Realization of a 4 kHz, large energy single-frequency ns optical parametric oscillator by suppressing optical parametric generation.

Large energy single-frequency nanosecond (ns) near-infrared light source is an essential device in the field of the remote chemical analysis based on the laser-induced breakdown spectroscopy (LIBS). In this paper, a large energy single-frequency ns 824 nm light source with high repetition rate is presented, which is generated from a seed-injection locked optical parametric oscillator (OPO). By optimizing the spot radius of the pump laser and the mode-matching between the pump laser and signal light, the optical parametric generation (OPG) process is effectively eliminated.

Hemodynamic investigations on the portal hypertension and treatment of transjugular intrahepatic portosystemic shunt (TIPS) based on CFD simulation.

Hemodynamic processes from the portal vein(PV) to the inferior vena cava(IVC) were mimicked for three patients with portal hypertension(PH) and the effects of stent parameters on the outcomes of transjugular intrahepatic portosystemic shunt(TIPS) were investigated through computational fluid dynamics(CFD). The liver region was simulated with porous media model and the spatial distributions of superior mesenteric vein(SMV) and splenic vein(SV) blood were solved through the Eulerian multiphase model. The present method is able to simulate the PH flow and predict the PV pressure, the stent shunt rate and the SMV blood proportion after TIPS treatment.

Flow chemistry-enabled asymmetric synthesis of cyproterone acetate in a chemo-biocatalytic approach.

Flow chemistry has many advantages over batch synthesis of organic small-molecules in terms of environmental compatibility, safety and synthetic efficiency when scale-up is considered. Herein, we report the 10-step chemo-biocatalytic continuous flow asymmetric synthesis of cyproterone acetate (4) in which 10 transformations are combined into a telescoped flow linear sequence from commercially available 4-androstene-3, 17-dione (11). This integrated one-flow synthesis features an engineered 3-ketosteroid-Δ-dehydrogenase (ReM2)-catalyzed Δ-dehydrogenation to form the C1, C2-double bond of A ring, a substrate-controlled Co-catalyzed Mukaiyama hydration of 9 to forge the crucial chiral C17α-OH group of D ring with excellent stereoselectivity, and a rapid flow Corey-Chaykovsky cyclopropanation of 7 to build the cyclopropyl core of A ring.

A facile combined therapy of chemotherapeutic agent and microRNA for hepatocellular carcinoma using non-cationic nanogel.

High drug resistance remains a challenge for chemotherapy against hepatocellular carcinoma (HCC). Combining chemotherapeutic agents with microRNA (miRNA), which simultaneously regulates multiple pathways, offers a promising approach to improve therapeutic efficacy against HCC. Although cationic amphiphilic copolymers have been used to co-deliver these agents, their effectiveness is often limited by low co-encapsulation efficiency and inherent cationic toxicity.

Cross-Domain Person Re-Identification Based on Multi-Branch Pose-Guided Occlusion Generation.

Aiming at the problems caused by a lack of feature matching due to occlusion and fixed model parameters in cross-domain person re-identification, a method based on multi-branch pose-guided occlusion generation is proposed. This method can effectively improve the accuracy of person matching and enable identity matching even when pedestrian features are misaligned. Firstly, a novel pose-guided occlusion generation module is designed to enhance the model's ability to extract discriminative features from non-occluded areas.