Experimental Investigation of Dynamic Properties of AerMet 100 Steel

AbstractThe dynamic properties characterization of AerMet 100 Steel at four different strain rates, namely 560/s, 1200/s, 2500/s and 4200/s were carried by a SHPB system. The stress-strain curves at these strain rates are obtained and they were compared with the quasi-static test results to analyze its strain effects. By comparing the stress-strain curves under different strain rates and quasi-static results, it can be found that the AerMet 100 shows strong strain rate sensitivity. For example, its yield stress under quasi-static compression is 1800MP while the yield stress is around 2300MP under strain rate 4200/s with an incensement of 24%. The hardening modulus under static compression is larger than that under dynamic compression due to the softening by the high temperature during high velocity impacting

Soft-Defined Heterogeneous Vehicular Network: Architecture and Challenges

Heterogeneous Vehicular NETworks (HetVNETs) can meet various quality-of-service (QoS) requirements for intelligent transport system (ITS) services by integrating different access networks coherently. However, the current network architecture for HetVNET cannot efficiently deal with the increasing demands of rapidly changing network landscape. Thanks to the centralization and flexibility of the cloud radio access network (Cloud-RAN), soft-defined networking (SDN) can conveniently be applied to support the dynamic nature of future HetVNET functions and various applications while reducing the operating costs. In this paper, we first propose the multi-layer Cloud RAN architecture for implementing the new network, where the multi-domain resources can be exploited as needed for vehicle users. Then, the high-level design of soft-defined HetVNET is presented in detail. Finally, we briefly discuss key challenges and solutions for this new network, corroborating its feasibility in the emerging fifth-generation (5G) era

Effects of rotational velocity on microstructures and mechanical properties of surface compensation friction stir welded 6005A-T6 aluminum alloy

Surface compensation friction stir welding (SCFSW) is successfully applied to weld 6005A-T6 aluminum alloy in order to eliminate disadvantages caused by flash and arc corrugation. The effects of rotational velocity on the microstructures and mechanical properties of SCFSW joints are investigated. The joints with equal thickness with respect to the workpiece to be welded are obtained using 4 mm thick plates with a convex platform in this study. The results show that welding process parameters exert a significant influence on the microstructures of nugget zone (NZ). Tensile strength and elongation of joints are both firstly increased and then decreased with an increase in the rotational velocity from 800 rpm to 1500 rpm under a constant welding speed of 200 mm/min. When the rotational velocity is 1300 rpm, the tensile strength and elongation reach the maximum values of 226 MPa and 6.5%, which are 75% and 67% of base metal (BM), respectively. The fracture surface morphology represents the typical ductile fracture. The hardness of NZ is lower than that of BM and the lowest hardness of joint is located at thermo-mechanically affected zone (TMAZ) on the advancing side (AS)

MLPerf Inference Benchmark

Machine-learning (ML) hardware and software system demand is burgeoning. Driven by ML applications, the number of different ML inference systems has exploded. Over 100 organizations are building ML inference chips, and the systems that incorporate existing models span at least three orders of magnitude in power consumption and five orders of magnitude in performance; they range from embedded devices to data-center solutions. Fueling the hardware are a dozen or more software frameworks and libraries. The myriad combinations of ML hardware and ML software make assessing ML-system performance in an architecture-neutral, representative, and reproducible manner challenging. There is a clear need for industry-wide standard ML benchmarking and evaluation criteria. MLPerf Inference answers that call. In this paper, we present our benchmarking method for evaluating ML inference systems. Driven by more than 30 organizations as well as more than 200 ML engineers and practitioners, MLPerf prescribes a set of rules and best practices to ensure comparability across systems with wildly differing architectures. The first call for submissions garnered more than 600 reproducible inference-performance measurements from 14 organizations, representing over 30 systems that showcase a wide range of capabilities. The submissions attest to the benchmark's flexibility and adaptability.Comment: ISCA 202

Immune microenvironment analysis and novel biomarkers of early-stage lung adenocarcinoma evolution

BackgroundLung cancer is the deadliest and most diagnosed type of cancer worldwide. The 5-year survival rate of lung adenocarcinoma (LUAD) dropped significantly when tumor stages advanced. Patients who received surgically resecting at the pre-invasive stage had a 5-year survival rate of nearly 100%. However, the study on the differences in gene expression profiles and immune microenvironment among pre-invasive LUAD patients is still lacking.MethodsIn this study, the gene expression profiles of three pre-invasive LUAD stages were compared using the RNA-sequencing data of 10 adenocarcinoma in situ (AIS) samples, 12 minimally invasive adenocarcinoma (MIA) samples, and 10 invasive adenocarcinoma (IAC) samples.ResultsThe high expression levels of PTGFRN (Hazard Ratio [HR] = 1.45; 95% Confidence Interval [CI]: 1.08-1.94; log-rank P = 0.013) and SPP1 (HR = 1.44; 95% CI: 1.07-1.93; log-rank P = 0.015) were identified to be associated with LUAD prognosis. Moreover, the early LUAD invasion was accompanied by the enhancement of antigen presentation ability, reflected by the increase of myeloid dendritic cells infiltration rate (Cuzick test P < 0.01) and the upregulation of seven important genes participating in the antigen presentation, including HLA-A (Cuzick test P = 0.03), MICA (Cuzick test P = 0.01), MICB (Cuzick test P = 0.01), HLA-DPA1 (Cuzick test P = 0.04), HLA-DQA2 (Cuzick test P < 0.01), HLA-DQB1 (Cuzick test P = 0.03), and HLA-DQB2 (Cuzick test P < 0.01). However, the tumor-killing ability of the immune system was inhibited during this process, as there were no rising cytotoxic T cell activity (Cuzick test P = 0.20) and no increasing expression in genes encoding cytotoxic proteins. ConclusionIn all, our research elucidated the changes in the immune microenvironment during early-stage LUAD evolution and may provide a theoretical basis for developing novel early-stage lung cancer therapeutic targets

Open source board based acoustofluidic transwells for reversible disruption of the blood–brain barrier for therapeutic delivery

Background: Blood–brain barrier (BBB) is a crucial but dynamic structure that functions as a gatekeeper for the central nervous system (CNS). Managing sufficient substances across the BBB is a major challenge, especially in the development of therapeutics for CNS disorders. Methods: To achieve an efficient, fast and safe strategy for BBB opening, an acoustofluidic transwell (AFT) was developed for reversible disruption of the BBB. The proposed AFT was consisted of a transwell insert where the BBB model was established, and a surface acoustic wave (SAW) transducer realized using open-source electronics based on printed circuit board techniques. Results: In the AFT device, the SAW produced acousto-mechanical stimulations to the BBB model resulting in decreased transendothelial electrical resistance in a dose dependent manner, indicating the disruption of the BBB. Moreover, SAW stimulation enhanced transendothelial permeability to sodium fluorescein and FITC-dextran with various molecular weight in the AFT device. Further study indicated BBB opening was mainly attributed to the apparent stretching of intercellular spaces. An in vivo study using a zebrafish model demonstrated SAW exposure promoted penetration of sodium fluorescein to the CNS. Conclusions: In summary, AFT effectively disrupts the BBB under the SAW stimulation, which is promising as a new drug delivery methodology for neurodegenerative diseases. Graphical Abstract

An enhanced tilted-angle acoustic tweezer for mechanical phenotyping of cancer cells

Acoustofluidic devices becomes one of the emerging and versatile tools for many biomedical applications. Most of the previous acoustofluidic devices are used for cells manipulation, and the few devices for cell phenotyping with a limitation in throughput. In this study, an enhanced tilted-angle (ETA) acoustofluidic device is developed and applied for mechanophenotyping of live cells. The ETA Device consists of an interdigital transducer which is positioned along a microfluidic channel. An inclination angle of 5° is introduced between the interdigital transducer and the liquid flow direction. The pressure nodes formed inside the acoustofluidic field in the channel deflect the biological cells from their original course in accordance with their mechanical properties, including volume, compressibility, and density. The threshold power for fully converging the cells to the pressure node is used to calculate the acoustic contrast factor. To demonstrate the ETA device in cell mechanophenotyping, and distinguishing between different cell types, further experimentation is carried out by using A549 (lung cancer cells), MDB-MA-231 (breast cancer cells), and leukocytes. The resulting acoustic contrast factors for the lung and breast cancer cells are different from that of the leukocytes by 27.9% and 21.5%, respectively. These results suggest this methodology can successfully distinguish and phenotype different cell types based on the acoustic contrast factor

Attenuating effect of Polygala tenuifolia Willd. seed oil on progression of MAFLD

Introduction: Metabolic-associated fatty liver disease (MAFLD) is a common chronic metabolic disease that seriously threatens human health. The pharmacological activity of unsaturated fatty acid-rich vegetable oil interventions in the treatment of MAFLD has been demonstrated. This study evaluated the pharmacological activity of Polygala tenuifolia Willd, which contains high levels of 2-acetyl-1,3-diacyl-sn-glycerols (sn-2-acTAGs).Methods: In this study, a mouse model was established by feeding a high-fat diet (HFD, 31% lard oil diet), and the treatment group was fed a P. tenuifolia seed oil (PWSO) treatment diet (17% lard oil and 14% PWSO diet). The pharmacological activity and mechanism of PWSO were investigated by total cho-lesterol (TC) measurement, triglyceride (TG) measurement and histopathological observation, and the sterol regulatory element-binding protein-1 (SREBP1), SREBP2 and NF-κB signaling pathways were evaluated by immunofluorescence and Western blot analyses.Results: PWSO attenuated the increases in plasma TC and TG levels. Furthermore, PWSO reduced the hepatic levels of TC and TG, ameliorating hepatic lipid accumulation. PWSO treatment effectively improves the level of hepatitic inflammation, such as reducing IL-6 levels and TNF-α level.Discussion: PWSO treatment inactivated SREBP1 and SREBP2, which are involved in lipogenesis, to attenuate hepatic lipid accumulation and mitigate the inflammatory response induced via the NF-κB signaling pathway. This study demonstrated that PWSO can be used as a relatively potent dietary supplement to inhibit the occurrence and development of MAFLD

Transcriptomic analysis of the late stages of grapevine (Vitis vinifera cv. Cabernet Sauvignon) berry ripening reveals significant induction of ethylene signaling and flavor pathways in the skin

Background: Grapevine berry, a nonclimacteric fruit, has three developmental stages; the last one is when berrycolor and sugar increase. Flavors derived from terpenoid and fatty acid metabolism develop at the very end of thisripening stage. The transcriptomic response of pulp and skin of Cabernet Sauvignon berries in the late stages ofripening between 22 and 37 \ub0Brix was assessed using whole-genome micorarrays.Results: The transcript abundance of approximately 18,000 genes changed with \ub0Brix and tissue type. There were alarge number of changes in many gene ontology (GO) categories involving metabolism, signaling and abioticstress. GO categories reflecting tissue differences were overrepresented in photosynthesis, isoprenoid metabolismand pigment biosynthesis. Detailed analysis of the interaction of the skin and pulp with \ub0Brix revealed that therewere statistically significantly higher abundances of transcripts changing with \ub0Brix in the skin that were involved inethylene signaling, isoprenoid and fatty acid metabolism. Many transcripts were peaking around known optimalfruit stages for flavor production. The transcript abundance of approximately two-thirds of the AP2/ERF superfamilyof transcription factors changed during these developmental stages. The transcript abundance of a unique clade ofERF6-type transcription factors had the largest changes in the skin and clustered with genes involved in ethylene,senescence, and fruit flavor production including ACC oxidase, terpene synthases, and lipoxygenases. The transcriptabundance of important transcription factors involved in fruit ripening was also higher in the skin.Conclusions: A detailed analysis of the transcriptome dynamics during late stages of ripening of grapevine berriesrevealed that these berries went through massive transcriptional changes in gene ontology categories involvingchemical signaling and metabolism in both the pulp and skin, particularly in the skin. Changes in the transcriptabundance of genes involved in the ethylene signaling pathway of this nonclimacteric fruit were statisticallysignificant in the late stages of ripening when the production of transcripts for important flavor and aroma compoundswere at their highest. Ethylene transcription factors known to play a role in leaf senescence also appear to play a role infruit senescence. Ethylene may play a bigger role than previously thought in this non-climacteric fruit