Time-Resolved Reflection High-Energy Electron Diffraction Study of the Ge(111)-c(2×8)-(1×1) Phase Transition

The dynamics of the Ge(111)-c(2×8)-(1×1) phase transition is investigated by 100-ps time-resolved reflection high-energy electron diffraction. A laser pulse heats the surface while a synchronized electron pulse is used to obtain the surface diffraction pattern. Slow heating shows that the adatoms in Ge(111)-c(2×8) start to disorder at ∼510 K and are converted to a disordered adatom arrangement at 573 K. For heating with 100-ps laser pulses, the Ge(111)-c(2×8) reconstructed adatom arrangement starts to disorder at 584±16K, well above the onset temperature of ∼510 K for the disordering of Ge(111)-c(2×8) observed for slow heating. © 1999 The American Physical Society

Preventive effect of the flavonoid, quercetin, on hepatic cancer in rats via oxidant/antioxidant activity: molecular and histological evidences

<p>Abstract</p> <p>Background</p> <p>The incidence of hepatocellular carcinoma is increasing in many countries. The estimated number of new cases annually is over 500,000, and the yearly incidence comprises between 2.5 and 7% of patients with liver cirrhosis. The incidence varies between different geographic areas, being higher in developing areas; males are predominantly affected, with a 2:3 male/female ratio</p> <p>Methods</p> <p>Experiments were designed to examine the effect of <it>N</it>-Nitrosodiethylamine (NDEA) as cancer-inducer compound and to confirm the preventive effect of the flavonoid quercetin on hepatocellular carcinoma in rats. Briefly, thirty six male albino rats of Wistar strain were divided into 3 groups: the 1^stgroup was administered NDEA alone (NDEA-treated), the 2^ndgroup was treated simultaneously with NDEA and quercetin (NDEA+Q) and the 3^rdgroup was used as control (CON). Randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) as well as <it>p53</it>-specifi PCR assays were employed to determine genomic difference between treated, and control animals. Histological confirmation as well as oxidant/antioxidant status of the liver tissue was done.</p> <p>Results</p> <p>RAPD analysis of liver samples generated 8 monomorphic bands and 22 polymorphic bands in a total of 30-banded RAPD patterns. Cluster analysis and statistical analyses of RAPD data resulted in grouping control and NDEA+Q samples in the same group with 80% similarity cut-off value. NDEA-treated samples were clustered in a separate group. Specific PCR assay for polymorphism of <it>P</it>⁵³gene revealed a uniform pattern of allele separation in both control and NDEA+Q samples. Quercetin anticancer effect was exhibited in significant decrease of oxidative stress and significant decrease of antioxidant activity. Histopathological studies showed normal liver histology of the NDEA+Q samples. Meanwhile, several cancer-induced features were clearly observable in NDEA-treated samples.</p> <p>Conclusion</p> <p>This paper demonstrated that preventive effect of quercetin on hepatocarcinoma in rats by RAPD-PCR, tracing the effect on <it>p53 </it>gene and by histopathological evidence. Hereby, it was proved that quercetin exerted its preventive effect via decreased oxidative stress and decreased antioxidant activity.</p

What predicts word reading in Arabic?

Efficient and accurate word reading ability is critical for later reading success. As such, it is important to understand the component skills that underlie strong word reading ability. Although a growing research base points to the importance of phonological processing, morphological processing and orthographic processing for accurate and fluent word reading in Arabic, there are few studies that examine all three areas at one time to better understand their role in word reading. Additionally, it remains unclear whether the contribution of the various processes might differ across the early years when children are learning to read. 1,098 pupils in grades 1–3 participated in this study and took tests for phonological processing, morphological processing, orthographic processing, and word reading accuracy and fluency. According to the findings of regression analyses, the relative contribution of these underlying processes differed according to the method used to test word reading and the student’s grade level. Regarding accuracy, several subscales of phonological processing and two measures of orthographic processing accounted for significant differences in word reading accuracy for first graders. For second grade students, nonword repetition, elision, and all three measures of orthographic processing accounted for variance. In third grade, elision and memory for digits, word creation and morpheme identification, and letter/sound identification and orthographic fluency were significant predictors of word reading accuracy. In terms of fluency, two subscales of phonological processing, two measures of orthographic processing, and two measures of morphological processing explained significant differences in word reading fluency for first graders. For second grade students, nonword repetition, elision, RAN-digits, isolation, segmenting and all the measures of orthographic processing and word creation explained unique variance in word reading fluency. In third grade, elision, RAN-letters, RAN-digits and phoneme isolation, all measures of orthographic processing and morphological processing, explained variance in word reading fluency. Implications and future directions in research are discussed

Enhance Safety Performance through Quantitative and Qualitative Analysis of Accidents in Egyptian National Railway

Rail transport plays an important role in creating a sustainable future for transport. Safety can be defined as qualitatively or quantitatively to prevent unacceptable risks. Improving safety is the main goal of each railway company as safe operation helps in increasing the level of service offered to the users. This paper deals with quantitative and qualitative analysis of accidents in Egyptian National Railway for annual accidents during the period of 2011 till 2017 for the six zones classified according to causes as absolute values and relative values to determine the worst zones and the most popular causes to improve the safety level and put the corrective plan to minimize the effective of accidents on both economic and safety of the society, to realize this goal a data collections were obtained and traffic fluction were calculated by the use of the official time table in train.km/year for the six zones. The study proposes effective solution for the decision maker to enface this very dangerous problem and improve the economic efficiency of the system, and preserve the environment surrounding the system

Comparative study of the chemical composition and anti-proliferative activities of the aerial parts and roots of Apium graveolens L. (celery) and their biogenic nanoparticles

Apiaceae plants are multipurpose folk remedies and bioactive foods that show a remarkable ability to biosynthesize a large number of secondary metabolites with antitumor and chemopreventive potential. Among the various members of the Apiaceae, celery (Apium graveolens L.) has long been used as a popular edible and medicinal plant owing to its plentiful health benefits and nutraceutical properties; however, the anticancer potential of this important species has been seldom studied, mostly focusing on its seeds. Therefore, this work was designed to delve into the chemical composition and anti-proliferative potential of the total ethanolic extracts of the aerial parts (TEEAGA) and roots (TEEAGR) of A. graveolens var. dulce (Mill.) Pers. as well as their green synthesized silver nanoparticles (AgNPs). In general, both TEEAGA and TEEAGR exhibited moderate to potent inhibitory activities against human liver (HepG-2), colon (Caco-2), and breast (MCF-7) cancer cell lines, with interesting IC50 profiles [(41.37 ± 0.12, 27.65 ± 0.27, and 9.48 ± 0.04 μg/mL) and (11.58 ± 0.02, 7.13 ± 0.03, and 6.58 ± 0.02 μg/mL), respectively] as compared with doxorubicin, while more pronounced anti-proliferative effects were observed for their biogenic AgNPs, which showed IC50 values ranging between 25.41 ± 0.16 and 1.37 ± 0.03 μg/mL. Moreover, HPLC‒HESI‒HRMS-based metabolomics analysis of both extracts showed the presence of a varied group of secondary metabolites, including flavonoids, phenylpropanoids, phthalides, coumarins, and sesquiterpenes that further displayed moderate to promising binding affinities to the active site of cyclin G-associated kinase (GAK), particularly graveobioside A, graveobioside B, and celeroside C, suggesting their possible contribution as GAK modulators to the anti-proliferative potential of celery. These findings can help broaden future research on the utilization of different parts of celery and their NPs as functional foods and medicines in cancer chemoprevention and therapy

Presymptomatic breast cancer in Egypt: role of BRCA1 and BRCA2 tumor suppressor genes mutations detection

<p>Abstract</p> <p>Background</p> <p>Breast cancer is one of the most common diseases affecting women. Inherited susceptibility genes, <it>BRCA1 </it>and <it>BRCA2</it>, are considered in breast, ovarian and other common cancers etiology. <it>BRCA1 </it>and <it>BRCA2 </it>genes have been identified that confer a high degree of breast cancer risk.</p> <p>Objective</p> <p>Our study was performed to identify germline mutations in some exons of <it>BRCA1 </it>and <it>BRCA2 </it>genes for the early detection of presymptomatic breast cancer in females.</p> <p>Methods</p> <p>This study was applied on Egyptian healthy females who first degree relatives to those, with or without a family history, infected with breast cancer. Sixty breast cancer patients, derived from 60 families, were selected for molecular genetic testing of <it>BRCA1 </it>and <it>BRCA2 </it>genes. The study also included 120 healthy first degree female relatives of the patients, either sisters and/or daughters, for early detection of presymptomatic breast cancer mutation carriers. Genomic DNA was extracted from peripheral blood lymphocytes of all the studied subjects. Universal primers were used to amplify four regions of the <it>BRCA1 </it>gene (exons 2,8,13 and 22) and one region (exon 9) of <it>BRCA2 </it>gene using specific PCR. The polymerase chain reaction was carried out. Single strand conformation polymorphism assay and heteroduplex analysis were used to screen for mutations in the studied exons. In addition, DNA sequencing of the normal and mutated exons were performed.</p> <p>Results</p> <p>Mutations in both <it>BRCA1 </it>and <it>BRCA2 </it>genes were detected in 86.7% of the families. Current study indicates that 60% of these families were attributable to <it>BRCA1 </it>mutations, while 26.7% of them were attributable to <it>BRCA2 </it>mutations. Results showed that four mutations were detected in the <it>BRCA1 </it>gene, while one mutation was detected in the <it>BRCA2 </it>gene. Asymptomatic relatives, 80(67%) out of total 120, were mutation carriers.</p> <p>Conclusions</p> <p><it>BRCA1 </it>and <it>BRCA2 </it>genes mutations are responsible for a significant proportion of breast cancer. <it>BRCA </it>mutations were found in individuals with and without family history.</p

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

FBXW7 influences murine intestinal homeostasis and cancer, targeting Notch, Jun, and DEK for degradation

The E3 ubiquitin ligase component FBXW7 modulates homeostasis and inhibits tumorigenesis in the murine intestine