43 research outputs found
Automatic Hotspots Detection for Intracellular Calcium Analysis in Fluorescence Microscopic Videos
Get PDFIn recent years, life-cell imaging techniques and their software applications have become powerful tools to investigate complex biological mechanisms such as calcium signalling. In this paper, we propose an automated framework to detect areas inside cells that show changes in their calcium concentration i.e. the regions of interests or hotspots, based on videos taken after loading living mouse cardiomyocytes with fluorescent calcium reporter dyes. The proposed system allows an objective and efficient analysis through the following four key stages: (1) Pre-processing to enhance video quality, (2) First level segmentation to detect candidate hotspots based on adaptive thresholding on the frame level, (3) Second-level segmentation to fuse and identify the best hotspots from the entire video by proposing the concept of calcium fluorescence hit-ratio, and (4) Extraction of the changes of calcium fluorescence over time per hotspot. From the extracted signals, different measurements are calculated such as maximum peak amplitude, area under the curve, peak frequency, and inter-spike interval of calcium changes. The system was tested using calcium imaging data collected from Heart muscle cells. The paper argues that the automated proposal offers biologists a tool to speed up the processing time and mitigate the consequences of inter-intra observer variability
SEISMIC ANALYSIS OF BASE-ISOLATED WATER STORAGE TANKS SUBJECTED TO LONG-PERIOD EARTHQUAKES USING CRITICAL EXCITATION METHOD
Full text linkIn this paper, the seismic behavior of base-isolated water storage tanks under
the effect of long-period earthquakes has been investigated; as relatively high
period of these types of structures causes them to be sensitive against long-period earthquakes. In this regard, an efficient and new method called critical excitation method (CEM), is employed for seismic behavior of base-isolated water storage tanks, for the first time. In the CEM, it is tried to produce critical earthquakes for each structure based on its characteristics and parameters, and then apply them to the undertaken structure so that the seismic behavior of structures during and after the earthquake may be increased. To investigate behavior of base-isolated water storage tanks under long-period earthquakes, three types of broad, middle and slender storage tanks have been used, for which two types of isolators (i.e., lead rubber bearing (LRB) and friction pendulum system (FPS)) are equipped. In order to model seismic behavior of water storage tanks considering fluid-structure dynamic interaction effects, a simplified and practical model proposed by Haroun has been employed in this research. The base-isolated water storage tanks have been exposed to long-period earthquakes to magnify responses. In addition, in order to develop the CEM, it has been used to analyze base-isolated water storage tanks through modifying available matrices in the equation of motion, rewriting the required formulas and developing the necessary codes in MATLAB environment. According to the results obtained from this research for the specific cases considered, it was found that using energy dissipation systems has caused these structures to perform better. Moreover, by proposing the CEM, this method was investigated for the first time with regard to base-isolated water storage tanks. In addition to introducing the critical parameters of this method, it was found that using this method leads to critical conditions in base-isolated water storage tanks
Effect of Amphotericin B and Fluconazole on hospital wards fungi
Full text linkBackground and Objective: Nosocomial fungal infections have considerably increased due to incrasing of immunocompromised diseases. This study was done to evaluate the antifungal activity of Amphotericin B and Fluconazole on hospital wards fungi. Methods: In this descriptive - analytic study, 33 fungal samples isolated from Imam Khomini hospital in Tehran, Iran during 2013. Samples were identified using slide culture method. Serial dilution of drugs and fungal suspensions were supplied from 0.25-128 µg/ml and range 0.5–5×105 cfu/ml, respectively. Minimum inhibitory concentration (MIC) was determined in accordance with NCCLS M38-p guideline. Results: The most frequent isolated fungus was Aspergillus spp. with 39.4% while the low frequent were Alternaria Spp. and Circinella with similar frequency (3%). MIC range for Fluconazole and Amphotericin B were 64-128 µg/ml and 16-64 µg/ml, respectively. Amphotericin B showed a MIC significant reduction in comparision with Fluconazole (P<0.05). Conclusion: Hospital wards fungi were resistant to Amphotericin B and Fluconazole
Mechansim and outcome of hip fracture: a multi-center study
Full text linkBackground: We aimed to demonstrate the mechanism of fracture and functional outcome of patients with hip injury in our clinical setting. Methods: In a historical cohort, all women 50 years of age and older admitted to three university hospitals of Tehran University of Medical Sciences (Shariati, Imam Khomeini and Sina) with the diagnosis of hip fracture from 21 March 2003 to 21 March 2004 were included in this study (n=115). Follow up was conducted via telephone post and even home visit to record the functional status of the patients at the time of study (5 Jan 2005) measured with Barthel index in addition to the exact mechanism of injuries. Results: The mean and standard deviation of age were 76.3 ± 10.6 years. About 88.7% of injuries had occurred at home (65.2% on the carpet), the remaining happening in the streets. Mean length of hospitalization was 11 ± 7.9 days. Among our patients, 71% could mobilize spontaneously without aids before injuries. This had reduced to 20% at the time of follow-up. The mean Barthel index was 97.2 ± 8.2 before fracture and 75 ± 21.1 at the present. Among our patients, five cases died during hospitalization and 29 of them died afterwards (total: 34 or 29.6%). Conclusion: The most common external cause of injuries in our cases was stumbling at home especially on carpeted surfaces. This necessitates preventive measures aimed at physical standards of houses and education of elderly on healthy locomotion, indoors
Helicopter emergency medical system in a region lacking trauma coordination (experience from Tehran)
Full text linkBackground: The helicopter emergency medical service (HEMS) has been working in Iran since 2000. The present study is the first prospective research to determine the epidemiological characteristics of injured patients transported by helicopter in Tehran. Methods: All injured patients brought to three hospitals from the injury scene by HEMS were reviewed in a 4-month period. Results: The mean transport time was 54 minutes. The most common mechanism of trauma was road traffic accidents (96.2%). The mean injury severity score was 8.6 (SD 8.6) and 9.6% of patients were sent to the intensive care unit; 10.2% of patients died. Conclusion: This study shows that overtriage in HEMS (transportation of patients without severe injuries) and the long transportation time is mainly a result of not having a trauma system. The study has shown HEMS to be an effective and feasible option in countries with heavy traffic and no trauma system
Optogalvanic spectroscopy with microplasma sources—current status and development towards a lab on a chip
Full text linkEPIDEMIOLOGICAL STUDY OF PATIENTS WITH PENETRATING ABDOMINAL TRAUMA IN TEHRAN-IRAN
Full text linkTrauma continues to be the most frequent cause of death in the first four decades of life that is a main public health problem in some countries. We perform an epidemiological study of Penetrating Abdominal Trauma (PAT). We describe epidemiological of patients in PAT. In a cross-sectional study we evaluated epidemiological PAT admitted to emergency department in six general hospitals in Tehran. The data was collected through a questionnaire that was completed by trained physician trauma center. Statistical analysis was performed using the SPSS software (version 11.5 for windows). Statistical analysis using the chi-square and P&lt;0.05 was accepted as being statistically significant. During the study period, 0.86 % (69/8000) of our patients sustained PAT. Sixty-six (95.7%) patients were male and 3(4.3%) cases were female. The peak age incidence was 15-29 years, with 43(62.3%) patients. Stab wound was the leading cause of PAT in male and female, with 62(89.9%) cases. Firearm was responsible for 7(10.1%) cases. Young males are the most common victims. This is the most productive age group and this has grave implication for the national economy
Women Pose Innocent Victims of Landmines in Postwar Iran
Full text link"nBackground: Although in the last few years there has been an increasing attention to the problem of landmines, to date, the implications of women being victims of landmine has not been duly dealt with in the world including Iran, which is estimated to be the second most landmine infested country in the world. Still, provinces by the west border of Iran, 18 years after cessation of Iraq-Iran war suffer from the burden of vast areas, highly infested with landmines. This study aimed to provide a gender focused insight into landmine accidents in Iran."nMethods: In this retrospective study, women with documented deaths or injuries due to landmine and/or unexploded ordnances (UXO) explosions as documented in their medical records between Jul 1988 (after ceasefire) and Feb 2003 were studied in 5 western provinces of Iran. Data was analyzed by SPSS for Windows Version 11.P value under 0.05 was consid&shy;ered statistically significant."nResults: During the 14-year study period, 252 women from 5 western provinces of Iran were reported to have injuries or death due to landmine and UXOs. All of the victims were civilians and the majority of them (47.6%) had one or more amputations. Most of them were injured in the period between1994 and 1998. The majority of the patients were young."nConclusion: Women who should take care of themselves as well as their families are more prone to sufferings inflicted by landmines and UXO
