Xiao Zhifeng

Human placenta-derived mesenchymal stem cells loaded on linear ordered collagen scaffold improves functional recovery after completely transected spinal cord injury in canine

Traumatic spinal cord injury (SCI) is a major challenge in the clinic. In this study, we sought to examine the synergistic effects of linear ordered collagen scaffold (LOCS) and human placenta-derived mesenchymal stem cells (hPMSCs) when transplanted into completely transected beagle dogs. After 36 weeks observation, we found that LOCS+hPMSCs implants promoted better hindlimb locomotor recovery than was observed in the non-treatment (control) group and LOCS group. Histological analysis showed that the regenerated tissue after treatment was well integrated with the host tissue, and dramatically reduced the volume of cystic and chondroitin sulfate proteoglycans (CSPGs) expression. Furthermore, the LOCS+hPMSCs group also showed more neuron-specific βIII-tubulin (Tuj-1)- and NeuN-positive neurons in the lesion area, as well as axonal regeneration, remyelination and synapse formation in the lesion site. Additionally, dogs in the LOCS+hPMSCs group experienced enhanced sprouting of both ascending (CGRP-positive) sensory fibers and descending (5-HT- and TH-positive) motor fibers at the lesion area. All these data together suggested that the combined treatment had beneficial effects on neuronal regeneration and functional improvement in a canine complete transection model. Therefore, LOCS+hPMSCs implantation holds a great promise for bridging the nerve defect and may be clinically useful in the near future.

SENS-U: Remote Human in Loop Health-Monitoring System at Home

Personal health status is becoming a matter of concern while pressure of work growing gradually in everyday life, in the meantime, the ageing population needs more attention. Thanks to many challenging problems of wireless sensor networks (WSNs) solved, exploring work of human body monitoring based on WSNs achieved great progress, we called it wireless body sensor networks(BSNs). In this paper, we propose a novel health-monitoring system based on BSNs; we named it SENS-U. It consists of wireless multi-parameters monitoring terminals and two medical care centers; with human body, they form a remote human in loop 4 vital signs and ECG monitoring system.

Palaeoclimatic cycles, global environmental changes and new glacial periods induced by the impact of extraterrestrial bodies

In terms of Earth-Sun geometry, the Milankovitch theory has successfully explained most of the cyclic palaeoclimatic variations during the history of the Earth, especially in the Quaternary. In this paper, the authors suggest that the impact of extraterrestrial bodies on the Earth may be another mechanism to cause palaeoclimatic cycles, global environmental changes and new glacial periods. Based on geological and geochemical records in the boundary layers produced by six huge Cenozoic bolide-impact events (65, 34, 15, 2.4, 1.1, 0.73 Ma B.P.), including those at 34, 15, 1.1 and 0.73 Ma B. P. which are represented by four famous tektite-strewn fields, the process and mechanics of palaeoclimatic cycles and global environmental catastrophes induced by extraterrestrial impact are discussed in detail. Impact-generated dust, soot and aerosol floating in the stratosphere could result in short-term (<1 year), rapid drop in temperature immediately after impact. Through self-regulation of the Earth’s climate system, the temperature at the surface slowly went up within 100a and maintained stable for a long time at 250K. If there were no other factors leading to the break-down of the newly-established equilibrium, a new glacial pound would be initiated. Estimating from the thickness of δ13C and δ18O anomalies in sediments across the impact boundary layer and deposition rate, the duration of two stages of the palaeoclimate cycle in the form of cold weather—greenhouse effect—normal weather was 104 – 105a, respectively. The conclusion deduced from the above model is supported by palaeotemperature change recorded by oxygen isotope in sediments across the impact boundary layer.

Geochemical kinetic simulation on wall rock alteration zoning in the Baoban gold field, South China

The Baoban gold field, located in the area of Hainan Island. South China, bears three gold deposits: Tuwaishan, Baoban, and Erjia, which belong to the wall-rock alteration type. In terms of the petrography data, four alteration zones can be recognized from the ore-vein outwards: (1) the silicification zone; (2) the serialization zone; (3) the chloritization zone; and (4) the calcitization zone. The geochemical kinetic simulation was carried out on serialization and chloritization. Results of the study showed that the formation of the alteration zones is connected with the properties of hydrothermal fluids: the initial concentration of Al (O H)3, the diflusion coefficient and the velocity of fluid flow. The alteration zones in this field are the result of multiple interaction between hydrothermal fluids and wall rocks.