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1.
Eur Rev Med Pharmacol Sci ; 28(3): 899-906, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38375696

RESUMEN

OBJECTIVE: The pathogenesis of Parkinson's disease (PD) is associated with abnormal iron accumulation. Magnetic resonance imaging (MRI) studies have shown that patients with Parkinson's disease have an increased amount of iron in their substantia nigra (SN). We have undertaken a meta-analysis of studies using MRI in PD, to explore the potential role of MRI in diagnosing PD using abnormal iron deposition in SN as a candidate biomarker. MATERIALS AND METHODS: Searches of PubMed, Embase, and Medline databases revealed 16 studies that compared PD patients and healthy controls (HC). A sensitivity analysis and subgroup analysis were performed to evaluate the reliability of our results. Estimates were pooled by the fixed-effects model. As an expression of I2, we computed the proportion of variation due to heterogeneity. RESULTS: We included 16 studies with sample sizes of 435 PD and 355 HC in our meta-analysis. Results showed that SN iron deposition was significantly elevated (p<0.00001) in patients with PD compared to HC ones (SMD=0.72, 95% confidence interval 0.57 to 0.87, p<0.00001). CONCLUSIONS: Our findings, based on a homogeneous group-level analysis, suggest that MRI-based SN iron deposition could be used to distinguish PD from HC. For a more rigorous investigation of SN iron deposition in PD, larger cohort studies are needed.


Asunto(s)
Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/metabolismo , Reproducibilidad de los Resultados , Sustancia Negra/diagnóstico por imagen , Sustancia Negra/metabolismo , Imagen por Resonancia Magnética/métodos , Hierro/metabolismo
2.
Artículo en Chino | MEDLINE | ID: mdl-37805721

RESUMEN

Objective: To investigate the application effects of nitrous oxide and oxygen mixed inhalation technology on analgesia and sedation during debridement and dressing change in children with moderate or severe burns. Methods: A retrospective non-randomized contemporary controlled study was conducted. From December 2019 to November 2021, 140 burn children with moderate or severe burns, aged 1 to 3 years, who met the inclusion criteria were admitted to Central Hospital Affiliated to Shandong First Medical University. During debridement and dressing change 3 to 14 days after injury, 42 children, including 23 males and 19 females, who received nurse-centered pain management mode and analgesia and sedation with nitrous oxide and oxygen mixed inhalation technology were included in nitrous oxide group (the dressing change process using the above-mentioned technology for the first time was selected for the follow-up study). Another 42 children, including 24 males and 18 females, were included in non-nitrous oxide group from 98 children who did not apply analgesia or sedation treatment during dressing change with stratified random sampling (one dressing change process was randomly selected for the follow-up study). The face, legs, activity, cry, and consolability scale and Ramsay sedation scale were used to evaluate the pain intensity and degree of sedation, respectively, at 30 minutes before dressing change (hereinafter referred to as before dressing change), immediately after debridement, and at 30 minutes after finishing dressing change (hereinafter referred to as after dressing change). After dressing change, the self-made satisfaction scale was used to evaluate the satisfaction degree of dressing change surgeons and guardians of children for analgesic effects during dressing change. The duration of dressing change and the healing time of deep partial-thickness burn wounds were recorded. The heart rate and percutaneous arterial oxygen saturation (SpO2) before, during, and after dressing change and the occurrence of adverse events such as nausea and vomiting during dressing change were recorded. Data were statistically analyzed with Mann-Whitney U test, chi-square test, analysis of variance for repeated measurement, independent sample t test, and Bonferroni correction. Results: There were no significant differences in the score of pain intensity and score of sedation degree between children in two groups before and after dressing change (P>0.05). Immediately after debridement, the score of pain intensity of children in nitrous oxide group was 2.5±0.7, which was significantly lower than 7.6±1.0 in non-nitrous oxide group (t=-26.69, P<0.05); the score of sedation degree of children in nitrous oxide group was 1.83±0.38, which was significantly higher than 1.21±0.42 in non-nitrous oxide group (t=7.15, P<0.05). After dressing change, the satisfaction degree scores of dressing change surgeons and guardians of children for analgesic effects during dressing change of children in nitrous oxide group were significantly higher than those in non-nitrous oxide group (with t values of 10.53 and 2.24, respectively, P<0.05). The dressing change duration of children in nitrous oxide group was significantly shorter than that in non-nitrous oxide group (t=-5.33, P<0.05). The healing time of deep partial-thickness burn wounds in children between the two groups had no significant difference (P>0.05). The heart rate of children in nitrous oxide group was significantly lower than that in non-nitrous oxide group during dressing change (t=-12.40, P<0.05), while the SpO2 was significantly higher than that in non-nitrous oxide group (t=5.98, P<0.05). During dressing change, 2 children had nausea and 1 child had euphoria in nitrous oxide group, while heart rate of all children in non-nitrous oxide group continued to be higher than the normal range. Conclusions: In the process of debridement and dressing change in children with moderate or severe burns, the use of nurse-centered pain management mode and the standardized use of nitrous oxide and oxygen mixed inhalation technology can safely and effectively control pain and sedation.


Asunto(s)
Analgesia , Quemaduras , Masculino , Femenino , Humanos , Niño , Óxido Nitroso/uso terapéutico , Manejo del Dolor , Desbridamiento , Oxígeno , Estudios de Seguimiento , Estudios Retrospectivos , Resultado del Tratamiento , Quemaduras/cirugía , Dolor , Náusea , Infección de la Herida Quirúrgica , Vendajes , Analgésicos
4.
Osteoarthritis Cartilage ; 31(2): 267-278, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36334697

RESUMEN

OBJECTIVES: To develop and validate a nomogram to detect improved knee pain in osteoarthritis (OA) by integrating magnetic resonance imaging (MRI) radiomics signature of subchondral bone and clinical characteristics. METHODS: Participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. The primary outcome was 20% improvement of knee pain score over 2 years in participants administrated either vitamin D or placebo. Radiomics features of subchondral bone and clinical characteristics from 216 participants were extracted and analyzed. The participants were randomly split into the training and validation cohorts at a ratio of 8:2. Least absolute shrinkage and selection operator (LASSO) regression was used to select features and generate radiomics signatures. The optimal radiomics signature and clinical indicators were fitted into a nomogram using multivariable logistic regression model. RESULTS: The nomogram showed favorable discrimination performance [AUCtraining, 0.79 (95% CI: 0.72-0.79), AUCvalidation, 0.83 (95% CI: 0.70-0.96)] as well as a good calibration. Additional contributing value of fusion radiomics signature to the nomogram was statistically significant (NRI, 0.23; IDI, 0.14, P < 0.001 in training cohort and NRI, 0.29; IDI, 0.18, P < 0.05 in validating cohort). Decision curve analysis confirmed the clinical usefulness of nomogram. CONCLUSION: The radiomics-based nomogram comprising the MR radiomics signature and clinical variables achieves a favorable predictive efficacy and accuracy in differentiating improvement in knee pain among OA patients. This proof-of-concept study provides a promising way to predict clinically meaningful outcomes.


Asunto(s)
Nomogramas , Osteoartritis de la Rodilla , Humanos , Imagen por Resonancia Magnética/métodos , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/diagnóstico por imagen , Estudios Retrospectivos , Vitamina D , Prueba de Estudio Conceptual
5.
Rev Sci Instrum ; 93(11): 113501, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36461431

RESUMEN

The EAST plasmas heated with deuterium neutral beam injection and ion cyclotron resonance heating (ICRH) have been simulated by the TRANSP code. The analysis has been conducted using the full wave solver TORIC5, the radio frequency (RF)-kick operator, and NUBEAM to model the RF heating effects on fast ion velocity distribution. In this work, we present several simulated results compared with experiments for high power EAST scenarios, indicating that the interactions between ICRH and fast ions can significantly accelerate fast ions, which are confirmed by the increased neutron yield and broadened neutron emission spectrum measurements.

6.
Beijing Da Xue Xue Bao Yi Xue Ban ; 54(6): 1202-1207, 2022 Dec 18.
Artículo en Chino | MEDLINE | ID: mdl-36533356

RESUMEN

OBJECTIVE: To explore the feasibility of preparing different doses of tablets for personalized treatment by fused deposition modeling (FDM) 3D printing technology, and to evaluate the in vitro quality of the FDM 3D printed tablets. METHODS: Three different sizes of hollow tablets were prepared by fused deposition modeling 3D printing technology with polyvinyl alcohol (PVA) filaments. Theophylline was chosen as the model drug. In the study, 20 mg, 50 mg and 100 mg of theophylline was filled into the cavity of the tablets, respectively. The microscopic morphology of the tablets was observed by scanning electron microscopy (SEM). The weight variation of the tablets was investigated by weighing method. The hardness of the tablets was measured by tablet hardness tester. The contents of the drugs in the tablets were determined by ultraviolet and visible spectrophotometry (UV-Vis), and the dissolution apparatus was used to assay the in vitro drug release of the tablets. RESULTS: The prepared FDM 3D printed tablets were all in good shape without printing defects. And there was no leakage phenomenon. The diameter and thickness of the tablets were consistent with the design. The layers were tightly connected, and the fine structure of the formulation could be clearly observed without printing defects by scanning electron microscopy. The average weight of the three sizes of tablets was (150.5±2.3) mg, (293.6±2.6) mg and (456.2±5.6) mg, respectively. The weight variation of the three sizes of tablets were boss less than 5%, which met the requirements; The hardness of the tablets all exceeded 200 N; The contents of theophylline in the three tablets were 98.0%, 97.2% and 97.9% of the dosage (20 mg, 50 mg and 100 mg), and the relative standard deviation (RSD) was 1.06%, 1.15% and 0.63% respectively; The time for 80% drug released from the three dosage of tablets was within 30 min. CONCLUSION: Three different dosages of theophylline tablets were successfully prepared by FDM 3D printing technology in this study. The exploration may bring beneficial for the preparation of personalized dose preparations. We expect that with the development of 3D printing technology, FDM 3D printed personalized tablets can be used in the clinic as soon as possible to provide personalized treatment for patients.


Asunto(s)
Impresión Tridimensional , Teofilina , Humanos , Teofilina/química , Comprimidos/química , Liberación de Fármacos , Alcohol Polivinílico/química , Tecnología Farmacéutica/métodos
7.
Acta Biomater ; 151: 446-456, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35963519

RESUMEN

Structures made by scleractinian corals support diverse ocean ecosystems. Despite the importance of coral skeletons and their predicted vulnerability to climate change, few studies have examined the mechanical and crystallographic properties of coral skeletons at the micro- and nano-scales. Here, we investigated the interplay of crystallographic and microarchitectural organization with mechanical anisotropy within Porites skeletons by measuring Young's modulus and hardness along surfaces transverse and longitudinal to the primary coral growth direction. We observed micro-scale anisotropy, where the transverse surface had greater Young's modulus and hardness by ∼ 6 GPa and 0.2 GPa, respectively. Electron backscatter diffraction (EBSD) revealed that this surface also had a higher percentage of crystals oriented with the a-axis between ± 30-60∘, relative to the longitudinal surface, and a broader grain size distribution. Within a region containing a sharp microscale gradient in Young's modulus, nanoscale indentation mapping, energy dispersive spectroscopy (EDS), EBSD, and Raman crystallography were performed. A correlative trend showed higher Young's modulus and hardness in regions with individual crystal bases (c-axis) facing upward, and in crystal fibers relative to centers of calcification. These relationships highlight the difference in mechanical properties between scales (i.e. crystals, crystal bundles, grains). Observations of crystal orientation and mechanical properties suggest that anisotropy is driven by microscale organization and crystal packing rather than intrinsic crystal anisotropy. In comparison with previous observations of nanoscale isotropy in corals, our results illustrate the role of hierarchical architecture in coral skeletons and the influence of biotic and abiotic factors on mechanical properties at different scales. STATEMENT OF SIGNIFICANCE: Coral biomineralization and the ability of corals' skeletal structure to withstand biotic and abiotic forces underpins the success of reef ecosystems. At the microscale, we show increased skeletal stiffness and hardness perpendicular to the coral growth direction. By comparing nano- and micro-scale indentation results, we also reveal an effect of hierarchical architecture on the mechanical properties of coral skeletons and hypothesize that crystal packing and orientation result in microscale anisotropy. In contrast to previous findings, we demonstrate that mechanical and crystallographic properties of coral skeletons can vary between surface planes, within surface planes, and at different analytical scales. These results improve our understanding of biomineralization and the effects of scale and direction on how biomineral structures respond to environmental stimuli.


Asunto(s)
Antozoos , Ecosistema , Animales , Anisotropía , Módulo de Elasticidad , Dureza
8.
Osteoarthritis Cartilage ; 30(9): 1270-1277, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35750239

RESUMEN

OBJECTIVES: Although subchondral bone marrow lesions (BMLs) and synovitis have been well acknowledged as important sources of pain in knee osteoarthritis (KOA), it is unclear if synovitis plays the mediating role in the relationship between BMLs and knee pain. METHODS: We analyzed 600 subjects with magnetic resonance imaging (MRI) in the Foundation for National Institutes of Health Osteoarthritis Biomarkers Consortium (FNIH) cohort at baseline and 24-month. BMLs and synovitis were measured according to the MRI Osteoarthritis Knee Score (MOAKS) scoring system. BMLs were scored in five subregions. A summary synovitis score of effusion and Hoffa-synovitis was calculated. Knee pain was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Linear regression models were applied to analyze the natural direct effect (NDE) of BMLs and synovitis with knee pain, respectively, and natural indirect effect (NIE) mediated by synovitis. RESULTS: 590 participants (58.8% females, with a mean age of 61.5) were included in the present analyses. For NDE, knee pain was cross-sectionally associated with medial femorotibial BMLs (ß = 0.23, 95% CI: 0.09, 0.38) and synovitis (ß = 0.40, 95% CI: 0.20, 0.60). Longitudinal associations retained significant [medial femorotibial BMLs (ß = 0.37, 95% CI: 0.21, 0.53); synovitis (ß = 0.72, 95% CI: 0.45, 0.99)]. In the NIE analyses, synovitis mediated the association between medial femorotibial BML and knee pain at baseline (ß = 0.051, 95% CI: 0.01, 0.09) and over 24 months (ß = 0.079, 95% CI: 0.023, 0.15), with the mediating proportion of 17.8% and 22.4%, respectively. CONCLUSION: Synovitis partially mediates the association between medial femorotibial BMLs and knee pain.


Asunto(s)
Enfermedades Óseas , Enfermedades de los Cartílagos , Osteoartritis de la Rodilla , Sinovitis , Biomarcadores , Enfermedades Óseas/patología , Médula Ósea/patología , Enfermedades de los Cartílagos/patología , Femenino , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/patología , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , National Institutes of Health (U.S.) , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/patología , Dolor/patología , Sinovitis/patología , Estados Unidos
9.
Beijing Da Xue Xue Bao Yi Xue Ban ; 54(3): 572-577, 2022 Jun 18.
Artículo en Chino | MEDLINE | ID: mdl-35701138

RESUMEN

OBJECTIVE: To explore the feasibility of preparing compound tablets for the treatment of hypertension by fused deposition modeling (FDM) 3D printing technology and to evaluate the quality of the printed compound tablets in vitro. METHODS: Polyvinyl alcohol (PVA) filaments were used as the exci-pient to prepare the shell of tablet. The ellipse-shaped tablets (the length of major axes of ellipse was 20 mm, the length of the minor axes of ellipse was 10 mm, the height of tablet was 5 mm) with two separate compartments were designed and printed using FDM 3D printer. The height of layer was 0.2 mm, and the thickness of roof or floor was 0.6 mm. The thickness of shell was 1.2 mm, and the thickness of the partition wall between the two compartments was 0.6 mm. Two cardiovascular drugs, captopril (CTP) and hydrochlorothiazide (HCT), were selected as model drugs for the printed compound tablet and filled in the two compartments of the tablet, respectively. The microscopic morphology of the tablets was observed by scanning electron microscopy (SEM). The weight variation of the tablets was investigated by electronic scale. The hardness of the tablets was measured by a single-column mechanical test system. The contents of the drugs in the tablets were determined by high performance liquid chromatography (HPLC), and the dissolution apparatus was used to measure the in vitro drug release of the tablets. RESULTS: The prepared FDM 3D printed compound tablets were all in good shape without printing defects. The average weight of the tablets was (644.3±6.55) mg. The content of CTP and HCT was separately (52.3±0.26) mg and (49.6±0.74) mg. A delayed in vitro release profile was observed for CTP and HCT, and the delayed release time for CTP and HCT in vitro was 20 min and 40 min, respectively. The time for 70% of CTP and HCT released was separately 30 min and 60 min. CONCLUSION: CTP and HCT compound tablets were successfully prepared by FDM 3D printing technology, and the printed tablets were of good qualities.


Asunto(s)
Captopril , Hidroclorotiazida , Citidina Trifosfato , Liberación de Fármacos , Impresión Tridimensional , Comprimidos/química , Tecnología Farmacéutica/métodos
10.
Zhonghua Yi Xue Za Zhi ; 102(18): 1398-1401, 2022 May 17.
Artículo en Chino | MEDLINE | ID: mdl-35545587

RESUMEN

the early and med-term follow-up results and technical points of new re-dilated stent in the treatment of pulmonary artery bifurcation opening stenosis, and explore its feasibility and advantages. From March 2019 to October 2020, 10 children [5 males, mean age (7±3) years], mean weight 18.75(13.35,23.05) kg with pulmonary artery bifurcation opening stenosis were treated with new re-dilated stents in the Central China Fuwai Hospital. Including 5 cases of tetralogy of Fallot, 4 cases of pulmonary atresia, 1 case of anomalous origin of coronary artery, all children were given new re-dilated stent implantation. Echocardiography, chest X-ray and electrocardiogram were performed 1 day, 3, 6, 12 months after intervention. Pulmonary artery CTA was performed after 6 or 12 months to evaluate the results, including restenosis, malposition and rupture. A total of 16 stents were implanted in 10 children, 5 cases had simultaneous stenosis of bifurcation openings of pulmonary arteries, and 1 stent was implanted in each of the left and right pulmonary artery openings. The pressure of right ventricular and gradient was significantly decreased immediately after intervention, from preoperative (38-80) mmHg(1 mmHg=0.133 kPa) to postoperative (0-22) mmHg, only one patient's pressure gradient is over 20 mmHg (22 mmHg), and all cases discharged successfully. Stent restenosis, malposition, fracture and other abnormalities were not observed in follow-up. Stents implantation for patients with pulmonary artery bifurcation opening stenosis is very more difficult. A good strategy can ensure that the intervention is safe and effective. It not only avoids the risk of repeated surgery, but also achieves good med-term follow-up results.


Asunto(s)
Cardiopatías Congénitas , Arteria Pulmonar , Niño , Preescolar , Constricción Patológica , Femenino , Cardiopatías Congénitas/cirugía , Humanos , Masculino , Pronóstico , Stents , Resultado del Tratamiento
11.
Int J Oral Maxillofac Surg ; 51(2): 143-151, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33888383

RESUMEN

The aim of this study was to better understand posterior oral cavity cancer (POCC) and its surgical treatment. This was a retrospective study of 76 patients who were diagnosed with POCC and underwent surgical treatment. Twenty-eight patients were treated with anatomical unit resection surgery (AURS) and 48 patients with conventional surgery. After initial treatment with curative intent, the patients were followed-up regularly with clinical examinations and imaging; the median duration of follow-up was 30.9 months (range 2-67 months). The 3-year overall survival was 64.3% in the experimental AURS group and 39.6% in the conventional surgery control group (hazard ratio 0.49, 95% confidence interval 0.26-0.93; P=0.031). The 3-year disease-free survival was 64.3% in the experimental group and 37.5% in the control group (hazard ratio 0.53, 95% confidence interval 0.27-1.02; P=0.114). In conclusion, AURS is an effective surgical treatment for POCC that can considerably improve patient survival rates.


Asunto(s)
Neoplasias de la Boca , Supervivencia sin Enfermedad , Humanos , Neoplasias de la Boca/cirugía , Recurrencia Local de Neoplasia , Estudios Retrospectivos , Base del Cráneo , Resultado del Tratamiento
12.
Artículo en Chino | MEDLINE | ID: mdl-34666437

RESUMEN

Objective: To analyse the clinical application of thoracodorsal artery perforator flaps (TDAPF) in the repair of head and neck defects. Methods: A retrospective review was conducted on 38 patients with oral and maxillofacial head and neck malignant tumors who underwent radical resection of oral and oropharyngeal carcinoma and TDAPF repair in the Department of Oral and Maxillofacial Head and Neck Oncology of the Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from June 2017 to November 2018. Among them, 32 were males and 6 were females, aged 30-74 years. Flap size, vessel pedicle length, diameter and number of perforators, and flap fat thickness were recorded and counted. Elasti Meter and Skin Fibro Meter were applied to measure the skin elasticity and hardness in the donor areas of 4 kinds of skin flaps before the flap preparation. SPSS 19.0 statistical software was used for statistical analysis of the data. Results: All the flaps survived (100%). The mean elasticity of TDAPF [(41.2±12.9) N/m] was significantly lower than that of anterolateral thigh [(77.6±23.3) N/m, χ²=88.89, P<0.05], anterolateral thigh [(62.6±17.7) N/m, χ²=59.99, P<0.05] and or forearm flap [(51.7±8.6) N/m, χ²=37.82, P<0.05]. The hardness of TDAPF [(0.037±0.016) N] was also significantly lower than that of anterolateral femoral [(0.088±0.019) N, F=93.27, P<0.05], anteromedial femoral [(0.059±0.020) N, F=25.71, P<0.05] or forearm flap [(0.062±0.016) N, F=29.11, P<0.05]. Follow-up period ranged from 2 to 14 months. The 38 patients treated with TDAPF had a good recovery of the functions in the recipient areas, and the scars of the donor areas were not obvious after surgery, without serious complications. Conclusion: TDAPF is suitable for reconstruction of head and neck defect, with ductile texture and good recovery of the morphology and function of head and neck.


Asunto(s)
Colgajo Perforante , Procedimientos de Cirugía Plástica , China , Femenino , Arteria Femoral/cirugía , Humanos , Masculino , Estudios Retrospectivos , Trasplante de Piel , Muslo/cirugía
13.
Zhonghua Yi Shi Za Zhi ; 51(3): 151-157, 2021 May 28.
Artículo en Chino | MEDLINE | ID: mdl-34645199

RESUMEN

Church General Hospital in Wuchang, China planned to establish a psychiatric hospital in 1930. Chi-liang Kwei, received his PhD at Johns Hopkins Medical School of America and was appointed to be in charge of the preparation. After working out a draft plan for the hospital, Dr. Kwei applied for the Henderson Research Scholarship on Mental Diseases. She planned to study under the guidance of Dr. D.K. Henderson in the Glasgow Mental Royal Hospital for a full year in preparation for the establishment of the hospital. By drawing on the correspondence files of Chi-liang Kwei and psychiatrists Adolf Meyer and David Kennedy Henderson, the paper describes the background conditions and planning for the hospital establishment and interprets the significance and value of Chi-liang Kwei's efforts to establish a psychiatric hospital from the perspective of the historic development of modern psychiatry in China.


Asunto(s)
Psiquiatría , Trastornos Psicóticos , China , Femenino , Historia del Siglo XX , Hospitales Psiquiátricos , Humanos , Psiquiatría/educación , Facultades de Medicina
14.
Sci Rep ; 11(1): 16053, 2021 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-34362969

RESUMEN

Originated at heterogeneous interfaces with distinct coefficient of thermal expansion (CTE), thermal mismatch stress is one of the critical influential factors to mechanical properties of metal matrix composites (MMCs). This stress is normally accommodated plastically by various defects, for example, high-density dislocations and twins in Al near heterogeneous interfaces in SiC/Al composites. Basic knowledge on the influence of defect characteristics is important but difficult to extrapolate from experimental results. However, existed theoretical models more focus on the influence of dislocation density, but less focus on defects variety, volume and distribution. In this paper, we propose a physics-based crystal plasticity model that has the capability of dealing with thermal mismatch stress induced dislocations and twins (denoted as TMDT model). The proposed TMDT model that is implemented in the Visco-Plastic Self-Consistent (VPSC) method considers defect heterogeneous distribution (gradient range), defect type (dislocations vs. twins) and defect volume fraction (twin spacing vs. twin volume). We demonstrate the validity and the capability of the VPSC-TMDT model in SiC/Al composites with thermal mismatch induced dislocations or twins. Furthermore, this model predicts the ultra-high strength of Graphene/Copper composites with high-density nanoscale twins, which is in turn the future aim for such nanocomposites.

15.
Rev Sci Instrum ; 92(4): 043506, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-34243369

RESUMEN

Stilbene crystal detectors are widely used as fast neutron measurement tools based on recoil proton detection, such as liquid scintillators. A compact stilbene crystal neutron spectrometer (CSCNS) has been installed at the Experimental Advanced Superconducting Tokamak (EAST) to obtain information on fuel ions produced in the plasma core because of its merits of good n/γ discrimination capability, high detection efficiency, and fast response. For the first time, CSCNS has been used for neutron emission spectroscopy measurements in EAST plasmas with neutral beam injection (NBI) heating. The CSCNS has the same horizontal line of sight as the time-of-flight enhanced diagnostics neutron spectrometer. Under NBI heating scenarios, the time trace of the neutron yield monitored by the CSCNS is similar to the one monitored by a standard 235U fission chamber. The experimental pulse height spectra are also similar to the simulated ones generated by folding the simulated neutron energy spectrum with the detector response functions. These results demonstrate the capability of the CSCNS for neutron diagnostics and the study of fast-ion physics in EAST.

16.
Rev Sci Instrum ; 92(4): 043552, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-34243473

RESUMEN

Neutron emission spectroscopy and neutron yield measurements are important for high neutral beam injection (NBI) power heating at the Experimental Advanced Superconducting Tokamak (EAST). The neutron yields mainly depend on the deposition from NBI to the deuterium plasmas in the EAST. We have recently used TRANSP with time dependent diagnostic results to simulate the transport process of 30 s long pulse deuterium plasma discharges in the EAST, obtaining the time dependent fast ion distribution, neutron emission spectrum, and total neutron emission rate. Combined with the time trace of the result measured by a standard 235U fission chamber, the effects of different configurations of NBI heating in EAST fusion plasmas have been evaluated.

17.
Osteoarthritis Cartilage ; 29(9): 1296-1305, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34216729

RESUMEN

OBJECTIVES: To investigate the longitudinal association between MRI-detected osteophyte scores and progression of knee symptoms, and whether the association was modified in the presence of bone marrow lesions (BMLs) or effusion-synovitis. METHODS: Data from Vitamin D Effects on Osteoarthritis (VIDEO) study, a randomized, double-blinded and placebo-controlled clinical trial in symptomatic knee osteoarthritis (OA) patients, were analyzed as an exploratory study. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to assess knee symptoms. Osteophytes, BMLs and effusion-synovitis were measured using MRI. RESULTS: 334 participants with MRI information and WOMAC score (baseline and follow-up) were included in the analyses, with 24.3% of them having knee pain increased 2 years later. Statistically significant interactions were found between MRI-detected osteophytes and BMLs or effusion-synovitis on increased knee symptoms. In participants with BMLs, higher baseline scores of MRI-detected osteophytes in most compartments were significantly associated with increased total knee pain, weight-bearing pain, stiffness, and physical dysfunction, after adjustment for age, sex, body mass index, intervention and effusion-synovitis. In participants with effusion-synovitis, higher baseline scores of MRI-detected osteophytes in almost all the compartments were significantly associated with increased total knee pain, weight-bearing pain, stiffness, and physical dysfunction, after adjustment for age, sex, body mass index, intervention and BMLs. In contrast, MRI-detected osteophyte scores were generally not associated with knee symptom progression in participants without baseline BMLs or effusion-synovitis. CONCLUSIONS: MRI-detected OPs are associated with increased total knee pain, weight-bearing knee pain, stiffness and physical dysfunction in participants presenting BMLs or effusion-synovitis, but not in participants lacking BMLs or effusion-synovitis. This suggests they could interact with bone or synovial abnormalities to induce symptoms in knee OA.


Asunto(s)
Enfermedades de la Médula Ósea/diagnóstico , Imagen por Resonancia Magnética , Osteoartritis de la Rodilla/diagnóstico , Osteofito/diagnóstico por imagen , Sinovitis/diagnóstico , Anciano , Progresión de la Enfermedad , Exudados y Transudados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto
18.
Zhonghua Yi Xue Za Zhi ; 101(22): 1690-1694, 2021 Jun 15.
Artículo en Chino | MEDLINE | ID: mdl-34126718

RESUMEN

Objective: To evaluate the safety, short- and mid-term outcomes of percutaneous balloon mitral valvuloplasty (PBMV) guided by the ultrasound. Methods: In this retrospective study, medical data of 15 patients [9 males and 6 females, with an age of (53±13) years] with PBMV under the guidance of ultrasound in Heart Center of Henan Provincial People's Hospital between December 2016 and January 2019 were collected and reviewed. The short-and mid-term outcomes were analyzed. Results: PBMV was successfully performed in all the patients. One patient underwent surgical valve replacement due to severe mitral regurgitation, and the other 14 patients were all followed up successfully. The average follow-up time was (13.8±4.6) months. Comparisons of preoperative and postoperative data showed significant differences in valve area [(1.84±0.43) cm2 vs (0.89±0.24) cm2], left atrial pressure [(11.9±4.5) mmHg (1 mmHg=0.133 kPa) vs (21.9±6.0) mmHg] and mean mitral valve pressure gradient [(10.9±3.2) mmHg vs (20.1±3.6) mmHg](all P<0.01), with no significant differences in mitral regurgitation area (P=0.67). Postoperative follow-up showed that there were no significant differences in mitral valve area, regurgitation area and N-terminal pro-B-type natriuretic peptide (NT-proBNP) between short-and mid-term postoperatively (all P>0.05). There was no secondary operation due to mitral stenosis in 14 patients, and 3 patients with moderate or severe tricuspid regurgitation showed significant improvement, with gradually recovered cardiac function, and there were no deaths in these patients. Conclusion: PBMV guided by the ultrasound is feasible and effective, and exhibits favorable short-and mid-term outcomes.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Estenosis de la Válvula Mitral , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/cirugía , Estenosis de la Válvula Mitral/diagnóstico por imagen , Estenosis de la Válvula Mitral/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Ultrasonografía
19.
Artículo en Chino | MEDLINE | ID: mdl-33832196

RESUMEN

Objective: To study the effects of superficial temporal artery and vein as recipient vessels for the free anterolateral thigh flap on the appearance and functions after maxillectomy. Methods: Clinical data of 21 patients with malignant maxillary tumors in Department of Oral and Maxillofacial Surgery, the Second Xiangya Hospital of Central South University from January 2014 to November 2019, who were treated by free anterolateral thigh flap with temporal superficial vessels as the recipient vessels were analyzed retrospectively. There were 18 males and 3 females, with the age ranging from 29 to 73 years old, including 19 cases of squamous carcinoma, 1 case of adenoid cystic carcinoma and 1 case of osteosarcoma. Of those 7 patients underwent primary surgery, 14 patients received resurgery, and 6 patients had a history of postoperative radiotherapy and chemotherapy. Among 14 patients with resurgery, 13 had recurrent ipsilateral second site tumor and 1 had recurrent tumor, and all of them received the maxillectomy and reconstructive surgery with the free anterolateral thigh flap. Patients were evaluated with water swallow test and speech intelligibility score in 1, 3 and 6 months after operation. The data were statistically analyzed with SPSS 22.0 statistical software. Water swallow test results before and after operation were compared using the Wilcoxon rank sum test. The mean speech intelligibility scores before and after operation were compared by the paired t test. Results: Patients were followed up for 10-60 months. All free flaps survived after operation. No diplopia occurred. Breathing, swallowing and speaking functions were normal. No movement disorders caused by the donor of thigh flap. Water swallow test showed no phenomenon of water flowing into the nasal cavity or oral and nasal leakage with level Ⅰ for 4 cases, level Ⅱ for 13 cases, level Ⅲ for 3 cases and level Ⅳ for 1 case. The mean speech intelligibility scores before surgery and 1, 3 and 6 months after surgery were 4.31±0.13, 1.46±0.21, 2.15±0.45 and 2.87±0.76 respectively. There was statistically significant difference in the mean speech intelligibility scores between 1 and 6 months after surgery (F=78.456, P<0.05). Conclusion: It is safe and reliable to use the superficial temporal vessels as recipient vessels for free anterolateral thigh flap in the reconstruction of defect after maxillectomy in malignant tumors, with good outcomes of functions and a satisfactory restoration of outward appearance.


Asunto(s)
Colgajos Tisulares Libres , Procedimientos de Cirugía Plástica , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Estudios Retrospectivos , Trasplante de Piel , Muslo/cirugía
20.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(2): 348-354, 2021 Mar 19.
Artículo en Chino | MEDLINE | ID: mdl-33879910

RESUMEN

OBJECTIVE: To explore the feasibility of preparing gastric floating formulations by fused de-position modeling (FDM) 3D printing technology, to evaluate the in vitro properties of the prepared FDM 3D printed gastric floating formulations, and to compare the influence of different external shapes of the formulation with their in vitro properties. METHODS: Verapamil hydrochloride and polyvinyl alcohol (PVA) were used as the model drug and the excipient, respectively. The capsule-shaped and hemisphere-shaped gastric floating formulations were then prepared by FDM 3D printing. The infill percentages were 15%, the layer heights were 0.2 mm, and the roof or floor thicknesses were 0.8 mm for both the 3D printed formulations, while the number of shells was 3 and 4 for capsule-shaped and hemisphere-shaped formulation, respectively. Scanning electron microscopy (SEM) was used to observe the morpho-logy of the surface and cross section of the formulations. Gravimetric method was adopted to measure the weights of the formulations. Texture analyzer was employed to evaluate the hardness of the formulations. High performance liquid chromatography method was used to determine the drug contents of the formulations. The in vitro floating and drug release behavior of the formulations were also characterized. RESULTS: SEM showed that the appearance of the FDM 3D printed gastric floating formulations were both intact and free from defects with the filling structure which was consistent with the design. The weight variations of the two formulations were relatively low, indicating a high reproducibility of the 3D printing fabrication. Above 800.0 N of hardness was obtained in two mutually perpendicular directions for the two formulations. The drug contents of the two formulations approached to 100%, showing no drug loss during the 3D printing process. The two formulations floated in vitro without any lag time, and the in vitro floating time of the capsule-shaped and hemisphere-shaped formulation were (3.97±0.41) h and (4.48±0.21) h, respectively. The in vitro release of the two formulations was significantly slower than that of the commercially available immediate-release tablets. CONCLUSION: The capsule-shaped and hemisphere-shaped verapamil hydrochloride gastric floating formulations were prepared by FDM 3D printing technology successfully. Only the floating time was found to be influenced by the external shape of the 3D printed formulations in this study.


Asunto(s)
Excipientes , Impresión Tridimensional , Liberación de Fármacos , Reproducibilidad de los Resultados , Comprimidos
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