3D suspension characterization of a rapid transit vehicle using a multi-body dynamic model

In this work, suspension characterization of a rapid transit vehicle is performed with a multi-body dynamic model that represents full degrees of freedom of a rapid transit vehicle. The effects of lateral suspension properties on passenger ride comfort and stability are investigated by variation of critical suspension parameters using design of experiment method. The critical suspension properties are obtained for the best values of car body lateral acceleration and car body lateral stroke. The tangent track time response of the car body verified the negligible effect of both lateral viscous dampers at primary suspensions and longitudinal anti-yaw dampers at secondary suspensions on the passenger ride comfort and stability of a rapid transit vehicle

Podwójne znakowanie immunologiczne CD133 i Ki-67 wskazuje na ich istotną współlokalizację w podtypie włóknistym oponiaków

Background and purpose A unique molecular and/or cellular marker for meningiomas, the most common intracranial tumours, has not been identified yet. Material and methods We investigated the co-localization fraction of CD133/Ki-67 in meningioma tissue array slide composed of 80 meningioma tissue samples of various histological variants. CD133 – a cell membrane stem cell marker – was previously proved to be associated with the initiation and progression of intracerebral gliomas and medulloblastomas. Results Immunohistochemical co-localization of CD133/Ki-67 was significantly higher in fibroblastic variant than in meningothelial and transitional subtypes. However, since there were only 3 atypical and 1 malignant meningioma spots in the tumour tissue array slide, it is difficult to draw a firm conclusion regarding the actual co-localization percentage and persistence of CD133/Ki-67 in atypical and malignant meningiomas. Conclusions Far higher co-staining percentage of CD133/Ki-67 in fibroblastic meningioma samples compared to meningothelial subtype, a histological meningioma variant, architectonically resembling the non-neoplastic meningeal cells, gave us the impression that CD133 may play a role in the formation and progression of fibroblastic meningioma variants. The persistency and the validity of this finding need to be verified by further histopathological and molecular research in order to clarify the possible role of CD133 in meningiogenesis.Wstęp i cel pracy Nie określono dotąd unikalnego znacznika molekularnego lub komórkowego dla oponiaków, najczęstszych guzów wewnątrzczaszkowych. Wcześniej wykazano, że CD133 – znacznik błony komórkowej komórek macierzystych – jest związany z zapoczątkowaniem, a także wzrostem wewnątrzczaszkowych glejaków i rdzeniaków płodowych. Materiał i metody Zbadano odsetek współlokalizacji CD133/Ki-67 w zestawach macierzy tkankowych oponiaków, złożonych z próbek 80 rozmaitych odmian histologicznych oponiaków. Wyniki Immunohistochemiczna współlokalizacja CD133 i Ki-67 była stwierdzana istotnie częściej w podtypie włóknistym oponiaka niż w podtypach meningotelialnym lub przejściowym. Ze względu na małą liczbę preparatów opo-niaków atypowych (3) oraz złośliwych (1) w badanej macierzy tkankowej trudno wyciągnąć jednoznaczne wnioski dotyczące rzeczywistego odsetka współlokalizacji i utrzymywania się CD133/Ki-67 w oponiakach atypowych i złośliwych. Wnioski Znacząco większy odsetek wspólnie występującej reaktywności CD133/Ki-67 w preparatach oponiaka włóknistego w porównaniu z podtypem meningotelialnym, którego architektonika przypomina nienowotworowe komórki opon, sprawia wrażenie, że CD133 może odgrywać rolę w powstawaniu i rozwoju oponiaków włóknistych. Trafność tego spostrzeżenia wymaga weryfikacji w dalszych badaniach histopatologicznych i molekularnych w celu wyjaśnienia możliwej roli CD133 w powstawaniu oponiaków

The impact of hybrid capture-based comprehensive genomic profiling on treatment strategies in patients with solid tumors

Objective: The development of bioinformatics and comprehensive genomic profiling (CGP) has provided insights into the ap-plicability and functionality of the genomic alterations (GA). In this study, we evaluated the impact of CGP on the treatment plan and outcomes in a significant number of patients. Material and Methods: We carried out a retrospective case-control study on 164 adult patients with advanced solid tumors from 15 oncology centers in Türkiye. Results: In all cases, CGP was performed within 23.8 [standard deviation (SD)±32.1] months of initial diagnosis. Non-small cell lung carcinoma, breast cancer, unknown primary carcinoma, colorectal carcinoma, and sarcoma were among the most common tumor types, accounting for 61.5% of all cases. CGP was performed immediately after the diagnosis of advanced cancer in 13 patients (7.9%). In 158 patients (96.4%), at least one GA was found as per the CGP report. Also, in the reports, the average tumor mutational burden (TMB) and GAs were 7.3 (SD±8.7) mut/Mb and 3.5 (SD±2.0), respectively. According to CGP reports, 58 patients had 79 evidence-based drug suggestions for their particular tumor type, whereas 97 patients had 153 evidence-based drug suggestions for another tumor type. After the primary oncologist interpreted the CGP reports, significant changes were made to the treatment of 35 (21.3%) patients. Conclusion: We strongly believe that in the future, high-TMB or other tumor-agnostic biomarkers will become much more afford-able, and CGP will serve as one of the major decision-making tools for the treatment of patients along with pathological, radiological or lab-oratory tests

Bilgisayar destekli tasarım ortamında mekanizma sentezi.

CADSYN (Computer Aided Design SYNthesis) is a visual, interactive computer program working under Computer Aided Design (CAD) enviroment, which accomplishes the synthesis and analysis of planar four-bar mechanisms. The synthesis tasks are motion generation, path generation and function generation. During synthesis, the dyadic approach is utilized which introduces vector pairs and complex number algebra to model the motion. The possible solutions can be limited for link dimensions, the center circle point curves within a certain region, transmission angle characteristics, branch and order defects. The designed mechanism can be analyzed for velocity, acceleration and transmission angle and any of the data can be exported to Excel® for further analysis. The software is designed to provide the user maximum feasible number of solutions. In four multiply separated position synthesis, if there is flexibility in the value(s) of one or any number of input parameter(s), designer can obtain different Burmester curves by changing those parameter(s). Designer can also simulate the kinematics of the mechanism by using drawing functions that are available from the CAD enviroment at any time. Drawing parts in the design plane can be attached to any link of the mechanism and can be simulated throughout the motion as part of the link it is attached. As a whole, this computer program is designed to satisfy the needs of mechanism designers while working in CAD enviroment.M.S. - Master of Scienc

A physically based constitutive model for FCC single crystals with a single state variable per slip system

A new, simple and physically consistent dislocation-density-based continuum model is developed in a large-strain crystal plasticity framework. All the constitutive laws are expressed in a simple and unique way in terms of a single state variable dislocation density. The proposed physically based model predicts experimental single-crystal stress-strain curves along different crystal directions more accurately than a classical model with widely accepted constitutive laws. The polycrystal texture predictions from the dislocation-density-based and classical models having the same single-crystal stress-strain characteristics are in good agreement with the classical model when Taylor-type homogenization is used in conjunction with enough number of grains

Design of variable stiffness composites for maximum fundamental frequency considering manufacturing constraints of tow steering

In this study, an in-house finite element approach is developed to optimize fundamental frequency of variable stiffness composites considering manufacturing constraints of tow steering process. The method uses the lamination parameters as the design variables. Tow angles or fiber angles and their stacking sequence are computed from the optimum lamination parameters by direct search method. The Least-Squares and Continuity (LSC) method is applied to maintain the fiber or tow continuity within a prescribed curvature limit for manufacturability. Finally the discrete fiber angles or tow directions were converted into paths by using stream functions to have continuous manufacturable paths. The results of the method were compared to various literature findings for constant, balanced variable, and general variable stiffness designs for different boundary conditions, aspect ratios, and material properties. The optimum lamination parameter distributions were in good agreement with literature findings. The fundamental frequency improvements up to 11.9% and 10.2% were computed by the LSC method with respect to the optimum constant stiffness results for fully simply-supported and fully clamped cases, respectively

A thermomechanical finite element model and its comparison to inherent strain method for powder-bed fusion process

In this study, a thermomechanical model is developed to predict the melt-pool dimensions and residual stresses for laser powder bed fusion process. Inherent strain method is also used to predict residual stresses by using only the thermal solution that is free the complexities involved with the mechanical solution. A unique approach is developed to define the surface heat losses as volumetric heat losses in order to avoid the definition of traction-free surfaces and their re-definition after layer deposition. The thermal process simulations predict melt-pool dimensions of experimental cross-sections of single tracks within approximately 10% agreement. The thermomechanical process model is used to forecast the effect of process parameters on the melt-pool dimensions and residual stresses. The inherent strain method reproduces the residual stresses within 15% accuracy, approximately six times faster in comparison to the thermomechanical model, and free of any convergence issues related with the displacement field solution