Hydrogels Fibers

With the ever increasing demand for suitable tissue engineering and drug delivery systems, hydrogel fiber spinning has drawn increasing attention due to its ability to create three-dimensional (3D) structures using biomaterials. Hydrogel materials have shown a great promise to be used as templates for tissue engineering and implantable devices. Among the many production techniques available, advanced fiber processing, such as coaxial and triaxial spinning of natural hydrogels, has attracted a great deal of attention because the basic core-sheath structure provides a drug delivery system capable of delivering high concentrations of drug for localized drug delivery and tissue engineering applications. Encapsulating the drug and bioactive cores with a more bio-friendly coating allows for a versatile system for producing devices with appropriate mechanical, chemical and biological properties that can mimic the native extracellular matrix, better supporting cell growth and maintenance. This chapter presents a novel fabrication method using a wet-spinning process that allows for the routine production of multifunctional coaxial hydrogel fibers that take advantage of the encapsulating properties of a hydrogel core while also promoting good cell growth and biocompatibility via the use of bio-friendly material in the sheath

An investigation on body weights, blood glucose levels and pituitary-gonadal axis hormones in diabetic and metformin-treated diabetic female rats

Diabetes is a metabolic disorder which affects whole body systems including reproductive system. Diabetes is also a contributing factor to infertility. Metformin is one of the most common drugs to control hyperglycemia. In this study, 36 adult Sprague-Dawley female rats (170-210 g) were divided into 3 groups (control, diabetic and diabetic-treated by metformin). In second and third groups, diabetes was induced by streptozotocin injection (45 mg kg-1, IP) and the third group was treated by metformin hydrochloride (100 mg kg-1 day-1, PO) for 8 weeks. Body weights were compared and blood glucose, gonadotropins and sexual hormones were measured. In diabetic group the blood glucose level significantly (P < 0.05) increased in comparison with that of control and metformin-treated diabetic rats. The results also revealed that, in the untreated diabetic rats, the mean body weights and pituitary-gonadal axis hormones were significantly (P < 0.05) reduced in comparison with the control. Although there were significant (P < 0.05) reduction in mean body weights in metformin-treated diabetic rats, reduction in pituitary-gonadal axis hormones was not as sharp as in untreated diabetic rats and only level of progesterone was significantly (P < 0.05) reduced in comparison with the control. The results of this investigation revealed that there was a clear relationship between experimental diabetes with body weight and pituitary-gonadal axis hormones, and treatment with metformin relatively restored diabetic complications

The Frequency of Stx1 and Stx2 Genes in Uropathogenic Escherichia coli Isolated From Patients in Kermanshah, Iran

1) Background: Uropathogenic E. coli (UPEC) is responsible for 70-90% of urinary tractinfections. On the other hand, E. coli producing Shiga toxin (STEC), the so-called Verotoxinproducing E. coli (VTEC), has two stx1 and stx2 genes (Producing Stx1 and Stx2 toxins). Since these genes are plasmidal and can be transmitted between E. coli strains, it is likely that stx1 and stx2 genes are also found in the Uropathogenic E. coli. Studies in different parts of the world indicate some cases of dangerous syndromes such as Haemolytic-Uraemic Syndrome (HUS)following urinary tract infections. Also, the incidence of urinary tract infections caused by Verotoxigenic E. coli strains is increasing. Therefore, the present study was conducted to investigate the presence of verotoxin genes in Uropathogenic E. coli; 2)Methods: A total of 180 clinical specimens were collected during five months. After diagnostic tests and differential biochemistry tests, 100 samples were confirmed as E. coli and the presence of stx2 and stx1 genes was investigated by Muliplex-PCR; 3) Results: The results showed that the prevalence rates of stx1 and stx2 genes were 15% and 13%, respectively, in UPEC samples examined in this study, which is in agreement with the results of few similar studies in Iran; and 4) Conclusions: It seems that the frequency of verotoxin genes in E. coli causing urinary tract infections in Kermanshah is more than the other parts of Iran. Therefore, the potential risks of these bacteria could not be ignored

Development and characterization of novel hybrid hydrogel fibers

Biopolymeric continuous core-sheath fibres, with an inner core of chitosan and alginate as the sheath, were fabricated for the first time without using a template. Hereby, the necessary conditions to achieve chitosan-alginate core-sheath fibre via a wet-spinning process are presented. SEM micrographs show the cylinder-shaped monofilament structure of the chitosan core surrounded by the alginate sheath. The coaxial fibres exhibit a 260% increase in ultimate stress and more than 300% enhancement in the Young\u27s modulus compared to the alginate counterpart. Release profiles from the coaxial fibre were determined using a model component. The obtained results suggest that the fibres are likely to find applications as 3D tissue scaffolds capable of drug delivery

Knowledge, attitude and practice of students of Kermanshah University of Medical Sciences about food hygiene and safety

زمینه و اهداف: بهداشت و ایمنی موادغذایی به­عنوان یک اصل مهم براي جلوگیري از مبتلاشدن انسان به بیماري­ها و نیز حفظ محیط از نظر آلودگی در نظر گرفته می­شود. از آنجا که بخش عظیمی از جمعیت کشور را جوانان تشکیل می­دهند و درصد بالایی از آنان دانشجو هستند، پژوهش حاضر با هدف تعیین آگاهی، نگرش و عملکرد دانشجویان دانشگاه علوم ­پزشکی کرمانشاه در خصوص بهداشت و ایمنی­ مواد غذایی انجام گردید. مواد و روش­ ها: مطالعه حاضر یک مطالعه توصیفی-تحلیلی است که در بین 307نفر از دانشجویان دانشگاه علوم­پزشکی کرمانشاه با روش نمونه­گیري در دسترس انجام شد. جهت جمع ­آوری داده­ها از پرسشنامه شامل مشخصات دموگرافیک و سوالاتی در سه بخش برای سنجش آگاهی، نگرش و عملکرد استفاده گردید. داده ­های به ­دست­ آمده با استفاده از آزمون‌های مجذور کای در محیط نرم­افزار SPSS نسخه26 مورد تجزیه و تحلیل قرار گرفت. اخلاق در پژوهش و محرمانه بودن پاسخ های شرکت­کنندگان در صفحه اول پرسشنامه ذکر شد. یافته­ ها: افراد شرکت­کننده در این مطالعه اکثراً مذکر و مجرد بوده­اند که بیشترین شرکت­کننده (127نفر) مربوط به دانشکده پزشکی بود (4/41%). علیرغم اینکه اکثر دانشجویان آگاهی و نگرش خوب نسبت به بهداشت و ایمنی ­موادغذایی داشتند، اما حدود 4/70% دانشجویان عملکرد ضعیفی داشتند که ضعیف­ترین عملکرد مربوط به دانشجویان دانشکده پرستاری-مامایی بود درخصوص آگاهی و نگرش، تفاوت معنی­داری در بین دانشجویان دانشکده­های مختلف وجود داشت. همچنین ارتباط معنی­داری بین جنسیت و عملکرد دیده شد. نتیجه ­گیری: باتوجه به عملکرد ضعیف دانشجویان در بحث رعایت اصول ­بهداشتی مواد غذایی به نظر می­رسد برگزاری کارگاه­های آموزشی و اضافه ­کردن واحد­های درسی در این زمینه احتمالاً مي­تواند باعث بهبود عملکرد دانشجویان شود.Background and Aims: Food hygiene and safety is considered as an important principle to prevent humans from contracting diseases and also to protect the environment from contamination. Because a large part of Iran's population is young and a high percentage of them are students, therefore, this study was conducted to determine the knowledge, attitude and practice of students of Kermanshah University of Medical Sciences about food hygiene and safety. Materials and Methods: The present descriptive-analytical study was conducted on 307 students at Kermanshah University of Medical Sciences through a convenience sampling method. A questionnaire including demographic characteristics and questions in three sections were used to assess students' knowledge, attitude and practice towards food health and safety. The data were analyzed using SPSS version 26 software. Ethics&nbsp; approval&nbsp; and confidentiality&nbsp; of&nbsp; answers&nbsp; were&nbsp; given&nbsp; on&nbsp; the&nbsp; first&nbsp; page of&nbsp; the questionnaire. Results: The participants were mostly male and single, with the majority belonging to the medical school. Despite the fact that most of the students had good knowledge and attitude towards food hygiene and safety, but about 70.4% of respondents showed poor performance, from which the weakest performance was related to nursing and midwifery students. Students' knowledge and attitude had a statistically significant difference between different faculties. Functionally, a significant relationship was seen between gender and performance. Conclusion: Given the poor performance of students in relation to the principles of food hygiene, it seems that holding workshops and adding courses can probably improve student performance

Fabrication of Coaxial Wet-Spun Graphene-Chitosan Biofibers

One-step continuous wet-spinning of coaxial electroactive fibres of chitosan/graphene oxide (Chit/GO) via a facile method is introduced for the first time, eliminating the need for post-treatment processes. Spinnability of coaxial fibres as well as their characterization for several properties is investigated. L-ascorbic acid was found to reduce graphene oxide under mild conditions to create conductivity in the final fibre. As-prepared fibres were found to be cytocompatible with good electrical conductivity and mechanical properties. SEM images from the cross-section of Chit/GO fibres showed an irregular shaped multifilament GO fibre covered with a cylinder-shaped sheath of chitosan. Coaxial fibres had an ultimate tensile stress and elastic modulus that increased 8 500% and 3 350%, respectively compared to the graphene oxide fibres alone

Development and Characterization of a Sucrose Microneedle Neural Electrode Delivery System

Stable brain-machine interfaces present extraordinary therapeutic and scientific promise. However, the electrode-tissue interface is susceptible to instability and damage during long‐term implantation. Soft, flexible electrodes demonstrate improved longevity, but pose a new challenge with regard to simple and accurate surgical implantation. A high aspect ratio water‐soluble microneedle is developed based on sucrose which permits straightforward surgical implantation of soft, flexible microelectrodes. Here, a description of the microneedle manufacturing process is presented, along with in vitro and in vivo safety and efficacy assessments. Successful fabrication requires control of the glass transition temperature of aqueous sucrose solutions. The insertion force of 5 different microneedle electrode vehicles is studied in agarose brain phantoms, with the sucrose microneedle eliciting the lowest insertion force and strain energy transfer. Short‐ and long‐term assessments of the pathological response to sucrose microneedle implantations in the brain suggest minimal tissue reactions, comparable to those observed following stainless‐steel hypodermic needle punctures. Finally, microelectrodes fabricated from graphene, carbon nanotubes, or platinum are embedded in sucrose microneedles and implanted into an epileptic rat model for 22 d. All electrodes are functional throughout the implantation period, with the graphene electrode exhibiting the largest seizure signal‐to‐noise ratio and only modest changes in impedance