فهرست مطالب مهران کریمی

Flexible sheet explosive is a plastic bonded explosive (PBX) based on hydroxyl-terminated polybutadiene (HTPB), isophorone diisocyanate (IPDI) curing agent, cyclotrimethylenetrinitramine explosive (RDX), dioctyl adipate plasticizer (DOA) and diethylol dimethylhydantoin (DHE) bonding agent. In this research, the effect of polyethylene glycol-600 (PEG-600) chain extender additive compared to DHE bonding agent on some mechanical properties of product such as tensile strength and shore A hardness has been investigated. For this purpose, different formulations containing PEG-600 or DHE additives were prepared and various production conditions including different amounts of additives and the molar ratio of isocyanate to hydroxyl group were optimized and quality of samples were evaluated from the perspective of various mechanical and safety characteristics. Also, the completion of the polyurethane reaction and the presence of excess IPDI were monitored using the attenuated total reflectance infrared spectroscopy (ATR-IR) method. The final results in optimal conditions showed that by using of DHE or PEG-600 in the PBX formulation, the ultimate tensile strength and the yield strength of the material in the presence of two additives are close to each other and at least twice that of PBX without additive. Also, the shore A hardness is also decreases from 39 to 31 and 32, respectively. The additive-free material is a flexible elastomer with more plastic behavior, and by using chain extender or bonding agent, its stress-strain behavior approaches to semi-ductile mode. The results of this research can be used to replace the expensive substance of DHE with cheap, domestically produced PEG-600 polymer in the formulation of flexible sheet explosives.

To evaluate the effect of biofertilizers and nitrogen levels on agronomic traits and nitrogen efficiency indices of corn

This experiment was performed during 2016 and 2017 in the Animal Science Research Farm of Alborz Province as a split plot and in the form of a randomized complete block design with three replications. Experimental factors include nitrogen fertilizer at four levels (0, 50, 100, 200 kg.ha-1) as the main plots and biofertilizer at eight levels (no inoculation, Aztobacter, Mycorrhiza, Azospirillum, Aztobacter + Mycorrhiza, Aztobacter + Azospirillum, Mycorrhiza + Azospirillum, Mycorrhiza + Azotobacter + Azospirillum) as sub-plots were considered.

The results of analysis of variance showed that the interaction effect of nitrogen fertilizers on forage yield was significant. The results showed that increasing nitrogen application to 200 kg.ha-1 increased forage yield. The use of biofertilizers, either alone or in combination in all nitrogen fertilizer applications, increased forage yield. But the combined effect of biofertilizers had the greatest effect. However, the increase in yield was higher at lower levels of nitrogen fertilizer, especially in the control treatment (no nitrogen application). The highest nitrogen agronomical efficiency was observed in the treatment of 50 kg.ha-1 and in this case, the difference between the biofertilizer treatments was more obvious, so that the combined use of biofertilizers had the highest nitrogen agronomical efficiency.

Combined application of biofertilizers with less nitrogen fertilizer (100 kg.ha-1) can improve the nitrogen use efficiency in corn production while achieving acceptable grain and forage yield.

Microbial resistance due to antibiotics overuse can endanger the general health of society. Various factors play a role in mothers' overuse of antibiotics for their children. This study aimed to investigate mothers' attitude and behavior about the use of antibiotics in children under five years old in Yazd City.

In this cross-sectional descriptive study, 302 mothers with children under five years old were included in 2019-2020; a questionnaire of mothers' attitudes and practices regarding antibiotic use was completed. Then, the obtained data were analyzed by SPSS software version 16 and P-value less than 0.05 was considered statistically significant.

The mothers' attitude level was poor, moderate, and good in 60 (20%), 180 (59.5%), and 62 patients (20.5%), respectively. Furthermore, mothers' practice level was poor in 55 (18.2%), moderate in 210 (69.5%) and good in 37 (12.3%). The level of attitude (P = 0.000) and practice (P = 0.007) in mothers with a higher level of education was significantly higher. With increasing the number of children, mothers' attitude (P = 0.03) and practice (P = 0.02) were significantly lower.

The study results showed that most mothers have a moderate level of attitude and practice in using antibiotics in their children. A significant number of them also mentioned antibiotic use without a prescription. Therefore, to reduce the improper use of antibiotics, it is recommended to pay attention to educational programs with proper planning by the public media. It makes sense to train physicians, monitor their performance and closely monitor the sale of antibiotics in pharmacies to reduce their use without a doctor's prescription.

Motor Imagery provides a special context for representation of movements. This feature has been investigated in typical developing children in several studies, but there is little information in the field of motor imagery in children with autism. Therefore, the aim of the present study was to investigate this component in children with autism spectrum disorder aged 8 to 12 years compared to typical developing peers. 40 ASD children and 40 TD children who were age and IQ matched, purposefully and available selected and participated in the research voluntarily. To investigate motor imagery, the hand rotation paradigm in 3D software was used. The task involves two blocks of 12 hand-pattern which rotates randomly three times at six angles. The reaction time and error numbers were recorded as the performance scores of each subject. In order to analyze the data, two analysis of variance tests were used to evaluate and compare the reaction times and the U-man Whitney test used for the number of errors separately for back and palm view of hand. The findings confirmed that children with autism are able to use this feature same TD, although this operation is less accurate and longer. So that in the reaction time and the number of error variables, the ASD group performed worse than TD peers. Although the disorder may effect on cognitive function underlying motor behaviors in these children, nevertheless the capacity required to learn and develop motor skills in these children is developed, usable, and exploitable.

There are significant interactions between motor and cognitive development through life span. Investigation of cognitive processes and behavioral infrastructure is very valuable, so the present study aimed to determine the developmental changes of motor imagery in typical and high functioning autism spectrum disorder children aged 8 to 12 years.

The present study was a semi- quasi one that done in a cross - sectional design. 40 children aged 8 to 10 and 40 children aged 10 to 12 years (in each age group 20 autism spectrum disorder (ASD) and 20 typical development (TD)), who matched in terms of age and IQ, were selected purposefully and accessibly selected and participated in the research voluntarily. To investigate the motor imagery, the hand rotation paradigm was used in the form of 3-D software. After calculating the reaction time and the number of errors related to the medial and lateral stimuli, repeated measures ANOVA used to analyze the reaction time data and the Mann Whitney U test used to analyze the error numbers data. All statistical tests were performed using SPSS software version 21.

The findings showed that the typical development (TD) group decreased its reaction time (P=0.001) and number of errors (P=0.001) by age increasing, which was not seen in the autism spectrum disorder (ASD) group.

It seems that the cognitive and important processes involved in learning and controlling motor skills will not improve by age and will require specialized interventions and coherent programs for this purpose.

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is the most common form of enzymopathy of red blood cells that has affected more than 400 million people worldwide. G6PD deficient erythrocytes show decreased levels of antioxidant capacity and they make one susceptible to chemical induced hemolysis such as drugs and oxidant food ingredients. To this end, antioxidants can play a pivotal role in the prevention of oxidative damage to the erythrocyte membrane in such patients. The present study was conducted with the aim of investigating the impact of Ginkgo biloba in preventing t-BHP-induced hemolysis in G6PD deficient patients.

Twenty-one male G6PD deficient patients all of whom had experienced at least one hemolytic attack were included in the study. To assess the property of Ginkgo biloba extract (EGb) to prevent hemolysis in G6PD deficient erythrocytes, tert-butyl hydroperoxide (t-BHP), an oxidant, was used to induce hemolysis. Different concentrations of EGb (100, 200, 300, 400 µg/ml) were used in this experiment.

Erythrocytes incubated with t-BHP released 30.47±1.61% (mean ± SD) hemoglobin in the supernatant which decreased in the presence of EGb in the concentration dependent manner.  Concentrations of 300 µg/ml and 400 µg/ml EGb showed significant reduction in hemolysis compared to the control group.

Based on the results of this study, we propose that EGb may decrease chemical induced hemolysis and the following complications in G6PD deficient patients. Therefore, it may be possible to recommend Ginkgo supplement to these patients before exposure to oxidant agents.

Epilepsy is regarded as one of the prevalent neurological disorders in children. The role of anti-oxidants in protection of epilepsy has been discussed in several studies. Vitamin E can be mentioned as a natural antioxidant to neutralize free radicals. Therefore, the present study aimed to evaluate the effects of vitamin E on oxidative stress markers such as malone dialdehyde(MDA) and protein carbonyl(PC) in children suffering from idiopathic epilepsy and vitamin D deficiency.
In the current study, children suffering from idiopathic epilepsy and vitamin D deficiency were randomly divided into two groups. One group was treated with 50000 units of vitamin D oral capsules (per week) for 8 weeks and the other group was treated with 100 units of vitamin E (per day) for one month as well as 50000 unit of vitamin D for 8 weeks. The amount of MDA and PC were measured by the spectrophotometer method. The obtained data were analyzed via the SPSS software (ver, 19) using t-test.
The results indicated that the amount of MAD and PC revealed a significant decrease after the treatment. In fact, in the group treated with vitamin E, the amount of PC decreased significantly compared with the other group, though MDA reduction was not proved to be significant.
The findings of the present study revealed that treatment with vitamin E could reduce the PC amount in regard with epileptic patients.

There are many genetic and non-hereditary risk factors that are known to causes venous thromboembolic (VTE) disorders, Cardiovascular diseases and types of cancer. One of these is the Prothrombin G20210A mutation. Prothrombin mutation (guanine to adenine; G→A) at nucleotide position 20210, which is present in the 3′ untranslated region of the prothrombin gene. Prothrombin G20210A mutation is present outside the coding region for prothrombin, and hence it does not affect the actual structure of the prothrombin molecule and it does not affect its function as a strong clotting factor when activated into thrombin. However, several studies have shown that, G20210A heterozygosity was associated with a threefold increased risk for VTE. Moreover, the association of PTH G20210A polymorphisms with cancer has been reported. The present study was designed to determine the frequency of PTH G20210A polymorphism in Southern Iran.

In this cross-sectional study, 140 healthy women were from Southern Iran recruited among participants in Namazi Hospital, Shiraz, Iran, from March 2013 to February 2014. A total of 5 ml of peripheral blood was taken from individuals then Genomic DNA was extracted using blood DNA kit (Ron’s Blood and Cell DNA Mini Kit, BioRon, Germany). The amplification refractory mutation system- polymerase chain reaction (ARMS-PCR) method was used for the detection of PTH G20210A single nucleotide polymorphism in each subject.

The frequencies of the GG and GA genotypes were as 97.9%, 2.1% respectively. The frequency of G allele was and the frequency of A allele was 1.1%.

Results of the present study might be important in understanding the distribution of PTH G20210A polymorphism in the Southern Iran. Minor allele frequency in this population is higher than in the Iranian and European population but similar to the prevalence in the Western Iran, Iranian Jews, American, Irish, Tunisian and Bahraini population.

Low birth weight (LBW) is one of the most important problems in the world. Many morbidity are more prevalent in LBW included in attention deficit and hyper activity disorder (ADHD). This study was done to find the Relation between low birth weight with attention deficit and hyper activity disorder in children. This historical cohort study was done on 226 rural children in Yazd province, central area of Iran. ADHD symptoms were evaluated in LBW and NBW using DSM-IV criteria. Frequency of ADHD was 22.8% in LBW and 12.5% in NBW (P<0.05). The mean of family members was 4.7±0.6 and 4.2±0.8 in child with ADHD versus child without ADHD (P<0.05). Odd's ratio for ADHD was 3.1 in patient with more than one sister or brother (95% CI: 1.2-7.9, P<0.001), and 5.7 in patients with positive familial history (95% CI: 2.6-12.4, P<0.001). Relationship between ADHD and LBW was statistically significant. Positive familial history for ADHD and over-crowded family were social factors related with ADHD. LBW is one of the risk factors for ADHD and can be considered in children health program ADHD was frequent in child with low birth weight than child with normal birth weight.

Diarrhea is the common complication after using antibiotics. The prevalence of diarrhea with Amoxicillin clavulanic is 10-25 %. Zinc sulfate can support the immune system and also can be useful in resistance of skin and mucosa to infection, increase nerve system development. zinc is one of the important Anti- oxidants and cell membrane stabilizers. The present study evaluate the effect of oral zinc sulfate in prevention of Amoxicillin clavulanic associated diarrhea in children aged 6 – 60 months In this randomized control trial, 120 children age range of 6 -60 months were divided into two equal group.The case group received zinc sulfate and co Amoxi clave, whereas control group received only co Amoxi clave. Data was gathered with questionnaire and then analyzed with independent statistical t.test and chi-squared test. Results indicated that prevalence of diarrhea after using co-Amoxi clave was 21.7% (30.5 % in the case and 13.1% in the control group)(P-value= 0.018) The results of this study pointed out that diarrhea was common after using co-Amoxiclave and using zinc sulfate cannot prevent Amoxiclave associated diarrhea and perhaps it can increase diarrhea.

The diagnosis of hereditary red blood cell (RBC) membrane disorders, in particular hereditary spherocytosis (HS), and SAO is based on clinical history and RBC morphology and other conventional tests such as osmotic fragility. However, there are some milder cases of these disorders which are difficult to be diagnosed. The application of eosin-5'-maleimide (EMA) was evaluated for screening of RBC membrane defect along with some other anemia. We used EMA dye which binds mostly to band 3 protein and in lesser extent to some other membrane proteins for screening of some membrane defects such as HS. Fresh RBCs from hematologically normal controls and also patients with HS, SAO, hereditary elliptocytosis, Hereditary spherocytosis with pincered cells, severe iron deficiency, thalassemia minor, and autoimmune hemolytic anemia were stained with EMA dye, and analyzed for mean fluorescent intensity(MFI) using a flow cytometer. Results and RBCs from patients with HS and iron deficiency showed a significant reduction in MFI compared to those from normal controls (ρ<0.0001 and ρ<0.001 respectively), while macrocytic RBCs showed a significant increase in MFI (ρ<0.01). A significant correlation was shown between MCV and MFI, which the only exceptions were HS and thalassemia minor. Our results showed that the flow cytometric method could be a reliable screening and confirming diagnostic method with high sensitivity and specificity (95% and 93%, respectively) than conventional routine tests for HS patients prior further specific membrane protein molecular tests.

Planning for preparation of adolescent girls to encounter puberty problems should be predicted and defined on the basis of exact information with regard to their behavior patterns as well as educational needs. Therefore، this study aimed to determine the level of knowledge، attitude and performance of female students concerning menstrual hygiene. In this descriptive cross-sectional study، 600 female high school students were chosen randomly from different regions in Yazd. Data collection instrument included a questionnaire which was completed by the students and the study data was analyzed via Epi 6 software. The study results indicated that 46. 6% of participants recognized the social، physical and mental growth as characteristics of puberty age; almost half of them considered menstruation merely as physical changes of puberty; 12. 2% regarded menstruation as a disease; and 20% took lack of menstruation as unimportant. Hygienic points were not appropriately observed during menstruation period as only 53% took a bath during menses period and 37. 1% did cleaning themseleves. Moreover، 75. 5% mentioned they were infrmed by their mothers or some relatives in the house in regard to puberty issues. Regarding poor knowledge and inappropriate performance of female students about menses issues، it seems essential to present educational programs especially with regard to hygienic issues. Moreover، rectifying untrue beliefs of mothers and their daughters via educational classes by health instructors in schools can be fruitful.

The lumbar puncture is one of the most important diagnostic and therapeutic procedures within children which child’s non-cooperativeness and procedural sedation are regarded necessary to conduct it. This study aimed to compare efficacy and safety of melatonin and gabapentin in reducing anxiety and pain of lumbar puncture in children.

In a parallel single-blinded randomized clinical trial، sixty children aged 6 months -7 years، were evaluated in Pediatric Ward of Shahid Sadoughi Hospital، in Yazd (Iran) in 2012. The children were distributedrandomly into two groups (30 children in each group). In group one، they received 0. 3 mg/kg/dose of melatonin and theother group received 15 mg/kg/dose of gabapentin. Primary endpoints were success rate in reducing anxiety (anxiety score of≥ four) and reducing pain when the needle was inserted to skin for lumbarpuncture (pain score of less than four). The clinicalside effects were investigated as well.

Twenty two girls (36. 7%) and 38 boys (63. 3%) with mean age of 2. 79 ± 1. 92 years were evaluated. Anxiety reduction (achieving the anxiety score of ≥ four) was obtained in 43. 3% in melatonin and in 36. 7% in gabapentin groups، respectively and both drugs were equally effective in anxiety reduction (p. value = 0. 598). Pain reduction (achieving the pain score of less than four) was obtained in 23. 3% in melatonin and in 50% in gabapentin groups، respectively and thus، gabapentin wasproved to be more effective in pain reduction (p. value = 0. 032). Mild side effects were observed in 10% of melatonin group and in 16. 7% of gabapentin group. No statistically significant differences were seen from viewpoint of safety between the two drugs (p. value=0. 448).

Melatonin and gabapentin were not effective drugs in anxiety reduction for lumbar puncture of children. However، gabapentin is a safe and effective drug in pain reduction in painful diagnostic therapeutic procedures.

Migraine is the most frequent and most important headache in childhood. Therefore, prophylactic therapy should be exerted in children with frequent or disabling headaches. The purpose of this study was to evaluate efficacy and safety of propranolol for children’s migraine prophylaxis.

In this quasi- experimental study, monthly frequency, severity and duration of headache, migraine disability and side effects of fifty migrainous children were evaluated who were treated with 1mg/kg/day of propranolol for three months and referred to Pediatric Neurology Clinic of Shahid Sadoughi Medical Sciences University, Yazd, Iran from April 2011.

Twenty seven (54%) girls and 23(46%) boys with mean age of 10.68± 2.35 years were evaluated. Monthly frequency, severity and duration of headache decreased with treatment, from 16.2±6.74 to 8.88±4.54 attacks, from 6. 1±1.54 to 4.18±1.61, and from 2.2±1.36 to 1.08±1.08 hours, respectively. Pediatric Migraine Disability Assessment score reduced with TPM from 33.08±8.98 to 23.64 ± 9.88. (p<0.05). Transient side effects were seen in 10%(N=5) of the patients including mild hypotension in three and drowsiness in two children.

Propranolol is partially effective and safe for pediatric migraine prophylaxis.

Leukemia is the most prevalent cancer among children that its survival rate varies in different parts of the world. The aim of the present study was to estimate five-year survival rate of acute pediatric leukemia including acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML) and then to reveal its determinants among a group of 15 years old children visiting Shiraz ShahidFaghihi hospital from 2004 to 2008.

In a retrospective cohort study, to measure survival rate, all of the diagnosed patients with ALL and MLL (280 patients) were entered into analysis. The required data were obtained from patients registered files. To conduct analyses, Kaplan-Meyer and ordinal logarithm methods were used. Modeling of data was undertaken using by SPSS software and Cox regression method.

The average follow-up period was about 28.2±16.1 months (range: 6.4-67.4) during which 60 patients (24.7%) (47 ALL cases and 15 MLL cases) passed away. Cumulative five-year survival rate was estimated to be 53.3±0.055 percent. Cox regression model revealed that there was a significant relationship between Platelet count and number of elapses with leukemia survival rate.

Our study showed that platelet count and number of relapses are effective factors on leukemia patient's survival. Thus, to extend the survival of these patients, these factors should be counted on.

Methyl tetrahydrofolate reductase (MTHFR) plays a major role in the reduction of methyl tetrahydrofolate. Single nucleotide polymorphism C677T in the MTHFR gene is associated with elevated levels of homocysteine، which serves as a risk factor for cardiovascular disease since elevated homocysteine levels damage endothelial cells (coronary arteries). Lowering homocysteine levels with folic acid effectively prevents this condition. In this study، blood samples were collected from 400 individuals (200 patients with premature CAD and 200 controls without symptoms) and the levels of homocysteine and folic acid along with C677T polymorphism of the MTHFR gene were evaluated under chemical and genetic tests. The percentage distribution of CC، CT and TT genotypes (MTHFR gene) was 52. 7%، 42. 79% and 4. 51% in cases and 53. 3%، 42. 8% and 4% in controls، respectively. Mean homocysteine level was found to be 14. 36 in patients and 11. 97 in controls and mean folic acid level was assessed to be 11. 569 in controls and 10. 92 in patients. Then، logistic regression analysis was used to investigate the relationship between homocysteine and C677T polymorphism and early coronary artery disease but no relationship was found (p > 0. 05) No significant relationship was detected between blood levels of homocysteine and folic acid and MTHFR T allele of the gene with premature coronary artery disease (men under 45 and women under 55 years). It is suggested to conduct further studies on other cardiac genes in countries that are genetically close to the Iranian population. It is also suggested to evaluate polymorphism and HCY levels in patients with late-onset form of the disease.

Allergic diseases are among the common diseases in children and one of the common causes of disability in many societies. Increased incidence of these diseases in recent years in many countries has been reported. Allergies in children have several risk factors, including maternal stress during pregnancy. In this descriptive-analytic study, 290 pregnant women referred to two general and private hospitals in Yazd were studied. Subjects were selected during 2010 by non-randomized simple sampling. Anxiety level in pregnant mothers was determined by PRAQ (Pregnancy Anxiety Questionnaire). IgE (Immunoglobulin E) levels in Cord blood and maternal blood were determined by ELISA method. The results were analyzed by SPSS version 16. Our findings showed that the average anxiety score in mothers whose newborns had IgE level above 0.35 IU/ml is more than mothers whose babies blood IgE was less than 0.35 IU/ml, and there was a significant relationship between cord blood IgE level and pregnancy anxiety score (P<0.001). There wasnt any significant relationship between other variables such as gender, gestational age and birth weight with cord blood IgE levels (P> 0.05). It seems that anxiety and fear during pregnancy are risk factors for elevation of cord blood IgE level in newborns.