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1.
Eur J Clin Microbiol Infect Dis ; 43(6): 1205-1212, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38557925

RESUMEN

Acute encephalitis syndrome (AES) outbreaks in children of Eastern Uttar Pradesh (E-UP) region of India have been a longstanding public health issue, with a significant case fatality rate of 20-25%. Since past decade, a rise in chikungunya (CHIK) cases has been occurring, which is a reported etiology of AES. However, the burden of chikungunya virus (CHIKV) among pediatric AES (pAES) is unknown from E-UP. We included 238 hospitalized pAES cases. The presence of IgM antibodies for CHIKV, and Dengue virus (DENV) was tested, and RT-PCR was performed for CHIKV and DENV in serologically confirmed CHIKV and DENV pAES cases. Positive samples were sequenced using Sangers sequencing. Further, to check for co-infection, IgM antibodies for other AES etiologies including Japanese encephalitis virus (JEV), Leptospira and Orientia tsutsugamushi (OT) in serum were also investigated. IgM ELISA demonstrated 5.04% (12) positivity for CHIKV. Among CHIKV IgM positive, 3 (25%, 3/12) pAES patients died. CHIKV genome was detected in 3 pAES specimens. Among which, 2 CHIKV cases were also positive for OT DNA. Partially sequenced CHIKV were genotyped as ECSA. The overall finding indicates evidence of CHIKV infection with high case fatality among pAES patients from E-UP. This study advocates constant serological and molecular surveillance of CHIKV in AES endemic regions of India.


Asunto(s)
Encefalopatía Aguda Febril , Anticuerpos Antivirales , Fiebre Chikungunya , Virus Chikungunya , Inmunoglobulina M , Humanos , India/epidemiología , Fiebre Chikungunya/mortalidad , Fiebre Chikungunya/epidemiología , Niño , Masculino , Femenino , Preescolar , Virus Chikungunya/genética , Virus Chikungunya/inmunología , Anticuerpos Antivirales/sangre , Inmunoglobulina M/sangre , Encefalopatía Aguda Febril/epidemiología , Lactante , Adolescente , Coinfección/mortalidad , Coinfección/virología , Coinfección/epidemiología , Virus del Dengue/genética , Virus del Dengue/inmunología , Filogenia , Brotes de Enfermedades
2.
Curr Microbiol ; 81(8): 236, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38907107

RESUMEN

During evolution Orientia tsutsugamushi became a smarter obligate bacterium to establish as intracellular pathogens. O. tsutsugamushi is a human pathogenic bacterium responsible for 1 billion infections of scrub typhus. Several novel mechanisms make this bacterium unique (cell wall, genetic constitutions, secretion system, etc.). In 2007, O. tsutsugamushi Boryong was pioneer strain for whole-genome sequencing. But the fundamental biology of this bacterial cell is a mystery till date. The unusual biology makes this organism as model for host cell interaction. Only a few antibiotics are effective against this intracellular pathogen but emergence of less susceptibility toward antibiotics make the situation alarming. The review was captivated to highlight the unusual aspects of adaptation, antibiotics, and drugs beyond antibiotics.


Asunto(s)
Antibacterianos , Orientia tsutsugamushi , Tifus por Ácaros , Orientia tsutsugamushi/genética , Orientia tsutsugamushi/efectos de los fármacos , Tifus por Ácaros/microbiología , Tifus por Ácaros/tratamiento farmacológico , Antibacterianos/farmacología , Humanos , Adaptación Fisiológica , Animales
3.
Chem Biodivers ; 21(4): e202301820, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38372508

RESUMEN

As a part of novel discovery of drugs from natural resources, present study was undertaken to explore the antibacterial potential of chalcone Indl-2 in combination with different group of antibiotics. MIC of antibiotics was reduced up to eight folds against the different cultures of E. coli by both chalcones. Among the two compounds, the i. e. 1-(3', 4,'5'-trimethoxyphenyl)-3-(3-Indyl)-prop-2-enone (6, Indl-2), a chalcone derivative of gallic acid (Indl-2) was better along with tetracycline (TET) worked synergistically and was found to inhibit efflux transporters as obvious by ethidium bromide efflux confirmed by ATPase assays and docking studies. In combination, Indl-2 kills the MDREC-KG4 cells, post-antibiotic effect (PAE) of TET was prolonged and mutant prevention concentration (MPC) of TET was also decreased. In-vivo studies revealed that Indl-2 reduces the concentration of TNF-α. In acute oral toxicity study, Indl-2 was non-toxic and well tolerated up-to dose of 2000 mg/kg. Perhaps, the study is going to report gallic acid derived chalcone as synergistic agent acting via inhibiting the primary efflux pumps.


Asunto(s)
Chalcona , Chalconas , Chalcona/farmacología , Chalconas/farmacología , Escherichia coli , Ácido Gálico/farmacología , Antibacterianos/farmacología , Tetraciclina/farmacología , Proteínas de Transporte de Membrana , Pruebas de Sensibilidad Microbiana , Proteínas Bacterianas/metabolismo
4.
Arch Microbiol ; 205(5): 178, 2023 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-37029825

RESUMEN

Scrub typhus (ST) caused by Orientia tsutsugamushi (OT), has long been known to cause acute encephalitis syndrome (AES) and acute febrile illness (AFI). The immunodominant 56 kDa protein of OT, which is encoded by the 56 kDa gene (1600 bp encoding 516-541 amino acids) is a commonly studied antigen for genotype and serotype assignment. Previous studies from India have utilized partial type specific antigen (TSA) 56 kDa sequences for OT strain characterisation. On the other hand, understanding the antigenic diversity of current OT strains, is critical for developing specific diagnostic tests and vaccines against ST. As a result, the current study analyses antigenic variants using the entire TSA56 ORF of OT from AES cases. Phylogenetic investigation using complete TSA56 ORF sequences revealed Karp and Gilliam were the circulating predominant strains of OT. Furthermore, Immuno-informatical analysis demonstrated that the majority of high-binding affinity CD4 TCEs against the most prevalent Indian human leukocyte antigen alleles were present in the S-VDIII/IV and S-VDIV spacer regions of TSA56 ORF. TSA56 conserved spacer is crucial for OT immunological response investigations. Further, the pathophysiological effects of spacer domains in ST require further investigation. Furthermore, the characterization of the TSA56 spacer region of the OT from different parts of India is critical for developing region-specific ST diagnostic assays and vaccines.


Asunto(s)
Encefalopatía Aguda Febril , Orientia tsutsugamushi , Tifus por Ácaros , Humanos , Orientia tsutsugamushi/genética , Filogenia , Encefalopatía Aguda Febril/genética , Tifus por Ácaros/diagnóstico , Tifus por Ácaros/epidemiología , India
5.
J Pharmacokinet Pharmacodyn ; 50(6): 429-444, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37140724

RESUMEN

Pediatric populations represent a major fraction of rare diseases and compound the intrinsic challenges of pediatric drug development and drug development for rare diseases. The intertwined complexities of pediatric and rare disease populations impose unique challenges to clinical pharmacologists and require integration of novel clinical pharmacology and quantitative tools to overcome multiple hurdles during the discovery and development of new therapies. Drug development strategies for pediatric rare diseases continue to evolve to meet the inherent challenges and produce new medicines. Advances in quantitative clinical pharmacology research have been a key component in advancing pediatric rare disease research to accelerate drug development and inform regulatory decisions. This article will discuss the evolution of the regulatory landscape in pediatric rare diseases, the challenges encountered during the design of rare disease drug development programs and will highlight the use of innovative tools and potential solutions for future development programs.


Asunto(s)
Farmacología Clínica , Farmacología , Médicos , Niño , Humanos , Enfermedades Raras/tratamiento farmacológico , Desarrollo de Medicamentos
6.
Appl Opt ; 61(5): B181-B189, 2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-35201139

RESUMEN

This paper describes detection of cracks in ceramic tableware using a portable digital holographic camera working on the principle of double-exposure digital holographic interferometry. Digital image processing techniques are applied on amplitude and phase information obtained from the numerically reconstructed wavefronts of the test object to locate position of the defect. Speckles generated due to illumination of the rough surface of the ceramic cup with the coherent light source deteriorate quality of the interferometric phase. Several iterations of the averaging filter with optimized kernel size are applied on sine and cosine components of the interferometric phase to minimize the speckle noise. The effect of kernel size of the matrix used in the averaging filter on quality of the interferometric phase is analyzed by evaluating the signal-to-noise ratio. The experimentally obtained size of crack on a ceramic cup (0.08 mm) is validated by a mechanical profiler with an error of 6.6%. This study may help in improving the quality criteria of tableware items.

7.
Indian J Med Res ; 156(2): 186-190, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-36629178

RESUMEN

Background & objectives: The tribal population in India is considered as one of the vulnerable groups with respect to their achievements in health and other developmental issues. In this context, this mapping review attempted to understand the health profile of the Tharu tribal community residing in the northern State of Uttar Pradesh, India through literature mining. Tharu tribe is one of the indigenous groups living in the Terai plain on the Indo-Nepal border. In 1967, this tribe was documented as a Scheduled Tribe by the Government of India. The present review aimed to map the health-seeking behaviour of the Tharu population and review other factors pertaining to their health such as socioeconomic, developmental, employment, education, etc. Methods: Online data search was carried out on PubMed and Google Scholar using search terms 'Tharu' AND 'India'. In addition, official reports avaibale in public domain and grey literature was also searched. Results: Twenty seven studies including reviews, articles, books/book chapters were evaluated along with 13 reports (including reports from government organizations and grey literature) were retrieved and analyzed. Of the 27 published reports, 16 were found relevant to Tharu tribe in India. A total of 29 (16 articles + 13 reports ) were included in this review. Interpretation & Conclusions: This mapping review highights the health seeking behaviour of the Tharu tribe in India that can help inform future interventions to improve the health status of the Tharu tribe as well as other aspects of their development.


Asunto(s)
Conductas Relacionadas con la Salud , Estado de Salud , Humanos , India/epidemiología , Nepal , Aceptación de la Atención de Salud
8.
Curr Microbiol ; 79(12): 388, 2022 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-36329256

RESUMEN

There are several bacteria called superbugs that are resistant to multiple antibiotics which can be life threatening specially for critically ill and hospitalized patients. This article provides up-to-date treatment strategies employed against some major superbugs, like methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, vancomycin-resistant Enterococcus, multidrug-resistant Pseudomonas aeruginosa, and multidrug-resistant Escherichia coli. The pathogen-directed therapeutics decrease the toxicity of bacteria by altering their virulence factors by specific processes. On the other hand, the host-directed therapeutics limits these superbugs by modulating immune cells, enhancing host cell functions, and modifying disease pathology. Several new antibiotics against the global priority superbugs are coming to the market or are in the clinical development phase. Medicinal plants possessing potent secondary metabolites can play a key role in the treatment against these superbugs. Nanotechnology has also emerged as a promising option for combatting them. There is urgent need to continuously figure out the best possible treatment strategy against these superbugs as resistance can also be developed against the new and upcoming antibiotics in future. Rational use of antibiotics and maintenance of proper hygiene must be practiced among patients.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Humanos , Farmacorresistencia Bacteriana Múltiple , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pseudomonas aeruginosa , Escherichia coli , Pruebas de Sensibilidad Microbiana
9.
Int J Mol Sci ; 23(11)2022 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-35682737

RESUMEN

The early management, diagnosis, and treatment of emerging and re-emerging infections and the rising burden of non-communicable diseases (NCDs) are necessary. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system has recently acquired popularity as a diagnostic tool due to its ability to target specific genes. It uses Cas enzymes and a guide RNA (gRNA) to cleave target DNA or RNA. The discovery of collateral cleavage in CRISPR-Cas effectors such as Cas12a and Cas13a was intensively repurposed for the development of instrument-free, sensitive, precise and rapid point-of-care diagnostics. CRISPR/Cas demonstrated proficiency in detecting non-nucleic acid targets including protein, analyte, and hormones other than nucleic acid. CRISPR/Cas effectors can provide multiple detections simultaneously. The present review highlights the technical challenges of integrating CRISPR/Cas technology into the onsite assessment of clinical and other specimens, along with current improvements in CRISPR bio-sensing for nucleic acid and non-nucleic acid targets. It also highlights the current applications of CRISPR/Cas technologies.


Asunto(s)
Sistemas CRISPR-Cas , Ácidos Nucleicos , Sistemas CRISPR-Cas/genética , ADN , Ácidos Nucleicos/genética , ARN , ARN Guía de Sistemas CRISPR-Cas
10.
PLoS Med ; 18(12): e1003877, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34890407

RESUMEN

BACKGROUND: India began COVID-19 vaccination in January 2021, initially targeting healthcare and frontline workers. The vaccination strategy was expanded in a phased manner and currently covers all individuals aged 18 years and above. India experienced a severe second wave of COVID-19 during March-June 2021. We conducted a fourth nationwide serosurvey to estimate prevalence of SARS-CoV-2 antibodies in the general population aged ≥6 years and healthcare workers (HCWs). METHODS AND FINDINGS: We did a cross-sectional study between 14 June and 6 July 2021 in the same 70 districts across 20 states and 1 union territory where 3 previous rounds of serosurveys were conducted. From each district, 10 clusters (villages in rural areas and wards in urban areas) were selected by the probability proportional to population size method. From each district, a minimum of 400 individuals aged ≥6 years from the general population (40 individuals from each cluster) and 100 HCWs from the district public health facilities were included. The serum samples were tested for the presence of IgG antibodies against S1-RBD and nucleocapsid protein of SARS-CoV-2 using chemiluminescence immunoassay. We estimated the weighted and test-adjusted seroprevalence of IgG antibodies against SARS-CoV-2, along with 95% CIs, based on the presence of antibodies to S1-RBD and/or nucleocapsid protein. Of the 28,975 individuals who participated in the survey, 2,892 (10%) were aged 6-9 years, 5,798 (20%) were aged 10-17 years, and 20,285 (70%) were aged ≥18 years; 15,160 (52.3%) participants were female, and 21,794 (75.2%) resided in rural areas. The weighted and test-adjusted prevalence of IgG antibodies against S1-RBD and/or nucleocapsid protein among the general population aged ≥6 years was 67.6% (95% CI 66.4% to 68.7%). Seroprevalence increased with age (p < 0.001) and was not different in rural and urban areas (p = 0.822). Compared to unvaccinated adults (62.3%, 95% CI 60.9% to 63.7%), seroprevalence was significantly higher among individuals who had received 1 vaccine dose (81.0%, 95% CI 79.6% to 82.3%, p < 0.001) and 2 vaccine doses (89.8%, 95% CI 88.4% to 91.1%, p < 0.001). The seroprevalence of IgG antibodies among 7,252 HCWs was 85.2% (95% CI 83.5% to 86.7%). Important limitations of the study include the survey design, which was aimed to estimate seroprevalence at the national level and not at a sub-national level, and the non-participation of 19% of eligible individuals in the survey. CONCLUSIONS: Nearly two-thirds of individuals aged ≥6 years from the general population and 85% of HCWs had antibodies against SARS-CoV-2 by June-July 2021 in India. As one-third of the population is still seronegative, it is necessary to accelerate the coverage of COVID-19 vaccination among adults and continue adherence to non-pharmaceutical interventions.


Asunto(s)
COVID-19/sangre , COVID-19/epidemiología , COVID-19/inmunología , Inmunoglobulina G/sangre , SARS-CoV-2 , Adolescente , Adulto , Anciano , Niño , Estudios Transversales , Femenino , Personal de Salud , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Población Rural , Población Urbana , Adulto Joven
11.
Bioorg Chem ; 106: 104454, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33213895

RESUMEN

Being crucial part of plant-based novel discovery of drug from natural resources, a study was done to explore the antibacterial potential of curcumin mimics in combination with antibiotics against multidrug resistant isolates of Pseudomonas aeruginosa. The best candidate Van D, a curcumin mimics reduced the MIC of tetracycline (TET) up to 16 folds against multidrug resistant clinical isolates. VanD further inhibited the efflux pumps as evident by ethidium bromide efflux and by in-silico docking studies. In another experiment, it was also found that Van D inhibits biofilm synthesis. This derivative kills the KG-P2, an isolate of P. aeruginosa in a time dependent manner, the post-antibiotic effect (PAE) of tetracycline was extended as well as mutant prevention concentration (MPC) of TET was also decreased. In Swiss albino mice, Van D reduced the proinflammatory cytokines concentration. In acute oral toxicity study, this derivative was well tolerated and found to be safe up to 1000 mg/kg dose. To the best of our knowledge, this is the first report on curcumin mimics as synergistic agent via inhibition of efflux pump.


Asunto(s)
Antibacterianos/uso terapéutico , Chalconas/uso terapéutico , Farmacorresistencia Bacteriana/efectos de los fármacos , Animales , Antibacterianos/síntesis química , Antibacterianos/metabolismo , Antibacterianos/toxicidad , Proteínas de la Membrana Bacteriana Externa/metabolismo , Biopelículas/efectos de los fármacos , Chalconas/síntesis química , Chalconas/metabolismo , Chalconas/toxicidad , Curcumina/química , Curcumina/farmacología , Diseño de Fármacos , Sinergismo Farmacológico , Femenino , Masculino , Proteínas de Transporte de Membrana/metabolismo , Ratones Endogámicos BALB C , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Unión Proteica , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/fisiología , Tetraciclina/farmacología
12.
Appl Opt ; 60(4): A120-A130, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33690361

RESUMEN

In this work, quality evaluation of a reconstructed amplitude image in digital holography is presented. The digital holograms are recorded using three different digital holographic experimental configurations, namely, conventional off-axis digital holography, concave-lens-based digital holography, and the digital holographic camera developed for non-destructive testing applications [Opt. Lasers Eng.137, 106359 (2021)OLENDN0143-816610.1016/j.optlaseng.2020.106359]. The quality of reconstructed images is measured by calculating the quality evaluation parameters such as speckle index, peak signal-to-noise ratio, and structural similarity index measure for these experimental configurations. Optimization of the power of the light source and exposure time of the recording sensor is performed for the three configurations based on the quality evaluation of reconstructed images. A comparison of the quality of reconstructed images is made for the three experimental configurations to analyze their performance for different source power and exposure time of the recording image sensor.

13.
Indian J Med Res ; 152(1 & 2): 48-60, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32952144

RESUMEN

BACKGROUND & OBJECTIVES: Population-based seroepidemiological studies measure the extent of SARS-CoV-2 infection in a country. We report the findings of the first round of a national serosurvey, conducted to estimate the seroprevalence of SARS-CoV-2 infection among adult population of India. METHODS: From May 11 to June 4, 2020, a randomly sampled, community-based survey was conducted in 700 villages/wards, selected from the 70 districts of the 21 States of India, categorized into four strata based on the incidence of reported COVID-19 cases. Four hundred adults per district were enrolled from 10 clusters with one adult per household. Serum samples were tested for IgG antibodies using COVID Kavach ELISA kit. All positive serum samples were re-tested using Euroimmun SARS-CoV-2 ELISA. Adjusting for survey design and serial test performance, weighted seroprevalence, number of infections, infection to case ratio (ICR) and infection fatality ratio (IFR) were calculated. Logistic regression was used to determine the factors associated with IgG positivity. RESULTS: Total of 30,283 households were visited and 28,000 individuals were enrolled. Population-weighted seroprevalence after adjusting for test performance was 0.73 per cent [95% confidence interval (CI): 0.34-1.13]. Males, living in urban slums and occupation with high risk of exposure to potentially infected persons were associated with seropositivity. A cumulative 6,468,388 adult infections (95% CI: 3,829,029-11,199,423) were estimated in India by the early May. The overall ICR was between 81.6 (95% CI: 48.3-141.4) and 130.1 (95% CI: 77.0-225.2) with May 11 and May 3, 2020 as plausible reference points for reported cases. The IFR in the surveyed districts from high stratum, where death reporting was more robust, was 11.72 (95% CI: 7.21-19.19) to 15.04 (9.26-24.62) per 10,000 adults, using May 24 and June 1, 2020 as plausible reference points for reported deaths. INTERPRETATION & CONCLUSIONS: Seroprevalence of SARS-CoV-2 was low among the adult population in India around the beginning of May 2020. Further national and local serosurveys are recommended to better inform the public health strategy for containment and mitigation of the epidemic in various parts of the country.


Asunto(s)
Anticuerpos Antivirales/sangre , Betacoronavirus/genética , Infecciones por Coronavirus/epidemiología , Inmunoglobulina G/sangre , Neumonía Viral/epidemiología , Adolescente , Adulto , Anciano , Betacoronavirus/patogenicidad , COVID-19 , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/virología , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/sangre , Neumonía Viral/virología , SARS-CoV-2 , Estudios Seroepidemiológicos , Adulto Joven
14.
PLoS Comput Biol ; 11(11): e1004582, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26562652

RESUMEN

Quantifying the magnitude and dynamics of protein oxidation during cell signaling is technically challenging. Computational modeling provides tractable, quantitative methods to test hypotheses of redox mechanisms that may be simultaneously operative during signal transduction. The interleukin-4 (IL-4) pathway, which has previously been reported to induce reactive oxygen species and oxidation of PTP1B, may be controlled by several other putative mechanisms of redox regulation; widespread proteomic thiol oxidation observed via 2D redox differential gel electrophoresis upon IL-4 treatment suggests more than one redox-sensitive protein implicated in this pathway. Through computational modeling and a model selection strategy that relied on characteristic STAT6 phosphorylation dynamics of IL-4 signaling, we identified reversible protein tyrosine phosphatase (PTP) oxidation as the primary redox regulatory mechanism in the pathway. A systems-level model of IL-4 signaling was developed that integrates synchronous pan-PTP oxidation with ROS-independent mechanisms. The model quantitatively predicts the dynamics of IL-4 signaling over a broad range of new redox conditions, offers novel hypotheses about regulation of JAK/STAT signaling, and provides a framework for interrogating putative mechanisms involving receptor-initiated oxidation.


Asunto(s)
Interleucina-4/metabolismo , Transducción de Señal/fisiología , Biología de Sistemas/métodos , Algoritmos , Humanos , Células Jurkat , Modelos Biológicos , Oxidación-Reducción , Proteínas Tirosina Fosfatasas
15.
Appl Microbiol Biotechnol ; 100(5): 2311-25, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26658982

RESUMEN

The purpose of the present study was to study the synergy potential of gallic acid-based derivatives in combination with conventional antibiotics using multidrug resistant cultures of Escherichia coli. Gallic acid-based derivatives significantly reduced the MIC of tetracycline against multidrug resistant clinical isolate of E. coli. The best representative, 3-(3',4,'5'-trimethoxyphenyl)-4,5,6-trimethoxyindanone-1, an indanone derivative of gallic acid, was observed to inhibit ethidium bromide efflux and ATPase which was also supported by in silico docking. This derivative extended the post-antibiotic effect and decreased the mutation prevention concentration of tetracycline. This derivative in combination with TET was able to reduce the concentration of TNFα up to 18-fold in Swiss albino mice. This derivative was nontoxic and well tolerated up to 300 mg/kg dose in subacute oral toxicity study in mice. This is the first report of gallic acid-based indanone derivative as drug resistance reversal agent acting through ATP-dependent efflux pump inhibition.


Asunto(s)
Antibacterianos/farmacología , Sinergismo Farmacológico , Inhibidores Enzimáticos/farmacología , Escherichia coli/efectos de los fármacos , Ácido Gálico/farmacología , Indanos/farmacología , Tetraciclina/farmacología , Administración Oral , Animales , Modelos Animales de Enfermedad , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Ácido Gálico/administración & dosificación , Ácido Gálico/efectos adversos , Indanos/administración & dosificación , Indanos/efectos adversos , Macrófagos/efectos de los fármacos , Ratones , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Choque Séptico/prevención & control
16.
Artículo en Inglés | MEDLINE | ID: mdl-39172339

RESUMEN

In this investigation, the effects of blending microalgae biodiesel with silicon dioxide (SiO2) nanoparticles in a diesel engine are evaluated. For the study, test fuels (diesel, B20, B20n25, B20n50, B20n75, and B20n100) were prepared by blending pure diesel with microalgae biodiesel with the addition of SiO2 nanoparticles having particle sizes ranging from 25 to 100 ppm. A liquid-cooled, two-cylinder, four-stroke, compression ignition engine having a load range between 2 and 12 kW, fuel injection timing of 23° bTDC, and 16.5:1 compression ratio was chosen for this study. The results demonstrated that the test fuels enhanced the engine performance and declined emissions. Performance parameters such as brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) were all improved by 1.6-4.8% and 8.55-15.33%, respectively, by the biodiesel containing SiO2 nanoparticles. At full engine load, emissions such as carbon dioxide (CO2), smoke opacity (BSN), and NOx declined by 1.8-9%, 6.2-21.4%, and 19-34% respectively. The study backs the use of SiO2 nanoadditives for better performance and lower emissions in diesel engines. Test results were analyzed by Taguchi and RSM method to find optimized conditions.

17.
Artículo en Inglés | MEDLINE | ID: mdl-38724843

RESUMEN

A two-step treatment  of mahua oil was conducted to synthesize mahua biodiesel using heterogeneous biomass-based catalyst derived from mahua shell. Mahua oil having higher free fatty acid (FFA) content (about 19%) was esterified to reduce the FFA content up to 1%. The esterification process was carried out using 200 mL mahua oil, 5:1 molar ratio (methanol:oil), and 2.25 weight% of H2SO4 at a temperature of 60 °C for 3 h. Post esterification, a set of 16 experiments were created using a Box-Behnken design (BBD)-based response surface methodology (RSM) approach to conduct the transesterification of the esterified oil. Molar ratio, catalyst loading, reaction temperature, and reaction time were the four input variables chosen for the design of experiments. The optimized conditions for maximum biodiesel yield (87.7%) were found to be 14.88 molar ratio, 3.578% catalyst loading, 69.7 °C reaction temperature, and 81.9 min reaction time. The Diesel RK engine simulation tool which was experimentally validated for baseline diesel fuel was used for numerical simulation of mahua biodiesel. The performance, combustion, and emission behavior of mahua biodiesel analyzed using numerical simulation presented the sustainability of mahua biodiesel as an alternate fuel.

18.
Artículo en Inglés | MEDLINE | ID: mdl-39088172

RESUMEN

The introduction of hydrogen into the engine could enhance its combustion efficiency and emission characteristics. The current study examines the attributes of compression ignition (CI) engines by introducing hydrogen into a biodiesel blend derived from algae. The improved thermal properties of hydrogen, when combined with algae biodiesel, significantly affect the performance, combustion, and emissions of dual-fuel engines. A study was conducted to evaluate the impact of hydrogen enrichment levels of 5%, 10%, 15%, and 20% of the nozzle volume on a biodiesel blend fuel. In comparison to diesel, algal biodiesel reduces emissions of unburned hydrocarbons (HC), carbon monoxide (CO), and oxygen (O2) by 5.19%, 3.61%, and 2.83%, respectively, while increasing nitrogen oxide (NO) emissions by 4.73%. In contrast to biodiesel, diesel demonstrated superior brake thermal efficiency (BTE) and lower specific energy consumption (SEC). Injecting hydrogen into A20 blend fuel at volumes of 5%, 10%, 15%, and 20% results in a respective increase in brake thermal efficiency of 2.65%, 2.97%, 3.50%, and 4.15%. The addition of hydrogen gas to biodiesel blends further enhances their combustion qualities, leading to elevated peak cylinder pressure, temperature, and heat release rate. The results indicate that A20H5, A20H10, A20H15, and A20H20 fuel reduced CO emissions by 3.75%, 8.75%, 12.5%, and 16.25%, respectively, compared to the A20 blend. In the same vein, HC emissions decreased by 5.76%, 10.29%, 15.52%, and 18.98%, respectively, as compared to A20 fuel. However, NO emissions rose by 5.36%, 10.20%, 15.28%, and 23.23%, respectively, for A20H5, A20H10, A20H15, and A20H20 test fuels. Ultimately, the utilization of algal biodiesel and hydrogen enrichment in diesel engines was proven to substantially reduce pollutants while increasing efficiency. This study contributes valuable insights into the intersection of renewable fuels, hydrogen enrichment, and engine technology, with the potential to drive significant advancements in sustainable transportation and environmental conservation.

19.
Infect Dis Now ; 54(2): 104865, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38350558

RESUMEN

OBJECTIVES: To identify the potential target genes for detection of Orientia tsutsugamushi (OT) in pediatric acute encephalitis syndrome (pAES). METHODS: DNA was extracted from whole blood of 100 pAES cases having tested positive (n = 41) and negative (n = 59) for scrub typhus (ST) by IgM ELISA. These samples were subjected to standard PCR for 56 kDa, 47 kDa, 16 s rRNA, groEL, traD genes and the newly identified 27 kDa gene. RESULTS: Among the selected gene targets, 56 kDa demonstrated its superiority for OT detection over the other tested genes. The presence of OT was confirmed via PCR targeting 56 kDa gene in 17 out of the 41 (41.4 %) IgM-positive ST AES cases and 38 out of the 59 (64.4 %) ST IgM negative cases. None of the other gene targets were amplified. CONCLUSION: Integration of serological diagnosis with molecular diagnostics targeting the 56 kDa gene for routine testing of AES patients would facilitate detection of OT in AES endemic regions.


Asunto(s)
Encefalopatía Aguda Febril , Tifus por Ácaros , Niño , Humanos , Tifus por Ácaros/diagnóstico , Encefalopatía Aguda Febril/diagnóstico , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina M , Reacción en Cadena de la Polimerasa
20.
Artículo en Inglés | MEDLINE | ID: mdl-37145359

RESUMEN

Sustainable renewable energy fuel is used to reduce fossil fuel consumption and mitigate global warming pollution. The effect of diesel and biodiesel blends on engine combustion, performance, and emissions were studied at various engine loads, compression ratios, and engine speed. Chlorella vulgaris biodiesel is derived through a transesterification process and diesel and biodiesel blends are prepared at 20% incremental volume up to CVB100. The performance such as brake thermal efficiency reduced by 1.49%, specific fuel consumption increased by 2.78%, and exhaust gas temperature increased by 0.43% for CVB20 as compared to diesel. Similarly, emissions were reduced such as smoke, particulate matters. CVB20 shows close performance and lower emission than diesel at a 15.5 compression ratio and 1500 rpm engine speed. The increasing compression ratio has a positive impact on engine performance and emission except for NOx. Similarly, increasing engine speed has a positive impact on engine performance and emission except for exhaust gas temperature. The performance of a diesel engine fueled with a blend of diesel and Chlorella vulgaris biodiesel is optimized by varying compression ratio, engine speed, load, and blend. It was found that at 8 compression ratio, 1835 rpm speed, 88% engine load, and 20% biodiesel blend the maximum BTE obtained 34% while minimum SFC 0.158 kg/kWh is obtained employing research surface methodology tool.

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