فهرست مطالب hassan taheri

‎Consider a simple‎, ‎undirected graph $ G=(V,E)$‎, ‎where $A$ represents the adjacency matrix and $Q$ represents the Laplacian matrix of $G$‎. ‎The second smallest eigenvalue of Laplacian matrix of $G$ is called the algebraic connectivity of $G$‎. ‎In this article‎, ‎we present a Python program for studying the Laplacian eigenvalues of a graph‎. ‎Then‎, ‎we determine the unique graph of minimum algebraic connectivity in the set of all tricyclic graphs‎.

The increasing importance of knowledge in the age of knowledge has led to the formation of a knowledge-based economy. As new technologies increase production power and production efficiency, governments around the world, both industrial and developing, are determined to transform education and skills acquisition into a knowledge-based economy. Therefore, the main purpose of this study is to investigate the effect of knowledge-based economy indicators on labor productivity in the selected Islamic countries. In this study, using Eviews software and econometric techniques, the relationship between variables and their impact on labor productivity was investigated in the period 5110 to 2052. The results show that the indicators of public education expenditure, the number of published articles and ICT have a positive and significant effect on labor productivity, while the R&D and Internet indicators do not have a significant effect on labor productivity.

Pediatric radial neck fractures are rare, comprising about a tenth of all elbow injuries in children ( 1 ) . They typically affect the children between 4 to 14 years of age with a peak of incidence ranging between 8 and 10 years of age ( 2 ) . Because radial head ossification starts at age 5 and is completed when the physis closes at 14 years of age for boys and 17 for girls ( 3 ) . The most common mechanism of this fracture is falling over an out stretched extended hand with a valgus force ( 4 ) . The most common radial neck fractures are extra - physeal fractures of the metaphysis or Salter - Harris I or II fractures of the proximal radial physis ( 4 ) . Closed fractures are more common than open ones and near half of these fractures are associated with the ipsilateral elbow dislocation, olecranon fractures, and ruptured collateral ligaments ( 5 ) . The classification systems in radial neck fractures including the Jeffery, O’Brien, and Judet and Letournel classification systems are the most commonly cited o nes in the literature ( 3 ) . The management of radial neck fractures is based on fracture angulation, dislocation , and skeletal maturity ( 6 ) . Treatment options that have been used for fractures with dislocation are closed reduction, percutaneous pin - assisted reduction, Metaizeau technique (elastic intramedullary nailing), and if the se closed methods are not successful, open reduction with or without internal fixation can be used ( 6 ) . Although good results have been reported after these varying treatment methods, the optimal treatment is still unclear ( 7 ) .

Gastric cancer is among the most common cancers worldwide that currently lacks effective diagnostic biomarkers and therapeutic targets. Next-generation RNA sequencing is a powerful tool that allows rapid and accurate transcriptome-wide profiling to detect differentially expressed transcripts involved in normal biological and pathological processes. Given the function of this technique, it has the potential to identify new molecular targets for the early diagnosis of disease, particularly in gastric adenocarcinoma.

In this study, whole-transcriptome analysis was performed with RNA sequencing on tumoral and non-tumoral tissue samples from patients with early-stage gastric cancer. Gene ontology and pathway enrichment analysis were used to determine the main function of the specific genes and pathways present in tissue samples.

Analysis of the differentially expressed genes revealed 5 upregulated and 234 downregulated genes in gastric cancer tissues. Pathway enrichment analysis revealed significantly dysregulated signalling pathways, including those involved in gastric acid secretion, drug metabolism and transporters, molecular toxicology, O-linked glycosylation of mucins, immunotoxicity, metabolism of xenobiotics by cytochrome P450, and glycosylation. We also found novel downregulated non-coding RNAs present in gastric cancer tissues, including GATA6 antisense RNA 1, antisense to LYZ, antisense P4HB, overlapping ACER2, long intergenic non-protein coding RNA 2688 (LINC02688) and uncharacterized LOC25845 (PP7080).

The transcriptomic data found in this study illustrates the power of RNA-sequencing in discovering novel genes ‎and tumorigenic pathways involved in human carcinogenesis. The anomalies present in these genes may serve as promising tools for the development of accurate diagnostic biomarkers for the detection of early-stage gastric cancer.

This paper considers the power-efficient resource allocation problem in a cloud radio access network (C-RAN). The C-RAN architecture consists of a set of base-band units (BBUs) which are connected to a set of radio remote heads (RRHs) equipped with massive multiple input multiple output (MIMO), via fronthaul links with limited capacity. We formulate the power-efficient optimization problem in C-RANs as a joint resource allocation problem in order to jointly allocate the RRH and transmit power to each user, and fronthaul link and BBU assign to active RRHs while satisfying the minimum required rate of each user. To solve this non-convex optimization problem we suggest iterative algorithm with two-step based on the complementary geometric programming (CGP) and the successive convex approximation (SCA). The simulation results indicate that our proposed scheme can significantly reduce the total transmission power by switching off the under-utilized RRHs.

Ever increasing development of wireless devices and wireless networks have increased the value of spectral space‎. ‎Many efforts have been conducted to increase spectral utilization‎. The radio environment mapping opens new gates for developing low cost wireless devices. ‎In this paper‎, ‎a new method is proposed for increasing spectral utilization in distributed networks‎. ‎In this method‎ ‎distributed Kalman filter, which is modified to increase estimation accuracy, is used to estimate position‎, ‎velocity and power of primary transmitters‎. ‎These data are used to select spectrum holes optimally and increase spectral utilization compared to centralized methods‎. Obtained r‎esults are evaluated through practical implementations and simulations‎. ‎Innovations of this research include introducing and employing a linear model for estimating position of a transmitter using received power in line of sight (LoS) and non-line of sight (NLS) conditions, ‎‎‎modifying extended kalman filter and‎ ‎implementation of distributed spectrum sensing; advantages of this method are illustrated compared to centralized methods.‎‎

This study aimed at evaluating oxidant and antioxidant markers (including nitrite, nitrate, total antioxidant capacity (TAC), malondialdehyde (MDA), iron, selenium, glutathione peroxidase (GPx), and glutathione reductase (GR) in patients with inflammatory bowel disease (IBD) and compare them with healthy controls.
Serum samples were obtained from 35 patients (19 ulcerative colitis (UC) and 16 Crohn’s disease (CD) in the active phase of the disease) and 30 healthy controls. Serum levels of nitrite and nitrate, TAC, MDA, iron, selenium, glutathione peroxidase, and glutathione reductase were measured. The results were compared between the two groups using independent t-student test. The Pearson’s correlation coefficient (for continuous data) was performed using the SPSS software.
Serum levels of nitrite, nitrate, and MDA were significantly higher (P = 0.001) in patients with IBD, while the levels of TAC, trace elements, glutathione peroxidase (GPx), and Glutathione Reductase (GR) levels were lower (P There is an imbalance between oxidant and antioxidant properties in patients with IBD, which highlights the role of oxidative stress in the pathogenesis of this disease.

Due to the importance and various applications of nitriles especially in medicinal productions, a new method for conversion of aldehydes to nitriles has been presented. Several nitrile-containing aromatic compounds were synthesized through the treatment of various aldehydes and hydroxylamine hydrochloride as nucleophile in the presence of ferric hydrogen sulfate as a heterogeneous, efficient, and recyclable catalyst in DMF in good to excellent yields.

The appropriate colon cleansing is a major determinant of quality of colonoscopy. The aim of this study was to compare the efficacy and tolerability of the morning (AM) PEG (polyethylene glycol) solution to previous-evening (PM) PEG solution for the afternoon colonoscopy. This comparative study compared the AM to PM prep for afternoon outpatient colonoscopy. The subjects randomly received PEG PM dose; 4 liters of water plus 4 pack PEG powder at 6 pm before colonoscopy (250 ml every 15 min) or AM (the same dose solution at 6 am on the day of colonoscopy). The preparation and colonoscopy quality, PEG side effects, sleep quality, lesion detection, flush need and suction fluid were compared in these two groups. One hundred seven cases received AM prep and 102 received PM prep. The colon prep was adequate in 94.4% in AM group and in 90.2% cases in PM group (P=0.2). The incidence of adverse events in these two groups was similar. Sleep quality and the need for flush was lower in the AM group (P=0.004 and P=0.03). The mean volume of suction fluid was higher in the AM group (P=0.01). The detected lesions were similar between the two groups. Adequate prep was associated with lower flush need in AM group (P=0.001). AM and PM PEG solutions were clinically equivalent with cleansing efficacy and side effect and lesion detection. AM group was associated with a better sleep quality and less flush need, but more suction fluid.

Electronic devices in space applications may be Radiation Tolerant or Commercial off-the Shelf (COTS). Due to cost and unavailability in many applications، the latter is usually used. In applications such as spatial ones، the COTS equipment lacks reliability against threats like heavy ion radiation; therefore، some alternatives should be considered to make the equipment resistant against the probable threats. In this paper to checking an Intra-Inter block control flow، a software redundancy method in instruction level is delivered. In comparison with other methods، the proposed method has less memory overhead، better performance and more fault coverage.

The majority of dyspeptic patients do not have identifiable disease, which is also known as functional dyspepsia. The therapeutic approach to patients with functional dyspepsia is still a matter of debate; prokinetic agents are commonly used for symptom relief. This study aims to evaluate the efficacy of domperidone and pyridostigmine (an inhibitor of cholinesterase) in patients with functional dyspepsia.This was a single-blind, randomized clinical trial performed on 117 patients (December 2007 to November 2009) diagnosed with functional dyspepsia according to ROME II criteria. The effects of 4 weeks of treatment with domperidone (10 mg tid), pyridostigmine (60 mg tid), and placebo were compared. We scored each patient according to VAS to rank the severity of 8 different upper GI symptoms (epigastric fullness, early satiety, gnawing, nausea, vomiting, belching, bloating, and epigastric pain) both before and at the end of treatment. Data were entered into SPSS software version 16 and analyzed. p ‹ 0.05 was considered significant.At the end of treatment, the total dyspeptic symptom score decreased from 24 to 13. According to ANOVA, there were significant differences between the 3 groups in 3 out of 8 symptom scores of bloating (p=0.039), early satiety (p=0.006), and nausea (p=0.016). The post hoc test determined that domperidone was more effective than pyridostigmine and placebo in improvement of early satiety (p=0.038 and p=0.014, respectively). Domperidone was more effective than pyridostigmine in the control of nausea (p=0.024). Domperidone (p =0.023) and pyridostigmine (p=0.042) were superior in relieving bloating symptoms compared to placebo. Overall, in the control of GI symptoms domperidone was more effective than placebo (p=0.045).Domperidone and pyridostigmine are useful in improving bloating, early satiety, and nausea. However they are similar to placebo in controlling epigastric pain, fullness, belching and gnawing.

Basic fibroblast growth factor (bFGF) is a glycoprotein with stimulating ability of angiogenesis. In addition, bFGF plays an important role in wound healing process in some tissues for example gastrointestinal tract, but its ability for discrimination of various stages of wound severity in these diseases was not reported. Therefore, we aimed to determine the bFGF levels in gastric ulcer patients compared with healthy control as a biomarker for staging the severity of wound The study group consisted of 33 patients with gastric ulcer and 27 healthy controls. The diagnosis of patients was based on standard clinical, endoscopic, and histological criteria. Serum levels of bFGF were analyzed by an ELISA kit. According to the histological findings, 19 (57.6%) patients were in moderate stage of ulcer and 14 (42.4%) patients were in the severe stage of gastric ulcer. The mean bFGF serum levels in patients group (7.8±1.3pg/ml) were lower than the healthy group (8.2±1.4pg/ml) in crude data, but in statistical analysis the differences were not significant (p=0.082). The mean bFGF serum levels in patients with severe stage of gastric ulcer were greater than patients in moderate gastric ulcer (8.4±1.3 vs. 7.4±1.2 pg) and the differences were statistically significant (p<0.05). Differences in serum bFGF levels in patients with severe stage of gastric ulcer vs. moderate gastric ulcer was significant. Therefore, serum bFGF level measurements can be used as a useful clinical tool for discrimination of patients with severe stage of gastric ulcer vs. moderate gastric ulcer, when endoscopic and histological examination are not possible to perform.

The outcome of Hepatitis B virus (HBV) infection is chronic or resolved HBV infection. Over the time, the levels of HBsAg or Anti-HBs declined and were not detectable in their sera and was named as isolated anti-HBc. The purpose of this study was to assess the prevalence of isolated anti-HBc in previously HBV infected individuals. From April 2000 to September 2008, the results of HBV markers on 2036 cases of previously infected individuals were recorded. Those who were HBsAg or anti-HBs negative but anti-HBc and anti-HBe positive was named as isolated anti-HBc. The prevalence of isolated anti HBc in both males and females was determined. Among the 1160 males with past HBV infection, isolated anti-HBc was seen in 35 (3%) cases. The mean age of these cases was 33.8±13 years. Isolated anti-HBc was seen in 44 (5%) cases of 876 females with previous HBV infection (p=0.014). The prevalence of isolated anti-HBc was 79 (3.9%). The result of this study emphasizes on the differentiation of occult or resolved HBV infection in isolated anti-HBc cases in endemic regions of HBV.

Major thalassemia is the most common form of anemia requiring blood transfusion in Iran. Since ribavirin provokes anemia in the treated patients, interferon monotherapy may be an appropriate treatment in major thalassemic patients. The aim of this study was to determine the safety and efficacy of interferon monotherapy in thalassemic patients with hepatitis C virus infection. Forty major thalassemic patients (20 male), with hepatitis C infection (detectable HCV RNA«by qualitative PCR««amplification assay) and elevated liver enzymes were enrolled. Liver biopsy was done for all patients. Then the patients were treated with interferon (3 MU, three times per week) for six months. They were followed by HCV RNA at the end of treatment, and at 6, 12, 24, 36, and 48 months later. Primary outcome measure was sustained virologic response defined by undetectable serum HCV RNA 6 months after end of treatment. Secondary endpoint was negative HCV RNA at the end of follow up (48 months posttreatment). Mean age of the patient at the beginning of the study was 17. 37±5 years. Three patients discontinued treatment because of interferon side effects. Twenty six (65% on intention to treat analysis) had undetectable HCV RNA 6 months after end of treatment but eleven of them became HCV RNA positive on follow up. Finally, 15 patients (37. 5%) had undetectable HCV RNA at the end of follow up. Interferon monotherapy is an effective treatment for major thalassemic patients with HCV infection. Definition of sustained virologic response for hepatitis C may require revision in high risk patients.

Background- Hepatitis B virus (HBV) infection is a major worldwide health problem. Most of the patients are asymptomatic and at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. The aim of the present study was to determine the frequency of chronic active hepatitis in asymptomatic HBV carriers in Babol, northern Iran.Methods- This study was performed in 410 HBV carriers older than 15 years who were diagnosed by positive serum hepatitis B surface antigen (HBsAg) from January 1998 to September 2000. Family members of infected patients were also screened. For each patient, HBsAg, hepatitis B early antigen (HBeAg), hepatitis B early antibody (HBeAb) and alanine aminotransferase (ALT) were measured at the time of screening and again 6 months later. In patients with raised ALT, liver biopsy was performed and a Knodell score ≥ 4 was considered as chronic active hepatitis. Proportions were then analyzed using the chi-square test.Results- Of the 410 patients, 229 (53.3%) were males and 181 (46.5%) were females. Mean age ± standard deviation (SD) was 28 ± 12.7 years. Of these, 362 (88.3%) were HBeAb-positive and 48 (11.7%) were HBeAg-positive. ALT was elevated in 73 (17.8%) of patients. Chronic active hepatitis was found in 8% and 10.4% of the HBeAb-positive and HBeAg-positive cases, respectively (p = 0.57). Chronic hepatitis was significantly higher in males than females (p = 0.0001)Conclusion- The results show that the frequency of chronic active hepatitis is high in asymptomatic HBV carriers. It is almost equal in HBeAb-positive and HBeAg-positive cases and is higher in males than females. Assessment of HBV precore mutants in anti-HBeAg- positive cases is highly recommended.