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In this paper, a highly sensitive ammonia (N H 3) sensor based on a polymethyl methacrylate/polyaniline (PMMA/PANI) microwire structure is designed and implemented. First, a micron-sized PMMA microwire was fabricated and connected with two tapered single-mode fibers to form a coupling structure; thus, the Mach-Zehnder (MZ) interference was successfully excited due to the good light conductivity of the PMMA. It was demonstrated that the coupling structure behaved with a high refractive index detection sensitivity of 3044 nm/RIU. To make it sensitive to N H 3, the PANI was selected to mix with PMMA and then formed a micron-level PMMA/PANI fiber. The experimental results showed that the PMMA/PANI fiber can selectively sense N H 3 with a high sensitivity of 65.3 pm/ppm. This proposed N H 3 sensor not only solves the problem of sensitive film shedding, but also possesses the advantages of good integration, high sensitivity, good selectivity, and short response time.
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Accelerometers are commonly used to measure vibrations for condition monitoring in mechanical and civil structures; however, their high cost and point-based measurement approach present practical limitations. With rapid advancements in computer vision and deep learning, research into tracking the motion of individual pixels with vision cameras has increased. The recently developed CoTracker, a transformer-based model, has demonstrated excellence in motion tracking, yet its performance in measuring structural vibrations has not been fully explored. This paper investigates the efficacy of the CoTracker model in extracting full-field structural vibrations using cameras. It is initially applied to capture the dense point movements in video sequences of a cantilever beam recorded using a high-speed camera. Subsequently, modal analysis using delay-embedding dynamic mode decomposition (DMD) is conducted to extract modal parameters including natural frequencies, damping ratios, and mode shapes. The results, benchmarked against those from a reference accelerometer and the Finite Element Method (FEM) result, demonstrate CoTracker's high potential for general applicability in structural vibration measurements.
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BACKGROUND: Recently, tranexamic acid (TXA) and epsilon aminocaproic acid (EACA) have been applied in total hip arthroplasty (THA). However, doubts in clinicians' minds about which medicine is more efficient and economical in THA need to be clarified. Therefore, this study compared the efficacy and cost of the intraoperative administration of TXA and EACA per surgery in decreasing perioperative blood transfusion rates in THA. METHODS: This study enrolled patients who underwent THA between January 2019 to December 2020. A total of 295 patients were retrospectively divided to receive topical combined with intravenous TXA (n = 94), EACA (n = 97) or control (n = 104). The primary endpoints included transfusions, estimated perioperative blood loss, cost per patient and the drop in the haemoglobin and haematocrit levels. RESULTS: Patients who received EACA had greater total blood loss, blood transfusion rates, changes in HGB levels and mean cost of blood transfusion per patient (P < 0.05) compared with patients who received TXA. In addition, both TXA and EACA groups had significantly fewer perioperative blood loss, blood transfusion, operation time and changes in haemoglobin and haematocrit levels than the control group (P < 0.05). Cost savings in the TXA and EACA groups were 736.00 RMB and 408.00 RMB per patient, respectively. CONCLUSIONS: The application of perioperative antifibrinolytics notably reduces the need for perioperative blood transfusions. What's more, this study demonstrated that TXA is superior to EACA for decreasing blood loss and transfusion rates while at a lower cost per surgery. These results indicate that TXA may be the optimum antifibrinolytics for THA in Chinese area rather than EACA.
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Antifibrinolíticos , Artroplastia de Quadril , Ácido Tranexâmico , Humanos , Artroplastia de Quadril/efeitos adversos , Estudos Retrospectivos , Perda Sanguínea Cirúrgica/prevenção & controle , Aminocaproatos , Ácido Aminocaproico , HemoglobinasRESUMO
For ground-based lidars in atmospheric observation, their data acquisition unit and control unit usually work independently. They usually require the cooperation of large-volume, high-power-consumption Industrial Personal Computer (IPC). However, the space-borne lidar has high requirements on the stability and integration of the acquisition control system. In this paper, a new data acquisition and lidar control system (DALCS) was developed based on System-on-Chip Field-Programmable Gate Array (SoC FPGA) technology. It can be used in lidar systems with high repetition rate and photon-counting mode and has functions such as data storage, laser control, automatic collimation, wireless communication, and fault self-test. DALCS has two working modes: in online mode, the echo data collected by DALCS are transmitted to the computer for display in real-time and then stored with the current time as the file name; in offline mode, the data are stored in local non-volatile memory, which can be read remotely and can work autonomously when there is no IPC. The test results showed that in the frequency range of 0-70 M, the counting linearity of DALCS reached 0.9999, and the maximum relative error between the DALCS card and the standard signal source was 0.211%. The comparison results showed that the correlation coefficient between DALCS and MCS-PCI was as high as 0.99768. The DALCS was placed in a self-developed lidar sensor system for continuous observation, and the system worked stably under different weather conditions. The range-squared-corrected signal profiles obtained from the observations reflect the spatial and temporal distribution characteristics of aerosols and clouds well. This provides scheme verification and experimental support for the development of space-borne lidar data acquisition and control system.
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BACKGROUND: In meta-analyses of a binary outcome, double zero events in some studies cause a critical methodology problem. The generalized linear mixed model (GLMM) has been proposed as a valid statistical tool for pooling such data. Three parameter estimation methods, including the Laplace approximation (LA), penalized quasi-likelihood (PQL) and adaptive Gauss-Hermite quadrature (AGHQ) were frequently used in the GLMM. However, the performance of GLMM via these estimation methods is unclear in meta-analysis with zero events. METHODS: A simulation study was conducted to compare the performance. We fitted five random-effects GLMMs and estimated the results through the LA, PQL and AGHQ methods, respectively. Each scenario conducted 20,000 simulation iterations. The data from Cochrane Database of Systematic Reviews were collected to form the simulation settings. The estimation methods were compared in terms of the convergence rate, bias, mean square error, and coverage probability. RESULTS: Our results suggested that when the total events were insufficient in either of the arms, the GLMMs did not show good point estimation to pool studies of rare events. The AGHQ method did not show better properties than the LA estimation in terms of convergence rate, bias, coverage, and possibility to produce very large odds ratios. In addition, although the PQL had some advantages, it was not the preferred option due to its low convergence rate in some situations, and the suboptimal point and variance estimation compared to the LA. CONCLUSION: The GLMM is an alternative for meta-analysis of rare events and is especially useful in the presence of zero-events studies, while at least 10 total events in both arms is recommended when employing GLMM for meta-analysis. The penalized quasi-likelihood and adaptive Gauss-Hermite quadrature are not superior to the Laplace approximation for rare events and thus they are not recommended.
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Modelos Estatísticos , Simulação por Computador , Humanos , Funções Verossimilhança , Modelos Lineares , Razão de Chances , Revisões Sistemáticas como AssuntoRESUMO
On March 1, 2012, the Chinese government implemented the Administrative Measures on Heatstroke Prevention (AMHP2012) to combat the occupational health impacts of extreme heat, and reducing occupational injury was one of the main purposes. This study aimed at quantifying the intervention effects of the AMHP2012 on extreme heat-related occupational injuries and subsequent insurance payouts in Guangzhou, China. Data on occupational injuries and insurance payouts were collected from March 1, 2011, to February 28, 2013, from the occupational injury insurance system of Guangzhou. A quasi-experimental design with before-after control was adopted. Interrupted time series analysis was performed to quantify the change of occupational injuries and insurance payouts after policy implementation. The distributed lag non-linear model was used to explore whether injury claims and insurance payouts due to extreme heat decreased. A total of 9851 injury claims were included in the analysis. After policy implementation, the risk of occupational injuries and insurance payouts decreased by 13% (RR = 0.87, 95%CI: 0.75, 0.99) and 24% (RR = 0.76, 95% CI: 0.58, 0.94), respectively. The attributable fraction of extreme heat-related occupational injuries decreased from 3.17% (95%eCI: 1.35, 4.69) to 1.52% (95%eCI: -0.36, 3.15), which contributed to 0.86 million USD reduction of insurance payouts. Both males and females, low-educated, young and middle-aged workers, workers at small or medium-sized enterprises, engaging in manufacturing, and with both minor and severe injuries were apparently associated with decreased rates of extreme heat-related occupational injuries. The AMHP2012 policy contributed to the reduction of extreme heat-related occupational injuries and insurance payouts in Guangzhou, China, and this research provided novel evidence for decision-makers to better understand the necessity of implementing health protection policies among laborers under climate change.
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Calor Extremo , Exposição Ocupacional , Traumatismos Ocupacionais , China/epidemiologia , Cidades , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Traumatismos Ocupacionais/epidemiologia , Traumatismos Ocupacionais/prevenção & controleRESUMO
At present, there is no uniform standard for the treatment of femoral neck fractures (FNFs) in young adults, and the current strategy is inclined to the native hip joint preservation. Femoral neck fractures in young adult are mostly caused by high-energy violence, and the blood supply of femoral head is severely damaged, which is prone to secondary femoral head avascular necrosis. In this article, we report 10 cases of young adult Garden III FNF treated with open reduction and internal fixation (ORIF) and microsurgical exploration of the superior retinacular vessels from 2015 to 2018, to more intuitively understand the involvement of superior retinacular vessels after displaced FNF in young adults. The results show that the SRA injury of Garden III FNF could be categorized into 3 types (type A-C), type A (6/10): the SRA vessels were kept intact, while they were pulled or compressed by displaced fracture fragment and could be revascularized by reduction; type B (3/10): the SRA vessels were avulsed with the superior retinaculum attachment avulsion fracture and could not be revascularized by reduction; and type C (1/10): the SRA vessels were ruptured, and the remnant of the vessel is present, which can be revascularized by vascular anastomosis. The previously mentioned results showed that the vascular damage of femoral head in Garden III FNF is quite complicated and might have the potential for being further classified into several subtypes.
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Fraturas do Colo Femoral , Necrose da Cabeça do Fêmur , Fraturas do Colo Femoral/cirurgia , Fixação Interna de Fraturas , Humanos , Redução Aberta , Adulto JovemRESUMO
BACKGROUND: To investigate the prevalence of protocol registration (or development) among published dose-response meta-analyses (DRMAs), and whether DRMAs with a protocol are better than those not. METHODS: Three databases were searched for eligible DRMAs. The modified AMSTAR (14 items) and PRISMA checklists (26 items) were used to assess the methodological and reporting quality, with each item assigned 1 point if it met the requirement or 0 if not. We matched (1,2) DRMAs with registered or published protocol to those not, by region and publication years. The summarized quality score and compliance rate of each item were compared between the two groups. Multivariable regression was employed to see if protocol registration or development was associated with total quality score. RESULTS: We included 529 DRMAs, with 45 (8.51%) completed protocol registration or development. We observed a higher methodological score for DRMAs with protocol than the matched controls (9.47 versus 8.58, P < 0.01); this embodied in 4 out of 14 items of AMSTAR [e.g., Duplicate data extraction (rate difference, RD = 0.17, 95% CI: 0.04, 0.30; P = 0.01). A higher reporting score (cubic transformed) for DRMAs with protocol than the matched controls was also observed (11,875.00 versus 10,229.53, P < 0.01); which embodied in 6 out of 26 items of PRISMA [e.g. Describe methods for publication bias (RD = 0.08, 95% CI: 0.01, 0.14; P = 0.02)]. Regression analysis suggested positive association between protocol registration or development and total reporting score (P = 0.012) while not for methodological score (P = 0.87). CONCLUSIONS: Only a small proportion of DRMAs completed protocol registration or development, and those with protocol were better reported than those not. Protocol registration or development is highly desirable.
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Metanálise como Assunto , Publicações Periódicas como Assunto , Projetos de Pesquisa/normas , Relatório de Pesquisa/normas , Literatura de Revisão como Assunto , HumanosRESUMO
Tantalum rod implantation with vascularized bone transplantation has been reported to be an effective method for the treatment of osteonecrosis of the femoral head (ONFH). However, long-term follow-up results were unclear. Sixty-five patients (71 hips) with ONFH treated with this technique were retrospectively reviewed. According to the Association Research Circulation Osseous (ARCO) classification, 21 hips were stage II, 30 were stage III, and 15 were stage IV. Sixty-one patients (66 hips) were followed for more than 10 years. Fifteen hips had to be converted to total hip arthroplasty (THA), the proportion of THA conversion surgery over 10 years postoperative was 4.76% for stage II, 16.7% for stage III, and 60% for stage IV, respectively. The 10-year joint-preserving success rate of the entire group was 77.2%. The Harris Hip Score (HHS) in the patients not receiving THA therapy increased from a mean of 51.35 points (ranged from 32 to 62 points) to 90.12 points (ranged from 72 to 99 points). The technique of tantalum rod implantation with vascularized bone grafting was an effective joint-preserving method for the treatment of ARCO stage II-III ONFH.
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Transplante Ósseo , Necrose da Cabeça do Fêmur , Cabeça do Fêmur/cirurgia , Necrose da Cabeça do Fêmur/cirurgia , Seguimentos , Humanos , Estudos Retrospectivos , Análise de Sobrevida , Tantálio , Resultado do TratamentoRESUMO
BACKGROUND: Dose-response meta-analysis (DRMA) is a useful tool to investigate potential dose-response relationship between certain exposure or intervention and the outcome of interest. A large number of DRMAs have been published in the past several years. However, the standard of reporting for such studies is not known. METHODS: Medline, Embase, and Wiley Library were searched for systematic reviews with DRMAs (SR-DRMAs) published from January 2011 to July 2017. We used the combination of PRISMA and MOOSE statements, containing 33 items, to assess the reporting of included SR-DRMAs. The adherence of reporting was defined as the proportion of SR-DRMAs meeting the reporting requirement of an item. We explored the association between five pre-specified variables with the total score of reporting on both fully as well as each domain of the checklist. RESULTS: In total, 529 SR-DRMAs were eligible. Ten out of 33 items were under reported, and this mainly refers to the methods domain: only a small proportion of SR-DRMAs stated whether a review protocol existed (45, 8.5%); clarified the qualifications of searchers (1.7%); presented full electronic search strategy (25.9%); described any effort to include all available studies (22.9%), described methods for languages other than English (27.4%), and stated the process for selecting studies (20.2%). Multiple regression analysis suggested that studies with more authors (regression coefficient = 0.78; 95% CI: 0.35, 1.20; P < 0.001), published more recently (regression coefficient = 0.38; 95% CI: 0.28 to 0.47; trend P < 0.001), used reporting guideline (regression coefficient = 0.98; 95% CI: 0.68 to 1.32; P < 0.001), and involvement of methodologist (regression coefficient = 0.86; 95% CI: 0.42 to 1.32; P < 0.001) were associated with higher score of reporting. Further regression suggested that the improvement on the quality mainly concentrated on the methods and results domains. CONCLUSIONS: The reporting of SR-DRMAs needs to be further improved, particularly in the issues refer to the methods. The quality of reporting may improve when involving more authors and methodologists and employing any reporting guidelines.
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Metanálise como Assunto , Publicações Periódicas como Assunto/normas , Relatório de Pesquisa/normas , Revisões Sistemáticas como Assunto , Estudos Transversais , Confiabilidade dos Dados , Coleta de Dados/métodos , Coleta de Dados/normas , Relação Dose-Resposta a Droga , Humanos , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/normasRESUMO
A fiber-optic urea sensor based on surface plasmon resonance (SPR) and Mach-Zehnder interference (MZI) combined principle was designed and implemented. By plating gold film on the single-mode-no-core-thin-core-single-mode fiber structure, we successfully excited both SPR and MZI, and constructed two parallel detection channels for simultaneously measurement of urea concentration and temperature. Urease was immobilized on the gold film by metal-organic zeolite skeleton (ZIF-8), which can not only fix a large number of urease to improve measurement sensitivity of urea, but also protect urease activity to ensure the sensor stability. Experimental results indicate that the designed urea sensor with temperature compensation function can detect urea solution with concentration of 1-9 mM, and the sensitivity is 1.4 nm/mM. The proposed measurement method provides a new choice for monitoring urea concentration in the field of medical diagnosis and human health monitoring.
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Tecnologia de Fibra Óptica , Ressonância de Plasmônio de Superfície , Ureia , Urease , Ureia/química , Ureia/análise , Ressonância de Plasmônio de Superfície/métodos , Ressonância de Plasmônio de Superfície/instrumentação , Urease/química , Tecnologia de Fibra Óptica/instrumentação , Tecnologia de Fibra Óptica/métodos , Desenho de Equipamento , Ouro/química , Enzimas Imobilizadas/química , Interferometria/métodos , Interferometria/instrumentaçãoRESUMO
BACKGROUND: Succinate dehydrogenase inhibitor (SDHI) fungicides play important roles in the control of plant fungal diseases. However, they are facing serious challenges from issues with resistance and cross-resistance, primarily attributed to their frequent application and structural similarities. There is an urgent need to design and develop SDHI fungicides with novel structures. RESULTS: Aiming to discover novel potent SDHI fungicides, 31 innovative pyrazole ß-ketonitrile derivatives with diphenyl ether moiety were rationally designed and synthesized, which were guided by a 3D-QSAR model from our previous study. The optimal target compound A23 exhibited not only outstanding in vitro inhibitory activities against Rhizoctonia solani with a half-maximal effective concentration (EC50) value of 0.0398 µg mL-1 comparable to that for fluxapyroxad (EC50 = 0.0375 µg mL-1), but also a moderate protective efficacy in vivo against rice sheath blight. Porcine succinate dehydrogenase (SDH) enzymatic inhibitory assay revealed that A23 is a potent inhibitor of SDH, with a half-maximal inhibitory concentration of 0.0425 µm. Docking study within R. solani SDH indicated that A23 effectively binds into the ubiquinone site mainly through hydrogen-bonds, and cation-π and π-π interactions. CONCLUSION: The identified ß-ketonitrile compound A23 containing diphenyl ether moiety is a potent SDH inhibitor, which might be a good lead for novel fungicide research and optimization. © 2024 Society of Chemical Industry.
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BACKGROUND: The concentration of cytochrome C is demonstrated to be an effective indicator of the microbial corrosion strength of metals. Traditional cytochrome C sensor can detect cytochrome C with a low detection limit, but their use is limited by their high cost, cumbersome operation, and susceptibility to malignant environments. In addition, studies on the monitoring of cytochrome C in the field of microbial corrosion has still not been carried out. Therefore, there is a need for a highly sensitive, selective, low-cost, anti-interference, and stable cytochrome C sensor with online monitoring and remote sensing capabilities for in-situ measurement of microbial corrosion strength. RESULTS: This paper proposed a highly sensitive label-free fiber-optic sensor based on Mach-Zehnder interferometer (MZI) for in-situ measurement of the microbial corrosion marker cytochrome C. Two-dimensional Ti2C-MXene material is uniformly immobilized onto the surface of the sensing area to improve the sensitivity, hydrophilicity, and specific surface area of the sensing area, as well as to facilitate the immobilization of specific sensitive materials. The cytochrome C antibody is modified on the surface of Ti2C-MXene to specifically recognize cytochrome C, whose concentration variation can be measured by monitoring the spectral shift of MZI sensor. Results demonstrate a measurement sensitivity of 1.428 nm/µM for cytochrome C concentrations ranging from 0 to 7.04 µM. The detection limit of the sensor is calculated to be 0.392 µM with remarkable performance, including selectivity, stability, and reliability. Besides, the measurement result of the proposed sensor in real microbial corrosive environment is consistent with that of the ideal environment. SIGNIFICANCE AND NOVELTY: This is the first instance of achieving in-situ and label-free measurement of cytochrome C by using a fiber-optic MZI sensor, which undoubtedly provides a feasible solution for the effective monitoring of microbial metal corrosion in the environment.
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Citocromos c , Tecnologia de Fibra Óptica , Interferometria , Titânio , Citocromos c/análise , Citocromos c/metabolismo , Titânio/química , Técnicas Biossensoriais/métodos , Limite de Detecção , Fibras Ópticas , CorrosãoRESUMO
Porous tantalum scaffolds offer a high degree of biocompatibility and have a low friction coefficient. In addition, their biomimetic porous structure and mechanical properties, which closely resemble human bone tissue, make them a popular area of research in the field of bone defect repair. With the rapid advancement of additive manufacturing, 3D-printed porous tantalum scaffolds have increasingly emerged in recent years, offering exceptional design flexibility, as well as facilitating the fabrication of intricate geometries and complex pore structures that similar to human anatomy. This review provides a comprehensive description of the techniques, procedures, and specific parameters involved in the 3D printing of porous tantalum scaffolds. Concurrently, the review provides a summary of the mechanical properties, osteogenesis and antibacterial properties of porous tantalum scaffolds. The use of surface modification techniques and the drug carriers can enhance the characteristics of porous tantalum scaffolds. Accordingly, the review discusses the application of these porous tantalum materials in clinical settings. Multiple studies have demonstrated that 3D-printed porous tantalum scaffolds exhibit exceptional corrosion resistance, biocompatibility, and osteogenic properties. As a result, they are considered highly suitable biomaterials for repairing bone defects. Despite the rapid development of 3D-printed porous tantalum scaffolds, they still encounter challenges and issues when used as bone defect implants in clinical applications. Ultimately, a concise overview of the primary challenges faced by 3D-printed porous tantalum scaffolds is offered, and corresponding insights to promote further exploration and advancement in this domain are presented.
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Materiais Biocompatíveis , Substitutos Ósseos , Osso e Ossos , Osteogênese , Impressão Tridimensional , Tantálio , Engenharia Tecidual , Alicerces Teciduais , Tantálio/química , Alicerces Teciduais/química , Porosidade , Humanos , Materiais Biocompatíveis/química , Engenharia Tecidual/métodos , Animais , Substitutos Ósseos/química , Teste de Materiais , Regeneração ÓsseaRESUMO
As one of the most intriguing nanozymes, the platinum (Pt) nanozyme has attracted tremendous research interest due to its various catalytic activities but its application is still limited by its poor colloidal stability and low affinity to substrates. Here, we design a highly stable Pt@carbon dot (Pt@CD) hybrid nanozyme with enhanced peroxidase (POD)-like activity (specific activity of 1877 U mg-1). The Pt@CDs catalyze the decomposition of hydrogen peroxide (H2O2) to produce singlet oxygen and hydroxyl radicals and exhibit high affinity to H2O2 and high specificity to 3,3',5,5'-tetramethyl-benzidine. We reveal that both the hydroxyl and carbonyl groups of CDs could coordinate with Pt2+ and then regulate the charge state of the Pt nanozyme, facilitating the formation of Pt@CDs and improving the POD-like activity of Pt@CDs. Colorimetric detection assays based on Pt@CDs for H2O2, dopamine, and glucose with a satisfactory detection performance are achieved. Moreover, the Pt@CDs show a H2O2-involving antibacterial effect by destroying the cell membrane. Our findings provide new opportunities for designing hybrid nanozymes with desirable stability and catalytic performance by using CDs as nucleating templates and stabilizers.
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Carbono , Platina , Carbono/química , Platina/química , Peróxido de Hidrogênio/química , Glucose , Peroxidases/química , Peroxidase/químicaRESUMO
OBJECTIVE: Many methods of acetabular reconstruction with total hip arthroplasty (THA) for Crowe type II and III adult developmental dysplasia of the hip (DDH) acetabular bone defect have been implemented clinically. However, there was no study comparing the results of integrated acetabular prosthesis (IAP) with bone grafting (BG). This study aims to investigate the efficacy of IAP and BG for acetabular reconstruction in Crowe type II and III DDH. METHODS: The clinical data of 45 patients with unilateral Crowe type II and III DDH who underwent THA from January 2020 to January 2023 were retrospectively analyzed. The patients were divided into two groups: 25 patients using 3D-printed IAP (IAP group) and 20 patients using BG (BG group). The operation time and intraoperative blood loss were recorded. The clinical outcomes were assessed by Harris Hip Score (HHS) and full weight-bearing time. The radiological outcomes were evaluated by the radiological examination. Accordingly, intraoperative and postoperative complications were observed as well. The data between the two groups were compared by independent sample t-tests and the Mann-Whitney U rank sum test. RESULTS: There were no significant differences between the two groups in Harris Hip Score (HHS) (preoperative, 6 months postoperative, and the last follow-up), leg length discrepancy (LLD), cup inclination, cup anteversion, vertical center of rotation (V-COR), horizontal center of rotation (H-COR) (p > 0.05). The mean HHS in the IAP group was higher than in the BG group at 1 and 3 months postoperative (p < 0.001). The mean surgical time and blood loss in the IAP group were less than in the BG group (p < 0.001). The mean full weight-bearing time in the IAP group was shorter than in the BG group (p < 0.01). No complications were observed in either group during the follow-up period. CONCLUSION: IAP and BG have similar radiographic outcomes and long-term clinical efficacy in THA for Crowe type II and III DDH, but the IAP technique has higher surgical safety and facilitates the recovery of hip joint function, which is worthy of clinical promotion.
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The joint prosthesis plays a vital role in the outcome of total hip arthroplasty. The key factors that determine the performance of joint prostheses are the materials used and the structural design of the prosthesis. This study aimed to fabricate a porous tantalum (Ta) hip prosthesis using selective laser melting (SLM) technology. The feasibility of SLM Ta use in hip prosthesis was verified by studying its chemical composition, metallographic structure and mechanical properties. In vitro experiments proved that SLM Ta exhibited better biological activities in promoting osteogenesis and inhibiting inflammation than SLM Ti6Al4V. Then, the topological optimization design of the femoral stem of the SLM Ta hip prosthesis was carried out by finite element simulation, and the fatigue performance of the optimized prosthesis was tested to verify the biomechanical safety of the prosthesis. A porous Ta acetabulum cup was also designed and fabricated using SLM. Its mechanical properties were then studied. Finally, clinical trials were conducted to verify the clinical efficacy of the SLM Ta hip prosthesis. The porous structure could reduce the weight of the prosthesis and stress shielding and avoid bone resorption around the prosthesis. In addition, anti-infection drugs can also be loaded into the pores for infection treatment. The acetabular cup can be custom-designed based on the severity of bone loss on the acetabular side, and the integrated acetabular cup can repair the acetabular bone defect while achieving the function of the acetabular cup.
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As the application of bone scaffolds becomes more and more widespread, the requirements for the high performance of bone scaffolds are also increasing. The stiffness and porosity of porous structures can be adjusted as needed, making them good candidates for repairing damaged bone tissues. However, the development of porous bone structures is limited by traditional manufacturing methods. Today, the development of additive manufacturing technology has made it very convenient to manufacture bionic porous bone structures as needed. In the present paper, the current state-of-the-art optimization techniques for designing the scaffolds and the settings of different optimization methods are introduced. Additionally, various design methods for bone scaffolds are reviewed. Furthermore, the challenges in designing high performance bone scaffolds and the future developments of bone scaffolds are also presented.
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Objective: To summarize the characteristics and biomechanical research progress of common acetabular reconstruction techniques in patients with Crowe type â ¡ and â ¢ developmental dysplasia of the hip (DDH) undergoing total hip arthroplasty (THA), and provide references for selecting appropriate acetabular reconstruction techniques for clinical treatment of Crowe type â ¡ and â ¢ DDH. Methods: The domestic and foreign relevant literature on biomechanics of acetabular reconstruction with Crowe type â ¡ and â ¢ DDH was reviewed, and the research progress was summarized. Results: At present, there are many acetabular reconstruction techniques in Crowe type â ¡ and â ¢ DDH patients undergoing THA, with their own characteristics due to structural and biomechanical differences. The acetabular roof reconstruction technique enables the acetabular cup prosthesis to obtain satisfactory initial stability, increases the acetabular bone reserve, and provides a bone mass basis for the possible secondary revision. The medial protrusio technique (MPT) reduces the stress in the weight-bearing area of the hip joint and the wear of the prosthesis, and increases the service life of the prosthesis. Small acetabulum cup technique enables shallow small acetabulum to match suitable acetabulum cup to obtain ideal cup coverage, but small acetabulum cup also increases the stress per unit area of acetabulum cup, which is not conducive to the long-term effectiveness. The rotation center up-shifting technique increases the initial stability of the cup. Conclusion: Currently, there is no detailed standard guidance for the selection of acetabular reconstruction in THA with Crowe type â ¡ and â ¢ DDH, and the appropriate acetabular reconstruction technique should be selected according to the different types of DDH.
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Artroplastia de Quadril , Displasia do Desenvolvimento do Quadril , Luxação Congênita de Quadril , Prótese de Quadril , Humanos , Acetábulo/cirurgia , Luxação Congênita de Quadril/cirurgia , Displasia do Desenvolvimento do Quadril/complicações , Displasia do Desenvolvimento do Quadril/cirurgia , Articulação do Quadril/cirurgia , Artroplastia de Quadril/métodos , Resultado do Tratamento , Estudos RetrospectivosRESUMO
Introduction: Dopamine is one of the most significant neurotransmitters and plays an important role in the management of cognitive functions such as learning, memory, and behavior. The disorder of dopamine is associated with many major mental diseases. It is necessary to develop selective methods for the detection of dopamine. Methods: In this work, carbon dots (CDs) were synthesized by a solvothermal route using glutathione, L-histidine, and formamide as sources. Results: Under light irradiation, The CDs convert dissolved oxygen to singlet oxygen (1O2), which could oxidize TMB. When reduced dopamine was present, it suppressed the catalysis of CDs, then the absorption of the CDs-coupled TMB complex at 652 nm was diminished. Furthermore, it was revealed that the surface groups including hydroxyl, amino, carbonyl, and carboxyl groups of CDs were related to their light-responsive catalytic activity by surface modification. In the range of 0.5-15 µM, the CDs could afford a LOD of 0.25 µM for dopamine detection with fine linearity, also showing good selectivity. Discussion: The results from fetal bovine serum indicated the good applicability of the CDs in the determination of dopamine.