Disturbances such as forest fires,intense winds,and insect damage exert strong impacts on forest ecosystems by shaping their structure and growth dynamics,with contributions from climate change.Consequently,there is a...Disturbances such as forest fires,intense winds,and insect damage exert strong impacts on forest ecosystems by shaping their structure and growth dynamics,with contributions from climate change.Consequently,there is a need for reliable and operational methods to monitor and map these disturbances for the development of suitable management strategies.While susceptibility assessment using machine learning methods has increased,most studies have focused on a single disturbance.Moreover,there has been limited exploration of the use of“Automated Machine Learning(AutoML)”in the literature.In this study,susceptibility assessment for multiple forest disturbances(fires,insect damage,and wind damage)was conducted using the PyCaret AutoML framework in the Izmir Regional Forest Directorate(RFD)in Turkey.The AutoML framework compared 14 machine learning algorithms and ranked the best models based on AUC(area under the curve)values.The extra tree classifier(ET)algorithm was selected for modeling the susceptibility of each disturbance due to its good performance(AUC values>0.98).The study evaluated susceptibilities for both individual and multiple disturbances,creating a total of four susceptibility maps using fifteen driving factors in the assessment.According to the results,82.5%of forested areas in the Izmir RFD are susceptible to multiple disturbances at high and very high levels.Additionally,a potential forest disturbances map was created,revealing that 15.6%of forested areas in the Izmir RFD may experience no damage from the disturbances considered,while 54.2%could face damage from all three disturbances.The SHAP(Shapley Additive exPlanations)methodology was applied to evaluate the importance of features on prediction and the nonlinear relationship between explanatory features and susceptibility to disturbance.展开更多
To determine the shear wave velocity structure and predominant period features of Tmaztepe in izmir, Turkey, where new building sites have been planned, active-passive surface wave methods and single-station microtrem...To determine the shear wave velocity structure and predominant period features of Tmaztepe in izmir, Turkey, where new building sites have been planned, active-passive surface wave methods and single-station microtremor measurements are used, as well as surface acquisition techniques, including the multichannel analysis of surface waves (MASW), refraction microtremor (ReMi), and the spatial autocorrelation method (SPAC), to pinpoint shallow and deep shear wave velocity. For engineering bedrock (V 〉 760 m/s) conditions at a depth of 30 m, an average seismic shear wave velocity in the upper 30 m of soil (AVs30) is not only accepted as an important parameter for defining ground behavior during earthquakes, but a primary parameter in the geotechnical analysis for areas to be classified by V30 according to the National Earthquake Hazards Reduction Program (NEHRP). It is also determined that Z1.0, which represents a depth to V = 1000 m/s, is used for ground motion prediction and changed from 0 to 54 m. The sediment-engineering bedrock structure for Tmaztepe that was obtained shows engineering bedrock no deeper than 30 m. When compared, the depth of engineering bedrock and dominant period map and geology are generally compatible.展开更多
In this study, using the constant rate of supply model, sedimentation rates of Izmir Bay were calculated and discussed. For this purpose, eight sediment cores were collected from inner part of the bay and sedimentatio...In this study, using the constant rate of supply model, sedimentation rates of Izmir Bay were calculated and discussed. For this purpose, eight sediment cores were collected from inner part of the bay and sedimentation rates were calculated from vertical distribution of^(210)Pb.^(210)Pb activities were determined indirectly from ^(210)Po activities.Sedimentation rates ranged from 0.10 to 0.52 cm/year. The highest sedimentation rates were determined in stations close to the Poligon stream. It was concluded that main transporting mechanism for sediments is river and streams in the area. In addition, sediment cores taken from the harbor were mixed due to bioturbation, water circulation and/or other factors.展开更多
Architectural artefacts form the identity of the cities, especially when these artifacts dated to historical times, it becomes more valuable. The importance of preserving the architectural heritage is more meaningful ...Architectural artefacts form the identity of the cities, especially when these artifacts dated to historical times, it becomes more valuable. The importance of preserving the architectural heritage is more meaningful when the building is preserved with its whole environment, with the other historical buildings around as a site protection. Preservation of historical monuments not only individually but also with their environments help the city regain its identity that it has lost. The Conservation Approach to Cultural Assets in Turkey has reached to its peek starting from 1985's through introducing the effects of the recent amendment on cultural heritage law and the impact of the EU integration process. The municipalities started to use this recent amendment on cultural heritage laws as a method of recovering their cities for the local identity searches. This paper will deal with the current challenges for conservation practice in Turkey, through introducing the effects of the recent amendment on cultural heritage law and the impact of the EU integration process, and examine some major promising conservation and renovation, rehabilitation projects continuing in Izmir the third biggest city of Turkey for which local solutions are being devised for problems of global context in the meaning of local identity searches for the city.展开更多
Protecting the historical heritage is a very important task because it makes up the identity of the society and the cities. Considering the future, the most important problem recently is how to protect the historical ...Protecting the historical heritage is a very important task because it makes up the identity of the society and the cities. Considering the future, the most important problem recently is how to protect the historical heritage, and how to benefit from it. And as an answer to this question, by benefiting from our cultural background, it is necessary to provide the contemporary requirements and to transfer this attitude to the future generations. Throughout the time, functions may change but old buildings may stay. This situation requires that the old buildings are open to a new contemporary uses. Nowadays, the variations in the functions loaded onto the places we live in are frequently put on the agenda due to the requirements which are continuously changed and developed by social and cultural effects. While faced with this kind of functional variations in order to protect the mean values, the scope of this study is described in a systematically manner as: (1) re-functioning process; (2) adaptation of the new function to the old building; and (3) design concept in the revalorization. The scope will be discussed with many implementations from Turkey and the cases are chosen from the Izmir city.展开更多
In this editorial,we comment on the article by Stafie et al.Inflammatory bowel disease(IBD)constitutes a cluster of chronic and progressive inflammatory disorders affecting the digestive system.IBD can impede an indiv...In this editorial,we comment on the article by Stafie et al.Inflammatory bowel disease(IBD)constitutes a cluster of chronic and progressive inflammatory disorders affecting the digestive system.IBD can impede an individual’s capacity to perform daily activities,hinder work productivity,limit physical capabilities,and negatively impact medical outcomes.Although physical activity and structured exercise programs are becoming increasingly important in many chronic inflammatory diseases,they are not being sufficiently implemented in IBD patients.Effective prevention of future disability and drug dependence in IBD patients requires timely diagnosis and treatment of musculoskeletal problems,including sarcopenia,as well as decreased muscle strength,aerobic capacity,and bone mineral density.To improve treatment outcomes for IBD patients,it is crucial to develop individualized rehabilitation programs tailored to their unique needs.Equally critical is the active participation of pertinent departments in this process.It is imperative to highlight the significance of creating a personalized rehabilitation program with a multidisciplinary approach in IBD management.展开更多
AIM:To investigate tomographic features of late corneal ectasia after keratoplasty for keratoconus and compare penetrating keratoplasty(PK)and deep anterior lamellar keratoplasty(DALK)in terms of incidence,time of ons...AIM:To investigate tomographic features of late corneal ectasia after keratoplasty for keratoconus and compare penetrating keratoplasty(PK)and deep anterior lamellar keratoplasty(DALK)in terms of incidence,time of onset and risk factors of corneal ectasia.METHODS:Sixty eyes with PK and 30 eyes with DALK operated between 1999 and 2021 were analyzed.Final Pentacam scans were evaluated together with vision and previous topographies.Main outcome measures were vision,K values,apparent thinning on graft-host cornea and the difference between opposing quadrants in the thinnest point measurements.Anterior segment optic coherence tomography was performed for further evaluation.RESULTS:Mean follow-up was 127.2mo(24–282mo)in PK,and 64.3mo(24–144mo)in DALK.K max was higher in DALK(60.6 vs 56.7 D,P=0.012).Inferior recipient was thinner(595.9μm)in PK than DALK(662.2μm,P=0.021),due to longer follow-up.Overall corneal ectasia rate was 20.0%within 24y.Ectasia rate was the same(6.7%)in DALK 2/30 and in PK 4/60 in 10y and 13.3%in 12y(4/30 and 8/60,respectively).It increased to 23.3%(14/60)in PK over 24y.While ectasia was not seen before 7y in PK,it could be seen in DALK starting from the 5^(th) year.The intervals between keratoplasty and ectasia were 144.5mo in PK and 99mo in DALK.Inferior recipient was significantly thinner in 18 eyes with ectasia(502.7μm)compared to 76 non-ectasia(649.1μm,P=0.000).Inferior graft was thinner(561.0 vs 620.4μm,P=0.006),K max(63.3 vs 56.5 D,P=0.000),and anterior elevation was higher in ectasia(89.1 vs 48.6μm,P=0.002).Accelerated crosslinking was performed on 5 eyes.CONCLUSION:Inferior-superior recipient and inferior graft thinning on tomography,with high K max and anterior elevation emerge as the most reliable criteria for the diagnosis of late ectasia.The incidence of corneal ectasia increases with the time.展开更多
Class Title:Radiological imaging method a comprehensive overview purpose.This GPT paper provides an overview of the different forms of radiological imaging and the potential diagnosis capabilities they offer as well a...Class Title:Radiological imaging method a comprehensive overview purpose.This GPT paper provides an overview of the different forms of radiological imaging and the potential diagnosis capabilities they offer as well as recent advances in the field.Materials and Methods:This paper provides an overview of conventional radiography digital radiography panoramic radiography computed tomography and cone-beam computed tomography.Additionally recent advances in radiological imaging are discussed such as imaging diagnosis and modern computer-aided diagnosis systems.Results:This paper details the differences between the imaging techniques the benefits of each and the current advances in the field to aid in the diagnosis of medical conditions.Conclusion:Radiological imaging is an extremely important tool in modern medicine to assist in medical diagnosis.This work provides an overview of the types of imaging techniques used the recent advances made and their potential applications.展开更多
Following surface rupture observations in populated areas affected by the KahramanmaraşEarthquake(Mw 7.7)on February 6th,2023,along the Pazarcık segment of the East Anatolian Fault Zone(EAFZ),this study presents novel...Following surface rupture observations in populated areas affected by the KahramanmaraşEarthquake(Mw 7.7)on February 6th,2023,along the Pazarcık segment of the East Anatolian Fault Zone(EAFZ),this study presents novel insights into physical criteria for delineating surface fault-rupture hazard zones(SRHZs)along ruptured strike-slip faults.To achieve this objective,three trench studies across the surface rupture were conducted on the Pazarcık segment of the EAFZ to collect field data,and earthquake recurrence intervals were interpreted using Bayesian statistics from previously conducted paleoseismological trenchings.The results of the proposed model indicate that the Pazarcık segment produced five significant surface-rupturing earthquakes in the last∼11 kyr:E1:11.13±1.74 kyr,E2:7.62±1.20 kyr,E3:5.34±1.05 kyr,E4:1.82±0.93 kyr,and E5:0.35±0.11 kyr.In addition,the recurrence intervals of destructive earthquakes on the subject in question range from 0.6 kyr to 4.8 kyr.Considering that the last significant earthquake occurred in 1513,the longest time since the most recent surface fault rupturing earthquake on this particular segment was 511 years.These results indicate that,in terms of the theoretical recurrence interval of earthquakes that can create surface ruptures on the Pazarcık segment,the period in which the February 6,2023,earthquake occurred was within the end of the expected return period.As a result,the potential for a devastating earthquake in the near future is not foreseen on the same fault.Finally,the SRHZ proposed for the Pazarcık section of Gölbaşıvillage was calculated as a 61-meter-wide offset on the fault lineament to reduce the negativities that may occur in the ruptured area in the future.It is recommended to take into account this width in the settlement of this area and nearby areas.展开更多
Neurodegeneration is a catastrophic process that develops progressive damage leading to functional andstructural loss of the cells of the nervous system and is among the biggest unavoidable problems of our age.Animalm...Neurodegeneration is a catastrophic process that develops progressive damage leading to functional andstructural loss of the cells of the nervous system and is among the biggest unavoidable problems of our age.Animalmodels do not reflect the pathophysiology observed in humans due to distinct differences between the neuralpathways,gene expression patterns,neuronal plasticity,and other disease-related mechanisms in animals andhumans.Classical in vitro cell culture models are also not sufficient for pre-clinical drug testing in reflecting thecomplex pathophysiology of neurodegenerative diseases.Today,modern,engineered techniques are applied to developmulticellular,intricate in vitro models and to create the closest microenvironment simulating biological,biochemical,and mechanical characteristics of the in vivo degenerating tissue.In THIS review,the capabilities and shortcomings ofscaffold-based and scaffold-free techniques,organoids,and microfluidic models that best reflect neurodegeneration invitro in the biomimetic framework are discussed.展开更多
The snow cover over the Taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly Snow Cover Extent(SCE) from November to April in the Central ...The snow cover over the Taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly Snow Cover Extent(SCE) from November to April in the Central Taurus Mountains(Bolkar, Aladaglar, Tahtali and Binboga Mountains) from 1981 to 2021. Linear trends of snow cover season(November to April) over the last 41 years showed decreases in SCE primarily at lower elevations. The downward trend in SCE was found to be more pronounced and statistically significant for only November and March. SCE in the Central Taurus Mountains has declined about-6.3% per decade for 2500-3000 m in November and about-6.0% per decade for 1000-1500 m and 3000+ m in March over the last 41 years. The loss of SCE has become evident since the 2000s, and the lowest negative anomalies in SCE have been observed in 2014, 2001, and 2007 in the last 41 years, which are consistent with an increase in air temperature and decreased precipitation. SCE was correlated with both mean temperature and precipitation, with temperature having a greater relative importance at all elevated gradients. Results showed that there is a strong linear relationship between SCE and the mean air temperature(r =-0.80) and precipitation(r = 0.44) for all elevated gradients during the snow season. The Arctic Oscillation(AO), the North Atlantic Oscillation(NAO), and the Mediterranean Oscillation(MO) winter indices were used to explain the year-to-year variability in SCE over the Central Taurus Mountains. The results showed that the inter-annual variability observed in the winter SCE on the Central Taurus Mountains was positively correlated with the phases of the winter AO, NAO and MO, especially below 2000 m elevation.展开更多
Cells are surrounded by a double-layered phospholipid cell membrane responsible for the isolation of intracellular contents, active regulation of uptake from the extracellular environment, and intercellular connection...Cells are surrounded by a double-layered phospholipid cell membrane responsible for the isolation of intracellular contents, active regulation of uptake from the extracellular environment, and intercellular connection and communication. These cell membranes must be intact and functionally active for cell survival and biological functioning. Compromised damage repair mechanisms usually result in impaired cellular homeostasis, leading to early or late problems. Chronic myopathies, certain myocardial diseases, aging, and acute or chronic neurodegenerative diseases (like Parkinson and Alzheimer) are directly related to cell membrane damage. This study examined the effect of a cholesterol-loaded nanoparticle (methyl-beta cyclodextrin) or the silk protein sericin on cell membrane and DNA integrity and cell viability in an in vitro cell damage model (frozen-thawed rabbit sperm cells). The cells were stored in liquid nitrogen (-196°C), thawed in small batches, and treated with cholesterol-loaded cyclodextrin or sericin before incubation at 35°C for 4 hours. Cell membrane integrity, DNA damage, and viability rates were assessed immediately after thawing and after the incubation period. The administration of sericin and cholesterol in a cell damage model increased cell survival and reduced DNA damage over a 4-hour post-thaw incubation period, suggesting their potential use as a “first aid” intervention at the cellular level.展开更多
BACKGROUND Currently,the primary treatment for gastroesophageal reflux is acid suppression with proton pump inhibitors,but they are not a cure,and some patients don’t respond well or refuse long-term use.Therefore,al...BACKGROUND Currently,the primary treatment for gastroesophageal reflux is acid suppression with proton pump inhibitors,but they are not a cure,and some patients don’t respond well or refuse long-term use.Therefore,alternative therapies are needed to understand the disease and develop better treatments.Laparoscopic anti-reflux surgery(LARS)can resolve symptoms of these patients and plays a significant role in evaluating esophageal healing after preventing harmful effects.Successful LARS improves typical gastroesophageal reflux symptoms in most patients,main-ly by reducing the exposure time to gastric contents in the esophagus.Amelio-ration of the inflammatory response and a recovery response in the esophageal epithelium is expected following the cessation of the noxious attack.AIM To explore the role of inflammatory biomolecules in LARS and assess the time required for esophageal epithelial recovery.METHODS Of 22 patients with LARS(pre-and post/5.8±3.8 months after LARS)and 25 healthy controls(HCs)were included.All subjects underwent 24-h multichannel intraluminal impedance-pH monitoring and upper gastrointestinal endoscopy,during which esophageal biopsy samples were collected using endoscopic tech-niques.Inflammatory molecules in esophageal biopsies were investigated by reverse transcription-polymerase chain reaction and multiplex-enzyme-linked immunosorbent assay.RESULTS Post-LARS samples showed significant increases in proinflammatory cytokines[interleukin(IL)-1β,interferon-γ,C-X-C chemokine ligand 2(CXCL2)],anti-inflammatory cytokines[CC chemokine ligand(CCL)11,CCL13,CCL17,CCL26,CCL1,CCL7,CCL8,CCL24,IL-4,IL-10],and homeostatic cytokines(CCL27,CCL20,CCL19,CCL23,C-CL25,CXCL12,migration inhibitory factor)compared to both HCs and pre-LARS samples.CCL17 and CCL21 levels were higher in pre-LARS than in HCs(P<0.05).The mRNA expression levels of AKT1,fibroblast growth factor 2,HRAS,and mitogen-activated protein kinase 4 were significantly decreased post-LARS vs pre-LARS.CCL2 and epidermal growth factor gene levels were significantly increased in the pre-LARS compared to the HCs(P<0.05).CONCLUSION The presence of proinflammatory proteins post-LARS suggests ongoing inflammation in the epithelium.Elevated homeostatic cytokine levels indicate cell balance is maintained for about 6 months after LARS.The anti-inflam-matory response post-LARS shows suppression of inflammatory damage and ongoing postoperative recovery.展开更多
Purpose of the Research: Our study aimed to determine and understand the risk factors of surgical site infections in patients operated on in general surgery wards. Method of Research: Between May 2008 and November 200...Purpose of the Research: Our study aimed to determine and understand the risk factors of surgical site infections in patients operated on in general surgery wards. Method of Research: Between May 2008 and November 2008, 422 consecutive patients who underwent emergency and elective surgeries, excluding breast, goitre and laparoscopic surgeries, were included in the study to determine surgical site infections and risk factors. The patients’ risk factors were selected in the preoperative period, and postoperative 3<sup>rd</sup>, 7<sup>th</sup>, and 30<sup>th</sup> days were checked by the physician responsible for conducting the study regarding surgical site infection. Results and Conclusion: Surgical site infections were defined as incisional and organ/space based on NNIS data. Gender, diabetes mellitus, malignancy, degree of contamination, ASA score ≥ 3, preoperative skin cleansing, duration of intensive care unit stay, duration of hospital stay, growth in wound culture, duration of surgery and incision length were determined as risk factors increasing CAI rates. Especially the degree of contamination, duration of intensive care unit stay, hospitalisation, duration of operation, and growth in wound culture were decisive factors in the development of CAI. As a result of our study, in the light of these data, we concluded that to prevent the development of CAI can be modified, interventions to foreseeable factors can be assessed.展开更多
The effect of sediment size on metals bioleaching from bay sediments was investigated by using fine (〈 45 μm), medium (45-300 μm), and coarse (300-2000 μm) size fractions of a sediment sample contaminated wi...The effect of sediment size on metals bioleaching from bay sediments was investigated by using fine (〈 45 μm), medium (45-300 μm), and coarse (300-2000 μm) size fractions of a sediment sample contaminated with Cr, Cu, Pb, and Zn. Chemical speciation of the metals in bulk and size fractions of sediment were studied before and after bioleaching. Microbial activity was provided with mixed cultures of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans. The bioleaching process was carried out in flask experiments for 48 days, by using 5% (W/V) of solid concentration in suspension. Bioleaching was found to be efficient for the removal of selected heavy metals from every size fraction of sediments, where the experiments with the smaller particles resulted in the highest solubilization ratios. At the end of the experimental period, Cr, Cu, Pb and Zn were solubilized to the ratios of 68%, 88%, 72%, and 91% from the fine sediment, respectively. Higher removal efficiencies can be explained by the larger surface area provided by the smaller particles. The changes in the chemical forms of metals were determined and most of the metal releases were observed from the reducible and organic fractions independent from grain size. Higher concentrations were monitored in the residual fraction after bioleaching period, suggesting they are trapped in this fraction, and cannot be solubilized under natural conditions.展开更多
This study examines the effect of nanosilica(NS)additive to improve the mechanical properties of clay,clayey sand,and sand.The engineering properties of the soils were investigated through Atterberg limits,compaction,...This study examines the effect of nanosilica(NS)additive to improve the mechanical properties of clay,clayey sand,and sand.The engineering properties of the soils were investigated through Atterberg limits,compaction,unconfined compression,ultrasonic pulse velocity(UPV),freeze-thaw,and direct shear tests.The NS content varied from 0%to 0.7%and cement content was 5%and 10%by the dry weight of the soil.The curing period varied from 7 d to 150 d.The consistency,compaction,and strength properties of the soils were affected by the presence of NS and cement.The optimum NS contents in clay specimens with 5%and 10%cement were 0.5%and 0.7%,respectively.It was 0.7%in sand specimens with both cement ratios,as well as 0.3%and 0.7%in clayey sand specimens with 5%and 10%cement,respectively.In terms of freeze-thaw resistance,clayey sand specimens containing 0.5%NS and 10%cement had the minimum strength loss.Exponential relationships existed between the ultrasonic pulse velocity(UPV)and the unconfined compressive strength(UCS)of soil specimens having the same curing period.The shear strength parameters of the soils also improved with the addition of NS.Scanning electron microscope(SEM)images demonstrated that cement and NS contributed to the improvement of the soils by producing a denser and more uniform structure.It was concluded that the minor addition of NS could potentially improve the geomechanical properties of the soils.展开更多
In this study,the recycled short carbon fiber(CF)-reinforced magnesium matrix composites were fabricated using a combination of stir casting and hot extrusion.The objective was to investigate the impact of CF content(...In this study,the recycled short carbon fiber(CF)-reinforced magnesium matrix composites were fabricated using a combination of stir casting and hot extrusion.The objective was to investigate the impact of CF content(2.5 and 5.0 wt.%)and fiber length(100 and 500μm)on the microstructure,mechanical properties,and creep behavior of AZ91 alloy matrix.The microstructural analysis revealed that the CFs aligned in the extrusion direction resulted in grain and intermetallic refinement within the alloy.In comparison to the unreinforced AZ91 alloy,the composites with 2.5 wt.%CF exhibited an increase in hardness by 16-20%and yield strength by 5-15%,depending on the fiber length,while experiencing a reduction in ductility.When the reinforcement content was increased from 2.5 to 5.0 wt.%,strength values exhibited fluctuations and decline,accompanied by decreased ductility.These divergent outcomes were discussed in relation to fiber length,clustering tendency due to higher reinforcement content,and the presence of interfacial products with micro-cracks at the CF-matrix interface.Tensile creep tests indicated that CFs did not enhance the creep resistance of extruded AZ91 alloy,suggesting that grain boundary sliding is likely the dominant deformation mechanism during creep.展开更多
通过脆性岩石试样巴西圆盘试验研究了疲劳效应对脆性岩石断裂韧度KIC的影响,阐释了脆性岩石的疲劳损伤机制,首次展示了脆性岩石破坏前宏观裂纹的张开和闭合行为。巴西圆盘试验结果表明,循环荷载作用下,脆性岩样的KIC降低了35%,巴西劈裂...通过脆性岩石试样巴西圆盘试验研究了疲劳效应对脆性岩石断裂韧度KIC的影响,阐释了脆性岩石的疲劳损伤机制,首次展示了脆性岩石破坏前宏观裂纹的张开和闭合行为。巴西圆盘试验结果表明,循环荷载作用下,脆性岩样的KIC降低了35%,巴西劈裂拉伸强度降低了30%。通过高速相机数小时的观测并记录到了岩石力学领域从未观测到的过程,即脆性岩样破坏前,疲劳裂纹在正弦荷载作用下弹性张合。扫描电镜和计算机断层扫描结果显示,巴西圆盘和V形切槽巴西圆盘试样的破坏是由断裂过程区(fracture process zone,简称FPZ)引起的,FPZ中包含许多异于循环荷载作用下单条宏观裂纹的微裂纹,切槽裂纹尖端FPZ的形成导致未破坏脆性岩样中可视疲劳裂纹弹性张合。室内试验和数值计算结果表明,切槽裂纹倾角为60°时获得最大FPZ(即FPZmax),这表明最大FPZ的形成可能与Ⅰ-Ⅱ型(拉伸和剪切)组合加载模式有关。展开更多
Background:Low levels of antioxidant paraoxonase 1(PON 1)enzyme activity,PON1-Q192R polymorphism(a glutamine(Q)to arginine(R)substitution at position 192),PON1-L55M polymorphism(a leucine(L)to methionine(M)substitutio...Background:Low levels of antioxidant paraoxonase 1(PON 1)enzyme activity,PON1-Q192R polymorphism(a glutamine(Q)to arginine(R)substitution at position 192),PON1-L55M polymorphism(a leucine(L)to methionine(M)substitution at position 55),and oxidized low-density lipoprotein(oxLDL)are risk factors for coronary heart disease.Aerobic exercise improves PON1 activity,but the effects of hypoxic exercise are yet unclear.The aim of this study was to determine the effects of hypoxic underwater rugby training on PON1 activity and oxLDL levels and the role of the mentioned polymorphisms.Methods:Serum PON1 and arylesterase activities(ARE),PON1,PON3,and oxLDL protein levels(by using the enzyme-linked immunosorbent assays)were determined in an athletic group(42 trained male underwater rugby players;age=21.7±4.2 years,mean±SD)and a control group(43 sedentary men;age=23.9±3.2 years).The polymorphisms were determined from genomic DNA samples.Results:PON1 activity(25.1%,p=0.052),PON3(p<0.001),and oxLDL(p<0.001)of the athletic group,including most genotype groups,were higher than those of the control group.In comparison to the controls,PON1 activity levels(p=0.005)of the PON1-Q192R homozygote QQ genotype group and PON1 activity levels(30%,p=0.116)of the PON1-L55M homozygote LL genotype group were higher,whereas ARE activity values of athletic R allele carrier(Rc=QR+RR)(p=0.005)and LL group(p=0.002)were lower than the control genotype groups related to their polymorphisms.Conclusion:Hypoxic training can cause(1)significant oxidative stress,including oxLDL,and an antioxidant response(increase in PON1 activity and PON3),(2)differences in the activity of PON1 and ARE,which are modified by PON1-Q192R and PON1-L55M polymorphisms,respectively,and(3)improvements in PON1 activity of QQ and LL groups.However,hypoxic training can cause a disadvantage of LL and Rc groups for ARE.展开更多
文摘Disturbances such as forest fires,intense winds,and insect damage exert strong impacts on forest ecosystems by shaping their structure and growth dynamics,with contributions from climate change.Consequently,there is a need for reliable and operational methods to monitor and map these disturbances for the development of suitable management strategies.While susceptibility assessment using machine learning methods has increased,most studies have focused on a single disturbance.Moreover,there has been limited exploration of the use of“Automated Machine Learning(AutoML)”in the literature.In this study,susceptibility assessment for multiple forest disturbances(fires,insect damage,and wind damage)was conducted using the PyCaret AutoML framework in the Izmir Regional Forest Directorate(RFD)in Turkey.The AutoML framework compared 14 machine learning algorithms and ranked the best models based on AUC(area under the curve)values.The extra tree classifier(ET)algorithm was selected for modeling the susceptibility of each disturbance due to its good performance(AUC values>0.98).The study evaluated susceptibilities for both individual and multiple disturbances,creating a total of four susceptibility maps using fifteen driving factors in the assessment.According to the results,82.5%of forested areas in the Izmir RFD are susceptible to multiple disturbances at high and very high levels.Additionally,a potential forest disturbances map was created,revealing that 15.6%of forested areas in the Izmir RFD may experience no damage from the disturbances considered,while 54.2%could face damage from all three disturbances.The SHAP(Shapley Additive exPlanations)methodology was applied to evaluate the importance of features on prediction and the nonlinear relationship between explanatory features and susceptibility to disturbance.
文摘To determine the shear wave velocity structure and predominant period features of Tmaztepe in izmir, Turkey, where new building sites have been planned, active-passive surface wave methods and single-station microtremor measurements are used, as well as surface acquisition techniques, including the multichannel analysis of surface waves (MASW), refraction microtremor (ReMi), and the spatial autocorrelation method (SPAC), to pinpoint shallow and deep shear wave velocity. For engineering bedrock (V 〉 760 m/s) conditions at a depth of 30 m, an average seismic shear wave velocity in the upper 30 m of soil (AVs30) is not only accepted as an important parameter for defining ground behavior during earthquakes, but a primary parameter in the geotechnical analysis for areas to be classified by V30 according to the National Earthquake Hazards Reduction Program (NEHRP). It is also determined that Z1.0, which represents a depth to V = 1000 m/s, is used for ground motion prediction and changed from 0 to 54 m. The sediment-engineering bedrock structure for Tmaztepe that was obtained shows engineering bedrock no deeper than 30 m. When compared, the depth of engineering bedrock and dominant period map and geology are generally compatible.
文摘In this study, using the constant rate of supply model, sedimentation rates of Izmir Bay were calculated and discussed. For this purpose, eight sediment cores were collected from inner part of the bay and sedimentation rates were calculated from vertical distribution of^(210)Pb.^(210)Pb activities were determined indirectly from ^(210)Po activities.Sedimentation rates ranged from 0.10 to 0.52 cm/year. The highest sedimentation rates were determined in stations close to the Poligon stream. It was concluded that main transporting mechanism for sediments is river and streams in the area. In addition, sediment cores taken from the harbor were mixed due to bioturbation, water circulation and/or other factors.
文摘Architectural artefacts form the identity of the cities, especially when these artifacts dated to historical times, it becomes more valuable. The importance of preserving the architectural heritage is more meaningful when the building is preserved with its whole environment, with the other historical buildings around as a site protection. Preservation of historical monuments not only individually but also with their environments help the city regain its identity that it has lost. The Conservation Approach to Cultural Assets in Turkey has reached to its peek starting from 1985's through introducing the effects of the recent amendment on cultural heritage law and the impact of the EU integration process. The municipalities started to use this recent amendment on cultural heritage laws as a method of recovering their cities for the local identity searches. This paper will deal with the current challenges for conservation practice in Turkey, through introducing the effects of the recent amendment on cultural heritage law and the impact of the EU integration process, and examine some major promising conservation and renovation, rehabilitation projects continuing in Izmir the third biggest city of Turkey for which local solutions are being devised for problems of global context in the meaning of local identity searches for the city.
文摘Protecting the historical heritage is a very important task because it makes up the identity of the society and the cities. Considering the future, the most important problem recently is how to protect the historical heritage, and how to benefit from it. And as an answer to this question, by benefiting from our cultural background, it is necessary to provide the contemporary requirements and to transfer this attitude to the future generations. Throughout the time, functions may change but old buildings may stay. This situation requires that the old buildings are open to a new contemporary uses. Nowadays, the variations in the functions loaded onto the places we live in are frequently put on the agenda due to the requirements which are continuously changed and developed by social and cultural effects. While faced with this kind of functional variations in order to protect the mean values, the scope of this study is described in a systematically manner as: (1) re-functioning process; (2) adaptation of the new function to the old building; and (3) design concept in the revalorization. The scope will be discussed with many implementations from Turkey and the cases are chosen from the Izmir city.
文摘In this editorial,we comment on the article by Stafie et al.Inflammatory bowel disease(IBD)constitutes a cluster of chronic and progressive inflammatory disorders affecting the digestive system.IBD can impede an individual’s capacity to perform daily activities,hinder work productivity,limit physical capabilities,and negatively impact medical outcomes.Although physical activity and structured exercise programs are becoming increasingly important in many chronic inflammatory diseases,they are not being sufficiently implemented in IBD patients.Effective prevention of future disability and drug dependence in IBD patients requires timely diagnosis and treatment of musculoskeletal problems,including sarcopenia,as well as decreased muscle strength,aerobic capacity,and bone mineral density.To improve treatment outcomes for IBD patients,it is crucial to develop individualized rehabilitation programs tailored to their unique needs.Equally critical is the active participation of pertinent departments in this process.It is imperative to highlight the significance of creating a personalized rehabilitation program with a multidisciplinary approach in IBD management.
文摘AIM:To investigate tomographic features of late corneal ectasia after keratoplasty for keratoconus and compare penetrating keratoplasty(PK)and deep anterior lamellar keratoplasty(DALK)in terms of incidence,time of onset and risk factors of corneal ectasia.METHODS:Sixty eyes with PK and 30 eyes with DALK operated between 1999 and 2021 were analyzed.Final Pentacam scans were evaluated together with vision and previous topographies.Main outcome measures were vision,K values,apparent thinning on graft-host cornea and the difference between opposing quadrants in the thinnest point measurements.Anterior segment optic coherence tomography was performed for further evaluation.RESULTS:Mean follow-up was 127.2mo(24–282mo)in PK,and 64.3mo(24–144mo)in DALK.K max was higher in DALK(60.6 vs 56.7 D,P=0.012).Inferior recipient was thinner(595.9μm)in PK than DALK(662.2μm,P=0.021),due to longer follow-up.Overall corneal ectasia rate was 20.0%within 24y.Ectasia rate was the same(6.7%)in DALK 2/30 and in PK 4/60 in 10y and 13.3%in 12y(4/30 and 8/60,respectively).It increased to 23.3%(14/60)in PK over 24y.While ectasia was not seen before 7y in PK,it could be seen in DALK starting from the 5^(th) year.The intervals between keratoplasty and ectasia were 144.5mo in PK and 99mo in DALK.Inferior recipient was significantly thinner in 18 eyes with ectasia(502.7μm)compared to 76 non-ectasia(649.1μm,P=0.000).Inferior graft was thinner(561.0 vs 620.4μm,P=0.006),K max(63.3 vs 56.5 D,P=0.000),and anterior elevation was higher in ectasia(89.1 vs 48.6μm,P=0.002).Accelerated crosslinking was performed on 5 eyes.CONCLUSION:Inferior-superior recipient and inferior graft thinning on tomography,with high K max and anterior elevation emerge as the most reliable criteria for the diagnosis of late ectasia.The incidence of corneal ectasia increases with the time.
文摘Class Title:Radiological imaging method a comprehensive overview purpose.This GPT paper provides an overview of the different forms of radiological imaging and the potential diagnosis capabilities they offer as well as recent advances in the field.Materials and Methods:This paper provides an overview of conventional radiography digital radiography panoramic radiography computed tomography and cone-beam computed tomography.Additionally recent advances in radiological imaging are discussed such as imaging diagnosis and modern computer-aided diagnosis systems.Results:This paper details the differences between the imaging techniques the benefits of each and the current advances in the field to aid in the diagnosis of medical conditions.Conclusion:Radiological imaging is an extremely important tool in modern medicine to assist in medical diagnosis.This work provides an overview of the types of imaging techniques used the recent advances made and their potential applications.
基金This contribution was partially supported by the Turkish government through the 1002-C project in Natural Disasters Focused Fieldwork Emergency Support Program managed by the TUBITAK.I am grateful to F.Koçbulut and S.Koşaroğlu for helping me with the trenching studies.I also gratefully acknowledge H.Sözbilir,M.Nas,and E.Akgün for comments and suggestions.Furthermore,I extend my gratitude to the anonymous referees for their constructive criticisms and insightful feedback during the evaluation phase of this manuscript.
文摘Following surface rupture observations in populated areas affected by the KahramanmaraşEarthquake(Mw 7.7)on February 6th,2023,along the Pazarcık segment of the East Anatolian Fault Zone(EAFZ),this study presents novel insights into physical criteria for delineating surface fault-rupture hazard zones(SRHZs)along ruptured strike-slip faults.To achieve this objective,three trench studies across the surface rupture were conducted on the Pazarcık segment of the EAFZ to collect field data,and earthquake recurrence intervals were interpreted using Bayesian statistics from previously conducted paleoseismological trenchings.The results of the proposed model indicate that the Pazarcık segment produced five significant surface-rupturing earthquakes in the last∼11 kyr:E1:11.13±1.74 kyr,E2:7.62±1.20 kyr,E3:5.34±1.05 kyr,E4:1.82±0.93 kyr,and E5:0.35±0.11 kyr.In addition,the recurrence intervals of destructive earthquakes on the subject in question range from 0.6 kyr to 4.8 kyr.Considering that the last significant earthquake occurred in 1513,the longest time since the most recent surface fault rupturing earthquake on this particular segment was 511 years.These results indicate that,in terms of the theoretical recurrence interval of earthquakes that can create surface ruptures on the Pazarcık segment,the period in which the February 6,2023,earthquake occurred was within the end of the expected return period.As a result,the potential for a devastating earthquake in the near future is not foreseen on the same fault.Finally,the SRHZ proposed for the Pazarcık section of Gölbaşıvillage was calculated as a 61-meter-wide offset on the fault lineament to reduce the negativities that may occur in the ruptured area in the future.It is recommended to take into account this width in the settlement of this area and nearby areas.
文摘Neurodegeneration is a catastrophic process that develops progressive damage leading to functional andstructural loss of the cells of the nervous system and is among the biggest unavoidable problems of our age.Animalmodels do not reflect the pathophysiology observed in humans due to distinct differences between the neuralpathways,gene expression patterns,neuronal plasticity,and other disease-related mechanisms in animals andhumans.Classical in vitro cell culture models are also not sufficient for pre-clinical drug testing in reflecting thecomplex pathophysiology of neurodegenerative diseases.Today,modern,engineered techniques are applied to developmulticellular,intricate in vitro models and to create the closest microenvironment simulating biological,biochemical,and mechanical characteristics of the in vivo degenerating tissue.In THIS review,the capabilities and shortcomings ofscaffold-based and scaffold-free techniques,organoids,and microfluidic models that best reflect neurodegeneration invitro in the biomimetic framework are discussed.
文摘The snow cover over the Taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly Snow Cover Extent(SCE) from November to April in the Central Taurus Mountains(Bolkar, Aladaglar, Tahtali and Binboga Mountains) from 1981 to 2021. Linear trends of snow cover season(November to April) over the last 41 years showed decreases in SCE primarily at lower elevations. The downward trend in SCE was found to be more pronounced and statistically significant for only November and March. SCE in the Central Taurus Mountains has declined about-6.3% per decade for 2500-3000 m in November and about-6.0% per decade for 1000-1500 m and 3000+ m in March over the last 41 years. The loss of SCE has become evident since the 2000s, and the lowest negative anomalies in SCE have been observed in 2014, 2001, and 2007 in the last 41 years, which are consistent with an increase in air temperature and decreased precipitation. SCE was correlated with both mean temperature and precipitation, with temperature having a greater relative importance at all elevated gradients. Results showed that there is a strong linear relationship between SCE and the mean air temperature(r =-0.80) and precipitation(r = 0.44) for all elevated gradients during the snow season. The Arctic Oscillation(AO), the North Atlantic Oscillation(NAO), and the Mediterranean Oscillation(MO) winter indices were used to explain the year-to-year variability in SCE over the Central Taurus Mountains. The results showed that the inter-annual variability observed in the winter SCE on the Central Taurus Mountains was positively correlated with the phases of the winter AO, NAO and MO, especially below 2000 m elevation.
文摘Cells are surrounded by a double-layered phospholipid cell membrane responsible for the isolation of intracellular contents, active regulation of uptake from the extracellular environment, and intercellular connection and communication. These cell membranes must be intact and functionally active for cell survival and biological functioning. Compromised damage repair mechanisms usually result in impaired cellular homeostasis, leading to early or late problems. Chronic myopathies, certain myocardial diseases, aging, and acute or chronic neurodegenerative diseases (like Parkinson and Alzheimer) are directly related to cell membrane damage. This study examined the effect of a cholesterol-loaded nanoparticle (methyl-beta cyclodextrin) or the silk protein sericin on cell membrane and DNA integrity and cell viability in an in vitro cell damage model (frozen-thawed rabbit sperm cells). The cells were stored in liquid nitrogen (-196°C), thawed in small batches, and treated with cholesterol-loaded cyclodextrin or sericin before incubation at 35°C for 4 hours. Cell membrane integrity, DNA damage, and viability rates were assessed immediately after thawing and after the incubation period. The administration of sericin and cholesterol in a cell damage model increased cell survival and reduced DNA damage over a 4-hour post-thaw incubation period, suggesting their potential use as a “first aid” intervention at the cellular level.
基金Supported by the Scientific and Technological Research Council of Turkiye/TUBİTAK,No.118S260Turkish Society of Gastroenterology,No.797-TGD-2021.
文摘BACKGROUND Currently,the primary treatment for gastroesophageal reflux is acid suppression with proton pump inhibitors,but they are not a cure,and some patients don’t respond well or refuse long-term use.Therefore,alternative therapies are needed to understand the disease and develop better treatments.Laparoscopic anti-reflux surgery(LARS)can resolve symptoms of these patients and plays a significant role in evaluating esophageal healing after preventing harmful effects.Successful LARS improves typical gastroesophageal reflux symptoms in most patients,main-ly by reducing the exposure time to gastric contents in the esophagus.Amelio-ration of the inflammatory response and a recovery response in the esophageal epithelium is expected following the cessation of the noxious attack.AIM To explore the role of inflammatory biomolecules in LARS and assess the time required for esophageal epithelial recovery.METHODS Of 22 patients with LARS(pre-and post/5.8±3.8 months after LARS)and 25 healthy controls(HCs)were included.All subjects underwent 24-h multichannel intraluminal impedance-pH monitoring and upper gastrointestinal endoscopy,during which esophageal biopsy samples were collected using endoscopic tech-niques.Inflammatory molecules in esophageal biopsies were investigated by reverse transcription-polymerase chain reaction and multiplex-enzyme-linked immunosorbent assay.RESULTS Post-LARS samples showed significant increases in proinflammatory cytokines[interleukin(IL)-1β,interferon-γ,C-X-C chemokine ligand 2(CXCL2)],anti-inflammatory cytokines[CC chemokine ligand(CCL)11,CCL13,CCL17,CCL26,CCL1,CCL7,CCL8,CCL24,IL-4,IL-10],and homeostatic cytokines(CCL27,CCL20,CCL19,CCL23,C-CL25,CXCL12,migration inhibitory factor)compared to both HCs and pre-LARS samples.CCL17 and CCL21 levels were higher in pre-LARS than in HCs(P<0.05).The mRNA expression levels of AKT1,fibroblast growth factor 2,HRAS,and mitogen-activated protein kinase 4 were significantly decreased post-LARS vs pre-LARS.CCL2 and epidermal growth factor gene levels were significantly increased in the pre-LARS compared to the HCs(P<0.05).CONCLUSION The presence of proinflammatory proteins post-LARS suggests ongoing inflammation in the epithelium.Elevated homeostatic cytokine levels indicate cell balance is maintained for about 6 months after LARS.The anti-inflam-matory response post-LARS shows suppression of inflammatory damage and ongoing postoperative recovery.
文摘Purpose of the Research: Our study aimed to determine and understand the risk factors of surgical site infections in patients operated on in general surgery wards. Method of Research: Between May 2008 and November 2008, 422 consecutive patients who underwent emergency and elective surgeries, excluding breast, goitre and laparoscopic surgeries, were included in the study to determine surgical site infections and risk factors. The patients’ risk factors were selected in the preoperative period, and postoperative 3<sup>rd</sup>, 7<sup>th</sup>, and 30<sup>th</sup> days were checked by the physician responsible for conducting the study regarding surgical site infection. Results and Conclusion: Surgical site infections were defined as incisional and organ/space based on NNIS data. Gender, diabetes mellitus, malignancy, degree of contamination, ASA score ≥ 3, preoperative skin cleansing, duration of intensive care unit stay, duration of hospital stay, growth in wound culture, duration of surgery and incision length were determined as risk factors increasing CAI rates. Especially the degree of contamination, duration of intensive care unit stay, hospitalisation, duration of operation, and growth in wound culture were decisive factors in the development of CAI. As a result of our study, in the light of these data, we concluded that to prevent the development of CAI can be modified, interventions to foreseeable factors can be assessed.
基金supported by the Research Fund of Dokuz Eylul University (No. 03.KB.FEN.018)by the Turkish State Planning Organization (No. DPT.2003K120360)
文摘The effect of sediment size on metals bioleaching from bay sediments was investigated by using fine (〈 45 μm), medium (45-300 μm), and coarse (300-2000 μm) size fractions of a sediment sample contaminated with Cr, Cu, Pb, and Zn. Chemical speciation of the metals in bulk and size fractions of sediment were studied before and after bioleaching. Microbial activity was provided with mixed cultures of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans. The bioleaching process was carried out in flask experiments for 48 days, by using 5% (W/V) of solid concentration in suspension. Bioleaching was found to be efficient for the removal of selected heavy metals from every size fraction of sediments, where the experiments with the smaller particles resulted in the highest solubilization ratios. At the end of the experimental period, Cr, Cu, Pb and Zn were solubilized to the ratios of 68%, 88%, 72%, and 91% from the fine sediment, respectively. Higher removal efficiencies can be explained by the larger surface area provided by the smaller particles. The changes in the chemical forms of metals were determined and most of the metal releases were observed from the reducible and organic fractions independent from grain size. Higher concentrations were monitored in the residual fraction after bioleaching period, suggesting they are trapped in this fraction, and cannot be solubilized under natural conditions.
基金The authors thank to Ege University Central Research Test and Analysis Laboratory Application and Research Center(EGE-MATAL)for SEM images.
文摘This study examines the effect of nanosilica(NS)additive to improve the mechanical properties of clay,clayey sand,and sand.The engineering properties of the soils were investigated through Atterberg limits,compaction,unconfined compression,ultrasonic pulse velocity(UPV),freeze-thaw,and direct shear tests.The NS content varied from 0%to 0.7%and cement content was 5%and 10%by the dry weight of the soil.The curing period varied from 7 d to 150 d.The consistency,compaction,and strength properties of the soils were affected by the presence of NS and cement.The optimum NS contents in clay specimens with 5%and 10%cement were 0.5%and 0.7%,respectively.It was 0.7%in sand specimens with both cement ratios,as well as 0.3%and 0.7%in clayey sand specimens with 5%and 10%cement,respectively.In terms of freeze-thaw resistance,clayey sand specimens containing 0.5%NS and 10%cement had the minimum strength loss.Exponential relationships existed between the ultrasonic pulse velocity(UPV)and the unconfined compressive strength(UCS)of soil specimens having the same curing period.The shear strength parameters of the soils also improved with the addition of NS.Scanning electron microscope(SEM)images demonstrated that cement and NS contributed to the improvement of the soils by producing a denser and more uniform structure.It was concluded that the minor addition of NS could potentially improve the geomechanical properties of the soils.
基金the German Academic Exchange Service (DAAD) for providing a scholarship to Dr. Sinan Kandemir during his tenure at Helmholtz-Zentrum Hereon (HZH)
文摘In this study,the recycled short carbon fiber(CF)-reinforced magnesium matrix composites were fabricated using a combination of stir casting and hot extrusion.The objective was to investigate the impact of CF content(2.5 and 5.0 wt.%)and fiber length(100 and 500μm)on the microstructure,mechanical properties,and creep behavior of AZ91 alloy matrix.The microstructural analysis revealed that the CFs aligned in the extrusion direction resulted in grain and intermetallic refinement within the alloy.In comparison to the unreinforced AZ91 alloy,the composites with 2.5 wt.%CF exhibited an increase in hardness by 16-20%and yield strength by 5-15%,depending on the fiber length,while experiencing a reduction in ductility.When the reinforcement content was increased from 2.5 to 5.0 wt.%,strength values exhibited fluctuations and decline,accompanied by decreased ductility.These divergent outcomes were discussed in relation to fiber length,clustering tendency due to higher reinforcement content,and the presence of interfacial products with micro-cracks at the CF-matrix interface.Tensile creep tests indicated that CFs did not enhance the creep resistance of extruded AZ91 alloy,suggesting that grain boundary sliding is likely the dominant deformation mechanism during creep.
文摘通过脆性岩石试样巴西圆盘试验研究了疲劳效应对脆性岩石断裂韧度KIC的影响,阐释了脆性岩石的疲劳损伤机制,首次展示了脆性岩石破坏前宏观裂纹的张开和闭合行为。巴西圆盘试验结果表明,循环荷载作用下,脆性岩样的KIC降低了35%,巴西劈裂拉伸强度降低了30%。通过高速相机数小时的观测并记录到了岩石力学领域从未观测到的过程,即脆性岩样破坏前,疲劳裂纹在正弦荷载作用下弹性张合。扫描电镜和计算机断层扫描结果显示,巴西圆盘和V形切槽巴西圆盘试样的破坏是由断裂过程区(fracture process zone,简称FPZ)引起的,FPZ中包含许多异于循环荷载作用下单条宏观裂纹的微裂纹,切槽裂纹尖端FPZ的形成导致未破坏脆性岩样中可视疲劳裂纹弹性张合。室内试验和数值计算结果表明,切槽裂纹倾角为60°时获得最大FPZ(即FPZmax),这表明最大FPZ的形成可能与Ⅰ-Ⅱ型(拉伸和剪切)组合加载模式有关。
基金Science and Technology Centre unit of Ege University for its financial support(No.33.102.2014.0001)。
文摘Background:Low levels of antioxidant paraoxonase 1(PON 1)enzyme activity,PON1-Q192R polymorphism(a glutamine(Q)to arginine(R)substitution at position 192),PON1-L55M polymorphism(a leucine(L)to methionine(M)substitution at position 55),and oxidized low-density lipoprotein(oxLDL)are risk factors for coronary heart disease.Aerobic exercise improves PON1 activity,but the effects of hypoxic exercise are yet unclear.The aim of this study was to determine the effects of hypoxic underwater rugby training on PON1 activity and oxLDL levels and the role of the mentioned polymorphisms.Methods:Serum PON1 and arylesterase activities(ARE),PON1,PON3,and oxLDL protein levels(by using the enzyme-linked immunosorbent assays)were determined in an athletic group(42 trained male underwater rugby players;age=21.7±4.2 years,mean±SD)and a control group(43 sedentary men;age=23.9±3.2 years).The polymorphisms were determined from genomic DNA samples.Results:PON1 activity(25.1%,p=0.052),PON3(p<0.001),and oxLDL(p<0.001)of the athletic group,including most genotype groups,were higher than those of the control group.In comparison to the controls,PON1 activity levels(p=0.005)of the PON1-Q192R homozygote QQ genotype group and PON1 activity levels(30%,p=0.116)of the PON1-L55M homozygote LL genotype group were higher,whereas ARE activity values of athletic R allele carrier(Rc=QR+RR)(p=0.005)and LL group(p=0.002)were lower than the control genotype groups related to their polymorphisms.Conclusion:Hypoxic training can cause(1)significant oxidative stress,including oxLDL,and an antioxidant response(increase in PON1 activity and PON3),(2)differences in the activity of PON1 and ARE,which are modified by PON1-Q192R and PON1-L55M polymorphisms,respectively,and(3)improvements in PON1 activity of QQ and LL groups.However,hypoxic training can cause a disadvantage of LL and Rc groups for ARE.