1,387 research outputs found
Role of ambient air on photoluminescence and electrical conductivity of assembly of ZnO Nanoparticles
Effect of ambient gases on photoluminescence (PL) and electrical conductivity
of films prepared using ZnO nanoparticles (NPs) have been investigated. It is
observed that NPs of size below 20 nm kept inside a chamber exhibit complete
reduction in their visible PL when oxygen partial pressure of the surrounding
gases is decreased by evacuation. However the visible PL from ZnO NPs is
insensitive to other major gases present in the ambient air. The rate of change
of PL intensity with pressure is inversely proportional to the ambient air
pressure and increases when particle size decreases due to the enhanced surface
to volume ratio. On the other hand an assembly of ZnO NPs behaves as a complete
insulator in the presence of dry air and its major components like N2, O2 and
CO2. Electrical conduction having resistivity ~102 - 103 {\Omega}m is observed
in the presence of humid air. The depletion layer formed at the NP surface
after acquiring donor electrons of ZnO by the adsorbed oxygen, has been found
to control the visible PL and increases the contact potential barrier between
the NPs which in turn enhances the resistance of the film.Comment: arXiv admin note: significant text overlap with arXiv:1008.249
Admission and Discharge Practices Among Assisted Living Communities: the Role of State Regulations and Organizational Characteristics
A better understanding of factors associated with assisted living admission and discharge practices can help identify communities that are more likely to allow residents to age in place. This study examined how state regulations and assisted living organizational characteristics relate to community admission and discharge practices for bathing, getting out of bed, and feeding
Dupilumab shows long-term safety and efficacy in patients with moderate to severe atopic dermatitis enrolled in a phase 3 open-label extension study
BACKGROUND: Significant unmet need exists for long-term treatment of moderate to severe atopic dermatitis (AD). OBJECTIVE: To assess the long-term safety and efficacy of dupilumab in patients with AD. METHODS: This ongoing, multicenter, open-label extension study (NCT01949311) evaluated long-term dupilumab treatment in adults who had previously participated in phase 1 through 3 clinical trials of dupilumab for AD. This analysis examined patients given 300 mg dupilumab weekly for up to 76 weeks at data cutoff (April 2016). Safety was the primary outcome; efficacy was also evaluated. RESULTS: Of 1491 enrolled patients (1042.9 patient-years), 92.9% were receiving treatment at cutoff. The safety profile was consistent with previously reported trials (420.4 adverse events/100 patient-years and 8.5 serious adverse events/100 patient-years), with no new safety signals; common adverse events included nasopharyngitis, conjunctivitis, and injection-site reactions. Sustained improvement was seen up to 76 weeks in all efficacy outcomes, including measures of skin inflammation, pruritus, and quality of life. LIMITATIONS: Lack of control arm, limited number of patients with 76 weeks or longer of treatment (median follow-up, 24 weeks), and patients not receiving the approved dose regimen of 300 mg every 2 weeks. CONCLUSION: The safety and efficacy profile from this study supports the role of dupilumab as continuous long-term treatment for patients with moderate to severe AD
Long term extension of a randomised controlled trial of probiotics using electronic health records
Most randomised controlled trials (RCTs) are relatively short term and, due to costs and available resources, have limited opportunity to be re-visited or extended. There is no guarantee that effects of treatments remain unchanged beyond the study. Here, we illustrate the feasibility, benefits and cost-effectiveness of enriching standard trial design with electronic follow up. We completed a 5-year electronic follow up of a RCT investigating the impact of probiotics on asthma and eczema in children born 2005-2007, with traditional fieldwork follow up to two years. Participants and trial outcomes were identified and analysed after five years using secure, routine, anonymised, person-based electronic health service databanks. At two years, we identified 93% of participants and compared fieldwork with electronic health records, highlighting areas of agreement and disagreement. Retention of children from lower socio-economic groups was improved, reducing volunteer bias. At 5 years we identified a reduced 82% of participants. These data allowed the trial's first robust analysis of asthma endpoints. We found no indication that probiotic supplementation to pregnant mothers and infants protected against asthma or eczema at 5 years. Continued longer-term follow up is technically straightforward
Molecular Epidemiology of HIV-1 Subtypes in India: Origin and Evolutionary History of the Predominant Subtype C
This thesis describes the translational genomics of HIV-1subtype C in India from its origin to therapeutic response with the aim to improve our knowledge for better therapeutic and preventive strategies to combat HIV/AIDS. In a systemic approach, we identified the molecular phylogeny of HIV-1 subtypes circulating in India and the time to most recent common ancestors (tMRCA) of predominant HIV-1 subtype C strains. Additionally, this thesis also studied drug resistance mutations in children, adolescents and adults, the role of host factors in evolution of drug resistance, and population dynamics of viremia and viral co-receptor tropism in perinatal transmission. Finally, the long term therapeutic responses on Indian national first-line antiretroviral therapy were also studied.
In Paper I, we reported an increase in the HIV-1 recombinant forms in the HIV-1 epidemiology using a robust subtyping methodology. While the study confirmed HIV- 1 subtype C as a dominant subtype, its origin was dated back to the early 1970s from a single or few genetically related strains from South Africa, whereafter, it has evolved independently. In Paper II, the lethal hypermutations due to the activity of human apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (hA3G) was significantly associated with antiretroviral therapy (ART) failure in Indian HIV-1 subtype C patients. The presence of M184I and M230I mutations were observed due to the editing of hA3G in the proviral compartment but stop codons were also found in the open reading frames and the same drug resistance mutations were absent in plasma virus. Therefore, it is unlikely that the viral variants which exhibit hypermutated sequences and M184I and/or M230I will mature and expand in vivo and hence are unlikely to have any clinical significance. The high concordance of drug resistance genotyping in the plasma and proviral compartments in therapy-naïve patients, gives weight to the idea of using whole blood for surveillance of drug resistance mutations which precludes logistic challenges of cold chain transport.
In Papers III and IV, we identified a substantial proportion of HIV-1 subtype C perinatally-infected older children who had a high burden of plasma viremia but also had high CD4+ T-cell counts. In addition, older children with HIV-1 subtype C infection presented a high prevalence of predicted X4 and R5/X4 tropic strains which indicates that HIV-1 subtype C strains required longer duration of infection and greater disease progression to co-receptor transition from R5- to X4-tropic strains (IV). Our studies also indicate that transmitted drug resistance is low among Indian HIV-1 infected children, adolescents (III) and adults (II).
In Paper V, in a longitudinal cohort study, a good long-term response to the Indian national first-line therapy for a median of nearly four years with 2.8% viral failure, indicating the overall success of the Indian ART program. Our study also showed that three immunologically well patients with virological rebound and major viral drug resistance mutations (M184V, K103N and Y181C) during one study visit had undetectable viral load at their next visit. These findings suggest that use of multiple parameters like patients’ immunological (CD4+ T-cell count), virological (viral load) and drug resistance data should all be used to optimize the treatment switch to second line therapy.
In conclusion, this translational genomics study enhances our knowledge about the HIV-1 subtype C strains circulating in India which are genetically distinct from prototype African subtype C strains. Considerably more research using appropriate models need to be performed to understand the phenotypic and biological characteristics of these strains to guide efficient disease intervention and management strategies
Use of Saliva for Early Dengue Diagnosis
The importance of laboratory diagnosis of dengue cannot be undermined. In recent years, many dengue diagnostic tools have become available for various stages of the disease, but the one limitation is that they require blood as a specimen for testing. In many incidences, phlebotomy in needle-phobic febrile individuals, especially children, can be challenging, and the tendency to forgo a dengue blood test is high. To circumvent this, we decided to work toward a saliva-based assay (antigen-capture anti-DENV IgA ELISA, ACA-ELISA) that has the necessary sensitivity and specificity to detect dengue early. Overall sensitivity of the ACA-ELISA, when tested on saliva collected from dengue-confirmed patients (EDEN study) at three time points, was 70% in the first 3 days after fever onset and 93% between 4 to 8 days after fever onset. In patients with secondary dengue infections, salivary IgA was detected on the first day of fever onset in all the dengue confirmed patients. This demonstrates the utility of saliva in the ACA-ELISA for early dengue diagnostics. This technique is easy to perform, cost effective, and is especially useful in dengue endemic countries
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Dupilumab in adolescents with uncontrolled moderate‐to‐severe atopic dermatitis : results from a phase IIa open‐label trial and subsequent phase III open‐label extension
Background
Dupilumab (monoclonal antibody inhibiting IL‐4/IL‐13 signalling) is approved for use in adolescents aged ≥ 12 years with inadequately controlled moderate‐to‐severe atopic dermatitis (AD). Dupilumab significantly improved AD signs/symptoms in a 16‐week, randomised, placebo‐controlled phase III trial in adolescents (NCT03054428).
Objectives
To characterize the pharmacokinetics of dupilumab, and long‐term safety and efficacy in adolescents.
Methods
This was a global, multicentre, phase IIa, open‐label, ascending‐dose, sequential cohort study with a phase III open‐label extension (OLE) in adolescents with moderate‐to‐severe AD. In the phase IIa study, patients received one dupilumab dose (2 mg kg−1 or 4 mg kg−1) and 8 weeks of pharmacokinetic sampling. Thereafter, patients received the same dose weekly for 4 weeks, with 8‐week safety follow‐up. Patients then enrolled in the OLE, continuing 2 mg kg−1 or 4 mg kg−1 dupilumab weekly. Primary end points were dupilumab concentration–time profile and incidence of treatment‐emergent adverse events (TEAEs). Secondary outcomes included Eczema Area and Severity Index (EASI).
Results
Forty adolescents received dupilumab in the phase IIa study; 36 enrolled in the OLE. Dupilumab showed nonlinear, target‐mediated pharmacokinetics. Mean ± SD trough dupilumab concentrations in serum at week 48 (OLE) were 74 ± 19 mg L−1 and 161 ± 60 mg L−1 for 2 mg kg−1 and 4 mg kg−1, respectively. Dupilumab was well tolerated over 52 weeks; the most common TEAEs were nasopharyngitis (week 52: 41% [2 mg kg−1], 47% [4 mg kg−1]) and AD exacerbation (29%, 42%). After one dupilumab dose in the phase IIa study, EASI improved from baseline to week 2 [mean ± SD reduction −34% ± 20% (2 mg kg−1) and −51% ± 29% (4 mg kg−1)]. With continuing treatment, EASI scores improved further [week 52: −85% ± 12% (2 mg kg−1) and −84% ± 20% (4 mg kg−1)].
Conclusions
In adolescents with moderate‐to‐severe AD, dupilumab's pharmacokinetic profile was similar to that in adults. These 52‐week safety and efficacy data support long‐term use of dupilumab in this patient population
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