3,891 research outputs found
Effect of halide-mixing on the switching behaviors of organic-inorganic hybrid perovskite memory
Mixed halide perovskite materials are actively researched for solar cells with high efficiency. Their hysteresis which originates from the movement of defects make perovskite a candidate for resistive switching memory devices. We demonstrate the resistive switching device based on mixed-halide organic-inorganic hybrid perovskite CH3NH3PbI3−xBrx (x = 0, 1, 2, 3). Solvent engineering is used to deposit the homogeneous CH3NH3PbI3−xBrx layer on the indium-tin oxide-coated glass substrates. The memory device based on CH3NH3PbI3−xBrx exhibits write endurance and long retention, which indicate reproducible and reliable memory properties. According to the increase in Br contents in CH3NH3PbI3−xBrx the set electric field required to make the device from low resistance state to high resistance state decreases. This result is in accord with the theoretical calculation of migration barriers, that is the barrier to ionic migration in perovskites is found to be lower for Br− (0.23 eV) than for I− (0.29–0.30 eV). The resistive switching may be the result of halide vacancy defects and formation of conductive filaments under electric field in the mixed perovskite layer. It is observed that enhancement in operating voltage can be achieved by controlling the halide contents in the film.1119Ysciescopu
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Phase I clinical trial of the Src inhibitor dasatinib with dacarbazine in metastatic melanoma.
BackgroundSrc inhibitors sensitise melanoma cells to chemotherapy in preclinical models. The combination of dasatinib and dacarbazine was tested in a phase I trial in melanoma.MethodsPatients had ECOG performance status 0-2 and normal organ function. Dacarbazine was administered on day 1 and dasatinib on day 2 through 19 of each 21-day cycle. Both were escalated from 50 mg b.i.d. of dasatinib and 800 mg m(-2) of dacarbazine. Available pre-treatment biopsies were sequenced for BRAF, NRAS, and C-Kit mutations.ResultsDose-limiting toxicity was reached at dasatinib 70 mg b.i.d./dacarbazine 1000 mg m(-2), and was predominantly haematological. In 29 patients receiving dasatinib 70 mg b.i.d., the objective response rate (ORR) was 13.8%, the clinical benefit rate (ORR+SD) was 72.4%, the 6-month progression-free survival (PFS) was 20.7%, and the 12-month overall survival (OS) was 34.5%. Two out of three patients who were wild type for BRAF, NRAS, and c-KIT mutations had confirmed partial responses, and one had a minor response.ConclusionThe recommended phase II dose is dasatinib 70 mg b.i.d with dacarbazine 800 mg m(-2). PFS and OS data for dasatinib at 70 mg b.i.d. with dacarbazine compared favourably with historical controls. Preliminary data support evaluating tumour mutation status further as a biomarker of response
Complete nucleotide sequence and organization of the mitogenome of endangered Eumenis autonoe (Lepidoptera: Nymphalidae)
Eumenis autonoe, a member of the lepidopteran family, Nymphalidae (superfamily Papilionoidea) is an endangered species and is found only on one isolated remote island Jeju in South Korea, on Halla Mt, at altitudes higher than 1,400 m. In this study, the complete mitochondrial genome (mitogenome) of E. autonoe was reported. The 15,489-bp long E. autonoe genome evidenced the typical gene content found in animal mitogenomes, and harbors the gene arrangement identical to all other sequencedlepidopteran insects, which differs from the most common type found in insects, due to the movement of tRNAMet to a position 5’-upstream of tRNAIle. As has been observed in many other lepidopteran insects, no typical ATN codon for the COI gene is available. Thus, we also designated the CGA (arginine) found at the beginning of the COI gene as a lepidopteran COI starter, in accordance with previous suggestions. The 678 bp long A + T-rich region, which is second longest in sequencedlepidopteran insects, harbored 10 identical 27 bp long tandem repeats plus one 13 - bp long incomplete final repeat. Such a repeat sequence has been, thus far, only rarely detected in lepidopteran mitogenomes. The E. autonoe A + T-rich region harbored a poly-T stretch of 19 bp and a conserved ATAGA motif located at the end of the region, which have been suggested to function as structural signals for minor-strand mtDNA replication. Phylogenetic reconstruction using the concatenated 13amino acid and nucleotide sequences of the protein-coding genes (PCGs) consistently supported a close relationship between Bombycoidea and Geometroidea among six available lepidopteran superfamilies (Tortricoidea, Pyraloidea, Papilionoidea, Bombycoidea, Geometroidea and Noctuoidea). Among the true butterflies (Pieridae, Nymphalidae, Lycaenidae and Papilionidae), a closer relationship between Lycaenidae and Pieridae, excluding Nymphalidae was consistently concluded to exist,although this result deviated from the traditional view
Asymmetric interlimb transfer of concurrent adaptation to opposing dynamic forces
Interlimb transfer of a novel dynamic force has been well documented. It has also been shown that unimanual adaptation to opposing novel environments is possible if they are associated with different workspaces. The main aim of this study was to test if adaptation to opposing velocity dependent viscous forces with one arm could improve the initial performance of the other arm. The study also examined whether this interlimb transfer occurred across an extrinsic, spatial, coordinative system or an intrinsic, joint based, coordinative system. Subjects initially adapted to opposing viscous forces separated by target location. Our measure of performance was the correlation between the speed profiles of each movement within a force condition and an ‘average’ trajectory within null force conditions. Adaptation to the opposing forces was seen during initial acquisition with a significantly improved coefficient in epoch eight compared to epoch one. We then tested interlimb transfer from the dominant to non-dominant arm (D → ND) and vice-versa (ND → D) across either an extrinsic or intrinsic coordinative system. Interlimb transfer was only seen from the dominant to the non-dominant limb across an intrinsic coordinative system. These results support previous studies involving adaptation to a single dynamic force but also indicate that interlimb transfer of multiple opposing states is possible. This suggests that the information available at the level of representation allowing interlimb transfer can be more intricate than a general movement goal or a single perceived directional error
Computer Assisted Planning for Curved Laser Interstitial Thermal Therapy
IEEE Laser interstitial thermal therapy (LiTT) is a minimally invasive alternative to conventional open surgery for drug-resistant focal mesial temporal lobe epilepsy (MTLE). Recent studies suggest that higher seizure freedom rates are correlated with maximal ablation of the mesial hippocampal head, whilst sparing of the parahippocampal gyrus (PHG) may reduce neuropsychological sequelae. Current commercially available laser catheters are inserted following manually planned straight-line trajectories, which cannot conform to curved brain structures, such as the hippocampus, without causing collateral damage or requiring multiple insertions. The clinical feasibility and potential of curved LiTT trajectories through steerable needles has yet to be investigated. This is the focus of our work. We propose a GPU-accelerated computer-assisted planning (CAP) algorithm for steerable needle insertions that generates optimized curved 3D trajectories with maximal ablation of the amygdalohippocampal complex and minimal collateral damage to nearby structures, while accounting for a variable ablation diameter (). Simulated trajectories and ablations were performed on 5 patients with mesial temporal sclerosis (MTS), which were identified from a prospectively managed database. The algorithm generated obstacle-free paths with significantly greater target area ablation coverage and lower PHG ablation variance compared to straight line trajectories. The presented CAP algorithm returns increased ablation of the amygdalohippocampal complex, with lower patient risk scores compared to straight-line trajectories. This is the first clinical application of preoperative planning for steerable needle based LiTT. This study suggests that steerable needles have the potential to improve LiTT procedure efficacy whilst improving the safety and should thus be investigated further
Crystal Structure of the Rad3/XPD regulatory domain of Ssl1/p44
The Ssl1/p44 subunit is a core component of the yeast/mammalian general transcription factor TFIIH, which is involved in transcription and DNA repair. Ssl1/p44 binds to and stimulates the Rad3/XPD helicase activity of TFIIH. To understand the helicase stimulatory mechanism of Ssl1/p44, we determined the crystal structure of the N-terminal regulatory domain of Ssl1 from Saccharomyces cerevisiae. Ssl1 forms a von Willebrand factor A fold in which a central six-stranded beta-sheet is sandwiched between three alpha helices on both sides. Structural and biochemical analyses of Ssl1/p44 revealed that the beta 4-alpha 5 loop, which is frequently found at the interface between von Willebrand factor A family proteins and cellular counterparts, is critical for the stimulation of Rad3/XPD. Yeast genetics analyses showed that double mutation of Leu-239 and Ser-240 in the beta 4-alpha 5 loop of Ssl1 leads to lethality of a yeast strain, demonstrating the importance of the Rad3-Ssl1 interactions to cell viability. Here, we provide a structural model for the Rad3/XPD-Ssl1/p44 complex and insights into how the binding of Ssl1/p44 contributes to the helicase activity of Rad3/XPD and cell viability.X1165Ysciescopu
PGC-Enriched miRNAs Control Germ Cell Development
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