356 research outputs found

    A Review and Comparative Study of Firefly Algorithm and its Modified Versions

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    Firefly algorithm is one of the well-known swarm-based algorithms which gained popularity within a short time and has different applications. It is easy to understand and implement. The existing studies show that it is prone to premature convergence and suggest the relaxation of having constant parameters. To boost the performance of the algorithm, different modifications are done by several researchers. In this chapter, we will review these modifications done on the standard firefly algorithm based on parameter modification, modified search strategy and change the solution space to make the search easy using different probability distributions. The modifications are done for continuous as well as non-continuous problems. Different studies including hybridization of firefly algorithm with other algorithms, extended firefly algorithm for multiobjective as well as multilevel optimization problems, for dynamic problems, constraint handling and convergence study will also be briefly reviewed. A simulation-based comparison will also be provided to analyse the performance of the standard as well as the modified versions of the algorithm

    Determination of Alpha-i Antitrypsin Genetic Deficiency in Duodenal Ulcer by Polymerase Chain Reaction

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    Objective: To confirm alpha-I-AT deficiency status in duodenal ulcer using a combination of PCR and restricted enzyme digestion. Methods: Fifty patients with endoscopically proven duodenal ulcer and hundred controls with no signs of the disease were included. Alpha-i-AT phenotypes were confirmed by polymerase chain reaction followed by restriction enzyme digestion. Results:Alpha-I-AT concentration in duodenal ulcer patients showed a mean value of 2.12 ± 0.11g/1 (range: 0.52-3.95 g/1, p Conclusion: Alpha-1 AT deficiency was found in 10% of duodenal ulcer patients. DNA analysis more accurately resolved the phenotypes as S and Z mutations (JPMA 52:545; 2002)

    HCV genotype-specific correlation with serum markers: Higher predictability for genotype 4a

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    Several factors have been proposed to assess the clinical outcome of HCV infection. The correlation of HCV genotypes to possible serum markers in clinical prediction is still controversial. The main objective of this study was to determine the existence of any correlation between HCV genotypes to viral load and different clinical serum markers.We performed a prospective cross-sectional and observational study. About 3160 serum HCV RNA positive patients were chosen from 4020 randomly selected anti-HCV positive patients. Statistical analysis was performed using the SPSS 16 software package. ROC (receiver operating characteristics) curves were used to compare diagnostic values of serum markers to predict genotypes.The most prevalent genotype was 3a (73.9%) followed by 1a (10.7%), 4a (6.4%) and 3b (6.1%) in Pakistani population. No correlation was found between viral load and serum markers for genotype 3a in a large no. of sample (n = 2336). While significant correlation was observed between viral load and AST in genotype 3b, ALP with viral load and ALT for genotype 1a. Patients with genotype 4a showed a significant inverse correlation with viral load and Hb level and AST with ALP. For genotype 4a, AUC (area under the curve) of ALT, ALP, AST, bilirubin, Hb level and viral load was 0.790, 0.763, 0.454, 0.664, 0.458 and 0.872 respectively.In conclusion, there was a significant variable response of HCV genotypes with serum markers. Severity of disease is independent of serum marker level in genotype 3a, while the liver damage in genotype 4a may associate with viral cytopathic effect as well as the immune-mediated process. An index using six serum markers may correctly predict genotype 4a in patients with ≥ 75% accuracy

    Comparative study of pattern recognition methods for predicting glaucoma diagnosis

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    © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2020. Glaucoma is the second leading cause of blindness globally; it is characterised by degeneration of the optic nerve with particular patterns of corresponding defects in the visual field. Aiding doctors in early diagnosis and detection of progression is crucial, as glaucoma is asymptomatic in nature. Furthermore there are good therapeutic results in early cases before irreversible visual loss occurs. Thus it is of great importance to find automated methods to discriminate glaucomatous diseases giving insight to doctors. In order to develop a Computer-Aided Diagnosis system (CAD), we realised an extensive competitive study of pattern recognition methods should be undertaken. A range of methods has been evaluated including the use of Deep Neural Networks (DNN), Support Vector Machines (SVM), Decision Trees (DT), and K-Nearest Neighbours (KNN) for diagnosing glaucoma. Using a range of classification techniques, this paper aims to diagnose glaucomatous diseases. Results have been produced with data comprising of Visual Field and OCT Disc readings from anonymous patients with and without glaucoma. Multiple systems are proposed that can predict diagnosis for ocular hypertension, primary open-angle glaucoma, normal tension glaucoma, and healthy patients with a reasonable confidence. Best performance has been obtained from voting classier comprised of SVM and KNN at 0.87 (AUC) and DNN at 0.87 (AUC) which possibly could be used as an automatic diagnosis aid in order to streamline the diagnosis of glaucoma for complex cases or flagging of urgent cases

    N,N-Dibenzyl-4-methyl­benzene­sulfonamide

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    The asymmetric unit of the title compound, C21H21NO2S, comprises two mol­ecules with similar conformations. The benzene rings of the nitro­gen-bound benzyl groups lie to the same side of the mol­ecule but are splayed in opposite directions precluding π–π inter­actions between them. In the crystal, each independent mol­ecule self-associates via inter­molecular C—H⋯O inter­actions, forming a supra­molecular chain propagating along the b axis

    Low Resistance Polycrystalline Diamond Thin Films Deposited by Hot Filament Chemical Vapour Deposition

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    Polycrystalline diamond thin films with outgrowing diamond (OGD) grains were deposited onto silicon wafers using a hydrocarbon gas (CH4) highly diluted with H2 at low pressure in a hot filament chemical vapour deposition (HFCVD) reactor with a range of gas flow rates. X-ray diffraction (XRD) and SEM showed polycrystalline diamond structure with a random orientation. Polycrystalline diamond films with various textures were grown and (111) facets were dominant with sharp grain boundaries. Outgrowth was observed in flowerish character at high gas flow rates. Isolated single crystals with little openings appeared at various stages at low gas flow rates. Thus, changing gas flow rates had a beneficial influence on the grain size, growth rate and electrical resistivity. CVD diamond films gave an excellent performance for medium film thickness with relatively low electrical resistivity and making them potentially useful in many industrial applications

    Claudin-1 required for HCV virus entry has high potential for phosphorylation and O-glycosylation

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    HCV is a leading cause of hepatocellular carcinoma and cirrhosis all over the world. Claudins belong to family of tight junction's proteins that are responsible for establishing barriers for controlling the flow of molecules around cells. For therapeutic strategies, regulation of viral entry into the host cells holds a lot of promise. During HCV infection claudin-1 is highly expressed in liver and believed to be associated with HCV virus entry after HCV binding with or without co-receptor CD81. The claudin-1 assembly with tight junctions is regulated by post translational modifications. During claudins assembly and disassembly with tight junctions, phosphorylation is required at C-terminal tail. In cellular proteins, interplay between phosphorylation and O-β-GlcNAc modification is believed to be functional switch, but it is very difficult to monitor these functional and vibrant changes in vivo. Netphos 2.0 and Disphos 1.3 programs were used for potential phosphorylation; NetPhosK 1.0 and KinasePhos for kinase prediction; and YinOYang 1.2 and OGPET to predict possible O-glycosylation sites. We also identified Yin Yang sites that may have potential for O-β-GlcNAc and phosphorylation interplay at same Ser/Thr residues. We for the first time proposed that alternate phosphorylation and O-β-GlcNAc modification on Ser 192, Ser 205, Ser 206; and Thr 191 may provide an on/off switch to regulate assembly of claudin-1 at tight junctions. In addition these phosphorylation sites may be targeted by novel chemotherapeutic agents to prevent phosphorylation lead by HCV viral entry complex

    Methyl 2-(4-acetamido­benzene­sulfon­amido)­benzoate

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    The mol­ecule of the title compound, C16H16N2O5S, has the shape of the letter V but with a small twist; the dihedral angle formed between the benzene rings is 79.66 (9)°. The presence of an intra­molecular N—H⋯O hydrogen bond, leading to an S(6) ring, correlates with the near coplanarity of the carboxyl­ate ester group with the benzene ring to which it is connected. The acetamide residue is slightly twisted out of the plane of its benzene ring [C—C—N—C = 13.1 (3)°]. In the crystal, supra­molecular chains along the a axis are mediated by N—H⋯O hydrogen bonds. These are connected into layers via C—H⋯O inter­actions

    A brief review on molecular, genetic and imaging techniques for HCV fibrosis evaluation

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    <p>Abstract</p> <p>Background</p> <p>Chronic HCV is one of the major causes of morbidity and mortality in the present day world. The assessment of disease progression not only provides useful information for diagnosis and therapeutic supervision judgment but also for monitoring disease. Different invasive and non invasive methods are applied to diagnose the disease from initial to end stage (mild fibrosis to cirrhosis). Although, liver biopsy is still considered as gold standard to identify liver histological stages, an assessment of the disease development based on non-invasive clinical findings is also emerging and this may replace the need of biopsy in near future. This review gives brief insight on non-invasive methods currently available for predicting liver fibrosis in HCV with their current pros and cons to make easier for a clinician to choose better marker to assess liver fibrosis in HCV infected patients.</p> <p>Methods</p> <p>More than 200 studies regarding invasive and noninvasive markers available for HCV liver disease diagnosis were thoroughly reviewed. We examined year wise results of these markers based on their sensitivity, specificity, PPV, NPV and AUROCs.</p> <p>Results</p> <p>We found that in all non-invasive serum markers for HCV, FibroTest, Forn's Index, Fibrometer and HepaScore have high five-year predictive value but with low AUROCs (0.60~0.85) and are not comparable to liver biopsy (AUROC = 0.97). Even though from its beginning, Fibroscan is proved to be best with high AUROCs (> 0.90) in all studies, no single noninvasive marker is able to differentiate all fibrosis stages from end stage cirrhosis. Meanwhile, specific genetic markers may not only discriminate fibrotic and cirrhotic liver but also differentiate individual fibrosis stages.</p> <p>Conclusions</p> <p>There is a need of marker which accurately determines the stage based on simplest routine laboratory test. Genetic marker in combination of imaging technique may be the better non invasive diagnostic method in future.</p

    NS4A protein as a marker of HCV history suggests that different HCV genotypes originally evolved from genotype 1b

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    <p>Abstract</p> <p>Background</p> <p>The 9.6 kb long RNA genome of Hepatitis C virus (HCV) is under the control of RNA dependent RNA polymerase, an error-prone enzyme, for its transcription and replication. A high rate of mutation has been found to be associated with RNA viruses like HCV. Based on genetic variability, HCV has been classified into 6 different major genotypes and 11 different subtypes. However this classification system does not provide significant information about the origin of the virus, primarily due to high mutation rate at nucleotide level. HCV genome codes for a single polyprotein of about 3011 amino acids which is processed into structural and non-structural proteins inside host cell by viral and cellular proteases.</p> <p>Results</p> <p>We have identified a conserved NS4A protein sequence for HCV genotype 3a reported from four different continents of the world i.e. Europe, America, Australia and Asia. We investigated 346 sequences and compared amino acid composition of NS4A protein of different HCV genotypes through Multiple Sequence Alignment and observed amino acid substitutions C<sub>22</sub>, V<sub>29</sub>, V<sub>30</sub>, V<sub>38</sub>, Q<sub>46 </sub>and Q<sub>47 </sub>in NS4A protein of genotype 1b. Furthermore, we observed C<sub>22 </sub>and V<sub>30 </sub>as more consistent members of NS4A protein of genotype 1a. Similarly Q<sub>46 </sub>and Q<sub>47 </sub>in genotype 5, V<sub>29</sub>, V<sub>30</sub>, Q<sub>46 </sub>and Q<sub>47 </sub>in genotype 4, C<sub>22</sub>, Q<sub>46 </sub>and Q<sub>47 </sub>in genotype 6, C<sub>22</sub>, V<sub>38</sub>, Q<sub>46 </sub>and Q<sub>47 </sub>in genotype 3 and C<sub>22 </sub>in genotype 2 as more consistent members of NS4A protein of these genotypes. So the different amino acids that were introduced as substitutions in NS4A protein of genotype 1 subtype 1b have been retained as consistent members of the NS4A protein of other known genotypes.</p> <p>Conclusion</p> <p>These observations indicate that NS4A protein of different HCV genotypes originally evolved from NS4A protein of genotype 1 subtype 1b, which in turn indicate that HCV genotype 1 subtype 1b established itself earlier in human population and all other known genotypes evolved later as a result of mutations in HCV genotype 1b. These results were further confirmed through phylogenetic analysis by constructing phylogenetic tree using NS4A protein as a phylogenetic marker.</p
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