Synthesis, characterization and evaluation of new alternative ruthenium complex for dye sensitized solar cells.

For first time, new innovative ruthenium N3-Dye anchored with selenium (Se) and N3 dye anchored with sulphur atoms were synthesized in a good yield. Dyes are applied and evaluated in performance of dye sensitized solar cell. N3-Se dye showed superior photochemical& electrochemical behavior and high rate electron transfer across anode surface than N3-S dye. The better optical and electrochemical activities would make Se-dye a candidate for applications in solar cells. Half life time of N3-S showed a single exponential decay with an average lifetime of 0.8 ns. For N3-Se dye, decay curve was fitted by sum two exponential functions with 75% and 25% counts have 2.5 ns and 30 ns respectively. Solar cells were fabricated and analyzed to determine their solar-to-electric conversion efficiency under standard AM 1.5 sunlight. Commercial N3 dyes showed current density (Jsc) of 17.813 mA cm-2, open circuit potential (Voc) of 0.678 V, filling factor (FF) of 0.607 and conversion efficiencies (η) of 7.3%. Corresponding values for N3-S dye, Jsc 11.2 mA cm-2, Voc 0.650 V, FF 0.681 and η 5%. Se-N3 dye, showed Jsc = 6.670 mA cm-2, Voc = 0.6004 V, FF = 0.77 and η = 3.09%. Long lifetime of N3-Se caused low practical performance.

COVID-19 parent stress in Middle Eastern and North African countries: Relations to family adjustment.

The COVID-19 pandemic has been stressful for individuals worldwide, including parents. Most research investigating stress during the pandemic has focused on single stressors in relation to outcomes and has been conducted in Western countries. Among parents from Middle Eastern and North African (MENA) countries, the present study used latent class analysis to identify specific subgroups of individuals based on combinations of stressful events experienced during the first two waves of the COVID-19 global pandemic. Whether individuals in these classes differed on levels of both adaptive (individual resilience, family cohesion) and maladaptive outcomes (depressive symptoms) was tested. Finally, perceived marital satisfaction was tested as a moderator of relations between class membership and adjustment outcomes. Participants were 545 parents (66.8% women, Mage = 35.79 years) recruited online who indicated presence or absence of experiencing 21 stressors across domains such as a family member contracting COVID, increased caregiving burden, work-related stress, and child adjustment problems. Three latent classes were identified, with one group characterized by work and child adjustment stress, one by child adjustment stress only, and one by low levels of stress across domains. The two higher stress groups reported increased depression. No associations with positive outcomes were found. Martial quality was most important for impacting greater resilience for those individuals experiencing child adjustment stress. This study provides evidence that COVID-related stress had disproportionate impact across parents in MENA countries. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Structural and Magnetic Properties of Transition-Metal-Doped Zn 1-x Fe x O.

The ability to produce high-quality single-phase diluted magnetic semiconductors (DMS) is the driving factor to study DMS for spintronics applications. Fe-doped ZnO was synthesized by using a low-temperature co-precipitation technique producing Zn 1-x Fe x O nanoparticles (x= 0, 0.02, 0.04, 0.06, 0.08, and 0.1). Structural, Raman, density functional calculations, and magnetic studies have been carried out in studying the electronic structure and magnetic properties of Fe-doped ZnO. The results show that Fe atoms are substituted by Zn ions successfully. Due to the small ionic radius of Fe ions compared to that of a Zn ions, the crystal size decreases with an increasing dopant concentration. First-principle calculations indicate that the charge state of iron is Fe (2+) and Fe (3+) with a zinc vacancy or an interstitial oxygen anion, respectively. The calculations predict that the exchange interaction between transition metal ions can switch from the antiferromagnetic coupling into its quasi-degenerate ferromagnetic coupling by external perturbations. This is further supported and explains the observed ferromagnetic bahaviour at magnetic measurements. Magnetic measurements reveal that decreasing particle size increases the ferromagnetism volume fraction. Furthermore, introducing Fe into ZnO induces a strong magnetic moment without any distortion in the geometrical symmetry; it also reveals the ferromagnetic coupling.

Frequency of Helicobacter pylori infection in dyspeptic patients in Libya.

OBJECTIVE: Helicobacter pylori infection is a very common infection worldwide particularly in the developing countries. The organism plays an important role in peptic ulcer diseases. The aim of the study was to detect and correlate the prevalence of Helicobacter pylori with such diseases and to evaluate the histopathological grading of gastritis. METHODS: One hundred thirty two patients of 15-83 years of age (average 38) attending the endoscopy unit at the El-Jamahiria Hospital, Binghazi, Libya, mainly complaining from epigastric pain were randomly selected. Three antral biopsies for rapid urease test, direct smear stain and histology together with serum samples were obtained from each patient. Grading of gastritis and the presence of Helicobacter pylori was scored according to the Sydney system. RESULTS: Patients were considered infected when 2 of the biopsy-based tests were positive. Helicobacter pylori was detected in 108 (82%) of 132 patients examined (86% by rapid urease test, 77% by direct smear stain, 95% by histology). The endoscopic findings revealed that 77 (77%) of 100 patients with non-ulcer dyspepsia, 26 (96%) of 27 with duodenal ulcer, 4 (100%) of 4 with gastric ulcer and in one patient with gastric cancer were Helicobacter pylori positive. The enzyme-linked immunosorbent assay test showed 94% sensitivity and 88% specificity. Histopathological sections from the majority of duodenal ulcer and gastric ulcer patients revealed higher grade (II and III) of gastritis than non-ulcer dyspepsia patients. CONCLUSION: Helicobacter pylori infection is significantly correlated with peptic ulcer diseases than with non-ulcer dyspepsia. Patients with duodenal ulcer and gastric ulcer had a significantly higher grade of gastritis than patients with non-ulcer dyspepsia.

[Molar pregnancy. Retrospective study of 60 cases in Tunisia]. / Les grossesses môlaires. Etude rétrospective de 60 cas en Tunisie.

To identify the epidemiologic, clinical end therapeutic particularities of molar pregnancies in Tunisia. A retrospective study of 60 cases of molar pregnancy Diagnosis of MP was base on elevated urine HCG level and/or histologic examination of uterine revision done for all patients. The incidence of MP is 1/793(60/47624) pregnancies. The mean age of patients was 31.7 years and 16 patients had more than 35 years. The metrorragia is the main symptom (91.6%). Excessive uterine enlargement and lutein ovarian cysts were observed respectively in 57 and 6.6% of cases. Human chorionic gonadotropin level was upper than 50,000 UI/l in 91.4% of cases. Ultrasonography contributed to diagnosis in 82.8% of cases. Histological findings were complete molar in 33 cases and partial molar in 27 cases. 6 of 33 patients having complete molar developed persistent gestational trophoblastic tumor. Actinomycin D induced complete remission in all cases. Molar pregnancy is a relatively common disease in Tunisia. Careful and reliable human chorionic gonadotropin monitoring is essential for the early detection of post molar persistent gestational trophoblastic tumor.