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Flooding is a major natural hazard worldwide, causing catastrophic damage to communities and infrastructure. Due to climate change exacerbating extreme weather events robust flood hazard modeling is crucial to support disaster resilience and adaptation. This study uses multi-sourced geospatial datasets to develop an advanced machine learning framework for flood hazard assessment in the Arambag region of West Bengal, India. The flood inventory was constructed through Sentinel-1 SAR analysis and global flood databases. Fifteen flood conditioning factors related to topography, land cover, soil, rainfall, proximity, and demographics were incorporated. Rigorous training and testing of diverse machine learning models, including RF, AdaBoost, rFerns, XGB, DeepBoost, GBM, SDA, BAM, monmlp, and MARS algorithms, were undertaken for categorical flood hazard mapping. Model optimization was achieved through statistical feature selection techniques. Accuracy metrics and advanced model interpretability methods like SHAP and Boruta were implemented to evaluate predictive performance. According to the area under the receiver operating characteristic curve (AUC), the prediction accuracy of the models performed was around > 80%. RF achieves an AUC of 0.847 at resampling factor 5, indicating strong discriminative performance. AdaBoost also consistently exhibits good discriminative ability, with AUC values of 0.839 at resampling factor 10. Boruta and SHAP analysis indicated precipitation and elevation as factors most significantly contributing to flood hazard assessment in the study area. Most of the machine learning models pointed out southern portions of the study area as highly susceptible areas. On average, from 17.2 to 18.6% of the study area is highly susceptible to flood hazards. In the feature selection analysis, various nature-inspired algorithms identified the selected input parameters for flood hazard assessment, i.e., elevation, precipitation, distance to rivers, TWI, geomorphology, lithology, TRI, slope, soil type, curvature, NDVI, distance to roads, and gMIS. As per the Boruta and SHAP analyses, it was found that elevation, precipitation, and distance to rivers play the most crucial roles in the decision-making process for flood hazard assessment. The results indicated that the majority of the building footprints (15.27%) are at high and very high risk, followed by those at very low risk (43.80%), low risk (24.30%), and moderate risk (16.63%). Similarly, the cropland area affected by flooding in this region is categorized into five risk classes: very high (16.85%), high (17.28%), moderate (16.07%), low (16.51%), and very low (33.29%). However, this interdisciplinary study contributes significantly towards hydraulic and hydrological modeling for flood hazard management.
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Inundações , Aprendizado de Máquina , Índia , Medição de Risco , Análise de Dados , AlgoritmosRESUMO
Fecal pollution of surface waters in the karst-dominated Edwards aquifer is a serious concern as contaminated waters can rapidly transmit to groundwaters, which are used for domestic purposes. Although microbial source tracking (MST) detects sources of fecal pollution, integrating data related to environmental processes (precipitation) and land management practices (septic tanks) with MST can provide better understanding of fecal contamination fluxes to implement effective mitigation strategies. Here, we investigated fecal sources and their spatial origins at recharge and contributing zones of the Edwards aquifer and identified their relationship with nutrients in different environmental/land-use conditions. During March 2019 to March 2020, water samples (n = 295) were collected biweekly from 11 sampling sites across four creeks and analyzed for six physico-chemical parameters and ten fecal indicator bacteria (FIB) and MST-based qPCR assays targeting general (E. coli, Enterococcus, and universal Bacteroidales), human (BacHum and HF183), ruminant (Rum2Bac), cattle (BacCow), canine (BacCan), and avian (Chicken/Duck-Bac and GFD) fecal markers. Among physico-chemical parameters, nitrate-N (NO3-N) concentrations at several sites were higher than estimated national background concentrations for streams. General fecal markers were detected in the majority of water samples, and among host-associated MST markers, GFD, BacCow, and Rum2Bac were more frequently detected than BacCan, BacHum, and HF183, indicating avian and ruminant fecal contamination is a major concern. Cluster analysis results indicated that sampling sites clustered based on precipitation and septic tank density showed significant correlation (p < 0.05) between nutrients and FIB/MST markers, indicating these factors are influencing the spatial and temporal variations of fecal sources. Overall, results emphasize that integration of environmental/land-use data with MST is crucial for a better understanding of nutrient loading and fecal contamination.
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Água Subterrânea , Microbiologia da Água , Cães , Animais , Bovinos , Humanos , Escherichia coli , Marcadores Genéticos , Monitoramento Ambiental/métodos , Poluição da Água/análise , Fezes/microbiologia , Bactérias/genética , Água/análiseRESUMO
The COVID-19 pandemic has been challenging for various institutions such as school systems due to widespread closures. As schools re-open their campuses to in-person education, there is a need for frequent screening and monitoring of the virus to ensure the safety of students and staff and to limit risk to the surrounding community. Wastewater surveillance (WWS) of SARS-CoV-2 is a rapid and economical approach to determine the extent of COVID-19 in the community. The focus of this review is on the emergence of WWS as a tool for safe return to school campuses, taking into account methodological considerations such as site selection, sample collection and processing, SARS-CoV-2 quantification, and data interpretation. Recently published studies on the implementation of COVID-19 WWS on school and college campuses were reviewed. While there are several logistical and technical challenges, WWS can be used to inform decision-making at the school campus and/or building level.
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The purpose of this study was to conduct a correlative assessment of SARS-CoV-2 RNA concentrations in wastewater with COVID-19 cases and a systematic evaluation of the effect of using different virus concentration methods and recovery and normalization approaches. We measured SARS-CoV-2 RNA concentrations at two different wastewater treatment plants (WWTPs) in the Bexar County of Texas from October 2020 to May 2021 (32 weeks) using reverse transcription droplet digital PCR (RT-ddPCR). We evaluated three different adsorption-extraction (AE) based virus concentration methods (acidification, addition of MgCl2, or without any pretreatment) using bovine coronavirus (BCoV) as surrogate virus and observed that the direct AE method showed the highest mean recovery. COVID-19 cases were correlated significantly with SARS-CoV-2 N1 concentrations in Salitrillo (ρ = 0.75, p < 0.001) and Martinez II (ρ = 0.68, p < 0.001) WWTPs, but normalizing to a spiked recovery control (BCoV) or a fecal marker (HF183) reduced correlations for both treatment plants. The results generated in this 32-week monitoring study will enable researchers to prioritize the virus recovery method and subsequent correlation studies for wastewater surveillance.
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INTRODUCTION: Intravenous leiomyomatosis (ILV) is a rare pathology, part of leiomyoma beyond the uterus (LBU), characterized by benign smooth muscle cell tumor outside of the uterus and mainly affecting premenopausal woman with a medical history of leiomyoma or gynecologic surgical treatment. The treatment depends on the localization of the tumor, age of the patient, initial size, symptoms and the suitability for surgery but should always aims in toto surgical resection. CASE PRESENTATION: Retrospective case series and review of literature. CLINICAL DISCUSSION: Symptoms presented by the patient were aspecific and only localized in the pelvic area. All cases were fortuitous histopathological diagnosis. No relapse was. Two out of 5 patients have pulmonary nodules, only one was biopsied and diagnosed with PBML (pulmonary benign metastasizing leiomyoma). CONCLUSION: IVL and BML are rare disease that can co-exist. Because of tumoral hormonal receptors, hormonotherapy could be an optional treatment but to date no clear efficacy is demonstrated. In case of high recurrence risk such as voluminous initial mass, impairment of broad ligament, failure of total surgical resection, adjuvant hormonotherapy could be useful. Recurrence rate is about 16.6-30% and can occur even dozen years later and even after radical surgery, justifying a regular follow up.
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The purpose of this study was to conduct a preliminary assessment of the levels of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater at the Salitrillo Wastewater Treatment Plant in Texas during the initial peak of coronavirus disease 2019 (COVID-19) outbreak. Raw wastewater influent (24 h composite, time-based 1 L samples, n = 13) was collected weekly during June-August 2020. We measured SARS-CoV-2 RNA in wastewater by reverse transcription droplet digital PCR using the same N1 and N2 primer sets as employed in COVID-19 clinical testing. Virus RNA copies for positive samples (77%) ranged from 1.4 × 102 to 4.1 × 104 copies per liter of wastewater, and exhibited both increasing and decreasing trends, which corresponded well with the COVID-19 weekly infection rate (N1: ρ = 0.558, P = 0.048; N2: ρ = 0.487, P = 0.092). A sharp increase in virus RNA concentrations was observed during July sampling dates, consistent with the highest number of COVID-19 cases reported. This could be attributed to an increase in the spread of COVID-19 infection due to the Fourth of July holiday week gatherings (outdoor gatherings were limited to 100 people during that time). Our data show that wastewater surveillance is an effective tool to determine trends in infectious disease prevalence, and provide complementary information to clinical testing.
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The short-term effects of Mn2O3 nanoparticles (NPs) were examined for nitrifying bacterial enrichments exposed under low and high dissolved oxygen (DO) conditions using substrate (ammonia) specific oxygen uptake rates (sOUR), reverse transcriptase - quantitative polymerase chain reaction (RT-qPCR) assays, and by analysis of 16S rRNA sequences. Samples from nitrifying bioreactor were exposed in batch vessels to Mn2O3 NPs (1, 5 and 10 mg/L) for either 1 or 3 h under no additional aeration or 0.25 L/min aeration. There was increase in nitrification inhibition as determined by sOUR with increasing dosages of Mn2O3 NPs for both low and high DO. At 10 mg/L Mn2O3 NPs, the inhibition was about 7-10% for 1 and 3 h exposure in both cases. There was notable reduction in the transcript levels of amoA, hao and nirK for 10 mg/L of Mn2O3 NPs under 3 h, high DO exposure, which corresponded well with sOUR. The 16S rRNA sequencing showed that there was an inhibitory effect on ammonia oxidizers activity upon exposure to 10 mg/L of Mn2O3 NPs. Collectively, the findings in this study advanced understanding of the different effects of Mn2O3 NPs on nitrifying bacteria.
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Nanopartículas/toxicidade , Nitrificação/fisiologia , Amônia/metabolismo , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Expressão Gênica , Nitrificação/efeitos dos fármacos , Oxirredução , Oxigênio/metabolismo , RNA Ribossômico 16S/genéticaRESUMO
The interaction of anaerobic microorganisms with carbon nanotube/polymer nanocomposites (CNT/PNC) will play a major role in determining their persistence and environmental fate at the end of consumer use when these nano-enabled materials enter landfills and encounter wastewater. Motivated by the need to understand how different parameters (i.e., polymer type, microbial phenotype, CNT characteristics) influence CNT/PNC biodegradation rates, we have used volumetric biogas measurements and kinetic modeling to study biodegradation as a function of polymer type and CNT properties. In one set of experiments, oxidized multiwall carbon nanotubes (O-MWCNTs) with a range of CNT loadings 0-5% w/w were incorporated into poly-ε-caprolactone (PCL) and polyhydroxyalkanoates (PHA) matrices and subjected to biodegradation by an anaerobic microbial community. For each CNT/PNC, complete polymer biodegradation was ultimately observed, although the rate of biodegradation was inhibited above certain critical CNT loadings dependent upon the polymer type. Higher loadings of pristine MWCNTs were needed to decrease the rate of polymer biodegradation compared to O-MWCNTs, an effect ascribed principally to differences in CNT dispersion within the polymer matrices. Above certain CNT loadings, a CNT mat of similar shape to the initial PNC was formed after polymer biodegradation, while below this threshold, CNT aggregates fragmented in the media. In situations where biodegradation was rapid, methanogen growth was disproportionately inhibited compared to the overall microbial community. Analysis of the results obtained from this study indicates that the inhibitory effect of CNTs on polymer biodegradation rate is greatest under conditions (i.e., polymer type, microbial phenotype, CNT dispersion) where biodegradation of the neat polymer is slowest. This new insight provides a means to predict the environmental fate, persistence, and transformations of CNT-enabled polymer materials.
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Nanocompostos , Nanotubos de Carbono , Biodegradação Ambiental , PolímerosRESUMO
The properties and commercial viability of biodegradable polymers can be significantly enhanced by the incorporation of carbon nanotubes (CNTs). The environmental impact and persistence of these carbon nanotube/polymer nanocomposites (CNT/PNCs) after disposal will be strongly influenced by their microbial interactions, including their biodegradation rates. At the end of consumer use, CNT/PNCs will encounter diverse communities of microorganisms in landfills, surface waters, and wastewater treatment plants. To explore CNT/PNC biodegradation under realistic environmental conditions, the effect of multi-wall CNT (MWCNT) incorporation on the biodegradation of polyhydroxyalkanoates (PHA) was investigated using a mixed culture of microorganisms from wastewater. Relative to unfilled PHA (0% w/w), the MWCNT loading (0.5-10% w/w) had no statistically significant effect on the rate of PHA matrix biodegradation. Independent of the MWCNT loading, the extent of CNT/PNC mass remaining closely corresponded to the initial mass of CNTs in the matrix suggesting a lack of CNT release. CNT/PNC biodegradation was complete in approximately 20â¯days and resulted in the formation of a compressed CNT mat that retained the shape of the initial CNT/PNC. This study suggests that although CNTs have been shown to be cytotoxic towards a range of different microorganisms, this does not necessarily impact the biodegradation of the surrounding polymer matrix in mixed culture, particularly in situations where the polymer type and/or microbial population favor rapid polymer biodegradation.
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Biodegradação Ambiental , Nanocompostos , Nanotubos de Carbono , Polímeros/metabolismo , AerobioseRESUMO
Conducting polymers such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate ( PEDOT: PSS) are increasingly used to interface electronics with biology. Their wettability, however, remains poorly understood. We show that the frequently-used sessile drop technique yields results that are strongly dependent on the experimental conditions (measurement duration and relative humidity), due to the hydrogel-like behavior of PEDOT: PSS. In contrast, the captive bubble technique on a fully wet film overcomes these limitations. Dynamic wettability measurements provide hysteresis values for this polymer and clarify the physical meaning of the static contact angles measured by sessile drop and captive bubble. Finally we show that aging the films in water leads to loss of PSS chains which makes the films more hydrophobic. The addition of a crosslinker reduces and slows down these effects.
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Kinematic functional evaluation with body-worn sensors provides discriminative and responsive scores after shoulder surgery, but the optimal movements' combination has not yet been scientifically investigated. The aim of this study was the development of a simplified shoulder function kinematic score including only essential movements. The P Score, a seven-movement kinematic score developed on 31 healthy participants and 35 patients before surgery and at 3, 6 and 12 months after shoulder surgery, served as a reference. Principal component analysis and multiple regression were used to create simplified scoring models. The candidate models were compared to the reference score. ROC curve for shoulder pathology detection and correlations with clinical questionnaires were calculated. The B-B Score (hand to the Back and hand upwards as to change a Bulb) showed no difference to the P Score in time*score interaction (P > .05) and its relation with the reference score was highly linear (R(2) > .97). Absolute value of correlations with clinical questionnaires ranged from 0.51 to 0.77. Sensitivity was 97% and specificity 94%. The B-B and reference scores are equivalent for the measurement of group responses. The validated simplified scoring model presents practical advantages that facilitate the objective evaluation of shoulder function in clinical practice.
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Movimento/fisiologia , Exame Físico/métodos , Índice de Gravidade de Doença , Ombro/fisiologia , Ombro/fisiopatologia , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Úmero/fisiologia , Úmero/fisiopatologia , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Análise de Regressão , Ombro/cirurgia , Inquéritos e Questionários , Fatores de Tempo , Resultado do TratamentoRESUMO
In clinical settings, the cervical range of motion (ROM) is commonly used to assess cervical spine function. This study aimed at assessing cervical spine mobility based on head and thorax kinematics measured with a wearable inertial system (WS). Sequences of imposed active head movements (lateral bending, axial rotation and flexion-extension) were recorded in ten controls and 13 patients who had undergone an arthrodesis. Orientation of the head relative to the thorax was computed in terms of 3D helical angles and compared with the values obtained using an optoelectronic reference system (RS). Movement patterns from WS and RS showed excellent concurrent validity (CMC up to 1.00), but presented slight differences of bias (mean bias<2.5°) and dispersion (mean dispersion<4.2°). ROM obtained using WS also showed some differences compared to RS (mean difference<5.7°), within the range of those reported in literature. WS enabled the observation of the same significant differences between controls and patients as RS. Moreover, ROM from WS presented good test-retest repeatability (ICC between 0.63 and 0.99 and SEM<6.2°). In conclusion, WS can provide angles and ROM comparable to those obtained with RS and relevant for the cervical assessment after treatment.
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Vértebras Cervicais/fisiologia , Equipamentos e Provisões Elétricas , Movimento , Dispositivos Ópticos , Amplitude de Movimento Articular , Adulto , Idoso , Artrodese , Estudos de Casos e Controles , Vértebras Cervicais/fisiopatologia , Vértebras Cervicais/cirurgia , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Adulto JovemRESUMO
BACKGROUND: Evaluation of cervical spine mobility after surgery is mainly based on the measurement of the range of motion during imposed movements. It can thus be questionable if this assessment represents the mobility experienced during daily life. The goal of this study was to propose a new evaluation tool based on the monitoring of cervical spine movement during daily activities. METHODS: The detection of cervical movement and the determination of primary motion component (lateral bending, axial rotation or flexion-extension), using two inertial sensors, were first validated in laboratory settings. Fifteen patients who underwent a cervical arthrodesis and nine healthy control subjects were monitored during their daily activity for half a day. The frequency of cervical movement was quantified according to posture, i.e. static and walking periods. The amplitude and velocity of cervical movement were evaluated using the median and cumulative distribution function. FINDINGS: The movement detection and classification showed an excellent performance (sensitivity and specificity>94%). For the daily monitoring, the patients presented a movement frequency similar to controls, whereas the amplitude and velocity in patients were lower than in controls (P<0.05). The differences between patients and controls were larger for the velocity parameters (effect sizes>0.37 and >0.54 for static and walking periods respectively) than for the amplitude parameters. INTERPRETATION: Body-worn inertial sensors enable the quantitative evaluation of global cervical movement. The movement amplitude and velocity during free-living conditions can be used as objective parameters to evaluate the cervical spine mobility after treatment.
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Atividades Cotidianas , Vértebras Cervicais/fisiopatologia , Monitorização Fisiológica/métodos , Amplitude de Movimento Articular , Vértebras Cervicais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Movimento , Postura , Rotação , Fusão VertebralRESUMO
AIM OF STUDY: To report cases from Vietnam of intestinal tuberculosis disease, which is uncommon but did not disappear in occidental countries. MATERIALS AND METHODS: Seventy-six patients were included in this retrospective study. Mean age was 40 years and sex ratio M/F was 6. Diagnosis was established on pathological examination of resected specimen or on presence of Mycobacterium tuberculosis or by polymerase chain reaction. RESULTS: Intestinal obstruction or subobstruction was the most usual symptom (68%), and thereafter peritoneal symptoms with pain and tenderness (17%). Five patients had intractable digestive haemorrhage. Thirty-six patients had no past history or active pulmonary tuberculosis (47%). Lesions of stenosis on barium enema and thickness of intestinal wall on CT-scan were not specific. Sixty-two patients were operated on (82%) and 14 were not. Surgical techniques differed according symptoms, site and type of lesions. Intestinal resections were performed in half of the patients, others undergoing stomies or enterolysis. There were eight postoperative deaths (13% of patients operated on), seven out of these deaths were attributable to cachexy. In the postoperative period, all the patients were medically treated and follow-up in the antituberculosis centre of Hanoi. CONCLUSION: Symptomatology and operative findings of intestinal tuberculosis are similar to those observed in Crohn's disease, and sometimes in amoeboma or lymphoma. In face of stenosis and intestinal wall thickness, probability of intestinal tuberculosis is high in endemic area, but diagnosis must be suspected in occidental countries, mainly in patients immigrated coming from these areas, patients with immuno-deficiency even if they did not have past or present pulmonary tuberculosis.
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Tuberculose Gastrointestinal/epidemiologia , Adolescente , Adulto , Idoso , Antituberculosos/uso terapêutico , Caquexia/mortalidade , Constrição Patológica/epidemiologia , Enterostomia , Feminino , Seguimentos , Hemorragia Gastrointestinal/epidemiologia , Humanos , Obstrução Intestinal/epidemiologia , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Complicações Pós-Operatórias , Estudos Retrospectivos , Saúde da População Rural/estatística & dados numéricos , Tuberculose Gastrointestinal/mortalidade , Tuberculose Pulmonar/epidemiologia , Saúde da População Urbana/estatística & dados numéricos , Vietnã/epidemiologiaRESUMO
Aggressive angiomyxoma (AAM) is a rare tumor that preferentially involves the pelvis and perineal regions and arises from the connective tissue. Its cause and pathogenesis are unknown at present. Treatment typically involves surgery, and despite apparently complete resection, local recurrences are common. We describe a case of a large angiomyxoma of the left pelvis in a 59-year-old woman who underwent two surgical excisions. The first had been done in May 1998. She developed a local recurrence in December 1998. A palliative resection with macroscopic residuals was performed in February 2001, followed by radiation therapy with a total dose of 60 Gy. The diagnosis was revised at the time of the second operation. Initially, the tumor was diagnosed as angiomyofibroblastoma. Follow-up 3 years after the radiation treatment revealed no recurrence. The time of the local control achieved as yet is already longer than the former time to progression between the first two surgical procedures. This is, to our knowledge, the second description of a therapeutic irradiation of a recurrent AAM. Radiation therapy is able to control a recurrent AAM for at least 3 years.
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Mixoma/radioterapia , Recidiva Local de Neoplasia/radioterapia , Neoplasias Pélvicas/radioterapia , Neoplasias Retroperitoneais/radioterapia , Nádegas , Feminino , Humanos , Pessoa de Meia-Idade , Mixoma/patologia , Mixoma/cirurgia , Invasividade Neoplásica , Recidiva Local de Neoplasia/patologia , Neoplasias Pélvicas/patologia , Neoplasias Pélvicas/cirurgia , Períneo , Reoperação , Neoplasias Retroperitoneais/patologia , Neoplasias Retroperitoneais/cirurgiaAssuntos
Anticorpos Monoclonais/efeitos adversos , Antirreumáticos/efeitos adversos , Trombose Intracraniana/induzido quimicamente , Tromboflebite/induzido quimicamente , Adulto , Humanos , Infliximab , Angiografia por Ressonância Magnética , Masculino , Espondilite Anquilosante/tratamento farmacológicoRESUMO
The new antiepileptic drug vigabatrin (VGB) increases gamma-aminobutyric acid (GABA) in the brain. We compared GABA+/Cr signals measured focus-near and focus-distant and correlated it with the degree of response to VGB. Brain GABA+/Cr signals were measured in 17 epileptic patients in structurally normal appearing tissue by nuclear proton magnetic resonance (1H-NMR) spectroscopy using a special editing sequence for GABA. In 11 patients the measurements were done in brain areas distant to focus and in six near to focus. Full-responders (seizure reduction of >or=50% at the end of the treatment phase) and partial-responders (seizure reduction of >or=50% at the end of the first month of treatment but Assuntos
Encéfalo/efeitos dos fármacos
, Epilepsia Parcial Complexa/tratamento farmacológico
, Espectroscopia de Ressonância Magnética/métodos
, Vigabatrina/farmacologia
, Ácido gama-Aminobutírico/análise
, Adolescente
, Adulto
, Encéfalo/metabolismo
, Radioisótopos de Cromo
, Epilepsia Parcial Complexa/metabolismo
, Feminino
, Humanos
, Espectroscopia de Ressonância Magnética/estatística & dados numéricos
, Masculino
, Pessoa de Meia-Idade
, Estatísticas não Paramétricas
, Vigabatrina/uso terapêutico
, Ácido gama-Aminobutírico/metabolismo
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Synthesis and physico-chemical properties of some 3-benzyl- and 3-phenacyl-4-thioxo-5-benzylidenethiazolidin-2-one derivatives are described. Fifteen new compounds were synthesized from thiazolidin-2-one by thionation of the 4-carbonyle, alkylation of the 3-N and aldolisation-crotonisation of 5-CH(2) with aromatic aldehydes. Soon, these new compounds will be tested for their bacteriostatic activity.
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Anti-Infecciosos/síntese química , Tiazóis/síntese química , Tiazóis/farmacologia , Alquilação , Anti-Infecciosos/farmacologia , Indicadores e ReagentesRESUMO
The synthesis and physicochemical properties of 4-butyl-2H-benzo[1,4]thiazin-3-one derivatives are described. These new compounds were synthesised by alkylation in 4-N position and acylation and/or alkylation of 6-NH2 by phase transfer catalysis. Acid hydrolysis of 6-alkylacylamino group yielded 6-alkylamino-4-butyl-2H-benzo[1,4]thiazin-3-ones. The antimicrobial in vitro activity was determined on five compounds.
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Anti-Infecciosos/síntese química , Tiazinas/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Testes de Sensibilidade Microbiana , Tiazinas/farmacologiaRESUMO
Control of Salmonella enterica serovar Typhimurium (S. typhimurium) infection in the mouse model of typhoid fever is critically dependent on the natural resistance-associated macrophage protein 1 (Nramp1). In this study, we examined the role of genetic polymorphisms in the human homologue, NRAMP1, in resistance to typhoid fever in southern Vietnam. Patients with blood-culture-confirmed typhoid fever and healthy control subjects were genotyped for 6 polymorphic markers within and near NRAMP1 on chromosome 2q35. Four single base-pair polymorphisms (274 C/T, 469+14 G/C, 1465-85 G/A, and D543N), a (GT)(n) repeat in the promoter region of NRAMP1 and D2S1471, and a microsatellite marker approximately 130-kb downstream of NRAMP1 were examined. The allelic and genotypic frequencies for each polymorphism were compared in case patients and control subjects. No allelic association was identified between the NRAMP1 alleles and typhoid fever susceptibility. In addition, neither homozygotes nor heterozygotes for any NRAMP1 variants were at increased risk of typhoid fever.