The fabrication of boron carbide reinforced aluminum matrix composites(Al-B_(4)C)with various contents of B_(4)C(1wt%,6wt%,15wt%,and 30wt%)was performed by powder metallurgy,and the influence of the content of B_(4)C ...The fabrication of boron carbide reinforced aluminum matrix composites(Al-B_(4)C)with various contents of B_(4)C(1wt%,6wt%,15wt%,and 30wt%)was performed by powder metallurgy,and the influence of the content of B_(4)C on their mechanical and tribological behavior was examined.The Al-30B_(4)C composites recorded the highest density(~2.54 g/cm^(3)),lowest porosity(4%),maximum Vickers hardness(HV~75),lowest weight loss(0.4 mg),and lowest specific wear rate(0.00042 mm^(3)/(N·m))under a load of 7 N,with an enhancement of 167%in hardness,a decrease of 75.8%in weight loss,and a decrease of 76.7%in the specific wear rate compared with pure aluminum.In addition,the scanning electron microscope images of the worn surface revealed that the Al-B_(4)C composite has the narrowest wear groove of 0.85 mm at a load of 7 N,and the main wear mechanism was observed as an abrasive wear mechanism.According to the friction analysis,the coefficient of friction between surfaces increased with increasing boron carbide content and with decreasing applied load.In conclusion,B_(4)C is an effective reinforcement material in terms of tribological and mechanical performance of the Al-B_(4)C composites.展开更多
The multiple cracking and deflection hardening performance of polyvinyl alcohol fiber reinforced engineered cementitious composites(PVA-ECC)under four-point flexural loading have been investigated.Matrices with differ...The multiple cracking and deflection hardening performance of polyvinyl alcohol fiber reinforced engineered cementitious composites(PVA-ECC)under four-point flexural loading have been investigated.Matrices with different binder combinations and W/B ratios(from 0.44 to 0.78)providing satisfactory PVA fiber dispersion were specially designed.Effect of pre-existing flaw size distribution modification on deflection hardening behavior was comparatively studied by adding 3 mm diameter polyethylene beads into the mixtures(6%by total volume).Natural flaw size distributions of composites without beads were determined by cross sectional analysis.The crack number and crack width distributions of specimens after flexural loading were characterized and the possible causes of changes in multiple cracking and deflection hardening behavior by flaw size distribution modification were discussed.Promising results from the view point of deflection hardening behavior were obtained from metakaolin incorporated and flaw size distribution modified PVA-ECCs prepared with W/B=0.53.The dual roles of W/B ratio and superplasticizer content on flaw size distribution,cracking potential and fiber-matrix bond behavior were evaluated.Flaw size distribution modification is found beneficial in terms of ductility improvement at an optimized W/B ratio.展开更多
Objective: We aimed to investigate the clinical and demographical characteristics of patients admitted to the Emergency Department (ED) due to maxillofacial trauma (MFT). Methods: This sectional and retrospective stud...Objective: We aimed to investigate the clinical and demographical characteristics of patients admitted to the Emergency Department (ED) due to maxillofacial trauma (MFT). Methods: This sectional and retrospective study was conducted in Ankara Numune Education and Research Hospital ED between 1st March 2010 and 31st March 2017. Into the study, patients with MFT older than 15 years of age were included. Characteristics of patients were recorded. Patients’ characteristics were compared according to presence of fractures. Results: Mean age of the patients was 41.1 ± 18.0 years and a statistically significant relationship was determined between age and presence of fracture (p > 0.05). Of the patients, 74.5% was male and fracture presence was significantly more in males than females (p 0.05). Conclusion: The MFT is a pathology that either leads to its own, or can lead to life-threatening consequences as a result of additional organ injuries. The physician evaluating the patient should determine the MFT and additional pathologies and ensure that the interventions start as soon as possible.展开更多
Objective:To investigate health literacy,behavioral and psychosocial characteristics in coronary artery patients.Methods:Between March 2019 and 2020 years,275 coronary artery patients aged≥50 years were included in t...Objective:To investigate health literacy,behavioral and psychosocial characteristics in coronary artery patients.Methods:Between March 2019 and 2020 years,275 coronary artery patients aged≥50 years were included in the study.Turkish Health Literacy Scale-32 and Beck Depression Inventory were used to collect the data.Results:General health literacy index score was 31.7 and the prevalence of limited health literacy was 59.3%.Adequate health literacy was 2.8 fold higher in the 50-64 age group,3.1 fold higher among men,3.4 fold higher among married and 5.3 fold higher among those who believed in the necessity of individual protective practices(P<0.05).Significant differences were also found in different working status,living places,perceived economic situation,perceived general health status,comorbidities,family history of coronary artery disease,angiography history,material skills on reading and understanding,level of depressive syptom,commitment to individual protective practices health check-ups,utilizing health services,cigarette and alcohol use,and exercise and nutrition between limited and adequate health literacy(P<0.05).Logistic regression analysis showed that adequate health literacy was significantly higher among younger patients(OR:2.81;95%CI:1.46-5.62),male gender(OR:3.10;95%CI:1.46-6.58),married(OR:3.42;95%CI:1.39-8.44)and those with belief in individual protective practices(OR:5.3;95%CI:1.93-14.96).Conclusions:Health literacy is poor among coronary artery patients and behavioral and psychosocial variables differ with health literacy levels.To keep cardiovascular health among these patients,health literacy-based interventions should be adopted in coronary artery clinics,especially for risky population.展开更多
Objective:To investigate the clinical symptoms of coronavirus disease 2019(COVID-19)patients with and without B.1.1.7 mutation.Methods:This retrospective observational study included COVID-19 patients who were divided...Objective:To investigate the clinical symptoms of coronavirus disease 2019(COVID-19)patients with and without B.1.1.7 mutation.Methods:This retrospective observational study included COVID-19 patients who were divided into two groups,the mutation and the non-mutation group.Demographics characteristics,clinical characteristics,laboratory parameters,and mortality rates were recorded and compared between the two groups.Results:A total of 196 patients were included in the study.The relationship between the mutant virus status and sex,age,comorbidity,survival status,and disease severity was not significant(P>0.05).No significant differences were found in duration of hospitalization between the mutation and the non-mutation group(P>0.05).However,there was a statistically significant difference between patients with and without mutant viruses in hemoglobin,mean platelet volume,procalcitonin,low density lipoprotein,iron-binding capacity,potassium,calcium,C-reactive protein,folate,creatine kinase myocardial band,D-dimer,and international normalized ratio(P<0.05).Conclusions:No significant difference is found in mortality rate,disease severity or duration of hospitalization between the patients with and without variant B.1.1.7.Careful monitoring of COVID-19 patients is required for all variants.展开更多
This article focuses on the performance analysis of both real-time and post-mission kinematic precise point positioning(PPP)in challenging marine environments.For this purpose,a real dynamic experiment lasting 6 h was...This article focuses on the performance analysis of both real-time and post-mission kinematic precise point positioning(PPP)in challenging marine environments.For this purpose,a real dynamic experiment lasting 6 h was carried out on a lake dam in?orum City of Turkey.While the kinematic test was continuing,the real-time PPP coordinates were obtained for each measurement epoch with a commercial real-time PPP(RT-PPP)service,namely the Trimble Center Point RTX.Then the post-mission PPP(PM-PPP)coordinates were calculated by using Multi-GNSS data and the Multi-GNSS Experiment(MGEX)precise products.The kinematic RT-PPP and PM-PPP results showed that the PPP coordinates were consistent with the relative solution at centimetre and decimetre level in horizontal and height components,respectively.This study implies that PPP technique is a powerful tool for highly accurate positioning in both real-time and post-mission modes,even for dynamic applications in harsh environments.展开更多
Takayasu arteritis is a large vessel vasculitis of the young women with giant cells and granuloma formation. The diagnosis and management of the disease are really not so easy because of the insidious onset and the di...Takayasu arteritis is a large vessel vasculitis of the young women with giant cells and granuloma formation. The diagnosis and management of the disease are really not so easy because of the insidious onset and the difficulties in assessment of disease activity. Nearly 60% of the patients are corticosteroid resistant or dependent and relapses are very frequent during taper of the dose [1]. The novel biologic agents as Anti-TNF, Rutiximab and Tocilizumab provide acceptable response rates with low toxicity. Herein, we reviewed the efficacy of Tocilizumab in Takayasu arteritis.展开更多
Background:This study aimed to determine the relationship between compassion fatigue and empathic disposition and skill levels of pediatric clinic nurses.Methods:This research was carried out as a descriptive and cros...Background:This study aimed to determine the relationship between compassion fatigue and empathic disposition and skill levels of pediatric clinic nurses.Methods:This research was carried out as a descriptive and cross-sectional study.The research was carried out with 233 nurses determined by using a stratified sampling method from 648 nurses working in two University Hospital and two City Hospital children’s clinics.Data were collected using the“Personal Information Form”,“Compassion Scale(CS)”,“Empathic Tendency Scale(ETS)”and“Empathic Skill Scale(ESS)”.Pearson Correlation test,Student’s t-test,ANOVA test,and Scheffe test were used in the analysis of the data.Results:The mean age of the nurses participating in the study was 30.93±6.23 years,81.1%were women and 54.9%were married.Pediatric clinic nurses’mean compassion score was 96.29±11.64,empathic tendency mean score was 69.30±8.39,and empathic skill mean score was 140.82±23.15.According to the findings obtained,the mean compassion score of the male,married,and nurses who were not satisfied with working in the pediatric clinics and working in the pediatric emergency clinics was found to be the lowest(p<0.05,p<0.01,p<0.001).The empathic disposition mean scores of the nurses working in the pediatric inpatient clinics,who were satisfied with working in the pediatric clinic,and who did not have the thought of moving to another clinic,were found to be significantly higher(p<0.01,p<0.001).The mean scores of empathic skills of nurses working only during the daytime were found to be significantly higher(p<0.001).Conclusion:This study confirms that pediatric clinic nurses are experiencing compassion fatigue at the end of COVID-19 and how this situation negatively affects their empathic tendencies and skills.The study highlights the need for both clinical and management-based planning to prevent compassion fatigue and increase empathic tendencies and skills in Pediatric clinic nurses.展开更多
In this study,the effect of different sampling rates(i.e.observation recording interval)on the Precise Point Positioning(PPP)solutions in terms of accuracy was investigated.For this purpose,a field test was carried ou...In this study,the effect of different sampling rates(i.e.observation recording interval)on the Precise Point Positioning(PPP)solutions in terms of accuracy was investigated.For this purpose,a field test was carried out inÇorum province,Turkey,on 11 September 2019.Within this context,a Geodetic Point(GP)was established and precisely coordinated.A static GNSS measurement was occupied on the GP for about 4-hour time at 0.10 second(s)/10 Hz measurement intervals with the Trimble R10 geodetic grade GNSS receiver.The original observation file was converted to RINEX format and then decimated into the different data sampling rates as 0.2 s,0.5 s,1 s,5 s,10 s,30 s,60 s,and 120 s.All these RINEX observation files were submitted to the Canadian Spatial Reference System-Precise Point Positioning(CSRS-PPP)online processing service the day after the data collection date by choosing both static and kinematic processing options.In this way,PPP-derived static coordinates,and the kinematic coordinates of each measurement epoch were calculated.The PPP-derived coordinates obtained from each decimated sampling intervals were compared to known coordinates of the GP for northing,easting,2D position,and height components.According to the static and kinematic processing results,high data sampling rates did not change the PPP solutions in terms of accuracy when compared to the results obtained using lower sampling rates.The results of this study imply that it was not necessary to collect GNSS data with high-rate intervals for many surveying projects requiring cm-level accuracy.展开更多
基金financially supported by the Scientific Researched Project Department of Ondokuz Mayιs University(No.PYO.MUH.1901.20.001)。
文摘The fabrication of boron carbide reinforced aluminum matrix composites(Al-B_(4)C)with various contents of B_(4)C(1wt%,6wt%,15wt%,and 30wt%)was performed by powder metallurgy,and the influence of the content of B_(4)C on their mechanical and tribological behavior was examined.The Al-30B_(4)C composites recorded the highest density(~2.54 g/cm^(3)),lowest porosity(4%),maximum Vickers hardness(HV~75),lowest weight loss(0.4 mg),and lowest specific wear rate(0.00042 mm^(3)/(N·m))under a load of 7 N,with an enhancement of 167%in hardness,a decrease of 75.8%in weight loss,and a decrease of 76.7%in the specific wear rate compared with pure aluminum.In addition,the scanning electron microscope images of the worn surface revealed that the Al-B_(4)C composite has the narrowest wear groove of 0.85 mm at a load of 7 N,and the main wear mechanism was observed as an abrasive wear mechanism.According to the friction analysis,the coefficient of friction between surfaces increased with increasing boron carbide content and with decreasing applied load.In conclusion,B_(4)C is an effective reinforcement material in terms of tribological and mechanical performance of the Al-B_(4)C composites.
基金Project(114M246)supported by the Scientific and Technological Research Council of Turkey
文摘The multiple cracking and deflection hardening performance of polyvinyl alcohol fiber reinforced engineered cementitious composites(PVA-ECC)under four-point flexural loading have been investigated.Matrices with different binder combinations and W/B ratios(from 0.44 to 0.78)providing satisfactory PVA fiber dispersion were specially designed.Effect of pre-existing flaw size distribution modification on deflection hardening behavior was comparatively studied by adding 3 mm diameter polyethylene beads into the mixtures(6%by total volume).Natural flaw size distributions of composites without beads were determined by cross sectional analysis.The crack number and crack width distributions of specimens after flexural loading were characterized and the possible causes of changes in multiple cracking and deflection hardening behavior by flaw size distribution modification were discussed.Promising results from the view point of deflection hardening behavior were obtained from metakaolin incorporated and flaw size distribution modified PVA-ECCs prepared with W/B=0.53.The dual roles of W/B ratio and superplasticizer content on flaw size distribution,cracking potential and fiber-matrix bond behavior were evaluated.Flaw size distribution modification is found beneficial in terms of ductility improvement at an optimized W/B ratio.
文摘Objective: We aimed to investigate the clinical and demographical characteristics of patients admitted to the Emergency Department (ED) due to maxillofacial trauma (MFT). Methods: This sectional and retrospective study was conducted in Ankara Numune Education and Research Hospital ED between 1st March 2010 and 31st March 2017. Into the study, patients with MFT older than 15 years of age were included. Characteristics of patients were recorded. Patients’ characteristics were compared according to presence of fractures. Results: Mean age of the patients was 41.1 ± 18.0 years and a statistically significant relationship was determined between age and presence of fracture (p > 0.05). Of the patients, 74.5% was male and fracture presence was significantly more in males than females (p 0.05). Conclusion: The MFT is a pathology that either leads to its own, or can lead to life-threatening consequences as a result of additional organ injuries. The physician evaluating the patient should determine the MFT and additional pathologies and ensure that the interventions start as soon as possible.
文摘Objective:To investigate health literacy,behavioral and psychosocial characteristics in coronary artery patients.Methods:Between March 2019 and 2020 years,275 coronary artery patients aged≥50 years were included in the study.Turkish Health Literacy Scale-32 and Beck Depression Inventory were used to collect the data.Results:General health literacy index score was 31.7 and the prevalence of limited health literacy was 59.3%.Adequate health literacy was 2.8 fold higher in the 50-64 age group,3.1 fold higher among men,3.4 fold higher among married and 5.3 fold higher among those who believed in the necessity of individual protective practices(P<0.05).Significant differences were also found in different working status,living places,perceived economic situation,perceived general health status,comorbidities,family history of coronary artery disease,angiography history,material skills on reading and understanding,level of depressive syptom,commitment to individual protective practices health check-ups,utilizing health services,cigarette and alcohol use,and exercise and nutrition between limited and adequate health literacy(P<0.05).Logistic regression analysis showed that adequate health literacy was significantly higher among younger patients(OR:2.81;95%CI:1.46-5.62),male gender(OR:3.10;95%CI:1.46-6.58),married(OR:3.42;95%CI:1.39-8.44)and those with belief in individual protective practices(OR:5.3;95%CI:1.93-14.96).Conclusions:Health literacy is poor among coronary artery patients and behavioral and psychosocial variables differ with health literacy levels.To keep cardiovascular health among these patients,health literacy-based interventions should be adopted in coronary artery clinics,especially for risky population.
文摘Objective:To investigate the clinical symptoms of coronavirus disease 2019(COVID-19)patients with and without B.1.1.7 mutation.Methods:This retrospective observational study included COVID-19 patients who were divided into two groups,the mutation and the non-mutation group.Demographics characteristics,clinical characteristics,laboratory parameters,and mortality rates were recorded and compared between the two groups.Results:A total of 196 patients were included in the study.The relationship between the mutant virus status and sex,age,comorbidity,survival status,and disease severity was not significant(P>0.05).No significant differences were found in duration of hospitalization between the mutation and the non-mutation group(P>0.05).However,there was a statistically significant difference between patients with and without mutant viruses in hemoglobin,mean platelet volume,procalcitonin,low density lipoprotein,iron-binding capacity,potassium,calcium,C-reactive protein,folate,creatine kinase myocardial band,D-dimer,and international normalized ratio(P<0.05).Conclusions:No significant difference is found in mortality rate,disease severity or duration of hospitalization between the patients with and without variant B.1.1.7.Careful monitoring of COVID-19 patients is required for all variants.
文摘This article focuses on the performance analysis of both real-time and post-mission kinematic precise point positioning(PPP)in challenging marine environments.For this purpose,a real dynamic experiment lasting 6 h was carried out on a lake dam in?orum City of Turkey.While the kinematic test was continuing,the real-time PPP coordinates were obtained for each measurement epoch with a commercial real-time PPP(RT-PPP)service,namely the Trimble Center Point RTX.Then the post-mission PPP(PM-PPP)coordinates were calculated by using Multi-GNSS data and the Multi-GNSS Experiment(MGEX)precise products.The kinematic RT-PPP and PM-PPP results showed that the PPP coordinates were consistent with the relative solution at centimetre and decimetre level in horizontal and height components,respectively.This study implies that PPP technique is a powerful tool for highly accurate positioning in both real-time and post-mission modes,even for dynamic applications in harsh environments.
文摘Takayasu arteritis is a large vessel vasculitis of the young women with giant cells and granuloma formation. The diagnosis and management of the disease are really not so easy because of the insidious onset and the difficulties in assessment of disease activity. Nearly 60% of the patients are corticosteroid resistant or dependent and relapses are very frequent during taper of the dose [1]. The novel biologic agents as Anti-TNF, Rutiximab and Tocilizumab provide acceptable response rates with low toxicity. Herein, we reviewed the efficacy of Tocilizumab in Takayasu arteritis.
文摘Background:This study aimed to determine the relationship between compassion fatigue and empathic disposition and skill levels of pediatric clinic nurses.Methods:This research was carried out as a descriptive and cross-sectional study.The research was carried out with 233 nurses determined by using a stratified sampling method from 648 nurses working in two University Hospital and two City Hospital children’s clinics.Data were collected using the“Personal Information Form”,“Compassion Scale(CS)”,“Empathic Tendency Scale(ETS)”and“Empathic Skill Scale(ESS)”.Pearson Correlation test,Student’s t-test,ANOVA test,and Scheffe test were used in the analysis of the data.Results:The mean age of the nurses participating in the study was 30.93±6.23 years,81.1%were women and 54.9%were married.Pediatric clinic nurses’mean compassion score was 96.29±11.64,empathic tendency mean score was 69.30±8.39,and empathic skill mean score was 140.82±23.15.According to the findings obtained,the mean compassion score of the male,married,and nurses who were not satisfied with working in the pediatric clinics and working in the pediatric emergency clinics was found to be the lowest(p<0.05,p<0.01,p<0.001).The empathic disposition mean scores of the nurses working in the pediatric inpatient clinics,who were satisfied with working in the pediatric clinic,and who did not have the thought of moving to another clinic,were found to be significantly higher(p<0.01,p<0.001).The mean scores of empathic skills of nurses working only during the daytime were found to be significantly higher(p<0.001).Conclusion:This study confirms that pediatric clinic nurses are experiencing compassion fatigue at the end of COVID-19 and how this situation negatively affects their empathic tendencies and skills.The study highlights the need for both clinical and management-based planning to prevent compassion fatigue and increase empathic tendencies and skills in Pediatric clinic nurses.
文摘In this study,the effect of different sampling rates(i.e.observation recording interval)on the Precise Point Positioning(PPP)solutions in terms of accuracy was investigated.For this purpose,a field test was carried out inÇorum province,Turkey,on 11 September 2019.Within this context,a Geodetic Point(GP)was established and precisely coordinated.A static GNSS measurement was occupied on the GP for about 4-hour time at 0.10 second(s)/10 Hz measurement intervals with the Trimble R10 geodetic grade GNSS receiver.The original observation file was converted to RINEX format and then decimated into the different data sampling rates as 0.2 s,0.5 s,1 s,5 s,10 s,30 s,60 s,and 120 s.All these RINEX observation files were submitted to the Canadian Spatial Reference System-Precise Point Positioning(CSRS-PPP)online processing service the day after the data collection date by choosing both static and kinematic processing options.In this way,PPP-derived static coordinates,and the kinematic coordinates of each measurement epoch were calculated.The PPP-derived coordinates obtained from each decimated sampling intervals were compared to known coordinates of the GP for northing,easting,2D position,and height components.According to the static and kinematic processing results,high data sampling rates did not change the PPP solutions in terms of accuracy when compared to the results obtained using lower sampling rates.The results of this study imply that it was not necessary to collect GNSS data with high-rate intervals for many surveying projects requiring cm-level accuracy.