Lise Öğrencilerinin ve Biyoloji Öğretmenlerinin Biyoloji Alanındaki Yeni Gelişmelerden Haberdar Olmasında Basının Rolü

In this study, the level of awareness of high school students and biology teachers on the latest developments in “Biology– the science of 2000s” from the printed media is evaluated. To perform this evaluation, a questionnaire is implemented to high school students and biology teachers. The survey consists of 3 chapters. The survey is answered by  314 high school students and 18 biology teachers. Rates and frequencies of the students’ answers are found through descriptive analysis and. factor analysis for the questions in the second chapter is performed.Bu çalışmada, lise öğrencileri ve biyoloji öğretmenlerinin, biyoloji biliminde son yıllarda gerçekleşen ve biyoloji öğretim programındaki “2000’li Yılların Bilimi Biyoloji” bölümünde yer alan gelişmeleri, basından takip etme alışkanlıkları ve bu haberlere ilgi seviyeleri araştırılmıştır. Bu amaçla lise öğrencileri ile biyoloji öğretmenlerine yönelik anket uygulanmıştır. Uygulanan anket üç bölümden oluşmaktadır. Anket toplam 314 lise öğrencisi ve 18 biyoloji öğretmenine uygulanmıştır. Öğrencilerin anket sorularına verdikleri cevapların yüzde ve frekansları belirlenmiştir. Anketin ikinci bölümündeki sorularla ilgili faktör analizi yapılmıştır. Öğretmenlerin anket sorularına verdikleri cevapların yüzde ve frekansları belirlenmiş ve betimsel analiz yapılmıştır

Kinetic model of photosensitized homolysis of erythrocytes: multihit target theory

Fotosensitize edilmis eritrositlerdeki hemoliz hız kinetigini örnek sistem olarak kullanarak, hücre zarındaki fotosensitizasyon mekanizmasının açıklanması amaçlanmıstır. Fotohemolizin ısıga baglı olusan hasar (fotokimyasal safha) ve termal aktivasyonun (termal safha) birlikte olan etkisiyle olustugunu kabul eden “Çok Vuruslu HedefTeori” 'de; her safhadaki kinetik düzen özel vuru sayıları ile belirlenebilmektedir. Fotohemoliz hızı formülüyle hesaplanmıs olup, sistemde %50 hemoliz olması için gerekli olan karanlık inkübasyon zamanını, uygulanan ısık dozunu, protoporfirin konsantrasyonu , reaksiyon sabitini, ve ise ölçülen üssel degerleri belirtmektedir. Deneyde, pH 7.4, 10 mM tuzlu fosfat tamponda hazırlanan insan eritrositleri degisik konsantrasyonlarda protoporfirin IX ile fotosensitif hale getirilmis ve ısıga maruz bırakılarak gecikmis fotohemoliz ölçümleri yapılmıstır. Ayrıca gecikmis fotohemoliz verileri “ÇokVuruslu HedefTeori” kullanılarak incelenmistir. Fotohemoliz egrileri s-seklinde olup, düsük protoporfirin konsantrasyonu ve ısınlama zamanında t degeri daha uzamıs olarak ölçülmüstür. Gecikmis fotohemoliz ölçümlerinde, fotohemoliz hızının sogurulan ısınımın karesiyle orantılı oldugu belirlenmistir. Deneysel ve modelle hesaplanan fotohemoliz egrileri uyum içindedir. “Çok Vuruslu Hedef Teori” ile, fotohemoliz sonuçlarının karakterize edilmesi ve karsılastırması açısından önemli oldugu gösterilmistir. Bu kinetik modelle belirlenen degisik konsantrasyonda fotosensitif ajan ve ısık dozunun fotohemoliz egrileri üzerine olan etkisinin, ölçülen deneysel verilerle uyum içinde olması ile “ÇokVuruslu HedefTeori” desteklenmektedir.By using rate kinetics of photosensitized hemolysis of erythrocyte as a model system, understanding the mechanism of photosensitization on the cell membrane was purposed in this work. Photohemolysis required the combined effect of the light activated (photochemical stage) and thermal (thermal stage) process, and these stages can be represented by “MultihitTarget Theory”, defined with photochemical and thermal hit numbers. Photohemolysis rate was calculated by using where is the dark incubation time required for 50% hemolysis, L is the incident light dose, is the bound dye concentration, and are the “as measured” exponents, and g is the reaction constant. Erythrocyte suspension, which was prepared in pH 7.4 10 mM phosphate buffered saline, was photosensitized with various concentration of protoporphyrin IX and was irradiated by visible light. Then, delayed photohemolysis was measured for each sample, and data were analyzed using “MultihitTarget Theory”. Prolonged t values were measured on delayed photohemolysis curve (s-shaped) with low protoporphyrin IX concentration and irradiation time. Delayed photohemolysis measurements are indicative of second power dependence of the photohemolysis rate on the absorbed light energy. Photohemolysis data obtained from experiments and kinetic model calculations were in good agreement. “Multihit Target Theory” is important for characterizing and comparing photohemolysis results. The effects of various concentrations of photosensitizers and light doses on photohemolysis curve were analyzed with kinetic model. Thus, experimental data were in good agreement with recent kinetic model, based on “MultihitTarget Theory”

Preliminary assessment of an injectable extracellular matrix from decellularized bovine myocardial tissue

WOS:000717618000007PubMed ID34043893The goal of this study was to develop an injectable form of decellularized bovine myocardial tissue matrix which could retain high levels of functional ECM molecules, and could gel at physiological temperature. Dissected ventricular tissue was processed by a detergent-based protocol, lyophilized, enzymatically-digested, and neutralized to form the injectable myocardial matrix (IMM). Histochemical analysis, DNA quantification, and agarose gel electrophoresis demonstrated the efficiency of the applied protocol. Chemical, thermal, morphological, and rheological characterization; protein and sulfated glycosaminoglycan (sGAG) content analysis were performed, in vitro biological properties were evaluated. An in vivo histocompatibility and biodegradability study was performed. Histochemistry revealed complete removal of myocardial cells. DNA content analysis revealed a significant decrease (87%) in the nuclear material, while protein and sGAG contents were highly preserved following decellularization. Soluble IMM was capable of turning into gel form at ∼37 °C, indicating selfassembling property. In vitro findings showed the biomaterial was noncytotoxic, nonhemolytic, and supported the attachment and proliferation of mesenchymal stem cells. In vivo study demonstrated IMM was well-tolerated by rats receiving subcutaneous injection. This work demonstrates that the IMM from decellularized bovine myocardial tissue has the potential for use as a feasible regenerative biomaterial in prospective tissue engineering and regenerative medicine studies

Assessment of dopamine-conjugated decellularized bovine tendon extracellular matrix as a bioadhesive

In this study, a bioadhesive based on catechol and extracellular matrix was developed and characterized in detail. At first, cells were removed from bovine tendon tissue to obtain tendon extracellular matrix (t-ECM), then its acellularity was confirmed. The decellularized tissue was digested enzymatically to yield an injectable form of t-ECM with a high content of protein, collagen and sulfated glycosaminoglycans. Next, conjugation of dopamine to t-ECM was performed under acidic, neutral, and basic pH conditions, either in the presence of O2 or under N2 flow. Conjugation of dopamine to t-ECM was determined by FT-IR, 1H NMR and UV–vis analysis, while catechol groups in the structures were quantified by Arnow method. The findings revealed that neutral and basic conditions are more suitable for dopamine conjugation. The physical properties of the bioadhesive were also determined by swelling and mass loss analysis. The conjugates exhibited good cytocompatibility and hemocompatibility and showed good cell adhesion. The lap-shear test using skin tissue showed that the t-ECM-dopamine conjugate has high adhesive strength and can be considered as a potential bioadhesive for the future

Evaluation of Human Osteoblasts on NIPS Micro-Patterned PCL Carriers Containing Nanohydroxyapatite and Reduced Graphene Oxide Using PSµM

The content and surface topology of tissue engineering scaffolds are two important parameters in regulating the cell behavior. In this study, a phase separation micromolding (PSµM) method was implemented to develop micro-groove-imprinted poly(ε-caprolactone) (PCL)–nano hydroxyapatite (nHAp)–reduced graphene oxide (rGO) ternary blend constructs. Physical and chemical characterizations of cell-devoid constructs were performed by FTIR, XRD, TGA, DSC, porosity, swelling, wettability analysis, tensile and compression mechanical tests. The in vitro biological performance of human osteoblasts cultured on micro-patterned blend constructs was evaluated by MTT and alamarBlue viability assays. The findings revealed that nHAp and rGO significantly promote cell viability and proliferation, while the micro-pattern determines the direction of cell migration. Alkaline phosphatase and Ca2+ analyses were carried out to determine the osteogenic properties of cell-laden constructs. This study describes a simple method to generate topologically modified ternary blend PCL/nHAp/rGO constructs using the PSµM method, which contributes to cell proliferation and migration, which is particularly important in regenerative medicine

A comparative study on the <i>in vitro</i> cytotoxic responses of two mammalian cell types to fullerenes, carbon nanotubes and iron oxide nanoparticles

<p>The present study was designed to evaluate and compare the time- and dose-dependent cellular response of human periodontal ligament fibroblasts (hPDLFs), and mouse dermal fibroblasts (mDFs) to three different types of nanoparticles (NPs); fullerenes (C₆₀), single walled carbon nanotubes (SWCNTs) and iron (II,III) oxide (Fe₃O₄) nanoparticles via <i>in vitro</i> toxicity methods, and impedance based biosensor system. NPs were characterized according to their morphology, structure, surface area, particle size distribution and zeta potential by using transmission electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller, dynamic light scattering and zeta sizer analyses. The Mössbauer spectroscopy was used in order to magnetically characterize the Fe₃O₄ NPs. The hPDLFs and mDFs were exposed to different concentrations of the NPs (0.1, 1, 10, 50 and 100 μg/mL) for predetermined time intervals (6, 24 and 48 h) under controlled conditions. Subsequently, NP exposed cells were tested for viability, membrane leakage and generation of intracellular reactive oxygen species. Additional to <i>in vitro</i> cytotoxicity assays, the cellular responses to selected NPs were determined in real time using an impedance based biosensor system. Taken together, information obtained from all experiments suggests that toxicity of the selected NPs is cell type, concentration and time dependent.</p

Mesenchymal stem cell infusion in haploidentical hematopoietic stem cell transplantation in patients with hematological malignancies

Ctr Int Blood & Marrow Transplant Res, Amer Soc Blood & Marrow Transplanta