Nonvolatile memory with molecule-engineered tunneling barriers

We report a novel field-sensitive tunneling barrier by embedding C60 in SiO2 for nonvolatile memory applications. C60 is a better choice than ultra-small nanocrystals due to its monodispersion. Moreover, C60 provides accessible energy levels to prompt resonant tunneling through SiO2 at high fields. However, this process is quenched at low fields due to HOMO-LUMO gap and large charging energy of C60. Furthermore, we demonstrate an improvement of more than an order of magnitude in retention to program/erase time ratio for a metal nanocrystal memory. This shows promise of engineering tunnel dielectrics by integrating molecules in the future hybrid molecular-silicon electronics.Comment: to appear in Applied Physics Letter

Soluble Fas might serve as a diagnostic tool for gastric adenocarcinoma

<p>Abstract</p> <p>Background</p> <p>Fas (Apo-1/CD95) and its specific ligand (FasL) are key elements in apoptosis. They have been studied in different malignancies but there are few published studies about the soluble forms of these markers (i.e. sFas/sFasL) in gastric cancer. We have compared the serum levels of sFas/sFasL in gastric adenocarcinoma patients and cases with pre-neoplastic lesions as potential markers for early diagnosis, and investigated their relation with clinicopathological characteristics.</p> <p>Methods</p> <p>Fifty-nine newly-diagnosed cases of gastric adenocarcinoma who had undergone gastrectomy, along with 62 endoscopically- and histologically-confirmed non-cancer individuals were enrolled in this study. sFas/sFasL serum levels were detected by Enzyme Linked Immunosurbent Assay.</p> <p>Results</p> <p>Mean serum sFas level was significantly higher in gastric cancer patients than in control group (305.97 ± 63.71 (pg/ml) vs. 92.98 ± 4.95 (pg/ml), P < 0.001); while the mean serum level of sFasL was lower in patients with gastric adenocarcinoma (0.138 ± 0.04 (pg/ml) vs. 0.150 ± 0.02 (pg/ml), P < 0.001). Mean serum levels of sFas/sFasL were significantly different in both intestinal/diffuse and cardiac/non-cardiac subtypes when compared to the control group (P < 0.001). There was an increase in the serum level of sFas from the first steps of pre-neoplastic lesions to gastric adenocarcinoma (P < 0.001). Patients who had no lymph node involvement (<it>N₀</it>) showed significantly higher serum levels of sFas compared to others (P = 0.044).</p> <p>Conclusions</p> <p>Production of sFas may play a critical role in the carcinogenesis of intestinal-type gastric cancer. sFas serum level may serve as a non-invasive tool for early diagnosis of gastric cancer.</p

Meta-analysis of the prevalence of helicobacter pylori infection among children and adults of Iran

Helicobacter pylori infection is a common health problem related to many gastrointestinal disorders. This study aims to estimate the total and age specific prevalence of Helicobacter Pylori infection in Iran. We systematically reviewed all national and international databases and finally identified 21 studies were eligible for meta-analysis. Each of them were assigned a quality score using STROBE checklist. Due to significant heterogeneity of the results, random effects model was used to estimate the pooled prevalence and 95% confidence interval of Helicobacter Pylori infection. All statistical analyses were performed using STATA. V11 software. The pooled prevalence (95% confidence interval) of Helicobacter Pylori infection among all population, children and adults were estimated as 54% (53%- 55%), 42% (41%- 44%) and 62% (61%- 64%) respectively. Helicobacter Pylori, has infected more than half of Iranian people during the last decade. Preventive strategies as well as taking into account this infection during clinical visits should be emphasized to reduce its transmission and prevalence within the community

Empowering teachers to screen, guide, and refer schoolchildren with behavioral and mental health problems. A pilot study to promote mental health in Iran

Background Schools are ideal for promoting the mental health of school-age children, but the teachers' current knowledge is insufficient to play an influential role in mental health services at schools. Fortunately, however, teachers have a high sense of responsibility, interest, and talent to receive knowledge and the ability to participate in this field. This study aimed to examine whether a protocol focused on the role of teachers could identify, guide, and care for school-age children with behavioral and mental health problems. Method The current research was a “before and after” pilot quasi-experimental study conducted in three elementary, secondary, and high schools. The main intervention consisted of a 5-h workshop based on a ready-to-use booklet for teachers conducted separately in each school. A total of 58 teachers and 872 school-age children were included using a judgmental sampling technique. Results The pre-and post-workshop mean scores of teachers' knowledge about common mental disorders in school-age children were 6.21 ± 4.58 and 12.50 ± 7.27, respectively. According to the Strengths and Difficulties Questionnaire (SDQ), the teachers made 127 referrals, of whom 102 school-age children had problems. Consultants diagnosed 114 school children who reflected 90% of all teachers' recommendations needing psychological care and counseling. Finally, only 50 diagnosed school-age children were followed up and attended therapy sessions at counseling centers. The sensitivity and specificity of this brief intervention in detecting school-age children with psychological problems were respectively 80.3 and 98.0%. Conclusions This study's results support teacher empowerment training's effectiveness in identifying and guiding school-age children needing mental health care. Psychological counseling programs in schools in various quantitative and qualitative dimensions, including responding to school-age children's needs and psychological problems, should be adequately evaluated, and appropriate measures should be taken to promote mental health services. Collaboration between health systems and the education department will increase the effectiveness of mental health programs' promotion and drug abuse prevention. These pilot data lead the way to designing scientifically sound follow-up studies that will concretely ascertain the benefit of this program

Democracy without capitalism: retheorizing Iran's constitutional revolution

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