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1.
Electrophoresis ; 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31943244

RESUMO

We study herein numerically the use of induced-charge electrokinetic phenomena to enable a flexible control of ion transport of dilute electrolyte in a straight ion concentration polarization system. The effect of three convection modes of induced-charge electrokinetic phenomena, including induced-charge electroosmosis, flow-field effect transistor, and alternating-current electroosmosis (ACEO), on convective arrestment of diffusive wave-front propagation is investigated by developing a cross-scale and fully coupled transient numerical simulation model, wherein multiple frequency electrochemical polarization and nonlinear diffuse charge dynamics in spatiotemporally varying solution conductivity are taken into account. We demonstrate by detailed comparative simulation studies that ACEO vortex flow field above a metal strip array arranged along the anodic chamber's bottom surface serves as the most efficient way for adjusting the salt density distribution at micrometer and even millimeter dimension, due to its high flexibility in controlling the stirring flow state with the introduction of two extra electrical parameters. The specific operating status is determined by whether the electrode array is floating in potential (induced-charge electroosmosis) or biased to ground (flow-field effect transistor) or forced to oscillate at another Fourier mode (ACEO). These results prove useful for on-chip electric current control with electroconvective stirring.

2.
Anal Chem ; 92(3): 2468-2475, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31782306

RESUMO

Effective characterization and imaging of endogenous RNA transcripts have important value in the diagnosis, treatment, and prognosis of diseases. Traditional qRT-PCR as a liquid-based RNA detection method might lead to false-negative results due to the admixture of too many nontarget cells. Also, many in situ RNA imaging methods were hindered by long turnaround time and insufficient signals. Here, we describe and evaluate a CRISPR/dCas9-MS2-based RNA fluorescence in situ hybridization assay (RCasFISH) for in situ amplified imaging and quantification of RNA transcripts in fixed cells as well as formalin-fixed, paraffin-embedded (FFPE) tissue sections at a single-molecular level in individual cells. Compared to single molecular FISH (smFISH), RCasFISH yields brighter dot signals and a better signal-to-noise ratio (SNR) with lower costs and less than 1.5 h of hybridization. In addition, by using human epidermal growth factor receptor 2 (HER2) as a model, we quantified individual HER2 mRNA molecules in clinical breast cancer FFPE tissue sections and demonstrated its potential to resolve FISH-equivocal cases. Therefore, RCasFISH may provide a new approach for gene expression studies in basic research and hold the potential for molecular diagnostic applications.

3.
Exp Hematol ; 81: 42-49.e3, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31863797

RESUMO

For patients with chronic myeloid leukemia, reverse transcription quantitative polymerase chain reaction is widely used in laboratories to quantify BCR-ABL1 fusion gene transcripts for disease management. Many efforts have been made to standardize the BCR-ABL1 testing assay, including the primary and secondary reference reagents, but the secondary standards have not been developed and used in the standardization program in China. With the use of armored RNA technology, armored RNA of BCR-ABL1 and control genes was manufactured to prepare the secondary reference material anchored to the World Health Organization primary reference calibrators for standardization of BCR-ABL1 testing assays. The secondary reference was sent to 30 laboratories in China for validation. Data from an external quality assessment after the standardization process were collected and analyzed as well. The assigned %BCR-ABL1/ABL1IS values of the four levels of the secondary material panels were 0.0118, 0.1345, 1.3808, and 19.4266, respectively. In validation trials, 70.0% (21/30) of laboratories obtained valid conversion factors for the BCR-ABL1 assay. All valid conversion factors from 11 international scale laboratories were equivalent to their respective previous values. External quality assessment data indicated that the accuracy and precision between laboratories were improved. Moreover, the quantity of the panels is abundant to be used as quality control samples for monitoring the shift of data. In this study, we established a secondary genetic reference panel for BCR-ABL1 quantification. This study will play a role in facilitating the worldwide dissemination of the international scale, especially in promoting the standardization of molecular monitoring in China.

4.
Adv Sci (Weinh) ; 6(19): 1900775, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31592413

RESUMO

Solution-processed 2D organic semiconductors (OSCs) have drawn considerable attention because of their novel applications from flexible optoelectronics to biosensors. However, obtaining well-oriented sheets of 2D organic materials with low defect density still poses a challenge. Here, a highly crystallized 2,9-didecyldinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (C10-DNTT) monolayer crystal with large-area uniformity is obtained by an ultraslow shearing (USS) method and its growth pattern shows a kinetic Wulff's construction supported by theoretical calculations of surface energies. The resulting seamless and highly crystalline monolayers are then used as templates for thermally depositing another C10-DNTT ultrathin top-up film. The organic thin films deposited by this hybrid approach show an interesting coherence structure with a copied molecular orientation of the templating crystal. The organic field-effect transistors developed by these hybrid C10-DNTT films exhibit improved carrier mobility of 14.7 cm2 V-1 s-1 as compared with 7.3 cm2 V-1 s-1 achieved by pure thermal evaporation (100% improvement) and 2.8 cm2 V-1 s-1 achieved by solution sheared monolayer C10-DNTT. This work establishes a simple yet effective approach for fabricating high-performance and low-cost electronics on a large scale.

5.
ACS Appl Mater Interfaces ; 11(36): 33231-33237, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31436953

RESUMO

Auxetic materials, known with negative Poisson's ratio, are highly desirable for many advanced applications, but the candidates are rather scarce, especially at low dimension. Motivated by the re-entrant structure that often exposes negative Poisson's ratio, we predict a two-dimensional (2D) planar B4N monolayer as a promising auxetic material with unusual in-plane negative Poisson's ratio within the framework of density functional theory calculations. B4N monolayer also exhibits a highly emerged mechanical anisotropy, characterized by Young's modulus and Poisson's ratio. In addition, this monolayer shows superior mechanical flexibility in ideal tensile strength and critical strain values. The phonon dispersion calculations and ab initio molecular dynamics simulations further demonstrate that this monolayer also owns excellent dynamical and thermal stabilities. The fantastic mechanical properties coupled with robust structural stability render the auxetic B4N monolayer promising for future nanomechanical devices.

6.
Ann Hematol ; 98(10): 2347-2355, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31446458

RESUMO

Molecular measurable residual disease (MRD) monitoring based on real-time quantitative reverse transcription PCR (RT-qPCR) plays an important role in acute promyelocytic leukemia (APL) management, but the performance status of clinical reports is unknown. This study focuses on the specific elements in molecular MRD monitoring report and their impact on clinical decision-making. The participating laboratories were asked to submit real and formal clinical reports for mock samples panel with APL clinical case. The MRD-specific elements were analyzed and summarized. The significance of longitudinal MRD monitoring curve and the missing MRD-specific elements for clinical decision-making were assessed. MRD-specific elements were significantly missing in clinical reports. The element "testing results" existed great inconsistencies in the written form of testing items and data. The longitudinal MRD monitoring curve of false-negative or false-positive MRD result was obviously different from all-correct. It not only identified MRD time point of tissue sampling relative to treatment and ensured the reliability of the negative MRD results, but also gave MRD diagnosis, clinical interpretation, and further recommendation. Clinician-friendly reports with MRD-specific elements can better serve clinical practice. The correctly intuitive results and clinically important MRD-specific elements can provide a good description of the reliability and clinical significance of MRD results.


Assuntos
Registros Eletrônicos de Saúde , Leucemia Promielocítica Aguda , Reação em Cadeia da Polimerase em Tempo Real/métodos , Humanos , Leucemia Promielocítica Aguda/sangue , Leucemia Promielocítica Aguda/genética , Monitorização Fisiológica/métodos , Neoplasia Residual
7.
J Phys Chem Lett ; 10(13): 3773-3778, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31244267

RESUMO

It remains a pressing task to search for new two-dimensional (2D) semiconducting materials for future-generation electronic applications. By using density functional theory computations and global structure prediction methods, we demonstrate two new gold sulfide monolayers (2D Au2S and AuS), both exhibiting excellent electronic properties and high stabilities. All the gold sulfide monolayers are semiconductors with band gaps in the range 1.0-3.6 eV. In particular, the α-Au2S monolayer is predicted to possess a direct band gap of 1.0 eV and extremely high electron and hole mobilities of 8.45 × 104 and 0.40 × 104 cm2 V-1 S-1, respectively. The phonon dispersion calculations and ab initio molecular dynamics simulations indicate that the gold sulfide monolayers exhibit robust dynamical and thermal stabilities. Moreover, the α-Au2S monolayer appears to show strong oxidation resistibility. The novel electronic properties, coupled with structural and chemical stabilities, endow the new gold sulfide monolayers to be highly promising for future applications in nanoelectronics.

8.
J Clin Lab Anal ; 33(6): e22894, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31131502

RESUMO

BACKGROUND: The confirmation of clinical diagnosis, molecular remission, and sequential minimal residual disease monitoring required PML-RARα detection in acute promyelocytic leukemia (APL). The current status of PML-RARα detection in various laboratories remains unknown. METHODS: In 2018, external quality assessment (EQA) for PML-RARα detection was carried out in China. Three EQA sample panels for PML-RARα isoform L/S/V were prepared by different mock leukocyte samples. The performances of PML-RARα detection, including admission screening, and qualitative and quantitative detection by real-time quantitative reverse transcription PCR (RT-qPCR), were assessed based on APL simulated clinical case. RESULTS: The mock leukocyte samples met the requirements of a clinically qualified sample for PML-RARα EQA panel. Among the laboratories, 13/50 (26.0%) were "competent," 21/50 (42%) classified as "acceptable," and 16/50 (32.0%) classified as "improvable." One (1/50, 2.0%) laboratory reported one screening mistake. Twenty-six (26/50, 52.0%) laboratories reported 29 false-positive and 19 false-negative results. Twenty-three (23/50, 46.0%) laboratories reported 42 quantitative incorrect results. CONCLUSION: Significant differences were not found in PML-RARα detection performance among laboratories that used different extraction methods. The performances of qualitative and quantitative RT-qPCR detection were worse accurate for PML-RARα isoform V. Quantitative variation was higher for low-level samples. Further continuous external assessment and education are needed in the management of PML-RARα detection.


Assuntos
Técnicas de Laboratório Clínico/normas , Leucemia Promielocítica Aguda/genética , Proteínas de Fusão Oncogênica/genética , Reação em Cadeia da Polimerase em Tempo Real/normas , China , Humanos , Leucócitos/fisiologia , Proteínas de Fusão Oncogênica/sangue , Isoformas de Proteínas/genética , Controle de Qualidade , RNA Ribossômico 23S
9.
Electrophoresis ; 40(20): 2683-2698, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30883820

RESUMO

The phenomenon of electrothermal (ET) convection has recently captured great attention for transporting fluidic samples in microchannels embedding simple electrode structures. In the classical model of ET-induced flow, a conductivity gradient of buffer medium is supposed to arise from temperature-dependent electrophoretic mobility of ionic species under uniform salt concentrations, so it may not work well in the presence of evident concentration perturbation within the background electrolyte. To solve this problem, we develop herein a microscopic physical description of ET streaming by fully coupling a set of Poisson-Nernst-Planck-Navier-Stokes equations and temperature-dependent fluid physicochemical properties. A comparative study on a standard electrokinetic micropump exploiting asymmetric electrode arrays indicates that, our microscopic model always predicts a lower ET pump flow rate than the classical macroscopic model even with trivial temperature elevation in the liquid. Considering a continuity of total current density in liquids of inhomogeneous polarizability, a moderate degree of fluctuation in ion concentrations on top of the electrode array is enough to exert a significant influence on the induction of free ionic charges, rendering the enhanced numerical treatment much closer to realistic experimental measurement. Then, by placing a pair of thin-film resistive heaters on the bottom of an anodic channel interfacing a cation-exchange medium, we further provide a vivid demonstration of the enhanced model's feasibility in accurately resolving the combined Coulomb force due to the coexistence of an extended space charge layer and smeared interfacial polarizations in an externally-imposed temperature gradient, while this is impossible with conventional linear approximation. This leads to a reliable method to achieve a flexible regulation on spatial-temporal evolution of ion-depletion layer by electroconvective mixing. These results provide useful insights into ET-based flexible control of micro/nanoscale solid entities in modern micro-total-analytical systems.

10.
Nanoscale ; 11(10): 4204-4209, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30806404

RESUMO

Recent experimentally demonstrated intrinsic two-dimensional (2D) magnetism has sparked intense interest for advanced spintronic applications. However, the rather low Curie temperature and small magnetic anisotropic energy (MAE) greatly limit their application scope. Here, by using density functional theory calculations, we predict a series of stable 2D MnX (X = P, As, Sb) monolayers, among which MnP and MnAs monolayers exhibit intrinsic ferromagnetic (FM) ordering and considerably large MAEs of 166 and 281 µeV per Mn atom, respectively. More interestingly, the 2D MnP and MnAs monolayers exhibit highly desired half-metallicity with wide spin gaps of about 3 eV. Monte Carlo simulations suggest markedly high Curie temperatures of MnP and MnAs monolayers, ∼495 K and 711 K, respectively. Besides, these monolayers are the lowest energy structures in the 2D search space with excellent dynamic and thermal stabilities. A viable experimental synthesis route is also proposed to produce MnX monolayers via the selective chemical etching method. The outstanding attributes of MnP and MnAs monolayers would substantially broaden the applicability of 2D magnetism for a wide range of applications.

11.
Electrophoresis ; 40(6): 979-992, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30256428

RESUMO

Induced-charge electroosmosis (ICEO) has attracted tremendous popularity for driving fluid motion from the microfluidic community since the last decade, while less attention has been paid to ICEO-based nanoparticle manipulation. We propose herein a unique concept of hybrid electroosmotic kinetics (HEK) in terms of bi-phase ICEO (BICEO) actuated in a four-terminal spiral electrode array, for effective electrokinetic enrichment of fluorescent polystyrene nanoparticles on ideally polarizable metal strips. First, by alternating the applied AC voltage waves between consecutive discrete terminals, the flow stagnation lines where the sample nanoparticles aggregate can be switched in time between two different distribution modes. Second, we innovatively introduce the idea of AC field-effect flow control on BICEO; by altering the combination of gating voltage sequence, not only the number of circulative particle trapping lines is doubled, but the collecting locations can be flexibly reconfigured as well. Third, hydrodynamic streaming of DC-biased BICEO is tested in our device design, wherein the global linear electroosmosis dominates BICEO contributed from both AC and DC components, resulting in a reduction of particle enrichment area, while with a sharp increase in sample transport speed inside the bulk phase. The flow field associated with HEK is predicted using a linear asymptotic analysis under Debye-Huckel limit, with the simulation results in qualitative agreement with in-lab observations of nanoparticle trapping by exploiting a series of improved ICEO techniques. This work provides an affordable and field-deployable platform for real-time nanoparticle trapping in the context of dilute electrolyte.


Assuntos
Eletro-Osmose/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Nanopartículas/química , Eletricidade , Eletro-Osmose/métodos , Desenho de Equipamento , Cinética , Microeletrodos
12.
Int J Lab Hematol ; 41(1): 46-54, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30203581

RESUMO

INTRODUCTION: External quality assessment (EQA) is an essential tool for quality assurance of analytical testing processes of p210 BCR-ABL1 transcripts by RT-qPCR. As an EQA provider, the National Center for Clinical Laboratories organized an EQA scheme of p210 BCR-ABL1 testing in China for the first time to identify existing problems and ensure the reliability of p210 BCR-ABL1 testing. METHODS: Using armored RNA technology, we first constructed pACYC-MS2-p210 and CG recombinant plasmids and expressed p210 and CG armored RNAs, with packaging segments of p210 BCR-ABL1 fusion gene (FG) and four common control gene (CG) transcripts. Using these armored RNAs, we prepared lyophilized p210 quality control (QC) sample panels and evaluated detection performance of participating laboratories in China. RESULTS: Of the 66 participating laboratories, great variation was found with coefficient of variation (CV%) of raw p210 BCR-ABL1 results basically ranging from 60.0% to 100.0%. In 24 International Scale (IS) laboratories, the CV% of results decreased from 82.4% to 61.6%, and the percentage of laboratories within 2-, 3-, and 5-fold of the median values increased from 78.2%, 87.0%, and 92.1% to 80.1%, 89.4%, and 97.2%, respectively, after conversion with a laboratory-specific conversion factor (CF); however, poorly converted results were also observed in laboratories resulting from changed components of RT-qPCR procedures. False-negative and false-positive results were also found in the EQA. CONCLUSIONS: Various problems were found for p210 BCR-ABL1 detection in the EQA. By solving the existing problems, the performance of p210 BCR-ABL1 detection can be improved, ensuring robust laboratory diagnostic capacities in China.


Assuntos
Proteínas de Fusão bcr-abl/genética , Controle de Qualidade , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Humanos , Reação em Cadeia da Polimerase em Tempo Real
13.
Micromachines (Basel) ; 9(3)2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30424036

RESUMO

Induced-charge electroosmosis has attracted lots of attention from the microfluidic community over the past decade. Most previous researches on this subject focused on induced-charge electroosmosis (ICEO) vortex streaming actuated on ideally polarizable surfaces immersed in electrolyte solutions. Starting from this point, we conduct herein a linear asymptotic analysis on nonlinear electroosmotic flow next to leaky dielectric blocks of arbitrary electrical conductivity and dielectric permittivity in harmonic AC electric fields, and theoretically demonstrate that observable ICEO fluid motion can be generated at high field frequencies in the vicinity of nearly insulating semiconductors, a very low electrical conductivity, of which can evidently increase the double-layer relaxation frequency (inversely proportional to the solid permittivity) to be much higher than the typical reciprocal RC time constant for induced double-layer charging on ideally polarizable surfaces. A computational model is developed to study the feasibility of this high-frequency vortex flow field of ICEO for sample mixing in microfluidics, in which the usage of AC voltage signal at high field frequencies may be beneficial to suppress electrochemical reactions to some extent. The influence of various parameters for developing an efficient mixer is investigated, and an integrated arrangement of semiconductor block array is suggested for achieving a reliable mixing performance at relatively high sample fluxes. Our physical demonstration with high-frequency ICEO next to leaky dielectric blocks using a simple channel structure offers valuable insights into the design of high-throughput micromixers for a variety of lab-on-a-chip applications.

14.
Micromachines (Basel) ; 9(4)2018 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-30424112

RESUMO

We introduce herein the induced-charge electrokinetic phenomenon to nanometer fluidic systems; the design of the nanofluidic ion diode for field-effect ionic current control of the nanometer dimension is developed by enhancing internal ion concentration polarization through electrochemical transport of inhomogeneous inducing-counterions resulting from double gate terminals mounted on top of a thin dielectric layer, which covers the nanochannel connected to microfluidic reservoirs on both sides. A mathematical model based on the fully-coupled Poisson-Nernst-Plank-Navier-Stokes equations is developed to study the feasibility of this structural configuration causing effective ionic current rectification. The effect of various physiochemical and geometrical parameters, such as the native surface charge density on the nanochannel sidewalls, the number of gate electrodes (GE), the gate voltage magnitude, and the solution conductivity, permittivity, and thickness of the dielectric coating, as well as the size and position of the GE pair of opposite gate polarity, on the resulted rectification performance of the presented nanoscale ionic device is numerically analyzed by using a commercial software package, COMSOL Multiphysics (version 5.2). Three types of electrohydrodynamic flow, including electroosmosis of 1st kind, induced-charge electroosmosis, and electroosmosis of 2nd kind that were originated by the Coulomb force within three distinct charge layers coexist in the micro/nanofluidic hybrid network and are shown to simultaneously influence the output current flux in a complex manner. The rectification factor of a contrast between the 'on' and 'off' working states can even exceed one thousand-fold in the case of choosing a suitable combination of several key parameters. Our demonstration of field-effect-tunable nanofluidic ion diodes of double external gate electrodes proves invaluable for the construction of a flexible electrokinetic platform for ionic current control and may help transform the field of smart, on-chip, integrated circuits.

15.
Micromachines (Basel) ; 9(2)2018 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-30393361

RESUMO

We present herein a novel method of bipolar field-effect control on DC electroosmosis (DCEO) from a physical point of view, in the context of an intelligent and robust operation tool for stratified laminar streams in microscale systems. In this unique design of the DC flow field-effect-transistor (DC-FFET), a pair of face-to-face external gate terminals are imposed with opposite gate-voltage polarities. Diffuse-charge dynamics induces heteropolar Debye screening charge within the diffuse double layer adjacent to the face-to-face oppositely-polarized gates, respectively. A background electric field is applied across the source-drain terminal and forces the face-to-face counterionic charge of reversed polarities into induced-charge electroosmotic (ICEO) vortex flow in the lateral direction. The chaotic turbulence of the transverse ICEO whirlpool interacts actively with the conventional plug flow of DCEO, giving rise to twisted streamlines for simultaneous DCEO pumping and ICEO mixing of fluid samples along the channel length direction. A mathematical model in thin-layer approximation and the low-voltage limit is subsequently established to test the feasibility of the bipolar DC-FFET configuration in electrokinetic manipulation of fluids at the micrometer dimension. According to our simulation analysis, an integrated device design with two sets of side-by-side, but upside-down gate electrode pair exhibits outstanding performance in electroconvective pumping and mixing even without any externally-applied pressure difference. Moreover, a paradigm of a microdevice for fully electrokinetics-driven analyte treatment is established with an array of reversed bipolar gate-terminal pairs arranged on top of the dielectric membrane along the channel length direction, from which we can obtain almost a perfect liquid mixture by using a smaller magnitude of gate voltages for causing less detrimental effects at a small Dukhin number. Sustained by theoretical analysis, our physical demonstration on bipolar field-effect flow control for the microfluidic device of dual functionalities in simultaneous electroconvective pumping and mixing holds great potential in the development of fully-automated liquid-phase actuators in modern microfluidic systems.

16.
ACS Appl Mater Interfaces ; 10(41): 35395-35403, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30234961

RESUMO

Crystals of organic semiconductors are excellent candidates for flexible and array-based electronics. Large-scale synthesis of organic crystals in a controllable way while maintaining homogeneous single-crystal property has been a great challenge. The existence of grain boundaries and small crystal domains, however, restrict the device performance and limit the access to commercially viable organic electronics in the industry. Herein, we report the inch-scale synthesis of highly oriented 2,7-dioctyl[1]benzothieno[3,2- b][1]benzothiophene (C8-BTBT) organic single crystal by nucleation seed-controlled shearing method. The organic field-effect transistors developed from such single crystal have excellent carrier mobility as high as 14.9 cm2 V-1 s-1 and uniformity (standard deviation is 1.3 cm2 V-1 s-1) of 225 devices. We also found that the rotation of the principal axis in the crystal is governed by the orientations of seeds and the possible mechanism behind this phenomenon is proposed based on the density functional theory calculations. We anticipate that this proposed approach will have great potential to be developed as a platform for the growth of organic crystals with high crystallinity on a large scale.

17.
J Phys Chem Lett ; 9(15): 4260-4266, 2018 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-30001619

RESUMO

Two-dimensional (2D) ferromagnetic materials with intrinsic half-metallicity are highly desirable for nanoscale spintronic applications. Here, we predict a new and stable family of 2D transition-metal dihydride (MH2; M = Sc, Ti, V, Cr, Fe, Co, Ni) monolayers with novel properties. Our density functional theory computation shows that CoH2 and ScH2 monolayers are ferromagnetic metals, while the others are antiferromagnetic semiconductors. In particular, the CoH2 monolayer is a perfect half-metal with a wide spin gap of 3.48 eV. The ScH2 monolayer can also possess half-metallicity through hole doping. Most importantly, our Monte Carlo simulations show that the CoH2 monolayer possesses an above-room-temperature Curie point (339 K), while that of the ScH2 monolayer can also reach 160 K. A synthetic approach is proposed to realize CoH2 and ScH2 monolayers in the laboratory. Notably, their half-metallicity can be well maintained on substrates. The new family of MH2 monolayers are promising functional materials for spintronic applications due to their novel magnetic properties.

18.
J Clin Lab Anal ; 32(9): e22612, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29959790

RESUMO

BACKGROUND: Standards play an important role in detection of the BCR-ABL1 fusion gene (FG) transcript. However, the standards widely used in laboratories are mainly based on plasmids or cDNA, which cannot accurately reflect the process of RNA extraction and cDNA synthesis. Therefore, we aimed to develop armored RNA-based standards for p210 and p190 BCR-ABL1FG transcripts' quantification. METHODS: Using overlapping polymerase chain reaction (PCR) technology, we first linked a segment of the p210 or p190 BCR-ABL1FG transcript with four control genes (CGs; ABL1, BCR, GUSB, and B2M) to form p210FG-CG and p190FG-CG. Subsequently, using armored RNA technology, we prepared p210FG-CG- and p190FG-CG-armored RNAs and the p210FG-CG and p190FG-CG standards, the values of which were assigned by digital PCR (dPCR). RESULTS: The p210FG-CG and p190FG-CG standards were stable and homogeneous, and were significantly linear with r2  > 0.98. A field trial including 52 laboratories across China showed that the coefficient of variation (CV%) of BCR-ABL1 values among samples was in the range of 58.6%-129.6% for p210 samples and 73.2%-194.0% for p190 samples when using local standards. By contrast, when using the p210FG-CG and p190FG-CG standards, the CV% of BCR-ABL1 values was decreased to 35.6%-124.9% and 36.6%-170.6% for p210 and p190 samples, respectively. In addition, 33.3% (3/9) of the p210 and p190 samples had CV% values <50.0%, whereas 44.4% (4/9) and 77.8% (7/9) of the samples had lower CV% values when using the p210FG-CG and p190FG-CG standards. CONCLUSION: The overall variability of detection of BCR-ABL1 transcripts decreased significantly when using the p210FG-CG or p190FG-CG standards, especially the p190FG-CG standard.


Assuntos
Proteínas de Fusão bcr-abl/análise , Proteínas de Fusão bcr-abl/genética , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/análise , Humanos , Distribuição Normal , RNA/análise , Valores de Referência
19.
Sensors (Basel) ; 18(5)2018 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-29758000

RESUMO

In spatial spectrum estimation, difference co-array can provide extra degrees-of-freedom (DOFs) for promoting parameter identifiability and parameter estimation accuracy. For the sake of acquiring as more DOFs as possible with a given number of physical sensors, we herein design a novel sensor array geometry named cascade array. This structure is generated by systematically connecting a uniform linear array (ULA) and a non-uniform linear array, and can provide more DOFs than some exist array structures but less than the upper-bound indicated by minimum redundant array (MRA). We further apply this cascade array into multiple input multiple output (MIMO) array systems, and propose a novel joint direction of departure (DOD) and direction of arrival (DOA) estimation algorithm, which is based on a reduced-dimensional weighted subspace fitting technique. The algorithm is angle auto-paired and computationally efficient. Theoretical analysis and numerical simulations prove the advantages and effectiveness of the proposed array structure and the related algorithm.

20.
ACS Appl Mater Interfaces ; 10(19): 16739-16746, 2018 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-29687988

RESUMO

Aurophilicity, known as aurophilic interaction, is a strong attractive van der Waals interaction between cationic gold(I) centers, whose strength is comparable to the hydrogen bond. Here, we show that aurophilicity can serve as an engineering approach to expand the structural dimensionality for nanomaterials design. Specifically, based on a global-structure search method and density functional theory calculations, we predict a series of stable two-dimensional (2D) AuMX2 (M = Al, Ga, In; X = S, Se) structures featuring intracrystalline aurophilic interactions. All the AuMX2 monolayers designed are semiconductors with moderate band gaps, excellent carrier mobilities, and good optical properties. The intriguing chemistry of aurophilicity coupled with novel electronic properties render AuMX2 monolayers a potentially new series of 2D materials that are of fundamental importance in gold chemistry and of technological importance for nanoelectronics.

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