•Single crystals of SrC4H4O6·5H2O and CuSrC4H4O6·5H2O are grown by gel method.•Grown crystals are characterized using various standard techniques.•Studies unveil interesting and useful structural ...features of the crystals.•Results show the usefulness of crystals both as thermal isolators and NLO devices.
Single crystals of intrinsic strontium L(+) tartrate (IST) and Cu2+ doped strontium L(+) tartrate (CuDST) are synthesized using single test tube gel diffusion technique. At ambient temperature, specific gravities of 1.050 and 1.055 and gel pH of 4.0 and 4.2 (with 0.5 M inner and upper reactants) are found to ensure optimized growth and quality of IST and CuDST crystals, respectively. These crystals show maximum sizes of 4.2 × 1.7 × 1.3 mm3 (for IST) and 5.1 × 0.9 × 0.8 mm3 (CuDST). Doping is observed to change the morphology of IST crystal. The stoichiometric composition and cationic distribution of the grown crystals are determined using Energy Dispersive X-Ray Analysis (EDAX) technique. The functional groups present in the crystals are identified by Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectral studies. Thermal studies confirm the presence of five water molecules in the IST and CuDST crystals.
Optical studies reveal that the crystals are transparent to visible and near Infrared (IR) wavelengths. Doping is observed to cause an increase in the peak absorbance in Ultraviolet (UV) region. Both IST and CuDST crystals show low absorbance in the entire visible region, indicating their usefulness in Nonlinear Optical (NLO) applications. The optical transmittance of the IST crystal is seen to increase on doping. Both IST and CuDST crystals show bandgap energies suggestive of their insulating nature, indicating their usefulness in electronic applications. The Voltage-Current (V-I) characteristics of the crystals show that the electrical conductivity of CuDST crystals is larger than the conductivity of IST crystals.
Paucity of epidemiological data on tuberculosis in India prompted the National Tuberculosis Institute, Bangalore to embark upon a nation-wide survey to estimate the Annual Risk of Tuberculosis ...Infection in different parts of the country. The survey in Junagadh district, one of the 26 districts drafted under the nation-wide survey is reported here. The prevalence of infection from the analysis of 3164 children not displaying scars of the BCG vaccination was 4.16% (CI: 3.17-5.14) and from this data the ARI was computed as 0.73% (CI: 0.55-0.91). The inclusion of vaccinated children into the study group yielded similar results. The estimate of the ARI in Junagadh district is lesser than that in several other parts of India which is probably in consonance with its better socio-economic development.
Existing buildings are retrofitted to formulate them to be more resistant to seismic activity, earth motion, and other natural disasters. Many available reinforced concrete buildings across the globe ...are in desperate need of rehabilitation, repair, or replacement owing to degradation caused by a variety of reasons such as corrosion, lack of detailing, and failure of beam-column bonding, among others. In the construction sector, fibre reinforced polymer (FRP) composites have been recognized as a potential option for repairing and increasing the strength of existing structures. In this study, comparisons are done in terms of load bearing capability of the beams for configurations between FE model predictions and field data (experimental). To assess the FRP retrofit, structural responses for strengthened and control post tensioned concrete (PTC) beams are compared, with strengthening using various wrapping methods. The load bearing capacities of the beams retrofitted with sisal and jute fibre employing strip and full wrapping procedures around all four sides is increased by 35.55 percent and 42.85 percent for sisal FRP and 7.14 percent and 12.01 percent for jute FRP, respectively, as compared to the control specimen. The FRP retrofit model is expected to result in a considerable increase in structural performance.
Aluminium, an environmentally abundant non-redox trivalent cation has long been implicated in the pathogenesis of Alzheimer's disease (AD). However, the definite mechanism of aluminium toxicity in AD ...is not known. Evidence suggests that trace metal homeostasis plays a crucial role in the normal functioning of the brain, and any disturbance in it can exacerbate events associated with AD. The present paper reviews the scientific literature linking aluminium with AD. The focus is on aluminium levels in brain, region-specific and subcellular distribution, its relation to neurofibrillary tangles, amyloid beta, and other metals. A detailed mechanism of the role of aluminium in oxidative stress and cell death is highlighted. The importance of complex speciation chemistry of aluminium in relation to biology has been emphasized. The debatable role of aluminium in AD and the cross-talk between aluminium and genetic susceptibility are also discussed. Finally, it is concluded based on extensive literature that the neurotoxic effects of aluminium are beyond any doubt, and aluminium as a factor in AD cannot be discarded. However, whether aluminium is a sole factor in AD and whether it is a factor in all AD cases still needs to be understood.
A family of compounds, A3BC3D2O14 (A = Ba, Pb; B = Te, Sb; C = Al, Ga, Fe, Zn; D = Si, Ge, P, V), with the Dugganite structure was prepared employing traditional solid-state chemistry methods. PXRD ...and Rietveld refinement studies indicate that the compounds are stabilized in P321 space group (no. 150). The compounds are found to be SHG active with values ranging from 1.9 to 15.0 × KDP. The compounds exhibit high dielectric constants and low loss in our studies. The noncentrosymmetry related properties of the new Dugganites were understood by band structure calculations. We also explored the present Dugganite-structured oxides for the development of new inorganic colored materials by substituting Co2+, Ni2+, Cu2+, and Fe3+ in place of Zn2+. Thus, substitution of Co2+ and Fe3+ together tunes the blue color of the cobalt compound to blue-green color arising from metal-to-metal charge transfer (MMCT) of Fe3+ and Co2+ ions. The tetrahedrally coordinated Ni2+ in the Dugganite imparts a magenta color.
Existing structures require repair and strengthening owing to degradation caused by incorrect design and construction, environmental impacts, or structural upgradation to meet new seismic design ...standards or to correct execution problems that occurred during construction. These strengthening requirements can be satisfied by a variety of strengthening techniques. The creation of a fibre-reinforced polymer (FRP) composite system offers a new design method for the strengthening of existing structures. In this study, posttensioned beams are strengthened by using sustainable materials such as natural jute fibre-reinforced polymer (FRP) composites. The performance of these composite systems in the flexural strengthening of posttensioned beams was used to assess their effectiveness. Consequential result for longitudinal reinforcement throughout the length of the beam for flexural strengthening was evaluated. Flexural performance, crack width, ductility, and load-deflection relationship study of control beams (Scheme A) and retrofitted beams (Schemes B and C) under different wrappings were considered in the investigation. An experimental study depicts that using the full wrapping (FW) technique increases the flexural strength of PSC beams wrapped in JFRP by 23% and, by using the strip wrapping (SW) technique, the flexural strength is increased by 10%. The JFRP composite system of strengthening has shown the highest deformability index and showed that the JFRP material has enormous potential as a structural strengthening material.
Invasive aspergillosis (IA) is associated with poor outcomes in patients with hematologic malignancies (HMs) and hematopoietic cell transplantation (HCT). Small studies suggest a role for combination ...antifungal therapy.
To assess the safety and efficacy of voriconazole and anidulafungin compared with voriconazole monotherapy for treatment of IA.
Randomized, double-blind, placebo-controlled multicenter trial. (ClinicalTrials.gov: NCT00531479).
93 international sites.
454 patients with HM or HCT and suspected or documented IA were randomly assigned to treatment with voriconazole and anidulafungin or placebo. Primary analysis was done in the modified intention-to-treat population of 277 patients in whom IA was confirmed.
The primary outcome was 6-week mortality; secondary outcomes included 12-week mortality, mortality in major subgroups, and safety measures.
Mortality rates at 6 weeks were 19.3% (26 of 135) for combination therapy and 27.5% (39 of 142) for monotherapy (difference, -8.2 percentage points 95% CI, -19.0 to 1.5; P = 0.087). Secondary mortality outcomes favored combination therapy. Multivariable regression analysis suggested that maximum galactomannan value, Karnofsky score, and baseline platelet count had prognostic significance. Most patients (218 of 277 78.7%) had IA diagnosis established by radiographic findings and maximum galactomannan positivity. In a post hoc analysis of this dominant subgroup, 6-week mortality was lower in combination therapy than monotherapy (15.7% 17 of 108 vs. 27.3% 30 of 110; difference, -11.5 percentage points CI, -22.7 to -0.4; P = 0.037). Safety measures, including hepatotoxicity, were not different.
Mortality at 6 weeks was higher than expected, and the difference in mortality was lower than expected, which reduced power to detect a treatment effect. Enrollment was restricted to patients with HM or HCT, which limited generalizability.
Compared with voriconazole monotherapy, combination therapy with anidulafungin led to higher survival in subgroups of patients with IA. Limitations in power preclude definitive conclusions about superiority.
Pfizer.
Allergic rhinitis (AR) has shown an increasing prevalence leading to a considerable medical and social burden. Nasal congestion is the cardinal symptom of AR, and the upper respiratory tract is most ...affected by this long-lasting ailment. Intranasal corticosteroids alleviate nasal congestion, along with other symptoms of AR, but their effect is not evident immediately. Oxymetazoline has a rapid onset of action, but its use should be limited to 3-5 days.
The study aimed to evaluate the safety and effectiveness of the fixed-dose combination nasal spray containing fluticasone furoate and oxymetazoline hydrochloride (FF + OXY) 27.5/50 mcg once daily in patients with AR in a real-world clinical setting.
The study was a prospective, open-label, single-arm, multicenter, real-world observational study conducted in patients with AR for a period of 28 days. Patients (n = 388) with a diagnosis of AR were treated with a combination of FF + OXY nasal spray. Total nasal symptom score (TNSS), total ocular symptom score (TOSS) and total symptom score (TSS) were documented at baseline and at the end of study period. The overall effectiveness of treatment with FF + OXY was rated by the investigators as very good/good/satisfactory/poor (4-point Likert scale) for each patient.
Treatment with FF + OXY resulted in significant reduction in the TNSS, TOSS and TSS, from 7.18 ± 3.38 at baseline to 0.20 ± 0.84 (p < 0.001), from 2.34 ± 2.29 at baseline to 0.09 ± 0.53 (p < 0.001), from 9.51 ± 4.94 at baseline to 0.29 ± 1.32 (p < 0.001) at 28 days respectively. With respect to effectiveness, the investigators reported very good effectiveness in 52.12% of patients. No serious adverse events were reported.
The fixed-dose combination of once-daily fluticasone furoate and oxymetazoline hydrochloride nasal spray 27.5/50 mcg was effective in relieving the nasal congestion and reduction of TNSS, TOSS and TSS in patients suffering from AR. The combination was safe and well tolerated with no rebound congestion throughout the treatment period.
In the current work, the effect of weight percentage and orientation of multi-walled carbon nanotubes (MWCNTs) on the mechanical properties of unidirectional (UD) carbon fiber (CF)/MWCNT/epoxy ...composites was studied by using multiscale material modelling and finite element analysis (FEA). Nanoscale representative elementary volume (RVE) consisting of MWCNTs and microscale RVE consisting of carbon fibers were generated using DIGIMAT FE Software. The equivalent elastic properties obtained from MWCNT/epoxy composites were used to estimate effective elastic constants of UD carbon fiber/MWCNT/epoxy composites. The weight percentage of MWCNTs was varied 0%–5%, while MWCNTs were orientated at 0°, 30°, 45°, 60° and 90°. It was found that the E1, E2, G12, υ12 and υ23 increased by 1.79%, 6.14%, 2.83%, 8.8% and 5% at 5 wt% addition of MWCNTs respectively. It was also found that except transverse young's modulus (E2) all other elastic constants decreased by increasing the orientations and at 90° the transverse Young's modulus (E2) increased by 16.57% compared to 0° orientation at 1 wt% addition of MWCNTs. The multiscale FE analysis results were compared by multiscale micromechanics model.
Towards rational synthesis of inorganic solids Gopalakrishnan, Jagannatha; Bhuvanesh, Nattamai SP; Rangan, Krishnaswamy K
Current opinion in solid state & materials science,
04/1996, Letnik:
1, Številka:
2
Journal Article
Recenzirano
There have been major advances in the past couple of years in the rational synthesis of inorganic solids: synthesis of mercury-based superconducting cuprates showing transition temperatures up to 150 ...K; ZrP
2−xV
xO
7 solid solutions showing zero or negative thermal expansion; copper oxides possessing ladder structures such as La
1−xSr
xCuO
2.5; synthesis of mesoporous oxide materials having adjustable pore size in the range 15–100 Å; and synthesis of a molecular ferromagnet showing a critical temperature of 18.6 K. Despite great advances in probing the structures of solids and measurement of their physical properties, the design and synthesis of inorganic solids possessing desired structures and properties remain a challenge today. With the availability of a variety of mild chemistry-based approaches, kinetic control of synthetic pathways is becoming increasingly possible, which, it is hoped, will eventually make rational design of inorganic solids a reality.
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