To evaluate the cryoinjury prediction of spermatozoa in relation to its cholesterol content at fresh and frozen-thaw stages.
Ejaculates (n=12) were processed for cryopreservation, acrosome integrity ...(fluorescent and giemsa stains), cryoinjury (distribution of non capacitated, capacitated and acrosome reacted, pattern F, B and AR, respectively of Chlortetracycline, CTC assay), in vitro fertiltiy (IVF) and cholesterol content of spermatozoa at fresh, pre-freeze and frozen-thaw stages were evaluated. Values were fitted in prediction equation to predict acrosome integrity (AI) and cryoinjury.
Study indicated that cholesterol content of fresh spermatozoa can be used to predict cholesterol content of spermatozoa at pre-freeze and frozen-thaw stages of cryopreservation protocol with medium to high level of accuracy (P<0.05 and P<0.01, respectively). Cholesterol content of fresh spermatozoa can be used to predict AI, pattern B and AR and Penetration Index (PI) of IVF with medium level of accuracy (P<0.05) at frozen-thaw but not at pre-freeze stage. Similarly cholesterol content of frozen-thaw spermatozoa can be used to predict AI and pattern AR of frozen-thaw spermatozoa with medium level of accuracy (P<0.05).
This study revealed strong evidence that cholesterol content of fresh as well as frozen-thaw bull spermatozoa can be a good predictor of level of cryoinjury following preservation at ultra low temperature.
Clopidogrel-induced fixed drug eruption Ghosh, SK; Bandyopadhyay, D
Journal of the European Academy of Dermatology and Venereology,
October 2009, Letnik:
23, Številka:
10
Journal Article
Background Symmetrical peripheral gangrene (SPG) is characterized by sudden onset of peripheral, frequently symmetrical gangrene in the absence of major vascular occlusive disease. SPG is associated ...with a wide range of underlying medical problems and usually has disseminated intravascular coagulation (DIC) in the background. Although sporadic cases and a few retrospective case series of SPG have been reported, lack of any prospective study on the profile and outcome of these patients prompted us to undertake the present work.
Objectives To study the clinical profile, aetiological factors, and outcome of a group of patients of SPG from eastern India.
Patients/methods Prospective, observational study of consecutive patients presented at or referred to the Dermatology Department of a tertiary‐care hospital during 2001 to 2008.
Results We observed 14 patients (5 males, 9 females; mean age: 43.36 years) of SPG during the study period. All had clinical and laboratory evidence of DIC in association with a shock syndrome. Associated purpura fulminans was noted in 11 patients. In 12 patients, the cause of SPG was infective, Pneumococcus being the commonest organism involved. Two patients developed DIC and SPG postoperatively. Nine patients survived and the remaining five patients died. Three patients had leukopenia and all of them died. Amongst the survivors, four patients had auto‐amputation of some parts of distal limbs; surgical amputation was done in two patients.
Conclusions SPG carries a high mortality rate frequently requiring multiple limb amputations in survivors. Leukopenia may be a poor prognostic factor of SPG and DIC may occur universally.
To describe India's National Antimalarial Drug Resistance Monitoring System, measure the efficacy of first-line malaria treatments, and determine risk factors for treatment failure.
In 2009-2010, ...prospective studies with 28 days of follow-up were conducted at 25 sentinel sites. Patients infected with Plasmodium falciparum were given artesunate plus sulfadoxine-pyrimethamine (AS+SP); those infected with P. vivax were given chloroquine. Polymerase chain reaction was used to distinguish post-treatment reinfection from treatment failure. Isolates of P. falciparum were checked for dhfr and dhps mutations.
Overall, 1664 patients were enrolled. Kaplan-Meier survival analysis showed an efficacy of 98.8% for AS+SP. Most patients with P. falciparum parasitaemia cleared their parasitaemias within 24 hours of treatment initiation, but six, including four with treatment failure, remained parasitaemic after 72 hours. Double mutants in dhfr were found in 68.4% of the genotyped isolates. Triple or quadruple mutants in dhfr and mutations in dhps were rare. A daily dose of artesunate of < 3 mg per kg of body weight, age of less than 5 years, and fever at enrolment were associated with an increased risk of treatment failure. Chloroquine remained 100% efficacious and generally cleared P. vivax parasitaemias within 48 hours. Vomiting (seen in 47 patients) was the most common adverse event.
India's National Antimalarial Drug Resistance Monitoring System provides wide coverage. The first-line antimalarials used in the country remain safe and efficacious. The treatment of malaria in young children and the relative benefits of age- and weight-based dosing need further exploration.
The present study aims to examine the deformation and annealing behaviour of Fe–0.07C–20Mn–2.6Si–1.6Al TWIP steel in the viewpoint of microstructural characterisation, fault analysis, triaxial ...residual stress measurement and mechanism of twin formation. 50% cold deformation results in improvement of hardness and tensile strength (428 HV and 1419 MPa, respectively), whereas annealing at 900 °C of the same leads to improvement in ductility (61%) with the decrease in strength (873 MPa). The residual stress is maximum and compressive in nature in deformed sample which has been diminishing after annealing. Hot rolled and hot rolled-solution treated samples develop dual phase microstructure along with annealing twins, whereas fine nano twins and high dislocation density with dual phase microstructure are apparent after 50% cold deformation. The presence of Shockley partial dislocation, overlapping of stacking faults, Lomer-Cottrell lock, intrinsic and extrinsic stacking faults affect the mechanical properties as obstacles of dislocation movements or assisting twin formation. Goss and Brass components of texture are dominating after rolling, whereas annealing results in weakening of rolling texture components. The nucleation mechanism of twin has been consistent with the pole mechanism along with the deviation process. Hence the present work amplifies the present understanding of deformation and annealing behaviour on low carbon dual phase TWIP steel from different characterisation perspectives.
•Microstructure and corrosion performance are compared for two structural steels.•Microstructure evolution shows primarily ferrite-pearlite in both the steels.•Steels show higher corrosion rate in 1% ...HCl solution than in 3.5% NaCl solution.•The corrosion products show the presence of oxide, hydroxide and oxy-hydroxides.•The corroded surface reveals morphologies like flowery, cotton balls and rosette.
A comparison on microstructure and corrosion performance has been made between the two structural steels used in old railway girder bridge (Sample A) and modern grades of weathering structural steel (Sample B). The microstructures, viewed under optical microscope and scanning electron microscope (SEM), show mainly ferrite-pearlite phase constituents in both the steels, A and B. The phase fraction analysis shows higher amount of pearlite in steel A compared to that of steel B. The grain size of steel A is larger than that of steel B under identical processing condition. The immersion corrosion test in 3.5% NaCl shows that the corrosion rate of steel A increases with time, while the same for steel B decreases with time. On the other hand, corrosion test in 1% HCl shows that the corrosion rate of both steel A and B is higher as compared to that of NaCl which always decreases with time. The XRD analysis of corrosion products show the presence of many oxides, hydroxide and oxy-hydroxide like Lepidocrocite (γ-FeOOH), Goethite (α-FeOOH), Akaganeite (β-FeOOH), Magnetite (Fe3O4) and Maghemite (γ-Fe2O3) in both the steels. The SEM images of corroded surfaces reveal different morphologies like flowery, cotton balls and rosette etc. which indicate that the corrosion products primarily contain Lepidocrocite (γ-FeOOH), Goethite (α-FeOOH) and Akaganeite (β-FeOOH).
Bimetallic Pt–Ni nanoparticles (bi-MNPs) have been prepared at room temperature by a wet chemical technique from a micellar solution containing the corresponding metal salts. Co-reduction of the ...salts produced alloyed particles in bulk quantity. Use of different ratios of the respective metal salts supported the synthesis of tunable compositions of the Pt–Ni alloys. These alloyed bi-MNPs of variable compositions were exploited to study their catalytic activities towards the reduction of aromatic nitro compounds. The kinetics of the reduction was monitored under different experimental conditions. The catalytic activity of the Pt–Ni bi-MNPs has been found to be superior to the activities of monometallic Pt nanoparticles. Moreover, it was found that the rate of reduction of nitroaromatics is sensitive to the composition of the alloy catalysts. This could be attributed to the electronic effect and the segregation behavior of the material in the alloy.
Ultrahigh strength steel is designed for light-weight cost-effective parts with improved safety by dint of high strength coupled with better fuel efficiency for automotive and aerospace applications. ...The current steel with medium carbon (0.28 wt%) and alloying elements (∼8%) such as Mn, Ni, Mo along with micro-alloying of Ti and Nb has been processed by thermo-mechanical controlled processing with different finish rolling temperature (FRT) followed by air cooling and water quenching. Microstructure of air cooled specimen consists of lower bainite with a few amount of lath martensite, whereas a mixture of lath martensite and lower bainite in prior pan-caked austenite grains has also been obtained on water quenching. It is observed that microstructure becomes gradually finer with reduction of FRT for both cooling conditions and fine-scale carbide/carbonitride precipitates, enriched with Ti/Nb along with dislocation sub-structures within bainite and martensite laths have performed as strengtheners. Ultrahigh strength (1991–2032 MPa) with lower elongation (5–7%) is obtained in water quenched samples, whereas air cooled samples show comparatively lower strength (1841–1928 MPa) with marginally higher elongation (8–9%). Different strengthening mechanisms have been quantified which cumulatively contribute to the yield strength of the current steels.
Display omitted
•Newly designed ultrahigh strength steel achieved 2000 MPa by TMCP.•Bainite and martensite with carbide/carbonitride precipitates acted strengtheners.•Microstructure becomes finer with reduction of finish rolling temperature.•Different strengthening mechanisms cumulatively contribute to yield strength.
The present study aims to investigate the evolution of microstructure of 304 austenitic stainless steel (SS) due to reversion annealing of cold deformed samples under different schedules. Evolution ...of phases in selected samples was identified and quantified by X-ray diffraction analysis along with corresponding microstructural characterisation through optical, scanning and transmission electron microscopy. Mechanical properties of the samples were determined by carrying out tensile test. Electron microscopy of selected samples has revealed that, while strain induced martensite, deformation twins, ε-martensite and high dislocated structures are the dominant microstructural features of the cold deformed samples, reversion annealing of the same results into ultrafine-grained reverted austenite, cell type dislocation sub-structures with some amount of untransformed martensite. The maximum tensile strength of 1589MPa with an elongation of 9% has been obtained after 20% deformation at −196°C (20LND), whereas 40% deformation at 0°C (40ZCD) results into a tensile strength of 1225MPa with 13% elongation. Annealing of 40ZCD and 20LND specimens at 300°C results in significant improvement in tensile strength, while annealing at 725°C increases the elongation with a decrease in tensile strength. During reversion annealing, strain induced martensite transforms to austenite through shear and diffusional processes. However, the reversion is essentially diffusional in nature at a higher temperature.
Ce(NO3)3·6H2O or Pr(NO3)3·6H2O and pyridine-2,6-dicarboxylic acid form a linear coordination polymeric structure under hydrothermal conditions. Hexameric water clusters join these linear chains ...through bonding to the metal ions. Other coordinated water and the carboxylate oxygen form an intricate array of hydrogen bonding resulting in a 3D network where each metal ion shows 9-coordination with an approximate D 3 symmetry. Dimeric water clusters are also located in the void spaces. In the structure containing Pr(III), the water dimers are hydrogen-bonded to the hexamers, whereas in the Ce(III) structure, the dimers and the hexamers are far apart.
PDF
