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There is a growing need for small-diameter (6 mm) off-the-shelf synthetic vascular conduits for different surgical bypass procedures, with actual synthetic conduits showing unacceptable thrombosis rates. The goal of this study was to build vascular grafts with better compliance than standard synthetic conduits and with an inner layer stimulating endothelialization while remaining antithrombogenic.Tubular vascular conduits made of a scaffold of polyurethane/polycaprolactone combined with a bioactive coating based on chondroitin sulfate (CS) were created using electrospinning and plasma polymerization. In vitro testing followed by a comparative in vivo trial in a sheep model as bilateral carotid bypasses was performed to assess the conduits' performance compared to the actual standard.In vitro, the novel small-diameter (5 mm) electrospun vascular grafts coated with chondroitin sulfate (CS) showed 10 times more compliance compared to commercial expanded polytetrafluoroethylene (ePTFE) conduits while maintaining adequate suturability, burst pressure profiles, and structural stability over time. The subsequent in vivo trial was terminated after electrospun vascular grafts coated with CS showed to be inferior compared to their expanded polytetrafluoroethylene counterparts.The inability of the experimental conduits to perform well in vivo despite promising in vitro results may be related to the low porosity of the grafts and the lack of rapid endothelialization despite the presence of the CS coating. Further research is warranted to explore ways to improve electrospun polyurethane/polycaprolactone scaffold in order to make it prone to transmural endothelialization while being resistant to strenuous conditions.

The study was carried out to analyse the price spread, marketing efficiency and marketing cost of tomato. The Prayagraj district of Uttar Pradesh was selected purposively for the study because of the large amount of tomato production. Due to the perishable nature of tomato the farmers couldn’t stock up and had to sale in lean month. So, there wasn’t much difference in marketable and marketed surplus of tomato. The percentage of marketable surplus was highest in medium size farm group i.e., 95.28 percent followed by small farmers with 94.94 percent and large size farmers with 94.02 percent. The average marketable surplus was 320.09 quintals that is 94.75 percent. The average total marketing cost was Rs 800/qtls, the average net price received by the farmers was Rs 2000/qtls the average price spread was Rs 800/qtls, and the average Marketing efficiency was Rs 2.5/qtls.

This work highlights the importance of surface modification on the quality and quantity of spheroid formation on microfluidic-based biochips.

Tailoring a bilayer hydrogel's 3D deformation by utilizing the CNCs’ constraint effect on PNIPAM in a nano-sized fibrous structure.

Les maladies cardiovasculaires sont une des causes de mortalités les plus élevées mondialement. Parmi celles-ci, on retrouve l’infarctus du myocarde, qui n’a pour traitement que la transplantation cardiaque. Or, dû à la faible quantité de donneur, une solution alternative est recherchée. De ce fait, l’ingénierie tissulaire permet le développement de tissus et d’implants thérapeutiques tels les patchs cardiaques, qui peuvent être bioimprimés. Or, une des limitations actuelles de l’utilisation d’une telle stratégie est la vascularisation de tissu bioimprimés. Dans cette étude, la bioimpression 3D a été utilisée afin de bioimprimer des patchs perfusables de gélatine méthacrylate (GelMA) à utiliser potentiellement pour le tissu cardiaque. Il a été possible de développer une bioencre pouvant être utilisée pour une application dans le tissu cardiaque, d’évaluer l’imprimabilité de l’encre et de bioimprimer de patchs standards et perfusables. Pour ce faire, GelMA a été synthétisé et les propriétés mécaniques ont été évaluées pour finalement sélectionner une encre de 10 % GelMA, ayant un module de Young approprié pour le tissu cardiaque, de 23,7±5,1 kPa. Par la suite, les processus d’impression, standard et coaxial, de patchs standards et perfusables ont pu être optimisés. Finalement, des patchs perfusables de GelMA 10% et gélatine 2% ont pu être imprimés avec une viabilité cellulaire élevée, jusqu’à 79,7±8,7 % et 83,5±5,7 % obtenue aux jours 1 et 7 de culture respectivement, avec des fibroblastes 3T3. La présence de canaux vides et la perfusabilité des patchs démontrent le potentiel de cette méthode pour éventuellement bioimprimer des patchs cardiaques vascularisés épais., Cardiovascular diseases are a leading cause of death worldwide. Myocardial infarction captures a significant segment of this population, and the end-stage myocardial infarction can only be treated by heart transplantation. However, due to the scarcity donors, tissue engineering has been considered as an alternative solution. Tissue engineering allows the development of tissues and therapeutic implants such as cardiac patches. However, one of the main hurdles in the use of such a strategy is the vascularization of bioprinted tissue. In this study, 3D bioprinting was used to bioprint perfusable gelatin methacrylate (GelMA) patches for a potential use in cardiac tissue. This work consists in the development of a bioink that can be used for the cardiac tissue, the evaluation of the printability of the ink, and the final bioprinting of standard and perfusable patches. For this purpose, GelMA was synthesized and a final concentration of 10 % was selected as it showed an appropriate Young's modulus for cardiac tissue, of 23.7±5.1 kPa, while maintaining high biocompatibility. Subsequently, the printing process of standard and perfusable patches could be optimized with the use of GelMA and gelatin inks. Finally, 10% GelMA and 2% gelatin vascularized patches could be printed with high cell viability, of up to 79,7±8,7 % and 83,5±5,7 % on days 1 and 7 of culture respectively for 3T3 fibroblasts. Additionally, the presence of hollow channels of the perfusable patches demonstrates the potential of this method to be eventually applied to the bioprinting of thick vascularized cardiac patches.

This poster was given by Sayeda Musaad Hussain and Saleh Al Ajji, Rawda Bint Jassim Secondary School for Girls تعزيز التعاون بين مركز مصادر التعلم مع مؤسسات المجتمع المحلي في نشر ثقافة القراءة. تتنوع أدوار هذه المراكز كما هو متعارف عليه عالمياً ما بين أدوار تعليمية وثقافية وترفيهية، وذلك من خلال المشاركة مع مؤسسات الدولة كمكتبة قطر الوطنية , مكتبة متحف الفن الإسلامي , دور النشر المختلفة , جامعة قطر , مؤسسة حمد الطبية , وزارة الأوقاف والشؤون الإسلامية وغيرها من مؤسسات الدولة وذلك لرفع مستوى ثقافة الفرد، والمساهمة الفاعلة في تحقيق التقدم والرقي للمجتمع، والرفعة للوطن وتحقيق رؤية قطر 2030

Polyethylene terephthalate (PET) pre-prepared nano/micro fibers were treated by sodium hydroxide (NaOH) aqueous solution and then AgNPs were loaded on them through the soaking process. In total, eight samples were created. Then they were characterized by field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), X-ray energy diffraction (EDS) spectroscopy and Fourier transform infrared (FTIR). Disk diffusion and colony counting tests were also performed. Samples containing AgNPs had growth inhibition zones with diameters between 19 and 26 mm while control samples had no inhibition zone. PET microfibers containing AgNPs had a larger inhibition zone on Staphylococcus aureus compared to other samples. The innovation of this research is the placement of AgNPs on the hydrophilic PET micro/nano fibers.

PurposeBid/no-bid decision is a significant and strategic decision, which must be finalized at an early stage of the bidding process. Such decision-making may have significant impact on the performance of the contractors. Using Chi-square Automatic Interaction Detector (CHAID) and Classification and Regression (CRT) decision tree algorithms, this paper aims to develop bid/no-bid models for design-bid-build projects for contractors.Design/methodology/approachThe models in this study have been developed using CHAID and CRT algorithms. Thirty-four bid/no-bid key factors were collected via extensive research. The bid/no-bid factors were listed based on their importance index as a result of a questionnaire distributed among the construction professionals. These factors were divided into five main risk categories – owner, project, bidding situation, contract and contractor – which were taken as inputs for the models. Split-sample validation was applied for testing and measuring the accuracy of the CHAID and CRT models. Moreover, Spearman's rank correlation and Analysis of Variance (ANOVA) tests were employed to identify the statistical features of the received 169 responses.FindingsThe key bid/no-bid factors in construction industry were categorized in five related groups and ranked based on the relative importance index. It was found that the top 6 ranked bid/no-bid factors were (1) current workload, (2) need for work, (3) previous experience with employer; (4) timely payment by the employer; (5) availability of other projects for bidding (6) reputation of employer in the industry. Matrix comparison between all bid/no-bid groups was performed using Spearman's correlation to measure the relationship between each of the two paired groups. It was concluded that all the relationships were positive.Originality/valueExisting bidding models require many inputs and advanced understanding of mathematics and software to run the model. Contractors tend to use easy, fast and available support methods. Excluding a great number of the bid/no-bid factors may affect the final decision. This paper proposes a bid/no-bid decision tree models for contractors of different sizes. It is the first study in the literature, to the best of authors' knowledge, to study bid/no-bid decision with the proposed decision tree algorithm. The proposed models in this study overcome the shortfalls of most previous models such as avoiding the complexity and difficulties of applying the concept. The proposed model will provide the contractors with a bid/no-bid decision based on the input for the defined bid factor groups. The proposed models display the soft spots and hot spots between the independent and dependent variables, which leads to a better decision. The proposed models display the result effectively in visual terms, easy to understand and easy to apply. The proposed models are a form of multiple effect (or variable) analysis which allows the companies to explain, describe, predict or classify an outcome.