Biyomühendislik Bölümü Koleksiyonu

Bu koleksiyon için kalıcı URI

https://hdl.handle.net/20.500.12899/17

Listeleniyor 1 - 20 / 30

Enhancement of Heat Transfer Performance of a Heat Pipe by Using Calcium Magnesium Carbonate-Ethylene Glycol/Water Nanofluid with Sodium Dodecylbenzene Sulfonate
(Budapest University of Technology and Economics, 2022) Yılmaz Aydın, Duygu; Gürü, Metin; Sözen, Adnan
In this paper, the effect of using CaMg(CO3)2/Ethylene Glycol-water (50:50%) as a working fluid on the thermal performance of thermosyphon heat pipe was experimentally studied. Nanofluid was prepared by two-step method using 2% concentration of CaMg(CO3)2 nanoparticle and 0.05% surfactant (Sodium dodecylbenzene sulfonate). For the experimental set-up, a straight copper pipe of one-meter length was used. The inner diameter of the pipe is 13 mm, and the outer diameter is 15 mm. Experiments were conducted at three different cooling water mass flow rates (5, 7.5, and 10 g/s) and different heating powers (200, 300, 400 W) to test heat pipe performance. It was observed that the CaMg(CO3)2 nanofluid reduced the average wall temperature of the heat pipe according to the base fluid. Furthermore, the efficiency and thermal resistance of the heat pipe were investigated separately for EG/water and CaMg(CO3)2 nanofluid. The maximum heat transfer enhancement was obtained as 9.55% under 400 W heating power and 10 g/s cooling water mass flow rate conditions and the maximum improvement in thermal resistance was observed as 21% at 200 W and 10 g/s cooling mass flow rate. Viscosity and specific heat of base fluid and CaMg(CO3)2 nanofluid were also determined and compared to each other.
The Effects of SARS CoV-2 nsp13 Mutations on the Structure and Stability of Helicase in Chinese Isolates
(İstanbul Üniversitesi / İstanbul University, 2022) Akbulut, Ekrem
Objective: Coronavirus Disease 2019 (COVID19) is a viral disease caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2). The high mutation propensity of the SARS CoV-2 genome is one of the biggest threats to the long-term validity of treatment options. Helicases are anti-viral targets because of the vital role they play in the viral life cycle. In this study, changes in the protein structure caused by SARS CoV-2 nsp13 mutations were investigated to contribute to the development of effective antiviral drugs. Materials and Methods: Genome data of 298 individuals located in the China location were examined. The mutant model was built using deep learning algorithms. Model quality assessment was done with QMEAN. Protein stability analyses were performed with DynaMut2 and Cutoff Scanning Matrix stability. Changes in substrate affinity were performed with Haddock v2.4. Results: In this study, twenty-eight mutations in nsp13 were identified (23 sense, 5 missense). The changes in protein structure caused by the five missense mutations (Leu14Phe, Arg15Ser, Arg21Ser, Leu235Phe, Ala454Thr) were modeled. The mutations caused a decrease in the stability of SARS CoV-2 helicase (-0.99, -1.66, -1.15, -0.54, and -0.73 for Leu14Phe, Arg15Ser, Arg21Ser, Leu235Phe, Ala454Thr, respectively). The mutations reduced the helicase's affinity to the substrate. The docking scores for wild-type and mutant helicase were -84.4±1.4 kcal.mol-1 and -71.1±6.7 kcal.mol-1, respectively. Conclusion: Helicase mutations caused a decrease in the protein stability and nucleic acid affinity of the SARS CoV-2 helicase. The results provide important data on the development of potential antivirals and the effect of mutation on the functions of viral proteins.
Preparation of 10-undecenoic acid based polyurethane/PCL fibers by electrospinning method and investigation of their antifungal properties
(Springer, 2022) Açarı Karaca, İdil; Boran, Filiz; Kolak, Seda; Tatlıcı, Eray; Yeşilada, Özfer; Köytepe, Süleyman; Ateş, Burhan
Nowadays, in the treatment of such fungal infections, antifungal drugs in various forms are one of the most preferred methods. These medications can be in the form of creams and lotions, shampoos, pills, suppositories, powders, or sprays. The dose of the drugs is adjusted according to the type and growth area of the fungus, the severity of the symptoms, and the medical history of the patients. Dressing materials with antifungal properties are an alternative treatment method used for the treatment of fungal skin infections. These covers not only treat fungal infections but also prevent their spread. Within the scope of this study, polyurethane-based wound dressing materials (PU-UDA/PCL) with antifungal properties were developed. Electrospining method was used to produce these dressing materials and the surface area of the wound dressing material was increased, thereby increasing the effect of antifungal property. Polypropylene glycol, glycerol, and catechin as polyol were preferred in polyurethane (PU) synthesis. These structures were polymerized with isophorone diisocyanate and modified with 10-undecenoic acid. Obtained 10-undecenoic acid modified polyurethane (PU-UDA) structures were transformed into wound dressing structure with polycaprolactone (PCL) by electrospinning method. Structural, morphological, and thermal properties of the wound dressing materials were analyzed with different instrumental analysis methods. The antifungal activities of PU-UDA/PCL were tested. Antifungal tests were performed on C. albicans and C. tropicalis. Therefore, PU-UDA/PCL series could be used as an efficient antifungal agent. Finally, it was determined that the obtained 10-undecenoic acid-based polyurethane fibers have a suitable structure and feature for the treatment of many fungal infections.
Investigation of changes in protein stability and substrate affinity of 3CL-protease of SARS-CoV-2 caused by mutations
(Sociedade Brasileira de Genetica, 2022) Akbulut, Ekrem
3CLpro of SARS-CoV-2 is one of the enzymes required for the replication process of the virus responsible for the COVID-19 pandemic. In this study, changes in protein stability and substrate affinity caused by mutations were investigated to stir the development of potent inhibitors. Sequence data of samples were obtained from the NCBI Virus database. Mutation analyses were performed with RDP4 and MegaX. 3CLpro tertiary models were created using Robetta. Molecular docking for peptidomimetic substrate and inhibitor ligand was done with Autodock v4.2 and Haddock v2.4. Protein stability analysis was performed using mCSM stability and DynaMut2. Twenty-four missense mutations in 3CLpro were identified in this study. Changes in the 3CLpro structure induced by the mutations Met49Thr, Leu167Ser, and Val202Ala resulted in significant levels of instability (-2.029,-2.612,-2.177 kcal.mol-1, respectively). The lowest interaction energy for substrate was-58.7 kcal.mol-1 and-62.6 kcal.mol-1 in wild-type and mutant, respectively. The lowest docking energy for ligand was-6.19 and-9.52 kcal.mol-1 for wild-type and mutant, respectively. This study reports for the first time that mutations cause increased substrate affinity of 3CLpro from SARS-CoV-2. This research provides important data for the development of potent peptidomimetic inhibitors for the treatment of COVID-19.
Chemistry and engineering of brush type polymers: Perspective towards tissue engineering
(Elsevier, 2022) Karaca Açarı, İdil; Sel, Evren; Özcan, İmren; Ateş, Burhan; Köytepe, Süleyman; Thakur, Vijay Kumar
In tissue engineering, it is imperative to control the behaviour of cells/stem cells, such as adhesion, proliferation, propagation, motility, and differentiation for tissue regeneration. Surfaces that allow cells to behave in this way are critical as support materials in tissue engineering. Among these surfaces, brush-type polymers have an important potential for tissue engineering and biomedical applications. Brush structure and length, end groups, bonding densities, hydrophilicity, surface energy, structural flexibility, thermal stability, surface chemical reactivity, rheological and tribological properties, electron and energy transfer ability, cell binding and absorption abilities for various biological molecules of brush-type polymers were increased its importance in tissue engineering applications. In addition, thanks to these functional properties and adjustable surface properties, brush type polymers are used in different high-tech applications such as electronics, sensors, anti-fouling, catalysis, purification and energy etc. This review comprehensively highlights the use of brush-type polymers in tissue engineering applications. Considering the superior properties of brush-type polymer structures, it is believed that in the future, it will be an effective tool in structure designs containing many different biomolecules (enzymes, proteins, etc.) in the field of tissue engineering.
Çukurova Yöresi Yapı Taşlarının Fiziksel Özellikleri Üzerine Bir Araştırma
(2020) Biçer, Ayşe
Bu çalışmada, Adana ve yöresinde bina yapı elemanı olarak kullanılan Saimbeyli taşı, Kozan taşı, Kadirli taşı ve İçel taşları incelenmiştir. Amaç bölgede bina yapı elemanı olarak kullanılan bu taşların ısıl ve mekanik özelliklerini araştırarak bina yapı elemanı olarak özelliklerinin belirlenmesidir. Her taş için, iki farklı ocaktan numuneler alınmış kimyasal içerikleri ve oranları belirlendikten sonra, ısıl iletkenlik, özgül ısı kapasitesi, basınç gerilmesi, su emme, teneffüs kabiliyeti ve aşınma oranları deneylerine tabi tutulmuştur. Sonuçlar, geleneksel yapı malzemeleri ile karşılaştırıldığında, taşların mekanik değerleri kabul edilebilir fakat ısıl özellikleri yönünden zayıf olduğu görülmüştür.
Determination of thechemicalstructure of dietbiscuitswith modern enstrumentaltechniques
(2021) Karaca Açarı, İdil
There are too many deficiencies in the studies in terms of diet biscuit in the literature. This study aims to fill this gap in the literature. The % moisture content, structural content verification, thermal stability, degradation properties and % ash content of diet biscuit samples, structural characterizations, surface micromorphology and detailed structural analysis were determined with fast, precise, new instrumental techniques. Thermal degradation of the lemon-fiber diet biscuit sample started at 250 °C in four stages and completed at 585 °C. There is three-stage thermal degradation in wholemeal diet biscuit samples, starting at 229 °C and completed at 580 °C. There are 46.06% C, 1.60% N, 0.12% S and 6.68% H in lemon-fiber diet biscuits, and 45.51% C, 2.39% N, 0.15% S and 7.05% H in whole-wheat diet biscuits. Ca, K, Mg, Na, Zn element contents in diet biscuit samples were determined by AAS technique. In the diet biscuit samples, K was determined as the element with the highest amount and the element with the least amount was Zn. As a result, the work is comprehensive and original. It is believed that the study will fill an important gap in the literature and will be a useful resource for researchers.
Endoplasmic reticulum aminopeptidase-1 polymorphism increases the risk of rheumatoid arthritis
(2022) Akbulut, Ekrem; Yıldırım, Tülay; Öztürk, Onur
Objectives: Endoplasmic reticulum aminopeptidase-1 (ERAP1) polymorphic changes cause autoimmunity. To understand the contribution of ERAP1 to the occurrence of rheumatoid arthritis (RA) disease, we investigated the relationship between ERAP1 and RA. Methods: This study was conducted with 201 patients and 171 healthy controls. The rs26653, rs27044, rs27582, rs28096, and rs30187 polymorphic regions of ERAP1 were investigated. The comparison was done with Arlequin software and logistic regression. Haplotypes were analyzed with Phylogenetic Network software. ERAP1 was modeled using Promod3. Topological changes in ERAP1were analyzed with TM-Score. Results: The results showed that rs26653G>C (p=0.002, OR=2.001, 95%CI=1.276–3.137), rs27044C>G (p=0.037, OR=1.583, 95%CI=1.028–2.440), rs27582G>A (p<0.05, OR=0.348, 95%CI=0.194–0.622) and rs30187C>T (p=0.006, OR=1.849, 95%CI=1.191–2.870) polymorphisms are associated with RA disease risk. The relationship between rs28096 polymorphism and RA disease risk could not be determined (p=0.509). The risk haplotype for rheumatoid arthritis was determined as [CGAAT]. It was determined that polymorphisms of ERAP1 cause changes in the entry pocket of substrate and ligand. Conclusions: We report a haplotype [CGAAT] that is associated with RA risk from Turkey that has not been described before. These data will make important contributions to elucidating the molecular mechanism of RA.
THERMAL AND MECHANICAL PROPERTIES OF BUILDING STONES IN AFYON AND KARAMAN REGION
(Bartın Üniversitesi, 2020) Biçer, Ayşe
In this study, some of the physical properties of the Seydiler and Sorkun stones from Afyon and Kızılören and Kazım Karabekir stones from Karaman which have been used extensively as a building material in cities and even in neighbor cities were investigated. Used as construction components, these stones are highly praised by the people living in those areas due to their ease of handling and convenient thermal characteristics. The aim is to determine the thermal and mechanical properties of these stones. Samples were taken from two different quarries for each stone and after chemical analysis, they were subjected to thermal conductivity, specific heat capacity, water absorption, inhalation ability and mechanical strength tests. The results were compared with other building materials, especially in terms of energy saving, strength and comfort aspects.
A Research On The Physical Features Of Concretes With Ferro-Chromium Slag
(Bartın Üniversitesi, 2020) Biçer, Ayşe
In this study, waste ferrochromium slag is used instead of using natural aggregate, and low density concrete is produced. For this purpose, slag aggregate is mixed with 10%, 30%, 50% and 70% cement to produce samples. The tests applied to the samples show that an increase in slag in the mix decreases thermal conductivity, specific heat capacity and comprehensive and tensile strength while porosity and water absorption capacity increases. If slag aggregated concrete is used for the structural member of a building, i) factory waste ferro chromium slag will be utilized and contributed to economy. ii) The use of slag in building concrete, bricks, briquettes and panel walls will lower the heating expenses and facilitate energy saving.
Kalsiyum floroborat sentezi, kinetik ve alev geciktirici özelliklerinin belirlenmesi
(TENMAK Bor Araştırma Enstitüsü, 2021) Yılmaz Aydın, Duygu; Güngör, Gülden; Gürü, Metin; Çakanyıldırım, Çetin
Bu çalışmada özel bor bileşiklerinden olan kalsiyum floroboratın sentez parametreleri belirlenmiş ve pamuklu kumaştaki alev geciktirici özelliği incelenmiştir. Ayrıca kinetik çalışmalar yapılarak reaksiyon mertebesi ve aktivasyon enerjisi hesaplanmıştır. Kalsiyum floroborat, reaktant olarak kalsiyum oksit ve floroborik asit kullanılarak yaş yöntemle sentezlenmiştir. İncelenen parametreler; reaktant mol oranı (nCaO/nHBF4), sıcaklık ve reaksiyon süresidir. Karakterizasyon çalışmaları için FT-IR, XRD ve BF4- iyon seçici elektrot kullanılmıştır. Termal davranışın karakterize edilmesinde termogravimetrik-diferansiyel termal analiz (TG-DTA) kullanılmıştır. Kalsiyum floroborat, 1:4 reaktant mol oranı, 90?C sıcaklık ve 100 dakika reaksiyon süresinde %97 verimle sentezlenmiştir. Ayrıca yapılan kinetik çalışmada reaksiyonun birinci mertebeden olduğu belirlenmiş ve reaksiyonun aktivasyon enerjisi 19,14 kJ/mol olarak bulunmuştur. Sentezlenen kalsiyum floroboratın alev geciktirici özelliğini tespit etmek için LOI testinden yararlanılmıştır. Testler sonucunda kalsiyum floroboratın çok iyi alev geciktirici özellik gösterdiği gözlemlenmiştir.
Assessment of The Experience and Mood of COVID-19 Pandemic Care Nurses
(Malatya Turgut Özal Üniversitesi, 2020) Aksoy, Aziz; Demirtaş, Havva; Bayraktar, Havva
Epidemics and pandemics have affected many societies at various times throughout human history. In the 21st century, the world is still struggling with epidemics and pandemics. Nurses play important roles in healthcare practices during infectious disease pandemics and other epidemic diseases. Therefore, they are at risk of direct patient care and exposure to contagious diseases. In this study, during the COVID-19 outbreak, pandemic care nurses; It is aimed to examine their experiences and moods with a questionnaire. This work; was conducted with the participation of 50 (13 Male + 37 Female) volunteer nurses who directly care for COVID-19 patients or suspects. Online survey questions were asked to determine the experiences and moods of the nurses during the interventions. The data obtained were analyzed with IBM SPSS 20® program. All of the participants were trained in care nursing. Participants were forced, 60% (30) of them in the habit of using personal protective, disinfectant and clothing. 78% (39) experienced insomnia, stress and anxiety, but only 2% (1) reported using sleeping pills, 36% (17) practiced meditation, muscle relaxation and breathing exercises. During this difficult period, 62% (31) of the nurses were found to be exposed to verbal/physical aggression by their patients/relatives. A significant relationship has been found between exposure to verbal or physical violence by patients / patient relatives and the Marital status-professional working year (P <0.05). As a result, the COVID-19 Pandemic process imposes both an intense work pace and a heavy responsibility for nurses. Changes in work habits brought along both psychological and physical stress and looking at the data, the fact that the COVID-19 Pandemic process took longer than expected created psychological burnout in nurses. Despite all this, nurses overcome these difficulties with their experiences.
Fenol ve Bor Esaslı Çevre Dostu Pigmentin Deniz Araçlarında Boya Olarak Kullanılabilirliği
(Gazi Üniversitesi, 2021) Olgun, Şeyma; Yılmaz Aydın, Duygu; Gürü, Metin; Ertürk, Aybüke Ayşe
Türkiye, etrafı denizlerle çevrili bir ülke olması sebebiyle deniz araçlarında kullanılan boyalar oldukça önemli hale gelmektedir. Cu2O2 içeren antifouling boyaların salınım sınırlamalarında kontrol gerekmektedir ve bakır içermeyen çevre dostu antifouling boyaların kullanımının zorunlu olacağı öngörülmektedir. Deniz araçlarında kullanılan antifouling boya pigmenti ilk olarak milli kaynaklardan sentezlenecek olup antifouling boya piyasasındaki ihtiyaç karşılanmış olacaktır. Bu çalışmada ilk olarak özel bor bileşiklerinden biri olan fenil floroborat sentez parametreleri belirlenerek daha sonra elde edilen pigmentin boyada kullanılabilirliği ve disk yöntemi ile antibakteriyel özelliği test edilmiştir. Yaş yöntem ile fenil floroborat sentezinde reaktant olarak fenol ve floroborik asit kullanılmış olup H2SO4 katalizör olarak tercih edilmiştir. Reaktant mol oranı ((nC6H5OH / nHBF4) = 1:1; 1,5:1; 2:1 ve 2,5: 1), sıcaklık (30 °C, 35 °C, 40 °C, 50 °C ve 60 °C) ve reaksiyon veriminde etkili reaksiyon süresi sentez parametreleri olarak incelenmiştir. Karakterizasyon çalışmaları için FT-IR ve BF4- iyon seçici elektrot kullanılmıştır. Fenil floroborat, reaktant mol oranı, sıcaklık ve reaksiyon süresi sırasıyla 2:1, 35 °C ve 90 dakika olduğunda % 62 verimle sentezlenmiştir. Pigment epoksi tür bağlayıcı ile solvent bazlı antifouling boya haline dönüştürülmüş olup deniz suyunda bekletildiğinde boya formunu korumuştur. Antibakteriyel aktivite, agar disk difüzyon yöntemi kullanılarak incelenmiş olup boya halindeki numunede difüzyondan kaynaklı antibakteriyel özellik görünmezken fenil floroborat pigmenti antibakteriyel özellik göstermiştir.
Effect of Alkaloids on SARS-CoV-2
(Malatya Turgut Özal Üniversitesi, 2020) Yılmaz Aydın, Duygu; Gürü, Metin; Gürü, Selahattin
The use of herbs in treatment has started with the history of humanity and a significant number of effective drugs are being developed from herbal sources. Primary and secondary metabolites, which are natural products produced by plants, are the most basic products of the industry directly or indirectly. One of these groups is alkaloids. Alkaloids show antiviral effects in viral diseases. COVID-19, which started in China and spread to many countries, has become an epidemic that threatens all humanity worldwide as a "Coronavirus Pandemic". No reliable and certified drug has yet been developed for this virus. Recent important research shows that plant-based substances can be potential candidates for developing effective and safe drugs against this virus. Referring to such recent studies, this study primarily shows that the antiviral potentials of some alkaloids especially quinine and artemisinin and its derivatives. In addition, the importance of antiviral plant substances in the development of a broad-spectrum drug for SARS-CoV-2 is emphasized.
Temperature and Relative Humidity Models of The Malatya City
(Malatya Turgut Ozal University, 2020) Biçer, Ayşe
In this study, the temperature changes Malatya provinces located in the Euphrates Basin are analyzed and modeled on the basis of 24 years of observation process (1996-2019). Relative humidity models were analyzed by observing the yearly mean temperatures of provinces, the lowest mean temperatures of winter months (December, January and February) and the highest mean temperatures of summer months (June, July and August). With the help of these models; temperature and humidity estimations can be made for future years and these models can be used in energy related studies
Investigation of Obesity Tendency of University Students with Bioelectric Impedance Body Analyzer
(Malatya Turgut Ozal University, 2020) Aksoy, Aziz; Sele, Halime; Oğur, Seda
Aim: In this study, it was tried to investigate the obesity tendency of the students of Bitlis Eren University with Bioelectrical Impedance Body Analyzer. Materials and Methods: A total of 400 volunteer students, 200 girls and 200 boys, were included in the study. Findings: According to Body Mass Index (BMI) values were found that 19.5% of the girl students were weak, 68.5% of them were normal weight, 11.0% of them were overweight and 1.0% of them were obese, 4.5% of the boy students were weak, 71.0% of them were normal weight, 22.0% of them were overweight and 2.5% of them were obese. According to body fat ratio were determined that 40.0% of the girl students were in the obesity tendency risk group and 48.0% of them were obese, 56.0% of the boy students were in the obesity tendency risk group and 26.0% of them were obese. According to the waist/hip ratio were revealed that 95.5% of the girl students were in the obesity tendency group and 4.0% of them were obese, 85.5% of the boy students were in the obesity tendency group and 4.0% of them were obese. The difference between sex and fat ratio, waist/hip ratio, and BMI values and the difference between age and fat ratio, waist/hip ratio, and BMI values were found significant (p<0.05). Result: Obesity is at a high level among university students.
Analyzing of the Viscosity by Using Artificial Neural Networks
(2020) Işık, Esme
The nano networks with many thousands of devices which are working cooperatively to complete challenging tasks, ultra-responsive to changes in the environment, and self-replicating devices are called nano devices (nano machine). It is thought that the studies in this field will contribute greatly to the developments in the field of nano technology. Many models have been proposed to provide nano or macro-scale systems such as molecular communication, interstitial or inter-neural communication. In these systems, information is carried by the molecules in the diffusion medium and the viscosity of the medium is an important parameter. In this study, some of the system parameters, the viscosity and distance (d) between transmitter and receiver are examined detailed by using Artificial Neural Network (ANN) algorithm in Matlab. Viscosity and d are simulated and predicted by using ANN and they also compared with results of the proposed system model.
Interaction of nickel ferrite nanoparticles with nucleic acids
(Elsevier B.V., 2022) Topkaya, Seda Nur; Kaya, Hüseyin Oğuzhan; Özcan, İmren; Köytepe, Süleyman; E.Cetin, Arif
In this article, we introduced an electrochemical biosensor employing graphite electrodes (GE) decorated with Nickel ferrite (NiFe2O4) nanoparticles for nucleic acid detection. NiFe2O4 nanoparticles in a narrow size distribution were synthesized with co-precipitation technique. Their chemical and crystallographic properties were characterized with FTIR and X-ray spectroscopies. Nanoparticle size distribution and hydrodynamic diameter were determined with particle size analyzer. Elemental content and purity of nanoparticles were analyzed with EDX analysis. Our analyses showed a diameter of ~10 nm for NiFe2O4 nanoparticles. Electrochemical properties of NiFe2O4 nanoparticles were examined with different analysis methods. Conductivity properties of NiFe2O4 nanoparticles were investigated with Cyclic Voltammetry (CV), which confirmed that nanoparticles on GE surface have a high surface area and conductivity. More importantly, in this article, the interactions between NiFe2O4 nanoparticles and double stranded DNA (dsDNA), single stranded DNA (ssDNA), and RNA were for the first time examined using Differential Pulse Voltammetry (DPV), CV, and Electrochemical Impedance Spectroscopy (EIS). Oxidation peak currents of NiFe2O4 nanoparticles and guanine bases of dsDNA, ssDNA, and RNA showed that NiFe2O4 nanoparticles effectively interacts with nucleic acids via an electrostatic mode.
Effects of Salicylic Acid on Fatty Acid Gene Expression in Carthamus tinctorious L. cv. Dinçer under Pendimethalin Stress
(Munzur Üniversitesi, 2020) Akbulut, Ekrem
Pendimethalin is a member of the dinitroaniline class herbicide. It used to control most annual grasses and many annual broad-leaved weeds. Salicylic acid acts as an endogenous signal molecule in charge of inducing environmental stress tolerance in plants. Omega-3 fatty acid desaturase is a key enzyme for ?-linolenic acid biosynthesis. Here, we searched to understand the beneficial impacts of salicylic acid on fatty acid desaturase gene (FAD3 and FAD7) expression during pendimethalin stress in safflower (Carthamus tinctorious cv. “Dinçer). In this study, 0.004 and 0.01 M pendimethalin was applied to safflower plants grown under controlled climatic conditions in 36 pots. 0.05 mM salicylic acid was applied to the samples where pendimethalin was applied. After application, gene expression analyze were performed using quantitative polymerase chain reaction. The floor change between the test and control groups was calculated with the formula 2 ^ (delta delta CT). The change between gene expression levels was evaluated by t test (p <0.05). FAD3 and FAD7 expression levels decreased at low pendimethalin concentration. A down-regulation in FAD3 expression was observed in high pendimethalin stress, while an up-regulation in FAD7 expression was detected. Salicylic acid had a ameliorative effect on the negative effect of pendimethalin stress on FAD3 and FAD7 gene expression.
Mutations in the SARS CoV-2 spike protein may cause functional changes in the protein quaternary structure
(Turkish Journal of Biochemistry, 2021) Akbulut, Ekrem
Objectives: This study aimed to model the changes resulting from mutations in surface (spike/S) glycoproteins, which play a key role in the entry of the severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) into host cells, in a protein quaternary structure and to evaluate their possible effects on the functional structure. Methods: Genome sequence information of SARS CoV-2-infected patients located in Turkey was obtained from the GISAID EpiCoV database. Structural analysis of spike proteins was done using bioinformatics tools (MAFFT, PSIPRED, ProMod3, PyMoL and DynOmics). Results: We identified 76 Thr>Ile mutations in the N-terminal domain; 468 Ile>Val mutations in the receptor binding site and 614 Asp>Gly, 679 Asn>Lys, 771 Ala>Val and 772 Val>Ile mutations in the S1 subunit. It has been observed that the mutations, except those of residues 771 and 772, may cause significant conformational, topological and electrostatic changes in a protein quaternary structure. It has been determined that the mutations in the receptor binding site transform the protein structure into a formation that can mask the binding site and affect receptor affinity. Conclusions: It has been considered that SARS CoV-2 S glycoprotein mutations may cause changes in a protein functional structure that can affect the severity of disease.

Güncel Gönderiler