Objective:In order to optimize the crystallization technics, the effects of heat-treatment on the flexible strength and microstructure of a novel dental mica glass-ceramic were studied in present study. Methods:7 groups were treated respectively with different crystallization temperature and different crystallization time.Then the flexible strength, X-ray diffraction (XRD)and scanning electron microscope(SEM) were used to study the flexible strength and microstructure of such a novel dental mica glass-ceramic. Results: The result of the study indicated that along with the rise of crystallizing temperature and crystallizing time, this dental mica glass-ceramic showed the peak of bending strength (173.68 MPa) at 680 ℃ for 120 min.Conclusion:This material is promising as esthetic all-ceramic dental material.

Aim To observe histopathological changes of hippocampus after acute epilepsy induced by penty-lenetetrazole (PTZ)in rats.Methods Five groups as control group,PTZ-induced 24 hours(h)group,PTZ-induced 72 hours group,PTZ-induced 1 20 hours group and PTZ-induced 1 44 hours group were designed.PTZ (64 mg·kg -1 )was administered with a single intrap-eritoneal injection for generalized tonic-clonic sei-zures in the current experiment.Control and PTZ trea-ted animals were sacrificed after specific time points. Brain was dissected out and then evaluated for neuro-pathological changes using Nissl staining and immuno-histochemical technique.Results In this study PTZ-induced hippocampal neuron status apoptosis occurred at 24 hours and was sustained for 1 44 hours after status epilepticus.Whereas,activated caspase-3 and AIF ap-peared at 24 hours and were sustained for 1 44 hours af-ter status epilepticus.Conclusion The results of this study show that the significant histopathological chan-ges of hippocampus appear in the vicinity of 1 20 hours after intraperitoneal injection of pentylenetetrazole.

BACKGROUND: The development of cartilage tissue engineering provides novel ideas for treatment of articular cartilage defects and implements construction of tissue-engineered cartilage in vivo.OBJECTIVE: To investigate the feasibility of constructing tissue-engineered osteochondral composite through bone marrow stem cells(BMSCs) cultured on the poly(lactide-co-glycolic acid) (PLGA), which was modified with collagen and cellular growth factors.METHODS: PLGA was made by phase separation technique, composited with collagen Ⅱ, basic fibroblast growth factor, and transforming growth factor-β1. The BMSCs of passage 3 were cultured on the above scaffolds. Thirty-six SD rats were randomly divided into experimental, control, and blank groups. These three groups received implantation of BMSCs composited with growth factors and collagen-PLGA, implantation of BMSCs composited with collagen-PLGA, and implantation of collagen-PLGA into the muscle, respectively. At 4, 8, and 12 weeks after surgery, cell directional differentiation and growth were examined by gross observation, hematoxylin-eosin staining, toluidine blue staining, collagen Ⅱ staining, and scanning electron microscope.RESULTS AND CONCLUSION: Gross observation showed that there were many chondroid tissues in the experimental group and fibrous tissues in the control and black groups. Stainings and electron microscope revealed that many chondroblasts and a few osteoclasts appeared in the composite of the experimental group. Toluidine blue and collagen Ⅱ stainings were positive in the experimental group and negative in the control and blank groups. These findings demonstrate that PLGA modified with collagen had a good cellular compatibility. BMSCs cultured on PLGA, which was modified with collagen and cellular growth factors, can construct the tissue-angineered osteochondral composite in rats.

The present study evaluated the effect of non-thermal plasma on skin wound healing in BalB/c mice. Two 6-mm wounds along the both sides of the spine were created on the back of each mouse (n=80) by using a punch biopsy. The mice were assigned randomly into two groups, with 40 animals in each group: a non-thermal plasma group in which the mice were treated with the non-thermal plasma; a control group in which the mice were left to heal naturally. Wound healing was evaluated on postoperative days (POD) 4, 7, 10 and 14 (n=5 per group in each POD) by percentage of wound closure. The mice was euthanized on POD 1, 4, 7, 10, 14, 21, 28 and 35 (n=1 in each POD). The wounds were removed, routinely fixed, paraffin-embedded, sectioned and HE-stained. A modified scoring system was used to evaluate the wounds. The results showed that acute inflammation peaked on POD 4 in non-thermal plasma group, earlier than in control group in which acute inflammation reached a peak on POD 7, and the acute inflammation scores were much lower in non-thermal group than in control group on POD 7 (P<0.05). The amount of granular tissue was greater on POD 4 and 7 in non-thermal group than in control group (P<0.05). The re-epithelialization score and the neovasularization score were increased significantly in non-thermal group when compared with control group on POD 7 and 10 (P<0.05 for all). The count of bacterial colonies was 10(3) CFU/mL on POD 4 and <20 CFU/mL on POD 7, significantly lower than that in control group (10(9) CFU/mL on POD 4 and >10(12) CFU/mL on the POD 7) (P<0.05). It was suggested that the non-thermal plasma facilitates the wound healing by suppressing bacterial colonization.

Objective:To measure the change in Young′s modulus of the biceps brachii during passive stretching and to assess the potential of shear wave elastography (SWE) as an auxiliary quantitative technique for assessing muscle tone.Methods:Forty-nine stroke survivors and 30 healthy subjects were evaluated using the modified Ashworth scale (MAS). According to their MAS scores they were divided into a healthy group, a healthy elbow group, an MAS class-0 group, an MAS class-1 group, an MAS class-1 + group and an MAS class-2 group. During passive extension of the subjects′ elbows, shear wave elastography was used to image the biceps brachii. Six points of the elbow were selected to record the instantaneous Young′s modulus ( EX) and calculate its change during the movement (Δ E). Those data were correlated with the MAS scores and compared among the groups. Results:Persons with higher MAS scores tended to have a higher Young′s modulus of the biceps brachii, and the modulus was likely to increase more with increases in the angle of elbow extension. From half of the range of motion to full extension there were significant differences in EX and Δ E between MAS class-0 and class-1 groups, as well as between the class-0 and class-1 + groups. There were, however, no significant differences between MAS class-1 and MAS class-1 + . Conclusions:MAS scores can usefully predict biceps brachii stiffness during passive elbow flexion. Shear wave elastography can quantify that stiffness and also muscle tone.

This article was aimed to study the general reproductive toxicity in mice in order to give a better evalua-tion of the medicinal plant of pineapple leaves (A nanas comasus L). Adult male and female mice were orally admin-istered with pineapple leaves. And then, each of the male and female mice was put together in one cage for mating. The mating success females were fed continuously. The experimental observation was conducted in pregnancy, fetal development, as well as the offspring of mice. The results showed that in addition to a large dose of pineapple leaves (4 g·kg-1) of the parental male rats having a lower body weight, pineapple leaves did not significantly affect on other parameters. There were no significant effects on pregnant mice and their offspring of mice. It was concluded that the pineapple leaves did not influence the general reproductive function of mice apparently.

Objective To investigate the effect and related mechanism of microRNA (miR)-494 on the hepatic ischemia-reperfusion injury (HIRI). Methods Twenty-four male SD rats were randomly divided into four groups (n=6 in each group). In the sham operation group, abdominal surgery without hepatic ischemia-reperfusion was performed. In the HIRI group, partial liver ischemia was performed for 60 min, followed by 6 h perfusion. In the HIRI+agomir-miR-494 group, intraperitoneal injection of agomir-miR-494 (20 μL) was daily given within preoperative 7 d. In HIRI+agomir-NC group, an equivalent quantity of agomir-NC was daily injected intraperitoneally within preoperative 7 d. The expression level of miR-494 messenger RNA(mRNA) in the liver tissues in each group was detected by reverse transcription polymerase chain reaction (RT-PCR). The expression levels of liver injury and oxidative stress related indexes were measured by relevant kits. The histopathological changes of the liver in each group were observed. The quantity of apoptotic cells and cytoplasmic histone-related DNA fragments in the liver tissues of rats was detected by relevant kits. The expression levels of the proteins related to the phosphatidylinositol-3-kinase(PI3K)/protein kinase(AKT) signaling pathway were measured by Western blot. Results The expression level of miR-494 mRNA in the rat liver tissues in the HIRI+agomir-miR-494 group was significantly higher than that in the HIRI+agomir-NC group (P < 0.01). The levels of the serum liver injury and oxidative stress related indexes in the HIRI+agomir-miR-494 group were significantly lower than those in the HIRI+agomir-NC group (all P < 0.01). Compared with those in the HIRI+agomir-NC group, the quantity of cellular necrosis was significantly reduced, the cell integrity was considerably increased and the quantity of TUNELpositive cells was evidently decreased in the HIRI+agomir-miR-494 group (all P < 0.05). The expression levels of poly ADP-ribose polymerase(PARP), cysteinyl aspartate specific proteinase-3(Caspase-3) and Bax in the HIRI+agomirmiR-494 group were significantly lower than those in the HIRI+agomir-NC group (all P < 0.05). The quantity of DNA fragments in the HIRI+agomir-miR-494 group was significantly less than that in the HIRI+agomir-NC group (P < 0.01). The expression levels of p-AKT, p-mammalian target of rapamycin(mTOR) and p-p70S6K in the HIRI+agomir-miR-494 group were significantly higher than those in the HIRI+agomir-NC group (all P < 0.05). Conclusions miR-494 can alleviate the severity of HIRI in rats by activating the PI3K/AKT signaling pathway.

There have been many reports on berberine (BBR) effect of the inhibition on gut bacteria,but more from the protein level.In view of the preference of BBR for DNA binding,we here investigated the expression of BBR from the transcriptional expression level of the gene.The results showed that BBR had a higher affinity for UP element of Escherichia coli (E.coli) gene,and the transcription initiation region of this element contained TATA base sequence.The expression of genes sulA,recA and 16S which contain the genes of the UP element regulatory elements in the upstream of the promoter could be suppressed by BBR,and the expression of lpxC,secG and mutT which did not contain the genes of the UP element regulatory elements in the upstream of the promoter could not be inhibited by BBR.It is shown that the TATA sequence is the target of BBR.This result provides a new perspective for exploring the effect of BBR's inhibition of microbiota from gene transcription.

The present study evaluated the effect of non-thermal plasma on skin wound healing in BalB/c mice.Two 6-mm wounds along the both sides of the spine were created on the back of each mouse (n=80) by using a punch biopsy.The mice were assigned randomly into two groups,with 40animals in each group:a non-thermal plasma group in which the mice were treated with the non-thermal plasma; a control group in which the mice were left to heal naturally.Wound healing was evaluated on postoperative days (POD) 4,7,10 and 14 (n=5 per group in each POD) by percentage of wound closure.The mice was euthanized on POD 1,4,7,10,14,21,28 and 35 (n=1 in each POD).The wounds were removed,routinely fixed,paraffin-embedded,sectioned and HE-stained.A modified scoring system was used to evaluate the wounds.The results showed that acute inflammation peaked on POD 4 in non-thermal plasma group,earlier than in control group in which acute inflammation reached a peak on POD 7,and the acute inflammation scores were much lower in non-thermal group than in control group on POD7 (P＜0.05).The amount of granular tissue was greater on POD 4 and 7 in non-thermal group than in control group (P＜0.05).The re-epithelialization score and the neovasularization score were increased significantly in non-thermal group when compared with control group on POD 7 and 10 (P＜0.05 for all).The count of bacterial colonies was 103 CFU/mL on POD 4 and ＜20 CFU/mL on POD 7,significantly lower than that in control group (109 CFU/mL on POD 4 and ＞1012 CFU/mL on the POD 7) (P＜0.05).It was suggested that the non-thermal plasma facilitates the wound healing by suppressing bacterial colonization.

Under the combination of postgraduate education and standardized medical residents training, via exploring current situation, we put forward the limitations of routine rotation training, disconnection of theory and practice, inefficient of scientific ability. We arouse a new model by improving teaching model, enriching teaching content, optimizing teaching method, making better arrangement of rotations and cultivating scientific ability to provide references for enhancing the ability of clinical thinking, practice, scientific research and communication.