587 research outputs found

    Theoretical Study of Physisorption of Nucleobases on Boron Nitride Nanotubes: A New Class of Hybrid Nano-Bio Materials

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    We investigate the adsorption of the nucleic acid bases, adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) on the outer wall of a high curvature semiconducting single-walled boron nitride nanotube (BNNT) by first principles density functional theory calculations. The calculated binding energy shows the order: G>A\approxC\approxT\approxU implying that the interaction strength of the (high-curvature) BNNT with the nucleobases, G being an exception, is nearly the same. A higher binding energy for the G-BNNT conjugate appears to result from a stronger hybridization of the molecular orbitals of G and BNNT, since the charge transfer involved in the physisorption process is insignificant. A smaller energy gap predicted for the G-BNNT conjugate relative to that of the pristine BNNT may be useful in application of this class of biofunctional materials to the design of the next generation sensing devices.Comment: 17 pages 6 figure

    Gains From Training in Phonological Awareness in Kindergarten Predict Reading Comprehension in Grade 9

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    The effects of a kindergarten training program in phonological awareness with 209 Swedish-speaking children were followed up until the end of Grade 9. Initial levels of letter knowledge and phonological awareness were positively associated with the level of decoding skill in Grade 3 but not with its growth afterward. The intervention group performed significantly better in decoding in Grade 3, and the difference was maintained until Grade 6. The trained children also scored higher in Grade 9 reading comprehension. Although the results give empirical support for a connection between early phonological awareness training, later word decoding development, and still later reading comprehension, the theoretical explanation for the link between especially word decoding and reading comprehension is far from clear.</p

    The detection of patients at risk of gastrointestinal toxicity during pelvic radiotherapy by electronic nose and FAIMS : a pilot study

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    It is well known that the electronic nose can be used to identify differences between human health and disease for a range of disorders. We present a pilot study to investigate if the electronic nose and a newer technology, FAIMS (Field Asymmetric Ion Mobility Spectrometry), can be used to identify and help inform the treatment pathway for patients receiving pelvic radiotherapy, which frequently causes gastrointestinal side-effects, severe in some. From a larger group, 23 radiotherapy patients were selected where half had the highest levels of toxicity and the others the lowest. Stool samples were obtained before and four weeks after radiotherapy and the volatiles and gases emitted analysed by both methods; these chemicals are products of fermentation caused by gut microflora. Principal component analysis of the electronic nose data and wavelet transform followed by Fisher discriminant analysis of FAIMS data indicated that it was possible to separate patients after treatment by their toxicity levels. More interestingly, differences were also identified in their pre-treatment samples. We believe these patterns arise from differences in gut microflora where some combinations of bacteria result to give this olfactory signature. In the future our approach may result in a technique that will help identify patients at ā€œhigh riskā€ even before radiation treatment is started

    Concept of Pathyapathya w.s.r. to Mutravaha Sroto Vikaras

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    Mutravaha Sroto Vikaras are the diseases of urinary tract including kidney, ureters, urinary bladder and urethra. Prevalence of the disease is on increasing trend every year. In Ayurveda classical texts Mutravaha Srotogata Vikaras are mainly compiled under Mutraghata, Mutrakriksha and Mutrashmari. The risk factors for these Vikaras can be broadly categorised under dietary and non dietary factors. Non dietary factors include age, gender, ethnic background, genetic predisposition, climate, economic status etc. Nothing much can be done with the Non dietary factors. Moreover, dietary factors and lifestyle plays a very important role in initiation, progression as well as regression of the disease. This is an attempt to review the Pathyapathya (Doā€™s &amp; Donā€™ts of diet &amp; lifestyle) related to Mutravaha Srotas

    OC-163 identification of inflammatory bowel disease (IBD) using field asymmetric ion mobility spectrometry (FAIMS)

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    Introduction Resident colonic bacteria, principally anaerobes and firmicutes, ferment undigested fibre. The resultant volatile organic compounds (VOCs) formed are dissolved in the faeces but also absorbed and excreted in the urine. We have previously shown that electronic nose (E-nose) analysis of urine VOCs distinguishes between Crohn's disease (CD), ulcerative colitis (UC) and healthy volunteers (HV): the underlying principle is pattern recognition of disease-specific ā€œchemical fingerprintā€. High-Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) offers a possible alternative. The underlying principle is separation of VOC chemical components based on their different ion mobilties in high electric fields. We performed a pilot study in the above groups, the patients in remission (Rem) or with active disease (AD), to assess if this technology could achieve separation between the groups. The results were validated against E-nose analysis. Methods 59 subjects were studied; HV n=14, UC (Rem) n=18, UC (AD) n=4; CD (Rem) n=19, CD (AD) n=4. Urine samples (7ā€…ml) in universal containers (25ā€…ml) were heated to 40Ā±0.1 C. The headspace (the air above the sample) was then analysed using FAIMS. The data were analysed by Fisher Discriminant Analysis. Results The technique distinguished between the three groups. Additionally, patients with active disease could be distinguished from those in remission. These results were concordant with E-nose analysis. Conclusion This pilot shows that urine VOCs, analysed by the different approaches of E-nose and FAIMS, the latter a novel application, can distinguish the healthy from those with UC and CD when disease is active or in remission. The two technologies together offer a non-invasive approach to diagnosis and follow-up in inflammatory bowel disease

    Spin Density wave instability in a ferromagnet

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    Ferromagnetic (FM) and incommensurate spin-density wave (ISDW) states are an unusual set of competing magnetic orders that are seldom observed in the same material without application of a polarizing magnetic field. We report, for the first time, the discovery of an ISDW state that is derived from a FM ground state through a Fermi surface (FS) instability in Fe3_3Ga4_4. This was achieved by combining neutron scattering experiments with first principles simulations. Neutron diffraction demonstrates that Fe3_3Ga4_4 is in an ISDW state at intermediate temperatures and that there is a conspicuous re-emergence of ferromagnetism above 360 K. First principles calculations show that the ISDW ordering wavevector is in excellent agreement with a prominent nesting condition in the spin-majority FS demonstrating the discovery of a novel instability for FM metals; ISDW formation due to Fermi surface nesting in a spin-polarized Fermi surface.Comment: 6 pages with 4 figures. Supplemental Materials Include

    Penggunaan Metode Semiempirik AM1 Untuk Pemilihan Monomer Fungsional Efektif Pada Prasintesis Polimer Tercetak Diazinon

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    Pemilihan monomer fungsional yang efektif untuk sintesis Molecular Imprinted Polymer (MIP)untuk diazinon dapat dilakukan dengan pendekatan kimia komputasi dengan menerapkan metode semiempirik AM1. Proses seleksi menggunakan parametermomen dipol, energi interaksi, dan ikatan hidrogen yang terbentuk. Energi interaksi yang optimum menunjukkan kompleks yang terbentuk stabildan mengindikasikan MIP akan dapat terbentuk baik.Semua perhitungan pada penelitian ini dilakukan dengan menggunakan software Hyperchem 7.5. Hasil penelitian menunjukkan monomer fungsional efektif untuk prasintesis polimer tercetak diazinon yaitu akrilamida, asam akrilat, asam metakrilat, hidroksi etil metakrilat, asam urokanat, asam itakonat, dan asam urokanat etil ester. Hasil ini secara teoritik dapat memberikan informasi mengenai monomer fungsional efektif yang dapat digunakan sebagai pertimbangan sintesis MIP untuk diazinon dengan selektivitas relatif baik

    Performance of coconut (Cocos nucifera L.) hybrids for yield and quality in the Utkal plain region of Odisha state, India

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    Cocos nucifera L. is a perennial oil yielding crop with a long productive life span (&gt;60 years); thus, identifying a suitable high yielding hybrid to a particular agro-climatic region plays a prime role in achieving sustainable coconut yield. In this context, an evaluation trial with varietal cross combinations involving Tall Ɨ Dwarf (six crosses) and Dwarf Ɨ Tall (two crosses) was conducted at All India Coordinated Research Project (AICRP) on Palms, Bhubaneshwar Centre, Odisha, for 15 years. The experiment was laid out in randomized block design with four replications maintaining six palms per replication. Observations on yield and yield attributing characters during 2018 to 2020 revealed the superior performance of ECT Ɨ GBGD (99.1 nuts), which was followed by ECT Ɨ MYD (86.9 nuts) over the local check (ECT) by recording higher nut yield. Copra output per palm was significantly the highest under ECT Ɨ GBGD (20.6 kg palm-1), followed by LCT Ɨ COD (18.6 kg palm-1). Hybrids possessed a higher quantity of organoleptically ā€˜goodā€™ tender nut water (270.3 to 354.1 mL) with TSS of 5.8 to 6.9 Ā°Brix, 25.4 to 34.0 ppm of sodium and 2065.9 to 2885.0 ppm of potassium

    Areas of Polar Coronal Holes from 1996 Through 2010

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    Polar coronal holes (PCHs) trace the magnetic variability of the Sun throughout the solar cycle. Their size and evolution have been studied as proxies for the global magnetic field. We present measurements of the PCH areas from 1996 through 2010, derived from an updated perimeter-tracing method and two synoptic-map methods. The perimeter tracing method detects PCH boundaries along the solar limb, using full-disk images from the SOlar and Heliospheric Observatory/Extreme ultraviolet Imaging Telescope (SOHO/EIT). One synoptic-map method uses the line-of-sight magnetic field from the SOHO/Michelson Doppler Imager (MDI) to determine the unipolarity boundaries near the poles. The other method applies thresholding techniques to synoptic maps created from EUV image data from EIT. The results from all three methods suggest that the solar maxima and minima of the two hemispheres are out of phase. The maximum PCH area, averaged over the methods in each hemisphere, is approximately 6 % during both solar minima spanned by the data (between Solar Cycles 22/23 and 23/24). The northern PCH area began a declining trend in 2010, suggesting a downturn toward the maximum of Solar Cycle 24 in that hemisphere, while the southern hole remained large throughout 2010
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