3036 research outputs found
Sort by
Production and characterization of non-leaching antimicrobial and hydrophilic polycaprolactone based nanofiber mats
No full textNovel antimicrobial and hydrophilic nanofiber biomaterial was fabricated with a combination of surface modification and nanotechnology, in this study. For this purpose, firstly poly(lactic acid) (PLA) bearing quaternary ammonium salt as an antimicrobial agent on its backbone in the rates of 5% by mole were successfully fabricated with a combination of ring-opening copolymerization and copper(I)-catalysed azide-–alkyne cycloaddition click reaction in a two-step reaction procedure. Then, this synthesized polymer was blended into polycaprolactone (PCL) matrix in three different proportions via electrospining technique. The prepared nanofiber mats were then characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and contact angle analysis. In addition, thermal properties of mats were examined through differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) experiments. Its importance as an antimicrobial biomaterial was analyzed using Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) which were types of Gram-positive and Gram-negative bacteria, respectively. As a result, it was observed that as the rate of antimicrobial polymer in the nanofiber material increased, its antimicrobial activity against both bacteria also increased. As a result of the highest blending ratio of antimicrobial PLA copolymer, the bacterial population amount decreased by 99.5% and 92% for S. aureus and E. coli, respectively, as compared to neat PCL nanofiber mat. Besides, thermal properties of PCL nanofiber mats did not changed negatively after the blending process, even char yield increased slightly with increasing rate of antimicrobial PLA content. Also, the results showed that the blending of PCL nanofiber mat with antimicrobial PLA having quaternary ammonium salts on its backbone maked it highly hydrophilic. © 2021 Elsevier Lt
DESIGN PRINCIPLES OF THE HOSPITAL CLEAN ROOMS
No full textClean rooms can be defined as areas that are specifically controlled for particulate and microbial contamination and where they are constructed and used to reduce the number of infectious disease agents settling and multiplying and accessing from outside.
In this study, the design and implementation of the air conditioning system in accordance with international standards, in particular DIN 1946-4, has been explained for an operating room in hospitals which is in the clean room and has the highest risk of infection. The tasks of physicians, engineers and architects in operating room design were mentioned and finally the cleaning, testing, adjustment and balancing (TAB) and validation process of the air conditioning system were mentioned.
In particular, the risks of infections that may arise during the surgical intervention in the operating room and its relation to the air conditioning system have been mentioned and it has been emphasized that the biggest responsibility for hospital infections falls to engineers and architects, especially doctors and medical staff
DIGITAL PERCEPTION MANAGEMENT
No full textThe 21st century has witnessed the emergence of digital society in various parts of the world as a consequence of the increasing use of new communication and information technologies which have brought profound socio-economic changes into our lives. With the advent of computer technology, it has become possible to digitize almost everything. Change has always been a characteristic of human evolution but the speed at which these transformations have taken place has been unprecedented. Needless to say, various forms of traditional media have significantly been influenced by advanced innovations and it can easily be foreseen that this change will continue into the future. Throughout all these changes, perception management has had to be exercised in a more rigorous way. This study aims to provide an introduction to the topic of change and transformation in perception management in the light of digitalization, a topic which has already attracted much attention from scholars and researchers, particularly in the last decade
The in-vivo Assessment of Turkish Propolis and its Nano form on Testicular Damage Induced by Cisplatin
No full textChemotherapeutic drugs, such as cisplatin (CP), which are associated with oxidative stress and apoptosis, may adversely affect the reproductive system. This study tests whether administration of propolis and nano-propolis (NP) can alleviate oxidative stress and apoptosis in rats with testicular damage induced by CP. In this study, polymeric nanoparticles including propolis were synthesized with a green sonication method and characterized using Fourier transform-infrared spectroscopy, Brunauer-Emmett-Teller, and wet scanning transmission electron microscopy techniques. In total, 56 rats were divided into the following seven groups: control, CP, propolis, NP-10, CP + propolis, CP + NP-10, and CP + NP-30. Propolis (100 mg/kg), NP-10 (10 mg/kg), and NP-30 (30 mg/kg) treatments were administered by gavage daily for 21 d, and CP (3 mg/kg) was administered intraperitoneally in a single dose. After the experiment, oxidative stress parameters, namely, malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT), and apoptotic pathways including B cell leukemia/lymphoma-2 protein (Bcl-2) and Bcl-2-associated X protein (Bax) were measured in testicular tissues. Furthermore, sperm quality and weights of the testis, epididymis, right cauda epididymis, seminal vesicles and prostate were evaluated. Propolis and NP (especially NP-30) were able to preserve oxidative balance (decreased MDA levels and increased GSH, CAT, and GPx activities) and activate apoptotic pathways (decreased Bax and increased Bcl-2) in the testes of CP-treated rats. Sperm motility in the control, CP, and CP + NP-30 groups were 60%, 48.75%, and 78%, respectively (P < 0.001). Especially, NP-30 application completely corrected the deterioration in sperm features induced by CP. The results show that propolis and NP treatments mitigated the side effects of CP on spermatogenic activity, antioxidant situation, and apoptosis in rats
Measurement of Cross Section for e(+)e(-) -> Xi(0)(Xi)over-bar(0) Near Threshol
No full textUsing e(+)e(-) collision data at ten center-of-mass energies between 2.644 and 3.080 GeV collected with the BESIII detector at BEPCII and corresponding to an integrated luminosity of about 500 pb(-1), we measure the cross sections and effective form factors for the process e(+)e(-) -> Xi(0)(Xi) over bar (0) utilizing a single-tag method. A fit to the cross section of e(+)e(-) -> Xi(0)(Xi) over bar (0) with a pQCD-driven power function is performed, from which no significant resonance or threshold enhancement is observed. In addition, the ratio of cross sections for the processes e(+)e(-) -> Xi(0)(Xi) over bar (0) and Xi(0)(Xi) over bar (0) is calculated using recent BESIII measurement and is found to be compatible with expectation from isospin symmetry. (C) 2021 The Author(s). Published by Elsevier B.V
Oscillating Features in The Electromagnetic Structure of The Neutron
No full textThe complicated structure of the neutron cannot be calculated using first-principles calculations due to the large colour charge of quarks and the self-interaction of gluons. Its simplest structure observables are the electromagnetic form factors1, which probe our understanding of the strong interaction. Until now, a small amount of data has been available for the determination of the neutron structure from the time-like kinematical range. Here we present measurements of the Born cross section of electron–positron annihilation reactions into a neutron and anti-neutron pair, and determine the neutron’s effective form factor. The data were recorded with the BESIII experiment at centre-of-mass energies between 2.00 and 3.08 GeV using an integrated luminosity of 647.9 pb−1. Our results improve the statistics on the neutron form factor by more than a factor of 60 over previous measurements, demonstrating that the neutron form factor data from annihilation in the time-like regime is on par with that from electron scattering experiments. The effective form factor of the neutron shows a periodic behaviour, similar to earlier observations of the proton form factor. Future works—both theoretical and experimental—will help illuminate the origin of this oscillation of the electromagnetic structure observables of the nucleon
A novel technique for the reduction of pesticide residues by a combination of low-intensity electrical current and ultrasound applications: A study on lettuce samples
No full textIn this study, effects of low-intensity electrical currents (200, 800 and 1400 mA), ultrasound frequencies (24 and 40 kHz) and their combinations were applied at the duration period of 2, 4, 6, 8, and 10 min for the degradation of captan, thiamethoxam and metalaxyl residues in lettuce samples. Residues of the pesticides were determined by gas chromatography with tandem mass spectrometry and electron capture detector. The results indicated that the combination of low-intensity electrical current and ultrasound was found to be effective for the reduction of the pesticides. The most effective combination was obtained to be current of 1400 mA and ultrasound frequency of 24 kHz at 10 min. Under this circumstance, 92.57, 81.99 and 93.09% of captan, thiamethoxam and metalaxyl residues were decreased, respectively. The findings suggest that the combination of low-intensity electrical current and ultrasound applications has an important potential for the degradation of pesticide residues
Two-point Discrimination Assessment of the Lower Extremities of Healthy Young Turkish Individuals
No full textObjectives: To investigate the normative two-point discrimination (TPD) values of the lower extremities of healthy young Turkish individuals.
Patients and methods: Fifty-five healthy, young adults were recruited in this prospective study. Ten lower extremity parts were tested with esthesiometer: proximal thigh, midlateral thigh, midmedial thigh, midposterior thigh, proximal lateral leg, distal lateral leg, medial leg, the tip of great toe, skin over 1-2 metatarsal interspace, skin over 5th metatars at both dominant and non-dominant sides.
Results: There were 27 (49.1%) female and 28 (50.9%) male participants with a mean age of 22.06 ± 1.76 years. The reference values of the TPD of the lower extremities were between 42.4 ± 5.4 mm and 4.0 ± 1.3 mm by females and between 42.6 ± 6.4 mm and 4.4 ± 2.4 mm by males. Test values in the combined group of men and women were statistically greater at the dominant sides than the non-dominant sides at the following areas: proximal lateral leg (p = 0.01), distal lateral leg (p = 0.046), medial leg (p = 0.001), tip of great toe (p = 0.02), skin over 1-2 metatarsal interspace (p = 0.010), skin over 5th metatars (p = 0.002). There was no statistical difference in the test scores of men and women in any of the measured areas, with additional evaluation of both the dominant and the non-dominant sides (p > 0.05).
Conclusion: The results of the present study demonstrated that TPD ability varied in different skin areas within the same individual. We found that laterality, though with lower scores on the non-dominant side in some lower extremity parts, but not the gender had an effect on TPD
On a New Approach by Modified (P; Q)-Szasz-Mirakyan Operators
No full textIn this paper, we introduce a new type of (p; q) exponential function with some properties and a modified (p; q)-Szasz-Mirakyan operators by virtue of this function by investigating approximation properties. We obtain moments of generalized (p; q)-Szasz-Mirakyan operators. Furthermore, we derive direct results, rate of convergence, weighted approximation result, statistical convergence and Voronovskaya type result of these operators with numerical examples. Graphical representations reveal that modified (p; q)-Szasz-Mirakyan operators have a better approximation to continuous functions than pioneer one
Detection and Prevention of Attacks on the Internet of Things (IoT) and Wireless Sensor Network
No full textIoT (Internet of Things) ya da diğer adıyla Nesnelerin İnterneti kavramı, internete bağlanan ve diğer cihazlarla iletişimde olan her nesneyi kapsamaktadır. Artık hayatımızın bir parçası haline gelecek otonom araçlar, akıllı buzdolabılar, akıllı çamaşır makineleri, akıllı tost makineleri, akıllı saatler gibi birçok IoT cihazı birbiriyle farklı kablosuz ağ teknolojilerini kullanarak haberleşebilirler. IoT cihazların birçok kritik alanda kullanılmasıyla birlikte IoT güveniğine karşı yapılan saldırılar da artmıştır. Bu saldırılarda IoT katmanlarına yapılarak veri gizliliği, veri bütünlüğü, veri tazeliği, veri erişilebilirliği, kimlik doğrulama gibi kriterler ihlal edilebilmektedir. Bu saldırıları önlemek amacıyla birçok güvenlik çözümü önerilmiştir, fakat sınırlı enerji, kısıtlı batarya süresi, zayıf işlemci gücü ve sınırlı hafıza gibi sınırlamalardan dolayı düşük güçlü IoT cihazlar üzerinde geleneksel güvenlik yöntemlerinin uygulanması mümkün değildir. Bu çalışmada, IoT cihazların güvenliğini tehdit eden saldırılar incelenerek, ağ katmanlarına göre detaylı şekilde sınıflandırılmış ve savunma teknikleri önerilmiştir