Compact metal nano-powder generator of 273 MW average power and synthesis of copper nano-powder.

The synthesis of metal nanoparticles holds significant promise for various applications ranging from electronics to catalysis. Their high specific surface area makes them more applicable in the form of lubricant and sorbent. Some of the metal nano-powders, such as silver, copper, and zinc, possess anti-microbial properties; hence, they are very useful in medical sciences. This paper presents a novel approach to the design and implementation of a compact metal nano-powder generator of 273 MW average power through the electrical explosion of wire method. The design focuses on achieving the automatic and repetitive operation of a compact metal nano-powder generator and minimizing its geometric inductance to achieve a fast rise time current across the exploding wire load. Copper nano-powder is produced with a copper wire of 450 µm thickness and 30 mm length at charging voltages of 8.5, 9.0, and 9.5 kV and achieving a superheat of 1.75, 1.92, and 2.06, respectively. The synthesis process is characterized by a detailed analysis of the copper nano-powder's structural, morphological, and chemical composition using techniques such as x-ray diffraction, scanning electron microscopy, and energy-dispersive x-ray spectroscopy. The particle size distribution studies are performed by adopting the log-normal probability distribution. The results demonstrate the effectiveness of the proposed compact nano-powder generator in producing copper nano-powder with tailored properties suitable for diverse applications.

Miniaturized double transit magnetic field measurement probe using the Faraday rotation principle.

This paper presents the design and experimental results of a double transit magnetic field measurement probe based on the Faraday rotation principle using terbium doped borosilicate glass as a sensor element. When the magnetic field is applied in the direction of propagation of light through the glass, the Faraday effect produces non-reciprocal circular birefringence. This property of the Faraday effect adds rotations when the light beam is reflected using a mirror placed at the other end of the glass and passed through the glass, making double transit of light through the sensor element. Experiments were carried out to verify the characteristics of the designed probe by inserting it inside the solenoid load coil. The Verdet constant of the glass is determined using the slope of the linear least-squares fitted curve between the Faraday rotation angle and the applied magnetic field, obtained as 89.22r a d/(T⋅m) with a relative uncertainty of 2.43%. The magnetic field was measured with 0.28% accuracy. In the optics experiments, alignment of components is the major task. To the authors' knowledge, this is the first of its kind double transit miniaturized magnetic field measurement probe configuration in which components are aligned inside the single probe structure. The probe is easily portable and can be used in inaccessible locations in various applications such as accelerators, Z/θ pinch devices, or fusion reactors such as tokamaks, in which the magnetic field is one of the main parameters.

Modular electromagnetic railgun accelerator for high velocity impact studies.

A modular electromagnetic railgun accelerator facility named "RAFTAR" (i.e., Railgun Accelerator Facility for Technology and Research) has been commissioned and its performance has been characterized for high velocity impact testing on materials in a single-shot mode. In the first tests, RAFTAR demonstrated an acceleration of more than 1000 m/s for an 8 g solid aluminum-7075 armature projectile. The current fed was 220 kA, having a muzzle time of about 1.75 ms. It is a single pulse breech-fed rectangular bore (14 × 13 mm2) railgun, and its 1.15 m long barrel assembly consists of two parallel copper bars with an inter-gap of 13 mm that are encased within 50 mm thick high strength reinforced fiberglass sheets (Garolite G10-FR4) and bolted from both the sides. RAFTAR is powered by two capacitor bank modules that have a maximum stored energy of 160 kJ each (containing eight 178 µF/15 kV capacitors), two high power ignitron switches, and a pulse shaping inductor. To obtain consistent acceleration of the armature inside the barrel, reversal of driving current is prevented, and its pulse duration is stretched by tactical integration of the crowbar switch and bitter coil inductor in the circuit. Armature projectile velocity measurement in-bore and outside in free space was performed by the time-of-flight technique using indigenously made miniature B-dot sensors and a novel shorting-foil arrangement, respectively. The time resolved measurement of the in-bore armature evidenced a velocity-skin-effect in the high acceleration phase. There is good agreement between the experimentally measured and theoretically predicted efficiency, confirming the optimal choice of operating parameters. The conclusion summarizes important experimental findings and analyzes the underlying causes that limit the performance of railguns.

Influence of tillage based crop establishment and residue management practices on soil quality indices and yield sustainability in rice-wheat cropping system of Eastern Indo-Gangetic Plains.

Rice-wheat cropping system (RWCS) is the most important system occupying around 26 M ha spread over the Indo Gangetic Plains in South Asia and China. Many long-term trials were led to assess the agronomic productivity and economic profitability of various combinations of conservation agricultural (CA) practices (zero tillage, residue management and crop establishment) in RWCS of Eastern Indo-Gangetic Plains (EIGP) of India. The purpose of this study was to investigate the best management practices involving different tillage-based crop establishment and residue retention techniques and their contribution to agricultural system sustainability through improvement in soil health by developing soil quality index (SQI). We have used SQI as an instrument based on physical [macro aggregate stability (MAS), available water capacity (AWC) and soil penetration resistance (SPR)], chemical [soil organic carbon (OC), available N, available P and available K] and biological [microbial biomass carbon (MBC), fluorescein diacetate (FDA) and dehydrogenase activity (DHA)] properties of soil, because these are very useful indicators of soil's functions for agronomic productivity and soil fertility. Soil properties like MAS, OC, MBC, FDA and DHA were higher by 47, 18, 56, 48 and 53%, respectively, under ZTDSR-ZTW (T7: Zero-till direct seeded rice - Zero-till wheat) than RPTR-CTW (T1: Random puddled transplanted rice - Conventional till broadcasted wheat), at 0-10 cm. CA based treatment T7 also recorded lower SPR (126 N cm-1). SQI for different treatments were calculated by performing principal component analysis based on the total data set method. The higher system rice equivalent yield of 12.41 t ha-1 was observed at SQI value of 0.90 at 0-10 cm and 0.86 at 10-20 cm in T7. It can be concluded that crop residue retention on the surface with zero tillage is beneficial for the sustainability and productivity of the RWCS in EIGP of India.

Human occupation of northern India spans the Toba super-eruption ~74,000 years ago.

India is located at a critical geographic crossroads for understanding the dispersal of Homo sapiens out of Africa and into Asia and Oceania. Here we report evidence for long-term human occupation, spanning the last ~80 thousand years, at the site of Dhaba in the Middle Son River Valley of Central India. An unchanging stone tool industry is found at Dhaba spanning the Toba eruption of ~74 ka (i.e., the Youngest Toba Tuff, YTT) bracketed between ages of 79.6 ± 3.2 and 65.2 ± 3.1 ka, with the introduction of microlithic technology ~48 ka. The lithic industry from Dhaba strongly resembles stone tool assemblages from the African Middle Stone Age (MSA) and Arabia, and the earliest artefacts from Australia, suggesting that it is likely the product of Homo sapiens as they dispersed eastward out of Africa.

Synthesis and characterization of monodispersed water dispersible Fe3O4 nanoparticles and in vitro studies on human breast carcinoma cell line under hyperthermia condition.

Monodispersed Fe3O4 magnetic nanoparticles (MNPs) having size of 7 nm have been prepared from iron oleate and made water dispersible by functionalization for biomedical applications. Three different reactions employing thioglycolic acid, aspartic acid and aminophosphonate were performed on oleic acid coated Fe3O4. In order to achieve a control on particle size, the pristine nanoparticles were heated in presence of ferric oleate which led to increase in size from 7 to 11 nm. Reaction parameters such as rate of heating, reaction temperature and duration of heating have been studied. Shape of particles was found to change from spherical to cuboid. The cuboid shape in turn enhances magneto-crystalline anisotropy (Ku). Heating efficacy of these nanoparticles for hyperthermia was also evaluated for different shapes and sizes. We demonstrate heat generation from these MNPs for hyperthermia application under alternating current (AC) magnetic field and optimized heating efficiency by controlling morphology of particles. We have also studied intra-cellular uptake and localization of nanoparticles and cytotoxicity under AC magnetic field in human breast carcinoma cell line.

Avalanches dynamics in reaction fronts in disordered flows.

We report on numerical studies of avalanches of an autocatalytic reaction front in a porous medium. The front propagation is controlled by an adverse flow resulting in upstream, static, or downstream regimes. In an earlier study focusing on front shape, we identified three different universality classes associated with this system by following the front dynamics experimentally and numerically. Here, using numerical simulations in the vicinity of the second-order transition, we identify an avalanche dynamics characterized by power-law distributions of avalanche sizes, durations, and lateral extensions. The related exponents agree well with the quenched-Kardar-Parisi-Zhang theory, which describes the front dynamics. However, the geometry of the propagating front differs slightly from that of the theoretical one. We show that this discrepancy can be understood in terms of the nonquasistatic correction induced by the finite front velocity.

Gregarine infection accelerates larval development of the cat flea Ctenocephalides felis (Bouché).

A high degree of specialization between host and parasite is a well-known outcome of a long history of coevolution, and it is strikingly illustrated in a coordination of their life cycles. In some cases, the arms race ensued at the establishment of a symbiotic relationship results in the adoption of manipulative strategies by the parasite. We have already learned that Steinina ctenocephali, a gregarine living in the alimentary canal of cat flea, Ctenocephalides felis follows its phenology and metamorphosis. Despite these findings the outcome of their symbiotic partnership (mutualist, parasitic or commensal) remains unclear. To address this important question, we measured life history parameters of the flea in the presence of varying infection intensities of gregarine oocysts in laboratory conditions. We found that neither the emergence nor survival rate of fleas was affected by harbouring the gregarines. More surprisingly, our results show that flea larvae infected with gregarines developed faster and emerged earlier than the control group. This gregarine therefore joins the selected group of protists that can modify physiological host traits and provides not only new model taxa to be explored in an evolutionary scenario, but also potential development of control strategies of cat flea.

Spontaneous nontraumatic subarachnoid hemorrhage without cerebrovascular malformations in a maintenance hemodialysis patient.

Nontraumatic subarachnoid hemorrhage (SAH) in a dialysis patient is an uncommon occurrence and is often associated with high mortality. We report for the first time in India, a case of spontaneous nontraumatic, nonaneurysmal SAH without any cerebrovascular malformation in a maintenance hemodialysis patient, following a session of hemodialysis. The dialysis prescription needs to be modified in these patients, in order to prevent worsening of cerebral edema and progression of hemorrhage. Where available, continuous forms of renal replacement therapies, with regional anticoagulation seem to be the best option for such patients, till neurologic stabilization is achieved.

Correlation of serum phosphate with carotid intimal-medial thickness in chronic kidney disease patients.

While increased serum phosphate concentration is a significant risk factor for vascular calcification, it is unclear whether serum phosphate is also a risk factor for increased arterial wall thickness in chronic kidney disease (CKD) patients. Using B-mode ultrasonography, we examined carotid intimal-medial thickness (CIMT) of CKD patients and analyzed risk factors for increased IMT with regard to the effect of serum phosphate. One hundred patients were enrolled (73 patients without diabetes, 27 patients with diabetes; 57 men, 43 women; age, 46.2 ± 15.3 years). CIMT of patients with diabetes was significantly greater than that of patients without diabetes (0.78 ± 0.250 versus 0.66 ± 0.178 mm; P < 0.0001). For the group of all patients, CIMT correlated strongly and significantly with serum phosphate (r = 0.911; P < 0.001). In multiple regression analysis serum phosphate level (ß = 0.356; <0.0001) was found to be a significant independent risk factor for increased CIMT, in addition to other independent risk factors, including advanced age, higher systolic blood pressure, urinary albumin and the presence of diabetes (R2 = 0.956; P < 0.00001). In conclusion, high serum phosphate level is a significant and independent factor associated with advanced arteriosclerosis in CKD patients with and without diabetes in addition to advanced age.

Vismodegib: the first drug approved for advanced and metastatic basal cell carcinoma.

Treatment of basal cell carcinoma (BCC) usually involves surgical interventions and laser ablation, but in locally advanced BCC, which arise either from earlier untreated lesions or from recurrence of aggressive BCC, surgery and radiotherapy are not helpful. Vismodegib, the first oral-targeted therapy for locally advanced and metastatic BCC, unsuitable for surgery or radiotherapy, was recently approved by US Food and Drug Administration (FDA). The drug was under the priority review program of FDA and was approved on the basis of promising results of phase II trial. Vismodegib acts by targeting the hedgehog pathway, which is activated abnormally in most BCCs. Approval of vismodegib is a big step ahead in the treatment of advanced BCC, where there was no other effective drug therapy till now.

Purification and characterization of pectin lyase secreted by Aspergillus flavus MTCC 10938.

An indigenously isolated fungal strain Aspergillus flavus MTCC 10938 was subjected to pectin lyase (PNL) production under submerged fermentation conditions. The enzyme was purified to homogeneity from the culture filtrate of the fungus involving concentration by ultrafiltration, anion exchange chromatography on DEAE cellulose and gel filtration chromatography on Sephadex G-100. The purified PNL gave a single protein band in SDS-PAGE analysis with a relative molecular mass corresponding to 50 kDa. Using citrus pectin as the substrate the K(m) and k(cat) values of the enzyme lyase were obtained as 1.7 mg/mL and 66 s(-1), respectively. The optimum pH of the purified PNL from A. flavus MTCC 10938 was 8.0 and up to 90% of its activity retained in the pH range from 3.0 to 11.0 after 24 h incubation. The optimum temperature of the purified enzyme was revealed at 55 degrees C and it was completely stable up to 40 degrees C when exposed for 30 min. The purified A. flavus MTCC 10938 PNL showed efficient retting of Crotalaria juncea fibres.

Paroxysmal neuralgia in pediatric population--a diagnostic dilemma for physicians and dental practioners.

Paroxysmal neuralgia is relatively uncommon in children. Neuropathic orofacial pain is a challenge for the clinician, as no obvious dental pathology exists either clinically or radiographically. Dentist and physician should be able to recognize the characteristics of neuropathic pain so as to correctly diagnose these conditions hence avoid unnecessary dental intervention. This article reviews the conditions with paroxysmal neuralgia in children and available treatment strategies.

Biological cell-electrical field interaction: stochastic approach.

The present work demonstrates how a stochastic model can be implemented to obtain a realistic description of the interaction of a biological cell with an external electric field. In our model formulation, the stochasticity is adopted by introducing various levels of forcing intensities in model parameters. The presence of noise in nuclear membrane capacitance has the most significant effect on the current flow through a biological cell. A plausible explanation based on underlying physics and biological structure of the nuclear membrane is proposed to explain such results.

Monoclonal antibodies in ophthalmology.

The monoclonal antibodies can selectively target specific molecules, proteins or receptors in the body responsible for pathogenesis of a particular disorder. Some cytokines play key role in the development of proliferative diabetic retinopathy, neovascular age related macular degeneration, glaucoma and many other inflammatory conditions of eye. Monoclonal antibodies against VEGF and TNF-alpha such as bevacizumab, ranibizumab, infliximab and adalimumab have been used to control neovascularization and inflammation in eye with significant positive results whereas others have been used to target CD20, CD52, CD11a, and IL-2. The growing interest in these drugs with current progress in biotechnology and genetic engineering has kindled active research and with more understanding of the molecular basis of many ocular disorders these antibodies are being explored in a variety of different pathological conditions of the eye. Various sight threatening serious eye disorders which are resistant to the conventional available therapy have responded favorably to these drugs. Despite the limitations of high cost and uncertainty around long term safety profile, rational use of the monoclonal antibodies holds immense promise in management of various ocular conditions.

Suppression of high-p{T} neutral pion production in central Pb+Pb collisions at sqrt[S{NN}]=17.3 GeV relative to p+C and p+Pb collisions.

Neutral pion transverse momentum spectra were measured in p+C and p+Pb collisions at sqrt[S{NN}]=17.4 GeV at midrapidity (2.3 less than or approximately equal eta{lab} less than or approximately equal 3.0) over the range 0.7 less than or approximately equal p{T} less than or approximately equal 3.5 GeV/c. The spectra are compared to pi{0} spectra measured in Pb+Pb collisions at sqrt[S{NN}]=17.3 GeV in the same experiment. For a wide range of Pb+Pb centralities (N{part} less than or approximately equal 300), the yield of pi{0}'s with p{T} greater than or approximately equal 2 GeV/c is larger than or consistent with the p+C or p+Pb yields scaled with the number of nucleon-nucleon collisions (N{coll}), while for central Pb+Pb collisions with N{part}greater than or approximately equal 350, the pi{0} yield is suppressed.

Kinetic disposition of albendazole in goats subclinically infected with gastrointestinal nematodes vis-à-vis naive animals following oral and intraruminal administration.

The influence of subclinical nematodosis on the kinetic disposition of albendazole was evaluated in goats following oral and intraruminal administration. The disposition curves of its metabolites indicated increased uptake of the drug in parasitized goats following intraruminal compared to oral dosing (P < 0.05). The midpoint for the pharmacologically active metabolite, albendazole sulphoxide, in the circulatory compartment was around 0.6 mug ml- 1 both in parasitized and naïve goats. The period of exposure to this concentration was around 14 h (oral route), 18 h (intraruminal route) and 16 h (oral route), 17 h (intraruminal route) in parasitized and naïve goats, respectively. As the duration of exposure of parasites to the toxic concentration of the anthelmintically active metabolite was prolonged, it could be assumed that intraruminal delivery of the drug would improve the efficacy of albendazole in parasitized goats.

Prescribing patterns in the orthopaedics outpatient department in a teaching hospital in Pokhara, western Nepal.

OBJECTIVES: Information on the utilization patterns of drugs in the orthopaedics outpatient department (OPD) are lacking in hospitals in western Nepal. The present study was carried out to obtain demographic information about the respondents selected for analysis, information on the average number of drugs prescribed and the average cost of drugs per prescription. The prescriptions were critically analyzed using predetermined criteria. MATERIALS AND METHODS: The study was carried out over a four-month period (01.09.2002 to 31.12.2002) at the Manipal Teaching hospital, Pokhara, Nepal. The percentage of encounters with an injection or an antibiotic prescribed was noted. The percentage of drugs prescribed from the Essential drug list of Nepal and the mean cost of drugs per prescription was calculated. RESULTS: 1238 patients attended the orthopaedics OPD during the study period. 186 prescriptions were randomly selected for analysis. The mean number of drugs per prescription was 1.9. Low backache was the most common reason for attending the OPD. Nonsteroidal anti-inflammatory drugs (NSAIDs) were the most commonly prescribed drug group. Diclofenac and meloxicam were the most commonly prescribed drugs. Mean cost of drugs was 166.2 Nepalese rupees. Injections and antibiotics were prescribed in 16 (8.6%) and 7 (3.8%) encounters respectively. 51 prescriptions (27.4%) had various problems. Absence of diagnosis on the prescriptions and the duration of treatment were most commonly observed. CONCLUSIONS: Percentage of prescribing by generic name was low. Educational sessions for the doctors at different levels to encourage prescribing by generic names and on correct writing of prescriptions may be considered. Studies covering a larger number of patients and for a longer time period are required. A greater number of patients can be studied, seasonal variations can be overcome and drug utilization can be measured quantitatively.

Knowledge about heart attack and hypertension among individuals attending a cardiac camp in Pokhara city.

OBJECTIVES: Previous studies in other countries had shown lacunae in patients' and general publics' understanding of cardiovascular diseases. Such studies are lacking in Nepal. Hence the present study was carried out to: a) note the respondent's knowledge regarding myocardial infarction and hypertension and b) note the association, if any, of the knowledge with demographic and personal characteristics. MATERIALS AND METHODS: Respondents attending a cardiac camp organized in the Manipal Teaching hospital during September 2002 were interviewed by previously briefed seventh semester students using a structured questionnaire. Basic demographic information and knowledge about myocardial infarction and hypertension was collected. The median score was calculated. Differences in scores among different subgroups of respondents were noted using appropriate statistical tests (p<0.05). RESULTS: Sixty-six respondents were interviewed; 44 were male. The knowledge scores for heart attack and hypertension were 6 (maximum score 8) and 11 (maximum score 14) respectively. The scores were significantly lower among respondents with a monthly family income below 2000 rupees and was higher among respondents/family members suffering from cardiovascular disease. CONCLUSION: The respondents were aware of the basic facts regarding myocardial infarction and hypertension. However, lacunae in knowledge were noted. Further studies are required.