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1.
Angew Chem Int Ed Engl ; 63(22): e202403695, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38436549

ABSTRACT

Aqueous zinc ion batteries (AZIBs) show a great potential for next-generation energy storage due to their high safety and high energy density. However, the severe side reactions of zinc negative electrode largely hinder the further application of AZIBs. Herein, trace tris(hydroxymethyl)aminomethane (Tris) additive with rich lone-pair-electrons and zincophilic sites is firstly introduced to achieve long-term and highly reversible Zn plating/stripping. Specifically, Tris not only regulates the solvation structure of Zn2+, but is also adsorbed vertically on the Zn anode surface with a changed coordination intensity during the plating/stripping process of Zn to generate an in situ dynamic adsorption layer for the first time. The dynamic adsorption layer could successively attract the solvated Zn2+ and then promote the de-solvation of the solvated Zn2+ owing to the orientation polarization with regularly-changed applied electric field, the volume rejection effect, and strong intermolecular force towards H2O of the vertically-adsorbed Tris. Therefore, an improved Zn2+-transport kinetics as well as the inhibition of side reactions of Zn anode are successfully realized. Accordingly, the Zn||Zn symmetric cell provides an ultra-long cycle life of 2600 h. Furthermore, the Zn||MnO2 full cell with Tris could demonstrate a high capacity and structural stability for practical applications.

2.
Chemistry ; 28(31): e202200363, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35332603

ABSTRACT

As competitive next-generation rechargeable batteries, lithium-sulfur batteries (LSBs) suffer from the shuttle effect and the sluggish kinetics of intermediate polysulfides during charge and discharge processes, adversely affecting their electrochemical performances and actual applications. Herein, we demonstrate a polymer encapsulation strategy to synthesize atomic Fe and N co-doped hollow carbon nanospheres (Fe-NHC) with Fe-Nx sites for modifying commercial PP separator of LSBs to suppress the shuttle effect and promote the kinetics of intermediate polysulfides. Benefiting from the excellent structural design, the doped-N with positive charges could effectively adsorb negatively charged soluble polysulfides, help attract the soluble polysulfides to the Fe atoms and boost the catalytic transformation of the soluble polysulfides. Additionally, such a thin carbon shell could provide a short mass diffusion pathway and hence promote the adsorption and the catalytic conversion. Therefore, the battery with the Fe-NHC/PP separator delivers outstanding cycling and rate performances. At the large current density of 1 C, the specific capacity is 1079 mA h g-1 and maintains a low loss of 0.076 % per cycle within 500 cycles. Even at a harsh current density of 4 C, a high capacity of 824 mA h g-1 is still achieved, indicating the advantage of the Fe-NHC/PP separator in LSBs.

3.
J Sep Sci ; 45(3): 771-779, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34851555

ABSTRACT

Polysaccharides with antioxidant and hypoglycemic activities were first isolated from jackfruit (Artocarpus heterophyllus Lam.) peel through the one-step high-speed countercurrent chromatography. The separation process was completed using the polymer two-phase aqueous system constituted by PEG1000-K2 HPO4 -KH2 PO4 -H2 O (0.8:1.25:1.25:6.5, w/w). For every separation process, two main polysaccharides, namely, fraction-1 and fraction-2 (165 and 225 mg, respectively) were obtained from a 2.0 g crude sample. As suggested by high-performance gel permeation chromatography, jackfruit peel polysaccharides had the mean molecular weight values of 113.3 and 174.3 kDa, separately. Physicochemical analysis suggested that two polysaccharides were dominant in galacturonic acid, galactose, rhamnose, arabinose, glucose, mannose, as well as fucose, which were highly esterified. Biological activity analysis showed that fraction-1 exhibited stronger antioxidant activity in vitro and hypoglycemic activity in streptozotocin-induced diabetic mice compared with fraction-2. The results suggest that polysaccharide fraction-1 may be developed as a potential functional food supplement.


Subject(s)
Artocarpus , Diabetes Mellitus, Experimental , Animals , Antioxidants/chemistry , Antioxidants/pharmacology , Artocarpus/chemistry , Countercurrent Distribution/methods , Diabetes Mellitus, Experimental/drug therapy , Hypoglycemic Agents/pharmacology , Mice , Polysaccharides/chemistry
4.
Immunol Invest ; 50(6): 662-670, 2021 Aug.
Article in English | MEDLINE | ID: mdl-32613870

ABSTRACT

Interleukin-31 (IL-31) has diverse biological functions. Increased IL-31 has been found in some skin and autoimmune diseases. There has been no study reporting the association between IL-31 and primary biliary cholangitis (PBC). This study was designed to determine serum IL-31 level and to explore its diagnostic value for PBC as well as the association of IL-31 with inflammatory and fibrotic progression. 60 PBC patients, 32 age- and sex-matched patients with chronic hepatitis B (CHB) and 30 age- and sex-matched healthy controls (HC) were recruited. The sera were detected for IL-31, IL-4, interferon gamma (IFN-γ), IL-17 and other laboratory indicators. Serum IL-31 levels were significantly higher in PBC patients (median, IQR, 20.6, 16.7-26.2, pg/ml) than CHB patients (median, IQR, 11.3, 8.0-13.0, pg/ml) and HC (median, IQR, 11.0, 10.0-12.2 pg/ml) (P < .001). Serum IL-31 performed well for identifying PBC, especially for antimitochondrial antibodies (AMA)-negative PBC with AUC of 0.900, optimal cutoff value of 13.6 pg/ml, sensitivity of 87.5% and specificity of 83.9%. Serum IL-31 was positively correlated with platelet count (r = 0.368, P = .004), but negatively with FIB4 (r = -0.307, P = .017) and histological stages (r = -0.364, P = .004) in PBC patients. It was also significantly correlated with IFN-γ (r = 0.404, P = .001) and IL-4 (r = 0.291, P = .026), but not with IL-17 (r = 0.151, P = .259) in PBC patients. Serum IL-31 is increased in and may be a useful marker for PBC, in particular, for AMA-negative PBC. Furthermore, it is inversely associated with fibrotic progression of PBC.


Subject(s)
Autoantibodies/blood , Interleukins/blood , Liver Cirrhosis, Biliary/diagnosis , Aged , Aged, 80 and over , Biomarkers/blood , Disease Progression , Feasibility Studies , Female , Fibrosis , Humans , Interleukins/immunology , Liver Cirrhosis, Biliary/blood , Liver Cirrhosis, Biliary/immunology , Male , Middle Aged , ROC Curve
5.
Cytokine ; 136: 155291, 2020 12.
Article in English | MEDLINE | ID: mdl-32956949

ABSTRACT

Although chemokines have been believed to exert a pivotal role in pathogenesis of primary biliary cholangitis (PBC), comprehensive analysis of circulating chemokine profile in PBC has been little performed. The aim of this study is to determine serum chemokine profile and to explore its association with the development and progression of PBC. Sixty PBC patients and 30 healthy controls (HC) were enrolled. The sera were detected for 14 chemokines using multiplex immunoassay. The expression of CD3 and CD68 in the portal area of liver tissues was determined by immunohistochemistry in 6 PBC patients. The characteristics of chemokine profile in PBC were analyzed. Serum concentrations of most chemokines were higher, but TARC/CCL17, MDC/CCL22 and ENA-78/CXCL5 were lower in PBC patients than those in HC (all P < 0.05). Most of increased chemokines remained significant in both early and advanced PBC patients. PBC stage was correlated inversely with MCP-4/CCL13(r = -0.373), TARC/CCL17(r = -0.365), ENA-78/CXCL5 (r = -0.418) and I-TAC/CXCL11(r = -0.262), but positively with fractalkine/CX3CL1(r = 0.325). There were significant correlations between serum levels of IP-10/CXCL10 (r = 0.971, P = 0.001) and I-TAC/CXCL11 (r = 0.883, P = 0.020) and CD3 expression within the portal area, and between MIP-3α/CCL20 and CD68 expression within the portal area (r = 0.886, P = 0.019). In PBC patients, there were significant correlations among each other of MCP-4/CCL13, TARC/CCL17, MDC/CCL22, CTACK/CCL27, ENA-78/CXCL5, IP-10/CXCL10, I-TAC/CXCL11, excepting correlations of CTACK/CCL27 with IP-10/CXCL10 and I-TAC/CXCL11. Also, there were strong correlations among each other of CCL3/MIP-1α, CCL4/MIP-1ß and IL-8/CXCL8. The only negative correlation was found in the serum between fractalkine/CX3CL1 and TARC/CCL17 (r = -0.311, P = 0.016). Serum levels of most chemokines are increasing throughout the development and progression of PBC, with the exception of chemokines, mainly attractive for neutrophil and eosinophil (e.g. ENA-78/CXCL5, MCP-4/CCL13), decreasing in advanced PBC, and of chemokines, dominantly responsible for Th2 chemotaxis (e.g. TARC/CCL17), decreasing in early PBC and associating negatively with PBC progression.


Subject(s)
Chemokines/blood , Liver Cirrhosis, Biliary/blood , Aged , Aged, 80 and over , Disease Progression , Female , Humans , Male
6.
J Nanosci Nanotechnol ; 19(9): 5825-5830, 2019 Sep 01.
Article in English | MEDLINE | ID: mdl-30961745

ABSTRACT

A N-doped graphene/melamine formaldehyde composite carbon foam (G/C) with a porous structure was prepared by a physical foaming method and high-temperature carbonization. Samples of the G/C with various graphene content (i.e., 0%, 1% and 2%) were synthesized and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FESEM). The XPS and TEM analyses show that the as-prepared G2%/C foam has the highest nitrogen content of 14.7%, with an apparent porous structure. The electrochemical performances of the G/C samples were investigated by charge-discharge cycles. The G2%/C exhibits a high capacitance of 619.3 Fg-1 at a current density of 0.5 Ag-1. The N-doped graphene/melamine formaldehyde composite carbon foam is a promising electric double-layer capacitor material for binder-free electrodes with excellent properties for supercapacitors.

7.
Appl Opt ; 58(27): 7597-7602, 2019 Sep 20.
Article in English | MEDLINE | ID: mdl-31674414

ABSTRACT

The residual intensity modulation (RIM) is one of the major sources of instability in optical detection based on phase modulation. In resonator fiber optic gyroscopes (RFOGs), the RIM leads to a nonzero output signal at the resonance center frequency, which degrades the bias stability of the RFOG. While the origins of the RIM are not fully understood, we present experimental results of the RIM in the Y-branch waveguide modulator with triangular phase modulation. We establish a model to analyze the RIM-induced error in the RFOG with triangular phase modulation and pointed out that symmetrical acquisition in a triangular wave period can reduce the RIM-induced error. We experimentally study the equivalent modulation depth of the RIM with different acquisition times in a triangular wave period and symmetrical acquisition in a triangular wave period. The results show that symmetrical acquisition in a triangular wave period can eliminate the RIM-induced error.

8.
Sensors (Basel) ; 19(14)2019 Jul 23.
Article in English | MEDLINE | ID: mdl-31340511

ABSTRACT

In the case of space-based space surveillance (SBSS), images of the target space objects captured by space-based imaging sensors usually suffer from low spatial resolution due to the extremely long distance between the target and the imaging sensor. Image super-resolution is an effective data processing operation to get informative high resolution images. In this paper, we comparably study four recent popular models for single image super-resolution based on convolutional neural networks (CNNs) with the purpose of space applications. We specially fine-tune the super-resolution models designed for natural images using simulated images of space objects, and test the performance of different CNN-based models in different conditions that are mainly considered for SBSS. Experimental results show the advantages and drawbacks of these models, which could be helpful for the choice of proper CNN-based super-resolution method to deal with image data of space objects.

9.
J Sci Food Agric ; 99(12): 5283-5292, 2019 Sep.
Article in English | MEDLINE | ID: mdl-30953352

ABSTRACT

BACKGROUND: Water is generally considered to be a safe and green solvent suitable for use in natural product extraction. In this study, an eco-friendly subcritical water method was used to extract pectin from waste jackfruit peel (JFP-S), which was compared with pectin obtained by the traditional citric acid method (JFP-C). RESULTS: The extraction process was optimized using response surface methodology (RSM), and the optimum process parameters were as follows: extraction temperature 138 °C, extraction time 9.15 min, liquid / solid (L/S) ratio 17.03 mL g-1 . Under these conditions, the pectin yield was 149.6 g kg-1 (dry basis). Pectin obtained from the two extraction methods displayed a high degree of esterification and the monosaccharide composition was consistent. The galacturonic acid content of JFP-S and JFP-C was 52.27% and 56.99%, respectively. JFP-S had more hairy regions and side chains than JFP-C. The molecular weight of JFP-S was 113.3 kDa, which was significantly lower than that of JFP-C (174.3 kDa). Fourier-transform infrared spectroscopy (FTIR) indicated that two samples had similar pectin typical absorption peaks. According to differential scanning calorimetry (DSC), both JFP-S and JFP-C had relatively good thermal stability. JFP-S demonstrated lower apparent viscosity and elasticity than JFP-C. Meanwhile, the G' and G'' moduli of JFP-S were lower, which found expression in the gel textural characterization of the samples. CONCLUSION: This work showed that the subcritical water method is an efficient, time-saving, and eco-friendly technology for the extraction of pectin from jackfruit peel compared with the traditional citric acid method. The physicochemical properties of pectin could be changed during subcritical water extraction. © 2019 Society of Chemical Industry.


Subject(s)
Artocarpus/chemistry , Green Chemistry Technology/methods , Pectins/chemistry , Pectins/isolation & purification , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Waste Products/analysis , Esterification , Molecular Weight , Spectroscopy, Fourier Transform Infrared , Temperature , Viscosity
10.
J Food Sci Technol ; 56(8): 3877-3886, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31413413

ABSTRACT

An efficient ultrasonic microwave-assisted extraction (UMAE) coupled with macroporous resin chromatography technique was successfully used for the extraction and purification of antioxidant phenolics from jackfruit by-products (peels). After optimization by single factor experiments and response surface methodology, the optimum extraction conditions for UMAE were: ethanol concentration 63%, solvent-to-solid ratio 34 mL/g, microwave power 160 W and irradiation time 20 min. Under the optimal condition, the phenolics extraction yield was 8.14 mg GAE/g DW. After the purification by macroporous resin AB-8, the purity of antioxidant phenolics from UMAE extracts improved from 13.59 to 49.07%. Furthermore, ABTS radical scavenging activities were also significantly increased from 35.95 ± 2.21 to 162.36 ± 10.26 mg TE/g. HPLC analysis revealed that gallic acid, chlorogenic acid, and catechin were three dominant antioxidant phenolics in jackfruit peels. All of the results demonstrated that waste jackfruit peels could be utilized as a good source of phenolics with strong antioxidant activities in food and pharmaceutical industry.

11.
Chemistry ; 24(65): 17339-17344, 2018 Nov 22.
Article in English | MEDLINE | ID: mdl-30226279

ABSTRACT

Although the electrochemical catalytic conversion process is effective in increasing the reversible capacity of lithium-ion batteries, the low contact efficiency between metal catalyst and substrate and pulverization of the solid electrolyte interface (SEI) film without protection are not beneficial for the electrochemical reactions. Herein, Fe7 S8 nanoparticles are confined by both reduced graphene oxide (RGO) and in-situ-formed amorphous carbon (C) to form dual-carbon-confined Fe7 S8 as a lithium-ion anode. The dual-carbon-confined structure provides a confined space to prevent pulverization of the SEI film and increases the local concentration of intermediate phases, which could be electrocatalytically decomposed by Fe nanoparticles formed in situ to increase the reversibility of the electrochemical reactions and gain high reversible capacity. In addition, the dual-carbon-confined structure ensures fast transfer of electrons and boosts transport of lithium ions due to the highly conductive dual-carbon shell. Thus, the Fe7 S8 /C/RGO anode delivers an excellent rate performance and long cycling stability. At current densities of 2000 and 5000 mA g-1 , the reversible capacities are 520 mA h g-1 over 1500 cycles and 294 mA h g-1 over 2000 cycles, respectively.

12.
Sensors (Basel) ; 18(4)2018 Mar 21.
Article in English | MEDLINE | ID: mdl-29561828

ABSTRACT

Automatic component detection of spacecraft can assist in on-orbit operation and space situational awareness. Spacecraft are generally composed of solar panels and cuboidal or cylindrical modules. These components can be simply represented by geometric primitives like plane, cuboid and cylinder. Based on this prior, we propose a robust automatic detection scheme to automatically detect such basic components of spacecraft in three-dimensional (3D) point clouds. In the proposed scheme, cylinders are first detected in the iteration of the energy-based geometric model fitting and cylinder parameter estimation. Then, planes are detected by Hough transform and further described as bounded patches with their minimum bounding rectangles. Finally, the cuboids are detected with pair-wise geometry relations from the detected patches. After successive detection of cylinders, planar patches and cuboids, a mid-level geometry representation of the spacecraft can be delivered. We tested the proposed component detection scheme on spacecraft 3D point clouds synthesized by computer-aided design (CAD) models and those recovered by image-based reconstruction, respectively. Experimental results illustrate that the proposed scheme can detect the basic geometric components effectively and has fine robustness against noise and point distribution density.

14.
Appl Opt ; 56(34): 9414-9422, 2017 Dec 01.
Article in English | MEDLINE | ID: mdl-29216054

ABSTRACT

This paper is concerned with the angular random walk (ARW) limited by Rayleigh backscattering in the resonator fiber optic gyro (RFOG) with a light source of arbitrary temporal coherence. First, a model of Rayleigh backscattering noise in RFOGs is established to predict the fluctuation characteristics of backscattered intensity and interference intensity. Next, the formula for the ARW limited by Rayleigh backscattering is derived, and the requirement of carrier suppression level is calculated to make sure the ARW is limited by the detector's shot noise rather than Rayleigh scattering noise. Finally, the influences of the cavity length, the linewidth, and the finesse on the ARW limited by Rayleigh backscattering are investigated. The results predict that the influence of the cavity length L and the laser linewidth ΔυL on the ARW is dominantly related to the factor e-2πΔυLneL/c, and under the finesse 88, the best ARW is obtained when there is a relation L·ΔυL≈4×105 m·Hz.

15.
Sensors (Basel) ; 17(7)2017 Jul 22.
Article in English | MEDLINE | ID: mdl-28737675

ABSTRACT

In this paper, a novel 3D reconstruction framework is proposed to recover the 3D structural model of a space object from its multi-view images captured by a visible sensor. Given an image sequence, this framework first estimates the relative camera poses and recovers the depths of the surface points by the structure from motion (SFM) method, then the patch-based multi-view stereo (PMVS) algorithm is utilized to generate a dense 3D point cloud. To resolve the wrong matches arising from the symmetric structure and repeated textures of space objects, a new strategy is introduced, in which images are added to SFM in imaging order. Meanwhile, a refining process exploiting the structural prior knowledge that most sub-components of artificial space objects are composed of basic geometric shapes is proposed and applied to the recovered point cloud. The proposed reconstruction framework is tested on both simulated image datasets and real image datasets. Experimental results illustrate that the recovered point cloud models of space objects are accurate and have a complete coverage of the surface. Moreover, outliers and points with severe noise are effectively filtered out by the refinement, resulting in an distinct improvement of the structure and visualization of the recovered points.

16.
Microb Pathog ; 93: 152-7, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26835657

ABSTRACT

Reovirus not only causes considerable economic loss in the swine industry of the United States and other countries, but also threatens the public health due to its zoonotic potential. According to previous reports, LiCl has antiviral activity against a number of viruses. The inhibitory effects of LiCl on reovirus life cycle in Vero cells were evaluated. The unpaired t-test and one-way ANOVA were used to analyze the differences between experimental groups. We first found that LiCl treatment significantly inhibited reovirus replication in a dose-dependent manner. Furthermore, we found that this antiviral activity of LiCl targets the early stage of viral replication. LiCl could be a potential drug against reovirus infection.


Subject(s)
Antiviral Agents/pharmacology , Lithium Chloride/pharmacology , Orthoreovirus, Mammalian/drug effects , Animals , Cell Line , Chlorocebus aethiops , Humans , Orthoreovirus, Mammalian/physiology , Reoviridae Infections/virology , Vero Cells , Virus Replication/drug effects
17.
Surg Endosc ; 30(10): 4272-8, 2016 10.
Article in English | MEDLINE | ID: mdl-26743105

ABSTRACT

OBJECTIVE: To clarify the contribution of the subcutaneous area during breast approach endoscopic thyroidectomy (BAET), with regard to invasiveness-related outcomes. METHODS: Seventy-two patients were randomly assigned to two groups: standard dissection and limited dissection. Postoperative pain and inflammatory response were compared between groups. RESULTS: The groups were well matched except for subcutaneous dissection area (137.11 ± 21.10 vs. 83.69 ± 12.10 cm(2), p < 0.0001). No significant difference was found with regard to VAS score and postoperative inflammatory response. CONCLUSION: Our RCT indicated that the subcutaneous area plays a less important role with regard to BAET-related postoperative pain.


Subject(s)
Dissection , Endoscopy , Thyroidectomy/methods , Adult , Female , Humans , Male , Pain, Postoperative , Visual Analog Scale
18.
Surg Endosc ; 30(7): 2865-72, 2016 07.
Article in English | MEDLINE | ID: mdl-26487237

ABSTRACT

AIM: The aim of this study was to evaluate the issue of improvement of disadvantages of different type meshes. METHODS: A retrospective analysis was performed on 101 gastroesophageal reflux disease patients who underwent reinforcement of crura with or without prosthetic mesh. Three types of mesh, 4-ply biologic small intestine submucosa (SIS, Surgisis(®), since November 2010), 6-ply SIS (Biodesign™ Surgisis(®), since March 2011), and composite synthetic mesh (Crurasoft(®), since May 2010), were used. All patients were assigned to simple suture group (n = 35), 4-ply SIS group (n = 13), 6-ply Biodesign™ group (n = 26) or Crurasoft(®) group (n = 27). Postoperative follow-up was performed via clinical visit or phone call contact. Subjective assessment included dysphagia, patients' symptomatic outcome judgment according to Visick and patients' satisfaction. Objective evaluation included hiatal hernia recurrence according to upper endoscopy and barium contrast swallow. Follow-up was completed in 83 patients with a mean duration of 45 months (range 16-149 months). RESULTS: For the objective outcomes, although anatomic recurrence of hiatal hernia did not significantly differ between groups at 6 months postoperatively, long-term results showed a protective effect of mesh implantation on hernia recurrence (p = 0.047). For the subjective outcomes, the mesh group had a more significant improvement in Visick score (p = 0.020) compared to the simple suture group. Patient satisfaction was significantly higher in the mesh group (p = 0.014), and subgroup analysis showed a clear trend as follows: Crurasoft(®) ≈ Biodesign(®) > SIS(®). A higher frequency of postoperative dysphagia was presented in the Crurasoft group compared with other two groups at 6 months postoperatively, but the difference was not significant over time (p = 0.227). CONCLUSION: Mesh cruroplasty results in satisfactory symptom control with a low recurrence rate. 6-ply biologic mesh is promising with respect to the reduction in anatomic recurrences. Postoperative dysphagia does not occur commonly following mesh cruroplasty with PTFE/ePTFE mesh.


Subject(s)
Biological Products , Deglutition Disorders/epidemiology , Gastroesophageal Reflux/surgery , Hernia, Hiatal/surgery , Postoperative Complications/epidemiology , Surgical Mesh , Adult , Aged , Barium Compounds , Female , Gastroscopy , Humans , Intestine, Small , Laparoscopy/methods , Male , Middle Aged , Patient Satisfaction , Prostheses and Implants , Radiography , Recurrence , Retrospective Studies , Sutures
19.
Neural Plast ; 2016: 1726848, 2016.
Article in English | MEDLINE | ID: mdl-27830093

ABSTRACT

The present study examined functional connectivity (FC) between functional MRI (fMRI) signals of the primary motor cortex (M1) and each of the three subcortical neural structures, cerebellum (CB), basal ganglia (BG), and thalamus (TL), during muscle fatigue using the quantile regression technique. Understanding activation relation between the subcortical structures and the M1 during prolonged motor performance should help delineate how central motor control network modulates acute perturbations at peripheral sensorimotor system such as muscle fatigue. Ten healthy subjects participated in the study and completed a 20-minute intermittent handgrip motor task at 50% of their maximal voluntary contraction (MVC) level. Quantile regression analyses were carried out to compare the FC between the contralateral (left) M1 and CB, BG, and TL in the minimal (beginning 100 s) versus significant (ending 100 s) fatigue stages. Widespread, statistically significant increases in FC were found in bilateral BG, CB, and TL with the left M1 during significant versus minimal fatigue stages. Our results imply that these subcortical nuclei are critical components in the motor control network and actively involved in modulating voluntary muscle fatigue, possibly, by working together with the M1 to strengthen the descending central command to prolong the motor performance.


Subject(s)
Brain Mapping , Motor Activity/physiology , Muscle Fatigue/physiology , Muscle, Skeletal/physiology , Neural Pathways/physiology , Adult , Cerebellum/physiology , Hand Strength/physiology , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Motor Cortex/physiology
20.
Gastroenterology ; 146(5): 1212-21, 2014 May.
Article in English | MEDLINE | ID: mdl-24480616

ABSTRACT

BACKGROUND & AIMS: The study of intrinsic fluctuations in the blood oxygen level-dependent signal of functional magnetic resonance imaging can provide insight into the effect of physiologic states on brain processes. In an effort to better understand the brain-gut communication induced by the absorption and metabolism of nutrients in healthy lean and obese individuals, we investigated whether ingestion of nutritive and non-nutritive sweetened beverages differentially engages the hypothalamus and brainstem vagal pathways in lean and obese women. METHODS: In a 2-day, double-blind crossover study, 11 lean and 11 obese healthy women underwent functional magnetic resonance imaging scans after ingestion of 2 beverages of different sucrose content, but identical sweetness. During scans, subjects rested with eyes closed. RESULTS: Blood oxygen level-dependent fluctuations demonstrated significantly greater power in the highest frequency band (slow-3: 0.073-0.198 Hz) after ingestion of high-sucrose compared with low-sucrose beverages in the nucleus tractus solitarius for both groups. Obese women had greater connectivity between the right lateral hypothalamus and a reward-related brain region and weaker connectivity with homeostasis and gustatory-related brain regions than lean women. CONCLUSIONS: In a functional magnetic resonance imaging study, we observed sucrose-related changes in oscillatory dynamics of blood oxygen level-dependent fluctuations in brainstem and hypothalamus in lean and obese women. The observed frequency changes are consistent with a rapid vagally mediated mechanism due to nutrient absorption, rather than sweet taste receptor activation. These findings provide support for altered interaction between homeostatic and reward networks in obese individuals.


Subject(s)
Brain Stem/physiopathology , Dietary Sucrose/administration & dosage , Hypothalamus/physiopathology , Obesity/physiopathology , Thinness/physiopathology , Administration, Oral , Adult , Beverages , Brain Mapping/methods , Brain Stem/metabolism , Cross-Over Studies , Dietary Sucrose/metabolism , Double-Blind Method , Female , Homeostasis , Humans , Hypothalamus/metabolism , Magnetic Resonance Imaging , Obesity/metabolism , Obesity/psychology , Oscillometry , Oxygen/blood , Reward , Satiation , Thinness/metabolism , Thinness/psychology , Time Factors , Vagus Nerve/physiopathology , Young Adult
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