RÉSUMÉ
The formation of an asymmetric junction is key to graphene-based photodetectors of high-sensitive photodetectability, because such a junction can not only facilitate the diffusion or drift of photogenerated carriers but also realize a self-powered operation. Here, a monolayer-multilayer graphene junction photodetector is accomplished by selectively thinning part of a multilayer graphene to a high-quality monolayer. Benefiting from the large photoabsorption cross section of multilayer graphene and strong asymmetry caused by the significant differences in optoelectronic properties between monolayer and multilayer graphene, the monolayer-multilayer graphene junction shows a 7-fold increase in short-circuit photocurrent as compared with that at the monolayer graphene-metal contact in scanning photocurrent images. The asymmetric configuration also enables the photodetector to work at zero bias with minimized dark current noise and stand-by power consumption. Under global illumination with visible light, a photoswitching ratio of 3.4 × 103, a responsivity of 8.8 mA W-1, a specific detectivity of 1.3 × 108Jones and a response time of 11 ns can be obtained, suggesting a promising photoresponse. Moreover, it is worth mentioning that such a performance enhancement is achieved without compromising the broadband spectral response of graphene photodetector and it is hence applicable for long wavelength spectral range including infrared and terahertz.
RÉSUMÉ
The electronic structure and magnetic properties of Li(ZnMn)As with antisite defects have been investigated by using first-principles calculations within the Perdew-Burke-Ernzerhof generalized gradient approximation. The cation antisite defect induced by Zn substitution for As was considered. Mn-3d, As-4p, Zn-4s, and Zn-4p were involved in the formation of d-sp hybrid orbitals, which enhanced the non-localized properties of Mn-3d electrons and provided a channel of Mn(↑)-As(↓)-ZnAs(↓)-Mn(↑) for indirect exchange of electrons between the magnetic ions. The antisite defect of Zn-substituted As belonged to the acceptor doping, rendering the compound p-type characteristics. The existence of the extra free hole carriers regulated the magnetic ordering transition. The ferromagnetic coupling between the Mn magnetic dopants was more favorable in the system with an antisite defect. In this paper, a novel type of dilute magnetic semiconductor with controllable carriers was designed and the mechanism of ferromagnetic coupling was revealed, which provided a theoretical reference for the subsequent studies.
RÉSUMÉ
Due to their atomically ultrathin thickness, the development of high-performance transition-metal dichalcogenides (TMDCs) based photodetectors demands device designs distinct from architectures adopted in conventional bulk semiconductor devices. Here, we demonstrate a field-induced Schottky barrier photodiode with three different TMDC materials, WSe2, MoTe2, and WS2. Owing to the high gate efficiency of a high-κ dielectric film, the Schottky barrier at metal contacts is effectively modulated by external bias, giving rise to a strong diode-like rectifying characteristic with high current on/off ratio. The WSe2 photodiode shows a linear dynamic range of 112 dB, a responsivity of 0.17 A/W, and response time of 8 ns. When this fast WSe2 device is employed for visible light communication data linking, a maximum real-time data transmission rate of 110 Mbps is achieved. Meanwhile, infrared light communication was also realized with a maximum data rate of 30 Mbps using a field-induced MoTe2 Schottky barrier photodiode as a light sensor. This work provides a general CMOS-compatible and controllable fabrication strategy for TMDC-based photodetectors.
RÉSUMÉ
BACKGROUND: The introductions of anti- human epidermal growth factor receptor-2 (HER2) agents have significantly improved the treatment outcome of patients with HER2-positive breast cancer. BAT8001 is a novel antibody-drug conjugate targeting human epidermal growth factor receptor-2 (HER2)-expressing cells composed of a trastuzumab biosimilar linked to the drug-linker Batansine. This dose-escalation, phase I study was designed to assess the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of BAT8001 in patients with HER2-positive locally advanced or metastatic breast cancer. METHODS: This trial was conducted in subjects with histologically confirmed HER2-positive breast cancer (having evaluable lesions and an Eastern Cooperative Oncology Group performance status of 0 or 1) using a 3 + 3 design of escalating BAT8001 doses. Patients received BAT8001 intravenously in a 21-day cycle, with dose escalation in 5 cohorts: 1.2, 2.4, 3.6, 4.8, and 6.0 mg/kg. The primary objective was to evaluate the safety and tolerability of BAT8001. Preliminary activity of BAT8001 was also assessed as a secondary objective. RESULTS: Between March 2017 to May 2018, 29 HER2-positive breast cancer patients were enrolled. The observed dose-limiting toxicities were grade 4 thrombocytopenia and grade 3 elevated transaminase. The maximum tolerated dose was determined to be 3.6 mg/kg. Grade 3 or greater adverse events (AEs) occurred in 14 (48.3%) of 29 patients, including thrombocytopenia in 12 (41.4%) patients, aspartate aminotransferase increased in 4 (13.8%) patients, γ-glutamyl transferase increased in 2 (6.9%) patients, alanine aminotransferase increased in 2 (6.9%) patients, diarrhea in 2 (6.9%) patients. Objective response was observed in 12 (41.4%; 95% confidence interval [CI] = 23.5%-61.1%) and disease control (including patients achieving objective response and stable disease) was observed in 24 (82.8%; 95% CI = 64.2%-94.2%) patients. CONCLUSIONS: BAT8001 demonstrated favorable safety profiles, with promising anti-tumor activity in patients with HER2-positive locally advanced or metastatic breast cancer. BAT8001 has the potential to provide a new therapeutic option in patients with metastatic HER2-positive breast cancer.
Sujet(s)
Tumeurs du sein , Immunoconjugués , Anticorps monoclonaux humanisés/usage thérapeutique , Tumeurs du sein/traitement médicamenteux , Femelle , Humains , Dose maximale tolérée , Trastuzumab/usage thérapeutiqueRÉSUMÉ
OBJECTIVE: To investigate the role and clinical value of radionuclide imaging in hepatic impact injuries in rabbits. METHODS: Rabbits were experimentally impacted on the liver with BIM-IV bio-impact machine. Liver imaging was performed with 99mTc labeled sodium phytate. Liver blood pool imaging was performed with 99mTc-stannous pyrophosphate labeled red blood cells. The results of radionuclide imaging were compared with the anatomic results. RESULTS: There was significant difference between the images of the injured liver and the control. Radio diminution and defect were shown in the injured liver areas. Various sorts of abnormal radioactivity distribution were observed with hepatic blood pool imaging. The results of the liver imaging and liver blood pool imaging were accorded with the results of the anatomic findings. CONCLUSIONS: Radionuclide imaging may well display the changes of hepatocellular structures and functions after injury, which is valuable in locating the concrete injured position and differentiating the injured degrees of liver.