A SnO2-CuO composite nanofiber was prepared by the coaxial electrospinning method. A new thin-film-type hydrogen sulfide gas sensor was designed by coating SnO2-CuO composite nanofibers onto an alumina ceramic tube with Au electrodes by dip-coating method. The crystalline phase and microstructure of SnO2-CuO composite nanofibers were characterized using X-ray diffraction ( XRD ) and scanning electron microscope ( SEM) . The influence of chemical composition and thickness of sensitive film on the sensitive mechanism and electrochemical characteristic of SnO2-CuO nanofibers were analyzed. The characteristic tests of hydrogen sulfide sensor including sensitive performance, temperature, relative humidity, dynamic response, interference and stability were carried out by WS-30A type multifunction analyzer in gas sensor test system. The results demonstrated that, when the operating temperature was 25℃ and hydrogen sulfide gas concentration increased from 10 to 60 mg/L, the hydrogen sulfide sensor based on C50 composite nanofibers with 70 nm sensitive film thickness had the best linearity (92. 3%) and sensitivity (98. 2%). Besides, its highest response values and relatively humidity level were 1080 and 95%, respectively, and its dynamic response time and recover time were 4 s and 12 s, respectively. This sensor showed good anti-disturbance to the gases, such as CO, NO2 , SO2 , NH3 , CO2 , CH4 and H2 . The response value of the sensor was attenuated about 9. 2% when it was applied continually in the mine about 12 months, and its normal response time was 10. 9 months.

TiO2-SnO2 composite nanocrystalline was prepared by the low temperature hydrothermal method. A new film-type ozone sensor was developed by using TiO2-SnO2 composite nanocrystallines transferred onto an alumina ceramic tube with Au electrodes by dip-coating method. The crystalline phase and microstructure of TiO2-SnO2 nanocrystallines were characterized by X-ray diffraction ( XRD) , field emission scanning electron microscope ( FE-SEM) , energy dispersive X-ray analysis ( EDAX) and ultraviolet-visible spectrometry ( UV-Vis) . The ozone sensitive mechanism and photoelectrochemical properties of TiO2-SnO2 nanocrystallines were analyzed by using ultraviolet-visible spectrometry and electrochemical method. These characteristic tests of ozone sensor were carried out on the traits of sensitive performance, dynamic response, interference and stability under ultraviolet-visible illumination by the XEDWS-60 A type multifunction analyzer in gas sensor static test system. the conclusion demonstrates that when the ozone sensor based on TiO2-SnO2 composite nanocrystalline ( molar ratio of Ti and Sn is 6 ) was under conditions of 40% relative humidity and 25 ℃operating temperature, when ozone concentration was increased from 0. 1 to 1. 8 μg/L, the best linearity of ozone sensor upon ultraviolet illumination and visible illumination were 97 . 5% and 78 . 5%, the dynamic response time was 2 s and 9 s, the recovery time was 5. 5 s and 15 s. This kind of sensor showed good anti-disturbance to the gases, such as CO, NOx , formaldehyde, acetone, butanol and methanol. The response value of ozone sensor was attenuated about 4 . 7%, when ozone sensor was applied continually on the automobile about 12 months, and its normal time was 8. 5 months.

BACKGROUND:There are a variety of methods for establishing osteoarthritis animal model, and different methods and different animals have their own characteristics.
OBJECTIVE:To review the status of the research on osteoarthritis animal models.
METHODS:The relevant articles to the osteoarthritis animal models were searched in Medline database from January 2002 to October 2011, with the key words of“animal model, osteoarthritis”in English by the computer. Similarly, Chinese Journal Ful-text Database was retrieved for related articles published in Chinese from January 2002 to October 2011, with the key words of“animal model, osteoarthritis, research development”in Chinese. Total y 423 relevant articles were col ected and 128 of them conformed the standard. At last 40 articles were included to review after ful-text reading.
RESULTS AND CONCLUSION:The artificial induced animal models are the principal means to establish animal models of osteoarthritis and they have been widely used in the study of osteoarthritis pathogenesis, drug efficacy, cartilage physiology and pathology. Spontaneous osteoarthritis animal models have great advantages in the study addressing the initial mechanism of osteoarthritis, the biochemical changes of articular cartilage and the comparison of prevention and cure effects. Transgenic animal models have great application prospects on studying cartilage repairing mechanisms and testing a gene to prevent, delay or reversal the morphological changes. Accordingly the choice of models should be based on research needs.

Objective To investigate the differential expression profiles of microRNAs in the liver of 60Co γ-ray irradiated mice using microRNA microarray and to explore their main functions by bioinformatic analysis.Methods After SPF C57BL/6J mice expose to 4 Gy-single whole body radiation,total number of peripheral WBC and the fMNPCE were measured at 3 d.The differentially expressed miRNAs in mouse liver were detected with miRNA microarray,miRNA-124 and miR-34a were confirmed by real time RT-PCR assay.Bioinformatic analysis was applied to explore target genes and the main functions of the differential expressed miRNAs.Results Compared with control group,the total number of peripheral WBC decreased( t = 2.87,P ＜ 0.05 ) ,while the fMNPCE in bone marrow increased ( t =-2.91,P ＜0.05) after 4 Gy γ-ray irradiation.miRNA microarray revealed that 17 miRNAs were differentially expressed,in which 9 up-regulated,8 down-regulated.The expression levels of miR-124 and miR-34a were coincident with the result of real time RT-PCR.GO analysis showed that some pathways including adherens junction and cell cycle were suppressed,while some immune-related pathways were activated.Conclusions miR-34a and miR-194 were involved in the regulation of acute radiation damage,some other miRNAs including miR-124、miR-382 and miR-92a* also played important roles in radiation process.

Objective Changes of small intestine villus microcirculation perfusion in sidestream dark-field (SDF) imaging in the rabbits during endotoxic shock after fluid resuscitation with different target mean arterial pressure (MAP), and evaluation of feasibility of monitoring small intestine villus microcirculation by SDF were studied. Methods Sixty standard New Zealand white rabbits were randomly divided into two groups: low target MAP group (group A, n = 30) and high target MAP group (group B,n = 30). Fistula operation of ileum was madein vitro, and lipopolysaccharide (LPS, 2 mg/kg) was injected to establish endotoxic shock model. Group A was administered with the lower dose fluid resuscitation (lactated Ringer solution, 20 mL·kg-1·h-1) for target MAP of 65 mmHg (1 mmHg =0.133 kPa); group B was administered with the higher dose fluid resuscitation (lactated Ringer solution, 30 mL·kg-1·h-1) for MAP of 80 mmHg. Continuous norepinephrine intravenous injection (0.5-1.0μg·kg-1·min-1) was administered only after fluid therapy couldn't reach the target MAP. The changes of small intestine villus microcirculation perfusion indexes such as vessels per villus (VV), proportion of perfused villi (PPV), microvascular flow index (MFI), borders of villus score (BVS), vessels villus score (VVS) were continuously observed and recorded before the shock, during the shock and after fluid resuscitation using SDF imaging. The differences of microcirculation perfusion were compared between two groups using the specific parameter evaluation system to determine severity of villi microcirculation and injury scores at different stages.Results VV and borders of villus were clear and contact before shock in two groups. After shock, VV, PPV were significantly decreased in both two groups, the borders of villus were destroyed, MFI, BVS, VVS and the total score of villi injury microcirculation were obviously and severely decreased. Partial blood flow of villous capillaries after fluid resuscitation was recovered in two groups, but the perfusion of some region was un-balanced with the outworn borders of villus. VV were rose as compared before and after fluid resuscitation in groups A and B (vessels: 1.21±0.22 vs. 0.81±0.12, 1.54±0.28 vs. 0.79±0.13), and PPV [(31±4)% vs. (12±2)%, (38±5)% vs. (13±3)%], MFI (1.55±0.09 vs. 1.09±0.03, 1.97±0.11 vs. 1.05±0.03), VVS (points: 1.22±0.08 vs. 0.89±0.02, 2.06±0.15 vs. 0.90±0.02) and the sum of MFI, BVS, VVS (3.70±0.19 vs. 2.85±0.07, 5.01±0.29 vs. 2.88±0.08) were significant rose (allP< 0.05). The recovery of group B was better than that of group A, and the injury score was reduced. But BVS were not increased in both groups compared with before and after shock (points: 0.93±0.05 vs. 0.87±0.03, 0.98±0.09 vs. 0.93±0.05, bothP > 0.05).Conclusions For the small intestine villus microcirculation perfusion, the higher target MAP (80 mmHg) after fluid resuscitation or/and vasoconstrictor drugs usage were probably better than the relatively lower target MAP (65 mmHg) during endotoxic shock. SDF imaging is a very promising technique for intestinal villi microcirculatory visualization and assessment.

AIM: To investigate the changes of small intestine villus and sublingual microcirculation perfusion in the rabbits during endotoxic shock by sidestream dark-field imaging (SDF) after resuscitation to a mean arterial pressure (MAP) level.METHODS: New Zealand white rabbits (n=60) were randomly divided into 2 groups (group of villus and group of sublingua).The fistula operation of ileum was performed.Lipopolysaccharide was injected to establish endotoxic shock model, and fluid resuscitation (lactated Ringer's solution, 30 mL·kg-1·h-1) was given to maitain the MAP of the animals to 80 mmHg.Continuous norepinephrine was intravenously injected at 0.5~1 μg·kg-1·min-1 only if fluid therapy did not maintain the MAP level.The changes of microcirculatory perfusion indexes in small intestine villus and sublingual tissues such as vessels per villus (VV), microvascular flow index (MFI), proportion of perfused villi (PPVi), villus border score, villus vessel score, total vessel density (TVD), perfused vessel density (PVD) and proportion of perfused vessels (PPVe) were continuously observed and recorded by SDF before shock, during shock and after fluid resuscitation.RESULTS: MFI and PPVi in small intestine villus, and MFI, PPVe, TVD and PVD in sublingual tissues were significantly decreased after shock (P<0.01).Compared with MFI in sublingual microcirculation, MFI in villus was significantly decreased (P<0.01).MFI and PPVi in small intestine villus, and MFI, PPVe, TVD and PVD in sublingual tissues were improved after recovered to the target MAP by fluid resuscitation (P<0.05).However, MFI in small intestine villus was significantly lower than that in sublingual tissues after fluid resuscitation (P<0.01).CONCLUSION: The difference between small intestine villus and sublingual microcirculation perfusion during endotoxic shock is observed.The descent degree of microcirculation perfusion in small intestine villus is larger than that in sublingual tissues after shock, and the recovery degree of small intestine villus microcirculation is lower than that of sublingual microcirculation afer fluid resuscitation.

Objective To evaluate the two-stage repair in hypospadias cripples.Methods 35 patients with hypospadias cripples underwent two-stage repair.At the first stage,a full-thickness graft of skin or buccal mucosa was used for urethral plate reconstruction after the release of chordee.The second stage was performed 6 months after completion of the first stage.Tubularization of the replaced urethral plate was the preferred technique.Results There was no urethra stricture or “preplaced urethral plate ” atrophy.Fistula developed in 2 of 35 cases.Conclusion The twostaged technique was a useful strategy to deal with the myriad abnormalities encountered in crippled hypospadias.This technique could not only create a neourethra successfully,but also give the penis a near-normal shape and appearance.

Objective:To investigate the early- and mid-term clinical, functional and radiographic outcomes of patellofemoral arthroplasty (PFA).Methods:A retrospective analysis was conducted in 64 patients (80 knees) who suffered from severe patellofemoral osteoarthritis (PFOA) and underwent PFA from January 2013 to December 2020. These patients were aged 60.50±8.82 (range from 27 to 82) years, including 9 males (12 knees) and 55 females (68 knees). All enrolled individuals presented typical PFOA. Unilateral PFA was performed in 48 cases, bilateral PFA in 16 cases, including one-stage PFA in 9 cases and two-stage PFA in 7 cases. The visual analogue scale (VAS), Hospital for Special Surgery (HSS) knee score and Oxford knee score (OKS) of patients with more than 5 years' follow-up were assessed to evaluate the clinical effects of PFA at the time before surgery, 1 year and 5 years after surgery. In addition, the patellar tilt angle (PTA) and hip-knee-ankle (HKA) angle were measured and analyzed to evaluate the improvement of patellar tracking and progression of tibiofemoral osteoarthritis, based on axial X-ray imaging (skyline view) of knee and the full length standing X-ray imaging of the lower limbs at before surgery and 5 years after surgery. Meanwhile, the complications of all patients that related to the operation were recorded.Results:A total of 64 patients were followed up for 4.31±1.79 (range, 1.5 to 8.2) years. Twenty-five patients (32 knees) who followed up more than 5 years were analyzed. The VAS, HSS and OKS improved from 5.91±0.82, 68.06±6.03 and 21.22±3.46 preoperatively to 0.88±1.01, 90.09±3.30 and 39.06±3.37 at 1 year after surgery, and to 0.41±0.76, 94.53±2.99 and 42.13±3.17 at 5 years after surgery, respectively ( F=89.38, 81.47, 56.73, P<0.001). Additionally, comparing to the preoperative radiological data, the patellar tract was improved with the PTA decreased from 8.21°±3.14° preoperatively to 3.58°±4.48°at 5 years after surgery ( t=4.96, P<0.001). The HKA angle changed from 179.01°±1.43° preoperatively to 178.77°±1.67° at 5 years follow up ( t=1.71, P=0.096). There was no case of prosthesis loosening or wear and no case of obvious progression of tibiofemoral osteoarthritis that needed revision in all patients. Conclusion:Satisfied early- and mid-term clinical outcomes could be achieved by PFA in treating severe PFOA patients. PFA could relieve pain and improve function of knee joint.