Objective To study the bone disuse behavior with electric field under low load stimulation frequency. Methods A disuse model was proposed to describe the effects of mechanical and electrical stimulation on bone remodeling through the activation frequency. By establishing the finite element model of proximal femur and using the finite element method, the process of bone remodeling under low load stimulation frequency coupled with electrical stimulation was simulated, and the loss of bone density was analyzed. Results The density was significantly decreased by decreasing the frequency of daily load stimulation frequency. The electrical stimulation could resist density loss caused by the low load stimulation frequency to a certain degree, and its main influence areas were distributed in the femoral head and femoral neck. The duration of electrical stimulation significantly affected density loss of the cortical bone and cancellous bone. Conclusions The model can simulate the process of disuse caused by the decrease of daily load stimulation frequency. Meanwhile, the effect of electric field is taken into account to show the resistance to bone density loss.

Objective:To examine the characteristics of blood lipid profile and the correlation with clinic-pathological features of pancreatic cancer patients.Methods:The clinical and pathological data of 265 pancreatic cancer patients who received radical surgical treatment at Department of General Surgery,Qilu Hospital,Shandong University from January 2013 to September 2020 were collected and analyzed retrospectively. Among the 265 pancreatic cancer patients,there were 170 males and 95 females,with age of (61.0±9.6)years(range:28 to 86 years). General information,lipid indicators and clinic-pathological information were collected from electronic medical record system,and follow-up information gained by telephone. According to level of serum lipid in pancreatic cancer patients,265 patients were divided into dyslipidemia group( n=115) and normal lipid group( n=150). Pearson χ 2,Student′s t tests, variance analysis or univariate Logistic regression was used to analyze the correlation between dyslipidemia and clinico-pathological characteristics of pancreatic cancer,respectively. Kaplan-Meier survival curve was used to assessed the influence of dyslipidemia on prognosis of pancreatic cancer patients. Results:In 265 pancreatic cancer patients,115(43.4%)of them had dyslipidemias,and the most common form was increase of triglyceride(TG)(72.2%). In pancreatic cancer with dyslipidemias group,patients with body mass index ≥25 kg/m 2 had higher proportion than normal lipid group(36.1%(26/72) vs. 21.2%(21/99),χ2=4.643, P=0.031); The proportion of carcinoma located at head of pancreas(83.5%(96/115) vs. 40.7%(61/150),χ2=49.412, P<0.01), staging of T1/T2(79.1%(91/115) vs. 60.7%(91/150),χ2=10.316, P<0.01) and lymphatic metastasis(36.5%(42/115) vs. 22.7%(34/150),χ2=6.007, P<0.01) were higher. In patients of pancreatic cancer, dyslipidemias were closely associated with tumor location( OR=10.529, P<0.01)and body mass index( OR=3.671, P=0.008). Serum lipid profile results showed that TG,total cholesterol and high-density lipoprotein(HDL) disorders were associated with tumor location( P<0.05). TG disorder had association with body mass index( P<0.05), and HDL disorder had association with tumor stage( P<0.05). Moreover, the result of survival analysis showed that dyslipidemia was not a factor to impact the prognosis of pancreatic cancer patients underwent surgery( P>0.05). Conclusions:In pancreatic cancer patients,TG disorder was the most common type of dyslipidemia. Dyslipidemia has closely association with clinicopathologic features,including tumor location,body mass index,tumor stage. However,dyslipidemia had little effect on prognosis of pancreatic cancer patients.