42 research outputs found
The Double Loaded LV: High Prevalence of Hypertensive LVH Preceding the Development of Severe Aortic Stenosis
Background: It is generally assumed that left ventricular hypertrophy (LVH) in aortic stenosis (AS) is a compensatory adaptation to chronic outflow obstruction. However the advent of TAVR has stimulated more focus on AS in older patients, most of whom have antecedent hypertension (HTN). Accordingly our aim was to investigate the interaction between HTN and AS on LV remodeling in contemporary practice.
Methods: We studied 33 consecutive patients with AV peak velocity (PV) \u3e2.5 m/s on their initial echo and a PV of \u3e3.5 m/s on a subsequent study performed at least 5 years later. Patients’ demographics and clinical information were collected. Peak intraventricular pressure (IVP, mmHg) was defined as the sum of systolic arterial pressure and peak intraventricular gradient.Data were analyzed using descriptive statistics, paired- samples T test, and linear correlation.
Results: Of our sample (46% women, mean age of 82±11 y), 29 (88%) had a history of hypertension. The average interval between the two echo studies was 6.2±1 years. As expected, wall thickness, LV Mass, and relative wall thickness increased over time. There was no correlation between change in LV mass index (LVMi, g/m2) and peak IVP, PV or AV MG. However change in LVMi did correlate inversely with baseline LVMi (r= -0.37, p= 0.03).
Conclusion: Most patients seen in our practice with severe AS have antecedent hypertension and LVH. LVH worsens in parallel with worsening severity of AS. Remodeling in these patients features increasing concentric remodeling of the LV, rather than LV dilation. Given these findings, we speculate that regression of LVH to normal will not be effected by AVR because LVH proceeded hemodynamically severe AS. Strict control of blood pressure might be of equal importance in preventing and ameliorating pressure overload in these patients
Research Performance Of IFLA Journals Based On Scopus Database
This study examined the performance of selected IFLA journals for 22 years between 2001 to 2021. The methodology used in this study includes Annual Growth Rate (AGR), Relative Growth Rate (RGR), and Doubling Time (Dt), as well as countries and institutions. With the highest productivity and distribution of publications per year, used to evaluate research productivity. To obtain the information required for this study, the Scopus database was consulted. During the research period, 813 publications were retrieved. Based on the study, the most articles were published in 2021, 84 (10.33%), and the lowest number was 25 (3.07%) in 2018. Due to the annual increase in the constant fluctuations in publications, research shows an average, productivity in IFLA journals
Genetic mapping of legume orthologs reveals high conservation of synteny between lentil species and the sequenced genomes of Medicago and chickpea.
Lentil (Lens culinaris Medik.) is a global food crop with increasing importance for food security in south Asia and other regions. Lens ervoides, a wild relative of cultivated lentil, is an important source of agronomic trait variation. Lens is a member of the galegoid clade of the Papilionoideae family, which includes other important dietary legumes such as chickpea (Cicer arietinum) and pea (Pisum sativum), and the sequenced model legume Medicago truncatula. Understanding the genetic structure of Lens spp. in relation to more fully sequenced legumes would allow leveraging of genomic resources. A set of 1107 TOG-based amplicons were identified in L. ervoides and a subset thereof used to design SNP markers for mapping. A map of L. ervoides consisting of 377 SNP markers spread across seven linkage groups was developed using a GoldenGate genotyping array and single SNP marker assays. Comparison with maps of M. truncatula and L. culinaris documented considerable shared synteny and led to the identification of a few major translocations and a major inversion that distinguish Lens from M. truncatula, as well as a translocation that distinguishes L. culinaris from L. ervoides. The identification of chromosome-level differences among Lens spp. will aid in the understanding of introgression of genes from L. ervoides into cultivated L. culinaris, furthering genetic research and breeding applications in lentil
Chemoenzymatic synthesis, nanotization and anti- aspergillus activity of optically enriched fluconazole analogues
Despite recent advances in diagnostic and therapeutic advances in antifungal research, aspergillosis still remains a leading cause of morbidity and mortality. One strategy to address this problem is to enhance the activity spectrum of known antifungals, and we now report the first successful application of Candida antarctica lipase (CAL) for the preparation of optically enriched fluconazole analogs. Anti-Aspergillus activity was observed for an optically enriched derivative, (-)-S-2-(2’ ,4’ -difluorophenyl)-1-hexyl-amino-3-(1‴,2‴,4‴) triazol-1‴-yl-propan-2-ol, which exhibits MIC values of 15.6 μg/mL and 7.8 μg/disc in microbroth dilution and disc diffusion assays, respectively. This compound is tolerated by mammalian erythrocytes and cell lines (A549 and U87) at concentrations of up to 1000 μg/mL. When incorporated into dextran nanoparticles, the novel, optically enriched fluconazole analog exhibited improved antifungal activity against Aspergillus fumigatus (MIC = 1.63 μg/mL). These results not only demonstrate the ability of biocatalytic approaches to yield novel, optically enriched fluconazole derivatives but also suggest that enantiomerically pure fluconazole derivatives, and their nanotised counterparts, exhibiting anti-Aspergillus activity may have reduced toxicity
Comparative study of Optimization methods for Unconstrained Multivariable Nonlinear Programming Problems
Abstract- In this paper we propose to discuss unconstrained multivariable search methods that are used for optimization of nonlinear programming problems. Earlier Dr.William P.Fox and Dr.William H.Richardson [1] have attempted to solve such problems by using MAPPLE. But we have preferred to solve these problems by OR methods as our present area of research is OR. Although several OR methods are known but we have confined our discussions to Gradient search method, Newton’s method and Quasi- Newton methods. We propose to conclude the discussion by taking a suitable example. Key Words- Multivariable,Optimization, Quasi-Newton methods, steepest ascent/descen
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Typicality Gradients in Computer Vision Models
Rosch (1975) proposed that some exemplars are more typical of a category than others. Typicality gradients have historically been estimated from data collected from human participants. Here, we investigated whether they can be estimated from a computer vision model, VGG19, guided by cognitive science models of concepts and categorization. Following prototype models, we estimated the similarity of each exemplar to the concept prototype computed in two ways (average across all exemplars, most typical exemplar). Following exemplar models, we computed the pairwise similarities between pairs of exemplars and used MDS to order them on a continuum. The prototype-average model achieved the highest rank-order correlation to human typicality ratings of exemplars of the bird category. Thus, computer vision models may have some promise for generating human-like typicality gradients. We are extending this work to utilize newer computer vision models such as ResNet, and to encompass a broader range of categories
The molecular mechanism of vernalization in Arabidopsis and cereals: role of Flowering Locus C and its homologs
Winter varieties of plants can flower only after exposure to prolonged cold. This phenomenon is known as vernalization and has been widely studied in the model plant Arabidopsis thaliana as well as in monocots. Through the repression of floral activator genes, vernalization prevents flowering in winter. In Arabidopsis, FLOWERING LOCUS C or FLC is the key repressor during vernalization, while in monocots vernalization is regulated through VRN1, VRN2 and VRN3 (or FLOWERING LOCUS T). Interestingly, VRN genes are not homologous to FLC but FLC homologs are found to have a significant role in vernalization response in cereals. The presence of FLC homologs in monocots opens new dimensions to understand, compare and retrace the evolution of vernalization pathways between monocots and dicots. In this review, we discuss the molecular mechanism of vernalization-induced flowering along with epigenetic regulations in Arabidopsis and temperate cereals. A better understanding of cold-induced flowering will be helpful in crop breeding strategies to modify the vernalization requirement of economically important temperate cereals.status: publishe
Using a symptom observation chart for dying patients: review of a service improvement tool
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