogenesis. These data indicate that WDR87 is located in the middle piece of the sperm tail and interacts with CFAP47 to form a complex which is involved in spermatozoa tail assembly.

Intestinal Epithelial Cell-Derived LKB1 Suppresses Colitogenic Microbiota.

Dysregulation of the immune barrier function of the intestinal epithelium can often result in dysbiosis. In this study we report a novel role of intestinal epithelial cell (IEC)-derived liver kinase B1 (LKB1) in suppressing colitogenic microbiota. IEC-specific deletion of LKB1 (LKB1ΔIEC) resulted in an increased susceptibility to dextran sodium sulfate (DSS)-induced colitis and a definitive shift in the composition of the microbial population in the mouse intestine. Importantly, transfer of the microbiota from LKB1ΔIEC mice was sufficient to confer increased susceptibility to DSS-induced colitis in wild-type recipient mice. Collectively, the data indicate that LKB1 deficiency in intestinal epithelial cells nurtures the outgrowth of colitogenic bacteria in the commensal community. In addition, LKB1 deficiency in the intestinal epithelium reduced the production of IL-18 and antimicrobial peptides in the colon. Administration of exogenous IL-18 restored the expression of antimicrobial peptides, corrected the outgrowth of several bacterial genera, and rescued the LKB1ΔIEC mice from increased sensitivity to DSS challenge. Taken together, our study reveals an important function of LKB1 in IECs for suppressing colitogenic microbiota by IL-18 expression.

Lipid flippases promote antiviral silencing and the biogenesis of viral and host siRNAs in Arabidopsis.

Dicer-mediated processing of virus-specific dsRNA into short interfering RNAs (siRNAs) in plants and animals initiates a specific antiviral defense by RNA interference (RNAi). In this study, we developed a forward genetic screen for the identification of host factors required for antiviral RNAi in Arabidopsis thaliana Using whole-genome sequencing and a computational pipeline, we identified aminophospholipid transporting ATPase 2 (ALA2) and the related ALA1 in the type IV subfamily of P-type ATPases as key components of antiviral RNAi. ALA1 and ALA2 are flippases, which are transmembrane lipid transporter proteins that transport phospholipids across cellular membranes. We found that the ala1/ala2 single- and double-mutant plants exhibited enhanced disease susceptibility to cucumber mosaic virus when the virus-encoded function to suppress RNAi was disrupted. Notably, the antiviral activity of both ALA1 and ALA2 was abolished by a single amino acid substitution known to inactivate the flippase activity. Genetic analysis revealed that ALA1 and ALA2 acted to enhance the amplification of the viral siRNAs by RNA-dependent RNA polymerase (RdRP) 1 (RDR1) and RDR6 and of the endogenous virus-activated siRNAs by RDR1. RNA virus replication by plant viral RdRPs occurs inside vesicle-like membrane invaginations induced by the recruitment of the viral RdRP and host factors to subcellular membrane microdomains enriched with specific phospholipids. Our results suggest that the phospholipid transporter activity of ALA1/ALA2 may be necessary for the formation of similar invaginations for the synthesis of dsRNA precursors of highly abundant viral and host siRNAs by the cellular RdRPs.

Study on the lifetime of photocatalyst by photocatalytic membrane reactors (PMR).

The continuously photocatalytic degradation of methyl orange (MO) was carried out using a photocatalytic membrane reactor (PMR). The lifetime, cause of deactivation, and regeneration of Degussa P25 titanium dioxide (TiO2) were investigated. The photocatalyst was deactivated when the concentration of MO in the effluent of the PMR was stable. To characterize the lifetime of the photocatalyst, we applied g MO/g TiO2. The lifetime of the photocatalyst during the photocatalytic degradation of 10 mg/L MO was 3.71 times that of 5 mg/L MO. Changing the hydraulic retention time of the PMR from 0.75 to 3 h prolonged the lifetime of the photocatalyst. Deactivation of the photocatalyst was not due to pore blocking by the reactant (MO) or intermediate products. The surface adsorption of MO and the reaction intermediates deactivated the catalyst. The spent catalysts were regenerated after washing with methanol and hydrogen peroxide (H2O2) and then treated with heat. H2O2 treatment generated the highest regeneration rate, because H2O2 is a strong oxidizing agent that oxidized the deposited species on the surface of the photocatalyst.

Efficient degradation of tetracycline by ultraviolet-based activation of peroxymonosulfate and persulfate.

In this study, the difference in oxidative capacity for removing antibiotics and the mechanism between the Cu(II)/peroxymonosulfate (PMS)/UV and Cu(II)/persulfate (PDS)/UV systems were compared under various conditions. The optimal Cu(II) concentration in the Cu(II)/PMS/UV system was 30 µM, and in the Cu(II)/PDS/UV system was 50 µM. With the PMS or PDS concentration increasing, higher tetracycline (TC) degradation in these two systems occurred. Investigation on the mechanism revealed that •OH was the primary radical in the Cu(II)/PMS/UV system, while SO4 -• was the primary radical in the Cu(II)/PDS/UV system where •OH also played an important role. In these two systems, it was observed that Cu(I) was generated by PMS or PDS activated via UV illumination; however, oxygen alone could not promote TC removal. The degradation of TC was increased with the increasing pH level. In addition, TC degradation in the Cu(II)/PMS/UV system followed the pseudo-first-order kinetics model during the entire reaction period. It was found that the TC degradation kinetics in the Cu(II)/PDS/UV system can be divided into two parts (0 to 7 min and 10 to 50 min) and these two parts had good agreement with the pseudo-first-order kinetics model, respectively.

Correlation of Plasma Vascular Endothelial Growth Factor and Endostatin Levels with Symptomatic Intra- and Extracranial Atherosclerotic Stenosis in a Chinese Han Population.

BACKGROUND: Symptomatic intracranial atherosclerotic stenosis (ICAS) and extracranial atherosclerotic stenosis (ECAS) are different in many aspects. Here, we explored the association between the location or severity of atherosclerotic stenosis and pro- or antiangiogenic factors, specifically vascular endothelial growth factor (VEGF) and endostatin (ES). METHODS: We evaluated 198 consecutive patients with acute ischemia stroke: 132 with large-artery atherosclerosis (LAA) and 66 with small-artery occlusion (small-vessel occlusion). The LAA group was subclassified into 102 patients with ICAS and 30 with ECAS. Independent associations of VEGF, ES levels, and VEGF/ES ratio with the location of cerebral stenosis and the severity or short-term prognosis (14th day modified Rankin Scale) of ICAS were evaluated. RESULTS: Plasma concentrations of VEGF and ES were lower (P < .05) in ICAS (38.07, 32.76-46.28 pg/mL and 58.95, 55.04-59.77 ng/mL) than those in ECAS (45.00, 34.30-83.34 pg/mL and 140.74, 85.63-231.21 ng/mL). Logistic regression analysis showed that VEGF concentrations and dyslipidemia were independently associated with ICAS, with odds ratios of .987 [95% CI = (.976, .998)] and .265 [95% CI = (.103, .792)], respectively. Moreover, plasmatic VEGF levels increased gradually along with the severity of ICAS (P = .003), and lower levels of ES (P = .040) or a higher VEGF/ES ratio (P = .048) were related to unfavorable short-term prognosis of ICAS. CONCLUSION: Lower VEGF levels are associated with the presence of symptomatic ICAS, but not with ECAS. Furthermore, the severity of ICAS is positively correlated with the levels of VEGF, and lower ES levels or a predominance of VEGF over ES are predictors of poor short-term prognosis of ICAS.

Comparative Mammalian Cell Cytotoxicity of Wastewaters for Agricultural Reuse after Ozonation.

Reusing wastewater in agriculture is becoming increasingly common, which necessitates disinfection to ensure reuse safety. However, disinfectants can react with wastewater constituents to form disinfection byproducts (DBPs), many of which are toxic and restrict the goal of safe reuse. Our objective was to benchmark the induction of mammalian cell cytotoxicity after ozonation against chlorination for three types of real wastewaters: municipal secondary effluent and two sources of minimally treated swine farm wastewaters. A new method to evaluate samples of suspected high cytotoxicity was devised. For the secondary effluent, ozonation reduced the cytotoxicity by as much as 10 times; chlorination lowered the cytotoxicity only when followed by dechlorination. The swine farm wastewaters were up to 2000 times more cytotoxic than the secondary effluent, and the highest reduction in cytotoxicity was 17 times as achieved by ozonation. These results indicate that secondary effluent is preferred over swine wastewaters for agricultural reuse regardless of the tested disinfectants. Ozonation consistently reduced the cytotoxicity of both the full strength and the organic extracts of all tested wastewaters more than chlorination. The only significant correlation was observed in the secondary wastewater between total haloacetonitriles and cytotoxicity. While the association of reduced toxicity with the modification or reduction of specific compound(s) is unclear, regulated DBPs may not be the primary forcing agents.

Astakine LvAST binds to the ß subunit of F1-ATP synthase and likely plays a role in white shrimp Litopeneaus vannamei defense against white spot syndrome virus.

Cytokines play a critical role in innate and adaptive immunity. Astakines represent a group of invertebrate cytokines that are related to vertebrate prokineticin and function in promoting hematopoiesis in crustaceans. We have identified an astakine from the white shrimp Litopeneaus vannamei and named it LvAST in a previous research. In the present research, we investigated the interactions among LvAST, the envelope protein VP37 of white spot syndrome virus (i.e., WSSV), and the ß subunit of F1-ATP synthase (ATPsyn-ß) of the white shrimp (i.e., BP53) using binding assays and co-precipitations. We also examined the effects of LvAST on shrimp susceptibility to WSSV. We found that LvAST and VP37 competitively bound to BP53, but did not bind to each other. Shrimps that had been injected with recombinant LvAST exhibited significantly lower mortality and longer survival time in experimental infections by WSSV. In contrast, shrimps whose LvAST gene expression had been inhibited by RNA interference showed significantly higher WSSV infection intensity and shorter survival time following viral challenges. These results suggested that LvAST and WSSV both likely use ATPsyn-ß as a receptor and LvAST plays a role in shrimp defense against WSSV infection. This represented the first research showing the involvement of astakines in host antiviral immunity.

The Drosophila ortholog of breast cancer metastasis suppressor gene, dBrms1, is critical for developmental timing through regulating ecdysone signaling.

BRMS1 was first discovered as a human breast carcinoma metastasis suppressor gene. However, the mechanism of BRMS1 in tumor metastasis and its developmental role remain unclear. In this paper, we first report the identification of the Drosophila ortholog of human BRMS1, dBrms1. Through a genetic approach, the role of dBrms1 during development has been investigated. We found that dBrms1 is an essential gene and loss of dBrms1 function results in lethality at early developmental stages. dBrms1mutants displayed phenotypes such as developmental delay and failure to initiate metamorphosis. Further analysis suggests that these phenotypes are contributed by defective ecdysone signaling and expression of target genes of the ecdysone pathway. Therefore, dBrms1 is required for growth control by acting as a modulator of ecdysone signaling in Drosophila and is required for metamorphosis for normal development.

Association of BSG genetic polymorphisms with atherosclerotic cerebral infarction in the Han Chinese population.

The Basigin (BSG, also known as CD147/extracellular matrix metalloproteinase inducer) belongs to the immunoglobulin superfamily (IgSF). It is a cellular receptor for cyclophilin A (CypA), and is originally known as tumor cell collagenase stimulatory factor (TCSF), which could abundantly expressed on the surface of tumor cells, haematopoietic, monocytes, epithelial endothelial cells and smooth muscle cells. Accumulating evidence showed that BSG played an important role in stimulating the secretion of matrix metalloproteinases (MMPs), which has been reported to be involved in the development of atherosclerosis. Since atherosclerosis is an important risk factor for atherosclerotic cerebral infarction (ACI), we speculate that BSG genetic polymorphisms may influence formation of atherosclerosis and then development of ACI. This study aimed to detect the potential association of the single nucleotide polymorphisms (SNP, -631 G > T, -318 G > C, 10141 G > A and 10826 G > A) of BSG gene in Hunan Han Chinese population with ACI. We genotyped 199 ACI patients and 188 matched healthy controls for the four BSG SNP by method of matrix-assisted laser desorption/ionization-time-offlight mass spectrometry (MALDI-TOF MS). Our results suggested that all the polymorphisms were observed in the subjects from Changsha area of Hunan Province. However, no significant difference was observed between the distribution of these SNP in cases and controls. Therefore, we speculate that BSG genetic polymorphisms might not be an important factor in the development of ACI in our Chinese Han population.

A multi-omics approach to unravelling the coupling mechanism of nitrogen metabolism and phenanthrene biodegradation in soil amended with biochar.

The presence of polycyclic aromatic hydrocarbons (PAHs) in soil negatively affects the environment and the degradation of these contaminants is influenced by nitrogen metabolism. However, the mechanisms underlying the interrelationships between the functional genes involved in nitrogen metabolism and phenanthrene (PHE) biodegradation, as well as the effects of biochar on these mechanisms, require further study. Therefore, this study utilised metabolomic and metagenomic analysis to investigate primary nitrogen processes, associated functional soil enzymes and functional genes, and differential soil metabolites in PHE-contaminated soil with and without biochar amendment over a 45-day incubation period. Results showed that dissimilatory nitrate reduction to ammonium (DNRA) and denitrification were the dominant nitrogen metabolism processes in PHE-contaminated soil. The addition of biochar enhanced nitrogen modules, exhibiting discernible temporal fluctuations in denitrification and DNRA proportions. Co-occurrence networks and correlation heatmap analysis revealed potential interactions among functional genes and enzymes responsible for PHE biodegradation and nitrogen metabolism. Notably, enzymes associated with denitrification and DNRA displayed significant positive correlation with enzymes involved in downstream phenanthrene degradation. Of particular interest was stronger correlation observed with the addition of biochar. However, biochar amendment inhibited the 9-phenanthrol degradation pathway, resulting in elevated levels of glutathione (GSH) in response to environmental stress. These findings provide new insights into the interactions between nitrogen metabolism and PHE biodegradation in soil and highlight the dual effects of biochar on these processes.

Enhanced antibiotic degradation via photo-assisted peroxymonosulfate over graphitic carbon nitride nanosheets/CuBi2O4: Highly efficiency of oxygen activation and interfacial charge transfer.

Improving the activation capacity of peroxymonosulfate (PMS) to increase radical and non-radical production is critical for antibiotic degradation. However, how to boost reactive oxygen species (ROS) and speed interfacial charge transfer remains an essential challenge. We report a coupling system of 10 %CNNS/CuBi2O4 photocatalyst and sulfate radical-based advanced oxidation processes (SO4--AOPs) to enhance the activation of PMS and improve antibiotic degradation. Owing to highly efficient oxygen activation and interfacial charge transfer, the degradation efficiency of the photo-assisted PMS system was as high as 51.6 times and 2.8 times that of photocatalyst and SO4--AOPs alone, respectively. Importantly, the highly efficient oxygen activation resulted in the production of O2-, which in turn could utilize the excess electrons generated through efficient interfacial charge transfer to convert into non-radical 1O2. The total organic carbon (TOC) elimination effectiveness of the photo-assisted PMS system reached 82 % via the synergy of radicals and non-radicals (O2-, OH, 1O2, SO4-, h+). This system also had excellent potential for reducing the generation and toxicity of disinfection by-products (DBPs), as evidenced through significant reductions in concentrations of trichloromethane (TCM), dichloroacetic acid (DCAA), and trichloronitromethane (TCNM) by 76 %, 64 %, and 35 %, respectively, providing an effective and eco-friendly strategy for antibiotic treatment.

Integrated model of ozone mass transfer and oxidation kinetic: Construction, solving and analysis.

Ozone-based advanced oxidation process (O3-AOPs) is rapidly evolving, but the surge of emerging pollutants brings new challenges for ozone oxidation research. Herein, we proposed a state-of-the-art model for simultaneously analyzing both ozone mass transfer and oxidation kinetics during ozone oxidation of emerging organic contaminants. The numerical solution and graphical representations of the integrated model were utilized to analyze the dynamics of ozone and pollutant concentration. An in-depth analysis of the integrated model revealed that the reaction rate constants in this present study were higher than previously reported apparent reaction rate constants, and catalysts were not always necessary. Finally, we developed an installable mobile application (APP) that allowed the simulation of the dynamic process for ozone oxidizing organic pollutants in the laboratory, which offered theoretical support for the selection of experimental conditions. The results of model simulation not only provide scientific explanations for counter-intuitive experimental phenomena, but also optimized experimental conditions to enhance ozone utilization.

Metagenomics next-generation sequencing (mNGS) reveals emerging infection induced by Klebsiella pneumoniaeniae.

OBJECTIVES: The increasing emergence of hypervirulent Klebsiella pneumoniae (hv-Kp) and carbapenem-resistant K. pneumoniae (CR-Kp) is a serious and substantial public health problem. The use of the last resort antimicrobials, tigecycline and polymyxin to combat infections is complicated by the expanding repertoire of newly-identified CR-hvKp. The transmission and co-occurrence of the corresponding antimicrobial resistance and virulence determinants are largely unknown. The aim of this study was to investigate the dissemination and dynamics of CR-Kp and its antibiotic resistance in a hospitalised patient. METHODS: Metagenomic next-generation sequencing (mNGS) was conducted for different specimens collected from an elderly male hospitalised patient. CR-Kp strains were examined using antibiotic susceptibility and string testing. Antimicrobial and virulence genes were annotated using whole-genome sequencing (WGS). RESULTS: A clinical case of a patient infected with a variety of CR-Kp isolates was reported. The co-occurrence of KPC-2 and NDM-1 in the patient was revealed. The CR-Kp isolates, such as BALF2, and Sputum T1 and T3, were classified into ST11 and ST147, respectively. The genetic signature (iuc operon) of hypervirulence was identified in strain T1, although string testing indicated its intermediate virulence. CONCLUSIONS: In this study, multiple infections of CR-Kp isolates were revealed by mNGS, and their dissemination was attributed to plasmid variations, mgrB inactivation and integrative conjugative elements (ICEs). Furthermore, the finding indicated one likely convergence to form CR-hvKp, different from acquisition of carbapenem-resistance determinants in hvKp. A combination of mNGS and WGS is beneficial for clinical diagnosis and anti-infection therapy, and facilitates a better understanding of genetic variants conferring antimicrobial and virulence properties.

Thoracic paravertebral block for perioperative lung preservation during VATS pulmonary surgery: study protocol of a randomized clinical trial.

BACKGROUND: Postoperative pulmonary complications (PPCs) extend the length of stay of patients and increase the perioperative mortality rate after video-assisted thoracoscopic (VATS) pulmonary surgery. Thoracic paravertebral block (TPVB) provides effective analgesia after VATS surgery; however, little is known about the effect of TPVB on the incidence of PPCs. The aim of this study is to determine whether TPVB combined with GA causes fewer PPCs and provides better perioperative lung protection in patients undergoing VATS pulmonary surgery than simple general anaesthesia. METHODS: A total of 302 patients undergoing VATS pulmonary surgery will be randomly divided into two groups: the paravertebral block group (PV group) and the control group (C group). Patients in the PV group will receive TPVB: 15 ml of 0.5% ropivacaine will be administered to the T4 and T7 thoracic paravertebral spaces before general anaesthesia induction. Patients in the C group will not undergo the intervention. Both groups of patients will be subjected to a protective ventilation strategy during the operation. Perioperative protective mechanical ventilation and standard fluid management will be applied in both groups. Patient-controlled intravenous analgesia is used for postoperative analgesia. The primary endpoint is a composite outcome of PPCs within 7 days after surgery. Secondary endpoints include blood gas analysis, postoperative lung ultrasound score, NRS score, QoR-15 score, hospitalization-related indicators and long-term prognosis indicators. DISCUSSION: This study will better evaluate the impact of TPVB on the incidence of PPCs and the long-term prognosis in patients undergoing VATS lobectomy/segmentectomy. The results may provide clinical evidence for optimizing perioperative lung protection strategies. TRIAL REGISTRATION: ClinicalTrials.gov NCT05922449 . Registered on June 25, 2023.