99 research outputs found

    The CDEX-1 1 kg Point-Contact Germanium Detector for Low Mass Dark Matter Searches

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    The CDEX Collaboration has been established for direct detection of light dark matter particles, using ultra-low energy threshold p-type point-contact germanium detectors, in China JinPing underground Laboratory (CJPL). The first 1 kg point-contact germanium detector with a sub-keV energy threshold has been tested in a passive shielding system located in CJPL. The outputs from both the point-contact p+ electrode and the outside n+ electrode make it possible to scan the lower energy range of less than 1 keV and at the same time to detect the higher energy range up to 3 MeV. The outputs from both p+ and n+ electrode may also provide a more powerful method for signal discrimination for dark matter experiment. Some key parameters, including energy resolution, dead time, decay times of internal X-rays, and system stability, have been tested and measured. The results show that the 1 kg point-contact germanium detector, together with its shielding system and electronics, can run smoothly with good performances. This detector system will be deployed for dark matter search experiments.Comment: 6 pages, 8 figure

    Ciprofloxacin-resistant Salmonella enterica Typhimurium and Choleraesuis from Pigs to Humans, Taiwan

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    We evaluated the disk susceptibility data of 671 nontyphoid Salmonella isolates collected from different parts of Taiwan from March 2001 to August 2001 and 1,261 nontyphoid Salmonella isolates from the National Taiwan University Hospital from 1996 to 2001. Overall, ciprofloxacn resistance was found in 2.7% (18/671) of all nontyphoid Salmonella isolates, in 1.4% (5/347) of Salmonella enterica serotype Typhimurium and in 7.5% (8/107) in S. enterica serotype Choleraesuis nationwide. MICs of six newer fluoroquinolones were determined for the following isolates: 37 isolates of ciprofloxacin-resistant (human) S. enterica Typhimurium (N = 26) and Choleraesuis (N = 11), 10 isolates of ciprofloxacin-susceptible (MIC <1 ÎŒg/mL) (human) isolates of these two serotypes, and 15 swine isolates from S. enterica Choleraesuis (N = 13) and Typhmurium (N = 2) with reduced susceptibility to ciprofloxacin (MIC >0.12 ÎŒg/mL). Sequence analysis of the gryA, gyrB, parC, parE, and acrR genes, ciprofloxacin accumulation; and genotypes generated by pulsed-field gel electrophoresis with three restriction enzymes (SpeI, XbaI, and BlnI) were performed. All 26 S. enterica Typhimurium isolates from humans and pigs belonged to genotype I. For S. enterica Choleraesuis isolates, 91% (10/11) of human isolates and 54% (7/13) of swine isolates belonged to genotype B. These two genotypes isolates from humans all exhibited a high-level of resistance to ciprofloxacin (MIC 16–64 ÎŒg/mL). They had two-base substitutions in the gyrA gene at codons 83 (Ser83Phe) and 87 (Asp87Gly or Asp87Asn) and in the parC gene at codon 80 (Ser80Arg, Ser80Ile, or Ser84Lys). Our investigation documented that not only did these two S. enterica isolates have a high prevalence of ciprofloxacin resistance nationwide but also that some closely related ciprofloxacin-resistant strains are disseminated from pigs to humans

    Real-world Effectiveness and Tolerability of Interferon-free Direct-acting Antiviral for 15,849 Patients with Chronic Hepatitis C: A Multinational Cohort Study

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    BACKGROUND AND AIMS: As practice patterns and hepatitis C virus (HCV) genotypes (GT) vary geographically, a global real-world study from both East and West covering all GTs can help inform practice policy toward the 2030 HCV elimination goal. This study aimed to assess the effectiveness and tolerability of DAA treatment in routine clinical practice in a multinational cohort for patients infected with all HCV GTs, focusing on GT3 and GT6. METHODS: We analyzed the sustained virological response (SVR12) of 15,849 chronic hepatitis C patients from 39 Real-World Evidence from the Asia Liver Consortium for HCV clinical sites in Asia Pacific, North America, and Europe between 07/01/2014-07/01/2021. RESULTS: The mean age was 62±13 years, with 49.6% male. The demographic breakdown was 91.1% Asian (52.9% Japanese, 25.7% Chinese/Taiwanese, 5.4% Korean, 3.3% Malaysian, and 2.9% Vietnamese), 6.4% White, 1.3% Hispanic/Latino, and 1% Black/African-American. Additionally, 34.8% had cirrhosis, 8.6% had hepatocellular carcinoma (HCC), and 24.9% were treatment-experienced (20.7% with interferon, 4.3% with direct-acting antivirals). The largest group was GT1 (10,246 [64.6%]), followed by GT2 (3,686 [23.2%]), GT3 (1,151 [7.2%]), GT6 (457 [2.8%]), GT4 (47 [0.3%]), GT5 (1 [0.006%]), and untyped GTs (261 [1.6%]). The overall SVR12 was 96.9%, with rates over 95% for GT1/2/3/6 but 91.5% for GT4. SVR12 for GT3 was 95.1% overall, 98.2% for GT3a, and 94.0% for GT3b. SVR12 was 98.3% overall for GT6, lower for patients with cirrhosis and treatment-experienced (TE) (93.8%) but ≄97.5% for treatment-naive patients regardless of cirrhosis status. On multivariable analysis, advanced age, prior treatment failure, cirrhosis, active HCC, and GT3/4 were independent predictors of lower SVR12, while being Asian was a significant predictor of achieving SVR12. CONCLUSIONS: In this diverse multinational real-world cohort of patients with various GTs, the overall cure rate was 96.9%, despite large numbers of patients with cirrhosis, HCC, TE, and GT3/6. SVR12 for GT3/6 with cirrhosis and TE was lower but still excellent (\u3e91%)

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Comparing the outcomes of different postgraduate year training programs in Taiwan

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    Background: Postgraduate year training programs play an important role in the development of a comprehensive medical education. The goal of these training programs is to inculcate in physicians the expected level of skill in patient care. After the initiation of such programs in the USA, Europe, and Japan, studies were conducted in Taiwan to investigate relevant training methods, and a training system was established in 2003. Beginning with 3-month programs, followed by 6-month programs, the programs were constantly modified and enhanced by the establishment of the 1-year training program in 2011. This year was the transition period from the 6-month programs to the 1-year programs. Methods: We used a 50-item multiple choice question (MCQ) test and six 10-min stations for objective structured clinical examination (OSCE), which was composed of four stations relating to standardized patients and two stations concerning the clinical skill evaluation, to evaluate the learning results of the trainees. The trainees were divided into four groups according to the training program. Results: There was no significant difference between the performance of the 6 months and 1-year groups. The p values were 0.424 in the MCQ test and 0.082 in the OSCE evaluation. Conclusion: A well-designed postgraduate training program should develop trainees’ competencies. The results of this study may provide useful insight for ways to improve the design of training programs. Further investigation to better understand the impact of different programs is warranted

    C-reactive protein levels can predict positive 18F-FDG PET/CT findings that lead to management changes in patients with bacteremia

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    Background/purpose: Bacteremia portends high rates of morbidity and mortality. Although 18F-fluorodeoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT) imaging has clinical value in assessing fever of unknown origin, its usefulness in bacteremia has not been entirely elucidated. We therefore designed the current single-center retrospective study to investigate 1) the clinical value of 18F-FDG PET/CT imaging in assessing bacteremia and 2) the association between laboratory data and imaging findings. Methods: We examined 102 patients with bacteremia who had undergone 18F-FDG PET/CT imaging. The patients’ clinical and laboratory data were reviewed and analyzed in relation to 18F-FDG PET/CT findings. Patients showing positive results underwent quantitative measurements of 18F-FDG uptake. Results: Positive 18F-FDG PET/CT findings were identified in 74 (72.5%) patients, and 40 (54.1%) underwent modified treatment or management because of the imaging results (p = 0.003). Positive 18F-FDG PET/CT findings were significantly associated with higher white blood cell (WBC) counts and C-reactive protein (CRP) levels (p = 0.012 and 54.025 mg/L were accurate predictors of positive 18F-FDG PET/CT results. Keywords: Bacteremia, C-reactive protein, 18F-fluorodeoxyglucose positron emission tomography and computed tomograph

    Potential usefulness of FDG PET/CT in patients with sepsis of unknown origin.

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    PURPOSE: The role of FDG PET in the evaluation of patients with sepsis of unknown origin remains unclear. We sought to assess the value of FDG PET/CT in patients with sepsis of unknown cause and to define its priority in this group of subjects. METHODS: A total of 53 patients with sepsis of unknown origin underwent FDG PET/CT within two weeks of diagnosis. All of the patients were followed up for at least 3 months after discharge to determine the clinical outcomes. The impact of FDG PET/CT was assessed according to the number of cases who had their treatment modified on the basis of the imaging results. Logistic regression analysis was used to identify the independent predictors of positive FDG PET/CT findings. RESULTS: Of the 53 study patients, 35 (66%) had positive FDG PET/CT findings, and 13 (25%) had their treatment modified on the basis of the imaging results. Logistic regression analysis identified normal serum aspartate aminotransferase (odds ratio [OR]  = 6.134; 95% confidence interval [CI]  = 1.443-26.076, P = 0.014) and increased serum alkaline phosphatase levels (OR = 5.813; 95% CI = 1.386-24.376, P = 0.016) at diagnosis as independent predictors of positive FDG PET/CT findings. A scoring system using these two covariates was developed, which defined three distinct priority groups for FDG PET/CT imaging. CONCLUSION: Our findings suggest that FDG PET/CT may be clinically useful for the detection of occult foci of infection in patients with sepsis of unknown origin

    Clinical outcomes of patients with oral cavity squamous cell carcinoma and retropharyngeal lymph node metastasis identified by FDG PET/CT.

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    PURPOSE: Retropharyngeal lymph node (RPLN) metastasis is an uncommon finding in patients with oral cavity squamous carcinoma (OSCC). We sought to investigate the clinical outcomes, clinicopathological characteristics, and the priority of treatment with curative intent in OSCC patients with RPLN involvement. METHODS AND MATERIALS: Between January 2007 and January 2011, we identified 36 patients with primary RPLN metastases (n = 10) or RPLN relapse (n = 26). The follow-up continued until June 2013. Disease-specific survival (DSS), disease-free survival (DFS), and the potential benefits of salvage therapy served as the main outcome measures. RESULTS: The 2-year DSS and DFS rates of untreated patients with RPLN involvement were 20% and 24%, respectively. Level IV/V neck lymph node involvement was an adverse prognostic factor for DSS (P = 0.048) and DFS (P = 0.018). All of the patients presenting with neck lymph node involvement at level IV/V died within 6 months. Among patients who were treated for RPLN relapse, the 2-year DSS and DFS rates from the relapse day were 12.8% and 9.6%, respectively. Concomitant contralateral neck lymph node metastases (N2c) were associated with lower 2-year DSS (P = 0.005) and DFS (P = 0.011) rates. Moreover, five (55%) of the nine patients with recurrent disease in the contralateral RPLN had distant metastases within 6 months. Salvage therapy yielded the maximum survival benefit in patients without N2c disease and ipsilateral RPLN involvement alone (P = 0.005). CONCLUSION: OSCC patients with RPLN involvement have poor outcomes. The risk factor for definitive treatment in OSCC patients with FDG PET/CT defined RPLN disease in primary disease was neck lymph node involvement at level IV/V and N2c and/or contralateral RPLN disease in recurrent disease. Treatment efforts with curative intent should be tailored according to individual risk factors
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