| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Huang, Yansong, 1992, et al.
(författare)
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Linear and nonlinear kinematic design of multilink suspension
- 2023
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Ingår i: SAE International Journal of Passenger Vehicle Systems. - : SAE International. - 2770-3479. ; 16:2
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Tidskriftsartikel (refereegranskat)abstract
- In the design of suspensions for passenger cars, it is time-consuming to find a solution that works for both kinematics and packaging. The design must provide clash-free packaging within the suspension components and sufficient clearance to surrounding parts, such as the body and the subframe. In addition, the design has to ensure a reasonable kinematic performance, in which the dynamic behaviors of the car are safe and stable at all speeds. The objective of this study was to provide a method that automatically controls specified linear and nonlinear kinematic targets at the same time as engineers test different packaging solutions. The kinematic performance is controlled when design engineers test different packaging solutions by using the proposed method. The method optimizes the linearized constraint matrices by means of given performance targets as input and proposes a hardpoint configuration. The result shows a major potential to reduce design lead time by using this method. We conclude that the design of the suspension architecture can be more efficient and precise by automatic kinematic control.
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| 3. |
- Huang, Yansong, 1992, et al.
(författare)
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Optimized Rear-Axle Concept for Battery Electric Vehicles
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- One of the main challenges for Battery Electric Vehicles (BEV) is a sufficient range. Therefore, a maximized battery volume is desirable in any recent vehicle concept. Suspension, as one of the largest subsystems, has a significant impact on that. Starting from a conventional car with an internal combustion engine (ICE), a suspension is developed to fulfill new packaging requirements for BEVs, while at the same time maintaining typical requirements concerning driving dynamics. The objective of this study is to use automated methods for suspension development. And the application is to introduce a new steerable rear suspension concept with electric propulsion system. The suspension concept was optimized for premium cars with large battery sizes. Moreover, advanced active systems such as air springs and active rear wheel steering with large steering angles were also considered. The concept also proposes a packaging solution with a well-tuned kinematic performance which meets the OEMs tuning philosophy. In order to address the resulting high complexity, newly developed methods were used. The kinematic optimization was done with an innovative method, which automatically proposes new hard points, depending on the given requirements. For the design, simplified models were used to represent the shape of sophisticated parts. So, it was possible to automatically judge whether a kinematic concept is feasible from a packaging point of view. The results show that the new suspension concept can handle the challenge packaging issues and complex kinematic requirements.
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| 4. |
- Huang, Yansong, 1992
(författare)
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Target-driven road vehicle suspension design
- 2022
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is focused on suspension hardpoint and bushing compliance design with new reverse engineering methods that are based on kinematics and compliance constraints. The kinematic reverse design method is implemented into a conceptual front axle development. The results show that, using this method, the design lead time is reduced by half. It is concluded that the design of the suspension architecture can be more efficient and precise by automatic suspension design algorithms. The wheel suspension is one of the most architecture-heavy systems in a car and much of the car’s overall motion characteristics and limitations are determined by it. Among other things, electrification, and fierce global competition place ever higher demands on faster and more efficient development of new vehicle concepts, even within a classic area such as mechanical wheel suspension design. The wheel suspension system has many design parameters and prerequisites that have very complex relations. Traditionally the development process has been dependent on very skilled engineering teams. A clear bottleneck in the development of a new wheel suspension today is how to balance the complex performance requirements and which today require time-consuming calculations to evaluate for each iteration of the design. One solution to the above problem can be to look over the total development process, from target setting to verification, via re-design or optimization loops.
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| 5. |
- Naik, Akshay, et al.
(författare)
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Target Driven Bushing Design for Wheel Suspension Concept Development
- 2023
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Ingår i: SAE Technical Papers. - 0148-7191 .- 2688-3627.
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Konferensbidrag (refereegranskat)abstract
- Bushing elasticity is one of the most important compliance factors that significantly influence driving behavior. The deformations of the bushings change the wheel orientations under external forces. Another important factor of bushing compliance is to provide a comfortable driving experience by isolating the vibrations from road irregularities. However, the driving comfort and driving dynamics are often in conflict and need to be balanced in terms of bushing compliance design. Specifically, lateral force steer and brake force steer are closely related to safety and stability and comprises must be minimized. The sensitivity analysis helps engineers to understand the critical bushing for certain compliance attributes, but optimal balancing is complicated to understand. The combination of individual bushing stiffness must be carefully set to achieve an acceptable level of all the attributes. Traditional bushing tuning method involves an optimization process in Adams Car or any other multi-body simulation software. Though they provide reliable results, it is a time-consuming process to build models for the complete Kinematic and Compliance analysis. Therefore, a method to set the bushing specifications automatically according to the compliance targets is proposed by the author. The method makes sure the instant motion of the wheel meets the targets. The bushing stiffness values are calculated according to force distribution and motion ratios between the wheel and each bushing. The method decouples the axial stiffness and radial stiffness. It provides a method to set up the radial stiffness automatically. The new method will reverse the traditional trial-and-error approach, to avoid extensive iterations and significantly reduce the development time.
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| 6. |
- Pasche, Boris, et al.
(författare)
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Somatic acquisition and signaling of TGFBR1*6A in cancer
- 2005
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 294:13, s. 1634-1646
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Tidskriftsartikel (refereegranskat)abstract
- Context: TGFBR1*6A is a common polymorphism of the type I transforming growth factor 0 receptor (TGFBR1). Epidemiological studies suggest that TGFBR1*6A may act as a tumor susceptibility allele. How TGFBR1*6A contributes to cancer development is largely unknown.. Objectives: To determine whether TGFBR1*6A is somatically acquired by primary tumors and metastases during cancer development and whether the 3-amino acid deletion that differentiates TGFBR1*6A from TGFBR1 is part of the mature receptor or part of the signal sequence and to investigate TGFBR1*6A signaling in cancer cells. Design, Setting, and Patients: Tumor And germline tissues from 531 patients with a diagnosis of head and neck, colorectal, or breast cancer recruited from 3 centers in the United States and from 1 center in Spain from June 1, 1994, through June 30, 2004, In vitro translation assays, MCF-7 breast cancer cells stably transfected with TGFBR1*6A, TGFBR1, or the vector alone, DLD-1 colorectal cancer cells that endogenously carry TGFBR1*6A, and SW48 colorectal cancer cells that do not carry TGFBR1*6A. Main Outcome Measures: TGFBR1*6A somatic acquisition in cancer. Determination of the amino terminus of the mature TGFBR1*6A and TGFBR1 receptors. Determination of TGF-beta-dependent cell proliferation. Results: TGFBR1*6A was somatically acquired in 13 of 44 (29.5%) colorectal cancer metastases, in 4 of 157 (2.5%) of colorectal tumors, in 4 of 226 (1.8%) head and neck primary tumors, and in none of the 104 patients with breast cancer. TGFBR1*6A somatic acquisition is not associated with loss of heterozygosity, microsatellite instability, or a mutator phenotype. The signal sequences of TGFBR1 and TGFBR1*6A are cleaved at the same site resulting in identical mature receptors. TGFBR1*6A may switch TGF-beta growth inhibitory signals into growth stimulatory signals in MCF-7 breast cancer cells and in DLD-1 colorectal cancer cells. Conclusions: TGFBR1*6A is somatically acquired in 29.5% of liver metastases from colorectal cancer and may bestow cancer cells with a growth advantage in the presence of TGF-beta. The functional consequences of this conversion appear to be mediated by the TGFBR1*6A signal sequence rather than by the mature receptor. The results highlight a new facet of TGF-beta signaling in cancer and suggest that TGFBR1*6A may represent a potential therapeutic target in cancer.
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