281 research outputs found

    Electron paramagnetic resonance evidence for Jahn-Teller glasses

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    Single crystal E.P.R. studies of copper as a dopant in lithium potassium sulphate, lithium ammonium sulphate and lithium sodium sulphate have been carried out from room temperature down to 77K. The three Jahn-Teller (JT) systems behave very similarly to one another. The room temperature dynamic JT spectra with giso = 2.19 ± 0.01 and Aiso = ±(33 ± 4)× 10-4 cm-1 transform around 247 K to spectra characterized by randomly frozen-in axial strains with g = 2.4307 ± 0.0005, g = 2.083 ± 0.001, A = ±(116 ± 2) × 10-4 cm-1 and A = ±(14 ± 4) ×10-4 cm-1. We proposed that the low temperature phase (below 247 K) of each of these systems provides an example of a Jahn-Teller glass

    Growth and characterization of benzil single crystals using nanotranslation by the modified vertical Bridgman technique

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    Benzil single crystals have been grown by the modified vertical Bridgman technique using the double wall ampoule with nanotranslation for the first time. The characterization studies of benzil crystals grown by both single and double wall ampoules were analyzed. The grown benzil crystal was confirmed by single crystal and powder X-ray diffraction analyses. Fourier transform infrared analysis confirms the functional groups of the grown benzil. High resolution X-ray diffraction analysis indicates the crystalline perfection of the grown crystals. The UV-Vis-NIR studies show that the grown benzil crystals cutoff wavelength is around 434 nm. The green emission of the grown benzil was identified by photoluminescence studies. The thermal property of the grown benzil was studied by thermogravimetric and differential thermal analyses. The dielectric measurements of benzil crystals were carried out with different frequencies and temperatures and the results indicate an increase in dielectric and conductivity parameters with the increase of temperature at all frequencies. The second harmonic conversion efficiency of the grown benzil was determined

    Design and Implementation of home security system with feedback and control of electric gadgetry

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    An embedded system is designed for providing security to home, as the home security is the more prior among all other aspects which are among to home. The system has two sections, one is main station and other is feedback and control section. The main station consists LPC 2148, HLK-RM04, and feedback and control system consists HLK-RM04, GSM-SIM300, and data processing module

    Altered circulating levels of B cell growth factors and their modulation upon anti-tuberculosis treatment in pulmonary tuberculosis and tuberculous lymphadenitis

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    B cell activating factor/a proliferation-inducing ligand (BAFF/APRIL) are members of the tumor necrosis factor alpha (TNF) α family of ligands, which are essential for B cell survival, development, and modulation of the immune system. To examine the association of circulating levels of BAFF and APRIL with pulmonary tuberculosis (PTB) and tuberculous lymphadenitis (TBL), we measured the systemic levels of APRIL and BAFF in individuals with PTB, TBL, latent tuberculosis (LTB) and healthy controls (HC). Further, we also examined the pre and post-treatment plasma levels of above-mentioned parameters in PTB and TBL individuals upon completion of anti-TB chemotherapy. Next, the association of these cytokines either with extent of disease, disease severity, bacterial burden in PTB and lymph node culture grade or the lymph node size in TBL was also assessed. Finally, ROC analysis was performed to examine the discrimination capacity of APRIL and BAFF between PTB or TBL with LTB. Our study revealed significantly diminished plasma levels of APRIL in PTB and higher plasma levels of BAFF in both PTB and TBL individuals compared to LTB and HC. Furthermore, we observed a significant increase in APRIL levels in TBL and significantly decreased plasma levels of BAFF in both PTB and TBL after the completion of successful anti-TB treatment. There was no statistically positive relationship between BAFF and APRIL levels and the extent of disease, disease severity and bacterial burden in PTB. In TBL, there was a significant correlation between APRIL (but not BAFF) levels with lymph node culture grades. In contrast, APRIL in PTB and BAFF in TBL were able to clearly discriminate from LTB in ROC analysis. In summary, our results showed altered levels of BAFF/APRIL and their modulation upon chemotherapy, suggesting that these cytokines might be involved in the immune-modulation of TB infection

    Plasma chemokines as immune biomarkers for diagnosis of pediatric tuberculosis

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    Abstract Background Diagnosing tuberculosis (TB) in children is challenging due to paucibacillary disease, and lack of ability for microbiologic confirmation. Hence, we measured the plasma chemokines as biomarkers for diagnosis of pediatric tuberculosis. Methods We conducted a prospective case control study using children with confirmed, unconfirmed and unlikely TB. Multiplex assay was performed to examine the plasma CC and CXC levels of chemokines. Results Baseline levels of CCL1, CCL3, CXCL1, CXCL2 and CXCL10 were significantly higher in active TB (confirmed TB and unconfirmed TB) in comparison to unlikely TB children. Receiver operating characteristics curve analysis revealed that CCL1, CXCL1 and CXCL10 could act as biomarkers distinguishing confirmed or unconfirmed TB from unlikely TB with the sensitivity and specificity of more than 80%. In addition, combiROC exhibited more than 90% sensitivity and specificity in distinguishing confirmed and unconfirmed TB from unlikely TB. Finally, classification and regression tree models also offered more than 90% sensitivity and specificity for CCL1 with a cutoff value of 28 pg/ml, which clearly classify active TB from unlikely TB. The levels of CCL1, CXCL1, CXCL2 and CXCL10 exhibited a significant reduction following anti-TB treatment. Conclusion Thus, a baseline chemokine signature of CCL1/CXCL1/CXCL10 could serve as an accurate biomarker for the diagnosis of pediatric tuberculosis

    Ternary Cu2SnS3: synthesis, structure, photoelectrochemical activity, and heterojunction band offset and alignment

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    Ternary Cu2SnS3 (CTS) is an attractive nontoxic and earth-abundant absorber material with suitable optoelectronic properties for cost-effective photoelectrochemical applications. Herein, we report the synthesis of high-quality CTS nanoparticles (NPs) using a low-cost facile hot injection route, which is a very simple and nontoxic synthesis method. The structural, morphological, optoelectronic, and photoelectrochemical (PEC) properties and heterojunction band alignment of the as-synthesized CTS NPs have been systematically characterized using various state-of-the-art experimental techniques and atomistic first-principles density functional theory (DFT) calculations. The phase-pure CTS NPs confirmed by X-ray diffraction (XRD) and Raman spectroscopy analyses have an optical band gap of 1.1 eV and exhibit a random distribution of uniform spherical particles with size of approximately 15–25 nm as determined from high-resolution transmission electron microscopy (HR-TEM) images. The CTS photocathode exhibits excellent photoelectrochemical properties with PCE of 0.55% (fill factor (FF) = 0.26 and open circuit voltage (Voc) = 0.54 V) and photocurrent density of −3.95 mA/cm2 under AM 1.5 illumination (100 mW/cm2). Additionally, the PEC activities of CdS and ZnS NPs are investigated as possible photoanodes to create a heterojunction with CTS to enhance the PEC activity. CdS is demonstrated to exhibit a higher current density than ZnS, indicating that it is a better photoanode material to form a heterojunction with CTS. Consistently, we predict a staggered type-II band alignment at the CTS/CdS interface with a small conduction band offset (CBO) of 0.08 eV compared to a straddling type-I band alignment at the CTS/ZnS interface with a CBO of 0.29 eV. The observed small CBO at the type-II band aligned CTS/CdS interface points to efficient charge carrier separation and transport across the interface, which are necessary to achieve enhanced PEC activity. The facile CTS synthesis, PEC measurements, and heterojunction band alignment results provide a promising approach for fabricating next-generation Cu-based light-absorbing materials for efficient photoelectrochemical applications
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