Spent graphite regeneration:Exploring diverse repairing manners with impurities-catalyzing effect towards high performance and low energy consumption

Spent battery recycling has received considerable attention because of its economic and environmental potential.A large amount of retired graphite has been produced as the main electrode material,accompanied by a detailed exploration of the repair mechanism.However,they still suffer from unclear repair mechanisms and physicochemical evolution.In this study,spent graphite was repaired employing three methodologies:pickling-sintering,pyrogenic-recovery,and high-temperature sintering.Owing to the catalytic effect of the metal-based impurities and temperature control,the as-obtained samples displayed an ordered transformation,including the interlayer distance,crystalline degree,and grain size.As anodes of lithium ions batteries,the capacity of repaired samples reached up to 310 mA h g^(-1)above after 300loops at 1.0 C,similar to that of commercial graphite.Meanwhile,benefitting from the effective assembly of carbon atoms in internal structure of graphite at>1400℃,their initial coulombic efficiency were>87%.Even at 2.0 C,the capacity of samples remained approximately 244 mA h g^(-1)after 500 cycles.Detailed electrochemical and kinetic analyses revealed that a low temperature enhanced the isotropy,thereby enhancing the rate properties.Further,economic and environmental analyses revealed that the revenue obtained through suitable pyrogenic-recovering manners was approximately the largest value(5500$t^(-1)).Thus,this study is expected to clarify the in-depth effect of different repair methods on the traits of graphite,while offering all-round evaluations of repaired graphite.

Effects of β-Glucan Supplementation on Repairing of Phenol-Induced Vaginal Mucosal Epithelium Damage in Rats

Objective: To investigate the effects of different concentrations of β-glucan on the repair of damaged vaginal mucosa, the expression of vascular endothelial growth factor (VEGF), and the inflammatory factor-6 (IL-6) in vaginal tissues. Methods: Thirty-six adult female specific pathogen free (SPF)-grade Wistar rats were randomly divided into 3 phase groups with 12 rats each. Vaginal inflammation rat models were established by injecting phenol gel into the vagina of each rat at a dose of 0.1 ml/100g body weight. After modeling, rats were divided into 4 groups based on different concentrations of the test agent. The control group was injected with 0.5 ml of saline, experimental group A was injected with 0.375 ml saline 0.125 ml β-glucan, experimental group B was injected with 0.25 ml saline 0.25 ml β-glucan, and experimental group C was injected with 0.50 ml β-glucan. The injection sites were selected at the 3 o’clock and 9 o’clock positions of the vagina. Rats were sacrificed at 7-, 14-, and 28-days post-injection, and tissue samples were collected from the injection sites and prepared for histological analysis. New blood vessels and fibroblast numbers in the tissues were observed after Hematoxylin-eosin (HE) staining. The expression levels of VEGF and IL-6 in the tissues were measured using quantificational reverse transcription polymerase chain reaction (qRT-PCR). Results: Histological examination of vaginal tissue specimens at 7-, 14-, and 28-days post-injection showed that on day 7, there were no significant changes in the experimental groups compared to the control group. However, on days 14 and 28, the experimental groups showed more new blood vessels, macrophages, and fibroblasts with increased activity compared to the control group. The expression levels of VEGF in vaginal tissues were elevated on days 14 and 28 in the experimental groups. The comparison of IL-6 levels in vaginal tissues on day 28 showed that serum IL-6 levels returned to normal, and there was no statistically significant difference between the experimental and control groups. Conclusion: In the 3 experimental phases, the increase in VEGF levels in vaginal tissues on day 14 post-injection was more pronounced with higher concentrations of β-glucan, and IL-6 levels returned to normal on day 28. β-Glucan can enhance VEGF levels in damaged vaginal tissues, promote the repair of damaged vaginal tissues, and higher concentrations of β-glucan have a better effect.

Polyethylene glycol fusion repair of severed sciatic nerves accelerates recovery of nociceptive sensory perceptions in male and female rats of different strains

Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Wallerian Degeneration and maintain their myelin sheaths;(3)promote primarily motor,voluntary behavioral recoveries as assessed by the Sciatic Functional Index;and,(4)rapidly produce correct and incorrect connections in many possible combinations that produce rapid and extensive recovery of functional peripheral nervous system/central nervous system connections and reflex(e.g.,toe twitch)or voluntary behaviors.The preceding companion paper describes sensory terminal field reo rganization following PEG-fusion repair of sciatic nerve transections or ablations;howeve r,sensory behavioral recovery has not been explicitly explored following PEG-fusion repair.In the current study,we confirmed the success of PEG-fusion surgeries according to criteria(1-3)above and more extensively investigated whether PEG-fusion enhanced mechanical nociceptive recovery following sciatic transection in male and female outbred Sprague-Dawley and inbred Lewis rats.Mechanical nociceptive responses were assessed by measuring withdrawal thresholds using von Frey filaments on the dorsal and midplantar regions of the hindpaws.Dorsal von Frey filament tests were a more reliable method than plantar von Frey filament tests to assess mechanical nociceptive sensitivity following sciatic nerve transections.Baseline withdrawal thresholds of the sciatic-mediated lateral dorsal region differed significantly across strain but not sex.Withdrawal thresholds did not change significantly from baseline in chronic Unoperated and Sham-operated rats.Following sciatic transection,all rats exhibited severe hyposensitivity to stimuli at the lateral dorsal region of the hindpaw ipsilateral to the injury.However,PEG-fused rats exhibited significantly earlier return to baseline withdrawal thresholds than Negative Control rats.Furthermore,PEG-fused rats with significantly improved Sciatic Functional Index scores at or after 4 weeks postoperatively exhibited yet-earlier von Frey filament recove ry compared with those without Sciatic Functional Index recovery,suggesting a correlation between successful PEG-fusion and both motor-dominant and sensory-dominant behavioral recoveries.This correlation was independent of the sex or strain of the rat.Furthermore,our data showed that the acceleration of von Frey filament sensory recovery to baseline was solely due to the PEG-fused sciatic nerve and not saphenous nerve collateral outgrowths.No chronic hypersensitivity developed in any rat up to 12 weeks.All these data suggest that PEG-fusion repair of transection peripheral nerve injuries co uld have important clinical benefits.

Study on Repairing Permanent Transportation Roadway in Deep Mining by Bolt-Shotcrete and Mesh Supporting

The roadway support in many places of Jiulongkou Colliery, Fengfeng Mining Bureau, such as in the Permanent transportation roadway, was failed or locally caved, which seriously affected the colliery’s coal production performance and safety. Based on analysis of supporting objects for roadway repairing, this paper proposes the supporting parameters and condruction technics. The industrial ted of 70m long roadway repairing shows that the proposed parameters and technics of bolt shotcrete and mesh support for roadway repairing are reasouable, bring good technical and economic results for the colliery, and the repairing is successful.

The New Technology of Composite Materials Repairing by Light Wave

The repairing of damaged composite materials becomes a hot research subject in the late 1990s.In this paper a new technology of repairing composite materials is given on the basis of our previous research.The light wave of 675nm transmitted by optical fiber is used as repairing light source,special repairable adhesive which can be stimulated by the light is adopted.By comparing the stiffness of the composite material before and after being damaged,it can be concluded that the mechanical property will not be changed with the feasible repairing technology.

Effect of low intensity pulsed ultrasound on repairing the periodontal bone of Beagle canines

Objective:To investigate the repairing effect of low intensity pulsed ultrasound(LIPUS)on the Beagle canines periodontal bone defect.Methods:A total of 12 Beagle dogs with periodontal bone defect model were randomly divided into control group,LIPUS group,guided tissue regeneration(GTR)group and LIPUS+GTR group,with three in each.After completion of the models,no other proceeding was performed in control group;LIPUS group adopt direct exposure to radiation line LIPUS processing 1 week after modeling;GTR group adopted treatment with GTR,following the CTR standard operation reference;LIPUS+GTR group was treated with LIPUS joint GTR.Temperature change before treatment and histopathological change of periodontal tissue after repair was observed.Results:There was no significant difference in temperature changes of periodontal tissue between groups(P>0.05).The amount and maturity of LIPUS+GTR group were superior to other groups;new cementum,dental periodontal bones of GTR group were superior to the control group but less than LIPUS group;new collagen and maturity of the control group is not high relatively.Conclusions:LIPUS can accelerate the calcium salt deposition and new bone maturation,thus it can serve as promoting periodontal tissue repair,and shortening the periodontal tissue repair time.

Passive smart self-repairing concrete beams by using shape memory alloy wires and fibers containing adhesives

An innovative approach to increase structural survivability of concrete and maintain structural durability of concrete was developed in case of earthquakes and typhoons. This approach takes advantage of the superelastic effect of shape memory alloy(SMA) and the cohering characteristic of repairing adhesive. These SMA wires and brittle fibers containing adhesives were embedded into concrete beams during concrete casting to form smart reinforced concrete beams. The self-repairing capacity of smart concrete beams was investigated by three-point bending tests. The experimental results show that SMA wires add self-restoration capacity,the concrete beams recover almost completely after incurring an extremely large deflection and the cracks are closed almost completely by the recovery forces of SMA wires. The number or areas of SMA wires has no influence on the tendency of deformation during loading and the tendency of reversion by the superelasticity. The adhesives released from the broken-open fibers fill voids and cracks. The repaired damage enables continued function and prevents further degradation.

Post-Synthetic and In Situ Vacancy Repairing of Iron Hexacyanoferrate Toward Highly Stable Cathodes for Sodium-Ion Batteries

Iron hexacyanoferrate(FeHCF)is a promising cathode material for sodium-ion batteries.However,FeHCF always suffers from a poor cycling stability,which is closely related to the abundant vacancy defects in its framework.Herein,post-synthetic and in-situ vacancy repairing strategies are proposed for the synthesis of highquality FeHCF in a highly concentrated Na_(4)Fe(CN)_(6) solution.Both the post-synthetic and in-situ vacancy repaired FeHCF products(FeHCF-P and FeHCF-I)show the significant decrease in the number of vacancy defects and the reinforced structure,which can suppress the side reactions and activate the capacity from low-spin Fe in FeHCF.In particular,FeHCF-P delivers a reversible discharge capacity of 131 mAh g^(−1) at 1 C and remains 109 mAh g^(−1) after 500 cycles,with a capacity retention of 83%.FeHCF-I can deliver a high discharge capacity of 158.5 mAh g^(−1) at 1 C.Even at 10 C,the FeHCF-I electrode still maintains a discharge specific capacity of 103 mAh g^(−1) and retains 75% after 800 cycles.This work provides a new vacancy repairing strategy for the solution synthesis of high-quality FeHCF.

Application of a venous conduit as a stent for repairing rabbit facial nerve injury

BACKGROUND： Recently, many investigators have tried to use natural biomaterials, such as, artery, vein, decalcified bone, etc., as conduits for nerve repair. However, immunological rejection of conduits made of natural biomaterials limits their application. Therefore, it is essential to identify more suitable types of biomaterials. OBJECTIVE： To observe the characteristics of a bioengineering processing method using venous conduit as a stent for repairing facial nerve injury. DESIGN： A controlled observational experiment. SETTING： Animal Laboratories of the Third Hospital Affiliated to Sun Yat-sen University and the 157 Hospital. MATERIALS： Thirty-three male New Zealand rabbits of pure breed, weighing 1.5 to 2.0 kg, were provided by Medical Experimental Animal Room of Sun Yat-sen University. The protocol was carried out in accordance with animal ethics guidelines for the use and care of animals. Venous conduits and autogenous nerves were transplanted into the left and right cheeks, respectively. Eleven animals were chosen for anatomical observations at 5, 10 and 15 weeks after surgery. METHODS： This experiment was carried out in the Animal Laboratories of the Third Hospital Affdiated to Sun Yat-sen University and the 157 Hospital between May and November 2006. After animals were anesthetized, 15 mm of retromandibular vein was harvested for preparing a venous conduit. Approximately 3 cm of low buccal branch of facial nerve was exposed. A segment of 1.2 cm nerve was resected from the middle, and a gap of 1.5 cm formed due to bilateral retraction. The prepared venous conduit of 1.5 cm was sutured to the outer membrane of the severed ends of the nerve. Muscle and skin were sutured layer by layer. Using the same above-mentioned method, the low buccal branch of right autogenous facial nerve was resected, and the left facial nerve segment from the same animal was transplanted using end-to-end neurorrhaphy for control. MAIN OUTCOME MEASURES： （1）Post-operatively, food intake, vibrissae activity and wound healing of each animal were observed daily. （2） Animals were anesthetized at 5, 10 and 15 weeks after operation for observing the structural change of the venous conduit, the appearance of regenerated nerve, and the relationship between conduit and peripheral muscle tissue. （3） The action potential and latency of bilateral nerves of animals were measured by electrophysiologic examination, and nerve conduction velocity was calculated. （4）Neural myelination and neurite growth were observed by histological staining using an optical microscope. RESULTS： Thirty-three New Zealand rabbits were involved in the final analysis. （1）Immediately following the operation, vibrissae activity and orbicularis otis muscle activity of the upper lip on venous conduit side were more prominent, and their amplitudes of movement were larger as compared with autogenous nerve side. （2） At postoperative 10 weeks, by visual inspection, we found that on the venous conduit side, the venous conduit exhibited membrane structure which encased regenerated nerve. Regenerated nerve adhered to the muscle edge of orbicularis oris muscle. Muscle and nerve could be separated with a forceps. The muscle of musculus orbicularis oris of rabbit was darker and thicker as compared with autogenous nerve side. After the venous conduit was longitudinally split, the regenerated nerve and nerves at two the severed ends were connected together. When compared with postoperative 5 weeks, the connected nerve was thickened, texture was tough and its middle part was thicker than its two ends. On the autogenous nerve side, the regenerated nerve stem was enwrapped by scar tissue. It was bulky and adhered to peripheral muscle. Its neural profile structure was unclear. The two stomas were obviously enlarged. （3）At postoperative 10 weeks and 15 weeks, nerve action potentials could be elicited from both the venous conduit and autologous nerve side. The mean nerve conduction velocity on the venous conduit side was greater than that of the autologous nerve side. （4）At postoperative 10 weeks, using histochemical staining, it was found that in the venous conduit, regenerated medullated nerve fibers were densely distributed, with well split facial nerve structure, while on the autologous nerve side, nerve fibers were sparsely scattered, with immature medullated nerve structure. CONCLUSION： Biological natural venous conduit processed by bioengineering technology overcomes the tissue inflammatory reactions and connective tissue reactions caused by natural biomaterials. It is more conducive to promote neural regeneration and functional recovery than autologous nerve transplantation.

Research on Hot Gunning Repairing in Laboratory

The lining of blast furnace may be damaged partly, so that gunning repair is needed. The bonding strength of boundary surface between the repairing layer and remained lining of blast furnace has been studied by thermal simulation. The factors influencing the bonding strength are the ingredient gunning repair temperature, remained lining condition and water content of gunning refractory. The bonding strength decreases with the increases of remained lining temperature.

ROLE OF TRANSFORMING GROWTH FACTOR β(TGF-β)IN REPAIRING OF BONE DEFECTS

TGF-β is a multifunctional cytokine that regulates many aspects of cellular function, including periosteal mesenchymal cell proliferation, differentiation. This experiment is to study its effects on bone defect repair. A rabbit radial bone defect model was used to evaluate the effect of TGF-β, which was extracted and purified from bovine blood platelets, on the healing of a large segmental osteoperiosteal defect. A 1. 5-centimeter segmental defect was created in the mid-upper part of the radial shaft of adult rabbits. The defect was filled with implant containing TGF-β that consisted of carrier and bovine TGF-β. Limbs served as controls received carrier alone. The defectswere examined radiographically and histologically at 4, 8,12 , 16 and 20 weeks after implantation. The results showed that in TGF-β implant group . the defect areas at 12 weeks post operation were bridged by uniform new bone and the cut ends of cortex could not be seen;while in control group, the defects remained clear. Only a small amount of new bone formed as a cap on the cut bone ends. In the experimental group, new lamellar and woven bone formed in continuity with the cut ends of the cortex. An early medullar canal appears to be forming and contained normal-appearancing marrow elements; while the control group displayed entirely fibrous tissue within the defect site. Remnants of the cancellous bone carrier were observed in the control specimen. These data demonstrate that exogenous TGF-β initiate osteogenesis and stimulate the bone defects repair in animal model.

Repairing peripheral nerve injury using tissue engineering techniques

Each year approximately 360,000 people in the United States suffer a peripheral nerve injury （PNI）, which is a leading source of lifelong disability （Kelsey et al., 1997; Noble et al., 1998）. The most frequent cause of PNIs is motor vehicle accidents, while gunshot wounds, stabbings, and birth trauma are also common factors. Patients suffering from disabilities as a result of their PNIs are also burdensome to the healthcare system, with aver- age hospital stays of 28 days each year （Kelsey et al., 1997; Noble et al., 1998）.

Interface repairing for AA5083/T2 copper explosive composite plate by friction stir processing

Multi-pass friction stir processing(M-FSP)was performed to repair the interface defects of AA5083/T2 copper explosive composite plates.The interface morphology and its bonding mechanism were explored.The results show that higher rotation speed and lower transverse speed produce more heat generated during FSP.The defect-free and good mechanical properties of the AA5083/T2 copper composite plate can be obtained under the condition of the rotation speed of 1200 r/min,the transverse speed of 30 mm/min and the overlap of 2/24.Moreover,M-FSP changes the interface bonding mechanism from metallurgical bonding to vortex connection,improving the bonding strength of composite plate,which can guarantee the repairing quality of composite plates.

Laser repairing surface crack of Ni-based superalloy components

Surface crack of components of the cast nickel base superalloy was repaired with twin laser beams under proper technological conditions. One laser beam was used to melt the substrate material of crack, and the other to fill in powder material to the crack region. The experimental results show that the surface crack with the width of 0.1 ～ 0.3?mm could be repaired under the laser power of 3?kW and the scanning speed of 6 ～ 8?mm/s. The repaired deepness of crack region is below 6.5?mm. The microstructure of repaired region is the cellular crystal, columnar crystal dendrite crystal from the transition region to the top filled layer. The phases in repaired region mainly consisted of supersaturated α Co with plenty of Ni, some Cr and Al, Cr 23 C 6, Co 2B, Co Ni Mo, Ni 4B 3, TiSi and VSi. The hardness of filled layer in repaired region ranged from HV 0.2 450 to HV 0.2 500, and the hardness decreases gradually from the filled layer to joined zone.

Progress in the application of cold gas dynamic spraying to repairing continuous casting molds

A new continuous casting mold repairing method--cold gas dynamic spraying （CGDS） is introduced. The study investigates the advantages of the CGDS process regarding repairing operation, such as convenient, in-situ repairation,little heat delivery, microstructural and dimensional stability and other special applications. Microstructure and mechanical properties of the copper alloy coating, nickel coating, ceramic composite coating, and their interface to the substrates ,which are usually used in repairing operation have been researched by means of optical microscopy （ OM）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and micro-hardness tests. Experimental results have demonstrated the relative density of the copper alloy coating is as high as 98.7%, and that no obvious difference can be observed between the CrZrCu substrate and the Cu alloy coating in terms of microstructures; thus the interface is quite difficult to be identified. The bonding strength and micro-hardness of the Cu alloy coating reach up to 37 MPa and 310 HV0.2 ,respectively. The interface between the copper alloy coating and the nickel coating is either zigzag or wave shaped, and the cohesion is relatively good. As-sprayed nickel coating is dominated by severely deformed particles,and the relative density is up to 98.5%. Complete recrystallization occurred after annealing at 900℃ for one hour,while its micro-hardness remains as high as 124.1 HV02. All these results have indicated that CGDS is a promising technology for repairing the continuous casting mold and that its future development is prosperous as well.

Study on the Repairing Effect of Cosmetics Containing <i>Artemisia annua</i>on Sensitive Skin

In view of the increasing sensitivity of consumer skin in recent years, cosmetics containing Artemisia annua extract was tested to evaluate its effectiveness in repairing sensitive skin. Through the experiment of xylene-induced ear swelling in mice, it was found that the inhibition rates of ear swelling in mice induced by xylene in three groups of cosmetics containing Artemisia annua extract reached 60.40%, 73.36% and 74.01%, respectively, close to the positive drug group. Twenty-five sensitive skin volunteers were selected for human clinical trial, and the skin TEWL value, cuticle hydration degree and skin heme (ultra-high concentration) were tested. The results showed that using cosmetics containing Artemisia annua extract for four weeks could effectively increase the hydration degree of cheek cuticle by 63.90% and reduce transepidermal waterloss (TEWL) by 21.51%. The skin heme (ultra-high concentration) decreased by 69.14% and the affected area decreased by 77.47%. The results show that the cosmetics containing Artemisia annua extract can inhibit inflammation, repair skin barrier, improve damaged skin, and reduce redness and other sensitive skin symptoms.

Compatibility research of laser additive repairing TA15 forgings with Ti6Al4V-xTA15 alloy

The application of mixed powders with different mass fraction on laser additive repairing(LAR)can be an effective way to guarantee the performance and functionality of repaired part in time.A convenient and feasible approach is presented to repair TA15 forgings by employing Ti6Al4V-xTA15 mixed powders in this paper.The performance compatibility of Ti6Al4V-xTA15 powders from the aspects of microhardness,tensile property,heat capacity,thermal expansion coefficient and corrosion resistance with the TA15 forgings was fully investigated.The primaryαlaths were refined and the volume fraction of the secondaryαphase was increased by increasing the mass fraction of TA15 in the mixed Ti6Al4V-xTA15 powders,leading to varied performances.In conclusion,the mixed Ti6Al4V-70%TA15(x=70%)powders is the most suitable candidate and is recommended as the raw material for LAR of TA15 forgings based on overall consideration of the compatibility calculations of the laser repaired zone with the wrought substrate zone.

The application of anterolateral thigh flap in post-operative repairing of vulva tumor

Objective： The aim of this study was to evaluate the value of the application of anterolateral thigh flap in postoperative repairing of vulva tumor. Methods： Anterolateral thigh flap with the descending branch of the lateral circumflex femoral artery and the pedicle of anterolaterat thigh cutaneous nerve was used in primary repairing of the defect from postoperative vulva tumor, the sizes of the flaps ranged from 10 cm ×14 cm-14 cm× 20 cm. Results： All flaps survived, during a follow-up of 2 to 12 months, the appearance of the flaps was satisfactory with sensitive function without local recurrences. Conclusion： Anterelateral thigh flap has fairly long vessel pedicle, wider vessel diameter, and is in the covert area. Anterolateral thigh flap with sensory nerve is the ideal choice for postoperative repairing of vulva tumor.

Introduction of a New Method for Regulating Laves Phases in Inconel 718 Superalloy during a Laser-Repairing Process

The morphology,size,and distribution of Laves phases have important influences on the mechanical properties of laser-repaired Inconel 718(IN718)superalloy.Due to the deterioration of the substrate zone,the Laves phase in the laser cladding zone of IN718 superalloy cannot be optimized by a hightemperature solution treatment.In this study,an in situ laser heat-treatment method was proposed to regulate the morphology and size of the Laves phase in the laser cladding zone of IN718 superalloy without impacting the substrate zone.In the in situ laser heat-treatment process,a laser was used to heat previously deposited layers with optimized manufacturing parameters.A thermocouple and an infrared camera were used to analyze thermal cycles and real-time temperature fields,respectively.Microstructures and micro-segregations were observed by optical microscopy,scanning electron microscopy,and electron probe microanalysis.It was found that the in situ laser heat treatment effectively changed the morphology and size of the Laves phase,which was transformed from a continuous striplike shape to a discrete granular shape.The effective temperature range and duration were the two main factors influencing the Laves phase during the in situ laser heat-treatment process.The effective temperature range was determined by the laser linear energy density,and the peak temperature increased with the increase of the linear energy density.In addition,the temperature amplitude could be reduced by simultaneously increasing the laser power and the scanning velocity.Finally,a flow diagram was developed based on the in situ laser heat-treatment process,and the deposition of a single-walled sample with fine and granular Laves phases was detected.

Biological and artificial nerve conduit for repairing peripheral nerve defect

OBJECTIVE： Recently, with the development of biological and artificial materials, the experimental and clinical studies on application of this new material-type nerve conduit for treatment of peripheral nerve defect have become the hotspot topics for professorial physicians. DATA SOURCES ： Using the terms ＂nerve conduits, peripheral nerve, nerve regeneration and nerve transplantation＂ in English, we searched Pubmed database, which was published during January 2000 to June 2006, for the literatures related to repairing peripheral nerve defect with various materials. At the same time, we also searched Chinese Technical Scientific Periodical Database at the same time period by inputting ＂ peripheral nerve defect, nerve repair, nerve regeneration and nerve graft＂ in Chinese. STUDY SELECTION ： The materials were firstly selected, and literatures about study on various materials for repairing peripheral nerve defect and their full texts were also searched. Inclusive criteria： nerve conduits related animal experiments and clinical studies. Exclusive criteria： review or repetitive studies. DATA EXTRACTION： Seventy-nine relevant literatures were collected and 30 of them met inclusive criteria and were cited. DATA SYNTHESIS ： Peripheral nerve defect, a commonly seen problem in clinic, is difficult to be solved. Autogenous nerve grafting is still the gold standard for repairing peripheral nerve defect, but because of its application limitation and possible complications, people studied nerve conduits to repair nerve defect. Nerve conduits consist of biological and artificial materials. CONCLUSION： There have been numerous reports about animal experimental and clinical studies of various nerve conduits, but nerve conduit, which is more ideal than autogenous nerve grafting, needs further clinical observation and investigation.