Dynamic Analysis of Interaction of Gravity Dam and Reservoir in Time Domain

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

On the inverse eigenvalue problem for a special kind of acyclic matrices

summary:We study an inverse eigenvalue problem (IEP) of reconstructing a special kind of symmetric acyclic matrices whose graph is a generalized star graph. The problem involves the reconstruction of a matrix by the minimum and maximum eigenvalues of each of its leading principal submatrices. To solve the problem, we use the recurrence relation of characteristic polynomials among leading principal minors. The necessary and sufficient conditions for the solvability of the problem are derived. Finally, a numerical algorithm and some examples are given

A New Spectrophotometric Method for Determination of Selenium in Cosmetic and Pharmaceutical Preparations after Preconcentration with Cloud Point Extraction

A simple, rapid, and sensitive spectrophotometric method for the determination of trace amounts of selenium (IV) was described. In this method, all selenium spices reduced to selenium (IV) using 6 M HCl. Cloud point extraction was applied as a preconcentration method for spectrophotometric determination of selenium (IV) in aqueous solution. The proposed method is based on the complexation of Selenium (IV) with dithizone at pH < 1 in micellar medium (Triton X-100). After complexation with dithizone, the analyte was quantitatively extracted to the surfactant-rich phase by centrifugation and diluted to 5 mL with methanol. Since the absorption maxima of the complex (424 nm) and dithizone (434 nm) overlap, hence, the corrected absorbance, Acorr, was used to overcome the problem. With regard to the preconcentration, the tested parameters were the pH of the extraction, the concentration of the surfactant, the concentration of dithizone, and equilibration temperature and time. The detection limit is 4.4 ng mL−1; the relative standard deviation for six replicate measurements is 2.18% for 50 ng mL−1 of selenium. The procedure was applied successfully to the determination of selenium in two kinds of pharmaceutical samples

A TWO-STAGE GREEDY HEURISTIC FOR A FLOWSHOP SCHEDULING PROBLEM UNDER TIME-OF-USE ELECTRICITY TARIFFS

This paper studies a two-machine flowshop scheduling problem under time-dependent electricity tariffs, in which electricity prices may vary from time to time throughout the day. The main issue is to assign a set of jobs to available time slots with different electricity prices to minimise the total resource cost required for processing the jobs. The main contribution of this work is two-fold. First, a new continuous-time mixed-integer linear programming (MILP) model is proposed for the problem. Second, a two-stage greedy heuristic is developed. A computational experiment on randomly generated instances demonstrates that the greedy algorithm can improve the objective function by almost 40 percent. The algorithm can be applied by production managers to scheduling jobs in a flowshop under time-of-use (TOU) electricity tariffs to save electricity costs

Distribution of socioeconomic factors among the new patients of skin cancer in Iran

Background: The global burden of cancer due to population growth and aging, and various environmental factors is increasing. Skin cancer is the most common cancer among Iranians and among men, is more common. There is strong evidence from Industrialized and less developed countries that cancer incidence and survival is related to socioeconomic factors. The aim of this study was to investigate the relationship between socioeconomic variables including Human Development Index, unemployment rate and Urbanization ratio with the incidence of skin cancer in Iran. Method: The panel data were for 30 provinces for 6 years) 2007 to 2012(. Data of socioeconomic factors were collected from the Statistical Center of Iran and the data related to the incidence of cancer were collected from the reports on cancer registry of Health and Medical Education Ministry. For data analysis Stata11th version was used. Result: There is no relation between unemployment and the incidence of skin cancer. There is negative relationship between urbanization and incidence of skin cancer in both sexes. There is negative relation between HDI and the incidence of skin cancer in both sexes. Conclusion: Among the three variables selected in this study, the human development index and the urbanization, influenced on the cancer incidence. Therefore, in order to prevent skin cancer, paying attention appears to be necessary for policymakers. Key words: Socioeconomic Factors, Skin Neoplasm, Ira

Bacterial Contamination of Mobile Phones Carried by Medical Staff in Maternity, Neonatal, and ICU Wards of Shahid Beheshti and Imam Sajjad Hospitals in Yasuj

The use of mobile phones by healthcare personnel, doctors, patients, and patients’ companions are unavoidable in health centers, especially in hospitals. Besides being rarely clean, the mobile phone is a potential reservoir of disease and pathogens and hospital infections on bedside of hospitalized patients. In this study, the microbial contamination of mobile phones and potential of transmitting infections and their antibiotic resistance pattern were investigated. In this descriptive cross-sectional study, a questionnaire was prepared to assess the importance of maternity, neonatal, and intensive care unit (ICU) staff attention to how to use and clean the cell phones in terms of valid sources. Samples were taken from 116 cell phones using a sterile swab. The standard plate count was used to detect the existing bacteria, and the antimicrobial resistance patterns of isolated bacteria were determined by standard methods. The microbial culture experiments indicated that 107 cell phones had microbial contamination, accounting for 92.24% of mobile phones. From 132 isolated strains, 115 strains (87.12%) were gram-positive while 17 were Gram-negative (12.88%). Furthermore, 67 (57.76%), 9 (7.7%), 4 (3.45%), 10 (8.62%), 12 (10.35%), 22 (19%), and 8 (6.9%) strains were coagulase-negative staphylococci, Pseudomonas aeruginosa, Staphylococcus aureus, Corynebacterium, Bacillus, Streptococcus, and Escherichia coli, respectively. The results of this study indicated that cell phones were contaminated with different types of bacteria, and that all species isolated partially played an important role in the development of hospital-acquired and opportunistic infections. Therefore, continuous disinfection of mobile phones and non-use or limited use of them in the hospitals are recommended

میزان همخوانی یافته های سی تی اسکن شکم با یافته های آزمایش ادرار در کودکان دچار هماچوری در اثر ضربه غیرنافذ شکمی

Introduction: The present study compares the diagnostic accuracy of urinalysis with computed tomography (CT) scan in pediatrics with blunt abdominal trauma. The aim of this study was comparing the diagnostic value of urinalysis and abdominal CT scan with contrast, as the gold standard, for predicting probable abdominal organ injury in these patients. Methods: The present diagnostic accuracy study was done on children with blunt abdominal trauma aged less than 16 years who were presented to emergency department and both urinalysis and abdominal CT scan had been done for them. Demographic data, trauma mechanism, and results of urinalysis, ultrasonography and abdominal CT scan regarding abdominal organs were recorded. To evaluate the diagnostic power of urinalysis, statistical indices such as sensitivity, specificity, positive and negative predictive value were used. Results: In this study, 70 children under 16 years old who visited ED were evaluated. Mean age of the studied population was 7.1 ± 4.86 years and 48 of the patients (68.6%) were male. The correlation between hematuria and positive CT scan findings was confirmed. Sensitivity, specificity and positive and negative predictive values of hematuria were calculated to be 26.67%, 92.73%, 50% and 82.26%, respectively. Conclusion: Based on the results of the present study, although presence of hematuria has acceptable specificity, its sensitivity is very low compared to CT scan for prediction of abdominal organ injuries in pediatrics with blunt abdominal trauma. In other words, absence of hematuria is not a good reference to dismiss abdominal organ injury, yet its presence can be an indicator of serious injury. مقدمه: مطالعه حاضر به بررسی دقت تشخیصی نتیجه آزمایش ادرار در مورد کودکان دچار آسیب غیرنافذ شکم، در مقایسه با سی تی اسکن می پردازد. هدف از این مطالعه بررسی مقایسه ای میان ارزش تشخیصی آزمایش ادرار و سی تی اسکن شکم با کنتراست به عنوان روش استاندارد طلایی تشخیص در پیشگویی آسیب احتمالی احشای شکمی در این بیماران است. روش کار: مطالعه حاضر از نوع ارزیابی دقت تشخیصی بر روی کودکان دچار ترومای بلانت شکم کوچکتر از 16 سال که به بخش اورژانس مراجعه کرده بودند و برای آنها آزمایش ادرار و سی تی اسکن شکم درخواست شده بود، انجام گرفت. اطلاعات دموگرافیک، مکانیسم تروما، نتایج آزمایش ادرار، سونوگرافی و سی تی اسکن شکم در خصوص آسیب احشای شکمی ثبت گردید. برای سنجش قدرت تشخیصی بیماران توسط آزمایش ادرار از شاخصهای آماری حساسیت، ویژگی، ارزش اخباری مثبت و منفی استفاده شد. يافته ها: در این مطالعه تعداد70 کودک بین 0 تا 16 سال مراجعه کننده به بخش اورژانس وارد مطالعه شدند. 48 نفر (6/68 درصد) از بیماران پسر بودند. میانگین سنی ایشان 6/4±1/7 سال بود. در این مطالعه ارتباط بین وجود خون در ادرار و یافته های مثبت سی تی اسکن تایید شد. میزان حساسیت،ویژگی،ارزش اخباری مثبت و منفی به ترتیب 67/26 % و 73/92 % و 50 % و 26/82 % بدست آمد. نتيجه گيری: طبق نتایج مطالعه حاضر وجود هماچوری با وجود ویژگی قابل قبول، از حساسیت بسیار پایینی در مقایسه با سی تی اسکن در پیشگویی آسیب احشای شکمی در کودکان دچار ترومای بلانت شکم دارد. به بیانی دیگر عدم وجود هماچوری معیار مناسبی برای رد آسیب احشای شکمی نیست ولی وجود آن می تواند مطرح کننده آسیب جدی باشد

Levels of Blood Biomarkers among Patients with Myocardial Infarction in Comparison to Control Group

BACKGROUND: Myocardial infarction (MI) as a term for a heart attack happens due to reduced blood flow to heart myocardium and lack of oxygen supply caused by plaques inthe interior walls of coronary arteries. With respect to the importance of MI etiology, we aimed to study the relationship of MI and blood examination variables.METHODS: This study was conducted in Mazandaran Heart Center as a hospital-based case-control Comprising 894 participants including 465 cases and 429 controls, individually matched by sex and age. Considered blood markers were analyzed using routine laboratory methods and equipment.RESULTS: Of all participants, 64.3% of the cases and 51.0% of the controls were males with a mean age of 61.2 (±13.8) in cases and 62.4 (±14.) in controls. We could not find any differences between cases and controls for total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and alkaline-phosphatase (ALP) (P&gt;0.05). However, levels of creatine-kinase-muscle/brain (CK-MB) (P&lt;0.0001), fasting-blood-sugar (FBS) (P&lt;0.0001), aspartateaminotransferase (AST) (P&lt;0.0001), alanine-transferase (ALT) (P&lt;0.0001) and erythrocyte sedimentation rate (ESR) (P=0.001) were significantly higher in cases compared to the controls (P&lt;0.05). Multivariable analyses revealed that the risk of MI was associated with high levels of AST (adjusted OR=24.3, 95%CI=3.5±165.6, P=0.001) and LDL (adjusted OR=7.4, 95%CI=1.0±51.8, P=0.001).CONCLUSION: Our investigation indicated that the levels of CK-MB, FBS, AST, ALT and ESR were significantly higher in patients with MI. Besides, our findings showed that the risk of MI in cases with high levels of AST and LDL was about 24 and 7 times more than the control group respectively

A Comparative Analysis of Clinical Characteristics and Laboratory Findings of COVID-19 between Intensive Care Unit and Non-Intensive Care Unit Pediatric Patients: A Multicenter, Retrospective, Observational Study from Iranian Network for Research in Viral

Introduction: To date, little is known about the clinical features of pediatric COVID-19 patients admitted to intensive care units (ICUs).&nbsp;Objective: Herein, we aimed to describe the differences in demographic characteristics, laboratory findings, clinical presentations, and outcomes of Iranian pediatric COVID-19 patients admitted to ICU versus those in non-ICU settings.&nbsp;Methods: This multicenter investigation involved 15 general and pediatrics hospitals and included cases with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on positive real-time reverse transcription polymerase chain reaction (RT-PCR) admitted to these centers between March and May 2020, during the initial peak of the COVID-19 pandemic in Iran.&nbsp;Results: Overall, 166 patients were included, 61 (36.7%) of whom required ICU admission. The highest number of admitted cases to ICU were in the age group of 1–5 years old. Malignancy and heart diseases were the most frequent underlying conditions. Dyspnea was the major symptom for ICU-admitted patients. There were significant decreases in PH, HCO3 and base excess, as well as increases in creatinine, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and potassium levels between ICU-admitted and non-ICU patients. Acute respiratory distress syndrome (ARDS), shock, and acute cardiac injury were the most common features among ICU-admitted patients. The mortality rate in the ICU-admitted patients was substantially higher than non-ICU cases (45.9% vs. 1.9%, respectively; p&lt;0.001).&nbsp;Conclusions: Underlying diseases were the major risk factors for the increased ICU admissions and mortality rates in pediatric COVID-19 patients. There were few paraclinical parameters that could differentiate between pediatrics in terms of prognosis and serious outcomes of COVID-19. Healthcare providers should consider children as a high-risk group, especially those with underlying medical conditions