The Portevin-Le Chatelier (PLC) effect manifests itself as an unstable plastic flow during tensile tests of some dilute alloys under certain regimes of strain rate and temperature. The plastic strain ...becomes localized in the form of bands which move along a specimen gauge in various ways as the PLC effect occurs. Because the localization of strain causes degradation of the inherent structural properties and surface quality of materials, understanding the effect is crucial for the effective use of alloys. The characteristic behaviors of localized strain bands and techniques commonly used to study the PLC effect are summarized in this review. A brief overview of experimental findings, the effect of material properties and test parameters on the PLC effect, and some discussion on the mechanisms of the effect are included. Tests for predicting the early failure of structural materials due to embrittlement induced by the PLC effect are also discussed.
Introduction and objective: Hepatitis A Virus (HAV), reportedly the most common cause of acute viral hepatitis in developing countries, infects millions of people worldwide each year. The aim of the ...study is to investigate the seropositivity of anti-hepatitis A virus (HAV) IgG and IgM in all age groups in Erzurum, and to determine the effect of various factors such as age, gender, climatic conditions and HAV vaccination (included in 2012 in the National Immunization Schedule on seroprevalence) on the seropositivity. Material and methods: The serological results of 25,007 individuals referred to Erzurum Public Health Microbiology Laboratory between January 2015 – December 2018 were retrospectively reviewed to test for the presence of anti-HAV IgG and IgM. The patient ages were 0–93 years. Serum samples were analyzed by ELISA. S/CO values of ≥1.00 and >1.21 were considered positive for anti-HAV IgG and IgM, respectively; results below this value were considered negative. Results: Anti-HAV IgG and IgM seropositivities were 87.3% and 0.2%, respectively. Anti-HAV IgG prevalence – 88.5% and 86.4%, anti-HAV IgM positivity – 0.1% and 0.3% in men and women. Anti-HAV IgG seroprevalence – 87%, 73.2%, 58.7%, 75.2%, 86.1%, 89.8%, 96.1%, 99.1%, 99.1% and 99.3%, respectively, at 0–4, 5–9 10–14, 15–19, 20–24, 25–29, 30–39, 40–49, 50–59 and >60 age groups. Anti-HAV IgM seropositivity – 0, 0.1%, 0.7%, 0.7%, 0.3%, 0, 0.1%, 0.2%, 0.1%, and 0.2%, respectively, in the same age groups. Anti-HAV IgM positivity was the highest in November – 36(0.97%. Conclusions: In Erzurum, anti-HAV IgG prevalence is tremendously high, whereas prevalence of anti-HAV IgM is exceptionally low, especially in the paediatric age group. Therefore, HAV vaccine is provided free of charge in Turkey, including Erzurum, since 2012.
Natural killer (NK) cells are a critical component of the innate immune system. Chimeric antigen receptors (CARs) re-direct NK cells toward tumor cells carrying corresponding antigens, creating major ...opportunities in the fight against cancer. CAR NK cells have the potential for use as universal CAR cells without the need for human leukocyte antigen matching or prior exposure to tumor-associated antigens. Exciting data from recent clinical trials have renewed interest in the field of cancer immunotherapy due to the potential of CAR NK cells in the production of "off-the-shelf" anti-cancer immunotherapeutic products. Here, we provide an up-to-date comprehensive overview of the recent advancements in key areas of CAR NK cell research and identify under-investigated research areas. We summarize improvements in CAR design and structure, advantages and disadvantages of using CAR NK cells as an alternative to CAR T cell therapy, and list sources to obtain NK cells. In addition, we provide a list of tumor-associated antigens targeted by CAR NK cells and detail challenges in expanding and transducing NK cells for CAR production. We additionally discuss barriers to effective treatment and suggest solutions to improve CAR NK cell function, proliferation, persistence, therapeutic effectiveness, and safety in solid and liquid tumors.
Introduction: Physicians are the most burn-outed group among the occupations. Among the physicians, family physicians have the highest burnout rates. Our objective in this study is to determine ...factors that are effective on work satisfaction of family physicians and their correlations with their burnout, anxiety-depression levels. Subjects and Methods: This cross-sectional descriptive study was carried out in primary health care professionals in region of Southeastern Anatolia from Diyarbakır Turkey. A survey form consists of 74 questions, and which questions burnout, job satisfaction, and anxiety-depression level has been applied on family medicine doctors, supplementary items in a questionnaire. Total of 343 family medicine doctors were reached, and the questionnaires were administered by face-to-face interview. Statistical Package for Social Sciences for Windows 18.0 software was used for statistical analysis. Results: Work satisfaction of family physicians who are on call lower compared to doctors who are not on call among family physicians who have joined to study (P < 0.005). It is determined that there is negative correlation between work satisfaction level of family physicians and emotional burnout, desensitisation, anxiety and depression point (P = 0.001 r = -0.23, P = 0.015, r = -0.16, P = 0.06, r = -0.124, P = 0.0001, r = -0.23), there is positive correlation between emotional burnout levels and anxiety, depression average points (P = 0.001, r = 0.34, P = 0.0001, r = 0.41), there is positive correlation between anxiety and depression points (P = 0.0001, r = 0.57). Conclusion: The work satisfaction level of family physicians, who are on call and whose financial income expectation is not satisfied, was found low. It is seen that there is strong correlation between inadequacy of work satisfaction with burnout and anxiety, depression. As this can have negative effects on work performance, there is a need to look for solutions to increase work performance of family physicians.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract The aim of this study, research the potential use of probiotics in reducing the toxic effect of Aflatoxin M1 in cow milk, goat milk, sheep milk, and Phosphate-buffered saline (PBS). Milk and ...Phosphate-buffered saline were contaminated with Aflatoxin M1 at a concentration of 100 ppt. Then, various study groups were formed by adding Lactobacillus acidophilus DSMZ 20079, Lactobacillus rhamnosus GG, and Bifidobacterium bifidum DSMZ 20456 probiotic bacteria at a density of 108 CFU/ml. Then, working groups were stored for 1 day and Aflatoxin M1 levels were analyzed by an Enzyme-Linked Immunosorbent Assay kit. The binding level of Aflatoxin M1 by probiotic bacteria varies between 2.32-12.52% in Phosphate-buffered saline, 9.08-40.14% in cow milk, 15.01-38.01% in goat milk, and 32.49-42.90% in sheep milk. The highest binding level of Aflatoxin M1 was detected in sheep milk and the lowest in Phosphate-buffered saline. The binding ability of Aflatoxin M1 is ranked from highest to lowest in sheep milk, cow milk, and goat milk. The data obtained from this study is important because it is the first study to show that if sheep and goat milk is enriched with probiotics, it can reduce AFM1 exposure.
An efficient converter topology for extracting maximum power from a photovoltaic module is presented in this paper. The proposed topology is implemented on a stand-alone battery charging system. A ...reversed buck-boost converter enabling parallel power processing (PPP) with a power switch referenced to the common return is the core of the charging system. Small-signal analysis of the proposed charging system is carried out to facilitate the design of a compensator for maximum power point (MPP) tracking. The simulation and experimental results confirm the validity of the model and verify the high efficient operation while tracking the MPP. The use of the PPP with split loads is also presented which would improve the converter size, efficiency, and step-down duty ratio.
In recent studies, it was shown that blood agar can be used at least as effectively as Löwenstein-Jensen medium for growing Mycobacterium tuberculosis. It was also shown that susceptibility testing ...can be performed on blood agar. Additional validation of blood agar was performed on regional M. tuberculosis isolates from Turkey to determine critical concentrations of isoniazid (INH), rifampicin (RIF), ethambutol (ETM), and streptomycin (STR). In the current study, 40 M. tuberculosis clinical isolates were tested. H37Rv, which is susceptible to all antituberculosis agents, ATCC 35822 (INH-resistant), ATCC 35838 (RIF-resistant), ATCC 35837 (ETM-resistant), and ATCC 35820 (STR-resistant) quality control strains were used as control strains. Proportion method on 7H11 agar was considered as gold standard in the study. MIC values of the control strains and clinical isolates were detected on blood and 7H11 agar. Categorical agreements were 100% for each antibiotic, and essential agreements were 100%, 97.5%, 82.5%, and 95% for INH, RIF, ETM, and STR, respectively. According to the data, 0.2 µg/mL for INH, 1 µg/mL for RIF, 4 µg/mL for ETM, and 2 µg/mL for STR were appropriate breakpoint values for susceptibility testing on blood agar. Blood agar may be recommended for use in both developed and developing countries for the susceptibility testing of M. tuberculosis isolates to primary antituberculosis drugs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background: The aim of this study was the validation of AYC.2.2 agar and AYC.2.1 broth for the breakpoint values of first- and second-line drugs for Mycobacterium tuberculosis. Method: A total of 12 ...isolates including 5 reference strains and 7 well-defined clinical isolates were tested for their antituberculosis susceptibilities. Inhibitory effects of first- and second-line antituberculous drugs including isoniazid, rifampicin, streptomycin, ethambutol, amikacin, capreomycin, kanamycin, para-aminosalicylic acid, ethionamide, rifabutin, ofloxacin, levofloxacin, and moxifloxacin were tested. Results: According to the minimal inhibitory concentration values obtained in 7H10 agar, 7H9-S broth, AYC.2.2 agar, and AYC.2.1 broth, category agreement is 100%, and very major discrepancy (MAD), MAD, and minor discrepancy ratios were determined as 0 for all drugs. Conclusion: It was concluded that breakpoint values by CLSI recommendation for 7H10 agar can be also used for AYC.2.2 agar and AYC.2.1 broth. In addition, further multicenter studies are needed to use the new medium in routine mycobacteriology laboratories.
•High-temperature inactivation of airborne SARS-CoV-2.•Electric heater inactivates SARS CoV-2 in continuous airflow.•The viability of airborne SARS-CoV-2 reduced by 99.999 % at the outlet air ...temperature of 220 °C.
Airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the leading mechanisms of spread, especially in confined environments. The study aims to assess the thermal inactivation of SARS-CoV-2 at high temperatures in the time scale of seconds. An electric heater with a coiled resistance wire is located perpendicularly to the airflow direction inside an air tunnel. The airflow rate through the tunnel was 0.6 m3/h (10 L/ min). SARS-CoV-2 were suspended in Dulbecco’s modified Eagle’s medium (DMEM) with 10 % fetal bovine serum (FBS), aerosolized by a nebulizer at a rate of 0.2 L/min and introduced to the airflow inside the heater with the use of a compressor and an aspirator. In the control experiment, with the heater off, SARS-CoV-2 passed through the system. In the virus inactivation test experiments, the heater’s outlet air temperature was set to 150 ± 5 °C and 220 ± 5 °C, and the air traveling through the tunnel was exposed to heat for 1.44 s. An inline gelatine filter harvested SARS-CoV-2 that passed through the system. The viral titer obtained from the gelatine filter in the control experiment was about 5.5 log10 TCID50. The virus's loss in viability in test experiments at 150 °C and 220 °C were 99.900 % and 99.999 %, respectively. The results indicate that high-temperature thermal inactivation substantially reduces the concentration of SARS-CoV-2 in the air within seconds.
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