Objective:To compare the fracture resistance of roots of mandibular premolar with different apical preparation diameters.Methods:Sixty single-rooted single canal permanent mandibular premolar teeth extracted newly for orthodontic reason without immatureness,fracture or cracks were selected,with a curvature less than 10°,and internal length:short diameter of less than 2 at a level 5 mm from the apex.All the teeth were decoronated,leaving roots 13 mm in length.The initial apical file size for the teeth was ≤ 15#.The roots were assigned to 6 groups based on weights with random block design.Group A:blank control group,no instrumentation was performed.Groups B-F:the master apical file (MAF) was 40#,45#,50#,55# and 60#,respectively.In the five experimental groups the roots were instrumented using hand files with step-back technique at 1 mm increments,resulting in a taper of 0.05.The irrigant used was distilled water.After mounted in acrylic resin,all the teeth were subject to vertical loading using an Instron testing machine until fractured.The occurrence of fractures was detected when the applied load suddenly decreased.The fracture load values and fracture modes were recorded.Oneway ANOVA and post-hoc Tukey test were used to determine the difference of fracture load values between the groups (P ＜ 0.05).Chi-square tests were used to compare the modes of root fracture.Results:Five experimental groups exhibited lower fracture load values than that of control group [(1 444 ± 155) N].The mean fracture load values for roots instrumented to an apical diameter of 50# [(1 027 ± 128) N],55# [(994 ± 150) N] and 60# [(983 ± 166) N] were significantly lower than that of control group and 40# group [(1 339 ± 131) N] and 45# [(1 287 ± 144) N] (P ＜0.05).Buccal-lingual fracture,mesio-distal fracture and compound fracture occurred 55％,13％ and 32％,respectively.No difference of fracture mode was detected in the six groups.Conclusion:The fracture resistance reduced significantly when the roots were instrumented to an apical diameter of 50# or larger.

Objective to evaluate the clinical efficacy and safety of ADSCs infusion in patients with type 2 diabetes mellitus(t2DM). Methods Autologous ADSCs were cultured and identified. totally 48 cases of type 2 diabetes patients were divided into two groups:24 cases in A group re-ceived ADSCs and conventional treatment,while the other 24 cases in B group received conventional treatment. With 15 months′follow-up,FPG,2h-PGh,HbA1c,FC-P,AUCC,insulin medication changes and security on post-treatment 3,6,12 and 15 months were calculated. Results the AD-SCs which cultured met the clinical application of standards. FPG,2h-PGh and HbA1c in both groups were significantly decreased,and the values in A group were more impressive than B. there were significant improvement in FC-P,AUCC and insulin of A group compared with B group. there was not treatment related adverse events. Conclusion the clinical data demonstrate that the treatment with ADSCs can improve metabolic control and beta cell function in patients with t2DM. Moreover,the safety of the treatment method was considerable.

ObjectiveTo investigate the prevalence and the characteristics of heart failure (HF) in medical intensive care unit (ICU) so as to explore the factors contributing to HF.Methods A retrospective analysis of the data of HF was carried out in 887 HF patients (54. 2％ ) males; age (69.83± 13.57) years oldadmitted to the medical ICU from October 2006 through June 2010. Clinical variables were systematically reviewed for all enrolled patients. HF as either major or additional diagnosis was recorded and the potential risk factors for HF were explored. Left ventricular systolic function was evaluated in HF patients by using ejection fraction (EF) measured by echocardiography. Multivariate Logistic regression analysis was used to identify the independent factors contributing to HF in medical ICU patients. Results Of the 887 patients, 74. 1％ aged 65 years or over, and 53％ had organ dysfunction. The prevalence of HF in medical ICU patients was 22. 8％. Echocardiography measurement revealed that left ventricular systolic function was preserved in 62. 5％ of HF patients with an EF ＞ 50％. Underlying heart diseases were identified in 72. 8％ of the HF patients, and coronary artery disease accounted for the vast majority (52. 5％ ), followed by valvular heart disease ( 17. 8％ ). Structural heart diseases were not identified in 27. 2％ of the HF patients. 4) After the adjustment of age and gender, multivariate regression analysis showed that coronary artery disease ( OR =7. 364, 95％ CI: 4. 979 ～ 10. 890, P ＜0. 01 ), valvular heart disease ( OR =18. 023, 95％ CI: 9. 280 ～ 35. 002, P ＜ 0. 01 ), diabetes mellitus ( OR =2. 154, 95％ CI: 1. 227 ～ 3. 784, P =0. 0076), respiratory failure ( ( OR =1. 527, 95％ CI: 1. 045 ～ 2. 229, P =0. 0285 ), and renal dysfunction ( OR =2. 638, 95％ CI: 1. 621 ～ 4. 294, P =0. 0001 ) were associated with risk increased for HF in medical ICU. ConclusionsHF is highly prevalent in medical ICU and its etiology is multi-factorial. The high rate of HF with preserved EF highlights the importance of enhanced alertness for HF with preserved systolic function in ICU.

Objective To investigate epidermal growth factor receptor(EGFR)expression and tumor residual to the prognostic value in patients with nasopharyngeal cancer(NPC).Methods 200 patients with NPC were examined for EGFR expression by immunohistochemistry analysis,neck cancer and nasopharyngeal residual.Results In 200 cases with NPC,expression of EGFR of positive and negative were 160 cases(80.0%) and 40 cases (20.0%);the rate of overall survival(OS),disease-free survival (DFS),loeoregional relapse-free survival (LRFS) and distant metastasis-free survival(DMFS)in patients with positive EGFR were 72.3%,63.6%,72.2%,63.8% and negative EGFR were 90.0%,90.0%,90.0%,90.0%,respectively in 3-year(X2=3.95,X2=4.12,X2=3.98,X2=4.15,P＜0.05),the rate of local recurrence,distant metastasis rate in residual were 26.6%,32.5% which is significantly higher than 8.1%,18.1% in without residual(X2=4.75,X2=4.94,P＜0.05);the hish expression of EGFR with DFS,OS were significantly correlated(r=6.457,P＜0.05).Conclusion The overexpress of EGFR had the tendency of poor prognosis.tumor residual after radiotherpy can be a prognostic indicator for patients with NPC.

0.05).The major toxicity and side effects were bone marrow inhibition,gastrointestinal reaction and mucosal reaction.The difference of hematologic toxicity and gastrointestinal between the two groups was statistically significant(P0.05).The GEM group could be well tolerated for the concurrent chemoradiotherap of patients with stage Ⅲ～Ⅳa nasopharyngeal carcinoma(NPC).

Objective:To measure the real temperatures on the pluggers of three continuous-wave de-vices, and to provide theoretical reference to evaluate thermal damage and heat ’s influence on the filling materials.Methods:The dual channel K type thermocouple was contacted to various sizes ’ pluggers in three different continuous-wave devices (BeeFill, Elements, B&L), and the highest temperatures at dif-ferent points ( tip, and 2 mm, 5 mm, 10 mm from the tip) of the pluggers ( preset temperature was 200℃) were recorded.The measurements were performed 5 times.T-test was used to compare the real tem-peratures at the tips with that set on the display and one-way ANOVA was used to compare the tempera-tures of the pluggers in different devices , sizes and points .Results:The highest temperature was at the tip of BeeFill 40/0.03 plugger (198.7 ±7.7) ℃, but there was on statistical differences between that and the preset temperature 200℃.The temperatures of the remaining pluggers were obviously lower than 200 ℃(P<0.05).The lowest temperature of the pluggers was detected at 10 mm from the tip of BeeFill 60/0.06 plugger (69.9 ±4.0) ℃.The highest temperature of each plugger was detected at the tip or 2 mm from the tip (112.1 to 198.7℃,and the median was 140.8℃).Conclusion:The real temperature of most continuous-wave pluggers included in this study is below the set temperature 200 ℃.

AIM: To study the effects of astragalosides (AS) on the proliferation and cell cycle of rat glomerular mesangial cell (MC), and verify the correlation between the influence and the AS concentration. METHODS: The experiment was carried out in the Physiological Laboratory of Liaoning Medical University from December 2006 to July 2007. Rat glomerular MCs were cultured in high glucose for 4-7 passages. The experiments were randomly divided into control group and three AS groups with different concentrations (50, 100, 200 mg/L), which were treated with high-glucose liquid and AS respectively. MC proliferation was determined with MTT colorimetric method in each group at hours 48 after intervention. MC cell cycle was detected with flow cytometry. RESULTS: ①MTT results showed that, the values of A490 nm in AS groups were lower than that in the control group at hours 48 (P

Objective To study collagen changes in dermis of hairless mice that were exposed to ultraviolet. Methods The hairless mice was irradiated under UVA, UVB and the combination of the two for 20 weeks, total dose of UVA was 222J/cm~2, and that of UVB was 5.9J/cm~2. After irradiation, the dorsal skin's collagens of animals were analysed by computer imaging analysis system, histopathologic examination, specific stains and electorn microscopy. Results The hairless mice exposed to ultraviolet A were unchanged in dermis collagen. The hairless mice was irradiated under UVB and the both UVA and UVB, and the content of collagen was decreased with less affinity for collagen staining. These findings were supported by electron microscopy, which showed fraying, thickened, and proliferating collagen, coalesced into extensive denaturalization. The ratio of types Ⅲ/Ⅰ+Ⅲ collagen was significantly increased. Conclusion The qualitative and quantitative changes of the collagen in the ultraviolet irradiated skin of hairless mice are related to ultraviolet B but not to UVA. UVB is a key factor of skin collagen damage in UV-irradiation.

Objective To study the changes of skin wrinkles in hairless mice while exposed to ultraviolet. Methods The hairless mice were irradiated under long-wave ultraviolet ray (UVA), medium-frequency wave ultraviolet ray (UVB) and the combination of the two for 20 weeks. Total dose of UVA was 222J/cm~2, and that of UVB was 5.9J/ cm~2. After irradiation, the skin wrinkling of animals were analysed by the naked eye, dermatoglyphics enlarges and applied color skin system of pathologic portrait quantitative analysis. Results Control group: The hairless mice skin were fine and delicate, the ditch and ridge of skin distributed even, and had no the obvious cornification. Long wave ultraviolet ray (UVA) set: The skin was slightly rough, skin ditch and ridge distributed still even, and had no obvious cornification; quantitative analysis had no the obvious difference from that of control group. Medium-frequency wave ultraviolet ray (UVB) set: The dermatoglyphics were disorderly, and the skin ditch deepened, widened, and the skin ridge increased the breadth and obvious cornification, and quantitative analysis had obvious difference from that of control group. Long wave and medium-frequency wave ultraviolet ray (UVA+ UVB) set: The dermatoglyphics was disorderly, and the skin ditch deepened, widened, the skin ridge increased the breadth, skin cornification was more obvious, quantitative analysis had obvious difference from that of control group. Conclusions The qualitative and quantitative changes of the wrinkles in the ultraviolet irradiated skin of hairless mice are related to ultraviolet B but not to UVA. UVB is a key factor of skin wrinkling in UV-irradiation.

Objective To promote the use of chemical peeling in facial rejuvenation with the phenol and croton oil peeling agents to the UVA/B-irradiated skin of hairless mice, and to provide the experimental evidence for the clinical application of the treatment of irradiated skin.Methods Sixty BALB/C hairless mice were photo-aged by use of chronic ultraviolet A and ultraviolet B irradiation for 20 weeks. After irradiation the animals were randomly divided into two groups:untreated (10 mice) and treated (50 mice). The phenol and croton oil chemical peeling agents were applied to the dorsal skin of treated animal group while it was full anesthetized. Punch biopsies were taken at 7, 14, 30, 60, and 90 days after peel for histological analysis. At 60 days after irradiation, the skin wrinkling of animals were analyzed by macroscopy, cleavage line amplification, and computer imaging analysis system. Results The treated areas of irradiated skin recovered rejuvenation and exhibited a unique connective tissue layer composed of fine collagen fibers beneath the epidermis. Conclusion The mixture of phenol-croton oil may reverses the visible stigmata of photoaging skin. Our results will be of great help to promote the use of chemical peeling in facial rejuvenation.