Modulation of intrinsic defects in vertically grown ZnO nanorods by ion implantation.

Intrinsic defects created by chemically inert gas (Xe) ion implantation in vertically grown ZnO nanorods are studied by optical and X-ray absorption spectroscopy (XAS). The surface defects produced due to dynamic sputtering by ion beams control the fraction of O and Zn with ion fluence, which helps in tuning the optoelectronic properties. The forbidden Raman modes related to Zn interstitials and oxygen vacancies are observed because of the weak Fröhlich interaction, which arises due to disruption of the long-range lattice order. The evolution of the lattice disorder is identified by O K-edge and Zn K-edge scans of XAS. The hybridization strength between the O 2p and Zn 4p states increases with ion fluence and modulates the impact of intrinsic defects. The ion irradiation induced defects also construct intermediate defects bands which reduce the optical bandgap. Density functional theory (DFT) calculations are used to correlate the experimentally observed trend of bandgap narrowing with the origin of electronic states related to Zn interstitial and O vacancy defects within the forbidden energy gap in ZnO. Our finding can be beneficial to achieve enhanced conductivity in ZnO by accurately varying the intrinsic defects through ion irradiation, which may work as a tuning knob to control the optoelectronic properties of the system.

Anthropogenic arsenic menace in contaminated water near thermal power plants and coal mining areas of India.

Coal mining and coal combustion in thermal power plants (TPPs) are the major anthropogenic sources of arsenic (As) contamination in many different industrial regions. In this study of industrial regions of West Bengal and Singrauli, it is observed that there is an anthropogenic contribution to the contamination from As-bearing coal. Up to 14.53 mg/kg of As is obtained in coal of West Bengal which also has very high average Fe concentration (16,095 mg/kg) along with high concentration of Cu, Mn and Hg. Similar observations are also found in Singrauli Industrial Region where 3.14 mg/kg of As with very high concentration of Fe 43,867 mg/kg along with high Cu, Mn and Hg concentration is found in coal samples. This low-grade bituminous coal contains arsenopyrite as observed by SEM-EDX. Arsenopyrite is converted to arsenolite upon combustion in these TPPs as observed in XRD. The fly ash has average As concentration of 1.53 mg/kg for West Bengal and 2.38 mg/kg for Singrauli Industrial Region and high concentration of toxic elements. The soil near these TPPs and mining areas is enriched in As, Fe, Hg, Cu and Mn. Not only As but high concentrations of Fe, Hg, Mn are also observed from analysis of water which relates to the anthropogenic inputs. The dissolution of arsenolite in reducing environments caused by periodic flooding releases As into water. Hence, the As contamination in the study area also has anthropogenic origin from coal consumption in TPPs.

Deciphering the role of meteorological parameters controlling the sediment load and water discharge in the Sutlej basin, Western Himalaya.

The Sutlej River basin of the western Himalaya (study area), owing to its unique geographical disposition, receives precipitation from both the Indian summer monsoon (ISM) and the Westerlies. The characteristic timing and intensity of the ISM and Westerlies, leaves a distinct footprint on the sediment load of the River. Analysis with the last forty years data, shows an increasing trend for temperature. While for precipitation during the same period, the Spiti watershed on the west has highest monthly accumulated precipitation with long term declining trend, in contrast to the other areas where an increasing trend has been observed. Thus, to probe the hydrological variability and the seasonal attributes, governed by the Westerlies and ISM in the study area, we analyzed precipitation, temperature, snow cover area (in %), discharge, suspended sediment concentration (SSC) and suspended sediment load (SSL) for the period 2004 - 2008. To accomplish the task, we used the available data of five hydrological stations located in the study area. Inter-annual shift in peak discharge during the monsoon period is controlled by the variation in precipitation, snow melt, glacier melt and temperature. Besides seasonal variability has been observed in generation of the sediments and its delivery to the river. Our analysis indicates, dominance of the Westerlies footprints in the hydrological parameters of the Spiti region, towards western part of the study area. While, it is observed that the hydrology of the Khab towards eastern part of the study area shows dominance of ISM. Further downstream, the hydrology of Nathpa station also shows dominance of ISM. It also emerged out that the snowmelt contribution to the River flow is mostly during the initial part, at the onset of the monsoon, while for rest and major part of the summer monsoon season, the River flow is augmented by the precipitation, glacial melt and some snow melt. We observed, that the SSC increases exponentially in response to increase in temperature and correlates positively with River discharge. The average daily SSL in the summer monsoon is many times more than that in the winter monsoon. The downstream decrease in steepness of the sediment rating curve is attributed to either a change in the River-sediment dynamics or on account of the anthropogenic forcing. The top 1% of the extreme summer monsoon events (only 4 events) in our study area contribute up to 45% of SSL to the total sediment load budget. It has also been observed that the River-sediment dynamics in the upstream catchments are more vulnerable and sensitive to the extreme events in comparison to the downstream catchments. The present study for the first time gives a holistic insight in to the complex dynamics of the hydrological processes operational in the study area. The research findings would be crucial for managing the water resources of the region and the linked water and food security.

Findings from the 2017 HIV estimation round & trend analysis of key indicators 2010-2017: Evidence for prioritising HIV/AIDS programme in India.

Background & objectives: The National AIDS Control Organisation (NACO) and the ICMR-National Institute of Medical Statistics, the nodal agency for conducting HIV estimations in India, have been generating HIV estimates regularly since 2003. The objective of this study was to describe India's biennial HIV estimation 2017 process, data inputs, tool, methodology and epidemiological assumptions used to generate the HIV estimates and trends of key indicators for 2010-2017 at national and State/Union Territory levels. Methods: Demographic Projection (DemProj) and AIDS Impact Modules (AIM) of Spectrum 5.63 software recommended by the United Nations Programme on HIV and AIDS Global Reference Group on HIV Estimates, Modelling and Projections, were used for generating HIV estimations on key indicators. HIV sentinel surveillance, epidemiological and programme data were entered into Estimation Projection Package (EPP), and curve fitting was done using EPP classic model. Finally, calibration was done using the State HIV prevalence of two rounds of National Family Health Survey (NFHS) -3 and -4 and Integrated Biological and Behavioural Surveillance (IBBS), 2014-2015. Results: The national adult prevalence of HIV was estimated to be 0.22 per cent in 2017. Mizoram, Manipur and Nagaland had the highest prevalence over one per cent. An estimated 2.1 million people were living with HIV in 2017, with Maharashtra estimated to have the highest number. Of the 88 thousand annual new HIV infections estimated nationally in 2017, Telangana accounted for the largest share. HIV incidence was found to be higher among key population groups, especially people who inject drugs. The annual AIDS-related deaths were estimated to be 69 thousand nationally. For all indicators, geographic variation in levels and trends between States existed. Interpretation & conclusions: With a slow decline in annual new HIV infections by only 27 per cent from 2010 to 2017 against the national target of 75 per cent by 2020, the national target to end AIDS by 2030 may be missed; although at the sub-national level some States have made better progress to reduce new HIV infection. It calls for reinforcement of HIV prevention, diagnosis and treatment efforts by geographical regions and population groups.

Redundant and regulatory roles for Toll-like receptors in Leishmania infection.

Toll-like receptors (TLRs) are germline-encoded, non-clonal innate immune receptors, which are often the first receptors to recognize the molecular patterns on pathogens. Therefore, the immune response initiated by TLRs has far-reaching consequences on the outcome of an infection. As soon as the cell surface TLRs and other receptors recognize a pathogen, the pathogen is phagocytosed. Inclusion of TLRs in the phagosome results in quicker phagosomal maturation and stronger adaptive immune response, as TLRs influence co-stimulatory molecule expression and determinant selection by major histocompatibility complex (MHC) class II and MHC class I for cross-presentation. The signals delivered by the TCR-peptide-MHC complex and co-stimulatory molecules are indispensable for optimal T cell activation. In addition, the cytokines induced by TLRs can skew the differentiation of activated T cells to different effector T cell subsets. However, the potential of TLRs to influence adaptive immune response into different patterns is severely restricted by multiple factors: gross specificity for the molecular patterns, lack of receptor rearrangements, sharing of limited number of adaptors that assemble signalling complexes and redundancy in ligand recognition. These features of apparent redundancy and regulation in the functioning of TLRs characterize them as important and probable contributory factors in the resistance or susceptibility to an infection.

The influence of carbon concentration on the electronic structure and magnetic properties of carbon implanted ZnO thin films.

The influence of carbon concentration on the electronic and magnetic properties of C-implanted ZnO thin films has been studied using synchrotron radiation based X-ray absorption spectroscopic techniques and vibrating sample magnetometer measurements. 20 keV carbon ions were implanted in ZnO films with different fluences (2 × 1016, 4 × 1016 and 6 × 1016 ions per cm2). The pristine ZnO film shows diamagnetic behaviour while the C-implanted films exhibit room temperature ferromagnetism. Our first-principles calculations based on density functional theory show an appreciable magnetic moment only when the implanted C atom sits either in the O-site (2 µB) or in the interstitial position (1.88 µB), whereas the C atom in the Zn substitutional position does not possess any magnetic moment. X-ray absorption near edge structure analysis at the O K-edge reveals that the charge transfer from O-2p to the C-defect site causes the ferromagnetism in the C-implanted ZnO film at low fluence. However at high fluence, the implanted C replaces the lattice and produces more Zn vacancies, as evidenced by extended X-ray absorption fine structure studies at the Zn K-edge, which favors the ferromagnetism. The persistence of the implanted carbon and ferromagnetism of the C-implanted ZnO film has also been studied by isothermal annealing at 500 °C and discussed in detail.

Efficient multicolor tunability of ultrasmall ternary-doped LaF3 nanoparticles: energy conversion and magnetic behavior.

Luminescence-tunable multicolored LaF3:xCe3+,xGd3+,yEu3+ (x = 5; y = 1, 5, 10, and 15 mol%) nanoparticles have been synthesized via a low cost polyol method. Powder X-ray diffraction and high-resolution transmission electron microscopy studies confirm the hexagonal phase of the LaF3:xCe3+,xGd3+,yEu3+ nanophosphors with average sizes (oval shape) ranging from 5 to 7 nm. Energy-dispersive X-ray spectroscopy analyses show the uniform distribution of Ce3+, Gd3+, and Eu3+ dopants in the LaF3 host matrix. The photoluminescence spectra and electron paramagnetic resonance measurements guarantee the presence of Eu2+, corroborated through DC susceptibility measurements of the samples displaying paramagnetic behavior at 300 K, whereas weak ferromagnetic ordering is shown at 2 K. The non-radiative energy transfer processes from the 4f(2F5/2) → 5d state (Ce3+) to the intraconfigurational 4f excited levels of rare earth ions and simultaneous emissions in the visible region from the 4f65d1 (Eu2+) and 5D0 (Eu3+) emitting levels, leading to overlapped broad and narrow emission bands, have been proclaimed. The energy transfer mechanism proposes involvement of the Gd3+ ion sub-lattice as the bridge and finally trapping by Eu2+/3+, upon excitation of the Ce3+ ion. The calculation of experimental intensity parameters (Ω2,4) has been discussed and the highest emission quantum efficiency (η = 85%) of the Eu3+ ion for the y = 10 mol% sample is reported. The advantageous existence of the Eu2+/Eu3+ ratio along with variously doped nanomaterials described in this work, results in tunable emission color in the blue-white-red regions, highlighting the potential application of the samples in solid-state lighting devices, scintillation devices, and multiplex detection.

Synthesis, phase composition, Mössbauer and magnetic characterization of iron oxide nanoparticles.

The present work describes the synthesis of iron oxide nanoparticles by thermal decomposition of Fe-precursors in argon and vacuum environments with control over particle size distribution, phase composition and the resulting magnetic properties. The Rietveld refinement analysis of X-ray diffraction data revealed the crystallinity as well the single-phase of γ-Fe2O3 nanoparticles prepared under vacuum, whereas the argon environment leads to the formation of multi-phase composition of γ-Fe2O3/Fe3O4 (90%) and wustite (10%). Synchrotron X-ray absorption near edge structure (XANES) indicates that the predominant phase in both samples is γ-Fe2O3, which is subsequently verified from the Mössbauer spectra. DC magnetic measurements indicate behavior typical of a superparamagnetic system validated by Mössbauer analysis. However, further investigation of ac susceptibility by typical Néel-Arrhenius and Vogel Fulcher magnetic models suggests an influence of interparticle interactions on the overall magnetic behavior of the system.

Electronic structure modification and Fermi level shifting in niobium-doped anatase titanium dioxide thin films: a comparative study of NEXAFS, work function and stiffening of phonons.

The electronic structure and tuning of work function (WF) by electronic excitations (EEs) induced by swift heavy ions (SHIs) in anatase niobium-doped titanium dioxide (NTO) thin films is reported. The densities of EEs were varied using 80 MeV O, 130 MeV Ni and 120 MeV Ag ions for irradiation. The EE-induced modifications in electronic structure were studied by O K-edge and Ti L3,2 edge absorption spectra using near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The reduction of hybridized O 2p and Ti 3d unoccupied states in the conduction band with a decrease in energy of the crystal field strength of ∼ 480 meV and the correlated effect on the decrease in the WF value of ∼ 520 meV upon increasing the total energy deposition in the lattice are evident from the study of NEXAFS and scanning Kelvin probe microscopy (SKPM), respectively. The observed stiffening in the low frequency Raman mode (LFRM) of ∼ 9 cm(-1) further validates the electronic structure modification under the influence of EE-induced strain in TiO6 octahedra. The reduction of hybridized valence states, stiffening behavior of LFRM and decrease in WF by nano-crystallization followed by amorphization and defects in NTO lattice are explained in terms of continuous, discontinuous amorphous ion tracks containing intestinally created defects and non-stoichiometry in the lattice. These studies are very appropriate for better insights of electronic structure modification during phase transformation and controlled Fermi level shifting, which plays a crucial role in controlling the charge carrier injection efficiency in opto-electronic applications and also provides a deeper understanding of the involved physical processes.

Toll-like receptors and CD40 modulate each other's expression affecting Leishmania major infection.

Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns and results in innate immune system activation that results in elicitation of the adaptive immune response. One crucial modulator of the adaptive immune response is CD40. However, whether these molecules influence each other's expression and functions is not known. Therefore, we examined the effects of TLRs on CD40 expression on macrophages, the host cell for the protozoan parasite Leishmania major. While polyinosinic-polycytidylic acid [poly (I:C)], a TLR-3 ligand, lipopolysaccharide (LPS), a TLR-4 ligand, imiquimod, a TLR-7/8 ligand and cytosine-phosphate-guanosine (CpG), a TLR-9 ligand, were shown to enhance CD40 expression, CD40 stimulation enhanced only TLR-9 expression. Therefore, we tested the synergism between CD40 and CpG in anti-leishmanial immune response. In Leishmania-infected macrophages, CpG was found to reduce CD40-induced extracellular stress-regulated kinase (ERK)1/2 activation; with the exception of interleukin (IL)-10, these ligands had differential effects on CD40-induced IL-1α, IL-6 and IL-12 production. CpG significantly enhanced the anti-leishmanial function of CD40 with differential effects on IL-4, IL-10 and interferon (IFN)-γ production in susceptible BALB/c mice. Thus, we report the first systematic study on CD40-TLR cross-talk that regulated the experimental L. major infection.

Resonant scattering and diffraction beamline P09 at PETRA III.

The resonant scattering and diffraction beamline P09 at PETRA III is designed for X-ray experiments requiring small beams, energy tunability, variable polarization and high photon flux. It is highly flexible in terms of beam size and offers full higher harmonic suppression. A state-of-the-art double phase-retarder set-up provides variable linear or circular polarization. A high-precision Psi-diffractometer and a heavy-load diffractometer in horizontal Psi-geometry allow the accommodation of a wide variety of sample environments. A 14 T cryo-magnet is available for scattering experiments in magnetic fields.

Electric-field-induced polar order and localization of the confined electrons in LaAlO3/SrTiO3 heterostructures.

With ellipsometry, x-ray diffraction, and resistance measurements we investigated the electric-field effect on the confined electrons at the LaAlO3/SrTiO3 interface. We obtained evidence that the localization of the electrons at negative gate voltage is induced, or at least enhanced, by a polar phase transition in SrTiO3 which strongly reduces the lattice polarizability and the subsequent screening. In particular, we show that the charge localization and the polar order of SrTiO3 both develop below ∼50 K and exhibit similar, unipolar hysteresis loops as a function of the gate voltage.

Long-term variability of trace gases over the Indian Western Himalayan Region.

The four-year continuous measurements of CO, NOx, NH3, SO2, and O3 were carried at a high altitude site (32.12°N, 76.56°E at 1347 m AMSL) of the Indian Western Himalayan area to study the mixing ratios of these gases for understanding the changing trends of these trace gases over the region. Each of these trace gases showed significant daily and monthly variabilities. The highest variability was recorded in the monthly mean values of O3 as it varied from 10 to 63 ppb during the study period. All the trace gases except CO showed maximum variability in the pre-monsoon seasons due to the strong advection and vertical circulation of air masses at the site. The seasonal mean maxima of CO were recorded during the monsoon season, while the mean maxima of NH3 were recorded during the post-monsoon seasons. The meteorological parameters have been found to influence the mixing ratios of trace gases. The least variability in the mean seasonal mixing ratios of SO2 during the study period indicated the constant point source of SO2 near the site. The trajectories analysis revealed that the area receives maximum air masses from the southeast to the west directions where a number of the coal-based thermal power plants, industries, cement plants, and agricultural fields are also located. The influence of valley-to-mountain circulations was also observed at the site, resulting in the transport of pollutant-rich air masses from local and distant sources to the site. A comparison of the mixing ratios of different trace gases obtained in the present study is also made with the values reported for other high altitude stations in the world.

Women in Neurosurgery: Historical Path to Self-Segregation and Proposal for an Integrated Future.

Despite the rising percentage of women accessing the medical profession over the last few decades, surgical specialties are still largely male-dominated; in particular, a remarkable gender disparity is evident in neurosurgery, where only 19% of practitioners are females. Although women may be reluctant to choose a challenging specialty like neurosurgery due to concerns around how to balance family and career, it must be admitted that prejudices against female neurosurgeons have been deeply rooted for long, prompting many to give up and switch track to less demanding subspecialties. Among those who have persisted, many, if not most, have experienced difficulties in career progression and received unequal treatment in comparison with their male counterparts. In 1989, a group of 8 female neurosurgeons founded Women in Neurosurgery (WINS), an organization that aimed to guarantee inclusivity in neurosurgery, encouraging a better and more egalitarian working environment. Thereafter, WINS sessions were regularly promoted at international conferences, offering female neurosurgeons a platform to report issues related to gender discrimination. Over recent years, the mission of WINS sessions in national and international conferences has taken an unexpected deviation; they have progressively become supplementary scientific sessions with only women neurosurgeons as speakers, thus paving the road to a form of self-segregation. This tendency has also resulted in the establishment of sections of only female neurosurgeons within some national societies. Although there remains a faction that fiercely supports the WINS mindset of reserved spaces for women, such segregation is an upsetting prospect for those who believe that science and professionalism have no gender; a growing part of the global neurosurgical community believes that the conception of a "female neurosurgery" and a "male neurosurgery" is misguided and counterproductive and consider the existence of the WINS as anachronistic and no longer necessary.

Prevalence of diabetes and prediabetes (impaired fasting glucose and/or impaired glucose tolerance) in urban and rural India: phase I results of the Indian Council of Medical Research-INdia DIABetes (ICMR-INDIAB) study.

AIMS/HYPOTHESIS: This study reports the results of the first phase of a national study to determine the prevalence of diabetes and prediabetes (impaired fasting glucose and/or impaired glucose tolerance) in India. METHODS: A total of 363 primary sampling units (188 urban, 175 rural), in three states (Tamilnadu, Maharashtra and Jharkhand) and one union territory (Chandigarh) of India were sampled using a stratified multistage sampling design to survey individuals aged ≥ 20 years. The prevalence rates of diabetes and prediabetes were assessed by measurement of fasting and 2 h post glucose load capillary blood glucose. RESULTS: Of the 16,607 individuals selected for the study, 14,277 (86%) participated, of whom 13,055 gave blood samples. The weighted prevalence of diabetes (both known and newly diagnosed) was 10.4% in Tamilnadu, 8.4% in Maharashtra, 5.3% in Jharkhand, and 13.6% in Chandigarh. The prevalences of prediabetes (impaired fasting glucose and/or impaired glucose tolerance) were 8.3%, 12.8%, 8.1% and 14.6% respectively. Multiple logistic regression analysis showed that age, male sex, family history of diabetes, urban residence, abdominal obesity, generalised obesity, hypertension and income status were significantly associated with diabetes. Significant risk factors for prediabetes were age, family history of diabetes, abdominal obesity, hypertension and income status. CONCLUSIONS/INTERPRETATIONS: We estimate that, in 2011, Maharashtra will have 6 million individuals with diabetes and 9.2 million with prediabetes, Tamilnadu will have 4.8 million with diabetes and 3.9 million with prediabetes, Jharkhand will have 0.96 million with diabetes and 1.5 million with prediabetes, and Chandigarh will have 0.12 million with diabetes and 0.13 million with prediabetes. Projections for the whole of India would be 62.4 million people with diabetes and 77.2 million people with prediabetes.

Effect of camel milk on glucose metabolism in adults with normal glucose tolerance and type 2 diabetes in Raica community: a crossover study.

BACKGROUND: To investigate effects of camel milk consumption on insulin sensitivity and glycemic control in normal and type-2 diabetics of Raika and Non-Raika community. METHODS: 28 raika and non-raika male were enrolled in study, categorized in 2 groups, non-diabetic and diabetic after one month stabilization. Non-diabetics were supplemented with cow milk and diabetics with camel milk; followed by one-month washout period. Afterwards regimen was interchanged for 3 months. Biochemical and anthropometric data was recorded at baseline, after stabilization, before and after washout and at end of study. RESULTS: An improving trend was observed in both the groups for camel milk effect (FBS 203.86 +/- 24.09 to 161.43 +/- 11.39 mg/dl; p<0.05, OGTT 320.86 +/- 25.34 to 213.79 +/- 15.96 mg/dl; p<0.05 in diabetics and FBS 101.79 +/- 3.06 to 96.79 +/- 2.56 mg/dl, OGTT 114.36 +/- 7.99 to 100.36 +/- 6.74 mg/dl in control). HbAlc improved due to camel milk consumption (8.39 +/- 0.64 to 7.27 +/- 0.67%) whereas deteriorated in the case of cow milk (7.36 +/- 0.66 to 8.26 +/- 0.60%) in diabetic group. The HOMA-IR reduced from 13.21 +/- 4.88 to 4.38 +/- 0.75, AUC-glucose from 37253.57 +/- 2859.08 to 30724.29 +/- 3677.33 and AUC-insulin from 5871.86 +/- 1210.73 to 3301.86 +/- 629.98 in the camel milk group. CONCLUSIONS: In type-2 diabetics camel milk reduces FBS, post-prandial glucose and HbA1c. AUC-insulin and AUC-glucose also decreased significantly along with HOMA-IR. It shows hypoglycemic effect of camel milk reducing insulin resistance. (www.actabiomedica.it).

Bovine cancellous xenograft in the treatment of tibial plateau fractures in elderly patients.

The objective was to evaluate the efficacy of xenografts to improve the outcomes in elderly patients with tibial plateau fractures. Nineteen cases with a mean age of 74 years were followed prospectively from 1998 to 2003. Six patients each belonged to Schatzker types III, IV and V and one patient belonged to type II. Open reduction with fixation and xenograft impaction was carried out. Clinical and radiological union was assessed including infection rate, incorporation of the xenograft and average collapse of the fracture. The average union time was 20 weeks. No patient had wound infection and all had excellent incorporation of the xenograft with union. The average collapse was 4 mm on follow-up. This series shows the use of only an xenograft in acute fixation of these fractures with favourable outcome. Furthermore, it reduces operative time, bleeding and associated co-morbidities, which is of more significance in an elderly age group.

Odontoid metastasis: a potential lethal complication.

Nearly one third of cervical spine metastasis has a primary breast malignancy. Patients with cervical metastasis have higher mortality due to advanced stage of the malignancy. Treatment is palliative to relieve pain, prevent pathological fracture, improve mobility and function, and prolong survival. We describe a 40-year-old woman with a history of breast cancer who presented with neck and shoulder pain of 1 week duration with no neurological deficit. Following clinical examination, radiographs taken of the cervical spine was normal. Radiographs repeated 3 weeks later revealed a large lytic lesion of the odontoid occupying 70-80% of the peg. Further investigation including magnetic resonance imaging and bone scan showed no further spinal lesions. She underwent cyclical radiotherapy with complete resolution of the odontoid peg lesion and clinically was asymptomatic at 2 years. Metastatic lesions of the odontoid are atypical, and this case reinforces the necessity of early detection to evade disastrous consequences.

A setup for Seebeck coefficient measurement through controlled heat pulses.

A setup is designed for measuring the Seebeck coefficient (S) of materials in the form of thin films, bars, and wires. The main feature of this setup is its control in heating and cooling cycles. In this setup, a heat pulse is used to generate the temperature gradient. To demonstrate the capabilities of this setup, S versus T of standard wire samples such as Au-Fe (0.07%), chromel, Pt, and thin films of Pt and F doped SnO2 are presented. The standard uncertainty of the repeatability in the S measurement is found to be ∼±0.056 µV/K while the temperature stability is ∼±10 mK (at 320 K), estimated for a chromel wire sample. We have tested the setup in the temperature range 100 K-320 K, while it does not have any intrinsic limitations in going down to liquid He temperatures. For temperatures above 320 K, the limitation is due to gluing materials such as varnish.

High temperature-mediated rocksalt to wurtzite phase transformation in cadmium oxide nanosheets and its theoretical evidence.

Herein, a high temperature-induced phase transformation (PT) in chemically grown CdO thin films is demonstrated, and its corresponding electronic origin further investigated by density functional theory. In particular, the cubic rocksalt to hexagonal wurtzite PT in the CdO thin film annealed at 900 °C was confirmed by X-ray diffraction (XRD), which was consistent with the high-resolution transmission electron microscopy (TEM) results. Moreover, atomic force microscopy and scanning electron microscopy clearly evidenced the morphological evolution via the formation of a nanosheet network in the wurtzite-phase CdO film. The high temperature treatment also led to a significant enhancement in the optical band gap from 2.2 to 3.2 eV, as manifested by UV-visible spectroscopy. The enhanced surface roughness of the nanosheet caused a deviation in the net dipole moment, which may break the polarizable bonds and help in reducing the average dielectric constant, resulting in a band gap opening for the transformed phase. Furthermore, X-ray absorption spectroscopy at the oxygen k-edge revealed a notable shift in the inflection point of the absorption edge, while the X-ray photoelectron spectroscopy (XPS) Cd 3d and O 1s spectra suggested a gradual reduction in the CdO2 phase with an increase in annealing temperature. In addition, different complementary techniques including Rutherford backscattering and Raman spectroscopy were exploited to understand the aforementioned PT and its structural correlation. Finally, molecular dynamics simulation together with density functional theory calculation suggested that the symmetry modification at the Brillouin zone boundary provides a succinct signature for the PT in the CdO thin film.