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Currently, pultruded glass fibre-reinforced polymer (pGFRP) composites have been extensively applied as cross-arm structures in latticed transmission towers. These materials were chosen for their high strength-to-weight ratio and lightweight characteristics. Nevertheless, several researchers have discovered that several existing composite cross arms can decline in performance, which leads to composite failure due to creep, torsional movement, buckling, moisture, significant temperature change, and other environmental factors. This leads to the composite structure experiencing a reduced service life. To resolve this problem, several researchers have proposed to implement composite cross arms with sleeve installation, an addition of bracing systems, and the inclusion of pGFRP composite beams with the core structure in order to have a sustainable composite structure. The aforementioned improvements in these composite structures provide superior performance under mechanical duress by having better stiffness, superiority in flexural behaviour, enhanced energy absorption, and improved load-carrying capacity. Even though there is a deficiency in the previous literature on this matter, several established works on the enhancement of composite cross-arm structures and beams have been applied. Thus, this review articles delivers on a state-of-the-art review on the design improvement and mechanical properties of composite cross-arm structures in experimental and computational simulation approaches.

In this study, the main goal of this study was to understand the effect of carbon nanotube (CNT) additives on the elastic behaviors of textile-based composites. The materials have three phases: carbon fiber fabric, epoxy matrix, and carbon nanotubes. Different weight fractions of CNTs were used (0% as a reference, 0.3%). Mechanical tests were performed, such as tension and three-point bending beam tests. In addition, the composite material damages were examined in detail. The experimental results show that the samples with CNT carried 9% and 23% more axial tensile force and bending capacity on average than those with NEAT. Besides, it was understood that adding 0.3% by weight of MWCNT increases the tensile modulus by approximately 9%. Finally, the mechanical tensile and bending tests are supported by analytical solutions successfully applied in the literature.

Aims Recent evidence from randomized trials demonstrates that colchicine can reduce the risk of major adverse cardiovascular events (MACE) in patients with coronary artery disease. Colchicine's effect on lower-extremity peripheral artery disease (PAD) is not known. Methods and results To make inferences about the real-world effectiveness of colchicine in PAD, we emulated two target trials leveraging the variable prescribing practice of adding colchicine vs. a non-steroidal anti-inflammatory drug (NSAID) to urate-lowering therapy in patients with gout and PAD. Emulated Trial 1 compared colchicine initiators with NSAID initiators. Emulated Trial 2 compared long-term (indefinite) and short-term (3 months) treatment strategies after initiating colchicine. Eligible individuals were those continuously enrolled in Medicare receiving care at a multicentre academic health system between July 2007 and December 2019. The primary outcome for both trials was a 2 year composite of major adverse limb events (MALE), MACE, and all-cause mortality. Secondary outcomes included MALE and death, MACE and death, and individual components of the primary outcome. Inverse probability weighting was used to adjust for confounding. Percentile-based 95% confidence intervals (CIs) were estimated using non-parametric bootstrapping. A total of 1820 eligible patients were included; the mean age was 77 years [standard deviation (SD) 7], 32% were female, and 9% were non-White. The mean (SD) duration of colchicine and NSAID therapy was 247 (345) and 137 (237) days, respectively. In the emulation of Trial 1, the risk of the primary composite outcome of MALE, MACE, and death at 2 years was 29.9% (95% CI 27.2%, 32.3%) in the colchicine group and 31.5% (28.3%, 34.6%) in the NSAID group, with a risk difference of −1.7% (95% CI −6.5%, 3.1%) and a risk ratio of 0.95 (95% CI 0.83, 1.07). Similar findings were noted in the emulation of Trial 2, with a risk of the primary composite outcome at 2 years of 30.7% (95% CI 23.7%, 38.1%) in the long-term colchicine group and 33.4% (95% CI 29.4%, 37.7%) in the short-term group, with a risk difference of −2.7% (95% CI −10.3%, 5.4%) and risk ratio of 0.92 (95% CI 0.70, 1.16). Conclusion In a real-world sample of patients with PAD and gout, estimates of the effect of colchicine were consistent across two analyses and provided no conclusive evidence that colchicine decreased the risk of adverse cardiovascular or limb events and death. The cardiovascular and limb benefits of colchicine in older, comorbid populations with PAD and advanced systematic atherosclerosis remain uncertain. [ABSTRACT FROM AUTHOR]

Category: Ankle; Midfoot/Forefoot; Other Introduction/Purpose: Progressive collapsing foot deformity (PCFD) is a degenerative disorder of ligaments and tendons that encompasses a wide range of deformities, including arch height loss, hindfoot valgus, and forefoot abduction. The posterior tibial tendon (PTT) is the main active stabilizer of the arch. We hypothesize that it may become injured secondarily as it attempts to maintain foot stability when the ligaments, passive stabilizers, are attenuated. Several cadaveric studies have been conducted on the role of the PTT in PCFD, but the ability of the PTT to compensate for the loss of the ligamentous stabilizers has not been clearly characterized. We developed a high-fidelity finite element model of the foot to determine the PTT's ability to maintain foot stability when the principle ligamentous stabilizers are attenuated. Methods: The encapsulating soft tissue (EST), cartilage, and cortical and trabecular bones were reconstructed in Mimics from CT scan images of a female cadaveric foot weighing 60 kg. Tension-only spring elements were used to reflect all the ligaments in ANSYS. Bodyweight and tendon forces were applied using force vectors in the direction of their lines of action. The proximal tibia was fixed only in the vertical direction, allowing it to translate and rotate in all other degrees of freedom. Nonlinear frictional contacts were used between the EST and the ground, and between the cartilages. The flatfoot was simulated by removing all of the ligaments. We measured the foot alignment angles for the flatfoot and the foot with ruptured spring/deltoid ligament, while we gradually increased the force within the PTT. The measured angles were then compared to the intact foot to evaluate the ability of the PTT to restore foot alignment. Results: The models were validated by comparing the Meary's (MA), calcaneal pitch (CPA), hindfoot alignment (HAA), and talonavicular coverage angles (TCA) to clinically-derived values. In the flatfoot, an increase of the PTT force to approximately 700% of normal ('7 ×25.71 N=180 N') led to a nearly complete restoration of foot alignment (Fig. 1). The angles associated with arch height (MA/CPA) were restored to a lesser extent than those associated with hindfoot and forefoot alignment (HAA/TCA). For the foot with ruptured deltoid ligament, increasing force within the PTT by 500% led to a restoration of near normal hindfoot alignment (Fig. 1c). For the foot with ruptured spring ligament, the forefoot abduction was completely compensated only when the PTT force was increased to 1100% of normal (Fig. 1d). Conclusion: Almost seven times the normal PTT force is required to restore the foot to neutral alignment. Augmentation of PTT force to this extent is unrealistic. However, a lesser increase in PTT force provides partial alignment compensation. Furthermore, the restoration achieved by overloading the PTT primarily impacts the alignment of the hindfoot and forefoot rather than the arch. Because the PTT can partially restore foot alignment, it may become secondarily injured when the ligaments are torn. Strengthening of the PTT through therapeutic exercise can improve its ability to restore foot alignment and should be a cornerstone of non-operative treatment of PCFD.

Tüketicilerin helal gıda konusunda algı ve tutumları ülkeler ve bölgeler arasında farklılık gösterebilen sosyal, kültürel, ekonomik, yasal ve politik faktörlere bağlıdır. Bu kapsamda tüketicilerin helal gıda konusunda satın alma davranışları hakkındaki farkındalıklarını, algılarını ve tutumlarını incelemek politika önerisinde bulunulması açısından gereklidir. Bu nedenle Konya ilinde tüketicilerin helal gıda konusundaki bilinç düzeylerinin ve algılarının belirlenmesi, helal gıda konusundaki duyarlılıkların ölçülmesi ve helal gıda satın almaya etki eden sosyo-ekonomik faktörlerin belirlenmesi çalışmanın temel amacıdır. Bu amaca yönelik olarak Konya ilinde basit tesadüfi örnekleme yöntemine göre belirlenen 383 kişi ile tüketici anketi yapılmıştır. Yapılan çalışmada tüketici talep yapısını incelemek için tüketicilerin sosyo-ekonomik özelliklerine göre helal gıda ürünlerine tutum ve algıları beşli likert ölçeği ile analiz edilmiş olup helal gıda tüketimi ile tüketicilerin sosyo-ekonomik özellikleri arasındaki ilişkinin belirlenmesi için Mann-Whitney U testi ve Kruskal-Wallis testleri yapılmıştır. Yapılan analizlere göre tüketicilerin gelir ve eğitim düzeyleri artıkça daha fazla helal gıda satın alacakları tahmin edilmiştir. Sonuç olarak Konya ilinde tüketicilerin helal gıda ürünlerinde bilinç düzeylerinin yüksek olduğu ve helal gıda tüketimi konusunda duyarlılıklarının arttığı belirlenmiştir.

Elyaf takviyeli polimer (FRP) donatılar korozyona karşı direnç, ağırlıkça yüksek mukavemet oranı, iyi yorulma özellikleri ve kullanım kolaylığı gibi avantajlar nedeniyle, alternatif olarak tercih edilmekte ve kullanımı giderek artmaktadır. İnşaat mühendisliği uygulamalarında düşük maliyetlerinden dolayı en yaygın olarak Cam-FRP (GFRP) donatılar kullanılmaktadır. Son zamanlarda, kiriş ve kolonlarda kullanılan çelik donatılar yerine Cam FRP donatılar ve çelik ile Cam FRP donatının birlikte kullanıldığı “Hibrit” donatı düzeni üzerinde birçok araştırma yapılmıştır. Bu çalışmada; Cam FRP ve Hibrit donatıların betonarme kirişlerde geleneksel çelik donatılara göre avantajları araştırılmıştır. Çelik çubuklardan ve farklı sayıda cam çubuklardan oluşan betonarme kirişler üretilmiştir. Üretilen betonarme kirişlere dört nokta eğilme testleri yapılmıştır. Deney sonucu her üç numune için yaklaşık eşit maksimum yük taşıma kapasitesi elde edilmiştir. Bununla birlikte, çelik donatılı ve hibrit donatılı kiriş, gevrek bir davranış sergilerken, GFRP donatılı kiriş sünek bir davranış sergilemiştir. Tamamen GFRP donatılı numunenin enerji emme kapasitesi diğer numunelere göre ciddi oranda artış gösterdi. Numunelerde oluşan hasarları açıklamak için hasar analizi sunuldu.

Fibre-reinforced polymer (FRP) composites have been selected as an alternative to conventional wooden timber cross arms. The advantages of FRP composites include a high strength-to-weight ratio, lightweight, ease of production, as well as optimal mechanical performance. Since a non-conductive cross arm structure is exposed to constant loading for a very long time, creep is one of the main factors that cause structural failure. In this state, the structure experiences creep deformation, which can result in serviceability problems, stress redistribution, pre-stress loss, and the failure of structural elements. These issues can be resolved by assessing the creep trends and properties of the structure, which can forecast its serviceability and long-term mechanical performance. Hence, the principles, approaches, and characteristics of creep are used to comprehend and analyse the behaviour of wood and composite cantilever structures under long-term loads. The development of appropriate creep methods and approaches to non-conductive cross arm construction is given particular attention in this literature review, including suitable mitigation strategies such as sleeve installation, the addition of bracing systems, and the inclusion of cross arm beams in the core structure. Thus, this article delivers a state-of-the-art review of creep properties, as well as an analysis of non-conductive cross arm structures using experimental approaches. Additionally, this review highlights future developments and progress in cross arm studies.

The aim of this article was to investigate the effect of carbon nanotubes (CNTs) on the buckling behavior of fiber-reinforced polymer (FRP) composites. The materials used included three layers: carbon-fiber-reinforced polymer (CFRP), epoxy and CNTs. A set of mechanical tests, such as compression and buckling tests, was performed, and also analytical solutions were developed. Damage analysis was also carried out by controlling the damage initiation and crack progression on the composite samples. Experimental results revealed that using 0.3% with CNT additives enhanced the buckling performance of the composite. Finally, the average load-carrying capacity for the clamped–clamped boundary condition was 268% higher in the CNT samples and 282% higher in the NEAT samples compared to the simple–simple condition.

Amaç: Karsinoid tümörler KT , 15 yaş altı çocuklarda 1-1.4/1.000.000 sıklıkta görülmektedir. Akciğer ve gastrointestinal sistemin diğer bölgelerinde de görülmekle beraber çoğunlukla apendikste görülür. Bu çalışmada kliniğimizde KT tanısı ile izlenen hastaların epidemiyolojik ve klinik özellikleri ile tedavileri retrospektif olarak değerlendirildi. Gereç ve Yöntem: Selçuk Üniversitesi Tıp Fakültesi, Çocuk Onkoloji Kliniği’nde 2010-2017 arasında KT tanısı ile tedavi edilen hastaların dosyaları retrospektif olarak incelendi. Bulgular: Tanı alıp, tedavisi ve izlemi yapılan 10 KT hastası çalışmaya dâhil edildi. Hastaların 7’si kız % 70 ve 3’ü erkekti % 30 . Hastaların yaşları 10-17 yıl arasında değişiyordu ortanca yaş:15 yıl . Tümör yerleşimleri apendiks n: 9, % 90 ve akciğerdi n: 1, % 10 . Apendiks kaynaklı KT hastaların hepsinde başvuru şikâyeti karın ağrısı olup akut apendisit tanısıyla ameliyat edilmişti. Tümör çapları 0,3-2,5cm arasında değişiyordu ortanca 0,7 cm . Beş hastada tümör apendikste sınırlı iken2 hastada tümör apendiks serozasını aşmıştı. Bu hastalarda tümör çapı 1,7 cm ve 2,5 cm idi. Tümör çapı 2,5 cm olan hastaya sağ hemikolektomi yapıldı. Apendiks kaynaklı KT hastaların hepsi hastalıksız olarak izlemleri devam etmektedir. Akciğer kaynaklı KT hastası, geçmeyen öksürük şikâyeti ile başvurmuş, yapılan bronkoskopide sol akciğer alt lobda KT saptanmıştır. Bu hastaya, lobektomi yapıldı. Bu hasta da halen hastalıksız olarak izlemi devam etmektedir. Hastaların hiçbirinde karsinoid sendrom bulguları yoktu.Sonuç: Çocukluk çağında nadir görülen karsinoid tümörlerin tanısı insidantel olarak konduğu için akut apandisit tanısı ile ameliyatedilen hastaların patolojik incelemelerinin takibi önemlidir

The most crucial components in the case of roofs with two levels or a variable floor height are variable depth beams. In order to investigate the flexural behavior of reinforced concrete (RC) beams with varying depths under static loads, experimental research was conducted. Under the four-point bending flexural test, two reference beams with constant depth, six dapped beams at the soffit, and four dapped beams at the top were tested. For all beams with a 150 mm depth, a 100 mm increase in depth occurred at the middle span of the beams. The primary characteristics included the impact of increasing depth, the impact of stirrups’ absence and their various ratios, and the characteristics of the longitudinal bars at the locations of sudden depth changes in either the top or bottom bars. Both the cracks’ progression and the load-deflection relationship along the beam’s length were observed. The ultimate carrying load (Pu) was reduced by 23.56% and 27.35% as a result of the 100 mm increase in the half-span of the beam over the constant depth in case of changes at the top and soffit, respectively. The Pu was increased by a ratio ranging from 20.9% to 31.35% for the bottom dapped beams and by a ratio of 29.79% for the top dapped beams due to the various stirrup ratios in the dapped area. The ductility was significantly impacted by the elevated stirrup ratios in the dapped area. The predicted results and the experimental results matched when the Pu of the tested beams was evaluated using the strut and tie model.

PurposeFor adult survivors of childhood cancer, knowledge about the long-term risk of intestinal obstruction from surgery, chemotherapy, and radiotherapy is limited.MethodsIntestinal obstruction requiring surgery (IOS) occurring 5 or more years after cancer diagnosis was evaluated in 12,316 5-year survivors in the Childhood Cancer Survivor Study (2,002 with and 10,314 without abdominopelvic tumors) and 4,023 sibling participants. Cumulative incidence of IOS was calculated with second malignant neoplasm, late recurrence, and death as competing risks. Using piecewise exponential models, we assessed the associations of clinical and demographic factors with rate of IOS.ResultsLate IOS was reported by 165 survivors (median age at IOS, 19 years; range, 5 to 50 years; median time from diagnosis to IOS, 13 years) and 14 siblings. The cumulative incidence of late IOS at 35 years was 5.8% (95% CI, 4.4% to 7.3%) among survivors with abdominopelvic tumors, 1.0% (95% CI, 0.7% to 1.4%) among those without abdominopelvic tumors, and 0.3% (95% CI, 0.1% to 0.5%) among siblings. Among survivors, abdominopelvic tumor (adjusted rate ratio [ARR], 3.6; 95% CI, 1.9 to 6.8; P < .001) and abdominal/pelvic radiotherapy within 5 years of cancer diagnosis (ARR, 2.4; 95% CI, 1.6 to 3.7; P < .001) increased the rate of late IOS, adjusting for diagnosis year; sex; race/ethnicity; age at diagnosis; age during follow-up (as natural cubic spline); cancer type; and chemotherapy, radiotherapy, and surgery within 5 years of cancer diagnosis. Developing late IOS increased subsequent mortality among survivors (ARR, 1.8; 95% CI, 1.1 to 2.9; P = .016), adjusting for the same factors.ConclusionThe long-term risk of IOS and its association with subsequent mortality underscore the need to promote awareness of this complication among patients and providers.

Pultruded fiber-reinforced polymer (PFRP) profiles have started to find widespread use in the structure industry. The position of the web openings on these elements, which are especially exposed to axial pressure force, causes a change in the behavior. In this study, a total of 21 pultruded box profiles were tested under vertical loads and some of them were strengthened with carbon-FRP (CFRP) and glass-FRP (GFRP). The location, number and reinforcement type of the web openings on the profiles were taken into account as parameters. As a result of the axial test, it was understood that when a hole with a certain diameter is to be drilled on the profile, its position and number are very important. The height-centered openings in the middle of the web had the least effect on the reduction in the load-carrying capacity and the stability of the profile. In addition, it has been determined that the web openings away from the center and especially the eccentric opening significantly reduces the load carrying capacity. Furthermore, when double holes were drilled close to each other, a significant decrease in the capacity was observed and strengthening had the least effect on these specimens. It was also determined that the specimens reinforced with carbon FRP contribute more to the load-carrying capacity than GFRP.

The application of pultruded fiber reinforced polymer (FRP) composites in civil engineering is increasing as a high-performance structural element or reinforcing material for rehabilitation purposes. The advantageous aspects of the pultrusion production technique and the weaknesses arising from the 0° fiber orientation in the drawing direction should be considered. In this direction, it is thought that the structural performance of the profiles produced by the pultrusion technique can be increased with 90° windings by using different fiber types. This paper presents experimental studies on the effect of FRP composite wrapping on the flexure performance of reinforced concrete (RC) filled pultruded glass-FRP (GFRP) profile hybrid beams with damage analysis. The hybrid beams are wrapped fully and partially with Glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) composites. Hybrid beam specimens with 0° to 90° fiber orientations were tested under three- and four-point bending loads. Based on the experimental load–displacement relationship results, initial stiffness, ductility, and energy dissipation capacity were compared. The experimental findings revealed that the maximum load-carrying capacities of beams produced with pultrude profiles increased by 24% with glass wrapping and 64.4% with carbon wrapping due to the change in the damages. A detailed damage analysis is provided. Similarly, significant increases were observed in structural performance ratios such as initial stiffness and ductility ratio.

Web openings often need to be created in structural elements for the passage of utility ducts and/or pipes. Such web openings reduce the cross-sectional area of the structural element in the affected region, leading to a decrease in its load-carrying capacity and stiffness. This paper experimentally studies the effect of web openings on the response of pultruded fiber-reinforced polymer (PFRP) composite profiles under compressive loads. A number of specimens have been processed to examine the behavior of PFRP profiles strengthened with one or more web openings. The effects of the size of the web opening and the FRP-strengthening scheme on the structural performance of PFRP profiles with FRP-strengthened web openings have been thoroughly analyzed and discussed. The decrease in load-carrying capacity of un-strengthened specimens varies between 7.9% and 66.4%, depending on the diameter of the web holes. It is observed that the diameter of the hole and the type of CFRP- or GFRP-strengthening method applied are very important parameters. All CFRP- and GFRP-strengthening alternatives were successful in the PFRP profiles, with diameter-to-width (D/W) ratios between 0.29 and 0.68. In addition, the load-carrying capacity after reinforcements made with CFRP and GFRP increased by 3.1–30.2% and 1.7–19.7%, respectively. Therefore, the pultruded profiles with openings are able to compensate for the reduction in load-carrying capacity due to holes, up to a D/W ratio of 0.32. The capacity significantly drops after a D/W ratio of 0.32. Moreover, the pultruded profile with CFRP wrapping is more likely to improve the load-carrying capacity compared to other wrappings. As a result, CFRP are recommended as preferred composite materials for strengthening alternatives.

Background: Observational studies are used for estimating vaccine effectiveness under real-world conditions. The practical performance of two common approaches--cohort and test-negative designs--need to be compared for COVID-19 vaccines. Methods: We compared the cohort and test-negative designs to estimate the effectiveness of the BNT162b2 vaccine against COVID-19 outcomes using nationwide data from the United States Department of Veterans Affairs. Specifically, we (1) explicitly emulated a target trial using follow-up data and evaluated the potential for confounding using negative controls and benchmarking to a randomized trial, (2) performed case-control sampling of the cohort to confirm empirically that the same estimate is obtained, (3) further restricted the sampling to person-days with a test, and (4) implemented additional features of a test-negative design. We also compared their performance in limited datasets. Results: Estimated BNT162b2 vaccine effectiveness was similar under all four designs. Empirical results suggested limited residual confounding by healthcare-seeking behavior. Analyses in limited datasets showed evidence of residual confounding, with estimates biased downward in the cohort design and upward in the testnegative design. Conclusion: Vaccine effectiveness estimates under a cohort design with explicit target trial emulation and a test-negative design were similar when using rich information from the VA healthcare system, but diverged in opposite directions when using a limited dataset. In settings like ours with sufficient information on confounders and other key variables, the cohort design with explicit target trial emulation may be preferable as a principled approach that allows estimation of absolute risks and facilitates interpretation of effect estimates. [ABSTRACT FROM AUTHOR]