OBJECTIVETo evaluate wear resistance and hardness of three kinds of new composite resins.

METHODSThree kinds of new composite resins, Solidex, Spectrum, Filtek Z350, were tested. Enamel as control group. A refited MG-200 wear machine was used in this study. Scanning electron microscope (SEM) was used to observe the friction surface of each tested material. Hardness of each tested material was determined by Vickers indentation technique. The data of wear and hardness were analyzed by Mann-Whitney test and 1-way ANOVA. The relationship between the hardness of the composites and the amount of wear of them was determined by a regression analysis method.

RESULTSFiltek Z350 showed the lowest volumetric wear and highest Vickers hardness in the composites (P < 0.05). No significant differences in wear and hardness were observed between Solidex and Spectrum (P > 0.05). Significant relationships were observed between the hardness of the composites and the amount of wear of them (r = 0.968 6) (P < 0.05). Different wear characters of the friction surface of the tested materials were observed by SEM.

CONCLUSIONNanofilled composite was superior to the hybrid composite in wear resistance and hardness.

Composite Resins ; Dental Enamel ; Dental Materials ; Dental Restoration Wear ; Hardness ; In Vitro Techniques ; Materials Testing ; Surface Properties

To develop Students' Practical Ability according to the teaching requirement and culture aim of preventive medicine major,the teaching plan,teaching content,teaching methods,and experimental check-ing methods were explored and the experimental teaching pattern of medical microbiology adapted to pre-ventive medicine major was constructed.The investigation showed that the experimental teaching pattern helped to cultivate the students' operating ability,thinking of scientific research and ability of aggregate and solving analysis.Moreover,it helped to develop the students' co-operative consciousness and team spirit.It indicated that the new pattern was superior to the traditional experimental teaching.

OBJECTIVETo evaluate the clinic effects of alginate impression and agar/alginate combined impression.

METHODS237 patients of fixed partial denture were collected and divided into group A and group B. Group A was taken impression by aglinate impression, including 81 patients (207 abutments). Group B was taken impression by agar/alginate combined impression, include 156 patients (392 abutments). The impressions were observed by megaloscope, and the number of abutment, the types and number of defect were recorded.

RESULTSIn the aglinate impressions, 57.0 percent of abutment had some defect. But in the agar/alginate combined impressions, 36.0 percent of abutment had some defect. There were significant difference between group A and group B in the abutment, air bubbles in cervical margin, unsharpness of the gingival sulcus and shoulders (P<0.05). There were no significant difference between group A and group B in the split and defect of the impressions on the cervical margin.

CONCLUSIONThere were less defects in the agar/alginate combined impression than in the alginate impression.

Alginates ; Dental Impression Materials ; Dental Impression Technique ; Dental Models ; Denture, Partial, Fixed ; Gingiva ; Glucuronic Acid ; Hexuronic Acids ; Humans

Bilingual teaching is adapted to the development of higher education in china.Based on actual fact of college,teaching mode,evaluation and effect of bilingual teaching on medical microbiology were studied,which started with necessity of bilingual teaching to use original edition teaching material in English. The result would provide some gist to choice the suitable pattern of bilingual teaching for other subject of our college.

OBJECTIVETo estimate the size of female sex workers and clients in Taizhou city.

METHODSA household survey using network scale-up method (NSUM) was conducted among the 3000 community residents in Taizhou city from August to October in 2011, which aimed to estimate the social network size (c value) of Taizhou residents, and the c value was adjusted by demographic characteristics, back estimation and outlier elimination. Using the adjusted c value, the number of acquaintance of female sex workers or clients and the respect level toward female sex workers or clients were used to estimate the size of female sex workers and clients.

RESULTSA total of 2783 valid questionnaires were collected, among which 1380 (49.6%) were collected from Taixing city, 1403 (50.4%) were collected from Jingjiang city. 1334 respondents were male (47.9%) and 1449 (47.9%) respondents were female. The mean age was (39.4 ± 10.7) years. The average personal social network size using original data for Taizhou residents was 525, which differed from place, sex, age, educational level and marriage status. Using the remaining known populations through back estimation, the social network size was 419 and became 424 after the elimination of outliers. The estimated population size for female sex worker was 6370 (95%CI: 5886 - 6853), which accounted for 0.52% (6370/1 229 980) of the total number of female aged from 15 to 49. The estimated population size for clients was 15 202 (95%CI: 14 560 - 15 847), which accounted for 1.28% (15 202/1 190 340) of the total number of males aged from 15 to 49 and the ration of clients to female sex worker was 2.39:1.

CONCLUSIONNSUM is an easy and quick way to estimate the size of female sex workers or clients, but the estimated sizes are subject to bias and error due to estimate effect and sample representativeness.

Adolescent ; Adult ; China ; Female ; Humans ; Male ; Middle Aged ; Sex Work ; statistics & numerical data ; Sex Workers ; statistics & numerical data ; Surveys and Questionnaires ; Young Adult

OBJECTIVETo explore the effect of microRNA (miRNA)-mediated p65 gene knockdown on the proliferation and apoptosis of human breast cancer MDA-MB-231 cells.

METHODSp65-targeted miRNA plasmid was constructed and transfected into MDA-MB-231 cells via lipofectamine(TM)2000. The expression of p65 gene in the transfected cells at the mRNA and protein levels were detected by RT-PCR and Western blotting, respectively. The cell proliferation and apoptosis were measured by MTT assay and flow cytometry (FCM), respectively. The expressions of apoptosis-related proteins were detected by Western blotting in the transfected cells.

RESULTSCompared with the negative control group, the expressions of p65 mRNA and protein in p65miRNA-trasnfected cells were significantly down-regulated (P<0.05). MTT assay showed significantly lowered viability of MDA-MB-231 cells after the transfection (P<0.05). FCM showed an increased cell apoptosis rate in p65miRNA group compared with that in the negative control group (P<0.05). Caspase-3 and PARP were both cleaved into their active forms and the expression of these active forms was increased in p65miRNA group.

CONCLUSIONThe miRNA targeting p65 gene can inhibit the proliferation and induce apoptosis of breast cancer cells, and p65 gene might become a new target in gene therapy for human breast cancer.

Apoptosis ; genetics ; Breast Neoplasms ; genetics ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Female ; Gene Knockdown Techniques ; Gene Silencing ; Humans ; MicroRNAs ; genetics ; RNA, Messenger ; genetics ; metabolism ; Transcription Factor RelA ; genetics ; metabolism ; Transfection

OBJECTIVETo build animal model of skull defect for the basic research of skull defects reconstruction with autogenous cranial bone dust and its relevance to the clinical application.

METHODSThree full-thickness parietal skull defects (A, B and C) were created in 30 New Zealand white rabbits. The size of all the defects was 1 cm in diameter. The defect A was left untreated as control. Defects B and C were reconstructed with autogenous cranial bone dust. Two pieces of pyroxylin membrane were placed on the top and bottom of the defect B. every 10 rabbits were killed for analysis at 4, 8, 12 weeks after operation.

RESULTSDefect A was largely repaired with connective tissue. Defect B was repaired rapidly with newly formed cancellous bone in the early period, but the following process of the growth, remodeling and maturing of the newly-formed cancellous bone was slowly. The bone ingrowth in defect C was more mature, but could not repair the defect completely, especially in the central zone. The grafted bone dust was absorbed gradually. Active angiogenesis could be observed in the newly formed bone. For the same defect, new bone had a greater amount of calcium at 12 weeks than at 4 and 8 weeks after operation (P < 0.05). And the calcium content of new bone was higher in defect C than in defect B at 8, 12 weeks after operation (P < 0.05).

CONCLUSIONSThe osteogenesis and angiogenesis are closely related to the time and location. The pyroxylin membrane can significantly promote the formation of cancellous bone in defect with autogenous bone dust graft during the early period.

Animals ; Bone Regeneration ; Bone Substitutes ; Bone Transplantation ; Female ; Male ; Materials Testing ; Osteogenesis ; Rabbits ; Skull ; Transplantation, Autologous

OBJECTIVETo distinguish spermatic cord torsion from acute orchitis by color Doppler flow imaging (CDFI).

METHODSThirteen patients with acute orchialgia were examined by CDFI. The clinical data of diagnosis and treatment were reviewed and analyzed.

RESULTSThe findings of CDFI showed lower or even no blood flow in the testes in 8 cases, which were diagnosed as spermatic cord torsion. Among them, 1 received manual detorsion and 7 were proved by operations. The other 5 showed abundant blood flow signal in the testes and were diagnosed as acute orchitis or epididymo-orchitis. After the use of antibiotics, their symptoms were relieved and the blood flow of the testes reduced upon reexamination.

CONCLUSIONSCDFI plays an important role in the diagnosis and differential diagnosis of spermatic cord torsion, and could be regarded as a detecting method of first choice for patients of acute orchialgia.

Adolescent ; Adult ; Child ; Diagnosis, Differential ; Humans ; Male ; Middle Aged ; Orchitis ; diagnostic imaging ; Spermatic Cord Torsion ; diagnostic imaging ; Testis ; blood supply ; diagnostic imaging ; Ultrasonography, Doppler, Color ; methods

OBJECTIVETo evaluate the clinical value of simultaneously combined pelvic floor dynamic MRI and pelvic organography in diagnosing female pelvic floor disorders and search for the best imaging model for diagnosing pelvic floor disorders.

METHODSThirty women with pelvic floor disorders received pelvic floor dynamic MRI and simultaneously combined pelvic organography including cystourethrography, peritoneography, vaginography and defecography. Clinical diagnostic value was compared between this two methods.

RESULTSThe diagnostic accuracy of pelvic floor dynamic MRI and simultaneously combined pelvic organograph for cystocele,anorectal junction abnormal descent, pelvic floor hernia,uterocervical prolapse was 100%, 95.2 %, 86.7%, 85.7% respectively. Rectocele and prolapse of rectal were diagnosed by pelvic organograph in 12 and 28 cases respectively, while only 6 and 0 cases were diagnosed by pelvic floor dynamic MRI respectively. The mean examining time of pelvic floor dynamic MRI and simultaneously combined pelvic organography was (16 +/- 3)min, (34 +/- 9)min respectively (P< 0.01).

CONCLUSIONPelvic floor dynamic MRI combined with defecography is the best imaging model for diagnosing pelvic floor disorders.

Adult ; Aged ; Encopresis ; diagnosis ; diagnostic imaging ; Female ; Genital Diseases, Female ; diagnosis ; diagnostic imaging ; physiopathology ; Humans ; Magnetic Resonance Imaging ; methods ; Middle Aged ; Pelvic Floor ; physiopathology ; Pelvis ; diagnostic imaging ; Radiography, Abdominal ; Urinary Incontinence, Stress ; diagnosis ; diagnostic imaging

OBJECTIVETo construct lentivector carrying Tie2-Small interfering RNA (SiRNA), so as to study its influence on malignant melanoma cells.

METHODSRecombinant plasmid pSilencer 1.0-U6-Tie2-siRNA and plasmid pNL-EGFP were digested with XbaI, ligated a target lentiviral transfer plasmid of pNL-EGFP-U6-Tie2-I or pNL-EGFP-U6-Tie2-II, and then the electrophoresis clones was sequenced. Plasmids of pNL-EGFP-U6-Tie2-I and pNL-EGFP-U6-Tie2-II were constructed and combined with pVSVG and pHelper, respectively, to constitute lentiviral vector system of three plasmids. The Lentiviral vector system was transfected into 293T cell to produce pNL-EGFP-U6-Tie2- I and pNL-EGFP-U6-Tie2-II lentivirus. Then the supernatant was collected to determine the titer. Malignant melanoma cells were infected by both lentiviruses and identified by Realtime RT-PCR to assess inhibitory efficiency.

RESULTSThe recombinant lentiviral vectors of Tie2-RNAi were constructed successfully which were analyzed with restriction enzyme digestion and identified by sequencing. And the titer of lentiviral vector was 8.8 x 10(3)/ml, which was determined by 293T cell. The results of Realtime RT-PCR demonstrated that the lentiviral vectors of Tie2-RNAi could infect malignant melanoma cells and inhibit the expression of Tie2 genes in malignant melanoma cells (P<0.01). There was no significant difference in the expression level (P>0.05) between the two lentiviral vectors of Tie2-RNAi.

CONCLUSIONSLentivector carrying Tie2-SiRNA can be constructed successfully and inhibit the expression of Tie2 gene in vitro significantly. The study will supply the theory basis for the further research on the inhibition of tumor growth in vivo.

Cell Line, Tumor ; Genetic Vectors ; Humans ; Lentivirus ; genetics ; Melanoma ; genetics ; Plasmids ; RNA Interference ; RNA, Small Interfering ; genetics ; Receptor, TIE-2 ; genetics ; Transfection