180 research outputs found

    A dynamic Bayesian nonlinear mixed-effects model of HIV response incorporating medication adherence, drug resistance and covariates

    Full text link
    HIV dynamic studies have contributed significantly to the understanding of HIV pathogenesis and antiviral treatment strategies for AIDS patients. Establishing the relationship of virologic responses with clinical factors and covariates during long-term antiretroviral (ARV) therapy is important to the development of effective treatments. Medication adherence is an important predictor of the effectiveness of ARV treatment, but an appropriate determinant of adherence rate based on medication event monitoring system (MEMS) data is critical to predict virologic outcomes. The primary objective of this paper is to investigate the effects of a number of summary determinants of MEMS adherence rates on virologic response measured repeatedly over time in HIV-infected patients. We developed a mechanism-based differential equation model with consideration of drug adherence, interacted by virus susceptibility to drug and baseline characteristics, to characterize the long-term virologic responses after initiation of therapy. This model fully integrates viral load, MEMS adherence, drug resistance and baseline covariates into the data analysis. In this study we employed the proposed model and associated Bayesian nonlinear mixed-effects modeling approach to assess how to efficiently use the MEMS adherence data for prediction of virologic response, and to evaluate the predicting power of each summary metric of the MEMS adherence rates.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS376 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Effect of resistive load on the performance of an organic Rankine cycle with a scroll expander

    Get PDF
    An experimental investigation is performed for an organic Rankine cycle system with different electrical resistive loads. The test rig is set up with a small scroll expander-generator unit, a boiler and a magnetically coupled pump. R134a is used as the working fluid in the system. The experimental results reveal that the resistive load coupled to the scroll expander-generator unit affects the expander performance and power output characteristics. It is found that an optimum pressure ratio exists for the maximum power output. The optimal pressure ratio of the expander decreases markedly as the resistive load gets higher. The optimum pressure ratio of the scroll expander is 3.6 at a rotation speed of 3450 r/min for a resistive load of 18.6 Ω. The maximum electrical power output is 564.5 W and corresponding isentropic and volumetric efficiencies are 78% and 83% respectively

    Design and thermal performances of Semi-Parabolic Linear Fresnel Reflector solar concentration collector

    Get PDF
    A Semi-Parabolic Linear Fresnel Reflector (SPLFR) solar concentrator is proposed in this paper. The SPLFR is formed by linear plate mirrors whose edges located at a parabolic line. The ray trace simulation results show the SPLFR has the same concentrating efficiency as that of the parabolic trough concentrator (PTC), but lower manufacture cost. The SPLFR concentrator has higher ground utilization ratio compared with that of Linear Fresnel Reflector (LFR) concentrator because it has no shading and blocking shortcomings. The SPLFR concentrated radiation distribution along the circumference of absorber pipe cross section is investigated and compared with that of LFR concentrator. The thermal performance of linear evacuated absorber for the SPLFR is simulated numerically as well. The nonuniform radiation distribution induces two convection eddies at each side of absorber pipe which enhances the heat transfer from the wall of absorber to the working fluid

    A feasibility study of a novel combined solar concentration/wind augmentation system

    Get PDF
    For deeper understanding of the formation of elite at enterprises, the article proposed to consider a hierarchy of an enterprise from the point of view of two main factors: social and organizational-occupational status.It was determined that the status of an individual in the structure of an enterprise is an integral characteristic, based on the synthesis of hierarchical aspects of organizational structure of an enterprise. It was noted that the current establishment at an enterprise is characterized by a position of an individual in the system of interpersonal relations, his/her rights, duties and privileges.As a social status, we suggested the amount of power, social perspective of the status and prestige of an individual. It was emphasized that the organizational-occupational status of the elite is characterized by different levels of management.It was noted that at enterprises each element serves to meet corresponding challenges to achieve a common goal. It was concluded that the structural-functional approach provides the possibility of further system analysis of the elite at enterprises.В статье рассмотрены проблемы становления элиты на современном предприятии с позиции социального и организационно-профессионального статуса. Определено, что статус индивида в структуре предприятия является интегральной характеристикой, основу которой составляет синтез иерархических аспектов организационной структуры предприятия. Отмечено, что современный истеблишмент на предприятии характеризуется позицией индивида в системе межличностных отношений, его прав, обязанностей и привилегий.У статті розглянуто проблеми становлення еліти на сучасному підприємстві з позиції соціального та організаційно-професійного статусу. Визначено, що статус індивіда в структурі підприємства є інтегральною характеристикою, основу якої складає синтез ієрархічних аспектів організаційної структури підприємства. Зазначено, що сучасний істеблішмент на підприємстві характеризується позицією індивіда у системі міжособистих відносин, його прав, обов’язків та привілеїв

    Percutaneous Nephrolithotomy under Local Infiltration Anesthesia in Kneeling Prone Position for a Patient with Spinal Deformity

    Get PDF
    Urolithiasis, a common condition in patients with spinal deformity, poses a challenge to surgical procedures and anesthetic management. A 51-year-old Chinese male presented with bilateral complex renal calculi. He was also affected by severe kyphosis deformity and spinal stiffness due to ankylosing spondylitis. Dr. Li performed the percutaneous nephrolithotomy under local infiltration anesthesia with the patient in a kneeling prone position, achieving satisfactory stone clearance with no severe complications. We found this protocol safe and effective to manage kidney stones in patients with spinal deformity. Local infiltration anesthesia may benefit patients for whom epidural anesthesia and intubation anesthesia are difficult

    New Insight into the Anti-liver Fibrosis Effect of Multitargeted Tyrosine Kinase Inhibitors: From Molecular Target to Clinical Trials

    Get PDF
    Tyrosine kinases (TKs) is a family of tyrosine protein kinases with important functions in the regulation of a broad variety of physiological cell processes. Overactivity of TK disturbs cellular homeostasis and has been linked to the development of certain diseases, including various fibrotic diseases. In regard to liver fibrosis, several TKs, such as vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), fibroblast growth factor receptor (FGFR) and epidermal growth factor receptor (EGFR) kinases, have been identified as central mediators in collagen production and potential targets for anti-liver fibrosis therapies. Given the essential role of TKs during liver fibrogenesis, multitargeted inhibitors of aberrant TK activity, including sorafenib, erlotinib, imatinib, sunitinib, nilotinib, brivanib and vatalanib, have been shown to have potential for treating liver fibrosis. Beneficial effects are observed by researchers of this field using these multitargeted TK inhibitors in preclinical animal models and in patients with liver fibrosis. The present review will briefly summarize the anti-liver fibrosis effects of multitargeted TK inhibitors and molecular mechanisms

    Self-Guided Smartphone Application to Manage Chronic Musculoskeletal Pain: A Randomized, Controlled Pilot Trial

    Get PDF
    OBJECTIVE: The goal of this study is to evaluate the feasibility and efficacy of an auricular point acupressure smartphone app (mAPA) to self-manage chronic musculoskeletal pain. METHODS: A prospective, longitudinal, randomized, controlled pilot trial was conducted using a three-group design (self-guided mAPA ( RESULTS: After a 4-week APA intervention, participants in the in-person mAPA group had improved physical function of 32% immediately post-intervention and 29% at the 1M follow-up. Participants in the self-guided mAPA group had higher improvement (42% at post-intervention and 48% at the 1M follow-up). Both mAPA groups had similar degrees of pain intensity relief at post-intervention (45% for in-person and 48% for the self-guided group) and the 1M follow-up (42% for in-person and 45% for the self-guided group). Over 50% of the participants in each group reached at least 30% reduced pain intensity at post-intervention, and this was sustained in the mAPA groups at the 1M follow-up. Approximately 80% of the participants in both mAPA groups were satisfied with the treatment outcomes and adhered to the suggested APA practice; however, participants in the self-guided group had higher duration and more frequency in APA use. The attrition rate was 16% at the 1M follow-up. No adverse effects of APA were reported, and participants found APA to be beneficial and the app to be valuable. CONCLUSIONS: The study findings indicate that participants effectively learned APA using a smartphone app, whether they were self-guided or received in-person training. They were able to self-administer APA to successfully manage their pain. Participants found APA to be valuable in their pain self-management and expressed satisfaction with the intervention using the app

    Nurse-Administered Auricular Point Acupressure for Cancer-Related Pain

    Get PDF
    PURPOSE: The study aimed to (1) examine the feasibility of providing a training course on auricular point acupressure (APA) for clinical oncology nurses to integrate APA into real-world nursing care settings, and (2) examine the effectiveness of APA on cancer-related pain (CRP) under usual inpatient oncology ward conditions. METHODS: This was a 2-phase feasibility study. Phase 1, an in-person, 8 hour training program was provided to oncology nurses. Phase 2, a prospective and feasibility study was conducted to evaluate the integration of APA into nursing care activities to manage CRP. Oncology patients were included if their pain was rated at ≥4 on a 0 to 10 numeric rating scale in the past 24 hours. Patients received 1 APA treatment administered by the nurses and were instructed to stimulate the points for 3 days. Study outcomes (pain intensity, fatigue, and sleep disturbance), pain medication use, and APA practice were measured by a phone survey daily. RESULTS: Ten oncology nurses received APA training in phase 1. APA had been added to the hospital\u27s electronic health records (EHRs) as a pain treatment. In phase 2, 33 oncology patients received APA treatment with a 100% adherence rate (pressing the seeds 3 times per day, 3 minutes per time based on the suggestion). The side effects of APA were minimal (~8%-12% felt tenderness on the ear). After 3 days of APA, patients reported 38% pain relief, 39% less fatigue, and 45% improvement in sleep disturbance; 24% reduced any type of pain medication use and 19% reduced opioid use (10 mg opioids using milligram morphine equivalent). The major barrier to integrating APA into routine nursing practice was time management (how to include APA in a daily workflow). CONCLUSION: It is feasible to provide 8-hour training to oncology nurses for mastering APA skill and then integrating APA into their daily nursing care for patients with CRP. Based on the promising findings (decreased pain, improved fatigue and sleep disturbance, and less opioid use), the next step is to conduct a randomized clinical trial with a larger sample to confirm the efficacy of APA for oncology nurses to treat CRP in real-world practice.ClinicalTrial.gov identifier number: NCT04040140
    corecore