OBJECTIVE: To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. METHODS: The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. RESULTS: The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. CONCLUSION The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans ; Finite Element Analysis ; Knee Joint/physiology* ; Tibia/anatomy & histology* ; Cartilage, Articular/physiology* ; Menisci, Tibial/physiopathology* ; Tomography, X-Ray Computed ; Osteoarthritis, Knee/diagnostic imaging* ; Weight-Bearing ; Bone Density ; Adult ; Stress, Mechanical ; Male ; Middle Aged ; Biomechanical Phenomena ; Female

Objective:To establish HPLC chromatogram for Aspongopus; To determine 8 nucleoside components of uracil, adenine, uridine, uric acid, hypoxanthine, adenosine, xanthine and canine quinolinic acid; To provide reference for quality control and evaluation.Methods:The Agilent ZORBAX SB-Aq chromatographic column (4.6 mm×250 mm, 5 μm) was used for gradient elution with mobile phases consisting of a methanol (A) and 0.05% phosphoric acid (B). The column temperature was 25 ℃, the flow rate was 0.8 ml/min, and the detection wavelength was 254 nm. HPLC chromatograms for Aspongopus were established and the contents of 8 components were determined.Results:The characteristic chromatogram of 15 batches aspongopus herbs was established. A total of 10 common characteristic peaks were identified and 8 were identified. The similarity between the characteristic chromatogram of samples and the control chromatogram was 0.969-0.997. The content determination showed that the linear range of uracil, adenine, urin, uric acid, hypoxanthine, adenosine, xanthine and xanuric acid was among 0.002 0-0.644 0, 0.001 4-0.448 0, 0.001 0-1.257 0, 0.005 4-6.221 0, 0.001 0-0.724 0, 0.001 0-0.644 0, 0.002 0-1.113 0, 0.003 8-2.059 0 μg, respectively, with a good linear relationship ( r≥0.999); the repeatability and stability of RSD were <2.0%, and the average sampling recovery rate was between 99.36% and 103.40%. Conclusion:The characteristic chromatogram and content determination method established in this study are simple, reliable, reproducible and accurate, and can be used for the qualitative and quantitative analysis of Aspongopus and can provide a reference for the quality evaluation method of the Aspongopus.

OBJECTIVE To establish the specific chromatogram of Qianghuo Shengshi Tang(QHSS) reference sample, clarify the key quality attributes of QHSS, providing reference for the quality evaluation of QHSS reference sample. METHODS The SilGreen C18 column(4.6 mm×250 mm, 5 μm) was used. The mobile phase consisted acetonitrile and 0.2% formic acid aqueous solution. The detection wavelength was 328 nm. Established an HPLC characteristic spectrum analysis method for the reference sample of QHSS. A variety of chromatographic columns and different instruments were applied to investigate the adaptability of the system. HPLC-LTQ-Orbitrap MS was used to identify the specific peaks of the QHSS reference samples in positive ion mode. RESULTS There were 14 peaks in the specific chromatogram, which belonged to Notopterygii Rhizoma Et Radix, Angelicae Pubescentis Radix, Ligustici Rhizoma Et Radix, Chuanxiong Rhizome, Viticis Fructus, respectively. Ferulic acid(peak 3) was reference peak. A total of 22 compounds were identified by mass spectrometry, including coumarin and flavonoids. CONCLUSION The established specific chromatogram method of QHSS is simple, stable and reproducible. The material basis of QHSS reference sample is basically determined, providing a reference for the development and quality control of QHSS.

ObjectiveTo investigate the different effects of Yunvjian with or without Achyranthis Bidentatae Radix on glucose and lipid metabolism and inflammatory response in diabetic rats with the syndrome of Yin deficiency and internal heat. MethodThe rat model of diabetes due to Yin deficiency and internal heat was established by feeding with a high-sugar and high-fat diet and injection of thyroxine and streptozotocin. The successfully modeled rats were randomized into model control， Yunvjian without Achyranthis Bidentatae Radix （11.8 g·kg^-1）， Yunvjian with Achyranthis Bidentatae Radix （12.8 g·kg^-1）， and Achyranthis Bidentatae Radix （1.0 g·kg^-1） groups （n=10）， and another 10 rats were taken as the normal control group. Each group was administrated with corresponding drugs or saline by gavage for 28 days. The fasting blood glucose （FBG）， fasting insulin （FINS）， total cholesterol （TC）， triglycerides （TG）， low-density lipoprotein cholesterol （LDL-C）， and high-density lipoprotein cholesterol （HDL-C） in rats were measured. Enzyme-linked immunosorbent assay was employed to determine the levels of cyclic adenosine monophosphate （cAMP）， cyclic guanosine monophosphate （cGMP）， triiodothyronine （T₃）， thyroxine （T₄）， interleukin （IL）-1β， IL-6， tumor necrosis factor （TNF）-α， and C-reactive protein （CRP） in the serum. The histopathological changes of the liver were observed. The expression of lipoxygenase-2 （COX-2） was detected by immunofluorescence. The mRNA levels of nuclear transcription factors-κB （NF-κB）， monocyte chemotactic protein-1 （MCP-1）， and intercellular adhesion molecule-1 （ICAM-1） were determined by real-time polymerase chain reaction （Real-time PCR）.Western blot was employed to determine the protein levels of NF-κB in hibitory protein（IκB） kinase β （IKKβ）， IκBα， and phosphorylated IκBα （p-IκBα） in the liver and the protein levels of NF-κB in the cytoplasm and nucleus. ResultCompared with the normal group， the model group showed elevated levels of FBG， FINS， insulin resistance index， TC， TG， LDL-C， cAMP， T₃， T₄， IL-1β， IL-6， TNF-α， and CRP， up-regulated mRNA levels of NF-κB， MCP-1， and ICAM-1， and up-regulated protein levels of COX-2， p-IκBα， and nuclear NF-κB （P<0.01）. Compared with the model group， Yunvjian without Achyranthis Bidentatae Radix lowered the levels of FBG， FINS， insulin resistance index， TC， TG， LDL-C， cAMP， T₃， T₄， IL-1β， IL-6， TNF-α， and CRP， down-regulated the mRNA levels of NF-κB， MCP-1， and ICAM-1， and down-regulated the protein levels of COX-2， p-IκBα and nuclear NF-κB （P<0.05， P<0.01）. Compared with the Yunvjian without Achyranthis Bidentatae Radix， Yunvjian with Achyranthis Bidentatae Radix showed lowered levels of FBG， FINS， insulin resistance index， and inflammatory cytokines， down-regulated mRNA levels of NF-κB， MCP-1， and ICAM-1， and down-regulated protein levels of p-IκBα and nuclear NF-κB （P<0.05， P<0.01）. ConclusionAchyranthis Bidentatae Radix can enhance the performance of Yunvjian in reducing blood glucose and inhibiting inflammation in diabetic rats with the syndrome of yin deficiency and internal heat by down-regulating the IKK/IκB/NF-κB signaling pathway.

Objective To analyze the risk factors for postoperative gastroparesis syndrome (PGS) in gastric cancer patients undergoing laparoscopic radical gastrectomy (LRG) and to construct and validate a nomogram prediction model for PGS. Methods The clinical data of 439 gastric cancer patients were retrospectively analyzed. Patients were divided into PGS group and control group based on whether PGS occurred within 2 months after surgery. Logistic regression analysis was used to screen for risk factors of PGS in LRG patients, and a nomogram prediction model was constructed based on the screening results. The discriminative ability of the nomogram was assessed by the receiver operating characteristic (ROC) curve, and its consistency was evaluated by the calibration curve. Results Among 439 patients, 52 developed PGS, with an incidence rate of 11.85%. The proportions of patients aged ≥60 years, complicating with diabetes, having a history of abdominal surgery, complicating with pyloric obstruction, having surgery duration ≥4 hours, and intraoperative anastomosis type of B-Ⅱ were higher in the PGS group than those in the control group (P < 0.05). The results of multivariate Logistic regression analysis showed that diabetes, a history of abdominal surgery, pyloric obstruction, surgery duration ≥4 hours, and intraoperative anastomosis type of B-Ⅱ were risk factors for PGS in LRG patients (P < 0.05). Internal validation results showed that the area under the ROC curve was 0.839 (95%CI, 0.773 to 0.905), the calibration curve fitted well, and the Hosmer-Lemeshow goodness-of-fit test result was good(χ²=9.078, P=0.247). Conclusion Diabetes, a history of abdominal surgery, pyloric obstruction, surgery duration ≥4 hours, and intraoperative anastomosis type of B-Ⅱ are risk factors for PGS in LRG patients. The nomogram constructed based on these factors can effectively predict the risk of PGS in LRG patients.

Objective To explore the optimization for parameters of 5.0T pseudo continuous arterial spin labeling(pCASL)MRI of whole brain.Methods Nine healthy adults were prospectively enrolled,and single-delay pCASL scanning was performed based on a 5.0T MR scanner with 3 sets of labeling gradients:Group A,average gradient(Gavg)=1 mT/m and the ratio of maximum gradient(Gmax)to Gavg(Gratio)=10,group B,Gavg=0.6 mT/m and Gratio=10,group C,Gavg=0.3 mT/m and Gratio=9.The labeling efficiency and cerebral blood flow(CBF)of 3 groups were compared to screen the best labeling gradient group.Results When the marked average blood flow velocity was 40 cm/s,the gradient field tolerance of group C was better than that of group A and B at the situation of reduced B1+and larger B0 offset frequency range.Under the gradient field of group C,the level of labeled artery B1 ranged from 54.19％to 75.36％,with an average of 64.71％.The labeling efficiencies of group C were all ≥85％,and all ≥90％at the average B1 level(64.71％).In the whole gray matter and almost all brain regions,CBF on pCASL under gradient field of group C was significantly higher than that of group A and B(all P＜0.05).Conclusion Low Gavg and low Gmax were the optimal parameters for 5.0T whole brain pCASL MRI.

In order to meet the needs of the comprehensive development of life sciences and medicine,and fulfill the coher-ence and intersectionality of undergraduate experimental courses,it is necessary to break the teaching contents of conventional single experiment courses,and carry out the teaching reform of tumor comprehensive experimental course.Molecular biology and immuno-logy are two basic subjects which are closely related to the scientific research of life science,basic medicine and clinical medicine.Meantime,they are important sources for students to acquire skill training and scientific thinking as well.In this study,we try to inte-grate the experimental courses about the analysis and intervention of tumor-related genes based on the molecular biology and immunology technologies,facilitating to establish a new tumor comprehensive experimental course system.The course focuses on the development of students'logical thinking,and simulates the scientific research process through database screening,experimental operation,experi-mental report and paper writing,so as to significantly improve undergraduates'interest in scientific research and their ability to com-bine theory with practice,and cultivate students'rigorous scientific and innovative thinking ability as well as their ability to compre-hensively analyze and solve problems.It lays a solid foundation for future postgraduate related scientific research.At the same time,it is helpful to train teachers with multi-disciplinary knowledge reserves,and promote the coordinated development of scientific research through teaching.

Alzheimer' disease(AD)is a neurodegenerative disorder characterized by memory impairment and multiple cognitive deterioration.Acupuncture intervention in AD has potential efficacy,but the mechanism of onset is not clear.Blood oxygen level-dependent functional magnetic resonance imaging(BOLD-fMRI)has the unique advantages of accurately locating abnormal AD brain areas and monitoring and analyzing functional activities,providing technical support for the study of AD brain effects.It have found that abnormal changes in functional activity in response to brain regions and brain networks are closely related to the development of AD.Previous studies have shown that acupuncture can exert therapeutic effects by improving the functional impairment of multiple cognitive-related brain regions and brain networks in AD,which may be the mechanism of brain function in AD.Based on BOLD-fMRI technology,this paper elaborates on three aspects:commonly used data analysis methods of AD,the brain function mechanism of AD pathogenesis,and the brain effect study of acupuncture intervention in AD.In order to provide a reference for further exploring the brain effect of acupuncture intervention in AD.

Humans ; HIV-1/genetics* ; Anti-Retroviral Agents/therapeutic use* ; Mutation/genetics* ; Treatment Failure ; HIV Infections/genetics* ; Drug Resistance, Viral/genetics* ; Anti-HIV Agents/therapeutic use* ; Genotype

Based on the national policies, regulations and documents on residency training, this paper sorts out the historical evolution of the standardized residency training system in China, and divides its development into four stages: preliminary exploration, local pilot, national trials, and implementation. It also puts forward some practical thoughts on its development law and future trend, such aspects as that the system reform follows the top-down administrative order and indicative plan, the system pays attention to the gradual implementation on the basis of summing up practical experience, and the system needs continuous implementation and improvement from the overall perspective.