The long service life and high reliability of SiC sliding bearings are crucial for the long-term normal operation of aerospace power equipment.In response to the fracture phenomenon observed in the sliding bearing assembly of a certain delivery pump during operation,this paper analyzes the issue from the perspectives of stress characteristics and thermal expansion effects,proposing a structural optimization design method based on temperature coefficient compensation.The research indicates that the primary cause of bearing fracture is the difference in thermal expansion coefficients between the bearing and the metal rotor under elevated temperatures,leading to axial loosening of the bearing.Additionally,the gap between the bearing and the pin,combined with unstable lubrication of the friction pair,exacerbates bearing stalling and pin impact,ultimately causing cracks and localized chipping.By optimizing the bearing structure and employing a rubber pad for torque transmission,this issue has been successfully resolved.The improved structure demonstrated high reliability and stability in bench tests,providing important theoretical and technical references for the design of bearings under similar extreme operating conditions.

Objective To explore the effects from different contact areas of the instrument causing trauma on biomechanical response parameters of rabbit skull fractures under quasi-static compression conditions. Methods The rabbits were divided into the scalp preservation group and scalp removal group. Each group was subdivided into 3 mm group, 6 mm group, 9 mm group according to contact diameter of the instrument causing trauma. There were 9 rabbits in each group, 54 rabbits in total. All rabbits were put to death by over anesthesia and made into a skull compression model. An electronic universal material testing machine was used to perform quasi-static compression of rabbit skulls to fractures, and biomechanical response parameters such as ultimate load, deformation under ultimate load and compressive strength of rabbit skulls in each group were detected. Results The differences in ultimate load, deformation under ultimate load, and compressive strength of rabbit skulls in scalp preservation group and scalp removal group under different contact areas were statistically significant. The ultimate load was positively correlated with the contact area, and the compressive strength was negatively correlated with the contact area. No correlation was found between deformation under ultimate load and contact area. For scalp preservation group and scalp removal group, the difference in deformation under ultimate load was statistically significant in the 3 mm contact surface diameter group, and there was no statistical significance in the other groups. Conclusions The contact area is positively correlated with the ultimate load of rabbit skull fracture and negatively correlated with compressive strength, while it has no correlation with deformation under ultimate load and is unrelated to whether the scalp is removed.

PURPOSE: Survival of metastatic breast cancer (MBC) patient remains unknown and varies greatly from person to person. Thus, we aimed to construct a nomogram to quantify the survival probability of patients with MBC. MATERIALS AND METHODS: We had included 793 MBC patients and calculated trends of case fatality rate by Kaplan-Meier method and joinpoint regression. Six hundred thirty-four patients with MBC between January 2004 and July 2011 and 159 patients with MBC between August 2011 and July 2013 were assigned to training cohort and internal validation cohort, respectively. We constructed the nomogram based on the results of univariable and multivariable Cox regression analyses in the training cohort and validated the nomogram in the validation cohort. Concordance index and calibration curves were used to assess the effectiveness of nomogram. RESULTS: Case fatality rate of MBC was increasing (annual percentage change [APC], 21.6; 95% confidence interval [CI], 1.0 to 46.3; p < 0.05) in the first 18 months and then decreased (APC, -4.5; 95% CI, -8.2 to -0.7; p < 0.05). Metastasis-free interval, age, metastasis location, and hormone receptor status were independent prognostic factors and were included in the nomogram, which had a concordance index of 0.69 in the training cohort and 0.67 in the validation cohort. Calibration curves indicated good consistency between the two cohorts at 1 and 3 years. CONCLUSION: In conclusion, the fatality risk of MBC was increasing and reached the summit between 13th and 18th month after the detection of MBC. We have developed and validated a nomogram to predict the 1- and 3-year survival probability in MBC.
Breast Neoplasms* ; Breast* ; Calibration ; Cohort Studies ; Humans ; Methods ; Mortality ; Neoplasm Metastasis* ; Nomograms ; Risk Assessment*

Objective To explore the clinical effect of different scheme of moxifloxacin and levofloxacin for elderly multi drug resistant pulmonary tuberculosis.Methods 136 cases of elderly patients included in the study were randomly divided into the observation group 1 and observation group 2 with 68 cases in each group according to the sequence in group.The observation group 1 used moxifloxacin regimen for treatment of pulmonary tuberculosis while the observation group 2 used levofloxacin regimen.The two groups were treated for 18 months and observed the clinical curative effect,and the sputum negative,pulmonary lesions absorption,empty changes and adverse reactions.Results The total efficiency of the observation group 1 was 92.6％,which in the observation group 2 was 72.1％,the total efficiency of the two groups had a significant difference (x2 =9.917,P =0.002) ;the sputum negative conversion rate of the observation group 1 at the end of 3 months was significantly higher than that of the observation group 2 (x2 =4.115,P =0.043),no significant difference was found at the other time points (all P ＞ 0.05) ; after treatment,the obvious absorption + absorption of lung lesion in the observation group 1 was 59 cases,accounting for 86.8％,that in observation group 2 was 48 cases,accounting for 70.6％,two groups of lung lesions absorption had significant difference (x2 =5.303,P =0.021) ; the pulmonary cavity closure + reduced in the observation group 1 was 52 cases,accounting for 76.4％,that in the observation group 2 was 41 cases,accounting for 60.3％,with significant difference between the two groups (x2 =4.115,P =0.043) ;there was no significant difference in adverse reaction of the two groups (P ＞ 0.05).Conclusion Moxifloxacin anti tuberculosis regimen has a better curative effect in treatment of elderly patients with multi drug resistant pulmonary tuberculosis,which should be expanded the application.

Objective To verify the performance of HBV detection reagents for Roche MODULRA E170 electrochemical lumi-nescence analyzer .Methods Referring to CLSI EP15-A document ,the minimum detection limit ,linear range ,precision and accuracy of the HBV detection reagents were verified .Results The intra-assay coefficient of variation ,total coefficient of variation ,linear range of HBsAb ,and minimum detection limits of HBsAg and HBeAg of the HBV detection reagents for MODULRA E170 electro-chemical luminescence analyzer all reached the performance claimed by manufacturer .Conclusion The performance of HBV detec-tion reagents for MODULRA E170 electrochemical luminescence analyzer is excellent ,and it can meet the needs of clinical diagnosis and treatment .

Animal health systems initially established in Australia,Canada and other countries,played a very important role in prevention and control of animal diseases.Based on comparing the animal health systems of Australia with the veterinary medical system in China,some strategies was obtained for establishing a more reasonable official veterinary system and animal health system in China,thus speeding up the integration process of veterinary and human medical public health system.

The research on novel scaffold materials is now characterized by a transition from single element to composition, from inert materials to bioactive materials, and from macro- level to micro- level. With the rapid development of nano- technology and life sciences, the two concepts of nano- modification and biomimic construction joined the mainstream of the scaffold research. And in this field, the theory of bone generation net has been recently explored systematically and comprehensively. As a result, it has now become a research focus to obtain ideal bioactive scaffolds on the basis of current investigation. This paper highlights several types of promising scaffolds, discusses their recent research and application, and reviews the present situation concerning bioactive scaffolds

Objective To observe the effect of Yiqi Huaxian Decoction (YHD) on transforming growth factor ?1(TGF-?1 )mRNA expression in rats alveolar macrophages (AM) and pulmonary interstitial macrophages (IM).Methods Ninety-six Wistar rats were randomized into sham-operation group,model group,YHD (4 g?kg-1?d-1) group,and hydrocortisone (20 mg?kg-1?d-1) group.Bleomycin A5 was injected into the rats' trachea to induce pulmonary fibrosis.AM and IM were isolated for the culturing after modeling for 7 and 28 days.Molecular in-situ hybridization (ISH) was used for the detection of TGF-?1 expression in AM and IM.Results Percentage of cells in AM and IM with TGF-?1 positive expression and the score of optic density were increased in the model group (P