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1.
Int Urogynecol J ; 34(8): 1831-1835, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36752848

RESUMO

INTRODUCTION AND HYPOTHESIS: Health state utility values estimate an individual's valuation of their health-related quality of life. Despite prevalence of recurrent urinary tract infections (rUTIs), the health state utility value of rUTIs is unknown. The primary aim was to determine the utility value of rUTIs using the standard gamble (SG). The secondary aim was to compare the SG utility value with that derived from the EuroQol 5 dimensions (EQ-5D) and visual analog scale (VAS). We hypothesized that a utility value would be successfully derived from the SG and would differ from that derived using the EQ-5D and VAS. METHODS: Nonpregnant, adult English-speaking female patients with a diagnosis of rUTI were recruited and completed the EQ-5D, VAS, and SG (n = 25). Utility values were evaluated using Wilcoxon signed-rank tests and Spearman's rho correlation. RESULTS: Health state utility values varied depending on the assessment tool used: EQ-5D 0.76 (IQR 0.52), VAS 0.70 (IQR 0.30), and SG 0.85 (IQR 0.25). There were differences between VAS and the other two assessment methods (p<0.001), as well as between EQ-5D and SG (p=0.013). Spearman correlation demonstrated a moderately positive correlation between EQ-5D and VAS values (r(25) = 0.59, p=0.0019). CONCLUSIONS: Our data suggest that 0.85 reflects the true health state utility value of rUTIs among nonpregnant adult English-speaking women. The utility value for recurrent UTIs is worse (lower) than that previously published for nonrecurrent UTIs, reflecting the ability of the SG to convey the compounding impact of recurrent disease. In this study, neither the EQ-5D nor the VAS produced results consistent with those found using the SG, which suggests limited validity in this population.


Assuntos
Qualidade de Vida , Infecções Urinárias , Adulto , Humanos , Feminino , Inquéritos e Questionários , Medição da Dor , Escala Visual Analógica , Nível de Saúde
2.
Mymensingh Med J ; 25(2): 349-56, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27277370

RESUMO

The anterior maxilla, also called pre-maxilla, is an area frequently requiring surgical interventions. Rehabilitation of this area remains a complex restorative challenge. The most prominent anatomical structure within the anterior maxilla is the Nasopalatine Canal. Thorough knowledge about this anatomical structure plays an important role in the successful outcomes of surgical procedures. This retrospective study was done to evaluate the anatomy and morphology of the Nasopalatine Canal using cone-beam computed tomography (CBCT). The study included 125 subjects aged between 15 and 78 years who were divided into the following 5 groups: i) 15-30 years, ii) 30-45 years, iii) 45-60 years, iv) 60-75 years, v) ≥75 years in the Department of Oral Medicine & Radiology, Sri Aurobindo College of Dentistry, Indore, Madhya Pradesh, India from January 2012 to January 2015. Cone-beam computed tomography (CBCT) was performed using a standard exposure and patient positioning protocol. The data of the CBCT images were sliced in three dimensions. Image planes on the three axes (X, Y, and Z) were sequentially analyzed for the location, morphology and dimensions of the Nasopalatine Canal. The correlation of age and gender with all the variables were evaluated. ANOVA and Z-test was used. P value <0.05 was considered statistically significant. Males and females showed significant differences in the length of the canal and anterior bone width in the sagittal sections. Inverted L was identified as a new dimension to the morphological shape of Nasopalatine Canal in central Madhya Pradesh population. The present study highlighted important variability observed in the anatomy and morphology of the Nasopalatine Canal.


Assuntos
Maxila/diagnóstico por imagem , Adolescente , Adulto , Idoso , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
3.
BJOG ; 122(9): 1216-24, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25492692

RESUMO

OBJECTIVE: To determine the association between reductions in government healthcare spending (GHS) on maternal mortality in 24 countries in the European Union (EU) over a 30-year period, 1981-2010. DESIGN: Retrospective study. SETTING AND POPULATION: Twenty-four EU countries (a total population of 419 million as of 2010). METHODS: We used multivariate regression analysis, controlling for country-specific differences in healthcare, infrastructure, population size and demographic structure. GHS was measured as a percentage of gross domestic product. Five-year lag-time analyses were performed to estimate longer standing effects. MAIN OUTCOME MEASURES: Maternal mortality rates. RESULTS: An annual 1% decrease in GHS is associated with significant rises in maternal mortality rates [regression coefficient [R] 0.0177, P = 0.0021, 95% confidence interval [95% CI] 0.0065-0.0289]. For every annual 1% decrease in GHS, we estimate 89 excess maternal deaths in the EU, a 10.6% annual increase in maternal mortality. The impact on maternal mortality was sustained for up to 1 year (R 0.0150, P = 0.0034, 95% CI 0.0050-0.0250). The associations remained significant after accounting for economic, infrastructure and hospital resource controls, in addition to out-of-pocket expenditure, private health spending and total fertility rate. However, accounting for births attended by skilled staff removed the significance of these effects. CONCLUSIONS: Reductions in GHS were significantly associated with increased maternal mortality rates, which may occur through changes in the provision of skilled health professionals attending births. Examples of reduced GHS such as the implementation of austerity measures and budgetary reductions are likely to worsen maternal mortality in the EU.


Assuntos
Atenção à Saúde/economia , União Europeia/estatística & dados numéricos , Financiamento Governamental/economia , Gastos em Saúde/estatística & dados numéricos , Mortalidade Materna , Adulto , Comparação Transcultural , Bases de Dados Factuais , Atenção à Saúde/estatística & dados numéricos , Feminino , Necessidades e Demandas de Serviços de Saúde , Humanos , Gravidez , Estudos Retrospectivos
4.
Plant Cell Rep ; 34(1): 37-45, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25236159

RESUMO

KEY MESSAGE: The mapping analysis resulted in identification of five significant QTLs for opaque2 modifiers influencing the tryptophan content in quality protein maize using functional and genomic SSR markers. Quality protein maize (QPM) was developed by selecting genetic modifiers that convert opaque2 mutant containing high lysine and tryptophan. There are several unlinked opaque2 modifier loci (Opm) in QPM whose location, nature and mode of action are not clear. To identify these Opm QTLs, we developed a population of 218 F2:3 individuals from a cross between VQL2 and VQL8, two isogenic QPM inbreds significantly differing in tryptophan content. Based on the data of the F2:3 population, five significant QTLs on chromosomes 5, 7 and 9 with LOD values more than 2.5 were identified and together explained 38.6 % of the total phenotypic variance (R (2)). The Wx1 gene which has influence on the amino acid composition of the maize endosperm was mapped on chromosome 9 near the marker phi022 and also validated by bulk analysis. The QTL near the SSR marker ZmASK3, developed from the aspartate kinase 2 gene of the lysine pathway, mapped on chromosome 5 and had LOD of 2.7 with R (2) of 5.1 %. On chromosome 9, the QTL between the loci umc1430 and bnlg1401 had an LOD of 4.5 with R (2) of 9.1 %, whereas the QTL between the loci bnlg1401 and phi022 had an LOD of 4.2 with R (2) of 8.4 %. The third QTL was observed to be close to the marker umc2207 with an LOD of 4.8 and R (2) of 8.4 %. The identified QTLs will be very useful in the marker-assisted back-cross breeding and transgressive breeding for the development of QPM maize.


Assuntos
Lisina/metabolismo , Repetições de Microssatélites/genética , Locos de Características Quantitativas/genética , Triptofano/metabolismo , Zea mays/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Cruzamentos Genéticos , DNA de Plantas/genética , Eletroforese em Gel de Ágar , Genes de Plantas/genética , Genômica/métodos , Redes e Vias Metabólicas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polimorfismo Genético , Zea mays/metabolismo
6.
Mol Biol Rep ; 41(7): 4329-39, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24584576

RESUMO

In order to understand the population structure and genetic diversity among a set of 82 rice genotypes collected from different parts of the Asian countries including India were characterized using 39 microsatellite loci. The Population structure analysis suggested that the optimum number of subpopulations was four (K = 4) among the rice genotypes, whereas phylogenetic analysis grouped them into three populations. The results obtained from phylogenetic and STRUCTURE analysis proved to be very powerful for the differentiation of rice genotypes based on their place of origin. The genetic diversity analysis using 39 SSR loci yielded 183 scorable alleles, out of which 182 alleles were observed to be polymorphic with an average of 4.8 alleles per locus. The Polymorphism Information Content (PIC) values for all the polymorphic primers across 82 rice genotypes varied from 0.02 to 0.77, with an average of 0.50. Gene diversity (He) was found to be in the range of 0.02 (RM484) to 0.80 (OSR13) with an average value of 0.55, while heterozygosity (Ho) was observed with an average of 0.07, ranging from 0.01 (RM334) to 0.31 (RM316). The present study resulted in identification of seven highly polymorphic SSR loci viz., OSR13, RM152, RM144, RM536, RM489, RM259 and RM271 based on the parameters like PIC value (≥ 0.70), gene diversity (≥ 0.71), and polymorphic alleles (≥ 6). These seven polymorphic primers can effectively be used in further molecular breeding programs and QTL mapping studies of rice since they exhibited very high polymorphism over other loci. SSR analysis resulted in a more definitive separation of clustering of genotypes indicating a higher level of efficiency of SSR markers for the accurate determination of relationships between accessions.


Assuntos
Variação Genética , Repetições de Microssatélites , Oryza/genética , Filogenia , Alelos , Loci Gênicos , Marcadores Genéticos , Genótipo , Heterozigoto , Índia , Família Multigênica , Oryza/classificação , Filogeografia
7.
Mol Biol Rep ; 41(5): 3081-90, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24477586

RESUMO

In recent years, the increased availability of the DNA sequences has given the possibility to develop and explore the expressed sequence tags (ESTs) derived SSR markers. In the present study, a total of 1956 ESTs of finger millet were used to find the microsatellite type, distribution, frequency and developed a total of 545 primer pairs from the ESTs of finger millet. Thirty-two EST sequences had more than two microsatellites and 1357 sequences did not have any SSR repeats. The most frequent type of repeats was trimeric motif, however the second place was occupied by dimeric motif followed by tetra-, hexa- and penta repeat motifs. The most common dimer repeat motif was GA and in case of trimeric SSRs, it was CGG. The EST sequences of NBS-LRR region of finger millet and rice showed higher synteny and were found on nearly same positions on the rice chromosome map. A total of eight, out of 15 EST based SSR primers were polymorphic among the selected resistant and susceptible finger millet genotypes. The primer FMBLEST5 could able to differentiate them into resistant and susceptible genotypes. The alleles specific to the resistant and susceptible genotypes were sequenced using the ABI 3130XL genetic analyzer and found similarity to NBS-LRR regions of rice and finger millet and contained the characteristic kinase-2 and kinase 3a motifs of plant R-genes belonged to NBS-LRR region. The In-silico and comparative analysis showed that the genes responsible for blast resistance can be identified, mapped and further introgressed through molecular breeding approaches for enhancing the blast resistance in finger millet.


Assuntos
Biologia Computacional , Eleusine/genética , Genômica , Repetições de Microssatélites , Sequência de Aminoácidos , Biologia Computacional/métodos , Etiquetas de Sequências Expressas , Frequência do Gene , Genes de Plantas , Loci Gênicos , Genômica/métodos , Genótipo , Dados de Sequência Molecular , Oryza/genética , Filogenia , Alinhamento de Sequência
8.
Mol Biol Rep ; 41(8): 5287-97, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24861452

RESUMO

Identification of alleles responsible for various agro-morphological characters is a major concern to further improve the finger millet germplasm. Forty-six genomic SSRs were used for genetic analysis and population structure analysis of a global collection of 190 finger millet genotypes and fifteen agro-morphological characters were evaluated. The overall results showed that Asian genotypes were smaller in height, smaller flag leaf length, less basal tiller number, early flowering and early maturity nature, small ear head length, and smaller in length of longest finger. The 46 SSRs yielded 90 scorable alleles and the polymorphism information content values varied from 0.292 to 0.703 at an average of 0.442. The gene diversity was in the range of 0.355 to 0.750 with an average value of 0.528. The 46 genomic SSR loci grouped the 190 finger millet genotypes into two major clusters based on their geographical origin by the both phylogenetic clustering and population structure analysis by STRUCTURE software. Association mapping of QTLs for 15 agro-morphological characters with 46 genomic SSRs resulted in identification of five markers were linked to QTLs of four traits at a significant threshold (P) level of ≤ 0.01 and ≤ 0.001. The QTL for basal tiller number was strongly associated with the locus UGEP81 at a P value of 0.001 by explaining the phenotypic variance (R (2)) of 10.8%. The QTL for days to 50% flowering was linked by two SSR loci UGEP77 and UGEP90, explained 10 and 8.7% of R (2) respectively at a P value of 0.01. The SSR marker, FM9 found to have strong association to two agro-morphological traits, flag leaf width (P-0.001, R(2)-14.1 %) and plant height (P-0.001, R(2)-11.2%). The markers linked to the QTLs for above agro-morphological characters found in the present study can be further used for cloning of the full length gene, fine mapping and their further use in the marker assisted breeding programmes for introgression of alleles into locally well adapted germplasm.


Assuntos
Mapeamento Cromossômico , Eleusine/genética , Genótipo , Repetições de Microssatélites , Alelos , DNA de Plantas/genética , Genômica , Índia , Fenótipo , Filogenia , Filogeografia , Polimorfismo Genético , Locos de Características Quantitativas
9.
Cardiovasc Drugs Ther ; 28(3): 247-62, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24842559

RESUMO

Atrial fibrillation (AF) is the most common cardiac arrhythmia that can potentially result in stroke. Vitamin K antagonists (VKA) like warfarin were for many decades the only oral anticoagulants available for stroke prevention in patients with non-valvular atrial fibrillation (AF) at high risk of stroke. Recently, new oral anticoagulants (NOACS) have been introduced that act via direct inhibition of thrombin (dabigatran) or activated factor X (edoxaban, rivaroxaban and apixaban). Unlike VKAs, these anticoagulants do not require routine INR monitoring and posses favorable pharmacological properties. NOACs act rapidly, and have a stable and predictable dose-related anticoagulant effect with few clinically relevant drug-drug interactions. Phase III trials comparing these agents to warfarin for stroke prevention in patients with non-valvular AF demonstrated that they are at least as efficacious and safe as warfarin. Evolution of clinical guidelines to incorporate the new anticoagulants for stroke prevention in non-valvular AF may result in a reduction in the incidence of AF-related strokes. Safe and effective use of these new drugs in clinical practice requires understanding of their distinct pharmacological properties.


Assuntos
Anticoagulantes/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Acidente Vascular Cerebral/prevenção & controle , Anticoagulantes/efeitos adversos , Anticoagulantes/farmacologia , Antitrombinas/efeitos adversos , Antitrombinas/uso terapêutico , Fibrilação Atrial/complicações , Fibrilação Atrial/fisiopatologia , Monitoramento de Medicamentos/métodos , Inibidores do Fator Xa/efeitos adversos , Inibidores do Fator Xa/uso terapêutico , Humanos , Coeficiente Internacional Normatizado , Guias de Prática Clínica como Assunto , Acidente Vascular Cerebral/etiologia , Varfarina/efeitos adversos , Varfarina/uso terapêutico
10.
Clin Radiol ; 69(3): 315-22, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24290774

RESUMO

Abdominal tuberculosis (TB) is the sixth most common extrapulmonary site of involvement. The sites of involvement in abdominal tuberculosis, in descending order of frequency, are lymph nodes, genitourinary tract, peritoneal cavity, and gastrointestinal tract. The radiological armamentarium for evaluating tuberculosis of the small bowel (SBTB) includes barium studies (small bowel follow-through, SBFT), CT (multidetector CT, CT enterography, and CT enteroclysis), ultrasound (sonoenteroclysis), and magnetic resonance imaging (MRI; enterography and enteroclysis). In this review, we illustrate the abnormalities at MDCT enterography in 20 consecutive patients with SB TB and also describe extraluminal findings in these patients. MDCT enterography allows non-invasive good-quality assessment of well-distended bowel loops and the adjacent soft tissues. It displays the thickness and enhancement of the entire bowel wall in all three planes and allows examination of all bowel loops, especially the ileal loops, which are mostly superimposed. The terminal ileum and ileocaecal junction are the most common sites of small bowel involvement in intestinal TB. The most common abnormality is short-segment strictures with symmetrical concentric mural thickening and homogeneous mural enhancement. Other findings include lymphadenopathy, ascites, enteroliths, peritoneal thickening, and enhancement. In conclusion, MDCT enterography is a comprehensive technique for the evaluation of SB TB.


Assuntos
Intestino Delgado/diagnóstico por imagem , Intestino Delgado/microbiologia , Tomografia Computadorizada Multidetectores , Tuberculose Gastrointestinal/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Tuberculose Gastrointestinal/patologia
11.
J Assoc Physicians India ; 62(3): 267-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25327074

RESUMO

Bulbar Palsy is B/L impairment of function of cranial N. 9, 10, 11, 12 at lower motor neuron level either at nuclear or fascicular level in medulla or B/L lesion of lower cranial N. outside brainstem. We present case of viral hepatitis who initially presented with classical signs and symptoms of hepatitis B followed by characteristic features of bulbar palsy in form of difficulty in swallowing and slurring of speech reduced gag reflex, weak palatal movement. Other causes for bulbar palsy were excluded and indirect laryngoscopy confirmed presence of bulbar palsy. Patient had no previous neurological abnormality, there are many studies in the past for association of hepatitis B and bulbar palsy but no one confirmed about a direct association between hepatitis B and bulbar palsy. To best of knowledge this is the first case report which shows direct association between hepatitis B and bulbar palsy.


Assuntos
Paralisia Bulbar Progressiva/diagnóstico , Paralisia Bulbar Progressiva/virologia , Hepatite B/complicações , Hepatite B/diagnóstico , Adulto , Humanos , Masculino
12.
J Assoc Physicians India ; 61(7): 462-3, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24772749

RESUMO

AIM: Role of blood C - reactive protein levels in upper urinary tract infection and lower urinary tract infection in adult patients (>16 years). MATERIAL AND METHODS: Study included 2 groups of patients -Test group (n=58). Control group (n=28).Test group further classified into 2 groups- a). Patients having upper urinary tract infection b). Patients having lower urinary tract infection. Patients were subjected to following tests - complete hemogram, blood C-reactive protein levels, urinalysis. RESULTS: The mean value of C-reactive protein in the cases of upper urinary tract infection 127.33 mg/L which is statistically significantly raised when compared to control(t-value 12.370 and p-value<0.01). C-reactive protein was significantly raised in upper urinary tract infection in comparison to control group( p<0.01), while in lower urinary tract infection this difference was insignificant (p<0.05). CONCLUSION: C-reactive protein has a good diagnostic role in differentiating upper and lower urinary tract infection. The simple size of our study is very small to say these authentically, hence, further studies of large number of cases is required.


Assuntos
Proteína C-Reativa/metabolismo , Cistite/diagnóstico , Pielonefrite/diagnóstico , Uretrite/diagnóstico , Infecções Urinárias/diagnóstico , Adolescente , Adulto , Estudos de Casos e Controles , Cistite/metabolismo , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Prognóstico , Pielonefrite/metabolismo , Uretrite/metabolismo , Infecções Urinárias/metabolismo , Adulto Jovem
14.
Acta Virol ; 56(2): 91-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22720698

RESUMO

UNLABELLED: Recently, transgenic plants expressing immunogenic proteins of foot-and-mouth disease virus (FMDV) have been used as oral or parenteral vaccines against foot-and-mouth disease (FMD). They exhibit advantages like cost effectiveness, absence of processing, thermostability, and easy oral application. FMDV VP1 protein of single serotype has been mostly used as immunogen. Here we report the development of a bivalent vaccine with tandem-linked VP1 proteins of two serotypes, A and O, present in transgenic forage crop Crotalaria juncea. The expression of the bivalent protein in the transgenic plants was confirmed by Western blot analysis. Guinea pig reacted to orally or parenterally applied vaccine by humoral as well as cell-mediated immune responses including serum antibodies and stimulated lymphocytes, respectively. The vaccine protected the animals against a challenge with the virus of serotype A as well as O. This is the first report on the development of a bivalent FMD vaccine using a forage crop. KEYWORDS: foot-and-mouth disease; sunnhemp; Agrobacterium tumefaciens; FMDV-VP1 gene; serotype O and A; in planta transformation; transgenic plants; bivalent vaccine.


Assuntos
Vírus da Febre Aftosa , Plantas Geneticamente Modificadas , Animais , Anticorpos Antivirais/imunologia , Proteínas do Capsídeo/genética , Febre Aftosa/imunologia , Vírus da Febre Aftosa/genética , Cobaias , Plantas Geneticamente Modificadas/imunologia , Sorogrupo , Vacinas Sintéticas , Vacinas Virais/imunologia
17.
Mymensingh Med J ; 29(4): 983-990, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33116106

RESUMO

The objective of the study was to evaluate the changes in microbiology through quantitative analysis of aerobic and anaerobic colonies and periodontal measurements during and after 1 month of removal of fixed orthodontic appliances. This prospective study comprised 30 patients, aged 12-30 years seeking orthodontic treatment in the department of Orthodontics and Dentofacial Orthopaedics of People's College of Dental Sciences and Research Centre, Bhopal from May 2016 to November 2017. Microbiological samples (supra- and subgingival plaque) and periodontal measurements like bleeding on probing (BOP), periodontal pocket depth (PPD) with oral hygiene assessment indices {plaque index (PI), gingival index (GI)} were used at 2 time interval: when patient undergoing orthodontic treatment >12 month (baseline, T1) and 1 month after the removal of appliance (T2). Bacterial culture method used to detect aerobic and anaerobic colony forming units (CFU) and their ratio (aerobic/anaerobic). Data analyzed using paired t-test and chi-square test. There was a significant decrease in an aerobic and anaerobic CFU (both supra- and subgingivally) and increase in CFU ratio (relatively less anaerobes) (p≤0.05) at T2. Supragingival plaque sampling showed greater diminution in the CFU count as compared to the subgingival CFU, as these sites are more accessible for maintaining hygiene. Also, periodontal measurements showed significant decrement (PI, GI, PPD and BOP) at T2 (p≤0.05). Fixed orthodontic treatment has transient effect on periodontium as supra- and subgingival CFU count decreases and periodontal health was ameliorated after removal of appliances which was accompanied with periodontopathic bacteria and clinical periodontal signs of inflammation during treatment.


Assuntos
Bactérias Anaeróbias , Aparelhos Ortodônticos Fixos , Adolescente , Adulto , Criança , Humanos , Índice Periodontal , Bolsa Periodontal , Estudos Prospectivos , Adulto Jovem
18.
J Phys Chem A ; 113(5): 869-77, 2009 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-19123779

RESUMO

Previous methods proposed for obtaining analytic potential-energy surfaces (PES) from ab initio electronic structure calculations are not self-starting. They generally require that the sampling of configuration space important in the reaction dynamics of the process being investigated be initiated by using chemical intuition or a previously developed semiempirical potential-energy surface. When the system under investigation contains four or more atoms undergoing three- and four-center reactions in addition to bond scission processes, obtaining a sufficiently converged initial sampling can be very difficult due to the extremely large volume of configuration space that is important in the reaction dynamics. It is shown that by combining direct dynamics (DD) with previously reported molecular dynamics (MD), novelty sampling (NS), and neural network (NN) methods, an analytical surface suitable for MD computations for large systems may be obtained. Application of the method to the investigation of N-O bond scission and cis-trans isomerization reactions of HONO followed by comparison of the resulting neural network potential-energy surface to one obtained by using a semiempirical potential to initiate the sampling shows that the two potential surfaces are the same within the fitting accuracy of the surfaces. It is concluded that the combination of direct dynamics, molecular dynamics, novelty sampling, and neural network fitting provides a self-starting, robust, and accurate DD/MD/NS/NN method for the execution of first-principles, ab initio, molecular dynamics studies in systems containing four or more atoms which are undergoing simultaneous two-, three-, and four-center reactions.

19.
J Chem Phys ; 130(18): 184102, 2009 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-19449903

RESUMO

A general method for the development of potential-energy hypersurfaces is presented. The method combines a many-body expansion to represent the potential-energy surface with two-layer neural networks (NN) for each M-body term in the summations. The total number of NNs required is significantly reduced by employing a moiety energy approximation. An algorithm is presented that efficiently adjusts all the coupled NN parameters to the database for the surface. Application of the method to four different systems of increasing complexity shows that the fitting accuracy of the method is good to excellent. For some cases, it exceeds that available by other methods currently in literature. The method is illustrated by fitting large databases of ab initio energies for Si(n) (n=3,4,...,7) clusters obtained from density functional theory calculations and for vinyl bromide (C(2)H(3)Br) and all products for dissociation into six open reaction channels (12 if the reverse reactions are counted as separate open channels) that include C-H and C-Br bond scissions, three-center HBr dissociation, and three-center H(2) dissociation. The vinyl bromide database comprises the ab initio energies of 71 969 configurations computed at MP4(SDQ) level with a 6-31G(d,p) basis set for the carbon and hydrogen atoms and Huzinaga's (4333/433/4) basis set augmented with split outer s and p orbitals (43321/4321/4) and a polarization f orbital with an exponent of 0.5 for the bromine atom. It is found that an expansion truncated after the three-body terms is sufficient to fit the Si(5) system with a mean absolute testing set error of 5.693x10(-4) eV. Expansions truncated after the four-body terms for Si(n) (n=3,4,5) and Si(n) (n=3,4,...,7) provide fits whose mean absolute testing set errors are 0.0056 and 0.0212 eV, respectively. For vinyl bromide, a many-body expansion truncated after the four-body terms provides fitting accuracy with mean absolute testing set errors that range between 0.0782 and 0.0808 eV. These errors correspond to mean percent errors that fall in the range 0.98%-1.01%. Our best result using the present method truncated after the four-body summation with 16 NNs yields a testing set error that is 20.3% higher than that obtained using a 15-dimensional (15-140-1) NN to fit the vinyl bromide database. This appears to be the price of the added simplicity of the many-body expansion procedure.

20.
Indian J Nephrol ; 29(1): 50-52, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30814794

RESUMO

Monoclonal gammopathy of undetermined significance does not have end organ damage, but a proportion of cases manifest with renal injury when it is called monoclonal gammopathy of renal significance (MGRS). Herein, we describe a case of acute hepatitis E infection, which precipitated the development of MGRS. The patient underwent kidney biopsy for elevated creatinine with clinical suspicion of drug-induced interstitial nephritis. On light microscopy, there were periodic acid-Schiff negative-fractured casts in tubules with giant cell reaction around them. The tubular epithelial cells showed intracytoplasmic bile pigment. On direct immunofluorescence, casts showed kappa restriction. A diagnosis of bilirubin proximal tubulopathy and light chain cast nephropathy was made, and possibility of myeloma was suggested. On further evaluation, κ:λ ratio was 27, ß2 microglobulin was 8036 ng/ml, and bone marrow examination showed 5% plasma cells. There were no bony lesions, and serum calcium was 8.6 mg/dl. The present case is unique in two aspects. First, the patient developed MGRS triggered by acute hepatitis E in less than a month. Second, the MGRS lesion was manifested in the form of light chain cast nephropathy.

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