Objective To study the chemical constituents of Fallopia aubertii L.Henry Holub. Methods The chemical constituents of Fallopia aubertii L.Henry Holub. were separated and purified by online two-dimensional preparative liquid chromatography and identified by physical and chemical constants and spectral analysis. The inhibitory activities on xanthine oxidase were determined by ultraviolet spectrophotometry. Results Ten compounds were isolated from the extract of Fallopia aubertii L.Henry Holub, including isotachioside（1）, 3,4,5-trimethoxyphenyl-（6'-O-galloyl）-O-β-D-Glucopyranoside（2）, 1-hydroxy-,4,5-1-O-[6'-O-（4''-carboxy-1'',3'',5'trihydrotrimethoxyphenylxy）-phenyl]-β-D-glucopyranoside（3）, myricetrin（4）, myricetin（5）, rutin（6）, quercetin-3-O-β-D-galactoside（7）, quercetin-3-O-β-D-glucopyranoside（8）, lyciumideA（9）, and N-trans-Feruloyltyramine（10）. The inhibitory activity test results showed that the IC₅₀ of compound 5 was 15.92 μmol/L, and the IC₅₀ of compound 6 was 87.36 μmol/L. Conclusion Compounds 1,2,3,4 and 8 were isolated from Medicago polymorpha for the first time. Compounds 5 and 6 had xanthine oxidase inhibitory activity.

Objective:To evaluate the mechanical performance of customized metal prosthesis with tibia stems of varying lengths for tibial bone defects reconstruction.Methods:Morphologically matched postoperative finite element models of bone defect revision were developed, with three gradients (15 mm, 30 mm, and 45 mm) according to the degree of bone defect and were reconstructed with 3D printed tantalum metal prosthesis using three tibial stem lengths (80 mm, 120 mm, and 150 mm), respectively. Conventional static and dynamic (walking gait) loading was performed to analyze the peak tibial stress distribution and accumulated sliding distance at the prosthetic interface, and to assess the effects of the three tibial stems of different lengths on the stability of the customized tibial defect restorations and the internal tibial stress state.Results:The peak accumulated sliding distance of the dynamically loaded morphologically matched restorations ranged from 17.94 to 21.31 mm with static loading, which were 68% to 84.3% higher than those of 10.26 to 11.69 mm with static loading. The peak tibial stresses in the dynamically loaded model were greater than those in the statically loaded model, with an increase of 28%-49.2%, including 132.94-143.88 MPa in the statically loaded model and 170.41-200.14 MPa in the dynamically loaded model. The overall accumulated sliding distance of the tibia prosthetic model gradually decreased from the tibial osteotomy surface, and the accumulated peak sliding distances ranged from 10.26 to 11.69 mm for static loading, and from 17.94 to 21.31 mm for dynamic loading. The bone tissue stresses in the anterolateral and medial-posterior tibia increased gradually from top to bottom, and the maximum stress value in each section was in the posterior medial tibia (the maximum value was 200.14 MPa). The highest bone tissue stress in the lateral tibia was affected by the tibial stem length, which resulted in a different location, and it was the area most affected by stress shielding (maximum value of 170.65 MPa).Conclusion:For stability assessment of morphologically matched tantalum customized prosthesis, physiological gait dynamic loading studies are more reliable than static loading; the choice of tibial stem length depends on a combination of accumulated peak sliding distances and tibial bone stress distribution factors.

BACKGROUND:Avascular necrosis of the femoral head is a refractory orthopedic disease that seriously affects the normal life of patients.Hip preservation is recommended for young patients due to the limited prosthesis longevity and revision.Accurate prediction of the mechanical properties of the necrotic area in the early stage and then intervention is the key to hip preservation. OBJECTIVE:To establish a dynamic contact mechanics finite element model of necrotic femoral head based on human hip CT data and predict effects of both necrotic volume magnitude and its position on biomechanics of the necrotic region under walking movement. METHODS:CT data of a volunteer were collected and then geometry model of the hip was rebuilt.Finite element model of the necrotic femoral head was established using the Abaqus software.Nine different necrotic femoral models were constructed by combined both three different necrotic volume magnitudes(small,medium and big volume)and three different necrotic positions(coincided with,medium deviated with and kept away from the line of the force).The Von Mises of the necrotic region for all models were predicted under both 3 000 N static load and dynamical loads of one whole ISO walking gait cycle.The collapse risk for all models was evaluated based on collapse criterion. RESULTS AND CONCLUSION:(1)More approaching of the necrotic region to the line of force and bigger collapse volume made the maximum Von Mises increasing.This also enlarged the collapse risk of the necrotic region.(2)For different load types,walking movement increased the maximum Von Mises of the necrotic region than that of the value under static load under the same necrotic volume and location.(3)In conclusion,dynamic load would result in increasing of the maximum Von Mises of the necrotic region comparing to static load during exercise.Therefore,the risk of local collapse will increase due to greater Von Mises.However,the overall collapse risk is lower than that of static load due to the dynamic change of bearing area.This factor should be carefully considered by surgeons when they evaluate the mechanical performance of the necrotic femoral head.

Objective For patient-specific open-wedge high tibial osteotomy(OWHTO),a novel anatomical fixation plate was designed,and the effects of geometric parameters and material selection on biomechanical fixation were studied.Methods A patient-specific OWHTO anatomical fixation plate was designed and constructed,and the effects of design parameters(thickness,width,and length of the fixation plate)and four different materials(stainless steel,titanium alloy,magnesium alloy,and PEEK)on the biomechanics of the OWHTO fixation system were studied using finite element analysis.The biomechanical differences between the anatomical fixation plate and TomoFix fixation plate were also compared.Results The thickness had a greater effect on the micromotion of the osteotomy space than the length and width of the fixation plate did.Titanium alloy or magnesium alloy fixation plates were more conducive than stainless steel and PEEK materials in obtaining reasonable stability and mechanical transfer simultaneously.Compared with that of the TomoFix plate,the maximum von Mises stress of the anatomical fixation plate was reduced by 13.5%;the maximum von Mises stress of the screws and tibia was increased by 9.8%and 18.4%,respectively;and the micromotion at the maximum osteotomy space cc was increased by 49.3%.Conclusions Anatomical fixation plates have a positive effect on reducing the stress-shielding effect and improving biomechanical properties under the premise of ensuring stability.This study provides a reference for the development of OWHTO anatomical fixation plates.

Background::Findings on the association of genetic factors and colorectal cancer (CRC) survival are limited and inconsistent, and revealing the mechanism underlying their prognostic roles is of great importance. This study aimed to explore the relationship between functional genetic variations and the prognosis of CRC and further reveal the possible mechanism.Methods::We first systematically performed expression quantitative trait locus (eQTL) analysis using The Cancer Genome Atlas (TCGA) dataset. Then, the Kaplan-Meier analysis was used to filter out the survival-related eQTL target genes of CRC patients in two public datasets (TCGA and GSE39582 dataset from the Gene Expression Omnibus database). The seven most potentially functional eQTL single nucleotide polymorphisms (SNPs) associated with six survival-related eQTL target genes were genotyped in 907 Chinese CRC patients with clinical prognosis data. The regulatory mechanism of the survival-related SNP was further confirmed by functional experiments.Results::The rs71630754 regulating the expression of endoplasmic reticulum aminopeptidase 1 ( ERAP1) was significantly associated with the prognosis of CRC (additive model, hazard ratio [HR]: 1.43, 95% confidence interval [CI]: 1.08-1.88, P = 0.012). The results of dual-luciferase reporter assay and electrophoretic mobility shift assay showed that the A allele of the rs71630754 could increase the binding of transcription factor 3 (TCF3) and subsequently reduce the expression of ERAP1. The results of bioinformatic analysis showed that lower expression of ERAP1 could affect the tumor immune microenvironment and was significantly associated with severe survival outcomes. Conclusion::The rs71630754 could influence the prognosis of CRC patients by regulating the expression of the immune-related gene ERAP1. Trial Registration::No. NCT00454519 (https://clinicaltrials.gov/)

Hypoxia is the common characteristic of almost all solid tumors,which prevents therapeutic drugs from reaching the tumors.Therefore,the development of new targeted agents for the accurate diagnosis of hypoxia tumors is widely concerned.As carbonic anhydrase Ⅸ(CA Ⅸ)is abundantly distributed on the hypoxia tumor cells,it is considered as a potential tumor biomarker.4-(2-Aminoethyl)benzenesulfo-namide(ABS)as a CA Ⅸ inhibitor has inherent inhibitory activity and good targeting effect.In this study,Ag2S quantum dots(QDs)were used as the carrier to prepare a novel diagnostic and therapeutic bio-probe(Ag2S@polyethylene glycol(PEG)-ABS)through ligand exchange and amide condensation reaction.Ag2S@PEG-ABS can selectively target tumors by surface-modified ABS and achieve accurate tumor im-aging by the near infrared-Ⅱ(NIR-Ⅱ)fluorescence characteristics of Ag2S QDs.PEG modification of Ag2S QDs greatly improves its water solubility and stability,and therefore achieves high photothermal sta-bility and high photothermal conversion efficiency(PCE)of 45.17％.Under laser irradiation,Ag2S@PEG-ABS has powerful photothermal and inherent antitumor combinations on colon cancer cells(CT-26)in vitro.It also has been proved that Ag2S@PEG-ABS can realize the effective treatment of hypoxia tumors in vivo and show good biocompatibility.Therefore,it is a new efficient integrated platform for the diagnosis and treatment of hypoxia tumors.

Objective To observe and analyze functional areas of the cerebral cortex in C57BL/6 mice of various ages.Methods Improved alkaline phosphatase staining was used to reveal the microvascular morphology of the cerebral cortex in C57BL/6 mice,including the motor cortex(primary and secondary motor cortex),sensory cortex(primary and secondary somatosensory cortex),visual cortex(primary and secondary visual cortex),and auditory cortex(primary and secondary auditory cortex),olfactory cortex(extrarhinal and entorhinal cortex).Images were captured under an OLYMPUS BX51 microscope with Image-Pro Plus 5.1 software.The microvascular length density(Lv),microvascular surface area density(Sv),and microvascular volume density(Vv)were analyzed by Image-Pro Plus 5.1 software.Results Expression of alkaline phosphatase was abundant in cerebral cortical microvessels of adult and elderly mice,and slightly expressed in juvenile mice,but not in lactating mice.Pial blood vessels enter the cortex in T shape,Y shape,large arc,and small arc four manners.Lv,Sv and Vv in different parts of the same aged mice showed a decreasing trend in motor,sensory,visual,auditory and olfactory cortexes,and the microvascular density of Lv,Sv and Vv in motor and sensory cortexes was statistically significant compared with the olfactory cortex(P<0.05).The vascular density in all functional areas in elderly mice was lower than that in adult mice,but no statistical significance was found(P>0.05).Conclusions The expression of alkaline phosphatase in microvessels in functional areas of the cerebral cortex in C57BL/6 mice increases with age and reached its peak value in adulthood.The microvascular architecture in the brain provides morphological parameters to establish cerebrovascular disease models.

The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients' walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427-0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.
Humans ; Arthroplasty, Replacement, Knee ; Knee Joint/surgery* ; Knee Prosthesis ; Gait ; Rotation

Objective:To analyze the clinical characteristics and short-term prognosis of patients with acute asthmatic attack and comorbid bronchiectasis.Methods:The data of patients hospitalized for acute asthmatic attack in the Department of Respiratory and Critical Care Medicine of Peking University Third Hospital from January 1, 2012 to December 31, 2021 were retrospectively collected and analyzed. According to whether or not co-existing with bronchiectasis, all the patients were divided into asthmatic with bronchiectasis group and asthmatic without bronchiectasis group. Then the general conditions, comorbidities, pulmonary function test, grades of asthma severity, laboratory examination and in-hospital short-term prognosis of two groups were analyzed.Results:A total of 580 hospitalized patients with acute asthma attack were included, of which 132 cases (22.76%) were classified into asthmatic with bronchiectasis group and 448 cases (77.24%) were classified into asthmatic without bronchiectasis group. Co-existing with obsolete pulmonary tuberculosis and anxiety/depression in asthmatic with bronchiectasis group were more common than that in asthmatic without bronchiectasis group (13.64% vs 5.36%; 7.58% vs 2.68%) (both P<0.05). The pre-bronchodilator forced vital capacity (FVC) and its percentage to the predicted value (FVC%pred), forced expiratory volume in 1 second (FEV 1) and its percentage to the predicted value (FEV 1%pred), FEV 1/FVC and post-bronchodilator FEV 1 in asthmatic with bronchiectasis group were lower than those in the asthmatic without bronchiectasis group [2.44 (1.90, 3.01) vs 2.69 (2.10, 3.68) L, 1.55 (1.13, 2.00) vs 1.78 (1.25, 2.52) L, 70.14% (67.39%, 85.92%) vs 79.63% (70.00%, 89.52%), 70.00% (54.38%, 78.11%) vs 70.00% (61.47%, 85.00%), 61.57% (56.29%, 73.03%) vs 66.67% (60.00%, 75.00%), 1.72 (1.21, 2.18) vs 1.89 (1.37, 2.55) L] (all P<0.05). In previous year, the proportion of patients receiving hospitalization due to acute asthmatic attack in asthmatic with bronchiectasis group was higher than that in asthmatic without bronchiectasis group (15.15% vs 8.93%) ( P<0.05). The peak months of hospitalization due to acute asthmatic attack in asthmatic with bronchiectasis group were April, July and October, and the peak months in asthmatic without bronchiectasis group were April and September. The length of hospital stay was longer and the proportion of patients receiving invasive ventilation was higher in asthmatic with bronchiectasis group than those in asthmatic without bronchiectasis group [10.06 (7.62, 13.94) vs 9.95 (7.15, 13.76) d; 5.30% vs 2.01%] (both P<0.05). The risk factors for invasive mechanical ventilation in asthmatic patients with acute attack during hospitalization were co-existing with bronchiectasis, smoking, high level of partial pressure of carbon dioxide in arterial blood, serum creatinine and creatine kinase. Conclusion:Asthma patients with comorbid bronchiectasis have more frequent acute attack, a longer hospitalization due to acute asthmatic attack and a higher probability of invasive ventilation during hospitalization.

Posterior-stabilized total knee prostheses have been widely used in orthopedic clinical treatment of knee osteoarthritis, but the patients and surgeons are still troubled by the complications, for example severe wear and fracture of the post, as well as prosthetic loosening. Understanding the in vivo biomechanics of knee prostheses will aid in the decrease of postoperative prosthetic revision and patient dissatisfaction. Therefore, six different designs of posterior-stabilized total knee prostheses were used to establish the musculoskeletal multibody dynamics models of total knee arthroplasty respectively, and the biomechanical differences of six posterior-stabilized total knee prostheses were investigated under three simulated physiological activities: walking, right turn and squatting. The results showed that the post contact forces of PFC Sigma and Scorpio NGR prostheses were larger during walking, turning right, and squatting, which may increase the risk of the fracture and wear as well as the early loosening. The post design of Gemini SL prosthesis was more conductive to the knee internal-external rotation and avoided the edge contact and wear. The lower conformity design in sagittal plane and the later post-cam engagement resulted in the larger anterior-posterior translation. This study provides a theoretical support for guiding surgeon selection, improving posterior-stabilized prosthetic design and reducing the prosthetic failure.
Arthroplasty, Replacement, Knee/methods* ; Biomechanical Phenomena ; Humans ; Knee Joint/surgery* ; Knee Prosthesis ; Prosthesis Design ; Range of Motion, Articular/physiology* ; Tibia/surgery*