20 research outputs found

    Low-Power Instrumentation Amplifier IC Design for ECG System Applications

    Get PDF
    AbstractThis paper describes the development of a low-power instrumentation amplifier (IA) intended for use in recording of the human electrocardiogram (ECG). With the wide-swing cascade bias circuit design, the IA realizes a very high power-supply rejection ratio (PSRR), and can be operated at signal supply voltage in the rage between 2.5 and 5.5 V. It was fabricated using 0.5um double-poly triple-metal CMOS technology, and occupies a die area of 0.2mm2.The amplifier provides a gain of 40 dB and has high common-mode rejection ration (CMRR) better than 100 dB. The IA has a power consumption of 160uW operating from a 3.3 V power supply

    Comparative Studies of the Pyrolytic and Kinetic Characteristics of Maize Straw and the Seaweed Ulva pertusa

    Get PDF
    Seaweed has attracted considerable attention as a potential biofuel feedstock. The pyrolytic and kinetic characteristics of maize straw and the seaweed Ulva pertusa were studied and compared using heating rates of 10, 30 and 50°C min−1 under an inert atmosphere. The activation energy, and pre-exponential factors were calculated by the Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Popescu methods. The kinetic mechanism was deduced by the Popescu method. The results indicate that there are three stages to the pyrolysis; dehydration, primary devolatilization and residual decomposition. There were significant differences in average activation energy, thermal stability, final residuals and reaction rates between the two materials. The primary devolatilization stage of U. pertusa can be described by the Avramic-Erofeev equation (n = 3), whereas that of maize straw can be described by the Mampel Power Law (n = 2). The average activation energy of maize straw and U. pertusa were 153.0 and 148.7 KJ mol−1, respectively. The pyrolysis process of U.pertusa would be easier than maize straw. And co-firing of the two biomass may be require less external heat input and improve process stability. There were minor kinetic compensation effects between the pre-exponential factors and the activation energy

    Parasympathetic neurogenesis is strongly associated with tumor budding and correlates with an adverse prognosis in pancreatic ductal adenocarcinoma

    No full text
    To investigate the frequency of parasympathetic neurogenesis and determine its association with tumor budding and prognosis in pancreatic ductal adenocarcinoma (PDAC).Parasympathetic neurogenesis was defined as the distribution of abnormal parasympathetic nerves in the stroma tissue. Staining of vesicular acetylcholine transporter (VAChT), as a marker for parasympathetic neurogenesis, was performed on a representative specimen of the tumor for 59 PDAC patients with available clinical, pathologic, and follow-up information. Three specimens containing normal pancreatic tissues were stained in parallel. The number of parasympathetic nerve fibers was counted in five high-power microscopic fields (5×0.785 mm(2)). Cut-off values were calculated by receiver operating characteristic curve analysis.VAChT-positive parasympathetic nerve fibers were not seen in the stroma of 3 cases of normal pancreatic tissues. In 59 PDAC cases, the range of parasympathetic neurogenesis was 4-38 fibers/(5×0.785) mm(2), with a median of 18 fibers/(5×0.785) mm(2). Patients with parasympathetic neurogenesis >15 fibers/(5×0.785) mm(2) were defined as the high-density group (39 patients, 66.1%), and those with parasympathetic neurogenesis 15 fibers/(5×0.785) mm(2) as the low-density group (20 patients, 33.9%). The high-density group had a higher occurrence of tumor budding (P=0.001) and a higher rate of early recurrence (P=0.035). Parasympathetic neurogenesis appeared to be an independent adverse prognostic factor [hazard ratio (HR)=2.45, 95% confidence interval (95% CI): 1.25-4.81, P=0.009], in addition to American Joint Committee on Cancer (AJCC) stage (P=0.010) and tumor budding (P=0.009).Parasympathetic neurogenesis is strongly associated with tumor budding and correlates with an adverse prognosis in PDAC.grants from China Cancer Research Foundation Y-N2013-008 and the Doctoral Program of the Ministry of Education 20130001110089 to DR Xiu; the National Natural Science Foundation of China 81272709 to W Fu; Peking University Third Hospital Grant Y81524-01 to LF ZhangSCI(E)PubMed中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)[email protected]

    Enhanced Phenol Tert-Butylation Reaction Activity over Hierarchical Porous Silica-Alumina Materials

    No full text
    Hierarchical aluminum-silicon materials have been successfully prepared by mixing pre-crystallization of silica-alumina sol and citric acid under hydrothermal conditions. The influence of pre-crystallization time on the micro-mesoporous structure is studied using Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), N2 physical adsorption, and high-resolution transmission electron microscopy (HRTEM). The catalytic performance of hierarchical silica-alumina material is evaluated by alkylation of phenol with tert-butanol. The results show that the silica-alumina materials with a pre-crystallization time of 16 h show micro-mesoporous structure and excellent catalytic activity

    Preoperative Multiparametric Quantitative Magnetic Resonance Imaging Correlates with Prognosis and Recurrence Patterns in Pancreatic Ductal Adenocarcinoma

    No full text
    Magnetic resonance imaging (MRI) has been shown to be associated with prognosis in some tumors; however, the correlation in pancreatic ductal adenocarcinoma (PDAC) remains inconclusive. In this retrospective study, we ultimately included 136 patients and analyzed quantitative MRI parameters that are associated with prognosis and recurrence patterns in PDAC using survival analysis and competing risks models; all the patients have been operated on with histopathology and immunohistochemical staining for further evaluation. In intravoxel incoherent motion diffusion-weighted imaging (DWI), we found that pure-diffusion coefficient D value was an independent risk factor for overall survival (OS) (HR: 1.696, 95% CI: 1.003–2.869, p = 0.049) and recurrence-free survival (RFS) (HR: 2.066, 95% CI: 1.252–3.409, p = 0.005). A low D value (≤1.08 × 10−3 mm2/s) was significantly associated with a higher risk of local recurrence (SHR: 5.905, 95% CI: 2.107–16.458, p = 0.001). Subgroup analysis revealed that patients with high D and f values had significantly better outcomes with adjuvant chemotherapy. Distant recurrence patients in the high-D value group who received chemotherapy may significantly improve their OS and RFS. It was found that preoperative multiparametric quantitative MRI correlates with prognosis and recurrence patterns in PDAC. Diffusion coefficient D value can be used as a noninvasive biomarker for predicting prognosis and recurrence patterns in PDAC

    Prospective cohort study on tuberculosis incidence and risk factors in the elderly population of eastern China

    No full text
    Background: Tuberculosis continues to be a significant public health concern in China, particularly among the elderly population. This study aimed to assess the risk factors of tuberculosis among elderly individuals in China through a cohort study, focusing on this high-risk population. Methods: The population-based census was strategically designed to cover diverse regions and demographics across the city. The survey captured demographic and lifestyle information, as well as a clinical examination. Participants were prospectively followed up over a specified duration to monitor the incidence of tuberculosis cases. Results: After a follow-up period of more than 7 years, 246 individuals developed tuberculosis, resulting in an incidence rate of 92.21 per 100,000 person-years (95 % CI 81.2–104.3). In multivariate analysis, the following factors were found to have significant associations with active tuberculosis. Increasing age correlated with a higher risk of active tuberculosis (AHR = 1.03 per 1-year increase in age, 95%CI: 1.01, 1.04, P < 0.001). Males continued to have a higher risk compared to females (HR = 2.73, 95%CI: 2.08, 3.58, P < 0.001). Individuals with a normal Body Mass Index (BMI) faced nearly three times higher risk compared to their obese counterparts (HR = 2.87, 95 % CI: 1.51, 5.46, P = 0.001). Conversely, those with an underweight BMI had a ten-fold higher risk compared to the obese group (HR = 9.89, 95 % CI: 4.92, 19.85, P < 0.001). Elderly individuals who quit smoking had a 1.35-fold increased risk compared to non-smokers (HR = 1.35, 95%CI: 1.12, 1.64, P < 0.001). Conclusions: Tuberculosis incidence among the elderly population in China remained alarmingly high. This finding emphasizes the urgent need for implementing proactive case detection measures specifically tailored to address the specific needs of this vulnerable demographic, particularly in individuals who are male, have a history of former or current smoking, and have a low BMI. Moreover, we must not underestimate the influence of former smoking on tuberculosis risk

    Combined Therapy with Cytokine-Induced Killer Cells and Oncolytic Adenovirus Expressing IL-12 Induce Enhanced Antitumor Activity in Liver Tumor Model

    Get PDF
    <div><p>Both adoptive immunotherapy and gene therapy hold a great promise for treatment of malignancies. However, these strategies exhibit limited anti-tumor activity, when they are used alone. In this study, we explore whether combination of cytokine-induced killer (CIK) adoptive immunotherapy with oncolytic adenovirus-mediated transfer of human interleukin-12 (hIL-12) gene induce the enhanced antitumor potency. Our results showed that oncolytic adenovirus carrying hIL-12 (AdCN205-IL12) could produce high levels of hIL-12 in liver cancer cells, as compared with replication-defective adenovirus expressing hIL-12 (Ad-IL12). AdCN205-IL12 could specifically induce cytotoxocity to liver cancer cells. Combination of CIK cells with AdCN205-IL12 could induce higher antitumor activity to liver cancer cells <em>in vitro</em> than that induced by either CIK or AdCN205-IL12 alone, or combination of CIK and control vector AdCN205-GFP. Furthermore, treatment of the established liver tumors with the combined therapy of CIK cells and AdCN205-IL12 resulted in tumor regression and long-term survival. High level expression of hIL-12 in tumor tissues could increase traffic of CIK cells to tumor tissues and enhance their antitumor activities. Our study provides a novel strategy for the therapy of cancer by the combination of CIK adoptive immunotherapy with oncolytic adenovirus-mediated transfer of immune stimulatory molecule hIL-12.</p> </div
    corecore