A gas-jet transport and catcher technique for on-line production of radioactive ion beams using an electron cyclotron resonance ion-source

Radioactive ion beams (RIB) have been produced on-line, using a gas-jet recoil transport coupled Electron Cyclotron Resonance (ECR) ion-source at the VECC-RIB facility. Radioactive atoms∕molecules carried through the gas-jet were stopped in a catcher placed inside the ECR plasma chamber. A skimmer has been used to remove bulk of the carrier gas at the ECR entrance. The diffusion of atoms∕molecules through the catcher has been verified off-line using stable isotopes and on-line through transmission of radioactive reaction products. Beams of (14)O (71 s), (42)K (12.4 h), (43)K (22.2 h), and (41)Ar (1.8 h) have been produced by bombarding nitrogen and argon gas targets with proton and alpha particle beams from the K130 cyclotron at VECC. Typical measured intensity of RIB at the separator focal plane is found to be a few times 10(3) particles per second (pps). About 3.2 × 10(3) pps of 1.4 MeV (14)O RIB has been measured after acceleration through a radiofrequency quadrupole linac. The details of the gas-jet coupled ECR ion-source and RIB production experiments are presented along with the plans for the future.

Global air quality and climate

Emissions of air pollutants and their precursors determine regional air quality and can alter climate. Climate change can perturb the long-range transport, chemical processing, and local meteorology that influence air pollution. We review the implications of projected changes in methane (CH(4)), ozone precursors (O(3)), and aerosols for climate (expressed in terms of the radiative forcing metric or changes in global surface temperature) and hemispheric-to-continental scale air quality. Reducing the O(3) precursor CH(4) would slow near-term warming by decreasing both CH(4) and tropospheric O(3). Uncertainty remains as to the net climate forcing from anthropogenic nitrogen oxide (NO(x)) emissions, which increase tropospheric O(3) (warming) but also increase aerosols and decrease CH(4) (both cooling). Anthropogenic emissions of carbon monoxide (CO) and non-CH(4) volatile organic compounds (NMVOC) warm by increasing both O(3) and CH(4). Radiative impacts from secondary organic aerosols (SOA) are poorly understood. Black carbon emission controls, by reducing the absorption of sunlight in the atmosphere and on snow and ice, have the potential to slow near-term warming, but uncertainties in coincident emissions of reflective (cooling) aerosols and poorly constrained cloud indirect effects confound robust estimates of net climate impacts. Reducing sulfate and nitrate aerosols would improve air quality and lessen interference with the hydrologic cycle, but lead to warming. A holistic and balanced view is thus needed to assess how air pollution controls influence climate; a first step towards this goal involves estimating net climate impacts from individual emission sectors. Modeling and observational analyses suggest a warming climate degrades air quality (increasing surface O(3) and particulate matter) in many populated regions, including during pollution episodes. Prior Intergovernmental Panel on Climate Change (IPCC) scenarios (SRES) allowed unconstrained growth, whereas the Representative Concentration Pathway (RCP) scenarios assume uniformly an aggressive reduction, of air pollutant emissions. New estimates from the current generation of chemistry-climate models with RCP emissions thus project improved air quality over the next century relative to those using the IPCC SRES scenarios. These two sets of projections likely bracket possible futures. We find that uncertainty in emission-driven changes in air quality is generally greater than uncertainty in climate-driven changes. Confidence in air quality projections is limited by the reliability of anthropogenic emission trajectories and the uncertainties in regional climate responses, feedbacks with the terrestrial biosphere, and oxidation pathways affecting O(3) and SOA.

Consanguinity, prematurity, birth weight and pregnancy loss: a prospective cohort study at four primary health center areas of Karnataka, India

OBJECTIVE

To determine whether consanguinity adversely influences pregnancy outcome in South India, where consanguinity is a common means of family property retention.

STUDY DESIGN

Data were collected from a prospective cohort of 647 consenting women, consecutively registered for antenatal care between 14 and 18 weeks gestation, in Belgaum district, Karnataka in 2005. Three-generation pedigree charts were drawn for consanguineous participants. χ (2)-Test and Student's t-test were used to assess categorical and continuous data, respectively, using SPSS version 14. Multivariate logistic regression adjusted for confounding variables.

RESULT

Overall, 24.1% of 601 women with singleton births and outcome data were consanguineous. Demographic characteristics between study groups were similar. Non-consanguineous couples had fewer stillbirths (2.6 vs 6.9% P=0.017; adjusted P=0.050), miscarriages (1.8 vs 4.1%, P=0.097; adjusted P=0.052) and lower incidence of birth weight <2500 g (21.8 vs 29.5%, P=0.071, adjusted P=0.044). Gestation <37 weeks was 6.2% in both the groups. Adjusted for consanguinity and other potential confounders, age <20 years was protective of stillbirth (P=0.01), pregnancy loss (P=0.023) and preterm birth (P=0.013), whereas smoking (P=0.015) and poverty (P=0.003) were associated with higher rates of low birth weight.

CONCLUSION

Consanguinity significantly increases pregnancy loss and birth weight <2500 g.

A rare case of perforated caecum after acute pancreatitis

Isolated caecal perforation following pancreatitis is a rare event. We report a case of severe non-necrotising pancreatitis complicated by caecal perforation that was managed successfully.

Coulomb explosion sputtering of selectively oxidized Si

We have studied the sputtering of a unique system comprising of coexisting silicon and silicon oxide surfaces due to the impact of multiply charged Ar(q+) ions. Such surfaces are produced by oblique angle oxygen ion bombardment on Si(100), which results in one side oxidized ripple formation due to preferential oxygen implantation. It is observed by atomic force microscopy and conducting atomic force microscopy studies that the higher the potential energy of the Ar(q+) ion, the higher the sputtering yield of the nonconducting (oxide) side of the ripple as compared to the semiconducting side while ensuring an identical irradiation and measurement condition. It also shows experimentally the potential of highly charged ions in the gentle cleaning or tailoring of nanostructures. The results are explained in terms of the Coulomb explosion model, where potential sputtering depends on the conductivity of the ion impact sites.

Design and development of a radio frequency quadrupole linac postaccelerator for the Variable Energy Cyclotron Center rare ion beam project

A four-rod type heavy-ion radio frequency quadrupole (RFQ) linac has been designed, constructed, and tested for the rare ion beam (RIB) facility project at VECC. Designed for cw operation, this RFQ is the first postaccelerator in the RIB beam line. It will accelerate A/q < or = 14 heavy ions coming from the ion source to the energy of around 100 keV/u for subsequent acceleration in a number of Interdigital H-Linac. Operating at a resonance frequency of 37.83 MHz, maximum intervane voltage of around 54 kV will be needed to achieve the final energy over a vane length of 3.12 m for a power loss of 35 kW. In the first beam tests, transmission efficiency of about 90% was measured at the QQ focus after the RFQ for O(5+) beam. In this article the design of the RFQ including the effect of vane modulation on the rf characteristics and results of beam tests will be presented.

33.7 MHz heavy-ion radio frequency quadrupole linac at VECC Kolkata

A 33.7 MHz heavy-ion radio frequency quadrupole (RFQ) linear accelerator has been designed, built, and tested. It is a four-rod-type RFQ designed for acceleration of 1.38 keVu, qA> or =116 ions to about 29 keVu. Transmission efficiencies of about 85% and 80% have been measured for the unanalyzed and analyzed beams, respectively, of oxygen ((16)O(2+), (16)O(3+), (16)O(4+)), nitrogen ((14)N(3+), (14)N(4+)), and argon ((40)Ar(4+)). The system design and measurements along with results of beam acceleration test will be presented.

Changes in bone mineral density following treatment of osteomalacia

Osteomalacia is characterized by defective mineralization and low bone mineral density (BMD). Clinical and biochemical improvements typically occur within a few weeks of starting treatment, though the bone mineral deficits may take longer to correct. We report a case series of 26 patients with frank osteomalacia (pseudo fractures on X-rays, elevated serum total alkaline phosphatase and parathyroid hormone, normal/low serum calcium and phosphorus, and low serum 25-hydroxy vitamin D) who were followed-up for changes in BMD during treatment using dual- energy X-ray absorptiometry (DXA). There were 23 patients with nutritional vitamin D deficiency, 2 with malabsorption syndrome, and 1 with renal tubular acidosis. All patients were treated with vitamin D and calcium; the 3 patients with associated disorders were treated accordingly. At baseline, there was low BMD at all sites tested. The rate of increase in vertebral and hip BMD was rapid in the initial few months, which subsequently slowed down. In contrast to the large increases in BMD at the femoral neck and lumbar spine, the radial BMD did not recover. At the time when most patients had marked clinical and biochemical improvement (2.8+/-1.4 mo), the vertebral and hip BMD, although improved from baseline, had not completely recovered. Bone loss at the forearm (cortical site) appears to be largely irreversible. Although the clinical correlates of these changes are presently unclear, BMD measurements are useful in assessing the initial severity of bone loss as well as the response to therapy.

239.Sensitivity of bovine morulae and blastocysts to heat shock in vitro

Thermotolerance of blastocysts and morulae is greater than that of zygotes. However, lower rates of pregnancy have been recorded when morulae rather than blastocysts were transferred. The aim of this study was to determine if morulae displayed lower thermotolerance than blastocysts in vitro. Embryos were produced from oocytes collected from abattoir-sourced ovaries. On Day 7 post fertilisation, embryos were classified as morulae or blasotcysts and subjected to either an increase in temperature from 39�C to 41.5�C over 1 h followed by a decrease to 39�C over 2 h (HS) or maintained at 39�C (NHS), using a water jacketed CO2 incubator. The number of embryos progressing to expanded and hatched blastocysts was recorded after 48 h further culture at 39�C. After arcsine transformation, the proportions progressing were submitted to a general linear model using adjusted sum of squares for tests of difference. Factors were embryonic stage, treatment and sire and the interaction terms of stage and sire with treatment. The Kruskall-Wallis test was also applied to the untransformed, non-parameteric data set. Non-parameteric , univariant analysis indicated non-significant effects of treatment (NHS median proportion progressing =72%, HS = 64%, P = 0.12) and of sire (NHS = 78%, HS = 64%, P = 0.168), while the effect of stage was highly significant (morulae = 35%, blastocysts = 79%, P�=�0.0000). However, according to the general linear model, treatment and stage were significant factors (F�=�5.39 and 38.3, respectively, and P�=�0.032 and 0.000, respectively) and sire approached significance (F�=�4.09, P�=�0.058). Neither of the interaction terms was significant. It was concluded that embryos, which were morulae on Day 7, were less likely to progress to expanded or hatched blastocysts and that heat shock reduced developmental progression.

Influence of geoengineered climate on the terrestrial biosphere

Various geoengineering schemes have been proposed to counteract anthropogenically induced climate change. In a previous study, it was suggested that a 1.8% reduction in solar radiation incident on the Earth's surface could noticeably reduce regional and seasonal climate change from increased atmospheric carbon dioxide (CO2). However, the response of the terrestrial biosphere to reduced solar radiation in a CO2-rich climate was not investigated. In this study, we hypothesized that a reduction in incident solar radiation in a Doubled CO2 atmosphere will diminish the net primary productivity (NPP) of terrestrial ecosystems, potentially accelerating the accumulation of CO2 in the atmosphere. We used a dynamic global ecosystem model, the Integrated Biosphere Simulator (IBIS), to investigate this hypothesis in an unperturbed climatology. While this simplified modeling framework effectively separated the influence of CO2 and sunlight on the terrestrial biosphere, it did not consider the complex feedbacks within the Earth's climate system. Our analysis indicated that compared to a Doubled CO2 scenario, reduction in incident solar radiation by 1.8% in a double CO2 world will have negligible impact on the NPP of terrestrial ecosystems. There were, however, spatial variations in the response of NPP-engineered solar radiation. While productivity decreased by less than 2% in the tropical and boreal forests as hypothesized, it increased by a similar percentage in the temperate deciduous forests and grasslands. This increase in productivity was attributed to an approximately 1% reduction in evapotranspiration in the Geoengineered scenario relative to the Doubled CO2 scenario. Our initial hypothesis was rejected because of unanticipated effects of engineered solar radiation on the hydrologic cycle. However, any geoengineering approaches that reduce incident solar radiation need to be thoroughly analyzed in view of the implications on ecosystem productivity and the hydrologic cycle.

Dyslipidemia with particular regard to apolipoprotein profile in association with polycystic ovary syndrome: a study among Indian women

OBJECTIVE

To investigate putative dyslipidemia in women with polycystic ovary syndrome (PCOS) with particular emphasis on specific parameters of atherosclerotic risk, and to assess the independent influence of obesity and hyperandrogenemia on these parameters.

SUBJECTS

Women investigated were among those attending the infertility clinics. Three groups of women were studied: (I) a core study group consisting of oligomenorrhoeic, chronically anovulatory women with or without obesity in whom polycystic ovaries were confirmed through ultrasound evidence, and were established to be the cause of infertility; II) a control group of non-hirsute, non-obese women with regular menstrual cycles; and (III) a group of controls consisting of women with obesity, but with normal ovarian morphology and regular menstrual cycles.

METHODS

All three study groups were investigated for androgen (total testosterone) and lipid-lipoprotein profile, including apolipoproteins, ApoA1 and ApoB. Retrospective analysis of the data was carried out to assess hyperandrogenism in the study group of women with PCOS as well as to investigate changes in the lipid-lipoprotein profile, particularly the measures of cardiovascular risk, ApoA1 and ApoB.

RESULTS

Triglycerides showed a significant increase in the PCOS group compared to controls, whereas HDL-cholesterol as well as HDL-carrying ApoA1 showed a significant decrease (P < .05). Also a significant finding was the decrease in ApoA1/ApoB ratio among the women with PCOS compared to both controls and obese women. A direct negative correlation of this decrease in ApoA1/ApoB ratio with the Body Mass Index was also confirmed in the study. Hyperandrogenemia in terms of significantly raised total testosterone levels was found in 30% of the PCOS women. However, no direct correlation of this increase with changes in lipid-lipoprotein profile could be observed.

CONCLUSION

The study confirms the trend toward dyslipidemia among women with PCOS, particularly in parameters associated with cardiovascular risk. A significant association of obesity rather than raised testosterone with this dyslipidemia was also confirmed by the study.

Tunnelling of caudal epidural catheters in infants

The working conditions in the developing world necessitate the development of many adaptations and improvizations of accepted anaesthetic techniques to improve patient care. Subcutaneous tunnelling of caudally placed epidural catheters is one such improvization to prevent the soiling of the catheter by urine and faeces. This study compares the duration of retention of catheter in a group with tunnelled catheters with an untunnelled group. The absence of a catheter emerging through skin at the site of catheter insertion hastens healing thus prolonging the retention of catheter in the tunnelled group and soiling ceases to be a major problem.