505 research outputs found

    An Elusive Vector Dark Matter

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    Even though the sensitivity of direct dark matter search experiments reach the level about 1045 cm210^{-45}~{\rm cm}^2, there is no confident signal of dark matter been observed. We point out that, if dark matter is a vector boson, the null result in direct dark matter search experiments may due to the destructive effects in dark-matter-nucleon elastic scattering. We illustrate the scenario using a modified Higgs portal model that includes exotic quarks. The significant cancellation can occur for certain mass gap between heavy quark and dark matter. As a result, the spin-independent dark-matter-nucleon elastic scattering is so suppressed that the future direct search experiments can hardly observe the signal of dark matter.Comment: 11 pages, 5 figure

    Epidemiology and management of gout in Taiwan: a nationwide population study

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    INTRODUCTION: Gout is the most common inflammatory arthritis worldwide and is the only type of chronic arthritis that potentially can be ‘cured’. However, data on gout incidence, prevalence and management, assessed at multiple time points in the same population, are sparse, particularly in Asian populations. The aim of this study was to describe trends in the epidemiology of gout in the general population of Taiwan. METHODS: The National Health Insurance Research Database was used to identify patients with gout and to estimate the prevalence and incidence of gout for each calendar year from 2005 to 2010. The pattern of gout management was also examined. RESULTS: Of 23,371,362 beneficiaries in 2010, there were 1,458,569 prevalent and 56,595 incident cases of gout, giving a prevalence of 6.24% (95% confidence interval (CI), 6.23% to 6.25%) and an incidence of 2.74 (95% CI, 2.72 to 2.76) per 1,000 person-years. The annual percentage change (APC) of the standardised prevalence was −0.7% (95% CI, −1.7% to 0.3%; P = 0.14), suggesting that the prevalence of gout was essentially the same throughout the study period. However, The APC of incidence was −13.4 (95% CI, −16.1 to −10.6) between 2005 and 2007 and −2.1 (95% CI, −10.4 to 7.1) between 2007 and 2010. Regions with the highest prevalence and incidence were eastern coastal counties and offshore islets, where indigenous people are clustered. Among prevalent gout cases in 2010, only 22.93% (95% CI, 22.87% to 23.00%) were prescribed urate-lowering treatment (ULT), which remained unchanged between 2005 and 2010 at an APC of 0.0 (95% CI, −3.8 to 4.0). Uricosuric agents were more commonly prescribed than xanthine oxidase inhibitors in Taiwan. CONCLUSIONS: In Taiwan, 1 in 16 people have gout. Whereas the incidence has decreased recently, the prevalence remains unchanged. Management of gout in Taiwan is poor, with only one in five affected people being treated with ULT

    Experimental Investigation on Compressive Strength, Ultrasonic Characteristic and Cracks Distribution of Granite Rock Irradiated by a Moving Laser Beam

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    Efficient fracturing is the key issue for the exploitation of geothermal energy in a Hot Dry Rock reservoir. By using the laser irradiation cracking method, this study investigates the changes in uniaxial compressive strength, ultrasonic characteristics and crack distributions of granite specimens by applying a laser beam under various irradiation conditions, including different powers, diameters and moving speeds of the laser beam. The results indicate that the uniaxial compressive strength is considerably dependent on the power, diameter and moving speed of the laser beam. The ultrasonic-wave velocity and amplitude of the first wave both increase with a decreased laser power, increased diameter or moving speed of the laser beam. The wave form of irradiated graphite is flattened by laser irradiation comparing with that of the original specimen without laser irradiation. The crack angle and the ratio of the cracked area at both ends are also related to the irradiation parameters. The interior cracks are observed to be well-developed around the bottom of the grooving kerf generated by the laser beam. The results indicate that laser irradiation is a new economical and practical method that can efficiently fracture graphite

    Familial aggregation of systemic lupus erythematosus and coaggregation of autoimmune diseases in affected families

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    IMPORTANCE: Relatives of patients with systemic lupus erythematosus (SLE) appear to be at higher risk of SLE and other autoimmune diseases, but estimates of individual familial risks are largely unavailable or unreliable. Furthermore, relative contributions of genetic, shared, and unshared environmental factors to SLE susceptibility remain unclear. OBJECTIVE: To examine familial aggregation and heritability of SLE and the relative risks (RRs) of other autoimmune diseases in relatives of patients with SLE. DESIGN, SETTING, AND PARTICIPANTS: A population-based family study using the Taiwan National Health Insurance Research Database was conducted. Participants included all individuals (N = 23,658,577) registered with that database in 2010; of these, 18,283 had SLE. We identified 21,009,551 parent-child relationships, 17,168,340 full sibling pairs, and 342,066 twin pairs. Diagnoses of SLE were ascertained from March 1, 1995, to December 31, 2010, and analysis was conducted between March 1 and August 15, 2014. MAIN OUTCOMES AND MEASURES: The prevalence and RRs of SLE and other autoimmune diseases in relatives and spouses of patients with SLE as well as the relative contributions of heritability, shared, and nonshared environmental factors to SLE susceptibility. RESULTS: Among the more than 23 million participants, the RRs (95% CIs) for SLE were 315.94 (210.66-473.82) for twins of the patients, 23.68 (20.13-27.84) for siblings, 11.44 (9.74-13.43) for parents, 14.42 (12.45-16.70) for offspring, and 4.44 (2.38-8.30) for spouses without genetic similarity. The accountability for phenotypic variance of SLE was 43.9% for heritability, 25.8% for shared environmental factors, and 30.3% for nonshared environmental factors. The RRs (95% CIs) in individuals with a first-degree relative with SLE were 5.87 (4.89-7.05) for primary Sjogren syndrome, 5.40 (3.37-8.65) for systemic sclerosis, 2.95 (2.04-4.26) for myasthenia gravis, 2.77 (1.45-5.32) for idiopathic inflammatory myositis, 2.66 (2.28-3.11) for rheumatoid arthritis, 2.58 (1.16-5.72) for multiple sclerosis, 1.68 (1.22-2.32) for type 1 diabetes mellitus, 1.39 (0.66-2.91) for inflammatory bowel diseases, and 0.86 (0.43-1.71) for vasculitis. CONCLUSIONS AND RELEVANCE: The individual risks of SLE and other autoimmune diseases were increased in families that included patients with SLE. The heritability of SLE was estimated to be 43.9%. These data should be considered when counseling families with affected members

    Familial risk of Sjögren's syndrome and co-aggregation of autoimmune diseases in affected families: a nationwide population study

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    Objective: To investigate familial aggregation of Sjögren's syndrome (SS) and the relative risks (RRs) of other autoimmune disease in relatives of patients with SS. Methods: We identified 23,658,577 beneficiaries enrolled in the Taiwan National Health Insurance system in 2010, of whom 12,754 had SS. We identified 21,009,551 parent–child relationships and 17,168,340 pairs of full siblings. The familial risks of SS and other autoimmune diseases, tetrachoric correlation, and familial transmission were estimated. Results: We identified 105 patients with SS who had an affected first-degree relative. The RR of SS was 18.99 (95% confidence interval [95% CI] 9.76–36.93) in siblings of patients with SS, 11.31 (95% CI 8.34–15.33) in offspring, and 12.46 (95% CI 9.34–16.62) in parents. Tetrachoric correlation coefficients were 0.53 (95% CI 0.41–0.65) for cotwins of affected individuals and 0.21 (95% CI 0.16–0.26) for full siblings. The familial transmission (heritability plus shared environmental contribution) was 0.54 (95% CI 0.44–0.77). In first-degree relatives of patients with SS, the RRs were 2.95 (95% CI 2.33–3.73) for rheumatoid arthritis, 6.25 (95% CI 5.15–7.58) for systemic lupus erythematosus, 2.39 (95% CI 0.77–7.41) for systemic sclerosis, 0.71 (95% CI 0.10–5.07) for idiopathic inflammatory myopathy, 1.97 (95% CI 1.29–3.02) for type 1 diabetes mellitus, 3.38 (95% CI 1.26–9.05) for multiple sclerosis, 1.67 (95% CI 0.83–3.33) for myasthenia gravis, 1.25 (95% CI 1.04–1.50) for psoriasis, 1.21 (95% CI 0.39–3.76) for inflammatory bowel disease, and 2.29 (95% CI 1.19–4.40) for vasculitis. Conclusion: The risk of SS and other autoimmune diseases is increased in relatives of patients with SS, and more than one-half of phenotypic variance in SS can be explained by familial factors

    The design of a prospective, randomized, open-labeled study to compare the efficacy of lercanidipine with amlodipine on renal function in hypertensive patients aged at least 55 years (LEADER study)

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    AbstractBackgroundAlthough all classes of antihypertensive treatment can successfully reduce morbidity and mortality of cardiac pathology, prevention of target organ damages is of great importance beyond blood pressure lowering. Unlike most dihydropyridines, lercanidipine dilates both afferent and the efferent arterioles of nephrons, so it may provide renoprotective effects, which other CCBs may not have. The main purpose of this study is to compare the renoprotective effect of lercanidipine and amlodipine among hypertensive people aged 55years and older with newly diagnosed hypertension or those who were treatment-naïve for one month.MethodsThe study is a prospective, open-labelled, randomized, controlled trial to enrol 232 hypertensive patients aged ≥55 years. Subjects will be randomized into lercanidipine arm (10–20mg/day) and amlodipine arm (5–10mg/day) by 1:1 ratio. The dosage can be up-titrated to 20mg/day (lercanidipine group) and 10mg/day (amlodipine group), respectively, at week 4 or any following visit thereafter. Efficacy and safety data will be collected at week 4, 12 and 24 by evaluating the blood pressure lowering, estimated glomerular filtration rate, creatinine clearance, and urine albumin-creatinine ratio.ConclusionsThe reno-protective effects of new generation of CCBs such as lercanidipine administered to patients with hypertension are not investigated well. After all, this study will bring benefit to older patients who need drugs with both excellent anti-hypertensive and reno-protective efficacy. And the results will be provided for future treatment guideline of elder population in Taiwan

    Gene expression profiling of breast cancer survivability by pooled cDNA microarray analysis using logistic regression, artificial neural networks and decision trees

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    BACKGROUND: Microarray technology can acquire information about thousands of genes simultaneously. We analyzed published breast cancer microarray databases to predict five-year recurrence and compared the performance of three data mining algorithms of artificial neural networks (ANN), decision trees (DT) and logistic regression (LR) and two composite models of DT-ANN and DT-LR. The collection of microarray datasets from the Gene Expression Omnibus, four breast cancer datasets were pooled for predicting five-year breast cancer relapse. After data compilation, 757 subjects, 5 clinical variables and 13,452 genetic variables were aggregated. The bootstrap method, Mann–Whitney U test and 20-fold cross-validation were performed to investigate candidate genes with 100 most-significant p-values. The predictive powers of DT, LR and ANN models were assessed using accuracy and the area under ROC curve. The associated genes were evaluated using Cox regression. RESULTS: The DT models exhibited the lowest predictive power and the poorest extrapolation when applied to the test samples. The ANN models displayed the best predictive power and showed the best extrapolation. The 21 most-associated genes, as determined by integration of each model, were analyzed using Cox regression with a 3.53-fold (95% CI: 2.24-5.58) increased risk of breast cancer five-year recurrence… CONCLUSIONS: The 21 selected genes can predict breast cancer recurrence. Among these genes, CCNB1, PLK1 and TOP2A are in the cell cycle G2/M DNA damage checkpoint pathway. Oncologists can offer the genetic information for patients when understanding the gene expression profiles on breast cancer recurrence

    Serum Bone Resorption Markers after Parathyroidectomy for Renal Hyperparathyroidism: Correlation Analyses for the Cross-Linked N-telopeptide of Collagen I and Tartrate-Resistant Acid Phosphatase

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    Patients on long-term dialysis may develop secondary hyperparathyroidism (SHPT) with increased serum concentrations of bone resorption markers such as the cross-linked N-telopeptide of type I collagen (NTX) and type-5b tartrate-resistant acid phosphatase (TRAP). When SHPT proves refractory to treatment, parathyroidectomy (PTX) may be needed. Renal patients on maintenance HD who received PTX for refractory SHPT (n=23) or who did not develop refractory SHPT (control subjects; n=25) were followed prospectively for 4 weeks. Serum intact parathyroid hormone (iPTH), NTX, TRAP, and bone alkaline phosphatase (BAP) concentrations were measured serially and correlation analyses were performed. iPTH values decreased rapidly and dramatically. BAP values increased progressively with peak increases observed at 2 weeks after surgery. NTX and TRAP values decreased concurrently and progressively through 4 weeks following PTX. A significant correlation between TRAP and NTX values was observed before PTX but not at 4 weeks after PTX. Additionally, the fractional changes in serum TRAP were larger than those in serum NTX at all times examined after PTX. Serum iPTH, TRAP, and NTX values declined rapidly following PTX for SHPT. Serum TRAP values declined to greater degrees than serum NTX values throughout the 4-week period following PTX
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