1,186 research outputs found

    Periodic orbit theory for Rydberg atoms in external fields

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    Although hydrogen in external fields is a paradigm for the application of periodic orbits and the Gutzwiller trace formula to a real system, the trace formula has never been applied successfully to other Rydberg atoms. We show that spectral fluctuations of general Rydberg atoms are given with remarkable precision by the addition of diffractive terms. Previously unknown features in atomic spectra are exposed: there are new modulations that are neither periodic orbits nor combinations of periodic orbits; “core shadowing” generally decreases primitive periodic orbit amplitudes but can also lead to increases

    Single intra-articular injection of high concentrated hyaluronic acid – A pilot study in horses

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    Distal limb osteoarthritis (OA) is a common cause of lameness in horses and hyaluronic acid (HA) is frequently used, alone or in combination with other drugs, for intra-articular (IA) treatment. Therefore, we decided to investigate a product with high concentration of high molecular weight (HMW)-HA for a single IA injection that has been approved for humans (Goldenberg, 2014). The aim of this study was to assess the treatment efficacy and safety in horses using a body mounted inertial sensor device technology and synovial fluid (SF) analysis before and after treatment. In conclusion, our results suggest that high concentration of a single IA injection of HMW-HA in horses is safe, induce modest subjective lameness and asymmetry improvement and reduces TP in SF. This could represent an alternative, in the short-term period, to drugs that are forbidden in competition for pain relief while preserving joint metabolism. A randomized, double blind and controlled study, with a larger number of horses should be performed in order to confirm the clinical interest of this therapy

    Ketamine induction of p53-dependent apoptosis and oxidative stress in zebrafish (Danio rerio) embryos

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    Ketamine is a widely used pharmaceutical that has been detected in water sources worldwide. Zebrafish embryos were used in this study to investigate the oxidative stress and apoptotic signals following a 24h exposure to different ketamine concentrations (0, 50, 70 and 90 mg L-1). Early blastula embryos (∼2 h post fertilisation-hpf) were exposed for 24 h and analysed at 8 and 26 hpf. Reactive oxygen species and apoptotic cells were identified in vivo, at 26 hpf. Enzymatic activities (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), lactate dehydrogenase (LDH) and acetylcholinesterase (AChE)), glutathione levels (oxidised (GSSG) and reduced (GSH)), oxidative damage (lipid peroxidation (LPO) and protein carbonyls (CO)) as well as oxidative stress (gclc, gstp1, sod1 and cat), apoptosis (casp3a, casp6, casp8, casp9, aifm1 and tp53) and cell proliferation (pcna) related-genes were evaluated at 8 and 26 hpf. Caspase (3 and 9) activity was also determined at both time-points by colorimetric methods. Superoxide dismutase (SOD), catalase (CAT), glutathione levels (GSSG), caspase-9 and reactive oxygen species (ROS) were shown to be affected by ketamine exposure while in vivo analysis showed no difference in ROS. A significant up-regulation of superoxide dismutase (sod1) and catalase (cat) genes expression was also perceived. Ketamine-induced apoptosis was observed in vivo and confirmed by the apoptotic-related genes up-regulation. The overall results suggest that ketamine induced oxidative stress and apoptosis through the involvement of p53-dependent pathways in zebrafish embryos which could be important for the evaluation of the overall risk of ketamine in aquatic environments.This work was supported by European Investment Funds by FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145-FEDER-006958 and FCOMP-01-0124-FEDER-028683 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the projects PTDC/CVT-WEL/4672/2012 and UID/AGR/04033/2013 and by individual funding provided by postdoctoral fellowship SFRH/BPD/103006/2014 issued by FCT

    Opportunities for topical antimicrobial therapy: permeation of canine skin by fusidic acid

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    BACKGROUND: Staphylococcal infection of the canine epidermis and hair follicle is amongst the commonest reasons for antimicrobial prescribing in small animal veterinary practice. Topical therapy with fusidic acid (FA) is an attractive alternative to systemic therapy based on low minimum inhibitory concentrations (MICs, commonly <0.03 mg/l) documented in canine pathogenic staphylococci, including strains of MRSA and MRSP (methicillin-resistant Staphylococcus aureus and S. pseudintermedius). However, permeation of canine skin by FA has not been evaluated in detail. This study aimed to define the degree and extent of FA permeation in canine skin in vitro from two sites with different hair follicle density following application of a licensed ophthalmic formulation that shares the same vehicle as an FA-betamethasone combination product approved for dermal application in dogs. Topical FA application was modelled using skin held in Franz-type diffusion cells. Concentrations of FA in surface swabs, receptor fluid, and transverse skin sections of defined anatomical depth were determined using high-performance liquid chromatography and ultraviolet (HPLC-UV) analysis. RESULTS: The majority of FA was recovered by surface swabs after 24 h, as expected (mean ± SEM: 76.0 ± 17.0%). FA was detected within 424/470 (90%) groups of serial sections of transversely cryotomed skin containing follicular infundibula, but never in 48/48 (100%) groups of sections containing only deeper follicular structures, nor in receptor fluid, suggesting that FA does not permeate beyond the infundibulum. The FA concentration (mean ± SEM) in the most superficial 240 μm of skin was 2000 ± 815 μg/g. CONCLUSIONS: Topically applied FA can greatly exceed MICs for canine pathogenic staphylococci at the most common sites of infection. Topical FA therapy should now be evaluated using available formulations in vivo as an alternative to systemic therapy for canine superficial bacterial folliculitis.Peer reviewedFinal Published versio

    A new portable monitor for measuring odorous compounds in oral, exhaled and nasal air

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    <p>Abstract</p> <p>Background</p> <p>The B/B Checker<sup>®</sup>, a new portable device for detecting odorous compounds in oral, exhaled, and nasal air, is now available. As a single unit, this device is capable of detecting several kinds of gases mixed with volatile sulfur compounds (VSC) in addition to other odorous gasses. The purpose of the present study was to evaluate the effectiveness of the B/B Checker<sup>® </sup>for detecting the malodor level of oral, exhaled, and nasal air.</p> <p>Methods</p> <p>A total of 30 healthy, non-smoking volunteers (16 males and 14 females) participated in this study. The malodor levels in oral, exhaled, and nasal air were measured using the B/B Checker<sup>® </sup>and by organoleptic test (OT) scores. The VSCs in each air were also measured by gas chromatography (GC). Associations among B/B Checker<sup>® </sup>measurements, OT scores and VSC levels were analyzed using Spearman correlation coefficients. In order to determine the appropriate B/B Checker<sup>® </sup>level for screening subjects with malodor, sensitivity and specificity were calculated using OT scores as an identifier for diagnosing oral malodor.</p> <p>Results</p> <p>In oral and nasal air, the total VSC levels measured by GC significantly correlated to that measured by the B/B Checker<sup>®</sup>. Significant correlation was observed between the results of OT scores and the B/B Checker<sup>® </sup>measurements in oral (r = 0.892, p < 0.001), exhaled (r = 0.748, p < 0.001) and nasal air (r = 0.534, p < 0.001). The correlation between the OT scores and VSC levels was significant only for oral air (r = 0.790, p < 0.001) and nasal air (r = 0.431, p = 0.002); not for exhaled air (r = 0.310, p = 0.096). When the screening level of the B/B Checker<sup>® </sup>was set to 50.0 for oral air, the sensitivity and specificity were 1.00 and 0.90, respectively. On the other hand, the screening level of the B/B Checker<sup>® </sup>was set to 60.0 for exhaled air, the sensitivity and specificity were 0.82 and 1.00, respectively.</p> <p>Conclusion</p> <p>The B/B Checker<sup>® </sup>is useful for objective evaluation of malodor in oral, exhaled and nasal air and for screening subjects with halitosis.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01139073">NCT01139073</a></p

    A cross-sectional study of vascular risk factors in a rural South African population : data from the Southern African Stroke Prevention Initiative (SASPI)

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    Background: Rural sub-Saharan Africa is at an early stage of economic and health transition. It is predicted that the 21st century will see a serious added economic burden from non-communicable disease including vascular disease in low-income countries as they progress through the transition. The stage of vascular disease in a population is thought to result from the prevalence of vascular risk factors. Already hypertension and stroke are common in adults in sub-Saharan Africa. Using a multidisciplinary approach we aimed to assess the prevalence of several vascular risk factors in Agincourt, a rural demographic surveillance site in South Africa. Methods: We performed a cross sectional random sample survey of adults aged over 35 in Agincourt (population ≈ 70 000). Participants were visited at home by a trained nurse who administered a questionnaire, carried out clinical measurements and took a blood sample. From this we assessed participants' history of vascular risk, blood pressure using an OMRON 705 CP monitor, waist circumference, body mass index (BMI), ankle brachial index (ABI), and total and HDL cholesterol. Results: 402 people (24% men) participated. There was a high prevalence of smoking in men, but the number of cigarettes smoked was small. There was a striking difference in mean BMI between men and women (22.8 kg/m2 versus 27.2 kg/m2), but levels of blood pressure were very similar. 43% of participants had a blood pressure greater than 140/90 or were on anti-hypertensive treatment and 37% of participants identified with measured high blood pressure were on pharmacological treatment. 12% of participants had an ABI of < 0.9, sugesting the presence of sub-clinical atheroma. 25.6% of participants had a total cholesterol level > 5 mmol/l. Conclusion: We found a high prevalence of hypertension, obesity in women, and a suggestion of subclinical atheroma despite relatively favourable cholesterol levels in a rural South African population. South Africa is facing the challenge of an emerging epidemic of vascular disease. Research to establish the social determinates of these risk factors and interventions to reduce both individual and population risk are required

    Potencial hidrogeniônico de antimicrobianos, segundo os fatores ambientais temperatura e luminosidade

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    The objective of this experimental study was to measure the pH of antibiotics administered by intravenous infusion - ceftriaxone sodium, vancomycin hydrochloride, metrodinazole, penicillin G potassium and amikacin sulfate - after reconstitution with sterile water and dilution with NaCl 0.9% or dextrose 5% in water, according to temperature and luminosity of the environment. The results showed that variation in the drugs' pH was less than 1.0 value and that some antibiotics remained acidic after dilution and maintained this chemical profile in all situations studied, suggesting that the studied environmental factors did not change the solutions' acid base characteristic. Some pH values measured characterize risk for the development of chemical phlebitis and infiltration, and it is important for clinical practice to emphasize the profile of intravenous solutions of antibiotics, considering method of dilution, and time to infusion.El objetivo de este estudio experimental fue medir el pH de los antibióticos de administración intravenosa ceftriaxona sódica, clorhidrato de vancomicina, metronidazol, penicilina G potásica y sulfato de amikacina, después de reconstitución con agua destilada y dilución con NaCl a 0,9%, o suero glucosado a 5%, considerando la influencia de la temperatura y luminosidad ambientales, así como el tiempo de exposición, en el comportamiento químico de esos fármacos. Los resultados demostraron variaciones que no ultrapasaron 1,0 (valor de pH) y que algunos antimicrobianos, eminentemente ácidos después de la dilución, mantuvieron ese comportamiento en todas las situaciones estudiadas, no sugiriendo la influencia de factores ambientales en el comportamiento químico de las soluciones. Considerando que algunos valores de pH encontrados pueden contribuir para el desarrollo de flebitis química e infiltración, es importante enfatizar que para la práctica clínica en salud, existe la necesidad de conocer las características de las soluciones de infusión intravenosa, considerando el tipo de dilución y el tiempo de infusión.O objetivo deste estudo experimental foi medir o pH dos antibióticos de administração intravenosa ceftriaxona sódica, cloridrato de vancomicina, metronidazol, penicilina G potássica e sulfato de amicacina, após reconstituição com água destilada e diluição com NaCl 0,9%, ou soro glicosado 5%, considerando a influência da temperatura e luminosidade ambientais, assim como do tempo de exposição, no comportamento químico desses fármacos. Os resultados demonstraram variações que não ultrapassaram 1,0 valor de pH e que alguns antimicrobianos, eminentemente ácidos após a diluição, mantiveram esse comportamento em todas as situações estudadas, não sugerindo a influência de fatores ambientais no comportamento químico das soluções. Como alguns valores de pH encontrados podem contribuir para o desenvolvimento de flebite química e infiltração, é importante enfatizar para a prática clínica em saúde, a necessidade de conhecer as características das soluções de infusão intravenosa, considerando tipo de diluição e tempo de infusão.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP) Departamento de EnfermagemUNIFESP, Depto. de EnfermagemCNPq: 476295/2004-1CNPq: 502382/2007-4SciEL

    Environmental Costs of Government-Sponsored Agrarian Settlements in Brazilian Amazonia

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    Brazil has presided over the most comprehensive agrarian reform frontier colonization program on Earth, in which ~1.2 million settlers have been translocated by successive governments since the 1970's, mostly into forested hinterlands of Brazilian Amazonia. These settlements encompass 5.3% of this ~5 million km2 region, but have contributed with 13.5% of all land conversion into agropastoral land uses. The Brazilian Federal Agrarian Agency (INCRA) has repeatedly claimed that deforestation in these areas largely predates the sanctioned arrival of new settlers. Here, we quantify rates of natural vegetation conversion across 1911 agrarian settlements allocated to 568 Amazonian counties and compare fire incidence and deforestation rates before and after the official occupation of settlements by migrant farmers. The timing and spatial distribution of deforestation and fires in our analysis provides irrefutable chronological and spatially explicit evidence of agropastoral conversion both inside and immediately outside agrarian settlements over the last decade. Deforestation rates are strongly related to local human population density and road access to regional markets. Agrarian settlements consistently accelerated rates of deforestation and fires, compared to neighboring areas outside settlements, but within the same counties. Relocated smallholders allocated to forest areas undoubtedly operate as pivotal agents of deforestation, and most of the forest clearance occurs in the aftermath of government-induced migration
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