Browse Articles

In the last years, health care professionals faced with an increasing number of patients suffering from wounds, burns and bedsores difficult to treat and heal. During the wound healing process, the dressing protects the injured area and contributes to the recovery of dermal and epidermal tissues. Because their biocompatibility, biodegradability and similarity to macromolecules recognized by the human body, some natural polymers such as polysaccharides (alginates, chitin, chitosan), proteoglycans and proteins (collagen, gelatin, fibrin) are extensively are used in wounds and burns management. The study presents a research of new semi-solid formulations of bio-composites based on chitosan extracted from the stone crab Pachygrapsus Mormoratus found on the Black Sea shores. The bio-composites were obtained from natural polymeric compounds, Chitosan (CT), hyaluronic acid (HA) and lanolin(L), to which silver sulfadiazine (S), was added. Several semi-solid formulations have been performed for which the antimicrobial activity on gram-positive and gram-negative germ cultures and the rheological behavior was studied. The bio-composites that were obtained provide an optimal micro-environment for cell proliferation, migration and differentiation, due to their biocompatibility, biodegradability, peculiar structure and good antimicrobial activity.

The paper treats Finite Element Analysis (FEA) specific to the mechanical behavior of a structural layer cap type with polymer cellular cores within a pressure vessel. The layered composite structure comprises two outer polymer shells (synthetic glass/ plexiglass) and cellular polymer core with triangular shaped cells. This analysis uses the Autodesk Inventor 2016 Professional 3D design and modeling software, in conjunction with the FEA analysis program, ANSYS 14.5 - Workbench, using the Mesh module. Mechanical behavior of the structural models specific to the four types of test caps, each having different cellular polymer core (ABS, PLA, PC and CF, 3 and 5 mm thickness), is revealed through the analysis of the state of stresses and deformations and correlating the FEA simulation results with experimental testing. Since the analysis leads to quasi-equivalent results under identical conditions of application until the fracture of the caps, it is found that such an FEA approach of the mechanical system components occupies an important place in the modern design process, being one of the ways of identifying the deformation fields and equivalent stresses in the analyzed composite structures.

This paper presents the solvents effect on the mechanical and thermal properties of films of styrene-butadiene and styrene-isoprene block copolymers with the majority diene phase, obtained by spin casting.

The article presents the process of manufacturing by adding solid state material (thermoplastic extrusion) in order to achieve new composite deposition materials and to provide new models, raw materials and functional prototypes with superior mechanical features and characteristics. The authors describe the extrusion device as well as the parts manufactured of thermoplastic material.

Placental blood circulation has certain features that allow the exchange of nutrients between the maternal and fetus blood, respectively allow exchanges of nutrients between the mother and the fetus. We studied 50 human placentas. The method used in the case of our study is a standardized method of the Laboratory of Anatomy and Embryology, Victor Babes University of Medicine and Pharmacy, Timisoara, for over 50 years. The making of corrosion concoction followed the recipe of the laboratory using type AGO II plastic substances, differently coloured and then subjected to the corrosive action of hydrochloric acid. The model of corrosion preparations showed the distributions known as dichotomic and magisterial distribution. The normal development of placenta remains a major factor in the growth and development of the fetus, and maternal-fetal vasculature in the placenta is essential in this regard.

In this paper we present a study that was conducted to determine the classification of causes that generate defects in products obtained by injection of plastic material. A classification of the causes of defects is made by applying a quality management tool - the Ishikawa diagram. The causes are grouped into M categories, for defects generated by the design process and for defects generated by the injection process. A new model of the diagram is created by composing two fish skeletons (model 4M + 5M). At the end of the paper, the importance of the Ishikawa diagram is shown.

Collagen hydrolysers are three-dimensional polymeric materials with limited cross-linking and high hydrophilicity, having multiple medical applications. The most used collagen is the one extracted from bovine skin, which is now the industrial source of collagen. Due to the outbreak of some threatening diseases such as BSE, transmissible spongiform encephalopathy, foot-and-mouth disease, researchers have sought a safer alternative to collagen. This was the marine resource, which offered multiple opportunities to capitalize on clean sea-water raw material. This paper presents a comparative study of the physico-chemical properties of collagen hydrogels derived from collagen obtained from calf and skin from the Black Sea. Physico-chemical and spectrophotometric analyzes were performed to determine the structure. Studies have been conducted to analyze rheological behavior, antioxidant activity and antimicrobial activity. The total antioxidant capacity (ACL) is higher for collagen mixtures with 40% ethyl alcohol and shows higher values for fish collagen compared to calf collagen. Antimicrobial analysis shows that all collagen hydrogels show antimicrobial activity, both gram-positive (Staphylococcus aureus ATCC 6538P) and gram-negative (Escherichia coli ATCC 10536), which increases with increasing collagen concentrations.

Postoperative pain is a common symptom in the postoperative period in patients treated for incisional hernia, often refractory to treatment. The purpose of the this paper was to conduct a comparative study on the need for analgesic medication in patients operated for incisional hernia through a classical open approach and a laparoscopic approach. In this respect, we performed a retrospective observational study over a period of 4 years in which we introduced 92 patients operated for incisional hernia in the Surgery Clinic No. 1 of the Emergency County Hospital Tirgu Mures. For the reconstruction of the abdominal wall we used prosthetic materials (surgical meshes). All patients included in the study received only metamizole sodium as analgesic medication. The patients studied were divided into two groups: group A (consisting of 57 patients where open, classic surgical approach was used) and group B (consisting of 35 patients treated using a minimally invasive laparoscopic approach). It was observed that on the day of surgery and during the first two postoperative days there are no statistically significant differences in the need for analgesic medication between the studied groups. Instead, starting with the third postoperative day, the need for analgesic medication is much lower in patients where laparoscopic surgical procedure was used than in those where open, classic surgical approach was used.

The aim of the present study is to model the steady heat transfer of the engine polyamide intake manifold. Under the condition of a steady flow, the intake manifold wall temperature and the intake air temperature were measured to examine the effect of the thermal boundary layer on the heat transfer. Experimental data is used to generate the numerical model of airflow simulation through the intake manifold.

Hepatocellurar carcinoma (HCC) is the most frequent primary hepatic tumor, the vast majority of patients have less than a 12 month survival rate. The aim of this study was to evaluate the efficacy of TACE in patients with HCC, based on a case series and literature review. The study included 12 consecutive patients with HCC who underwent surgical treatment (resection, liver transplantation ± resection) at the Department of Transplantation and Surgery, Semmelweis University, Budapest, during 2009-2015. All the patients received at least one TACE session. Patients with BCLC B-stage who benefit from TACE and another alternative therapy (eg, RFA) may be associated with or exhibit tumor stagnation, or tumor necrosis in most cases. In C BCLC stages, desperate cases - the two patients to whom TACE was the last therapeutic attitude, despite the predicted prognosis, TACE assured the prolongation of life and increased life quality. In the majority of patients in this study, stage A BCLC, chemoembolization was a therapeutic attitude that allowed subsequent liver transplantation (when it was not feasible initially due to tumor size) or liver resection in apparently inoperable cases. The arterial chemotherapy is the unanimously accepted indication in patients with stage B, BCLC. The data presented encourages us to opt for TACE with the intention of destaging BCLC and giving an operability character to the hepatic tumors (resection ± hepatic transplantation). In stage C BCLC, TACE can be a last attempt to improve the quality of life and to control tumor progression.