Small vessel disease (SVD) is responsible for brain chronic circular disorder, and accounts for 20%-30% cases of ischemic stroke as well as cerebral hemorrhage, and to a great extent, encephalopathy. Binswanger's disease and multiple small strokes, which are common in older people, are also closely associated with SVD. These disorders often cause decline in cognition, vascular dementia, impairment in gait and balance, mood depression, and urinary incontinence, and often brings great social and economic burdens. SVD-related encephalopathy increases the incidences of fall, disability and death in elderly people. With the aging of the society, more attention should be paid to the importance of early diagnosis and prophylactic treatment of SVD. Here the clinical manifestations and pathophysiology of SVD are reviewed.
The versatility of carbon in forming the hybridization states allows one to design more carbon allotropes with various fascinating properties by replacing some aromatic bonds with acetylenic linkages. We investigate thermal conductivities of carbon allotrope sheets with different configurations by nonequilibrium molecular dynamic simulations. It is found that the acetylenic linkages not only considerably reduce thermal conductivity but also can effectively tune thermal conductivity through the various bonding methods. We suggest that the structure of stripes of benzene rings transversely bonded with the acetylenic linkages can potentially be one of high thermoelectric materials. We find that the reason for the manipulation of thermal conductivity by the acetylenic linkage can be attributed to the strong localizations of phonon modes that result in the reduced phonon group velocity and the shortened lifetime of phonons. It is also observed that thermal conductivity of graphyne sheet shows a power-law divergence with respect to the length. We propose a new approach to manipulating thermal conductivities in the carbon allotropes through the assembling of acetylenic linkages. Our findings conclusively clarify the role of acetylenic linkages in thermal transport and offer some valuable insights into the exploration of new thermoelectric materials as well as the experimental control of heat flux.
This paper presents a compact C band RF receiver. The miniaturization is based on the multilayer structure, the use of MMIC and LTCC filters, and the efforts on the electromagnetic compatibility design. In addition, this receiver accommodates to the planar feeding of local oscillator by using microstrip feed network which is very important in the application of digital beam forming (DBF) system. All the devices and circuits are packaged into the volume of 24mm by 32mm by 68mm. The measured noise figure (NF) is better than 2.32dB, the gain 62dB at a frequency bandwidth of 6.5-7.1GHz.
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