271 research outputs found

    Serrated plastic flow in slowly-deforming complex concentrated alloys: universal signatures of dislocation avalanches

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    Under plastic flow, multi-element high/medium-entropy alloys (HEAs/MEAs) commonly exhibit complex intermittent and collective dislocation dynamics owing to inherent lattice distortion and atomic-level chemical complexities. Using atomistic simulations, we report on an avalanche study of slowly-driven model face-centered cubic (fcc) NiCoCrFeMn and NiCoCr chemically complex alloys aiming for microstructural/topological characterization of associated dislocation avalanches. The results of our avalanche simulations reveal a close correspondence between the observed serration features in the stress response of the deforming HEA/MEA and the incurred slip patterns within the bulk crystal. We show that such correlations become quite pronounced within the rate-independent (quasi-static) regime exhibiting scale-free statistics and critical scaling features as universal signatures of dislocation avalanches

    Diagnostic Accuracy of Abdominal wall Ultrasonography and Local Wound Exploration in Predicting the Need for Laparotomy following Stab Wound

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    Introduction: Screening of patients with anterior abdominal penetrating trauma in need for laparotomy is an important issue in management of these cases. This study aimed to compare the accuracy of abdominal wall ultrasonography (AWU) and local wound exploration (LWE) in this regard.Methods: This diagnostic accuracy study was conducted on ≥ 18 year-old patients presenting to emergency department with anterior abdominal stab wound and stable hemodynamics, to compare the characteristics of AWU and LWE in screening of patients in need of laparotomy.Results: 50 cases with the mean age of 28.44 ± 7.14 years were included (80% male). Sensitivity, specificity and area under the receiver operating characteristic (ROC) curve of AWU were 70.58 (95% CI: 44.04 – 88.62), 93.33 (95% CI: 76.49 – 98.83), and 81.96 (95% CI: 69.91 – 94.01), respectively. These measures were 88.23 (62.25 – 97.93), 93.33 (76.49 – 98.83), and 90.78 (95% CI: 81.67 – 99.89) for LWE, respectively. The difference in overall accuracy of the two methods was not statistically significant (p = 0.0641).Conclusion: Based on the findings of the present study, AWU and LWE had the same specificity but different sensitivities in screening of anterior abdominal stab wound patients in need of laparotomy. The overall accuracy of LWE was slightly higher (91.48% versus 85.1%)

    Quality of Cardiopulmonary Resuscitation in Emergency Department Based on the AHA 2015 Guidelines; a Brief Report

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    Introduction: Adhering to existing guidelines on cardiopulmonary resuscitation (CPR) can increase the survival rate of the patients. The present study has been designed with the aim of determining the quality of CPR performed in the emergency department based on the latest protocol by the American heart association (AHA).Methods: In this prospective cross-sectional study CPR process was audited in patients above 18 years old in need of CPR presenting to the emergency departments of 3 teaching hospitals based on the AHA 2015 guidelines. Less than 60% agreement was considered as fail, 60-70% as poor, 70-80% as moderate, 80-90% as good, and 90-100% as excellent.Results: 80 cases of CPR were audited (55% male).  Location of arrest was the hospital in 58 (72.5%) cases and 48 (60.0%) of the cases happened during the day. 28 (35.0%) cases had orotracheal intubation before the initiation of CPR. 30 (37.5%) patients had a shockable rhythm at the initiation of CPR. Based on the findings, out of the 31 studied items, 9 (29.03%) had excellent agreement, 10 (32.25%) had good, 4 (12.90%) had moderate, 2 (6.45%) had poor, and 6 (19.35%) had fail agreement rate.Conclusion: Based on the findings of the present study, the quality of applying the principles of basic and advanced CPR in the emergency department of the studied hospital had intermediate, poor and fail agreement with the recommendations of the AHA 2015 in at least one third of the cases

    Integrative computational mRNA-miRNA interaction analyses of the autoimmune-deregulated miRNAs and well-known Th17 differentiation regulators: An attempt to discover new potential miRNAs involved in Th17 differentiation

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    Th17 cells are a lineage of CD4(+) T helper cells in immune system which differentiate from naive CD4(+) T cells and have demonstrated to play a critical role in the pathogenesis of different autoimmune disorders. miRNAs are a novel group of non-coding RNAs which participate in post-transcriptional regulation of gene expression mostly by pairing with 3'UTR of their mRNA targets and inhibition of its translation. It has been demonstrated that miRNAs function in various cellular processes such as differentiation, proliferation, and apoptosis. By now, several signaling pathways and their downstream positive and negative regulators involve in Th17 differentiation have been discovered. Several studies have reported the aberrant miRNA expression profile in patients with autoimmune disease called autoimmune-deregulated miRNAs. Here, using integrative miRwalk database which assembles the data gathered from ten different bioinformatics databases designed to predict miRNA-target interaction, we analyzed possible targeting effect of ``autoimmune-deregulated miRNAs'' on prominent positive and negative regulators of Th17 differentiation. Our resulting mRNA-miRNA network simply nominated several miRNAs with strong possibility which probably may have inducing (miR-27b, miR-27a, miR-30c, miR-1, and miR-141) or inhibitory (miR-20b, miR-93, miR-20a, miR-152, miR-21, and miR-106a) role in Th17 differentiation by targeting negative or positive regulators of Th17 differentiation, respectively. (C) 2015 Elsevier B.V. All rights reserved

    MiR-218 as a multifunctional regulator of oncogenic processes in different solid tumors

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    MicroRNAs are highly conserved small non-coding regulatory RNAs that involve in post transcriptional regulating of gene expression during different cellular mechanisms. Aberration of miR-218 expression during tumorigenesis of different solid tumors has been reported by numerous studies. In current systematic review article, by using the terms “miR-218” and “cancer” we first searched for English language articles in the PubMed database, published from 1993 to April 2014. Then by a comprehensive review of related articles, we provided some new insights that highlight novel features and functions of miR-218 in initiation and progression of solid tumors. The majority of these studies propose a tumor suppressing role for miR-218 considering the fact that it is significantly down-regulated in tumor tissues compared with normal specimens. Despite accumulating body of evidence regarding tumor suppressor functions of miR-218 in solid tumors; more intensive reviewing about available miR-218 recent original studies and interpretation of existing data, revealed the multifunctional role of miR-218 in these kinds of malignancies by targeting different corresponding target genes. Take all together, MiR-218 targets different cellular processes in cancer cells and its expression pattern is in an important association with various states and features of tumors. It seems that miR-218 can increase the speed of cell cycle and cell division in lower sample grades and along with progression of cancer cells it's function changes to stabilization the cancer cells and not allowing them to invade. thats why it often shows up-regulation in lower grades and down-regulation in metastatic phase. Therefore, it seems of great importance to check samples stage, grade, lymph node metastasis status and other tumor features before evaluation of miR-218 as a prognostic or diagnostic biomarker. © 2016, Iranian Neurogenetics Society. All rights reserved

    Adjunctive Local Application of Lidocaine during Scleral Buckling under General Anesthesia

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    Purpose: To evaluate the effect of local lidocaine application on the incidence of the oculocardiac reflex (OCR) during scleral buckling (SB) for rhegmatogenous retinal detachment (RRD) under general anesthesia. Methods: In a randomized clinical trial, eyes with RRD scheduled for SB under general anesthesia were randomized to adjunctive local application of 1 ml lidocaine 2% versus normal saline to the muscles after conjunctival opening. Surgical stimulation was initiated 5 minutes afterwards. Additionally, 100 mg of lidocaine 2% was added to 50 ml of normal saline in the treatment group which was used for irrigation during surgery; control eyes were irrigated with normal saline. The incidence of the OCR, rate of postoperative nausea/vomiting (PONV), total intravenous (IV) analgesic dose, duration of surgery, and period of hospitalization were compared between the study groups. Results: Thirty eyes of 30 patients including 22 (73.3%) male and 8 (26.7%) subjects with mean age of 49.4΁16.3 years were operated. OCR and PONV occurred less frequently, and total intravenous analgesic dose was significantly lower in the lidocaine group (P < 0.05 for all comparisons). However, no significant difference was noted between the study groups in terms of duration of surgery and period of hospitalization. Conclusion: Adjunctive local application of lidocaine during SB under GA for RRD decreases the rate of OCR and PONV, reduces the intravenous analgesic dose, but does not affect the duration of surgery or hospitalization

    Sensorless Control of a Single-Phase AC-DC Boost Converter without Measuring Input Voltage and Current

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    It is well-known that the accurate measurement of input voltage and current, as the feedforward and feedback terms, plays a crucial role in the nonlinear controller design for power factor compensation of an AC-DC boost converter. This paper addresses the problem of the simultaneous estimation of the input voltage and current from the output voltage in a full-bridge AC-DC boost converter. In the lossless model of the system, those variables are unobservable from the output voltage when the control input is zero. To overcome this, the system dynamics are immersed in a proper form by a new filtered transformation. The phase and amplitude of the input voltage, along with the input current, are globally estimated from the output voltage by a fifth-dimensional estimator. Unlike some existing results, the stability of the proposed estimator does not rely on a priori knowledge about the parasitic resistances and is guaranteed exponentially under the persistence of excitation conditions on the control signal. An application of the proposed estimator is presented in conjunction with a dynamic controller to form a sensorless control algorithm that does not require any sensor on the input side and controls the system only by the feedback from the output voltage. Processor-in-the-loop (PIL) studies conducted by OPAL-RT OP 5700 are used to assess the performances of the proposed estimator and controller

    Cryogenic heat treatment — a review of the current state

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    The deep cryogenic heat treatment is an old and effective heat treatment, performed on steels and cast irons to improve the wear resistance and hardness. This process includes cooling down to the liquid nitrogen temperature, holding the samples at that temperature and heating at the room temperature. The benefits of this process are significant on the ferrous materials, but recently some studies focused on other nonferrous materials. This study attempts to clarify the different behavior of some materials subjected to the deep cryogenic heat treatment, as well as explaining the common theories about the effect of the cryogenic heat treatment on these materials. Results showed that polymers exhibit different behavior regarding to their crystallinity, however the magnesium alloys, titanium alloys and tungsten carbide show a noticeable improvement after the deep cryogenic heat treatment due to their crystal structure

    NGOs, from the Promotion of Civic Participation to Public Problems Solving

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    In the contemporary world, NGOs are considered as important tool for motivating the community. So they committed their true mission and the promotion of civic participation and strengthen social identities. Functional characteristics of non-governmental organizations are the element to leverage the centers of political and social development of powerful governments since they are concrete and familiar with the problems of society and the operational strategies which would facilitate this process of mutual trust between the people and organizations. NGOs on the one hand offer reasonable solutions in line with approved organizations as agents to match between the facts and reality of society and on the other hand changes to a tool to have true political, social and economical behavior. However, the NGOs are active in the formulation of national relations and policy formulation in an organized and disciplined based on three main factors, ie, resources, policies, and institutions. Organizations are not restricted to state administration in centralized system bodies and this process in the democratic system limits the accumulation of desires and expectations and at the end reaches to the desired place. Hence, this research will attempt to emphasis on field research (questionnaire) and according to the development evolution and role of NGOs analyze the effects of this center on youth. Therefore, the hypothesis is that there is a direct relationship between the Enlightenment and the effectiveness of policy towards NGOs and solving social damages

    Poverty assessment of farming community in rice wheat zone of Punjab, Pakistan

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    Purpose. Poverty in Pakistan mostly exists as a rural poverty rather than urban poverty and presents a desolate vision. Rural poverty shows divergence with respect to area, region or any other administrative division. The tenacious rise of rural poverty in the history of Pakistan with some omissions, it affords plenty of material and remains a lot of questions related to poverty in the mind of researchers. The current study focused on three main poverty measures i.e. incidence, depth and severity of rural poverty in the rice-wheat zone of Punjab, Pakistan (Middle Punjab). Methodology / approach. To overcome the existing poverty issues in the area, we utilize secondary datasets at districts, regions, provinces or at national levels collected from Pakistan Bureau of Statistics, Islamabad (PBS). Poverty assessment for the year 2011–2012 is analyzed through Foster Greer and Thorbecke (FGT) method. Moreover, the Logit model is also used to find out the empirical values existing in the datasets. Results. The fluctuations in rural poverty for the year 2011–12 in the existing zone was analyzed by using logit regression model and data source was Household Integrated Economic Survey (HIES). The incidence of uni-dimensional and multidimensional poverty in middle Punjab (2011–12) were 35.38 and 27.40 percent has been seen after estimations. Originality / scientific novelty. The education level, health services, availability of assets, facilities and age of household head are the key factors related to incidence, depth and severity of poverty. All the above mentioned factors have negative relation with poverty measures. Practical value / implications. The decline in poverty can be achieved via implementation of sharp economic activities including the dimensions as analyzed in the manuscript. At this point, policy makers did not pay attention on the key factors that influence rural poverty at regional levels. There is a dire need to make development in basic standards of life to alleviate poverty in a long way in the middle Punjab
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