Meson Structure Functions in Valon Model

Parton distributions in a {\it{valon}} in the next-to-leading order is used to determine the patron distributions in pion and kaon. The validity of the valon model is tested and shown that the partonic content of the valon is universal and independent of the valon type. We have evaluated the valon distribution in pion and kaon, and in particular it is shown that the results are in good agreement with the experimental data on pion structure in a wide range of $x=[10^{-4},1]$Comment: 13 pages with 7 figures included, The manuscript is revised, figures are added and some errors are corrected. Accepted for publication in Physical Review

Homogenization of composites with extended general interfaces: comprehensive review and unified modeling

Abstract Interphase regions that form in heterogeneous materials through various underlying mechanisms such as poor mechanical or chemical adherence, roughness, and coating, play a crucial role in the response of the medium. A well- established strategy to capture a finite-thickness interphase behavior is to replace it with a zero-thickness interface model characterized by its own displacement and/or traction jumps, resulting in different interface models. The contributions to date dealing with interfaces commonly assume that the interface is located in the middle of its corresponding interphase. We revisit this assumption and introduce a universal interface model, wherein a unifying approach to the homogenization of heterogeneous materials embedding interfaces between their constituents is developed. The proposed novel interface model is universal in the sense that it can recover any of the classical interface models. Next, via incorporating this universal interface model into homogenization, we develop bounds and estimates for the overall moduli of fiber-reinforced and particle-reinforced composites as functions of the interface position and properties. Furthermore, we elaborate on the computational implications of this interface model. Finally, we carry out a comprehensive numerical study to highlight the influence of interface position, stiffness ratio and interface parameters on the overall properties of composites, where an excellent agreement between the analytical and computational results is observed. The developed interface-enhanced homogenization framework also successfully captures size effects, which are immediately relevant to emerging applications of nano-composites due their pronounced interface effects at small scales

The effect of green chemistry education based on practical activity on learning and attitude of pre-service chemistry teachers

Background and Objective:Chemistry plays a fundamental role in human civilization and its place in economics, politics and life is becoming more and more prominent and covers a wide range of chemical products such as drugs, dyes, fertilizers, etc. However, the environmental damage caused by it is a major human concern. Many of us today take steps to reduce environmental impact, for example by participating in chemical recycling programs and using energy-saving light bulbs; we buy local products and maybe drive hybrid cars. But what if "we could somehow prevent pollution from the start?" Thus, with a new approach called green chemistry, chemists are being led to a new phase of research activities to develop green reactions and use them instead of the old methods, to help human health and society by eliminating toxins from chemical processes. The purpose of this research is education of green chemistry through the curriculum related to the principles of green chemistry in General Chemistry Lab 1and the effect of this educational course on learning and attitude of the pre-service chemistry teachers toward green chemistry principles. Methods: This educational course involves two green experiments implemented according to green chemistry principles. The experiments include determination of molar mass relation in a chemical reaction and determination of the amount of ascorbic acid in a tablet of vitamin C. The research methods are practical, experimental and quasi-experimental and the used instruments were the researcher-constructed tests in the field of learning and attitude domain. Statistic population of this study consists of experimental group (N=30) and control group (N=30) of the student teachers at Shahid Rajaee Teacher Training University in the academic year 2017-2018. Data analysis was done using descriptive and inferential statistics with SPSS software. Findings: The obtained results show that among12 principles of Green Chemistry, students have learned the principles of 1 to 4 and 7 to 12 of these 12 principles and they have been attracted to them. In addition, the implementation of a curriculum related to the principles of green chemistry has had a positive impact on the attitude of the pre-service chemistry teachers. Conclusion: Findings from the research show that teaching the principles of green chemistry can be done based on the activity-oriented approach in the chemistry curriculum as in most developed countries. Student-teacher education can lead them to develop a positive attitude towards green chemistry and to have more motivation and desire to study chemistry based on the principles of green chemistry and to pass this attitude on to their students in the teaching process. Also, in designing the curriculum, it should be noted that in the sequence of practical activities, it should be done in such a way that it includes all the principles of green chemistry so that education based on it can give all the principles of green chemistry to learners or give them a positive attitude.   ===================================================================================== COPYRIGHTS  ©2019 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Treatment of female pattern hair loss

Female pattern hair loss (FPHL) as a distinctive entity was first described about 30 years ago. The objective of this study was to perform a systematic review of all randomized controlled trials for treatment of FPHL. A preliminary search was carried out in several databases up to August 2008 to identify all randomized controlled trials on nonsurgical interventions for treatment of FPHL. Studies reporting fewer than 10 patients and non-English articles were excluded. Additionally, references of relevant articles and reviews were checked manually in search for additional sources. Among 238 citations found in the preliminary search, 12 fulfilled all criteria to be included in the systematic review. Topical minoxidil 1 to 5 for 24 to 48 weeks was shown to be effective in FPHL and its effect was not related to age or androgen level of patients. In addition, it may be effective in women with FPHL, both with and without hyperandrogenism, and in young and old premenopausal or postmenopausal. In patients with increased serum androgens, oral flutamide but not finasteride or cyproterone acetate was more effective than no treatment. Topical minoxidil is effective in patients with FPHL, with or without hyperandrogenism, but there is limited evidence for the efficacy of antiandrogens. © 2012 Pulse Marketing & Communications, LLC

A Case Report of Mucopolysaccharidosis Type VI

BACKGROUND AND OBJECTIVE: Mucopolysaccharidosis type VI (MPS VI) is a lysosomal storage disorder and autosomal recessive caused by arylsulfatase B deficiency in the body and progressive accumulation of glycosaminoglycan in different organs. Considering that this disease has low prevalence in Iran and worldwide, we report a case of MPS VI diagnosis in this study. CASE REPORT: A five-year-old boy was referred to Imam Khomeini Clinic in Esfarayen due to impaired growth and dyspnea. In the biography of this boy, there is the history of previous hospitalization due to dyspnea when he was three months, two years and three years old and was treated with antibiotics and salbutamol spray for three days each time. The pediatrician got suspicious of MPS because of the child's peculiar face. Blood tests were performed in terms of the levels of lysosomal enzymes and the urine sample was sent to the Metabolic Laboratory of Hamburg University Medical Center to study the glycosaminoglycan levels. After six months, the results of the tests indicated low levels of serum arylsulfatase B and the increase in chondroitin and urinary levels of dermatan sulfate. To investigate the presence of complications, echocardiography, electromyography, eye and ear examinations as well as radiography for chest, back, hip and hand were performed. Clinical and paraclinical findings confirmed the MPS VI disease and therefore, treatment with naglazyme enzyme was started for the patient. CONCLUSION: Based on the results of this case report, growth impairment, history of hospitalization due to respiratory problems and the patient’s peculiar face are key points for further investigation regarding MPS VI disease

Striae gravidarum: Associated factors

Background: Striae gravidarum (SG) is the most common change in connective tissue of pregnant women and may cause cosmetic concerns. Objectives: To determine the frequency of SG in Iranian pregnant women and its possible associations with the characteristics of themselves and their newborns. Methods: One hundred and eighteen primigravid pregnant women were included in this prospective observational study at their first prenatal visit, among them 114 completed the study and gave birth. Results: One hundred (87.7) of 114 women developed SG with a mean Davey's score of 4.04±2.47. The mean gestational age at which SG first appeared was 27.57±5.38 weeks. Family history of SG in mother, baseline and delivery body mass index, greatest abdominal and hip girths, newborn weight, height and head circumference were significantly associated with the presence of SG. All of these factors were also correlated with Davey's score. Conclusion: Genetic and physical risk factors may be involved in the development of SG in primigravid women. © 2007 The Authors Journal compilation © 2007 European Academy of Dermatology and Venereology

Pimecrolimus cream in repigmentation of vitiligo

Background: Vitiligo is a chronic disease that mostly affects children and young adults. Nowadays many treatment options are available; however, most of them have limited efficacy and in most cases would result in undesirable complications. Objective: To determine the extent of repigmentation according to the location of the lesions after applying topical cream pimecrolimus 1 in vitiligo patients. Materials and Methods: Thirty consecutive patients with vitiligo lesions affecting less than 20 of body surface area without any previous history of spontaneous repigmentation were treated with pimecrolimus cream 1 twice daily for 12 weeks. The extent of repigmentation in vitiligo lesions was determined in each patient after 6 and 12 weeks. Results: Moderate to excellent response (repigmentation >26) was observed in 6.6 and 25.9 of vitiligo lesions 6 and 12 weeks after treatment, respectively. More responsive lesions were located on the trunk, face and elbow (85.7, 75 and 70). Conclusion: Pimecrolimus cream 1 results in repigmentation in vitiligo in different extents according to the location of the lesion; however, to clearly prove its efficacy as monotherapy or in combination with other available treatment options, double-blind placebo-controlled studies are essential. Copyright © 2007 S. Karger AG

Next-to-Leading Order Constituent Quark Structure and Hadronic Structure Functions

We calculate the partonic structure of a constituent quark in the Next-to-Leading Order framework. The structure of any hadron can be obtained thereafter using a convolution method. Such a procedure is used to generate the structure function of proton and pion in NLO, neglecting certain corrections to $\Lambda_{QCD}$. It is shown that while the constituent quark structure is generated purely perturbatively and accounts for the most part of the hadronic structure, there is a few percent contributions coming from the nonperturbative sector in the hadronic structure. This contribution plays the key role in explaining the SU(2) symmetry breaking of the nucleon sea and the observed violation of Gottfried sum rule. These effects are calculated. We obtained an Excellent agreement with the experimental data in a wide range of $x=[10^{-6}, 1]$ and $Q^{2}=[0.5, 5000]$ $GeV^{2}$ for the proton structure function. We have also calculated Pion structure and compared it with the existing data. Again, the model calculations agree rather well with the data from experiment.Comment: 32 pages,10 figures, Accepted to publish in Phys. Rev.

Concepts of patients with alopecia areata about their disease

BACKGROUND: Alopecia areata (AA) is a common and chronic skin disease with an unknown etiology. It may significantly affect the patient quality of life. This study was designed to evaluate the illness perception in patients with AA. METHODS: A questionnaire consisting of 25 questions about causes, timeline, consequences and control of disease were given to 80 patients with AA attending a skin clinic in Tehran, Iran. The impact of age, gender, duration of disease, education, extent of disease and family history of AA were also assessed. RESULTS: Eighty patients (38 male and 42 female) with a mean age of 27.5 years (SD = 9.3) and disease duration of 7.8 years (SD = 7.7) completed the questionnaire. 76.9% of the patients believed that the role of stress was the cause of disease. 17.1 % believed genetic background to be the main cause, this found to be more frequent in patients with positive family history of AA. More than half of patients believed that their illness had major consequences on their lives and 40% of patients believed that their illness would be likely to be permanent rather than temporary, more in patients with longer duration of disease. Only 57.5% of patients considered their treatments to be effective. CONCLUSION: AA may considerably affect various aspects of patients' lives. The patient knowledge about the causes and course of this disease is limited