Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 423
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Inorg Chem ; 59(6): 3856-3873, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32141738

RESUMO

For better exciton separation and high catalytic activity, the most trailblazing stratagem is to construct defect engineered low-dimensional p-n heterojunction framed photocatalytic systems. In this context, we have developed a rod-sheet (1D-2D) p-n heterojunction of MCeO2-BiFeO3 by a simple hydrothermal method and scrutinized its photocatalytic performance toward N2 fixation and phenol/Cr(VI) detoxification. The intimate contact between MCeO2 and BiFeO3 in the junction material is well established via X-ray diffraction (XRD), UV-vis diffuse reflectance spectrosopy (DRS), transmission electron microscopy (TEM), and photoelectrochemical studies. Further, scanning electron microscopy (SEM) and TEM pictures clearly support the decoration of MCeO2 nanorods over BiFeO3 sheets and also depict the junction boundary. Additionally, photoluminescence (PL), electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), and Raman measurements give solid evidence toward the presence of an oxygen vacancy. Moreover, the Mott-Schottky result indicates a feasible band edge potential favoring the p-n heterojunction with a built-in electric field between BiFeO3 and MCeO2 favoring a double charge dynamic. The MCeO2-BFO p-n junction displays a notable catalytic activity, i.e., 98.2% Cr(VI) reduction and 85% phenol photo-oxidation, and produces 117.77 µmol h-1 g-1 of ammonia under light irradiation. Electrochemical analysis suggests a four-electron/five proton-coupled N2 photoreduction pathway. The designed oxygen vacancy oriented p-n heterojunction suffering double charge migration shows significant catalytic performance due to effective electron-hole separation as justified via PL, electrochemical impedance spectra (EIS), and Bode phase analysis.

2.
Trop Anim Health Prod ; 52(4): 1759-1767, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31898029

RESUMO

To find out the effect of reducing energy intake during dry period on milk production, udder health, and body condition, the experiment was conducted on 14 Jersey crossbred cows during whole dry period and continued up to 120 days of lactation. Reduction in energy intake was done during far-off period for each dry cow of treatment group as compared to control group. Statistically analyzed data revealed that overall significantly (P < 0.01) lower DMI and WI were recorded in control than treatment group. Overall significantly (P < 0.01) higher total milk production was found in treatment than control group. Overall significantly (P < 0.01) lower milk SCC, MCMT, pH, and EC were found in treatment than control group. Nonsignificant difference in milk fat, SNF, total solid, total protein, and fat:protein ratio was found. Overall significantly (P < 0.01) better quality milk (MBRT) was found in treatment than control groups. BCS during dry period and at calving was significantly (P < 0.01) different between groups. Significantly (P < 0.01) higher plasma NEFA concentration was estimated in control than treatment groups in all stages. No significant difference was found for plasma concentrations of glucose, urea, and total protein. The coefficients of correlation indicated significant (P < 0.01) correlation among BCS, milk production, milk SCC, MCMT, pH, and EC. It can be concluded that reducing energy intake during far-off dry period can lead to achieve optimum BCS at calving. Suitable BCS at calving was beneficial to get higher milk production with improved quality, better maintenance of udder health and body condition of Jersey crossbred cows at tropical lower Gangetic region.


Assuntos
Bovinos/fisiologia , Dieta/veterinária , Metabolismo Energético/fisiologia , Glândulas Mamárias Animais/fisiologia , Leite/fisiologia , Ração Animal/análise , Animais , Bovinos/genética , Ingestão de Energia , Feminino , Lactação
3.
Am J Physiol Endocrinol Metab ; 316(1): E16-E33, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30153063

RESUMO

Polycystic ovary syndrome (PCOS) is highly associated with cardiometabolic risk and the metabolic syndrome (MetS), predisposing women to increased risk of developing type 2 diabetes and cardiovascular disease. Metformin is commonly used to treat insulin resistance-glucose intolerance, and flutamide, an androgen receptor (AR) antagonist, is used to target hyperandrogenemia and dyslipidemia. Currently, the physiological mechanism of action of these treatments on androgen, lipidogenic, and insulin signaling pathways remains unclear in PCOS. The aim of this study was to investigate the effects and mechanisms of action of metformin and flutamide on plasma lipid-apolipoprotein (Apo)B-lipoprotein and insulin-glucose metabolism, and endocrine-reproductive indices in a PCOS-prone MetS rodent model. PCOS-prone rodents were treated with metformin (300 mg/kg body wt), flutamide (30 mg/kg body wt), or metformin + flutamide combination treatment for 6 wk. Metformin was shown to improve fasting insulin and HOMA-IR, whereas flutamide and combination treatment were shown to reduce plasma triglycerides, ApoB48, and ApoB100, and this was associated with decreased intestinal secretion of ApoB48/triglyceride. Flutamide and metformin were shown to reduce plasma androgen indices and to improve ovarian primary and preovulatory follicle frequency. Metformin treatment increased hepatic estrogen receptor (ER)α, and metformin-flutamide decreased intestinal AR and increased ERα mRNA expression. Metformin-flutamide treatment upregulated hepatic and intestinal insulin signaling, including insulin receptor, MAPK1, and AKT2. In conclusion, cardiometabolic risk factors, in particular ApoB-hypertriglyceridemia, are independently modulated via the AR, and understanding the contribution of AR and insulin-signaling pathways further may facilitate the development of targeted interventions in high-risk women with PCOS and MetS.


Assuntos
Antagonistas de Androgênios/farmacologia , Glicemia/efeitos dos fármacos , Receptor alfa de Estrogênio/efeitos dos fármacos , Flutamida/farmacologia , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Síndrome Metabólica/metabolismo , Metformina/farmacologia , Animais , Apolipoproteína B-100/efeitos dos fármacos , Apolipoproteína B-100/metabolismo , Apolipoproteína B-48/efeitos dos fármacos , Apolipoproteína B-48/metabolismo , Apolipoproteínas B/efeitos dos fármacos , Apolipoproteínas B/metabolismo , Glicemia/metabolismo , Doenças Cardiovasculares , Modelos Animais de Doenças , Receptor alfa de Estrogênio/genética , Feminino , Fase Folicular , Resistência à Insulina , Mucosa Intestinal/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Folículo Ovariano/efeitos dos fármacos , Ovário/efeitos dos fármacos , Síndrome do Ovário Policístico/metabolismo , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro , Ratos , Receptor de Insulina/efeitos dos fármacos , Receptor de Insulina/metabolismo , Risco , Triglicerídeos/metabolismo
4.
Mol Biol Rep ; 46(2): 1809-1817, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30694457

RESUMO

Mulberry (Morus alba L.) is the sole food source for the mulberry silkworm, Bombyx mori and therefore important for sericulture industry. Different abiotic stress conditions like drought, salt, heat and cold stress adversely affect the productivity and quality of mulberry leaves. Quantitative real time PCR (qPCR) is a reliable and widely used method to identify abiotic stress responsive genes and molecular mechanism in different plant species. Selection of suitable reference genes is important requirement for normalizing the expression of genes through qRT-PCR study. In the present study, we have selected eight candidate reference genes in mulberry for analyzing their expression stability in different abiotic stress treatments including drought, salt, heat and cold stresses. The expression stability of these reference genes was determined using geNorm, NormFinder and RefFinder statistical algorithms. The results showed that Ubiquitin and protein phosphatase 2A regulatory subunit A (PP2A) were the most stable genes across all the treatment samples. However, analysis of individual stresses revealed different expression profiles and stability of reference genes. Actin3 and PP2A were most stable in drought and salt conditions respectively. RPL3 most preferred in heat stress and Ubiquitin was most stable in cold stress. We propose the ubiquitin and PP2A are the preferred reference genes for normalization of gene expression data from abiotic stresses. In addition, Actin3 are preferred for drought stress, PP2A for salt stress, RPL3 for heat stress and Ubiquitin for cold stress studies.


Assuntos
Expressão Gênica/genética , Morus/genética , Estresse Fisiológico/genética , Secas , Perfilação da Expressão Gênica/métodos , Perfilação da Expressão Gênica/normas , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Resposta ao Choque Térmico , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Padrões de Referência
5.
Acta Virol ; 63(1): 3-18, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30879308

RESUMO

Bluetongue (BT) is an economically important, infectious and non-contagious disease of ruminant animals. BT disease is caused by bluetongue virus (BTV) of the genus Orbivirus (the family Reoviridae). BTV is transmitted by certain species of biting midges of the genus Culicoides. Although originally BT was restricted to African continent, now it is present in all the continents except Antarctica. Conventional BT vaccines such as live attenuated and inactivated vaccines showed different degree of success in BT control. However, conventional vaccines have certain disadvantages of reversion to virulent strain and frequent booster dose requirement. Several BT outbreaks in India and the rest of the world open a new insight for development of better vaccines. The development in molecular biology techniques allowed the development and validation of several modern vaccines such as subunit vaccine, recombinant vector vaccine, disabled infections single cycle (DISC) vaccine, differentiating infected from vaccinated animals (DIVA) approach etc. Most of these vaccines are considered as safer, having better protective immune response and provided cross-protective immunization against more than one serotype. Keywords: bluetongue virus; live vaccine; inactivated vaccine; DISC; recombinant vaccine.


Assuntos
Vírus Bluetongue , Bluetongue , Vacinas Virais , Animais , Bluetongue/prevenção & controle , Bluetongue/virologia , Ruminantes/virologia , Ovinos , Vacinas Atenuadas , Vacinas Sintéticas
6.
Reprod Domest Anim ; 52(3): 505-512, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28294426

RESUMO

The enormous production potential of buffaloes has never been accomplished due to various reproductive insufficiencies. Among them, post-partum anoestrus, a multifactorial disorder, is predominant but any genetic association is yet to be established. This study focused to identify novel polymorphisms in heat-shock protein 70 (HSP70) gene and its possible association with post-partum anoestrus in Murrah buffaloes. A 579-bp fragment from 5' untranslated region of HSP70 gene was amplified by polymerase chain reaction from blood genomic DNA of 614 animals maintained under similar management conditions. In phase-I experiment, custom sequencing and restriction enzyme (RE) digestion of the amplified fragment were performed in 40 buffaloes with similar post-partum oestrous conditions over previous consecutive three or more gestations-20 animals each showing post-partum anoestrus (>120 days after parturition) and normal cyclicity (<65 days after parturition). While in phase-II experiment, herd screening by RE analysis was performed in remaining 574 animals. Four transversions at T-75G, C+31G, T+38G and C+97A and three transition mutations at T-153C, T+33C and A+44G positions were observed. Polymorphism at T+38G site revealed significant (p < .05) variation, where homozygous G was present only in post-partum anoestrous animals while nucleotide T was present randomly in both groups of phase-I animals whereas phase-II experiments revealed homozygous G in 55 animals. Regression analysis in relation to average post-partum interval against genotypic frequencies at T+38G also depicted significant association. HSP70 gene polymorphism at T+38G position can therefore be used as genetic marker for excluding probable post-partum anoestrous buffaloes from herd for breeding programmes.


Assuntos
Anestro/genética , Búfalos/genética , Proteínas de Choque Térmico HSP70/genética , Polimorfismo Genético , Regiões 5' não Traduzidas , Animais , Búfalos/fisiologia , Feminino , Marcadores Genéticos , Período Pós-Parto , Análise de Sequência de DNA
8.
Trop Anim Health Prod ; 49(3): 641-648, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28190130

RESUMO

Livestock is a one of the major sources of livelihood for most of the small and marginal farmers in India, particularly for rural households who live in below poverty line. Extension interventions have long been seen as a key element for enabling farmers to obtain information and technologies that can improve their livelihoods. It is also recognized that extension is an important factor in promoting dairy development. Ex-post-facto cause to effect research design was applied in this study to trace out the impact of extension interventions in improving knowledge, attitude, adoption towards scientific dairy farming practices and improvement in milk production of dairy animal and income from dairying which will be resulted into improved livelihood of rural poor in Nadia district of West Bengal, India. Therefore, 60 dairy farmers of experimental villages who were considered as beneficiaries and 60 dairy farmers of control villages who were considered as non-beneficiaries were selected as sample for the study. It was found that beneficiaries had significantly higher score in all the five components of livelihood improvement with its all sub components, i.e., knowledge, attitude, adoption of scientific dairy farming practices, milk production per household per day and monthly income from dairying except disease control, and marketing component of adoption. Hence, it may be concluded that extension interventions had a significant impact on improving livelihood of rural dairy farmers in Nadia district of West Bengal, India.


Assuntos
Criação de Animais Domésticos/economia , Indústria de Laticínios , Características da Família , Fazendeiros/psicologia , Animais , Bovinos , Feminino , Humanos , Índia , População Rural
9.
Haemophilia ; 22(4): 570-82, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27291889

RESUMO

INTRODUCTION: Inherited macrothrombocytopenia represents a heterogeneous group of disorders which are characterized by the presence of a reduced number of abnormally large platelets in the circulation, which may or may not be associated with a bleeding tendency. In spite of several causative genes having been identified, the underlying genetic defects remain to be identified in approximately half of the cases. AIMS: To understand the molecular pathology of isolated giant platelet disorder from India. MATERIALS AND METHODS: We studied 112 cases that were referred for investigation of macrothrombocytopenia. Agonist induced platelet aggregation and platelet GP1b/IX/V receptor expression were investigated to assess GP1b/IX/V receptor expression and the GP1BA, GP1BB, GP9, ABCG5, ABCG8, TUBB1 and MYH9 genes were analysed to identify candidate gene defects. RESULTS: Twenty-three candidate gene defects were identified in 48 of 112 cases, 20 of which were novel. Of the candidate defects identified, 91% were missense and 9% were nonsense variations. The missense variations were in GP9 (9), ABCG5 (4), GP1BB (3), GP1BA (3) and MYH9 (2), while the nonsense defects occurred in MYH9 (1) and GP1BA (1). CONCLUSIONS: This study increases the understanding of the molecular basis of an isolated giant platelet disorder, a common heterogeneous condition prevalent in north and eastern India.


Assuntos
Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Trombocitopenia/diagnóstico , Membro 5 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Adolescente , Adulto , Idoso , Testes de Coagulação Sanguínea , Plaquetas/citologia , Plaquetas/metabolismo , Criança , Códon sem Sentido , Feminino , Estudos de Associação Genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Genótipo , Hemorragia/etiologia , Heterozigoto , Humanos , Índia , Lipoproteínas/genética , Masculino , Pessoa de Meia-Idade , Proteínas Motores Moleculares/genética , Mutação de Sentido Incorreto , Cadeias Pesadas de Miosina/genética , Fenótipo , Complexo Glicoproteico GPIb-IX de Plaquetas/genética , Polimorfismo de Nucleotídeo Único , Trombocitopenia/congênito , Trombocitopenia/genética , Adulto Jovem
10.
J Assoc Physicians India ; 64(7 Suppl): 3-11, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28805048

RESUMO

Influenza is a global public health problem and concern especially in high risk people. Prevention plays a key role in avoiding complications of influenza related illnesses. Despite the existing prevalence of influenza, and documented importance of vaccination, the uptake of influenza vaccine is very poor. This document provide recommendations for influenza vaccination in high-risk individuals and help implement best practices in the South Asian region and improve coverage of influenza vaccination to achieve better outcomes in this population.


Assuntos
Vacinas contra Influenza/uso terapêutico , Influenza Humana/prevenção & controle , Adulto , Ásia/epidemiologia , Humanos , Influenza Humana/epidemiologia , Guias de Prática Clínica como Assunto , Medição de Risco , Estações do Ano
12.
Anim Genet ; 46(3): 255-64, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25752324

RESUMO

This study was carried out with the objective to investigate the differentially expressed genes (DEGs) between Jeju native pig (JNP) and Berkshire piglets. The RNA-Seq technique was used to investigate the transcriptomes in the fat, liver and longissimus dorsi muscle from these two breeds. Paired-end reads of the sequences that passed the quality filters were aligned to the Sus scrofa genome using tophat2 (v2.0.2). In this study, 65% of muscle, 20% of fat and 54% of liver genes showed higher expression in the piglets of JNP than in Berkshire. Gene Ontology and signaling pathways showed that immune response and lipid metabolisms were commonly enriched pathways in all three tissues. It was found that the genes pertaining to body growth and immune system are significantly (P < 0.01) more highly expressed in Berkshire piglets. DEGs explored between the piglets of the two breeds might influence the identification of the genetic markers for further breed improvement programs. Our findings provide a new perspective for understanding and identifying candidate genes that are involved in various biological functions. Moreover, transcriptome analysis makes it easier to understand the differences between genetic mechanisms of breeds.


Assuntos
Análise de Sequência de RNA/métodos , Sus scrofa/crescimento & desenvolvimento , Sus scrofa/genética , Sus scrofa/imunologia , Transcriptoma , Tecido Adiposo/metabolismo , Animais , Cruzamento , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Redes e Vias Metabólicas , Músculo Esquelético/metabolismo
13.
Curr Oncol ; 22(Suppl 1): S29-42, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25848337

RESUMO

Despite advancements in the treatment of early-stage breast cancer, many patients still develop disease recurrence; others present with de novo metastatic disease. For most patients with advanced breast cancer, the primary treatment intent is noncurative-that is, palliative-in nature. The goals of treatment should therefore focus on maximizing symptom control and extending survival. Treatments should be evaluated on an individualized basis in terms of evidence, but also with full respect for the wishes of the patient in terms of acceptable toxicity. Given the availability of extensive reviews on the roles of endocrine therapy and her2 (human epidermal growth factor receptor 2)-targeted therapies for advanced disease, we focus here mainly on treatment guidelines for the non-endocrine management of her2-negative advanced breast cancer in a Canadian health care context.

14.
J Appl Microbiol ; 116(3): 511-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24268027

RESUMO

AIMS: Microbial exopolymer with antimicrobial properties, in particular, has gathered considerable interest due to their enormous scope of modification and wide gamut of application. The purpose of present study was to evaluate the antibacterial spectrum of a chemically modified biopolymeric flocculant produced by Klebsiella terrigena. METHODS AND RESULTS: N,N,N trimethyl biopolymer (TMB) was synthesized using dimethyl sulfate as methylating agent and was characterized by nuclear magnetic resonance and mass spectroscopic analysis, which confirmed the presence of quaternary ammonium groups on the TMB structure. The antibacterial activity of TMB was investigated against three selected bacterial pathogens viz. Aeromonas hydrophila ATCC 35654, Listeria monocytogenes ATCC 19111 and Escherichia coli O157:H7 ATCC 32150. An inactivation of 3 log CFU ml(-1) of all pathogens was noticed for TMB when compared to native polymer over a short contact time (60 min) and low dosage (60-80 µg ml(-1) ) at ambient temperature. A marked increase in glucose level, protein content and lactate dehydrogenase (LDH) activity was observed concurrently in the cell supernatant suggesting damage of the cell membranes to be a possible reason for inactivation. CONCLUSIONS: The quaternization of amino rich biopolymer isolated from a bacterium led to a water-soluble bioactive agent with enhanced inhibitive capability against all the selected bacterial pathogens. SIGNIFICANCE AND IMPACT OF STUDY: The results of this study suggest a potential application of TMB as an effective disinfectant in water treatment.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Biopolímeros/química , Biopolímeros/farmacologia , Klebsiella/metabolismo , Aeromonas hydrophila/efeitos dos fármacos , Antibacterianos/biossíntese , Biopolímeros/biossíntese , Desinfetantes/química , Desinfetantes/metabolismo , Desinfetantes/farmacologia , Escherichia coli O157/efeitos dos fármacos , Floculação , Listeria monocytogenes/efeitos dos fármacos , Dados de Sequência Molecular
15.
J Nanosci Nanotechnol ; 14(4): 2752-71, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24734688

RESUMO

A coupled molecular dynamics (MD)-stochastic simulation based model has been proposed here for the thermal conductivity of ethylene glycol (EG) based copper nanofluid. The model is based on the thermal evolution of the nanoparticles dispersed in the nanofluid which is in contact with a heat source. It is natural that the nanoparticles dispersed in the nanofluid would move randomly by Brownian motion and repeatedly collide with the heat source. During each collision the nanoparticles would extract some heat by conduction mode from the heat source and this heat would be dissipated to the base fluid during Brownian motion by a combination of conduction and microconvection mode. Thus, in addition to normal conductive heat transfer through the base fluid (EG) itself (without nanoparticles) some amount of heat is transferred by the collision of the nanoparticles with the heat source. The extent of this additional heat transfer has been estimated in the present model to estimate the enhancement in thermal conductivity of EG based copper nanofluid, as a function of volume fraction loading of nanoparticles. The prediction of the present model has been compared with the experimental data available in literature, and it has shown a reasonable agreement between the theoretical prediction and the experimental data.

16.
Am Surg ; 89(9): 3732-3738, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37148273

RESUMO

INTRODUCTION: Despite a high prevalence of retained bullet fragments (RBFs) after firearm related injury (FRI) there is limited data on the full spectrum of their consequences, particularly the psychological impacts on those injured. Further, the experiences of FRI survivors with RBFs are missing from existing literature. The objective of this study was to explore the psychological impacts of RBFs on individuals who have experienced recent FRI. METHODS: Adult (18-65 years) survivors of FRI with radiographically confirmed RBFs were purposively selected from an urban Level 1 trauma center in Atlanta, Georgia, to participate in an in-depth interview. Interviews were conducted between March 2019 and February 2020. Thematic analysis was used to identify a range of psychological effects from RBFs. RESULTS: Interviews from 24 FRI survivors were analyzed: the majority of participants were Black males (N = 22, 92%) with a mean age of 32 years whose FRI occurred ∼8.6 months prior to data collection. The psychological effects of RBFs were grouped into four categories: physical health (eg, pain, limited mobility), emotional well-being (eg, anger, fear), social isolation, and occupational welfare (eg, disability leading to inability to work). A range of coping mechanisms were also identified. CONCLUSION: Survivors of FRI with RBFs experience a range of psychological impacts that are far-reaching and affect daily activities, mobility, pain and emotional wellbeing. Study results indicate a need for enhanced resources to support those with RBFs. Further, changes to clinical protocols are warranted on removal of RBFs and communication about the effects of leaving RBFs in situ.


Assuntos
Adaptação Psicológica , Dor , Adulto , Masculino , Humanos , Medo , Isolamento Social , Sobreviventes/psicologia
17.
Phys Rev E ; 108(3-2): 035209, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37849111

RESUMO

Laser-direct-drive fusion target designs with solid deuterium-tritium (DT) fuel, a high-Z gradient-density pusher shell (GDPS), and a Au-coated foam layer have been investigated through both 1D and 2D radiation-hydrodynamic simulations. Compared with conventional low-Z ablators and DT-push-on-DT targets, these GDPS targets possess certain advantages of being instability-resistant implosions that can be high adiabat (α≥8) and low hot-spot and pusher-shell convergence (CR_{hs}≈22 and CR_{PS}≈17), and have a low implosion velocity (v_{imp}<3×10^{7}cm/s). Using symmetric drive with laser energies of 1.9 to 2.5MJ, 1D lilac simulations of these GDPS implosions can result in neutron yields corresponding to ≳50-MJ energy, even with reduced laser absorption due to the cross-beam energy transfer (CBET) effect. Two-dimensional draco simulations show that these GDPS targets can still ignite and deliver neutron yields from 4 to ∼10MJ even if CBET is present, while traditional DT-push-on-DT targets normally fail due to the CBET-induced reduction of ablation pressure. If CBET is mitigated, these GDPS targets are expected to produce neutron yields of >20MJ at a driven laser energy of ∼2MJ. The key factors behind the robust ignition and moderate energy gain of such GDPS implosions are as follows: (1) The high initial density of the high-Z pusher shell can be placed at a very high adiabat while the DT fuel is maintained at a relatively low-entropy state; therefore, such implosions can still provide enough compression ρR>1g/cm^{2} for sufficient confinement; (2) the high-Z layer significantly reduces heat-conduction loss from the hot spot since thermal conductivity scales as ∼1/Z; and (3) possible radiation trapping may offer an additional advantage for reducing energy loss from such high-Z targets.

18.
Stat Med ; 31(20): 2196-208, 2012 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-22495822

RESUMO

The paper develops a class of priors that leads to equivalent posterior inference for odds ratio parameters based on prospective and retrospective models for categorical response data. The results are applicable to both unmatched and matched case-control studies. The results hold for a general class of link functions for categorical response. The proposed method can accommodate multiple and possibly ordered disease states. The results are applied to the analysis of discrete subtypes in an ongoing case-control study of colorectal cancer. A simulation study illustrates the need for carefully considering prior choices in Bayesian analysis of data collected under retrospective design.


Assuntos
Estudos de Casos e Controles , Interpretação Estatística de Dados , Estudos Prospectivos , Estudos Retrospectivos , Teorema de Bayes , Neoplasias Colorretais/epidemiologia , Simulação por Computador , Humanos , Funções Verossimilhança , Razão de Chances , Fatores de Risco
19.
Top Spinal Cord Inj Rehabil ; 18(1): 73-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23459000

RESUMO

Cell therapies have shown promise for repairing the injured spinal cord in experimental models and are now being evaluated in clinical trials for the treatment of human spinal cord injury (SCI). To date, experimental evaluation of implanted cell survival, migration, and integration within the injured central nervous system (CNS) of animals has been technically demanding, requiring tissue sectioning, staining, imaging, and manual reconstruction of 2-dimensional (2D) specimens in 3 dimensions (3D). Not only are these histological procedures laborious and fraught with processing artifacts during manual 3D reconstruction, but they are time-intensive. Herein we describe the utility of 3D ultramicroscopy for assessment of cell therapies after SCI, a new state-of-the-art imaging modality in which whole brain and spinal cord samples are optically sectioned to allow evaluation of intact, macroscopic specimens with microscopic resolution.

20.
Anal Chim Acta ; 1191: 339295, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033239

RESUMO

A methodology has been developed for the complete compositional characterization of lithium titanate (LTO) using neutron activation, which is quite challenging and no literature report is available so far. The concept of thermal neutron induced in-situ chain reactions 6Li(n,α)3H and 16O(3H,n)18F has been used for the determination of Li and O through the measurement of 18F activity. The method is capable of analyzing Li and O in percentage level as reported in the present analysis of two types of lithium titanate samples. Spectroscopic interference of the elements which can directly or indirectly affect the outcome, were evaluated meticulously. Determination of Ti was carried out using fast neutron activation through the product isotopes like 47Sc, 48Sc, generated via (n,p) nuclear reactions. Fast neutron activation methodology seems to be advantageous for Ti determination over thermal neutron activation, as it offers self validation through different isotopes and multiple gamma lines.


Assuntos
Terapia por Captura de Nêutron de Boro , Nêutrons Rápidos , Isótopos , Lítio , Nêutrons
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA