Antenatal dexamethasone effect on Doppler blood flow velocity in women at risk for preterm birth: prospective case series

Background: Maternal administration of corticosteroids is essential to improve fetal lung surfactant production and hasten the fetal lung maturity in women at risk for preterm birth.Objectives: The current study aims to evaluate the effects of dexamethasone on fetal and uteroplacental circulation in pregnancies at risk for preterm birth after 24 hours of its administration.Methods: A prospective cross-sectional study was carried out in a tertiary University Hospital and included 52 pregnant women with singleton pregnancies. Doppler studies were performed on maternal uterine arteries, umbilical artery, fetal middle cerebral artery (MCA) and fetal descending aorta and just before dexamethasone administration and repeated 24 hours after completion of the course.Results: There was a statistically significant difference between all Doppler indices in the umbilical artery (PI= 1.09±0.4 and 1.05±0.39, RI= 0.66±0.14 and 0.63±0.14; p=0.001), fetal MCA (RI= 0.86±0.12 and 0.83±0.13, PI= 2.19±0.72 and 2.15±0.72; p=0.001) and aorta (RI= 0.9±0.55 and 0.87±0.55; p=0.001, PI= 1.91±0.44 and 1.89±0.44; p=0.040) in comparison before and 24 hours after maternal dexamethasone administration respectively. Also uterine artery PI was significantly different (0.9±0.27 and 0.87±0.26; p=0.001).Conclusion: Antenatal dexamethasone for women at risk of preterm birth improves the fetal and uteroplacental blood flow at 24 hours after its administration.Keywords: Doppler; preterm birth; corticosteroids; dexamethasone

On the Free Vibration Modeling of Spindle Systems: A Calibrated Dynamic Stiffness Matrix

The effect of bearings on the vibrational behavior of machine tool spindles is investigated. This is done through the development of a calibrated dynamic stiffness matrix (CDSM) method, where the bearings flexibility is represented by massless linear spring elements with tuneable stiffness. A dedicated MATLAB code is written to develop and to assemble the element stiffness matrices for the system’s multiple components and to apply the boundary conditions. The developed method is applied to an illustrative example of spindle system. When the spindle bearings are modeled as simply supported boundary conditions, the DSM model results in a fundamental frequency much higher than the system’s nominal value. The simply supported boundary conditions are then replaced by linear spring elements, and the spring constants are adjusted such that the resulting calibrated CDSM model leads to the nominal fundamental frequency of the spindle system. The spindle frequency results are also validated against the experimental data. The proposed method can be effectively applied to predict the vibration characteristics of spindle systems supported by bearings

Effects of Machine Tool Spindle Decay on the Stability Lobe Diagram: An Analytical-Experimental Study

An analytical-experimental investigation of machine tool spindle decay and its effects of the system’s stability lobe diagram (SLD) is presented. A dynamic stiffness matrix (DSM) model for the vibration analysis of the OKADA VM500 machine spindle is developed and is validated against Finite Element Analysis (FEA). The model is then refined to incorporate flexibility of the system’s bearings, originally modeled as simply supported boundary conditions, where the bearings are modeled as linear spring elements. The system fundamental frequency obtained from the modal analysis carried on an experimental setup is then used to calibrate the DSM model by tuning the springs’ constants. The resulting natural frequency is also used to determine the 2D stability lobes diagram (SLD) for said spindle. Exploiting the presented approach and calibrated DSM model it is shown that a hypothetical 10% change in the natural frequency would result in a significant shift in the SLD of the spindle system, which should be taken into consideration to ensure chatter-free machining over the spindle’s life cycle

Enhancing the performance of spread spectrum techniques in different applications

Spread spectrum, Automotive Radar, Indoor Positioning Systems, Ultrasonic and Microwave Imaging, super resolution technique and wavelet transformMagdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2006von Omar Abdel-Gaber Mohamed Al

Designing story card in extreme programming using machine learning technique

Story card is one of the software development artifacts that can be used to gather requirements in extreme programming (XP).It can assists developers to translate and develop the system based on activities and rules stated in the story card.However, conventional XP story card framework or template is not well defined and only supports requirements in two or three sentences.It also does not states any information rather than system functionality.This may lead to conflicts, missing, and ambiguous requirements.In order to overcome this problem, Machine Learning is one of the techniques that can be used to extract the content from the list of requirements and produce the story cards based on the priority and rules of requirements.Thus, this study aims to to propose a new technique of designing story cards based on user requirements.The finding from the study is a conceptual model of designing story cards using machine learning technique.Future research will investigate how the technique adapt with the iterative changes of the requirements

A Novel CNN pooling layer for breast cancer segmentation and classification from thermograms

Breast cancer is the second most frequent cancer worldwide, following lung cancer and the fifth leading cause of cancer death and a major cause of cancer death among women. In recent years, convolutional neural networks (CNNs) have been successfully applied for the diagnosis of breast cancer using different imaging modalities. Pooling is a main data processing step in CNN that decreases the feature maps’ dimensionality without losing major patterns. However, the effect of pooling layer was not studied efficiently in literature. In this paper, we propose a novel design for the pooling layer called vector pooling block (VPB) for the CCN algorithm. The proposed VPB consists of two data pathways, which focus on extracting features along horizontal and vertical orientations. The VPB makes the CNNs able to collect both global and local features by including long and narrow pooling kernels, which is different from the traditional pooling layer, that gathers features from a fixed square kernel. Based on the novel VPB, we proposed a new pooling module called AVG-MAX VPB. It can collect informative features by using two types of pooling techniques, maximum and average pooling. The VPB and the AVG-MAX VPB are plugged into the backbone CNNs networks, such as U-Net, AlexNet, ResNet18 and GoogleNet, to show the advantages in segmentation and classification tasks associated with breast cancer diagnosis from thermograms. The proposed pooling layer was evaluated using a benchmark thermogram database (DMR-IR) and its results compared with U-Net results which was used as base results. The U-Net results were as follows: global accuracy = 96.6%, mean accuracy = 96.5%, mean IoU = 92.07%, and mean BF score = 78.34%. The VBP-based results were as follows: global accuracy = 98.3%, mean accuracy = 97.9%, mean IoU = 95.87%, and mean BF score = 88.68% while the AVG-MAX VPB-based results were as follows: global accuracy = 99.2%, mean accuracy = 98.97%, mean IoU = 98.03%, and mean BF score = 94.29%. Other network architectures also demonstrate superior improvement considering the use of VPB and AVG-MAX VPB

A Randomized Control Trial Comparing Transparent Film Dressings and Conventional Occlusive Dressings for Elective Surgical Procedures

BACKGROUND: Surgical site infection is one of the major health-care-associated problems causing substantial morbidity and mortality and constituting a financial burden on hospitals as well. The wound management is one of the crucial evidence-based strategies in the reduction of surgical site infection rates AIM: To study the impact of standardisation of transparent semipermeable dressing procedure on the rate of surgical site infection in comparison with conventional dressing in clean and clean-contaminated surgeries. METHODS: The study included 100 patients who were admitted to surgical wards in Cairo university hospitals, for clean and clean-contaminated operations, in the period from February 2017 to August 2017. Immunocompromised and uncontrolled diabetic patients were excluded. Patients were randomly allocated into two groups; in the first group, patients wounds were covered using transparent semipermeable dressing, while the second group patients’ wounds were covered using conventional occlusive gauze dressing. Patients were followed up for criteria of infection every other day during the first week then at two weeks, three weeks and four weeks. RESULTS: In clean and clean-contaminated operations, the transparent dressing group showed a significantly lesser rate of surgical site infection at (2%), compared with the conventional occlusive gauze dressing group with a surgical site infection rate of (14%) (p-value of 0.02). CONCLUSION: The transparent semipermeable dressing is effective in reducing surgical site infection rate in clean and clean-contaminated operations

Antenatal dexamethasone effect on Doppler blood flow velocity in women at risk for preterm birth: prospective case series

Background: Maternal administration of corticosteroids is essential to improve fetal lung surfactant production and hasten the fetal lung maturity in women at risk for preterm birth. Objectives: The current study aims to evaluate the effects of dexamethasone on fetal and uteroplacental circulation in pregnancies at risk for preterm birth after 24 hours of its administration. Methods: A prospective cross-sectional study was carried out in a tertiary University Hospital and included 52 pregnant women with singleton pregnancies. Doppler studies were performed on maternal uterine arteries, umbilical artery, fetal middle cerebral artery (MCA) and fetal descending aorta and just before dexamethasone administration and repeated 24 hours after completion of the course. Results: There was a statistically significant difference between all Doppler indices in the umbilical artery (PI= 1.09\ub10.4 and 1.05\ub10.39, RI= 0.66\ub10.14 and 0.63\ub10.14; p=0.001), fetal MCA (RI= 0.86\ub10.12 and 0.83\ub10.13, PI= 2.19\ub10.72 and 2.15\ub10.72; p=0.001) and aorta (RI= 0.9\ub10.55 and 0.87\ub10.55; p=0.001, PI= 1.91\ub10.44 and 1.89\ub10.44; p=0.040) in comparison before and 24 hours after maternal dexamethasone administration respectively. Also uterine artery PI was significantly different (0.9\ub10.27 and 0.87\ub10.26; p=0.001). Conclusion: Antenatal dexamethasone for women at risk of preterm birth improves the fetal and uteroplacental blood flow at 24 hours after its administration

N4-Substituted Piperazinyl Norfloxacin Derivatives with Broad-Spectrum Activity and Multiple Mechanisms on Gyrase, Topoisomerase IV, and Bacterial Cell Wall Synthesis

Fluoroquinolones are an important class of antibiotics with broad-spectrum antibacterial and antitubercular activity. Here, we describe the design and synthesis of a series of 38 N4-substituted piperazinyl norfloxacin derivatives. Their activity and mechanism of action were characterized using in silico, in vitro, and in vivo approaches. Several compounds displayed interesting activities against both Gram-negative and Gram-positive bacteria, and few displayed antimycobacterial activity, whereby some were as potent as norfloxacin and ciprofloxacin. Molecular docking experiments suggested that the new derivatives inhibit both DNA gyrase and DNA topoisomerase IV in a similar manner as norfloxacin. Selecting the most promising candidates for experimental mode of action analysis, we confirmed DNA gyrase and topoisomerase IV as targets of all tested compounds using enzymatic in vitro assays. Phenotypic analysis of both Escherichia coli and Bacillus subtilis confirmed a typical gyrase inhibition phenotype for all of the tested compounds. Assessment of possible additional targets revealed three compounds with unique effects on the B. subtilis cell wall synthesis machinery, suggesting that they may have an additional target in this pathway. Comparison with known cell wall synthesis inhibitors showed that the new compounds elicit a distinct and, so far, unique phenotype, suggesting that they act differently from known cell wall synthesis inhibitors. Interestingly, our phenotypic analysis revealed that both norfloxacin and ciprofloxacin displayed additional cellular effects as well, which may be indicative of the so far unknown additional mechanisms of fluoroquinolones