BL-02: a versatile X-ray scattering and diffraction beamline for engineering applications at Indus-2 synchrotron source.

A hard X-ray engineering applications beamline (BL-02) was commissioned recently and started operation in March 2019 at the Indian synchrotron source, Indus-2. This bending-magnet-based beamline is capable of operating in various beam modes, viz. white, pink and monochromatic beam. The beamline utilizes the X-ray diffraction technique in energy-dispersive and angle-dispersive modes to carry out experiments mainly focused on engineering problems, viz. stress measurement, texture measurement and determination of elastic constants in a variety of bulk as well as thin-film samples. An open-cradle six-circle diffractometer with ∼12 kg load capacity allows accommodation of a wide variety of engineering samples and qualifies the beamline as a unique facility at Indus-2. The high-resolution mode of this beamline is suitably designed so as to carry out line profile analysis for characterization of micro- and nano-structures. In the present article the beamline is described starting from the beamline design, layout, optics involved, various operational modes and experimental stations. Experiments executed to validate the beamline design parameters and to demonstrate the capabilities of the beamline are also described. The future facilities to be incorporated to enhance the capabilities of the beamline are also discussed.

Noninvasive assessment of cutaneous alterations in mice exposed to whole body gamma irradiation using optical imaging techniques.

We report the results of a study carried out to investigate the potential of optical techniques such as optical coherence tomography, Mueller matrix spectroscopy, and cross-polarization imaging for noninvasive monitoring of the ionizing radiation exposure-induced alterations in cutaneous tissue of mice. Radiation dose-dependent changes were observed in tissue microvasculature and tissue optical parameters like retardance and depolarization as early as 1 h post radiation exposure. Results suggest that these optical techniques may allow early detection of radiation dose-dependent alterations which could help in screening of population exposed to radiation.

Structural variation in a synchrotron-induced contamination layer (a-C:H) deposited on a toroidal Au mirror surface.

A carbon layer deposited on an optical component is the result of complex interactions between the optical surface, adsorbed hydrocarbons, photons and secondary electrons (photoelectrons generated on the surface of optical elements). In the present study a synchrotron-induced contamination layer on a 340 mm × 60 mm Au-coated toroidal mirror has been characterized. The contamination layer showed a strong variation in structural properties from the centre of the mirror to the edge region (along the long dimension of the mirror) due to the Gaussian distribution of the incident photon beam intensity/power on the mirror surface. Raman scattering measurements were carried out at 12 equidistant (25 mm) locations along the length of the mirror. The surface contamination layer that formed on the Au surface was observed to be hydrogenated amorphous carbon film in nature. The effects of the synchrotron beam intensity/power distribution on the structural properties of the contamination layer are discussed. The I(D)/I(G) ratio, cluster size and disordering were found to increase whereas the sp2:sp3 ratio, G peak position and H content decreased with photon dose. The structural parameters of the contamination layer in the central region were estimated (thickness ≃ 400 Å, roughness ≃ 60 Å, density ≃ 72% of bulk graphitic carbon density) by soft X-ray reflectivity measurements. The amorphous nature of the layer in the central region was observed by grazing-incidence X-ray diffraction.

Onset of acute and transient psychotic disorder in India: a study of socio-demographics and factors affecting its outcomes.

OBJECTIVE: Acute and transient psychotic disorder has been accepted as a distinct diagnostic entity in the ICD-10. However, there are few studies delineating its demographics and factors affecting its outcome. This study aimed to examine the socio-demographic profile of patients with acute and transient psychotic disorder and the variables associated with the onset of illness and their effect on illness outcome in an Indian setting. METHODS: This was a retrospective study in which case notes of patients admitted from 1 January to 31 December 2012 and diagnosed with acute and transient psychotic disorder (according to the ICD-10 diagnostic criteria) were analysed. Socio-demographic variables and variables associated with the onset of illness were noted. Duration of hospital stay was used as a proxy measure for clinical outcome. RESULTS: A total of 185 patient records were analysed. Overall, 49% of the patients were males and 51% were females. Most of the cases (60%) were aged between 20 and 39 years. The majority was married, unemployed, educated up to middle school, living in a nuclear family, and had a rural background. Age (p = 0.05) and marital status (p = 0.03) significantly affected the outcome. Overall, 46% of the patients had stress as a precipitating factor, 27% reported substance use, and 23% had a family history of psychiatric illness prior to the onset of their illness. The onset of illness was from May to October in 54% of the patients, with the duration of untreated illness ranging from 7 to 15 days in 38% of the patients. The clinical outcome was significantly affected by duration of untreated illness (p = 0.05). CONCLUSIONS: Acute and transient psychotic disorders show slight female preponderance and occur in early adulthood. There is no precipitating stress in most cases and shorter duration of untreated illness predicts favourable clinical outcome.

Effect of gold nanoparticles on depolarization characteristics of Intralipid tissue phantom.

We report results of studies on the effect of different shapes and sizes of gold nanoparticles (GNPs) on the depolarization characteristics of Intralipid tissue phantoms. For a given extinction coefficient, the absorption characteristics of the GNPs contributed more to the depolarization of the turbid medium, and the contribution of scattering was significant only for the larger-sized particles. For rod-shaped GNPs, their depolarization plays an important role in the low scattering regime in which the depolarization properties of the nanoparticles (NPs) dominate in the turbid medium even if the contribution of the scattering from the NPs is about an order of magnitude less. For highly scattering samples, GNP absorption significantly modulates the depolarization spectra of the turbid medium.

Emotional intelligence, perceived stress and burnout among resident doctors: an assessment of the relationship.

BACKGROUND: Burnout is an increasing problem among the medical fraternity, especially resident doctors. We assessed the relationship between burnout, emotional intelligence and perceived stress in an attempt to explore a probable solution. METHODS: Residents in the departments of medicine (n=29) and surgery (n=27) were assessed with a specially designed proforma consisting of participant's profile sheet, Shirom-Melamed Burnout Measure (SMBM), Trait Emotional Intelligence Questionnaire and Perceived Stress Scale (PSS). Correlation and mediational analysis were used to analyse the data. RESULTS: The findings showed a positive correlation of burnout with perceived stress and a negative correlation with trait emotional intelligence (EI). Perceived stress also showed a negative correlation with trait EI. Mediation analysis showed that perceived stress mediates the effect of trait EI on burnout. CONCLUSION: Enhancing EI through training may be an important intervention for targeting burnout.

Identification of vulnerability among first-degree relatives of patients with schizophrenia.

OBJECTIVES: To evaluate the status of schizotypy, neurological soft signs, and cognitive functions as vulnerability markers for schizophrenia and to investigate the potential value of their combination for early identification of people at high risk for schizophrenia. METHODS: A cross-sectional study was conducted. Subjects were drawn from first-degree relatives of inpatients and outpatients with schizophrenia (n = 50). Controls (n = 30) were recruited by word-of-mouth from hospital staff and attendants of hospitalised patients. Subjects who met inclusion criteria on screening were subjected to selected measures for assessment, including Schizotypal Personality Questionnaire-Brief Version, the Cambridge Neurological Inventory, digit span test, paired associate learning test, and visuospatial working memory matrix. Statistical analysis was completed using the independent t test and significance (p value), as well as calculation of effect size (Cohen's d). Discriminant function analysis was used to determine the effect of combining assessment measures. RESULTS: First-degree relatives showed higher schizotypy scores (Cohen's d = 0.88) and neurological soft signs (Cohen's d = 1.55). They scored significantly worse on all neurocognitive measures (Cohen's d = -1.27). Discriminant function analysis showed that Schizotypal Personality Questionnaire-Brief Version, neurological soft signs, and total cognitive index (the sum of weighted scores on individual cognitive scales) in combination better discriminated between the first-degree relative and control groups (Wilks' λ = 0.54). CONCLUSION: Use of multiple vulnerability markers could enhance the specificity of measures used to determine risk for schizophrenia.

Disability and quality of life in schizophrenia and obsessive compulsive disorder: a cross-sectional comparative study.

OBJECTIVE: To assess and compare the quality of life and disability in patients with schizophrenia and obsessive compulsive disorder. METHODS: A cross-sectional study was carried out in the outpatient psychiatry clinics at Jaipur of India. Fifty patients with obsessive compulsive disorder and 47 with schizophrenia (diagnosed as per criteria of the 10th revision of the International Classification of Diseases), and with a minimum duration of 2 years on maintenance treatments, were evaluated. Evaluation was based on the World Health Organization Quality of Life Instrument, the Global Assessment of Functioning scale, and the Indian Disability Evaluation Assessment Scale. The collected data were analysed using descriptive and inferential statistics. RESULTS: Regarding quality of life domains, there was no statistically significant difference between the 2 groups. Obsessive compulsive disorder patients had lower scores on all domains of disability, all such differences being statistically significant. CONCLUSIONS: The deleterious effect of illness on quality of life and functioning occur not only in schizophrenic but also in obsessive compulsive disorder patients. Thus management should be planned with this consideration to yield better outcomes in both conditions.

Mueller matrix approach for determination of optical rotation in chiral turbid media in backscattering geometry.

For in vivo determination of optically active (chiral) substances in turbid media, like for example glucose in human tissue, the backscattering geometry is particularly convenient. However, recent polarimetric measurements performed in the backscattering geometry have shown that, in this geometry, the relatively small rotation of the polarization vector arising due to the optical activity of the medium is totally swamped by the much larger changes in the orientation angle of the polarization vector due to scattering. We show that the change in the orientation angle of the polarization vector arises due to the combined effect of linear diattenuation and linear retardance of light scattered at large angles and can be decoupled from the pure optical rotation component using polar decomposition of Mueller matrix. For this purpose, the method developed earlier for polar decomposition of Mueller matrix was extended to incorporate optical rotation in the medium. The validity of this approach for accurate determination of the degree of optical rotation using the Mueller matrix measured from the medium in both forward and backscattering geometry was tested by conducting studies on chiral turbid samples prepared using known concentration of scatterers and glucose molecules.

Polar decomposition of 3 x 3 Mueller matrix: a tool for quantitative tissue polarimetry.

The polarization properties of any medium are completely described by the sixteen element Mueller matrix that relates the polarization parameters of the light incident on the medium to that emerging from it. Measurement of all the elements of the matrix requires a minimum of sixteen measurements involving both linear and circularly polarized light. However, for many diagnostic applications, it would be useful if the polarization parameters can be quantified with linear polarization measurements alone. In this paper, we present a method based on polar decomposition of Mueller matrix for quantification of the polarization parameters of a scattering medium using the nine element (3 x 3) Mueller matrix that requires linear polarization measurements only. The methodology for decomposition of the 3 x 3 Mueller matrix is based on the previously developed decomposition process for sixteen element (4 x 4) Mueller matrix but with an assumption that the depolarization of linearly polarized light due to scattering is independent of the orientation angle of the incident linear polarization vector. Studies conducted on various scattering samples demonstrated that this assumption is valid for a turbid medium like biological tissue where the depolarization of linearly polarized light primarily arises due to the randomization of the field vector's direction as a result of multiple scattering. For such medium, polar decomposition of 3 x 3 Mueller matrix can be used to quantify the four independent polarization parameters namely, the linear retardance (delta ), the circular retardance (psi), the linear depolarization coefficient (Delta) and the linear diattenuation (d) with reasonable accuracy. Since this approach requires measurements using linear polarizers only, it considerably simplifies measurement procedure and might find useful applications in tissue diagnosis using the retrieved polarization parameters.