Dual Oxygen-Supply Immunosuppression-Inhibiting Nanomedicine to Avoid the Intratumoral Recruitment of Myeloid-Derived Suppressor Cells.

Myeloid-derived suppressor cells (MDSCs) are reported to be responsible for the negative prognosis of colorectal cancer (CRC) patients due to the mediated immunosuppressive tumor microenvironment (TME). The selective and chronic circumvention of tumor-infiltrated MDSCs has potential clinical significance for CRC treatment, which unluckily remains a technical challenge. Because tumor hypoxia makes a significant contribution to the recruitment of MDSCs in tumor sites, a dual oxygen-supplied immunosuppression-inhibiting nanomedicine (DOIN) is demonstrated for overcoming tumor hypoxia, which achieves selective and long-term inhibition of intratumoral recruitment of MDSCs. The DOIN is constructed by the encasement of perfluorooctyl bromide (PFOB) and 4-methylumbelliferone (4-MU) into a TME-responsive amphiphilic polymer. This nanoplatform directly carries oxygen to the tumor region and simultaneously loosens the condensed tumor extracellular matrix for the normalization of tumor vasculature, which selectively remodels the TME toward one adverse to the intratumoral recruitment of MDSCs. Importantly, this nanoplatform offers a long-acting alleviation of the hypoxic TME, chronically avoiding the comeback of tumor-infiltrated MDSCs. Consequently, the immunosuppressive TME is relieved, and T cells are successfully proliferated and activated into cytotoxic T lymphocytes, which boosts a systemic immune response and contributes to lasting inhibition of tumor growth with a prolonged survival span of xenograft.

State-dependent and region-specific alterations of cerebellar connectivity across stable human wakefulness and NREM sleep states.

Sleep regulation and functioning may rely on systematic coordination throughout the whole brain, including the cerebellum. However, whether and how interactions between the cerebellum and other brain regions vary across sleep stages remain poorly understood. Here, using simultaneous EEG-fMRI recordings captured from 73 participants during wakefulness and non-rapid eye movement (NREM) sleep, we constructed cerebellar connectivity among intrinsic functional networks with intra-cerebellar, neocortical and subcortical regions. We uncovered that cerebellar connectivity exhibited sleep-dependent alterations: slight differences between wakefulness and N1/N2 sleep and greater changes in N3 sleep than other states. Region-specific cerebellar connectivity changes between N2 sleep and N3 sleep were also revealed: general breakdown of intra-cerebellar connectivity, enhancement of limbic-cerebellar connectivity and alterations of cerebellar connectivity with spatially specific neocortices. Further correlation analysis showed that functional connectivity between the cerebellar Control II network and regions (including the insula, hippocampus, and amygdala) correlated with delta power during N3 and beta power during N2 sleep. These findings systematically reveal altered cerebellar connectivity among intrinsic networks from wakefulness to deep sleep and highlight the potential role of the cerebellum in sleep regulation and functioning.

Variable functional connectivity architecture of the preterm human brain: Impact of developmental cortical expansion and maturation.

Functional connectivity (FC) is known to be individually unique and to reflect cognitive variability. Although FC can serve as a valuable correlate and potential predictor of (patho-) physiological nervous function in high-risk constellations, such as preterm birth, templates for individualized FC analysis are lacking, and knowledge about the capacity of the premature brain to develop FC variability is limited. In a cohort of prospectively recruited, preterm-born infants undergoing magnetic resonance imaging close to term-equivalent age, we show that the overall pattern could be reliably detected with a broad range of interindividual FC variability in regions of higher-order cognitive functions (e.g., association cortices) and less interindividual variability in unimodal regions (e.g., visual and motor cortices). However, when comparing the preterm and adult brains, some brain regions showed a marked shift in variability toward adulthood. This shift toward greater variability was strongest in cognitive networks like the attention and frontoparietal networks and could be partially predicted by developmental cortical expansion. Furthermore, FC variability was reflected by brain tissue characteristics indicating cortical maturation. Brain regions with high functional variability (e.g., the inferior frontal gyrus and temporoparietal junction) displayed lower cortical maturation at birth compared with somatosensory cortices. In conclusion, the overall pattern of interindividual variability in FC is already present preterm; however, some brain regions show increased variability toward adulthood, identifying characteristic patterns, such as in cognitive networks. These changes are related to postnatal cortical expansion and maturation, allowing for environmental and developmental factors to translate into marked individual differences in FC.

Functional connectivity of the human hypothalamus during wakefulness and nonrapid eye movement sleep.

Animal experiments indicate that the hypothalamus plays an essential role in regulating the sleep-wake cycle. A recent neuroimaging study conducted under resting wakefulness conditions suggested the presence of a wake-promoting region and a sleep-promoting region in the human posterior hypothalamus and anterior hypothalamus, respectively, and interpreted their anticorrelated organization in resting-state functional networks as evidence for their opposing roles in sleep-wake regulation. However, whether and how the functional networks of the two hypothalamic regions reorganize according to their wake- or sleep-promoting roles during sleep are unclear. Here, we constructed functional networks of the posterior and anterior hypothalamus during wakefulness and nonrapid eye movement (NREM) sleep using simultaneous electroencephalography and functional magnetic resonance imaging data collected from 62 healthy participants. The functional networks of the posterior and anterior hypothalamus exhibited inversely correlated organizations during both wakefulness and NREM sleep. The connectivity strength of the posterior hypothalamic functional network was stronger during wakefulness than during stable sleep. From wakefulness to sleep, the anterior cingulate gyrus, paracingulate gyrus, insular cortex, and fontal operculum cortex showed decreased positive connectivity, while the precentral gyrus and postcentral gyrus showed decreased negative connectivity with the posterior hypothalamus. Additionally, the insular cortex and frontal operculum cortex showed negative connectivity during wakefulness and positive connectivity during sleep with the anterior hypothalamus, exhibiting an increasing trend. These findings provide insights into the correspondence between the functional network organizations and hypothalamic sleep-wake regulation in humans.

Altered thalamic connectivity in insomnia disorder during wakefulness and sleep.

Insomnia disorder is the most common sleep disorder and has drawn increasing attention. Many studies have shown that hyperarousal plays a key role in the pathophysiology of insomnia disorder. However, the specific brain mechanisms underlying insomnia disorder remain unclear. To elucidate the neuropathophysiology of insomnia disorder, we investigated the brain functional networks of patients with insomnia disorder and healthy controls across the sleep-wake cycle. EEG-fMRI data from 33 patients with insomnia disorder and 31 well-matched healthy controls during wakefulness and nonrapid eye movement sleep, including N1, N2 and N3 stages, were analyzed. A medial and anterior thalamic region was selected as the seed considering its role in sleep-wake regulation. The functional connectivity between the thalamic seed and voxels across the brain was calculated. ANOVA with factors "group" and "stage" was performed on thalamus-based functional connectivity. Correlations between the misperception index and altered functional connectivity were explored. A group-by-stage interaction was observed at widespread cortical regions. Regarding the main effect of group, patients with insomnia disorder demonstrated decreased thalamic connectivity with the left amygdala, parahippocampal gyrus, putamen, pallidum and hippocampus across wakefulness and all three nonrapid eye movement sleep stages. The thalamic connectivity in the subcortical cluster and the right temporal cluster in N1 was significantly correlated with the misperception index. This study demonstrated the brain functional basis in insomnia disorder and illustrated its relationship with sleep misperception, shedding new light on the brain mechanisms of insomnia disorder and indicating potential therapeutic targets for its treatment.

EEG microstates are correlated with brain functional networks during slow-wave sleep.

Electroencephalography (EEG) microstates have been extensively studied in wakefulness and have been described as the "atoms of thought". Previous studies of EEG have found four microstates, i.e., microstates A, B, C and D, that are consistent among participants across the lifespan during the resting state. Studies using simultaneous EEG and functional magnetic resonance imaging (fMRI) have provided evidence for correlations between EEG microstates and fMRI networks during the resting state. Microstates have also been found during non-rapid eye movement (NREM) sleep. Slow-wave sleep (SWS) is considered the most restorative sleep stage and has been associated with the maintenance of sleep. However, the relationship between EEG microstates and brain functional networks during SWS has not yet been investigated. In this study, simultaneous EEG-fMRI data were collected during SWS to test the correspondence between EEG microstates and fMRI networks. EEG microstate-informed fMRI analysis revealed that three out of the four microstates showed significant correlations with fMRI data: 1) fMRI fluctuations in the insula and posterior temporal gyrus positively correlated with microstate B, 2) fMRI signals in the middle temporal gyrus and fusiform gyrus negatively correlated with microstate C, and 3) fMRI fluctuations in the occipital lobe negatively correlated with microstate D, while fMRI signals in the anterior cingulate and cingulate gyrus positively correlated with this microstate. Functional brain networks were then assessed using group independent component analysis based on the fMRI data. The group-level spatial correlation analysis showed that the fMRI auditory network overlapped the fMRI activation map of microstate B, the executive control network overlapped the fMRI deactivation of microstate C, and the visual and salience networks overlapped the fMRI deactivation and activation maps of microstate D. In addition, the subject-level spatial correlations between the general linear model (GLM) beta map of each microstate and the individual maps of each component yielded by dual regression also showed that EEG microstates were closely associated with brain functional networks measured using fMRI during SWS. Overall, the results showed that EEG microstates were closely related to brain functional networks during SWS, which suggested that EEG microstates provide an important electrophysiological basis underlying brain functional networks.

Co-existence of Citrobacter freundii exacerbated Pseudomonas aeruginosa infection in vivo.

The presence of bacterial species other than the pathogen at infection site can affect the progression of a bacterial infection. Based on the fact that Citrobacter freundii can coexist during Pseudomonas aeruginosa infection, this study aims to investigate the impact of the co-existing C. freundii on the pathogenesis of P. aeruginosa infection. A murine peritonitis model was used to compare the mortality rates and histopathology of P. aeruginosaPAO1 infection in the presence and absence of a C. freundii clinical isolate C9. We also investigated the intercellular interaction between PAO1 and C9 by examining pyocyanin production and comparing gene expression levels. The results demonstrate that co-infection with C9 significantly increased the mortality rate and tissue damages in PAO1 infected mice. At an inoculum of 106 CFU, no mortality was observed in the C9 infected group at three days post-infection, whereas the mortality rate in the PAO1-C9 co-infection group was 64%, compared with 24% in the PAO1 infected group. Pyocyanin production in P. aeruginosa PAO1 increased 8 folds approximately in the presence of C. freundii C9, and operons associated with phenazine synthesis, phzA1 and phzA2, were also upregulated. Disruption of the phzA1 and phzA2 eliminated the exacerbated pathogenicity in the co-infection group, indicating that the elevated pyocyanin production was the main contributing factor. The results suggest that co-existing C. freundii during P. aeruginosa infection can exacerbate the pathogenicity, which may have significant implications in patients infected with these bacteria.

miR-455-3p alleviates propofol-induced neurotoxicity by reducing EphA4 expression in developing neurons.

PURPOSE: Propofol, an aesthetic agent in paediatric patients, results in neurotoxicity in the developing neurons. To reduce side effects of propofol, the protective role of miR-455-3p (microRNA-455-3p) in developing rat brain was investigated. MATERIALS AND METHODS: Primary hippocampal neurons were isolated from postnatal day 1 or 2 SD (Sprague-Dawley) rats. The neurons were exposed to various concentrations of propofol (0, 10, 30, or 50 µM) for 6 h. Propofol-induced cell viability was assessed by MTT assay, expression levels of miR-455-3p and EphA4 (erythropoietin-producing hepatocellular A4) in propofol-induced neurons were determined using qRT-PCR and western blot, respectively. Binding ability between miR-455-3p and EphA4 was predicted, and then validated by luciferase reporter assay. Neurons expressing miR-455-3p mimics, were treated with 50 µM propofol for 6 h, and apoptosis status was evaluated by flow cytometry. RESULTS: Exposure to propofol significantly decreased cell viability of developing neurons isolated from neonatal rats. Propofol decreased miR-455-3p expression, while increased EphA4 level in the neurons. miR-455-3p mimics increased propofol-induced reduce in cell viability, and attenuated propofol-induced cell apoptosis of neurons. MiR-455-3p could target EphA4, and decreased expression of EphA4 in neurons exposure to propofol. EphA4 knockdown counteracted with the promotive effects of propofol on cell viability and apoptosis of neurons. CONCLUSION: Propofol treatment induces neurotoxicity and suppresses miR-455-3p levels in the developing hippocampal neurons. However, miR-455-3p could alleviate such neurotoxicity by reducing EphA4 expression, provided new insights into miR-455-3p as novel therapeutic target to prevent propofol-induced damages from bench to clinic.

High plasma levels of pro-inflammatory factors interleukin-17 and interleukin-23 are associated with poor outcome of cardiac-arrest patients: a single center experience.

BACKGROUND: Systemic inflammation is an important feature of post-cardiac arrest syndrome (PCAS). This study was designed to determine whether the plasma concentrations of some circulating pro-inflammatory cytokines (interleukin-17 [IL-8], IL-22, IL-23 and IL-33) are of value in predicting the outcome of patients after return of spontaneous circulation (ROSC) during the post-cardiac arrest period. METHODS: This was a prospective observational clinical study. In total, 21 patients (survivors, n = 10; non-survivors, n = 11) who experienced cardiac arrest and successful ROSC with expected survival of at least 7 days were consecutively enrolled from January 2016 to December 2017. Of the 21 enrolled patients, ten survived were designated "survivors". The other eleven patients died between 2 days and 1 months post ROSC. Venous blood was drawn at three time-points: baseline (< 1 h post ROSC), 2 days post ROSC and 7 days post ROSC. Plasma IL-8, IL-22, IL-23 and IL-33 were determined using commercial enzyme-linked immunosorbent assays. RESULTS: Plasma creatinine levels, but aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, were elevated in non-survivors compared with survivors. Plasma levels of IL-17, IL-22, IL-23 and IL-33 of the 21 total patients did not change at 2 or 7 days post ROSC compared to baseline. In survivors, the plasma levels of IL-17 and IL-23 at 2 or 7 days post ROSC were lower than baseline. In non-survivors, plasma levels of IL-17 increased compared with baseline. Receiver operating characteristic curve analysis showed that the plasma levels of IL-17 and IL-23 at 2 or 7 days post ROSC were able to predict the mortality of PCAS patients, and positively correlated with Acute Physiology and Chronic Health Evaluation (APACHE)-II score and time to ROSC. CONCLUSION: These results provide the first evidence that the elevated plasma IL-17 and IL-23 levels are associated with poor outcome in PCAS patients. The role of IL-17/IL-23 axis post ROSC is worth paying attention to in PCAS patients. TRIAL REGISTRATION: Clinicaltrial.govNCT02297776, 2014-11-21.

Dynamic functional connectivity states characterize NREM sleep and wakefulness.

According to recent neuroimaging studies, temporal fluctuations in functional connectivity patterns can be clustered into dynamic functional connectivity (DFC) states and correspond to fluctuations in vigilance. However, whether there consistently exist DFC states associated with wakefulness and sleep stages and what are the characteristics and electrophysiological origin of these states remain unclear. The aims of the current study were to investigate the properties of DFC in different sleep stages and to explore the relationship between the characteristics of DFC and slow-wave activity. We collected both eyes-closed wakefulness and sleep data from 48 healthy young volunteers with simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) recordings. EEG data were employed as the gold standard of sleep stage scoring, and DFC states were estimated based on fMRI data. The results demonstrated that DFC states of the fMRI signals consistently corresponded to wakefulness and nonrapid eye movement sleep stages independent of the number of clusters. Furthermore, the mean dwell time of these states significantly correlated with slow-wave activity. The inclusion or omission of regression of the global signal and the selection of parcellation schemes exerted minimal effects on the current findings. These results provide strong evidence that DFC states underlying fMRI signals match the fluctuations of vigilance and suggest a possible electrophysiological source of DFC states corresponding to vigilance states.

Dissociated resting-state functional networks between the dream recall frequency and REM sleep percentage.

Rapid eye movement (REM) sleep has been frequently associated with dreaming. However, mounting evidence obtained from behavioral, pharmacological, and brain imaging studies suggests that REM sleep is not indicative of the dream report and may originate from diverse neural substrates in brain functionality. The aim of the current study was to investigate the functional systems associated with inter-individual differences in dream recall and REM sleep through assessments of the resting-state functional connectivity. We collected resting-state functional magnetic resonance imaging (fMRI) data for functional connectivity evaluations from 43 healthy adult volunteers (23 men) before and after sleep. For assessment of the dream recall frequency, a 2-week sleep diary was maintained by all volunteers. In addition, whole-night polysomnography was performed for measuring the REM sleep percentage. Voxel-wise correlation analyses of 12 functional connectivity networks of interest with the dream recall frequency and REM sleep percentage were conducted using general linear model analysis. Both the dream recall frequency and REM sleep percentage showed negative associations with multiple brain functional networks. However, the dream recall frequency was mainly related to functional connectivity within the lateral visual network and thalamus, whereas the REM sleep percentage was mainly associated with connectivity within the frontoparietal networks and cerebellum. In addition, the dream recall frequency showed stronger coupling with the lateral visual network connectivity at night, whereas the coupling between the REM sleep percentage and cerebellum was higher in the morning. This indicated a significant time of day effect. Our results provide neuroimaging evidence that the functional system associated with the dream recall frequency is different from that associated with the REM sleep percentage.

Short-Term Pretreatment of Sub-Inhibitory Concentrations of Gentamycin Inhibits the Swarming Motility of Escherichia Coli by Down-Regulating the Succinate Dehydrogenase Gene.

BACKGROUND/AIMS: Motility is a feature of many pathogens that contributes to the migration and dispersion of the infectious agent. Whether gentamycin has a post-antibiotic effect (PAE) on the swarming and swimming motility of Escherichia coli (E. coli) remains unknown. In this study, we aimed to examine whether short-term pretreatment of sub-inhibitory concentrations of gentamycin alter motility of E. coli and the mechanisms involved therein. METHODS: After exposure to sub-inhibitory concentrations (0.8 µg/ml) of gentamicin, the swarming and swimming motility of E. coli was tested in semi-solid media. Real-time PCR was used to detect the gene expression of succinate dehydrogenase (SDH). The production of SDH and fumarate by E. coli pretreated with or without gentamycin was measured. Fumarate was added to swarming agar to determine whether fumarate could restore the swarming motility of E. coli. RESULTS: After pretreatment of E. coli with sub-inhibitory concentrations of gentamycin, swarming motility was repressed in the absence of growth inhibition. The expression of all four subunits of SDH was down-regulated, and the intracellular concentration of SDH and fumarate, produced by E. coli, were both decreased. Supplementary fumarate could restore the swarming motility inhibited by gentamycin. A selective inhibitor of SDH (propanedioic acid) could strongly repress the swarming motility. CONCLUSION: Sub-inhibitory concentrations of gentamycin inhibits the swarming motility of E. coli. This effect is mediated by a reduction in cellular fumarate caused by down-regulation of SDH. Gentamycin may be advantageous for treatment of E. coli infections.

In vivo post-contrast 1H-MRS evaluation of malignant and benign breast lesions: a meta-analysis.

The aim of this study is to perform a meta-analysis to evaluate the diagnostic performance of the in vivo post-contrast proton magnetic resonance spectroscopy (MRS) for benign/malignant discrimination of focal breast lesions. Sixteen studies with a total of 661 malignant breast lesions and 388 benign breast lesions were included. The pooled sensitivity and specificity of post-contrast 1H-MRS were 74 % (95 % confidence interval (CI) 70-77 %) and 78 % (95 % CI 73-82 %), respectively. The positive likelihood ratio (PLR) and the negative likelihood ratio (NLR) were 4.00 (95 % CI 2.74-5.84) and 0.25 (95 % CI 0.17-0.37), respectively. From the fitted summary receiver operating characteristics curve (SROC), the AUC and Q* index were 0.89 and 0.83. Publication bias was present (t = 2.43, P = 0.029). Meta-regression analysis suggested that neither threshold effect nor evaluated covariates including method of choline analysis, strength of field, pulse sequence, repetition time (TR), and time interval were sources of heterogeneity (all P values >0.05). In vivo post-contrast 1H-MRS was useful for differentiation between malignant and benign focal breast lesions. However, pooled diagnostic measures might be overestimated. The standardization of the acquisition protocol as well as the post-processing method for post-contrast proton MRS need to be established for the future study.

Advanced glycation end products activate the miRNA/RhoA/ROCK2 pathway in endothelial cells.

OBJECTIVE: AGEs induce endothelial cell dysfunction in HUVECs, resulting in ROS production and triggering apoptosis. This study sought to identify miRNAs involved in AGE-induced endothelial cell injury. METHODS: Microarray analysis to identify miRNAs altered with AGE stimulation was undertaken, and results were confirmed using real-time quantitative polymerase chain reaction. The interaction of miRNAs with the RhoA and ROCK2 genes was confirmed using luciferase assays, and their effects on expression were determined using Western blot analysis. The effects of AGEs and miRNAs on endothelial cell permeability were assessed. RESULTS: AGEs induced ROS production and apoptosis of HUVECs (p < 0.05). AGE-induced miR-200b and miR-200c downregulation led to increased expression of their target genes, RhoA and ROCK, respectively. AGE-induced endothelial cell permeability and F-actin expression were significantly reduced with both miR-200b and miR-200c mimics (p < 0.05). Furthermore, AGE-induced stress fiber formation was reduced in cells treated with miR-200b mimics. CONCLUSION: miR-200b and miR-200c are suppressed in AGE-induced endothelial cell injury, resulting in unregulated RhoA/ROCK2 signaling. Further studies are necessary to evaluate the therapeutic value of targeting miRNAs or their target genes for treatment of vascular diseases.

Immunosenescence and inflammaging: Mechanisms and role in diseases.

Age-related changes initiate a cascade of cellular and molecular alterations that lead to immune system dysfunction or abnormal activation, predisposing individuals to age-related diseases. This phenomenon, commonly referred to as immunosenescence, highlighting aging-associated progressive decline of the immune system. Moreover, mounting evidence suggests that immunosenescence contributes to a related pathological phenomenon known as inflammaging. Inflammaging refers to chronic, low-grade, and systemic inflammation associated with aging, occurring despite the absence of overt stimuli. In the body, inflammation is typically activated in response to overt stimuli such as bacterial/microbial invasion or a pathological state, however, inflammaging occurrence and its underpinning mechanisms seem to be independent and in the absence of such stimuli. Despite recent advancements in molecular characterization and the scrutiny of disease relevance, these two interconnected concepts have remained largely unexplored and unrecognized. In this comprehensive review, we aim to shed light on the mechanistic and cellular aspects of immunosenescence and inflammaging, as well as their pivotal roles in the pathogenesis of aging-related diseases, including cancer, infections, dementia, and neurodegenerative disorders.

Causal Relationship between Mitochondrial-Associated Proteins and Sepsis in ICU Patients: A Mendelian Randomization Study.

BACKGROUND: The alarming mortality rate of sepsis in ICUs has garnered significant attention. The precise etiology remains elusive. Mitochondria, often referred to as the cellular powerhouses, have been postulated to have a dysfunctional role, correlating with the onset and progression of sepsis. However, the exact causal relationship remains to be defined. METHOD: Employing the Mendelian randomization approach, this study systematically analyzed data from the IEUOpenGWAS and UKbiobank databases concerning mitochondrial function-related proteins and their association with sepsis, aiming to delineate the causal relationship between the two. RESULTS: The findings underscored a statistically significant association of GrpE1 with sepsis, registering a P value of 0.005 and an OR of 0.499 (95% CI: 0.307-0.810). Likewise, HTRA2, ISCU, and CUP3 each manifested significant associations with sepsis, yielding OR values of 0.585, 0.637, and 0.634, respectively. These results suggest potential implications of the aforementioned proteins in the pathogenesis of sepsis. CONCLUSION: The present study furnishes novel evidence elucidating the roles of GrpE1, HTRA2, ISCU, and CUP3 in the pathophysiology of sepsis. Such insights pave the way for a deeper understanding of the pathological mechanisms underpinning sepsis and hint at promising therapeutic strategies for the future.

Computational biomechanics for a standing human body: Modal analysis and simulation.

We develop computational mechanical modeling and methods for the analysis and simulation of the motions of a human body. This type of work is crucial in many aspects of human life, ranging from comfort in riding, the motion of aged persons, sports performance and injuries, and many ergonomic issues. A prevailing approach for human motion studies is through lumped parameter models containing discrete masses for the parts of the human body with empirically determined spring, mass, damping coefficients. Such models have been effective to some extent; however, a much more faithful modeling method is to model the human body as it is, namely, as a continuum. We present this approach, and for comparison, we choose two digital CAD models of mannequins for a standing human body, one from the versatile software package LS-DYNA and another from open resources with some of our own adaptations. Our basic view in this paper is to regard human motion as a perturbation and vibration from an equilibrium position which is upright standing. A linear elastodynamic model is chosen for modal analysis, but a full nonlinear viscoelastoplastic extension is possible for full-body simulation. The motion and vibration of these two mannequin models is analyzed by modal analysis, where the normal vibration modes are determined. LS-DYNA is used as the supercomputing and simulation platform. Four sets of low-frequency modes are tabulated, discussed, visualized, and compared. Higher frequency modes are also selectively displayed. We have found that these modes of motion and vibration form intrinsic basic modes of biomechanical motion of the human body. This view is supported by our finding of the upright walking motion as a low-frequency mode in modal analysis. Such a "walking mode" shows the in-phase and out-of-phase movements between the legs and arms on the left and right sides of a human body, implying that this walking motion is spontaneous, likely not requiring any directives from the brain. Dynamic motions of CAD mannequins are also simulated by drop tests for comparisons and the validity of the models is discussed through Fourier frequency analysis. All computed modes of motion are collected in several sets of video animations for ease of visualization. Samples of LS-DYNA computer codes are also included for possible use by other researchers.

Nanofiber-reinforced chitosan/gelatine hydrogel with photothermal, antioxidant and conductive capabilities promotes healing of infected wounds.

The wound healing process was often accompanied by bacterial infection and inflammation. The combination of electrically conductive nanomaterials and wound dressings could accelerate cell proliferation through endogenous electrical signaling, effectively promoting wound healing. In this study, polypyrrole was modified with dopamine hydrochloride by an in situ polymerization to form dopamine-polypyrrole (DA-Ppy) conductive nanofibers which successfully enhanced the water dispersibility and biocompatibility of polypyrrole. The DA-Ppy nanofibers were dispersed in an aqueous solution for >48 h and still maintained good stability. In addition, the DA-Ppy nanofibers showed good photothermal properties, and the temperature could reach 59.7 °C by 1.5 W/cm2 near-infrared light irradiation (NIR) for 10 min. DA-Ppy conductive nanofibres could be well dispersed in 3,4-dihydroxyphenylpropionic acid modified chitosan-carboxymethylated ß-cyclodextrin modified gelatin (CG) hydrogel due to the presence of DA, which endowed CG/DA-Ppy hydrogel with good adhesion properties, and the hydrogel adhered to the pigskin would not be dislodged by washing with running water. Under NIR, the CG/DA-Ppy hydrogel showed significant antimicrobial properties. Moreover, the CG/DA-Ppy hydrogel had excellent biocompatibility. In addition, CG/DA-Ppy hydrogel was effective in scavenging ROS, inducing macrophage polarization towards the M2 phenotype, and modulating the level of wound inflammation in vitro. Finally, it was confirmed in rat-infected wounds that the tissue regeneration effect and collagen deposition in the CG/DA-Ppy + NIR group were significantly better than the other groups in the repair of infected wounds, indicating better repair of infected wounds. The results suggested that the photothermal, antioxidant DA-Ppy conductive nanofiber had great potential for application in infected wound healing.

A novel tetrahedral framework nucleic acid-derived chemodynamic therapy agent for effective glioblastoma treatment.

Chemodynamic therapy (CDT) has garnered significant attention for treating diverse malignant tumours due to its minimally invasive nature, reduced damage to healthy tissues, and potential mitigation of side effects. However, its application in glioblastoma (GBM) is hindered by the diminished capacity of CDT agents to traverse the blood-brain barrier (BBB), inadequate tumour targeting efficiency, and restricted availability of H2O2 within the tumour microenvironment (TME). To address these challenges, we devised a novel CDT agent (Fe@tFNAs-ANG-3AT) based on a tetrahedral framework nucleic acids (tFNAs). Fe@tFNAs-ANG-3AT was constructed by anchoring iron ions (Fe3+) onto the dual appendages-modified tFNAs. Specifically, one appendage, Angiopep-2 (ANG, a penetrating peptide), facilitates Fe@tFNAs-ANG-3AT penetration across the BBB and selective targeting of tumour cells. Simultaneously, the second appendage, 3-Amino-1,2,4-triazole (3AT, a H2O2 enzyme inhibitor), augments the H2O2 levels required for effective CDT treatment. Upon tumour cell internalization, the loaded Fe3+ in Fe@tFNAs-ANG-3AT is reduced to Fe2+ by the overexpressed glutathione (GSH) in the TME, catalysing the generation of cytotoxic hydroxyl radicals (·OH) and inducing tumour cell death via elevated oxidative stress levels within tumour cells. It is anticipated that Fe@tFNAs-ANG-3AT holds promise as a transformative treatment strategy for GBM.