Background Vibrotactile feedback systems are widely used in assistive technology,wearable devices,and virtual environments to deliver precise tactile information.The timing of interstimulus intervals(ISIs)plays a crit...Background Vibrotactile feedback systems are widely used in assistive technology,wearable devices,and virtual environments to deliver precise tactile information.The timing of interstimulus intervals(ISIs)plays a critical role in determining how accurately users perceive and interpret vibrotactile patterns.The optimal use of ISIs can increase the effectiveness of these systems,improve user interaction,and enable reliable,intuitive feedback in diverse applications.We examined how different interstimulus intervals ISIs impact the accuracy of vibrotactile pattern recognition.Methods Participants wore a forearm-mounted device with six voice coil actuators arranged in a 3×2 grid,delivering Braille-based vibrotactile patterns sequentially at ISIs ranging from 10 to 2500 ms.Eight participants performed identification tasks involving Icelandic Braille patterns categorized as either short(2-3 actuators)or long(4-5 actuators).A repeated measures ANOVA was conducted to assess the effects of ISI,pattern type,and practice(across two testing blocks)on pattern recognition accuracy.Results For short patterns,accuracy was highest(92%-98%)at ISIs of 50-700 ms,with peak performance at 300 ms.For long patterns,accuracy reached 86%-94%at ISIs of 100-500 ms,peaking at 400 ms.Participants were more accurate with short patterns,and performance improved significantly over time for both short and long patterns,highlighting the importance of training for vibrotactile pattern recognition.Conclusions These results underscore the importance of careful selection of ISIs in vibrotactile feedback systems for accurate pattern identification.The findings provide valuable insights for conveying tactile information using wearable devices,contributing to better tactile feedback and performance in applications requiring precise vibrotactile information delivery.展开更多
Objective:The objective of this study was to compare the effect of nurse and beloved family member’s recording voice on consciousness and physical parameters in patients with coma state.Materials and Methods:A random...Objective:The objective of this study was to compare the effect of nurse and beloved family member’s recording voice on consciousness and physical parameters in patients with coma state.Materials and Methods:A randomized control trial parallel group design was conducted among 45 comatose patients divided into two intervention groups,i.e.nurse voice stimulus group,receiving nurses voice with standard care,family members voice stimulus group receiving their beloved family member voice with standard care and one control group receiving only standard care in medicine intensive care unit.The intervention was provided three times a day,each lasting 5 min for 7 days in addition to standard care.Repeated measure analysis of variance and independent t-test were used to compare within and between groups,respectively.Results:The study found significant differences in Glasgow coma scale(GCS)scores within both the nurse(F=2.78,P=0.042)and family member(F=10.27,P=0.0001)voice stimulus groups over 7 days.Comparing GCS scores between intervention groups showed significant variations before(P=0.028),during(P=0.047),and after(P=0.036)the intervention on day 7.Comparing GCS scores between the family members’voice stimulus group and the control group,significant changes were observed on days 5 and 7(P=0.043,0.030,0.030,and 0.014,0.012,0.012)before,during,and after the intervention.Conclusions:The use of beloved family members’voices proved more effective in elevating the patients’level of consciousness compared to both the nurse voice stimulus group and the control group.展开更多
Organic afterglow materials hold significant potential for applications in information storage,anticounterfeiting,and biological imaging.However,studies on afterglow materials capable of ultra-wide range excitation an...Organic afterglow materials hold significant potential for applications in information storage,anticounterfeiting,and biological imaging.However,studies on afterglow materials capable of ultra-wide range excitation and emission simultaneously are limited.To enhance the practicality of strong emission single-component organic afterglow systems,overcoming the constraints of crystalline or other rigid environments is essential.We have developed solid-state dual-persistent thermally activated delayed fluorescence(TADF)and room temperature phosphorescence(RTP)emissions spanning yellow to red under visible light excitation,utilizing a single-molecule terminal group regulation strategy.The RTP lifetime extends from 4.19 ms to 399.70 ms.These afterglow materials exhibit an ultra-wide absorption range from 200 nm to 800 nm,rendering them capable of being excited by both sunlight simulator and nearinfrared radiation.The upconversion phosphorescence lifetime under 808 nm excitation reaches 13.72μs.The double persistent emission of these compounds is temperature-sensitive.Moreover,following grinding or heat treatment,accompanied by extensive afterglow color conversion due to planarization of excited state conformations and additional efficient kRIsc generation.In addition,the amorphous state post melt annealing facilitates the afterglow transition from yellow to green.Crucially,these compounds also maintain stable ultra-long afterglow emission in aqueous and acid-base environments.Overall,we have successfully developed a series of single-component intelligent luminescent materials that demonstrate significant benefits,including dual TADF and RTP emissions,adjustable afterglow lifetimes,a broad range of excitation and emission wavelengths,multi-modal luminescence not restricted to crystalline states,and robust afterglow performance in challenging environments,setting the stage for the practical deployment of afterglow materials in engineering applications,the upconversion afterglow emission also holds promising potential for applications in the field of biological imaging.展开更多
Purpose: This study aimed to investigate the immediate effects of optokinetic stimulation (OKS) using virtual reality (VR) on visual dependency and sensory reweighting in postural control during static standing. Speci...Purpose: This study aimed to investigate the immediate effects of optokinetic stimulation (OKS) using virtual reality (VR) on visual dependency and sensory reweighting in postural control during static standing. Specifically, it examined whether VR-based OKS could reduce visual dependency more effectively than visual deprivation through eye closure. Methods: Ten healthy adults participated in this study. A balance function meter was used to measure postural stability, including Romberg ratios before and after two conditions: VR-based OKS (VR + OKS) and eye closure (EC). Participants performed a two-minute standing task under each condition in random order, with adequate rest between tasks. In the VR + OKS condition, a smartphone-based VR headset presented a rotational OKS, while in the EC condition, participants stood with their eyes closed. Statistical analyses were conducted using paired t-tests to compare pre- and post-task Romberg ratios. Results: No significant differences were observed in the pre-task Romberg ratios between conditions. After the VR + OKS condition, significant reductions in Romberg A and Romberg V were observed. In contrast, no significant changes were noted in Romberg ratios after the EC condition. Conclusion: VR-based OKS significantly reduced visual dependency, as indicated by decreased Romberg ratios, suggesting its potential to facilitate sensory reweighting during postural control. These findings highlight the utility of low-cost VR devices in balance rehabilitation for conditions involving high visual dependency. Future studies should expand on this preliminary research by including larger sample sizes and diverse populations to confirm its clinical applicability.展开更多
Objective: To observe the influence of acupuncture stimulus and thermal stimulus on the expression of mast cells(MCs) and 5-hydroxytryptamine(5-HT) in local acupoint area of Guanyuan(关元 CV 4) and serum 5-HT in rats....Objective: To observe the influence of acupuncture stimulus and thermal stimulus on the expression of mast cells(MCs) and 5-hydroxytryptamine(5-HT) in local acupoint area of Guanyuan(关元 CV 4) and serum 5-HT in rats.Methods: Thirty-nine male C57 BL/6 rats were randomly divided into blank control group, acupuncture stimulus group and thermal stimulus group, with 13 rats in each group. The rats were stimulated by manual acupuncture at CV 4 for 5 min in acupuncture stimulus group, while those in thermal stimulus group were stimulated by adopting a thermal moxibustion apparatus on CV 4 for 30 min. The expression of MC and 5-HT in the skin in the acupoint area of CV 4 before and after acupuncture stimulus and thermal stimulus was observed and analyzed via adopting toluidine blue staining method and immunofluorescence histochemical method(5 rats were selected from each group), and the 5-HT content in serum before and after stimulus was determined through enzyme-linked immunosorbent assay(ELISA)(8 rats were selected from each group). The influence of acupuncture stimulus and thermal stimulus on the contents of MC and 5-HT in the skin and serum 5-HT in rats was analyzed and compared.Results: ① After acupuncture stimulus or thermal stimulus on CV 4 of C57 BL/6 rats, the number of MC in the acupoint area significantly increased when compared with that in blank group(the acupuncture stimulus group 12.40 ± 2.07 vs. the blank group 3.00 ±5.96;thermal stimulus group 26.20 ± 10.85 vs. the blank group 12.40 ± 2.07, both P< 0.05), and MC aggregation and degranulation were observed(the acupuncture stimulus group 17.80 ±4.55 vs. the blank group 8.00 ±3.16;the thermal stimulus group24.00±9.05 vs. the blank group 8.00±3.16. P<0.05, P< 0.01).② After acupuncture stimulus or thermal stimulus, 5-HT was released by MCs in the acupoint area, which aggregated around the blood vessels,and the number of 5-HT in the acupoint area significantly increased when compared with that in blank group(the blank group 3.00 ±1.28 vs. the acupuncture stimulus group 10.02 ±3.21;the blank group3.00 ±1.28 vs. the thermal stimulus group 14.00 ±3.94, both P< 0.01).③ Compared with blank group,both acupuncture stimulus and thermal stimulus could reduce the 5-HT content in serum(the blank group 0.72 ±0.2372 vs. acupuncture stimulus group 0.43 ±0.21: the blank group 0.72 ±0.24 vs. thermal stimulus group 0.32 ±0.18, both P<0.01), and the effect in thermal stimulus group was slightly superior to that in acupuncture stimulus group(P<0.05).Conclusion: Both acupuncture stimulus and thermal stimulus can cause the aggregation and degranulation of MCs and high expression of 5-HT in the acupoint area. The effect of thermal stimulus was superior to that of acupuncture stimulus in degranulation.展开更多
Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. U...Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.展开更多
BACKGROUND： Electrophysiological studies using brain slices have revealed that the developmental regulation of synaptic plasticity in vocal learning pathway is essential for song learning in zebra finches. Publicatio...BACKGROUND： Electrophysiological studies using brain slices have revealed that the developmental regulation of synaptic plasticity in vocal learning pathway is essential for song learning in zebra finches. Publications reporting in vivo electrophysiological investigation are scarce. Many aspects of neural mechanisms underlying song learning and production still remain uncertain. OBJECTIVE： To observe the efficacy of paired pulses and the effect on synaptic transmission induced by low-frequency stimulations, high-frequency stimulations, and theta-burst stimulations. DESIGN, TIME AND SETTING： A comparative observation. The experiment was conducted from October 2006 to October 2007 in the Neurophysiology Laboratory of South-China Normal University. MATERIALS： Twenty-four adult male zebra finches were supplied by the Department of Animal Experiment of College of Life Sciences, South China Normal University. A SEN-7203 stimulator （NIHON KOHDEN）, as well as a DSJ-731WF microelectrode amplifier and DSJ-F amplifier （provided by South-China Normal University）, were used to stimulate and record, respectively. METHODS： Animals were randomly divided into low-frequency, high-frequency, and theta-burst frequency stimulation groups. After recording evoked potentials, an input-output curve was evaluated. Subsequently, the efficacy of paired pulses with different stimulus intensity （1/3, 1/2, 2/3, or 3/4 of the value that induced the largest synaptic response）, as well as interpulse intervals （50, 75, and 100 ms）, was measured in each group. The test stimulus intensity was set to a level that evoked 1/2 or 1/3 amplitude of the maximum response. MAIN OUTCOME MEASURES： Changes in amplitude, slope, and area of evoked potentials elicited by different stimulus patterns. RESULTS： （1） Efficacy of paired pulses： there was significant paired-pulse facilitation in the high vocal center and robust nucleus of the arcopallium （HVC-RA） synapse. Efficacy decreased when paired-pulse intervals or stimulus intensities were increased. （2） Low-frequency stimulations at 1 Hz had a negligible effect on efficacy of synaptic transmission, while 5 Hz depressed synaptic transmission for only 5 minutes. （3） High-frequency stimulations at 50 Hz or 100 Hz induced synaptic depression that lasted for up to 30 minutes. （4） Theta-burst stimulation depressed synaptic transmission efficiency significantly for about 10 minutes. However, in contrast to low-frequency or high-frequency stimulations, theta-burst stimulations also induced slight potentiation of synaptic transmission for up to 60 minutes following depression phase, although the slope or area did not change. CONCLUSION： Paired pulses induced a remarkable efficacy of paired pulses in the high vocal center and robust nucleus of the arcopallium pathway. Low-frequency, high-frequency, or theta-burst frequency stimulation did not induce long-lasting changes in synaptic transmission.展开更多
Summary: To study the mechanism of the innoxious touch-stimulus on the modulation of hyperalgesia and the expression of the C-fos and the nerve growth factor (NGF) receptor-TrkA in the spinal dorsal horn neurons follo...Summary: To study the mechanism of the innoxious touch-stimulus on the modulation of hyperalgesia and the expression of the C-fos and the nerve growth factor (NGF) receptor-TrkA in the spinal dorsal horn neurons following the chronic constriction injury (CCI) of the sciatic nerve in rats, 60 female Sprague-Dawley rats were randomly divided into sham-operation group and CCI group, with each group being further divided into 3 subgroups on the 7th,14th and 28th day after operation (n=10). The mechanical and the thermal withdrawal threshold were assessed following the touch stiumulation after the CCI, immunohistochemical methods were employed to observe the expression of the C-fos and TrkA in spinal dorsal horn. Our results showed that the hyperalgesia appeared on the 4th day and reached the maximal level on the 14th day after operation. The expression of the C-fos also increased significantly and reached its maximal level on the 14th day after the touch-stimulus. Meanwhile, the TrkA expression was elevated significantly in both groups, as compared with basic data, and the difference was statistically significant (P<0.05). It is concluded that the level of the C-fos expression changed with the paw withdrawal threshold variation and increased markedly following the innoxious touch-stimulus. The expression of the TrkA receptors also increased gradually following the development of the neuropathic pain. The results suggest that C-fos may play a crucial role in the development of the hyperalgesia in the earlier-time of the neuropathic pain, but TrkA receptors may be involved in the long-lasting adaptive changes of the central pathway in neuropathic pain.展开更多
The thermal stability of normal lead styphnate（ N-LTNR） has been studied under severe temperature（- 70 ℃- 130 ℃ for 5 days） with a high optical microscope and camera were used to observe apparent morphology and ...The thermal stability of normal lead styphnate（ N-LTNR） has been studied under severe temperature（- 70 ℃- 130 ℃ for 5 days） with a high optical microscope and camera were used to observe apparent morphology and thermal gravimetric analysis was applied to study the physical changes. In addition,vacuum stability analysis,differential scanning calorimetry（ DSC）,thermal gravimetric analysis（ TGA） and purity analysis were utilized to study the chemical changes. As well as flame sensitivity analysis were used to investigated the explosive changes. The results show that N-LTNR has good chemical stability and fire function stability between- 70 ℃ and 130 ℃,but poor physical stability. When the temperature was exceeded than 110 ℃,the N-LTNR lost crystal water which made the energetic material become darker in color,lager in volume and lighter in weight（ 3. 416%） when the temperature was below- 40 ℃,the phenomenon of crystal broking and jumping happened.展开更多
Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric network...Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric networks of the hydrogels is crucial to elucidate their mechanical and swelling properties at the molecular level.In this report,the poly(DMAEMA-co-AA)hydrogels were synthesized and characterized by the macroscopic swelling measurements under different pH conditions.Furthermore,the microscopic structural dynamics of pH stimulus-responsive hydrogels were studied using FTIR and ultrafast IR spectroscopies from the viewpoint of the SCN-anionic solute as the local vibrational reporter.Ultrafast IR spectroscopic measurements showed the time constants of the vibrational population decay of SCN-were increased from 14±1 ps to 20±1 ps when the pH of the hydrogels varied from2.0 to 12.0.Rotational anisotropy measurements further revealed that the rotation of SCNanionic probe was restricted by the three-dimensional network formed in the hydrogels and the rotation of SCN-anionic probe cannot decay to zero especially at the pH of 7.0.These results are expected to provide a molecular-level understanding of the microscopic structure of the cross-linked polymeric network in the pH stimulus-responsive hydrogels.展开更多
A screening of environmental conditions that would elicit robust biofilm in a collection of Serratia marcescens isolated from soil revealed that exogenous milk protein increased biofilm productivity up to ten-fold. A ...A screening of environmental conditions that would elicit robust biofilm in a collection of Serratia marcescens isolated from soil revealed that exogenous milk protein increased biofilm productivity up to ten-fold. A select screening of fish pathogens, freshwater and human isolates identified several other species that responded similarly to exogenous protein. The optimal protein concentration was species specific;S. marcescens at 5% milk protein, Aeromonas sp. at 2% - 3%, Flavobacterium columnare at 1% and Pseudomonas aeruginosa at 0.1% - 0.4%. Media supplemented with milk protein also increased the cell counts in biofilm as well as the protein incorporated into the biofilm matrix. These data suggest that relatively high concentrations of exogenous protein may serve as an environmental trigger for biofilm formation, particularly for pathogenic bacteria exposed to relatively high concentrations of protein in bodily fluids and mucosal surfaces.展开更多
Based on our preceding studies on the aerodynamics of a falcoperegrinus in diving flight along a vertical dam it is known that even when the body shape of the bird is rather streamlined in V-shape some feathers tips m...Based on our preceding studies on the aerodynamics of a falcoperegrinus in diving flight along a vertical dam it is known that even when the body shape of the bird is rather streamlined in V-shape some feathers tips may elevate in certain regions of the body. These regions were identified in wind tunnel tests for typical diving flight conditions as regions of locally separated flow. A life-size model in V-shape of a falcoperegrinus with artificial feathers fixed along the body was studied in a wind tunnel to focus on the fluid-structure interaction of feathers located in this sector. The distal ends of the feathers show flow-induced vibrations at typical flight conditions which grow linear in amplitude with increasing angle of incidence until incipient separation. In light of the proven existence of vibration-sensitive mechanoreceptors in the follicles of secondary feathers in birds it is hypothesized that this linear amplitude response offers the bird to sense the angle of incidence during the diving flight using the vibration magnitude as sensory stimulus. Thus the bird in streamlined shape has still a good measure to control its attitude to be in the narrow window of safe angle of incidence. This might have implications also for other birds or technical applications of airfoil sensors regarding incipient separation detection.展开更多
Previous study demonstrated mesenchymal stem cells were sensitive to mechanical stimulus, and mechanical stimulus played great role in differentiation of mesenchymal stem cells.
Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a lar...Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a large challenge to design such stimulus responsive materials,especially functional materials having both dielectric switch and second harmonic generation(SHG).Here,a new stimuli-responsive switchable material [(CH_(3))_(3)N(CH_(2))_(2)Cl]_(2)]Mn(SCN)_(4)(H_(2)O)_(2)] was discovered as a potential secondharmonic generation(SHG) dielectric switch.It is worth noting that it has SHG characteristics before and after undergoing reversible high-temperature phase transitions.In this work,we successfully refined the tetramethylammonium cation to obtain a quasi-spherical cation,which is tetramethylchloroethylamine(TMCEM) cation.By substituting H with a halogen,the increased steric hindrance of the molecular makes energy barrier increased,resulting in the reversible high-temperature phase transition.At the same time,the interactions of quasi-spherical cations and [Mn(SCN)_(4)(H_(2)O)_(2)]^(2-) anions affect a noncentrosymmetric structure to induce the SHG effect.These findings provide a new approach to design novel functional switch materials.展开更多
Although stimulus frequency otoacoustic emissions (SFOAEs) have been used as a non-invasive measure of cochlear mechanics, clinical and experimental application of SFOAEs has been limited by difficulties in accurately...Although stimulus frequency otoacoustic emissions (SFOAEs) have been used as a non-invasive measure of cochlear mechanics, clinical and experimental application of SFOAEs has been limited by difficulties in accurately deriving quantitative information from sound pressure measured in the ear canal. In this study, a novel signal processing method for multicomponent analysis (MCA) was used to measure the amplitude and delay of the SFOAE. This report shows the delay-frequency distribution of the SFOAE measured from the human ear. A low level acoustical suppressor near the probe tone significantly suppressed the SFOAE, strongly indicating that the SFOAE was generated at characteristic frequency locations. Information derived from this method may reveal more details of cochlear mechanics in the human ear.展开更多
Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses t...Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses to stimulus-response conflicts, we investigated the behavioral (accuracy and Reaction Times: RTs) as well as the physiological response (Lateralized Readiness Potentials: LRP) modulations in a positional blocked and a conditional mixed design in twelve university students. Results revealed that the performance was less accurate and the RTs, as well as the LRP onset, were delayed under the mixed conditional design. A greater compatibility effect was also noted on accuracy, RTs and LRP onset latency in the mixed design. Consistent with these findings, smaller peak activation at fronto-central areas suggests that more selective inhibition is needed in a mixed design context. Despite a smaller activation, the topographical distribution is similar in both designs. These results indicate that the translation time between stimulus- and response codes are greater under the mixed instruction, while the similar LRP topography suggests that common neural structures underlie LRPs in response to both type of designs.展开更多
Support SMEs Increase the scale of financial supports at various levels to support SMEs, sustain light & textile projects with promising market prospect, notable driving of employment and remarkable social benefit...Support SMEs Increase the scale of financial supports at various levels to support SMEs, sustain light & textile projects with promising market prospect, notable driving of employment and remarkable social benefits, and step up investments in construction of credit guarantee system and service展开更多
基金Supported by the Icelandic Technological Development Fund(Project No.1910271).
文摘Background Vibrotactile feedback systems are widely used in assistive technology,wearable devices,and virtual environments to deliver precise tactile information.The timing of interstimulus intervals(ISIs)plays a critical role in determining how accurately users perceive and interpret vibrotactile patterns.The optimal use of ISIs can increase the effectiveness of these systems,improve user interaction,and enable reliable,intuitive feedback in diverse applications.We examined how different interstimulus intervals ISIs impact the accuracy of vibrotactile pattern recognition.Methods Participants wore a forearm-mounted device with six voice coil actuators arranged in a 3×2 grid,delivering Braille-based vibrotactile patterns sequentially at ISIs ranging from 10 to 2500 ms.Eight participants performed identification tasks involving Icelandic Braille patterns categorized as either short(2-3 actuators)or long(4-5 actuators).A repeated measures ANOVA was conducted to assess the effects of ISI,pattern type,and practice(across two testing blocks)on pattern recognition accuracy.Results For short patterns,accuracy was highest(92%-98%)at ISIs of 50-700 ms,with peak performance at 300 ms.For long patterns,accuracy reached 86%-94%at ISIs of 100-500 ms,peaking at 400 ms.Participants were more accurate with short patterns,and performance improved significantly over time for both short and long patterns,highlighting the importance of training for vibrotactile pattern recognition.Conclusions These results underscore the importance of careful selection of ISIs in vibrotactile feedback systems for accurate pattern identification.The findings provide valuable insights for conveying tactile information using wearable devices,contributing to better tactile feedback and performance in applications requiring precise vibrotactile information delivery.
文摘Objective:The objective of this study was to compare the effect of nurse and beloved family member’s recording voice on consciousness and physical parameters in patients with coma state.Materials and Methods:A randomized control trial parallel group design was conducted among 45 comatose patients divided into two intervention groups,i.e.nurse voice stimulus group,receiving nurses voice with standard care,family members voice stimulus group receiving their beloved family member voice with standard care and one control group receiving only standard care in medicine intensive care unit.The intervention was provided three times a day,each lasting 5 min for 7 days in addition to standard care.Repeated measure analysis of variance and independent t-test were used to compare within and between groups,respectively.Results:The study found significant differences in Glasgow coma scale(GCS)scores within both the nurse(F=2.78,P=0.042)and family member(F=10.27,P=0.0001)voice stimulus groups over 7 days.Comparing GCS scores between intervention groups showed significant variations before(P=0.028),during(P=0.047),and after(P=0.036)the intervention on day 7.Comparing GCS scores between the family members’voice stimulus group and the control group,significant changes were observed on days 5 and 7(P=0.043,0.030,0.030,and 0.014,0.012,0.012)before,during,and after the intervention.Conclusions:The use of beloved family members’voices proved more effective in elevating the patients’level of consciousness compared to both the nurse voice stimulus group and the control group.
基金financially supported by the National Natural Science Foundation of China(No.21871122)。
文摘Organic afterglow materials hold significant potential for applications in information storage,anticounterfeiting,and biological imaging.However,studies on afterglow materials capable of ultra-wide range excitation and emission simultaneously are limited.To enhance the practicality of strong emission single-component organic afterglow systems,overcoming the constraints of crystalline or other rigid environments is essential.We have developed solid-state dual-persistent thermally activated delayed fluorescence(TADF)and room temperature phosphorescence(RTP)emissions spanning yellow to red under visible light excitation,utilizing a single-molecule terminal group regulation strategy.The RTP lifetime extends from 4.19 ms to 399.70 ms.These afterglow materials exhibit an ultra-wide absorption range from 200 nm to 800 nm,rendering them capable of being excited by both sunlight simulator and nearinfrared radiation.The upconversion phosphorescence lifetime under 808 nm excitation reaches 13.72μs.The double persistent emission of these compounds is temperature-sensitive.Moreover,following grinding or heat treatment,accompanied by extensive afterglow color conversion due to planarization of excited state conformations and additional efficient kRIsc generation.In addition,the amorphous state post melt annealing facilitates the afterglow transition from yellow to green.Crucially,these compounds also maintain stable ultra-long afterglow emission in aqueous and acid-base environments.Overall,we have successfully developed a series of single-component intelligent luminescent materials that demonstrate significant benefits,including dual TADF and RTP emissions,adjustable afterglow lifetimes,a broad range of excitation and emission wavelengths,multi-modal luminescence not restricted to crystalline states,and robust afterglow performance in challenging environments,setting the stage for the practical deployment of afterglow materials in engineering applications,the upconversion afterglow emission also holds promising potential for applications in the field of biological imaging.
文摘Purpose: This study aimed to investigate the immediate effects of optokinetic stimulation (OKS) using virtual reality (VR) on visual dependency and sensory reweighting in postural control during static standing. Specifically, it examined whether VR-based OKS could reduce visual dependency more effectively than visual deprivation through eye closure. Methods: Ten healthy adults participated in this study. A balance function meter was used to measure postural stability, including Romberg ratios before and after two conditions: VR-based OKS (VR + OKS) and eye closure (EC). Participants performed a two-minute standing task under each condition in random order, with adequate rest between tasks. In the VR + OKS condition, a smartphone-based VR headset presented a rotational OKS, while in the EC condition, participants stood with their eyes closed. Statistical analyses were conducted using paired t-tests to compare pre- and post-task Romberg ratios. Results: No significant differences were observed in the pre-task Romberg ratios between conditions. After the VR + OKS condition, significant reductions in Romberg A and Romberg V were observed. In contrast, no significant changes were noted in Romberg ratios after the EC condition. Conclusion: VR-based OKS significantly reduced visual dependency, as indicated by decreased Romberg ratios, suggesting its potential to facilitate sensory reweighting during postural control. These findings highlight the utility of low-cost VR devices in balance rehabilitation for conditions involving high visual dependency. Future studies should expand on this preliminary research by including larger sample sizes and diverse populations to confirm its clinical applicability.
文摘Objective: To observe the influence of acupuncture stimulus and thermal stimulus on the expression of mast cells(MCs) and 5-hydroxytryptamine(5-HT) in local acupoint area of Guanyuan(关元 CV 4) and serum 5-HT in rats.Methods: Thirty-nine male C57 BL/6 rats were randomly divided into blank control group, acupuncture stimulus group and thermal stimulus group, with 13 rats in each group. The rats were stimulated by manual acupuncture at CV 4 for 5 min in acupuncture stimulus group, while those in thermal stimulus group were stimulated by adopting a thermal moxibustion apparatus on CV 4 for 30 min. The expression of MC and 5-HT in the skin in the acupoint area of CV 4 before and after acupuncture stimulus and thermal stimulus was observed and analyzed via adopting toluidine blue staining method and immunofluorescence histochemical method(5 rats were selected from each group), and the 5-HT content in serum before and after stimulus was determined through enzyme-linked immunosorbent assay(ELISA)(8 rats were selected from each group). The influence of acupuncture stimulus and thermal stimulus on the contents of MC and 5-HT in the skin and serum 5-HT in rats was analyzed and compared.Results: ① After acupuncture stimulus or thermal stimulus on CV 4 of C57 BL/6 rats, the number of MC in the acupoint area significantly increased when compared with that in blank group(the acupuncture stimulus group 12.40 ± 2.07 vs. the blank group 3.00 ±5.96;thermal stimulus group 26.20 ± 10.85 vs. the blank group 12.40 ± 2.07, both P< 0.05), and MC aggregation and degranulation were observed(the acupuncture stimulus group 17.80 ±4.55 vs. the blank group 8.00 ±3.16;the thermal stimulus group24.00±9.05 vs. the blank group 8.00±3.16. P<0.05, P< 0.01).② After acupuncture stimulus or thermal stimulus, 5-HT was released by MCs in the acupoint area, which aggregated around the blood vessels,and the number of 5-HT in the acupoint area significantly increased when compared with that in blank group(the blank group 3.00 ±1.28 vs. the acupuncture stimulus group 10.02 ±3.21;the blank group3.00 ±1.28 vs. the thermal stimulus group 14.00 ±3.94, both P< 0.01).③ Compared with blank group,both acupuncture stimulus and thermal stimulus could reduce the 5-HT content in serum(the blank group 0.72 ±0.2372 vs. acupuncture stimulus group 0.43 ±0.21: the blank group 0.72 ±0.24 vs. thermal stimulus group 0.32 ±0.18, both P<0.01), and the effect in thermal stimulus group was slightly superior to that in acupuncture stimulus group(P<0.05).Conclusion: Both acupuncture stimulus and thermal stimulus can cause the aggregation and degranulation of MCs and high expression of 5-HT in the acupoint area. The effect of thermal stimulus was superior to that of acupuncture stimulus in degranulation.
基金National Natural Science Foundation of China(Grant No.11832006,U1530262,21975024).
文摘Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.
基金the National Natural Science Foundation of China, No. 30370197,30570232
文摘BACKGROUND： Electrophysiological studies using brain slices have revealed that the developmental regulation of synaptic plasticity in vocal learning pathway is essential for song learning in zebra finches. Publications reporting in vivo electrophysiological investigation are scarce. Many aspects of neural mechanisms underlying song learning and production still remain uncertain. OBJECTIVE： To observe the efficacy of paired pulses and the effect on synaptic transmission induced by low-frequency stimulations, high-frequency stimulations, and theta-burst stimulations. DESIGN, TIME AND SETTING： A comparative observation. The experiment was conducted from October 2006 to October 2007 in the Neurophysiology Laboratory of South-China Normal University. MATERIALS： Twenty-four adult male zebra finches were supplied by the Department of Animal Experiment of College of Life Sciences, South China Normal University. A SEN-7203 stimulator （NIHON KOHDEN）, as well as a DSJ-731WF microelectrode amplifier and DSJ-F amplifier （provided by South-China Normal University）, were used to stimulate and record, respectively. METHODS： Animals were randomly divided into low-frequency, high-frequency, and theta-burst frequency stimulation groups. After recording evoked potentials, an input-output curve was evaluated. Subsequently, the efficacy of paired pulses with different stimulus intensity （1/3, 1/2, 2/3, or 3/4 of the value that induced the largest synaptic response）, as well as interpulse intervals （50, 75, and 100 ms）, was measured in each group. The test stimulus intensity was set to a level that evoked 1/2 or 1/3 amplitude of the maximum response. MAIN OUTCOME MEASURES： Changes in amplitude, slope, and area of evoked potentials elicited by different stimulus patterns. RESULTS： （1） Efficacy of paired pulses： there was significant paired-pulse facilitation in the high vocal center and robust nucleus of the arcopallium （HVC-RA） synapse. Efficacy decreased when paired-pulse intervals or stimulus intensities were increased. （2） Low-frequency stimulations at 1 Hz had a negligible effect on efficacy of synaptic transmission, while 5 Hz depressed synaptic transmission for only 5 minutes. （3） High-frequency stimulations at 50 Hz or 100 Hz induced synaptic depression that lasted for up to 30 minutes. （4） Theta-burst stimulation depressed synaptic transmission efficiency significantly for about 10 minutes. However, in contrast to low-frequency or high-frequency stimulations, theta-burst stimulations also induced slight potentiation of synaptic transmission for up to 60 minutes following depression phase, although the slope or area did not change. CONCLUSION： Paired pulses induced a remarkable efficacy of paired pulses in the high vocal center and robust nucleus of the arcopallium pathway. Low-frequency, high-frequency, or theta-burst frequency stimulation did not induce long-lasting changes in synaptic transmission.
文摘Summary: To study the mechanism of the innoxious touch-stimulus on the modulation of hyperalgesia and the expression of the C-fos and the nerve growth factor (NGF) receptor-TrkA in the spinal dorsal horn neurons following the chronic constriction injury (CCI) of the sciatic nerve in rats, 60 female Sprague-Dawley rats were randomly divided into sham-operation group and CCI group, with each group being further divided into 3 subgroups on the 7th,14th and 28th day after operation (n=10). The mechanical and the thermal withdrawal threshold were assessed following the touch stiumulation after the CCI, immunohistochemical methods were employed to observe the expression of the C-fos and TrkA in spinal dorsal horn. Our results showed that the hyperalgesia appeared on the 4th day and reached the maximal level on the 14th day after operation. The expression of the C-fos also increased significantly and reached its maximal level on the 14th day after the touch-stimulus. Meanwhile, the TrkA expression was elevated significantly in both groups, as compared with basic data, and the difference was statistically significant (P<0.05). It is concluded that the level of the C-fos expression changed with the paw withdrawal threshold variation and increased markedly following the innoxious touch-stimulus. The expression of the TrkA receptors also increased gradually following the development of the neuropathic pain. The results suggest that C-fos may play a crucial role in the development of the hyperalgesia in the earlier-time of the neuropathic pain, but TrkA receptors may be involved in the long-lasting adaptive changes of the central pathway in neuropathic pain.
文摘The thermal stability of normal lead styphnate（ N-LTNR） has been studied under severe temperature（- 70 ℃- 130 ℃ for 5 days） with a high optical microscope and camera were used to observe apparent morphology and thermal gravimetric analysis was applied to study the physical changes. In addition,vacuum stability analysis,differential scanning calorimetry（ DSC）,thermal gravimetric analysis（ TGA） and purity analysis were utilized to study the chemical changes. As well as flame sensitivity analysis were used to investigated the explosive changes. The results show that N-LTNR has good chemical stability and fire function stability between- 70 ℃ and 130 ℃,but poor physical stability. When the temperature was exceeded than 110 ℃,the N-LTNR lost crystal water which made the energetic material become darker in color,lager in volume and lighter in weight（ 3. 416%） when the temperature was below- 40 ℃,the phenomenon of crystal broking and jumping happened.
基金supported by the National Natural Science Foundation of China(No.21873062)the Fundamental Research Funds for the Central Universities(GK202001009)+2 种基金the Natural Science Basis Research Plan in Shaanxi Province of China(No.2020JM-295)the 111 Project(B14041)Program for Changjiang Scholars and the Innovative Research Team in University(IRT-14R33)。
文摘Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric networks of the hydrogels is crucial to elucidate their mechanical and swelling properties at the molecular level.In this report,the poly(DMAEMA-co-AA)hydrogels were synthesized and characterized by the macroscopic swelling measurements under different pH conditions.Furthermore,the microscopic structural dynamics of pH stimulus-responsive hydrogels were studied using FTIR and ultrafast IR spectroscopies from the viewpoint of the SCN-anionic solute as the local vibrational reporter.Ultrafast IR spectroscopic measurements showed the time constants of the vibrational population decay of SCN-were increased from 14±1 ps to 20±1 ps when the pH of the hydrogels varied from2.0 to 12.0.Rotational anisotropy measurements further revealed that the rotation of SCNanionic probe was restricted by the three-dimensional network formed in the hydrogels and the rotation of SCN-anionic probe cannot decay to zero especially at the pH of 7.0.These results are expected to provide a molecular-level understanding of the microscopic structure of the cross-linked polymeric network in the pH stimulus-responsive hydrogels.
文摘A screening of environmental conditions that would elicit robust biofilm in a collection of Serratia marcescens isolated from soil revealed that exogenous milk protein increased biofilm productivity up to ten-fold. A select screening of fish pathogens, freshwater and human isolates identified several other species that responded similarly to exogenous protein. The optimal protein concentration was species specific;S. marcescens at 5% milk protein, Aeromonas sp. at 2% - 3%, Flavobacterium columnare at 1% and Pseudomonas aeruginosa at 0.1% - 0.4%. Media supplemented with milk protein also increased the cell counts in biofilm as well as the protein incorporated into the biofilm matrix. These data suggest that relatively high concentrations of exogenous protein may serve as an environmental trigger for biofilm formation, particularly for pathogenic bacteria exposed to relatively high concentrations of protein in bodily fluids and mucosal surfaces.
文摘Based on our preceding studies on the aerodynamics of a falcoperegrinus in diving flight along a vertical dam it is known that even when the body shape of the bird is rather streamlined in V-shape some feathers tips may elevate in certain regions of the body. These regions were identified in wind tunnel tests for typical diving flight conditions as regions of locally separated flow. A life-size model in V-shape of a falcoperegrinus with artificial feathers fixed along the body was studied in a wind tunnel to focus on the fluid-structure interaction of feathers located in this sector. The distal ends of the feathers show flow-induced vibrations at typical flight conditions which grow linear in amplitude with increasing angle of incidence until incipient separation. In light of the proven existence of vibration-sensitive mechanoreceptors in the follicles of secondary feathers in birds it is hypothesized that this linear amplitude response offers the bird to sense the angle of incidence during the diving flight using the vibration magnitude as sensory stimulus. Thus the bird in streamlined shape has still a good measure to control its attitude to be in the narrow window of safe angle of incidence. This might have implications also for other birds or technical applications of airfoil sensors regarding incipient separation detection.
文摘Previous study demonstrated mesenchymal stem cells were sensitive to mechanical stimulus, and mechanical stimulus played great role in differentiation of mesenchymal stem cells.
基金supported by the National Natural Science Foundation of China(Nos.21673038,21771037,21805033)Natural Science Foundation of Jiangsu Province(JSNSF,No.BK20170659)。
文摘Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a large challenge to design such stimulus responsive materials,especially functional materials having both dielectric switch and second harmonic generation(SHG).Here,a new stimuli-responsive switchable material [(CH_(3))_(3)N(CH_(2))_(2)Cl]_(2)]Mn(SCN)_(4)(H_(2)O)_(2)] was discovered as a potential secondharmonic generation(SHG) dielectric switch.It is worth noting that it has SHG characteristics before and after undergoing reversible high-temperature phase transitions.In this work,we successfully refined the tetramethylammonium cation to obtain a quasi-spherical cation,which is tetramethylchloroethylamine(TMCEM) cation.By substituting H with a halogen,the increased steric hindrance of the molecular makes energy barrier increased,resulting in the reversible high-temperature phase transition.At the same time,the interactions of quasi-spherical cations and [Mn(SCN)_(4)(H_(2)O)_(2)]^(2-) anions affect a noncentrosymmetric structure to induce the SHG effect.These findings provide a new approach to design novel functional switch materials.
基金Supported in part by research grants from the National Institute of Deafness and Other Communication Disorders(R01 DC 00141 and R03 DC033642)the National Institutes of Health+2 种基金the Research Fund of the American Otological Societythe Medical Research Foundation of OregonVA RR&D Center Grant RCTR-597-0160,Portland,VAMC
文摘Although stimulus frequency otoacoustic emissions (SFOAEs) have been used as a non-invasive measure of cochlear mechanics, clinical and experimental application of SFOAEs has been limited by difficulties in accurately deriving quantitative information from sound pressure measured in the ear canal. In this study, a novel signal processing method for multicomponent analysis (MCA) was used to measure the amplitude and delay of the SFOAE. This report shows the delay-frequency distribution of the SFOAE measured from the human ear. A low level acoustical suppressor near the probe tone significantly suppressed the SFOAE, strongly indicating that the SFOAE was generated at characteristic frequency locations. Information derived from this method may reveal more details of cochlear mechanics in the human ear.
文摘Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses to stimulus-response conflicts, we investigated the behavioral (accuracy and Reaction Times: RTs) as well as the physiological response (Lateralized Readiness Potentials: LRP) modulations in a positional blocked and a conditional mixed design in twelve university students. Results revealed that the performance was less accurate and the RTs, as well as the LRP onset, were delayed under the mixed conditional design. A greater compatibility effect was also noted on accuracy, RTs and LRP onset latency in the mixed design. Consistent with these findings, smaller peak activation at fronto-central areas suggests that more selective inhibition is needed in a mixed design context. Despite a smaller activation, the topographical distribution is similar in both designs. These results indicate that the translation time between stimulus- and response codes are greater under the mixed instruction, while the similar LRP topography suggests that common neural structures underlie LRPs in response to both type of designs.
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