OBJECTIVETo establish a perceived fatigue evaluating model during simulated load carriage that is based on objective variables through analyzing the characteristics and trends of shoulder force, shoulder pressure, waist pressure, back pressure, and perceived fatigue, and to provide an analytical technique for research on load carriage.

METHODSA 50-min simulated walking (at a speed of 5 km/h and a slope of 0%) experiment including 14 healthy male adults was conducted under four levels of backpack payloads (25, 29, 34, 37 kg). Shoulder force and trunk pressure were sampled simultaneously and analyzed with time- and frequency- domain methods. Multivariable linear regression was used to build a perceived fatigue evaluating model during load carriage.

RESULTSThe perceived fatigue evaluating model based on shoulder force, trunk pressure distribution ratio, load, and body mass index (BMI) was established. Its adjusted determination coefficient (aR2) was 0.709 and the absolute percentage error (APE) at the end of the experiment was less than 20%. The goodness of fit of the model based on frequency-domain independent variables was much higher compared with the model based on time-domain independent variables. The addition of BMI that represents the individual differences to the model obviously improved the goodness of fit.

CONCLUSIONThe perceived fatigue evaluating model established in this study does not rely on the physiological changes of individuals, and thus can be used to establish an evaluation system for human load carriage with dummy as a substitution for human in experiments and to provide a scientific basis for efficient human load carriage.

Objective To investigate the treatment of acute obstructive colorectal cancer.Methods The clinical data of 26 cases with acute obstructive colorectal cancer were analysed retrospectively and relevant literatures were reviewed.Results Radical right hemicolectomy was performed in 9 patients with obstructive right colonic cancer.Among 17 patients with obstructive left colorectal cancer,one-stage radical resection was perfomed in 12 cases,including one-stage anastomosis in 4 cases and Hartmann's operation in 8 cases.Palliative colostomy was performed in 3 cases.Right hemicolectomy and sigmoid colon loop colostomy was performed in 1 case of rectum cancer with ascending colon strangulation.One case refused surgery.Two cases died of MODS and 1 case with inflammatory ileus recovering from conservative treatment after operation.In the course of disease,septic shock and MODS happened in 3 cases,lung infection in 5 cases,heart disease in 2 cases and Hypoalbuminemia in 16 cases.Conclusions One-stage radical colectomy and anastomosis should be performed in patients with obstructive right colonic cancer.In order to reduce toxin absorption and prevent the deterioration of disease,Bowel decompression and removal of inflammatory exudate should be performed in patients with obstructive left colorectal cancer according to the damage control theory.Then effective and safe operation should be chosen in accordance with patients' status.Anti-infection and nutrition support treatment must be strengthened after operation.

Objective To investigate the significance of modified gold nanocages ( GNCs ) in photothermal therapy and radiosensitivity enhancement for murine mammary carcinoma 4T1 cells.Methods A molecule probe, CD44-PEG-GNCs, was constructed on the basis of GNCs.Inductively coupled plasma mass spectrometry ( ICP-MS) and transmission electron microscopy ( TEM) were used to analyze Au uptake by 4T1 cells.The cell counting kit-8( CCK-8) assay was used to determine the impact of the probe on the viability of 4T1 cells.The CCK-8 assay and the Hoechst/PI double staining were used to evaluate the photothermal killing effects of near infrared laser (NIR).The colony forming assay and the Hoechst/PI double staining were used to measure the viability of 4T1 cells after irradiation with 6 MV of X-ray.Results ICP-MS and TEM showed that 4T1 cells had an uptake of a large number of GNCs, in which the number of CD44-PEG-GNCs taken up by 4T1 was 3-4 times larger than that of PEG-GNCs.The cell toxicity assay revealed that in a certain range of concentration, GNCs showed little effect on the viability of 4T1 cells, which was reduced to 81.2%in 48 hours.The CCK-8 assay, the Hoechst/PI double staining, and the colony forming assay showed that after NIR irradiation and radiotherapy, large-scale apoptosis was induced in CD44-PEG-GNCs-contained tumor cells by photothermal therapy combined with radiotherapy, which had substantially better outcomes than other groups.Conclusions The GNC-based molecular probe actively targets 4T1 cells with little cytotoxicity, indicating that it enhances the sensitivity of tumor towards photothermal therapy and radiotherapy.

Objective:To compare the compressive strength of porcelain crown with Co-Cr,CAD/CAMpure titanium and CAD/CAM zirconia respectively.Methods:Metal models of simulating crown core of the ideal premolar were manufactured,digital data of the met-al model were obtained by CAD/CAMsystem,the basement crowns of Co-Cr,CAD/CAMpure titanium and CAD/CAMzirconia were respectively made(n =5),size of each crown was kept the same and the spcimens were set as group A,B and C respectively.Then masking porcelain and body porcelain were fired on basement crowns according to the instructions.The thickness of the porcelain was kept the same.All of the porcelain crowns were located on the Instron testing machine,the compression strength force values were measured.Data were statistically analysed by SPSS 1 3.0 software.The bonding surface of basement material and porcelain was observed by SEMafter compressive failure.Results:The compressive strength(N)of group A,B and C was 2 990 ±1 88,2 305 ±1 57,2 1 50 ± 1 31 ,A vs B or C,P <0.05,B vs C,P >0.05.Conclusion:All the 3 base materials with porcelain crown satisfy the clinical require-ments.The compressive strength of Co-Cr porcelain crown is stronger than that of CAD/CAMpure titanium porcelain crown and CAD/CAMzirconia porcelain crown.

Objective:To explore the influence of the veneering porcelain thickness on the compressive strength of zirconia all-ceramic crown.Methods:25 zirconia basement crowns with the thickness of 0.5 mm were made by CAD-CAMsystem,and then were divided into 5 groups randomly with the veneering porcelain thickness of 0.5(A),1.0(B),1.5(C),2.0(D)and 2.5 mm(E)respectively. The compressive strength of the samples was measured by a testing machine.Statistical analysis was conducted by SPSS13.0 software. The microstructure of the fractured bonding interface of the specimens was observed by scanning electron microscope(SEM).Results:The compressive strength in group A,B,C,D and E were:(1 279.96 ±42.85)N,(2 235.44 ±50.14)N,(2 216.38 ±48.97)N, (2 169.22 ±60.40)N and (2 028.70 ±47.37)N respectively(A or E vs B,C or D,P <0.01;A vs E,P <0.01;B vs C or D,P >0.05;C vs D,P >0.05).SEMobservation found that in group A and E the bonding interface was uneven and loose,the cracks and spores in veneering porcelain appeared more and larger,and had a more intensive distribution.Conclusion:When the veneering porce-lain is too thick or too thin,the compressive strength of zirconia all-ceramic crown decreases,the thickness of the veneering porcelain should be controled in an appropriate range.

Objective To investigate the relationship between the resting heart rate (RHR) and target organ damage (TOD) in elderly patients with metabolic syndrome(MS). Methods 264 elderly patients with MS were divided into four groups according to the level of RHR: RHR1 group, RHR<65 beats/minute (bpm) (46 cases) ;RHR2 group, 65≤RHR<75 bpm (77 cases);RHR3 group, 75 bpm≤RHR<85 bpm (89 cases);RHR4 group, RHR≥85 bpm (52 cases).Electrocardiography, echocardiography, carotid uhrasonography, crcatinine clearance rate (Ccr) and quantitative assay of 24 hours' albuminuria were performed. Results (1) Compared with RHR1, RHR2 and RHR3 groups, RHR4 group showed higher levels of carotid intima-medial thickness (IMT), carotid arterial diameter (CAD), left ventricular mass index (LVMI) and albuminuria(P< 0.05 or P<0.01), and lower levels of left ventricular ejection fraction (LVEF) and Ccr (all P< 0.01). (2) The IMT, CAD, LVMI and albuminuria were positively correlated with RHR (r=0.33, 0.23, 0.61, 0.58, respectively, all P<0.01). However, the LVEF and Ccr were negatively correlated with RHR (r=-0.59, -0.51, all P<0.01). (3) Logistic multivariate analysis showed that RHR and pulse pressure (PP) had effects on myocardial hypertrophy, coronary heart disease, heart failure, cerebral stroke and renal dysfunction(P<0.05 or P<0.01). Except heart failure, PP played a more important role than RHR. Coneinsions RHR may be an independent risk factors for TOD in elderly patients with MS,and RHR regulation is important for the development of MS in the elderly.

AIM: To study the possibility that yellow wine improves the pathological changes of atherosclerosis in vivo. METHODS: Six weeks old LDL receptor knockout mice (n=48) on a high-fat and L-methionine diet developed plasma hyperhomocysteinemia and atherosclerosis. The animals were randomly divided into yellow wine group, red wine group, ethanol group and control group (n=12 in each group) and were sacrificed after 14 weeks. The levels of plasma lipids and homocysteine in serum were examined. The morphological changes of aorta artery and the atherosclerosis of aorta sinus were observed under microscope. The expression and activation of matrix metalloproteinase-2 (MMP-2) were determined by the method of immunohistochemistry. RESULTS: No significant difference of plasma total cholesterol, triglyceride or high density lipoprotein cholesterol among groups was observed. Plasma homocysteine was significantly decreased in yellow wine group as compared to other three groups (P<0.01). Compared to ethanol and control groups, use of yellow wine and red wine significantly reduced the atherosclerosis lesion area (P<0.01). However, no significant discrepancy between the yellow wine group and red wine group was found. Compared to control group, the expression of MMP-2 in yellow wine group, red wine group and ethanol group decreased by 26.3%, 27.6% (P<0.01) and 5.7% (P>0.05), respectively. The activity of MMP-2 in yellow wine group, red wine group and ethanol group decreased by 31.7%, 32.5% (P<0.01) and 6.7% (P>0.05), respectively. CONCLUSION: Yellow wine and red wine inhibit the expression of MMP-2 and improve the pathologic changes of atherosclerosis, indicating that they have benefic effects on cardiovascular system.

Objective To observe the effects of rosuvastatin on the homocysteine (Hcy)-induced expression of matrix metalloproteinase 2 (MMP 2) and cell migration in rat vascular smooth muscle cells (VSMCs), and to explore the possible mechanism of Hcy-induced atherosclerosis and the role of statins in reversing atherosclerosis. Methods In one cell culture plate, the cultured rat VSMCs were incubated with different concentrations of Hcy (0, 50, 100, 500, 1000 μmol/L and 5000 μmol/L) in vitro for 24 h, 48 h and 72 h. And in another cell culture plate, the different concentrations of rosuvastatin (10-9, 10-8, 10-7, 10-6, 10-5 mol/L and 0 mol/L) were added to the cultured rat VSMCs (while the concentration of Hcy was 1000 μmol/L). The MMP 2 expression and enzyme activity were determined by gelatin zymography and Western blotting. The effects of Hcy and rosuvastatin on cell migration and invasiveness of VSMCs were observed. Results Hcy (50-5000 μmol/L) increased the protein expression, and Hcy (50-1000 μmol/L) increased enzyme activity of MMP 2 significantly. But Hcy (5000 μmol/L) inhibited activity of MMP 2 (F=9.31, 6.44 and 5.97, all P＜0.05). Rosuvastatin (10-9-10-5 mol/L) inhibited Hcy-induced expression and enzyme activity increasing of MMP 2. The counts of cell migration of VSMCs were 18.32±2.17, 32.68±4.34, 44.75±4.08, 61.39±5.21, 79.74±5.54 and 90.78±5.83, while the concentration of Hcy was 0, 50, 100, 500, 1000 μmol/L and 5000 μmol/L respectively (F=5.31, P＜0.05). The counts of cell migration of VSMCs were 79.74±5.54, 62.53±6.41, 48.37±5.66, 31.41±4.79, 19.27±3.62 and 11.17±2.33, while the concentration of rosuvastatin was 10-9, 10-8, 10-7, 10-6 and 10-5 mol/L respectively (F=4.99, P＜0.05). Rosuvastatin could decrease the stimulation of Hcy-induced migration of VSMCs. Conclusions Hcy can influence the MMP 2 protein expression/activity in VSMCs, and rosuvastatin can inhibit augmentation of Hcy-induced MMP 2 expression/activity and migration of VSMCs. It may be one of the multiple-effects of rosuvastatin reducing atherosclerosis.

Objective To evaluate the effect of dexmedetomidine on the quality of intraoperative wake-up test in the patients undergoing balloon occlusion test of the internal carotid artery.Methods Forty-two patients of either sex with intracranial aneurysm,aged 57-78 yr,weighing 53-86 kg,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,scheduled for elective balloon occlusion test of the internal carotid artery under general anesthesia,were assigned into 2 groups (n =21 each) using a random number table:propofol conbined with remifentanil group (group PR) and dexmedetomidine combined with propofol and remifentanil group (group DPR).In group DPR,dexmedetomidine was intravenously infused over 15 min in a loading dose of 0.5 μg · kg-1 before induction of anesthesia,followed by an infusion of 0.3 μg · kg-1 · h-1 throughout surgery.Propofol and remifentanil were given by target-controlled infusion (TCI) after infusion of the loading dose.The patients were mechanically ventilated after placement of the laryngeal mask airway.Maintenance of anesthesia was as follows:propofol and remifentanil were given by TCI with the target plasma concentrations of 0.5-1.0 μg/ml and 1-3 ng/ml,respectively,in group DPR;propofol and remifentanil were given by TCI with the target plasma concentrations of 3-5 μg/ml and 3-6 ng/ml,respectively,in group PR.Bispectral index (BIS) value was maintained at 40-60.Before wakeup test,propofol infusion was stopped and the target plasma concentration of remifentanil was decreased to 0.5 ng/ml in two groups,and the infusion rate of dexmedetomidine was decreased to 0.1 pg · kg-1 · h-1 in group DPR.The wake-up time was recorded and the wake-up quality was assessed.After admission to the operating room (T0,baseline),at 10 min before wake-up test (T1),immediately after patients were wakened (T2),at 10 min after patients were wakened (T3) and at the end of wake-up test (T4),the mean blood pressure (MAP),heart rate,respiratory rate (RR),SpO2 and BIS values were recorded.The development of intraoperative awareness,emergence time,postoperative agitation,nausea and vomiting,regurgitation and aspiration and severe pain was recorded.Results MAP,heart rate,SpO2 and RR were all within the normal range during wake-up period in two groups.Compared with the baseline at To,MAP was significantly decreased at Ti,3,4 in group PR,and BIS value was decreased at T1-4 in DPR and PR groups (P＜0.05).Compared with group PR,MAP was significantly increased at T1.3,BIS value was decreased at T24,the wake-up time was shortened,Ramsay sedation score and wake-up quality were increased,the emergence time was shortened,and the incidence of agitation was deceased (P＜0.05),and no significant change was found in verbal rating scale scores assessed after extubation in group DPR (P ＞ 0.05).No cardiovascular events,respiratory depression,intraoperative awareness,postoperative nausea and voniting,regurgitation and aspiration or severe pain was found in two groups.Conclusion Dexmedetomidine can raise the quality of intraoperative wake-up test in the patients undergoing balloon occlusion test of the internal carotid artery.

Objective To observe the effects of Weipixiao on the ultrastructure of gastric mucosa capillaries in rats with precancerous lesions of gastric cancer ( PLGC). Methods The rats were randomized into six groups, including normal group, model group, Vatacoenayme Tablets group ( 0.2 g·kg-1·d-1) , and high-, middle-, and low- dose Weipixiao groups ( 15, 7.5, and 3.75 g·kg-1·d-1 respectively) . The rats received spontaneous intake of N-methyl-N’-nitro-nitrosoguanidine ( MNNG, 200 μg/mL) solution combined with irregular diet and intragastric administration of purgative herbs Xiao Chengqi Decoction ( 2 mL, containing 1 g/mL crude drug) for 18 weeks to induce spleen-deficiency PLGC. The pathological changes in gastric mucosa and the ultrastructure of gastric mucosa capillaries were observed under the transmission electron microscope. Results The model has been established successfully. Transmission electron microscopy results in the model group showed as severely swollen endothelial cells of gastric mucosa capillaries, severely-narrowing or even blocked vascular lumens, rough and discontinuous basement membrane, and swollen, degenerated or even absent pericytes. And the ultrastructure of gastric mucosa capillaries in high-, middle-, and low- dose Weipixiao groups were improved to some degrees, the effect of low-dose Weipixiao group being the best. Conclusion The improvement of the mucosal microcirculation of spleen-deficiency PLGC rats may be one of the pathohistological mechanisms of Weipixiao for spleen-deficiency PLGC.