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1.
Opt Express ; 31(22): 37275-37283, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-38017860

RESUMO

We propose a concept for generation of ultrashort pulses based on transient field-induced plasmonic resonance in nanoparticle composites. Photoionization and free-carrier plasma generation change the susceptibility of nanoparticles on a few-femtosecond scale under the action of the pump pulse. This opens a narrow time window when the system is in plasmonic resonance, which is accompanied by a short burst of the local field. During this process, frequency-tunable few-fs pulses can be emitted. This paves a way to ultra-compact yet efficient generation of ultrashort pulses at short wavelengths.

2.
Polymers (Basel) ; 15(15)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37571064

RESUMO

α-tricalcium (α-TCP) phosphate is widely used as an osteoinductive biocompatible material, serving as an alternative to synthetic porous bone materials. The objective of this study is to obtain a highly filled fibrous nonwoven material composed of poly-3-hydroxybutyrate (PHB) and α-TCP and to investigate the morphology, structure, and properties of the composite obtained by the electrospinning method (ES). The addition of α-TCP had a significant effect on the supramolecular structure of the material, allowing it to control the crystallinity of the material, which was accompanied by changes in mechanical properties, FTIR spectra, and XRD curves. The obtained results open the way to the creation of new osteoconductive materials with a controlled release of the source of calcium into the living organism.

3.
Insects ; 14(3)2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36975956

RESUMO

The ecological plasticity of aphid populations is determined by their clonal and morphotypic diversity. Clones will be successful when the development of their component morphotypes is optimized. The purpose of this work was to reveal the peculiarities of clonal composition and the developmental characteristics of different summer morphotypes for the rose-grass aphid, Metopolophium dirhodum (Walk.), which is an important host-alternating cereal pest and a useful model species. During the experiments, aphids were kept under ambient conditions on wheat seedlings at natural temperatures and humidity levels. An analysis of the reproduction of summer morphotypes and the resulting composition of offspring found that variation among the clones and morphotypes, as well as generational effects and an influence of sexual reproduction (and interactions between all factors) influenced the population structure of M. dirhodum. The reproduction of emigrants was less among the clones than that of the apterous or alate exules. The number of offspring produced by apterous exules differed throughout the growing season (generational effects) and between years, with different clones exhibiting different responses. There were dispersing aphids only among the offspring of apterous exules. These results can contribute to future advances in the forecasting and monitoring of aphid populations.

4.
Materials (Basel) ; 16(3)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36770182

RESUMO

This paper focuses on the microstructure, phase composition, mechanical, tribological and corrosion properties of high-entropy alloys (HEAs) in the CoCrCuFeNi system depending on copper content, which was varied from 0 to 20 at. % with an increment of 5%. CoCrCuFeNi alloys were manufactured by powder metallurgy methods: mechanical alloying and hot pressing of element mixtures. The solubility limit of copper in CoCrFeNi solid solution was found to be 9 at. %. Segregation of irregularly shaped copper grains sized 1-30 µm is observed at concentrations above this solubility limit. As copper concentration increases, the phase composition of CoCrCuFeNi alloys changes from the single phase based on FCC1 solid solution (Cu = 0-5 at. %) to the dual-phase FCC1 + FCC2 alloy (Cu = 10-20 at. %), where FCC1 is the main phase and FCC2 is the secondary copper-rich phase. Tribological tests have shown that doping the CoCrFeNi alloy with copper increased wear resistance by 23% due to solid solution hardening. As copper content rises above 20%, the content of the secondary FCC2 phase increases, while wear resistance and alloy hardness decline. An analysis of wear tracks and wear products has shown that abrasion of CoCrCuFeNi alloys occurs via the abrasive-oxidative wear mechanism. The corrosion tests of CoCrCuFeNi HEAs in 3.5% NaCl solution had demonstrated that doping the alloy with copper at low concentrations (5-10%) leads to decreasing of corrosion resistance, possibly due to the formation of undesirable oxide Cu2O along with protective Cr2O3. At high copper concentrations (15-20%) galvanic corrosion is suppressed due to coarsening of FCC2 grains and thus decreasing the specific contact surface area between the cathode (FCC2) and the anode (FCC1).

5.
Materials (Basel) ; 16(3)2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36770289

RESUMO

This paper focuses on the study of the structure and mechanical properties of CoCrCuxFeNi high-entropy alloys and their adhesion to single diamond crystals. CoCrCuxFeNi alloys were manufactured by the powder metallurgy route, specifically via mechanical alloying of elemental powders, followed by hot pressing. The addition of copper led to the formation of a dual-phase FCC + FCC2 structure. The CoCrCu0.5FeNi alloy exhibited the highest ultimate tensile strength (1080 MPa). Reductions in the ductility of the CoCrCuxFeNi HEAs and the tendency for brittle fracture behavior were observed at high copper concentrations. The equiatomic alloys CoCrFeNi and CoCrCuFeNi demonstrated high adhesion strength to single diamond crystals. The diamond surface at the fracture of the composites having the CoCrFeNi matrix had chromium-rich metal matrix regions, thus indicating that chromium carbide, responsible for adhesion, was formed at the composite-diamond interface. Copper-rich areas were detected on the diamond surface within the composites having the CoCrCuFeNi matrix due to the predominant precipitation of the FCC2 phase at the interfaces or the crack propagation along the FCC/FCC2 interface, resulting in the exposure of the Cu-rich FCC2 phase on the surface.

6.
Sensors (Basel) ; 22(8)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35459002

RESUMO

The manuscript presents an algorithm for the optimal estimation of the amplitude and propagation delay time of an ultra-wideband radio signal, in systems for the passive location of fixed targets based on the hybrid RSS/TDoA method in two-dimensional space with two base stations. The optimal estimate is based on the Bayesian strategy of maximum a posteriori probability density, taking into account a priori data on the statistical properties of the Line of Sight radio channel during Gaussian monocycle propagation. The Bayesian Cramer-Rao lower bound (BCRLB) of the delay time and the amplitude estimates for a time-discrete signal are calculated, and the resulting parameter estimate is compared with BCRLB. An algorithm has been developed for optimal estimation of distances from the radiation source to base stations, based on the results of the measurements of the amplitude and the propagation delay time of the UWB radio signal. The calculation of the statistical characteristics of the obtained estimate is carried out, and the functional dependence of the characteristics on various parameters is analyzed.

7.
Sensors (Basel) ; 22(3)2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35161504

RESUMO

The development of hyperspectral remote sensing equipment, in recent years, has provided plant protection professionals with a new mechanism for assessing the phytosanitary state of crops. Semantically rich data coming from hyperspectral sensors are a prerequisite for the timely and rational implementation of plant protection measures. This review presents modern advances in early plant disease detection based on hyperspectral remote sensing. The review identifies current gaps in the methodologies of experiments. A further direction for experimental methodological development is indicated. A comparative study of the existing results is performed and a systematic table of different plants' disease detection by hyperspectral remote sensing is presented, including important wave bands and sensor model information.


Assuntos
Imageamento Hiperespectral , Tecnologia de Sensoriamento Remoto , Produtos Agrícolas , Doenças das Plantas
8.
Nanomaterials (Basel) ; 11(11)2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34835676

RESUMO

Recent studies reveal that carbon nanostructures show anomalous piezoelectric properties when the central symmetry of their structure is violated. Particular focus is given to carbon nanotubes (CNTs) with initial significant curvature of the graphene sheet surface, which leads to an asymmetric redistribution of the electron density. This paper presents the results of studies on the piezoelectric properties of aligned multi-walled CNTs. An original technique for evaluating the effective piezoelectric coefficient of CNTs is presented. For the first time, in this study, we investigate the influence of the growth temperature and thickness of the catalytic Ni layer on the value of the piezoelectric coefficient of CNTs. We establish the relationship between the effective piezoelectric coefficient of CNTs and their defectiveness and diameter, which determines the curvature of the graphene sheet surface. The calculated values of the effective piezoelectric coefficient of CNTs are shown to be between 0.019 and 0.413 C/m2, depending on the degree of their defectiveness and diameter.

9.
ACS Omega ; 6(39): 25338-25349, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34632192

RESUMO

Substituted calcium phosphates (CaPs) are vital materials for the treatment of bone diseases and repairing and replacement of defects in human hard tissues. In this paper, we present some applications of the rarely used pulsed electron paramagnetic resonance (EPR) and hyperfine interaction spectroscopy approaches [namely, electron spin-echo envelope modulation (ESEEM) and electron-electron double-resonance detected nuclear magnetic resonance (EDNMR)] to investigate synthetic CaPs (hydroxyapatite, tricalcium, and octacalcium phosphate) doped with various cations (Li+, Na+, Mn2+, Cu2+, Fe3+, and Ba2+). These resonance techniques provide reliable tools to obtain unique information about the presence and localization of impurity centers and values of hyperfine and quadrupole tensors. We show that revealed in CaPs by EPR techniques, radiation-induced stable nitrogen-containing species and carbonate radicals can serve as sensitive paramagnetic probes to follow CaPs' structural changes caused by cation doping. The most pulsed EPR, ESEEM, and EDNMR spectra can be detected at room temperature, reducing the costs of the measurements and facilitating the usage of pulsed EPR techniques for CaP characterization.

10.
JNCI Cancer Spectr ; 5(4)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34377931

RESUMO

Background: Unbiased estimates of penetrance are challenging but critically important to make informed choices about strategies for risk management through increased surveillance and risk-reducing interventions. Methods: We studied the penetrance and clinical outcomes of 7 breast cancer susceptibility genes (BRCA1, BRCA2, TP53, CHEK2, ATM, PALB2, and PTEN) in almost 13 458 participants unselected for personal or family history of breast cancer. We identified 242 female participants with pathogenic or likely pathogenic variants in 1 of the 7 genes for penetrance analyses, and 147 women did not previously know their genetic results. Results: Out of the 147 women, 32 women were diagnosed with breast cancer at an average age of 52.8 years. Estimated penetrance by age 60 years ranged from 17.8% to 43.8%, depending on the gene. In clinical-impact analysis, 42.3% (95% confidence interval = 31.3% to 53.3%) of women had taken actions related to their genetic results, and 2 new breast cancer cases were identified within the first 12 months after genetic results disclosure. Conclusions: Our study provides population-based penetrance estimates for the understudied genes CHEK2, ATM, and PALB2 and highlights the importance of using unselected populations for penetrance studies. It also demonstrates the potential clinical impact of genetic testing to improve health care through early diagnosis and preventative screening.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Penetrância , Adulto , Proteínas Mutadas de Ataxia Telangiectasia/genética , Neoplasias da Mama/diagnóstico , Quinase do Ponto de Checagem 2/genética , Intervalos de Confiança , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Feminino , Genes BRCA1 , Genes BRCA2 , Genes p53 , Testes Genéticos , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , PTEN Fosfo-Hidrolase/genética
11.
ACS Omega ; 6(11): 7487-7498, 2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33778261

RESUMO

Octacalcium phosphate (OCP), a new-generation bone substitute material, is a considered precursor of the biological bone apatite. The two-layered structure of OCP contains the apatitic and hydrated layers and is intensively involved in ion-exchange surface reactions, which results in OCP hydrolysis to hydroxyapatite and adsorption of ions or molecular groups presented in the environment. During various in vitro procedures, such as biomaterial solubility, additive release studies, or the functionalization technique, several model solutions are applied. The composition of the environmental solution affects the degree and rate of OCP hydrolysis, its surface reactivity, and further in vitro and in vivo properties. The performed study was aimed to track the structural changes of OCP-based materials while treating in the most popular model solutions of pH values 7.2-7.4: simulated body fluid (SBF), Dulbecco's phosphate-buffered saline (DPBS), supersaturated calcification solution (SCS), normal saline (NS), and Dulbecco's modified Eagle's medium (DMEM). Various degrees of OCP hydrolysis and/or precipitate formation were achieved through soaking initial OCP granules in the model solutions. Detailed data of X-ray diffraction, Fourier-transform infrared spectroscopy, atomic emission spectrometry with inductively coupled plasma, and scanning electron microscopy are presented. Cultivation of osteosarcoma cells was implemented on OCP pre-treated in DMEM for 1-28 days. It was shown that NS mostly degraded the OCP structure. DPBS slightly changed the OCP structure during the first treatment term, and during further terms, the crystals got thinner and OCP hydrolysis took place. Treatment in SBF and SCS caused the precipitate formation along with OCP hydrolysis, with a larger contribution of SCS solution to precipitation. Pre-treating in DMEM enhanced the cytocompatibility of materials. As a result, on performing the in vitro procedures, careful selection of the contact solution should be made to avoid the changes in materials structure and properties and get adequate results.

12.
JAMIA Open ; 4(1): ooab014, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33709066

RESUMO

How clinicians utilize medically actionable genomic information, displayed in the electronic health record (EHR), in medical decision-making remains unknown. Participating sites of the Electronic Medical Records and Genomics (eMERGE) Network have invested resources into EHR integration efforts to enable the display of genetic testing data across heterogeneous EHR systems. To assess clinicians' engagement with unsolicited EHR-integrated genetic test results of eMERGE participants within a large tertiary care academic medical center, we analyzed automatically generated EHR access log data. We found that clinicians viewed only 1% of all the eMERGE genetic test results integrated in the EHR. Using a cluster analysis, we also identified different user traits associated with varying degrees of engagement with the EHR-integrated genomic data. These data contribute important empirical knowledge about clinicians limited and brief engagements with unsolicited EHR-integrated genetic test results of eMERGE participants. Appreciation for user-specific roles provide additional context for why certain users were more or less engaged with the unsolicited results. This study highlights opportunities to use EHR log data as a performance metric to more precisely inform ongoing EHR-integration efforts and decisions about the allocation of informatics resources in genomic research.

13.
Sensors (Basel) ; 20(20)2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33081275

RESUMO

A rigorous mathematical description of the signal reflected from a moving object for radar monitoring tasks using linear frequency modulated continuous wave (LFMCW) microwave radars is proposed. The mathematical model is based on the quasi-relativistic vector transformation of coordinates and Lorentz time. The spatio-temporal structure of the echo signal was obtained taking into account the transverse component of the radar target speed, which made it possible to expand the boundaries of the range of measuring the range and speed of vehicles using LFMCW radars. An algorithm for the simultaneous estimation of the range, radial and transverse components of the velocity vector of an object from the observation data of the time series during one frame of the probing signal is proposed. For an automobile 77 GHz microwave LFMCW radar, a computer experiment was carried out to measure the range and velocity vector of a radar target using the developed mathematical model of the echo signal and an algorithm for estimating the motion parameters. The boundaries of the range for measuring the range and speed of the target are determined. The results of the performed computer experiment are in good agreement with the results of theoretical analysis.

14.
Int J Bioprint ; 6(3): 275, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33088987

RESUMO

The aim of the study was the development of three-dimensional (3D) printed gene-activated implants based on octacalcium phosphate (OCP) and plasmid DNA encoding VEGFA. The first objective of the present work involved design and fabrication of gene-activated bone substitutes based on the OCP and plasmid DNA with VEGFA gene using 3D printing approach of ceramic constructs, providing the control of its architectonics compliance to the initial digital models. X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and compressive strength analyses were applied to investigate the chemical composition, microstructure, and mechanical properties of the experimental samples. The biodegradation rate and the efficacy of plasmid DNA delivery in vivo were assessed during standard tests with subcutaneous implantation to rodents in the next stage. The final part of the study involved substitution of segmental tibia and mandibular defects in adult pigs with 3D printed gene-activated implants. Biodegradation, osteointegration, and effectiveness of a reparative osteogenesis were evaluated with computerized tomography, SEM, and a histological examination. The combination of gene therapy and 3D printed implants manifested the significant clinical potential for effective bone regeneration in large/critical size defect cases.

15.
Sensors (Basel) ; 20(19)2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-32987836

RESUMO

Accurate remote determination of the object coordinates in 3D space is one of the main questions in many applications. In one of the most popular methods, such determination of the location of an object uses the measurement by receiving an electromagnetic signal transmitted by several spatially distributed base stations (BS). The main problem is that it is necessary to reduce errors and computation time. To overcome these difficulties, an analytical method for determining the position of an object based on the analysis of time difference of arrival (TDoA) of signals from the transmitter of the object to the receivers of the BS is proposed. One of the main advantages of this method is that it is possible to eliminate the ambiguity in determining the coordinates of the object in space and to increase the accuracy of determining the coordinates when the TDoA measurement between base stations fluctuates. Applications for autonomous automotive vehicles and spacebased positioning systems are analyzed. The results obtained show that the proposed algorithm has an accuracy of determining coordinates several times higher than the method of linearization of hyperbolic equations and is less sensitive to TDoA fluctuations at base stations.

16.
Sci Rep ; 10(1): 4013, 2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-32132636

RESUMO

The calcium phosphate particles can be used as building blocks for fabrication of 3D scaffolds intended for bone tissue engineering. This work presents for the first time a rapid creation of 3D scaffolds using magnetic levitation of calcium phosphate particles. Namely, tricalcium phosphate particles of equal size and certain porosity are used, which undergo the process of recrystallization after magnetic levitational assembly of the scaffold to ensure stitching of the scaffold. Label-free levitational assembly is achieved by using a custom-designed magnetic system in the presence of gadolinium salts, which allows the levitation of calcium phosphate particles. Chemical transformation of tricalcium- to octacalcium phosphate under the condition of magnetic levitation in non-homogeneous magnetic field is also demonstrated. This approach allows obtaining rapidly the octacalcium phosphate phase in the final 3D product, which is biocompatible.


Assuntos
Regeneração Óssea , Osso e Ossos/metabolismo , Fosfatos de Cálcio/química , Campos Magnéticos , Impressão Tridimensional , Alicerces Teciduais/química , Osso e Ossos/citologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Porosidade
17.
Front Genet ; 10: 1059, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31737042

RESUMO

Genomic knowledge is being translated into clinical care. To fully realize the value, it is critical to place credible information in the hands of clinicians in time to support clinical decision making. The electronic health record is an essential component of clinician workflow. Utilizing the electronic health record to present information to support the use of genomic medicine in clinical care to improve outcomes represents a tremendous opportunity. However, there are numerous barriers that prevent the effective use of the electronic health record for this purpose. The electronic health record working groups of the Electronic Medical Records and Genomics (eMERGE) Network and the Clinical Genome Resource (ClinGen) project, along with other groups, have been defining these barriers, to allow the development of solutions that can be tested using implementation pilots. In this paper, we present "lessons learned" from these efforts to inform future efforts leading to the development of effective and sustainable solutions that will support the realization of genomic medicine.

18.
Genet Med ; 21(9): 2135-2144, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30890783

RESUMO

PURPOSE: To provide a validated method to confidently identify exon-containing copy-number variants (CNVs), with a low false discovery rate (FDR), in targeted sequencing data from a clinical laboratory with particular focus on single-exon CNVs. METHODS: DNA sequence coverage data are normalized within each sample and subsequently exonic CNVs are identified in a batch of samples, when the target log2 ratio of the sample to the batch median exceeds defined thresholds. The quality of exonic CNV calls is assessed by C-scores (Z-like scores) using thresholds derived from gold standard samples and simulation studies. We integrate an ExonQC threshold to lower FDR and compare performance with alternate software (VisCap). RESULTS: Thirteen CNVs were used as a truth set to validate Atlas-CNV and compared with VisCap. We demonstrated FDR reduction in validation, simulation, and 10,926 eMERGESeq samples without sensitivity loss. Sixty-four multiexon and 29 single-exon CNVs with high C-scores were assessed by Multiplex Ligation-dependent Probe Amplification (MLPA). CONCLUSION: Atlas-CNV is validated as a method to identify exonic CNVs in targeted sequencing data generated in the clinical laboratory. The ExonQC and C-score assignment can reduce FDR (identification of targets with high variance) and improve calling accuracy of single-exon CNVs respectively. We propose guidelines and criteria to identify high confidence single-exon CNVs.


Assuntos
Variações do Número de Cópias de DNA/genética , Éxons/genética , Genoma Humano/genética , Software , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Análise de Sequência de DNA
19.
Sci Rep ; 8(1): 6478, 2018 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-29691459

RESUMO

We study the penetration of ultra-intense (intensity I [Formula: see text] 1023-24 W/cm2) circularly polarized laser pulses into a thick subcritical plasma layer with accounting for radiation friction. We show that radiation pressure is enhanced due to radiation friction in the direction transverse to the laser pulse propagation, and that for stronger and longer laser pulses this mechanism dominates over the ordinary ponderomotive pressure, thus resulting in a substantionaly stronger charge separation than anticipated previously. We give estimates of the effect and compare them with the results of one and two dimensional particle-in-cell simulations. This effect can be important for laser-based acceleration schemes.

20.
J Pers Med ; 8(1)2018 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-29301385

RESUMO

We examined the Institutional Review Board (IRB) process at 9 academic institutions in the electronic Medical Records and Genomics (eMERGE) Network, for proposed electronic health record-based genomic medicine studies, to identify common questions and concerns. Sequencing of 109 disease related genes and genotyping of 14 actionable variants is being performed in ~28,100 participants from the 9 sites. Pathogenic/likely pathogenic variants in actionable genes are being returned to study participants. We examined each site's research protocols, informed-consent materials, and interactions with IRB staff. Research staff at each site completed questionnaires regarding their IRB interactions. The time to prepare protocols for IRB submission, number of revisions and time to approval ranged from 10-261 days, 0-11, and 11-90 days, respectively. IRB recommendations related to the readability of informed consent materials, specifying the full range of potential risks, providing options for receiving limited results or withdrawal, sharing of information with family members, and establishing the mechanisms to answer participant questions. IRBs reviewing studies that involve the return of results from genomic sequencing have a diverse array of concerns, and anticipating these concerns can help investigators to more effectively engage IRBs.

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