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Transport in GaN-based nanoscale devices is of supreme importance for various applications. While the transport in bulk and two-dimensional (2D) structures is relatively well understood, understanding one-dimensional (1D) transport is still at its nascent stage. More importantly, the nanoscale structures may not operate at an explicit dimension of 2D and 1D. The understanding of the transport becomes limited on such an occasion. Here, we investigate the evolution of low-field mobility in GaN-based nanostructures for increasing quantum confinement in a uniform framework. We have used a split-gate architecture to change the degree of quantum confinement electrostatically. The low-field mobility is experimentally determined, which is then matched using scattering theory. It is shown that acoustic phonon, polar optical phonon, and scattering from piezoelectric fields dominate these devices. Contrary to intuition, the piezoelectric fields play the most determining role in low-field regimes. In addition, the evolving density of states and 2D phonon confinement, in addition to electron confinement, lead to a non-monotonic change in mobility. A decrease in the number of states near conduction band minima tends to increase mobility by reducing the number of final scattering states for the electrons. A larger overlap between confined electrons and phonons aggravates scattering and reduces mobility. These two competing effects can lead to many possible values for mobility during device operation.
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BACKGROUND: Mural lesions of gallbladder on ultrasound (US) are often difficult to characterize as benign or malignant. PURPOSE: The aim of the study was to evaluate the role of contrast-enhanced US (CEUS) in characterization of gallbladder (GB) wall lesions and making distinction between benign wall thickening and GB adenocarcinoma, utilizing both quantitative and qualitative parameters. METHODS: A total of 26 patients with GB wall lesions detected on sonography underwent CEUS. Lesions were evaluated on the basis of morphological imaging features, enhancement pattern, dynamic real-time contrast uptake, and intralesional vascularity. RESULTS: Overall, 19 patients had final diagnosis of GB adenocarcinoma, whereas seven patients had benign etiology. CEUS has enabled the differentiation of nonenhancing tumefactive sludge from enhancing mural lesions, thus improving the accuracy of morphological assessment of lesions. The intactness of outer wall was better assessed on CEUS. The dynamic postcontrast assessment showed that carcinoma showed early washout of contrast compared to benign thickening (P = 0.002). Nonlayered mural enhancement or thick enhancing inner layer with nonenhancing thin outer layer was associated with adenocarcinoma. The classification of intralesional vascularity on CEUS was not helpful in distinguishing benign lesions and adenocarcinoma. CONCLUSION: CEUS can increase the diagnostic confidence in differentiation between benign mural lesions and adenocarcinoma of GB.
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Rhodamine group of molecules are widely used dyes for imaging of biological molecules. Application of these dyes however includes a limitation that these molecules absorb in the visible range of the spectrum, which does not fall in the 'biologically transparent window' (BTW). Two photon absorption (TPA) process could come up with an alternate solution to this as these dyes could be excited in the near infrared (NIR) window to extract similar information. To validate this we have investigated TPA cross section (TPACS, σ2) of two rhodamine dyes, namely Rhodamine 6G (R6G), Rhodamine B (RhB), site selectively bound with a model protein, bovine serum albumin (BSA), by exciting at 800 nm. Two photon spectroscopy and imaging confirms the binding of the dye to the protein. The decreases in TPACS with increasing temperature at a fixed BSA concentration excellently follows the temperature induced structural transition of BSA as the protein transforms from a molten globule to unfolded conformation beyond 60 °C, which has previously been established through circular dichroism (CD) measurements. The thus established resemblance in TPACS and CD measurement trends thus strongly affirms the suitability of TPA process in protein imaging and as an alternative marker to tracking its conformational transformations using NIR radiation.
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Corantes Fluorescentes/química , Fótons , Desnaturação Proteica , Rodaminas/química , Soroalbumina Bovina/química , Conformação Proteica , Espectrometria de FluorescênciaRESUMO
Pathogenetic mechanisms of primary immune thrombocytopenia (ITP) include antibody-mediated destruction of platelets; cell-mediated destruction and suppressed thrombopoiesis. Various morphological changes in megakaryocytes are reported in ITP patients, but never these were correlated with the response to various forms of therapy. In the present study, we intended to find out the impact of megakaryocytic abnormalities on the response to steroid, the first line of treatment. The mean age of patients (n = 33) was 28.9 ± 7.6 years. Male/female ratio was 1/1.8. The mean platelet count at presentation was 5.6 ± 4.4 × 10(9)/L. 63.6% (21/33) patients showed response to steroid. The non-responders were given 50 mg/d TPO-RA (eltrombopag) in addition to steroid, to which, 83.3% (10/12) responded. Two-third patients (66.7%, n = 22) had normal megakaryocyte morphology. Those with abnormal morphology commonly had hypolobated forms and micromegakaryocytes. Ninety-five percent of steroid responders had normal megakaryocytic morphology. Among steroid non-responders, most patients (n = 10, 83.3%) had abnormal megakaryocytic morphology. 80% steroid non-responders with abnormal morphology responded to the addition of eltrombopag. The findings suggest that the abnormal megakaryocyte morphology can be an evidence of dominant pathogenetic mechanism and thereby can help us in individualizing the treatment of ITP.
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Megacariócitos/patologia , Púrpura Trombocitopênica Idiopática/sangue , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Esteroides/uso terapêutico , Adulto , Plaquetas/patologia , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Estudos ProspectivosRESUMO
PURPOSE: To identify whether CGRP and PTHrP serve as screening biomarkers for early detection of preeclampsia or even before the development of preeclampsia in early pregnancy. METHODS: It was a nested case-control study. The subjects were divided into normotensive (controls) and preeclamptic (cases) groups. Serum samples of 132 cases and 132 controls were collected during pregnancy at three different gestational periods and one sample post delivery, from within the cohort of pregnant women reporting to antenatal clinic. Circulating levels of CGRP and PTHrP were analyzed by enzyme-linked immunosorbent assay. RESULTS: Maternal serum concentrations of CGRP and PTHrP increased with the advancement of gestation age in both normotensive and preeclamptic pregnancies but the significantly less increased levels were observed in preeclamptic pregnancies as compared with normotensive pregnancies. In postpartum period level of CGRP significantly falls in both groups although level of PTHrP continues to increase even after delivery. Maternal serum CGRP and PTHrP concentrations were positively correlated with the infant's birth weights. CONCLUSION: Maternal circulating CGRP and PTHrP concentrations were significantly lower in women with preeclampsia, which may contribute to the development of preeclampsia.
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Peptídeo Relacionado com Gene de Calcitonina/sangue , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Gravidez/sangue , Adulto , Peso ao Nascer , Pressão Sanguínea , Índice de Massa Corporal , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Sangue Fetal/química , Idade Gestacional , Humanos , Proteína Relacionada ao Hormônio Paratireóideo/sangue , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Período Pós-Parto/sangue , Pré-Eclâmpsia/sangue , Resultado da Gravidez , Fatores SocioeconômicosRESUMO
Childhood hypertension (HTN) is becoming one of the most important health concerns in children, and it is the most important predictor of adult HTN. The objective was to assess the level of knowledge and to develop and validate questionnaires about childhood HTN among final-year medical students. This facility-based cross-sectional study was conducted from January 2018 to September 2018 in 5 teaching hospitals of Central India. A total of 383 interviews were conducted by non-probability purposive sampling using a validated tool. Exploratory factor analysis was used to assess the validity of the questionnaire, and internal consistency of items was assessed with Cronbach α. A total of 26 items were finalized through consensus. The Kaiser-Meyer-Olkin (KMO) measure of sample adequacy was measures of sampling adequacy (MSA) = 0.83, and Bartlett's test of sphericity was (x2 = 15.89, P = .014). This study shows that the tool developed had acceptable validity and reliability to assess the knowledge about childhood HTN among undergraduate medical students.
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Cystic hygroma is a benign congenital tumor of lymphatic origin. Most common location is head and neck region. Bleomycin is an antineoplastic glycopeptide antibiotic agent with sclerosing property. In our present study, we used bleomycin for intralesional sclerotherapy for cystic hygromas of head neck region, as an alternative to surgical excision. We also statistically analyzed the pattern of cystic hygroma in head and neck region. Our present study was a prospective observational study of 40 patients. The study period was 18 months. All patients were given intralesional bleomycin at the dose of 0.5 mg /kg body weight, not exceeding 10 units at a time. The injection was repeated if required, at an interval of 4 weeks up to 4-5 times. Each patient was followed up at regular interval up to 1 year. Most common age group was found to be between 0-7 years (55%). Mean age was 6.9 years. Posterior triangle of neck was the commonest site (35%). Excellent response was noted in 24 patients (60%) while good response was noticed in 11 patients (27.5%). Poor response in 5 patients (12.5%). No major side effects noted with bleomycin sclerotherapy. No recurrence was noticed in our study. Intralesional bleomycin is a safe, simple, relatively cheaper and effective nonsurgical treatment method for cystic hygroma of head and neck region. It can be used as a first line treatment modality. Still, a lot of research is needed to establish it as a gold standard treatment modality for cystic hygroma.
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Purpose: Preeclampsia (PE) affects 5-7% of the pregnancies worldwide, and is one of the most dreaded disorders of pregnancy contributing to maternal and neonatal mortality. PE is mostly presented in the third trimester of pregnancy. Here, we used serum placental growth factor (PIGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) to develop a model for predicting PE in Indian women in early second trimester. Methods: In this case-control study, a total 1452 healthy pregnant women were recruited. Blood samples were collected at the following gestational weeks (GWs), 12-20 (GW1), 21-28 (GW2) and 29-term (GW3), and post-delivery. Body mass index (BMI) was calculated by anthropometric measurements. Serum sFlt-1, PIGF and VEGF were analyzed by ELISA. A predictive model for PE was developed using multivariable logistic regression analysis. Results: In PE cases, serum PlGF and VEGF levels were significantly lower at each GW, while serum sFlt-1 was lower only at GW1, relative to age-matched controls, (n = 132/group). Age-matched comparison between PE cases and controls indicated that sFlt-1 was associated with decreased PE outcome (Odds ratio. OR = 0.988, CI = 0.982-0.993), whereas sFlt-1/PlGF ratio (OR = 1.577, CI = 1.344-1.920) and BMI (OR = 1.334, CI = 1.187-1.520) were associated with increased PE outcome. Logistic regression was used to develop a predictive model for PE at GW1. Using testing dataset, model was externally validated which resulted in 88% accuracy in predicting PE cases at 0.5 probability cutoff. Conclusion: Prediction model using sFlt-1, sFlt-1/PlGF ratio and BMI may be useful to predict PE as early as 12-20 weeks in women with optimal sensitivity and specificity.
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Okra production in eastern India at present is severely threatened by whitefly-mediated okra enation leaf curl disease (OELCuD). Identification of resistant genotype and understanding the genetic control and biochemical relationship of OELCuD resistance are prerequisite for developing an effective breeding strategy. This study was conducted employing six populations (P1, P2, F1, F2, BC1 and BC2) of two selected (resistant x susceptible (RxS)) crosses. Associationship between severity of OELCuD and biochemical parameters of parents and hybrids at preflowering and flowering stages was studied. Segregation pattern of the genotypes in F2 generation showing OELCuD reaction of two crosses suggested that two duplicate recessive genes was operative for resistance to OELCuD. Generation mean analysis revealed involvement of both additive and nonadditive effects in the inheritance of disease resistance. Hence, postponement of selection in later generations or intermating among the selected segregates followed by one or two generations of selfing to break the undesirable linkage and allow the accumulation of favourable alleles could be suggested for the development of stable resistant genotype against this disease. Higher peroxidase activity and total phenol content in leaf emerged as reliable biochemical markers for early selection of genotype resistant to OELCuD.
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Abelmoschus/genética , Resistência à Doença/genética , Padrões de Herança/genética , Doenças das Plantas/genética , Folhas de Planta/genética , Abelmoschus/classificação , Abelmoschus/virologia , Alelos , Begomovirus/fisiologia , Cruzamentos Genéticos , Genótipo , Interações Hospedeiro-Patógeno , Índia , Peroxidase/genética , Peroxidase/metabolismo , Fenol/metabolismo , Fenótipo , Doenças das Plantas/virologia , Folhas de Planta/metabolismo , Folhas de Planta/virologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Okra production in eastern India at present is severely threatened by whitefly-mediated okra enation leaf curl disease(OELCuD). Identification of resistant genotype and understanding the genetic control and biochemical relationship of OELCuD resistanceare prerequisite for developing an effective breeding strategy. This study was conducted employing six populations (P1, P2, F1, F2, BC1 andBC2) of two selected (resistant 9 susceptible (R9S)) crosses. Associationship between severity of OELCuD and biochemical parametersof parents and hybrids at preflowering and flowering stages was studied. Segregation pattern of the genotypes in F2 generation showingOELCuD reaction of two crosses suggested that two duplicate recessive genes was operative for resistance to OELCuD. Generation meananalysis revealed involvement of both additive and nonadditive effects in the inheritance of disease resistance. Hence, postponement ofselection in later generations or intermating among the selected segregates followed by one or two generations of selfing to break theundesirable linkage and allow the accumulation of favourable alleles could be suggested for the development of stable resistant genotypeagainst this disease. Higher peroxidase activity and total phenol content in leaf emerged as reliable biochemical markers for early selectionof genotype resistant to OELCuD.
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Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterised by isolated thrombocytopenia (peripheral blood platelet count <100 × 10(9)/L) in the absence of other causes or disorders that may be associated with thrombocytopenia. The upfront treatment in newly diagnosed ITP patients is steroids; however, about one-third patients do not respond, and require other treatment, including IVIg, anti-D, or splenectomy. Previous studies have shown decreased platelet production in some ITP patients, aside from the evidence of enhanced platelet destruction. Thrombopoietin receptor agonists (TPO-RA), such as eltrombopag have been shown to provide good response in steroid non-responsive chronic ITP patients. We have studied response to eltrombopag in 25 newly diagnosed steroid non-responsive ITP patients; 80 % patients showed response at the end of 1 month, and 76 % sustained response at the end of 3 months. The platelet count rose from a mean value of 17.5 ± 3.6-152.5 ± 107.9 × 10(9)/L at the end of 1 month. Our results suggest a possible role of eltrombopag in newly diagnosed steroid non-responsive ITP patients. However, our study is limited in that it is a single-centre study, with a small sample size, and lacks a long-term safety profile. Our findings highlight the potential value of a larger prospective study on the upfront use of TPO-RA in patients of ITP.
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Benzoatos/uso terapêutico , Hidrazinas/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Pirazóis/uso terapêutico , Receptores de Trombopoetina/agonistas , Adolescente , Adulto , Resistência a Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Estudos Prospectivos , Esteroides/uso terapêutico , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
Ecthyma gangrenosum (EG) is a cutaneous manifestation of invasive infection usually caused by pseudomonas, but can be caused by many bacteria, fungal and viral infections. We present the first reported case of EG caused by invasive Escherichia coli in a neonate. A neonate presented with evidence of sepsis and a rapidly evolving 3×3.5 cm(2) well-circumscribed haemorrhagic and necrotic ulcer on the left groin. There was evidence of decreased perfusion of the lower limb owing to pressure effect of the ulcer. The child responded well to anticoagulation and antibiotic therapy. It is crucial to clinically suspect EG and promptly start empiric antibiotic therapy covering pseudomonas to decrease the morbidity and mortality. However, other viruses, fungus and bacteria including E coli should also be considered in the differential diagnosis of EG in a neonate.