45 research outputs found

    Analysing Mobile Random Early Detection for Congestion Control in Mobile Ad-hoc Network

    Get PDF
    This research paper suggests and analyse a technique for congestion control in mobile ad hoc networks. The technique is based on a new hybrid approach that uses clustering and queuing techniques. In clustering, in general cluster head transfers the data, following a queuing method based on a RED (Random Early Detection), the mobile environment makes it Mobile RED (or MRED), It majorly depends upon mobility of nodes and mobile environments leads to unpredictable queue size. To simulate this technique, the Network Simulator 2 (or NS2) is used for various scenarios. The simulated results are compared with NRED (Neighbourhood Random Early Detection) queuing technique of congestion control. It has been observed that the results are improved using MRED comparatively

    Density Independent Algorithms for Sparsifying k-Step Random Walks

    Get PDF
    We give faster algorithms for producing sparse approximations of the transition matrices of k-step random walks on undirected and weighted graphs. These transition matrices also form graphs, and arise as intermediate objects in a variety of graph algorithms. Our improvements are based on a better understanding of processes that sample such walks, as well as tighter bounds on key weights underlying these sampling processes. On a graph with n vertices and m edges, our algorithm produces a graph with about nlog(n) edges that approximates the k-step random walk graph in about m + k^2 nlog^4(n) time. In order to obtain this runtime bound, we also revisit "density independent" algorithms for sparsifying graphs whose runtime overhead is expressed only in terms of the number of vertices

    Paradoxical effect of coating on natural guar gum blended carbomer matrix systems for the neurological depressive disorders

    Get PDF
    Oral extended release products offer potential advantages in patient compliance and therapeutic outcomes like sustained blood levels with attenuation of adverse effects. In neuropsychiatric disorders like depression, most of the formulations serve a marketing objective rather than a clinical objective. The present investigation was aimed to develop a once daily sustained release formulation for delivery of an acid-labile, water soluble antidepressant, duloxetine HCl. The formulation was pragmatically designed using blend of natural and synthetic polymeric biomaterials that it releases the drug at alkaline pH in a sustained manner. The basic intention was to develop a tablet formulation with hydrophilic matrix core, using blend of release retarding natural biodegradable polymers such as guar gum, carbopol 71G-NF (a synthetic carbomer) and C-Pharm® gel. Barrier coating using HPMC-E5 was given to retard the initial release followed by enteric coating with HPMC-AS to prevent exposure of drug in acidic mileau of the stomach. The formulation exhibited desired release pattern and was described best-fit by Hixon-Crowell model. Stability analysis under stress conditions up to one month displayed good reproducibility. The matrix tablets successfully decreased the symptoms of depression (significant decrease in immobility time) in a rat forced swimming model. Pharmacokinetic data of the formulation revealed (tmax ~ 6 h, Cmax ~ 1157.58 ng/ml, mean AUCt~11145.04 ng*h/ml, and Ka~1.07h-1) good correlation in all animals.Keywords: Matrix tablets; Duloxetine HCl; Sustained release; Enteric coating; Hixon-crowell mode

    Paradoxical effect of coating on natural guar gum blended carbomer matrix systems for the neurological depressive disorders

    Get PDF
    Oral extended release products offer potential advantages in patient compliance and therapeutic outcomes like sustained blood levels with attenuation of adverse effects. In neuropsychiatric disorders like depression, most of the formulations serve a marketing objective rather than a clinical objective. The present investigation was aimed to develop a once daily sustained release formulation for delivery of an acid-labile, water soluble antidepressant, duloxetine HCl. The formulation was pragmatically designed using blend of natural and synthetic polymeric biomaterials that it releases the drug at alkaline pH in a sustained manner. The basic intention was to develop a tablet formulation with hydrophilic matrix core, using blend of release retarding natural biodegradable polymers such as guar gum, carbopol 71G-NF (a synthetic carbomer) and C-Pharm® gel. Barrier coating using HPMC-E5 was given to retard the initial release followed by enteric coating with HPMC-AS to prevent exposure of drug in acidic mileau of the stomach. The formulation exhibited desired release pattern and was described best-fit by Hixon-Crowell model. Stability analysis under stress conditions up to one month displayed good reproducibility. The matrix tablets successfully decreased the symptoms of depression (significant decrease in immobility time) in a rat forced swimming model. Pharmacokinetic data of the formulation revealed (tmax ~ 6 h, Cmax ~ 1157.58 ng/ml, mean AUCt~11145.04 ng*h/ml, and Ka~1.07h-1) good correlation in all animals.Keywords: Matrix tablets; Duloxetine HCl; Sustained release; Enteric coating; Hixon-crowell mode

    Near-direct bandgap WSe2WSe_2/ReS2ReS_2 type-II pn heterojunction for enhanced ultrafast photodetection and high-performance photovoltaics

    Full text link
    PN heterojunctions comprising layered van der Waals (vdW) semiconductors have been used to demonstrate current rectifiers, photodetectors, and photovoltaic devices. However, a direct or near-direct bandgap at the heterointerface that can significantly enhance optical generation, for high light absorbing few/multi-layer vdW materials, has not yet been shown. In this work, for the first time, few-layer group-6 transition metal dichalcogenide (TMD) WSe2WSe_2 is shown to form a sizeable (0.7 eV) near-direct bandgap with type-II band alignment at its interface with the group-7 TMD ReS2ReS_2 through density functional theory calculations. Further, the type-II alignment and photogeneration across the interlayer bandgap have been experimentally confirmed through micro-photoluminescence and IR photodetection measurements, respectively. High optical absorption in few-layer flakes, large conduction and valence band offsets for efficient electron-hole separation and stacking of light facing, direct bandgap ReS2ReS_2 on top of gate tunable WSe2WSe_2 are shown to result in excellent and tunable photodetection as well as photovoltaic performance through flake thickness dependent optoelectronic measurements. Few-layer flakes demonstrate ultrafast response time (5 ÎĽ\mus) at high responsivity (3 A/W) and large photocurrent generation and responsivity enhancement at the heterostructure overlap region (10-100X) for 532 nm laser illumination. Large open-circuit voltage of 0.64 V and short-circuit current of 2.6 ÎĽ\muA enables high output electrical power. Finally, long term air-stability and a facile single contact metal fabrication process makes the multi-functional few-layer WSe2WSe_2/ReS2ReS_2 heterostructure diode technologically promising for next-generation optoelectronic applications.Comment: Manuscript- 27 pages, 8 figures. Supporting Information- 17 pages, 17 figure

    Knowledge, anxiety and the use of hydroxychloroquine prophylaxis among health care students and professionals regarding COVID-19 pandemic

    Get PDF
    Introduction:  Data regarding knowledge and attitude about COVID-19, the prevalence of acceptance of hydroxychloroquine prophylaxis and anxiety amidst COVID-19 pandemic among health care students/professionals in India is scarce.Material and methods: A cross-sectional study was conducted during May 2020, using an online survey via Google forms. A self-administered validated structured questionnaire was applied, which comprised 28 questions among health care students/professionals at a tertiary care centrein North India.Results: A total of 956 respondents were included (10.2% nurses, 45.2% medical students, 24.3% paramedical students, 11.7% resident doctors and 8.6% consultant doctors). Overall knowledge score was 9.3/15; the highest for preventive practices (4/5), followed by clinical knowledge (2.7/5) and the use of personal protective equipment (PPE) (2.6/5). The overall score was the highest in consultant doctors (10.8) while the lowest in nurses (8.5) and paramedical students (8.4) (p < 0.001). Less than half of the respondents had knowledge about the correct sequence of doffing PPE and the use of N95 mask. About 21.8% of the participants experienced moderate to severe anxiety; higher among nurses (38%), followed by paramedical students (29.3%); and anxiety was higher when knowledge score was low (27.6% vs 14.7%); both factors were independent predictors on multivariate analysis (p < 0.001). Only 18.1% of the respondents applied HCQ prophylaxis — the highest proportion constituted consultants (42.7%), and the least — paramedical students (5.2%); (p < 0.001) and HCQ use was more frequently used if they had a family member of extreme age group at home (23.3% vs 12.2%; p < 0.001). Conclusions: The knowledge about correct PPE usage is low among all groups of HCWs and students, and there is a high prevalence of anxiety due to COVID-19. The lower COVID-19 knowledge scores were significantly associated with a higher likelihood of anxiety and inadequate use of HCQ prophylaxis. The appliance of HCQ prophylaxis had no significant association with anxiety levels of the respondents

    Bronchiectasis in India:results from the European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC) and Respiratory Research Network of India Registry

    Get PDF
    BACKGROUND: Bronchiectasis is a common but neglected chronic lung disease. Most epidemiological data are limited to cohorts from Europe and the USA, with few data from low-income and middle-income countries. We therefore aimed to describe the characteristics, severity of disease, microbiology, and treatment of patients with bronchiectasis in India. METHODS: The Indian bronchiectasis registry is a multicentre, prospective, observational cohort study. Adult patients ( 6518 years) with CT-confirmed bronchiectasis were enrolled from 31 centres across India. Patients with bronchiectasis due to cystic fibrosis or traction bronchiectasis associated with another respiratory disorder were excluded. Data were collected at baseline (recruitment) with follow-up visits taking place once per year. Comprehensive clinical data were collected through the European Multicentre Bronchiectasis Audit and Research Collaboration registry platform. Underlying aetiology of bronchiectasis, as well as treatment and risk factors for bronchiectasis were analysed in the Indian bronchiectasis registry. Comparisons of demographics were made with published European and US registries, and quality of care was benchmarked against the 2017 European Respiratory Society guidelines. FINDINGS: From June 1, 2015, to Sept 1, 2017, 2195 patients were enrolled. Marked differences were observed between India, Europe, and the USA. Patients in India were younger (median age 56 years [IQR 41-66] vs the European and US registries; p<0\ub70001]) and more likely to be men (1249 [56\ub79%] of 2195). Previous tuberculosis (780 [35\ub75%] of 2195) was the most frequent underlying cause of bronchiectasis and Pseudomonas aeruginosa was the most common organism in sputum culture (301 [13\ub77%]) in India. Risk factors for exacerbations included being of the male sex (adjusted incidence rate ratio 1\ub717, 95% CI 1\ub703-1\ub732; p=0\ub7015), P aeruginosa infection (1\ub729, 1\ub710-1\ub750; p=0\ub7001), a history of pulmonary tuberculosis (1\ub720, 1\ub707-1\ub734; p=0\ub7002), modified Medical Research Council Dyspnoea score (1\ub732, 1\ub725-1\ub739; p<0\ub70001), daily sputum production (1\ub716, 1\ub703-1\ub730; p=0\ub7013), and radiological severity of disease (1\ub703, 1\ub701-1\ub704; p<0\ub70001). Low adherence to guideline-recommended care was observed; only 388 patients were tested for allergic bronchopulmonary aspergillosis and 82 patients had been tested for immunoglobulins. INTERPRETATION: Patients with bronchiectasis in India have more severe disease and have distinct characteristics from those reported in other countries. This study provides a benchmark to improve quality of care for patients with bronchiectasis in India. FUNDING: EU/European Federation of Pharmaceutical Industries and Associations Innovative Medicines Initiative inhaled Antibiotics in Bronchiectasis and Cystic Fibrosis Consortium, European Respiratory Society, and the British Lung Foundation

    Acute hemorrhagic edema of infancy-a rare entity

    No full text
    A patient presenting with fever and purpura often presents a diagnostic challenge for the dermatologist. Acute hemorrhagic edema of infancy (AHEI) is a rare acute cutaneous leukocytoclastic vasculitic syndrome of infants leading to this presentation. We present an 18-month-old girl with AHEI who presented with fever, edema, and purpuric lesions involving the face, ears and extremities with uneventful complete recovery

    Early antiretroviral therapy: The pendulum shifts again

    No full text
    corecore