1,012 research outputs found
Ultrastructural and Molecular Changes in the Developing Small Intestine of the Toad Bufo regularis
The ontogenetic development of the small intestine of the toad Bufo regularis was investigated using twofold approaches, namely, ultrastructural and molecular. The former has been done using transmission electron microscope and utilizing the developmental stages 42, 50, 55, 60, 63, and 66. The most prominent ultrastructural changes were recorded at stage 60 and were more evident at stage 63. These included the appearance of apoptotic bodies/nuclei within the larval epithelium, the presence of macrophages, swollen mitochondria, distorted rough endoplasmic reticulum, chromatin condensation, and irregular nuclear envelop, and the presence of large vacuoles and lysosomes. The molecular investigation involved examining DNA content and fragmentation. The results showed that the DNA content decreased significantly during the metamorphic stages 60 and 63 compared with both larval (50 and 55) and postmetamorphic (66) stages. The metamorphic stages (60 and 63) displayed extensive DNA laddering compared with stages 50, 55, and 66. The percentage of DNA damage was 0.00%, 12.91%, 57.26%, 45.48%, and 4.43% for the developmental stages 50, 55, 60, 63, and 66, respectively. In conclusion, the recorded remodeling of the small intestine represents a model for clarifying the mechanism whereby cell death and proliferation are controlled
Evaluating Thermal Comfort and Overheating Risks in A Social Housing Prototype: As-Built Versus Retrofit Scenarios
Climate change has highlighted the importance of thermal comfort and its health-related outcomes, particularly for the most vulnerable members of society living in social housing. Due to their vulnerable living conditions, low-income people are more exposed to negative outcomes of overheating and cold indoor temperatures in buildings. Previous studies suggest that there is a significant risk of overheating in retrofitted buildings both for the current and future weather scenarios. The UK government has introduced new building regulations to assess and limit the risk of overheating in new buildings; however, there is still a need to assess and improve conditions for existing and retrofitted properties. This study aims to evaluate the effect of retrofit strategies on thermal comfort and the risk of overheating in social housing under current and future climatic conditions. A typical case study building was simulated in DesignBuilder to assess thermal comfort conditions for upgraded building fabric to Part L of the UK building regulations and Passive House standards. The summer results were analyzed according to CIBSE TM59 while the Predicted Mean Vote index (PMV) was used for winter analysis. Findings revealed that the south-facing bedrooms are most exposed to overheating. Risk of overheating significantly increased for the future weather scenarios by up to 10 times while winter thermal comfort improved for the retrofitted scenarios
Bacteriolytic Activity of Coliphages on Diarrhea Associated E. coli
There has been an alarming increase in drug-resistant strains of diarrheagenic Escherichia coli (DEC) in developing as well as developed countries. Several cases of antimicrobial resistance in DEC have been observed in different parts of the world as a result, there has been a renewed interest in alternative antimicrobial treatments, including bacteriophages. This study was conducted to isolation and characterization of a lytic coliphage from sewage water capable to infect a variety of multidrug resistance DEC strains isolated from children suffering diarrhea, as first step to further usage a lytic coliphage in future.in this study, a coliphage was isolated using spotting method and titrated, using agar overlay technique. The host range of coliphages was assessed on a lawn of E coli bacteria. This study included determination of the latent periods and burst size of coli phage then determines the stability of coliphages to physical and chemical condition (temperature, pH and sunlight exposure).The results shown that, five phages isolate (A, B, C, D and E) were exhibiting a potent lytic activity with clear plaques (1-4mm in diameter). Fifty percent of the E coli strains were infected by phage isolates. It seems, very likely, that the coliphages belonging to 3 different groups (1, 2 and3). The phage growth cycle with a detected latent period of 20 min, a burst size of 160 plaque forming units per infected cell, it was found that the phage could survive at varied pH conditions with reduction in its numbers. A temperature of above 60°C and direct sunlight beyond 8 days was found to be deleterious for survival of the phage. Keywords: key words, coliphages, E. coli, diarrhe
Investigation on Concrete Properties for Nano Silica Concrete by using Different Plasticizers
This paper presents results of the optimal dosage levels of polycarboxylate-based (PSP) (0.4 and 0.8%) and naphthalene-based (NSP) (0.8 and 1.6%) super plasticizers and different water to binder (w/b) ratios (0.4 and 0.45 ) that produce an adequate balance between strength and workability for concrete containing nano-SiO2 (NS) of 1%, 2%, and 3% as cement replacement. These results indicate that For two types super plasticizers mixes. Increasing the w/c ratio from 0.40 to 0.45 increased the slump of all mixes. Either those containing polycarboxylate or naphthalene sulphonate super plasticizer or the control mixes. For polycarboxylate super plasticizer mixes. Decreasing the w/c ratio from 0.45 to 0.40 increased the compressive strength of all mixes. Either those containing polycarboxylate super plasticizer. For naphthalene sulphonate super plasticizer mixes. Increasing the w/c ratio from 0.40 to 0.45 increased the compressive strength of all mixes. Either those containing 0.8 % naphthalene super plasticizer or the control mixes. While decreasing the w/c ratio from 0.45 to 0.40 increased the compressive strength of all mixes. Either those containing 1.6 % naphthalene sulphonate super plasticizer. the use of (1.6 %) sulphonated naphthalene super plasticizer (NSP) with 0.4 w/c ratio reached a gain in strength equivalent to the use of (0.8 %) polycarboxylic super plasticizer (PSP) for mix containing 3 % nano silica . the use of (1.6 %) naphthalene super plasticizer (NSP) with 0.45 w/c ratio reached a gain in strength equivalent to the use of (0.8 %) polycarboxylic super plasticizer (PSP) for mix containing 2 % nano silica. Keywords: Nano silica, concrete, plasticizers, workability, strength
Impact Factors on Subcontractor's Cash Flow Management
Objective: This study aims to define how to maintain and protect the subcontractor firms' cash flow from economic fluctuation through legally sustainable solutions. Methods/Analysis: We conducted a case study in the Eastern Delta Region of Egypt. A questionnaire containing a list of 22 impact factors on subcontractors' cash flow was distributed across multiple subcontractor firms with an 82% response rate. It was designed to explore the factors causing cash flow instability and analyze them using SPSS statistics. Findings: The study finds that inflation, late payments, non-compensation for late payments, poor subcontractor cash flow management, subcontractor firms' inclination to avoid disputes, material price fluctuation, and non-compensation terms, as well as suppliers rejection of payment delays, are the most critical factors of subcontractor cash flow problems. Novelty/Improvement:The study suggests adding three sub-articles to Article 57 in "Tender Law" as legally sustainable solutions to protect and maintain the firm's growth rate from inflation, late payment, and the inclination to avoid disputes. Also, the study recommends that the owner ensure that cash is available before procuring the general contractors, as stated in Egyptian Law 182 of 2018. This study will contribute to establishing a sustainable win-win relationship between subcontractors and general contractors. Doi: 10.28991/CEJ-SP2023-09-08 Full Text: PD
Molecular markers as a prognostic system for hepatocellular carcinoma
AbstractThe gene expression profile p16, c-erbB-3 and bcl2 in hepatocellular carcinoma (HCC) patients with and without associated HCV infection, was assessed. Forty-eight subjects were included in the study and divided equally into two groups: HCC with and without HCV associated infection. Adjacent paracancerous tissues were assessed as control samples. Correlations with various clinico-pathological parameters of the tumour were assessed: stage, grade, and tumour size. The c-erbB-3 oncogene was expressed in 83.33% (40/48) of the total HCC sample and in 31.25% (15/48) of the noncancerous lesions. C-erbB-3 was expressed in 87.5% (21/24) of the HCC cases with associated HCV infection and in 79.16% (19/24) of the HCC cases without associated HCV infection. Gene expression of c-erbB-3 was significantly correlated with the clinico-pathological parameters of the tumour. P16 gene expression was found in 12.5% (6/48) of the total HCC sample and in 25% (12/48) of the para-cancerous lesions. P16 was expressed in 12.5% (3/24) of HCC cases with and without associated HCV infection. Gene expression of p16 exhibited significant negative correlation with clinico-pathological parameters of the tumour. Bcl2 gene expression was found in 20.8% (10/48) of the total HCC sample and in the para-cancerous lesions. Bcl2 was expressed in 20.8% (5/24) of the HCC cases with and without HCV associated infection. Gene expression of bcl2 did not show significant correlations with the clinico-pathological parameters of the tumour. In conclusion, gene expression profiles of p16 and c-erbB-3 could be used as prognostic molecular markers in HCC
Cross-sectional evaluation of the Bronchitis Severity Score in Egyptian children: A move to reduce antibiotics
Background. Despite evidence of limited benefit of antibiotics in acute bronchitis, most paediatric patients are prescribed them.Objectives. To assess the validity of the Bronchitis Severity Score (BSS) in assessing the clinical response to treatment of acute bronchitis, and determine whether clinical data and basic laboratory measurements can be used to guide antibiotic prescription.Methods. We enrolled 200 patients (age range 6 months - 12 years) with clinically diagnosed acute bronchitis. They were divided into three groups according to age. All patients were evaluated three times during the bronchitis episode (days 0, 5 and 7). The primary outcome measurement was the change in the BSS from day 0 to day 7.Results. On the initial visit, the mean (standard deviation (SD)) BSS was 8.36 (2.6), indicating moderate severity of bronchitis. The mean BSS decreased to 4.03 (2.3) on day 5 and to 2.36 (1.45) on day 7. Initial blood tests showed anaemia (80%), leucocytosis (6%), bandaemia (3%) and lymphocytosis (52%). Only four patients were positive for C-reactive protein, while the erythrocyte sedimentation rate was elevated in 98% of cases. There were significant correlations between bandaemia, fever grade (p<0.001) and white blood cell count with clinical variables such as the presence of secretions on chest auscultation (p<0.05) and toxic facies on general examination (p<0.05).Conclusions. Acute bronchitis in children is a self-limiting disease that does not require routine administration of antibiotics. The BSS is a simple and practical clinical scoring system that is useful in evaluating disease severity and monitoring disease resolution in acute bronchitis
Flexural Behavior of Unbounded Pre-stressed Beams Modified With Carbon Nanotubes under Elevated Temperature
Since fire is one of the common reasons for rehabilitation and reconstructions during the service life of a building, it is necessary to assess the elements structural and technical conditions. The objective of the present paper is to investigate the flexural behavior in bending for unbounded full pre-stressed beams with and without the incorporation of carbon nanotubes (CNTs) under the exposure to elevated temperature in comparison with non-pre-stressed beams. The test Method was divided into two major stages where the principal stage’s goal was considering the flexural behavior of fully and non-prestressed concrete beams containing CNT of 0 and 0.04% as cement replacement at ambient temperature. In the second stage, a typical group of beams was prepared and the flexural behavior was explored under the exposure to temperature of 400ºC, for 120 minutes. The major findings upon monitoring the failure mechanisms, ultimate load capacity, and deflection at critical sections, was that the CNT had shown a significant impact on the behavior and extreme resistance of fully and non-prestressed normal concrete. With CNT beams also exhibited higher imperviousness to high-temperature than that of the normal beams. Finally the significant Improvement was that the ultimate load of the non-pre-stressed beam with the presence of the CNT at the lower 50mm in the tension zone showed a gain of 13%, while the ultimate load of the fully pre-stressed beam with the presence of the CNT at the lower 50mm in the tension zone showed a gain of 21% as compared to the same beam without CNT, respectively. For the non-pre-stressed beams, the load capacity of the beam with CNT after exposure had a similar load capacity as the beam without CNT before exposure to high temperature
Modeling and Measurements of Novel Monolithic Filters
This paper presents novel multilayer tuneable high Q-filters based on hairpin resonators including ferroelectric materials. This configuration allows the miniaturization of these filters to a size that makes them suitable for chip and package integration and narrow-band applications. The main focus was miniaturizing filters with coupled loops using multilayer dielectric substrates. A further goal was to increase the quality factor of these distributed filters by embedding high dielectric materials in a multilayer high- and low-k (dielectric constant) substrate that is supported by LTCC technology. An improved W-shape bandpass filter was proposed with a wide stopband and approximately 5% bandwidth
Neural network identification and control of a parametrically excited structural dynamic model of an F-15 tail section,
We investigated the design of a neural-network-based adaptive control system for a smart structural dynamic model of the twin tails of an F-15 tail section. A neural network controller was developed and tested in computer simulation for active vibration suppression of the model subjected to parametric excitation. First, an emulator neural network was trained to represent the structure to be controlled and thus used in predicting the future responses of the model. Second, a neurocontroller to determine the necessary control action on the structure was developed. The control was implemented through the application of a smart material actuator. A strain gauge sensor was assumed to be on each tail. Results from computer-simulation studies have shown great promise for control of the vibration of the twin tails under parametric excitation using artificial neural networks
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