Flow-injection chemiluminescence determination of gentamicin: optimization by central composite design.

A simple and sensitive flow-injection chemiluminescence (CL) method has been developed for the determination of gentamicin sulfate. The method is based on the inhibitory effect of gentamicin on the CL emission accompanying oxidation of luminol by H2 O2 in an alkaline medium in the presence of Cu(II) as a catalyst. Inhibition was caused by the formation of a strong complex between analyte and the catalyst. Experimental variables, including the concentrations of luminol (µmol/L), H2 O2 (mol/L), Cu(II) (mol/L) and NaOH (mol/L), were optimized using a central composite design. Under optimum conditions, the plot of CL intensity versus gentamicin concentration was found to have two linear ranges. One range was at low concentrations from 1.0 to 10.0 mg/L and the other was from 10.0 to 30.0 mg/L. Precision was calculated by analyzing samples containing 5.0 mg/L gentamicin (n = 11) and the relative standard deviation (RSD) was 1.7%. Also, a high injection throughput of 120 samples/h was achieved. This method was successfully applied to the determination of gentamicin sulfate in pharmaceutical formulations and water samples.

Prevalence of stress among Iranian medical students: a questionnaire survey.

A cross-sectional study measured the frequency of self-reported stress symptoms among a weighted random sample of medical students in Isfahan, Islamic Republic of Iran. The data were gathered using the Kessler 10-item psychological distress scale. The overall prevalence of stress among 222 students was 61.3% and there were no statistically significant differences in stress levels between students in the pre-clinical and clinical phases or different years of study. Married students had significantly lower scores than single students but there were no differences between the sexes. Students who chose to study medicine had lower stress scores than those who were influenced by family or had no choice about the subject. Students with mild to moderate stress were significantly more likely to suffer physical problems (OR = 4.42). Interventions are needed to tackle stress and improve Iranian medical students' physical and psychological well-being.

A Paul trap with sectored ring electrodes for experiments with two-dimensional ion crystals.

We have developed a trapped ion system for producing two-dimensional (2D) ion crystals for applications in scalable quantum computing, quantum simulations, and 2D crystal phase transition and defect studies. The trap is a modification of a Paul trap with its ring electrode flattened and split into eight identical sectors and its two endcap electrodes shaped as truncated hollow cones for laser and imaging optics access. All ten trap electrodes can be independently DC-biased to create various aspect ratio trap geometries. We trap and Doppler cool 2D crystals of up to 30 Ba+ ions and demonstrate the tunability of the trapping potential both in the plane of the crystal and in the transverse direction.

Global, Regional, and National Levels and Trends in Burden of Oral Conditions from 1990 to 2017: A Systematic Analysis for the Global Burden of Disease 2017 Study.

Government and nongovernmental organizations need national and global estimates on the descriptive epidemiology of common oral conditions for policy planning and evaluation. The aim of this component of the Global Burden of Disease study was to produce estimates on prevalence, incidence, and years lived with disability for oral conditions from 1990 to 2017 by sex, age, and countries. In addition, this study reports the global socioeconomic pattern in burden of oral conditions by the standard World Bank classification of economies as well as the Global Burden of Disease Socio-demographic Index. The findings show that oral conditions remain a substantial population health challenge. Globally, there were 3.5 billion cases (95% uncertainty interval [95% UI], 3.2 to 3.7 billion) of oral conditions, of which 2.3 billion (95% UI, 2.1 to 2.5 billion) had untreated caries in permanent teeth, 796 million (95% UI, 671 to 930 million) had severe periodontitis, 532 million (95% UI, 443 to 622 million) had untreated caries in deciduous teeth, 267 million (95% UI, 235 to 300 million) had total tooth loss, and 139 million (95% UI, 133 to 146 million) had other oral conditions in 2017. Several patterns emerged when the World Bank's classification of economies and the Socio-demographic Index were used as indicators of economic development. In general, more economically developed countries have the lowest burden of untreated dental caries and severe periodontitis and the highest burden of total tooth loss. The findings offer an opportunity for policy makers to identify successful oral health strategies and strengthen them; introduce and monitor different approaches where oral diseases are increasing; plan integration of oral health in the agenda for prevention of noncommunicable diseases; and estimate the cost of providing universal coverage for dental care.

CuO nanosheets-enhanced flow-injection chemiluminescence system for determination of vancomycin in water, pharmaceutical and human serum.

A novel, rapid and sensitive CuO nanosheets (NSs) amplified flow-injection chemiluminescence (CL) system, luminol-H2O2-CuO nanosheets, was developed for determination of the vancomycin hydrochloride for the first time. It was found that vancomycin could efficiently inhibit the CL intensity of luminol-H2O2-CuO nanosheets system in alkaline medium. Under the optimum conditions, the inhibited CL intensity was linearly proportional to the concentration of vancomycin over the ranges of 0.5-18.0 and 18.0-40.0 mg L(-1), with a detection limit (3σ) of 0.1 mg L(-1). The precision was calculated by analyzing samples containing 5.0 mg L(-1) vancomycin (n=11) and the relative standard deviation (RSD) was 2.8%. Also, a high injection throughput of 120 sample h(-1) was obtained. The CuO nanosheets were synthesized by a sonochemical method. Also, X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were employed to characterize the CuO nanosheets. The method was successfully employed to determine vancomycin hydrochloride in environmental water samples, pharmaceutical formulation and spiked human serum.

Determining nutrients degradation kinetics of chickpea (Cicer arietinum) straw using nylon bag technique in sheep.

Straw a by-product from grain legume crops is produced in large quantities in Iran. Straw is constant component of ruminant diets on small holder farms; however, there is little information about its nutritive value. Accordingly experiment was conducted to determine the chemical composition and ruminal organic matter (OM) and crude protein (CP) degradability of chickpea straw using nylon bags (in situ) technique. Replicated samples were incubated at 0, 2, 4, 8, 12, 24, 48 and 72 hours in three rumen canulated Ghezel rams with 50±3 kg body weight. Dry matter (DM), CP, ether extract (EE), OM, crude fiber (CF) and nitrogen free extract (NFE) content of chickpea straws were 92.2, 6.1, 5.5, 92.0, 34.3 and 46.2%, respectively. The soluble fraction (a) of the OM and CP of chickpea straw was 17.5 and 40.8% and potential degradability (a+b) of OM and CP was 56.7 and 72.0%, respectively. Effective degradability at different passage rates (2, 5 and 8% per hours) for OM was 51.0 44.9 and 40.7% and for CP were 68.4, 64.3 and 61.3%, respectively. In conclusion, based on chemical composition and degradation characteristics, chickpea straw could have moderate nutritive value for ruminants.

The effects of a PRECEDE-based educational program on depression, general health, and quality of life of coronary artery bypass grafting patients.

BACKGROUND: Depression is commonly reported as a consequence of coronary artery bypass grafting surgery. It is the most important barrier to proper treatment of cardiac patients, causing failure in accepting the condition, decreasing the motivation in following the therapeutic recommendations, and negatively affecting the patients' function and quality of life. OBJECTIVE(S): The objective of this study was to investigate the effects of a PRECEDE-based educational program on depression, general health, and quality of life in coronary artery bypass grafting surgery patients. METHODS: The experimental study included 54 post-bypass surgery patients in Isfahan Cardiovascular Research Center. The patients were randomly assigned to intervention and comparison groups (27 patients in each). The data were collected using four questionnaires (Cardiac Depression Scale, General Health Questionnaire-12, SF-36, and a PRCEDE-based questionnaire to measure predisposing, reinforcing, enabling factors, and self-help behaviors). All subjects were pre-tested. The intervention, consisting of nine educational sessions per week (60-90min each) was implemented. The patients were followed for 2 months post-intervention and post-tested at the end of the second month. RESULTS: Following the educational intervention, the mean scores of predisposing factors, enabling factors, reinforcing factors and self-helping behaviors were significantly increased in the intervention group, compared to the comparison group (p<0.001). The mean score for depression in the comparison group (104.5±30.4) and intervention group (112.8±21.9) decreased significantly following educational intervention, but the change was more pronounced in the intervention group compared with the control group (66.2±22 vs. 89.2±27.8). The difference between the two groups on the basis of general health was statistically significant (p<0.0001). Improvements in quality of life on the basis of physical function (p<0.04), role limitations resulting from emotional status (p<0.01), and mental health (p<0.04) were statistically significant. CONCLUSION: The findings of the study confirmed the effectiveness of an educational program based on the PRECEDE Model on decreasing depression level, improving general health, and increasing quality of life in coronary artery bypass grafting surgery patients.

Demographic, clinical features and treatment outcomes in 700 achalasia patients in iran.

BACKGROUND Achalasia is the most recognized motor disorder of the esophagus. Because it is an uncommon disease, most studies have reviewed small numbers of patients. Here, we report demographic, clinical features and treatment outcomes in 700 achalasia patients. METHODS In all patients, diagnosis was established based on clinical, radiological, endoscopic and manometric criteria. A questionnaire was completed for each patient and included the patient's age, gender, initial symptoms, frequency of different symptoms, presence of positive family history for achalasia, other accompanying diseases and treatment outcomes. RESULTS In our study men were affected more than women (54.3% vs. 45.7%). Patients' mean age was about 38 years. The most frequent symptoms noted were: dysphagia to solids and liquids, active regurgitation, passive regurgitation and weight loss, respectively. Women complained of chest pain more than men (59% vs. 47.1%, p=0.04). The vast majority of our patients were treated by pneumatic dilation (PD) of the LES and in long-term follow-up, 67% were in the responder group. Females responded better than males to PD. CONCLUSION Dysphagia to solids is the most common symptom in patients with achalasia. Chest pain was significantly higher among women. PD is an effective treatment for achalasia with long-term efficacy in the majority of patients.