Objective To study the relationship between land use/cover structure and changes and risk of plague prevalence.Methods Chifeng,Aohan,Alukeerqin and Wengniute were selected as typical areas of Spermophilus Dauricus plague foci in Inner Mongolia,density of Spermophilus Dauricus,plague epidemic and land use data in 1986,1995,2000 were collected,and risk of plague prevalence was represented by the density of Spermophilus Dauricus and epizooty of Spermophilus Dauricus.The percentage of land type structure,change degree of integrated land cover,division index of grassland for plague suitable habitat were calculated with ArcGIS 9.3.The relationship between the land use,cover change and the plague epidemic were analyzed by the methods of comparative.Results From 1982 to 2000,the density of Spermophilus Dauricus was lower than 0.4/hm2 and no epizooty of Spermophilus Dauricus was observed both in Aohan Banner and Chifeng City,which indicated low risk of plague prevalence.Contrarily,from 1982 to 2000,the density of Spermophilus Dauricus was higher than 1.0/hm2,and epizooty of Spermophilus Dauricus was prevalent in Alukerqin Banner,which implied high risk of plague prevalence.In Wenguiute Banner,the density of Spermophilus Dauricus was lower than 0.3/hm2 from 1982 to 1990,after then showed a rising trend,reached higher than 1.0/hm2 in 1991,1995-1997,and epizooty of Spermophilus Dauricus was also monitored,which denoted high risk of plague prevalence;In 1986,1995 and 2000,the proportions of grassland of Wengniute Banner,Alukerqinqi Banner (51.36％,49.14％,48.28％;56.97％,57.48％,57.44％) were much higher than Chifeng and Aohan Banner (35.99％,33.24％,32.95％;38.94％,34.46％,31.31％),but those of arable land (16.81％,18.78％,20.22％;13.28％,14.92％,15.15％) were lower than Chifeng and Aohan Banner (39.73％,42.25％,42.67％;41.21％,43.99％,49.53％).The highest of comprehensively dynamic degree of land cover changes appeared in Aohan Banner,and it was 0.53 and 1.11 in 1986 vs.1995 and 1995 vs.2000,respectively,and the lowest in Alukeerqin Banner,it was 0.22 and 0.05 during those periods.The grassland division index in Alukeerqin Banner was the lowest,which was 0.29 in 1986,0.28 in 1995,and 0.29 in 2000.The grassland division index was higher and showed a upward trends in Aohan Banner,which was 0.57 in 1986,0.69 in 1995 and 0.71 in 2000.Conclusion There is a certain relation between risk of plague prevalence and land use/cover structure and changes.

Objective To assess the value of upper airway narrowing with MSCT under quiet respiration in patients with the obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods CT scan of upper airway was performed in 63 patients with OSAHS during inspiration, expiration and quiet respiration respectively with 16-slice spiral CT. The state of the soft palate, the area of the smallest cross-sectional area of retropalatal and retroglossal space of the upper airway during the different respiratory phase were compared. The correlation between these dimensions and the polysomnography (PSG) results were analyzed. Results Some particular pattern of events occurred in 14 patients during the different phase of respiration, such as hooking of the soft palate, raising of the soft palate, artifacts, etc. These events occurred more often in the expiration phase. The cross-sectional area of the retropalatal space was the smallest during quiet breathing. There were statistically significant differences in the smallest cross-sectional area of retropalatal space among different phases of respiration (F=4.602, P＜0.05), also between inspiration and expiration, quiet breathing groups. No statistically significant difference was found between expiration and quiet breathing, nor in the smallest cross-sectional areas of retroglossal space among the three groups (P＞0.05). There was positive correlation between the smallest area of retropalatal space and LSaO_2 in quiet breathing and expiration groups (r=0.511, 0.300, P＜0.05). Conclusion MSCT scan of upper airway may be a better way to evaluate upper airway narrowing under quiet breathing when patients failed to carry out the required mode (keeping exhalation) or some undesirable events occurred.

Objective To analyze stress distributions of alveolar bone around implants with different types of implant thread shapes and thread depths during dental immediate implantation, so as to provide references for the design and selection of implants. Methods The simplified model of mandible bone block, implants and mandibular molar were established by Geomagic Studio, SolidWorks and ANSYS Workbench, and vertical and oblique loads were applied on this model, respectively. Stress distributions on implants with different thread shape and thread depth as well as alveolar bone around implants were calculated. Results Under vertical loading, the peak stresses of implants, cortical bone and cancellous bone were in the range of 120.51-129.63 MPa, 9.94-13.25 MPa and 3.92-8.01 MPa, respectively. And the stress of cortical bone around V-shaped, rectangular, buttress or reverse buttress implant remained stable in the range of 0.40-0.45 mm thread depth. Under oblique loading, the peak stresses of implants, cortical bone and cancellous bone were in the range of 220.23-286.51 MPa, 33.39-45.08 MPa, 4.96-12.5 MPa, respectively. Among the models, V-shaped, buttress, reverse buttress implant with 0.45 mm thread depth showed the minimum stress. Conclusions The V-shaped, buttress or reverse buttress implant with a thread depth of 0.45 mm, or the rectangular implant with a thread depth of 0.40 mm had better biomechanical properties.

Objective To investigate the differences in stress distribution at the bone-implant interface of dental implants with different length-diameter ratios, so as to provide references for the design of novel dental implants. Methods The three-dimensional finite element model of mandible was established using Geomagic studio, SolidWorks and ANSYS Workbench software. The mandibular molars were applied with different vertical or oblique forces, to compare and analyze stress distributions on dental implants and the surrounding bone tissues. Results Under the same length-diameter ratio, the maximum peak equivalent stress of implant under oblique loading was significantly higher than that under vertical loading. The Von Mises stresses of implants in Group A and Group B occurred in the neck under oblique and vertical loading. Under oblique loading, the implant stress variation in Group A and Group B was 144.74-374.67 MPa and 161.52-475.38 MPa, respectively. Under vertical loading, the implant stress variation in Group A and Group B was 101.28-187.40 MPa and 110.08-210.32 MPa, respectively. The maximum Von Mises stress of Group A was significantly smaller than that of Group B. Conclusions Dentists should focus on a length-diameter ratio of 2.67 to select the standard implants, and the jawbone quality of patients should be taken into full account.

Aim To investigate the effects of Shaoqiduogan(SQDG)on immunological hepatic fibrosis induced by human albumin in rats as well as its possible mechanisms.Methods The model of immunological hepatic fibrosis induced by human albumin was prepared.The rats were randomly divided into 6 groups,namely normal control group,liver fibrosis model group,SQDG(42.5,85,170 mg·kg~(-1))treated groups and colchicine(0.1 mg·kg~(-1)) treated group.HE staining was used to examine the histopathological change.The activities of transaminase in serum,malondiadehyde(MDA)content,superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activities,hydroxyproline(Hyp)content in liver homogenate were assayed byspectrophotometry.The levels of hyaluronic acid(HA)and procollagen Ⅲ (PCⅢ)in serum were determined by radioimmunoassay.In vitro,the collagen production of hepatic stellate cell(HSC)-T6 stimulated with transforming growth factor beta1(TGF-β1)was measured with 3H-Proline uptake.Results SQDG had obvious protective effects on human albumin induced hepatic fibrosis in rats.The results showed that the serum ALT and AST decreased by SQDG treatment,but had no significant difference compared with model group.Pathological examination showed that SQDG could remarkably alleviate the hepatic fibrosis.SQDG not only decreased the Hyp content in liver homogenates,but also the elevated level of HA,PCⅢ in serum.SQDG also ameliorated the oxidative stress state of hepatic fibrosis rats,decreased the production of MDA and enhanced the activities of antioxidative enzyme including SOD and GSH-Px.Furthermore,SQDG(20～160 mg·L~(-1))inhibited the collagen production of HSC stimulated with TGF-β1 in vitro.Conclusion sSQDG has protective effect on liver fibrosis rats induced by human albumin.The mechanisms of its anti-fibrotic effects may be associated with its action of ameliorating the oxidative stress in liver,and inhibiting the production of collagen in HSC.

Transforming growth factor β(TGF-β)superfamily ligands play an important role in regulating cellular homeostasis including proliferation,differentiation,apoptosis,immune sur-veillance and angiogenesis.Type Ⅲ TGF-βreceptor (TβRⅢ) is considered to be the coreceptor of TGF-βsuperfamily.TβRⅢnot only has an effect on classical Smad signaling pathway,but also on non-Smad signaling pathway.TβRⅢplays a crucial role in fibrosis,tumor,cardiovascular diseases via mediating kinds of signaling pathways.This paper reviews TβRⅢ mediated sig-naling pathway and its role in fibrotic diseases.

G protein- coupled receptors (GPCRs), also known as seven- transmembrane domain receptors, constitute the largest superfamily of cell surface receptors. By coupling to heterotrimeric G proteins, arrestins and other signaling molecules, GPCRs modulate diverse signal transduction pathways under physiological and pathological conditions. Recent studies have revealed crucial roles of GPCRs in tumorigenesis and development of cancer metastasis. This review summarizes roles of GPCRs, particularly the roles of those coupled to chemokines, prostaglandin, lysophosphatidic acid, endothelin, catecholamine and angiotensin in proliferation, invasion, metastasis and angiogenesis of hepatoma cells and development of hepatocellular carcinoma. The potential of GPCRs- based therapeutics being used for hepatocellular carcinoma is also highlighted.

Objective: To investigate the diagnosis and treatment effect of early inflammatory bowel obstruction after operation. Methods: The clinical data of 20 patients with early inflammatory bowel obstruction were analyzed.The therapeutic effect was analyzed. Results: 20 patients were treated with significant improvement in abdominal pain and abdominal distention, and gastrointestinal decompression volume was (221.6±138.6)mL/d.Patients with abdominal flat tablet showed that the intestinal canal was significantly reduced or disappeared, and all patients were cured and discharged. Conclusion For the patients with early inflammatory intestinal obstruction after operation, we should pay close attention to the clinical response of patients, adopt comprehensive treatment to relieve patients' pain.

Objective To evaluate the changes of the upper airway of the patients with obstructive sleep apnea syndrome (OSAS) before and after operations and to know the effects of operations by MSCT. Methods The upper airway dimensions of 26 patients with OSAS were measured on multiplanar reformatted (MPR), curved-planar reformatted (CPR), volume rendering(VR) images of 16-slice spiral CT. The measurements include the anteroposterior calibres and the areas on the reformatted axial images on the pharyngeal cavity levels, the calibres and the minimum areas in retropalatal and retroglossal regions, the areas of the soft palate and uvula on the reformatted sagittal view with maximum thickness, the maximum wall thickness of the right and left the upper airway on the coronary images, the volume of the upper airway before and after the operations. The measurements were correlated with the polysomnography (PSG) records. The data were analyzed paired-samples t-test and Pearson correlations. Results By comparison, the anteroposterior calibres and the cross-sectional areas on the reformatted axial view of the lower retropalatal region (slice 4) of the upper airway increased significantly after operations. The anteroposterior diameter increased from 5. 9 mm before operations to 12.8 mm after operations, where t = - 5.506, P < 0.05. The areas increased from 51.0 mm~2 before operations to 275.0 mm~2 after operations, where t = -5.011, P <0.05. In the higher retropalatal region (shce 2) of the upper airway, the anteroposterior diameter decresased from 14.8 mm before operations to 9.2 mm after operations, where t = 2.867, P < 0.05. The areas decreased from 241.0 mm~2 before operations to 128.0 mm~2 after operations, where t = 3.087, P < 0.05. The anteroposterior calibres of retroglossal region (slice 7) decreased from 12.7 mm before operations to 10.3 mm after operations,where t = 3.718, P <0.05. The L-R calibres and the minimum areas of of retropalatal increased significantly from 6.4 mm, 33.0 mm~2 before operation to 10.9 mm, 76. 0 mm~2 after operation, where t = -3.413, -2. 216, respectively and P < 0.05. Of the 9 cases whose apnea and hypopnea index (AHI) ≤5 events/hour after operations, the minimum areas of retropalatal region, the anterio-posterior diameter, L-R calibres increased significantly. The areas increased from 41.0 mm2 before operations to 76.0 mm~2 after operations, were t = -4. 932, P <0.05. The anteroposterior calibres increased from 4.6 mm before operations to 6.6 mm after operations, where t = - 7. 308, P < 0.05. The L-R calibres increased from 8.3 mm before operations to 13.6 mm after operations, where t = - 4.320, P < 0.05. Conclusions MPR、CPR、VR of MSCT can evaluate the not only the morphology but the function changes of the upper airways on the OSAS patients. The increasing of the minimum cross-sectional area may be one of the important indications for evaluating operations. The narrowing of the higher retropalatal region of the upper airway after operations should be an alert to the clinicians.

Objective To investigate the technical feasibility of medical robot in application to vascular intervention. Methods The independent-developed medical robot was used in the glass vessel model and vascular intervention experiments in a dog. Results The process of experiments were smooth,the system movement did not have any malfunction,and the animal experiments did not have any operative complications. The operative time was 50 minutes.Conclusions The medical robot can basically meet the requirements of cerebral angiography. It has laid a foundation for further development of intracranial vascular interventional procedures and clinical application.