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Purpose: This study was conducted to investigate the effectiveness of strain elastography in guiding precise and sufficient tissue sampling for perihilar cholangiocarcinoma (CCA) biopsies. Methods: Our retrospective analysis included 23 liver biopsies conducted between March 2019 and July 2022 for suspected perihilar CCA. An experienced radiologist performed the biopsies via an ultrasound machine with elastography configuration. Tissue stiffness color maps were used for guiding when the biopsies were performed. Strain index value calculations were made by radiologists on recorded images. Results: Patient demographics revealed a mean age of 65.17 ± 9.25 years, with a gender distribution of six females and 17 males. Gray-scale examinations unveiled diverse echogenic characteristics in liver lesions. Elastography-guided biopsies demonstrated no need for repeats, while gray-scale biopsies necessitated re-biopsy in four patients, resulting in cholangiocarcinoma diagnosis (P = 0.037). Strain index values showcased strong inter- and intra-observer agreements (P < 0.001). Notably, no post-biopsy complications emerged in either study group. Conclusion: The diagnostic advantage of elastography, particularly in enhancing accuracy in challenging isoechoic lesions, was demonstrated, although the substantial overlap between strain index values of benign and malignant liver masses limits clinical usefulness of this technique. [ABSTRACT FROM AUTHOR]

Background: Alterations in the cerebral venous system have been increasingly recognized as a significant component of the pathophysiology of multiple sclerosis (MS). This study aimed to explore the relationship between venous sinus diameter and MS to understand potential vascular alterations in MS patients compared with controls. We sought to determine whether these alterations were correlated with disease characteristics such as duration, lesion type, and disability score. Methods: This study included 79 MS patients diagnosed according to the 2017 McDonald criteria and 67 healthy individuals. Magnetic resonance imaging (MRI) scans via a 1.5 Tesla system provided measurements of the superior sagittal sinus, right and left transverse sinus, sinus rectus, and venous structures. Statistical analysis was conducted via SPSS, employing independent sample t tests, ANOVA, chi-square tests, and Pearson correlation analysis, with the significance level set at p < 0.05. Results: This study revealed significant differences in venous sinus diameter between MS patients and controls, with MS patients exhibiting larger diameters. Specifically, patients with brainstem and spinal lesions had larger diameters in certain sinus regions. No significant correlations were found between venous sinus diameter and demographic factors, expanded disability status scale scores, or lesion counts. However, a significant increase in perivenular lesions was noted in patients with longer disease durations. Conclusions: The findings indicate notable vascular alterations in MS patients, particularly in venous sinus diameters, suggesting a potential vascular component in MS pathology. The lack of correlation with conventional clinical and MRI metrics highlights the complexity of MS pathology. These insights underscore the need for further research, particularly longitudinal studies, to elucidate the role of venous changes in MS progression and their potential as therapeutic targets. [ABSTRACT FROM AUTHOR]

In this study, an experimental study was carried out on a heat pipe, whose evaporator is located between the compressor outlet and the condenser inlet of an industrial cooler on a vapor compression cycle (VCC). It absorbs heat from the new generation refrigerant fluid of 515B and transfers it to the outdoor air. The heat pipe is a looped thermosiphon-type heat pipe. R134a refrigerant is used as a working fluid in the heat pipe. By changing the condenser air inlet temperatures, the contribution of the heat pipe to the cooling cycle has been determined experimentally. While the evaporation pressure of the refrigeration cycle with the heat pipe remains approximately constant, the condensation pressure decreases, and the sub-cool temperature increases. For condenser air inlet temperatures of 30, 40, and 50°C, the COP of the cooler with heat pipe increases by 1.8%, 2.6%, and 2.76%, respectively. As the air temperature at the condenser inlet increases, the ratio of heat pipe power to the cooling capacity of the cycle also increases. In addition, the compressor outlet temperature is reduced by 1.5%–2.8% using of the heat pipe. [ABSTRACT FROM AUTHOR]

In this article, some geometric interpretations and applications of hybrid numbers, which unify elliptic, hyperbolic and dual numbers, are given. First, the definition of an elliptical (complex) plane is given, and elliptic rotations in this plane are examined using hybrid number multiplication. Also, mutually orthogonal planar elliptical rotations in four-dimensional space are discussed. At last, matrix forms of a non-parabolic rotation transformation are expressed, and Rodrigues and Cayley rotation transformations for an elliptical hybrid vector are proved. [ABSTRACT FROM AUTHOR]

In the 1950s, the concept of artificial intelligence emerged, suggesting that machines could possess the ability to think and learn. In the 21st century, with advancements in GPUs and CPUs, deep learning has become an integral part of human life. Proximal femoral fractures are known to be one of the leading causes of mortality and injuries among the elderly population. This study aims to detect proximal femoral fractures in X-ray images and compare the success of using the YOLOv4 algorithm and provide decision support system within the diagnosis. To retrain the algorithm, more than 500 patients' X-ray images were examined. Through data augmentation techniques, the initial set of 410 patients' femur proximal fracture X-ray images was expanded to 820 images. After retraining the YOLO algorithm, two different groups were included for comparing the algorithm's performance: orthopedic specialists and general practitioners. The results from these three groups were evaluated using specific criteria. The YOLOv4 model demonstrated an accuracy of 90.33%. In comparison, orthopedic and traumatology resident doctors achieved an accuracy of 91.42%, while the general practitioner group achieved an accuracy of 81.30%. [ABSTRACT FROM AUTHOR]

Introduction: Lemmel syndrome occurs when the primarily intrapancreatic portion of the common bile duct is compressed or obstructed by a duodenal diverticulum. This can cause jaundice due to the pressure. Case Presentation: A 65-year-old female patient was admitted to the emergency room with Lemmel syndrome. The patient underwent endoscopic retrograde cholangiopancreatography (ERCP), confirming the diagnosis of a diverticulum. The papilla was located in the diverticulum, and despite various attempts and maneuvers, it could not be cannulated. Subsequently, percutaneous transhepatic cholangiography (PTC) was performed, and an 8F drainage catheter was successfully placed in the duodenum. Conclusion: Lemmel syndrome is a rare condition that may cause acute abdomen with obstructive jaundice. Increased awareness and familiarity with imaging can help distinguish the diverticulum from tumors, potentially saving the patient from unnecessary surgeries. If ERCP fails, PTC may be a successful alternative for the treatment of jaundice. [ABSTRACT FROM AUTHOR]

Copyright of Online Turkish Journal of Health Sciences (OTJHS) / Online Türk Sağlık Bilimleri Dergisi is the property of Oguz KARABAY and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Erciyes Agriculture & Animal Science is the property of Erciyes Tarim ve Hayvan Bilimleri Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Parallel robots have many remarkable advantages over their conventional serial counterparts. Highly accurate positioning capability and high payload-to-weight ratio are among the main ones. The main factor underlying all these advantages is their closed-loop construction. However, this constructional feature also causes a special singularity problem, which constitutes their biggest disadvantage. Characteristic singularities classified as Type II exist inside their workspace, around which the magnitude of the inverse dynamic solution grows unboundedly. This naturally yields the saturation of the actuators and eventually in uncontrollability of the robot. Consequently, the whole workspace becomes impossible to be used. In order to pass through a Type II singularity, the consistency of the motion equations of the robot must be maintained at that singularity. However, any Type II singular configuration can transform into a high-order singularity, which, in order to be passed through, requires additional conditions other than the consistency. Therefore, full utilization of the whole workspace with a minimum number of conditions requires to avoid high-order singularities. The present article contributes to the literature by developing path and trajectory planning principles for preventing a two-degree-of-freedom planar parallel robot with RPRPR structure from experiencing high-order singularities. [ABSTRACT FROM AUTHOR]

Copyright of Sakarya Tıp Dergisi is the property of Sakarya Tip Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Current Pediatrics / Guncel Pediatri is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The electrical and mechanical properties of carbon fiber-reinforced polymer (CFRP) composites have a close dependence on the use of modifiers like polyvinylpyrrolidone (PVP), as well as on the processing techniques to disperse functional charges such as graphene-related materials into the epoxy base. In the present work, reduced graphene oxide (RGO), prepared by a natural antioxidant agent, astaxanthin, was used as a filler material in the epoxy matrix of the carbon fiber composites. The astaxanthin reduction leads to an increase in the sp2 ordering in RGO; some residual epoxy and C-O groups that enhance the interaction with the epoxy matrix remain after reduction. The effects of RGO and PVP-modified RGO (PVP-RGO) fillers with different contents (0.05, 0.1, and 0.15% wt.) on the electrical conductivity, bending properties, and dynamic mechanical properties of CFRP were investigated. The incorporation of 0.15 wt.% RGO with and without PVP-modification, leads to through-the-thickness (Z-direction testing) conductivity values 7.4 and 9.6 times higher than those of the neat composite, respectively. The conductivity tests indicate that the RGO/epoxy composite behaves as a continuous conductor due to the formation of agglomerates of RGO within the matrix, while at the added contents of the PVP-RGO filler, the composite is below the percolation threshold, then conducting by electron tunneling, due to a better dispersion of the PVP-RGO filler within the epoxy matrix. The dynamic mechanical analysis shows that the glass transition temperature is indicative of the interactions among the filler, the epoxy matrix, and the carbon fiber, that is, the PVP-RGO filler increases the chain mobility due to its higher dispersion in the matrix. While Tg of the neat epoxy/CFRP composite is 92.5°C, a minimum Tg of 88.5°C was achieved with a 0.10 % wt. PVP-RGO filler contents, and a maximum Tg of 94.5°C with a 0.15 % wt. of RGO filler amount. For constant filler content (0.15 wt.%), CFRP composite containing RGO and PVP-modified RGO exhibited 9.73% and 13.87% increase in flexural strength values, respectively, compared to the neat composite. The bending test revealed that PVP modification to RGO is beneficial to improve flexural strength of CFRP composites. Graphical Abstract [ABSTRACT FROM AUTHOR]

Introduction: Gemcitabine is a nucleoside analog antimetabolite used in various malignancies, including metastatic breast cancer. Objective response rates in its use as a single agent in the treatment of metastatic breast cancer are not to be underestimated. Cutaneous, hematological, pulmonary, and vascular side effects are well-known side effects. Venous thromboembolism may occur with antineoplastics, such as platinum compounds. Arterial thromboembolism is rare in cancer, almost rare with chemotherapy. Here, we present a metastatic breast cancer patient who had digital necrosis due to arterial occlusion with gemcitabine monotherapy. Case report: A 54-year-old metastatic breast cancer female patient had digital ischemia and necrosis in the left hand's fifth finger after the second course of single-agent gemcitabine as the fourth line setting. Gemcitabine was discontinued, and medical treatment was started. Thrombus was detected in the left subclavian artery digital angiography. Balloon angioplasty and stenting were applied. However, digital amputation had to be performed since tissue necrosis had not regressed despite radiological interventions and medical treatment. Management and outcome: Gemcitabine was discontinued. Low molecular weight heparin and acetylsalicylic acid were started. The distal phalanx was amputated due to necrosis during follow-up. Gemcitabine was permanently stopped. Discussion: Gemcitabine-related vascular events, including arterial thrombosis, may also occur in cancer patients, especially those with higher tumor burden. Therefore, predisposing factors for hypercoagulability and vascular occlusion should be questioned in more detail even before starting antineoplastics which are known to have a lower risk for thrombosis, such as gemcitabine monotherapy. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Contrary to popular belief, beekeeping, which dates back to prehistoric times and is one of the most important plant and animal production branches today, is not an innocent profession in terms of occupational health and safety. In this study, in order to determine the occupational health and safety risk factors in the beekeeping profession, Interviews with beekeepers were conducted in 10 apiaries operating in Bayburt, where especially wandering beekeeping is practiced. In light of the data obtained from the danger hunt applied by the occupational health and safety specialist, ergonomic, physical, biological, and chemical risks were revealed using the FMEA risk analysis method. The effect, probability, and detection values were found for each failure mode, and then Risk Priority Number values were calculated. As a result of the study, for the five basic stages of beekeeping, 15 processes, 39 failure modes, 72 potential effects, and 39 failure causes were determined. Failure modes with a Risk Priority Number value of 100 and above were evaluated as “situations where urgent action and axiom should be taken,” and preventive axioms were proposed for each relevant failure mode. The number of studies on the risk factors in the beekeeping profession is very limited in the literature. For this reason, it is predicted that this study will fill an important gap in the related field and make significant contributions to the literature. [ABSTRACT FROM AUTHOR]

Dry hard-turning is a vital manufacturing method for machining hardened steel due to its low cost, high machining efficiency, and green environmental protection. This study aims to analyze the effect of various machining parameters on cutting forces and surface roughness by employing RSM and ANOVA. In addition, multi-objective optimization (Grey Relation Analysis: GRA) is performed to determine the optimum machining parameters. Dry hard-turning tests were carried out on AISI 4140 steel (50 HRC) using coated carbide and CBN inserts with different nose radii. The results show that the cutting force components are greatly affected by the cutting depth and cutting speed for both cutting inserts. As the level of cutting depth and cutting speed rise, the cutting forces also increase. However, the feed rate was the main factor in surface roughness. A low feed rate and high cutting speed lead to good surface quality. According to the results, CBN inserts exhibited better performance compared to carbide inserts in terms of minimum cutting forces and surface roughness. The lowest radial force (Fx = 55.59 N), tangential force (Fy = 15.09 N), cutting force (Fz = 30.49 N), and best surface quality (Ra = 0.28 µm, Rz = 1.8 µm) were obtained using a CBN tool. Finally, based on the GRA, the (V = 120 m/min, f = 0.04 mm/rev, a = 0.06 mm, r = 0.8 mm) have been chosen as optimum machining parameters to minimize all responses simultaneously in the machining of AISI 4140 steel using both carbide and CBN inserts. [ABSTRACT FROM AUTHOR]

In this paper, we determine elliptical motions that occur on any given ellipsoid in 3D space without using affine transformations. To this end, first, we define the generalized Euclidean inner product whose sphere is the given ellipsoid, and determine skew symmetric matrices and the generalized vector product related to the 3D generalized Euclidean inner product space. Finally, we generate elliptical rotation matrices in 3D generalized Euclidean space using the famous Rodrigues, Cayley, and Householder methods. The formulas and results obtained are supported with numerical examples. We also give an algorithm for generalized elliptical rotation. [ABSTRACT FROM AUTHOR]

Introduction: Clozapine may affect the outcome of severe COVID-19 infection due to its anti-inflammatory and immunosuppressant effects. This study aimed to investigate whether the risk of COVID-19 changed in schizophrenic patients using clozapine and to compare patients using clozapine with other antipsychotics in terms of COVID-19 severity. Methods: A total of 732 patients who were registered and followed up with a diagnosis of schizophrenia were included in the study. These patients' sociodemographic data, smoking status, medications, comorbidities, COVID-19 PCR results, and COVID-19 outcomes (inpatient care admission, intensive care unit admission, death) were retrospectively analyzed. Results: Of the 732 patients included in our study, 177 were using clozapine. Ninety-six of 732 patients were diagnosed with COVID-19, and 34 of these were being treated with clozapine. We found that clozapine use was an independent risk factor for COVID-19 positivity (OR=1.81 95% CI=1.13-2.90), inpatient care admission (OR=3.01, 95% CI=1.12-8.06). Conclusion: In our study, clozapine use was associated with an increased risk of COVID-19 positivity and inpatient care admission; however, it was not associated with ICU admission or death. Due to the frequent followup of patients using clozapine and the effects of clozapine on immunity, the frequency and/or identification of COVID-19 may be increased in these patients. Clozapine toxicity, granulocytopenia or agranulocytosis during the COVID-19 infection may have increased these patients' hospitalisation frequency. [ABSTRACT FROM AUTHOR]

This experimental study presents the machinability comparison of TiCN-Al2O3-TiN, TiAlN-TiN, and TiAlSiN coated carbide inserts in hard turning AISI 4340 steel. The primary purpose of this research is to determine the most appropriate cutting inserts in turning hardened AISI 4340 (30–40 HRC) steel considering surface roughness (Ra), cutting sound (Cs), power consumption (P), radial force (Fx), tangential force (Fy), and feed force (Fz). To fulfill this objective, the turning experiments for each tool were executed based on the Taguchi L9 design. The comparative assessment of cutting tools revealed that the TiAlSiN coated tool exhibited superior performance compared to other tools. Machining with the TiCN-Al2O3-TiN coated tool showed 32.05% greater roughness than with the TiAlN-TiN coated tool, and 68.80% higher surface roughness than the TiAlSiN coated tool. The main novelty of this research is considering the cutting sound and power consumption as responses to select the most suitable cutting tools. Moreover, a novel grey-crow search hybrid was executed to perceive the optimal value of the input parameters. The optimal local value of cutting speed for the TiAlSiN coated tool was found to be 220 m/min, while for the TiCN-Al2O3-TiN and TiAlN-TiN tools, it was the same as 182 m/min. Considering the optimum cutting parameters, the material removal rate for TiCN-Al2O3-TiN, TiAlN-TiN, and TiAlSiN was found to be 639.9 mm3/min, 606.4 mm3/min, and 761.2 mm3/min, respectively. Thus, the TiAlSiN coated tool has greater MRR capability in comparison to other tools. Therefore, this leads to the conclusion that the TiAlSiN tool may be the better choice in comparison to other selected tools for turning hardened steels. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to evaluate the efficacy of percutaneous treatment in hydatid cysts (HCs) with at least one diameter larger than 10 cm. Materials and methods: 58 CE1 or CE3a HCs with at least one diameter larger than 10 cm which were treated with catheterization between September 2016 and December 2021 were retrospectively analyzed. Results: Mean age was 40 ± 17.7 (18–80). Majority of HCs were in the liver (89.6%). Median follow-up was 28 months. Technical success rate was 100%; however, a second procedure was needed in 13 cysts due to recollection (n = 4), infection (n = 6), and recurrence (n = 3). Conclusions: Giant HCs can be effectively treated with catheterization with low complication rates. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Higher Education & Science / Yüksekögretim ve Bilim Dergisi is the property of Zonguldak Bulent Ecevit Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Turkish Journal of Trauma & Emergency Surgery / Ulusal Travma ve Acil Cerrahi Dergisi is the property of KARE Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Quaternions are an important tool that provides a convenient and effective mathematical method for representing reflections and rotations in three‐dimensional space. A unit timelike split quaternion represents a rotation in the Lorentzian space. In this paper, we give some geometric interpretations of split quaternions for lines and planes in the Minkowski 3‐space with the help of mutual pseudo orthogonal planes. We classified mutual planes with respect to the casual character of the normals of the plane as follows; if the normal is timelike, then the mutual plane is isomorphic to the complex plane; if the normal is spacelike, then the plane is isomorphic to the hyperbolic number plane (Lorentzian plane); if the normal is lightlike, then the plane is isomorphic to the dual number plane (Galilean plane). [ABSTRACT FROM AUTHOR]

Copyright of Agri: Journal of the Turkish Society of Algology / Türk Algoloji (Ağrı) Derneği'nin Yayın Organıdır is the property of KARE Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this article, quaternions, which is a preferred and elegant method for expressing spherical rotations, are generalized with the help of generalized scalar product spaces, and elliptical rotations on any given ellipsoid are examined by them. To this end, firstly, we define the generalized elliptical scalar product space which accepts the given ellipsoid as a sphere and determines skew symmetric matrices, and the generalized vector product related to this scalar product space. Then we define the generalized elliptical quaternions by using these notions. Finally, elliptical rotations on any ellipsoid in the space are examined by using the unit generalized elliptical quaternions. The formulas and results obtained are supported with numerical examples. [ABSTRACT FROM AUTHOR]

In this study, graphene nanoplatelets (GNPs) added to epoxy matrix composite reinforced by aeronautical grade carbon fibers (CFs) were fabricated by the vacuum infusion method, and the effect of different GNPs contents (0.05, 0.25, and 1.25 wt%) on electrical conductivity, flexural properties, and dynamic mechanical properties were investigated. The results revealed an 8‐ and 73‐times improvement in conductivity values across the thickness with the addition of 0.05 and 0.25 wt% GNPs, respectively, compared to the neat composite. Flexural test results showed that with the addition of 0.05 GNP, only 6% increase in flexural strength was obtained, while with the addition of 0.25 wt% GNP flexural strength remained almost the same as for the neat composite. On the contrary, the addition of GNPs (1.25% by weight) causes a reduction in the flexural strength with respect to the neat composite. This was confirmed by the fractured surfaces examined by scanning electron microscope which reveals that considerable amount of fiber‐matrix debonding was observed with 1.25 GNPs loading. Dynamic mechanical analysis (DMA) revealed that the storage modulus of the neat composite increased by 12.6% with the addition of only a small amount of GNP (0.05% wt) compared to the neat composite. Composite with 1.25 GNP shows upward bending, affecting the shape of the cole–cole plot obtained from DMA results, indicating inappropriate interactions of GNPs in both the matrix and CF in the composite. [ABSTRACT FROM AUTHOR]

In this work, initially, the raw AISI 52100 bearing steel was heat-treated to obtain 40 HRC and 45 HRC workpiece hardness. Further, dry hard turning tests were carried out to study the impact of workpiece hardness (H), cutting speed (v), feed (f), and depth of cut (a) on cutting force (Fy), surface roughness (Ra), and sound intensity (SI). An economically viable PVD-coated carbide turning tool was implemented for the experiments. The Taguchi L 1 8 (2–3 mixed level) design of experiments was employed to establish the experimental plan in order to save the experimental time, energy, and cost of manufacturing. The results disclosed that the feed has the prevailing consequence on surface roughness with a 96.3% contribution, while it also significantly affects the cutting force with a contribution of 13.8%. The contribution of cutting speed and workpiece hardness on the cutting force was reported as 48.3% and 35.1%, respectively. Higher workpiece hardness required more energy for plastic deformation as a result the cutting force increases with leading hardness. The sound intensity was dominantly influenced by depth of cut (53.3%) and cutting speed (40%). Finally, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was performed to determine the optimum machining parameters. According to the TOPSIS, the optimum level of cutting parameters was predicted as 40 HRC hardness (H), 150 m/min cutting speed (V), 0.15 mm/rev feed (f), and 0.1 mm depth of cut (a) while the optimal result of Fy, SI, and Ra were noted as 27.66 N, 70.7 dB, and 0.86 μ m individually. [ABSTRACT FROM AUTHOR]

Copyright of Mevzu is the property of Ali Sever and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: The main objective of this study is to describe the retrograde guidewire-assisted remodeling technique (REGART), a novel technique, and assess its feasibility, safety, and effectiveness in the recanalization of ostial arterial occlusions without a visible stump in the critical limb ischemia (CLI). Materials and Methods: A retrospective review of 387 patients who underwent endovascular treatment (EVT) for peripheral artery disease between January 2020 and June 2021 was performed. Among these, 23 patients (14 males [60.8%]) with a mean age of 64.2 (range: 55–72) years who underwent REGART were included. Patient demographics, procedural details, and outcomes were noted. Results: The technical success rate was 95.6% (22/23). The angiographic success rate was 86.3% (19/22). The procedure-related complication rate was 21.7% (5/23), with 4 (17.4%) major complications and 1 (4.3%) minor complication. Conclusion: In the CLI, results of this trial suggest that REGART is feasible, effective, and with acceptable safety in the catheterization of occluded artery origins without a visible stump when conventional anterograde and retrograde techniques fail. Thus, the target occluded artery can be recanalized while preserving other arterial origins by minimizing dissection risk through subintimal balloon angioplasty at the bi-trifurcation level. [ABSTRACT FROM AUTHOR]

Objective: Adolescent idiopathic scoliosis (AIS) is a 3D spinal deformity consisting of lateral deviation and axial rotation of spine that develops during growth. Spinal musculus is closely related to head and neck muscles, such as sternocleidomastoideus muscle. In this study, according to axial trunk rotation in AIS patients, We aimed to contribute to literature by examining changes in biomechanical properties of sternocleidomastoideus muscle. Methods: This study was planned as prospective and descriptive. Study included 46 individuals (34 females, 12 males) who applied to Gaziantep University Department of Orthopedics and Traumatology, were between ages of 10-18, were diagnosed with AIS by relevant physician, and hadn't spinal deformity on all spine radiographs. Individuals who had undergone spine surgery, didn't have idiopathic scoliosis, had orthopedic, muscular, neurological diseases accompanying their scoliosis weren't included in study. Cobb angle was measured on AP radiographs. MyotonePro device, which is valid in literature was used to measure tone, hardness and elasticity of m. sternocleidomastoideus. Results: There is a statistically significant difference between pre-post-exercise D measurements of left m.sternocleidomastoideus in the participants. Left m. sternocleidomastoideus D measurement increased in second measurement. A statistically significant positive relationship was found between right sternocleidomastoideus S measurement and thoracic Cobb angle (p=0.045). A statistically significant negative relationship was found between left m.sternocleidomastoideus D measurement and lumbar Cobb angle (p=0.045). Conclusion: It has been determined that hardness and elasticity of m. sternocleidomastoideus may affect thoracic and lumbar Cobb angles. It is thought that knowing these changes may contribute to clinic. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cryogenic treatments have been applied to enhance both wear and abrasion resistance for the cutting inserts. Therefore, many investigations focused on the shallow and deep cryogenic treatments in terms of their performance on the machinability criteria. This paper presents a detailed analysis on machinability investigation of cryogenically treated hardened 4140 steel (55 HRC), and sustainability assessment in hard machining on finishing mode carried out at dry cutting regime. A series of machining trials have been performed under varied cutting conditions (feed, depth of cut and speed) following the L9 orthogonal array design experimental layout for analysis of various responses along with cost estimation in hard turning. Moreover, the machining parameters are optimized and mathematically formulated for the minimization of various responses using a multi-objective optimization method. Finally, considering the motivational idea of "Go green–Think green–Act green", a unique novel approach has been proposed concerning economic evaluation and sustainability assessment in hard turning for safer and cleaner approach of environment friendly manufacturing. According to statistical analysis, feed influenced both surface roughness and cutting force significantly. Because of cryogenic treatment both surface roughness and cutting force diminished. It is noticed that with high speed, low feed, and depth of cut both force and roughness value declined. The tool life of CBN was 44 min and considering the same, Gilbert's machining economic model calculated the overall machining cost per part of 80.86 in the machining of hardened AISI 4140 steel. The outcomes clearly established that machining under dry conditions provides environment friendliness, technologically viable, and economically feasible to improve sustainability. [ABSTRACT FROM AUTHOR]

Split-complex (hyperbolic) numbers are ordered pairs of real numbers, written in the form x + jy with j² = 1, used to describe the geometry of the Lorentzian plane. Since a null split-complex number does not have an inverse, some methods to calculate the exponential of complex matrices are not valid for split-complex matrices. In this paper, we examined the exponential of a 2 × 2 split-complex matrix in three cases: i. Δ = 0, ii. Δ ̸= 0 and Δ is not null split-complex number, iii. Δ ̸= 0 and Δ is a null split-complex number where Δ = (trA)2 - 4 detA. [ABSTRACT FROM AUTHOR]

Copyright of Van Tip Dergisi is the property of Yuzuncu Yil University, Faculty of Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: This study assessed the outcomes of transforaminal lumbar interbody fusion (TLIF) in patients with degenerative spine conditions above the age of 65 years and investigate the effects of fusion levels on the sagittal balance parameters. Materials and Methods: This retrospective study reviewed patients with degenerative spine diseases who underwent lumbar fusion with the TLIF procedure older than 65 years. Patients with three or less segments involved in the fusion were assigned to the short-level fusion group, and the patients with more than three segments involved in the fusion were assigned to the long-level fusion group. The anteroposterior and lateral spine radiographs of the patients were used to measure pelvic incidence (PI), pelvic tilt (PT), sacral slop (SS), lumbar lordosis (LL), distal lumbar lordosis, thoracolumbar kyphosis, thoracic kyphosis (TK), T1 spinopelvic inclination (T1SPI), T9 spinopelvic inclination (T9SPI) and T1 pelvic angle (TPA). Results: The study included 45 patients, 28 females and 17 males, who met the inclusion criteria. The long- and short-level fusion groups comprised 25 and 20 patients, with the mean ages of 68.87 and 67.72 years and mean follow-up periods of 26.96±15.53 and 27.61±11.83 months, respectively. TK and T9SPI values showed no difference between the groups before and after surgery, but a statistically significant increase in the values was observed postoperatively in the patients who underwent long-level fusion. The preoperative SVA values were significantly higher in the long-level fusion group than in the short-level fusion group. No difference in the postoperative SVA values was found between the groups. The PT, PI, SS, TPA, T1SPI was not statistically differ between the groups before and after surgery. Conclusion: TLIF contributes to the improvement of the sagittal balance parameters in both short- and long-level fusions in patients above the age of 65 years with degenerative spine conditions. [ABSTRACT FROM AUTHOR]

Purpose: This paper investigates the interview examination applied during the admission process of air traffic controller (ATCO) candidates. This paper aims to select the most appropriate candidates by minimizing any shortcomings of the process. Design/methodology/approach: ATCOs have a very important role in the air traffic system. They are responsible for ensuring the safe, regular and rapid flow of aircraft traffic. They carry out this challenging task by monitoring the aircraft under their responsibility and by giving instructions to the pilots when necessary. So the selection of ATCO candidates is of critical importance. This process is usually conducted through multistage examinations. It is a critical issue to use correct methods in the selection process to identify the most suitable candidates. Besides, the application of subjective examination in a standard way and standardization of criteria can assist in selecting the right candidates. Within this context, the analytic network process (ANP) and the rating method are used. The weights of the selection criteria are calculated by the ANP, and the candidates are evaluated by the rating method according to the defined criteria. Findings: 39 candidates were ranked using the ANP, and the rankings obtained by the ANP and the current system were compared. The ANP rankings were also compared with the results of a previous study conducted by analytic hierarchy process (AHP). The results indicate that using the ANP yields consistent results with those obtained from the AHP in terms of the rankings. Research limitations/implications: ATCOs are one of the most important operators in air transport system. They undertake critical tasks where even a small error may cause serious consequences. Therefore, selecting the appropriate candidate is an important first step in training qualified staff. The authors believe that this study will contribute to the training of more qualified ATCOs. On the other hand, the approach about the use of ANP method on the interview examination and the standardization of the criteria can provide insight into improving interview process in different area. Originality/value: To the best of the authors' knowledge, this is the first study that presents an ANP-based methodology for the selection process of ATCOs and the interview process. [ABSTRACT FROM AUTHOR]

The use of the entire workspace of a parallel robot calls for passing through type II singularities, which can be achieved by removing them from the inverse dynamics solution. Hypersingularities are type II singularities whose removal from the inverse dynamics requires satisfaction of additional higher order derivative conditions other than the acceleration-level ones for maintaining the consistency of the equations of motion. For this reason, the identification of hypersingularities constitutes an important and yet a new subject in the field of parallel robots. This paper contributes to the literature by deriving a condition for their occurrence in one of the mostly used parallel robots in applications, namely the 3-RRR planar parallel robot. It is shown that any type II singular configuration of the considered robot becomes a hypersingularity if the end-effector velocities at that configuration lie on a certain plane in the end-effector velocity space. The orientation of this hypersingularity plane changes according to the singular configuration. However, the said plane always passes through the origin of the end-effector velocity space. These findings are believed to bring new insights into the optimization of the singularity removal process of parallel robots through the minimization of the number of conditions to be satisfied in this regard. [ABSTRACT FROM AUTHOR]

Lemierre's syndrome refers to septic thrombophlebitis of the internal jugular vein that is rarely seen after an oropharyngeal infection. We present the case of a 64-year-old female patient with Covid-19 infection and Lemierre's syndrome. Contrast-enhanced computed tomography of the neck revealed thrombosis in the left internal jugular vein and non-contrast-enhanced computed tomography of the thorax was consistent with Covid-19 infection. The patient was immediately hospitalized. Systemic antibiotics, anticoagulation therapy, and favipiravir treatment for Covid-19 infection were started. Unfortunately, the patient died about two weeks after hospitalization. To the best of our knowledge, this is the first case of Lemierre's syndrome and Covid-19 overlap. Clinical suspicion of Lemierre's syndrome is important for rapid diagnosis. During this Covid-19 pandemic, we should keep in mind that any patient may have Covid-19 infection. In addition to the patient's primary disease, with clinical or laboratory suspicion of Covid-19 infection, diagnostic tests for it should also be conducted. [ABSTRACT FROM AUTHOR]

A great number of studies have been conducted pressure drop for packed bed and curved channel. However, pressure drop in the spiral packed beds has not been investigated. In this study, pressure drop in spiral packed beds which are made of two different channel widths (a = 10 mm and a = 15 mm) and three different ball diameters (d = 2.00, 2.38 and 3.17 mm) was investigated experimentally. Experiments were carried out with laminar air flow at steady-state. The friction factors, permeabilities, inertial and Ergun coefficients were determined for spiral packed beds. It was observed that the coefficients of the Ergün correlation were not suitable for the spiral packed beds. These coefficients were determined for spiral packed beds. In addition, considering the effect of the curvature ratio, a modified Dean number was defined. The relation between the pressure drop in spiral packed beds and the modified Dean number was presented. The effect of curvature ratio on pressure drop in spiral packed beds was investigated. The pressure drop correlation based on Rep and modified Dean numbers obtained from all experimental data was presented and compared with the Ergün equation. This study will be a pioneering study in terms of the effects of the porous medium on the spiral channel. [ABSTRACT FROM AUTHOR]

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