Dissociative multi-photon ionization of isolated uracil and uracil-adenine complexes

Recent multi-photon ionization (MPI) experiments on uracil revealed a fragment ion at m/z 84 that was proposed as a potential marker for ring opening in the electronically excited neutral molecule. The present MPI measurements on deuterated uracil identify the fragment as C3H4N2O+ (uracil+ less CO), a plausible dissociative ionization product from the theoretically predicted open-ring isomer. Equivalent measurements on thymine do not reveal an analogous CO loss channel, suggesting greater stability of the excited DNA base. MPI and electron impact ionization experiments have been carried out on uracil-adenine clusters in order to better understand the radiation response of uracil within RNA. Evidence for C3H4N2O+ production from multi-photon-ionized uracil-adenine clusters is tentatively attributed to a significant population of π-stacked configurations in the neutral beam

Sunlight exposure is just one of the factors which influence Vitamin D status

© The Royal Society of Chemistry and Owner Societies. Studies on the determinants of vitamin D status have tended to concentrate on input-exposure to ultraviolet B radiation and the limited sources in food. Yet, vitamin D status, determined by circulating concentrations of 25-hydroxyvitamin D (25(OH)D), can vary quite markedly in groups of people with apparently similar inputs of vitamin D. There are small effects of polymorphisms in the genes for key proteins involved in vitamin D production and metabolism, including 7-dehydrocholesterol reductase, which converts 7-dehydrocholesterol, the precursor of vitamin D, to cholesterol, CYP2R1, the main 25-hydroxylase of vitamin D, GC, coding for the vitamin D binding protein which transports 25(OH)D and other metabolites in blood and CYP24A1, which 24-hydroxylates both 25(OH)D and the hormone, 1,25-dihydroxyvitamin D. 25(OH)D has a highly variable half-life in blood. There is evidence that the half-life of 25(OH)D is affected by calcium intake and some therapeutic agents. Fat tissue seems to serve as a sink for the parent vitamin D, which is released mainly when there are reductions in adiposity. Some evidence is presented to support the proposal that skeletal muscle provides a substantial site of sequestration of 25(OH)D, protecting this metabolite from degradation by the liver, which may help to explain why exercise, not just outdoors, is usually associated with better vitamin D status

Effect of stage-based education provided by dedicated dietitians on hyperphosphataemic haemodialysis patients: results from the Nutrition Education for Management of Osteodystrophy randomised controlled trial

© 2017 The British Dietetic Association Ltd. Background: The Nutrition Education for Management of Osteodystrophy trial showed that stage-based nutrition education by dedicated dietitians surpasses existing practices in Lebanon with respect to lowering serum phosphorus among general haemodialysis patients. The present study explores the effect of nutrition education specifically on hyperphosphataemic patients from this trial. Methods: Hyperphosphataemic haemodialysis patients were allocated to a dedicated dietitian (DD), a trained hospital dietitian (THD) and existing practice (EP) protocols. From time-point (t)-0 until t-1 (6 months), the DD group (n = 47) received 15 min of biweekly nutrition education by dedicated dietitians trained on renal nutrition; the THD group (n = 89) received the usual care from trained hospital dietitians; and the EP group (n = 42) received the usual care from untrained hospital dietitians. Patients were followed-up from t-1 until t-2 (6 months). Analyses used two-way repeated measures analysis of variance and Cohen\u27s effect sizes (d). Results: At t-1, phosphataemia significantly decreased in all groups (DD:−0.27 mmol L−1; EP:−0.15 mmol L−1; THD:−0.12 mmol L−1; P \u3c 0.05); the DD protocol had the greatest effect relative to EP (d = −0.35) and THD (d = −0.50). Only the DD group showed more readiness to adhere to a low phosphorus diet at t-1; although, at t-2, this regressed to baseline levels. The malnutrition inflammation score remained stable only in the DD group, whereas the EP and THD groups exhibited a significant increase (DD: 6.74, 6.97 and 7.91; EP: 5.82, 8.69 and 8.13; THD: 5.33, 7.92 and 9.42, at t-0, t-1 and t-2, respectively). Conclusions: The results of the present study suggest that the DD protocol decreases serum phosphorus compared to EP and THD, at the same time as maintaining the nutritional status of hyperphosphataemic haemodialysis patients. Assessing the cost-effectiveness of the DD protocol is recommended

U.V. spectra parameters to investigate the influences of intensifications of soybean with sorghum and maize on the physical properties of soybean seed oils

Using U.V. spectra measurements as a tool to investigate the influences of intensifications or intercroping of crops on the physical properties of the constituents of the yielded grains or seeds. In this paper the authors used U.V. spectra measurement to deduce the effects of intensifications of Clark and Crowmord soybean varieties on some sorghum and maize varieties on the physical properties of the oils of the soybean seed varieties. Results of this work revealed that the highest U.V. spectra measurements at bands 270 nm, were 2.5 for the oils of Crowmord soybean seed variety intensificated on Giza 15 sorghum variety intensity 2:4 (2 rows soybean: 4 rows sorghum) and Giza 2, Hz 215 and Hz 310 maize varieties, intensity 2:2, 2:4, 2:4 and 2:2 respectively in the regions of spectra differences. The intensification of Clark and Crowmord soybean varieties on sorghum and maize is effective as the physical properties of their oils improved by increasing the cromophor and carotenoids compound levels.Se usaron medidas de espectros U.V. como una herramienta para investigar las influencias de intensificaciones o intercultivos sobre las propiedades físicas de los constituyentes de granos o semillas producidos. En este trabajo el autor usó medidas de espectros U.V. para deducir los efectos de intensificaciones de variedades de soja Clark y Crowmord con variedades de sorgo y maíz sobre las propiedades físicas de los aceites de soja. Los resultados de este trabajo revelaron que los valores de espectros U.V. más elevados a 270 nm, fueron 2'5 para los aceites de variedades de semilla de soja Crowmord intensificado con la variedad sorgo Giza 15 (2 filas soja: 4 filas sorgo) y las variedades de maíz Giza 2 (2:2 y 2:4), Hz 215 (2:4) y Hz 310 (2:2). La intensificación de variedades de soja Clark y Crowmord con sorgo y maíz es efectiva, ya que las propiedades físicas de sus aceites mejoraron por aumento de los niveles de compuestos cromóforos y carotenoides

Parámetros de espectros U.V. para investigar las influencias de intensificaciones de cultivos de soja con sorgo y maíz sobre las propiedades físicas de aceites de soja

Using U.V. spectra measurements as a tool to investigate the influences of intensifications or intercroping of crops on the physical properties of the constituents of the yielded grains or seeds. In this paper the authors used U.V. spectra measurement to deduce the effects of intensifications of Clark and Crowmord soybean varieties on some sorghum and maize varieties on the physical properties of the oils of the soybean seed varieties. Results of this work revealed that the highest U.V. spectra measurements at bands 270 nm, were 2.5 for the oils of Crowmord soybean seed variety intensificated on Giza 15 sorghum variety intensity 2:4 (2 rows soybean: 4 rows sorghum) and Giza 2, Hz 215 and Hz 310 maize varieties, intensity 2:2, 2:4, 2:4 and 2:2 respectively in the regions of spectra differences. The intensification of Clark and Crowmord soybean varieties on sorghum and maize is effective as the physical properties of their oils improved by increasing the cromophor and carotenoids compound levels.Se usaron medidas de espectros U.V. como una herramienta para investigar las influencias de intensificaciones o intercultivos sobre las propiedades físicas de los constituyentes de granos o semillas producidos. En este trabajo el autor usó medidas de espectros U.V. para deducir los efectos de intensificaciones de variedades de soja Clark y Crowmord con variedades de sorgo y maíz sobre las propiedades físicas de los aceites de soja. Los resultados de este trabajo revelaron que los valores de espectros U.V. más elevados a 270 nm, fueron 2'5 para los aceites de variedades de semilla de soja Crowmord intensificado con la variedad sorgo Giza 15 (2 filas soja: 4 filas sorgo) y las variedades de maíz Giza 2 (2:2 y 2:4), Hz 215 (2:4) y Hz 310 (2:2). La intensificación de variedades de soja Clark y Crowmord con sorgo y maíz es efectiva, ya que las propiedades físicas de sus aceites mejoraron por aumento de los niveles de compuestos cromóforos y carotenoides

Potent Delivery of Functional Proteins into Mammalian Cells in Vitro and in Vivo Using a Supercharged Protein

The inability of proteins to potently penetrate mammalian cells limits their usefulness as tools and therapeutics. When fused to superpositively charged GFP, proteins rapidly (within minutes) entered five different types of mammalian cells with potency up to ∼100-fold greater than that of corresponding fusions with known protein transduction domains (PTDs) including Tat, oligoarginine, and penetratin. Ubiquitin-fused supercharged GFP when incubated with human cells was partially deubiquitinated, suggesting that proteins delivered with supercharged GFP can access the cytosol. Likewise, supercharged GFP delivered functional, nonendosomal recombinase enzyme with greater efficiencies than PTDs in vitro and also delivered functional recombinase enzyme to the retinae of mice when injected in vivo.Chemistry and Chemical Biolog

A prospective antibiotic point prevalence survey in two primary referral hospitals during and after pilgrims stay in Madinah, Saudi Arabia

Purpose: To assess current patterns of antibiotic use by carrying out two point-prevalence surveys (PPS) in Madinah after the return of hajj pilgrims from Makkah and when Madinah is free from pilgrims. Methods: In September 2016 and November 2016, a prospective PPS was conducted on two separate dates (during the hajj pilgrims stay in Madinah and after they leave). Data on antibiotics use were generated during these two periods. This involved an audit from all the departments of two referral hospitals (King Fahad Hospital (KFH) - 425 beds, and Al Ansar Hospital - 100 beds) of inpatients records. Data were collected using standard forms adapted from the European Centre for Disease Control (ECDC). Results: A total of 675 inpatients were included in PPS; among them, 332 (49.18 %) patients were receiving antibiotic therapy. In September 2016, 168 patients were treated with antibiotics, with a prevalence rate of 50.60 %, whereas, in November 2016, the prevalence rate was 49.40 %. Overall, 198 patients were identified in surgical wards, of which 132 patients (66.6 %) were receiving antibiotic therapy; 121 patients in ICU of which 70 patients (57.8 %) received antibiotics; 13 patients in other wards of which 6 (46.1 %) received antibiotic treatment; and 343 patients in medical wards of which 126 patients (36.7 %) were treated with antibiotics. There was no significant difference in prevalence of antibiotic prescribing between the two surveys (Pearson Chi-square test, p = 0.56) and with regards to patient age between the two surveys (Mann-Whitney U-test, p = 0.32). Conclusion: The results demonstrate that antibiotic use with adherence to hospital guidelines and PPS helps in identifying targets for quality improvement. Moreover, to escalate the prudent use of antibiotics in hospitals, PPS provides a useful tool. Furthermore, this survey provides a background to evaluate antibiotic use by a standardized methodology. Keywords: Point prevalence survey, Antibiotic use, Prescribing practices, Antibiotic resistance, Quality improvement, Antibiotic stewardship, Hajj, Pilgrim

Overcoming the Challenges Associated with Image-based Mapping of Small Bodies in Preparation for the OSIRIS-REx Mission to (101955) Bennu

The OSIRIS-REx Asteroid Sample Return Mission is the third mission in NASA's New Frontiers Program and is the first U.S. mission to return samples from an asteroid to Earth. The most important decision ahead of the OSIRIS-REx team is the selection of a prime sample-site on the surface of asteroid (101955) Bennu. Mission success hinges on identifying a site that is safe and has regolith that can readily be ingested by the spacecraft's sampling mechanism. To inform this mission-critical decision, the surface of Bennu is mapped using the OSIRIS-REx Camera Suite and the images are used to develop several foundational data products. Acquiring the necessary inputs to these data products requires observational strategies that are defined specifically to overcome the challenges associated with mapping a small irregular body. We present these strategies in the context of assessing candidate sample-sites at Bennu according to a framework of decisions regarding the relative safety, sampleability, and scientific value across the asteroid's surface. To create data products that aid these assessments, we describe the best practices developed by the OSIRIS-REx team for image-based mapping of irregular small bodies. We emphasize the importance of using 3D shape models and the ability to work in body-fixed rectangular coordinates when dealing with planetary surfaces that cannot be uniquely addressed by body-fixed latitude and longitude.Comment: 31 pages, 10 figures, 2 table

Resistive switching in silicon suboxide films

We report a study of resistive switching in a silicon-based memristor/resistive RAM (RRAM) device in which the active layer is silicon-rich silica. The resistive switching phenomenon is an intrinsic property of the silicon-rich oxide layer and does not depend on the diffusion of metallic ions to form conductive paths. In contrast to other work in the literature, switching occurs in ambient conditions, and is not limited to the surface of the active material. We propose a switching mechanism driven by competing field-driven formation and current-driven destruction of filamentary conductive pathways. We demonstrate that conduction is dominated by trap assisted tunneling through noncontinuous conduction paths consisting of silicon nanoinclusions in a highly nonstoichiometric suboxide phase. We hypothesize that such nanoinclusions nucleate preferentially at internal grain boundaries in nanostructured films. Switching exhibits the pinched hysteresis I/V loop characteristic of memristive systems, and on/off resistance ratios of 104:1 or higher can be easily achieved. Scanning tunneling microscopy suggests that switchable conductive pathways are 10 nm in diameter or smaller. Programming currents can be as low as 2 μA, and transition times are on the nanosecond scale