[Comparative evaluation of the effect of CPP-ACP and resin infiltration on brown spot color parameters after using 20% carbamide peroxide]

Tooth colored restorations are the commonly used current approach for aesthetic problems associated with brown spots. Considering the importance of conservative dentistry, the aim of this in vitro study was to evaluate the efficacy of color correction using casein phophopeptide amorphous calcium phosphate [CPP-ACP] and resin infiltration after using 20% carbamide peroxide for brown spots in esthetic areas. In this experimental study, 70 humans teeth samples with brown spots were collected. In the first step, 20% carbamide peroxide was applied and then samples were divided into two groups to be treated with CPP-ACP or resin infiltration. Color parameters of the samples were evaluated at baseline, after bleaching, after using infiltration resin and CPP-ACP. Any color shift was measured using spectrophotometer. The results were analyzed by SPSS version 20. For statistical analysis, paired t test, indeipendent t-test and repeated measures ANOVA were used. P value <0.05 was considered significant. After using 20% carbamide peroxide, L[asterisk] and b[asterisk] increased and a [asterisk] decreased significantly [p<0.001]. By using CPP-ACP, decreases in a [asterisk] and b[asterisk] were not significant [p>0.05] but L[asterisk] increased significantly [p<0.001]. Application of infiltration resin caused a significant decrease in a [asterisk] [p<0.001]; however, the decrease in L[asterisk] and the increase in b[asterisk] were not statistically significant [p>0.05]. Comparison of the two groups showed that the degree of color shift [delta E] in brown spots and adjacent sound enamel did not change significantly in the two subgroups [p>0.05]. The results show that for esthetically unfavorable brown spots, using 20% carbamide peroxide with CPP-ACP or resin infiltration can improve the appearance. In general, application of resin infiltration with carbamide peroxide is preferably recommended for improving translucency

Antimicrobial resistance pattern of Gram-negative bacteria of nosocomial origin at a teaching hospital in the Islamic Republic of Iran

The emergence of antimicrobial resistance is a global problem in the community and in hospitals. Antibiotic resistance of Gram-negative bacteria from nosocomial infections were evaluated during a 6-month period at Shariati teaching hospital, Tehran, Islamic Republic of Iran. Susceptibility tests were performed on 570 Gram-negative isolates obtained from clinical samples of patients infected after at least 72 hours stay in the hospital. Escherichia coli was the most frequently isolated Gram-negative organism [42.6%]. The highest rate of resistance in Gram-negative isolates was seen in the intensive care unit, with Acinetobacter spp. as the most resistant organisms. Gentamicin was the most effective antibiotic against E. coli and all other isolates, while ciprofloxacin was also effective against a wide range of other species. Antibiotic resistant Gram-negative nosocomial infection is prevalent in this teaching hospital in Tehran

Genetic heterogeneity among Leishmania major isolates in Iran determined by restriction fragment length polymorphism [RFLP] and multilocus microsatellite typing [MLMT]

In recent years, molecular methods for characterizing genetic heterogeneity have found a major place in modern approaches. In this study, two different molecular techniques including Restriction Fragment Length Polymorphism [RFLP] and Multi Locus microsatellite typing [MLMT] were carried out in order to evaluate genetic heterogeneity among isolates of Leishmania major in Iran. In this experimental study, 24 Lmajor isolates from different endemic foci of cutaneous leishmaniasis were evaluated. All samples were amplified by specific primers for Internal Transcribed Spacer ribosomal RNA [ITS_rRNA] and miniexon genes [ME]. Ten different microsatellite markers were applied to 24 collected isolates as well. Restriction fragment length polymorphism of Polymerase chain reaction of ITS-rRNA and ME regions was identified in polyacrylamide gel electrophoresis. Size polymorphisms in PCR products of microsatellites markers were measured in the CEQ 8000 automated genetic analysis system. Population structure of the isolates was investigated by Structure Version 2.3.2 software. According to ITS- RFLP and ME-RFLP techniques, three and two different strains of Lmajor were determined, respectively, while microsattellites markers revealed 21 different genotypes, which were clustered in three genetic groups using structure software. Although genetic heterogeneity among studied L. major isolates was identified by molecular tools as used in this study, it seems that microsatellites markers are more useful in population structure and epidemiological studies. Our findings also showed correlation between different identified strains and their geographical regions

Micro-shear bond strength of a nanofiller bonding with and without thermocyding in a newly invented device

Estimation of the survival of dental materials is especially important when manufacturing new materials. Thermocycling can greatly help in this respect. The purpose of this study was to evaluate micro-shear bond strength of a nanofiller bonding with and without thermocycling in a newly invented device. In this experimental study, human third molars were sectioned into 1.5 mm slices after extraction and disinfection. Clearfil Tri-S nanofiller bond was applied to the dentin part of sections according to the manufacturer's instructions. Clearfil AP-X composite resin was placed over the dentin using tubes with 0.75 mm internal diameter and one mm height and light cured. Specimens were randomly divided into three groups and subjected to thermocycling in a newly invented device for zero, 3000 and 5000 cyclesbetween 5 +/- 2°C and 55 +/- 2°C. Micro-shear bond strength was measured by microtensile tester with a cross-head speed of 0.5 mm/min. Obtained data were analyzed using one-way ANOVA. Tukey's test was used for multiple comparisons with a 95% confidence interval. The mean micro-shear bond strength after zero, 3000 and 5000 thermal cycles was found to be 19.27 +/- 4,56, 17.00 +/- 6.52 and 11.58 +/- 4.64 MPa, respectively. The reduction in bond strength between zero and 3000 thermal cycles was not statistically significant [P=0.3] but this reduction between zero and 5000, as well as 3000 and 5000 cycles was statistically significant [P0.002 and P0.03, respectively]. Increase in number of thermal cycles for more than 3000 reduces the micro-shear bond strength of Tri-S bonding agent

Comparison between different models for rheological characterization of activated sludge

Activated sludge flow rheology is a very complicated phenomenon. Studies related to activated sludge tend to classify sludge as non-Newtonian fluid. Until now, several theories have been built to describe the complex behavior of activated sludge with varying degrees of success. In this article, seven different models for viscosity of non-Newtonian fluids [i.e., Power law, Bingham plastic, Herschel-Bulkley, Casson, Sisko, Carreau and Cross] were considered to evaluate their predictive capability of apparent viscosity of activated sludge. Results showed that although evaluating the constants in the four-parameter models is difficult, they provide the best prediction of viscosity in the whole range of shear rates for activated sludge. For easier prediction of viscosity at different mixed liquor suspended solids [2.74-31g/L], temperature [15-25°C] and shear rate [1-1000/s], simple correlations were proposed. Comparing the results with the experimental data revealed that the proposed correlations are in good agreement with real apparent viscosities

Nursing and midwifery students' perceptions of the characteristics of an effective clinical teacher

Background and Purpose: Clinical teaching is a vital element in Nursing and Midwifery education, and one of the best sources of clinical teacher evaluation is the students' perceptions. This study was conducted to investigate the characteristics of an effective clinical teacher from the perspective of Nursing and Midwifery Students at Sabzevar University of medical Sciences

Methods and Materials: This cross-sectional descriptive study was conducted at Sabzevar University of medical Sciences in 2007-2008, and involved 120 participants who were recruited by convenient sampling. A researcher-made questionnaire was used for data collection, which contained questions on professional competency, communication with students, and personal characteristics. Items values ranged from zero to five. Frequency, mean and standard deviation, independent t-test and Pearson correlation coefficient were used for data analysis was done in SPSS 11.5

Results: Mean score of professional competency was 4 +/- 0.5; students' perceptions of professional competency became more positive as their education approached higher semesters [r=0.22, p=0.016]. Also, Mean score of professional competency was higher than the mean of communication with students [3.8 +/- 0.6], and personal characteristics [3.7 +/- 0.6]

Concluson: Students experiencing clinical training considered professional competency, knowledge, and the capability of transferring it to them as more important than their ability to communicate

[Zinc plasma level in patient with human immunodeficiency virus infection that come to high risk behavior consult center or admit in infectious disease ward in Imam Khomeini Hospital and compare to HIV negative group in 2005]

Background: zinc is one of the essential micronutrients and its role in immune system function is an interesting matter for researchers. HIV/AIDS as an immune system disorder, presents with impairing in elements of immune system. This study was designed for assessment of zinc level of serum in a group of HIV+ patients and compare with non-HIV people. Determining relationship between zinc level of serum and count of immune cells was another aim of this study

Materials and Methods: this cross-sectional study was conducted with 96 people in 2 groups: 48 HIV+ and 48 HIV-. HIV negative group was divided in 2 subgroups: IV Drug Users (IDUs) and non- IDUs. Zinc level of serum was measured with atomic absorption method and statistical analysis was conducted with SPSS for Windows. Levels of zinc were compared in different groups

Results: overall means of main groups had significant differences, and HIV+ group showed a significant difference with 2 other groups too. In addition, 2 groups of HIV- had significant difference. There was a relationship between count of CD4 cells and zinc level of serum. Zinc showed lowest level in HIV+ IDUs, then HIV- IDUs and finally HIV- non-IDUs

Conclusions: the results demonstrate zinc level impairment in HIV+ cases and its association with decrease in determinant parameters of survival such as count of CD4 cells

Steady-state pharmacokinetic analysis of vancomycin in Iranian pediatric patients

Large inter-individual variability has been reported for vancomycin pharmacokinetics in pediatric patients. On the other hand, the pharmacokinetic parameters of vancomycin should be known in order to individualize its dosage regimen. Therefore, this study was designed and conducted to assess the steady-state vancomycin serum concentration and pharmacokinetics in a population of Iranian pediatric patients. Vancomycin serum concentration at steady-state was determined in 62 children who were treated with vancomycin intermittent intravenous infusion. Also individual steady-steady pharmacokinetic parameters [total body clearance, apparent volume of distribution and elimination half-life] were determined in 30 patients who had both peak and trough vancomycin levels assuming one-compartment model. Calculated pharmacokinetic parameters were compared among patients with different underlying diseases and also with the results of similar studies that used one-compartment pharmacokinetic model for description of serum concentration of vancomycin at steady-state. More than half of the measured vancomycin serum concentrations were outside the recommended therapeutic range. Median trough concentration was significantly lower in critically ill patients as compared to patients of other disease categories. Although critically care patients showed greater values of apparent volume of distribution and also vancomycin clearance, no statistically significant difference of the calculated pharmacokinetic parameters could be detected among different groups of patients. While calculated volume of distribution for patients of this study was greater than those of similar studies, this difference could not be considered statistically significant in the majority of disease categories. It may be concluded that design of vancomycin dosage regimens according to the recommended and general guidelines in literature [e.g. based on patient creatinine clearance] could not result in the desired therapeutic serum concentrations in the study population

[Zinc plasma level in patient with human immunodeficiency virus infection that come to high risk behavior consult center or admit in infectious disease ward in Imam Khomeini hospital and compare to HIV negative group in 2005]

Zinc is one of the essential micronutrients and its role in immune system function is an interesting matter for researchers. HIV/AIDS as an immune system disorder, presents with impairing in elements of immune system. This study was designed for assessment of zinc level of serum in a group of HIV[+] patients and compare with non-HIV people. Determining relationship between zinc level of serum and count of immune cells was another aim of this study. This cross-sectional study was conducted with 96 people in 2 groups: 48 HIV[+] and 48 HIV[-]. HIV negative group was divided in 2 subgroups: IV Drug Users [IDUs] and non- IDUs. Zinc level of serum was measured with atomic absorption method and statistical analysis was conducted with SPSS for Windows. Levels of zinc were compared in different groups. Overall means of main groups had significant differences, and HIV[+] group showed a significant difference with 2 other groups too. In addition, 2 groups of HIV[-] had significant difference. There was a relationship between count of CD4 cells and zinc level of serum. Zinc showed lowest level in HIV[+] IDUs, then HIV[-] IDUs and finally HIV[-] non-IDUs. The results demonstrate zinc level impairment in HIV[+] cases and its association with decrease in determinant parameters of survival such as count of CD4 cells

effect of seated crossed-leg position on the reading of blood pressure in patients with hypertension

Background and Purpose: One probable sources of error blood pressure measurement can be the cross-leg seating position but research findings in this regard are contradictory. Therefore, the present study was designed to investigate the effect of crossing legs while measuring the blood pressure on the reading of blood pressure in patients with hypertension

Methods and Materials: The quasi- experimental study involved 90 patients selected through purposive sampling from among the population of patients with primary hypertension admitted to Internal and Cardiac Clinics of Vase'ee Hospital in Sabzevar, Iran. Patients, blood pressure was measured according to a written protocol in three steps: first sitting with both feet straight on the floor, then sitting with crossed legs, and finally sitting with both feet straight on the floor [as in the first step]. Conventional stethoscope and sphygmomanometer were used for measurements; t- test was used for data analysis in SPSS

Results: Crossing legs while measuring blood pressure

increased systolic bp by 6.81 mmHg [from 144.43 +/- 21.782 to 156.24 +/- 22.082] and diastolic bp by 3.12 mmHg [from 89.06 +/- 13.610 to 92.18 +/- 14.920]. Mean systolic bp when the third step of the protocol was adopted reduced 9.59 mmHg [from 156 +/- 22.082 to 146.66 +/- 22.438] and diastolic bp reduced by 3.53 mmHg [from 92.18 +/- 14.920 to 88.64 +/- 14.839]

Conclusion: According to the findings, blood pressure reading increases in patients with hypertension when they take a seated cross-leg position during bp measurement

Comparison of critical thinking skills in students of nursing in continuous and interrupted BS sections of Semnan University of Medical Sciences

Critical thinking is a cognitive activity for the purpose of perception and evaluation of findings and phenomena on the basis of skills such as reasoning and analysis. In Iran the students of nursing may achieve their BS degree in two forms of continuous and interrupted. As the students of continuous and interrupted BS in nursing are regarded as a BS degree holder in nursing after their graduation, and the society expects a same level of critical thinking skills from both of the groups, we decided to compare the level of critical thinking skills in the students of continuous and discontinuous BS in nursing in Semnan university of medical sciences. This study is a comparative study to compare the level of critical thinking skills in students of continuous and interrupted BS of nursing in Semnan University of Medical Sciences. The sample volume includes all the students of continuous Bs in nursing from juniors to seniors [N = 70] and the students of interrupted BS in nursing who where passing their first or second years of study during the first semester of year 2000-2001. The tool used in this study is California test of critical thinking skills, form B that contains 34 multiple-choice questions with one true answer in five aspects' of cognitive skills of critical thinking [analysis, evaluation, inference, deductive and inductive reasoning]. All of the subjects' completed the above mentioned test which has been validated by the second author in another study before hand. Data were analyzed by software SPSS WIN and also ANOVA and t statistical tests. Mean scores of continuous Bs students and interrupted ones were 12.34 with SD = 2.45 and 11.27 with SD = 3.10 respectively and the difference between the mean scores of the two groups was statistically significant. [t = 1.76, p = 0.005], There was a meaningful difference between the mean scores of the students of different years in the continuous BS group. [F 3.60 = 4.28, P = 0.000] but the difference between the mean scores of the students of first and second year of interrupted BS in nursing [11.28 and 11.51 respectively,] was not statistically significant. In both groups' there were no significant correlation between the age or sex of the students and their mean score in California critical thinking skills test [CCTST] but there was a positive and significant but week correlation between the average of past terms and the mean score of CCTST. [r = 0.31, p = 0.01]. The results of the study showed that the students of continuous BS level in nursing had a higher level of critical thinking skills than the students of interrupted BS studies. Also in this group the students in advanced years of study own higher level of critical thinking skills than those in lower terms. In other words nursing education and higher education has led to a development of critical thinking skills in students

value of computerised tomography in the diagnosis of orbital lesions

Thirty five consequetive cases with exophthalmous presented to the Neurosurvica Hospital, are discussed. They were investigated primarily by computerised tomography [CT]. The pathology included: orbital haematoma, hydatid cyst, benign tumours, malignant tumours and others. In spite of the usefulness of computerised tomography in investigating orbital pathologies, there are some limitations especially in our country