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1.
Environ Res ; 246: 118533, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38417660

RESUMO

Real-time flood forecasting is one of the most pivotal measures for flood management, and real-time error correction is a critical step to guarantee the reliability of forecasting results. However, it is still challenging to develop a robust error correction technique due to the limited cognitions of catchment mechanisms and multi-source errors across hydrological modeling. In this study, we proposed a hydrologic similarity-based correction (HSBC) framework, which hybridizes hydrological modeling and multiple machine learning algorithms to advance the error correction of real-time flood forecasting. This framework can quickly and accurately retrieve similar historical simulation errors for different types of real-time floods by integrating clustering, supervised classification, and similarity retrieval methods. The simulation errors "carried" by similar historical floods are extracted to update the real-time forecasting results. Here, combining the Xin'anjiang model-based forecasting platform with k-means, K-nearest neighbor (KNN), and embedding based subsequences matching (EBSM) method, we constructed the HSBC framework and applied it to China's Dufengkeng Basin. Three schemes, including "non-corrected" (scheme 1), "auto-regressive (AR) corrected" (scheme 2), and "HSBC corrected" (scheme 3), were built for comparison purpose. The results indicated the following: 1) the proposed framework can successfully retrieval similar simulation errors with a considerable retrieval accuracy (2.79) and time consumption (228.18 s). 2) four evaluation metrics indicated that the HSBC-based scheme 3 performed much better than the AR-based scheme 2 in terms of both the whole flood process and the peak discharge; 3) the proposed framework overcame the shortcoming of the AR model that have poor correction for the flood peaks and can provide more significant correction for the floods with bad forecasting performance. Overall, the HSBC framework demonstrates the advancement of benefiting the real-time error correction from hydrologic similarity theory and provides a novel methodological alternative for flood control and water management in wider areas.


Assuntos
Inundações , Aprendizado de Máquina , Reprodutibilidade dos Testes , Simulação por Computador , Previsões
2.
Small ; 19(2): e2205257, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36344428

RESUMO

Nickel based materials are promising electrocatalysts to produce hydrogen from water in alkaline media. However, the stability is of great challenge, limiting its practical material functions. Herein, a new technique for electro-deposition flower-like NiCo2 S4 nanosheets on carbon-cloth (CC@NiCo2 S4 ) is proposed for energy-saving production of H2 from water/methanol coelectrolysis at high current density by constructing array architectures and regulating surface magnetism. The optimized and fine-tuned magnetism on the surface of the electrochemical in situ grown CC@NiCo2 S4 nanosheet array result in (0 1 -1) surface universally exposed, high catalytic activity for methanol electrooxidation, and long-term stability at high current density. X-ray photoelectron spectroscopy in combination of density functional theory calculations confirm the valence electron states and spin of d electrons for the surface of NiCo2 S4 , which enhance the surface stability of catalysts. This technology may be utilized to alter the surface magnetism and increase the stability of Ni-based electrocatalytic materials in general.

3.
Bioconjug Chem ; 34(11): 2133-2143, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37874952

RESUMO

Molecular imaging and targeted radiotherapy with radiolabeled fibroblast activation protein inhibitor (FAPI) targeting peptide probes hold great potential for enhancing the clinical management of patients with FAP-expressing cancers. However, the high cost of PET probes has prompted us to search for new FAP-targeting single-photon imaging agents. In this study, HYNIC-Glc-FAPT is synthesized and radiolabeled with technetium-99m using tricine/EDDA or dimer tricine as coligands to produce [99mTc]Tc-tricine/EDDA-HYNIC-Glc-FAPT and [99mTc]Tc-tricine(2)-HYNIC-Glc-FAPT. Both [99mTc]Tc-tricine/EDDA-HYNIC-Glc-FAPT and [99mTc]Tc-tricine(2)-HYNIC-Glc-FAPT were effectively synthesized with an excellent radiochemistry yield (both >97%, n = 6) in a single-step technique, and their stability in PBS and human serum was satisfactory. Compared to [99mTc]Tc-tricine(2)-HYNIC-Glc-FAPT, [99mTc]Tc-tricine/EDDA-HYNIC-Glc-FAPT exhibited a more hydrophilic nature with a log P of -3.53 ± 0.12. In vitro cellular uptake and blocking assays, internalization, efflux experiments, and affinity experiments all suggested a mechanism with high FAP-specificity and affinity. SPECT imaging and biodistribution of [99mTc]Tc-tricine/EDDA-HYNIC-Glc-FAPT demonstrated sustained high tumor uptake in BALB/c nude mice bearing U87MG tumors for 6 h. It demonstrated a long-range retention characteristic and more rapid clearance ability from nontarget organs. Collectively, we successfully synthesized [99mTc]Tc-tricine/EDDA-HYNIC-Glc-FAPT and [99mTc]Tc-tricine(2)-HYNIC-Glc-FAPT, and the excellent targeting properties of [99mTc]Tc-tricine/EDDA-HYNIC-Glc-FAPT suggest a potential diagnostic value in future clinical studies for advanced-stage FAP-expressing malignancies, especially in prognostic evaluation of tumors for it low price and convenient source.


Assuntos
Compostos Radiofarmacêuticos , Tecnécio , Camundongos , Animais , Humanos , Camundongos Nus , Distribuição Tecidual , Linhagem Celular Tumoral , Compostos Radiofarmacêuticos/química , Compostos de Organotecnécio/química
4.
Phys Chem Chem Phys ; 24(30): 18083-18093, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-35876809

RESUMO

Cesium (Cs+) and strontium (Sr2+) ions are the main fission byproducts in the reprocessing of spent nuclear fuels for nuclear power plants. Their long half-live period (30.17 years for 137Cs and 28.80 years for 90Sr) makes them very dangerous radionuclides. Hence the solidification of Cs+ and Sr2+ is of paramount importance for preventing them from entering the human food chain through water. Despite tremendous efforts for solidification, the long-term stability remains a great challenge due to the experimental limitation and lack of good evaluation indicators for such long half-life radionuclides. Using density functional theory (DFT), we investigate the origin of long-term stability for the solidification of Cs+ and Sr2+ inside sodalite and establish that the exchange energy and the diffusion barrier play an important role in gaining the long-term stability both thermodynamically and kinetically. The acidity/basicity, solvation, temperature, and diffusion effect are comprehensively studied. It is found that solidification of Cs+ and Sr2+ is mainly attributed to the solvation effect, zeolitic adsorption ability, and diffusion barriers. The present study provides theoretical evidence to use geopolymers to adsorb Cs+ and Sr2+ and convert the adsorbed geopolymers to zeolites to achieve solidification of Cs+ and Sr2+ with long-term stability.


Assuntos
Césio , Zeolitas , Adsorção , Difusão , Humanos , Estrôncio
5.
Pharm Biol ; 60(1): 1625-1634, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35980123

RESUMO

CONTEXT: Cnidium monnieri Cusson (Apiaceae) has been used in traditional Asian medicine for thousands of years. Recent studies showed its active compound, osthole, had a good effect on osteoporosis. But there was no comprehensive analysis. OBJECTIVE: This meta-analysis evaluates the effects of osthole on osteoporotic rats and provides a basis for future clinical studies. METHODS: Chinese and English language databases (e.g., PubMed, Web of Science, Cochrane Library, Google Scholar, Embase, China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, Weipu Chinese Sci-tech periodical full-text database, and Chinese BioMedical Literature Database) were searched from their establishment to February 2021. The effects of osthole on bone mineral density, osteoclast proliferation, and bone metabolism markers were compared with the effects of control treatments. RESULTS: To our knowledge, this is the first meta-analysis to evaluate osthole for the treatment of osteoporosis in rats. We included 13 randomized controlled studies conducted on osteoporotic rats. Osthole increased bone mineral density (standardized mean difference [SMD] = 3.08, 95% confidence interval [CI] = 2.08-4.09), the subgroup analysis showed that BMD significantly increased among rats in osthole <10 mg/kg/day and duration of osthole treatment >2 months. Osthole improved histomorphometric parameters and biomechanical parameters, also inhibited osteoclast proliferation and bone metabolism. CONCLUSIONS: Osthole is an effective treatment for osteoporosis. It can promote bone formation and inhibit bone absorption.


Assuntos
Cnidium , Osteoporose , Animais , Densidade Óssea , Cnidium/química , Cumarínicos/farmacologia , Cumarínicos/uso terapêutico , Osteoporose/tratamento farmacológico , Ratos
6.
J Cell Mol Med ; 24(4): 2507-2518, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31930674

RESUMO

Hepatitis B virus (HBV) is a human hepatotropic virus. However, HBV infection also occurs at extrahepatic sites, but the relevant host factors required for HBV infection in non-hepatic cells are only partially understood. In this article, a non-hepatic cell culture model is constructed by exogenous expression of four host genes (NTCP, HNF4α, RXRα and PPARα) in human non-hepatic 293T cells. This cell culture model supports HBV entry, transcription and replication, as evidenced by the detection of HBV pgRNA, HBV cccDNA, HBsAg, HBeAg, HBcAg and HBVDNA. Our results suggest that the above cellular factors may play a key role in HBV infection of non-hepatic cells. This model will facilitate the identification of host genes that support extrahepatic HBV infection.


Assuntos
Vírus da Hepatite B/patogenicidade , Hepatite B/virologia , Hepatócitos/virologia , Linhagem Celular , Linhagem Celular Tumoral , DNA Viral/genética , Células HEK293 , Células Hep G2 , Antígenos de Superfície da Hepatite B/genética , Antígenos E da Hepatite B/genética , Vírus da Hepatite B/genética , Humanos , Replicação Viral/genética
7.
Med Sci Monit ; 24: 1366-1372, 2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29508843

RESUMO

BACKGROUND Cardiac device infection (CDI) is a serious complication of cardiovascular implantable electronic device (CIED) implantations. Many risk factors have been identified, but several are still uncertain. This study aimed to identify and evaluate the risk factors. Moreover, an infection control protocol (ICP) was carried out, and its efficacy in reducing CDIs was investigated. MATERIAL AND METHODS A total of 1259 patients who received permanent pacemaker (PPM) implantations were enrolled in this study in a 3-year period in a high-volume center and low-volume centers in the central area of Shaanxi Province, China. Follow-up data of all enrolled patients were collected. The risk factors for CDIs were identified and analyzed. The ICP was adopted in the low-volume centers. Data, including CDI rates, medical costs, and microbiology, were collected and compared. RESULTS Male gender, diabetes, CKD, operation duration, PPM replacement, and low center volume were identified as the risk factors for CDIs. Furthermore, CDI rates in low-volume centers were significantly higher than in high-volume centers. The adoption of an ICP dramatically reduced CDI rates in low-volume centers without significant increases in medical costs. CONCLUSIONS ICPs were easily carried out, effective, and economical in controlling CDIs in low-volume centers, which was identified as a risk factor of CDIs.


Assuntos
Desfibriladores Implantáveis/efeitos adversos , Controle de Infecções/métodos , Marca-Passo Artificial/efeitos adversos , Idoso , China , Feminino , Cardiopatias , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Relacionadas à Prótese/microbiologia , Fatores de Risco
8.
Environ Monit Assess ; 190(6): 330, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29732470

RESUMO

Low-frequency grab sampling cannot capture fine dynamics of stream solute concentrations, which results in large uncertainties in load estimates. The recent development of high-frequency sensors has enabled monitoring solute concentrations at sub-hourly time scales. This study aimed to improve nitrate (NO3) load estimates using high-resolution records (15-min time interval) from optical sensors to capture the typical concentration response to storm events. An empirical model was developed to reconstruct NO3 concentrations during storm events in a 100-km2 agricultural catchment in Germany. Two years (Jan 2002 to Dec 2002 and Oct 2005 to Sep 2006) of high-frequency measurements of NO3 concentrations, discharge and precipitation were used. An Event Response Reconstruction (ERR) model was developed using NO3 concentration descriptor variables and predictor variables calculated from discharge and precipitation records. Fourteen events were used for calibration, and 27 events from four periods of continuous records of high-frequency measurement were used for validation. During all selected storm events, NO3 concentration decreased during flow rise and increased during the recession phase of the hydrograph. Three storm descriptor variables were used to describe these dynamics: relative change in concentration between initial and minimum NO3 concentrations (rdN), time to maximum change in NO3 concentration (TdN) and time to 50% recovery of NO3 concentration (TN rec ). The ERR consisted of building linear models of discharge and precipitation to predict these three descriptors. The ERR approach greatly improved NO3 load estimates compared to linear interpolation of grab sampling data (error decreased from 10 to 1%) or flow-weighted estimation of load (error is 7%). This study demonstrated that ERR based on a few months of high-resolution data enables accurate load estimates from low-frequency NO3 data.


Assuntos
Monitoramento Ambiental/métodos , Nitratos/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Agricultura/métodos , Alemanha , Óxidos de Nitrogênio , Rios/química
9.
BMC Genomics ; 18(1): 211, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-28241790

RESUMO

BACKGROUND: Cold tolerance is a key determinant of the geographical distribution range of a plant species and crop production. Cold acclimation can enhance freezing-tolerance of plant species through a period of exposure to low nonfreezing temperatures. As a subtropical evergreen broadleaf plant, oil-tea camellia demonstrates a relatively strong tolerance to freezing temperatures. Moreover, wild oil-tea camellia is an essential genetic resource for the breeding of cultivated oil-tea camellia, one of the four major woody oil crops in the world. The aims of our study are to identify variations in transcriptomes of wild oil-tea camellia from different latitudes and elevations, and discover candidate genes for cold acclimation. RESULTS: Leaf transcriptomes were obtained of wild oil-tea camellia from different elevations in Lu and Jinggang Mountains, China. Huge amounts of simple sequence repeats (SSRs), single-nucleotide polymorphisms (SNPs) and insertion/deletions (InDels) were identified. Based on SNPs, phylogenetic analysis was performed to detect genetic structure. Wild oil-tea camellia samples were genetically differentiated mainly between latitudes (between Lu and Jinggang Mountains) and then among elevations (within Lu or Jinggang Mountain). Gene expression patterns of wild oil-tea camellia samples were compared among different air temperatures, and differentially expressed genes (DEGs) were discovered. When air temperatures were below 10 °C, gene expression patterns changed dramatically and majority of the DEGs were up-regulated at low temperatures. More DEGs concerned with cold acclimation were detected at 2 °C than at 5 °C, and a putative C-repeat binding factor (CBF) gene was significantly up-regulated only at 2 °C, suggesting a stronger cold stress at 2 °C. We developed a new method for identifying significant functional groups of DEGs. Among the DEGs, transmembrane transporter genes were found to be predominant and many of them encoded transmembrane sugar transporters. CONCLUSIONS: Our study provides one of the largest transcriptome dataset in the genus Camellia. Wild oil-tea camellia populations were genetically differentiated between latitudes. It may undergo cold acclimation when air temperatures are below 10 °C. Candidate genes for cold acclimation may be predominantly involved in transmembrane transporter activities.


Assuntos
Aclimatação/genética , Camellia/genética , Camellia/fisiologia , Temperatura Baixa , Perfilação da Expressão Gênica , Folhas de Planta/genética , Mutação INDEL , Repetições de Microssatélites/genética , Anotação de Sequência Molecular , Polimorfismo de Nucleotídeo Único
10.
Am J Gastroenterol ; 112(4): 568-576, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27922025

RESUMO

OBJECTIVES: Adenoma detection rate (ADR) is a key colonoscopy quality indicator in Western clinical literature. Our low ADR prompted us to assess novel methods to improve performance. Western retrospective reports suggested that water exchange (WE) could increase ADR. However, most of these studies used pain score or intubation rate as the primary outcome. Here we test the hypothesis that WE significantly increases ADR among Chinese colonoscopists and design a prospective randomized controlled trial using ADR as our primary outcome. METHODS: This prospective, randomized controlled trial was performed at six centers in China. Screening, surveillance, and diagnostic cases were randomized to be examined by WE or traditional air insufflation (AI) method. The primary outcome was ADR. RESULTS: From April 2014 to July 2015, 3,303 patients were randomized to WE (n=1,653) and AI (n=1,650). The baseline characteristics were comparable. Overall ADR was 18.3% (WE) and 13.4% (AI) (relative risk 1.45, 95% confidential interval: 1.20-1.75, P<0.001). ADR in screening patients using AI was 25.8% (male) and 15.7% (female). ADR in screening patients aged >50 years old was 29.4% (WE) and 22.9% (AI) (relative risk 1.09, 95% confidential interval: 1.00-1.19, P=0.040). The increase by WE was reproducibly observed in all indication categories, and significant in screening and diagnostic cases. The limitation imposed by the unblinded investigators was mitigated by comparable inspection times in cases without polyps, similar adenoma per positive colonoscopy, and reproducible enhancement of ADR and adenoma per colonoscopy by WE across all eight investigators. CONCLUSIONS: This prospective study confirms Western retrospective data that WE significantly improves ADR among Chinese colonoscopists. WE may be superior to AI for screening colonoscopy in China. Colonoscopists elsewhere with low ADR might consider evaluating WE for performance improvement.


Assuntos
Adenoma/diagnóstico , Pólipos do Colo/diagnóstico , Colonoscopia/métodos , Neoplasias Colorretais/diagnóstico , Adulto , China , Colonoscopia/efeitos adversos , Detecção Precoce de Câncer , Feminino , Humanos , Insuflação , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Modelos de Riscos Proporcionais , Água
11.
Exp Appl Acarol ; 69(2): 117-28, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26947027

RESUMO

Cheyletus malaccensis is a predatory mite widely distributed in grain storages. It has been regarded as an important biological control agent for pest mites. In this study, we investigated the population genetic structure of C. malaccensis distributed in China based on the partial regions of mitochondrial COI and 12S rRNA genes. We collected 256 individuals of C. malaccensis from stored grain in 34 sites of China. We detected 50 COI gene haplotypes and nine 12S rRNA gene haplotypes. There were three clades in the haplotype network and Bayesian and maximum parsimony phylogenetic trees based on COI sequences, and two based on 12S rRNA sequences. The clustering of haplotypes was not correlated with their geographical distributions. The analysis of molecular variance, AMOVA, indicated that the genetic differentiation between populations was relatively weak. The major genetic differentiation was found within populations. We suggest that the genetic structure of C. malaccensis observed in this study may be the result of long-term climate fluctuations and recent human disturbances.


Assuntos
Proteínas de Artrópodes/genética , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Ácaros/genética , RNA Ribossômico/genética , Animais , China , Variação Genética , Genética Populacional , Haplótipos , Ácaros/classificação , Proteínas Mitocondriais/genética , Filogenia , Análise de Sequência de DNA
12.
mSystems ; 9(6): e0136323, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38752758

RESUMO

The emergence of nosocomial infections caused by hypervirulent and carbapenem-resistant K. pneumoniae (hv-CRKP) has become a significant public health challenge. The genetic traits of virulence and resistance plasmids in hv-CRKP have been extensively studied; however, research on the adaptive evolution strategies of clinical strains inside the host was scarce. This study aimed to understand the effects of antibiotic treatment on the phenotype and genotype characteristics of hv-CRKP. We investigated the evolution of hv-CRKP strains isolated from the same patient to elucidate the transition between hospital invasion and colonization. A comparative genomics analysis was performed to identify single nucleotide polymorphisms in the rmpA promoter. Subsequent validation through RNA-seq and gene deletion confirmed that distinct rmpA promoter sequences exert control over the mucoid phenotype. Additionally, biofilm experiments, cell adhesion assays, and animal infection models were conducted to illuminate the influence of rmpA promoter diversity on virulence changes. We demonstrated that the P12T and P11T promoters of rmpA possess strong activity, which leads to the evolution of CRKP into infectious and virulent strains. Meanwhile, the specific sequence of polyT motifs in the rmpA promoter led to a decrease in the lethality of hv-CRKP and enhanced cell adhesion and colonization. To summarize, the rmpA promoter of hv-CRKP is utilized to control capsule production, thereby modifying pathogenicity to better suit the host's ecological environment.IMPORTANCEThe prevalence of hospital-acquired illness caused by hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) is significant, leading to prolonged antibiotic treatment. However, there are few reports on the phenotypic changes of hv-CRKP in patients undergoing antibiotic treatment. We performed a comprehensive examination of the genetic evolutionary traits of hv-CRKP obtained from the same patient and observed variations in the promoter sequences of the virulence factor rmpA. The strong activity of the promoter sequences P11T and P12T enhances the consistent production of capsule polysaccharides, resulting in an invasive strain. Conversely, weak promoter activity of P9T and P10T is advantageous for exposing pili, hence improving bacterial cell attachment ability and facilitating bacterial colonization. This finding also explains the confusion of some clinical strains carrying wild-type rmpA but exhibiting a low mucoid phenotype. This adaptive alteration facilitates the dissemination of K. pneumoniae within the hospital setting.


Assuntos
Carbapenêmicos , Infecções por Klebsiella , Klebsiella pneumoniae , Regiões Promotoras Genéticas , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidade , Virulência/genética , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/tratamento farmacológico , Regiões Promotoras Genéticas/genética , Carbapenêmicos/farmacologia , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Camundongos , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/patogenicidade , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Polimorfismo de Nucleotídeo Único , Infecção Hospitalar/microbiologia , Infecção Hospitalar/tratamento farmacológico
13.
BMC Gastroenterol ; 13: 117, 2013 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-23865596

RESUMO

BACKGROUND: Oral immunization with vaccines may be an effective strategy for prevention of Clostridium difficile infection (CDI). However, application of previously developed vaccines for preventing CDI has been limited due to various reasons. Here, we developed a recombinant Lactococcus lactis oral vaccine and evaluated its effect on a C. difficile-infected animal model established in golden hamsters in attempt to provide an alternative strategy for CDI prevention. METHODS: Recombinant L. lactis vaccine was developed using the pTRKH2 plasmid, a high-copy-number Escherichia coli-L. shuttle vector: 1) L. lactis expressing secreted proteins was constructed with recombinant pTRKH2 (secreted-protein plasmid) carrying the Usp45 signal peptide (SPUsp45), nontoxic adjuvanted tetanus toxin fragment C (TETC), and 14 of the 38 C-terminal repeats (14CDTA) of nontoxic C. difficile toxin A (TcdA); and 2) L. lactis expressing secreted and membrane proteins was constructed with recombinant pTRKH2 (membrane-anchored plasmid) carrying SPUsp45, TETC, 14CDTA, and the cell wall-anchored sequence of protein M6 (cwaM6). Then, 32 male Syrian golden hamsters were randomly divided into 4 groups (n = 8 each) for gavage of normal saline (blank control) and L. lactis carrying the empty shuttle vector, secreted-protein plasmid, and membrane-anchored plasmid, respectively. After 1-week gavage of clindamycin, the animals were administered with C. difficile spore suspension. General symptoms and intestinal pathological changes of the animals were examined by naked eye and microscopy, respectively. Protein levels of anti-TcdA IgG/IgA antibodies in intestinal tissue and fluid were analyzed by enzyme-linked immunosorbent assay (ELISA). A cell culture cytotoxicity neutralization assay was done by TcdA treatment with or without anti-TcdA serum pre-incubation or treatment. Apoptosis of intestinal epithelial cells was examined by flow cytometry (FL) assay. Expression of mucosal inflammatory cytokines in the animals was detected by polymer chain reaction (PCR) assay. RESULTS: After the C. difficile challenge, the animals of control group had severe diarrhea symptoms on day 1 and all died on day 4, indicating that the CDI animal model was established in hamster. Of the 3 immunization groups, secreted-protein and membrane-anchored plasmid groups had significantly lower mortalities, body weight decreases, and pathological scores, with higher survival rate/time than the empty plasmid group (P < 0.05). The tilter of IgG antibody directed against TcdA was significantly higher in serum and intestinal fluid of secreted-protein and membrane-anchored plasmid groups than in the empty plasmid group (P < 0.05) while the corresponding titer of IgA antibody directed against TcdA had no substantial differences (P > 0.05). The anti-TcdA serum of membrane-anchored plasmid group neutralized the cytotoxicity of 200 ng/ml TcdA with the best protective effect achieved by anti-TcdA serum pre-incubation. The incidences of TcdA-induced death and apoptosis of intestinal epithelial cells were significantly reduced by cell pre-incubation or treatment with anti-TcdA serum of membrane-anchored plasmid group (P < 0.05). MCP-1, ICAM-1, IL-6, and Gro-1 mRNA expression levels were the lowest in cecum tissue of the membrane-anchored groups compared to the other groups. CONCLUSION: Recombinant L. lactis live vaccine is effective for preventing CDI in the hamster model, thus providing an alternative for immunization of C. difficile-associated diseases.


Assuntos
Anticorpos Antibacterianos/sangue , Toxinas Bacterianas/imunologia , Vacinas Bacterianas/uso terapêutico , Clostridioides difficile , Enterocolite Pseudomembranosa/imunologia , Enterocolite Pseudomembranosa/prevenção & controle , Enterotoxinas/imunologia , Animais , Anticorpos Antibacterianos/metabolismo , Apoptose/efeitos dos fármacos , Ceco/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CXCL1/genética , Cricetinae , Modelos Animais de Doenças , Enterocolite Pseudomembranosa/microbiologia , Células Epiteliais/efeitos dos fármacos , Soros Imunes/farmacologia , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Molécula 1 de Adesão Intercelular/genética , Interleucina-1/genética , Mucosa Intestinal/patologia , Intestinos/imunologia , Lactococcus lactis , Masculino , Plasmídeos , RNA Mensageiro/metabolismo , Vacinas Sintéticas
14.
Sci Total Environ ; 896: 164911, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37355120

RESUMO

The EU Water Framework Directive (WFD) has emphasized that altered stream/river morphology and diffuse pollution are the two major pressures faced by European water bodies at catchment scales. Increasing efforts have been directed toward restoration to meet WFD standards for ecological health, but this work has achieved limited success. One challenge is that little is known about how morphological changes (i.e., re-meandering) may affect nitrate retention within whole stream networks. We investigated this issue in the well-monitored Bode catchment (3200 km2) in central Germany. First, we implemented a fully distributed process-based mHM-Nitrate model, exploring its performance over the period from 2015 to 2018. Second, we simulated the effects of restoring more natural stream morphology (i.e., increasing sinuosity) on nitrate retention. The mHM-Nitrate model performed well in replicating daily discharge and nitrate concentrations (median Kling-Gupta values of 0.78 and 0.74, respectively). Within the stream network, mean and standard deviation (SD) of gross nitrate retention efficiency was 5.1 ± 0.61 % and 74.7 ± 23.2 % in the winter and summer, respectively; this measure took into account both denitrification and assimilatory uptake. In the summer, the denitrification rate was about twice as high in a lowland sub-catchment dominated by agricultural lands as in a mountainous sub-catchment dominated by forested areas (median ± SD of 204 ± 22.6 and 102 ± 22.1 mg N m-2 d-1, respectively). Similarly, in the same season, the assimilatory uptake rate was approximately five times higher in streams surrounded by lowland agricultural areas than in streams in higher-elevation, forested areas (median ± SD of 200 ± 27.1 and 39.1 ± 8.7 mg N m-2 d-1, respectively). This suggests that restoration strategies targeted at lowland agricultural areas may have a greater potential for increasing nitrate retention. In our simulation, restoring stream sinuosity was found to increase net nitrate retention efficiency by up to 25.4 ± 5.3 %; greater effects were seen in small streams. Taken together, our results indicate that restoration efforts should consider augmenting stream sinuosity to increase nitrate retention and decrease nitrate concentrations at the catchment scale.

15.
Mol Imaging Biol ; 25(4): 671-680, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37020127

RESUMO

PURPOSE: Compare the value of imaging using positron 18F-labeled fibroblast activation protein inhibitor-42 (18F-FAPI-42) and 18F-labeled deoxyglucose (18F-FDG) for assessment of AKI. PROCEDURES: This study analyzed cancer patients who received 18F-FAPI-42 and 18F-FDG PET/CT imaging. Eight patients had AKI with bilateral ureteral obstruction (BUO), eight had BUO (CKD1-2) with no acute kidney disease (AKD), and eight had no ureteral obstruction (UO) with normal renal function. The average standardized uptake value (SUVave) of the renal parenchyma (RP-SUVave), the blood pool SUVave (B- SUVave), SUVave in the highest region of the renal collective system (RCS-SUVave), and the highest serum creatinine level (top SCr) were recorded. RESULTS: The 18F-FAPI-42 and 18F-FDG results showed that radiotracer of renal parenchyma was more concentrated in the AKI group than in the other two groups, whereas the RP-SUVave from 18F-FAPI-42 was higher than that from 18F-FDG in the AKI group (all P < 0.05). 18F-FAPI-42 imaging in the AKI group showed uptake by the renal parenchyma with a diffuse increase, but very little radiotracer in the renal collecting system, similar to a "super kidney scan." The renal parenchyma also had an increase of SUVave, with accumulation of radiotracer in the renal collecting system. AKI was more severe when a patient had a "super kidney scan" in both kidneys (P < 0.05). The B-SUVave level was higher in the AKI group than in the other two groups in 18F-FAPI-42 (both P < 0.05). CONCLUSIONS: 18F-FAPI-42 imaging had higher RP-SUVave than 18F-FDG imaging in cancer patients who had BUO with AKI. An increased renal parenchyma uptake in both kidneys and low radiotracer distribution in the collecting system suggest more severe AKI.


Assuntos
Injúria Renal Aguda , Neoplasias , Quinolinas , Humanos , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Injúria Renal Aguda/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Rim/diagnóstico por imagem , Compostos Radiofarmacêuticos , Radioisótopos de Gálio , Neoplasias/complicações , Neoplasias/diagnóstico por imagem
16.
Water Res ; 243: 120347, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37490830

RESUMO

High-frequency nitrate-N (NO3--N) data are increasingly available, while accurate assessments of in-stream NO3--N retention in large streams and rivers require a better capture of complex river hydrodynamic conditions. This study demonstrates a fusion framework between high-frequency water quality data and hydrological transport models, that (1) captures river hydraulics and their impacts on solute signal propagation through river hydrodynamic modeling, and (2) infers in-stream retention as the differences between conservatively traced and reactively observed NO3--N signals. Using this framework, continuous 15-min estimates of NO3--N retention were derived in a 6th-order reach of the lower Bode River (27.4 km, central Germany), using long-term sensor monitoring data during a period of normal flow from 2015 to 2017 and a period of drought from 2018 to 2020. The unique NO3--N retention estimates, together with metabolic characteristics, revealed insightful seasonal patterns (from high net autotrophic removal in late-spring to lower rates, to net heterotrophic release during autumn) and drought-induced variations of those patterns (reduced levels of net removal and autotrophic nitrate removal largely buffered by heterotrophic release processes, including organic matter mineralization). Four clusters of diel removal patterns were identified, potentially representing changes in dominant NO3--N retention processes according to seasonal and hydrological conditions. For example, dominance of autotrophic NO3--N retention extended more widely across seasons during the drought years. Such cross-scale patterns and changes under droughts are likely co-determined by catchment and river environments (e.g., river primary production, dissolved organic carbon availability and its quality), which resulted in more complex responses to the sequential droughts. Inferences derived from this novel data-model fusion provide new insights into NO3- dynamics and ecosystem function of large streams, as well as their responses to climate variability. Moreover, this framework can be flexibly transferred across sites and scales, thereby complementing high-frequency monitoring to identify in-stream retention processes and to inform river management.


Assuntos
Nitratos , Rios , Secas , Estações do Ano , Ecossistema , Monitoramento Ambiental/métodos
17.
Sci Bull (Beijing) ; 68(7): 713-722, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36934013

RESUMO

The glacial-interglacial variability of precipitation and its driving mechanism in monsoonal regions has long been a subject of debate. However, there are few records of quantitative climate reconstruction dating to the last glacial cycle in areas dominated by the Asian summer monsoon. Here, using a pollen-based quantitative climate reconstruction based on three sites in areas exposed to the Asian summer monsoon, we demonstrate that climate has undergone great variability over the past 68 ka. The differences between the last glacial and the Holocene optimum could have been as much as 35%-51% for precipitation, and 5-7 °C for mean annual temperature. Our findings also reveal regional heterogeneity during the abrupt climate events of Heinrich Event 1 and Younger Dryas, that drove drier conditions in southwestern China dominated by the Indian summer monsoon, and a wetter climate in central eastern China. The pattern of variation in reconstructed precipitation, exhibiting strong glacial-interglacial variability, is broadly consistent with the stalagmite δ18O records from Southwest China and South Asia. Our results of reconstruction quantify the sensitivity of the MIS3 precipitation to orbital insolation changes, and highlight the prominent influence of interhemispheric temperature gradients on Asian monsoon variability. Comparison with transient simulations and major climate forcings has shown that the mode of precipitation variability during the transition from the last glacial maximum to the Holocene has been significantly modulated by weak or collapsed Atlantic meridional overturning circulation events in addition to insolation forcing.

18.
Cell Biosci ; 12(1): 197, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36471394

RESUMO

BACKGROUND: The synthesis and secretion of renin in juxtaglomerular (JG) cells are closely regulated by the blood pressure. To date, however, the molecular identity through which JG cells respond to the blood pressure remains unclear. RESULTS: Here we discovered that Piezo1, a mechanosensitive ion channel, was colocalized with renin in mouse kidney as well as As4.1 cells, a commonly used JG cell line. Activation of Piezo1 by its agonist Yoda1 induced an intracellular calcium increase and downregulated the expression of renin in these cells, while knockout of Piezo1 in JG cells abolished the effect of Yoda1. Meanwhile, mechanical stress using microfluidics also induced an intracellular calcium increase in wildtype but not Piezo1 knockout JG cells. Mechanistically, we demonstrated that activation of Piezo1 upregulated the Ptgs2 expression via the calcineurin-NFAT pathway and increased the production of Ptgs2 downstream molecule PGE2 in JG cells. Surprisingly, we discovered that increased PGE2 could decreased the renin expression through the PGE2 receptor EP1 and EP3, which inhibited the cAMP production in JG cells. In mice, we found that activation of Piezo1 significantly downregulated the renin expression and blood pressure in wildtype but not adeno-associated virus (AAV)-mediated kidney specific Piezo1 knockdown mice. CONCLUSIONS: In summary, these results revealed that activation of Piezo1 could downregulate the renin expression in JG cells and mice, subsequently a reduction of blood pressure, highlighting its therapeutic potential as a drug target of the renin-angiotensin system.

19.
Materials (Basel) ; 15(18)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36143731

RESUMO

This study presents underwater explosion tests with three different TNT charge weights to investigate the dynamic responses of a fixed steel sheet. A finite element model was established and benchmarked by comparing the bubble development and deformation distribution from the tests. The steel sheet shows a deformation process of hogging, sagging, and hogging again, due to the actions of shock waves, bubble expansion, bubble collapse, and bubble pulsation. The air may be sucked into the bubble during the hogging process, making the bubble collapse earlier and resulting in a relatively lower sagging deformation for large charge weights of TNT. The deformation caused by bubble pulsation is larger than that by the shock waves, owing to the large time duration of bubble pulsation. A parametric analysis was conducted to study the influence of steel grade, plate thickness, detonation distance, and the shape and position of charges on the dynamic behavior of steel plates subjected to underwater explosions. It shows that the damage to the steel plate gradually decreases, with the increase in steel strength, plate thickness, and detonation distance. The influence of the shape and position of charges is limited. The largest deformation is observed when the detonation distance increases to bubble radius.

20.
Viruses ; 14(12)2022 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-36560731

RESUMO

Anguillid herpesvirus 1 (AngHV-1) is a pathogen that causes hemorrhagic disease in various farmed and wild freshwater eel species, resulting in significant economic losses. Although AngHV-1 has been detected in the American eel (Anguilla rostrata), its pathogenicity has not been well characterized. In this study, an AngHV-1 isolate, tentatively named AngHV-1-FC, was isolated from diseased American eels with similar symptoms as those observed in AngHV-1-infected European eels and Japanese eels. AngHV-1-FC induced severe cytopathic effects in the European eel spleen cell line (EES), and numerous concentric circular virions were observed in the infected EES cells by transmission electron microscopy. Moreover, AngHV-1-FC caused the same symptoms as the naturally diseased European eels and Japanese eels through experimental infection, resulting in a 100% morbidity rate and 13.3% mortality rate. The whole genome sequence analyses showed that the average nucleotide identity value between AngHV-1-FC and other AngHV-1 isolates ranged from 99.28% to 99.55%. However, phylogenetic analysis revealed that there was a genetic divergence between AngHV-1-FC and other AngHV-1 isolates, suggesting that AngHV-1-FC was a new isolate of AngHV-1. Thus, our results indicated that AngHV-1-FC can infect farmed American eels, with a high pathogenicity, providing new knowledge in regard to the prevalence and prevention of AngHV-1.


Assuntos
Anguilla , Doenças dos Peixes , Herpesviridae , Animais , Filogenia , Herpesviridae/genética
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