Buckling Behaviour of Clamped-Clamped Rectangular Thin Plates Composite Materials for a Zig-Zag Model

 هذا البحث ركز بصورة رئيسية على سلوك الانبعاج للصفائح المستطيلة الرقيقة متعرجة الطراز مصنعة من ثلاثة أنواع من المواد المركبة وهي (ألياف الزجاج / البوليستر، ألياف الكاربون / البوليستر وألياف هجينة من ألياف الزجاج والكاربون معا / البوليستر) والمسلطة عليها أحمال انبعاج ستاتيكية ويجرى الاختبار عند درجة حرارة الغرفة. وقد تم دراسة تأثير نوع واحد من الشروط الحدية حيث تم تثبيت الصفائح من جهتين وحررت من الجهتين الأخرى. تحليل الانبعاج لهذه الصفائح درست عددياً وعمليا مع اختلاف نسبة الأطوال وثبوت نسبة السمك. الجانب العملي تضمن تصنيع صفائح رقيقة مصنعة من (ألياف الزجاج / البوليستر، ألياف الكاربون / البوليستر وألياف هجينة من ألياف الزجاج والكاربون معا / البوليستر) متعرجة الطراز، ثم استخراج الخصائص الميكانيكية لها عن طريق اختبار الشد والتي هي (معامل المرونة، إجهاد الخضوع، أعظم مقاومة شد، ونسبة بويسون). تضمن الجانب العملي كذلك اختبار القص لنماذج ثلاثة أنواع من المواد المركبة لمعرفة إمكانية حدوث الانفصال الطبقي أم لا أثناء اختبار الانبعاج. كما وان الجانب العملي استخدم لإيجاد حمل الانبعاج الحرج وأعظم انحراف للأنواع الثلاثة من الصفائح المستطيلة الطبائقية متعرجة الطراز تحت تأثير نسبة الأطوال وعند حمل ضغط ستاتيكي موزع بانتظام. تم حساب حمل الانبعاج الحرج وأقصى انحراف من التحليل العددي للأنواع الثلاثة من الصفائح المستطيلة الطبائقية متعرجة الطراز تحت تأثير نسبة الأطوال وعند حمل ضغط ستاتيكي موزع بانتظام، حيث استخدمت طريقة العناصر المحددة من خلال برنامج انسس 15.  الاستنتاج الرئيسي من هذا البحث هو ان استخدام الطراز المتعرج في تصنيع صفائح المواد المركبة قد حسن من الخصائص الميكانيكية لها كما وان حمل الانبعاج الحرج قد ازداد.  إن النتائج العملية والعددية كانت ذات نسب خطأ مئوية مقدارها 29.23%, 30.20%, و46.71% عند نسبة أطوال ((a/b = 1 للأنواع الثلاثة من المواد المركبة وهي (ألياف الزجاج / البوليستر، ألياف الكاربون / البوليستر وألياف هجينة من ألياف الزجاج والكاربون معا / البوليستر) على الترتيب.     ان قيمة الانحراف العظمى الناتجة من الانبعاج تزداد مع زيادة نسبة الأطوال وتحت ثبوت نسبة السمك، كما وان أعظم انحراف في صفائح المواد المركبة من نوع ألياف الزجاج / البوليستر متعرجة الطراز اعلي من نظيراتها المكونة من ألياف الكاربون / البوليستر وألياف هجينة من ألياف الزجاج والكاربون معا / البوليستر. هنالك تطابق جيد تحقق في نتائج الطريقتان العمليتان للحصول على حمل الانبعاج الحرج وأعظم انحراف ناتج من الانبعاج، وان أعظم نسبة معدل خطأ مطلق كان حوالي 1% و1.1% على الترتيبThis paper focused mainly on the behavior buckling for the rectangular laminated plates made from three types of composite materials of a zig-zag model such as E-glass fiber / polyester (GFRP), carbon fiber / polyester (CFRP) and hybrid fibers / polyester (HFRP), under static buckling load and at room temperature (25Co). All the effects of plate determinants on the buckling load were studied for one type of a boundary condition, which was fixed on both sides, is clamped-clamped and free-free in other sides. The buckling analysis of these plates has been studied numerically and experimentally with different aspect ratio and constant thickness ratio. The experimental part is including the manufacture of composite materials laminated plates of a zig-zag model and determine the mechanical properties such as modulus of elasticity, yield stress, ultimate tensile strength and Poisson's ratio by tensile test for three types of composite materials such as GFRP, CFRP, and HFRP. The experiments of shear stress test was used to determine whether the layers would be the plates is delaminate layers during buckling test or not into the three types of composite materials samples. Experiments were also used to find the critical buckling load and maximum buckling deflection for clamped-clamped rectangular laminated plates of three types of composite materials for a zig-zag model with the effect of aspect ratios under uniformly distributed static compression load. Numerical analysis of critical buckling load and maximum buckling deflection are calculated for three types of composite materials thin plates for a zig-zag model with the effect of aspect ratios under uniformly distributed static buckling load, the finite elements method was used in ANSYS program version (15.0). The main conclusion of this research is that the presence of zig-zag fibers in the plate can improve the mechanical properties and increase the critical buckling load.  The maximum percentage errors between the experimental and numerical results are 29.23%, 30.20%, and 46.71% at aspect ratio (a/b=1) for GFRP, CFRP, and HFRP, respectively. The maximum deflection value is increased when the aspect ratio is increased under constant thickness ratio; also, the maximum deflection in GFRP composite materials rectangular laminated plates is greater than that in CFRP and HFRP. A good agreement is achieved between the two experimental ways for determining the critical buckling load and maximum buckling deflection results, the maximum absolute percentage error rates are about 1% and 1.1%, respectively

ANN-Based Prediction of Kidney Dysfunction Using Clinical Laboratory Data

This paper presents the prediction of Kidney dysfunction using probabilistic neural network (PNN). Six hundred and sixty (660) sets of analytical laboratory test have been collected from one of the private Clinical laboratories in Baghdad. For each subject, Serum urea and Serum creatinin levels have been analyzed and tested by using clinical laboratory measurements. The collected Urea and cretinine levels are then used as inputs to the Artificial Neural network model in which the training process is done by PNN which is a class of radial basis function (RBF) network is used as a classifier to predict whether Kidney is normal or it will have a dysfunction. The accuracy of Prediction, sensitivity and Specificity were found to be equal to 99%, 98% and 99% respectively for this proposed network .We conclude that the proposed model gives faster and more accurate prediction of Kidney dysfunction and it works as promising tool for predicting of routine kidney dysfunction from the clinical laboratory data

Cytological and Immunocytochemical Study of Bronchial Wash in Bronchogenic Carcinoma

Background: - Carcinoma of the lung has became the most common type of cancer since 1985 & the most common cause of cancer death in both males & females. Aim of study: - To assess the diagnostic accuracy of bronchial wash cytology & application of immunocytochemical methods, using two tumor markers (low molecular weight cytokeratin & epithelial membrane antigen) for more accurate & precise diagnosis of lung tumors. Patients, materials and methods: - Fifty fifes suspected lung cancer cases according to their clinicoradiological examinations were included in this study. Bronchial wash cytology was performed for all the 55 patients. Smears were stained by conventional cytological stain in addition to immunocytochemial staining using low molecular weight cytokeratin & epithelial membrane antigen. The final results of bronchial wash were compared to histopathological results & final clinical diagnosis as. Results: - Cytological smears of bronchial wash revealed the presence of malignant cells in 33 cases (60%). The sensitivity of bronchial wash cytology was 82.5%; the specificity was 100.0%, with overall accuracy of 87.3%. Using cytokeratin staining, 26 cases (47%) were positive for malignant cells, & 29 were negative. The sensitivity, specificity & overall accuracy were 65%, 100%, & 74.5% respectively. With EMA staining, 19 cases (27%) were positive for malignant cells & 36 were negative. The sensitivity, specificity & overall accuracy were 47.5%, 100%, & 61.8% respectively. Combined use of CK & EMA raised the sensitivity to 72.5%, specificity of 100% & overall accuracy of 80%. Combined use of monoclonal antibodies & conventional cytology raised the sensitivity to 95%, specificity 100%, with overall accuracy of 96.3%.  Conclusions: - Using more than one monoclonal antibody, or using combined conventional cytology & immunocytochemistry increase the sensitivity for detection of malignant cells in bronchial wash smears

Paternal postnatal depression among fathers of newborn in Saudi Arabia

Paternal postnatal depression (PPND) is not a commonly recognized phenomenon. The aim of the study was to identify the Edinburgh Postnatal Depression Scale (EPDS) cutoff for Saudi fathers, to estimate PPND prevalence and to determine the risk factors of PPND among fathers of newborn in Saudi Arabia. A cross-sectional study of fathers with babies born up to 6 months prior to the survey was conducted. Fathers were screened using EPDS and demographic questionnaire. The fathers were selected using systematic random sampling from visitors to the birth registration office. A subsample of participants from the postnatal wards in a tertiary care was invited for additional evaluation by a psychologist using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for major depressive disorders. Receiver operating characteristic curve was utilized to identify fathers with depression; a cutoff of 8/9 was optimal to achieve sensitivity 77.8% and specificity 81.3%. Adjusted prevalence of PPND was reported with corresponding Wilson 95% confidence interval. Two hundred and ninety fathers completed the EPDS and demographic questionnaire. Of 72 invited participants, 57 (79.16%) attended the diagnostic interview. The average age of fathers was 34.97 ± 8.56 years, the average maternal age was 29.18 ± 7.41 years, average age of the newborn was 43.13 ± 35.88 days. PPND adjusted prevalence was 16.6% (95% CI [8.5, 25.6]). Paternal mental health needs equal attention during and postdelivery of newborn. Fathers should receive perinatal and postnatal mental health assessment to prevent behavioral problems in their children and disruption of relationship with their spouse

Immunohistochemical expression of matrix metalloproteinase-7 in human colorectal adenomas using specified automated cellular image analysis system: A clinicopathological study

Background/Aim: To evaluate the immunohistochemical expression of matrix metalloproteinase-7 (MMP-7) in colorectal adenomas, and to correlate this expression with different clinicopathological parameters. Patients and Methods: The study was retrospectively designed. Thirty three paraffin blocks from patients with colorectal adenoma and 20 samples of non-tumerous colonic tissue taken as control group were included in the study. MMP-7 expression was assessed by immunohistochemistry method. The scoring of immunohistochemical staining was conducted utilizing a specified automated cellular image analysis system (Digimizer). Results: The frequency of positive immunohistochemical expression of MMP-7 was significantly higher in adenoma than control group (45.45% versus 10%) (P value < 0.001). Strong MMP-7 staining was mainly seen in adenoma cases (30.30%) in comparison with control (0%) the difference is significant ( P < 0.001). The three digital parameters of MMP-7 immunohistochemical expression (Area (A), Number of objects (N), and intensity (I)) were significantly higher in adenoma than control. Mean (A and I) of MMP-7 showed a significant correlation with large sized adenoma (≥ 1cm) ( P < 0.05), also a significant positive correlation of the three digital parameters (A, N, and I) of MMP-7 expression with villous configuration and severe dysplasia in colorectal adenoma had been identified ( P < 0.05). Conclusion: MMP-7 plays an important role in the growth and malignant conversion of colorectal adenomas as it is more likely to be expressed in advanced colorectal adenomatous polyps with large size, severe dysplasia and villous histology. The use of automated cellular image analysis system (Digmizer) to quantify immunohistochemical staining yields more consistent assay results, converts semi-quantitative assay to a truly quantitative assay, and improves assay objectivity and reproducibility

Immunohistochemical expression of PCNA and CD34 in colorectal adenomas and carcinomas using specified automated cellular image analysis system: A clinicopathologic study

Background/Aim: To evaluate the immunohistochemical expression of proliferating cell nuclear antigen (PCNA) and CD34 in colorectal adenomas and carcinomas, and to correlate this expression with different clinicopathologic parameters. Materials and Methods: The study was retrospectively designed. A total of 86 tissue samples, including 33 paraffin blocks from patients with colorectal adenomas, 33 paraffin blocks from patients with colorectal adenocarcinomas, and a control group of 20 samples of nontumerous colonic tissue, were included in the study. From each block, 3 sections of 5 ΅m thickness were taken, 1 section was stained with hematoxylin and eosin (H and E) and the other 2 sections were stained immunohistochemically for PCNA and CD34. Scoring of the immunohistochemical staining was performed using a specified automated cellular image analysis system (Digimizer). Results: PCNA expression was significantly increased in a sequence of normal mucosa-adenoma-carcinoma. It was significantly higher in adenomas ≥ 1 cm and those with severe dysplasia, and it showed a significant positive correlation with grade and lymph node involvement in colorectal carcinoma. CD34 showed significantly higher expression in carcinoma than adenoma and in adenoma than in the control group. CD34 expression showed a significant correlation with adenomas carrying severe dysplasia and large-sized adenomas (≥1cm). It was significantly correlated with tumor grade, lymphovascular invasion, and lymph node involvement in colorectal carcinoma. Conclusion: PCNA plays an important role in colorectal neoplastic progression and can be utilized as ancillary marker for the risk of malignant transformation in colorectal adenomas as it correlates with high grade dysplasia and size. Intratumoral quantification of the mean (A and N) of CD34 in colorectal carcinoma reflects the grade of tumors and can predict lymph node involvement and lymphovascular invasion, to make a useful additional prognostic factor

Evaluation of the Sensitivity and Specificity of Immunohistochemical Markers in the Differential Diagnosis of Effusion Cytology

Objective: To evaluate the sensitivity and specificity of Calretinin and Carcinoembryonic antigen as immunocytochemical markers in distinguishing mesothelial cells from metastatic adenocarcinoma cells in effusion cytology.Methods: This study included 50 patients who presented with effusions (26 pleural and 24 peritoneal), at Al-Kadhimya Teaching Hospital who were selected according to their preliminary diagnosis from 1st December 2010 to 30th June 2011. Effusion fluids were aspirated and processed for both conventional cytological methods using Papanicolaou-stain and immunocytochemical staining with anti Calretinin and Carcinoembryonic antigen.Results: The sensitivity of cytology for detection of malignant cells was 77%, with 100% specificity and 86% accuracy. Calretinin was observed to be a specific (100%) and sensitive (90%) marker for mesothelial cells (of benign etiology). Carcinoembryonic antigen exhibited 70% sensitivity and 100% specificity for adenocarcinoma cells. When the results of both cytology and immunocytochemistry were considered in conjunction, the sensitivity for the detection of malignancy increased to 97%, with 100% specificity and 98% accuracy.Conclusion: Calretinin and Carcinoembryonic antigen were found to be useful markers for differentiating reactive mesothelial cells from metastatic adenocarcinoma cells in smears prepared from body fluids. Also, the combination of both cytology and immunocytochemical studies using the two markers can greatly enhance the diagnostic accuracy, sensitivity and specificity in malignant effusions

Immunohistochemical Expression of Estrogen and Progesterone Receptors in Human Colorectal Adenoma and Carcinoma Using Specified Automated Cellular Image Analysis System: A Clinicopathological Study

 Objectives: To evaluate the immunohistochemical expression of estrogen receptors (ER) and progesterone receptors (PR) in colorectal adenoma and adenocarcinoma and to correlate this immunohistochemical expression with different clinicopathological parameters.Methods: The study was retrospectively designed. A total of 86 tissue samples, including 33 paraffin blocks from patients with colorectal adenomas, 33 paraffin blocks from patients with colorectal adenocarcinomas and a control group of 20 samples of non-tumorous colonic tissue, were included in the study.Results: The frequency of expression of ER and PR showed a gradual increase from control through adenoma to carcinoma. The frequencies of expression of ER in the control, adenoma and carcinoma were (10�2015.15�0and 42.42�0respectively, p<0.001), while the frequency of expression for PR were (10�2024.24�0and 36.36�0respectively, p<0.001). Strong ER and PR staining was mainly seen in carcinoma cases (42.42�2036.36�20respectively) in comparison with adenoma (9.09�2015.15�20respectively) and control (0�200�20respectively). The three digital parameters of ER and PR immunohistochemical expression (Area [A], Number of objects [N], and intensity [I]) were significantly increased in a sequence of normal mucosa-adenoma-carcinoma. There was a significant positive correlation between ER and PR in adenoma (r=0.312, p=0.034) and carcinoma (r=0.321, p=0.0398).Conclusion: ER and PR expression increased in a sequence of; normal colonic mucosa-adenoma-carcinoma, and a positive correlation was observed between ER and PR expression in colonic adenoma and carcinoma specimen indicating that ER and PR may play a role in colorectal carcinogenesis

Immunohistochemical Expression of ki-67 and p53 in Colorectal Adenomas: A Clinicopathological Study

 Objectives: To evaluate the significance of P53 and Ki-67 expression as immunohistochemical markers in early detection of premalignant changes in different types of colorectal adenomas. Also, to correlate immunohistochemical expression of the two markers with different clinicopathological parameters including; age, and sex of the patient, type, site, size and grade of dysplasia of colorectal adenomas.Methods: Forty-seven polypectomy specimens of colorectal adenomas were retrieved from the archival materials of the Gastrointestinal and Hepatic Diseases Teaching Hospital in Baghdad from 2009 - 2010. Four µm section specimens were stained by immunohistochemical technique with Ki-67 and P53 tumor markers. P-values <0.05 were considered statistically significant.Results: Immunohistochemical expressions of Ki-67 and P53 had a significant correlation with the size and grade of dysplasia in colorectal adenomas. However, there was no significant correlation among the immunohistochemical expression of Ki-67 and P53 with the age and gender of the patient, and the type and site of colorectal adenomas. There was no significant correlation between Ki-67 and P53 expressions in colorectal adenomas. Villous adenomas of colorectum showed a significant correlation with the grade of dysplasia, while there was no significant correlation between size and site of colorectal adenoma with the grade of dysplasia.Conclusion: High grade dysplasia with significant positive immunohistochemical markers of Ki-67 and P53 could be valuable parameters for selecting from the total colorectal adenoma population, those most deserving of close surveillance in follow-up cancer prevention programs. It is closely linked with increasing age particularly in patients with a large size adenoma of villous component in their histology