In Vitro Effects of Biomaterials on Mesenchymal Stem Cells Viability and Proliferation
Mesenchymal stem cells (MSCs) are increasingly being used in regenerative medicine to repair various tissue types. This study aimed to assess changes in MSCs properties as a result of their interaction with two biomaterials in order to evaluate their in vitro compatibility. We have used two types of biomaterials, as follows: hydroxyapatite anodized titanium (HA-Ti) is used in bone reconstruction; it is hard and remains in the body, while patches of collagen combined with poly-e-caprolactone (C-PCL) are utilized in the reconstruction of soft tissue (particularly the skin); these patches resorb in the body, being only a temporary matrix that fosters and accelerates tissue formation. We have chosen to assess changes in morphology, viability and proliferation of MSCs obtained by lipoaspirate, through direct contact with the biomaterial or in eluate. MSCs properties were assessed by optical microscopy, fluorescence microscopy after acridine orange/ethidium bromide (AO/EB) staining, and the MTT assay. After result interpretation, we gained an image of the cytotoxicity phenomenon seen during the experiment and were able to assess viability of cell in contact with the biomaterials used. HA-Ti shows better interaction with cells, which preserve their viability, and does not influence MSCs growth, proliferation or morphology. In contrast, cells on C-PCL matrix become small, spherical, were detached from the plate and had lower viability percentage.
Numerical Analysis of a Plastic Deformation Composite Panel
The paper is focused on the comparison between the experimental test and numerical analysis of a composite panel wich is subject to plastic deformation. An experiment was done on a sandwich panel made from steel – extruded polystyrene – steel, wich was subjected to a static plastic deformation with help of an sferical indenter. During the test the force applied to the indenter and the vertical displacement of the steel panels were measured. The experimental values were compared with the results of numerical simulation, wich was done with help of ANSYS-Static Structural module. Important aspects of FEA, such as material idealization, contact approach between bodies, mesh size and boundary conditions, are discussed and their influence on the results are highlighted. The results of this study are vey useful for investigation of beahviour at impact of composite materials such as steel-polystyrene sandwich panels.
Possible Dynamics of Polymer Chains by Means of a Ricatti’s Procedure - an Exploitation for Drug Release at Large Time Intervals
In this paper, we propose an analyzis method for the dynamics of polymer chains, based on a Ricatti procedure induced by possible correlations through the compatibility of the thermal radiation-classical damped oscillator dynamics. Then, the quantification (radiation frecquency is directly proportional to the color temperature) and the erasure of one bit of information becomes a natural processes induced by the system structure itself. The theory has implications in the dynamics of biological structures (arhitecture of tumors, information on tumor growth and angiogenesis, etc.) in the form of Resonant Recognition Model.
Functional and Nonfunctional Parameters in Patients with Occupational Lung Diseases
Patients with occupational lung diseases (OLD) may present respiratory functional impairment, exertional dyspnea and decreased exercise tolerance. These factors lead to reduced daily physical activity, social isolation, decreased quality of life (QoL) and depression. Assessment of respiratory functional status in patients with OLD in correlation with the presence of anxiety and depression and the quality of life in patients with OLD, as extrapulmonary comorbidities. In patients with diagnosed OLD, the following parameters were evaluated: pulmonary function tests (FEV1, FVC), anxiety and depression with Hospital Anxiety and Depression Scale (HADS), and QoL by St George Respiratory Questionnaire (SGRQ). 46 non-smoking patients (9 females) were included in this study: occupational asthma (10), occupational COPD (20), pneumoconiosis (16). Mean aged 58.98±11.84SD years old. Anxiety and depression were present in 35 patients (76.08%). Mean HADS score was 14.3 points±7.25SD, and a severe psychological impairment (HADS > 16) was found in 16 cases (34.8%). The highest incidence of anxiety and depression was found in COPD (85%, mean HADS score 16.05 points±8.18SD), followed by pneumoconiosis (75%, mean HADS 13.5 points±6.87SD) and OA (60%, mean HADS score 12.2 points±5.45SD). The QoL was affected in all patients, with a mean SGRQ score of 52.7 points±16.1SD; the most affected was the activity domain. In patients with OLD, extrapulmonary manifestations may be encountered, such as anxiety, depression and ultimately impaired QoL. This may indicate that treatment of these patients should be multidisciplinary, including psychosocial support.
Flexural Strength of Single Polymer Polyester Composites as a Measure of Material Degradation
The study compares flexural strength of single polymer polyester composites. Composites under examination had the form of laminates differing in the content of the reinforcement phase and the type of material subject to simulated absorption of distilled water and sea water. Simulation tests of distilled water and sea water absorption for single polymer polyester composites with 5% to 20% reinforcing phase were made in accordance with the PN-EN ISO 62:2008 standard. The determination of the measure of degradation of the composites, the magnitude of the bending stress, was conducted in accordance with the PN-EN ISO:178 standard. This work is part of a research relating to the quality and recycling of single polymer composite materials. The testing part of the research is aimed to define the properties of examined materials before they are used commercially in specific products.
Dynamic Mechanical Properties of Hybrid Layered Silicates/Kaolin Geopolymer Filler in Epoxy Composites
Preparation epoxy based hybrid composites were involved kaolin geopolymer filler, organo-montmorillonite at 3phr by using high speed mechanical stirrer. A mechanical behaviour of neat epoxy, epoxy/organo-montmorillonite and its hybrid composites containing 1-8phr kaolin geopolymer filler was studied upon cyclic deformation (three-point flexion mode) as the temperature is varies. The analysis was determined by dynamic mechanical analysis (DMA) at frequency of 1.0Hz. The results then expressed in storage modulus (E’), loss modulus (E”) and damping factor (tan d) as function of temperature from 40 oC to 130oC. Overall results indicated that E’, E’’ and Tg increased considerably by incorporating optimum 1phr kaolin geopolymer in epoxy organo-montmorillonite hybrid composites.
Hematoxylin - Eosin-Methylene Blue Staining in a Dog Hepatic Amyloidosis Case
A post-mortem examination of an 1,5 years old Shar- Peis, dog was performed in order to find out the death cause. The macroscopically examination revealed a large amount of blood in the abdominal (hemoperitoneum) The liver was sampled for histopathological examination. Hematoxylin-eosin–methylene blue staining wasperformed in order to prepare the samples for microscopical examination. Based on the specific histopathological changes and taking into account all the pathological data, the diagnosis was liver amiloidosis.
Co-expression of p16/ki-67 in Associated with Human Papilloma Virus Type 16
The current trend in screening against cervical cancer is to improve the sensitivity of screening method and p16/Ki-67 dual-stained cytology, represents a promising approach. We performed a study to investigate the correlation between the p16/Ki-67 co-expression and HPV type on a group of patients with ASCUS and LSIL on Pap smear. On all patients, dual stain test and HPV genotyping were performed. In the group of patients with positive dual stain p16/ki-67 test, the number of patients with HPV type 16 was significantly higher than the number of patients with any other type of HPV. Also, all patients with CIN3 or above (cervical cancer) were positive for p16/Ki-67. Our study shows the potential use of those two tests to identify patients with high risk for severe dysplasia.
A-mode Ultrasound Analysis of Postoperative Thigh Edema in Patients with Hip Fracture
Postoperative edema and lean body mass may contribute to functional outcome in frailty hip fracture patients. Advances in body mass determination have produced consistent results with A-mode ultrasound. We therefore aimed to determine the utility of A-mode ultrasound in analyzing postoperative limb edema in patients receiving treatment for proximal femur fractures. 4 males and 6 females, with an average age of 74.3 years were included. 4 had fractures of the femoral neck treated by hemiarthroplasty and the rest had extracapsular fractures which were stabilized with short intramedullary nails. Measurements were done using a commercially available A-mode 2.5MHz transducer on the thighs approximately 15 cm proximal to the patella. Comparison showed significant difference between the operated and contralateral thigh circumference (P=0.001) as well as muscle layer thickness differences between femoral neck patients and those with fractures of the trochanteric region (P=0.016). There was no correlation between the A-mode ultrasound determined superficial layer difference and entire layer difference (R2=0.037; P=0.59). However, there was linear correlation between the A-mode ultrasound determined entire layer difference and limb circumference difference, (R2=0.414; P=0.044). Postoperative thigh edema is present in all surgically treated patients for proximal femur fractures. A-mode ultrasound might be a reliable tool to examine adipose and muscle layers separately in the immediate postoperative period. There may be a difference in edema distribution between femoral neck and peritrochanteric fractures but larger samples are required.
In vitro Study on the Dimensional Stability of Interocclusal Recording Materials
The teeth are found in the alveolar processes of both the upper and lower jaw and they form the two maxillary and mandibular dental arches, the various relations of which support the performance of the dental apparatus functions, one of the most important of which is mastication. These relations are also known as interocclusal relations, among which the moments in which the dento-dental contacts (occlusal relations) play an important role. Maximum intercuspation (MI) is the most frequent mandibulo-cranial functional position with dento-dental contact. The vast majority of functional food incision and mastication cycles end in MI. The highest number of dento-dental contacts, and the largest possible stability and surface of these contacts are also achieved in MI. Given the relative easiness of determination, recording and transfer of the MI position, it is used in many clinical situations to report the models of the two arches. The interocclusal recording materials used in our study were seven silicones, six of which with addition reaction, five with special destination for interocclusal relation determination and a putty-like silicone normally used for dental arch impression – Elite HD and one condensation silicone used for impressions. The reason for choosing the last two materials was the fact that some practitioners frequently use putty-like impression silicone to determine interocclusal relations. According to the findings of the measurements shown in table 1, further to the initial impression process, at the time T0, satisfactory results were obtained both for addition silicones and for condensation silicones, Registrado X-tra being the only recording material which exhibited major deviation from the standard dimension (3 mm). As for the Optosil condensation silicone, we noted a significant increase of the thickness of the material starting with the first hour after impression and reaching considerable values on the 5th day, which were 0.3 mm higher than the standard value. Rigid addition silicones have the lowest dimensional stability; putty-like silicones are frequently used to record interocclusal relations for fixed prosthetics, which is wrong since they grow rapidly and this impedes on the space between the treated tooth and the opposite tooth, the result being a high restoration, which may determine premature contacts. Except for Optosil, which exhibited a continuous increase, most materials may be used to mount models in the simulator after 24 h.