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1.
Ann Biomed Eng ; 2024 May 14.
Article in English | MEDLINE | ID: mdl-38744754

ABSTRACT

Bone tissue is subjected to increased mechanical stress during high-intensity work. Inadequate bone remodeling reparability can result in the continuous accumulation of microdamage, leading to stress fractures. The aim of this work was to investigate the characteristics and repair mechanisms of tibial microdamage under several degrees of overload. Also, we aimed at better understanding the effects of overload on the multi-scale structure and mechanical properties of bone. Sixty 5-month female rats were divided into three groups with different time points. Micro-CT was used to evaluate the three-dimensional microstructure, and three-point bending, quasi-static fracture toughness and creep mechanical test were carried out to evaluate the mechanical properties. SEM was used to observe the morphological characteristics of fracture surfaces. Section staining was used to count the microdamage parameters and numbers of osteoblasts and osteoclasts. The microarchitectures of cancellous and cortical bones in the three overload groups showed different degrees of damage. Overload led to a messy crystal structure of cortical bone, with slender microcracks mixed in, and a large number of broken fibers of cancellous bone. The properties associated with the elastic plasticity, fracture toughness, and viscoelasticity of cortical bone reduced in three groups, with that corresponding to day 30 presenting the highest damage. The accumulation of microdamage mainly occurred in the first 14 days, that is, the crack density peaked on day 14. Peak-targeted bone remodeling of cortical and cancellous bones occurred mainly between days 14 and 30. The influence of overload mechanical environment on bone quality at different time points was deeply investigated, which is of great significance for the etiology and treatment of stress fractures.

2.
Sci Rep ; 14(1): 5828, 2024 Mar 09.
Article in English | MEDLINE | ID: mdl-38461164

ABSTRACT

Global greenhouse gas emission, major factor driving climate change, has been increasing since nineteenth century. STIRPAT and CEVSA models were performed to estimate the carbon emission peaks and terrestrial ecosystem carbon sinks at the provincial level in China, respectively. Utilizing the growth characteristics and the peak time criteria for the period 1997-2019, the patterns of energy consumption and CO2 emissions from 30 Chinese provinces are categorized into four groups: (i) one-stage increase (5 provinces), (ii) two-stage increase (10 provinces), (iii) maximum around 2013 (13 provinces), and (iv) maximum around 2017 (2 provinces). According to the STIRPAT model, the anticipated time of peak CO2 emissions for Beijing from the third group is ~ 2025 in both business-as-usual and high-speed scenarios. For Xinjiang Uygur autonomous region from the first group and Zhejiang province from the second group, the expected peak time is 2025 to 2030. Shaanxi province from the fourth group is likely to reach carbon emission peak before 2030. The inventory-based estimate of China's terrestrial carbon sink is ~ 266.2 Tg C/a during the period 1982-2015, offsetting 18.3% of contemporary CO2 emissions. The province-level CO2 emissions, peak emissions and terrestrial carbon sinks estimates presented here are significant for those concerned with carbon neutrality.

3.
PLoS Comput Biol ; 20(3): e1011984, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38536788

ABSTRACT

Thymic stromal lymphopoietin is a key cytokine involved in the pathogenesis of asthma and other allergic diseases. Targeting TSLP and its signaling pathways is increasingly recognized as an effective strategy for asthma treatment. This study focused on enhancing the affinity of the T6 antibody, which specifically targets TSLP, by integrating computational and experimental methods. The initial affinity of the T6 antibody for TSLP was lower than the benchmark antibody AMG157. To improve this, we utilized alanine scanning, molecular docking, and computational tools including mCSM-PPI2 and GEO-PPI to identify critical amino acid residues for site-directed mutagenesis. Subsequent mutations and experimental validations resulted in an antibody with significantly enhanced blocking capacity against TSLP. Our findings demonstrate the potential of computer-assisted techniques in expediting antibody affinity maturation, thereby reducing both the time and cost of experiments. The integration of computational methods with experimental approaches holds great promise for the development of targeted therapeutic antibodies for TSLP-related diseases.


Subject(s)
Asthma , Cytokines , Humans , Antibody Affinity , Molecular Docking Simulation , Cytokines/metabolism , Asthma/drug therapy , Asthma/metabolism , Thymic Stromal Lymphopoietin
4.
BMC Musculoskelet Disord ; 25(1): 123, 2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38336651

ABSTRACT

BACKGROUND: The purpose of this study was to investigate the effects of four different doses of verapamil on the mechanical behaviors of solid and the characteristics of fluid flow in cancellous bone of distal femur of type 2 diabetes rats under dynamic external load. METHODS: Based on the micro-CT images, the finite element models of cancellous bones and fluids at distal femurs of rats in control group, diabetes group, treatment groups VER 4, VER 12, VER 24, and VER 48 (verapamil doses of 4, 12, 24, and 48 mg/kg/day, respectively) were constructed. A sinusoidal time-varying displacement load with an amplitude of 0.8 µm and a period of 1s was applied to the upper surface of the solid region. Then, fluid-solid coupling numerical simulation method was used to analyze the magnitudes and distributions of von Mises stress, flow velocity, and fluid shear stress of cancellous bone models in each group. RESULTS: The results for mean values of von Mises stress, flow velocity and FSS (t = 0.25s) were as follows: their values in control group were lower than those in diabetes group; the three parameters varied with the dose of verapamil; in the four treatment groups, the values of VER 48 group were the lowest, they were the closest to control group, and they were smaller than diabetes group. Among the four treatment groups, VER 48 group had the highest proportion of the nodes with FSS = 1-3 Pa on the surface of cancellous bone, and more areas in VER 48 group were subjected to fluid shear stress of 1-3 Pa for more than half of the time. CONCLUSION: It could be seen that among the four treatment groups, osteoblasts on the cancellous bone surface in the highest dose group (VER 48 group) were more easily activated by mechanical loading, and the treatment effect was the best. This study might help in understanding the mechanism of verapamil's effect on the bone of type 2 diabetes mellitus, and provide theoretical guidance for the selection of verapamil dose in the clinical treatment of type 2 diabetes mellitus.


Subject(s)
Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 2 , Rats , Animals , Cancellous Bone/diagnostic imaging , Diabetes Mellitus, Type 2/drug therapy , Verapamil/pharmacology , Diabetes Mellitus, Experimental/drug therapy , Computer Simulation , Stress, Mechanical , Finite Element Analysis
6.
Environ Sci Pollut Res Int ; 30(55): 117998-118012, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37874513

ABSTRACT

Under the constraints of the "dual-carbon" objectives, how China can sustain economic development while concurrently achieving carbon emission reduction has become a pressing issue. With the rapid expansion of China's outward foreign direct investment (OFDI), elucidating its impact on carbon emission efficiency (CEE) assumes pronounced significance. Employing the systematic generalized method of moments (GMM) approach, based on panel data spanning the years 2006 to 2019 for China, this study primarily delves into the influence of OFDI on China's CEE. Furthermore, it probes into the mechanisms and asymmetries underpinning the relationship between OFDI and CEE. The principal findings are as follows: (1) augmentation of OFDI exerts a constructive effect on domestic carbon emission reduction, concomitantly yielding a discernible enhancement in CEE. A 1% increase in the magnitude of OFDI flow gives rise to a 0.009% improvement in CEE. (2) Mechanism verification reveals that heightened levels of OFDI operate through elevating green total factor productivity (GTFP), fostering optimal industrial structural adjustments, and invigorating green technological innovation, thereby elevating the CEE of the home country. (3) Asymmetry characterizes the impact of OFDI on domestic CEE, signifying a significant enhancement in regions with lower CEE while exhibiting less conspicuous effects in areas with higher CEE. This study furnishes policymakers with insights into leveraging OFDI to enhance CEE, thereby facilitating the attainment of the "dual-carbon" objectives.


Subject(s)
Carbon , Economic Development , China , Industry , Internationality , Investments , Efficiency
7.
Med Biol Eng Comput ; 61(11): 3087-3101, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37624535

ABSTRACT

The load and stress distribution on cartilage and meniscus of the knee joint in typical lower limb movements of Chen-style Tai Chi (TC) and deep squat (DS) were analyzed using finite element (FE) analysis. The loadings for this analysis consisted of muscle forces and ground reaction force (GRF), which were calculated through the inverse dynamic approach based on kinematics and force plate measurements obtained from motion capture experiments. Thirteen experienced practitioners performed four typical TC movements, namely, single whip (SW), brush knee and twist step (BKTS), stretch down (SD), and part the wild horse's mane (PWHM), which exhibit lower posture and greater lower limb force compared to other TC styles. The results indicated that TC required greater lower limb muscle strength than DS, resulting in greater knee joint forces. The stress on the medial cartilage in SW and BKTS fell within a range conductive to maintaining the balance between anabolism and catabolism of cartilage matrix. This was due to the fact that SW and BKTS reduce the medial to total tibiofemoral contact force ratios through knee abduction, which may effectively alleviate mild medial knee osteoarthritis (KOA). However, the greater medial contact force ratios observed in SD and PWHM resulted in great contact stresses that may aggravate the pain of patients with KOA. To mitigate these effects, practitioners should consider elevating their postures appropriately to reduce knee flexion angles, especially during the single-leg support phase. This adjustment can decrease the required muscle strength, load and stress on the knee joint.


Subject(s)
Osteoarthritis, Knee , Tai Ji , Humans , Biomechanical Phenomena , Knee , Knee Joint/physiology , Lower Extremity , Movement/physiology , Finite Element Analysis
8.
Chem Biodivers ; 20(9): e202300991, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37580280

ABSTRACT

A new polyaromatic metabolite, ent-herqueidiketal (1), and a new phenalenone derivative, epi-peniciherqueinone (2), along with twelve known compounds 3-14, were isolated from the fungus Penicillium herquei YNJ-35, a symbiotic fungus of Pulveroboletus brunneopunctatus collected from Nangunhe Nature Reserve, Yunnan Province, China. The structures of 1-14 and the absolute configurations of 1 and 2 were determined by their spectroscopic data or by their single-crystal X-ray diffraction analysis or optical rotation values. Compound 1 showed strong antibacterial activity against Staphylococcus aureus (ATCC 29213) with minimum inhibitory concentration (MIC) of 8 µg/mL. In the cytotoxicity assays, compound 1 showed weak inhibitory activity against breast cancer MCF-7 and mice microglial BV2 cells with half maximal inhibitory concentration (IC50 ) of 17.58 and 29.56 µM; compound 14 showed stronger cytotoxicity against BV2 and MCF-7 cells with IC50 values of 6.57 and 10.26 µM.


Subject(s)
Agaricales , Penicillium , Animals , Mice , Molecular Structure , China , Penicillium/chemistry
9.
Health Commun ; : 1-10, 2023 Aug 29.
Article in English | MEDLINE | ID: mdl-37641852

ABSTRACT

Engaging the public and community organizations in local health actions greatly assists disease prevention and control. However, it remains unclear how organization-public relationships (OPR) and communication networks within communities contribute to community health actions. To fill this gap, a survey was conducted among community members in Shanghai, China, who were challenged by the Omicron wave of the COVID-19 pandemic. Results revealed that integrated connectedness to a storytelling network (ICSN) was a significant predictor of residents' community engagement. Trust, control mutuality, commitment, and ICSN were positively associated with community engagement intentions through the sense of community and organizational efficacy. This study is a step toward understanding how organizations and members collectively respond to health crises at the community level.

10.
BMC Surg ; 23(1): 211, 2023 Jul 26.
Article in English | MEDLINE | ID: mdl-37496026

ABSTRACT

BACKGROUND: Vacuum sealing drainage (VSD) is widely applied in complex wound repair. We aimed to compare traditional debridement and drainage and VSD in treating Fournier's gangrene (FG). METHODS: Data of patients surgically treated for FG were retrospectively analyzed. RESULTS: Of the 36 patients (men: 31, women: 5; mean age: 53.5 ± 11.3 [range: 28-74] years) included in the study, no patients died. Between-group differences regarding sex, age, BMI, time from first debridement to wound healing, number of debridements, FGSI, and shock were not statistically significant (P > 0.05). However, lesion diameter, colostomy, VAS score, dressing changes, analgesic use, length of hospital stay, and wound reconstruction method (χ2 = 5.43, P = 0.04) exhibited statistically significant differences. Tension-relieving sutures (6 vs. 21) and flap transfer (4 vs. 2) were applied in Groups I and II, respectively. CONCLUSION: VSD can reduce postoperative dressing changes and analgesic use, and shrunk the wound area, thereby reducing flap transfer in wound reconstruction.


Subject(s)
Fournier Gangrene , Negative-Pressure Wound Therapy , Male , Humans , Female , Adult , Middle Aged , Fournier Gangrene/surgery , Retrospective Studies , Debridement/methods , Drainage
11.
Chiropr Man Therap ; 31(1): 14, 2023 05 24.
Article in English | MEDLINE | ID: mdl-37226172

ABSTRACT

BACKGROUND: Spinal manipulative therapy (SMT) is a guideline-recommended treatment option for spinal pain. The recommendation is based on multiple systematic reviews. However, these reviews fail to consider that clinical effects may depend on SMT "application procedures" (i.e., how and where SMT is applied). Using network meta-analyses, we aim to investigate which SMT "application procedures" have the greatest magnitude of clinical effectiveness for reducing pain and disability, for any spinal complaint, at short-term and long-term follow-up. We will compare application procedural parameters by classifying the thrust application technique and the application site (patient positioning, assisted, vertebral target, region target, Technique name, forces, and vectors, application site selection approach and rationale) against: 1. Waiting list/no treatment; 2. Sham interventions not resembling SMT (e.g., detuned ultrasound); 3. Sham interventions resembling SMT; 4. Other therapies not recommended in clinical practice guidelines; and 5. Other therapies recommended in clinical practice guidelines. Secondly, we will examine how contextual elements, including procedural fidelity (whether the SMT was delivered as planned) and clinical applicability (whether the SMT is similar to clinical practice) of the SMT. METHODS: We will include randomized controlled trials (RCT) found through three search strategies, (i) exploratory, (ii) systematic, and (iii) other known sources. We define SMT as a high-velocity low-amplitude thrust or grade V mobilization. Eligibility is any RCT assessing SMT against any other type of SMT, any other active or sham intervention, or no treatment control on adult patients with pain in any spinal region. The RCTs must report on continuous pain intensity and/or disability outcomes. Two authors will independently review title and abstract screening, full-text screening, and data extraction. Spinal manipulative therapy techniques will be classified according to the technique application and choice of application sites. We will conduct a network-meta analysis using a frequentist approach and multiple subgroup and sensitivity analyses. DISCUSSION: This will be the most extensive review of thrust SMT to date, and will allow us to estimate the importance of different SMT application procedures used in clinical practice and taught across educational settings. Thus, the results are applicable to clinical practice, educational settings, and research studies. PROSPERO registration: CRD42022375836.


Subject(s)
Manipulation, Osteopathic , Manipulation, Spinal , Adult , Humans , Network Meta-Analysis , Spine , Pain , Meta-Analysis as Topic
12.
Front Bioeng Biotechnol ; 11: 1080241, 2023.
Article in English | MEDLINE | ID: mdl-36756384

ABSTRACT

Objectives: This study aimed to investigate the morphological and mechanical changes in articular cartilage and subchondral bone during spontaneous hip osteoarthritis in guinea pigs. Materials and methods: Hip joints of guinea pigs were investigated at 1, 3, 6, and 9 months of age (hereafter denoted as 1 M, 3 M, 6 M, and 9 M, respectively; n = 7 in each group). Morphological and mechanical alterations during spontaneous hip osteoarthritis in guinea pigs were investigated. The alterations included the micromechanical properties of articular cartilage (stiffness and creep deformation), microstructure of the subchondral bone (bone mineral density, bone volume fraction, trabecular thickness, trabecular number, and trabecular separation), micromorphology of the articular cartilage, and surface nanostructure (grain size and roughness) of the articular cartilage and subchondral bone. Results: Micromechanical properties of articular cartilage in 1 M showed the lowest stiffness and highest creep deformation with no significant differences in stiffness or creep deformation amongst 3 M, 6 M, and 9 M. Articular cartilage thickness decreased with age. The earliest degeneration of articular cartilage occurred at 6 months of age, characterised by surface unevenness and evident chondrocytes reduction in micromorphology, as well as increased grain size and decreased roughness in nanostructure. No degeneration at micro- or nanostructure of subchondral bone was observed before 9 months. Conclusion: Morphological degeneration of cartilage occurred before degeneration of mechanical properties. Meanwhile, degeneration of cartilage occurred before degeneration of subchondral bone during hip osteoarthritis. The current study provided novel insights into the structural and micromechanical interaction of hip osteoarthritis, which can serve as a theoretical basis for understanding the formation and progression of osteoarthritis.

13.
J Biomech Eng ; 145(7)2023 07 01.
Article in English | MEDLINE | ID: mdl-36752723

ABSTRACT

The cartilage endplates (CEPs) on the superior and inferior surfaces of the intervertebral disk (IVD), are the primary nutrient transport pathways between the disk and the vertebral body. Passive diffusion is responsible for transporting small nutrient and metabolite molecules through the avascular CEPs. The baseline solute diffusivities in healthy CEPs have been previously studied, however alterations in CEP diffusion associated with IVD degeneration remain unclear. This study aimed to quantitatively compare the solute diffusion in healthy and degenerated human CEPs using a fluorescence recovery after photobleaching (FRAP) approach. Seven healthy CEPs and 22 degenerated CEPs were collected from five fresh-frozen human cadaveric spines and 17 patients undergoing spine fusion surgery, respectively. The sodium fluorescein diffusivities in CEP radial and vertical directions were measured using the FRAP method. The CEP calcification level was evaluated by measuring the average X-ray attenuation. No difference was found in solute diffusivities between radial and axial directions in healthy and degenerated CEPs. Compared to healthy CEPs, the average solute diffusivity was 44% lower in degenerated CEPs (Healthy: 29.07 µm2/s (CI: 23.96-33.62 µm2/s); degenerated: 16.32 µm2/s (CI: 13.84-18.84 µm2/s), p < 0.001). The average solute diffusivity had an inverse relationship with the degree of CEP calcification as determined by the normalized X-ray attenuation values (ß = -22.19, R2 = 0.633; p < 0.001). This study suggests that solute diffusion through the disk and vertebral body interface is significantly hindered by CEP calcification, providing clues to help further understand the mechanism of IVD degeneration.


Subject(s)
Calcinosis , Intervertebral Disc Degeneration , Intervertebral Disc , Humans , Cartilage/metabolism , Intervertebral Disc/metabolism , Intervertebral Disc Degeneration/metabolism , Biological Transport , Diffusion
14.
Eur Radiol ; 33(6): 4214-4222, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36600123

ABSTRACT

OBJECTIVES: To elucidate the change in glutamate levels in preterm infants at different gestational ages by glutamate chemical exchange saturated transfer (GluCEST) magnetic resonance imaging and to compare the difference in glutamate levels among different brain regions between very early preterm infants and middle and late preterm infants. METHODS: Fifty-three preterm infants (59% males; median gestational age = 33.6 weeks) underwent MRI, including conventional MRI and GluCEST. The original data were postprocessed in MATLAB. Correlation analysis was used to determine the relationship between the MTRasym and gestational age. The differences in MTRasym signals among different ROIs were statistically analysed by one-way analysis of variance (ANOVA). The MTRasym difference of the bilateral hemispherical ROI was compared by a paired T test. RESULTS: In all ROIs, glutamate concentration was positively correlated with gestational age. The glutamate concentration in the thalamus was higher than that in the frontal lobe in very early, middle and late preterm infants. A difference in glutamate concentration was not found in the bilateral ROIs. CONCLUSIONS: The concentration of glutamate in the brains of preterm infants of different gestational ages increased with gestational age, which may be one of the factors contributing to the higher incidence of neurodevelopmental dysfunction in very early preterm infants compared to that in middle and late preterm infants. Meanwhile, the glutamate concentrations among different brain regions were also diverse. KEY POINTS: • The glutamate concentration was positively correlated with gestational age in preterm infants of the brain. • Glutamate concentrations were dissimilar in different brain regions of preterm infants. • Glutamate concentration during the process of brain development in premature infants was not found to be asymmetric.


Subject(s)
Infant, Premature, Diseases , Infant, Premature , Infant , Male , Infant, Newborn , Humans , Female , Gestational Age , Pilot Projects , Glutamic Acid , Brain/diagnostic imaging , Brain/pathology
15.
Comput Methods Biomech Biomed Engin ; 26(16): 1994-2007, 2023.
Article in English | MEDLINE | ID: mdl-36591917

ABSTRACT

Exploring the relationships between microstructure and mechanical properties of bones may provide effective suggestions for increasing bone strength and reducing osteoporotic fracture. In this research, the tissue-level mechanical parameters, microstructure parameters of cancellous bone, and apparent mechanical parameters of L6 vertebral body were calculated in female SD rats aged 1-, 3-, 5-, 7-, 9-, 11-, 13-, 15-, 16-, and 17-month-old. Data were processed with Kruskal-Wallis test, linear regression and Spearman's rank correlation analysis. Appropriately increasing the plate Tb.N could enhance mechanical properties of bone. Tb.Th and Tb.N were two key factors in determining the tissue-level mechanical properties of cancellous bone. The microstructure could significantly predict mechanical parameters. Our findings may help to further understand the mechanism of osteoporotic fractures.


Subject(s)
Bone and Bones , Lumbar Vertebrae , Female , Rats , Animals , Rats, Sprague-Dawley , Finite Element Analysis , Lumbar Vertebrae/diagnostic imaging , Cancellous Bone , Bone Density
16.
Fitoterapia ; 164: 105378, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36511342

ABSTRACT

19 compounds, including seven previously undescribed alkaloids ((-)-macleayin K (1), (+)-macleayin K (2), macleayin M (3), macleayin N (4), macleayin L (5), macleayin O (6), oxohydrastinine A (7), one new natural product (8), and 11 known compounds, were isolated from the fruit pods of Macleaya microcarpa. Their structures were defined based on NMR, HRESIMS, and electronic circular dichroism (ECD) data. A network pharmacology approach combined with molecular docking and in vitro validation was performed to determine the bioactivity, key targets of the 19 compounds against breast cancer (BC) and cervical cancer (CC). EGFR and PIK3CA could become potential therapeutic targets based a network pharmacology. Moreover, molecular docking suggested that the 19 compounds combined well with EGFR and PIK3CA, respectively. Their cytotoxicity of selected compounds was tested against the MCF-7 and HeLa cells, and the preliminary structure-activity relationship is discussed. Compounds 1 (IC50: 6.00 µM) and 2 (IC50: 6.82 µM) exhibited strong inhibitory activity against the HeLa cells and are worthy of further study.


Subject(s)
Alkaloids , Antineoplastic Agents , Papaveraceae , Humans , Fruit , HeLa Cells , Molecular Docking Simulation , Molecular Structure , Papaveraceae/chemistry , ErbB Receptors
17.
J Orthop Res ; 41(1): 170-182, 2023 01.
Article in English | MEDLINE | ID: mdl-35393726

ABSTRACT

Hip fracture is the most common complication of osteoporosis, and its major contributor is compromised femoral strength. This study aimed to develop practical machine learning models based on clinical quantitative computed tomography (QCT) images for predicting proximal femoral strength. Eighty subjects with entire QCT data of the right hip region were randomly selected from the full MrOS cohorts, and their proximal femoral strengths were calculated by QCT-based finite element analysis (QCT/FEA). A total of 50 parameters of each femur were extracted from QCT images as the candidate predictors of femoral strength, including grayscale distribution, regional cortical bone mapping (CBM) measurements, and geometric parameters. These parameters were simplified by using feature selection and dimensionality reduction. Support vector regression (SVR) was used as the machine learning algorithm to develop the prediction models, and the performance of each SVR model was quantified by the mean squared error (MSE), the coefficient of determination (R2 ), the mean bias, and the SD of bias. For feature selection, the best prediction performance of SVR models was achieved by integrating the grayscale value of 30% percentile and specific regional CBM measurements (MSE ≤ 0.016, R2 ≥ 0.93); and for dimensionality reduction, the best prediction performance of SVR models was achieved by extracting principal components with eigenvalues greater than 1.0 (MSE ≤ 0.014, R2 ≥ 0.93). The femoral strengths predicted from the well-trained SVR models were in good agreement with those derived from QCT/FEA. This study provided effective machine learning models for femoral strength prediction, and they may have great potential in clinical bone health assessments.


Subject(s)
Machine Learning , Tomography , Humans , Aged
18.
Med Eng Phys ; 110: 103918, 2022 12.
Article in English | MEDLINE | ID: mdl-36564133

ABSTRACT

The current study aimed to investigate the effects of whole-body vibration (WBV) before and after ovariectomy on lumbar vertebrae, and to observe whether the positive effects of WBV before and after ovariectomy on lumbar vertebrae in rats could be maintained after vibration stopped. Three-month-old female rats were divided into four groups (n = 45/group): control (CON), ovariectomy (OVA), WBV before ovariectomy (WBV-BO), and WBV after ovariectomy (WBV-AO) groups. For 1-8 weeks, WBV-BO group was subjected to vertical WBV. At the 9th week, the rats in WBV-BO, WBV-AO, and OVA groups were ovariectomized. During 11-18 weeks, WBV-AO group was subjected to vibration. For 19-26 weeks, no intervention was done for rats. The lumbar vertebrae were examined by Micro-CT, compressive test, creep test, and microindentation test. At the 8th week, the displacement of the L1-L2 annulus fibrosus in WBV-BO group was 18% smaller compared with CON group (p<0.05). At the 18th week, the elastic modulus of the L5 vertebral body in WBV-BO and WBV-AO groups was 53% and 57% higher than that in CON group, respectively (p<0.05); the displacement of the L1-L2 annulus fibrosus in WBV-BO group was 25% smaller than those in the other groups (p<0.05). At the 26th week, there was no significant difference in the displacement of the L1-L2 annulus fibrosus between WBV-BO group and other groups (p>0.05); the elastic modulus of the L5 vertebral body had no significant difference between WBV-AO group and CON group (p>0.05). Our results demonstrated that WBV before ovariectomy effectively prevented disc degeneration with significant effects up to 8 weeks after ovariectomy. The vertebral mechanical properties could be significantly improved by WBV after ovariectomy, but the residual effect did not maintain after WBV stopped.


Subject(s)
Intervertebral Disc Degeneration , Lumbar Vertebrae , Humans , Rats , Female , Animals , Vibration , X-Ray Microtomography/methods , Ovariectomy , Bone Density
19.
Health Commun ; : 1-10, 2022 Nov 28.
Article in English | MEDLINE | ID: mdl-36444114

ABSTRACT

Non-professional medical interpreters are frequent participants of bilingual health communication. Yet, scholarly attention paid to this group's roles in less routinized medical encounters is insufficient. Adopting the concept of "role-space," this study explores volunteer medical interpreters' (VMIs) roles in mediating provider-patient conflicts at a designated hospital tasked to admit and treat foreign patients in City Y, China. In-depth interviews with eight VMIs, two doctors, two patients, and one Foreign Affairs officer indicate that VMIs took on the roles of provider proxy, patient advocates, information gatekeepers, and emotional supporters while navigating through challenges at the macro-, meso- and micro-level; Their practices led to four role-spaces that featured high presentation of VMIs' self-driven actions during dyadic communication with patients only and, in most cases, minimal interaction management and participant alignment in provider-patient encounters.

20.
Front Bioeng Biotechnol ; 10: 981062, 2022.
Article in English | MEDLINE | ID: mdl-36225600

ABSTRACT

Orthopedic implants are widely used for the treatment of bone defects caused by injury, infection, tumor and congenital diseases. However, poor osseointegration and implant failures still occur frequently due to the lack of direct contact between the implant and the bone. In order to improve the biointegration of implants with the host bone, surface modification is of particular interest and requirement in the development of implant materials. Implant surfaces that mimic the inherent surface roughness and hydrophilicity of native bone have been shown to provide osteogenic cells with topographic cues to promote tissue regeneration and new bone formation. A growing number of studies have shown that cell attachment, proliferation and differentiation are sensitive to these implant surface microtopography. This review is to provide a summary of the latest science of surface modified bone implants, focusing on how surface microtopography modulates osteoblast differentiation in vitro and osseointegration in vivo, signaling pathways in the process and types of surface modifications. The aim is to systematically provide comprehensive reference information for better fabrication of orthopedic implants.

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