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1.
Small ; : e2310955, 2024 Apr 18.
Article in English | MEDLINE | ID: mdl-38634220

ABSTRACT

DNA origami is a flexible platform for the precise organization of nano-objects, enabling numerous applications from biomedicine to nano-photonics. Its huge potential stems from its high flexibility that allows customized structures to meet specific requirements. The ability to generate diverse final structures from a common base by folding significantly enhances design variety and is regularly occurring in liquid. This study describes a novel approach that combines top-down lithography with bottom-up DNA origami techniques to control folding of the DNA origami with the adsorption on pre-patterned surfaces. Using this approach, tunable plasmonic dimer nano-arrays are fabricated on a silicon surface. This involves employing electron beam lithography to create adsorption sites on the surface and utilizing self-organized adsorption of DNA origami functionalized with two gold nanoparticles (AuNPs). The desired folding of the DNA origami helices can be controlled by the size and shape of the adsorption sites. This approach can for example be used to tune the center-to-center distance of the AuNPs dimers on the origami template. To demonstrate this technique's efficiency, the Raman signal of dye molecules (carboxy tetramethylrhodamine, TAMRA) coated on the AuNPs surface are investigated. These findings highlight the potential of tunable DNA origami-based plasmonic nanostructures for many applications.

2.
Brain Neurorehabil ; 17(1): e4, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38585030

ABSTRACT

In this study, we conducted a survey targeting 191 physical therapists (PTs) and 159 occupational therapists (OTs) in South Korea to explore attitudes toward virtual rehabilitation. Utilizing the Korean version of the ADOPT VR by Glegg et al., OT exhibited significantly more experience with virtual reality (VR) and active video games (AVG) than PT. Therapists with VR/AVG experience scored significantly higher in most categories, and the scores in each category were significantly correlated with the Behavioral Intention category, reflecting the willingness to use VR/AVG. The biggest barriers identified were insufficient funds and setup assistance for the equipment. Differences in responses between the groups with and without VR/AVG experience were most prominent in terms of lack of interest and funding. Therapists' attitudes, perceptions, and intentions toward VR/AVG are crucial factors in the establishment and implementation of VR/AVG; thus, the results of this study provide valuable evidence for future policies related to VR/AVG in rehabilitation medicine.

3.
ChemSusChem ; : e202400303, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38507245

ABSTRACT

Advanced in situ analyses are indispensable for comprehending the catalyst aging mechanisms of Pt-based PEM fuel cell cathode materials, particularly during accelerated stress tests (ASTs). In this study, a combination of in situ small-angle and wide-angle X-ray scattering (SAXS & WAXS) techniques were employed to establish correlations between structural parameters (crystal phase, quantity, and size) of a highly active skeleton-PtCo (sk-PtCo) catalyst and their degradation cycles within the potential range of the start-up/shut-down (SUSD) conditions. Despite the complex case of the sk-PtCo catalyst comprising two distinct fcc alloy phases, our complementary techniques enabled in situ monitoring of structural changes in each crystal phase in detail. Remarkably, the in situ WAXS measurements uncover two primary catalyst aging processes, namely the cobalt depletion (regime I) followed by the crystallite growth via Ostwald ripening and/or particle coalescence (regime II). Additionally, in situ SAXS data reveal a continuous size growth over the AST. The Pt-enriched shell thickening based on the Co depletion within the first 100 SUSD cycles and particle growth induced by additional potential cycles were also collaborated by ex situ STEM-EELS. Overall, our work shows a comprehensive aging model for the sk-PtCo catalyst probed by complementary in situ WAXS and SAXS techniques.

4.
Healthcare (Basel) ; 11(18)2023 Sep 14.
Article in English | MEDLINE | ID: mdl-37761741

ABSTRACT

Sound waves generate acoustic resonance energy that penetrates deeply and safely into body areas normal mechanical vibrations cannot reach. The sonic balance pad utilizes these sound waves to create an optimal musculoskeletal response. The purpose of this study was to investigate the effects of a 4-week ankle stabilization exercise program using a sonic balance pad on proprioceptive sense and balance ability in individuals with ankle instability. This study was conducted as a randomized control-group pre-and post-test design in 30 participants (21 females and 9 males) who had experienced an ankle fracture or sprain within the last 5 years or who scored 11 points or more on The Identification of Functional Ankle Instability. The ankle stabilization exercise program was conducted for 4 weeks in the experimental group (n = 15), to which sonic pads were applied, and the control group (n = 15), to which balance pads were applied. All participants were assessed for their intrinsic proprioceptive sense of dorsiflexion and plantarflexion, static balance test, dynamic balance test, and long jump test were measured before and after 4 weeks as dependent variables. After 4 weeks of training, a significant difference was shown in the right dorsiflexion error (Balance pad = PRE: 2.47 ± 0.92; POST: 2.33 ± 1.40, Sonic pad = PRE: 3.27 ± 1.39; POST: 1.20 ± 0.77) and the left plantar flexion error (Balance pad = PRE: 2.00 ± 1.36; POST: 2.73 ± 1.22, Sonic pad = PRE: 3.53 ± 1.25; POST: 2.20 ± 1.01) (p < 0.05) between the experimental and control groups in the proprioception test. In the static balance test, there was no significant difference between the experimental and control groups during the pre, post, and variation stages. However, in the Y-Balance test, which is one of the dynamic balance tests, there was a significant difference between the experimental and control groups at various points, including anterior left (Balance pad = PRE: 72.85 ± 19.95; POST: 63.41 ± 8.66, Sonic pad = PRE: 68.16 ± 6.38; POST: 76.17 ± 3.67), posteromedial right (Balance pad = PRE: 78.59 ± 15.34; POST: 81.41 ± 10.37, Sonic pad = PRE: 86.33 ± 16.44; POST: 102.23 ± 11.53), posteromedial left (Balance pad = PRE: 78.00 ± 16.99; POST: 83.36 ± 10.15, Sonic pad = PRE: 88.96 ± 19.92; POST: 102.45 ± 12.98), posterolateral right (Balance pad = PRE: 78.16 ± 14.33; POST: 82.61 ± 10.73, Sonic pad = PRE: 87.95 ± 17.51; POST: 101.34 ± 15.37), and posterolateral left (Balance pad = PRE: 80.86 ± 14.96; POST: 81.31 ± 7.16, Sonic pad = PRE: 91.23 ± 17.35; POST: 104.18 ± 11.78) (p < 0.05). Moreover, in the single-leg long jump test, which is another dynamic balance test, the experimental group (Sonic pad = PRE: 100.27 ± 29.00; POST: 116.80 ± 28.86) also demonstrated a significant difference in the right single-leg long jump compared to the control group (Balance pad = PRE: 91.87 ± 17.74; POST: 97.67 ± 17.70) (p < 0.05). When a sonic balance pad using sound waves was applied in addition to a 4-week ankle stabilization exercise program for participants with ankle stability, it helped to improve proprioception and dynamic balance ability.

5.
Microsc Microanal ; 29(3): 1062-1070, 2023 Jun 09.
Article in English | MEDLINE | ID: mdl-37749694

ABSTRACT

The size of nanoparticles is a critical parameter with regard to their performance. Therefore, precise measurement of the size distribution is often required. While electron microscopy (EM) is a useful tool to image large numbers of particles at once, manual analysis of individual particles in EM images is a time-consuming and labor-intensive task. Therefore, reliable automatic detection methods have long been desired. This paper introduces a novel automatic particle analysis software package based on the circular Hough transform (CHT). Our software package includes novel features to enhance precise particle analysis capabilities. We applied the CHT algorithm in an iterative workflow, which ensures optimal detection over wide radius intervals, to deal with overlapping particles. In addition, smart intensity criteria were implemented to resolve common difficult cases that lead to false particle detection. Implementing these criteria enabled an effective and precise analysis by minimizing detection of false particles. Overall, our approach showed reliable particle analysis results by resolving common types of particle overlaps and deformation with only negligible errors.

6.
Nanotechnology ; 34(42)2023 Aug 02.
Article in English | MEDLINE | ID: mdl-37442100

ABSTRACT

This study explores important parameters for achieving a high-level positional control of DNA-nanoparticle hybrid structures by drop-casting onto a pre-structured silicon surface, in which the active adsorption sites were defined using electron beam lithography. By confining the adsorption sites to the scale of the DNA origami, we create multi-dimensional patterns and study the effect of diffusion and hybrid nanostructure concentration in the liquid on site occupation. We also propose a physical diffusion model that highlights the importance of surface diffusion in facilitating the adsorption of hybrid nanostructure onto active sites, particularly for two and one-dimensional adsorption sites. Our study shows prominent results of the hybrid nanostructure's selective adsorption, indicating high adsorption efficiency and precise control over the position, as well as the spatial orientation. We anticipate similar results in related systems, both in terms of different surfaces and similar DNA structures. Overall, our findings offer promising prospects for the development of large-scale nanoarrays on micrometer-scale surfaces with nanometer precision and orientation control.


Subject(s)
Nanoparticles , Nanostructures , Nanotechnology/methods , Gold/chemistry , Nanostructures/chemistry , DNA/chemistry , Nucleic Acid Conformation
7.
Nat Mater ; 22(8): 992-998, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37365226

ABSTRACT

Conventional antiferroelectric materials with atomic-scale anti-aligned dipoles undergo a transition to a ferroelectric (FE) phase under strong electric fields. The moiré superlattice formed in the twisted stacks of van der Waals crystals exhibits polar domains alternating in moiré length with anti-aligned dipoles. In this moiré domain antiferroelectic (MDAF) arrangement, the distribution of electric dipoles is distinguished from that of two-dimensional FEs, suggesting dissimilar domain dynamics. Here we performed an operando transmission electron microscopy investigation on twisted bilayer WSe2 to observe the polar domain dynamics in real time. We find that the topological protection, provided by the domain wall network, prevents the MDAF-to-FE transition. As one decreases the twist angle, however, this transition occurs as the domain wall network disappears. Exploiting stroboscopic operando transmission electron microscopy on the FE phase, we measure a maximum domain wall velocity of 300 µm s-1. Domain wall pinnings by various disorders limit the domain wall velocity and cause Barkhausen noises in the polarization hysteresis loop. Atomic-scale analysis of the pinning disorders provides structural insight on how to improve the switching speed of van der Waals FEs.

8.
Adv Mater ; 35(32): e2300200, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37154173

ABSTRACT

Complex oxide heterointerfaces contain a rich playground of novel physical properties and functionalities, which give rise to emerging technologies. Among designing and controlling the functional properties of complex oxide film heterostructures, vertically aligned nanostructure (VAN) films using a self-assembling bottom-up deposition method presents great promise in terms of structural flexibility and property tunability. Here, the bottom-up self-assembly is extended to a new approach using a mixture containing a 2Dlayer-by-layer film growth, followed by a 3D VAN film growth. In this work, the two-phase nanocomposite thin films are based on LaAlO3 :LaBO3 , grown on a lattice-mismatched SrTiO3001 (001) single crystal. The 2D-to-3D transient structural assembly is primarily controlled by the composition ratio, leading to the coexistence of multiple interfacial properties, 2D electron gas, and magnetic anisotropy. This approach provides multidimensional film heterostructures which enrich the emergent phenomena for multifunctional applications.

9.
Materials (Basel) ; 16(8)2023 Apr 18.
Article in English | MEDLINE | ID: mdl-37110036

ABSTRACT

The use of biodegradable materials for implants is a promising strategy to overcome known long-term clinical complications related to permanent implants. Ideally, biodegradable implants support the damaged tissue for a certain period and then degrade, while the physiological function of the surrounding tissue is restored. Although Mg-based alloys nearly ideally lend themselves to biodegradable implants, a few critical shortcomings promoted the development of alternative alloy systems. Due to their reasonably good biocompatibility, moderate corrosion rate without hydrogen evolution and adequate mechanical properties, increasing attention has been paid to Zn alloys. In this work, precipitation-hardening alloys in the system Zn-Ag-Cu were developed relying on thermodynamic calculations. After casting the alloys, their microstructures were refined by thermomechanical treatment. The processing was tracked and directed, respectively, by routine investigations of the microstructure, associated with hardness assessments. Although microstructure refinement increased the hardness, the material proved to be susceptible to aging as the homologous temperature of zinc is at 0.43 Tm. Besides mechanical performance and corrosion rate, long-term mechanical stability is another crucial factor that must be taken into consideration to ensure the safety of the implant and thus requires a profound understanding of the aging process.

10.
Brain Neurorehabil ; 16(1): e8, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37033001

ABSTRACT

The attitude toward telerehabilitation (TR) among therapists (191 physical therapists and 159 occupational therapists) in Korea was surveyed. The survey consisted of 15 questions in the following 8 domains: awareness(AW), attitude (AT), perceived usefulness (PU), perceived behavioral control (PBC), self-efficacy (SE), facilitating conditions (FC), barriers (B), and behavioral intention (BI). Therapists with experience in TR responded with higher scores in all domains except B, regardless of their specialty. The most perceived barriers to TR were unmatched insurance fees and a lack of technical support. Experience with TR was a major factor in attitude and behavior intention toward TR.

11.
Healthcare (Basel) ; 11(6)2023 Mar 20.
Article in English | MEDLINE | ID: mdl-36981553

ABSTRACT

The purpose of this study was to apply deep and slow breathing to the elderly, who can be classified as potential dementia patients, to confirm changes in the cognitive functions of learning and memory. Forty-five elderly subjects were randomly and evenly divided into a rest group (RG), a before group (BG), and an after group (AG). Measurements of their cognitive abilities were obtained before testing (PT), 30 min after learning (STT), and 24 h after learning (LTT). After PT measurements were obtained from all three groups, the RG and AG conducted new cognitive skills learning, while the BG performed deep and slow breathing (DSB) for 30 min before learning new cognitive skills. After all the three groups underwent 30 min of learning, the STT was performed. Subsequently, the AG performed DSB for 30 min. Finally, 24 h after learning, the LTT was conducted for all three groups. Changes were compared and analyzed by measuring the retention of new cognitive skills and attention, working memory, and spatial perception of cognitive functions. A two-way repeated measure analysis of variance measured the effect of the application of DSB in the three groups. These results demonstrated a significant interaction of time and time*group in all measurements of retention and attention, working memory, and spatial perception. This study confirms the benefit of DSB as part of a dementia prevention training protocol.

12.
Nano Lett ; 23(7): 2945-2951, 2023 Apr 12.
Article in English | MEDLINE | ID: mdl-36972518

ABSTRACT

Utilizing advanced transmission electron microscopy (TEM), the structure at the (110)-type twin boundary (TB) of Ce-doped GdFeO3 (C-GFO) has been investigated with picometer precision. Such a TB is promising to generate local ferroelectricity within a paraelectric system, while precise knowledge about its structure is still largely missing. In this work, a direct measurement of the cation off-centering with respect to the neighboring oxygen is enabled by integrated differential phase contrast (iDPC) imaging, and up to 30 pm Gd off-centering is highly localized at the TB. Further electron energy loss spectroscopy (EELS) analysis demonstrates a slight accumulation of oxygen vacancies at the TB, a self-balanced behavior of Ce at the Gd sites, and a mixed occupation of Fe2+ and Fe3+ at the Fe sites. Our results provide an informative picture with atomic details at the TB of C-GFO, which is indispensable to further push the potential of grain boundary engineering.

13.
Nature ; 609(7928): 695-700, 2022 09.
Article in English | MEDLINE | ID: mdl-36131038

ABSTRACT

Electrostriction is a property of dielectric materials whereby an applied electric field induces a mechanical deformation proportional to the square of that field. The magnitude of the effect is usually minuscule (<10-19 m2 V-2 for simple oxides). However, symmetry-breaking phenomena at the interfaces can offer an efficient strategy for the design of new properties1,2. Here we report an engineered electrostrictive effect via the epitaxial deposition of alternating layers of Gd2O3-doped CeO2 and Er2O3-stabilized δ-Bi2O3 with atomically controlled interfaces on NdGaO3 substrates. The value of the electrostriction coefficient achieved is 2.38 × 10-14 m2 V-2, exceeding the best known relaxor ferroelectrics by three orders of magnitude. Our theoretical calculations indicate that this greatly enhanced electrostriction arises from coherent strain imparted by interfacial lattice discontinuity. These artificial heterostructures open a new avenue for the design and manipulation of electrostrictive materials and devices for nano/micro actuation and cutting-edge sensors.


Subject(s)
Oxides , Oxides/chemistry
14.
Psychol Health Med ; 26(9): 1079-1090, 2021 10.
Article in English | MEDLINE | ID: mdl-32615794

ABSTRACT

The purpose of this study was to investigate the effects of the deep and slow breathing (DSB) on the chain-reaction changes of stress stimulation at over time by measuring electroencephalogram (EEG) and heart rate variability (HRV). Twenty-six healthy subjects were divided into two different groups: control group (CG) and DSB group (DSBG). All subjects were exposed to a stress-stimulated environment with 80% exercise intensity. After the 80% exercise intensity was maintained for 10 minutes, the subjects rested for 5 minutes and then measuring EEG and HRV. The chain-reaction changes of stress stimulation through EEG and HRV analysis showed that DSBG had higher values of alpha/high-beta ratio and High-Frequency (HF) value of HRV than CG (p <.05), and Low-Frequency/High-Frequency (LF/HF) ratio of DSBG is significant time-group interaction, indicating a significant difference between groups (p <.05). In consequence, DSB will be used as a meaningful intervention for patients of stress-related diseases or potential patients.


Subject(s)
Breathing Exercises , Exercise , Stress, Physiological , Adult , Electroencephalography , Exercise/physiology , Heart Rate , Humans , Treatment Outcome
15.
ACS Appl Mater Interfaces ; 11(8): 8276-8283, 2019 Feb 27.
Article in English | MEDLINE | ID: mdl-30719908

ABSTRACT

The light control of nonvolatile nanoscale memories could represent a fundamental step toward novel optoelectronic devices with memory and logic functionalities. However, most of the proposed devices exhibit insufficient control in terms of the reversibility, data retention, photosensitivity, limited-photoactive area, and so forth. Here, in a proof-of-concept work, we demonstrate the use of the tip-enhanced bulk photovoltaic (BPV) effect to realize programmable nanoscopic writing of nonphotoactive electronic devices by light control. We show that electronic properties of solid-state memory devices can be reversibly and location-precisely manipulated in the nanoscale using the BPV effect in combination with the nanoscale contact connection, that is, atomic force microscopy (AFM) probe technique in this work. More than 105% reversible switching of tunneling electroresistance of ferroelectric tunnel junctions is exclusively achieved by light control. Using the same light-controlled AFM probe technique, we also present precise nanoscopic and multiple-state writing of LaAlO3/SrTiO3 two-dimensional electron gas (2DEG)-based field-effect transistors. The tip-enhanced BPV effect can offer a novel avenue for reversible and multistate light control of a wide range of electronic memory devices in the nanoscale and may lead to more sophisticated functionalities in optoelectronic applications.

16.
J Stroke Cerebrovasc Dis ; 28(5): 1200-1211, 2019 May.
Article in English | MEDLINE | ID: mdl-30712955

ABSTRACT

BACKGROUND: Stroke weakens the respiratory muscles, which in turn may influence the trunk stability; it is unclear whether the progressive respiratory muscle training (RMT) is effective in improving the trunk stability. The aim of this study was to investigate the effects of progressive RMT with trunk stabilization exercise (TSE) on respiratory muscles thickness, respiratory muscle functions, and trunk stability in chronic stroke survivors. METHODS: This is a pilot randomized controlled trial. Chronic stroke survivors (n = 33) who were able to sit independently participated in the tstudy. The participants were allocated into the RMP with TSE group or the TSE group. The respiratory muscle thickness during resting and contraction were measured. Maximal expiratory pressure (MEP), peak expiratory flow (PEF), and forceful expiratory volume at 1 sec (FEV1) for forced expiratory muscle function and maximal inspiratory pressure (MIP), peak inspiratory flow (PIF), and vital capacity (VC) for inspiratory muscle function were examined. Trunk stability was estimated by maximal velocity and path length of the center of pressure (COP) by using a balance board with sitting posture. RESULTS: The respiratory muscle thickness was significantly increased on the affected side in the RMT group than in the TSE group. The MEP, PEF, MIP, and PIF were significantly increased in the RMT group than in the TSE group; however, FEV1 and VC showed no significant differences between the 2 groups. Trunk stability for the maximal velocity of COP of extension and affected side bending was significantly increased in the RMT group than in the TSE group. In addition, the maximal path length of COP of flexion, extension, affected/less affected side bending was significantly increased in the RMT group than in the TSE group. CONCLUSIONS: RMT combined with TSE can be suggested as an effective method to improve the respiratory muscle thickness, respiratory muscle functions, and trunk stability in chronic stroke survivors as opposed to TSE only.


Subject(s)
Breathing Exercises , Muscle Strength , Postural Balance , Respiratory Muscles/physiopathology , Stroke Rehabilitation/methods , Stroke/therapy , Aged , Female , Humans , Male , Middle Aged , Pilot Projects , Recovery of Function , Republic of Korea , Respiratory Function Tests , Respiratory Muscles/diagnostic imaging , Stroke/diagnosis , Stroke/physiopathology , Time Factors , Treatment Outcome , Ultrasonography
17.
Hong Kong Physiother J ; 39(2): 125-132, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31889763

ABSTRACT

BACKGROUND: The cut-off values of walking velocity and classification of functional mobility both have a role in clinical settings for assessing the walking function of stroke patients and setting rehabilitation goals and treatment plans. OBJECTIVE: The present study investigated whether the cut-off values of the modified Rivermead Mobility Index (mRMI) and walking velocity accurately differentiated the walking ability of stroke patients according to the modified Functional Ambulation Category (mFAC). METHODS: Eighty two chronic stroke patients were included in the study. The comfortable/maximum walking velocities and mRMI were used to measure the mobility outcomes of these patients. To compare the walking velocities and mRMI scores for each mFAC point, one-way analysis of variance and the post-hoc test using Scheffe's method were performed. The patients were categorized according to gait ability into either mFAC = VII or mFAC ≤ VI group. The cut-off values for mRMI and walking velocities were calculated using a receiver-operating characteristic curve. The odds ratios of logistic regression analysis (Wald Forward) were analyzed to examine whether the cut-off values of walking velocity and mRMI can be utilized to differentiate functional walking levels. RESULTS: Except for mFACs III and IV, maximum walking velocity differed between mFAC IV and mFAC V ( p < 0 . 01 ) , between mFAC V and mFAC VI ( p < 0 . 001 ) , and between mFAC VI and mFAC VII ( p < 0 . 05 ) . The cut-off value of mRMI is > 26 . 5 and the area under the curve is 0.87, respectively; the cut-off value for comfortable walking velocity is > 0 . 77 m/s and the area under the curve is 0.92, respectively; also, the cut-off value for maximum walking velocity is > 0 . 92 m/s and the area under the curve is 0.97, respectively. In the logistic regression analysis, the maximum walking velocity ( > 0 . 92 m/s, OR = 22 . 027 ) and mRMI ( > 26 . 5 scores, OR = 10 . 283 ) are able to distinguish mFAC = VII from mFAC ≤ VI. CONCLUSION: The cut-off values of maximum walking velocity and mRMI are recommended as useful outcome measures for assessing ambulation levels in chronic stroke patients during rehabilitation.

18.
Adv Mater ; 30(39): e1802025, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30133008

ABSTRACT

A surge in interest of oxide-based materials is testimony for their potential utility in a wide array of device applications and offers a fascinating landscape for tuning the functional properties through a variety of physical and chemical parameters. In particular, selective electronic/defect doping has been demonstrated to be vital in tailoring novel functionalities, not existing in the bulk host oxides. Here, an extraordinary interstitial doping effect is demonstrated centered around a light element, boron (B). The host matrix is a novel composite system, made from discrete bulk LaAlO3 :LaBO3 compounds. The findings show a spontaneous ordering of the interstitial B cations within the host LaAlO3 lattices, and subsequent spin-polarized charge injection into the neighboring cations. This leads to a series of remarkable cation-dominated electrical switching and high-temperature ferromagnetism. Hence, the induced interstitial doping serves to transform a nonmagnetic insulating bulk oxide into a ferromagnetic ionic-electronic conductor. This unique interstitial B doping effect upon its control is proposed to be as a general route for extracting/modifying multifunctional properties in bulk oxides utilized in energy and spin-based applications.

19.
Microsc Microanal ; 24(2): 139-146, 2018 04.
Article in English | MEDLINE | ID: mdl-29560845

ABSTRACT

Spiders are natural specialists in fiber processing. In particular, cribellate spiders manifest this ability as they produce a wool of nanofibers to capture prey. During its production they deploy a sophisticated movement of their spinnerets to darn in the fibers as well as a comb-like row of setae, termed calamistrum, on the metatarsus which plays a key role in nanofiber processing. In comparison to the elaborate nanofiber extraction and handling process by the spider's calamistrum, the human endeavors of spinning and handling of artificial nanofibers is still a primitive technical process. An implementation of biomimetics in spinning technology could lead to new materials and applications. Despite the general progress in related fields of nanoscience, the expected leap forward in spinning technology depends on a better understanding of the specific shapes and surfaces that control the forces at the nanoscale and that are involved in the mechanical processing of the nanofibers, respectively. In this study, the authors investigated the morphology of the calamistrum of the cribellate spider Uloborus plumipes. Focused ion beam and scanning electron microscopy tomography provided a good image contrast and the best trade-off between investigation volume and spatial resolution. A comprehensive three-dimensional model is presented and the putative role of the calamistrum in nanofiber processing is discussed.

20.
J Stroke Cerebrovasc Dis ; 26(10): 2313-2319, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28606661

ABSTRACT

BACKGROUND: Although the Kinect gaming system (Microsoft Corp, Redmond, WA) has been shown to be of therapeutic benefit in rehabilitation, the applicability of Kinect-based virtual reality (VR) training to improve motor function following a stroke has not been investigated. This study aimed to investigate the effects of VR training, using the Xbox Kinect-based game system, on the motor recovery of patients with chronic hemiplegic stroke. METHODS: This was a randomized controlled trial. Twenty patients with hemiplegic stroke were randomly assigned to either the intervention group or the control group. Participants in the intervention group (n = 10) received 30 minutes of conventional physical therapy plus 30 minutes of VR training using Xbox Kinect-based games, and those in the control group (n = 10) received 30 minutes of conventional physical therapy only. All interventions consisted of daily sessions for a 6-week period. All measurements using Fugl-Meyer Assessment (FMA-LE), the Berg Balance Scale (BBS), the Timed Up and Go test (TUG), and the 10-meter Walk Test (10mWT) were performed at baseline and at the end of the 6 weeks. RESULTS: The scores on the FMA-LE, BBS, TUG, and 10mWT improved significantly from baseline to post intervention in both the intervention and the control groups after training. The pre-to-post difference scores on BBS, TUG, and 10mWT for the intervention group were significantly more improved than those for the control group (P <.05). CONCLUSIONS: Evidence from the present study supports the use of additional VR training with the Xbox Kinect gaming system as an effective therapeutic approach for improving motor function during stroke rehabilitation.


Subject(s)
Motor Activity , Stroke Rehabilitation , Virtual Reality , Aged , Exercise Test , Female , Follow-Up Studies , Hemiplegia/physiopathology , Hemiplegia/rehabilitation , Humans , Male , Middle Aged , Motor Activity/physiology , Preliminary Data , Stroke/physiopathology , Stroke Rehabilitation/instrumentation , Stroke Rehabilitation/methods , Treatment Outcome , Video Games
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