1,241 research outputs found
The effects of lead on motility, viability and DNA denaturation of cauda epididymal spermatozoa of mouse
زمینه و هدف: سرب یکی از آلوده کننده های محیطی است. در این مطالعه اثرات سرب بر تحرک، زنده ماندن و دناتوره شدن DNA اسپرم موش مورد بررسی قرار گرفت. هدف ما بررسی اثرات سرب بر این فاکتورها و نیز قابل بازگشت بودن یا نبودن این اثرات بود. روش بررسی: در این مطالعه تجربی 24 موش نر به عنوان گروه آزمایش و 24 موش نیز، گروه کنترل در نظرگرفته شدند. به موش های گروه آزمایش 200 میلی گرم بر کیلوگرم محلول استات سرب و به موش های گروه کنترل تنها آب مقطر به صورت داخل صفاقی تزریق گردید. پس از آن هر کدام از گروه ها به سه زیر گروه مساوی تقسیم شدند و موش های هر زیر گروه در هفته های اول، دوم و سوم پس از تزریق کشته و اپیدیدیم آن ها برداشته شد. در تمامی گروه ها درصد اسپرم های متحرک، درصد اسپرم های زنده و میزان دناتوره شدن اسپرم های ناحیه دم اپیدیدیم اندازه گیری شد. داده ها به کمک آزمون های آماری من ویتنی و کروسکال والیس تجزیه و تحلیل شد. یافته ها: سرب سبب کاهش میزان تحرک و زنده ماندن اسپرم ها در هفته اول پس از تزریق شد (05/0
Air pollution at Rochester, NY: Long-term trends and multivariate analysis of upwind SO2 source impacts
There have been many changes in the air pollutant sources in the northeastern United States since 2001. To assess the effect of these changes, trend analyses of the monthly average values were performed on PM2.5 and its components including major ions, elemental carbon (EC), organic carbon (OC), and gaseous pollutant concentrations measured between 2001 (in some cases 1999) and 2015 at the NYS Department of Environmental Conservation sites in Rochester, NY. Mann-Kendall regression with Sen's slope was applied to estimate the trends and seasonality. Using piecewise regression, significant reductions in the air pollution of Rochester area were observed between 2008 and 2010 when a 260 MW coal-fired power plant was decommissioned, new heavy-duty diesel trucks had to be equipped with catalytic regenerator traps, and the economic recession that began in 2008 reduced traffic and other activities. The monthly average PM2.5 mass showed a downward trend (− 5 μg/m3; − 41%) in Rochester between 2001 and 2015. This change is largely due to reductions in particulate sulfate that showed a 65% decrease. The sulfate concentrations were compared to changes in SO2 emissions in seventeen upwind source domains, and other systematic changes by multivariate linear regression. Selectivity ratio obtained from target projection discriminated the most important source domains that are SO2 emissions from Georgia for winter, North Carolina for transition (spring and fall) and Ohio along with other influences for summer. North Carolina and Michigan were identified as the main sources for entire period. These observations suggest that any further reductions in the specified regional SO2 emissions would result in a proportional decrease in sulfate in Rochester
Patients and Health Professionals Views on Caring in Diabetes Disease
Background: Diabetes is a common problem with severe complications. The control of diabetes needs a close and honest relationship between patients and health professionals. The views of these two groups might influence the professional relationship.
Objectives: The purpose of this study was to identify the views of diabetic patients versus the views of diabetic care professionals on the content of caring.
Patients and Methods: This qualitative study was conducted with the content analysis method. The participants consisted of adults who had suffered from diabetes for a minimum of one year, and health care professionals working in diabetes care centers. Fifteen patients and fifteen health professionals participated in the interviews.
Results: The findings present four main themes which are as follows: what caring is and what means to care, the obstacles in providing care, the outcomes of caring, and specialist community-based care as a crucial intervention in diabetes care, the themes were identified and based on the data analysis, It appeared that patients were more outcome centered, while health professionals were more process- centered in the context of caring.
Conclusions: It appeared that patients were more outcome centered, while health professionals were more process -centered in the context of caring
A 6.0-mW 10.0-Gb/s Receiver With Switched-Capacitor Summation DFE
A low-power receiver with a one-tap decision feedback equalization (DFE) was fabricated in 90-nm CMOS technology. The speculative equalization is performed using switched-capacitor-based addition at the front-end sample-hold circuit. In order to further reduce the power consumption, an analog multiplexer is used in the speculation technique implementation. A quarter-rate-clocking scheme facilitates the use of low-power front-end circuitry and CMOS clock buffers. The receiver was tested over channels with different levels of ISI. The signaling rate with BER<10^-12 was significantly increased with the use of DFE for short- to medium-distance PCB traces. At 10-Gb/s data rate, the receiver consumes less than 6.0 mW from a 1.0-V supply. This includes the power consumed in all quarter-rate clock buffers, but not the power of a clock recovery loop. The input clock phase and the DFE taps are adjusted externally
Safety and efficacy of PDpoetin for management of anemia in patients with end stage renal disease on maintenance hemodialysis: Results from a phase IV clinical trial
Recombinant human erythropoietin (rHuEPO) is available for correcting anemia. PDpoetin, a new brand of rHuEPO, has been certified by Food and Drug Department of Ministry of Health and Medical Education of Iran for clinical use in patients with chronic kidney disease. We conducted this post-marketing survey to further evaluate the safety and efficacy of PDpoetin for management of anemia in patients on maintenance hemodialysis. Patients from 4 centers in Iran were enrolled for this multicenter, open-label, uncontrolled phase IV clinical trial. Changes in blood chemistry, hemoglobin and hematocrit levels, renal function, and other characteristics of the patients were recorded for 4 months; 501 of the patients recruited, completed this study. Mean age of the patients was 50.9 (±16.2) years. 48.7 of patients were female. Mean of the hemoglobin value in all of the 4 centers was 9.29 (±1.43) g/dL at beginning of the study and reached 10.96 (±2.23) g/dL after 4 months and showed significant increase overall (P<0.001). PDpoetin dose was stable at 50-100 U/kg thrice weekly. Hemorheologic disturbancesand changes in blood electrolytes was not observed. No case of immunological reactions to PDpoetin was observed. Our study, therefore, showed that PDpoetin has significantly raised the level of hemoglobin in the hemodialysis patients (about 1.7±0.6 g/dL). Anemia were successfully corrected in 49 of patients under study. Use of this biosimilar was shown to be safe and effective for the maintenance of hemoglobin in patients on maintenance hemodialysis. © A.N. Javidan et al., 2014
Hydrodynamic instabilities in gaseous detonations: comparison of Euler, Navier–Stokes, and large-eddy simulation
A large-eddy simulation is conducted to investigate the transient structure of an unstable detonation wave in two dimensions and the evolution of intrinsic hydrodynamic instabilities. The dependency of the detonation structure on the grid resolution is investigated, and the structures obtained by large-eddy simulation are compared with the predictions from solving the Euler and Navier–Stokes equations directly. The results indicate that to predict irregular detonation structures in agreement with experimental observations the vorticity generation and dissipation in small scale structures should be taken into account. Thus, large-eddy simulation with high grid resolution is required. In a low grid resolution scenario, in which numerical diffusion dominates, the structures obtained by solving the Euler or Navier–Stokes equations and large-eddy simulation are qualitatively similar. When high grid resolution is employed, the detonation structures obtained by solving the Euler or Navier–Stokes equations directly are roughly similar yet equally in disagreement with the experimental results. For high grid resolution, only the large-eddy simulation predicts detonation substructures correctly, a fact that is attributed to the increased dissipation provided by the subgrid scale model. Specific to the investigated configuration, major differences are observed in the occurrence of unreacted gas pockets in the high-resolution Euler and Navier–Stokes computations, which appear to be fully combusted when large-eddy simulation is employed
Analysis of duality constructions for variable dimension fixed point algorithms
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1987.Bibliography: leaves 57-58.Neda F. Emami.M.S
Explanatory Model of Diabetes Management; An Experience From Iran
Background: Managing diabetes requires changes in the patients’ life style and health habits which in turn need the comprehensive understanding of the disease and its impact.
Objectives: To understand the explanatory model of diabetes in Iran, a qualitative study was performed using the grounded theory method.
Patients and Methods: Thirty persons were interviewed: fifteen patients, eleven nurses, three physicians and one dietitian. The semi-structured interviews were transcribed and analyzed in three stages of open, axial and selective coding.
Results: The findings showed that patients’ personality can shape their self-care behavior; however, curing, caring and supporting systems are also necessary. The interactions between personality, curing, caring and supporting systems and society makes the outcome, which is the core variable in the designed explanatory model of diabetes.
Conclusions: This paper reflects an explanatory model of diabetes management. Understanding the factors that affect self-management behavior is important for nurses as key providers in the health care system
Causes and risk factors of urinary incontinence: Avicenna's point of view vs. contemporary findings
Purpose: To extract the causes and risk factors of urinary incontinence from an old medical text by Avicenna entitled "Canon of Medicine" and comparing it with contemporary studies. Materials and Methods: In this study, etiology and risk factors of urinary incontinence were extracted from Avicenna's "Canon of Medicine". Commentaries written on this book and other old reliable medical texts about bladder and its diseases were also studied. Then the achieved information was compared with contemporary findings of published articles. Results: Urinary incontinence results from bladder dysfunction in reservoir phase. Bladder's involuntary muscles and voluntary external sphincter are two main components which are involved in this process. Urinary incontinence can exist without obvious structural and neuronal etiologies. According to Avicenna, distemperment of muscular tissue of bladder and external sphincter is the cause for urinary incontinence in such cases. Distemperment is the result of bothering qualities in tissue, i.e.: "wet" and "cold". They are the two bothering qualities which are caused by extracorporeal and intracorporeal factors. Interestingly, the positive associations of some of these factors with urinary incontinence have been shown in recent researches. Conclusion: "Cold" and "wet" distemperment of bladder and external sphincter can be independent etiologies of urinary incontinence which should be investigated
A Capstone Project on Robust Dynamic Positioning and Data Acquisition Systems
The United States Coast Guard is responsible for enforcing Dynamic Positioning System (DPS) standards in the maritime industry. It is important for the members of the U. S. Coast Guard to understand how these systems work. Students have gained a much greater understanding of how DPS platforms work and what might be required to maintain them by building one from scratch. Aside from this, the project has served as a great opportunity to work on a one year term project that may resemble engineering or acquisitions projects that might be encountered in the students’ future careers.
The overall goal of the Robust Dynamic Positioning and Data Acquisition System project was to prototype a dynamic positioning system similar to the ones on buoy tenders in the fleet. The primary goal was to maintain a desired heading and position within a certain range. The secondary goals included robust capabilities (the ability to continue functioning despite motor failures) and data acquisition (to analyze system performance post-testing). Students built a vessel from scratch out of a salvage drum and an inner tube for buoyancy. The internal construction consists of three tiers containing batteries at the lowest level, an onboard computer at the second level, and control hardware at the top level (micro controllers, H-bridges, and fuse boxes). Students successfully used a light detection and ranging (LIDAR) device to determine the relative position to two stationary poles. They were able to communicate with the onboard computer via either a wired connection or a remote desktop connection through an ad-hoc wireless network. All programming for this project was done in MATLAB®. Students have completed all project milestones through the application of past courses they have taken in computer control systems, network communication, and digital signal processing at the U.S. Coast Guard Academy.
The first challenge of this project was to focus on constructing the vessel and installing the control hardware. One of the obstacles for the students was establishing communication between the various pieces of software, hardware, and the power distribution system. The LIDAR sensor determined the vessel’s relative position and heading to two stationary poles. Using the position and heading resolution algorithms, students conducted a set of system identification tests in an indoor tank to determine how the system reacts to various thrusts from the motors. This allowed students to collect “Open-Loop” system data. Using the data acquisition system, students were able to identify the system and calculate coefficients for the controller and implement a “Closed- Loop” control system. Students successfully implemented a proportional integral derivative (PID) controller that satisfies all design requirements including robust functionality. Currently, all milestones for the project have been accomplished and plans for continuation of the project are underway
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