Highly reversible extrinsic electrocaloric effects over a wide temperature range in epitaxially strained SrTiO3 films.

Electrocaloric effects have been experimentally studied in ferroelectrics and incipient ferroelectrics, but not incipient ferroelectrics driven ferroelectric using strain. Here we use optimally oriented interdigitated surface electrodes to investigate extrinsic electrocaloric effects in low-loss epitaxial SrTiO3 films near the broad second-order 243 K ferroelectric phase transition created by biaxial in-plane coherent tensile strain from DyScO3 substrates. Our extrinsic electrocaloric effects are an order of magnitude larger than the corresponding effects in bulk SrTiO3 over a wide range of temperatures including room temperature, and unlike electrocaloric effects associated with first-order transitions they are highly reversible in unipolar applied fields. Additionally, the canonical Landau description for strained SrTiO3 films works well if we set the low-temperature zero-field polarization along one of the in-plane pseudocubic <100> directions. In future, similar strain engineering could be exploited for other films, multilayers and bulk samples to increase the range of electrocaloric materials for energy efficient cooling.

Large electrocaloric effects in oxide multilayer capacitors over a wide temperature range.

Heat pumps based on magnetocaloric and electrocaloric working bodies-in which entropic phase transitions are driven by changes of magnetic and electric field, respectively-use displaceable fluids to establish relatively large temperature spans between loads to be cooled and heat sinks1,2. However, the performance of prototypes is limited because practical magnetocaloric working bodies driven by permanent magnets3-5 and electrocaloric working bodies driven by voltage6-16 display temperature changes of less than 3 kelvin. Here we show that high-quality multilayer capacitors of PbSc0.5Ta0.5O3 display large electrocaloric effects over a wide range of starting temperatures when the first-order ferroelectric phase transition is driven supercritically (as verified by Landau theory) above the Curie temperature of 290 kelvin by electric fields of 29.0 volts per micrometre. Changes of temperature in the large central area of the capacitor peak at 5.5 kelvin near room temperature and exceed 3 kelvin for starting temperatures that span 176 kelvin (complete thermalization would reduce these values from 5.5 to 3.3 kelvin and from 176 to 73 kelvin). If magnetocaloric working bodies were to be replaced with multilayer capacitors of PbSc0.5Ta0.5O3, then the established design principles behind magnetocaloric heat pumps could be repurposed for better performance without bulky and expensive permanent magnets.

Shear-strain-mediated magnetoelectric effects revealed by imaging.

Large changes in the magnetization of ferromagnetic films can be electrically driven by non-180° ferroelectric domain switching in underlying substrates, but the shear components of the strains that mediate these magnetoelectric effects have not been considered so far. Here we reveal the presence of these shear strains in a polycrystalline film of Ni on a 0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 substrate in the pseudo-cubic (011)pc orientation. Although vibrating sample magnetometry records giant magnetoelectric effects that are consistent with the hitherto expected 90° rotations of a global magnetic easy axis, high-resolution vector maps of magnetization (constructed from photoemission electron microscopy data, with contrast from X-ray magnetic circular dichroism) reveal that the local magnetization typically rotates through smaller angles of 62-84°. This shortfall with respect to 90° is a consequence of the shear strain associated with ferroelectric domain switching. The non-orthogonality represents both a challenge and an opportunity for the development and miniaturization of magnetoelectric devices.

Blood Procalcitonin Levels and Duration of Antibiotics in Neonatal Sepsis.

OBJECTIVE: To determine the time to normalization of procalcitonin (PCT) levels and duration of antibiotics in neonatal sepsis. METHODS: A prospective observational study design was used. The participants included were neonates with sepsis. The primary outcome measure was time to normalization of PCT levels and duration of antibiotics following clinical resolution. RESULTS: Time to normalization of PCT levels was 9.6 ± 4.2 days in neonates with septic shock, 6.2 ± 2.5 days in neonates without shock, 9.6 ± 3.1 days in neonates with culture-positive sepsis and 6.4 ± 3.1 days in neonates with culture-negative sepsis. Time to normalization of PCT levels according to the stage of systemic inflammatory response syndrome was 5.8 ± 2.8 days in neonates with sepsis, 6.1 ± 3.1 days in those with sepsis syndrome, 6.3 ± 3.3 days in those with early septic shock and 9.4 ± 3.6 days in those with multiorgan dysfunction syndrome. There was no morbidity and mortality in any neonate in the 4-week follow-up. CONCLUSION: The duration of antibiotics can be determined by observing the time to normalization of PCT following clinical resolution of sepsis.

Enterogenous Cyst Presenting as Mediastinal Mass in a Newborn.

Duplication cyst is a rare congenital malformation. Enterogenous cyst are foregut duplication cyst with or without a vertebral defect. We report a case of a 36hr old neonate with mediastinal enterogenous cyst associated with vertebral defects. The embryology, differentials, and management of enterogenous cyst in the newborn have been discussed.

Scaling up a tobacco control intervention in low resource settings: a case example for school teachers in India.

Research on processes of bringing effective tobacco control interventions to scale to increase quit rates among tobacco users is uncommon. This study examines processes to bring to scale one such intervention for school teachers, i.e. Tobacco Free Teacher-Tobacco Free Society (TFT-TFS). This intervention provides a foundation for an effective and low cost approach to promote cessation through schools. The present study was conducted in the states of Bihar and Maharashtra in 2014 using quantitative and qualitative methods. Focus group discussions (FGDs) were analysed using immersion crystallization method. The data presented are from a survey of 291 principals and seven FGDs. This study examined characteristics of principals and teachers, organizational environment, external environmental factors and program characteristics to determine facilitators and barriers for successful dissemination and implementation of the TFT-TFS program. Some facilitators were, incorporation of the program in existing channels like staff meetings and trainings, certification and recognition by the department of education; while some barriers were routine time bound duties (mainly teaching) of teachers and prevalence of tobacco use among teachers and administrators. Principals and teachers expressed a need and high level of interest in the adoption and implementation of the TFT-TFS program in their schools.

Long Spin Diffusion Length in Few-Layer Graphene Flakes.

We report a spin valve with a few-layer graphene flake bridging highly spin-polarized La_{0.67}Sr_{0.33}MnO_{3} electrodes, whose surfaces are kept clean during lithographic definition. Sharp magnetic switching is verified using photoemission electron microscopy with x-ray magnetic circular dichroism contrast. A naturally occurring high interfacial resistance ∼12 MΩ facilitates spin injection, and a large resistive switching (0.8 MΩ at 10 K) implies a 70-130 µm spin diffusion length that exceeds previous values obtained with sharp-switching electrodes.

Photo-convertible fluorescent proteins as tools for fresh insights on subcellular interactions in plants.

Optical highlighters comprise photo-activatable, photo-switchable and photo-convertible fluorescent proteins and are relatively recent additions to the toolbox utilized for live cell imaging research. Here, we provide an overview of four photo-convertible fluorescent proteins (pcFP) that are being used in plant cell research: Eos, Kaede, Maple and Dendra2. Each of these proteins has a significant advantage over other optical highlighters since their green fluorescent nonconverted forms and red fluorescent converted forms are generally clearly visible at expression levels that do not appear to interfere with subcellular dynamics and plant development. These proteins have become increasingly useful for understanding the role of transient and sustained interactions between similar organelles. Tracking of single organelles after green-to-red conversion has provided novel insights on plastids and their stroma-filled extensions and on the formation of mega-mitochondria. Similarly colour recovery after photo-conversion has permitted the estimation of nuclear endo-reduplication events and is being developed further to image protein trafficking within the lumen of the endoplasmic reticulum. We have also applied photo-convertible proteins to create colour-differentiation between similar cell types to follow their development. Both the green and red fluorescent forms of these proteins are compatible with other commonly used single coloured FPs. This has allowed us to develop simultaneous visualization schemes for up to five types of organelles and investigate organelle interactivity. The advantages and caveats associated with the use of photo-convertible fluorescent proteins are discussed.

Assessment of Adequacy of Supplementation of Vitamin D in Very Low Birth Weight Preterm Neonates: A Randomized Controlled Trial.

OBJECTIVES: To compare the effect of 400 IU and 1000 IU vitamin D for 6 weeks in very low birth weight preterm neonates. DESIGN: Randomized, double-blinded controlled trial in a teaching hospital. PARTICIPANTS: Fifty very low birth weight preterm neonates. INTERVENTION: Vitamin D 400 IU/day (Group 1) or 1000 IU/day (Group 2). OUTCOME MEASURES: Change in serum calcium, phosphate, alkaline phosphatase (ALP), 25-hydroxy vitamin D (25-OHD), parathormone, incidence of skeletal hypomineralization and growth. RESULTS: After 6 weeks of supplementation, the mean serum calcium and 25-OHD levels were significantly higher (p < 0.001 each), while ALP and parathormone levels significantly lower (p < 0.001 each) in group 2. Skeletal hypomineralization was lesser and growth better in group 2. CONCLUSION: Vitamin D supplementation in a dose of 1000 IU/day is more effective in maintaining serum calcium, phosphate, ALP, 25-OHD and parathormone levels with lower incidence of skeletal hypomineralization and better growth.

Caloric materials near ferroic phase transitions.

A magnetically, electrically or mechanically responsive material can undergo significant thermal changes near a ferroic phase transition when its order parameter is modified by the conjugate applied field. The resulting magnetocaloric, electrocaloric and mechanocaloric (elastocaloric or barocaloric) effects are compared here in terms of history, experimental method, performance and prospective cooling applications.

Giant tunnel electroresistance for non-destructive readout of ferroelectric states.

Ferroelectrics possess a polarization that is spontaneous, stable and electrically switchable, and submicrometre-thick ferroelectric films are currently used as non-volatile memory elements with destructive capacitive readout. Memories based on tunnel junctions with ultrathin ferroelectric barriers would enable non-destructive resistive readout. However, the achievement of room-temperature polarization stability and switching at very low thickness is challenging. Here we use piezoresponse force microscopy at room temperature to show robust ferroelectricity down to 1 nm in highly strained BaTiO(3) films; we also use room-temperature conductive-tip atomic force microscopy to demonstrate resistive readout of the polarization state through its influence on the tunnel current. The resulting electroresistance effect scales exponentially with ferroelectric film thickness, reaching approximately 75,000% at 3 nm. Our approach exploits the otherwise undesirable leakage current-dominated by tunnelling at these very low thicknesses-to read the polarization state without destroying it. We demonstrate scalability down to 70 nm, corresponding to potential densities of >16 Gbit inch(-2). These results pave the way towards ferroelectric memories with simplified architectures, higher densities and faster operation, and should inspire further exploration of the interplay between quantum tunnelling and ferroelectricity at the nanoscale.

Spinal cord injury: scenario in an Indian state.

STUDY DESIGN: Prospective observational study. OBJECTIVES: To find out the epidemiology and demographic factors associated with patients of traumatic spinal cord injury (SCI). SETTING: Sawai Man Singh Medical College and Hospital, Jaipur, India. METHODS: Consecutive SCI cases admitted from January 2000 to December 2008 were evaluated on a preformed proforma for demographic factors, epidemiological data and neurological status. RESULTS: In 2716 cases of SCI, 1400 were cervical and 1316 thoracolumbar, with male to female ratio of 4.2:1 and 71% in the age group of 20-49 years. Around 79% patients were from rural background. About 23.3% were farmers while 22.9% were laborers. Among the causes of injury, 53% patients had a fall from height and 28% suffered from road traffic accidents. Fall of heavy object over head and back (10.7%), fall with heavy object over head (3.0%) and fall following electric shock (4.0%) were uncommon causes. Complete paralysis was found in 20.5% cervical and 23.3% in thoracic injuries. Extremity and rib fractures (10.6%) and head injuries (7.2%) were common associated injuries. About 55% cases were initially attended at non-specialized centers. Proper bladder and bowel management in early phase was lacking. CONCLUSION: Epidemiological factors of SCI in Indian scenario are different from western countries with major cause being fall. The low socio-economic status and younger age group had a major financial, social and psychological impact as majority of the patients were the primary earning members of the family. Therefore, measures should be taken to reduce the incidence of SCI.

Evaluation of duration of antibiotic therapy in neonatal bacterial meningitis: a randomized controlled trial.

OBJECTIVES: To compare the effect of 10 days versus 14 days of antibiotic therapy in neonatal meningitis on treatment failure rate. METHODS: The study was a randomized controlled trial conducted at a referral neonatal unit. The participants were 70 neonates with meningitis randomized to receive 10 days (study group) or 14 days (control group) of antibiotics. The primary outcome measure studied was treatment failure in each group within 28 days of enrolment. RESULTS: None of the neonates among either of the groups had occurrence of meningitis during follow-up. Occurrence of sepsis was observed after discharge in three neonates in the control group and none in the study group. Brainstem-evoked response audiometry was abnormal in one neonate in the study group. Adverse effects of drugs and neurological deficits were not observed in the study population. CONCLUSIONS: Short course of antibiotic therapy (10 days) is effective, with potential benefits of shorter hospital stay.

Monitoring hospital wastewaters for their probable genotoxicity and mutagenicity.

Cancer is a leading cause of death worldwide. Excluding the genetic factors, environmental factors, mainly the pollutants, have been implicated in the causation of the majority of cancers. Wastewater originated from health-care sectors such as hospitals may carry vast amounts of carcinogenic and genotoxic chemicals to surface waters or any other source of drinking water, if discharged untreated. Humans get exposed to such contaminants through a variety of ways including drinking water. The aim of the present study was, thus, to monitor the genotoxic and mutagenic potential of wastewaters from three big hospitals located in Jaipur (Rajasthan), India. One of them was operating an effluent treatment plant (ETP) for treatment of its wastewater and therefore both the untreated and treated effluents from this hospital were studied for their genotoxicity. Two short-term bacterial bioassays namely the Salmonella fluctuation assay and the SOS chromotest were used for the purpose. Results of fluctuation assay revealed the highly genotoxic nature of all untreated effluent samples with mutagenicity ratios (MR) up to 23.13 ± 0.18 and 42.25 ± 0.35 as measured with Salmonella typhimurium strains TA98 and TA100, respectively. As determined with the chromotest, all untreated effluents produced significant induction factors (IF) ranging from 3.29 ± 1.11 to 13.35 ± 3.58 at higher concentrations. In contrast, treated effluent samples were found to be slightly genotoxic in fluctuation test only with an MR = 3.75 ± 0.35 for TA100 at 10 % concentration. Overall, the results indicated that proper treatment of hospital wastewaters may render the effluents safe for disposal contrary to the untreated ones, possessing high genotoxic potential.

Giant and reversible extrinsic magnetocaloric effects in La0.7Ca0.3MnO3 films due to strain.

Large thermal changes driven by a magnetic field have been proposed for environmentally friendly energy-efficient refrigeration, but only a few materials that suffer hysteresis show these giant magnetocaloric effects. Here we create giant and reversible extrinsic magnetocaloric effects in epitaxial films of the ferromagnetic manganite La(0.7)Ca(0.3)MnO(3) using strain-mediated feedback from BaTiO(3) substrates near a first-order structural phase transition. Our findings should inspire the discovery of giant magnetocaloric effects in a wide range of magnetic materials, and the parallel development of nanostructured bulk samples for practical applications.

A comparative study of the sensitivities of Salmonella typhimurium strains TA 98, TA 100 and TA 102 to hospital waste waters.

Hospitals are a release source of many chemical compounds in their wastewaters. In the present study Salmonella typhimurium strains TA 98, TA 100 and TA 102 were analyzed for their sensitivity to hospital waste waters. The results of the study showed that hospital waste waters consists of mutagens causing frame shift mutations and base pair substitutions and amongst the three strains used in this study, TA 102 was most effective which along with TA 98 can be used for quick assessment of genotoxicity of hospital waste waters prior to its discharge. Genotoxic potential of hospital waste waters from five major hospitals located in Jaipur and Delhi was studied. Such waste waters should be treated prior to their discharge. The results of this study call for further detailed study in this area of research.

Particulate matter concentration in ambient air and its effects on lung functions among residents in the National Capital Region, India.

The World Health Organization has estimated that air pollution is responsible for 1.4 % of all deaths and 0.8 % of disability-adjusted life years. NOIDA, located at the National Capital Region, India, was declared as one of the critically air-polluted areas by the Central Pollution Control Board of the Government of India. Studies on the relationship of reduction in lung functions of residents living in areas with higher concentrations of particulate matter (PM) in ambient air were inconclusive since the subjects of most of the studies are hospital admission cases. Very few studies, including one from India, have shown the relationship of PM concentration and its effects of lung functions in the same location. Hence, a cross-sectional study was undertaken to study the effect of particulate matter concentration in ambient air on the lung functions of residents living in a critically air-polluted area in India. PM concentrations in ambient air (PM(1,) PM(2.5)) were monitored at residential locations and identified locations with higher (NOIDA) and lower concentrations (Gurgaon). Lung function tests (FEV(1), PEFR) were conducted using a spirometer in 757 residents. Both air monitoring and lung function tests were conducted on the same day. Significant negative linear relationship exists between higher concentrations of PM(1) with reduced FEV(1) and increased concentrations of PM(2.5) with reduced PEFR and FEV(1). The study shows that reductions in lung functions (PEFR and FEV(1)) can be attributed to higher particulate matter concentrations in ambient air. Decline in airflow obstruction in subjects exposed to high PM concentrations can be attributed to the fibrogenic response and associated airway wall remodeling. The study suggests the intervention of policy makers and stake holders to take necessary steps to reduce the emissions of PM concentrations, especially PM(1,) PM(2.5), which can lead to serious respiratory health concerns in residents.

Interface-induced room-temperature multiferroicity in BaTiO3.

Multiferroic materials possess two or more ferroic orders but have not been exploited in devices owing to the scarcity of room-temperature examples. Those that are ferromagnetic and ferroelectric have potential applications in multi-state data storage if the ferroic orders switch independently, or in electric-field controlled spintronics if the magnetoelectric coupling is strong. Future applications could also exploit toroidal moments and optical effects that arise from the simultaneous breaking of time-reversal and space-inversion symmetries. Here, we use soft X-ray resonant magnetic scattering and piezoresponse force microscopy to reveal that, at the interface with Fe or Co, ultrathin films of the archetypal ferroelectric BaTiO3 simultaneously possess a magnetization and a polarization that are both spontaneous and hysteretic at room temperature. Ab initio calculations of realistic interface structures provide insight into the origin of the induced moments and bring support to this new approach for creating room-temperature multiferroics.

Multiferroic and magnetoelectric materials.

A ferroelectric crystal exhibits a stable and switchable electrical polarization that is manifested in the form of cooperative atomic displacements. A ferromagnetic crystal exhibits a stable and switchable magnetization that arises through the quantum mechanical phenomenon of exchange. There are very few 'multiferroic' materials that exhibit both of these properties, but the 'magnetoelectric' coupling of magnetic and electrical properties is a more general and widespread phenomenon. Although work in this area can be traced back to pioneering research in the 1950s and 1960s, there has been a recent resurgence of interest driven by long-term technological aspirations.

Cholinesterase levels and morbidity in pesticide sprayers in North India.

BACKGROUND: Pesticide sprayers in North India use different application methods for different crops. AIMS: To compare cholinesterase activity and symptoms in knapsack and tractor-mounted pesticide sprayers. METHODS: Blood cholinesterase activity and symptoms were recorded for 42 knapsack and 66 tractor-mounted sprayers attending a health camp in North India in 2009 and for 30 controls. RESULTS: One hundred and eight of 197 (55%) eligible sprayers consented to participate. Mean acetylcholinesterase (AChE) and butyrylcholinesterase activity was 33 and 60% lower, respectively, in knapsack sprayers than in controls (P < 0.001) and 56 and 62% lower, respectively, in tractor-mounted sprayers than in controls (P < 0.001). AChE depletion was greater in tractor-mounted sprayers than in knapsack sprayers (P < 0.001). In knapsack sprayers compared to controls, odds ratios (OR) were significantly raised for musculoskeletal symptoms (OR 3.9, 95% CI 1.03-18) but not for other symptoms. In tractor-mounted sprayers compared to controls, ORs were significantly raised for neurological (OR 7, 95% CI 2-23), ocular (OR 8.7, 95% CI 2.7-32), respiratory (OR 5.14, 95% CI 1-29), cardiovascular (OR 7.5, 95% CI 2-42), gastrointestinal (OR 5.43, 95% CI 2-18) and musculoskeletal (OR 6.12, 95% CI 2-26) symptoms but not for dermal symptoms (OR 1.93, 95% CI 0.3-20). CONCLUSIONS: The risk of cholinesterase inhibition and symptoms is greater in tractor-mounted than in knapsack pesticide sprayers and in both groups compared to controls. Occupational exposure in pesticide sprayers in North India needs better control, perhaps through redesign of spraying equipment.