An Experimental Study on the Establishment of Pulmonary Hypertension Model in Rats induced by Monocrotaline

Pulmonary hypertension is called PH for short. It is caused by the pulmonary artery vascular disease leading to pulmonary vascular resistance, and the increase right lung compartment load, which resulting in weakening or even collapse of the right ventricular function. The establishment of rat PH model under the action of monocrotaline is a repeatable, simple and accessible operation technique, which has been widely used in the treatment of pulmonary hypertension. This paper discusses the principle and properties of the PH model on rats under the monocrotaline action

P/D-Serve: Serving Disaggregated Large Language Model at Scale

Serving disaggregated large language models (LLMs) over tens of thousands of xPU devices (GPUs or NPUs) with reliable performance faces multiple challenges. 1) Ignoring the diversity (various prefixes and tidal requests), treating all the prompts in a mixed pool is inadequate. To facilitate the similarity per scenario and minimize the inner mismatch on P/D (prefill and decoding) processing, fine-grained organization is required, dynamically adjusting P/D ratios for better performance. 2) Due to inaccurate estimation on workload (queue status or maintained connections), the global scheduler easily incurs unnecessary timeouts in prefill. 3) Block-fixed device-to-device (D2D) KVCache transfer over cluster-level RDMA (remote direct memory access) fails to achieve desired D2D utilization as expected. To overcome previous problems, this paper proposes an end-to-end system P/D-Serve, complying with the paradigm of MLOps (machine learning operations), which models end-to-end (E2E) P/D performance and enables: 1) fine-grained P/D organization, mapping the service with RoCE (RDMA over converged ethernet) as needed, to facilitate similar processing and dynamic adjustments on P/D ratios; 2) on-demand forwarding upon rejections for idle prefill, decoupling the scheduler from regular inaccurate reports and local queues, to avoid timeouts in prefill; and 3) efficient KVCache transfer via optimized D2D access. P/D-Serve is implemented upon Ascend and MindSpore, has been deployed over tens of thousands of NPUs for more than eight months in commercial use, and further achieves 60\%, 42\% and 46\% improvements on E2E throughput, time-to-first-token (TTFT) SLO (service level objective) and D2D transfer time. As the E2E system with optimizations, P/D-Serve achieves 6.7x increase on throughput, compared with aggregated LLMs

Manipulating mid-infrared wavefront through reflective Ge₃Sb₂Te₆ metasurfaces

Abstract Due to the increasing complexity of modern communication systems, the requirements for electromagnetic wave are becoming more and more rigorous. Traditional natural materials are not easy to integrate into tunable systems. Metasurface is a two-dimensional array, and it has a more significant advantage in electromagnetic control and attracts great attention. Here, Ge3Sb2Te6-based metasurfaces are presented to control electromagnetic wavefront by changing the state of Ge3Sb2Te6 in the mid-infrared range. Eight meta-atoms are designed to form linear phase distribution with phase difference of 45° at 74 THz. When Ge3Sb2Te6 is in the amorphous state, the designed meta-atoms have low loss and high reflection. Ge3Sb2Te6 block is designed into a specific structure in a certain way, which realizes deflection of electromagnetic wavefront and vortex beam with orbital angular momentum l = 1 or l = 2. By means of convolution, anomalous reflection is combined with orbital angular momentum to form an anomalously deflected vortex beam. When the state of Ge3Sb2Te6 is crystalline, amplitudes of meta-atoms decrease and linear phase distribution is destroyed. Reflected wave becomes almost mirror reflection wave. Our design may open a pathway to novel types of metasurfaces.</jats:p

Terahertz bifunctional absorber based on a graphene-spacer-vanadium dioxide-spacer-metal configuration

A terahertz bifunctional absorber is presented with broadband and narrowband absorbing properties in a graphene-spacer-vanadium dioxide-spacer-metal configuration. Carrier relaxation time of graphene τ = 1.0ps (τ = 0.1ps) is chosen for narrowband (broadband) absorption. When vanadium dioxide is in the conducting state, the design behaves as a narrowband absorber, and it is composed of a square-shaped graphene, topas spacer, and metallic vanadium dioxide film. There is an absorption band with 100% absorptance at the frequency of 1.37 THz. Narrowband absorption is caused by the localized magnetic resonance. When vanadium dioxide is in the insulating state, the design behaves as a broadband absorber composed of a square-shaped graphene, topas layer, vanadium dioxide film, and metal film. It has a broadband absorption in the frequency range of 1.05-2.35 THz, and the corresponding absorptance is more than 90%. The merging of two resonances with overlapping region ensures broadband performance of the designed absorber. The working bandwidth and intensity of narrowband absorption and broadband absorption can be dynamically adjusted by changing the Fermi energy level of graphene. The influences of structure parameters are discussed on absorption performance. In addition, the designed absorber is not sensitive to incident angle. Because of the simple structure, our design can be applied to many promising fields in intelligent absorption and terahertz switch.</jats:p