BACKGROUND:Abutment screw loosening is one of the most common mechanical complications in implant restoration.Mechanical wear,as a potential cause of thread loosening,warrants attention due to its impact on mechanical performance and long-term stability.However,studies on the mechanical effects of thread wear in abutment screws remain limited,and no definitive conclusions have been reached.OBJECTIVE:To investigate the effect of different degrees of mechanical wear on the spatial stress distribution of the Morse taper connection implant system,with a view to providing a theoretical basis for the clinical assessment of the long-term stability of dental implants.METHODS:Three-dimensional finite element models of Morse taper implants with central screw thread wear levels of 0,0.1,1,10,and 100 μm were established using SolidWorks software,and simulation analysis with Ansys Workbench software was performed.The implant models were inserted into artificial bone blocks(simulating type Ⅱ bone,with a cortical bone thickness of 2 mm on the outer layer and cancellous bone inside).An alternating load of 300 N in the buccolingual direction was applied at the centroid of the abutment(forming an angle of 30° with the long axis of the implant).The von Mises stress,principal stress,displacement,and fatigue life of the abutment,central screw,implant,and bone tissue in the five groups of models were analyzed.RESULTS AND CONCLUSION:(1)As the degree of mechanical wear on the central screw thread increased,the von Mises stress,principal stress,and strain in the implant and abutment also increased.The stress in the model was concentrated at the top of the implant,at the shoulder level of the implant,at the neck of the abutment,and at the bottom edge of the abutment.(2)Under moderate wear conditions(≥ 10 μm),the fatigue life of the implant system decreased by 30％,and the maximum von Mises stress of the central screw decreased by 37％,with the stress still primarily concentrated at the transition area between the head and the body of the central screw.(3)Under significant wear conditions(≥ 100 μm),the von Mises stress of the central screw decreased by 98％,with the stress concentrated at the screw head,and the fatigue life of the implant system decreased by 63％.Therefore,when the wear level of the central screw thread reaches ≥ 10 μm,the risk of screw loosening is significantly increased,and the fatigue life of the implant system is markedly reduced,warranting clinical attention.

BACKGROUND:Abutment screw loosening is one of the most common mechanical complications in implant restoration.Mechanical wear,as a potential cause of thread loosening,warrants attention due to its impact on mechanical performance and long-term stability.However,studies on the mechanical effects of thread wear in abutment screws remain limited,and no definitive conclusions have been reached.OBJECTIVE:To investigate the effect of different degrees of mechanical wear on the spatial stress distribution of the Morse taper connection implant system,with a view to providing a theoretical basis for the clinical assessment of the long-term stability of dental implants.METHODS:Three-dimensional finite element models of Morse taper implants with central screw thread wear levels of 0,0.1,1,10,and 100 μm were established using SolidWorks software,and simulation analysis with Ansys Workbench software was performed.The implant models were inserted into artificial bone blocks(simulating type Ⅱ bone,with a cortical bone thickness of 2 mm on the outer layer and cancellous bone inside).An alternating load of 300 N in the buccolingual direction was applied at the centroid of the abutment(forming an angle of 30° with the long axis of the implant).The von Mises stress,principal stress,displacement,and fatigue life of the abutment,central screw,implant,and bone tissue in the five groups of models were analyzed.RESULTS AND CONCLUSION:(1)As the degree of mechanical wear on the central screw thread increased,the von Mises stress,principal stress,and strain in the implant and abutment also increased.The stress in the model was concentrated at the top of the implant,at the shoulder level of the implant,at the neck of the abutment,and at the bottom edge of the abutment.(2)Under moderate wear conditions(≥ 10 μm),the fatigue life of the implant system decreased by 30％,and the maximum von Mises stress of the central screw decreased by 37％,with the stress still primarily concentrated at the transition area between the head and the body of the central screw.(3)Under significant wear conditions(≥ 100 μm),the von Mises stress of the central screw decreased by 98％,with the stress concentrated at the screw head,and the fatigue life of the implant system decreased by 63％.Therefore,when the wear level of the central screw thread reaches ≥ 10 μm,the risk of screw loosening is significantly increased,and the fatigue life of the implant system is markedly reduced,warranting clinical attention.

BACKGROUND:According to existing clinical studies,vertebroplasty treatment with both the external pedicle approach and the pedicle approach can improve the pain and quality of life of patients with spinal compression fractures.Compared with the pedicle approach,the external pedicle approach has a freer puncture angle,and good bone cement dispersion effect can be obtained by adjusting the puncture angle. OBJECTIVE:To compare the impact of vertebroplasty through individualized unilateral external pedicle approach and bilateral pedicle approach on the treatment of spinal compression fractures by quantifying the dispersion effect of bone cement. METHODS:A total of 80 patients with thoracolumbar compression fracture were divided into two groups by random number table method.The bilateral pedicle group(n=40)underwent vertebroplasty through a bilateral pedicle approach,while the unilateral external pedicle group(n=40)underwent individualized vertebroplasty through a unilateral external pedicle approach.Anteroposterior and lateral X-rays of the affected vertebrae from two groups of patients were photographed to assess effect and type of bone cement dispersion within 3 days after surgery.Visual analog scale score,tenderness threshold around fracture,and Oswestry dysfunction index were assessed before,1,7 days,and 1 month after surgery. RESULTS AND CONCLUSION:(1)Dispersion effect of bone cement in unilateral external pedicle group was better than that in bilateral pedicle group(P<0.001),and the amount of bone cement perfusion was higher than that in bilateral pedicle group(P<0.001).In the bilateral pedicle group,the bone cement dispersion types were mainly concentrated in type Ⅰ and type Ⅲ,while in the unilateral external pedicle group,the bone cement dispersion types were mainly concentrated in type I and type Ⅱ,and there was a significant difference in bone cement dispersion types between the two groups(P<0.001).(2)Postoperative visual analog scale scores and Oswestry disability index of both groups were lower than those before surgery(P<0.001),and postoperative tenderness threshold around fracture showed a trend of decreasing first and then increasing.At the same time point after treatment,there were no significant differences in visual analog scale score,Oswestry disability index,and tenderness threshold around fracture between the two groups(P>0.05).(3)The results indicate that individualized vertebroplasty via unilateral external pedicle approach can achieve better bone cement dispersion,and the treatment effect is consistent with the vertebroplasty via classical bilateral pedicle approach.

Early-onset colorectal cancer (EOCRC) shows a different epidemiological trend compared to later-onset colorectal cancer, with its incidence rising in most regions and countries worldwide. However, the reasons behind this trend remain unclear. The etiology of EOCRC is complex and could involve both genetic and environmental factors. Apart from Lynch syndrome and Familial Adenomatous Polyposis, sporadic EOCRC exhibits a broad spectrum of pathogenic germline mutations, genetic polymorphisms, methylation changes, and chromosomal instability. Early-life exposures and environmental risk factors, including lifestyle and dietary risk factors, have been found to be associated with EOCRC risk. Meanwhile, specific chronic diseases, such as inflammatory bowel disease, diabetes, and metabolic syndrome, have been associated with EOCRC. Interactions between genetic and environmental risk factors in EOCRC have also been explored. Here we present findings from a narrative review of epidemiological studies on the assessment of early-life exposures, of EOCRC-specific environmental factors, and their interactions with susceptible loci. We also present results from EOCRC-specific genome-wide association studies that could be used to perform Mendelian randomization analyses to ascertain potential causal links between environmental factors and EOCRC.
Humans ; Colorectal Neoplasms/etiology* ; Risk Factors ; Genome-Wide Association Study ; Genetic Predisposition to Disease/genetics*

In order to compare the differences in growth and secondary metabolite accumulation of Panax quinquefolius between understory and field planting, growth indexes, photosynthetic characteristics, soil enzyme activities, secondary metabolite contents, and antioxidant activities of P. quinquefolius under different planting modes were examined and compared, and One-way analysis of variance(ANOVA) and correlation analyses were carried out by using the software SPSS 25.0 and GraphPad Prism 9.5. The Origin 2021 software was used for plotting. The results showed that compared with those under field planting, the plant height, leaf length, leaf width, photosynthetic rate, and chlorophyll content of P. quinquefolius under understory planting were significantly reduced, and arbuscular mycorrhizal fungi(AMF) infestation rate and infestation intensity, ginsenoside content, and antioxidant activity were significantly increased. The activities of inter-root soil urease, sucrase, and catalase increased, while the activities of non-inter-root soil urease and alkaline phosphatase increased. Correlation analyses showed that the plant height and leaf length of P. quinquefolius plant were significantly positively correlated with net photosynthetic rate, transpiration rate, chlorophyll content, and electron transfer rate(P<0.05), while ginsenoside content was significantly negatively correlated with net photosynthetic rate, chlorophyll content, and electron transfer rate(P<0.05) and significantly positively correlated with AMF infestation rate and infestation intensity(P<0.05). In addition, ginsenoside content was significantly positively correlated with the activities of inter-root soil sucrase, urease, and catalase(P<0.05). This study provides basic data for revealing the mechanism of secondary metabolite accumulation in P. quinquefolius under understory planting and for exploring and practicing the ecological mode of P. quinquefolius under understory planting.
Panax/microbiology* ; China ; Secondary Metabolism ; Soil/chemistry* ; Photosynthesis ; Plant Leaves/metabolism* ; Chlorophyll/metabolism* ; Mycorrhizae

The seed kernel of Momordica cochinchinensis, i.e., Momordicae Semen, is used for medicinal purposes, but to date, no research has been reported on its chemical constituents. In this study, the chemical constituents of Momordicae Semen were investigated for the first time using silica gel column chromatography, semi-preparative HPLC, HR-MS, and NMR. As a result, eight compounds were isolated and identified as: p-hydroxybenzoic acid-7-O-trehaloside(mubeside A, 1), 2,6-dimethoxyphenol-O-β-D-apiosyl-(1→2)-β-D-glucoside(mubeside B, 2), 1-O-p-methoxybenzoyl-1,4-benzenediol-4-O-β-D-apiosyl-(1→2)-β-D-glucoside(mubeside C, 3), 1-O-p-hydroxybenzoyl-1,4-benzenediol-4-O-β-D-apiosyl-(1→2)-β-D-glucoside(mubeside D, 4), gypsogenin-3-O-β-D-galactosyl-(1→2)-β-D-glucuronoside(5), quillaic acid-3-O-β-D-galactosyl-(1→2)-β-D-glucuronoside(6), violanthin(7), and kaempferitrin(8). Compounds 1-4 are new compounds, while compounds 5-8 were isolated from Momordicae Semen for the first time.
Glycosides/isolation & purification* ; Drugs, Chinese Herbal/isolation & purification* ; Molecular Structure ; Magnetic Resonance Spectroscopy ; Chromatography, High Pressure Liquid

OBJECTIVE: To evaluate the clinical efficacy of modified high tibial osteotomy combined with platelet-rich plasma in the treatment of moderate to severe knee osteoarthritis. METHODS: From January 2021 to March 2022, the clinical data of 60 patients with moderate to severe knee osteoarthritis admitted to the Third Affiliated Hospital of Beijing University of Chinese Medicine were analyzed. Among them, 30 patients were treated with modified tibia high osteotomy combined with platelet-rich plasma as the observation group, including 12 males and 18 females, aged from 51 to 74 years old, with an average age of (64.37±5.72) years old. The course of disease ranged from 1 to 7 years with an average of(3.43±1.41) years. Thirty patients were treated with modified high tibial osteotomy combined with sodium hyaluronate as control group, including 10 males and 20 females, aged from 50 to 78 years, with an average age of (64.33±8.18) years. The course of disease was 1 to 7 years with an average of(3.30±1.39) years. Knee X-rays were taken before surgery and at the last follow-up, and the changes of lower limb bearing-line ratio (WBLR), proximal medial tibial Angle (MPTA), femoro-tibial angle (FTA) and posterior tibial slope (PTS) were compared between the two times. Visual analogue scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Lysholm score were used to evaluate knee pain and functional changes before surgery and at 1, 3, and 6 months after surgery. RESULTS: The wounds of all patients healed in stage I after surgery. All 60 patients completed treatment and follow-up, with an average follow-up duration of (8.08±1.75) months, ranged from 6 to 12 months. No serious adverse events or complications occurred. At the last follow-up, WBLR, MPTA and FTA were significantly improved in both groups (P<0.05). At the last follow-up, there was no significant difference in PTS between the two groups compared with pre-operation(P>0.05). At the last follow-up, there were no significant differences in WBLR, MPTA, FTA and PTS between the observation group and the control group (P>0.05). The VAS scores, WOMAC scores and Lysholm scores of both groups were significantly Modified with time after operation (P<0.05). At 1, 3 and 6 months after operation, VAS score, WOMAC score and Lysholm score of the observation group were significantly better than those of the control group, with statistical significance (P<0.05). CONCLUSION For patients with moderate and severe knee osteoarthritis, modified high tibial osteotomy can significantly correct lower limb alignment, and combined with platelet-rich plasma therapy can further significantly relieve knee pain and improve knee function, the effect is better than combined with sodium hyaluronate.
Humans ; Male ; Female ; Osteoarthritis, Knee/physiopathology* ; Middle Aged ; Osteotomy/methods* ; Platelet-Rich Plasma ; Aged ; Tibia/surgery*

Testicular histology based on testicular biopsy is an important factor for determining appropriate testicular sperm extraction surgery and predicting sperm retrieval outcomes in patients with azoospermia. Therefore, we developed a deep learning (DL) model to establish the associations between testicular grayscale ultrasound images and testicular histology. We retrospectively included two-dimensional testicular grayscale ultrasound from patients with azoospermia (353 men with 4357 images between July 2017 and December 2021 in The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China) to develop a DL model. We obtained testicular histology during conventional testicular sperm extraction. Our DL model was trained based on ultrasound images or fusion data (ultrasound images fused with the corresponding testicular volume) to distinguish spermatozoa presence in pathology (SPP) and spermatozoa absence in pathology (SAP) and to classify maturation arrest (MA) and Sertoli cell-only syndrome (SCOS) in patients with SAP. Areas under the receiver operating characteristic curve (AUCs), accuracy, sensitivity, and specificity were used to analyze model performance. DL based on images achieved an AUC of 0.922 (95% confidence interval [CI]: 0.908-0.935), a sensitivity of 80.9%, a specificity of 84.6%, and an accuracy of 83.5% in predicting SPP (including normal spermatogenesis and hypospermatogenesis) and SAP (including MA and SCOS). In the identification of SCOS and MA, DL on fusion data yielded better diagnostic performance with an AUC of 0.979 (95% CI: 0.969-0.989), a sensitivity of 89.7%, a specificity of 97.1%, and an accuracy of 92.1%. Our study provides a noninvasive method to predict testicular histology for patients with azoospermia, which would avoid unnecessary testicular biopsy.
Humans ; Male ; Azoospermia/diagnostic imaging* ; Deep Learning ; Testis/pathology* ; Retrospective Studies ; Adult ; Ultrasonography/methods* ; Sperm Retrieval ; Sertoli Cell-Only Syndrome/diagnostic imaging*

Investigating the correlation between micronucleus formation and male infertility has the potential to improve clinical diagnosis and deepen our understanding of pathological progression. Our study enrolled 2252 male patients whose semen was analyzed from March 2023 to July 2023. Their clinical data, including semen parameters and age, were also collected. Genetic analysis was used to determine whether the sex chromosome involved in male infertility was abnormal (including the increase, deletion, and translocation of the X and Y chromosomes), and subsequent semen analysis was conducted for clinical grouping purposes. The participants were categorized into five groups: normozoospermia, asthenozoospermia, oligozoospermia, oligoasthenozoospermia, and azoospermia. Patients were randomly selected for further study; 41 patients with normozoospermia were included in the control group and 117 patients with non-normozoospermia were included in the study group according to the proportions of all enrolled patients. Cytokinesis-block micronucleus (CBMN) screening was conducted through peripheral blood. Statistical analysis was used to determine the differences in micronuclei (MNi) among the groups and the relationships between MNi and clinical data. There was a significant increase in MNi in infertile men, including those with azoospermia, compared with normozoospermic patients, but there was no significant difference between the genetic and nongenetic groups in azoospermic men. The presence of MNi was associated with sperm concentration, progressive sperm motility, immotile spermatozoa, malformed spermatozoa, total sperm count, and total sperm motility. This study underscores the potential utility of MNi as a diagnostic tool and highlights the need for further research to elucidate the underlying mechanisms of male infertility.
Humans ; Male ; Infertility, Male/genetics* ; Adult ; Micronucleus Tests ; Semen Analysis ; Oligospermia/genetics* ; Azoospermia/genetics* ; Chromosome Aberrations ; Sperm Count ; Micronuclei, Chromosome-Defective ; Middle Aged