Comparison of Pressures Applied by Digital Tourniquets in the Emergency Department

Background: Digital tourniquets used in the emergency department have been scrutinized due to complications associated with their use, including neurovascular injury secondary to excessive tourniquet pressure and digital ischemia caused by a forgotten tourniquet. To minimize these risks, a conspicuous tourniquet that applies the least amount of pressure necessary to maintain hemostasis is recommended.Objective: To evaluate the commonly used tourniquet methods, the Penrose drain, rolled glove, the Tourni-cot and the T-Ring, to determine which applies the lowest pressure while consistently preventing digital perfusion.Methods: We measured the circumference of selected digits of 200 adult males and 200 adult females to determine the adult finger size range. We then measured the pressure applied to four representative finger sizes using a pressure monitor and assessed the ability of each method to prevent digital blood flow with a pulse oximeter.Results: We selected four representative finger sizes: 45mm, 65mm, 70mm, and 85mm to test the different tourniquet methods. All methods consistently prevented digital perfusion. The highest pressure recorded for the Penrose drain was 727 mmHg, the clamped rolled glove 439, the unclamped rolled glove 267, Tourni-cot 246, while the T-Ring had the lowest at 151 mmHg and least variable pressures of all methods.Conclusion: All tested methods provided adequate hemostasis. Only the Tourni-cot and T-Ring provided hemostasis at safe pressures across all digit sizes with the T-Ring having a lower overall average pressure. [West J Emerg Med. 2011;12(2):242-249.

Gamma-Ray Bursts in the Swift Era

With its rapid-response capability and multiwavelength complement of instruments, the Swift satellite has transformed our physical understanding of gamma-ray bursts (GRBs). Providing high-quality observations of hundreds of bursts, and facilitating a wide range of follow-up observations within seconds of each event, Swift has revealed an unforeseen richness in observed burst properties, shed light on the nature of short-duration bursts, and helped realize the promise of GRBs as probes of the processes and environments of star formation out to the earliest cosmic epochs. These advances have opened new perspectives on the nature and properties of burst central engines, interactions with the burst environment from microparsec to gigaparsec scales, and the possibilities for non-photonic signatures. Our understanding of these extreme cosmic sources has thus advanced substantially; yet more than 40 years after their discovery, GRBs continue to present major challenges on both observational and theoretical fronts.Comment: 67 pages, 16 figures; ARAA, 2009; http://arjournals.annualreviews.org/toc/astro/47/

A rare and exclusive endoperoxide photoproduct derived from thiacalix[4]arene crown-shaped derivative bearing 9,10-substituted anthracene moiety

A rare and exclusive endoperoxide photoproduct was quantitatively obtained from a thiacalix[4]arene crown-shaped derivative upon irradiation at λ=365 nm; the structure was unambiguously confirmed by 1H/13C NMR spectroscopy and X-ray crystallography. The prerequisites for the formation of the endoperoxide photoproduct have also been discussed. Furthermore, the photochemical reaction rate could be greatly enhanced in the presence of the thiacalix[4]arene platform because it served as a host to capture oxygen

Protease inhibitor monotherapy for long-term management of HIV infection: a randomised, controlled, open-label, non-inferiority trial

BACKGROUND: Standard-of-care antiretroviral therapy (ART) uses a combination of drugs deemed essential to minimise treatment failure and drug resistance. Protease inhibitors are potent, with a high genetic barrier to resistance, and have potential use as monotherapy after viral load suppression is achieved with combination treatment. We aimed to assess clinical risks and benefits of protease inhibitor monotherapy in long-term clinical use: in particular, the effect on drug resistance and future treatment options. METHODS: In this pragmatic, parallel-group, randomised, controlled, open-label, non-inferiority trial, we enrolled adults (≥18 years of age) positive for HIV attending 43 public sector treatment centres in the UK who had suppressed viral load (<50 copies per mL) for at least 24 weeks on combination ART with no change in the previous 12 weeks and a CD4 count of more than 100 cells per μL. Participants were randomly allocated (1:1) to maintain ongoing triple therapy (OT) or to switch to a strategy of physician-selected ritonavir-boosted protease inhibitor monotherapy (PI-mono); we recommended ritonavir (100 mg)-boosted darunavir (800 mg) once daily or ritonavir (100 mg)-boosted lopinavir (400 mg) twice daily, with prompt return to combination treatment if viral load rebounded. All treatments were oral. Randomisation was with permuted blocks of varying size and stratified by centre and baseline ART; we used a computer-generated, sequentially numbered randomisation list. The primary outcome was loss of future drug options, defined as new intermediate-level or high-level resistance to one or more drugs to which the patient's virus was deemed sensitive at trial entry (assessed at 3 years; non-inferiority margin of 10%). We estimated probability of rebound and resistance with Kaplan-Meier analysis. Analyses were by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Number registry, number ISRCTN04857074. FINDINGS: Between Nov 4, 2008, and July 28, 2010, we randomly allocated 587 participants to OT (291) or PI-mono (296). At 3 years, one or more future drug options had been lost in two participants (Kaplan-Meier estimate 0·7%) in the OT group and six (2·1%) in the PI-mono group: difference 1·4% (-0·4 to 3·4); non-inferiority shown. 49 (16·8%) participants in the OT group and 65 (22·0%) in the PI-mono group had grade 3 or 4 clinical adverse events (difference 5·1% [95% CI -1·3 to 11·5]; p=0·12); 45 (six treatment related) and 56 (three treatment related) had serious adverse events. INTERPRETATION: Protease inhibitor monotherapy, with regular viral load monitoring and prompt reintroduction of combination treatment for rebound, preserved future treatment options and did not change overall clinical outcomes or frequency of toxic effects. Protease inhibitor monotherapy is an acceptable alternative for long-term clinical management of HIV infection. FUNDING: National Institute for Health Research

Theoretical model studies of intestinal drug absorption V. Non-steady-state fluid flow and absorption

A reasonably realistic physical model has been described for the simultaneous longitudinal spreading, fluid flow and absorption of drugs in solution under non-steady-state conditions m the small intestinal tract. Various input cases included first-order and zero-order stomach emptying and input from an infinite drug reservoir at constant infusion rate. The mathematical solutions were unique and rigorous. Theoretical simulations using reasonable physical parameter values illustrated the interrelationships of the longitudinal spreading diffusion coefficient, flow rate, apparent permeability coefficient and intestinal length on the change in concentration--distance profiles with time and the kinetics of appearance of unabsorbed drug at the end of the intestinal segment. The model is accessible to the design of intestinal absorption experiments and data interpretation on a quantitative mechanistic basis and also provides the way for studying intestinal absorption under more realistic situations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23297/1/0000235.pd

Doped Framework Iron Hydroxyl Phosphate as Photocatalyst for Hydrogen Production from Water/Methanol Mixtures

[EN] In the search for novel photocatalysts for hydrogen production and with the alpha-Fe2O3 photoelectrocatalyst as a recent precedent, we report herein the preparation, semiconductor properties and photocatalytic activity of metal-doped (0.1-5 wt.-% loading) iron hydroxyl phosphate (FeP). X-ray diffraction analyses of FeP samples subjected to extended photocatalytic irradiation showed the stability of this framework phosphate under photocatalytic conditions. Doping increased the photocatalytic efficiency of FeP for all dopants, with the optimal doping level between 0.1 and 1%. Under the optimized conditions (Cr at 1% doping), the photocatalytic activity of FeP reached a hydrogen production rate of 35.82 mu molg(Fe)(-1) in the absence of platinum as co-catalyst. The conduction flat band potential was estimated by photocurrent measurements or impedance spectroscopy to be 0.1 eV versus NHE and the charge carrier density 2.6 x 10(20) carriers cm(-3). Transient absorption spectroscopy revealed a transient species decaying on the microsecond time-scale characterized by a broad band spanning 300-750 nm. This transient was attributed to the charge-separated state. These results are promising for the development of novel photocatalytic materials based on framework metal phosphate.Financial support by the Spanish Ministry of Economy and Competitiveness (MEC) (Severo Ochoa and CTQ20212-32315) and the Generalidad Valenciana (Prometeo 2012/014) is gratefully acknowledged. M. S. thanks the Spanish Consejo Superior de Investigaciones Cientificas (CSIC) and Technical University of Valencia for a postgraduate scholarship.Serra, M.; García Baldoví, H.; Alvaro Rodríguez, MM.; García Gómez, H. (2015). Doped Framework Iron Hydroxyl Phosphate as Photocatalyst for Hydrogen Production from Water/Methanol Mixtures. European Journal of Inorganic Chemistry. 2015(25):4237-4243. https://doi.org/10.1002/ejic.201500629S42374243201525Amao, Y. (2011). Solar Fuel Production Based on the Artificial Photosynthesis System. ChemCatChem, 3(3), 458-474. doi:10.1002/cctc.201000293Centi, G., & Perathoner, S. (2010). Towards Solar Fuels from Water and CO2. ChemSusChem, 3(2), 195-208. doi:10.1002/cssc.200900289Gust, D., Moore, T. A., & Moore, A. L. (2009). Solar Fuels via Artificial Photosynthesis. Accounts of Chemical Research, 42(12), 1890-1898. doi:10.1021/ar900209bHammarström, L. (2009). Artificial Photosynthesis and Solar Fuels. Accounts of Chemical Research, 42(12), 1859-1860. doi:10.1021/ar900267kSerpone, N., Lawless, D., & Terzian, R. (1992). Solar fuels: Status and perspectives. Solar Energy, 49(4), 221-234. doi:10.1016/0038-092x(92)90001-qAbbott, D. (2010). Keeping the Energy Debate Clean: How Do We Supply the World’s Energy Needs? Proceedings of the IEEE, 98(1), 42-66. doi:10.1109/jproc.2009.2035162Dunn, S. (2002). Hydrogen futures: toward a sustainable energy system. International Journal of Hydrogen Energy, 27(3), 235-264. doi:10.1016/s0360-3199(01)00131-8Kamat, P. V. (2007). Meeting the Clean Energy Demand:  Nanostructure Architectures for Solar Energy Conversion. The Journal of Physical Chemistry C, 111(7), 2834-2860. doi:10.1021/jp066952uLewis, N. S., & Nocera, D. G. (2006). Powering the planet: Chemical challenges in solar energy utilization. Proceedings of the National Academy of Sciences, 103(43), 15729-15735. doi:10.1073/pnas.0603395103Bard, A. J., & Fox, M. A. (1995). Artificial Photosynthesis: Solar Splitting of Water to Hydrogen and Oxygen. Accounts of Chemical Research, 28(3), 141-145. doi:10.1021/ar00051a007Bensaid, S., Centi, G., Garrone, E., Perathoner, S., & Saracco, G. (2012). Towards Artificial Leaves for Solar Hydrogen and Fuels from Carbon Dioxide. ChemSusChem, 5(3), 500-521. doi:10.1002/cssc.201100661Chen, X., Shen, S., Guo, L., & Mao, S. S. (2010). Semiconductor-based Photocatalytic Hydrogen Generation. Chemical Reviews, 110(11), 6503-6570. doi:10.1021/cr1001645Crabtree, G. W., Dresselhaus, M. S., & Buchanan, M. V. (2004). The Hydrogen Economy. Physics Today, 57(12), 39-44. doi:10.1063/1.1878333Graetzel, M. (1981). Artificial photosynthesis: water cleavage into hydrogen and oxygen by visible light. Accounts of Chemical Research, 14(12), 376-384. doi:10.1021/ar00072a003Ni, M., Leung, M. K. H., Leung, D. Y. C., & Sumathy, K. (2007). A review and recent developments in photocatalytic water-splitting using TiO2 for hydrogen production. Renewable and Sustainable Energy Reviews, 11(3), 401-425. doi:10.1016/j.rser.2005.01.009NOWOTNY, J., SORRELL, C., SHEPPARD, L., & BAK, T. (2005). Solar-hydrogen: Environmentally safe fuel for the future. International Journal of Hydrogen Energy, 30(5), 521-544. doi:10.1016/j.ijhydene.2004.06.012Bahnemann, D. W. (2000). Current challenges in photocatalysis: Improved photocatalysts and appropriate photoreactor engineering. Research on Chemical Intermediates, 26(2), 207-220. doi:10.1163/156856700x00255Fox, M. A., & Dulay, M. T. (1993). Heterogeneous photocatalysis. Chemical Reviews, 93(1), 341-357. doi:10.1021/cr00017a016FUJISHIMA, A., ZHANG, X., & TRYK, D. (2008). TiO2 photocatalysis and related surface phenomena. Surface Science Reports, 63(12), 515-582. doi:10.1016/j.surfrep.2008.10.001Herrmann, J.-M. (1999). Heterogeneous photocatalysis: fundamentals and applications to the removal of various types of aqueous pollutants. Catalysis Today, 53(1), 115-129. doi:10.1016/s0920-5861(99)00107-8Linsebigler, A. L., Lu, G., & Yates, J. T. (1995). Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results. Chemical Reviews, 95(3), 735-758. doi:10.1021/cr00035a013Mills, A., & Le Hunte, S. (1997). An overview of semiconductor photocatalysis. Journal of Photochemistry and Photobiology A: Chemistry, 108(1), 1-35. doi:10.1016/s1010-6030(97)00118-4Beermann, N., Vayssieres, L., Lindquist, S.-E., & Hagfeldt, A. (2000). Photoelectrochemical Studies of Oriented Nanorod Thin Films of Hematite. Journal of The Electrochemical Society, 147(7), 2456. doi:10.1149/1.1393553Bjoerksten, U., Moser, J., & Graetzel, M. (1994). Photoelectrochemical Studies on Nanocrystalline Hematite Films. Chemistry of Materials, 6(6), 858-863. doi:10.1021/cm00042a026Hu, Y.-S., Kleiman-Shwarsctein, A., Forman, A. J., Hazen, D., Park, J.-N., & McFarland, E. W. (2008). Pt-Doped α-Fe2O3Thin Films Active for Photoelectrochemical Water Splitting. Chemistry of Materials, 20(12), 3803-3805. doi:10.1021/cm800144qKay, A., Cesar, I., & Grätzel, M. (2006). New Benchmark for Water Photooxidation by Nanostructured α-Fe2O3Films. Journal of the American Chemical Society, 128(49), 15714-15721. doi:10.1021/ja064380lSivula, K., Le Formal, F., & Grätzel, M. (2011). Solar Water Splitting: Progress Using Hematite (α-Fe2O3) Photoelectrodes. ChemSusChem, 4(4), 432-449. doi:10.1002/cssc.201000416Sivula, K., Zboril, R., Le Formal, F., Robert, R., Weidenkaff, A., Tucek, J., … Grätzel, M. (2010). Photoelectrochemical Water Splitting with Mesoporous Hematite Prepared by a Solution-Based Colloidal Approach. Journal of the American Chemical Society, 132(21), 7436-7444. doi:10.1021/ja101564fGrätzel, M. (2001). Photoelectrochemical cells. Nature, 414(6861), 338-344. doi:10.1038/35104607Wang, X., Pang, H., Zhao, S., Shao, W., Yan, B., Li, X., … Du, W. (2013). Ferric Phosphate Hydroxide Microcrystals for Highly Efficient Visible-Light-Driven Photocatalysts. ChemPhysChem, 14(11), 2518-2524. doi:10.1002/cphc.201300331Song, Y., Zavalij, P. Y., Chernova, N. A., Suzuki, M., & Whittingham, M. S. (2003). Comparison of one-, two-, and three-dimensional iron phosphates containing ethylenediamine. Journal of Solid State Chemistry, 175(1), 63-71. doi:10.1016/s0022-4596(03)00144-0Song, Y., Zavalij, P. Y., Chernova, N. A., & Whittingham, M. S. (2005). Synthesis, Crystal Structure, and Electrochemical and Magnetic Study of New Iron (III) Hydroxyl-Phosphates, Isostructural with Lipscombite. Chemistry of Materials, 17(5), 1139-1147. doi:10.1021/cm049406

Long-term efficacy and safety of a treatment strategy for HIV infection using protease inhibitor monotherapy: 8-year routine clinical care follow-up from a randomised, controlled, open-label pragmatic trial (PIVOT).

BACKGROUND: Treatment-simplification strategies are important tools for patient-centred management. We evaluated long-term outcomes from a PI monotherapy switch strategy. METHODS: Eligible participants attending 43 UK treatment centres had a viral load (VL) below 50 copies/ml for at least 24 weeks on combination ART. Participants were randomised to maintain ongoing triple therapy (OT) or switch to a strategy of physician-selected PI monotherapy (PI-mono) with prompt return to combination therapy if VL rebounded. The primary outcome, previously reported, was loss of future drug options after 3 years, defined as new intermediate/high level resistance to at least one drug to which the participant's virus was considered sensitive at trial entry. Here we report resistance and disease outcomes after further extended follow-up in routine care. The study was registered as ISRCTN04857074. FINDINGS: We randomised 587 participants to OT (291) or PI-mono (296) between Nov 4, 2008, and July 28, 2010 and followed them for a median of more than 8 years (100 months) until 2018. At the end of this follow-up time, one or more future drug options had been lost in 7 participants in the OT group and 6 in the PI-mono group; estimated cumulative risk by 8 years of 2.7% and 2.1% respectively (difference -0.6%, 95% CI -3.2% to 2.0%). Only one PI-mono participant developed resistance to the protease inhibitor they were taking (atazanavir). Serious clinical events (death, serious AIDS, and serious non-AIDS) were infrequent; reported in a total of 12 (4.1%) participants in the OT group and 23 (7.8%) in the PI-mono group (P = 0.08) over the entire follow-up period. INTERPRETATION: A strategy of PI monotherapy, with regular VL monitoring and prompt reintroduction of combination treatment following rebound, preserved future treatment options. Findings confirm the high genetic barrier to resistance of the PI drug class that makes them well suited for creative, patient-centred, treatment-simplification approaches. The possibility of a small excess risk of serious clinical events with the PI monotherapy strategy cannot be excluded. FUNDING: The National Institute for Health Research Health Technology Assessment programme

Far field scattering pattern of differently structured butterfly scales

The angular and spectral reflectance of single scales of five different butterfly species was measured and related to the scale anatomy. The scales of the pierids Pieris rapae and Delias nigrina scatter white light randomly, in close agreement with Lambert’s cosine law, which can be well understood from the randomly organized beads on the scale crossribs. The reflectance of the iridescent blue scales of Morpho aega is determined by multilayer structures in the scale ridges, causing diffraction in approximately a plane. The purple scales in the dorsal wing tips of the male Colotis regina act similarly as the Morpho scale in the blue, due to multilayers in the ridges, but the scattering in the red occurs as in the Pieris scale, because the scales contain beads with pigment that does not absorb in the red wavelength range. The green–yellow scales of Urania fulgens backscatter light in a narrow spatial angle, because of a multilayer structure in the scale body

Genome-wide association study for renal traits in the Framingham Heart and Atherosclerosis Risk in Communities Studies

Background: The Framingham Heart Study (FHS) recently obtained initial results from the first genome-wide association scan for renal traits. The study of 70,987 single nucleotide polymorphisms (SNPs) in 1,010 FHS participants provides a list of SNPs showing the strongest associations with renal traits which need to be verified in independent study samples. Methods: Sixteen SNPs were selected for replication based on the most promising associations with chronic kidney disease (CKD), estimated glomerular filtration rate (eGFR), and serum cystatin C in FHS. These SNPs were genotyped in 15,747 participants of the Atherosclerosis in Communities (ARIC) Study and evaluated for association using multivariable adjusted regression analyses. Primary outcomes in ARIC were CKD and eGFR. Secondary prospective analyses were conducted for association with kidney disease progression using multivariable adjusted Cox proportional hazards regression. The definition of the outcomes, all covariates, and the use of an additive genetic model was consistent with the original analyses in FHS. Results: The intronic SNP rs6495446 in the gene MTHFS was significantly associated with CKD among white ARIC participants at visit 4: the odds ratio per each C allele was 1.24 (95% CI 1.09–1.41, p = 0.001). Borderline significant associations of rs6495446 were observed with CKD at study visit 1 (p = 0.024), eGFR at study visits 1 (p = 0.073) and 4 (lower mean eGFR per C allele by 0.6 ml/min/1.73 $\text{m}^2$, p = 0.043) and kidney disease progression (hazard ratio 1.13 per each C allele, 95% CI 1.00–1.26, p = 0.041). Another SNP, rs3779748 in EYA1, was significantly associated with CKD at ARIC visit 1 (odds ratio per each T allele 1.22, p = 0.01), but only with eGFR and cystatin C in FHS. Conclusion: This genome-wide association study provides unbiased information implicating MTHFS as a candidate gene for kidney disease. Our findings highlight the importance of replication to identify common SNPs associated with renal traits

The Buffer Gas Beam: An Intense, Cold, and Slow Source for Atoms and Molecules

Beams of atoms and molecules are stalwart tools for spectroscopy and studies of collisional processes. The supersonic expansion technique can create cold beams of many species of atoms and molecules. However, the resulting beam is typically moving at a speed of 300-600 m/s in the lab frame, and for a large class of species has insufficient flux (i.e. brightness) for important applications. In contrast, buffer gas beams can be a superior method in many cases, producing cold and relatively slow molecules in the lab frame with high brightness and great versatility. There are basic differences between supersonic and buffer gas cooled beams regarding particular technological advantages and constraints. At present, it is clear that not all of the possible variations on the buffer gas method have been studied. In this review, we will present a survey of the current state of the art in buffer gas beams, and explore some of the possible future directions that these new methods might take