701 research outputs found

    Serum nitric oxide and malondialdehyde in a hypertensive population in Sokoto, Nigeria

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    Background: Hypertension is recognized as most common cardiovascular disorder and a leading cause of morbidity and mortality worldwide. Endothelial dysfunction, which is associated with impaired nitric oxide is an important risk factor for both hypertension and cardiovascular diseases. There is abnormal lipid peroxidation which suggested that oxidative stress is important in the pathogenesis of hypertension.  This study assessed serum levels of nitric oxide and malondialdehyde in hypertensive population in Sokoto-Nigeria.Methods: A total of 474 subjects who are within the age range of 25 to 76 years, including 316 hypertensive patients and 158 age- and sex- matched normotensive subjects were included in this study. Clinical and anthropometric parameters, nitric oxide and malondialdehyde were measured using standard techniques.Results: The result indicated that, mean systolic blood pressure (SBP) was significantly (p˂0.001) higher in hypertensive patients (166.00±1.39mmHg) than controls (124.97±0.95 mmHg) similarly the mean BMI was significantly (p˂0.001) higher in hypertensive patients (27.13±0.31 Kg/m2) than controls (23.54±0.12Kg/m2). Mean serum malondialdehyde (MDA) was significantly (p˂0.001) higher in hypertensive patients (3.62±0.07”mol/L) as compared to controls (1.97±0.03”mol/L), while serum nitric oxide (NO) was significantly (p=0.009) lower among hypertensive patients (7.12±0.14”mol/L) than controls (15.26±0.15”mol/L).Conclusions: Hypertension is a complex disorder that is strongly associated with other risk factors for cardiovascular disease. The aetiology of the association between impaired NO bioactivity, increase MDA and hypertension has not been fully elucidated. Further clarification of the role of impaired NO bioactivity and increased MDA level in hypertension could have important implications for the management of hypertension

    Safety and Efficacy of Long-Term Co-Administration of Fenofibrate and Ezetimibe in Patients With Mixed Hyperlipidemia

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    ObjectivesThis study sought to determine the long-term safety and efficacy of co-administered fenofibrate (FENO) and ezetimibe (EZE) in patients with mixed hyperlipidemia.BackgroundBoth EZE and FENO offer complementary benefits to the lipid profile of patients with mixed hyperlipidemia.MethodsAfter completing the 12-week randomized, double-blind base study that compared EZE 10 mg, FENO 160 mg, FENO 160 mg plus EZE 10 mg, and placebo in patients with mixed hyperlipidemia, patients continued into a double-blind, 48-week extension phase. Those patients in the FENO plus EZE and FENO groups continued on their respective base study treatment, and patients in the EZE and placebo groups were switched to FENO plus EZE and FENO, respectively.ResultsOf the 587 patients who completed the base study, 576 continued into the extension study (n = 340 in FENO plus EZE and n = 236 in FENO). The FENO plus EZE produced significantly greater reductions in low-density lipoprotein-cholesterol compared with FENO (−22% vs. −9%, respectively; p < 0.001). There were also significantly greater improvements in triglycerides, high-density lipoprotein cholesterol (HDL-C), total cholesterol, non–HDL-C, and apolipoprotein B with FENO plus EZE compared with FENO. Changes in apolipoprotein A-I and high-sensitivity C-reactive protein were similar between groups. Overall, FENO plus EZE was well tolerated during the extension study. The proportion of patients with consecutive elevations of alanine aminotransferase/aspartate aminotransferase ≄3 times upper limit of normal were similar between the FENO plus EZE (1.2%) and FENO (1.7%) groups. No cases of creatine phosphokinase elevations ≄10 times upper limit of normal or myopathy were observed in either group.ConclusionsLong-term, 48-week co-administration of FENO plus EZE was well tolerated and more efficacious than FENO in patients with mixed hyperlipidemia

    Measurement of Deeply Virtual Compton Scattering Off \u3csup\u3e4\u3c/sup\u3eHe with the CEBAF Large Acceptance Spectrometer at Jefferson Lab

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    We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off 4He using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab using a 6 GeV longitudinally polarized electron beam incident on a pressurized 4He gaseous target. We detail the method used to ensure the exclusivity of the measured reactions, in particular the upgrade of CLAS with a radial time projection chamber to detect the low-energy recoiling 4He nuclei and an inner calorimeter to extend the photon detection acceptance at forward angles. Our results confirm the theoretically predicted enhancement of the coherent (e4He→eâ€Č4HeÎłâ€Č) beam spin asymmetries compared to those observed on the free proton, while the incoherent (e4He→ eâ€Čpâ€ČÎłâ€ČXâ€Č) asymmetries exhibit a 30% suppression. From the coherent data, we were able to extract, in a model-independent way, the real and imaginary parts of the only 4He Compton form factor, HA, leading the way toward 3D imaging of the partonic structure of nuclei

    Tunnelling Methods and Hawking's radiation: achievements and prospects

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    The aim of this work is to review the tunnelling method as an alternative description of the quantum radiation from black holes and cosmological horizons. The method is first formulated and discussed for the case of stationary black holes, then a foundation is provided in terms of analytic continuation throughout complex space-time. The two principal implementations of the tunnelling approach, which are the null geodesic method and the Hamilton-Jacobi method, are shown to be equivalent in the stationary case. The Hamilton-Jacobi method is then extended to cover spherically symmetric dynamical black holes, cosmological horizons and naked singularities. Prospects and achievements are discussed in the conclusions.Comment: Topical Review commissioned and accepted for publication by "Classical and Quantum Gravity". 101 pages; 6 figure

    What next? Experiences of social support and signposting after a diagnosis of dementia

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    The experience of being diagnosed with dementia can be shocking. This may be compounded if individuals feel that there is a lack of signposting onto further avenues of support following diagnosis. This study, then, examines how social support is promoted in the diagnostic process. Using purposive sampling and a grounded theory approach, semi-structured interviews were conducted with 13 members of a dementia empowerment group in Northern Ireland, discussing both their experience of diagnosis and also their subsequent group membership. Respondents reported both positive and negative experiences of diagnosis. Feelings of shock and bewilderment accompanied this process. Only one was able to identify a direct link between a medical professional and referral to the empowerment group, others being referred by other health professionals or dementia navigators. The study indicates that, due to disorienting feelings, one diagnostic consultation is insufficient to explain both the diagnosis and offer follow-up support. Therefore, more explicit links to navigators or other services need to be made at the point of diagnosis to prioritise information regarding opportunities for social engagement for those being diagnosed.

    Quantitative nanoscale vortex-imaging using a cryogenic quantum magnetometer

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    Microscopic studies of superconductors and their vortices play a pivotal role in our understanding of the mechanisms underlying superconductivity. Local measurements of penetration depths or magnetic stray-fields enable access to fundamental aspects of superconductors such as nanoscale variations of superfluid densities or the symmetry of their order parameter. However, experimental tools, which offer quantitative, nanoscale magnetometry and operate over the large range of temperature and magnetic fields relevant to address many outstanding questions in superconductivity, are still missing. Here, we demonstrate quantitative, nanoscale magnetic imaging of Pearl vortices in the cuprate superconductor YBCO, using a scanning quantum sensor in form of a single Nitrogen-Vacancy (NV) electronic spin in diamond. The sensor-to-sample distance of ~10nm we achieve allows us to observe striking deviations from the prevalent monopole approximation in our vortex stray-field images, while we find excellent quantitative agreement with Pearl's analytic model. Our experiments yield a non-invasive and unambiguous determination of the system's local London penetration depth, and are readily extended to higher temperatures and magnetic fields. These results demonstrate the potential of quantitative quantum sensors in benchmarking microscopic models of complex electronic systems and open the door for further exploration of strongly correlated electron physics using scanning NV magnetometry.Comment: Main text (5 pages, 4 figures) plus supplementary material (5 pages, 6 figures). Comments welcome. Further information under http://www.quantum-sensing.c

    Why Are Regulations Changed? A Parcel Analysis of Upzoning in Los Angeles

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    Planners, officials, and neighborhood groups often debate zoning changes, yet there is little empirical evidence explaining why zoning and other land use regulations are changed. I use logistic regression models to examine density-enabling rezoning (“upzoning”) in Los Angeles. I find that upzoning occurs where there are development opportunities combined with limited political resistance. Upzoning is most likely on well-located parcels zoned for low-intensity, nonresidential uses. Meanwhile, homeowners—and particularly homeowners with access to valuable amenities—are associated with regulatory stasis. I conclude by recommending strategies for addressing homeowners’ concerns about higher density housing

    Back reaction, emission spectrum and entropy spectroscopy

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    Recently, an interesting work, which reformulates the tunneling framework to directly produce the Hawking emission spectrum and entropy spectroscopy in the tunneling picture, has been received a broad attention. However, during the emission process, most related observations have not incorporated the effects of back reaction on the background spacetime, whose derivations are therefore not the desiring results for the real physical process. With this point as a central motivation, in this paper we suitably adapt the \emph{reformulated} tunneling framework so that it can well accommodate the effects of back reaction to produce the Hawking emission spectrum and entropy spectroscopy. Consequently, we interestingly find that, when back reaction is considered, the Parikh-Wilczek's outstanding observations that, an isolated radiating black hole has an unitary-evolving emission spectrum that is \emph{not} precisely thermal, but is related to the change of the Bekenstein-Hawking entropy, can also be reproduced in the reformulated tunneling framework, meanwhile the entropy spectrum has the same form as that without inclusion of back reaction, which demonstrates the entropy quantum is \emph{independent} of the effects of back reaction. As our final analysis, we concentrate on the issues of the black hole information, but \emph{unfortunately} find that, even including the effects of back reaction and higher-order quantum corrections, such tunneling formalism can still not provide a mechanism for preserving the black hole information.Comment: 16 pages, no figure, use JHEP3.cls. to be published in JHE

    Quantum corrections and black hole spectroscopy

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    In the work \cite{BRM,RBE}, black hole spectroscopy has been successfully reproduced in the tunneling picture. As a result, the derived entropy spectrum of black hole in different gravity (including Einstein's gravity, Einstein-Gauss-Bonnet gravity and Ho\v{r}ava-Lifshitz gravity) are all evenly spaced, sharing the same forms as Sn=nS_n=n, where physical process is only confined in the semiclassical framework. However, the real physical picture should go beyond the semiclassical approximation. In this case, the physical quantities would undergo higher-order quantum corrections, whose effect on different gravity shares in different forms. Motivated by these facts, in this paper we aim to observe how quantum corrections affect black hole spectroscopy in different gravity. The result shows that, in the presence of higher-order quantum corrections, black hole spectroscopy in different gravity still shares the same form as Sn=nS_n=n, further confirming the entropy quantum is universal in the sense that it is not only independent of black hole parameters, but also independent of higher-order quantum corrections. This is a desiring result for the forthcoming quantum gravity theory.Comment: 14 pages, no figure, use JHEP3.cls. to be published in JHE

    Multi-wave coherent control of a solid-state single emitter

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    The authors acknowledge support by the European Research Council Starting Grant 'PICSEN' contract no. 306387.Coherent control of individual two-level systems (TLSs) is at the basis of any implementation of quantum information. An impressive level of control is now achieved using nuclear, vacancies and charge spins. Manipulation of bright exciton transitions in semiconductor quantum dots (QDs) is less advanced, principally due to the sub-nanosecond dephasing. Conversely, owing to their robust coupling to light, one can apply tools of nonlinear spectroscopy to achieve all-optical command. Here, we report on the coherent manipulation of an exciton via multi-wave mixing. Specifically, we employ three resonant pulses driving a single InAs QD. The first two induce a four-wave mixing (FWM) transient, which is projected onto a six-wave mixing (SWM) depending on the delay and area of the third pulse, in agreement with analytical predictions. Such a switch enables to demonstrate the generation of SWM on a single emitter and to engineer the spectro-temporal shape of the coherent response originating from a TLS. These results pave the way toward multi-pulse manipulations of solid state qubits via implementing the NMR-like control schemes in the optical domain.PostprintPeer reviewe
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