Ultrasonic wave propagation in ternary intermetallic CeCuGe compound.

The elastic and ultrasonic properties of the hexagonal intermetallic CeCuGe ternary compound have been evaluated along unique axis at room temperature. Higher order elastic constants have been calculated for CeCuGe compound using Lennard-Jones interaction potential model. The ultrasonic velocity, Debye average velocity, thermal relaxation time and acoustic coupling constant are evaluated along unique axis of the crystal and the temperature dependent ultrasonic velocities are evaluated along different angles with unique axis of the crystal. Finally temperature dependent ultrasonic attenuation is evaluated to extract important information about the material.

The Importance of Flexion MRI in Hirayama Disease with Special Reference to Laminodural Space Measurements.

BACKGROUND AND PURPOSE: Hirayama disease is a benign focal amyotrophy of the distal upper limbs involving C7, C8, and T1 segmental myotomes with sparing of the brachioradialis and proximal muscles of the upper limb innervated by C5-6 myotomes. The objective of the present study was to study the utility of MR imaging in young patients presenting with weakness and wasting of the distal upper extremity and to evaluate the importance of the laminodural space during flexion cervical MR imaging. MATERIALS AND METHODS: This was a prospective cross-sectional study conducted from January 2014 to July 2017 in a tertiary care center from Northeast India. Forty-five patients with clinically definite Hirayama disease underwent electrophysiologic evaluation followed by MR imaging of the cervical spine. RESULTS: The mean age at recruitment was 22.8 ± 5.5 years. Forty patients (88.9%) had unilateral and 5 (11.1%) had bilateral upper extremity involvement. Cervical cord T2-weighted hyperintensities were demonstrated in 16 patients (35.6%), of which 15 (33.3%) had anterior horn cell hyperintensities. Flexion MR imaging showed loss of the posterior dural attachment, forward shifting of the posterior dural sac with postcontrast enhancement, and prominent posterior epidural venous plexus in all patients. The laminodural space at maximum forward shifting of the posterior dural sac ranged from 3 to 9.8 mm, with a mean distance of 5.99 mm (95% confidence interval, 5.42-6.57 mm). CONCLUSIONS: Flexion cervical MR imaging is a very useful investigation in diagnosing Hirayama disease. The increase in the laminodural space and the presence of cervical cord flattening during flexion are essential for diagnosis.

Effect of graphene nanofillers on the enhanced thermoelectric properties of Bi2Te3 nanosheets: elucidating the role of interface in de-coupling the electrical and thermal characteristics.

In this report, we investigate the effect of graphene nanofillers on the thermoelectric properties of Bi2Te3 nanosheets and demonstrate the role of interface for enhancing the overall figure of merit (ZT) ∼ 53%. The enhancement in the ZT is obtained due to an increase in the electrical conductivity (∼111%) and decrease in the thermal conductivity (∼12%) resulting from increased conducting channels and phonon scattering, respectively at the interfaces between graphene and Bi2Te3 nanosheets. A detailed analysis of the thermal conductivity reveals ∼4 times decrease in the lattice thermal conductivity in contrast to ∼2 times increase in the electronic thermal conductivity after the addition of graphene. Kelvin probe measurements have also been carried which reveals presence of low potential barrier at the interface between graphene and Bi2Te3 nanosheets which assist the flow of charge carriers thereby, increasing the mobility of the carriers. Thus, our results reveals a significant decrease in the lattice thermal conductivity (due to the formation of interfaces) and increase in the electron mobility (due to conducting paths at the interfaces) strongly participate in deciding observed enhancement in the thermoelectric figure of merit.

One-dimensional solute transport for uniform and varying pulse type input point source through heterogeneous medium.

An analytical solution is developed for conservative solute transport in a one-dimensional heterogeneous porous medium. The solute dispersion parameter is considered uniform, while the seepage flow velocity is considered spatially dependent. Retardation factor is considered inversely proportional to square of the flow velocity. The seepage velocity flow is considered inversely proportional to the spatially dependent function. The solution is derived for two cases: the former one is for uniform pulse type input point source and the latter one is for varying pulse type input point source. The second condition is considered at the far end of the medium. It is of the second type (flux type) of homogeneous nature. Laplace transform technique (LLT) is employed to get the analytical solutions to the present problem. In the process, a new space variable is introduced. The solutions are graphically illustrated. The effects of heterogeneity of the medium on the solute transport behaviour, in the presence and absence of the source pollutant, are also studied. Laplace transformation technique is used to solve the present problems analytically.

Elastic and ultrasonic properties of single crystalline nickel nanowires.

In the present paper, we have theoretically calculated the non linear elastic constants of single crystalline Ni NWs at very broad temperature range 20-300K validating simple interaction potential model. The temperature dependent ultrasonic attenuation and other related properties are determined using their second and third order elastic constants (SOECs/TOECs). Where possible, the results are compared with experiments from literature. There is a correlation between the thermal conductivity and ultrasonic attenuation in the temperature range 100-300K. Also, a correlation between the resistivity and ultrasonic attenuation in the temperature range 40-100K has been established validating the theoretical approach.

Meridianins: marine-derived potent kinase inhibitors.

Marine invertebrates are a rich source of novel, bioactive secondary metabolites and have attracted a great deal of attention from scientists in the fields of chemistry, pharmacology, ecology, and molecular biology. This profilic natural source has produced several antitumor secondary metabolites and amongst these, indole alkaloids are of wide occurrence. Meridianins A-G (1-7) are indole alkaloids isolated from tunicate Aplidium meridianum and are known to inhibit variety of protein kinases associated with cancer and neurodegenerative diseases. These compounds also exhibited promising antiproliferative activity in several cancer cell lines. Amongst natural meridianins, meridianin E (5) showed potent and selective inhibition of CDK-1 and CDK-5. Several synthetic meridianin analogs exhibited potent and selective inhibition of glycogen synthase-3 (GSK-3) and dual-specificity tyrosine-phosphorylation regulated kinase 1A (Dyrk-1A) which are known to be implicated in progression of Alzheimer's disease. The present review provides the critical account of isolation, medicinal chemistry and pharmacology of meridianins. Our analysis of the structure-activity relationships of this family of compounds highlights the existence of various potential leads for the development of novel anticancer and anti-Alzheimer's agents.

Imaging characteristics of cavernous sinus cavernous hemangiomas.

Cavernous hemangiomas occur rarely in the cavernous sinus and are difficult to diagnose preoperatively. The imaging of these lesions resembles other benign paracavernous lesions such as schwannomas and meningiomas. Profuse intraoperative bleeding may be encountered during surgical resection of these lesions. A preoperative diagnosis is therefore important to alert the surgeon. We report on the imaging characteristics of two different histopathological types of cavernous sinus cavernous hemangiomas and the use of contrast-enhanced MRI, diffusion-weighted MRI and magnetic resonance spectroscopy in the differential diagnosis of these lesions.

Spontaneous resolution in dissecting aneurysms of the distal middle cerebral artery.

Spontaneous resolution of intracranial aneurysms is a rare phenomenon. We describe two cases of ruptured distal middle cerebral artery branch aneurysms associated with initial neurological deficit. Follow-up angiography showed complete resolution of the aneurysms.

Tree ring imprints of long-term changes in climate in western Himalaya, India.

Tree-ring analyses from semi-arid to arid regions in western Himalaya show immense potential for developing millennia long climate records. Millennium and longer ring-width chronologies of Himalayan pencil juniper (Juniperus polycarpos), Himalayan pencil cedar (Cedrus deodara) and Chilgoza pine (Pinus gerardiana) have been developed from different sites in western Himalaya. Studies conducted so far on various conifer species indicate strong precipitation signatures in ring-width measurement series. The paucity of weather records from stations close to tree-ring sampling sites poses diffi culty in calibrating tree-ring data against climate data especially precipitation for its strong spatial variability in mountain regions. However, for the existence of strong coherence in temperature, even in data from distant stations, more robust temperature reconstructions representing regional and hemispheric signatures have been developed. Tree-ring records from the region indicate multi-century warm and cool anomalies consistent with the Medieval Warm Period and Little Ice Age anomalies. Signifi cant relationships noted between mean premonsoon temperature over the western Himalaya and ENSO features endorse utility of climate records from western Himalayan region in understanding long-term climate variability and attribution of anthropogenic impact.

An ultrasonic characterization of ferrofluid.

Nanoparticles of Cr(2)O(3) are prepared through hydrothermal synthesis process using CrO(3)/PVA in aqueous solution using sucrose as a reducing agent. The calcination temperature is taken 300 and 350 degrees C. XRD and SEM of the powdered Cr(2)O(3) particles are done for the characterization. The average particle size is found 30-80 nm. It is found that average particle size increases with calcination temperature. The UV-visible absorption spectra are taken for the study of photo-physical properties of ferrofluids. Ultrasonic velocity and absorption measurements are performed in Cr(2)O(3) ferrofluid using variable path interferometer and pulse-echo techniques, respectively. The achieved results are discussed in correlation with the magnetic and other physical properties of Cr(2)O(3).

Case report. Non-secretory multiple myeloma presenting with diffuse sclerosis of affected bones interspersed with osteolytic lesions.

Non-secretory multiple myeloma (NSMM) is a rare variant of the classic form of multiple myeloma in which no monoclonal gammopathy can be demonstrated in the serum or urine. Most reported cases of NSMM show the presence of lytic lesions on skeletal radiography. We describe a rare case of non-secretory myeloma in a 32-year-old Indian woman. No monoclonal gammopathy was found in the serum or urine, but a skeletal survey showed diffuse osteosclerosis interspersed with osteolytic lesions; bone marrow biopsy revealed marked plasmacytosis. As diffuse osteosclerosis has never been reported in NSMM, we felt that this was a case worthy of report.

Endovascular management of infective intracranial aneurysms with acrylic glue. A report of two cases.

SUMMARY: Cerebral mycotic aneurysms (MAs) also called infective aneurysms, are uncommon and are usually encountered in patients with infective endocarditis. These aneurysms often present with intracranial hemorrhage. MAs may resolve on treatment with antibiotics alone. However prognosis with medical management alone is unpredictable. Good prognosis with surgery has been reported for single accessible ruptured MAs. However surgery is associated with significant morbidity. Endovascular treatment of MAs along with appropriate antibiotics is emerging as an acceptable option for these patients. We describe two cases of infective endocarditis complicated by ruptured MA treated successfully by liquid embolic glue material.

Genotoxicity of sludges, wastewater and effluents from three different industries.

Many surface waters in Europe, Asia and South America have been reported to be contaminated with genotoxic substances. Therefore, it is important to establish strategies for identification of the most critical sources. In this study, we used a battery of four genotoxicity assays namely chromosomal aberration, DNA strand break, DNA laddering and P53 accumulation tests in mononuclear blood cells. Before cleaning of wastewater high levels of genotoxic contamination could be observed. For instance, we observed an increase in chromosomal aberrations from 2.6 +/- 1.1 (aberrant cells in %; control), to 33.6 +/- 6.6 in a petrochemical plant, 29.4 +/- 3.3 in a petroleum refinery and 14.4 +/- 1.8 in a coke plant of steel industry. A good correlation between the four assays was found. The most sensitive and reproducible results were obtained with the chromosomal aberration assay. Interestingly, clear differences in the efficiency of wastewater cleaning in three different treatment plants were observed. The first and second treatment plants in petrochemical industry and coke plant of steel industry completely eliminated genotoxicity of the wastewater. However, the third plant in petroleum refinery could achieve a reduction in genotoxicity but significant genotoxic contaminations were still present. In conclusion, our battery of genotoxicity tests allows the identification of critical sources contributing to contamination of surface waters.

Ultrasonic properties of nanoparticles-liquid suspensions.

A polymer colloidal solution having dispersed nanoparticles of Cu and Au metals have been developed using a novel chemical method. Average size of the nanoparticles could be varied in the 4-10 nm range by conducting the reaction at an elevated temperature of 50-70 degrees C. Colloidal solutions of representative concentrations of 0.1-2.0 wt% Cu/Au contents in the primary solutions are used to study the modified ultrasonic attenuation and ultrasonic velocity in PVA polymer molecules on incorporating the Cu/Au particles. A characteristic behaviour of the ultrasonic velocity and the attenuation are observed at the particular temperature/particle concentration. The results demonstrate that the primary reaction during the nanoparticles-PVA colloidal formation occurs in divided groups in small micelles. The results are analyzed predicting the enhanced thermal conductivity of the samples.