Mersin Üniversitesi

Diesel engines have high efficiency, durability, and reliability together with their low-operating cost. These important features make them the most preferred engines especially for heavy-duty vehicles. The interest in diesel engines has risen substantially day by day. In addition to the widespread use of these engines with many advantages, they play an important role in environmental pollution problems worldwide. Diesel engines are considered as one of the largest contributors to environmental pollution caused by exhaust emissions, and they are responsible for several health problems as well. Many policies have been imposed worldwide in recent years to reduce negative effects of diesel engine emissions on human health and environment. Many researches have been carried out on both diesel exhaust pollutant emissions and aftertreatment emission control technologies. In this paper, the emissions from diesel engines and their control systems are reviewed. The four main pollutant emissions from diesel engines (carbon monoxide-CO, hydrocarbons-HC, particulate matter-PM and nitrogen oxides-NOx) and control systems for these emissions (diesel oxidation catalyst, diesel particulate filter and selective catalytic reduction) are discussed. Each type of emissions and control systems is comprehensively examined. At the same time, the legal restrictions on exhaust-gas emissions around the world and the effects of exhaust-gas emissions on human health and environment are explained in this study.

Migraine is a disabling primary headache disorder that directly affects more than one billion people worldwide. Despite its widespread prevalence, migraine remains under-diagnosed and under-treated. To support clinical decision-making, we convened a European panel of experts to develop a ten-step approach to the diagnosis and management of migraine. Each step was established by expert consensus and supported by a review of current literature, and the Consensus Statement is endorsed by the European Headache Federation and the European Academy of Neurology. In this Consensus Statement, we introduce typical clinical features, diagnostic criteria and differential diagnoses of migraine. We then emphasize the value of patient centricity and patient education to ensure treatment adherence and satisfaction with care provision. Further, we outline best practices for acute and preventive treatment of migraine in various patient populations, including adults, children and adolescents, pregnant and breastfeeding women, and older people. In addition, we provide recommendations for evaluating treatment response and managing treatment failure. Lastly, we discuss the management of complications and comorbidities as well as the importance of planning long-term follow-up.

Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19-79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change ±100) revealed a mean reduction of smell (-79.7 ± 28.7, mean ± standard deviation), taste (-69.0 ± 32.6), and chemesthetic (-37.3 ± 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms.

The development of new energy materials that can be utilized to make renewable and clean fuels from abundant and easily accessible resources is among the most challenging and demanding tasks in science today. Solar-powered catalytic water-splitting processes can be exploited as a source of electrons and protons to make clean renewable fuels, such as hydrogen, and in the sequestration of CO2 and its conversion into low-carbon energy carriers. Recently, there have been tremendous efforts to build up a stand-alone solar-to-fuel conversion device, the "artificial leaf", using light and water as raw materials. An overview of the recent progress in electrochemical and photo-electrocatalytic water splitting devices is presented, using both molecular water oxidation complexes (WOCs) and nano-structured assemblies to develop an artificial photosynthetic system.

Osteoarthritis (OA) is a complex "whole joint" disease pursued by inflammatory mediators, rather than purely a process of "wear and tear". Besides cartilage degradation, synovitis, subchondral bone remodeling, degeneration of ligaments and menisci, and hypertrophy of the joint capsule take parts in the pathogenesis. Pain is the hallmark symptom of OA, but the extent to which structural pathology in OA contributes to the pain experience is still not well known. For the knee OA, intraarticular (IA) injection (corticosteroids, viscosupplements, blood-derived products) is preferred as the last nonoperative modality, if the other conservative treatment modalities are ineffective. IA corticosteroid injections provide short term reduction in OA pain and can be considered as an adjunct to core treatment for the relief of moderate to severe pain in people with OA. IA hyaluronic acid (HA) injections might have efficacy and might provide pain reduction in mild OA of knee up to 24 wk. But for HA injections, the cost-effectiveness is an important concern that patients must be informed about the efficacy of these preparations. Although more high-quality evidence is needed, recent studies indicate that IA platelet rich plasma injections are promising for relieving pain, improving knee function and quality of life, especially in younger patients, and in mild OA cases. The current literature and our experience indicate that IA injections are safe and have positive effects for patient satisfaction. But, there is no data that any of the IA injections will cause osteophytes to regress or cartilage and meniscus to regenerate in patients with substantial and irreversible bone and cartilage damage.

Abstract Chitosan and poly(vinyl alcohol) (PVA) were used to form a semi‐interpenetrating polymeric network with glutaraldehyde as the cross‐linker. The molecular weight and degree of deacetylation of the chitosan were 612 kDa and 72 %, respectively. The chemical bonds formed by the cross‐linking reaction and transition of these bonds in different pH media were investigated. The gelation property of the chitosan–PVA pregel solution and mechanical properties of the hydrogel were studied. The FTIR spectra of the hydrogel before and after swelling at pH 3 and pH 7 indicated formation of Schiff's base (CN) and NH 3 + . They also showed pH‐induced transition of CN to CN, and NH 3 + to NH 2 , as well as the instability of the Schiff's base. The chitosan is essential for hydrogel formation through Schiff's base reaction between the amino groups of the chitosan and the aldehyde groups of the glutaraldehyde. The addition of PVA improved the mechanical properties of the hydrogel. However, PVA tends to leach out at longer swelling times in the acidic medium due to hydrolysis of the gel networks, Schiff's base. Copyright © 2004 Society of Chemical Industry

To date, there have been no randomized, controlled, prospective clinical studies that compare various techniques to describe the best method for the treatment of varicocele in infertile men. This meta-analysis aims to address the best treatment modality for palpable varicocele in infertile men. A MEDLINE search was performed for articles published between January 1980 and April 2008, and we analyzed 36 studies reporting postoperative spontaneous pregnancy rates and/or complication rates after varicocele repair using various techniques in infertile men with palpable unilateral or bilateral varicocele. Spontaneous pregnancy rates and postoperative complications such as hydrocele formation, recurrence, or persistence were compared among the techniques. In addition, interventional failure with radiologic embolization and reported complications with the laparoscopic approach were reviewed. Overall spontaneous pregnancy rates were 37.69% in the Palomo technique series, 41.97% in the microsurgical varicocelectomy techniques, 30.07% in the laparoscopic varicocelectomy techniques, 33.2% in the radiologic embolization, and 36% in the macroscopic inguinal (Ivanissevich) varicocelectomy series, revealing significant differences among the techniques (P = .001). Overall recurrence rates were 14.97% in the Palomo technique series, 1.05% in the microsurgical varicocelectomy techniques, 4.3% in the laparoscopic varicocelectomy techniques, 12.7% in the radiologic embolization, and 2.63% in the macroscopic inguinal (Ivanissevich) or subinguinal varicocelectomy series, revealing significant difference among the techniques (P = .001). Overall hydrocele formation rates were 8.24% in the Palomo technique series, 0.44% in the microsurgical varicocelectomy techniques, 2.84% in the laparoscopic varicocelectomy, and 7.3% in the macroscopic inguinal (Ivanissevich) or subinguinal varicocelectomy series, revealing significant difference among the techniques (P = .001). We conclude that the microsurgical varicocelectomy technique has higher spontaneous pregnancy rates and lower postoperative recurrence and hydrocele formation than conventional varicocelectomy techniques in infertile men. However, prospective, randomized, and comparative studies with large number of patients are needed to compare the efficacy of microsurgical varicocelectomy with that of other treatment modalities in infertile men with varicocele.

Structural and optical properties of ZnO nanoparticles can be fine tuned by a novel variant of milling performed at cryogenic temperatures. In this study intrinsic defect centers such as oxygen and zinc vacancies are characterized using electron paramagnetic resonance (EPR) and photoluminescence (PL) spectroscopy. Three different surface defects with different $g$ factors were identified by EPR for which the spectral intensities change upon decreasing the crystal size. EPR and PL intensities revealed a linear correlation giving detailed information about optical and electronic properties of ZnO. The core-shell model established from optical emission and EPR suggests distinguished electronic states in the band gap belonging to negatively charged Zn vacancies and positively charged oxygen vacancies. This model indicates a correlation between red emission and positively charged oxygen vacancies, which lead to a possible transition from a typical $n$-type to a $p$-type ZnO semiconductor.

The main objective of this study is to examine how the charge densities of four monovalent anions—fluoride (F–), chloride (Cl–), bromide (Br–), and nitrate (NO3–)—influence their Donnan (charge) exclusion by a charged nanofiltration (NF) membrane. We systematically studied the rejection behavior of ternary ion solutions containing sodium cation (Na+) and two of the monovalent anions as a function of the pH with a polyamide NF membrane. In the solutions containing F– and Cl– or F– and Br–, F– rejection was higher than Cl– or Br– rejection only when the solution pH was higher than 5.5, suggesting that F– (which has a higher charge density) was repelled more strongly by the negatively charged membrane. The order of change in the activation energy for the transport of the four anions through the polyamide membrane as a response to the increase of the membrane negative charge was the following: F– > Cl– > NO3– > Br–. This order corroborates our main hypothesis that an anion with a smaller ionic radius, and hence a higher charge density, is more affected by the Donnan (charge)-exclusion mechanism in NF. We conclude with a proposed mechanism for the role of ionic charge density in the rejection of monovalent anions in NF.

Graphene, on which numerous studies have been conducted since its discovery, exhibits extra-ordinary properties unlike conventional materials. Owing to these properties, graphene has a great potential usage in many applications and also can be used as reinforcing material in different composite materials. The use of graphene as reinforcing materials in metal matrix composite materials allows to develop new generation composites, as well. Numerous studies on metal matrix graphene reinforced composites have been conducted within the last ten years. Different studies have determined various properties in the graphene reinforced composites having the same metal matrix. This is caused by many factors such as the production method of the composite, production method of the graphenes, matrix/graphene interface, distribution of the graphenes and the orientation of the graphene in the matrix. By the optimization of these factors and simplifying and improving the production methods, the graphene reinforced metal matrix composites have great potential to be used in many applications. In this paper, the studies conducted on metal matrix composites, in which graphene was used as reinforcing material, were investigated. In these studies, the properties of the produced composites were presented and the factors affecting these properties were explained.

Given its non-invasive nature, there is increasing interest in the use of transcutaneous vagus nerve stimulation (tVNS) across basic, translational and clinical research. Contemporaneously, tVNS can be achieved by stimulating either the auricular branch or the cervical bundle of the vagus nerve, referred to as transcutaneous auricular vagus nerve stimulation(VNS) and transcutaneous cervical VNS, respectively. In order to advance the field in a systematic manner, studies using these technologies need to adequately report sufficient methodological detail to enable comparison of results between studies, replication of studies, as well as enhancing study participant safety. We systematically reviewed the existing tVNS literature to evaluate current reporting practices. Based on this review, and consensus among participating authors, we propose a set of minimal reporting items to guide future tVNS studies. The suggested items address specific technical aspects of the device and stimulation parameters. We also cover general recommendations including inclusion and exclusion criteria for participants, outcome parameters and the detailed reporting of side effects. Furthermore, we review strategies used to identify the optimal stimulation parameters for a given research setting and summarize ongoing developments in animal research with potential implications for the application of tVNS in humans. Finally, we discuss the potential of tVNS in future research as well as the associated challenges across several disciplines in research and clinical practice.

OBJECTIVES: To detect the prevalence of sexual dysfunction, and also to investigate possible risk factors that may cause sexual dysfunction in the Turkish women. MATERIALS AND METHODS: The study consisted of 179 women between the ages of 18 and 66 years living in households from different sociocultural areas. The women were divided into 5 groups according to their ages: 18-27 years (n = 23), 28-37 years (n = 55), 38-47 years (n = 43), 48-57 years (n = 44) and 58-67 years (n = 14). Female sexual function was evaluated with a detailed 19-item questionnaire to assess desire, arousal, lubrication, orgasm, satisfaction and pain. The prevalence of sexual dysfunction was calculated for each domain and compared among the groups. In addition, demographic characteristics and medical risk factors were assessed in all women, and the findings were compared between the women with and without sexual dysfunction. RESULTS: Based on total sexual function score, 84 (46.9%) out of 179 women had sexual dysfunction. The prevalence of female sexual dysfunction was 21.7% in the ages of 18-27 years, 25.5% in the ages of 28-37 years, 53.5% in the ages of 38-47 years, 65.9% in the ages of 48-57 years and 92.9% in the ages of 58-67 years. The prevalence of sexual dysfunction for each domain also increased with age. To investigate various factors that may cause female sexual dysfunction, no significant differences were detected in smoking history (p = 0.14), marriage age (p = 0.7), the presence of previous pelvic surgery (p = 0.09), and contraception methods used (p = 0.31). However, sexual dysfunction was observed as significantly higher in the presence of older age (p = 0.001), lower educational level (p = 0.012), unemployment status (p = 0.017), chronic disease (p = 0.032), multiparity (p = 0.0027) and menopause status (p = 0.0001). CONCLUSIONS: The prevalence of female sexual dysfunction including desire, arousal, lubrication, orgasm, satisfaction and pain problems increases with age. In addition, the presence of a lower educational level, unemployment status, chronic diseases, multiparity and menopause status are important risk factors that may cause sexual dysfunction.

Glyphosate is a widely used broad-spectrum weed control agent. In the present study, an in vivo study on the genotoxic effects of a technical herbicide (Roundup) containing isopropylamine salt of glyphosate was carried out on freshwater goldfish Carassius auratus. The fish were exposed to three doses of glyphosate formulation (5, 10 and 15 ppm). Cyclophosphamide at a single dose of 5 mg/l was used as positive control. Analysis of micronuclei, nuclear abnormalities and DNA damage were performed on peripheral erythrocytes sampled at intervals of 48, 96 and 144 h posttreatment. Our results revealed significant dose-dependent increases in the frequencies of micronuclei, nuclear abnormalities as well as DNA strand breaks. Our findings also confirmed that the alkaline comet assay and nuclear deformations in addition to micronucleus test on fish erythrocytes in vivo are useful tools in determining the potential genotoxicity of commercial herbicides.

BACKGROUND: Behçet's disease is a multisystem disease featuring mucocutaneous, ocular, articular, vascular, intestinal, urogenital, and neurologic involvement and occurs with a high prevalence in the Mediterranean including Turkey. Higher incidence of severe clinical course and systemic involvement is observed in male patients. OBJECTIVE: To determine the influence of sex on the clinical course of Behçet' s disease. METHODS: We retrospectively evaluated the clinical findings of 2313 Behçet patients followed up at the multidisciplinary Behçet's Disease Center at Ankara University. RESULTS: The male/female patient ratio was 1.03. Oral aphthae was seen in all patients. In male Behçet patients, the prevalence of mucocutaneous lesions and systemic manifestations was as follows: 85.6% genital aphthae, 45.5% erythema nodosum, 59.5% papulopustular lesions, 17.5% thrombophlebitis, 38.1% ocular involvement, 11.3% articular involvement, 11.7% vascular involvement, 3.3% neurologic involvement, 1.4% gastrointestinal involvement, and 1.8% pulmonary involvement. In female Behçet patients, the prevalence of manifestations were as follows: 91% genital aphthae, 49.8% erythema nodosum, 48.3% papulopustular lesions, 3.5% thrombophlebitis, 19.8% ocular involvement, 11.8% articular involvement, 2.1% vascular involvement, 1.3% neurologic involvement, 1.4% gastrointestinal involvement, and 0.03% pulmonary involvement. CONCLUSIONS: Only genital aphthae and erythema nodosum were more frequent in females. On the other hand papulopustular eruptions, thrombophlebitis, ocular, neurologic, pulmonary and vascular involvement were more frequent in males. While female patients had the best prognosis, male patients had a worse overall prognosis than females.

Abstract Multi-colored, water soluble fluorescent carbon nanodots (C-Dots) with quantum yield changing from 4.6 to 18.3% were synthesized in multi-gram using dated cola beverage through a simple thermal synthesis method and implemented as conductive and ion donating supercapacitor component. Various properties of C-Dots, including size, crystal structure, morphology and surface properties along with their Raman and electron paramagnetic resonance spectra were analyzed and compared by means of their fluorescence and electronic properties. α-Manganese Oxide-Polypyrrole (PPy) nanorods decorated with C-Dots were further conducted as anode materials in a supercapacitor. Reduced graphene oxide was used as cathode along with the dicationic bis-imidazolium based ionic liquid in order to enhance the charge transfer and wetting capacity of electrode surfaces. For this purpose, we used octyl-bis(3-methylimidazolium)diiodide (C8H16BImI) synthesized by N-alkylation reaction as liquid ionic membrane electrolyte. Paramagnetic resonance and impedance spectroscopy have been undertaken in order to understand the origin of the performance of hybrid capacitor in more depth. In particular, we obtained high capacitance value (C = 17.3 μF/cm 2 ) which is exceptionally related not only the quality of synthesis but also the choice of electrode and electrolyte materials. Moreover, each component used in the construction of the hybrid supercapacitor is also played a key role to achieve high capacitance value.

Abstract The measurement of the luminosity recorded by the CMS detector installed at LHC interaction point 5, using proton–proton collisions at $$\sqrt{s}=13\,{\text {TeV}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> <mml:mspace/> <mml:mtext>TeV</mml:mtext> </mml:mrow> </mml:math> in 2015 and 2016, is reported. The absolute luminosity scale is measured for individual bunch crossings using beam-separation scans (the van der Meer method), with a relative precision of 1.3 and 1.0% in 2015 and 2016, respectively. The dominant sources of uncertainty are related to residual differences between the measured beam positions and the ones provided by the operational settings of the LHC magnets, the factorizability of the proton bunch spatial density functions in the coordinates transverse to the beam direction, and the modeling of the effect of electromagnetic interactions among protons in the colliding bunches. When applying the van der Meer calibration to the entire run periods, the integrated luminosities when CMS was fully operational are 2.27 and 36.3 $$\,\text {fb}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mspace/> <mml:msup> <mml:mtext>fb</mml:mtext> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> in 2015 and 2016, with a relative precision of 1.6 and 1.2%, respectively. These are among the most precise luminosity measurements at bunched-beam hadron colliders.

Purpose To measure the service quality perceptions of Greek Cypriot bank customers and to examine the relationship between service quality, customer satisfaction and positive word of mouth, in the light of changing bank market dynamics due to EU accession. Design/methodology/approach A total of 260 retail bank customers responded to a Greek translated version of SERVQUAL. After descriptive and factor analysis, multivariate regression analysis was used to estimate the impact of service quality dimensions on overall customer satisfaction and the impact of satisfaction on positive word of mouth. Findings The SERVQUAL scale proved to be of a three‐dimensional structure in this study. Results revealed that the expectations of bank customers were not met where the largest gap was obtained in the responsiveness‐empathy dimension. Reliability items had the highest effect on customer satisfaction, which in turn had a statistically significant impact on the positive word of mouth. Research limitations/implications There were some difficulties in conducting interviews, which may have restricted the potential sample size. Future research could be directed at how the service is delivered by front‐line employees. Practical implications Findings of this study will help Greek Cypriot banks to redefine their corporate image to one that is customer‐focused and emphasizes service quality. The findings will also be important for other countries that need to restructure their banking system as a prerequisite to EU membership. Originality/value This study assesses the five‐factor fit of the much debated SERVQUAL instrument to a new country setting, that of Cyprus, whose already developed banking system has undergone significant restructuring prior to EU accession.

People high in learned resourcefulness are purported to be better than others at controlling their negative emotions and managing stressful tasks. We hypothesised that highly resourceful students would be more effective than others at protecting themselves from the adverse effects of academic stress, and not allowing that stress to impact their grades. A sample of 141 first-year undergraduate students completed measures of academic stress and learned resourcefulness. Their first-year grade point averages were obtained from university records. Analyses revealed that academic stress was negatively associated with academic performance. As expected, this negative association was moderated by learned resourcefulness. High academic stress adversely impacted the grades of low resourceful students but had no effect on high resourceful students. We discuss the implications of these findings for improving academic performance.

When questioned, about 10% of the parents report suspected hypersensitivity to at least one drug in their children. However, only a few of these reactions can be confirmed as allergic after a diagnostic workup. There is still a lack of knowledge on drug hypersensitivity (DH) epidemiology, clinical spectrum, and appropriate diagnostic methods particularly in children. Meanwhile, the tools used for DH management in adults are applied also for children. Whereas this appears generally acceptable, some aspects of DH and management differ with age. Most reactions in children are still attributed to betalactams. Some manifestations, such as nonsteroidal anti-inflammatory drug-associated angioedema and serum sickness-like reactions, are more frequent among young patients as compared to adults. Risk factors such as viral infections are particularly frequent in children, making the diagnosis challenging. The practicability and validity of skin test and other diagnostic procedures need further assessment in children. This study presents an up-to-date review on epidemiology, clinical spectrum, diagnostic tools, and current management of DH in children. A new general algorithm for the study of these reactions in children is proposed. Data are presented focusing on reported differences between pediatric and adult patients, also identifying unmet needs to be addressed in further research.

Abstract Measurements from the CMS experiment at the LHC of dihadron correlations for charged particles produced in PbPb collisions at a nucleon–nucleon centre-of-mass energy of 2.76 TeV are presented. The results are reported as a function of the particle transverse momenta ( p T ) and collision centrality over a broad range in relative pseudorapidity (Δ η ) and the full range of relative azimuthal angle (Δ ϕ ). The observed two-dimensional correlation structure in Δ η and Δ ϕ is characterised by a narrow peak at (Δ η ,Δ ϕ )≈(0,0) from jet-like correlations and a long-range structure that persists up to at least |Δ η |=4. An enhancement of the magnitude of the short-range jet peak is observed with increasing centrality, especially for particles of p T around 1–2 GeV/ c . The long-range azimuthal dihadron correlations are extensively studied using a Fourier decomposition analysis. The extracted Fourier coefficients are found to factorise into a product of single-particle azimuthal anisotropies up to p T ≈3–3.5 GeV/ c for at least one particle from each pair, except for the second-order harmonics in the most central PbPb events. Various orders of the single-particle azimuthal anisotropy harmonics are extracted for associated particle p T of 1–3 GeV/ c , as a function of the trigger particle p T up to 20 GeV/ c and over the full centrality range.