Dynamic color-tunable ultra-long room temperature phosphorescence polymers with photo-chromism and water-stimuli response for multilevel anti-counterfeiting

Developing dynamic color-tunable ultra-long room temperature phosphorescence(URTP)polymers with afterglow of over 1 s,photo-chromism,and multi-stimuli response for practical anti-counterfeiting and information security applications is attractive but very challenging.Herein,by doping multicolor phosphorescence pyri-dinium bromide L block or viologen-based photo-chromic V block into polyvinyl alcohol matrixes,the water-stimuli-responsive color-tunable URTP polymerfilms with afterglow of up to 8 s and the reversible viologen-based photochromic polymerfilms have been developed.More significantly,a series of dynamic color-tunable URTP polymerfilms with ultra-long afterglow of over 6 s,photo-chromism,and water-stimuli response have been successfully exploited by integrating L and V blocks into one polymer system.Mechanistic investigations have revealed that their photo-chromism mainly comes from the photo-generated viologen free radicals.Furthermore,their dynamic multilevel anti-counterfeiting applications have been demonstrated.These results pave the way to develop smarter multifunctional URTP materials for anti-counterfeiting and optical sensing.

Smart stimuli-responsive drug delivery systems in spotlight of COVID-19

The world has been dealing with a novel severe acute respiratory syndrome(SARS-CoV-2)since the end of 2019,which threatens the lives of many peopleworldwide.COVID-19 causes respiratory infection with different symptoms,from sneezing and coughing to pneumonia and sometimes gastric symptoms.Researchers worldwide are actively developing novel drug delivery systems(DDSs),such as stimuli-responsive DDSs.The ability of these carriers to respond to external/internal and even multiple stimuli is essential in creating“smart”DDS that can effectively control dosage,sustained release,individual variations,and targeted delivery.To conduct a comprehensive literature survey for this article,the terms“Stimuli-responsive”,“COVID-19”and“Drug delivery”were searched on databases/search engines like“Google Scholar”,“NCBI”,“PubMed”,and“Science Direct”.Many different types of DDSs have been proposed,including those responsive to various exogenous(light,heat,ultrasound andmagnetic field)or endogenous(microenvironmental changes in pH,ROS and enzymes)stimuli.Despite significant progress in DDS research,several challenging issues must be addressed to fill the gaps in the literature.Therefore,this study reviews the drug release mechanisms and applications of endogenous/exogenous stimuli-responsive DDSs while also exploring their potential with respect to COVID-19.

Lycium barbarum polysaccharide-glycoprotein preventative treatment ameliorates aversive stimuli-induced depression

Previous studies have shown that Lycium barbarum polysaccharide,the main active component of Lycium barbarum,exhibits antiinflammatory and antioxidant effects in treating neurological diseases.However,the therapeutic action of Lycium barbarum polysaccharide on depression has not been studied.In this investigation,we established mouse models of depression using aversive stimuli including exposure to fox urine,air puff and foot shock and physical restraint.Concurrently,we administered 5 mg/kg per day Lycium barbarum polysaccharide-glycoprotein to each mouse intragastrically for the 28 days.Our results showed that long-term exposure to aversive stimuli significantly enhanced depressive-like behavior evaluated by the sucrose preference test and the forced swimming test and increased anxietylike behaviors evaluated using the open field test.In addition,aversive stimuli-induced depressed mice exhibited aberrant neuronal activity in the lateral habenula.Importantly,concurrent Lycium barbarum polysaccharide-glycoprotein treatment significantly reduced these changes.These findings suggest that Lycium barbarum polysaccharide-glycoprotein is a potential preventative intervention for depression and may act by preventing aberrant neuronal activity and microglial activation in the lateral habenula.The study was approved by the Jinan University Institutional Animal Care and Use Committee(approval No.20170301003)on March 1,2017.

Sensory Consciousness is Experienced through Amplification of Sensory Stimuli via Lateral Inhibition

At present, researchers are unclear about which activity within the brain is responsible for the emergence of consciousness—the subconscious or unconscious. Current literature suggests that consciousness is isolated in the brain;however, we suggest consciousness emerges from both—subconscious and unconscious activity, in addition to sensory consciousness. This article contends that sensory consciousness arises from neurophysiological brain activity, intrapersonal space, sensory information, and parallel processing of the external and internal environment through vision, olfaction, the integumentary system, gustation, and audition. Traditionally, lateral inhibition is defined as the ability for an excited neuron to laterally inhibit its neighbors, and is an integral part of neurophysiology in all senses. In this article, we are connecting the science behind the well-established physiological observations of gamma wave activity in the interneurons of peripheral receptors with what is currently unknown regarding the functional significance of seemingly unrelated gamma activity in the cortico-thalamic gamma oscillations. We suggest that this allows for instantaneous integration of the brain with sensory receptors. This article uses existing literature on lateral inhibition to investigate its role in sensory organs and various areas of the body. We explain how sensory consciousness is only one component of unified consciousness. We propose that lateral inhibition also plays a vital role in consciousness theory, and understanding this can help illustrate the dynamic interactions between the central and peripheral nervous systems within the body.

Comfort in observing stereoscopic images reduced by vibration stimuli

Numerous studies have been conducted to illuminate the effect of image factors to reduce unexpected influence of stereoscopic images on healthy visual experience. In this paper, we introduce changes in the psychological and physiological indexes of observers of a stereo- scopic image disturbed by vibration stimuli. Forty-four healthy university students participated in the experiment. A programmable vibration table generated two types of vibrations (5 Hz and 20 Hz) and provided intermittent vibration stimuli to a stereoscopic projector installed on a vibration table. Our results showed that the frequency of vibration stimuli has a strong impact in evaluating the local comfort of subjects. Our results also showed that the indexes of visual fatigue increased after observation independent of the frequency. The activity status of the autonomic nervous system as a physiological index significantly increased after observing 3D images with vibration stimuli although the vibrational frequency did not have a significant effect on the activity status.

Multifunctional stimuli responsive polymer-gated iron and gold-embedded silica nano golf balls:Nanoshuttles for targeted on-demand theranostics

Multi-functional nanoshuttles for remotely targeted and on-demand delivery of therapeutic molecules and imaging to defined tissues and organs hold great potentials in personalized medicine, including precise early diagnosis, efficient prevention and therapy without toxicity. Yet, in spite of 25 years of research, there are still no such shuttles available. To this end, we have designed magnetic and gold nanoparticles （NP）-embedded silica nanoshuttles （MGNSs） with nanopores on their surface. Fluorescently labeled Doxombicin （DOX）, a cancer drug, was loaded in the MGNSs as a payload. DOX loaded MGNSs were encapsulated in heat and pH sensitive polymer P（NIPAM-co- MAA） to enable controlled release of the payload. Magnetically-guided transport of MGNSs was examined in： （a） a glass capillary tube to simulate their delivery via blood vessels; and （b） porous hydrogels to simulate their transport in composite human tissues, including bone, cartilage, tendon, muscles and blood-brain barrier {BBB）. The viscoelastic properties of hydrogels were examined by atomic force microscopy （AFM）. Cellular uptake of DOX- loaded MGNSs and the subsequent pH and temperature-mediated release were demonstrated in differentiated human neurons derived from induced pluripotent stem cells （iPSCs） as well as epithelial HeLa cells. The presence of embedded iron and gold NPs in silica shells and polymer-coating are supported by SEM and TEM. Fluorescence spectroscopy and microscopy documented DOX loading in the MGNSs. Time-dependent transport of MGNSs guided by an external magnetic field was observed in both glass capillary tubes and in the porous hydrogel. AFM results affirmed that the stiffness of the hydrogels model the rigidity range from soft tissues to bone. pH and temperature-dependent drug release analysis showed stimuli responsive and gradual drug release. Cells＇ viability MTT assays showed that MGNSs are non-toxic. The cell death from on-demand DOX release was observed in both neurons and epithelial cells even though the drug release efficiency was higher in neurons. Therefore, development of smart nanoshuttles have significant translational potential for controlled delivery of theranostics＇ payloads and precisely guided transport in specified tissues and organs （for example, bone, cartilage, tendon, bone marrow, heart, lung, liver, kidney, and brain） for highly efficient personalized medicine applications.

Effects of different cue positions on evoked potentials in the cerebral cortex during global and local processing of compound stimuli A study of event-related potential

BACKGROUND： Previous studies of attentional control have focused primarily on pre-cue control of attentional cue and direction. OBJECTIVE： To measure the differences in electrical activity of brain cells while processing pre-cue and post-cue compound stimuli, and to explore brain electrical activity during global and local processing of compound stimuli according to electroencephalogram （EEG） recordings. DESIGN, TIME AND SETTING： A within-subject design study was performed at the School of Psychology, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, China from March to May 2006. PARTICIPANTS： A total of 30 healthy, undergraduate students, aged 17-24 years, comprising 12 males and 18 females, were voluntarily enrolled from Beijing Normal University. Subjects exhibited normal or corrected-to-normal visual acuity. No significant non signal wave drift was detected during testing. METHODS： A total of 30 subjects were subjected to pre-cue and post-cue compound stimulus processing using event-related potential and EEG recordings. MAIN OUTCOME MEASURES： Evoked potential was recorded in different brain regions utilizing event-related potential to observe hemispheric symmetry, cue consistency and global-local features. RESULTS： Pre-cue compound stimuli resulted in hemispheric asymmetry for early wave （N1） and late wave （P3） in anterior brain regions. Early- and late-wave induced hemispheric asymmetry for electrode points （O1, 02, P3, P4, Pz, F3, F4, F7, F8, Fz, FP1, FP2, T7, TS, C3, C4, and Cz） during processing of pre-cue compound stimuli （P 〈 0.05）. Post-cue compound stimuli did not induce hemispheric asymmetry of brain waves induced by the above-described electrode points. No significant differences in global and local responses were determined during processing of post-cue compound stimuli. Under pre-cue conditions, significant differences were observed in N1 and P3 in the above-mentioned electrode points （P 〈 0.05）. However, under post-cue conditions, no significant differences were observed in N1 and P3 using the above-mentioned electrode points. Significant differences in early waves （N1 and P1） using the above-mentioned electrode points were detected between anterior and posterior brain regions, regardless of consistent or inconsistent, large or small letters （P 〈 0.05）. CONCLUSION： Cue location effected mechanisms underlying global and local processing of compound stimuli. Pre- or post-cue conditions resulted in differences in hemispheric symmetry, cue consistency, and global and local features. Under pre-cue conditions, hemispheric dominance was detected in global and local processing following compound stimuli. Under post-cue conditions, hemispheric dominance was not determined.

Performance and Implementations of Vibrotactile Brain-Computer Interface with Ipsilateral and Bilateral Stimuli

The tactile P300 brain-computer interface( BCI) is related to the somatosensory perception and response of the human brain,and is different from visual or audio BCIs. Recently,several studies focused on the tactile stimuli delivered to different parts of the human body. Most of these stimuli were symmetrically bilateral.Only a fewstudies explored the influence of tactile stimuli laterality.In the current study,we extensively tested the performance of a vibrotactile BCI system using ipsilateral stimuli and bilateral stimuli.Two vibrotactile P300-based paradigms were tested. The target stimuli were located on the left and right forearms for the left forearm and right forearm( LFRF) paradigm,and on the left forearm and calf for the left forearm and left calf( LFLC)paradigm. Ten healthy subjects participated in this study. Our experiments and analysis showed that the bilateral paradigm( LFRF) elicited larger P300 amplitude and achieved significantly higher classification accuracy than the ipsilateral paradigm( LFLC). However, both paradigms achieved classification accuracies higher than 70% after the completion of several trials on average,which was usually regarded as the minimum accuracy level required for BCI system to be deemed useful.

The Effect of Humorous Stimuli on Alleviating Pain during Mammography: A Preliminary Study

Mammography is widely performed as a standardized procedure for breast cancer screening;however, women often feel some degree of pain during this procedure. Currently, there are limited options available for alleviating pain related to mammography. A non-medicinal approach to the alleviation of pain involves the effects of laughter on physical and psychological wellbeing. We therefore examined the possibility that humorous stimuli would alleviate the physical burden on women undergoing mammography. We assessed 29 women, 15 women received only conventional mammography (neutral group), while 14 women (humor group) watched a funny video during the same examination. The intensity of pain experienced during mammography was assessed by visual analogue scale (VAS) and the VAS results showed a statistically significant difference (P = 0.007) between the two groups, with the humor group experiencing less pain. In an additional experiment, 14 women in the humor group also underwent conventional mammography without exposure to the funny video and pain was assessed by VAS. We found that the pain experienced during conventional mammography without the funny video was significantly greater than the pain experienced during the same mammography but with the funny video (P = 0.047). These findings suggested the possibility of alleviating pain during mammography by humorous stimuli.

The Emotional Expression Response of a Patient Based on their Facial Expression—Focus on Music Stimuli

Objective: To determine whether patients with unresponsive wakefulness syndrome respond to auditory stimuli based on changes in facial expressions. Participants: Six patients diagnosed with disorders of consciousness due to brain injury with permission for participation from their doctor. Design: In this hypothesis-driven observational study, the facial expressions of patients with unresponsive wakefulness syndrome were video-recorded for 5 min before and during auditory stimulation in three consecutive weekly sessions. Main Measures: Facial muscle movement was quantified using FaceReader® software (Noldus, Wageningen, Netherlands). Valence/action unit values were plotted to detail facial expression changes. Heart rate values were also plotted. These parameters were compared before and after stimulation. Results: No significant differences in valence integral values or average heart rate were observed between the pre- and intra-stimulus conditions. However, valence signals increased in approximately half of the sessions, indicating that some patients with unresponsive wakefulness syndrome may exhibit emotional responses to auditory stimuli. Analysis of action unit integral values indicated that movement of the eyebrows and eyelids on the upper part of the face occurred during auditory stimulation. Furthermore, the types of auditory stimuli differed depending on the session for the 12 sessions of voice stimuli, whereas the changes in average heart rate differed in each of nine sessions of music stimuli. Because the changes in average heart rate were similar, it is possible that musical stimuli are more suitable than voice stimuli. Conclusion: Some patients with unresponsive wakefulness syndrome may have an emotional response to auditory stimuli. Our findings indicate that it may be possible to distinguish the emotional expression response of a patient based on their facial expression.

EEG Correlations during a Working Memory Task with Emotional Stimuli in Girls with Post-Traumatic Stress Disorder Secondary to Sexual Abuse

Survivors of Child Sexual Abuse (CSA) can develop Post-Traumatic Stress Disorder (PTSD), alterations in the prefrontal cortex, changes in electroencephalographic (EEG) activity, and lower performance on working memory tasks. The aim of this study was to characterize brain electrical correlations in girls with PTSD secondary to CSA during a working memory task based on recognizing emotional facial stimuli. Girls aged 8 - 16 years old were evaluated: 12 with PTSD secondary to CSA, and 12 healthy girls with no history of abuse. EEG activity during a working memory task with emotional stimuli was recorded, and the inter- and intra-hemispheric correlations that assessed the functional connectivity among different cortical regions were analyzed. The PTSD group showed lower performance than controls on the working memory task while watching happy faces, while the EEG of this group showed greater intrahemispheric correlation among frontal areas and between frontal and posterior cortical regions. Also, the PTSD group had lower interhemispheric correlations between posterior temporal areas. The higher intrahemispheric correlation in the PTSD group could indicate that those girls used more brain areas when performing the task, likely because it required greater effort. The lower inter-posterior temporal correlation could be attributed to a reduction of the corpus callosum.

Extracting Human Reaction Time from Observations in the Method of Constant Stimuli

We consider the psychophysical experiments in which the test subject’s binary reaction is determined by the prescribed exposure duration to a stimulus and a random variable subjective threshold. For example, when a subject is exposed to a millimeter wave beam for a prescribed duration, the occurrence of flight action is binary (yes or no). In experiments, in addition to the binary outcome, the actuation time of flight action is also recorded if it occurs;the delay from the initiation time to the actuation time of flight action is the human reaction time, which is not measurable. In this study, we model the random subjective threshold as a Weibull distribution and formulate an inference method for estimating the human reaction time, from data of prescribed exposure durations, binary outcomes and actuation times of flight action collected in a sequence of tests. Numerical simulations demonstrate that the inference of human reaction time based on the Weibull distribution converges to the correct value even when the underlying true model deviates from the inference model. This robustness of the inference method makes it applicable to real experimental data where the underlying true model is unknown.

The Short-Term Effect of Online Violent Stimuli on Aggression

The significance of this study was to find whether violent stimuli exposure could escalate the following levels of aggression in order to better cultivate aggression education among contemporary undergraduates in China. This study mainly tested the effects of violent stimuli on aggression by employing modified Stroop task. A total of 188 undergraduates participated in this study. Results showed that undergraduates exposing to violent stimuli exhibited high levels of aggression, whereas undergraduates who exposed to non-violent stimuli displayed low levels of aggression. Specifically, males, but not females, manifested high levels of aggression after exposure to violent stimuli. Moreover, viewers with high-aggressiveness (HA), but not with moderate-aggressiveness (MA) and low-aggressiveness (LA), showed high levels of aggression after exposure to violent stimuli via internet.

Correlation between MEG and BOLD fMRI signals induced by visual flicker stimuli

The goal of this work was to investigate how the MEG signal amplitude correlates with that of BOLD fMRI. To investigate the correlation between fMRI and macroscopic electrical activity, BOLD fMRI and MEG was performed on the same subjects (n=5). A visual flicker stimulus of varying temporal frequency was used to elicit neural responses in early visual areas. A strong similarity was observed in frequency tuning curves between both modalities. Although, averaged over subjects, the BOLD tuning curve was somewhat broader than MEG, both BOLD and MEG had maxima at a flicker frequency of 10 Hz. Also, we measured the first and second harmonic components as the stimuli frequency by MEG. In the low stimuli frequency (less than 6 Hz), the second harmonic has comparable amplitude with the first harmonic, which implies that neural frequency response is nonlinear and has more nonlinear components in low frequency than in high frequency.

A high-sensitive and self-selective humanoid mechanoreceptor for spatiotemporal tactile stimuli cognition

The cognition of spatiotemporal tactile stimuli,including fine spatial stimuli and static/dynamic temporal stimuli,is paramount for intelligent robots to feel their surroundings and complete manipulation tasks.However,current tactile sensors have restrictions on simultaneously demonstrating high sensitivity and performing selective responses to static/dynamic stimuli,making it a challenge to effectively cognize spatiotemporal tactile stimuli.Here,we report a high-sensitive and self-selective humanoid mechanoreceptor(HMR)that can precisely respond to spatiotemporal tactile stimuli.The HMR with PDMS/chitosan@CNTs(PDMS:polydimethylsiloxane;CNT:carbon nanotube)graded microstructures and polyurethane hierarchical porous spacer exhibits high sensitivity of 3790.8 kPa^(-1).The HMR demonstrates self-selective responses to static and dynamic stimuli with mono signal through the hybrid of piezoresistive and triboelectric mechanisms.Consequently,it can respond to spatiotemporal tactile stimuli and generate distinguishable and multi-type characteristic signals.With the assistance of the convolutional neural network,multiple target objects can be easily identified with a high accuracy of 99.1%.This work shows great potential in object precise identification and dexterous manipulation,which is the basis of intelligent robots and natural human-machine interactions.

Development of stimuli responsive polymeric nanomedicines modulating tumor microenvironment for improved cancer therapy

The complexity of the tumor microenvironment(TME)severely hinders the therapeutic effects of various cancer treatment modalities.The TME differs from normal tissues owing to the presence of hypoxia,lowpH,and immunesuppressive characteristics.Modulation of the TME to reverse tumor growth equilibrium is considered an effective way to treat tumors.Recently,polymeric nanomedicines have been widely used in cancer therapy,because their synthesis can be controlled and they are highly modifiable,and have demonstrated great potential to remodel the TME.In this review,we outline the application of various stimuli responsive polymeric nanomedicines to modulate the TME,aiming to provide insights for the design of the next generation of polymeric nanomedicines and promote the development of polymeric nanomedicines for cancer therapy.

油气田刺激响应性材料应用现状及前景展望

油田化学品在钻井完井、压裂酸化、调剖堵水、乳化降黏、油水分离等环节发挥关键作用,但低渗透、高温、高盐、极端pH及使用过程中温度、pH变化等苛刻油气藏环境,给应用于油田化学品的聚合物和表面活性剂的研发带来了严峻的挑战。引入磺酸基等抗温抗盐基团或增大驱油剂相对分子质量等传统方式已难以满足油田需求。该文介绍了温度敏感聚合物、pH敏感聚合物、磁响应聚合物、CO_(2)敏感聚合物及表面活性剂、盐度敏感聚合物响应环境变化的刺激响应原理和性能;综述了5种刺激响应性材料在钻井完井、提高采收率、乳化破乳、压裂酸化、调剖堵水、油水分离等方向的应用,展望了刺激响应性材料在油气开采中的发展前景。

Modulation of the assay system for the sensory integration of 2 sensory stimuli that inhibit each other in nematode Caenorhabditis elegans

Objective To perform the modulation of an assay system for the sensory integration of 2 sensory stimuli that inhibit each other.Methods The assay system for assessing the integrative response to 2 reciprocally-inhibitory sensory stimuli was modulated by changing the metal ion barrier.Moreover,the hen-1,ttx-3 and casy-1 mutants having known defects in integrative response were used to evaluate the modulated assay systems.Based on the examined assay systems,new genes possibly involved in the sensory integration control were identified.Results In the presence of different metal ion barriers and diacetyl,locomotion behaviors,basic movements,pan-neuronal,cholinergic and GABAergic neuronal GFP expressions,neuronal development,structures of sensory neurons and interneurons,and stress response of nematodes in different regions of examined assay systems were normal,and chemotaxis toward different concentrations of diacetyl and avoidance of different concentrations of metal ions were inhibited.In the first group,most of the nematodes moved to diacetyl by crossing the barrier of Fe2＋,Zn2＋,or Mn2＋.In the second group,almost half of the nematodes moved to diacetyl by crossing the barrier of Ag＋,Cu2＋,Cr2＋,or Cd2＋.In the third group,only a small number of nematodes moved to diacetyl by crossing the barrier of Pb2＋ or Hg2＋.Moreover,when nematodes encountered different metal ion barriers during migration toward diacetyl,the percentage of nematodes moving back and then turning and that of nematodes moving straight to diacetyl were very different.With the aid of examined assay systems,it was found that mutations of fsn-1 that encodes a F-box protein,and its target scd-2 that encodes a receptor tyrosine kinase,caused severe defects in integrative response,and the sensory integration defects of fsn-1 mutants were obviously inhibited by scd-2 mutation.Conclusion Based on the nematode behaviors in examined assay systems,3 groups of assay systems were obtained.The first group may be helpful in evaluating or identifying the very subtle deficits in sensory integration,and the third group may be useful for the final confirmation of sensory integration defects of mutants identified in the first or the second group of assay systems.Furthermore,the important association of sensory integration regulation with stabilization or destabilization of synaptic differentiation may exist in C.elegans.

基于天然多糖的刺激响应型药物控释系统研究进展

刺激响应型药物控释系统一般以天然多糖生物大分子或其衍生物作为载体,通过化学结合或物理吸附等方式负载药物分子。具有刺激响应功能的天然多糖生物大分子或其衍生物能够感知其所处环境的变化,并由于其物理或化学性质的变化而做出应激响应,因此可在不同环境或条件的刺激下,通过药物与载体之间化学键断裂或载体自身降解等方式将药物从载体中释放,从而实现药物的控制释放。结合课题组的研究工作,介绍了常用的刺激方式,包括单一刺激和多重刺激、外源性刺激和内源性刺激,为开发新型刺激响应型药物控释系统提供了思路。