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1.
Cell Signal ; 118: 111055, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38246512

RESUMEN

Diabetic osteoporosis (DO) is a significant complication of diabetes, characterized by a decrease in bone mineral density and an increase in fracture risk. Magnetic nanoparticles (GMNPs) have emerged as potential drug carriers for various therapeutic applications. This study investigated the molecular mechanism of GMNPs loaded with bone marrow mesenchymal stem cell (BMSC) derived extracellular vesicles (EVs) overexpressing MEG3 target miR-3064-5p to induce NR4A3 for treating DO in rats. Initial analysis was carried out on GEO datasets GSE7158 and GSE62589, revealing a notable downregulation of NR4A3 in osteoporotic samples. Subsequent in vitro studies demonstrated the effective uptake of BMSC-EVs-MEG3 by osteoblasts and its potential to inhibit miR-3064-5p, activating the PINK1/Parkin signaling pathway and thus promoting mitochondrial autophagy, osteoblast proliferation, and differentiation. In vivo, experiments using DO rat models further substantiated the therapeutic efficacy of GMNPE-EVs-MEG3 in alleviating osteoporosis symptoms. In conclusion, GMNPs loaded with BMSC-EVs, through the delivery of MEG3 targeting miR-3064-5p, can effectively promote NR4A3 expression, activate the PINK1/Parkin pathway, and thereby enhance osteoblast proliferation and differentiation, offering a promising treatment for DO.


Asunto(s)
Diabetes Mellitus , Vesículas Extracelulares , Células Madre Mesenquimatosas , MicroARNs , Osteoporosis , Ratas , Animales , MicroARNs/genética , MicroARNs/metabolismo , Vesículas Extracelulares/metabolismo , Osteoporosis/genética , Osteoporosis/terapia , Osteoporosis/metabolismo , Células Madre Mesenquimatosas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas Quinasas/metabolismo , Diabetes Mellitus/metabolismo
2.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 37(12): 1471-1476, 2023 Dec 15.
Artículo en Chino | MEDLINE | ID: mdl-38130189

RESUMEN

Objective: To investigate the early effectiveness of the Ti-Robot assisted femoral neck system (FNS) in the treatment of elderly Garden type Ⅱ and Ⅲ femoral neck fractures. Methods: A retrospective analysis was conducted on the clinical data of 41 elderly patients with Garden type Ⅱ and Ⅲ femoral neck fractures who were admitted between December 2019 and August 2022 and met the selection criteria. Among them, 21 cases were treated with Ti-Robot assisted FNS internal fixation (study group), and 20 cases were treated solely with FNS internal fixation (control group). There was no significant difference in baseline data, including gender, age, side, cause of injury, time from injury to surgery, fracture Garden classification, and fracture line classification, between the two groups ( P>0.05). Surgical effectiveness was evaluated based on parameters such as operation time (including incision time and total operation time), reduction level, number of dominant pin insertions, intraoperative fluoroscopy frequency, incision length, whether to extend the incision, need for assisted reduction, postoperative hospital stay, fracture healing time, incidence of osteonecrosis of the femoral head, postoperative visual analogue scale (VAS) score at 1 day, and Harris hip score at last follow-up. Results: The study group showed significantly shorter incision time, fewer dominant pin insertions, fewer instances of extended incisions, fewer intraoperative fluoroscopy frequency, and smaller incisions than the control group ( P<0.05). There was no significant difference in total operation time, reduction level, and assisted reduction frequency between the two groups ( P>0.05). Both groups achieved primary wound healing postoperatively, with no complications such as incision leakage or skin infection. All patients were followed up 12-24 months with an average of 14.6 months. Fractures healed in both groups, with no significant difference in healing time ( P>0.05). There was no significant difference in postoperative hospital stay between the two groups ( P>0.05). The study group showed significantly better VAS score at 1 day after operation and Harris hip score at last follow-up when compared to the control group ( P<0.05). No complication such as internal fixation failure, fracture displacement, or hip joint varus occurred in both groups during the follow-up. Osteonecrosis of the femoral head occurred in 1 patient of the control group, while no was observed in the study group, and the difference in the incidence of osteonecrosis of the femoral head between the two groups was not significant ( P=0.488). Conclusion: Compared to sole FNS internal fixation treatment, Ti-Robot assisted FNS internal fixation for elderly Garden typeⅡ and Ⅲ femoral neck fractures can reduce incision time, achieve minimally invasive and accurate nail implantation, and decrease intraoperative fluoroscopy frequency, leading to improved postoperative hip joint function recovery.


Asunto(s)
Fracturas del Cuello Femoral , Osteonecrosis , Robótica , Herida Quirúrgica , Humanos , Anciano , Cuello Femoral , Estudios Retrospectivos , Resultado del Tratamiento , Titanio , Fracturas del Cuello Femoral/cirugía , Fijación Interna de Fracturas
3.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 37(8): 996-1001, 2023 Aug 15.
Artículo en Chino | MEDLINE | ID: mdl-37586801

RESUMEN

Objective: To investigate the effect of ultrasonic bone curette in anterior cervical spine surgery. Methods: A clinical data of 63 patients with cervical spondylosis who were admitted between September 2019 and June 2021 and met the selection criteria was retrospectively analyzed. Among them, 32 cases were operated with conventional instruments (group A) and 31 cases with ultrasonic bone curette (group B). There was no significant difference between the two groups (P>0.05) in gender, age, surgical procedure, surgical segment and number of occupied cervical space, disease type and duration, comorbidities, and preoperative Japanese Orthopaedic Association (JOA) score, cervical dysfunction index (NDI), and pain visual analogue scale (VAS) score. The operation time, intraoperative bleeding, postoperative drainage, postoperative hospital stay, and the occurrence of postoperative complications were recorded in both groups. Before operation and at 1, 3, and 6 months after operation, the JOA score and NDI were used to evaluate the function and the postoperative JOA improvement rate was calculated, and VAS score was used to evaluate the pain improvement. The anteroposterior and lateral cervical X-ray films were taken at 1, 3, and 6 months after operation to observe whether there was any significant loosening and displacement of internal fixators. Results: Compared with group A, group B had shorter operation time and postoperative hospital stay, less intraoperative bleeding and postoperative drainage, and the differences were significant (P<0.05). All incisions healed by first intention in the two groups, and postoperative complications occurred in 5 cases (15.6%) in group A and 2 cases (6.5%) in group B, showing no significant difference (P>0.05). All patients were followed up 6-12 months (mean, 7.9 months). The JOA score and improvement rate gradually increased in groups A and B after operation, while the VAS score and NDI gradually decreased. There was no significant difference in VAS score between 3 months and 1 month in group B (P>0.05), and there were significant differences between the other time points of each indicator in the two groups (P<0.05). At 1, 3, and 6 months after operation, the JOA score and improvement rate in group B were better than those in group A (P<0.05). X-ray films examination showed that there was no screw loosening or titanium plate displacement in the two groups after operation, and the intervertebral cage or titanium mesh significantly sank. Conclusion: Compared with traditional instruments, the use of ultrasonic bone curette assisted osteotomy in anterior cervical spine surgery has the advantages of shorter operation time, less intraoperative bleeding, less postoperative drainage, and shorter hospital stay.


Asunto(s)
Titanio , Ultrasonido , Humanos , Estudios Retrospectivos , Complicaciones Posoperatorias/epidemiología , Placas Óseas , Vértebras Cervicales/cirugía
4.
Sensors (Basel) ; 23(15)2023 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-37571440

RESUMEN

Various substances that possess liquid states include drinking water, various types of fuel, pharmaceuticals, and chemicals, which are indispensable in our daily lives. There are numerous real-world applications for liquid content detection in transparent containers, for example, service robots, pouring robots, security checks, industrial observation systems, etc. However, the majority of the existing methods either concentrate on transparent container detection or liquid height estimation; the former provides very limited information for more advanced computer vision tasks, whereas the latter is too demanding to generalize to open-world applications. In this paper, we propose a dataset for detecting liquid content in transparent containers (LCDTC), which presents an innovative task involving transparent container detection and liquid content estimation. The primary objective of this task is to obtain more information beyond the location of the container by additionally providing certain liquid content information which is easy to achieve with computer vision methods in various open-world applications. This task has potential applications in service robots, waste classification, security checks, and so on. The presented LCDTC dataset comprises 5916 images that have been extensively annotated through axis-aligned bounding boxes. We develop two baseline detectors, termed LCD-YOLOF and LCD-YOLOX, for the proposed dataset, based on two identity-preserved human posture detectors, i.e., IPH-YOLOF and IPH-YOLOX. By releasing LCDTC, we intend to stimulate more future works into the detection of liquid content in transparent containers and bring more focus to this challenging task.

5.
Front Genet ; 14: 1133615, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36911415

RESUMEN

Ferroptosis and immune infiltration play an important role in the pathogenesis of intervertebral disc degeneration (IDD). However, there is still a lack of comprehensive analysis on the interaction between ferroptosis-related genes (FRGs) and immune microenvironment in IDD patients. Therefore, this study aims to explore the correlation between FRGs characteristics and immune infiltration in the progression of IDD. The expression profiles (GSE56081 and GSE70362) and FRGs were downloaded from the comprehensive gene expression omnibus (GEO) and FerrDb database, respectively, and the differences were analyzed using R. The intersection of IDD related differential genes (DEGs) and FRGs was taken as differentially expressed FRGs (DE-FRGs) and GO and KEGG enrichment analysis was conducted. Then, we used least absolute shrinkage and selection operator (LASSO) regression algorithm and support vector machine (SVM) algorithm to screen feature genes and draw ROC curve judge the diagnostic value of key DE-FRGs. Then CIBERSORT algorithm is used to evaluate the infiltration of immune cells and analyze the correlation between key DE-FRGs and immune infiltration. Based on the analysis results, we conducted single gene GSEA analysis on key DE-FRGs. RT-PCR and immunohistochemistry further verified the clinical value of the results of biochemical analysis and screening. Seven key DE-FRGs were screened, including the upregulated genes NOX4 and PIR, and the downregulated genes TIMM9, ATF3, ENPP2, FADS2 and TFAP2A. Single gene GSEA analysis further elucidates the role of DE-FRGs in IDD associated with ferroptosis. Correlation analysis showed that seven key DE-FRGs were closely related to immune infiltration in the development of IDD. Finally, RT-PCR and immunohistochemical staining showed that NOX4, ENPP2, FADS2 and TFAP2A were statistically significant differences. In this study, we explored the connection between ferroptosis related characteristics and immune infiltration in IDD, and confirmed that NOX4, ENPP2, FADS2, and TFAP2A may become biomarkers and potential therapeutic targets for IDD.

6.
Heliyon ; 9(3): e13934, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36915567

RESUMEN

Background: Wound gnawing and/or scratching in rats often occurs in experimental models, causing suture breakage and wound dehiscence, and consequently affecting experimental results and wasting resources. This study aimed to investigate the impact of the combined postoperative use of the Allgower-Donati (A-D) suture pattern and sweet foods on suture breakage, inflammation, and healing in wounds. Materials and methods: Sprague Dawley (SD) rats (n = 48) were treated for linear wounds on the back by four procedures: simple suture, simple suture with postoperative sweet foods, A-D suture, and A-D suture with postoperative sweet foods. Additionally, CD68 immunofluorescence and CD31 immunohistochemistry were used to analyze wound inflammation and vascularization, respectively, on postoperative day 7. Sirius red staining was used to assess collagen deposition on postoperative day 14. Results: Gnawing and scratching of wound sutures were significantly reduced in treated rats (P < 0.01). Neovascularization and collagen deposition were significantly increased (P < 0.001), and inflammatory responses were significantly reduced (P < 0.001) in animals receiving AD sutures and postoperative sweet foods. CD31/CD68 analyses showed that A-D suture and postoperative sweet foods regulated wound angiogenesis and attenuated wound inflammation. Conclusions: Sweet food provision after A-D suture union surgery could reduce wound gnawing and/or scratching, suture breakage, incisional dehiscence, wound inflammation, and promote wound healing in rats.

7.
Pak J Med Sci ; 39(1): 96-100, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36694776

RESUMEN

Objective: To compare the functional and radiological outcome of combine compression interlocking intramedullary nail (InterTan) and proximal femoral nail anti-rotation II (PFNA-II) in the treatment of elderly patients with intertrochanteric fractures. Methods: As a retrospective cohort study, records of 88 patients with intertrochanteric fractures treated in our hospital from January 1st, 2019 to July 31st, 2021 were retrospectively reviewed. According to treatment records, it included 45 patients treated with InterTan (Group-A) and 43 patients treated with PFNA-II (Group-B). The operation safety and functional rehabilitation of the two groups were compared and analyzed. Results: This study included 88 patients with intertrochanteric fractures (mean [SD] age, 68.72 [0.10] years at baseline), of whom 52 (59.09%) were males and 36 (40.91%) were females. Operation time and intraoperative blood loss in Group-B were less than Group-A, while fracture healing time was shorter in Group-A. The fracture separation distance was measured four weeks after the operation. The widening rate of the fracture line in Group-A was lower than Group-B (4.4% vs.18.6%; P<0.05). The incidence of complications in Group-A was lower than Group-B (4.4% vs.18.6%; P<0.05). At three, six and twelve months after the operation, the Harris hip score of the two groups was higher than at discharge (P<0.05), with no significant difference between groups (P>0.05). Conclusions: We found no significant difference in the functional outcome in elderly patients with intertrochanteric fractures treated with InterTan and PFNA-II. Early fracture healing and reduced complication rate however has been noted with InterTan.

8.
Cell Biol Toxicol ; 39(4): 1257-1274, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36112264

RESUMEN

Extracellular vesicles derived from bone marrow mesenchymal stem cells (BMSC-EVs) are emerged as carriers of therapeutic targets against bone disorders, yet its isolation and purification are limited with recent techniques. Magnetic nanoparticles (MNPs) can load EVs with a unique targeted drug delivery system. We constructed gold-coated magnetic nanoparticles (GMNPs) by decorating the surface of the Fe3O4@SiO2 core and a silica shell with poly(ethylene glycol) (PEG)-aldehyde (CHO) and examined the role of BMSC-EVs loaded on GMNPs in diabetic osteoporosis (DO). The osteoporosis-related differentially expressed miR-150-5p was singled out by microarray analysis. DO models were then established in Sprague-Dawley rats by streptozotocin injection, where poor expression of miR-150-5p was validated in the bone tissues. Next, GMNPE was prepared by combining GMNPs with anti-CD63, after which osteoblasts were co-cultured with the GMNPE-BMSC-EVs. The re-expression of miR-150-5p facilitated osteogenesis in osteoblasts. GMNPE could promote the enrichment of EVs in the bone tissues of DO rats. BMSC-EVs delivered miR-150-5p to osteoblasts, where miR-150-5p targeted MMP14 and consequently activated Wnt/ß-catenin pathway. This effect contributed to the enhancement of osteoblast proliferation and maturation. Furthermore, GMNPE enhanced the EV-based delivery of miR-150-5p to regulate the MMP14/Wnt/ß-catenin axis, resulting in promotion of osteogenesis. Overall, our findings suggest the potential of GMNP-BMSC-EVs to strengthen osteoblast proliferation and maturation in DO, showing promise as an appealing drug delivery strategy against DO. 1. GMNPs-BMSCs-EVs-miR-150-5p promotes the osteogenesis of DO rats. 2. miR-150-5p induces osteoblast proliferation and maturation by targeting MMP14. 3. Inhibition of MMP14 activates Wnt/ß-catenin and increases osteogenesis. 4. miR-150-5p activates the Wnt/ß-catenin pathway by downregulating MMP14.


Asunto(s)
Diabetes Mellitus , Vesículas Extracelulares , Nanopartículas de Magnetita , Células Madre Mesenquimatosas , MicroARNs , Osteoporosis , Ratas , Animales , MicroARNs/metabolismo , beta Catenina/metabolismo , Metaloproteinasa 14 de la Matriz/metabolismo , Diferenciación Celular/fisiología , Dióxido de Silicio , Ratas Sprague-Dawley , Osteoporosis/terapia , Osteoporosis/metabolismo , Células Madre Mesenquimatosas/metabolismo , Diabetes Mellitus/metabolismo
9.
BMC Ophthalmol ; 22(1): 484, 2022 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-36510151

RESUMEN

BACKGROUND: To design and develop a surgical robot capable of assisting subretinal injection. METHODS: A remote center of motion (RCM) mechanical design and a master-slave teleoperation were used to develop and manufacture the assisted subretinal surgery robot (RASR). Ten fresh isolated porcine eyes were divided into the Robot Manipulation (RM) group and Manual Manipulation (MM) group (5 eyes for each group), and subretinal injections were performed by the robot and manual manipulation methods, respectively. A preliminary verification of the robot was performed by comparing the advantages and disadvantages of the robot manipulation and manual manipulation by using optical coherent tomography (OCT), fundus photography, and video motion capture analysis after the surgery. RESULTS: Both the robot and the manual manipulation were able to perform subretinal injections with a 100% success rate. The OCT results showed that the average subretinal area was 1.548 mm2 and 1.461 mm2 in the RM and MM groups, respectively (P > 0.05). Meanwhile the volume of subretinal fluid obtained using the retinal map mode built in OCT was not statistically different between the RM and MM groups (P > 0.05). By analyzing the surgical video using Kinovea, a motion capture and analysis software, the results suggest that the mean tremor amplitude of the RM group was 0.3681 pixels (x direction), which was significantly reduced compared to 18.8779 pixels (x direction) in the MM group (P < 0.0001). CONCLUSION: Robot-assisted subretinal injection system (RASR) is able to finish subretinal injection surgery with better stability and less fatigue than manual manipulation.


Asunto(s)
Robótica , Animales , Porcinos , Tomografía de Coherencia Óptica/métodos , Líquido Subretiniano , Retina/cirugía , Programas Informáticos
10.
Acta Ortop Bras ; 30(spe2): e233064, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36506861

RESUMEN

Objectives: Evaluate the application value of 3D printing technology in measuring acetabular bone defect area in adult patients diagnosed with developmental dysplasia of the hip (DDH). Methods: 23 cases of DDH requiring total hip replacement surgery were enrolled in this study. Preoperative examination confirmed the standard pelvic plain films Crowe, including 3 cases of Crowe I, 7 Crowe II, and 13 Crowe III. The 3D printing technology was used to print the hip model before the operation. Based on the pre-printed model, pre-operative planning and surgical procedures were established. The area of the acetabular bone defects was measured, the selected size prosthesis was recorded, and the surgery was performed (group A). The actual acetabular bone defect area and the prosthesis size were also recorded (group B). Results: The comparative results indicated that the actual acetabular defect area measured intraoperatively and the area measured using the 3D printing technology did not significantly differ for all participants (all P>0.05). Conclusion: Preoperative model can accurately measure the acetabular bone defect area for DDH. It is significant to develop individualized implants for DDH patients treated with the 3D printing technique. Level of Evidence IV: Case series .


Objetivos: Avaliar o potencial da aplicação da tecnologia de impressão 3D na medição da área de defeito ósseo acetabular em pacientes adultos diagnosticados com displasia do desenvolvimento do quadril (DDH). Métodos: 23 casos de DDH que requereram cirurgia de substituição total do quadril foram incluídos neste estudo. O exame pré-operatório confirmou os filmes pélvicos padrão Crowe, incluindo 3 casos de Crowe I, 7 Crowe II, e 13 Crowe III. A tecnologia de impressão 3D foi utilizada para imprimir o modelo de quadril antes da operação. Com base no modelo pré-impresso, o planejamento pré-operatório e os procedimentos cirúrgicos foram estabelecidos. A área dos defeitos ósseos acetabulares foi medida, a prótese de tamanho selecionado foi registrada, e a cirurgia foi realizada (grupo A). A área do defeito ósseo acetabular real e o tamanho da prótese também foram registrados (grupo B). Resultados: Os resultados comparativos indicaram que a área real do defeito acetabular medida intraoperativamente e a área medida usando a tecnologia de impressão 3D não diferiu significativamente para todos os participantes (todos P>0,05). Conclusão: O modelo pré-operatório pode medir com precisão a área de defeito ósseo acetabular para DDH. É relevante desenvolver implantes individualizados para pacientes com DDH tratados com a técnica de impressão 3D. Nível de Evidência IV: Série de casos .

11.
Sci Rep ; 12(1): 18743, 2022 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-36335187

RESUMEN

Metal-free chemical vapor deposition (CVD) of single-layer graphene (SLG) on c-plane sapphire has recently been demonstrated for wafer diameters of up to 300 mm, and the high quality of the SLG layers is generally characterized by integral methods. By applying a comprehensive analysis approach, distinct interactions at the graphene-sapphire interface and local variations caused by the substrate topography are revealed. Regions near the sapphire step edges show tiny wrinkles with a height of about 0.2 nm, framed by delaminated graphene as identified by the typical Dirac cone of free graphene. In contrast, adsorption of CVD SLG on the hydroxyl-terminated α-Al2O3 (0001) terraces results in a superstructure with a periodicity of (2.66 ± 0.03) nm. Weak hydrogen bonds formed between the hydroxylated sapphire surface and the π-electron system of SLG result in a clean interface. The charge injection induces a band gap in the adsorbed graphene layer of about (73 ± 3) meV at the Dirac point. The good agreement with the predictions of a theoretical analysis underlines the potential of this hybrid system for emerging electronic applications.

12.
J Org Chem ; 87(17): 11491-11502, 2022 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-35951357

RESUMEN

A convenient synthesis of methylene-bridged pyrrolo[2,1-a]isoquinolines has been developed. Treatment of pyrroloisoquinolines with acetyl chloride and dimethylsulfoxide (DMSO) at ambient temperature afforded bispyrroloisoquinolylmethanes in 17-85% yields. This reaction system can also be expanded to the synthesis of bispyrrolylmethanes (34-94% yields). Easy chemical transformation of methylene-bridged pyrroloisoquinoline provided an unsymmetric acid and amide possessing a privileged framework.


Asunto(s)
Isoquinolinas , Pirroles , Acetatos , Cloruros , Dimetilsulfóxido
13.
Materials (Basel) ; 15(11)2022 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-35683268

RESUMEN

Here we systematically investigate the crystallographic orientation relationship (OR) between MC-type precipitates (M, metal; C, carbon) and ferrite matrix in the Ti-Mo microalloyed steel with different processing. In the specimens without austenite deformation, the interphase precipitation can be obtained, and the precipitates obey Baker-Nutting (BN) OR with ferrite matrix. By contrast, in the specimens with austenite deformation, the supersaturated precipitates were formed in ferrite grains, which can obey BN, Nishiyama-Wasserman (NW), Kurdjumov-Sachs (KS) and Pitsch (P) ORs simultaneously. The cooling rate after austenite deformation can influence the OR between carbides and ferrite in the MC/ferrite system. At the cooling rate of 80 °C/s, carbides and ferrite can roughly satisfy these OR with the deviation ≥ 10°, while at the cooling rate of 20 °C/s, carbides and ferrite can strictly obey the specific OR. The energy accumulated in the deformation process and maintained in the fast-cooling process (80 °C/s) can offset the formation energy of the carbides. Thus, the carbides formed in the specimen with the cooling rate of 80 °C/s do not strictly satisfy the specific ORs to meet the rule of lowest energy, and then deviate by a small angle based on the specific ORs.

14.
Materials (Basel) ; 15(4)2022 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-35207926

RESUMEN

Ti-bearing microalloyed steel plates with a thickness of 40 mm were subjected to ultra-fast cooling (UFC) and traditional accelerate cooling after hot-rolling, aiming to investigate the effect of cooling rate on the microstructure and mechanical properties homogeneity, and thus obtain thick plates with superior and homogeneous mechanical properties. Yield strength, tensile strength, and elongation were 642 MPa, 740 MPa, 19.2% and 592 MPa, 720 MPa and 16.7%, respectively, in the surface and mid-thickness of the steel with ultra-fast cooling, while in the steel with traditional accelerate cooling, 535 MPa, 645 MPa, 23.4% and 485 MPa, 608 MPa, 16.2% were obtained in the surface and mid-thickness of the plate. The yield strength has been greatly improved after UFC, for the refinement of grain and precipitates produced by UFC. In addition, the equivalent grain size and precipitates size in the thick plate with UFC are homogeneous in the thickness direction, leading to uniform mechanical properties. The crystallographic characteristics of different precipitates have been studied. The precipitates formed in the austenite deformation stage obey Kurdjumov-Sachs orientation relationship with the ferrite matrix, while the fine precipitates formed in the ferrite obey [112]MC//[110]α and (1¯1¯1)MC//(1¯12)α orientation relationship with the ferrite matrix.

15.
Materials (Basel) ; 15(3)2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-35160676

RESUMEN

As a commonly reinforcing phase in wear-resistant materials, TiC is often added into wear-resistant materials to improve the wear resistance. The independently developed stepped molds with variable thicknesses were used to prepare the TiC-reinforced steels with the same composition though melt solidification processing to study the effect of the solidification rate on the particle size and wear performance. The effect of the hot rolling compression ratio on the particle size and wear performance was also studied. The length and aspect ratios of the particles in heat-treated TiC-reinforced steels with different billet thicknesses and rolling compression ratios were measured. With the increasing in the billet thickness and the decreasing in the rolling compression ratio, the length and aspect ratio of the particles increased in heat-treated TiC-reinforced steels, and the hardness decreased slightly. The three-body abrasive wear behavior of the TiC-reinforced steels was conducted using a standard dry sand rubber wheel wear testing procedure, and the modeling of the wear mechanism was established. The particle size is the main factor affecting wear resistance when the hardness of TiC-reinforced steels is similar. When the particles size is moderate, about 2-6 µm, the particle can break the sand tip and hinder the sand tip from sliding on the surface. In this manner, the mass loss decreased and the wear resistance improved. The large particles will be broken easily by the abrasive, and the small particles are removed easily by the abrasive in the wear process. So, the large and small particles cannot effectively prevent the damage of the abrasive to the matrix, and they have less of an effect on improving wear resistance.

16.
Environ Technol ; 43(1): 95-106, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32498610

RESUMEN

We reported the preparation of NGO-Fe3O4 by simple hydrothermal-co-precipitation. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). It was demonstrated that norfloxacin (NOR) could be effectively degraded by the UV/NGO-Fe3O4/PDS system. The degradation efficiency reached 100% within 13 min (the concentration of NOR and S2O82- were 100 mg L-1 and 1 mM, respectively; m(NGO-Fe3O4): m(PDS) = 4: 1; pH: 3.0). In addition, NGO-Fe3O4 showed stable catalytic activity in recycling. The analysis found that the in-situ generated ·OH was the main active free radicals but SO4-⋅ also participated in the NOR degradation. Based on the identified intermediates, the NOR degradation pathways were proposed with UV/NGO-Fe3O4/PDS system.


Asunto(s)
Grafito , Norfloxacino , Catálisis , Nitrógeno , Difracción de Rayos X
17.
Acta ortop. bras ; 30(spe2): e233064, 2022. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1403057

RESUMEN

ABSTRACT Objectives Evaluate the application value of 3D printing technology in measuring acetabular bone defect area in adult patients diagnosed with developmental dysplasia of the hip (DDH). Methods 23 cases of DDH requiring total hip replacement surgery were enrolled in this study. Preoperative examination confirmed the standard pelvic plain films Crowe, including 3 cases of Crowe I, 7 Crowe II, and 13 Crowe III. The 3D printing technology was used to print the hip model before the operation. Based on the pre-printed model, pre-operative planning and surgical procedures were established. The area of the acetabular bone defects was measured, the selected size prosthesis was recorded, and the surgery was performed (group A). The actual acetabular bone defect area and the prosthesis size were also recorded (group B). Results The comparative results indicated that the actual acetabular defect area measured intraoperatively and the area measured using the 3D printing technology did not significantly differ for all participants (all P>0.05). Conclusion Preoperative model can accurately measure the acetabular bone defect area for DDH. It is significant to develop individualized implants for DDH patients treated with the 3D printing technique. Level of Evidence IV: Case series.


RESUMO Objetivos Avaliar o potencial da aplicação da tecnologia de impressão 3D na medição da área de defeito ósseo acetabular em pacientes adultos diagnosticados com displasia do desenvolvimento do quadril (DDH). Métodos 23 casos de DDH que requereram cirurgia de substituição total do quadril foram incluídos neste estudo. O exame pré-operatório confirmou os filmes pélvicos padrão Crowe, incluindo 3 casos de Crowe I, 7 Crowe II, e 13 Crowe III. A tecnologia de impressão 3D foi utilizada para imprimir o modelo de quadril antes da operação. Com base no modelo pré-impresso, o planejamento pré-operatório e os procedimentos cirúrgicos foram estabelecidos. A área dos defeitos ósseos acetabulares foi medida, a prótese de tamanho selecionado foi registrada, e a cirurgia foi realizada (grupo A). A área do defeito ósseo acetabular real e o tamanho da prótese também foram registrados (grupo B). Resultados Os resultados comparativos indicaram que a área real do defeito acetabular medida intraoperativamente e a área medida usando a tecnologia de impressão 3D não diferiu significativamente para todos os participantes (todos P>0,05). Conclusão O modelo pré-operatório pode medir com precisão a área de defeito ósseo acetabular para DDH. É relevante desenvolver implantes individualizados para pacientes com DDH tratados com a técnica de impressão 3D. Nível de Evidência IV: Série de casos.

18.
Pak J Med Sci ; 37(7): 1753-1757, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34912390

RESUMEN

OBJECTIVES: To compare clinical efficacies of suprapatellar and infrapatellar intramedullary nailing approaches in treating tibial shaft fractures. METHODS: Patients (n=110) admitted with tibial shaft fractures in our hospital from January 2017 to June 2020, who underwent procedures with internal fixation intramedullary nails, were retrospectively divided into suprapatellar and infrapatellar approach groups (n = 55 each) based on the surgical method used for fracture repair. The clinical and functional outcomes of the knee were assessed six months after the surgery. RESULTS: Six months after the operation, the pooled value for excellent and good efficacy rates in the suprapatellar approach group, as indicated by Hospital for Special Surgery (HSS) Knee scoring system, was 90.91%, which was significantly higher than that in the infrapatellar approach group (76.36%). The degree of pain (visual analogue scale (VAS) score) of the patients in the suprapatellar approach group was over 2-fold lower than in the infrapatellar approach group (P < 0.001).The Lysholm knee score, range of motion (ROM), SF-36p, and SF-36M scores in the suprapatellar approach group were significantly higher than those in the infrapatellar approach group (P < 0.001). CONCLUSION: Suprapatellar approach had significantly higher clinical efficiency than infrapatellar approach, and can significantly reduce the degree of pain, promote the recovery of patients with knee joint involvement, improve the physical and psychological well-being, reduce the number of cases of postoperative delayed healing.

19.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 35(7): 904-912, 2021 Jul 15.
Artículo en Chino | MEDLINE | ID: mdl-34308601

RESUMEN

OBJECTIVE: To prepare a bone tissue engineering scaffold for repairing the skull defect of Sprague Dawley (SD) rats by combining exogenous transforming growth factor ß 1 (TGF-ß 1) with gelatin methacryloyl (GelMA) hydrogel. METHODS: Firstly, GelMA hydrogel composite scaffolds containing exogenous TGF-ß 1 at concentrations of 0, 150, 300, 600, 900, and 1 200 ng/mL (set to groups A, B, C, D, E, and F, respectively) were prepared. Cell counting kit 8 (CCK-8) method was used to detect the effect of composite scaffold on the proliferation of bone marrow mesenchymal stem cells (BMSCs) in SD rats. ALP staining, alizarin red staining, osteocalcin (OCN) immunofluorescence staining, and Western blot were used to explore the effect of scaffolds on osteogenic differentiation of BMSCs, and the optimal concentration of TGF-ß 1/GelMA scaffold was selected. Thirty-six 8-week-old SD rats were taken to prepare a 5 mm diameter skull bone defect model and randomly divided into 3 groups, namely the control group, the GelMA group, and the GelMA+TGF-ß 1 group (using the optimal concentration of TGF-ß 1/GelMA scaffold). The rats were sacrificed at 4 and 8 weeks after operation, and micro-CT, HE staining, and OCN immunohistochemistry staining were performed to observe the repair effect of skull defects. RESULTS: The CCK-8 method showed that the TGF-ß 1/GelMA scaffolds in each group had a promoting effect on the proliferation of BMSCs. Group D had the strongest effect, and the cell activity was significantly higher than that of the other groups ( P<0.05). The results of ALP staining, alizarin red staining, OCN immunofluorescence staining, and Western blot showed that the percentage of ALP positive area, the percentage of alizarin red positive area, and the relative expressions of ALP and OCN proteins in group D were significantly higher than those of the other groups ( P<0.05), the osteogenesis effect in group D was the strongest. Therefore, in vitroexperiments screened out the optimal concentration of TGF-ß 1/GelMA scaffold to be 600 ng/mL. Micro-CT, HE staining, and OCN immunohistochemistry staining of rat skull defect repair experiments showed that the new bone tissue and bone volume/tissue volume ratio in the TGF-ß 1+GelMA group were significantly higher than those in the GelMA group and control group at 4 and 8 weeks after operation ( P<0.05). CONCLUSION: The TGF-ß 1/GelMA scaffold with a concentration of 600 ng/mL can significantly promote the osteogenic differentiation of BMSCs, can significantly promote bone regeneration at the skull defect, and can be used as a bioactive material for bone tissue regeneration.


Asunto(s)
Gelatina , Osteogénesis , Animales , Diferenciación Celular , Células Cultivadas , Ratas , Ratas Sprague-Dawley , Cráneo , Ingeniería de Tejidos , Andamios del Tejido , Factor de Crecimiento Transformador beta1
20.
Clin Hemorheol Microcirc ; 79(4): 567-573, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34151780

RESUMEN

BACKGROUND: Application of tranexamic acid (TXA) in the treatment of acetabular fractures could reduce intraoperative and postoperative blood loss. OBJECTIVE: To investigate the effect of single and repeated intravenous infusion of TXA on blood loss of acetabular fractures. METHODS: 120 patients with acetabular fractures admitted to our hospital from January 2017 to September 2020 were retrospectively divided into three groups: Patients accepted 1g TXA at preoperative 30 minutes were defined as single TXA group (n = 40); Patients accepted 1g TXA at preoperative 30 minutes and 1g TXA at 3 hours after the start of surgery were defined as repeated TXA group (n = 40); Patients accepted normal saline at preoperative 30 minutes were defined as control group (n = 40). RESULTS: The total blood loss in single TXA group and repeated TXA group were significantly lower than control group, and the total blood loss in the repeated TXA group was significantly lower than single TXA group (P < 0.05). The hidden blood loss from surgery to postoperative 1 day in repeated TXA group was significantly lower than single TXA group and the control group(P < 0.05). No significant differences were observed in the operative time, postoperative transfusion rate and thrombosis rate among the three groups (P >  0.05). CONCLUSION: Repeated TXA is more recommended during acetabular fracture surgery since it can reduce the total blood loss without increasing the operative time, postoperative transfusion rate and thrombosis rate compared with single TXA.


Asunto(s)
Antifibrinolíticos , Fracturas de Cadera , Ácido Tranexámico , Antifibrinolíticos/uso terapéutico , Pérdida de Sangre Quirúrgica/prevención & control , Humanos , Estudios Retrospectivos , Ácido Tranexámico/uso terapéutico
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