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1.
Sensors (Basel) ; 24(11)2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38894228

RESUMEN

Piezoelectric effects were first discovered more than a hundred years ago and, since then, have been widely used across various fields [...].


Asunto(s)
Transductores , Humanos , Monitoreo Fisiológico/instrumentación , Monitoreo Fisiológico/métodos
2.
Chemistry ; 28(16): e202104339, 2022 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-35218101

RESUMEN

The mesopores formation in zeolite crystals has long been considered to occur through the stochastic hydrolysis and removal of framework atoms. Here, we investigate the NH4 F etching of representative small, medium, and large pore zeolites and show that the zeolite dissolution behavior, therefore the mesopore formation probability, is dominated by zeolite architecture at both nano- and sub-nano scales. At the nano-scale, the hidden mosaics of zeolite structure predetermine the spatio-temporal dissolution of the framework, hence the size, shape, location, and orientation of the mesopores. At the sub-nano scale, the intrinsic micropore size and connectivity jointly determine the diffusivity of reactant and dissolved products. As a result, the dissolution propensity varies from removing small framework fragments to consuming nanodomains and up to full digestion of the outmost part of zeolite crystals. The new knowledge will lead to new understanding of zeolite dissolution behavior and new adapted strategies for tailoring hierarchical zeolites.

3.
Mikrochim Acta ; 187(7): 418, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32613273

RESUMEN

An organic-inorganic hybrid monolithic column doped with gold nanorods (AuNRs) was prepared and evaluated for solid phase extraction (SPE) of polycyclic aromatic hydrocarbons (PAHs). Excellent dispersibility of AuNRs in binary green porogen system consisting of 1-hexyl-3-methylimidazolium tetrafluoroborate and deep eutectic solvents (DESs) was confirmed by energy dispersive spectrometry (EDS). The particle size of the resulting AuNRs (70-90 nm) was thoroughly examined by a transmission electron microscopy (TEM). The redox system including ammonium persulfate (APS) and tetramethylethylenediamine (TEMED) was used to initiate in situ polymerization at 4 °C to prepare the hybrid monolith. The mesoporous structure of the AuNR hybrid monoliths was confirmed by scanning electron microscopy (SEM) and nitrogen adsorption. With enrichment factors (EFs) of 150- to 292-fold, the developed method was successfully applied to the determination of 10 PAHs in wastewater samples. The recoveries at a spiked level were in the range 84.9 to 99.5% with limit of detections (LODs) and relative standard deviations (RSDs) ranging from 0.02 to 0.10 µg L-1 and 1.5 to 4.2%, respectively. The correlation coefficients (R2) for the calibration function obtained were better 0.9991 for the target compounds. Compared to the AuNR-free monolith, the extraction efficiency of the AuNR-incorporated monolith is more than two times higher. The results indicated that the doping of AuNRs is an effective approach to obtain the hybrid monolithic column with good separation ability for PAHs. Graphical abstract.

4.
Mikrochim Acta ; 186(12): 812, 2019 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-31745668

RESUMEN

A boronate affinity monolith with improved affinity and selectivity for glycoproteins was prepared starting from two monomers. The first is 3-aminopropyltriethoxysilane-methacrylic acid (APTES-MAA), and the other is a polyhedral oligomeric silsesquioxane (POSS) monomer. In the next step, 3-(acrylamido)benzeneboronic acid was adopted as boronate affinity ligand, and ethylene glycol dimethacrylate as the crosslinker, and iso-propanol and octanol as binary porogens. The synergistic effect of APTES-MAA and POSS warrants good affinity and selectivity for glycoproteins, which results in a number of attractive features including (a) a wide operation pH range (from 5 to 8); (b) higher enrichment factors ranging from 19.3 to 20.6; (c) greater recoveries of glycoproteins between 95.8 and 107.1%; (d) lower relative standard deviations of ≤4.2%. Compared to the corresponding APTES-MAA/POSS-free monolith, the new boronate material had 1.7-fold increased glycoprotein recovery from complex samples. Glycoproteins in 500-fold diluted serum samples can be enriched by the boronate monolith. Graphical abstractSchematic representation of the preparation of 3-aminopropyltriethoxysilane-methacrylic acid/polyhedral oligomeric silsesquioxanes boronate affinity monolith. This sorbent exhibits high selectivity and wide pH operation range for capturing glycopeptides.


Asunto(s)
Ácidos Borónicos/química , Glicoproteínas/aislamiento & purificación , Compuestos de Organosilicio/química , Ácidos Borónicos/síntesis química , Glicoproteínas/sangre , Humanos , Metacrilatos/síntesis química , Metacrilatos/química , Compuestos de Organosilicio/síntesis química , Microextracción en Fase Sólida/instrumentación , Microextracción en Fase Sólida/métodos
5.
IUBMB Life ; 70(7): 642-648, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29707886

RESUMEN

We aimed to investigate the role of telomerase reverse transcriptase (TERT) in hepatocellular cancer (HCC) cells. R software was used for differential expressed gene analysis. Western blot and quantitative real time polymerase chain reaction (qRT-PCR), respectively, were used to detect protein expression and mRNA level of TERT in tumor cell lines. Real-time quantitative telomeric repeat amplification protocol assay, MTT assay, colony formation assay, and flow cytometry (FCM) assay were used to analyze the telomerase activity, viability, proliferation, cell cycle progression and apoptosis of HCC cells. The proliferation ratio of HCC cells transfected with TERT-siRNA was significantly decreased compared with control group. Plate clone results suggested that the number of colonies also decreased in TERT-siRNA group. FCM results showed that more cells were arrested in G0/G1 phase and apoptosis rate increased in TERT-siRNA group compared with control group. TERT suppression inhibited cell proliferation but promoted cell cycle arrest and cell apoptosis. © 2018 IUBMB Life, 70(7):642-648, 2018.


Asunto(s)
Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Telomerasa/genética , Apoptosis , Carcinoma Hepatocelular/genética , Puntos de Control del Ciclo Celular/genética , Línea Celular Tumoral , Proliferación Celular , Regulación hacia Abajo , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Neoplasias Hepáticas/genética , ARN Interferente Pequeño , Telomerasa/metabolismo
6.
J Clin Lab Anal ; 32(3)2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28703321

RESUMEN

PURPOSE: This study was aimed to investigate the relationship between miR-211-5p and SOX11, and the effects of their interaction on the proliferation, viability, and invasion of human thyroid cancer (TC) cells. METHODS: We used quantitative real-time PCR (qRT-PCR) to determine the expression of miR-211-5p and SOX11mRNA in the thyroid tumorous and the adjacent tissues. The target relationship between miR-211-5p and SOX11 was confirmed using dual luciferase reporter gene assay. Flow cytometry, colony formation assay, Transwell assay, and MTT assay were performed to determine the cell-cycle progression, cell apoptosis, proliferation and invasion, respectively. In addition, the tumor formation assay in nude mice was done to assess the effect of miR-211-5p on TC development in vivo. RESULTS: MiR-211-5p was underexpressed, whereas SOX11 was overexpressed in TC. The overexpression of miR-211-5p inhibited the expression of SOX11. The cell cycle was arrested and the proliferation as well as invasiveness was suppressed by exogenous miR-211-5p in TC cell line. The antitumor role of miR-211-5p was proved by the animal experiment. CONCLUSION: MiR-211-5p affected the viability, proliferation and invasion of TC by negatively regulating SOX11 expression.


Asunto(s)
Movimiento Celular/genética , Proliferación Celular/genética , MicroARNs/genética , Factores de Transcripción SOXC/genética , Neoplasias de la Tiroides/genética , Animales , Regulación hacia Abajo/genética , Humanos , Ratones , Ratones Desnudos , MicroARNs/metabolismo , Invasividad Neoplásica/genética , Reproducibilidad de los Resultados , Factores de Transcripción SOXC/metabolismo , Glándula Tiroides/química , Glándula Tiroides/metabolismo , Neoplasias de la Tiroides/química , Neoplasias de la Tiroides/metabolismo
7.
Technol Health Care ; 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38517824

RESUMEN

BACKGROUND: Psychological factors are a risk factor for the incidence of breast cancer and have a significant impact on patient prognosis. OBJECTIVE: The present study aims to investigate the effects of personalised graded psychological intervention on negative emotion and quality of life in patients with breast cancer. METHODS: A total of 200 patients with breast cancer were randomly divided into two groups: an experimental group (n= 100) and control group (n= 100). Both groups received routine nursing care. The experimental group received personalised graded psychological intervention care, and the control group received routine nursing measures. After 2 months of standard treatment, the patients' quality of life and negative emotions were evaluated using the self-rating depression scale (SDS), self-rating anxiety scale (SAS), social support rating scale (SSRS) and quality of life measurement scale (FACT-B) scoring criteria. RESULTS: There were no significant differences in the general data between the two groups (p> 0.05). Furthermore, there were no significant differences in the SDS, SAS, SSRS and FACT-B scores between the two groups before personalised graded psychological intervention (p> 0.05). After the intervention, the experimental group exhibited an improved nursing effect compared with the control group. The SDS and SAS scores were lower in the experimental group than in the control group (p< 0.05); after the intervention, the SDS and SAS scores were significantly lower in the experimental group than in the control group (p< 0.05). The SSRS and FACT-B scores were higher in the experimental group than in the control group (p< 0.05), and the experimental group's post-intervention SSRS and FACT-B scores were significantly higher than before the intervention (p< 0.05). CONCLUSIONS: The use of personalised graded psychological intervention for the nursing of patients with breast cancer in clinical practice can significantly reduce patients' negative emotions as well as improve positive emotions and quality of life; thus, this method can be popularised in the nursing process.

8.
Indian J Cancer ; 2022 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-36861715

RESUMEN

Background: The combined treatment of transcatheter arterial chemoembolization (TACE) and apatinib had beneficial effects on the survival of patients with advanced hepatocellular carcinoma (HCC), but the efficacy of this regimen is still controversial and needs further investigation. Materials and Methods: The clinical records of advanced HCC patients between May 2015 and December 2016 were collected from our hospital. They were categorized into the TACE monotherapy group and the combination of TACE and apatinib group. After propensity score matching (PSM) analysis, the disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS), and occurrence of adverse events were compared between the two treatments. Results: There were 115 HCC patients included in the study. Among them, 53 received TACE monotherapy and 62 were treated with TACE plus apatinib. After PSM analysis, 50 pairs of patients were compared. The DCR of the TACE group was significantly lower than that of the combination of TACE and apatinib group (35 [70%] versus 45 [90%], P < 0.05). The ORR of the TACE group was also significantly lower than that of the combination of TACE and apatinib group (22 [44%] versus 34 [68%], P < 0.05). Patients who received the combined treatment of TACE and apatinib had longer PFS compared with those in the TACE monotherapy group (P < 0.001). Moreover, hypertension, hand-foot syndrome, and albuminuria were more common in the combination of TACE and apatinib group (P < 0.05), although all adverse events were well tolerated. Conclusions: The combined treatment of TACE and apatinib showed beneficial effects on tumor response, survival outcomes, and tolerance to treatment, which may be used as a routine regimen for advanced HCC patients.

9.
Ultrasonics ; 119: 106627, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34688981

RESUMEN

This article reports a new mechanism involving a non-perforated resonant elastic metamaterial to achieve the complete conversion of Lamb waves (A0 and S0) into the fundamental shear horizontal (SH0) wave. The proposed metamaterial ultrasound mode convertor is studied via the observation of the special resonant shear motion of its unit cells, initiating with a conventional additive stub design. Thereafter, such a stubbed structure is further modified to fully couple the Lamb modes with the shear horizontal stub motion. By investigating the band structure of the metamaterial unit cell through modal analysis and tuning the shear resonant motions, a complete SH0 mode generation band within the simultaneous Lamb modes bandgap can be established in a wide frequency range. Such a special bandgap situation enables the complete mode conversion from Lamb waves into shear horizontal waves. The transformation capability of the proposed ultrasound mode convertor is further substantiated via the harmonic analysis of metamaterial chain model, showcasing the frequency spectrum of the transmitted wave modes. The optimal configuration is determined by conducting a parametric study to identify the most effective mode conversion performance. Finally, a coupled-field transient finite element simulation is carried out to acquire the dynamic response of the structure. The frequency-wavenumber analysis of the transmitted wave field illuminates the successful realization of the mode conversion behavior. Experimental demonstrations are presented to validate the numerical predictions. The proposed complete mode conversion capability may possess great potential for wave control and manipulation.

10.
Br J Nutr ; 106(2): 243-7, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21320367

RESUMEN

Excessive iodine intake can cause thyroid function disorders as can be caused by iodine deficiency. There are many people residing in areas with high iodine levels in drinking-water in China. The main aim of the present study was to map the geographical distribution of drinking-water with high iodine level in China and to determine the relationship between high iodine level in drinking-water and goitre prevalence. Iodine in drinking-water was measured in 1978 towns of eleven provinces in China, with a total of 28,857 water samples. We randomly selected children of 8-10 years old, examined the presence of goitre and measured their urinary iodine in 299 towns of nine provinces. Of the 1978 towns studied, 488 had iodine levels between 150 and 300 µg/l in drinking-water, and in 246 towns, the iodine level was >300 µg/l. These towns are mainly distributed along the original Yellow River flood areas, the second largest river in China. Of the 56 751 children examined, goitre prevalence was 6.3 % in the areas with drinking-water iodine levels of 150-300 µg/l and 11.0 % in the areas with drinking-water iodine >300 µg/l. Goitre prevalence increased with water and urinary iodine levels. For children with urinary iodine >1500 µg/l, goitre prevalence was 3.69 times higher than that for those with urinary iodine levels of 100-199 µg/l. The present study suggests that drinking-water with high iodine levels is distributed in eleven provinces of China. Goitre becomes more prevalent with the increase in iodine level in drinking-water. Therefore, it becomes important to prevent goitre through stopping the provision of iodised salt and providing normal drinking-water iodine through pipelines in these areas in China.


Asunto(s)
Agua Potable/química , Bocio/etiología , Yodo/efectos adversos , Niño , China/epidemiología , Ingestión de Líquidos , Femenino , Bocio/epidemiología , Bocio/orina , Humanos , Yodo/administración & dosificación , Yodo/orina , Masculino , Prevalencia , Ríos
11.
Oncol Lett ; 22(5): 773, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34589152

RESUMEN

Long non-coding RNA transmembrane and coiled-coil domain family 1 antisense RNA 1 (TMCC1-AS1) has been frequently reported to be associated with prognosis in patients with liver cancer (LC). However, the biological role of TMCC1-AS1 in LC in vitro remains unclear. The expression levels of TMCC1-AS1 in primary tumor tissues and LC cell lines were determined using reverse transcription-quantitative PCR. The associations between TMCC1-AS1 expression and the clinicopathological factors of patients with LC were statistically analyzed using the χ2 test. The role of TMCC1-AS1 in LC prognosis was assessed using Kaplan-Meier curves and proportional hazards model (Cox) analysis. Cell proliferation was determined by Cell Counting Kit-8 and colony formation assays. Transwell assays were performed to determine migration and invasion. TMCC1-AS1 expression was found to be significantly upregulated in LC tissues and cell lines compared with the corresponding controls. High TMCC1-AS1 expression was associated with advanced TNM stage and lymph node metastasis. Furthermore, high TMCC1-AS1 expression predicted poor survival in patients with LC. Knockdown of TMCC1-AS1 significantly inhibited the proliferation, migration and invasion of HepG2 and SNU-182 cells, while overexpression of TMCC1-AS1 had the opposite effect in HepG2 and SNU-182 cells. At the molecular level, downregulation of TMCC1-AS1 expression resulted in increased E-cadherin expression and decreased proliferating cell nuclear antigen, Ki67, N-cadherin and Vimentin expression in HepG2 cells. Overexpression of TMCC1-AS1 had the opposite effects on these factors in SNU-182 cells. In conclusion, the present findings indicated that TMCC1-AS1 might be considered as a novel oncogene, which promotes cell proliferation and migration, and may be a potential therapeutic target for LC.

12.
PLoS One ; 16(8): e0256108, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34449783

RESUMEN

Aiming at conservative Maxwell equations with periodic oscillatory solutions, we adopt exponentially fitted trapezoidal scheme to approximate the temporal and spatial derivatives. The scheme is a multisymplectic scheme. Under periodic boundary condition, the scheme satisfies two discrete energy conservation laws. The scheme also preserves two discrete divergences. To reduce computation cost, we split the original Maxwell equations into three local one-dimension (LOD) Maxwell equations. Then exponentially fitted trapezoidal scheme, applied to the resulted LOD equations, generates LOD multisymplectic scheme. We prove the unconditional stability and convergence of the LOD multisymplectic scheme. Convergence of numerical dispersion relation is also analyzed. At last, we present two numerical examples with periodic oscillatory solutions to confirm the theoretical analysis. Numerical results indicate that the LOD multisymplectic scheme is efficient, stable and conservative in solving conservative Maxwell equations with oscillatory solutions. In addition, to one-dimension Maxwell equations, we apply least square method and LOD multisymplectic scheme to fit the electric permittivity by using exact solution disturbed with small random errors as measured data. Numerical results of parameter inversion fit well with measured data, which shows that least square method combined with LOD multisymplectic scheme is efficient to estimate the model parameter under small random disturbance.


Asunto(s)
Fenómenos Electromagnéticos , Modelos Teóricos , Algoritmos , Simulación por Computador , Electricidad
13.
ACS Omega ; 6(50): 34967-34976, 2021 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-34963978

RESUMEN

A silica-aluminum-based mineral (GL) was selected for inspecting the effects of interactions of minerals in coal blends on the coke reactivity index (CRI) and sulfur transformation during co-pyrolysis of long flame coal and high-sulfur coking coal. Results indicate a good compatibility for the supply of active hydrogen, decomposition of sulfur, and regulation of reactivity. The experimental values of sulfur content in different coal blend cokes are lower than the calculated values, which can be determined as a result of the directional regulation effect of long flame coal on sulfur transformation. The addition of GL in coal blends significantly reduces the CRI of the corresponding coke, and the effect of GL on coke reactivity is also verified by a 10 kg coke oven experiment. When increasing the ratio of long flame coal, the sulfur fixation in the solid phase has a tendency to be enhanced by alkaline minerals. Also, GL plays a role in reducing the capture of sulfur free radicals by alkaline minerals, which improves the sulfur removal during pyrolysis of coal blends and then reduces the sulfur content in coke. This work provides a reference for using silica-aluminum-based minerals to reduce the capture of sulfur and catalytic effect on coke reactivity.

14.
RSC Adv ; 11(61): 38537-38546, 2021 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-35493236

RESUMEN

For guiding a novel integrated process of low-rank coal pyrolysis and gasification with char gasification gas as a heat carrier, this study investigated the effect of simulated coal gas from char gasification (SCGG) on rapid pyrolysis products of low rank coal from 550 to 700 °C in a downer pyrolyzer. Results indicated that the component of SCGG directly affected the distribution and composition of pyrolysis products. Compared with N2, SCGG facilitated the formation of tar below 600 °C. H2 in SCGG and that from water gas shift reaction (WGS: CO + H2O → CO2 + H2) increased the tar yield by reacting with solid-phase free radicals in coal and inhibiting the secondary reaction of gas-phase volatile radicals. Also, CO2 in SCGG raised the tar yield due to its promotion to coal cracking. When the pyrolysis temperature exceeded 600 °C, the reforming reactions of nascent tar with steam occurred, resulting in a reduced tar yield. SCGG could distinctly reduce the coke yield (coke-S) and pitch content in tar due to the inhibiting effect of H2 from SCGG and WGS on the polycondensation reactions of volatile radicals and reforming reactions of nascent tar. The chemical composition analysis of tar by GC × GC-MS demonstrated that compared with under N2, the contents of phenols, oxygenated compounds, and heterocyclic compounds in tar under SCGG were decreased while the content of aromatics was the opposite mainly due to hydrogenation and reforming reactions of nascent tar. Also, the H/C and O/C ratios of char under the action of SCGG were higher than those under N2 at the same temperature.

15.
ACS Omega ; 6(5): 3800-3808, 2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33585759

RESUMEN

A suite of carbon materials is prepared from biochar and coal at three different blending ratios with 10, 20, and 30% biochar by mass. These carbon materials are activated by steam to obtain porous structures. The effect of the inactivated and activated carbon materials on the cracking of coal pyrolysis volatiles is evaluated. The results indicate that the inactivated carbon materials are beneficial to improve the yield of light oil with a boiling point below 170 °C. The steam-activated carbon materials are more conducive to cracking tar pitch than the inactivated carbon materials due to the increased defects in carbon structure. However, it is also easy to form more coke deposits. More components rich in hydrogen are cracked to generate radicals that could combine with the phenols' precursor over carbon materials, and the content of phenols in tar is increased. The carbon materials prepared from biochar and coal using this method show distinct advantages as filter media in the granular bed duster. It can improve the quality of tar along with reducing the dust content in tar.

16.
Adv Sci (Weinh) ; 8(17): e2100001, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34219412

RESUMEN

Hierarchical zeolites are regarded as promising catalysts due to their well-developed porosity, increased accessible surface area, and minimal diffusion constraints. Thus far, the focus has been on the creation of mesopores in zeolites, however, little is known about a microporosity upgrading and its effect on the diffusion and catalytic performance. Here the authors show that the "birth" of mesopore formation in faujasite (FAU) type zeolite starts by removing framework T atoms from the sodalite (SOD) cages followed by propagation throughout the crystals. This is evidenced by following the diffusion of xenon (Xe) in the mesoporous FAU zeolite prepared by unbiased leaching with NH4 F in comparison to the pristine FAU zeolite. A new diffusion pathway for the Xe in the mesoporous zeolite is proposed. Xenon first penetrates through the opened SOD cages and then diffuses to supercages of the mesoporous zeolite. Density functional theory (DFT) calculations indicate that Xe diffusion between SOD cage and supercage occurs only in hierarchical FAU structure with defect-contained six-member-ring separating these two types of cages. The catalytic performance of the mesoporous FAU zeolite further indicates that the upgraded microporosity facilitates the intracrystalline molecular traffic and increases the catalytic performance.

17.
Anal Chim Acta ; 1096: 184-192, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31883586

RESUMEN

A monolithic chip incorporated with graphene oxide (GO) based on deep eutectic solvents (DESs) was developed for solid phase extraction (SPE). The carboxylated GO was modified with p-aminostyrene (pAS) by amidation, and the obtained GO (pAS-COOH-GO) was covalently incorporated into poly(butyl methacrylate-co-ethylene glycol dimethyl methacrylate) monolithic chip. Due to the high viscosity characteristics of DESs, a uniform pAS-COOH-GO incorporated monolithic chip with good permeability can be achieved. A systematic study of the preparation parameters on the performance of the resulting monolith was carried out, including the content of pAS-COOH-GO, DESs composition and porogen ratio. The resulting pAS-COOH-GO incorporated monolith was characterized by nitrogen adsorption, scanning electron microscopy, and transmission electron microscopy. The GO-doped monolithic chip can be used for SPE of polycyclic aromatic hydrocarbons (phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, benzo(a) pyrene, dibenzo(a,h)anthracene and inden(1,2,3,-cd)pyrene). The recoveries were all higher than 90%, which was about twice as high as that of the monolithic chip prepared without GO. By comparing the SPE results with that of GO free monolithic chip, good enrichment effects were demonstrated on the pAS-COOH-GO incorporated monolithic chip.

18.
Ultrasonics ; 94: 202-217, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30301552

RESUMEN

This article presents an efficient numerical approach to the investigation of nonlinear scattering and mode conversion phenomena of Lamb waves as they interact with breathing cracks. A Local Interaction Simulation Approach (LISA) is adopted, which possesses the versatility to capture arbitrary damage profiles. The stick-slip contact dynamics is implemented in the LISA model via the penalty method, which captures the nonlinear interactions between Lamb waves and breathing cracks. The LISA framework achieves remarkable computational efficiency with its parallel implementation using Compute Unified Device Architecture (CUDA) executed on powerful GPUs. A small-size LISA model with absorbing boundaries is tailored for the purpose of extracting the Lamb wave scattering and mode conversion features. Due to the explicit parallel CUDA implementation and the small-size model setup, the computation is highly efficient. Numerical case studies on nonlinear scattering of Lamb waves from breathing cracks are given. Distinctive higher harmonic generation and selective mode conversion phenomena are presented using the complex-valued Wave Damage Interaction Coefficients (WDICs) containing both amplitude and phase information of the scattered wave field. The effect of oblique incident angle on nonlinear scattering phenomenon is investigated. The rough crack surface feature with initial openings and closures is also considered to better approximate fatigue cracks in practical engineering scenarios. In addition, the wave amplitude effect on the nonlinear scattering and mode conversion is studied. This research may provide guidelines for the effective design of sensor arrays utilizing nonlinear Lamb waves for fatigue crack detection.

19.
Ultrasonics ; 74: 106-123, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27770666

RESUMEN

This article presents a parallel algorithm to model the nonlinear dynamic interactions between ultrasonic guided waves and fatigue cracks. The Local Interaction Simulation Approach (LISA) is further developed to capture the contact-impact clapping phenomena during the wave crack interactions based on the penalty method. Initial opening and closure distributions are considered to approximate the 3-D rough crack microscopic features. A Coulomb friction model is integrated to capture the stick-slip contact motions between the crack surfaces. The LISA procedure is parallelized via the Compute Unified Device Architecture (CUDA), which enables parallel computing on powerful graphic cards. The explicit contact formulation, the parallel algorithm, as well as the GPU-based implementation facilitate LISA's high computational efficiency over the conventional finite element method (FEM). This article starts with the theoretical formulation and numerical implementation of the proposed algorithm, followed by the solution behavior study and numerical verification against a commercial finite element code. Numerical case studies are conducted on Lamb wave interactions with fatigue cracks. Several nonlinear ultrasonic phenomena are addressed. The classical nonlinear higher harmonic and DC response are successfully captured. The nonlinear mode conversion at a through-thickness and a half-thickness fatigue crack is investigated. Threshold behaviors, induced by initial openings and closures of rough crack surfaces, are depicted by the proposed contact LISA model.

20.
World J Gastroenterol ; 23(22): 4080-4089, 2017 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-28652661

RESUMEN

AIM: To observe the effect of targeted therapy with 64-slice spiral computed tomography (CT) combined with cryoablation for liver cancer. METHODS: A total of 124 patients (142 tumors) were enrolled into this study. According to the use of dual-slice spiral CT or 64-slice spiral CT as a guide technology, patients were divided into two groups: dual-slice group (n = 56, 65 tumors) and 64-slice group (n = 8, 77 tumors). All patients were accepted and received targeted therapy by an argon-helium superconducting surgery system. The guided scan times of the two groups was recorded and compared. In the two groups, the lesion ice coverage in diameter of ≥ 3 cm and < 3 cm were recorded, and freezing effective rate was compared. Hepatic perfusion values [hepatic artery perfusion (HAP), portal vein perfusion (PVP), and the hepatic arterial perfusion index (HAPI)] of tumor tissues, adjacent tissues and normal liver tissues at preoperative and postoperative four weeks in the two groups were compared. Local tumor changes were recorded and efficiency was compared at four weeks post-operation. Adverse events were recorded and compared between the two groups, including fever, pain, frostbite, nausea, vomiting, pleural effusion and abdominal bleeding. RESULTS: Guided scan times in the dual-slice group was longer than that in the 64-slice group (t = 11.445, P = 0.000). The freezing effective rate for tumors < 3 cm in diameter in the dual-slice group (81.58%) was lower than that in the 64-slice group (92.86%) (χ2 = 5.707, P = 0.017). The HAP and HAPI of tumor tissues were lower at four weeks post-treatment than at pre-treatment in both groups (all P < 0.05), and those in the 64-slice group were lower than that in the dual-slice group (all P < 0.05). HAP and PVP were lower and HAPI was higher in tumor adjacent tissues at post-treatment than at pre-treatment (all P < 0.05). Furthermore, the treatment effect and therapeutic efficacy in the dual-slice group were lower than the 64-slice group at four weeks post-treatment (all P < 0.05). Moreover, pleural effusion and intraperitoneal hemorrhage occurred in patients in the dual-slice group, while no complications occurred in the 64-slice group (all P < 0.05). CONCLUSION: 64-slice spiral CT applied with cryoablation in targeted therapy for liver cancer can achieve a safe and effective freezing treatment, so it is worth being used.


Asunto(s)
Criocirugía , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/cirugía , Tomografía Computarizada Multidetector , Imagen de Perfusión/métodos , Adulto , Anciano , Criocirugía/efectos adversos , Femenino , Humanos , Circulación Hepática , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Valor Predictivo de las Pruebas , Resultado del Tratamiento , Carga Tumoral
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