55 research outputs found
All-fiber normal-dispersion single-polarization passively mode-locked laser based on a 45°-tilted fiber grating
An all-fiber normal-dispersion Yb-doped fiber laser with 45- tilted fiber grating (TFG) isto the best of our knowledgeexperimentally demonstrated for the first time. Stable linearly-chirped pulses with the duration of 4 ps and the bandwidth of 9 nm can be directly generated from the laser cavity. By employing the 45 TFG with the polarization-dependent loss of 33 dBoutput pulses with high polarization extinction ratio of 26 dB are implemented in the experiment. Our result shows that the 45 TFG can work effectively as a polarizerwhich could be exploited to singlepolarization all-fiber lasers
Perpendicular magnetic anisotropy, tunneling magnetoresistance and spin-transfer torque effect in magnetic tunnel junctions with Nb layers
Nb and its compounds are widely used in quantum computing due to their high
superconducting transition temperatures and high critical fields. Devices that
combine superconducting performance and spintronic non-volatility could deliver
unique functionality. Here we report the study of magnetic tunnel junctions
with Nb as the heavy metal layers. An interfacial perpendicular magnetic
anisotropy energy density of 1.85 mJ/m2 was obtained in Nb/CoFeB/MgO
heterostructures. The tunneling magnetoresistance was evaluated in junctions
with different thickness combinations and different annealing conditions. An
optimized magnetoresistance of 120% was obtained at room temperature, with a
damping parameter of 0.011 determined by ferromagnetic resonance. In addition,
spin-transfer torque switching has also been successfully observed in these
junctions with a quasistatic switching current density of 7.3*10^5 A/cm2
PGK1 is a Potential Survival Biomarker and Invasion Promoter by Regulating the HIF-1α–Mediated Epithelial-Mesenchymal Transition Process in Breast Cancer
Background/Aims: Glycolysis, a multi-step enzymatic reaction, is considered to be the root of cancer development and progression. The aim of this study is to figure out which glycolysis enzyme participates in the progression of breast cancer and its possible mechanisms. Materials: We firstly screened out PGK1 by performing an RT-PCR array of glycolysis-related genes in three paired breast cancer samples, and further investigated PGK1 using TCGA and our own database. The effect and mechanism of PGK1 on cell invasion was further explored both in vitro and using patient samples. Results: PGK1 was most upregulated in T3N0 with distant metastases compared to those with no metastases. In the TCGA database, high PGK1 expression predicted poor overall survival (OS) in breast cancer and some other cancers (P< 0.001). In the validation cohort, high PGK1 expression was significantly correlated with larger tumor size (P=0.011) and advanced TNM stage (P=0.033), and PGK1 expression was an independent prognostic factor for OS and disease free survival (DFS) in both univariate and multivariate regression analyses (P< 0.05). Functional studies indicated that knockdown of PGK1 expression significantly inhibited invasion and reversed the epithelial-mesenchymal transition process in breast cancer cells (P< 0.05). Mechanistically, PGK1 increased HRE luciferase activity in a dose-dependent manner, while silencing PGK1 expression decreased HRE activity. Conclusion: High PGK1 expression was associated with poor prognosis in breast cancer, because PGK1 and HIF-1α formed a positive feed-forward loop and thus stimulated breast cancer progression and metastases. Based on these results, PGK1 may serve as a promising biomarker and target therapy for breast cancer
Dissection of Pleiotropic QTL Regions Controlling Wheat Spike Characteristics Under Different Nitrogen Treatments Using Traditional and Conditional QTL Mapping
Optimal spike characteristics are critical in improving the sink capacity and yield potential of wheat even in harsh environments. However, the genetic basis of their response to nitrogen deficiency is still unclear. In this study, quantitative trait loci (QTL) for six spike-related traits, including heading date (HD), spike length (SL), spikelet number (SN), spike compactness (SC), fertile spikelet number (FSN), and sterile spikelet number (SSN), were detected under two different nitrogen (N) supplies, based on a high-density genetic linkage map constructed by PCR markers, DArTs, and Affymetrix Wheat 660 K SNP chips. A total of 157 traditional QTLand 54 conditional loci were detected by inclusive composite interval mapping, among which three completely low N-stress induced QTL for SN and FSN (qSn-1A.1, qFsn-1B, and qFsn-7D) were found to maintain the desired spikelet fertility and kernel numbers even under N deficiency through pyramiding elite alleles. Twenty-eight stable QTL showing significant differencet in QTL detection model were found and seven genomic regions (R2D, R4A, R4B, R5A, R7A, R7B, and R7D) clustered by these stable QTL were highlighted. Among them, the effect of R4B on controlling spike characteristics might be contributed from Rht-B1. R7A harboring three major stable QTL (qSn-7A.2, qSc-7A, and qFsn-7A.3) might be one of the valuable candidate regions for further genetic improvement. In addition, the R7A was found to show syntenic with R7B, indicating the possibly exsting homoeologous candidate genes in both regions. The SNP markers involved with the above highlighted regions will eventually facilitate positional cloning or marker-assisted selection for the optimal spike characteristics under various N input conditions
QTL Detection for Kernel Size and Weight in Bread Wheat (Triticum aestivum L.) Using a High-Density SNP and SSR-Based Linkage Map
High-density genetic linkage maps are essential for precise mapping quantitative trait loci (QTL) in wheat (Triticum aestivum L.). In this study, a high-density genetic linkage map consisted of 6312 SNP and SSR markers was developed to identify QTL controlling kernel size and weight, based on a recombinant inbred line (RIL) population derived from the cross of Shixin828 and Kenong2007. Seventy-eight putative QTL for kernel length (KL), kernel width (KW), kernel diameter ratio (KDR), and thousand kernel weight (TKW) were detected over eight environments by inclusive composite interval mapping (ICIM). Of these, six stable QTL were identified in more than four environments, including two for KL (qKL-2D and qKL-6B.2), one for KW (qKW-2D.1), one for KDR (qKDR-2D.1) and two for TKW (qTKW-5A and qTKW-5B.2). Unconditional and multivariable conditional QTL mapping for TKW with respect to TKW component (TKWC) revealed that kernel dimensions played an important role in regulating the kernel weight. Seven QTL-rich genetic regions including seventeen QTL were found on chromosomes 1A (2), 2D, 3A, 4B and 5B (2) exhibiting pleiotropic effects. In particular, clusters on chromosomes 2D and 5B possessing significant QTL for kernel-related traits were highlighted. Markers tightly linked to these QTL or clusters will eventually facilitate further studies for fine mapping, candidate gene discovery and marker-assisted selection (MAS) in wheat breeding
Etude et amélioration de capteurs monolithiques actifs à pixels résistants aux rayonnements pour reconstruire la trajectoire des particules chargées
Les capteurs monolithiques actifs à pixels (Monolithic Active Pixel Sensors, MAPS) sont de bons candidats pour être utilisés dans des expériences en Physique des Hautes Énergies (PHE) pour la détection des particules chargées. Dans les applications en PHE, des puces MAPS sont placées dans le voisinage immédiat du point d interaction et sont directement exposées au rayonnement intense de leur environnement. Dans cette thèse, nous avons étudié et amélioré la résistance aux radiations des MAPS. Les effets principaux de l irradiation et le progrès de la recherche sur les MAPS sont étudiés tout d'abord. Nous avons constaté que les cœurs des SRAM IP incorporées dans la puce MAPS limitent sensiblement la tolérance aux radiations de la puce MAPS entière. Aussi, pour améliorer la radiorésistance des MAPS, trois mémoires radiorésistantes sont conçues et évaluées pour les expériences en PHE. Pour remplacer les cœurs des IP SRAM, une SRAM radiorésistante est développée sur une petite surface. Pour les procédés de plus petit taille de grille des transistors, dans lequel les effets SEU (Single Event Upset) deviennent significatifs, une SRAM radiorésistante avec une tolérance SEU accrue est réalisée à l aide d un algorithme de détection et de correction d'erreurs (Error Detection And Correction, EDAC) et un stockage entrelacé des bits. Afin d'obtenir une tolérance aux rayonnements et une densité de micro-circuits plus élevées, une mémoire à double accès avec une cellule à 2 transistors originale est développée et évaluée pour des puces MAPS futures. Enfin, la radiorésistance des puces MAPS avec des nouveaux procédés disponibles est étudiée, et les travaux futurs sont proposés.Monolithic Active Pixel Sensors (MAPS) are good candidates to be used in High Energy Physics (HEP) experiments for charged particle detection. In the HEP applications, MAPS chips are placed very close to the interaction point and are directly exposed to harsh environmental radiation. This thesis focuses on the study and improvement of the MAPS radiation hardness. The main radiation effects and the research progress of MAPS are studied firstly. During the study, the SRAM IP cores built in MAPS are found limiting the radiation hardness of the whole MAPS chips. Consequently, in order to improve the radiation hardness of MAPS, three radiation hard memories are designed and evaluated for the HEP experiments. In order to replace the SRAM IP cores, a radiation hard SRAM is developed on a very limited area. For smaller feature size processes, in which the single event upset (SEU) effects get significant, a radiation hard SRAM with enhanced SEU tolerance is implemented by an error detection and correction algorithm and a bit-interleaving storage. In order to obtain higher radiation tolerance and higher circuitry density, a dual-port memory with an original 2-transistor cell is developed and evaluated for future MAPS chips. Finally, the radiation hardness of the MAPS chips using new available processes is studied, and the future works are prospected.STRASBOURG-Bib.electronique 063 (674829902) / SudocSudocFranceF
Genetic diversity in accessions of wild rice Oryza granulata from South and Southeast Asia
Controlled micro-wrinkling of ultrathin indium-tin-oxide films for transparency tuning
Smart windows can electrically switch between clear and opaque states. Current smart windows based on polymer dispersed liquid crystal are expensive and they have moderate range of transparency tuning. Elastomeric tunable window devices are being researched as the low-cost alternates. They consist of a transparent elastomer substrate with surface electrodes that provide electrically controlled micro-wrinkling. They diffusely scatter the transmitted light and thus appear opaque when the surfaces are micro-wrinkled. On electrical activation the wrinkles are flattened, thus making the windows transparent like window blinds. However, the initial prototypes of these electrically tunable window devices showed limited transparency tuning because their transparent electrodes cannot be completely flattened. For example, the brownish e-beam evaporated indium-tin-oxide thin films (50 nm thick) remains mildly wrinkled (with 52.08% transmittance) even when subjected to 37% areal expansion, while its opaque state allows 39.14% transmittance. There is a need for more transparent thin-film electrode with better controllability of surface micro-wrinkling. This work reports a greatly improved tunable window device with enlarged range of transmittance tuning: a clear state of 71.5% transmittance and an opaque state of 2% transmittance. This new device made use of ultra-thin (6 nm) ITO thin films as the transparent compliant electrodes, which were initially wrinkled and can be flatten by 12.2% voltage-induced areal expansion. These ultra-thin ITO thin films are clearer with fewer thermally-induced wrinkles on the flat elastomer substrate (VHB 4905) as they were deposited at a lower surface growth temperature using the RF magnetron sputtering technique. In addition, they make compliant electrodes of higher electrical conductivity and can electrically unfold the mechanically induced micro-wrinkles by a small voltage-induced areal expansion (~12.2%). With the greatly enhanced performance, this electrically tunable window device is promising approach for low-cost smart windows.Published versio
Complex Self-Assembly of Hyperbranched Polyamidoamine/Linear Polyacrylic Acid in Water and Their Functionalization
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