536 research outputs found

    Caractérisation électrique de transistors sans jonctions avec simulation numérique

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    L'invention du premier transistor à Bell lab's, dans le groupe de W. Shockley, en 1947 a été suivie d'une ère de développement des circuits intégrés (IC). Depuis plusieurs dizaines d'années, la dimension critique des transistors métal/oxyde/semi-conducteurs (les transistors MOS), la longueur physique de la grille, a diminué à un rythme régulier. Cette évolution, motivée par des raisons économiques, a été anticipée par G. Moore, et est de ce fait connue sous le nom de "loi de Moore". La dimension de grille a d'ores et déjà été réduite de plus de 2 ordres de grandeur et, dans son édition2012, l'association ITRS prédit qu'elle décroîtra encore, de 22nm en 2011 à environ 6nm en 2026 [1].Toutefois, cette réduction des dimensions fait apparaître un certain nombre d'effets secondaires qui altèrent le fonctionnement idéal des transistors MOS [2].In this dissertation, the performance of junction less transistors (JLTs) as possible candidates for the continuation of Moore s law was investigated experimentally based on an in-depth study of their electrical characteristics. Current-voltage I-V and capacitance-voltage C-V were analyzed in a wide rangeof temperatures (from 80 K to 350 K) in correlation with device operation mechanism. Lowfrequencynoise was also studied and compared to that of inversion-mode transistors. This study requirednew parameter extraction methods to be defined for JLTs. Their validity was confirmed by 2-dimensional (2D) simulation results. They will be detailed in this dissertation.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

    Myositis unrelated to the inoculation site after COVID-19 vaccination: a case report

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    We describe the case of a 49-year-old right hand-dominant woman with myositis of the biceps brachii muscle unrelated to the inoculation site following Pfizer-BioNTech COVID-19 vaccination on the deltoid muscle of the left shoulder. Coronavirus disease 2019 (COVID-19) pandemic has involved global spread, and different vaccines including inactivated, protein, vectored, and nucleic acid vaccines have been developed and administered. Common side effects of COVID-19 vaccines include general manifestations such as headache, fever, and fatigue, and various musculoskeletal symptoms. Here, we present a case of myositis occurring in the biceps brachii muscle unrelated to the inoculation site, which has not been reported previously, accompanied by a literature review. Level of evidence V

    Diosgenin Induces Apoptosis in HepG2 Cells through Generation of Reactive Oxygen Species and Mitochondrial Pathway

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    Diosgenin, a naturally occurring steroid saponin found abundantly in legumes and yams, is a precursor of various synthetic steroidal drugs. Diosgenin is studied for the mechanism of its action in apoptotic pathway in human hepatocellular carcinoma cells. Based on DAPI staining, diosgenin-treated cells manifested nuclear shrinkage, condensation, and fragmentation. Treatment of HepG2 cells with 40 μM diosgenin resulted in activation of the caspase-3, -8, -9 and cleavage of poly-ADP-ribose polymerase (PARP) and the release of cytochrome c. In the upstream, diosgenin increased the expression of Bax, decreased the expression of Bid and Bcl-2, and augmented the Bax/Bcl-2 ratio. Diosgenin-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of JNK, p38 MAPK and apoptosis signal-regulating kinase (ASK)-1, as well as generation of the ROS. NAC administration, a scavenger of ROS, reversed diosgene-induced cell death. These results suggest that diosgenin-induced apoptosis in HepG2 cells through Bcl-2 protein family-mediated mitochndria/caspase-3-dependent pathway. Also, diosgenin strongly generated ROS and this oxidative stress might induce apoptosis through activation of ASK1, which are critical upstream signals for JNK/p38 MAPK activation in HepG2 cancer cells

    Overhydration measured by bioimpedance analysis and the survival of patients on maintenance hemodialysis: a single-center study

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    AbstractBackgroundBioimpedance analysis (BIA) helps measuring the constituents of the body noninvasively. Prior studies suggest that BIA-guided fluid assessment helps to predict survival in dialysis patients. We aimed to evaluate the clinical usefulness of BIA for predicting the survival rate of hemodialysis patients in Korea.MethodsWe conducted a single-center retrospective study. All patients were diagnosed with end-stage renal disorder and started maintenance hemodialysis between June 2009 and April 2014. BIA was performed within the 1st week from the start of hemodialysis. The patients were classified into 2 groups based on volume status measured by the body composition monitor (BCM; Fresenius): an overhydrated group [OG; overhydration/extracellular water (OH/ECW) >15%] and a nonoverhydrated group (NOG; OH/ECW ≤15%).ResultsA total of 344 patients met the inclusion criteria. Of these, 252 patients (73.3%) were categorized into the OG and 92 patients (26.7%) into the NOG. Age- and sex-matching patients were selected with a rate of 2:1. Finally, 160 overhydrated patients and 80 nonoverhydrated patients were analyzed. Initial levels of hemoglobin and serum albumin were significantly lower in the OG. During follow-up, 43 patients from the OG and 7 patients from the NOG died (median follow-up duration, 24.0 months). The multivariate-adjusted all-cause mortality was significantly increased in the OG (odds ratio, 2.569; P = 0.033) and older patients (odds ratio, 1.072/y; P < 0.001). No significant difference of all-cause or disease-specific admission rate was observed between the 2 groups.ConclusionThe ratio of OH/ECW volume measured with body composition monitor is related to the overall survival of end-stage renal disorder patients who started maintenance hemodialysis

    Development of Formation Flying CubeSats and Operation Systems for the CANYVAL-C Mission: Launch and Lessons Learned

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    The CubeSat Astronomy NASA and Yonsei using Virtual telescope ALignment for Coronagraph (CANYVAL-C) is a technology demonstration mission that shows the concept of a virtual space telescope using two CubeSats in formation flying. The final goal of the mission is to obtain several images of the solar corona during an artificial solar eclipse created by the two CubeSats, Timon (1U CubeSat) and Pumbaa (2U CubeSat). To implement this mission, two CubeSats in formation flying and a ground segment have been developed. The CubeSats were constructed mainly with commercial off the shelf components, sharing the bus architecture. The payload of each CubeSat is a visible camera and an occulter to block the light from the photosphere of the Sun. The occulter is composed of tape measures and a black-colored polyimide film; the system size is smaller than 0.5U (10 × 10 × 5 cm3) while it stowed and enlarged to 0.75 × 0.75 m2 after spreading the film. The 3D-printed propulsion system is smaller than 0.5U and facilitates accurate positioning maneuvers of Pumbaa. The on-board computer has multi-task processing capabilities and a space-saving configuration which is integrated with the GNSS receiver and the UHF transceiver. The core technology for the mission implementation is the precise formation flying guidance, navigation, and control system with a cold-gas propulsion system and an inter-satellite link system. The specification of each CubeSat system was evaluated using numerical simulations and ground testing. To operate CubeSats, the ground segment was constructed with some components, including the UHF ground station (UGS), flight dynamics system (FDS), mission analysis and planning system (MAPS), and spacecraft operation system (SOS). Each component works under the environment of an integrated graphic user interface. In particular, the UGS handles the RF communication, data storage, and instrument control for tracking CubeSats. The FDS processes the navigation data to precisely estimate absolute position and velocity. Then, the MAPS determines the allowable mission schedule and parameter set for implementing maneuvers of each CubeSat. Using the MAPS, feasibility of the mission operation canbe ensured through numerical simulations based on the solutions from the FDS. Finally, the SOS is the interface system between each component, processing telemetry and generating telecommand. The CubeSats were launched on March 22, 2021, by Soyuz-2.1a with a Fregat stage

    Angiographic analysis of the lateral intercostal artery perforator of the posterior intercostal artery: anatomic variation and clinical significance

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    PURPOSEKnowledge of the anatomic variations of the posterior intercostal artery (PICA) and its major branches is important during transthoracic procedures and surgery. We aimed to identify the anatomic features and variations of the lateral intercostal artery perforator (LICAP) of the PICA with selective PICA arteriography.METHODSWe retrospectively evaluated 353 PICAs in 75 patients with selective PICA arteriography for the following characteristics: incidence, length (as number of traversed intercostal spaces), distribution at the hemithorax (medial half vs. lateral half), and size as compared to the collateral intercostal artery of the PICA.RESULTSThe incidence of LICAPs was 35.9% (127/353). LICAPs were most commonly observed in the right 8th–11th intercostal spaces (33%, 42/127) and in the medial half of the hemithorax (85%, 108/127). Most LICAPs were as long as two (35.4%, 45/127) or three intercostal spaces (60.6%, 77/127). Compared to the collateral intercostal artery, 42.5% of LICAPs were larger (54/127), with most of these observed in the right 4th–7th intercostal spaces (48.8%, 22/54).CONCLUSIONWe propose the clinical significance of the LICAP as a potential risk factor for iatrogenic injury during posterior transthoracic intervention and thoracic surgery. For example, skin incisions must be as superficial as possible and directed vertically at the right 4th–7th intercostal spaces and the medial half of the thorax. Awareness of the anatomical variations of the LICAPs of the PICA will allow surgeons and interventional radiologists to avoid iatrogenic arterial injuries during posterior transthoracic procedures and surgery

    Examining the links between burnout and suicidal ideation in diverse occupations

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    IntroductionIt is uncertain whether burnout is associated with suicidal ideation among workers not in health care services. The aim of this study was to identify how burnout and suicidal ideation are linked among employees in various occupations and whether depression affects this link.MethodsThis cross-sectional study collected data from 12,083 participants aged 19–65 years from 25 companies and public institutions who underwent workplace mental health screening. Burnout and depression were assessed using both the Oldenburg Burnout Inventory and the Center for Epidemiologic Studies Depression Scale. Suicidal ideation was assessed by a self-rated questionnaire from the Korea National Health and Nutrition Examination Survey.ResultsExhaustion but not the cynicism dimension of burnout was associated with increased odds of suicidal ideation after adjustment for depression and other covariates (odds ratio [OR] = 1.47, 95% CI = 1.26–1.72). The association of exhaustion with suicidal ideation was significant in both depressed (OR = 1.36, 95% CI = 1.14–1.61) and not depressed (OR = 1.77, 95% CI = 1.13–2.76) participants. In exhausted participants, insufficient job control, an unfavorable occupational climate, low educational level, and depression were associated with increased odds of suicidal ideation.ConclusionExhaustion is linked with risk of suicidal ideation in employees not in health care service, regardless of depression status. Exhausted employees, particularly those having poor job resources, should be recognized as an at-risk group

    Clinical factors affecting progression-free survival with crizotinib in ALK-positive non-small cell lung cancer

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    Background/Aims: Although crizotinib is standard chemotherapy for advanced anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC), clinical factors affecting progression-free survival (PFS) have not been reported. The purpose of this study was to identify clinical factors affecting PFS of crizotinib and develop a prognostic model for advanced ALK-positive NSCLC. Methods: Clinicopathologic features of patients enrolled in PROFILE 1001, 1005, 1007, and 1014 (training cohort) were reviewed. We conducted multivariate Cox analysis for PFS and overall survival (OS) in the training cohort (n = 159) and generated a proportional hazards model based on significant clinicopathologic factors, and then validated the model in an independent validation cohort (n = 40). Results: In the training cohort, the objective response rate was 81.5%. Median PFS and OS from the start of crizotinib were 12.4 and 31.3 months, respectively. Multivariate Cox analysis showed poor performance status, number of metastatic organs (>= 3), and no response to crizotinib independently associated shorter PFS. Based on a score derived from these three factors, median PFS and OS of patients with one or two factors were significantly shorter compared to those without these factors (median PFS, 22.4 months vs. 10.5 months vs. 6.5 months; median OS, not reached vs. 29.1 months vs. 11.8 months, respectively; p < 0.001 for each group). This model also had validated in an independent validation cohort. Conclusions: Performance status, number of metastatic organs, and response to crizotinib affected PFS of crizotinib in ALK-positive NSCLC. Based on these factors, we developed a simple and useful prediction model for PFS.

    PI3K-Akt-Wnt Pathway Is Implicated in Exercise-Induced Improvement of Short-term Memory in Cerebral Palsy Rats

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    Purpose Maternal lipopolysaccharide (LPS) injection induces neurodevelopmental disorders, such as cerebral palsy. Exercise activates phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) signaling pathway that enhances neurogenesis. Wnt ligands are also implicated in the hippocampal neurogenesis and synaptic plasticity. Glycogen synthase kinase-3β (GSK-3β) is a downstream molecule of Akt, and GSK-3β is known to modulate hippocampal neurogenesis negatively. Methods Cerebral palsy was made by maternal LPS-injection. On the 5 weeks after birth, treadmill running was applied to the rat pups of the exercise groups, for 30 minutes, 5 times a week during 6 weeks. Results Treadmill running alleviated short-term memory impairments of the cerebral palsy rat pups. Hippocampal cell proliferation was increased and hippocampal apoptosis was suppressed by treadmill running in the cerebral palsy rat pups. Hippocampal phosphorylated-PI3K/PI3K ratio, phosphorylated-Akt/Akt ratio, and Wnt expression were enhanced by treadmill running in the cerebral palsy rat pups. In contrast, hippocampal phosphorylated-GSK-3β/GSK-3β ratio and β-catenin expression were suppressed by treadmill running in the cerebral palsy rat pups. Conclusions The results of this study showed that short-term memory improvement due to treadmill running in cerebral palsy occurs via activation of the PI3K-Akt-Wnt pathway

    Reconfigurable Si Nanowire Nonvolatile Transistors

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    Reconfigurable transistors merge unipolar p- and n-type characteristics of field-effect transistors into a single programmable device. Combinational circuits have shown benefits in area and power consumption by fine-grain reconfiguration of complete logic blocks at runtime. To complement this volatile programming technology, a proof of concept for individually addressable reconfigurable nonvolatile transistors is presented. A charge-trapping stack is incorporated, and four distinct and stable states in a single device are demonstrated
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