In silico design of a peptidomimetic carrier for levodopa

Ab initio molecular orbital calculations at the Hartree Fock level utilizing 6-31G basis set have been performed on small cyclic peptides and peptidomimetic compounds to explore their utility as carriers of levodopa (L-3,4-dihydroxyphenylalanine) to enhance its brain bioavailability. A cyclic peptidomimetic compound with hydrophobic CH2NH backbone is suggested as possible carrier. This carrier is predicted to efficiently carry Levodopa held by non covalent interactions encompassed in its cyclic backbone without chances of expulsion before delivery inside brain. Carrier is expected to undergo passive diffusion alongwith the drug held inside. Once inside the brain, drug may be delivered enzymatically or non enzymatically.

Amorphous Silicon Alloy Photovoltaic Technology - from R&D to Production

The key requirements for photovoltaic modules to be accepted for large-scale terrestrial applications are (i) low material cost, (ii) high efficiency with good stability, (iii) low manufacturing cost with good yield and (iv) environmental safety. Thin films of amorphous silicon alloy are inexpensive; the products are also environmentally benign. The challenge has been to improve the stable efficiency of these modules and transfer the R&D results into production. Using a Multijunction, Multi-bandgap approach to capture the solar spectrum more efficiently, we have developed one-square-foot modules with initial efficiency of 11.8%. After 1000 h of one-sun light soaking, a stable efficiency of 10.2% was obtained. Both the efficiency values were confirmed by National Renewable Energy Laboratory. The technology has been transferred to production using an automated roll-to-roll process in which different layers of the cell structure are deposited in a continuous manner onto stainless steel rolls, 14” wide and half a mile long. The rolls are next processed into modules of different sizes. This inexpensive manufacturing process produces high efficiency modules with subcell yields greater than 99%. The key features of the technology transfer and future scope for improvement are discussed.

Optimization of High Efficiency Amorphous Silicon Alloy based Triple-Junction Modules

A systematic approach has been used to scale up high efficiency 0.25cm2 active-area amorphous Si alloy based triple-junction devices to high-efficiency encapsulated modules of aperture area ~920cm2. In order to analyze the losses involved in the scale-up, intermediate aperture area, 40cm2 and 450cm2, modules have also been fabricated. The best stable active-area efficiency obtained on the small-area cells is 12.9%. The best initial efficiency of a ~920cm2 aperture area encapsulated module is 12.1%. National Renewable Energy Laboratory (NREL) has independently light soaked three of the ~920cm2 modules. They have measured a stable efficiency of 10.5% which represents a new world record. This paper presents various aspects of the large-area module work.

Application of calcined waste fish (Labeo rohita) scale as low-cost heterogeneous catalyst for biodiesel synthesis

This paper explores the feasibility of converting waste Rohu fish (Labeo rohita) scale into a high-performance, reusable, low-cost heterogeneous catalyst for synthesis of biodiesel from soybean oil. The thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) analysis revealed that a significant portion of the main component of fish scale i.e. HAP (hydroxyapatite) could be transformed into β-tri-calcium phosphate when calcined above 900°C for 2 h. Scanning Electron Microscopy (SEM) morphology studies of the calcined scale depicted a fibrous layer of porous structure; while a BET surface area of 39 m(2)/g was measured. Response surface methodology (RSM) was employed to determine the optimal parametric conditions viz. methanol/oil molar ratio, 6.27:1, calcination temperature, 997.42°C and catalyst concentration, 1.01 wt.% of oil corresponding to a maximum FAME yield of 97.73%. Reusability results confirmed that the prepared catalyst could be reemployed up to six times, procreating a potentially applicable avenue in biodiesel synthesis.

Familial history of stroke is associated with acute coronary syndromes in women

BACKGROUND

Stroke in female first-degree relatives (FDRs) is a powerful risk factor for ischemic stroke in women, but its association with acute coronary syndromes (ACS) is unknown. Family history (FH) of stroke is omitted from existing myocardial infarction risk prediction tools, which perform less well in women than in men. Our objective was to study the sex-of-parent and sex-of-proband interactions for FH of stroke in ACS patients.

METHODS AND RESULTS

In a prospective, population-based study (Oxford Vascular Study) of all patients with ACS or stroke/transient ischemic attack, FH data for stroke and myocardial infarction were analyzed by sex of proband and FDRs, and coronary angiograms were reviewed, where available; 942 of 1058 ACS probands and 1015 of 1152 stroke/transient ischemic attack probands had complete FH data; 24.1% of ACS probands and 24.3% of stroke/transient ischemic attack probands had history of stroke in ≥1 FDR. Maternal stroke was more common than paternal stroke in female ACS probands (odds ration [OR], 2.53; 1.39 to 4.61) but not in male probands (OR, 0.92; 0.64 to 1.32) (difference-P=0.004). Overall, female ACS probands were more likely to have female than male FDRs with stroke (OR, 2.09; 1.29 to 3.37), whereas the opposite trend was seen in male ACS probands (OR, 0.69; 0.50 to 0.97) (difference-P=0.0002). However, there was no association between parental history of stroke and disease localization or presence of multivessel disease on coronary angiography.

CONCLUSIONS

FH of stroke is as common in ACS patients as in stroke/transient ischemic attack patients and sex-of-parent/sex-of-proband interactions are similar. Stroke in female FDRs may help to identify women at increased risk of ACS as well as ischemic stroke.

Effect of induced shape anisotropy on magnetic properties of ferromagnetic cobalt nanocubes

We report on the synthesis of ferromagnetic cobalt nanocubes of various sizes using thermal pyrolysis method and the effect of shape anisotropy on the static and dynamic magnetic properties were studied. Shape anisotropy of approximately 10% was introduced in nanocubes by making nanodiscs using a linear chain amine surfactant during synthesis process. It has been observed that, ferromagnetism persisted above room temperature and a sharp drop in magnetic moment at low temperatures in zero-field cooled magnetization may be associated with the spin disorder due to the effective anisotropy present in the system. Dynamic magnetic properties were studied using RF transverse susceptibility measurements at different temperatures and the singularities due to anisotropy fields were probed at low temperatures. Symmetrically located broad peaks are observed in the frozen state at the effective anisotropy fields and the peak structure is strongly affected by shape anisotropy and temperature. Irrespective of size the shape anisotropy gave rise to higher coercive fields and larger transverse susceptibility ratio at all temperatures. The role of shape anisotropy and the size of the particles on the observed magnetic behaviour were discussed.