Importance Gastric and gastroesophageal junction cancers are diagnosed in more than 1 million people worldwide annually, and few effective treatments are available. Sintilimab, a recombinant human IgG4 monoclonal antibody that binds to programmed cell death 1 (PD-1), in combination with chemotherapy, has demonstrated promising efficacy. Objective To compare overall survival of patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction cancers who were treated with sintilimab with chemotherapy vs placebo with chemotherapy. Also compared were a subset of patients with a PD ligand 1 (PD-L1) combined positive score (CPS) of 5 or more (range, 1-100). Design, Setting, and Participants Randomized, double-blind, placebo-controlled, phase 3 clinical trial conducted at 62 hospitals in China that enrolled 650 patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma between January 3, 2019, and August 5, 2020. Final follow-up occurred on June 20, 2021. Interventions Patients were randomized 1:1 to either sintilimab (n = 327) or placebo (n = 323) combined with capecitabine and oxaliplatin (the XELOX regimen) every 3 weeks for a maximum of 6 cycles. Maintenance therapy with sintilimab or placebo plus capecitabine continued for up to 2 years. Main Outcomes and Measures The primary end point was overall survival time from randomization. Results Of the 650 patients (mean age, 59 years; 483 [74.3%] men), 327 were randomized to sintilimab plus chemotherapy and 323 to placebo plus chemotherapy. Among the randomized patients, 397 (61.1%) had tumors with a PD-L1 CPS of 5 or more; 563 (86.6%) discontinued study treatment and 388 (59.7%) died; 1 patient (<0.1%) was lost to follow-up. Among all randomized patients, sintilimab improved overall survival compared with placebo (median, 15.2 vs 12.3 months; stratified hazard ratio [HR], 0.77 [95% CI, 0.63-0.94]; P = .009). Among patients with a CPS of 5 or more, sintilimab improved overall survival compared with placebo (median, 18.4 vs 12.9 months; HR, 0.66 [95% CI, 0.50-0.86]; P = .002). The most common grade 3 or higher treatment-related adverse events were decreased platelet count (sintilimab, 24.7% vs placebo, 21.3%), decreased neutrophil count (sintilimab, 20.1% vs placebo, 18.8%), and anemia (sintilimab, 12.5% vs placebo, 8.8%). Conclusions and Relevance Among patients with unresectable locally advanced or metastatic gastric and gastroesophageal junction adenocarcinoma treated with first-line chemotherapy, sintilimab significantly improved overall survival for all patients and for patients with a CPS of 5 or more compared with placebo. Trial Registration ClinicalTrials.gov Identifier: NCT03745170
We demonstrated a Si-based photoelectric detector with silicon-on-insulator structure. The Si-based detector was successfully fabricated and showed broadband response from 20–40 GHz to 0.165–0.173 THz radiation at room temperature. It achieved a maximal responsivity of 49.3 kV W−1 and noise equivalent power (NEP) of 0.38 at 20–40 GHz, and achieved a responsivity of 3.3 kV W−1 and NEP of 5.7 at 0.165–0.173 THz; moreover, a short response time ∼810 ns was realized for the detector. The simple structure, excellent performance and easy integration of the detectors, which provides an avenue to the optoelectronic integration of sensitive room-temperature terahertz focal-plane arrays.
Mn-Co-Ni-O (MCNO) flexible thermistors are fabricated on polyethylene terephthalate or polyimide sheets by RF magnetron sputtering method at room temperature. The whole fabricating processes is completed at room temperature. The temperature coefficient of resistance (TCR) is -3.1% and resistivity as low as 110Ωcm at 295K. The bendingstraightening cycle test indicates the flexible MCNO sheet is stable. The temperature sensing test shows the thermistors respond to temperature change rapidly and sensitively. Due to the heat-treat free process, high TCR and moderate resistivity features, the technique we provide here allows a convenient and low cost industrial manufacture of high performance flexible thermistors and wide band infrared detectors.
Using infrared spectroscopic ellipsometry (IRSE), the infrared optical properties of LaNiO3 thin films with different film thicknesses on Pt/Ti/SiO2/Si substrates prepared by a modified metal-organic deposition technique have been investigated in the wavelength range of 2.5–12.6 µm. By fitting the measured ellipsometric parameter (Ψ and Δ) data with a three-phase model (Air/LaNiO3/Pt) and the classical Drude dispersion relation for the LaNiO3 thin films, the optical constants and thicknesses of the films have been obtained. The infrared optical constants (refractive index n and extinction coefficient κ) of the LaNiO3 films decrease with increasing thickness in the measured wavelength range. It is closely associated with the crystallinity of the thin films, the crystalline size effect and the influence of the interface layer. An obvious break has been observed between the 49.2-nm thick film and the 70.2-nm thick film for the infrared optical constants. LaNiO3 has a relative large absorption coefficient and the absorption coefficient monotonously decreases with increasing thickness in the entirely measured wavelength range.
Terahertz technologies are of great significance in a wide range of applications, such as astronomy, medicine, communications and nondestructive material characterization. However, the energy of terahertz photons is so small that it is difficult to detect directly at room temperature. Two-dimensional (2D) materials with excellent optoelectronic properties provide opportunities for the development of terahertz photodetectors. Herein, we develop a high-performance terahertz photodetector with a metal–semiconductor–metal structure via a Ta2NiSe5 nanosheet. The photodetector shows an excellent responsivity of 1350 A W–1 and an extremely low noise equivalent power of 0.01 pW Hz–0.5 with a fast response of ∼550 ns at room temperature. Electromagnetic induced well theory is utilized to explain the highly sensitive terahertz photoelectric response. In addition, long-term stability over 6 months is realized for the detector. The terahertz imaging experiments demonstrate the excellent performance of the detector and potential applications. The results suggest that our strategy can be a strong candidate for high-performance terahertz photodetection systems.
Photogenerated carrier relaxation process and terahertz conductivity of Cd<sub>0.96</sub>Zn<sub>0.04</sub>Te are investigated by optical pump-terahertz probe spectroscopy at room temperature. With photoexcitation at 800 nm, the photogenerated carrier recovery process can be fitted with a single exponential curve, and its recovery time lasts several nanoseconds, which decreases with the increase of photogenerated carrier densities in a certain range of photogenerated carrier densities, relating to the radiative recombination of electron-hole pairs. The transient transmittance change of terahertz pulse remains the same with the photogenerated carrier densities increasing from 4.51×10<sup>16</sup> cm<sup>–3</sup> to 1.81×10<sup>17</sup> cm<sup>–3</sup>, which is because the number of loss carriers by defect trapping is approximate to the augment of carriers by photoexcitation. As the photogenerated carrier density increases from 1.81×10<sup>17</sup> cm<sup>–3</sup> to 1.44×10<sup>18</sup> cm<sup>–3</sup>, the magnitude of photoinduced absorption increases linearly with the increase of photogenerated carrier density due to the fact that most of the defects are occupied. When the photogenerated carrier densities are higher than 1.44×10<sup>18</sup> cm<sup>–3</sup>, the magnitude of photoinduced absorption remains almost the same, because the absorption of 800 nm pump pulse reaches a saturation level. The evolution of complex conductivity with photogenerated carrier density in a delay time of about 50 ps can be well fitted with Drude-Smith model. Our analysis provides an important data support and theoretical basis for designing and fabricating of Cd<sub>1–<i>x</i></sub>Zn<sub><i>x</i></sub>Te detection.
Due to the huge number of users, Sina Weibo is an ideal platform of eWOM. Also, the enterprise aims to spread the product to its target customers through the way of improving the customers’ purchase intentions. This research aims to explore the drivers of purchase intentions from the aspect of eWOM behavior among Generation Y in Sina Weibo. It examines the relations among customer experience, social relationships, eWOM behavior and purchase intentions.
ZnO:Al (AZO) films have potential applications in ultraviolet detecting devices. The structural and optical properties of the AZO films are presented. Highly c axis oriented wurtzite phase AZO films are prepared on quartz substrate by rf sputtering method. The optical constants and the thickness of the AZO films are determined by fitting the measured transmission spectra with Tauc-Lorentz (TL) model. The refractive index n increases as the photon energy increases, and reaches the maximum of 2.50 at 3.66 eV, beyond which the refractive index n decreases with further increasing of photon energy. The peak of the refractive index n corresponds to the optical band gap of the AZO films, which is associated with interband transition between the valence and conduction bands. The extinction coefficient k also increases with the enhancement of the photon energy, and a strong absorption peak with maximum of 1.10 is prominent. The absorption peak due to an electronic transition accords with the peak transition energy E0 (3.79 eV) is obtained by TL model. The energy E0 of this model corresponds to the Penn gap, where the strong absorption of the material took place. By fitting the absorption coefficient, the optical band gap 3.62 eV of the film is evaluated. Based on the Tauc's power law, the optical band gap of the films is proved as a direct interband transition between the valence and conduction bands. This enhanced band gap compared with ZnO (3.37 eV) correlates to the Burstein-Moss band filling effect due to Al doping.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)