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1.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 33(1): 118-121, 2021 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-33565415

RESUMO

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a respiratory disorder with high morbidity and mortality caused by various causes. Exosomes can mediate cell communication through paracrine pathways, transfer proteins, lipids, nucleic acids, etc., and interfere with the biological functions of recipient cells. Various cell-derived exosomes have been reported to play an immunomodulatory role in the ALI/ARDS inflammatory model. This article reviews the mechanism of exosomes involved in immune regulation of ALI/ARDS and possible therapeutic approaches.


Assuntos
Lesão Pulmonar Aguda , Exossomos , Humanos
2.
Nanoscale ; 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33595027

RESUMO

Colorectal cancer is one of the malignant tumors with high morbidity and lethality. Its efficient diagnosis and treatment has important significance. In this study, the orthotopic cancer model mouse, which could perfectly simulate clinical inflammatory colorectal cancer, was constructed by chemical induction. Based on this model, a new pH/ultrasonic dual-response, step-targeting and precisely controlled-release enteric-coated granule was designed for the combined sonodynamic (SDT)-chemotherapy. The enteric-coated granule was fabricated by enwrapping carboxymethyl chitosan (CMC) on folic acid-modified phospholipid (SLB-FA) encapsulating mesoporous silicon-coated gold nanoparticles loaded with chlorin (Ce6) and doxorubicin hydrochloride (DOX), titled as Au@mSiO2/Ce6/DOX/SLB-FA@CMC (GMCDS-FA@CMC). The diameter of the Au@mSiO2/Ce6/DOX/SLB-FA (GMCDS-FA) nanoprobe was 61.21 nm and that of the GMCDS-FA@CMC enteric-coated granule was 1.1 µm. MTT results showed that the cell survival rate was still as high as 76.55 ± 1.27% when the concentration of GMCDS-FA was up to 200 µg mL-1, which can indicate the low cytotoxicity of the nanoprobe. According to CT imaging, the enteric-coated granule had the highest concentration in the colorectum of the orthotopic cancer mouse after 7-9 h with oral administration, and was nearly metabolized out of the body after 24 h. The in vitro and in vivo experiments showed that the targeting enteric-coated granule had the best effect of treatment and desired prognosis after combined SDT-chemotherapy.

3.
J Colloid Interface Sci ; 590: 226-237, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33548606

RESUMO

Dopant engineering in nanostructured materials is an effective strategy to enhance electrochemical performances via regulating the electronic structures and achieving more active sites. In this work, a robust electrode based on Fe and Mn co-doped Co3S4 (FM-Co3S4) ultrathin nanosheet arrays (NSAs) on the Ni foam substrate is prepared through a facile hydrothermal method followed by a subsequent sulfurization reaction. It has been found that the incorporation of Fe ions is beneficial to higher specific capacity of the final electrode and Mn ions contribute to the excellent rate capability in the reversible redox processes. Density functional theory (DFT) calculations further verify that the Mn doping in the Co3S4 obviously shorten the energy gap of Co3S4, which favors the electrochemical performances. Due to the synergetic effects of different transition metal ions, the as-prepared FM-Co3S4 ultrathin NSAs exhibit a high specific capacity of 390 mAh g-1 at 5 A g-1, as well as superior rate capability and excellent cycling stability. Moreover, the corresponding quasi-solid-state hybrid supercapacitors constructed with the FM-Co3S4 ultrathin NSAs and active carbon exhibit a high energy density of 55 Wh kg-1 at the power density of 752 W kg-1. These findings demonstrate a new platform for developing high-performance electrodes for energy storage applications.

4.
Knee ; 29: 1-8, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33524657

RESUMO

BACKGROUND: Motion axial system may affect contact stress of hinge knee prosthesis. However, it is unclear which axial system provides the better biomechanical effect. Therefore, the aim of this study was to compare the contact stress and stress distribution on the tibial insert and the bushing of hinge knee prostheses with a biaxial (BA) system and a spherical center axial (SA) system during a gait cycle. METHODS: Three-dimensional finite-element (FE) models of the prostheses with different motion systems were included. The comparisons between experimental tests and FE analyses were performed to verify the models. Dynamic implicit FE analyses were performed to investigate the peak contact stresses and stress distributions on the tibial insert and the bushing. RESULTS: The peak contact stresses on the tibial insert and the bushing of the BA prosthesis were higher than those of the SA prosthesis during most gait cycles. The contact time on the bushing is short in the SA prosthesis. The stress distributions on the superior surface of the tibial insert in the BA prosthesis were at the posterior side, but of the SA prosthesis were not fixed. CONCLUSION: The SA prosthesis has a lower peak contact stress on tibial insert and bushing than the BA prosthesis; in addition, the SA prosthesis has a 'self-adjustment' mechanism which could disperse high stress on the tibial insert to decrease the risk of wear and damage. The comparison could help designers and surgeons to better understand the future design of rotating hinge knee prostheses which should be able to achieve multiaxial motion and complete weight bearing by the tibial condylar to transmit the axial force better.

5.
Curr Med Sci ; 41(1): 108-117, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33582914

RESUMO

Microtubule-associated serine/threonine kinase (MASTL) functions to regulate chromosome condensation and mitotic progression. Therefore, aberrant MASTL expression is commonly implicated in various human cancers. This study analyzed MASTL expression in gastric cancer vs. adjacent normal tissue for elucidating the association with clinicopathological data from patients. This work was then extended to investigate the effects of MASTL knockdown on tumor cells in vitro. The level of MASTL expression in gastric cancer tissue was assessed from the UALCAN, GEPIA, and Oncomine online databases. Lentivirus carrying MASTL or negative control shRNA was infected into gastric cancer cells. RT-qPCR, Western blotting, cell viability, cell counting, flow cytometric apoptosis and cell cycle, and colony formation assays were performed. MASTL was upregulated in gastric cancer tissue compared to the adjacent normal tissue, and the MASTL expression was associated with advanced tumor stage, Helicobacter pylori infection and histological subtypes. On the other hand, knockdown of MASTL expression significantly reduced tumor cell viability and proliferation, and arrested cell cycle at G2/M stage but promoted tumor cells to undergo apoptosis. At protein level, knockdown of MASTL expression enhanced levels of cleaved PARP1, cleaved caspase-3, Bax and p-ERK1/2 expression, but downregulated expression levels of BCL-2 and p-NF-κB-p65 protein in AGS and MGC-803 cells. MASTL overexpression in gastric cancer tissue may be associated with gastric cancer development and progression, whereas knockdown of MASTL expression reduces tumor cell proliferation and induces apoptosis. Further study will evaluate MASTL as a potential target of gastric cancer therapeutic strategy.

6.
Sci Rep ; 11(1): 3106, 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542422

RESUMO

Artificial intelligence (AI) has been applied with considerable success in the fields of radiology, pathology, and neurosurgery. It is expected that AI will soon be used to optimize strategies for the clinical management of patients based on intensive imaging follow-up. Our objective in this study was to establish an algorithm by which to automate the volumetric measurement of vestibular schwannoma (VS) using a series of parametric MR images following radiosurgery. Based on a sample of 861 consecutive patients who underwent Gamma Knife radiosurgery (GKRS) between 1993 and 2008, the proposed end-to-end deep-learning scheme with automated pre-processing pipeline was applied to a series of 1290 MR examinations (T1W+C, and T2W parametric MR images). All of which were performed under consistent imaging acquisition protocols. The relative volume difference (RVD) between AI-based volumetric measurements and clinical measurements performed by expert radiologists were + 1.74%, - 0.31%, - 0.44%, - 0.19%, - 0.01%, and + 0.26% at each follow-up time point, regardless of the state of the tumor (progressed, pseudo-progressed, or regressed). This study outlines an approach to the evaluation of treatment responses via novel volumetric measurement algorithm, and can be used longitudinally following GKRS for VS. The proposed deep learning AI scheme is applicable to longitudinal follow-up assessments following a variety of therapeutic interventions.

7.
Endocr Pract ; 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33607263

RESUMO

OBJECTIVE: To investigate the management of patients with asymptomatic suspicious thyroid nodules ≤ 1 cm. METHODS: We retrospectively reviewed medical records of patients with sonographically suspicious thyroid nodules ≤ 1 cm and without distant metastases, suspicious lymph node metastasis (LNM), or extrathyroidal extension (ETE). RESULTS: Of the 386 enrolled patients, 174 (45.1%) performed immediate surgery (IS), while 212 (54.9%) underwent active surveillance (AS). In IS group, 166 (95.4%) patients were confirmed as having papillary thyroid microcarcinoma (PTMC). LNM and ETE were observed in 24.7% and 2.4% cases, respectively. In AS group, nodule size increased by ≥ 3 mm in 11 (5.2%) patients and 39 (18.4%) had a > 50% increase in nodule volume after a median follow-up of 12 months. Nodules with smaller volume at diagnosis are more likely to increase in volume later. Newly suspicious LNM was detected in 23 (10.8%) patients. Delayed surgery (DS) were performed in 101 patients, with 27 showing disease progression. ETE and LNM were detected in 3%, 36% respectively, of patients with PTMC. Compared with IS, tumors in DS group more frequently showed lateral LNM and capsular invasion (P < 0.05). No patient had recurrence or died of thyroid cancer during postoperative follow-up [median 26 (4-60) months]. CONCLUSION: IS or DS of patients with asymptomatic suspicious thyroid nodules ≤ 1 cm was relatively high in China. The inertia of low-risk nodules and the effectiveness of DS for those progressed make AS to be a feasible strategy.

8.
Ecotoxicol Environ Saf ; 208: 111719, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396050

RESUMO

Long-term exposure to high levels of arsenic has been documented to induce skin and liver damage, affecting hundreds of millions of people. While arsenic-induced skin and liver damage and trace element alterations have been studied, their correlations and risks have not been explained. Based on the above premise, this study included a total of 172 subjects from a coal-burning arsenic poisoning area. The levels of 18 trace elements in hair and six liver function indices in serum were detected, and the associations between and risks of trace elements related to skin and liver damage were analyzed. Finally, the receiver operating characteristic (ROC) curve and areas under the curve (AUC) were used to analyze the diagnostic values of certain trace elements for arsenic-induced skin and liver damage. The results found that a decrease in Se was a risk factor for arsenic-induced skin and liver damage (OR = 8.33 and 1.92, respectively). Furthermore, increases in Al and V were risk factors for arsenic-induced skin damage (OR = 1.05) and liver damage (OR = 13.16), respectively. In addition, the results found that Se and Al possessed certain diagnostic values for arsenic-induced skin damage (AUC = 0.93, 0.80), that Se possessed a diagnostic value for liver damage (AUC = 0.93), and that the combination of Se and Al increased the diagnostic value for skin damage (AUC = 0.96). This study provides an important research basis for further understanding the reasons for arsenic-induced skin and liver damage, for screening and identifying candidate diagnostic biomarkers, and for improving prevention and control strategies for arsenism.


Assuntos
Intoxicação por Arsênico/etiologia , Arsênico , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Carvão Mineral/efeitos adversos , Dermatopatias/induzido quimicamente , Oligoelementos/análise , Adulto , Intoxicação por Arsênico/diagnóstico , Biomarcadores/análise , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , China/epidemiologia , Feminino , Cabelo/química , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Dermatopatias/diagnóstico
9.
Artigo em Inglês | MEDLINE | ID: mdl-33491840

RESUMO

Anode-free lithium metal batteries can maximize the energy density at the cell level. However, without the Li compensation from the anode side, it faces much more challenging to achieve a long cycling life with a competitive energy density than Li metal-based batteries. Here, we prolong the lifespan of an anode-free Li metal battery by introducing Li-rich Li 2 [Ni 0.8 Co 0.1 Mn 0.1 ]O 2 into the cathode as a Li-ions extender. The Li 2 [Ni 0.8 Co 0.1 Mn 0.1 ]O 2 can release a large amount of Li-ions during the first charging process to supplement the Li loss in the anode, then convert into NCM811, thus extending the lifespan of the battery without the introduction of inactive elements. By the benefit of Li-rich cathode and high reversibility of Li metal on Cu foil, the anode-free pouch cells enable to achieve 447 Wh kg -1  energy density and 84% capacity retention after 100 cycles in the condition of limited electrolyte addition (E/C ratio of 2 g Ah -1 ).

10.
Adv Mater ; : e2005781, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33470470

RESUMO

The electrochemical utilization of organic electrode materials (OEMs) is highly dependent on an excess amount of inactive carbon at the expense of low packing density and energy density. In this work, the challenges by substituting inactive carbon with electronic conductive inorganic cathode (ECIC) materials, which are endowed with high electronic conductivity to transport electrons for redox reactions of the whole electrodes, high ion-storage capacity to act as secondary active materials, and strong affinity with OEMs to inhibit their dissolution, are addressed. Combining representative ECICs (TiS2 and Mo6 S8 ) with organic electrode materials (perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) and hexaazatrinaphthalene (HATN)) simultaneously achieves high capacity, low porosity, lean electrolyte, and thus high energy density. High gravimetric and volumetric energy densities of 153 Wh kg-1 and 200 Wh L-1 are delivered with superior cycling stability in a 30 mA h-level Li/PTCDA-TiS2 pouch cell. The proof-of-concept of organic-ECIC electrodes is also successfully demonstrated in monovalent Na, divalent Mg, and trivalent Al batteries, indicating their feasibility and generalizability. With the discovery of more ECIC materials and OEMs, it is anticipated that the proposed organic-ECIC system can result in further improvements at cell level to compete with transition metal-based Li-ion batteries.

12.
Chemistry ; 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33462895

RESUMO

BaZnSi 3 O 8 ceramic was prepared via the conventional solid-state method and sintered at 1100 °C. XRD and synchrotron Rietveld refinement analyses revealed the BaZnSi 3 O 8 ceramic presented monoclinic structure with a space group of P 2 1 /a (No.14), which was reported for the first time. The BaZnSi 3 O 8 ceramic presented a weak ferroelectricity, which was confirmed by the P-E loop and the 90° nanoscale ferroelectric domain. Although ε r - T displayed two ε r abnormal peaks at 400 °C and 460 °C, the Curie temperature ( T - c ) was located at 460 °C according to the dielectric loss and Curie-Weiss law. Moreover, the BaZnSi 3 O 8 ceramic exhibited optimised microwave dielectric properties with ε r = 6.55, Q × f = 52400 GHz, and τ f = -24.5 ppm/°C. Hence, the BaZnSi 3 O 8 ceramic in the ternary BaO-ZnO-SiO 2 system possessed both weak ferroelectricity and microwave dielectric properties. These results are expected to break the technical barrier of ferroelectric phase shifter applications in microwave and even millimeter-wave frequency bands.

13.
Artigo em Inglês | MEDLINE | ID: mdl-33406458

RESUMO

Currently, endothelium-dependent vasodilatation involves three main mechanisms: production of nitric oxide (NO) by endothelial nitric oxide synthase (eNOS), synthesis of prostanoids by cyclooxygenase, and/or opening of calcium-sensitive potassium channels. Researchers have proposed multiple mechanosensors that may be involved in flow-mediated vasodilation (FMD), including G protein-coupled receptors (GPCRs), ion channels, and intercellular junction proteins, among others. However, GPCRs are considered the major mechanosensors that play a pivotal role in shear stress signal transduction. Among mechanosensitive GPCRs, G protein-coupled receptor 68, histamine H1 receptors, sphingosine-1-phosphate receptor 1, and bradykinin B2 receptors have been identified as endothelial sensors of flow shear stress regulating flow-mediated vasodilation. Thus, this review aims to expound on the mechanism whereby flow shear stress promotes vasodilation through the proposed mechanosensitive GPCRs in ECs.

14.
Clin J Am Soc Nephrol ; 16(2): 213-224, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33462083

RESUMO

BACKGROUND AND OBJECTIVES: IgA nephropathy is the most common form of primary GN worldwide. The evidence of geographic and ethnic differences, as well as familial aggregation of the disease, supports a strong genetic contribution to IgA nephropathy. Evidence for genetic factors in IgA nephropathy comes also from genome-wide association patient-control studies. However, few studies have systematically evaluated the contribution of coding variation in IgA nephropathy. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a two-stage exome chip-based association study in 13,242 samples, including 3363 patients with IgA nephropathy and 9879 healthy controls of Han Chinese ancestry. Common variant functional annotation, gene-based low-frequency variants analysis, differential mRNA expression, and gene network integration were also explored. RESULTS: We identified three non-HLA gene regions (FBXL21, CCR6, and STAT3) and one HLA gene region (GABBR1) with suggestive significance (P meta <5×10-5) in single-variant associations. These novel non-HLA variants were annotated as expression-associated single-nucleotide polymorphisms and were located in enhancer regions enriched in histone marks H3K4me1 in primary B cells. Gene-based low-frequency variants analysis suggests CFB as another potential susceptibility gene. Further combined expression and network integration suggested that the five novel susceptibility genes, TGFBI, CCR6, STAT3, GABBR1, and CFB, were involved in IgA nephropathy. CONCLUSIONS: Five novel gene regions with suggestive significance for IgA nephropathy were identified and shed new light for further mechanism investigation.

15.
Plant Cell Environ ; 44(3): 842-855, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33377200

RESUMO

The phase transition from vegetative to reproductive growth is triggered by internal and external signals that participate in circadian clock in plants. We identified a rice floral inhibitor OsPRR73 encoding a CONSTANS protein. Overexpression of OsPRR73 resulted in late heading under both long-day (LD) and short-day (SD) conditions. Knockout mutants led to early heading under LD conditions but no change under SD. OsPRR73 mRNA accumulated at noon and exhibited a robust oscillation under constant light (LL) and constant darkness (DD) conditions. OsPRR73 overexpression exerted negative feedback on endogenous OsPRR73 expression and altered diurnal expressions of key flowering genes and circadian clock genes. OsPRR73 bound to the promoters of the floral gene Ehd1 and the circadian gene OsLHY, and significantly suppressed their expression at dawn. In LL and DD, the oscillatory patterns of the circadian genes OsLHY, OsTOC1, OsGI and OsELF3 were varied in OsPRR73OX and osprr73 mutants. OsPRR73 expression was decreased in osphyb mutants, and overexpression of OsPRR73 complemented the early heading date phenotype of osphyb, indicating OsPRR73 works downstream of OsPhyB. Therefore, OsPRR73 is involved in a feedback loop of the rice clock and connects the photoperiod flowering pathway by binding to the Ehd1 promoter in rice.

16.
Waste Manag ; 119: 63-71, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33045488

RESUMO

This study investigated the effects of the addition of micro- (Fe, Co, Ni, and Mo) and macro-(Sulfur) nutrients on mono-digestion of sorghum under mesophilic conditions. A continuous stirred-tank reactor was operated for more than 420 days under seven different experimental conditions. The experimental results showed poor performance for methane production and process stability without nutrient supplementation. Serious deficiencies in Co and S were confirmed by nutrient analysis of dry sorghum and digestate. Nutrient augmentation efficiently enhanced methane production and volatile fatty acid (VFA) removal. Methane production reached 223 mL-CH4/g-VS, almost matching the yield predicted by biochemical methane potential (BMP) test. S was demonstrated to have a critical effect on metal availability in the digester. Consequently, to maintain stable methane fermentation, suitable supplementations of S and Co are recommended for anaerobic sorghum mono-digestion.


Assuntos
Biocombustíveis , Sorghum , Anaerobiose , Reatores Biológicos , Metano , Nutrientes
17.
Int J Geriatr Psychiatry ; 36(1): 86-95, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32783270

RESUMO

OBJECTIVE: To investigate associations between vision impairment (VI), vision correction (VC) and depressive symptoms among middle-aged and older Chinese. METHODS: 22 203 participants aged ≥45 years from China Health and Retirement Longitudinal Study 2011 to 2015 were divided into four self-reported VI categories: no VI, distance VI (DVI) only, near VI (NVI) only, and both distance and near VI (DNVI); and four self-reported VI/VC subgroups: VI(+)/VC(-), VI(+)/VC(+), VI(-)/VC(-) and VI(-)/VC(+). Depressive symptoms were evaluated by 10-item Center for Epidemiological Studies Depression Scale (CESD-10). RESULTS: Compared with no VI, DVI only (OR = 2.12, 95% CI: 1.95, 2.31), NVI only (OR = 1.51, 95% CI: 1.39, 1.63) and DNVI (OR = 2.75, 95% CI: 2.47, 3.07) were associated with higher odds of depressive symptoms. Compared with VI(+)/VC(-), VI(+)/VC(+) (OR = 0.91, 95% CI: 0.83, 0.98), VI (-)/VC(-) (OR = 0.50, 95% CI: 0.48, 0.53) and VI(-)/VC(+) (OR = 0.49, 95% CI: 0.47, 0.54) were associated with lower odds of depressive symptoms. Compared with no VI at baseline, baseline DNVI was significantly associated with higher odds of depressive symptoms after two (OR = 1.48, 95% CI: 1.16, 1.88) and four (OR = 1.32, 95% CI: 1.04, 1.68) years. Baseline depressive symptoms were significantly associated with higher odds of VI after two (OR = 1.53, 95% CI: 1.34, 1.74) and four (OR = 1.54, 95% CI: 1.34, 1.76) years. CONCLUSION: Adults with DNVI were more likely to report depressive symptoms in the future and those with depressive symptoms were more likely to report VI in the future. VC might be a protective factor for preventing depressive symptoms among adults with VI.

18.
Hand Surg Rehabil ; 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33348058

RESUMO

We aimed to evaluate the effectiveness of surgical methods commonly used for the clinical treatment of giant cell tumors (GCT) of the distal radius. From 2010 to 2018, 32 patients with GCT of the distal radius who underwent surgical treatment were eligible for the study. Among them, 21 patients with available pathological results, complete imaging data and at least 18 months of follow-up were enrolled in the study. Eleven of the patients underwent en bloc resection and non-vascularized autologous fibula reconstruction (Group A), while 10 patients underwent microwave ablation, lesion curettage, and internal fixation with bone cement (Group B). Imaging was carried out to understand the effect of the surgical treatment and postoperative complications. Variables of interested included operation time and blood loss, preoperative and postoperative wrist joint mobility, and postoperative complications during follow-up. The operation time and intraoperative blood loss in group A were higher than in group B, and the difference between groups was statistically significant. The wrist range of motion before and after surgery was statistically significant both in Group A and Group B (p < 0.05). The scale deviation and MSTS scores of group A were better than group B (p > 0.05), flexion, extension, radial deviation index in group B was better than group A (p < 0.05). By evaluating the postoperative functional outcomes of the operated wrist in the two groups, we found that both surgical methods are reliable for treating GCT of the distal radius, with satisfactory postoperative functional recovery and a low incidence of postoperative recurrence (only 1 of 10 patients in group B). The two surgical methods have their own advantages and disadvantages and provide surgeons with one more choice in the clinical context.

19.
Comput Methods Programs Biomed ; 198: 105775, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33130494

RESUMO

BACKGROUND AND OBJECTIVES: To compare mechanical properties of femoral tumor treatments so that better operative strategy for limb tumors surgery is optimized. METHODS: Fourteen femoral CT images were randomly selected to rebuild 3D models by MIMICS. They were then executed by reverse engineering softwares for simulative modes. Mode #1: Intralesional curettage with cement filled plus fixator; Mode #2: Distal femur resection with tumorous prosthesis replaced. Finally, the mechanical aspects such as stress and displacement were compared by finite element analysis. RESULTS: Analyzed by AnSys, the observation indexes were measured as follows: for displacement of femurs, d=1.4762 (< a=3.9042 < c=3.9845 < b=4.1159) in mm is the most staple of all models; for displacement of implants (fixators or prostheses), it's similar to the behavior of femurs and with no significant difference; for stresses of femurs, no significant difference was found among all models; the stresses of implants (fixations and prostheses) were observed as d=39.6334 (< a=58.6206 < c=61.8150 < b=62.6626) in MPa correspondently, which is the least; for stresses of the general system, the average of peak values for integrated devices of all models are: d=40.8072 (< a=58.6206 < c=61.7831< b=62.6626) in MPa, which is also the least. As a final result, both maximum values for displacement and stress of mode 2 are lower than those of mode 1. CONCLUSIONS: Our finite element analysis of limb salvage simulation in biomechanics proved that, to treat distal femoral bone tumors, prosthetic replacement is more efficient than intralesional curettage.

20.
Eur J Radiol ; 134: 109455, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33296802

RESUMO

PURPOSE: To investigate the reproducibility of quantitative digital subtraction angiography (QDSA) measurements and their associations with brain arteriovenous malformation (BAVM) hemorrhage. METHODS: From 2011-2019, 37 patients with BAVMs who had undergone both diagnostic and stereotactic DSA were divided into hemorrhagic and nonhemorrhagic groups. QDSA analysis was performed on the 2 DSA exams. The inter-exam reliabilities of QDSA measurements across the diagnostic and stereotactic DSA were tested using intraclass correlation coefficients (ICCs). Demographics, BAVM characteristics, and QDSA results for the hemorrhagic and nonhemorrhagic groups were compared. RESULTS: Fifteen of 37 (40.5 %) patients presented with hemorrhage were associated with smaller BAVM volume and the presence of intranidal aneurysm and exclusive deep venous drainage. The median interval between the diagnostic and stereotactic DSA was 49 days and did not differ between the groups. In both groups, the inter-exam QDSA measurements were more reliable for drainage veins and transnidal time (ICCs ranged from 0.38-0.93) than for feeding arteries (ICCs ranged from 0.01-0.74). Among the venous parameters, the hemorrhagic group had lower peak density, area under the curve, inflow gradient, and outflow gradient on both DSA exams and larger full width at half maximum and stasis index on the stereotactic DSA exam than the nonhemorrhagic group. CONCLUSIONS: In BAVMs, the QDSA measurements for veins are more reliable than those for arteries. QDSA analysis reflecting stagnant venous drainage is associated with BAVM hemorrhage, but may be confounded by the acute hemodynamic change after hemorrhage.

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