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1.
J Hazard Mater ; 418: 126244, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34098263

RESUMO

Simultaneously capturing organic pollutants and heavy metal can greatly reduce the water remediation time and cost, however it is still a great challenge presently. Herein, two novel thiol/methylthio-functionalized porous aromatic frameworks were synthesized as sorbents via the Sonogashira-Hagihara reaction of 1,3,5-triethynylbenzene and 1,3,5-tris(4-bromophenyl) benzene, the subsequent chloromethylation of the phenyl rings, and the final nucleophile substitution of -Cl groups by NaSH/NaSMe. These two sorbents were characterized by FT-IR spectra, energy dispersive X-ray spectra, scanning electron microscope, nitrogen adsorption analysis, thermo-gravimetric analysis, and elemental analyses. Adsorption experiments displayed that new sorbents had high uptake abilities and fast adsorption kinetics for aromatic pollutants and mercury (II) (Hg(II)). The maximum adsorption capacity (Qmax) of toluene and m-xylene on both new sorbents were 531.9-571.4 mg/g with the kinetic binding rate constants (kobs) of 0.00276-0.02422 g/mg/min, and the Qmax values of Hg(II) were 148.1-180.3 mg/g with kobs of 0.00592-0.01573 g/mg/min. Moreover, new sorbents indicated high simultaneous uptake abilities for these pollutants with good reusability, and finally they were successfully applied to the simultaneous remediation of these pollutants in two simulated sewages with high and low concentration, indicating their great practical application potential in wastewater remediation.

2.
ACS Nano ; 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33881844

RESUMO

van der Waals crystals exhibit excellent material performance when exfoliated to few-atomic-layer thickness. In contrast, the van der Waals thin films more than 10 nm thick are believed to show bulk properties, in which outstanding material performance is rarely found. Here we report the largest anomalous Hall conductivity observed so far in a 170 nm van der Waals ferromagnetic 1T-CrTe2 flake, which reaches 67,000 Ω-1 cm-1. Such a colossal anomalous Hall conductivity in 1T-CrTe2 is dominated by the extrinsic skew scattering process rather than the intrinsic Berry phase effect, as evidenced by the linear relation between the anomalous Hall conductivity and the longitudinal conductivity. Defying the dilemma of mutually exclusive large anomalous Hall angle and high electric conductivity for most ferromagnets, 1T-CrTe2 achieves both in a thin film sample. Considering the shared physics of the anomalous Hall effect and the spin Hall effect, our finding offers a guideline for searching large spin Hall materials of high conductivity which may overcome the bottleneck of overheating in spintronics devices.

3.
Nanoscale Horiz ; 6(6): 462-467, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33908543

RESUMO

All-optical switching of magnetic materials is a potential method for realizing high-efficiency and high-speed data writing in spintronics devices. The current method, which utilizes two circular helicities of light to manipulate magnetic domains, is based on femtosecond pulsed lasers. In this study, we demonstrate a new all-optical switching method using a continuous-wave Laguerre-Gaussian beam (twisted light), which allows photons to carry orbital angular momentum with discrete levels, lℏ, to modify the magnetic anisotropy of an interlayer exchange coupling system. The easy axis of the heterojunction Pt(5 nm)/Co(1.2 nm)/Ru(1.4 nm)/Co(0.4 nm)/Pt(5 nm) on a SiO2/Si substrate dramatically changed after illuminating it with a laser beam carrying a sufficient quantum number of orbital angular momentum. Based on a simple numerical calculation, we deduced that the interaction between the dynamical phase rotation of the electric field and the metal surface could generate an in-plane circular current loop that consequently induces a perpendicular stray field to change the magnetic anisotropy. This finding paves the way for developments in the field of magnetic-based spintronics using light with orbital angular momentum.

4.
Adv Mater ; 33(12): e2006924, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33599001

RESUMO

Magnetic skyrmions, topological-chiral spin textures, have potential applications in next-generation high-density and energy-efficient spintronic devices for information storage and logic technologies. Tailoring the detailed spin textures of skyrmions is of pivotal importance for tuning skyrmion dynamics, which is one of the key factors for the design of skyrmionic devices. Here, the direct observation of parallel aligned elliptical magnetic skyrmions in Pt/Co/Ta multilayers with an oblique-angle deposited Co layer is reported. Domain wall velocity and spin-orbit-torque-induced out-of-plane effective field analysis demonstrate that the formation of unusual elliptical skyrmions is correlated to the anisotropic effective perpendicular magnetic anisotropy energy density (Keff u ) and Dzyaloshinskii-Moriya interaction (DMI) in the film plane. Structural analysis and first-principles calculations further show that the anisotropic Keff u and DMI originate from the interfacial anisotropic strain introduced by the oblique-angle deposition. The work provides a method to tune the spin textures of skyrmions in magnetic multilayers and, thereby, a new degree of freedom for the design of skyrmionic devices.

5.
J Biomed Opt ; 26(1)2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33515216

RESUMO

SIGNIFICANCE: There is an essential need to develop wearable multimodality technologies that can continuously measure both blood flow and oxygenation in deep tissues to investigate and manage various vascular/cellular diseases. AIM: To develop a wearable dual-wavelength diffuse speckle contrast flow oximetry (DSCFO) for simultaneous measurements of blood flow and oxygenation variations in deep tissues. APPROACH: A wearable fiber-free DSCFO probe was fabricated using 3D printing to confine two small near-infrared laser diodes and a tiny CMOS camera in positions for DSCFO measurements. The spatial diffuse speckle contrast and light intensity measurements at the two different wavelengths enable quantification of tissue blood flow and oxygenation, respectively. The DSCFO was first calibrated using tissue phantoms and then tested in adult forearms during artery cuff occlusion. RESULTS: Phantom tests determined the largest effective source-detector distance (15 mm) and optimal camera exposure time (10 ms) and verified the accuracy of DSCFO in measuring absorption coefficient variations. The DSCFO detected substantial changes in forearm blood flow and oxygenation resulting from the artery occlusion, which meet physiological expectations and are consistent with previous study results. CONCLUSIONS: The wearable DSCFO may be used for continuous and simultaneous monitoring of blood flow and oxygenation variations in freely behaving subjects.

6.
Phys Rev Lett ; 126(1): 017204, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33480795

RESUMO

A chiral bobber is a localized three-dimensional magnetization configuration, terminated by a singularity. Chiral bobbers coexist with magnetic skyrmions in chiral magnets, lending themselves to new types of skyrmion-complementary bits of information. However, the on-demand creation of bobbers, as well as their direct observation remained elusive. Here, we introduce a new mechanism for creating a stable chiral bobber lattice state via the proximity of two skyrmion species with comparable size. This effect is experimentally demonstrated in a Cu_{2}OSeO_{3}/[Ta/CoFeB/MgO]_{4} heterostructure in which an exotic bobber lattice state emerges in the phase diagram of Cu_{2}OSeO_{3}. To unambiguously reveal the existence of the chiral bobber lattice state, we have developed a novel characterization technique, magnetic truncation rod analysis, which is based on resonant elastic x-ray scattering.

7.
Sci Rep ; 11(1): 332, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33432005

RESUMO

Among multiple subtypes of tissue or cell, subtype-specific differentially-expressed genes (SDEGs) are defined as being most-upregulated in only one subtype but not in any other. Detecting SDEGs plays a critical role in the molecular characterization and deconvolution of multicellular complex tissues. Classic differential analysis assumes a null hypothesis whose test statistic is not subtype-specific, thus can produce a high false positive rate and/or lower detection power. Here we first introduce a One-Versus-Everyone Fold Change (OVE-FC) test for detecting SDEGs. We then propose a scaled test statistic (OVE-sFC) for assessing the statistical significance of SDEGs that applies a mixture null distribution model and a tailored permutation test. The OVE-FC/sFC test was validated on both type 1 error rate and detection power using extensive simulation data sets generated from real gene expression profiles of purified subtype samples. The OVE-FC/sFC test was then applied to two benchmark gene expression data sets of purified subtype samples and detected many known or previously unknown SDEGs. Subsequent supervised deconvolution results on synthesized bulk expression data, obtained using the SDEGs detected from the independent purified expression data by the OVE-FC/sFC test, showed superior performance in deconvolution accuracy when compared with popular peer methods.

8.
Angew Chem Int Ed Engl ; 60(1): 385-390, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-32935426

RESUMO

We here report glycosyl sulfoxides appended with an aryl iodide moiety as readily available, air and moisture stable precursors to glycosyl radicals. These glycosyl sulfoxides could be converted to glycosyl radicals by way of a rapid and efficient intramolecular radical substitution event. The use of this type of precursors enabled the synthesis of various complex C-linked glycoconjugates under mild conditions. This reaction could be performed in aqueous media and is amenable to the synthesis of glycopeptidomimetics and carbohydrate-DNA conjugates.

9.
J Biophotonics ; 14(4): e202000366, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33295142

RESUMO

We adapted and tested an innovative noncontact speckle contrast diffuse correlation tomography (scDCT) system for 3D imaging of cerebral blood flow (CBF) variations in perinatal disease models utilizing neonatal piglets, which closely resemble human neonates. CBF variations were concurrently measured by the scDCT and an established diffuse correlation spectroscopy (DCS) during global ischemia, intraventricular hemorrhage, and asphyxia; significant correlations were observed. Moreover, CBF variations associated reasonably with vital pathophysiological changes. In contrast to DCS measurements of mixed signals from local scalp, skull and brain, scDCT generates 3D images of CBF distributions at prescribed depths within the head, thus enabling specific determination of regional cerebral ischemia. With further optimization and validation in animals and human neonates, scDCT has the potential to be a noninvasive imaging tool for both basic neuroscience research in laboratories and clinical applications in neonatal intensive care units.

10.
Phys Med Biol ; 65(24): 245009, 2020 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-33113516

RESUMO

Extremely preterm infants' hemodynamic instability places them at high risk of brain injury. Currently there is no reliable bedside method to continuously monitor cerebral hemodynamics in the neonatal intensive care unit (NICU). This paper reports a feasibility study to adapt and test an innovative speckle contrast diffuse correlation tomography (scDCT) device for noncontact, high-density, 3D imaging of cerebral blood flow (CBF) in preterm infants. The scDCT scans a focused point near-infrared illumination to multiple source positions for deep tissue penetration, and controls an electron multiplying charge-coupled-device camera with thousands of pixels to achieve a high-density sampling. The optimized scDCT for use in preterm infants was first evaluated against an established diffuse correlation spectroscopy in an infant-head-simulating phantom with known properties. The observed significant correlation between the two measurements verified the capability of scDCT for transcranial brain imaging. The insignificant influence of transparent incubator wall on scDCT measurements was then confirmed by comparing adult forearm blood flow responses to artery cuff occlusions measured inside and outside the incubator. Finally, the scDCT device was moved to the NICU to image CBF variations in two preterm infants. Infant #1 with no major organ deficits showed little CBF fluctuation over the first 3 weeks of life. Infant #2 showed a significant CBF increase after the 2 h pharmacotherapy for patent ductus arteriosus closure. While these CBF variations meet physiological expectations, the fact that no significant changes are noted with peripheral monitoring of blood oxygen saturation suggests necessity of direct cerebral monitoring. This feasibility study with timely technology development is an important and necessary step towards larger clinical studies with more subjects to further validate it for continuous monitoring and instant management of cerebral pathologies and interventions in the NICU.


Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Hemodinâmica , Recém-Nascido Prematuro , Imagem Óptica/métodos , Circulação Cerebrovascular , Estudos de Viabilidade , Feminino , Humanos , Recém-Nascido , Masculino , Imagens de Fantasmas , Tomografia
11.
Curr Biol ; 30(24): 4896-4909.e6, 2020 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-33065003

RESUMO

Sensory stimuli with graded intensities often lead to yes-or-no decisions on whether to respond to the stimuli. How this graded-to-binary conversion is implemented in the central nervous system (CNS) remains poorly understood. Here, we show that graded encodings of noxious stimuli are categorized in a decision-associated CNS region in Drosophila larvae, and then decoded by a group of peptidergic neurons for executing binary escape decisions. GABAergic inhibition gates weak nociceptive encodings from being decoded, whereas escalated amplification through the recruitment of second-order neurons boosts nociceptive encodings at intermediate intensities. These two modulations increase the detection accuracy by reducing responses to negligible stimuli whereas enhancing responses to intense stimuli. Our findings thus unravel a circuit mechanism that underlies accurate detection of harmful stimuli.

12.
Artigo em Inglês | MEDLINE | ID: mdl-32966213

RESUMO

We developed a minimum-cost circulation framework for solving the global data association problem, which plays a key role in the tracking-by-detection paradigm of multi-object tracking. The problem was extensively studied under the minimum-cost flow framework, which is theoretically attractive as being flexible and globally solvable. However, the high computational burden has been a long-standing obstacle to its wide adoption in practice. While enjoying the same theoretical advantages and maintaining the same optimal solution as the minimum-cost flow framework, our new framework has a better theoretical complexity bound and leads to orders of practical efficiency improvement. Exploring the specialty that an overwhelming majority of the vertices are with unit capacity, we designed an implementation of the framework and proved it has the best theoretical complexity so far. We evaluated our method with 40 experiments on five MOT benchmark data sets. Our method was always the most efficient and averagely 53 to 1,192 times faster than the three state-of-the-art methods. When our method served as a sub-module for global data association methods using higher-order constraints, similar efficiency improvement was attained. We further illustrated through several case studies how the improved computational efficiency enables more sophisticated tracking models and yields better tracking accuracy.

13.
Oral Oncol ; 111: 104949, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32801084

RESUMO

OBJECTIVES: Recurrence rates for head and neck squamous cell carcinoma (HNSCC) approach 50% at 5 years. Current staging fails to identify patients with a worse prognosis who might benefit from intensified treatment, which warrants improved prognostic biomarkers. The purpose of this retrospective case study is to identify potential prognostic biomarkers in patients with HNSCC including APE1 (DNA repair/redox gene regulator), NRF2 and PPARGC1A (redox gene regulators), SOD3 and DCN (antioxidant proteins). MATERIALS AND METHODS: Differential protein expression between benign, carcinoma in situ (CIS), and invasive HNSCC tissue specimens from 77 patients was assessed using immunohistochemistry. Protein expression was analyzed with multivariate, pair-wise, and Kaplan-Meier survival analyses to identify potential prognostic biomarkers. Utilizing The Cancer Genome Atlas's transcriptome database, pair-wise and survival analysis was performed to identify potential prognostic biomarkers. RESULTS: APE1, NRF2, PPARGC1A, SOD3, and DCN expression in HNSCC in relation to, lymph node invasion, and patient survival were examined. Elevated APE1 protein expression in CIS corresponded with reduced survival (p = 0.0243). Increased APE1 gene expression in stage T4a HNSCC was associated with reduced patient survival (p < 0.015). Increased PPARGC1A in invasive tumor correlated with reduced survival (p = 0.0281). Patients with lymph node invasion at diagnosis had significantly increased APE1 protein in the primary sites (p < 0.05). Patients with poorly differentiated invasive tumors had reduced PPARGC1A in CIS proximal to the invasive tumor and had elevated DCN and SOD3 in proximal benign tissue (p < 0.05). CONCLUSIONS: The expression of APE1, DCN, and SOD3 is a potential prognostic signature that identifies patients with worsened survival.

14.
Medicine (Baltimore) ; 99(34): e21744, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32846797

RESUMO

BACKGROUND: In recent years, clinical studies about Yangxin Decoction combined acupuncture (YXDA) for the treatment of Qi Deficiency and Blood Stasis type of Chest Bi-Syndrome (CBS-QDBS) has been increased, but the results are different. The aim of this study is to investigate the effect of YXDA on blood lipid metabolism (BLMB) in patients with CBS-QDBS. METHODS: We will collect any randomized controlled trials that assess the effect of YXDA on BLMB in CBS-QDBS from PUBMED, EMBASE, Cochrane Library, PsycINFO, CINAHL, Allied and Complementary Medicine Database, and China National Knowledge Infrastructure. All of these databases will be searched from their initial time to the present. All language limitation will be imposed. Literature selection, information collection, and risk of bias assessment will be performed independently by two authors, respectively. All data analysis will be undertaken using RevMan 5.3 Software. RESULTS: This study will summarize the systematic nature of the literature search and its methods for assessing study quality and analyzing all relevant outcome data. Considering the inconsistent results, this study will improve the existing evidence on the effect of YXDA on BLMB in CBS-QDBS. CONCLUSION: The findings of this study will present the latest evidence of YXDA on BLMB in patients with CBS-QDBS. STUDY REGISTRATION: INPLASY202070047.


Assuntos
Terapia por Acupuntura/métodos , Dor no Peito/terapia , Medicamentos de Ervas Chinesas/uso terapêutico , Metabolismo dos Lipídeos/efeitos dos fármacos , Qi , Terapia Combinada , Medicamentos de Ervas Chinesas/farmacologia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa
15.
Adv Mater ; 32(39): e2003003, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32812294

RESUMO

The emergence of magnetic skyrmions, topological spin textures, has aroused tremendous interest in studying the rich physics related to their topology. While skyrmions promise high-density and energy-efficient magnetic memory devices for information technology, the manifestation of their nontrivial topology through single skyrmions and ordered and disordered skyrmion lattices could also give rise to many fascinating physical phenomena, such as chiral magnon and skyrmion glass states. Therefore, generating skyrmions at designated locations on a large scale, while controlling the skyrmion patterns, is the key to advancing topological magnetism. Here, a new, yet general, approach to the "printing" of skyrmions with zero-field stability in arbitrary patterns on a massive scale in exchange-biased magnetic multilayers is presented. By exploiting the fact that the antiferromagnetic order can be reconfigured by local thermal excitations, a focused electron beam with a graphic pattern generator to "print" skyrmions is used, which is referred to as skyrmion lithography. This work provides a route to design arbitrary skyrmion patterns, thereby establishing the foundation for further exploration of topological magnetism.

16.
Adv Mater ; 32(38): e1907452, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32743868

RESUMO

Magnetic skyrmions are attracting interest as efficient information-storage devices with low energy consumption, and have been experimentally and theoretically investigated in multilayers including ferromagnets, ferrimagnets, and antiferromagnets. The 3D spin texture of skyrmions demonstrated in ferromagnetic multilayers provides a powerful pathway for understanding the stabilization of ferromagnetic skyrmions. However, the manipulation mechanism of skyrmions in antiferromagnets is still lacking. A Hall balance with a ferromagnet/insulating spacer/ferromagnet structure is considered to be a promising candidate to study skyrmions in synthetic antiferromagnets. Here, high-density Néel-type skyrmions are experimentally observed at zero field and room temperature by Lorentz transmission electron microscopy in a Hall balance (core structure [Co/Pt]n /NiO/[Co/Pt]n ) with interfacial canted magnetizations because of interlayer ferromagnetic/antiferromagnetic coupling between top and bottom [Co/Pt]n multilayers, where the Co layers in [Co/Pt]n are always ferromagnetically coupled. Micromagnetic simulations show that the generation and density of skyrmions are strongly dependent on interlayer exchange coupling (IEC) and easy-axis orientation. Direct experimental evidence of skyrmions in synthetic antiferromagnets is provided, suggesting that the proposed approach offers a promising alternative mechanism for room-temperature spintronics.

17.
Phys Rev Lett ; 125(2): 027206, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32701308

RESUMO

Noninteracting particles exhibiting Brownian motion have been observed in many occasions of sciences, such as molecules suspended in liquids, optically trapped microbeads, and spin textures in magnetic materials. In particular, a detailed examination of Brownian motion of spin textures is important for designing thermally stable spintronic devices, which motivates the present study. In this Letter, through using temporally and spatially resolved polar magneto-optic Kerr effect microscopy, we have experimentally observed the thermal fluctuation-induced random walk of a single isolated Néel-type magnetic skyrmion in an interfacially asymmetric Ta/CoFeB/TaO_{x} multilayer. An intriguing topology-dependent Brownian gyromotion behavior of skyrmions has been identified. The onset of Brownian gyromotion of a single skyrmion induced by thermal effects, including a nonlinear temperature-dependent diffusion coefficient and topology-dependent gyromotion are further formulated based on the stochastic Thiele equation. The experimental and numerical demonstration of topology-dependent Brownian gyromotion of skyrmions can be useful for understanding the nonequilibrium magnetization dynamics and implementing spintronic devices.

18.
J Integr Neurosci ; 19(2): 303-311, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32706194

RESUMO

Cerebral ischemia-reperfusion injury is a common complication that occurs during stroke treatment. Increasingly, microRNAs have been found to participate in the modulation of neuron function; however, the role of microRNAs in cerebral ischemia-reperfusion injury remains unclear. We developed a mechanism of cerebral ischemia-reperfusion injury using a cellular model of oxygen-glucose deprivation and reoxygenation-induced injury in human neuroblastoma SH-SY5Y cells. We found that treatment of oxygen-glucose deprivation and reoxygenation promoted the apoptosis of SH-SY5Y cells. Analysis of microRNAs sequencing revealed that the expression of microRNA-27a-5p was induced, and microRNA-29b-3p expression was inhibited in neuroblastoma cells exposed to oxygen-glucose deprivation and reoxygenation. Either inhibition of microRNA-27a-5p or overexpression of microRNA-29b-3p mitigated oxygen-glucose deprivation and reoxygenation-induced cellular apoptosis. Bach1 was authenticated as a target gene of microRNA-27a-5p. Also, microRNA-27a-5p mediated the expression of Bach 1 along with its downstream signaling. N-hydroxy-N'-(4-butyl-2-methylphenyl)-formamidine protected against oxygen-glucose deprivation and reoxygenation-induced apoptosis while decreasing miR-27a-5p expression and increasing microRNA-29b-3p expression. These results suggested that microRNA-27a-5p and microRNA-29b-3p may contribute to oxygen-glucose deprivation and reoxygenation-induced cellular injury. At the same time, N-hydroxy-N'-(4-butyl-2-methylphenyl)-formamidine protects SH-SY5Y cells against oxygen-glucose deprivation and reoxygenation-induced injury partly through the inhibition of microRNA-27-a-5p and promotion of the Bach1/HO-1 signaling pathway.


Assuntos
Amidinas/farmacologia , Apoptose , Fatores de Transcrição de Zíper de Leucina Básica , Glucose/metabolismo , Hipóxia/metabolismo , MicroRNAs , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Fatores de Transcrição de Zíper de Leucina Básica/efeitos dos fármacos , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Linhagem Celular Tumoral , Humanos , MicroRNAs/efeitos dos fármacos , MicroRNAs/metabolismo
19.
J Biophotonics ; 13(10): e202000073, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32533642

RESUMO

Diagnosis of cerebrovascular disease (CVD) at early stages is essential for preventing sequential complications. CVD is often associated with abnormal cerebral microvasculature, which may impact cerebral-autoregulation (CA). A novel hybrid near-infrared diffuse optical instrument and a finger plethysmograph were used to simultaneously detect low-frequency oscillations (LFOs) of cerebral blood flow (CBF), oxy-hemoglobin concentration ([HbO2 ]), deoxy-hemoglobin concentration ([Hb]) and mean arterial pressure (MAP) in older adults before, during and after 70° head-up-tilting (HUT). The participants with valid data were divided based on Framingham risk score (FRS, 1-30 points) into low-risk (FRS ≤15, n = 13) and high-risk (FRS >15, n = 11) groups for developing CVD. The LFO gains were determined by transfer function analyses with MAP as the input, and CBF, [HbO2 ] and [Hb] as the outputs (CA ∝ 1/Gain). At resting-baseline, LFO gains in the high-risk group were relatively lower compared to the low-risk group. The lower baseline gains in the high-risk group may attribute to compensatory mechanisms to maintain stronger steady-state CAs. However, HUT resulted in smaller gain reductions in the high-risk group compared to the low-risk group, suggesting weaker dynamic CAs. LFO gains are potentially valuable biomarkers for early detection of CVD based on associations with CAs.


Assuntos
Circulação Cerebrovascular , Homeostase , Espectroscopia de Luz Próxima ao Infravermelho , Idoso , Pressão Sanguínea , Humanos , Microvasos , Medição de Risco
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