106 research outputs found
Temperature Response of the HTR-10 during the Power Ascension Test
The 10 MW High Temperature Gas-Cooled Reactor-Test Module (HTR-10) is the first High Temperature Gas-Cooled Reactor in China. With the objective of raising the reactor power from 30% to 100% rated power, the power ascension test was planned and performed in January 2003. The test results verified the practicability and validity of the HTR-10 power regulation methods.
In this study, the power ascension process is preliminarily simulated using the THERMIX code. The code satisfactorily reproduces the reactor transient parameters, including the reactor power, the primary helium pressure, and the primary helium outlet temperature. Reactor internals temperatures are also calculated and compared with the test values recorded by a number of thermocouples. THERMIX correctly simulates the temperature variation tendency for different measuring points, with good to fair agreement between the calculated temperatures and the measured ones. Based on the comparison results, the THERMIX simulation capability for the HTR-10 dynamic characteristics during the power ascension process can be demonstrated. With respect to the reactor safety features, it is of utmost importance that the maximum fuel center temperature during the test process is always much lower than the fuel temperature limit of 1620°C
Initial uptake, time to treatment, and real-world effectiveness of all-oral direct-acting antivirals for hepatitis C virus infection in the United States: A retrospective cohort analysis
BACKGROUND:
Data on initiation and utilization of direct-acting antiviral therapies for hepatitis C virus infection in the United States are limited. This study evaluated treatment initiation, time to treatment, and real-world effectiveness of direct-acting antiviral therapy in individuals with hepatitis C virus infection treated during the first 2 years of availability of all-oral direct-acting antiviral therapies.
METHODS:
A retrospective cohort analysis was undertaken using electronic medical records and chart review abstraction of hepatitis C virus-infected individuals aged >18 years diagnosed with chronic hepatitis C virus infection between January 1, 2014, and December 31, 2015 from the Indiana University Health database.
RESULTS:
Eight hundred thirty people initiated direct-acting antiviral therapy during the 2-year observation window. The estimated incidence of treatment initiation was 8.8%±0.34% at the end of year 1 and 15.0%±0.5% at the end of year 2. Median time to initiating therapy was 300 days. Using a Cox regression analysis, positive predictors of treatment initiation included age (hazard ratio, 1.008), prior hepatitis C virus treatment (1.74), cirrhosis (2.64), and history of liver transplant (1.5). History of drug abuse (0.43), high baseline alanine aminotransferase levels (0.79), hepatitis B virus infection (0.41), and self-pay (0.39) were negatively associated with treatment initiation. In the evaluable population (n = 423), 83.9% (95% confidence interval, 80.1-87.3%) of people achieved sustained virologic response.
CONCLUSION:
In the early years of the direct-acting antiviral era, <10% of people diagnosed with chronic hepatitis C virus infection received direct-acting antiviral treatment; median time to treatment initiation was 300 days. Future analyses should evaluate time to treatment initiation among those with less advanced fibrosis
An Integrated Surveillance System to Examine Testing, Services, and Outcomes for Sexually Transmitted Diseases
Despite laws that require reporting of sexually transmitted diseases (STDs) to governmental health agencies, integrated surveillance of STDs remains challenging. Data and information about testing are fragmented from information on treatment and outcomes. To overcome this fragmentation, data from multiple electronic systems spanning clinical and public health environments were integrated to create an STD surveillance registry. Electronic health records, disease case records, and birth registry records were linked and then stored in a de-identified, secure server for use by health officials and researchers. The registry contains nearly 6 million tests for 628,138 individuals over a 12-year period. The registry supports efforts to understand the epidemiology of STDs as well as health services and outcomes for those diagnosed with STDs. Specialized disease registries hold promise for collaboration across clinical and public health domains to improve surveillance efforts, reduce health disparities, and increase prevention efforts at the local level
A lag bloom pattern of phytoplankton after freshwater input events revealed by daily samples during summer in Qinhuangdao coastal water, China
Phytoplankton blooms have become a global concern due to their negative impacts on public health, aquaculture, tourism, and the economic stability of coastal regions. Therefore, elucidating the shifts in phytoplankton community structure and abundance, as well as their environmental drivers, is crucial. However, existing studies often fail to capture the detailed dynamics of phytoplankton blooms and their environmental triggers due to low temporal observation resolution. In this study, high temporal resolution (daily) samples were collected over 43 days to investigate the influence of environmental factors on phytoplankton in Qinhuangdao in the summer. During the observation period, a total of 45 phytoplankton species were identified, comprising 26 Bacillariophyta species, 16 Dinophyta species, 2 Euglenophyta species, and 1 Chromophyta species. Interestingly, a lag bloom pattern of phytoplankton behind freshwater input was observed across day-to-day samples. Phytoplankton blooms typically lagged 1–3 days behind periods of decreased salinity and nutrient input, suggesting that freshwater influx provides the foundational materials and benefits for these blooms. Moreover, the phytoplankton blooms were triggered by six dominant species, i.e., Chaetoceros spp., Pseudo-nitzschia delicatissima, Skeletonema costatum, Protoperdinium spp., Leptocylindrus minimus, Pseudo-nitzschia pungens, and Thalassiosira spp. Consequently, the succession of phytoplankton showed a predominant genera shift in the following sequence: Nitzschia, Protoperdinium, and Prorocentrum – Skeletonema – Pseudo-nitzschia – Gymnodinium – Leptocylindrus. Besides that, a deterministic process dominated phytoplankton community assembly across time series, and DIP is a key factor in shifting the phytoplankton community structures in this area. In summary, our study offers high-resolution observations on the succession of phytoplankton communities and sheds light on the complex and differentiated responses of phytoplankton to environmental factors. These findings enhance our understanding of the dynamics of phytoplankton blooms and their environmental drivers, which is essential for the effective management and mitigation of their adverse impacts
High level soluble expression, one-step purification and characterization of HIV-1 p24 protein
<p>Abstract</p> <p>Background</p> <p>P24 protein is the major core protein of HIV virus particle and has been suggested as a specific target for antiviral strategies. Recombinant p24 protein with natural antigenic activity would be useful for various studies, such as diagnostic reagents and multi-component HIV vaccine development. The aim of this study was to express and purify the p24 protein in soluble form in <it>E.coli</it>.</p> <p>Results</p> <p>According to the sequence of the p24 gene, a pair of primers was designed, and the target sequence of 700 bp was amplified using PCR. The PCR product was cloned into pQE30 vector, generating the recombinant plasmid pQE30-p24. SDS-PAGE analysis showed that the His-tagged recombinant p24 protein was highly expressed in soluble form after induction in <it>E. coli </it>strain BL21. The recombinant protein was purified by nickel affinity chromatography and used to react with HIV infected sera. The results showed that the recombinant p24 protein could specifically react with the HIV infected sera. To study the immunogenicity of this soluble recombinant p24 protein, it was used to immunize mice for the preparation of polyclonal antibody. Subsequent ELISA and Western-Blot analysis demonstrated that the p24 protein had proper immunogenicity in inducing mice to produce HIV p24 specific antibodies.</p> <p>Conclusion</p> <p>In this work, we report the high level soluble expression of HIV-1 p24 protein in <it>E. coli</it>. This soluble recombinant p24 protein specifically react with HIV infected sera and elicit HIV p24 specific antibodies in mice, indicating this soluble recombinant p24 protein could be a promising reagent for HIV diagnosis.</p
Analyzing the symptoms in colorectal and breast cancer patients with or without type 2 diabetes using EHR data
This research extracted patient-reported symptoms from free-text EHR notes of colorectal and breast cancer patients and studied the correlation of the symptoms with comorbid type 2 diabetes, race, and smoking status. An NLP framework was developed first to use UMLS MetaMap to extract all symptom terms from the 366,398 EHR clinical notes of 1694 colorectal cancer (CRC) patients and 3458 breast cancer (BC) patients. Semantic analysis and clustering algorithms were then developed to categorize all the relevant symptoms into eight symptom clusters defined by seed terms. After all the relevant symptoms were extracted from the EHR clinical notes, the frequency of the symptoms reported from colorectal cancer (CRC) and breast cancer (BC) patients over three time-periods post-chemotherapy was calculated. Logistic regression (LR) was performed with each symptom cluster as the response variable while controlling for diabetes, race, and smoking status. The results show that the CRC and BC patients with Type 2 Diabetes (T2D) were more likely to report symptoms than CRC and BC without T2D over three time-periods in the cancer trajectory. We also found that current smokers were more likely to report anxiety (CRC, BC), neuropathic symptoms (CRC, BC), anxiety (BC), and depression (BC) than non-smokers
Dynamic Modeling and Control Characteristics of the Two-Modular HTR-PM Nuclear Plant
The modular high temperature gas-cooled reactor (MHTGR) is a typical small modular reactor (SMR) with inherent safety feature. Due to its high reactor outlet coolant temperature, the MHTGR can be applied not only for electricity production but also as a heat source for industrial complexes. Through multimodular scheme, that is, the superheated steam flows produced by multiple MHTGR-based nuclear supplying system (NSSS) modules combined together to drive a common thermal load, the inherent safety feature of MHTGR is applicable to large-scale nuclear plants at any desired power ratings. Since the plant power control technique of traditional single-modular nuclear plants cannot be directly applied to the multimodular plants, it is necessary to develop the power control method of multimodular plants, where dynamical modeling, control design, and performance verification are three main aspects of developing plant control method. In this paper, the study in the power control for two-modular HTR-PM plant is summarized, and the verification results based on numerical simulation are given. The simulation results in the cases of plant power step and ramp show that the plant control characteristics are satisfactory
Where Do People Go for Gonorrhea and Chlamydia Tests: A Cross-sectional View of the Central Indiana population, 2003-2014
Background Despite major efforts to control their spread, reported sexually transmitted infections (STI) are increasing. Using data from a mid-sized Midwest metropolitan area, we examined the settings in which individuals are tested for gonorrhea and chlamydia in relation to demographics and test result to determine where interventions may best be focused.
Methods A de-identified and integrated registry, containing records from all patients tested for an STI from 2003-2014, was created by combining data from a large health information exchange and the reporting district’s STI Program located in Indianapolis, IN. Individual characteristics and visit settings where gonorrhea and chlamydia testing was performed were analyzed.
Results We identified 298,946 individuals with 1,062,369 visits where testing occurred at least once between the ages of 13 and 44 years. Females were tested significantly more often than males and received testing more often in outpatient clinics whereas males were most often tested in the STI clinic. Individuals who utilized both STI and non-STI settings were more likely to have a positive test at an STI or ED visit (6.4% - 20.8%) than outpatient or inpatient setting (0.0-11.3%) (p<.0001). Test visits increased over the study period particularly in emergency departments, which showed a substantial increase in the number of positive test visits.
Conclusions The most frequent testing sites remain STI clinics for men and outpatient clinics for women. Yet, emergency departments are increasingly a source of testing and morbidity. This makes them a valuable target for public health interventions that could improve care and population health
A decade of complex fractionated electrograms catheter-based ablation for atrial fibrillation: Literature analysis, meta-analysis and systematic review
AbstractBackgroundIt has been a decade since the complex fractionated atrial electrograms (CFAEs) were first established following the publication of Nademanee's standards. However, the status and focus of CFAE research are unclear, as is the efficacy of additional CFAE ablation in atrial fibrillation (AF). This literature review and meta-analysis were designed to determine the status of CFAE research and the efficacy and complications of CFAE ablation alone, pulmonary vein isolation (PVI) alone and PVI plus CFAE ablation in AF.MethodsWith the assistance from reference librarians and investigators trained in systematic review, we conducted a literature search of MEDLINE (via PubMed), Embase, the Cochrane Library, ScienceDirect, Wiley Blackwell and Web of Knowledge, using “complex fractionated atrial electrograms” for MeSH and keyword search.ResultsThe literature on CFAEs increased from 2007, mainly focusing on mapping studies, with mechanism studies increasing significantly from 2012. Fifteen trials with 1525 patients were qualified for our meta-analysis. Success rates were as follows. Overall (P < 0.001): CFAE ablation alone, 23.5–26.2%; PVI, 64.7%; PVI plus CFAE ablation, 67.0%. Single ablation: PVI, 60.4%; PVI plus CFAEs, 68.8% (OR 1.53, 95% CI 1.07–2.20, P = 0.02). Re-ablation: PVI, 69.0%; PVI plus CFAEs, 77.2% (OR 1.54, 95% CI 1.06–2.24, P = 0.02). Paroxysmal AF: PVI, 76.7%; PVI plus CFAEs, 79.1% (OR 1.20, 95% CI 0.79–1.81, P = 0.39). Persistent or permanent AF: PVI, 47.9%; PVI plus CFAEs, 58.7% (OR = 1.59, 95% CI 1.13–2.24, P = 0.008). Complication rates: PVI, 2.6%; PVI plus CFAEs, 3.4% (OR 1.22, 95% CI 0.58–2.57, P = 0.61).ConclusionsIn the literature, CFAE mapping studies preceded mechanism studies. CFAE ablation alone is insufficient for the treatment of AF. Additional CFAE ablation after adequate PVI or PVI plus linear ablation improves the outcome of single ablation and re-ablation without increasing complications, especially in persistent or permanent AF. There are insufficient data to support a similar improvement in paroxysmal AF or inducible AF after PVI for paroxysmal AF
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