Investigation of ballistic gelatin based phantom models for computed tomography, x-ray and ultrasound imaging devices

Simulation-based medical education provides a learner-centered environment in which novice, intermediate and advanced practitioners can learn or practice their skills without harming patients. Medical device phantoms are specially designed objects that are used in simulation based trainings as well as technical features such as evaluating, analyzing and adjusting the performance of devices. Ballistic gelatin is a member of the 250A-Bloom hydrogel family, which mimics human muscle tissue in terms of mechanical properties. In this study, ballistic gelatinbased phantoms were produced and examined on medical device images. According to the results, it is suggested to use phantom models as a medical device phantom in device training. The main advantages of these models are that their production is practical and economical.Simülasyon temelli tıbbi eğitim; acemi, orta ve ileri düzey pratisyenlerin hastalara zarar vermeden becerilerini öğrenebilecekleri veya pratik yapabilecekleri, öğrenen merkezli bir ortam sağlar. Tıbbi cihaz fantomları, cihazların performansını değerlendirmek, analiz etmek ve ayarlamak gibi teknik özelliklerinin yanında simülsyon temelli eğitimlerde de kullanılan ve özel olarak tasarlanan nesnelerdir. Balistik jelatin, mekanik özellikleri açısından insan kas dokusunu taklit eden 250A-Bloom hidrojel ailesinin bir üyesidir. Bu çalışmada balistik jelatin esaslı fantomlar üretilmiş ve tıbbi cihaz görüntülerinde incelenmiştir. Elde edilen sonuçlara göre, hazırlanan fantom modellerinin cihaz eğitimlerinde bir tıbbi cihaz fantomu olarak kullanılması önerilmektedir. Bu modellerin en büyük avantajları üretiminin pratik ve ekonomik olmasıdır

Freezing of Apheresis Platelet Concentrates in 6% Dimethyl Sulfoxide: The First Preliminary Study in Turkey

Objective: Transfusion of platelet suspensions is an essential part of patient care for certain clinical indications. In this pioneering study in Turkey, we aimed to assess the in vitro hemostatic functions of platelets after cryopreservation. Materials and Methods: Seven units of platelet concentrates were obtained by apheresis. Each apheresis platelet concentrate (APC) was divided into 2 equal volumes and frozen with 6% dimethyl sulfoxide (DMSO). The 14 frozen units of APCs were kept at -80 °C for 1 day. APCs were thawed at 37 °C and diluted either with autologous plasma or 0.9% NaCl. The volume and residual numbers of leukocytes and platelets were tested in both before-freezing and post-thawing periods. Aggregation and thrombin generation tests were used to analyze the in vitro hemostatic functions of platelets. Flow-cytometric analysis was used to assess the presence of frozen treated platelets and their viability. Results: The residual number of leukocytes in both dilution groups was <1x106. The mean platelet recovery rate in the plasma-diluted group (88.1±9.5%) was higher than that in the 0.9% NaCl-diluted group (63±10%). These results were compatible with the European Directorate for the Quality of Medicines quality criteria. Expectedly, there was no aggregation response to platelet aggregation test. The mean thrombin generation potential of postthaw APCs was higher in the plasma-diluted group (2411 nmol/L per minute) when compared to both the 0.9% NaCl-diluted group (1913 nmol/L per minute) and the before-freezing period (1681 nmol/L per minute). The flowcytometric analysis results for the viability of APCs after cryopreservation were 94.9% and 96.6% in the plasma and 0.9% NaCl groups, respectively. Conclusion: Cryopreservation of platelets with 6% DMSO and storage at -80 °C increases their shelf life from 7 days to 2 years. Besides the increase in hemostatic functions of platelets, the cryopreservation process also does not affect their viability rates

Smart tourniquet system for military use

Extremities are the most frequently injured regions of body encountered with the combat casualties. The extremity hemorrhages constitute the leading cause of preventable deaths in the first aid period. Thus, tourniquets are indispensable devices for combat casualty care. There are some military tourniquets, which are produced worldwide and can be manually applied by the wound to prevent blood loss. However, in military applications, there is no tourniquet system comprising these features that can be used with one hand, can be applied quickly and transmits information. We have developed a tourniquet system which applies the required pressure to the extremity of the person by moving a belt connected to the pulley with a motor. When the arm or leg buttons on the device are pressed, the system is activated. Once the belt is fitted to the extremity, the system automatically starts the tourniquet process and is continued until the bleeding is stopped. The information of the blood flow and force applied are acquired via the feedback from the motor encoder and the force sensor. The system starts the tourniquet process and the bluetooth transmits the location and application time of the tourniquet. The receiver informs the headquarters via the military communication standard. In this respect, it is possible to be informed about exact location of the injured soldiers in the hot zone. In order to test the developed tourniquet, we have produced the leg phantoms which consist of femur bones and plastics similar to in actual dimensions of the human leg and artificial veins. Tourniquet operation was applied to the point where the tourniquet operated blood flow stopped. It is thought that the developed system will be used in military applications and internal security

Geology and formation of Nevruztepe Fe-Cu skarn mineralization (Kayseri-Turkey)

The Nevruztepe iron-copper prospect is a skarn near Yeşilhisar (Kayseri). It has been overlooked as a potential producer of copper. the skarn was generated in Permian to Jurassic carbonate rocks by the Eocene Yahyalı granitic pluton. Lithologic units, including skarns, dip about 15 degrees southward. Skarns are both prograde (garnet and diopside) and retrograde (epidote); both exoskarn and endoskarn exist. Most of the magnetite is in a quartz-sulfide stage in retrograde skarn that is cut by veins and lenses containing quartz-pyrite-chalcopyrite. Granite and mineralized skarn are rare at the surface. From 2013 to 2015, 31 drill holes (totaling 6.178,5 m) encountered skarn to a depth of 450 m. Mineralized zones vary from 1,2 to 54,7 m thick. Fe mean grade ranges from 12% to 49%; mean copper grades vary from 10 to 4650 ppm. the deposit contains 5.096.788 tonnes of mineralized material. Microscopy on samples of drill core shows that the ore minerals are primarily magnetite, hematite, and chalcopyrite. Some magnetite is altered to hematite. Experiments show that with grinding to 100 microns the iron can be beneficiated to 66%. Waste from separation of the magnetite is 0.16 to 0.19% Cu; with flotation this was beneficiated to 19% Cu

Lower limb phantom design and production for blood flow and pressure tests

Phantoms are specifically designed objects that are utilized or imaged to evaluate, analyze and tune the performance of experimental devices. In this project, it is aimed to design a phantom that responds in a similar manner with how human blood circulation would act in specific flow and pressure tests such as pulse measurement. Ballistic gelatin is a member of hydrogel family with 250 Bloom value which resembles human muscle tissue in terms of mechanical features. That’s why we carried out a uniaxial compression test on our gelatin sample to analyze its similarity of human muscle tissue in terms of elastic modulus, stiffness and rupture strength. Test results indicated that our gelatin sample has approximate values with organic human muscle tissue. Designed model was X-rayed and the similarities of the model to human texture were compared. After producing of lower limb phantoms, we carried out a circulation test through them by the aid of a peristaltic pump to simulate the actual blood circulation of human body limbs. This designed phantom is made ready for available flow and pressure tests

Prevention of Intraabdominal Adhesions: An Experimental Study Using Mitomycin-C and 4% Icodextrin

Background: Intraabdominal adhesions remain a significant cause of morbidity and mortality. Moreover, intraabdominal adhesions can develop in more than 50% of abdominal operations. Aims: We compared the anti-adhesive effects of two different agents on postoperative adhesion formation in a cecal abrasion model. Study Design: Experimental animal study. Methods: Forty Wistar albino type female rats were anesthetized and underwent laparotomy. Study groups comprised Sham, Control, Mitomycin-C, 4% Icodextrin, and Mitomycin-C +4% Icodextrin groups. Macroscopic and histopathological evaluations of adhesions were performed. Results: The frequencies of moderate and severe adhesions were significantly higher in the control group than the other groups. The mitomycin-C and Mitomycin-C +4% Icodextrin groups were associated with significantly lower adhesion scores compared to the control group and 4% Icodextrin group scores (p=0.002 and p=0.008, respectively). The adhesion scores of the Mitomycin-C group were also significantly lower than those of the 4% Icodextrin group (p=0.008). Conclusion: Despite its potential for bone marrow toxicity, Mitomycin-C seems to effectively prevent adhesions. Further studies that prove an acceptable safety profile relating to this promising anti-adhesive agent are required before moving into clinical trial

Development and evaluation of orally disintegrating tablets comprising taste-masked mirtazapine granules

<p><b>Introduction:</b> Orally disintegrating tablets (ODTs) provide an important treatment option for pediatric, geriatric and psychiatric patients. In our previous study, we have performed the initial studies for the formulation development and characterization of new ODT formulations containing a bitter taste drug, mirtazapine, coated with 6% (w/w) Eudragit^® E-100 (first group of formulations, FGF) without taste evaluation. In present study, coating ratio of the drug was increased to 8% (w/w) (second group of formulations, SGF) to examine the effect of increased coating ratio of drug on <i>in vitro</i> characterization of the formulations including <i>in vitro</i> taste masking study.</p> <p><b>Materials and methods:</b> Coacervation technique using Eudragit^® E-100 was employed to obtain taste-masked mirtazapine granules. FGF and SGF were compared to original product (Remeron SolTab, an antidepressant drug which produced by pellet technology) in terms of <i>in vitro</i> permeability, <i>in vitro</i> taste masking efficiency which was performed by dissolution studies in salivary medium and dissolution stability. Also, the other tablet characteristics (such as diameter, thickness) of SGF were examined.</p> <p><b>Results and discussion:</b> The disintegration time of the SGF were found as A1 < A2 < A3 < A5 < A4 (8% Eudragit^® E-100), but all of the formulations dissolved under 30 seconds and friability values were less than 1%. <i>In vitro</i> taste masking efficiency studies demonstrated that C2 formulation (in FGF) had the most similar dissolution profile to Remeron SolTab.</p> <p><b>Conclusions:</b> According to these findings, B2 or C2 (with citric acid or sodium bicarbonate, respectively, with 6% Eudragit^® E-100) formulations could be promising alternatives to Remeron SolTab.</p