Tubular Electrospun Composite Scaffolds for Potential Bone Tissue Engineering

poster abstractElectrospinning is an adaptable method in which polymer solutions or melts converted into micro or nano scale fibers. In this procedure, polymer solutions are loaded into 10 mL syringes that contained millimeter scale nozzles. High voltage (20-30 kV) was applied to polymer solutions at the tip of the nozzle to stabilize the surface tension by electrostatic force. The critical point where this stabilization occurred is called Taylor cone and it lets the droplets to turn into polymer sprays. The fibers were collected onto a tubular rotational collector, which was grounded. Different tubular scaffolds composed of pure polycaprolactone (PCL), small intestinal submucosa (SIS), hydroxyapatite (HA) and tricalciumphosphate (TCP) were prepared by using the electrospinning technique. 13 and 15 wt% pure PCL stock solutions were prepared by dissolution in 1,1,1,3,3,3-hexafluoro-2-propanol (HPF) and stirring at the room temperature until a viscous translucent liquid was acquired. Composite PCL/SIS and PCL/HA dopes were prepared from 10 wt% PCL stock by adding SIS or HA in an 8:1 (PCL:SIS, PCL:HA) dry weight ratio. Similarly, PCL/HA/TCP solutions were made from 13 wt% PCL stock by adding HA and TCP in a 8:1:1 dry weight ratio. Each individual scaffold will be scanned through electron microscope (ECM) to gather information about the % porosity and the diameter of the electrospun fibers. Mechanical testing will be conducted to measure the tensile strength of the fibers. Finally, implanting the tubular scaffolds into axolotls will test cell biocompatibility of the scaffolds

Partially Demineralized Macroporous (PDM) Allografts for Cranial Tissue Engineering

poster abstractDecompressive Craniectomy is a cranial surgery where a large part of the cranial bone is removed in order to mitigate swelling in the brain tissue. Consequently, a scaffold biomaterial is required to substitute the lost bone. Ideal cranioplasty biomaterials should have the following features: fit the cranial defect and achieve complete closure, radiolucency, resistance to infections, no dilation with heat, resistance to biomechanical wear, pliability, and inexpensive. Partially Demineralized Macroporous (PDM) allografts exhibit such properties to correct these cranial defects. The main objectives of this study include: (1) examining the effects of demineralization and macroporosity formations on the mechanical and biological properties of allograft bone disks; (2) conducting finite element analysis (FEA) to stimulate the mechanical properties of the PDM allografts; and (3) evaluating the in vitro response of the PDM allografts utilizing pre-osteoblast cell lines. Tibias were harvested from Ossabaw mini-pigs and cylindrical cortical bone sections of 2 mm in thickness and 8 mm in diameter were obtained. Macropores of 600 micrometers in diameter were created to generate porosity levels of 0-40% in the bone disks. The bone disks were then demineralized in 14-wt% EDTA for 6 to 48 hours at 37℃. The relative stiffness was determined for each class using a material testing machine with a loading rate of 1 mm/min using a piston-on-ring set up. To analyze the deformation characteristics, FEA software LS-DYNA was employed. In order to understand the in vitro response, biocompatibility of PDM scaffolds were evaluated by culturing MC3T3-E1 cell lines where XTT and ALP assays were conducted. PDM allografts display the suitable stiffness required for cranial defects. The PDM allograft scaffolds aid in osteogenic proliferation and differentiation of pre-osteoblast cell lines in vitro. However, there will be further in vivo testing regarding the validity of PDM allografts in rat cranial defects. Mentor: Tien-Min Gabriel Chu, Department of Restorative DentistryDecompressive Craniectomy is a cranial surgery where a large part of the cranial bone is removed in order to mitigate swelling in the brain tissue. Consequently, a scaffold biomaterial is required to substitute the lost bone. Ideal cranioplasty biomaterials should have the following features: fit the cranial defect and achieve complete closure, radiolucency, resistance to infections, no dilation with heat, resistance to biomechanical wear, pliability, and inexpensive. Partially Demineralized Macroporous (PDM) allografts exhibit such properties to correct these cranial defects. The main objectives of this study include: (1) examining the effects of demineralization and macroporosity formations on the mechanical and biological properties of allograft bone disks; (2) conducting finite element analysis (FEA) to stimulate the mechanical properties of the PDM allografts; and (3) evaluating the in vitro response of the PDM allografts utilizing pre-osteoblast cell lines. Tibias were harvested from Ossabaw mini-pigs and cylindrical cortical bone sections of 2 mm in thickness and 8 mm in diameter were obtained. Macropores of 600 micrometers in diameter were created to generate porosity levels of 0-40% in the bone disks. The bone disks were then demineralized in 14-wt% EDTA for 6 to 48 hours at 37℃. The relative stiffness was determined for each class using a material testing machine with a loading rate of 1 mm/min using a piston-on-ring set up. To analyze the deformation characteristics, FEA software LS-DYNA was employed. In order to understand the in vitro response, biocompatibility of PDM scaffolds were evaluated by culturing MC3T3-E1 cell lines where XTT and ALP assays were conducted. PDM allografts display the suitable stiffness required for cranial defects. The PDM allograft scaffolds aid in osteogenic proliferation and differentiation of pre-osteoblast cell lines in vitro. However, there will be further in vivo testing regarding the validity of PDM allografts in rat cranial defects

Assessment of the requisites of microbiology based infectious disease training under the pressure of consultation needs

<p>Abstract</p> <p>Background</p> <p>Training of infectious disease (ID) specialists is structured on classical clinical microbiology training in Turkey and ID specialists work as clinical microbiologists at the same time. Hence, this study aimed to determine the clinical skills and knowledge required by clinical microbiologists.</p> <p>Methods</p> <p>A cross-sectional study was carried out between June 1, 2010 and September 15, 2010 in 32 ID departments in Turkey. Only patients hospitalized and followed up in the ID departments between January-June 2010 who required consultation with other disciplines were included.</p> <p>Results</p> <p>A total of 605 patients undergoing 1343 consultations were included, with pulmonology, neurology, cardiology, gastroenterology, nephrology, dermatology, haematology, and endocrinology being the most frequent consultation specialties. The consultation patterns were quite similar and were not affected by either the nature of infections or the critical clinical status of ID patients.</p> <p>Conclusions</p> <p>The results of our study show that certain internal medicine subdisciplines such as pulmonology, neurology and dermatology appear to be the principal clinical requisites in the training of ID specialists, rather than internal medicine as a whole.</p

A Central Asian Food Dataset for Personalized Dietary Interventions

Nowadays, it is common for people to take photographs of every beverage, snack, or meal they eat and then post these photographs on social media platforms. Leveraging these social trends, real-time food recognition and reliable classification of these captured food images can potentially help replace some of the tedious recording and coding of food diaries to enable personalized dietary interventions. Although Central Asian cuisine is culturally and historically distinct, there has been little published data on the food and dietary habits of people in this region. To fill this gap, we aim to create a reliable dataset of regional foods that is easily accessible to both public consumers and researchers. To the best of our knowledge, this is the first work on the creation of a Central Asian Food Dataset (CAFD). The final dataset contains 42 food categories and over 16,000 images of national dishes unique to this region. We achieved a classification accuracy of 88.70% (42 classes) on the CAFD using the ResNet152 neural network model. The food recognition models trained on the CAFD demonstrate the effectiveness and high accuracy of computer vision for dietary assessment

Incidence of Major Adverse Cardiac Events at 6-Months Follow-Up in Covid-19 Positive Versus Covid-19 Negative Patients

Background: The post-acute cardiovascular (CV) events due to COVID-19 is a topic of interest. We explored long-term major adverse cardiac events (MACE) related to COVID-19, defined as MI, thromboembolic events (TE), CHF, arrhythmias, and death. Methods: This is a longitudinal study of COVID-19 positive (CoVP) and negative patients (CoVN) in the first month of the pandemic with at least one follow-up encounter after 6 months. Continuous measures were summarized using means and standard deviation and compared between groups using Student's t-tests. Categorical measures were summarized using count and compared using Fisher's exact test. Results: Of 2298 patient tests between 3/6/20 and 4/5/20, 394 (50% CoVP, age 57.9±19.4, 49.2% F, and 50% CoVN, age 57.7±18.3, 49.2% F) were selected. Encounters included ED (29.7%) and inpatient (70.3%) visits. Prevalence of preexisting CV risk factors (HTN, HLD, DM, and tobacco use) were similar in CoVP and CoVN (65.5% vs 66.5%, p NS), while CHF (13.7% vs 21.8%, p 0.048), prior MI (8.6% vs 16.2%, p 0.032), and arrhythmias (15.2% vs 24.4%, p 0.031) were more prevalent in CoVN. In the cohort, 48.2% of CoVP and 60.9% of CoVN had a 6-month follow up encounter (p 0.015). The incidence of MACE in CoVP was 27.5%, whereas, in CoVN it was 42.5% (Figure 1). Conclusion: In a matched cohort of CoVP vs CoVN at the start of the pandemic, 6-month MACE was similar. False negative testing, limited access to healthcare early in the pandemic, and a high rate of comorbidities among CoVN may explain our results