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Microbial fuel cells (MFCs) that can harvest biomass energy from organic wastes through microbial catalysis have garnered more and more attention within the past decade due to its potential benefits to ecological environment. In this article, the updated progress in MFCs is reviewed, with a focus on frontier technologies such as chamber configurations, feedstock varieties and the integration of MFCs with microbial electrolysis cells for hydrogen production. And on the other hand, the challenges like development of cost-effective electrode materials, improvement of biomass energy recovery and power output, design and optimization of commercial MFC devices are presented.
Assuntos
Fontes de Energia Bioelétrica , Biomassa , Eletrodos , Economia , Hidrogênio , MetabolismoRESUMO
Objective To investig ate the expression of Schwann cell derived fa ctor （SDNF） in normal or under the condi tion of different injuries on the sciati c nerves of rats. Methods Sevent y-five S D rats were divided into three groups ac cording to different injuri es including transection， transection fo llowed by epineurial suture， and crush. Ten normal rats were treated as control. T he immunohistochemistry of both sciatic nerve and spinal cord were performed at 5，7，14，30，60 days after operation respec tively. Result （1）lower levels o f SDNF were detected in normal sciatic nerve， t he whole white matter and the laminae Ⅲ～ Ⅴ of dorsal horn of spinal cord. （2）In g roup transection， the SDNF levels reache d a maxium at 14 days after operation in proxi mal segment， at 7 days in distal segment ， and at 5 days in spinal cord. There ap peared a highest expression in related t issue of both group crushing and group s uturing at 60 days after operation. （3）SD N F staining of dorsal horn ipsilateral to the nerve lesion was stronger than that of contralateral. There was a transient expression in spinal motor neurons ipsi lateral to nerve lesion at 5 days in gro up crushing and group transection and at 30 days in group suturing. Conclusi on （1）There is a weaker expression i n norma l sciatic nerve and spinal cord. （2）The expression of SDNF varies with the diffe rent nerve lesions. （3）Significant quant ities of SDNF are released from Schwann cells after nerve lesion， and SDNF is then available to the axon of the lesioned neurons which may promote neuro n repair.
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Objective To explore whetherthere exists Schwann-cell derived neurotrophic factor (SDNF) receptor in peripheral nerve. Methods SDNF binding sites in rat sciatic nerve were studied using 125 Ⅰ-SDNF as a radioligand (radioligand binding assays). Results There exists SDNF specific binding sites in peripheral nerve,and the specific binding sites have the following characteristics:①The equilibrium dissociation constant (kd) was (93.11?0.52) pmol/L.②The maximal binding capacity (B max ) of SDNF was (8.91?0.26)fmol/mg protein.③Saturation.④Kinetic studies revealed that the association rate constant (K 1) was (3.91?0.63)?10 7M -1 ?min -1 and the dissociation constant (K -1 ) was (3.38?0.54)?10 -3 min -1 .⑤Specific studies of SDNF binding sites showed that the binding sites were highly specific for SDNF. Conclusion SDNF receptor exists in the peripheral nerve and the peripheral nerve may be one of target tissues of SDNF.
