Objective To investigate the infection effects of different strains(Prototype,Delta,Beta,and Omicron BA. 1)of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)on transgenic mice K18-hACE2 expressing angiotensinconverting enzyme 2(ACE2)by nasal drip.MethodsMice were challenged with each strain of different gradients of doses by nasal drip,which were monitored for body mass and survival daily for 6 d in Beta group and 14 d in the other three groups. The median lethal dose(LD_(50))was calculated by IBM SPSS Statistics 26 analysis software,and the virulence of different SARS-CoV-2 strains were compared by detection of the viral nucleic acid loads of lung,brain and turbinate tissues and the lesion of lung tissues.ResultsBeta strain showed the strongest virulence and the highest lethality,and the lowest dose(1 CCID_(50))was 100% lethal with a LD_(50)less than 1 CCID_(50);The LD_(50) of Delta,Prototype and Omicron BA.1 strains were 0. 52,0. 60 and 52. 92 CCID50respectively. The copy number of viral nucleic acid in lung tissue of mice infected with different strains elevated with the increase of challenge dose,and the copy number of viral nucleic acid in brain tissue of dead mice reached 10~8～ 10~(11) copies/mL. The lung tissues of mice infected with different strains of different doses showed different degrees of pathological damage.ConclusionThe virulence of different SARS-CoV-2 strains in K18-hACE2 mice from high to low were Beta,Delta,Prototype and Omicron BA.1.

Objective: To study the determinants that affect patient satisfaction to rural doctors. Methods:Based on survey data of Liupanshui City, Guizhou Province, structural equation modeling analysis was adopted, and the study was mainly from the following four aspects:the image of rural doctors, service quality, quality of diagnosis and treatment, and harmonious doctor-patient relationships. Results: The study found that the quality of diagnosis and treatment had the greatest direct impact on rural patient satisfaction, followed by service quality, the image of ru-ral doctors and harmonious doctor-patient relationships;rural patient satisfaction has a significant impact on rural pa-tient loyalty. Conclusion:Rural patient satisfaction and loyalty to rural doctors is mainly based on kinship and geopo-litical relations;given the state of medical technology, the medical environment, medical equipment, service aware-ness and other restrictions, rural doctors cannot fulfill the “gatekeeper” role, and consequently, the primary health-care system has been severely affected.

Objective To make the detection results of the different automated hematology analyzers in laboratory to be reliable and comparable.Methods With the Beckman Coulter LH750 after calibration as the reference instrument,the fresh whole blood was extracted from the patient and divided into 3 equal parts after mixing evenly.The first part was determined the target value in the LH750 instrument;the second part was used to calibrate the HMX and ABX PENTRA 60 instruments and the third part served as a calibration validation.After calibration,the fresh whole blood of patient was performed the detection for conducting the accuracy evaluation.Results After calibration,the detection results of RBC,HGB,WBC,HCT,MCV and PLT by each instrument were largely improved and the error of the results was less than 1/3 of CLIA′88 requirements.Conclusion Adopting fresh whole blood for calibrating the hematology analyzer is feasible.

Structural heart diseases refer to anatomic heart or great vessels abnormalities by congential or acquired factors, including congenital heart disease, acquired heart valve disease, cardiomyopathy. In recent years, interventional therapy in structural heart diseases has gradually matured and been widely applied in clinical practice. Due to the fragility of heart valves and valve related organizations, or the congenital dysplasia of valves, the complex interventional therapeutic procedures can cause valve-related complications. In this paper, the causes, prevention and treatment of valve-related complications induced by interventional therapy in structural heart diseases are introduced.

Objective Discussion of diagnosing insulinoma.Methods Retrospective analysis based on 45 cases of insulinoma patients that are collected by General Surgery Department in the First Affiliated Hospital of Zhengzhou University from June 2008 to October 2014.Results Forty-five cases of patients with insulinoma including 41 cases (91.11％) of functional insulinoma and 4 cases (8.89％) of non-functional insulinoma.Apply selective arteriography,preoperative ultrasound,intraoperative ultrasound and CT to diagnosis.Forty-five cases of patients with insulinoma,in which 18 cases with laparoscopic simple tumor resection,6 cases with laparoscopic splenectomy and tail of the pancreas resection;45 cases of insulinoma with laprotomy,in which 8 cases with pancreaticoduodenectomy,12 cases which the tumors were located in the neck,neck-line of the pancreas with local excision of the pancreas and pancreatic tail-jejunal Roux-en-Y anastomosis,one cases of laparotomy found no placeholder.Conclusions Surgery removal is currently the most successful way to eliminate insulinoma.And localization diagnosis can determine the outcome of the surgery.Co-operation of surgery removal and localization diagnosis can be the optimal approach to diagnose certain insulinoma.

Objective To explore the value of ultrasonographic diagnosis of deltoid contracture (DC). Methods A total of 37 children with bilateral asymmetric shoulder were reviewed retrospectively, and 8 cases with 9 shoulders were surgically confirmed DC. The results of the ultrasonography and surgery were compared. Results The sensitivity of ultrasonographic diagnosis of DC was 88.89% and specificity was 100%. No statistically significant difference of contracture thickness measurement was found between surgery and ultrasonography. Ultrasonographic findings of DC in children included hyperechoic areas (7 cases) or hypoechoic area (1 case). Conclusion Ultrasounogrphy is an effective method for diagnosis of DC in children.

Tissue factor (TF), a transmembrane glycoprotein with a molecular mass of 47000, plays an important role of coagulation within vessel wall. Recently, people also present that TF have identifying and regulating function in cells signaling. And it contributes in the pathogenesis of atherosclerosis, angiogenesis and restenosis. This review presents the development of TF in above mentioned .

Objective To analyze the fracture characteristics, operative indicators, complications and treatment results of intertrochanteric fractures of femur in over 80 years old cases. Methods A total of 87 cases (90 hips) of intertrochanteric fractures with mean age over 80 years treated with operative methods from October 1996 to October 2004 were reviewed upon fracture types, preoperative primary diseases, operative methods and postoperative complications. Results The average age was 83.5 years. Of all, 74 cases had different physical diseases included cardiovascular, cerebrovascular, respiratory, digestive system and others (average 2.4 diseases per person). Treatment methods included DHS and intramedullary interlocking nail such as Gamma nail, PFN and reconstructive nails. A follow up for six months in 63 cases showed that excellence rate of functional evaluation was 84%(53/63). Conclusions The full evaluation and treatment of preoperative diseases are the prerequisite for the intertrochanteric fractures in the elderly, for the intertrochanteric fractures in the elderly have high incidence and many preoperative diseases and severe complications.

Dendritic cells is the most powerful professional antigen presenting cells in vivo.In recent years,DC vaccine has become one of the research hotspots in tumor treatment.DC vaccine which is modified by varieties of genes can solve antigens dissociation and tumor immune escape and so on caused by the weak tumor cell immunogenicity and lower DC antigen commission ability,and can induce stronger antitumor immune response,which can achieve inhibitory tumor,reduce tumor effect and brings new hope for patients with tumor.

BACKGROUND:Majority of patients appeared different degrees of hip joint bursitis and gradual y developed into femoral head necrosis in the early rehabilitation process of severe acute respiratory syndrome. OBJECTIVE:To analyze various causes of the severe acute respiratory syndrome sequela, and to review the treatment method of femoral head necrosis. METHODS:The PubMed database, China Journal Ful-text database (CNKI), VIP database and Wanfang database were retrieved by the first author with computer for the related articles from January 1997 to August 2012. The key words of“infectious atypical pneumonia, sequela, femoral head necrosis, bone ischemia, etiology, infectious atypical pneumonia virus, conservative treatment, operation treatment, total hip replacement”in English and Chinese were put in the title and abstract to search articles. A total of 872 articles were screened out after primary retrieval, and eventual y 56 articles were included for review. RESULTS AND CONCLUSION:Severe acute respiratory syndrome sequela, femoral head necrosis, was related with the dose and duration of hormone, patient’s sensitivity to hormone, using method, the secretion of leptin and bone calcitonin, and also infectious atypical pneumonia virus. The femoral head necrosis caused by the above factors can be treated with conservative treatment to slow down the process of femoral head necrosis and delay prosthesis replacement. Eventual y, most of the patients wil receive surgical method. For the treatment of advanced severe acute respiratory syndrome sequelae femoral head necrosis, prosthesis replacement can get the best effect.