20 research outputs found

    Infrared surface polaritons on bismuth

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    Optical constants for evaporated bismuth (Bi) films were measured by ellipsometry and compared with those published for single crystal and melt-cast polycrystalline Bi in the wavelength range of 1 to 40 mu m. The bulk plasma frequency omega(p) and high-frequency limit to the permittivity epsilon(infinity) were determined from the long-wave portion of the permittivity spectrum, taking previously published values for the relaxation time tau and effective mass m*. This part of the complex permittivity spectrum was confirmed by comparing calculated and measured reflectivity spectra in the far-infrared. Properties of surface polaritons (SPs) in the long-wave infrared were calculated to evaluate the potential of Bi for applications in infrared plasmonics. Measured excitation resonances for SPs on Bi lamellar gratings agree well with calculated resonance spectra based on grating geometry and complex permittivity

    Colistin Utilization Evaluation in a Major Teaching Hospital in Iran

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    Objectives: Colistin is an old antibacterial agent which is used in multiple drug resistant (MDR) infections. Due to increased rate of MDR infections, the use of this agent is raised in worldwide. The aim of this study was to identify colistin utilization patterns in a teaching hospital and to demonstrate the importance of the need to reconsider prescribing strategies for colistin administration. Methods: This retrospective cross-sectional study was performed between Augusts 2017and December 2017 at Firoozgar hospital affiliated to Iran University of Medical Sciences, Tehran, Iran. All colistin prescriptions for adult patients during the study period were enrolled for appropriateness evaluation according to the Lexi comp acquired by Wolters Kluwer and NHS guideline. Results: Among 70 patients who received colistin, pneumonia (70%) was the chief indication of colistin prescription. In 93% of cases, colistin was prescribed according to microbiological laboratory results. In 14% of patients, colistin administration was before providing microbiological laboratory evidence. Seventeen percent of the patients received loading dose of colistin. The indication of colistin therapy was inappropriate in 16% of patients.  The initial and end dose, and duration of treatment of colistin were appropriate in 20%, 40%, and 52% of patients, respectively. Among 70 cases, 24 (34%) and 36 (51%) patients required dose adjustment in first and end dose of colistin therapy which only dose correction was performed in 13 (18%) and 15 (21%) cases, respectively.    Conclusions: These findings, along with aforementioned guidelines supports the requirement for physicians’ educational programs, proper strategies for appropriate prescriptions

    The effect of heparin after primary percutaneous coronary intervention on short-term clinical outcomes in patients with ST-segment elevation myocardial infarction

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    Background: Doing percutaneous coronary intervention (PCI) in the first hours of myocardial infraction (MI) is effective in re-establishment of blood flow. Anticoagulation treatment should be prescribed in patients undergoing PCI to decrease the side effects of ischemia. The aim of this study is to determine the effect of heparin prescription after PCI on short-term clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI). Materials: This randomized clinical trial study was conducted at Imam Ali cardiovascular center at Kermanshah university of medical science (KUMS), Iran. Between April 2019 to October 2019, 400 patients with STEMI which candidate to PCI were enrolled. Patients randomly divided in two groups: intervention group (received 5,000 units of heparin after PCI until first 24 hours, every 6 hours) and control group (did not receive heparin). Data were collected using a checklist developed based on the study's aims. Differences between groups were assessed using independent t-tests and chi-square (or Fisher exact tests).Result: Observed that, mean prothrombin time (PT) (13.30±1.60 vs. 12.21±1.15, p<0.001) and partial thromboplastin time (PTT) (35.30±3.08 vs. 34.41±3.01, p=0.003) were significantly higher in intervention group compared to control group. Thrombolysis in myocardial infarction (TIMI) flow grade 0/1 after primary PCI was significantly more frequently in control group (5.5% vs. 1.0%, p=0.034). The mean of ejection fraction (EF) after PCI (47.58±7.12 vs. 45.15±6.98, p<0.001) was significantly higher in intervention group. Intervention group had a statistically significant shorter length of hospital stay (4.71±1.03 vs. 6.12±1.10, p<0.001). There was higher incidence of re-vascularization (0% vs. 3.0%; p=0.013) and re-MI (0% vs. 2.5%; p=0.024) in the control group.Conclusion: Performing primary PCI with receiving heparin led to improve TIMI flow and consequently better EF. Receiving heparin is associated with lower risk of re-MI and re-vascularization

    Non-alcoholic fatty liver disease is not independent risk factor for cardiovascular disease event : a cohort study

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    There are no consistent results between previous studies for an independent association between non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD) events. To determine if there is an independent association between NAFLD and CVD events. In the present study, valid outcome data of 4808 subjects were available for phase 2 of our cohort study. These subjects had been followed up for seven years from phase 1, beginning in 2009-2010 to phase 2 during 2016-2017. Simple and multiple Cox proportional models were used to determine the association between NAFLD in the primary phase of the cohort and subsequent fatal and non-fatal CVD events during follow-up. The incidence of non-fatal CVD events in males with NAFLD was significantly higher ( = 0.004) than in males without NAFLD. A positive association was demonstrated between NAFLD and non-fatal CVD events in males (Hazard ratio = 1.606; 95%CI: 1.166-2.212; = 0.004) by the simple Cox proportional hazard model, but no independent association was detected between these in the multiple Cox models. No independent association was detected between NAFLD and CVD. It is likely that diabetes mellitus and age may be the principle mediators in this regard. [Abstract copyright: ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Intrathoracic Airway Tree Segmentation from CT Images Using a Fuzzy Connectivity Method

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    Introduction: Virtual bronchoscopy is a reliable and efficient diagnostic method for primary symptoms of lung cancer. The segmentation of airways from CT images is a critical step for numerous virtual bronchoscopy applications. Materials and Methods: To overcome the limitations of the fuzzy connectedness method, the proposed technique, called fuzzy connectivity - fuzzy C-mean (FC-FCM), utilized the FCM algorithm. Then, hanging-togetherness of pixels was handled by employing a spatial membership function. Another problem in airway segmentation that had to be overcome was the leakage into the extra-luminal regions due to the thinness of the airway walls during the process of segmentation. Results:   The result shows an accuracy of 92.92% obtained for segmentation of the airway tree up to the fourth generation. Conclusion:  We have presented a new segmentation method that is not only robust regarding the leakage problem but also functions more efficiently than the traditional FC method

    Fluorine-Doped Tin Oxides For Mid-Infrared Plasmonics

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    Fluorine-doped tin oxides (FTO) were investigated for infrared plasmonic applications. Nano-crystalline FTO thin films were grown by the SPEED chemical-spray deposition method. Complex permittivity spectra were measured from 1.6 to 12 μm wavelength. These spectra were used to calculate materials parameters, which compared well with values from transport measurements, and to predict characteristics of surface plasmon polaritons (SPP). Reflectivity spectra for lamellar FTO gratings revealed SPP coupling resonances in good agreement with predictions. The FTO film studied here is well suited for plasmonic applications in the important 3-5 μm wavelength range

    The relationship between depression and ischemic heart diseases and its risk factors among patients referred to the specialized clinic in Saqqez

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    AbstractBackground and Aim:Depression is a common disease among patients with cardiovascular disease. Depression can berelated to ischemic cardiovascular risk factors such as lack of physical activity, smoking, alcoholabuse, hypertension, diabetes, and hyperlipidemia. The purpose of this study was to determine thebetween depression and ischemic cardiovascular disease and its risk factors.Materials and Methods:This was a descriptive study. The subjects were 200 patients with ischemic and non-ischemic heartdisease in two groups. The instruments consisted of three sections: the demographic characteristics,heart diseases risk factor's assessment scale and beck depression inventory. Data were analyzedwith descriptive and analytical statistical (chip-square test) in SPSS software v.16.Conclusion:Depression was more frequent among ischemic heart disease patients than non-ischemic heartdisease patients. According to the results, it seems to be appropriate to consider depressionscreening and psychiatric consulting among patients with ischemic heart diseases as a preventiontool.Keywords:Depression; Coronary Artery Disease; Myocardial Ischemia; Risk Factor

    Optical And Electrical Properties Of Tin Oxide-Based Thin Films Prepared By Streaming Process For Electrodeless Electrochemical Deposition

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    Transparent conducting thin-films of SnO2: F were grown on preheated glass, Al2O3 coated glass, and quartz substrates by Streaming Process for Electrodeless Electrochemical Deposition (SPEED). Stannic chloride (SnCl4) and ammonium fluoride (NH4F) dissolved in a mixture of deionized water and organic solvents were used as precursors. The preheated substrate temperature was varied between 440 and 500 °C. High quality SnO2:F films were grown at all the substrate temperatures studied. The resulting typical film thickness was 250 nm. X-ray diffraction shows that the grown films are polycrystalline SnO2 with a tetragonal crystal structure. The average optical transmission of the films was around 93% throughout the wavelength range 400 to 1000 nm. The lowest electrical resistivity achieved was 6×10-4 Ω-cm. The Hall measurements showed that the film is an n-rype semiconductor, with carrier mobility of 8.3 cm2/V-s, and carrier concentration of 1 × 1021 cm-3. The direct bandgap was determined to be 4.0 eV from the transmittance spectrum
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