Liquid gallium-lead mixture phase diagram, surface tension near the critical mixing point, and prewetting transition

Quite recently, we reported a semianalytical equation of state (EOS) for the Ga-Pb alloy [Phys. Rev. B 78, 024205 (2008)], which was based on the first-order perturbation theory of fluid mixtures, within the simplified random phase approximation, in conjunction with the Grosdidier et al. model pair potentials for Ga-Ga and Pb-Pb with a suitable nonadditive pair potential between Ga-Pb unlike pairs. In the present work, we employ the present EOS to calculate the Ga-Pb phase diagram along the immiscibility gap region. The accuracy of the EOS is tested by consulting the empirical binodal curve. A statistical-mechanical-based theory for the surface tension is employed to obtain an analytical expression for the alloy surface tension. We calculated the surface tension along the bimodal curve and at extreme conditions of temperatures and pressures. The surface tension exhibits reasonably well the prewetting transition of Pb atoms at the surface of the Ga-rich liquid alloy and could qualitatively explain the prewetting phenomena occurring in the Ga-rich side of the phase diagram. The predicted prewetting line and wetting temperature qualitatively agree with the empirical measurements.

A Clinically Severe Variant of β-Mannosidosis, Presenting with Neonatal Onset Epilepsy with Subsequent Evolution of Hydrocephalus

β-Mannosidosis results from a functional deficiency of the lysosomal enzyme, β-mannosidase. While being a well recognised, naturally occurring disease in both goats and cattle, it is an extremely rare disorder in humans with the first cases only being recorded in 1986. Until now the severity of the human disease has not mirrored that of its bovine or caprine counterparts, whose presentation is typically in the neonatal period with both altered skull morphology and seizures. Human β-mannosidosis has previously appeared to be a more indolent disease, with its only consistent phenotypic feature being developmental delay of varying severity. We report a patient, homozygous for a private mutation, who presented in the immediate perinatal period with seizures and who subsequently developed communicating hydrocephalus at 2 years of age.These are two new phenotypic features for β-mannosidosis. The first being the neonatal onset of the seizures, for while seizures have been seen in 3 out of the previous 20 documented cases, they have never before manifested prior to 6 months of age. However, as in the previous documented cases, the seizures were difficult to control and were associated with severe developmental delay.The second unique feature about this case was the development of communicating hydrocephalus. We discuss the possible mechanisms of its development.In summary, β-mannosidosis must thus now be considered in the differential diagnosis of neonatal onset seizures, and the potential for the development of hydrocephalus should be monitored during subsequent clinical follow-up.

Ketotifen Fumarate and Salbutamol Sulphate Combined Transdermal Patch Formulations: In vitro release and Ex vivo Permeation Studies

The present work was performed to develop and evaluate transdermal patches of combined antiasthmatic drugs (salbutamol sulphate and ketotifen fumarate). Polyvinyl alcohol membrane was used as backing membrane and eudragit RL-100 was used as matrix material to suspend the drugs in the continuous thickness of the patch. Methanol was solvent and propylene glycol was used as plasticizer. Tween 20, isopropyl myristate, eucalyptus oil, castor oil and span-20 were used as permeability enhancers. Thickness, weight variation and drug uniformity were investigated. The patch formulations were also subjected to drug release in dissolution media and permeation through rabbit skin. Effects of different enhancers were evaluated on release and permeation of drugs. F3 formulations having isopropyl myristate as permeation enhancer, showed maximum amounts of drugs release (88.11% of salbutamol sulphate and 88.33% of ketotifen fumarate) at the end of 24 h dissolution study. F3 also showed maximum permeation of both drugs (4.235 mg salbutamol sulphate and 1.057 mg ketotifen fumarate) after 24 h permeation study through rabbit skin mounted in Franz cell. The patches having no enhancer in the formulation also showed some drug release and permeation due to the presence of plasticizer. The results of the study suggested that new controlled release transdermal formulations of combined antiasthmatic drugs can be suitably developed as an alternate to conventional dosage forms.

Dosimetric consideration of transient volume enlargement induced by edema in prostate brachytherapy seed implants

PURPOSE

To investigate enlargement of prostate volume by edema during brachytherapy seed implantation and develop a nomogram model to calculate air-kerma strength (AKS) required for implantation of the enlarged transient prostatic volume.

MATERIALS AND METHODS

The prostate volume was measured prior and after seed implantation using trans-rectal ultrasound imaging in the operating room to obtain volume enlargement. A nomogram model was developed that calculates AKS required for implantation of the enlarged transient prostate volume with optimal dose coverage.

RESULTS

The measured prostate enlargement in this study was up to 60% of the initial volume. The effective prostatic volume enlargement was calculated for three isotopes: 125I, 103Pd and 131Cs. The effective volume enlargement for 125I implants was relatively small (< 10%) because of its long half-life. For 103Pd and 131Cs with short half-lives, additional AKS up to 20% and 30%, respectively, might be required to provide appropriate dose coverage of possible enlarged prostatic volumes.

CONCLUSIONS

Prostate volume enlargement should be considered to obtain optimal dose coverage particularly for short half-life isotopes such as 131Cs and 103Pd. The nomogram model developed in this work provides the AKS required for implants with a wide range of prostatic volume enlargements (5-100%) for three isotopes.

KEYWORDS

prostate brachytherapy; nomogram; air-kerma strength; edema; volume enlargement.

Phase diagram and thermodynamic properties of H2

A statistical mechanical-based theory is used to develop the equation of state for the molecular fluid of H(2). We incorporate in this equation the long-range correlations through the double Yukawa potential, dimerization of the H(2) molecule by treating the fluid as a hard convex body fluid, and first-order quantum correction which is important at low temperatures. We use this to calculate the liquid-vapor equilibrium of H(2), including the temperature and pressure dependence of compressibility factor, entropy, specific heat, compressibility, and sound velocity.

Comparative analysis of case screening with varying cough duration and sputum samples for diagnosis of tuberculosis in patients attending the OPD at a tertiary care hospital at Srinagar, India

RESEARCH QUESTION

Can we minimize cough duration and number of sputum samples in chest symptomatic patients for screening of TB?

OBJECTIVE

To evaluate cough of 3 weeks versus 2 weeks duration using two sputum samples versus three samples in chest symptomatic patients attending the OPD.

STUDY DESIGN

Hospital-based cross-sectional study.

MATERIALS AND METHODS

Outpatients (2810) with H/O cough of 3 weeks and 2 weeks duration were screened by subjecting them to sputum microscopy for tuberculosis using two sputum samples as well as three samples following standard procedure for sputum collection, staining and acid-fast bacillus (AFB) identification. Those on drugs were not included.

RESULTS

Using ≥2 weeks cough, sputum positivity rate was 12%, nearly as high as the sputum positivity among patients with ≥3 weeks cough, i.e. 14%. First sputum smear alone on an average could detect 91.8% cases, while the first two sputum smears could detect on an average 96% cases. The study showed that maximum number of cases was diagnosed by only two sputum smears and added diagnostic value of third specimen was small, i.e. 4%.High sputum positivity rate using ≥2 weeks cough with two sputum samples was seen.

CONCLUSION

The sensitivity analysis of the study showed that using ≥2 weeks cough with two sputum samples gives almost similar values as ≥3 weeks cough with three sputum samples, but this needs further confirmatory results of culture sensitivity. Hence, using ≥2 weeks cough with two sputum samples as the diagnostic criteria for screening of cough patients for TB should be recommended as one way of improving efficient use of scarce resources.

Increased expression of gelatinase-a and timp-2 in primary human glioblastomas

The highly invasive growth of glioblastomas may be a consequence of an abnormal profile of proteinases and proteinase inhibitors involved in remodeling of the basement membrane and normal vasculature. We have detected a 1.5-3-fold increase in the transcription of gelatinase A and TIMP-2 (Tissue Inhibitor of Metalloproteinase) in glioblastomas as compared to the normal brain tissue. Increased expression of gelatinase A and TIMP-2 in these tumors was also evident by immunohistochemical analysis. Our data suggest that increased expression and perturbation of the balance between metalloproteinases and their inhibitors that are involved in extracellular matrix remodeling and angiogenesis may contribute to the invasive phenotype of glioblastomas.