488 research outputs found
Impact Factor: outdated artefact or stepping-stone to journal certification?
A review of Garfield's journal impact factor and its specific implementation
as the Thomson Reuters Impact Factor reveals several weaknesses in this
commonly-used indicator of journal standing. Key limitations include the
mismatch between citing and cited documents, the deceptive display of three
decimals that belies the real precision, and the absence of confidence
intervals. These are minor issues that are easily amended and should be
corrected, but more substantive improvements are needed. There are indications
that the scientific community seeks and needs better certification of journal
procedures to improve the quality of published science. Comprehensive
certification of editorial and review procedures could help ensure adequate
procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Search for R-parity-violating supersymmetry in events with four or more leptons in sqrt(s) =7 TeV pp collisions with the ATLAS detector
A search for new phenomena in final states with four or more leptons (electrons or muons) is presented. The analysis is based on 4.7 fb−1 of proton-proton collisions delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in two signal regions: one that requires moderate values of missing transverse momentum and another that requires large effective mass. The results are interpreted in a simplified model of R-parity-violating supersymmetry in which a 95% CL exclusion region is set for charged wino masses up to 540 GeV. In an R-parity-violating MSUGRA/CMSSM model, values of m 1/2 up to 820 GeV are excluded for 10 < tan β < 40
Assessing Mental Illness Referral Request Acceptance: A Nationwide E-Referral Data From Saudi Arabia
Abdullah A Alharbi,1 Nawfal A Aljerian,2– 4 Hani A Alghamdi,5 Meshary S Binhotan,4,6 Ali K Alsultan,2 Mohammed S Arafat,2 Abdulrahman Aldhabib,2 Ahmed I Aloqayli,2 Eid B Alwahbi,2 Ronnie D Horner7 1Family and Community Medicine Department, Faculty of Medicine, Jazan University, Jazan City, Kingdom of Saudi Arabia; 2Medical Referrals Centre, Ministry of Health, Riyadh, Kingdom of Saudi Arabia; 3Emergency Medical Services Department, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Science, Riyadh, Kingdom of Saudi Arabia; 4King Abdullah International Medical Research Centre, Riyadh, Kingdom of Saudi Arabia; 5Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia; 6Emergency Medical Services Department, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia; 7Health Services Research and Administration Department, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USACorrespondence: Meshary S Binhotan, Emergency Medical Services Department, College of Applied Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, 22490, Kingdom of Saudi Arabia, Email [email protected] and Objective: Mental disorders significantly impact quality of life and life expectancy, representing a leading cause of global disease burden. Healthcare systems worldwide face challenges in meeting mental health service demands, particularly due to specialist shortages and geographical barriers. Saudi Arabia has implemented an innovative nationwide electronic referral system (SMARC) as part of its digital health transformation strategy to enhance mental healthcare accessibility. This study examined SMARC’s effectiveness in facilitating mental health service access by analyzing patient transfer acceptance rates between healthcare facilities and identifying factors influencing these rates.Methods: This retrospective cross-sectional study analyzed 9722 mental health electronic referrals within SMARC from January 2020 to December 2021. Descriptive statistics characterized referral patterns, while bivariate and multivariable logistic regression analyses identified factors associated with referral acceptance, calculating adjusted odds ratios (aORs) and 95% confidence intervals.Results: The system achieved an overall acceptance rate of 82.5%, with different patterns across age groups and regions. Lower acceptance rates were observed for ages 15– 25 years (aOR = 0.84; 95% CI = 0.70– 0.99) and 46– 65 years (aOR = 0.83; 95% CI = 0.70– 0.99) compared to ages 26– 35 years. Life-saving referrals showed the highest acceptance (aOR = 2.60; 95% CI = 1.51– 4.48), while psychiatrist availability significantly influenced acceptance rates (aOR = 1.36; 95% CI = 1.17– 1.58). External referrals were half as likely to be accepted as internal ones (aOR = 0.51; 95% CI = 0.42– 0.64).Conclusion: SMARC demonstrates effectiveness in optimizing mental healthcare access through strategic matching of patient needs with available resources. The system’s selective acceptance patterns reflect its capability to prioritize care based on clinical urgency and resource availability. These findings provide valuable insights for policymakers to keep enhancing digital health infrastructure and mental healthcare delivery. The SMARC model offers a promising framework for implementing similar digital referral systems globally to improve mental healthcare coordination and accessibility.Keywords: mental health, psychiatry, referral systems, acceptance rates, health policy, Saudi Arabia, regional variation, Saudi Medical Referral Cente
Effects of TGF-β1 and IGF-1 on proliferation of human nucleus pulposus cells in medium with different serum concentrations
BACKGROUND: The low proliferative viability of human nucleus pulposus(NP) cells is considered as a cause of intervertebral discs degeneration. Growth factors, such as TGF-β1 and IGF-1, have been implicated in cell proliferation and matrix synthesis. OBJECTIVE: To investigate the dose-response and time-course effect of transforming growth factorβ1(TGF-β1) and insulin-like growth factor-1(IGF-1) on proliferation of NP cells. STUDY DESIGN: 3-(4,5-dimethylthiazolyl)-2,5-diphenyl-tetrazolium bromide (MTT) is reduced by dehydrogenase in mitochondria of live cells. The proliferative viability of cells corresponds to the amount of MTT reduced, which is measured with an enzyme-linked immunosorbent assay plate reader. In this study, we assessed dose- and time-dependent effects of NP cells to TGF-β1 and IGF-1 in medium with different serum concentrations by MTT assay. METHODS: After release of informed consent, tissue samples of NP were obtained from anterior surgical procedures performed on five donors with idiopathic scoliosis. Isolated cells were cultured in F12 medium supplemented with 10% fetal bovine serum(FBS). Cells were seeded in 96-well plates at 1 × 10(3 )cells/well. After synchronization, medium was replaced by F12 containing 1% or 10% FBS with either single or combination of TGF-β1 and IGF-1. Dose-response and time-course effect were examined by MTT assay. RESULTS: In the presence of 1% FBS, the response to IGF-1 was less striking, whereas TGF-β1 had a remarkably stimulating effect on cell proliferation. In 10% FBS, both of the two growth factors had statistical significant mitogenic effects, especially TGF-β1. The dose-dependent effect of TGF and IGF on cell proliferation was found within different concentrations of each growth factor(TGF-β1 1–10 μg/L, IGF-1 10–100 μg/L). The time-course effect showed a significant elevation three days later. CONCLUSION: TGF-β1 and IGF-1 were efficient to stimulate cell proliferation of human NP cells in vitro with a dose- and time-dependent manner. These results support the therapeutic potentials of the two growth factors in the treatment of disc degeneration
Remyelination after chronic spinal cord injury is associated with proliferation of endogenous adult progenitor cells after systemic administration of guanosine
Axonal demyelination is a consistent pathological sequel to chronic brain and spinal cord injuries and disorders that slows or disrupts impulse conduction, causing further functional loss. Since oligodendroglial progenitors are present in the demyelinated areas, failure of remyelination may be due to lack of sufficient proliferation and differentiation of oligodendroglial progenitors. Guanosine stimulates proliferation and differentiation of many types of cells in vitro and exerts neuroprotective effects in the central nervous system (CNS). Five weeks after chronic traumatic spinal cord injury (SCI), when there is no ongoing recovery of function, intraperitoneal administration of guanosine daily for 2 weeks enhanced functional improvement correlated with the increase in myelination in the injured cord. Emphasis was placed on analysis of oligodendrocytes and NG2-positive (NG2+) cells, an endogenous cell population that may be involved in oligodendrocyte replacement. There was an increase in cell proliferation (measured by bromodeoxyuridine staining) that was attributable to an intensification in progenitor cells (NG2+ cells) associated with an increase in mature oligodendrocytes (determined by Rip+ staining). The numbers of astroglia increased at all test times after administration of guanosine whereas microglia only increased in the later stages (14 days). Injected guanosine and its breakdown product guanine accumulated in the spinal cords; there was more guanine than guanosine detected. We conclude that functional improvement and remyelination after systemic administration of guanosine is due to the effect of guanosine/guanine on the proliferation of adult progenitor cells and their maturation into myelin-forming cells. This raises the possibility that administration of guanosine may be useful in the treatment of spinal cord injury or demyelinating diseases such as multiple sclerosis where quiescent oligodendroglial progenitors exist in demyelinated plaques
Disruption of the thrombospondin-2 gene alters the lamellar morphology but does not permit vascularization of the adult mouse lumbar disc
The p75 neurotrophin receptor is expressed by adult mouse dentate progenitor cells and regulates neuronal and non-neuronal cell genesis
<p>Abstract</p> <p>Background</p> <p>The ability to regulate neurogenesis in the adult dentate gyrus will require further identification and characterization of the receptors regulating this process. <it>In vitro </it>and <it>in vivo </it>studies have demonstrated that neurotrophins and the p75 neurotrophin receptor (p75<sup>NTR</sup>) can promote neurogenesis; therefore we tested the hypothesis that p75<sup>NTR </sup>is expressed by adult dentate gyrus progenitor cells and is required for their proliferation and differentiation.</p> <p>Results</p> <p>In a first series of studies focusing on proliferation, mice received a single BrdU injection and were sacrificed 2, 10 and 48 hours later. Proliferating, BrdU-positive cells were found to express p75<sup>NTR</sup>. In a second series of studies, BrdU was administered by six daily injections and mice were sacrificed 1 day later. Dentate gyrus sections demonstrated a large proportion of BrdU/p75<sup>NTR </sup>co-expressing cells expressing either the NeuN neuronal or GFAP glial marker, indicating that p75<sup>NTR </sup>expression persists at least until early stages of maturation. In p75<sup>NTR </sup>(-/-) mice, there was a 59% decrease in the number of BrdU-positive cells, with decreases in the number of BrdU cells co-labeled with NeuN, GFAP or neither marker of 35%, 60% and 64%, respectively.</p> <p>Conclusions</p> <p>These findings demonstrate that p75<sup>NTR </sup>is expressed by adult dentate progenitor cells and point to p75<sup>NTR </sup>as an important receptor promoting the proliferation and/or early maturation of not only neural, but also glial and other cell types.</p
Evaluation of vardenafil for the treatment of subjective tinnitus: a controlled pilot study
<p>Abstract</p> <p>Background</p> <p>Vardenafil (Levitra<sup>®</sup>) represents a potent and highly selective phosphodiesterase type 5 (PDE5) inhibitor, which is established for treatment of various diseases. There are several unpublished reports from patients stating that vardenafil has a considerable therapeutic effect on their concomitant tinnitus. This pilot study was conducted to specifically assess the effect of vardenafil in patients with chronic tinnitus.</p> <p>Methods</p> <p>This trial was based on a prospective, randomized, double-blind, placebo-controlled, parallel group design. Fourty-two consecutive subjects with mon- or binaural chronic tinnitus received 10 mg vardenafil (N = 21) or matching placebo tablets (N = 21) administered orally twice a day over a period of 12 weeks. Clinical examination and data acquisition took place at each visit: at baseline, after 4 weeks, after 12 weeks (end of treatment with study medication), and at non-medicated follow-up after 16 weeks. Assessment of clinical effectiveness was based on a standardized tinnitus questionnaire (TQ), the Short Form 36 health survey (SF-36), audiometric measurements (mode, pitch and loudness of tinnitus; auditory thresholds) and biomarkers of oxidative stress in patients' blood (malondialdehyde, protein carbonyl, homocysteine and total antioxidative status). Therapeutic efficacy was evaluated by comparison of subjective and objective parameters with baseline data between both treatment groups (ANCOVA).</p> <p>Results</p> <p>Vardenafil had no superior efficacy over placebo in the treatment of chronic tinnitus during this study. The primary efficacy criterion 'TQ total score' failed to demonstrate significant improvement compared to placebo. Subjective reports of TQ subscales and general quality of life areas (SF-36), objective audiometric examinations as well as investigated biomarkers for oxidative stress did not reveal any significant treatment effects. The safety profile was favorable and consistent with that in other vardenafil studies.</p> <p>Conclusion</p> <p>Although hypoxia and ischemia play a special role in the pathogenesis of tinnitus, the PDE5-inhibitor-induced increase of nitric oxide-mediated vasodilatation exerted no specific influence on tinnitus symptomatology. Considering the unclear risk of rarely associated hearing impairment, systemic application of vardenafil or other PDE5 inhibitors prove to be not appropriate for therapy of chronic tinnitus.</p
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