296 research outputs found

    Identification of a group of nontuberculous mycobacteria isolated from the South Indian BCG trial area by HPLC

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    Twenty-five isolates of nontuberculous mycobacteria isolated from the South Indian BCG trial area were analysed by high performance liquid chromatography (HPLC) for mycolic acid pattern. The chromatograms differentiated the isolates into four species, namely M. terrae complex, M. intracellulare, M. parafortuitum and M. fortuitum. Three strains were unidentified, one of which did not show any mycolic acid peaks. All isolates had been identified as M. diernhoferi by biochemical methods in a previous study. Nineteen of the isolates were analysed by gas chromatography-mass spectrometry (GC-MS) for the presence of tuberculostearic acid, 2-eicosanol and mycolic acid cleavage products, and were classified as nonchromogens or rapidly growing mycobacteria. The results show that HPLC can discriminate the described mycobacterial species better than biochemical methods and GC-MS

    Electronic phase separation in the rare earth manganates, (La1-xLnx)0.7Ca0.3MnO3 (Ln = Nd, Gd and Y)

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    All the three series of manganates showsaturation magnetization characteristic of ferromagnetism, with the ferromagnetic Tc decreasing with increasing in x up to a critical value of x, xc (xc = 0.6, 0.3, 0.2 respectively for Nd, Gd, Y). For x > xc, the magnetic moments are considerably smaller showing a small increase around TM, the value of TM decreasing slightly with increase in x or decrease in . The ferromagnetic compositions (x xc) show insulator-metal (IM) transitions, while the compositions with x > xc are insulating. The magnetic and electrical resistivity behavior of these manganates is consistent with the occurrence of phase separation in the compositions around xc, corresponding to a critical average radius of the A-site cation, , of 1.18 A. Both Tc and TIM increase linearly when < rA > > or x xc as expected of a homogenous ferromagnetic phase. Both Tc and TM decrease linearly with the A-site cation size disorder at the A-site as measured by the variance s2. Thus, an increase in s2 favors the insulating AFM state. Percolative conduction is observed in the compositions with > < rAc >. Electron transport properties in the insulating regime for x > xc conforms to the variable range hopping mechanism. More interestingly, when x > xc, the real part of dielectric constant (e') reaches a high value (104-106) at ordinary temperatures dropping to a very small (~500) value below a certain temperature, the value of which decreases with decreasing frequency.Comment: 27 pages; 11 figures, Submitted to J.Phys:Condens Matte

    Pyrite nanocrystals: shape-controlled synthesis and tunable optical properties via reversible self-assembly

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    Nanocrystals from non-toxic, earth abundant materials have recently received great interest for their potential large-scale application in photovoltaics and photocatalysis. Here, we report for the first time on the shape-controlled and scalable synthesis of phase-pure pyrite (FeS2) nanocrystals employing the simple, inexpensive, thermal reaction of iron–oleylamine complexes with sulfur in oleylamine. Either dendritic nanocrystals (nanodendrites) or nanocubes are obtained by adjusting the iron-oleylamine concentration and thereby controlling the nucleus concentration and kinetics of the nanocrystal growth. Pyrite nanodendrites are reversibly assembled by washing with toluene and redispersed by adding the ligand oleylamine. The assembly–redispersion-process is accompanied by an increased absorption in the red/near-infrared spectral region for the aggregated state. This increased low-energy absorption is due to interactions between the closed-packed nanocrystals. High-concentration nanodendrite dispersions are used to prepare pyrite thin films with strong broadband extinction in the visible and near-infrared. These films are attractive candidates for light harvesting in all inorganic solar cells based on earth abundant, non-toxic materials as well as for photocatalytic applications

    Reliability of Three Landmarking Methods for Dual Inclinometry Measurements of Lumbar Flexion and Extension

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    Background To examine the intra and inter-rater reliability of lumbar flexion and extension measurements attained using three landmarking methods for dual inclinometry. Methods This was a repeated measures reliability study. Convenience sampling was used to obtain forty volunteer subjects. Two assessors measured a series of lumbar flexion and extension movements using the J-Tech™ dual inclinometer. Three different landmarking methods were used: 1) straight palpation of PSIS and L1, 2) palpation of PSIS and the site of the nearest 5 cm interval point closest to L1 and 3) location of PSIS and 15 cm cephalad. Upon landmarking, adhesive tape was used to mark landmarks and the inclinometer was placed on sites for three trials of flexion and extension. Tape was removed and landmarks were relocated by the same assessor (intra-rater) for an additional three trials; and this process was repeated by a second assessor (inter-rater). Reliability was determined using intra-class correlation coefficients. Results Reliability within a set of three repetitions was very high (ICCs \u3e 0.90); intra-rater reliability after relocating landmarks was high (ICCs \u3e 0.80); reliability between therapists was moderate to high (0.60 \u3e ICCs \u3c 0.76). Assessment of flexion and extension movements by straight palpation of bony landmarks as in the Straight palpation of PSIS and L1 method (ICC: Flexion 0.60; Extension 0.74) was found to be marginally less reliable than the other two landmarking measurement strategies (ICC: Flexion 0.66; Extension 0.76). Conclusion All three methods of land marking are reliable. We recommend the use of the PSIS to 15 cm cephalad method as used in the modified-modified Schobers test as it is the simplest to perform and aligns with current clinical practice

    Morphological, physiological and biochemical trait analysis of maize inbreds under drought conditions

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    Maize (Zea mays L.) is a crucial cereal crop that is highly sensitive to drought, which disrupts its morphological, physiological and biochemical traits, impairing photoassimilate allocation. A 2-year field experiment was conducted to assess drought tolerance mechanisms in 6 maize inbred lines—CBM-DL 38, CBM-DL 111, CBM-DL 238, CBM-DL 448, CBM-DL 360 and UMI 1200—by evaluating morphological, physiological, biochemical changes as well as carbohydrate assimilation during sensitive growth stages. Drought stress was applied at different growth stages and observations were recorded 10 days after stress initiation. Drought stress significantly affected growth stages, canopy traits, carbon assimilation and yields. The chlorophyll index decreased by 17–23%, the vegetative index by 33–36% and chlorophyll fluorescence by 47–48%. Meanwhile, the leaf angle increased to 25–30° and the flagging point ratio was reduced to 0.8, resulting in 56–59% yield reduction. However, CBM-DL 38, CBM-DL 111, CBM-DL 448 and CBM-DL 360 demonstrated enhanced drought tolerance, with reduced malondialdehyde (1.5–1.8 times), increased proline (75–93%), improved antioxidant activities [catalase (52–76%), peroxidase (45–57%)] and higher leaf tissue water content (43–59%). Improved leaf architecture enhanced light captures and resource allocation, reducing oxidative damage and maintaining yields. In contrast, CBM-DL 238 and UMI 1200 showed greater reductions in cob weight and 100-grain weight (47–49%). Drought stress during 35–75 days after sowing (DAS) severely impaired photosynthesis, leading to reduced yields. Enhanced canopy traits and biochemical resilience made CBM-DL 38, CBM-DL 111, CBM-DL 448 and CBM-DL 360 more drought-tolerant

    Heptacarbonyl-1κ3 C,2κ4 C-(4-phenyl­pyridine-1κN)di-μ-phenyltellurido-1:2κ4 Te:Te-dirhenium(I)

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    In the title complex, [Re2(C6H5Te)2(C11H9N)(CO)7], two Re atoms are coordinated in slightly distorted octa­hedral coordination environments and are bridged by two Te atoms, which are coordinated in trigonal-pyramidal environments. The torsion angle for the Te—Re—Te—Re sequence of atoms is 17.06 (3)°. The crystal structure is stabilized by weak C—H⋯O and C—H⋯π inter­actions. In addition, there are Te⋯Te distances [4.0392 (12) Å] and O⋯O distances [2.902 (19) Å] which are shorter than the sum of the van der Waals radii for these atoms. A short inter­molecular lone pair⋯π distance [C O⋯Cg = 3.31 (2) Å] is also observed

    Experiences with implementation of continuous positive airway pressure for neonates and infants in low-resource settings: A scoping review.

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    BACKGROUND: Continuous positive airway pressure (CPAP) is the gold standard of care in providing non-invasive positive pressure support to neonates in respiratory distress in high-resource settings. While safety has been demonstrated in low-resource settings, there is a lack of knowledge on the barriers and facilitators to proper implementation. OBJECTIVE: To identify and describe the barriers, facilitators, and priorities for future implementation of CPAP for neonates and infants in low-resource settings. METHODS: A systematic search (database inception to March 6, 2020) was performed on MEDLINE, Embase, Web of Science, CINAHL, Global Health, and the WHO Global Index Medicus using PRISMA-ScR guidelines. Original research articles pertaining to implementation of CPAP devices in low-resource settings, provider or parent perspectives and experiences with CPAP, cost-benefit analyses, and cost-effectiveness studies were included. Inductive content analysis was conducted. FINDINGS: 1385 article were screened and 54 studies across 19 countries met inclusion criteria. Six major themes emerged: device attributes, patient experiences, parent experiences, provider experiences, barriers, and facilitators. Nasal trauma was the most commonly reported complication. Barriers included unreliable electricity and lack of bioengineering support. Facilitators included training, mentorship and empowerment of healthcare providers. Device design, supply chain infrastructure, and training models were imperative to the adoption and sustainability of CPAP. CONCLUSION: Sustainable implementation of CPAP in low resource settings requires easy-to-use devices, ready access to consumables, and holistic, user-driven training. Further research is necessary on standardizing metrics, interventions that support optimal provider performance, and conditions needed for successful long-term health system integration

    Detecting Endometrial Cancer by Blood Spectroscopy: A Diagnostic Cross-Sectional Study

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    Endometrial cancer is the sixth most common cancer in women, with a rising incidence worldwide. Current approaches for the diagnosis and screening of endometrial cancer are invasive, expensive or of moderate diagnostic accuracy, limiting their clinical utility. There is a need for cost-effective and minimally invasive approaches to facilitate the early detection and timely management of endometrial cancer. We analysed blood plasma samples in a cross-sectional diagnostic accuracy study of women with endometrial cancer (n = 342), its precursor lesion atypical hyperplasia (n = 68) and healthy controls (n = 242, total n = 652) using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and machine learning algorithms. We show that blood-based infrared spectroscopy has the potential to detect endometrial cancer with 87% sensitivity and 78% specificity. Its accuracy is highest for Type I endometrial cancer, the most common subtype, and for atypical hyperplasia, with sensitivities of 91% and 100%, and specificities of 81% and 88%, respectively. Our large-cohort study shows that a simple blood test could enable the early detection of endometrial cancer of all stages in symptomatic women and provide the basis of a screening tool in high-risk groups. Such a test has the potential not only to differentially diagnose endometrial cancer but also to detect its precursor lesion atypical hyperplasia—the early recognition of which may allow fertility sparing management and cancer prevention
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