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Quasi-static axial compression experiments were conducted on the composite thin-walled C-channels with different flange widths. The axial compression failure modes and failure mechanisms were analyzed through CT scanning，and the effects of different flange widths on the axial compression energy-absorption characteristics of C-channels were evaluated by using the energy-absorption indexes. The single-layer shell model and multi-layer shell model of composite C-channel were established，and the finite element models were verified by comparing the failure modes，load-displacement curves and energy-absorption indexes. The results show that the flange width has a significant effect on the axial compression failure modes and energy-absorption characteristics of C-channels. The C-channels with flange widths of 25 mm and 30 mm are failed in the stable and asymptotic manner under the axial compression loads and have good energy-absorption characteristics. The deviation of mean crushing force，energy absorption and specific energy absorption obtained by the multi-layer shell model is within 5%，while that obtained by the single-layer shell model is within 8%，which indicating that the multi-layer shell model of C-channel has the higher simulation accuracy.

The construction of cell differentiation trajectories from single-cell transcriptomic data or proteomic data by single-cell trajectory inference methods can help to understand the developmental process of normal tissues or provide pathologically relevant information. However, the accuracy and robustness of current single-cell trajectory inference algorithms are still a challenge, one of the reasons is the noise caused by the detection of a large number of unrelated genes in single-cell sequencing. In order to solve this problem, a trajectory inference method iterTIPD (iterative trajectory inference based on probability distribution) based on iterative feature selection is proposed. Its innovation lies in iteratively applying feature selection methods widely used for screening differentially expressed genes to linear or branching single-cell RNA sequencing data, and improving the accuracy and robustness of cell pseudotime ordering by selecting the gene subset that contributes the most to the constructed differentiation trajectory. Experimental results on four scRNA-seq datasets show that iterTIPD can effectively improve the accuracy and robustness of the single-cell trajectory inference algorithm. IterTIPD also improves the performance of other trajectory inference algorithms, proving generalization of iterTIPD. The differentiation trajectory of neural stem cells is reconstructed by iterTIPD algorithm, and the comparison shows that the differentiation trajectory is highly consistent with the known neural stem cell differentiation trajectory. Meanwhile, Top2a and Gja1 may be novel markers defining activated neural stem cell subpopulations.

The emergency evacuation demonstration test of transport aircraft is an important testing link through the type certification. The test involves a large number of personnel and the items, and types of airworthiness certification check are complicated. In order to formulate a more reasonable test plan, it is necessary to carry out a systematic analysis of documents related to airworthiness requirements for emergency evacuation of transport aircraft and their advisory notices. For the whole process of the aircraft emergency evacuation demonstration test, research is carried out from four aspects: pre-preparation, on-board inspection, test and post-test, test and post-test. Defining the basic process of airworthiness certification, summarizing the airworthiness certification elements and specific verification methods are necessary to support and guarantee the completing of emergency evacuation demonstration test.

The LRBL is one of the latest cabin security requirement for transport aircraft certification. According to(least risk bomb location, LRBL) airworthiness requirements and related advisory circular, based on design and layout of structures and systems around LRBL and the secondary effects and countermeasures after the explosion, the research progress on response characteristics and failure modes of aircraft structure subjected to internal explosion is discussed. The damage mechanism and damage model of human organs under blast shock wave is combed. The probability model of explosive debris is cleared. The design characteristics, advantages and disadvantages of blast-resistant containers at home and abroad is summarized. The related project studies on the response of fuselage structures under internal explosive load of Tianjin Key Laboratory of Civil Aircraft Airworthiness and Maintenance, Civil Aviation University of China are briefly described.

To study the crushing energy-absorbing characteristics and failure mode, the multi-shells finite element model of composite thin-walled C-channel specimen was established based on the quasi-static crushing test results. The simulation results show that the delamination failure, local buckling and beam bending failure of C-channel specimen can be simulated with the multi-shells finite element model. The load-displacement curve well fits the test results, and the deviation of initial peak load (Fmax), specific energy absorption (Es) and crushing mean load (Fmean) is small compared with the test results. The initial peak load of C-channel specimen is larger and the load efficiency is lower, so it is necessary to further reduce the initial peak load by the design optimization.

For the demand of crashworthiness verification and certification of composite aircraft structures,a finite element model of fuselage section with waved-plates under cargo floor was suggested,and rigid simplified model of cargo was also developed. The crashworthiness performance was researched under 7 m / s vertical impact velocity. A comparative analysis of failure modes,acceleration response and energy-absorbing characteristics were given for composite fuselage section with and without cargo loading and the analysis were helpful to design and analysis of civil aircrafts. The results show that the energy absorbed by waved-plates is increased because of cargo loading,the acceleration of junction between outside seats and floor for fuselage section with cargo loading are lower than that of fuselage section without cargo loading,and there is no cascading crash scenario.

Currently the majority of water quality assessment in China is based on comparison parameters of water with those of drinking water standards.However, to what extent the pollutants influence human health is less known.Herein, Shuangcun karst water samples in central-southern Shandong province were chosen to evaluate human health risk.Using the risk assessment model of USEPA, the risk induced by two carcinogenic substances, such as As, Cr(Ⅵ) and seven non-carcinogenic substances(Hg, F, CN-, NO2--N, NH4+-N, NO3--N, phenols) are evaluated.Results show that concentration of NO3--N and NO2--N in samples from several sites exceeds the limiting value of Hygienic Standard for Drinking Water(GB5749-2006).In terms of annual personal health risk caused by gene toxic substances through water drinking, Cr(Ⅵ) shows greater risk than As.In terms of risk caused by non-gene toxic substances, the induced risk has the sequence of NO3--N> F> NO2--N> Hg> CN-> NH4+-N> phenols.Moreover, the hazard of carcinogenic substances is much stronger than that of non-carcinogenic substances.Cr(Ⅵ) is the primary pollutant.For all the sampling sites, total risk values range from 5.0×10-5 to 10.0×10-5 a-1, and the risk level is Ⅳ(fair).It means that underground water in the sampling area is harmful to human health to some extent.Therefore, it is worth more attention when the studied water serves as the drinking water source.

Many methods, including single factor index method, Nemero comprehensive index method, potential ecological risk index method and geoaccumulation index method, have been employed to evaluate soil heavy metal pollution. However, no well-developed or standard method has yet been established. Herein, 77 samples of farmland soil in south Jining were collected and analyzed. The results show that average concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in the samples were 16.7, 0.270, 88.4, 33.0, 0.050, 40.4, 29.3 and 89.1 mg/kg, respectively. The values of Hg and Cd were 1.50 and 1.39 times higher than the benchmark value of the Huang-Huai-Hai Plain and values of other elements were 0.26-0.52 times higher than the benchmark value. All of the samples were evaluated by bivariate correlation analysis method, and the results show that soils are polluted by Hg. The enrichment coefficient method and geoaccumulation method were employed to evaluate the pollution level of 8 elements (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the target area soil. Both results show that there was light accumulation of Hg and Cd, while other elements were at normal levels. Combining heavy metal concentration in the selected area, the biotoxicity index of heavy metals, ecological effect and environmental effect, and the potential biological hazard index method were applied to evaluate the biological risk. The results show that the potential hazard sequence is as follows: Hg>Cd>As>Cu>Pb>Ni>Cr>Zn with obvious differences to the accumulation level. Although there was only light accumulation of Hg and Cd, their potential hazards contributed up to 81.26% of the total contribution of potential ecological risk index. The result was schematized by using MapGIS. It showed that about 6.83% of the selected area had the problem of strong or very strong potential ecological risk, and the remainder was at the medium level. Despite the junction of Fuxing River, Yaolou River and Jinghang canal faced the problem of very strong potential biological risk. According to the investigation on the anthropogenic emission sources in the research area, it was found that the risk had positive correlation with coal mining activities. Therefore, taking effective measures to remedy the polluted soil, especially the remediation of the Hg and Cd pollution, will be of great significance to prevent the further deterioration of the soil environment.

Apnea of prematurity (AOP) is onc of the common diseases in preterm infants. The main cause of AOP is immature development of the respiratory control center. If AOP is not treated timely and effectively, it will lead to respiratory failure, hypoxic brain injury, and even death in severe cases. Caffeine is the first choice for the treatment of AOP, but its effectiveness varies in preterm infants. With the deepening of AOP research, more and more genetic factors have been confirmed to play important roles in the pathogenesis and treatment of AOP; in particular, the influence of single nucleotide polymorphism on the efficacy of caffeine has become a research hotspot in recent years. This article reviews the gene polymorphisms that affect the efficacy of caffeine, in order to provide a reference for individualized caffeine therapy. [ABSTRACT FROM AUTHOR]

Silane modified polyether (MS) polymer was synthesized from polypropylene glycol and 3-isocyanate propyl trimethoxysilane by adjusting the temperature, ratio of the raw materials, and the content of catalyst. Results showed that under the temperature of 90°C; n (NCO): n(OH) = 1.2:1, and catalyst of 0.1wt%, the reaction could be finished in 3 h. Thus the polymer ons good storage stability. The MS sealant prepared by self-made polymer has high hardness and strength, low mass loss rate, good adhesion and water resistance, which was good for environmental protection in home decoration. [ABSTRACT FROM AUTHOR]

Well drilling, completion, and oil production are regarded as important constituent steps in the procedure of petroleum exploration and development. A concept of integral design pattern with oil production as priority is proposed and developed. The influences of well profile on well completion and oil production at later stages are taken into consideration at the beginning of drilling design, setting up the concept that drilling serves oil production, which changes the passive status of completion and lifting designs, and implements the process management for wells during the whole life cycles. Based on the observation of the influencing factors of well profile affecting oil production at later stages, the analytical hierarchy process and the fuzzy evaluation theory are applied to establish wellbore profile evaluation indicators for pumping wells, and to optimizing borehole trajectory. By the field applications in North China Oilfield, it is shown that novel pattern is able to improve the disadvantages in oil production management at later stages, and to provide references for sustainable development of oilfields. [ABSTRACT FROM AUTHOR]

Objective: To explore the clinical characteristics and genetic basis of a child with autism spectrum disorder (ASD) in conjunct with congenital heart disease (CHD)., Methods: A child who was hospitalized at the Third People's Hospital of Chengdu on April 13, 2021 was selected as the study subject. Clinical data of the child were collected. Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing (WES). A GTX genetic analysis system was used to analyze the WES data and screen candidate variants for ASD. Candidate variant was verified by Sanger sequencing and bioinformatics analysis. Real-time fluorescent quantitative PCR (qPCR) was carried out to compare the expression of mRNA of the NSD1 gene between this child and 3 healthy controls and 5 other children with ASD., Results: The patient, an 8-year-old male, has manifested with ASD, mental retardation and CHD. WES analysis revealed that he has harbored a heterozygous c.3385+2T>C variant in the NSD1 gene, which may affect the function of its protein product. Sanger sequencing showed that neither of his parent has carried the same variant. By bioinformatic analysis, the variant has not been recorded in the ESP, 1000 Genomes and ExAC databases. Analysis with Mutation Taster online software indicated it to be disease causing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic. By qPCR analysis, the expression level of mRNA of the NSD1 gene in this child and 5 other children with ASD was significantly lower than that of the healthy controls (P < 0.001)., Conclusion: The c.3385+2T>C variant of the NSD1 gene can significantly reduce its expression, which may predispose to ASD. Above finding has enriched the mutational spectrum the NSD1 gene.

Objective: To study the genetic variants of a child with Autism Spectrum Disorder (ASD) combined with epilepsy, and explore its possible pathogenic mechanism., Methods: Clinical data of the child were collected and evaluated, whole-exome sequencing (WES) technology was used to explore the genetic variants sites of the child and his parents and candidate genes were filtered out. Sanger sequencing were performed to verify the variants identified by WES and PolyPhen2 was utilized to predict the function of these variants. qPCR was carry out to determine the expression of the variant gene., Results: The proband carried a compound heterozygous mutation in the SIK3 gene (Chr11 q23.3, NM&#95;025164.6), which contains a missense mutation c.1295A>G (p.N432S) inherited from the father and a deletion [c.2389&#95;2391del(p.797del)] inherited from the mother. Both mutation sites are highly conservative, and PolyPhen2 predicted (c.1295A>G [p.N432S]) to be harmful. Compared to the mother, expression of SIK3in mRNA level in the peripheral blood of the proband and his father were both significantly decreased; compared to normal child, SIK3 expression in the peripheral blood of the proband and two other children with ASD were all decreased significantly too. In addition, studies on mice found that Sik3 gene has a marked higher level of expression in the brain., Conclusion: The SIK3 gene variants may probably be associated with ASD. The detailed mechanism needs to be studied further, which may involve lipid metabolism dysfunction in the brain.

Objective To investigate the characteristics of nocturnal intermittent hypoxemia in patients with heart failure(HF) with preserved ejection fraction(HFpEF).Methods Patients(n=854) who completed sleep test and echocardiography from January 2011 to December 2014 were retrospectively studied. HF patients with an ejection fraction(EF) of ≥50% were included in the HFpEF group(n=112) while HF patients with an EF of <50% included in the group of HF patients with reduced EF(HFrEF)(n=104). Respiratory events and minimum nocturnal saturation(minSaO 2 ) were recorded by home sleep testing,and the percentage of total sleep time with saturation <90%(T90SaO 2 ) were calculated.Results Compared with patients without HF,subjects with HFpEF and HFrEF had more breathing events[13(5,29)/h vs. 18(6,36)/h,and 21(8,45)/h,P<0.001],lower minSaO 2 [85(80,87)% vs. 82(77,86)% and 83(78,87)%,P<0.001] and relatively longer T90SaO 2 [3.0(0.4,15.5)% vs. 6.0(1.5,24.8)% and 6.7(1.3,14.4)%,P<0.001]. The HFpEF group had significantly higher odds of moderate-severe hypoxemia(minSaO 2 <85%) during sleep than those without HF(OR=2.02,95%CI=1.34-3.11,P<0.001),with the significance persisting after adjusting for covariates including age,gender,hypertension,diabetes,coronary heart disease,renal dysfunction,and smoking(OR=1.85,95%CI=1.20-2.90,P=0.006).Conclusion Patients with HFpEF have frequent nocturnal intermittent hypoxemia,which warrants further investigations to evaluate if remission of night-time hypoxemia may improve long-term prognosis in this cohort.

Objective: To investigate the effects of silencing transforming growth factor-β activating kinase 1 (TAK1)on the expressions of IL-6 and IL-8 induced by TNF-α in fibroblast-like synoviocytes, and to explore the role of TAK1 in rheumatoid arthritis (RA)., Methods: The synthesized TAK1 siRNA and scrambled siRNA (ScRNA) were transferred into cultured RA fibroblast-like synoviocyte line MH7A by lipofectamine. The expressions of the pro-inflammatory mediator IL-6 and IL-8 and the levels of phospho-P38(p-P38), phospho-C-Jun NH2-terminal kinase(p-JNK), phospho-extracellular signal-regulated kinase(p-ERK), phospho-p65(p-p65) and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha(IκBa) were examined., Results: Silencing of TAK was demonstrated in synoviocytes transfected by TAK siRNA. TAK1 silencing markedly attenuated the expression of IL-6 and IL-8 in the presence of TNF-α. TAK1 silencing inhibited the activation of p38 and JNK MAPK. TAK1 silencing also inhibited activation of nuclear factor-κB (NF-κB)., Conclusions: TAK1 silencing attenuated the expression of IL-6 and IL-8 in synoviocytes induced by TNF-α via inhibiting the activation of p38, JNK MAPK and NF-κB.

Objective: To analyze the clinical manifestations and gene mutation of a 6 year old boy with autism spectrum disorders (ASD)., Methods: Peripheral blood of the boy and his parents were subjected to genetic testing., Results: The patient was diagnosed with typical autism. Exome sequencing has identified mutations of four candidate genes, namely TUT1, DIAPH3, REELIN and SETD2, which were confirmed with Sanger sequencing. Analysis of family members confirmed that the missense mutations of DIAPH3 and SETD2 genes were of de novo origin., Conclusion: Missense mutations of DIAPH3 and SETD2 genes may have contributed to the risk of ASD. Disrupted neurogenesis associated with such mutations may have been the underlying mechanism for ASD.

Objective: To investigate the basic clinical characteristics and drug resistance of Haemophilus influenzae (Hi) infection in hospitalized children in the past two years., Methods: A retrospective cross-sectional study was conducted to analyze Hi strains isolated from the sputum and pharyngeal swabs of children aged 0-17 years who were hospitalized in the Third People's Hospital of Chengdu between June 2011 and May 2013., Results: A total of 117 strains were isolated from 111 hospitalized children. There were 102 cases (91.9%) of respiratory infection and 9 cases (8.1%) of other diseases. The positive rates of Hi in children with bronchopneumonia or pneumonia (50.8%, 30/59) and in children with acute laryngotracheobronchitis (50.0%, 2/4) were relatively high, followed by in children with capillary bronchitis (34.6%, 9/26), in children with acute bronchitis (24.2%, 32/132), in children with herpangina (19.0%, 4/21), in children with asthmatoid bronchitis (17.9%, 5/28), in children with acute upper respiratory tract infection (11.8%, 9/76), in children with acute tonsillitis (8.2%, 7/85), and in children with neonatal pneumonia (5.6%, 3/54). There were significant differences in the rates of resistance to amoxicillin-clavulanate (15% vs 23%; P=0.010) and chloramphenicol (25% vs 8%; P=0.015) between the two survey years. The frequencice of β-lactamase-nonproducing-ampicillin-resistant (BLNAR) strains and β-lactamase-producing-amoxicilli/clavulanate-resistant (BLPACR) strains increased from 12% to 21% and from 13% to 19% respectively during the two survey years (P>0.05)., Conclusions: Hi plays an important role in the respiratory tract infection of children aged 0-17 years. The increasing trend of BLNAR and BLPACR rates makes it harder for antibiotic selection in clinical practice.

CuBr2 in the multi-porous ceramic membrane can release Br2 at high temperature, which was employed as the oxidant for Hg0 oxidation. Hg0 oxidation efficiency was studied by a membrane catalysis device. Meanwhile, a reaction and in situ monitoring device was designed to avoid the impact of Br2 on the downstream pipe. The result showed that the MnO(x)/alpha-Al2O3 catalysis membrane had a considerable "controlled-release" effect on Br2 produced by CuBr2 decomposition. The adsorption and reaction of Hg0 and Br2 on the surface of catalysis membrane obeyed the Langmuir-Hinshelwood mechanism. The removal efficiency of Hg0 increased with the rising of Br2 concentration. However, when Br2 reached a certain concentration, the removal efficiency was limited by adsorption rate and reaction rate of Hg0 and Br2 on the catalysis membrane. From 473 K to 573 K, the variation of Hg0 oxidation efficiency was relatively stable. SO2 in flue gas inhibited the oxidation of Hg0 while NO displayed no obvious effect.

Objective: Cigarette smoking is a risk factor for the development of insulin resistance. However, whether a smoker has a lesser waist circumference (WC) and whether the potential changes in WC may reduce the benefits of smoking cessation remains in dispute. The aims of this study are to re-examines the relationships between smoking and metabolic risk factors by the data from Beijing adults., Methods: A total of 3710 men and 6344 women, aged 18 - 92 years old, were sampled from community centers in Beijing for this cross-sectional clinical study between April and August 2007. Their concentrations of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and plasma glucose (PG) were measured. And the anthropometric parameters (WC, body weight and height) and blood pressure (BP) were record according to a standard protocol. Their social, demographic, personal medical history and behavioral characteristics were collected by the well-trained staff. Metabolic syndrome was defined according to the International Diabetes Federation (IDF) criteria. The relationships between smoking and metabolic syndrome were analyzed by χ(2) test and logistic regression., Results: The mean age and glucose concentration were similar in both genders. Males tended to have a higher mean BP (systolic and diastolic), a higher level of TG and a lower HDL-C. Among the obesity indices, the mean WC was higher in males than that in females whereas the mean BMI higher in females. The means of BMI and WC were 24.99 kg/m(2) and 89.13 cm for males and 25.49 kg/m(2) and 85.49 cm for females respectively. Smoking was an independent risk factor of metabolic syndrome in male subjects. It was mainly due to a higher prevalence of dyslipidemia, i.e. a higher level of TG and a lower level of HDL-C in smokers. And the trough prevalence of central obesity was higher in former smokers than current smokers. With adjustment for age, alcohol intake, and regular physical activity, the odds ratios [OR (95%CI)] of never smokers, ex-smokers, and current smokers were 1.00, 1.10 (0.92 - 1.47), and 1.36 (1.02 - 1.69) for hypertriglyceridemia (P < 0.05) and 1.00, 1.08 (0.79 - 1.32), and 1.59 (1.13 - 1.89) for low HDL-C respectively (P < 0.05). The odds ratios of the MS were 1.00 (referent), 1.10 (0.76 - 1.43), and 1.49 (1.06 - 1.89) for never smokers, ex-smokers, and current smokers respectively (P < 0.05). Cessation of smoking had a general trend of lowering the risk of metabolic syndrome in a year-dependent manner in males. In females, the prevalence of metabolic syndrome and obesity was similar between smokers and nonsmokers. Among the features of metabolic syndrome, only a low HDL-C was associated with chronic smoking in females., Conclusion: Although smokers tend to have a lower waist circumference than nonsmokers, the males have higher risk factors for metabolic disorders. There is no significant relationship between smoking and metabolic syndrome in female subjects.

In the present paper, Eu0.5 Tb0.5 (TTA)3 Phen was synthesized and Eu0.5 Tb0.5 (TTA)3 Phen/PMMA was prepared by in-situ polymerization. The structure of Eu0.5 Tb0.5 (TTA)3 Phen/PMMA was characterized by FTIR spectra. Microscopic morphology and photoluminescence properties were investigated by SEM photographs and fluorescence spectra. The results indicated that polymer parts were attached with the rare-earth molecular parts in the composite luminescent materials. And Eu0.5 Tb0.5 (TTA)3 Phen/PMMA could emit mostly characteristic fluorescence of europium ion and intense red fluorescence with a peak wavelength at 611.8 nm and a bandwidth of 10.4 nm (Purity: 0.9905) under UV excitation at 365 nm. Its fluorescence intensity was found to be influenced with the content of MMA. It w as demonstrated that Eu0.5 Tb0.5 (TTA)3 Phen/PMMA was an excellent red photoluminescent rare-earth polymer material.

Objective: To investigate the dynamic changes of interlukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in gingival crevicular fluid (GCF) during orthodontic tooth movement, and to discuss the biological significance., Methods: Fifteen patients were chosen as subjects. For each patient, upper and lower canines at one side having one treatment for distal movement by elastic chain served as the experimental teeth, whereas the contralateral ones were used as controls. The GCF were taken before activation and at 1, 24, 48, 72, 168 hours respectively after initiation of the experiment. The levels of IL-1beta and TNF-alpha in GCF were determined by radioimmunoassay., Results: The levels of IL-1beta and TNF-alpha in experimental group began to increase at 24 hours and reached to its peak value at 72 hours after initiation of the experiment, but their levels returned to baseline at 168 hours. Both of them, however, remained at the baseline level in control group. The changes of the two cytokines level were found statistically significant at 48 and 72 hours (P<0.05) between experimental and control group. No statistically significant were observed before activation and at 1, 168 hours after application of orthodontic forces (P>0.05) between experimental and control group., Conclusion: The levels of IL-1beta and TNF-alpha in gingival crevicular fluid experience dynamic changes during the early phase of orthodontic treatment, indicate that they might play an important role in the process of alveolar regeneration and tooth movement.

Objective: To explore the role of the neuropeptide in fetal scarless wound healing., Methods: The animal models were replicated in which a full-thickness wound was inflicted on the back of rabbit fetuses at 22 days gestation (term=31 days). The progress of wound healing was observed on micro-and macro-levels at the 1 st, 2 nd, 3 rd, 5 th, 7 th, 14 th post-injury days respectively. The expression level of substance P(SP) and calcitonin gene-related peptide (CGRP) during wound healing was assessed by immunohistochemistry staining., Results: The cutaneous wounds in fetal rabbits healed more rapidly than that in adult and without the formation of scar. The expression of SP and CGRP of wound decreased in fetal rabbit at the early stage post-injury, down to the lowest levels on the 2 nd post-injury day (75%, 80%, vs. fetal control, both P<0.01), then increased gradually, up to the normal levels. The expression of SP and CGRP of wound decreased in adult rabbit at the early stage post-injury, down to the lowest levels on the post-injury 1 st day (60%, 76%, vs. adult control, both P<0.01), then increased quickly, up to a higher level than normal group, reaching the peak on the post-injury 7th day(168%, 126%, vs. adult control, both P<0.01), then returned to the normal levels., Conclusion: The low level of neuropeptide may contribute to scarless wound healing in fetal rabbit.

Objective: To study the effect of autogenous bone marrow on guided bone regeneration (GBR), and evaluate the repairing ability of GBR in bone defect with autogenous bone marrow., Methods: Ten mm segmental defects were produced in both radii of 18 rabbits. The defect was bridged with a silicon tube. Autogenous bone marrow was injected into the tube on the experimental group at 0, 2, 4 weeks after operation, and peripheral blood into the control group at the same time. The X-ray, gross, histological and biochemical examinations were observed in various times., Results: The new bone formation of experimental group was prior to that of control group; calcium and alkaline phosphatase of experimental group were higher than those of control group. The experimental group had all been healed at the tenth week, but no one healed in control group., Conclusion: It can be conclude that autogenous bone marrow can stimulate bone formation and facilitate GBR in bone defect.