135 research outputs found
Web-based contractor evaluation system for mass-housing projects in Turkey
Determining the most appropriate contractor for a construction project is a highly critical issue. Selecting the right contractor for the right job can significantly influence the overall project performance. In the selection process, construction clients have to know all financial, technical and general information about the contractors to determine the most appropriate one for the project. Within this context, clients should consider several criteria that may include quality of production, adequacy of technical staff and financial stability. In this study, a survey was carried out among 52 construction professionals working at the Public Housing Development Administration (PHDA) in Turkey. The objective of this survey is to examine the relative weights of the criteria that have been using by this owner in the construction contractor selection process. Afterwards, a web-based contractor evaluation system, WEB-CONTEST, by which the contractors can be evaluated based on a combined criterion, is proposed. The system facilitates the contractor selection process and enables the construction owner to select the most correct contractors for its relevant projects
Effects of the phosphodiesterase type-5 inhibitor tadalafil on nociception, morphine analgesia and tolerance in rats
Aim: Tadalafil is a potent, selective and reversible inhibitor of phosphodiesterase type 5 (PDE5) enzyme breakdowning cyclic guanosine monophosphate (cGMP). In this study, we aimed to investigate the effects of tadalafil on nociception, morphine analgesia and tolerance.
Methods: In this study, 54 Wistar Albino (230-250 g) male rats were used. First of all, four different doses (2, 4, 8, 16 mg/kg) were used to determine the optimum effective dose of tadalafil on nociception. Optimum activity was found at 8 mg/kg and animals were divided into six groups: Saline (S), 8mg/kg tadalafil, 5mg/kg morphine (M), M+ tadalafil, morphine tolerance (MT) and MT+ tadalafil. Saline was given to the control group, tadalafil intraperitoneally and morphine subcutaneously administered at the indicated doses. To develop tolerance to morphine, 10mg/kg morphine was injected daily in the morning and evening for five days and tolerance was evaluated with single dose of morphine on sixth days. The resulting analgesic effect was measured with hot plate and tail flick analgesia tests and recorded at 30th, 60th, 90th and 120th minutes.
Results: Tadalafil showed anti-nociceptive effect when given alone at different doses (p<0.05). However, tadalafil significantly decreased the analgesic effect of morphine (p<0.05). In addition, tadalafil significantly increased the tolerance to morphine (p<0.05).
Conclusions: The phosphodiesterase type 5 inhibitor tadalafil have anti-nociceptive properties and it decreases analgesic effect of morphine, in addition improves tolerance development. These effects probably may occur via NO/cGMP pathway.
 
Micromorphological, anatomical and cytogenetical studies in endemic Crepis macropus Boiss. & Heldr. (Asteraceae) from Turkey
In the present study, the micromorphological structure of achene, pappus and style using scanning electron microscope (SEM), stomatal characteristics, anatomy of stem and achene together with chromosome number and nuclear DNA content of the Turkish endemic Crepis macropus Boiss. & Heldr. are provided in order to expand knowledge of its taxonomy. The SEM studies in this species show that dense spiny cells are found on the achene surface, the pappus bristle has 3–5 spikes and the style possesses slender papillae. The stem structure is composed of epidermis, collenchyma, parenchymatous cortex and pith. The species has anomocytic stomata in both the upper and the lower surface of the leaves. The pericarp of the achene is mainly composed of several layers of sclerenchymatous cells. In this species, the chromosome number is 2n = 2x = 8, karyotype consists of two submetacentric and six subtelocentric chromosomes and nuclear DNA content (2Cvalue) is 12.96 pg. These data are presented here for the first time and their taxonomic values are discussed
Interaction between urethane and cannabinoid CB1 receptor agonist and antagonist in penicillin-induced epileptiform activity
“Hinge” Mitral Valve Repair for Active Valve Endocarditis and Long-term Follow-up Transesophageal Echocardiography Study.
Ciljevi: Liječenje mitralnog zalistka u endokarditisu zalistka izazovna je tema, a rekonstrukcija je poželjnija u odnosu na zamjenu, no često zahtijeva opsežan debridman vegetacije, infi ciranoga tkiva i složenu rekonstrukciju tijekom aktivne faze.
Metode: Donosimo prikaz uspješne rekonstrukcije mitralnoga zalistka u pacijenta s aktivnim endokarditisom.
Rezultati: Postoperativna ehokardiografi ja nije pokazala regurgitaciju na novoformiranom mitralnom zalistku.
Zaključak: Reparacija mitralnoga zalistka perikardijanom zakrpom prvi je izbor liječenja aktivnog endokarditisa, koja je tehnički zahtjevna, no ima zadovoljajuće rezultate. Rekonstrukcija mitralnog zalistka ovom metodom ne samo da podržava otvaranje područja mitralnih komisura, već i potpomaže ponovno uspostavljanje fizilološkoga kretanja mitralnoga zalistka.Aims: Mitral valve treatment in valve endocarditis is currently a challenging issue. Repair is preferred to replacement but it often requires extensive debridement of vegetation and infected tissue as well as complex reconstruction in the active phase.
Methods: We report on a successful repair of the mitral valve, as described in the case of active endocarditis.
Results: Postoperative echocardiography demonstrated no regurgitation at the newly formed mitral valve.
Conclusion: First preference is pericardial repair, a technically difficult procedure but with satisfactory results in mitral repair for active endocarditis. Reconstruction of the mitral commissure with this
technique not only supports the opening of the commissural area but also helps regain the physiological motion of the mitral valve
Morphometric analysis of the arteries of Willis Polygon
Objective: Willis polygon forms the basis of the arterial circulation of the cerebrum. Willis polygon is a vascular structure whom variations are not rare. Knowledge of the anatomy and preservation of its integrity is crucial for performing neurovascular surgery and intracranial tumour surgery. Because of the important vascular and neurological structures, approaches to this region are considered extremely risky. One of the main variations in-person basis is the diameter differences of the arteries, which forms Willis polygon, between the left and right hemispheres. About structure and variations, studies of Rhoton and Yasargil had formed the touchstone.Our aim is to contribute to the literature and clinical studies, to be done in the future, by comparing our results with previous studies about variations and morphometric features of Willis polygon.Methods: Arteries of 30 fresh cadaver brains were examined during autopsies in T.C. Ministry of Justice Istanbul Forensic Science Institute. Bilaterally anterior cerebral artery A1 segment lengths, distance between anterior communicating artery-callosomarginal artery outputs, posterior cerebral artery P1 segment lengths were measured using a digital calliper. After dissections and measures, photos of the region were taken and vascular anatomy and variations noted. From every single cerebrum samples were obtained from bilaterally A1, A2, callosomarginal artery, middle cerebral artery, posterior communicant artery, P1 and basilar artery. Samples were fixed by using 10% buffered-formalin. Taken samples were transported to Marmara University Faculty of Medicine, Department of Anatomy Laboratory. Samples were examined and interior diameters were measured under the microscope.Results: Our results with artery diameters and lengths were similar with literature. Different from literature, in anterior cerebral artery A1 segment, posterior cerebral artery P1 segment and posterior communicant artery no aplasia were noted. In 50% of the samples, callosomarginal artery were originate from A2 segment. In one case, we observed left and right pericallosal arteries were joined together at the end of the A2 segment and continued as a single pericallosal artery. We could not find any information about this variation in the literature.Conclusion: Before surgical operations, detailed knowledge of Willis polygon and evaluation of the pre-op cerebral angiography considering possible variations, reduce mortality and morbidity ratios. In addition, because of the role of flow gradients of Willis polygon in aneurysm formation, and in terms of better understanding the collateral circulation which is important in vascular occlusive diseases and vascular surgery, we believe, more anatomic studies about this region needed
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
Evaluation of nutritional status in pediatric intensive care unit patients: the results of a multicenter, prospective study in Turkey
IntroductionMalnutrition is defined as a pathological condition arising from deficient or imbalanced intake of nutritional elements. Factors such as increasing metabolic demands during the disease course in the hospitalized patients and inadequate calorie intake increase the risk of malnutrition. The aim of the present study is to evaluate nutritional status of patients admitted to pediatric intensive care units (PICU) in Turkey, examine the effect of nutrition on the treatment process and draw attention to the need for regulating nutritional support of patients while continuing existing therapies.Material and MethodIn this prospective multicenter study, the data was collected over a period of one month from PICUs participating in the PICU Nutrition Study Group in Turkey. Anthropometric data of the patients, calorie intake, 90-day mortality, need for mechanical ventilation, length of hospital stay and length of stay in intensive care unit were recorded and the relationship between these parameters was examined.ResultsOf the 614 patients included in the study, malnutrition was detected in 45.4% of the patients. Enteral feeding was initiated in 40.6% (n = 249) of the patients at day one upon admission to the intensive care unit. In the first 48 h, 86.82% (n = 533) of the patients achieved the target calorie intake, and 81.65% (n = 307) of the 376 patients remaining in the intensive care unit achieved the target calorie intake at the end of one week. The risk of mortality decreased with increasing upper mid-arm circumference and triceps skin fold thickness Z-score (OR = 0.871/0.894; p = 0.027/0.024). The risk of mortality was 2.723 times higher in patients who did not achieve the target calorie intake at first 48 h (p = 0.006) and the risk was 3.829 times higher in patients who did not achieve the target calorie intake at the end of one week (p = 0.001). The risk of mortality decreased with increasing triceps skin fold thickness Z-score (OR = 0.894; p = 0.024).ConclusionTimely and appropriate nutritional support in critically ill patients favorably affects the clinical course. The results of the present study suggest that mortality rate is higher in patients who fail to achieve the target calorie intake at first 48 h and day seven of admission to the intensive care unit. The risk of mortality decreases with increasing triceps skin fold thickness Z-score
Measurements of top-quark pair differential cross-sections in the channel in collisions at TeV using the ATLAS detector
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