Explore the vast range of titles available.

BackgroundAging skin is characterized by a disturbed structure and lack of blood supply, which makes it difficult to heal once injured. ADSCs secrete large amounts of cytokines, which promote wound healing and vascular regeneration through paracrine secretion, and the number of cytokines can be elevated by hypoxic pretreating. However, the components of ADSCs are difficult to retain in wounds. Gelatin methacrylate (GelMA) is a photopolymerizable hydrogel synthesized from gelatin and has recently emerged as a potentially attractive material for tissue engineering applications. GelMA loaded with concentrated hypoxic pretreated ADSCs conditioned medium could provide a new method of treating wounds in aged skin.MethodsPrimary ADSCs were isolated from human adipose tissue and characterized by flow cytometry and differentiation test. ADSCs in passages 4-6 were pretreated in the hypoxic and normoxic environments to collect conditioned medium, the conditioned medium was then concentrated to prepare concentrated ADSCs conditioned medium(cADSC-CM)(the one collected from ADSCs under hypoxia was called hypo-CM ,and the one from normoxia was called nor-CM). The concentration of cytokines was detected. After treated with cADSC-CM, the abilities of proliferation, migration, and tube formation of human umbilical vascular endothelial cells (HUVECs) were assayed, and Akt/mTOR and MAPK signal pathway was detected using western blotting. GelMA+hypo-CM hydrogel was prepared, and a comprehensive evaluation of morphology, protein release efficiency, degradation rate, mechanical properties, and rheology properties were performed. Full-thickness skin wounds were created on the backs of 20-month-old mice. After surgery, GelMA, GelMA+F12, GelMA+hypo-CM, and GelMA+nor-CM were applied to the wound surface respectively. H&E, Masson, and immunohistochemistry staining were performed, and a laser Doppler perfusion imager was used to evaluate the blood perfusion. The student’s t-test was used for analysis between two groups and a one-way analysis of variance (ANOVA) was used for analysis among multi groups.ResultsOur results revealed that 1) wounds in aged skin healed more slowly than that in young skin and exhibited poorer perfusion; 2) hypoxic pretreated ADSCs secreted more cytokines including VEGF by activating HIF1α; 3) hypo-CM promoted proliferation and migration of HUVECs through VEGF/Akt/mTOR and MAPK signal pathway; 4) GelMA-hypoCM accelerated wound healing and angiogenesis in aged skin in vivo.ConclusionGelMA loaded with concentrated hypoxic pretreated adipose-derived mesenchymal stem cells conditioned medium could accelerate wound healing in aged skin by promoting angiogenesis.

The Chengdu-Chongqing Economic Circle (CCEC) is becoming the fourth growth pole in China after the Yangtze River Delta Economic Circle (YRDEC); Guangdong, Hong Kong, and Macao Economic Circle (GBAEC); Beijing, Tianjin, and Hebei Economic Circle (BTHEC). The land use and landscape ecological management of the CCEC is critical to its social and economic development. Using ArcGIS modeling and Fragstats processing methods, we divided the CCEC into 5 km × 5 km ecological risk areas and constructed a landscape ecological risk index evaluation model to calculate the spatial and temporal dynamic changes in the urban expansion and landscape ecological risk over the last 20 years. The results show that the land use was mainly cultivated land, which exhibited a decreasing trend and was mainly converted to construction land and forest land. The change in the construction land exhibited a continuous expansion trend with the dual core in Chengdu-Chongqing. The average risk of 10,155 risk communities was about 0.16. The expansion of human activities increased the landscape ecological risk of the construction land, and the risk of the edge of the cultivated land was higher than the internal risk value. The ecological risk index values of 16 cities in the study area ranged from 0.02 to 0.28. The resistance of the landscape pattern to external disturbance was stronger than that in other regions of China. The landscape ecological risk is controllable overall. However, the higher level of economic development in Chengdu, Chongqing, and other mature cities poses a greater landscape ecological risk. The results of this research provide an important reference for promoting the optimization and construction of the land space in the CCEC, building ecological shelters, and preventing ecological risk in the upper reaches of the Yangtze River.

The present study focuses on the impact of exterior traffic noises on sound environment evaluation in office spaces, considering their interaction with interior noises. There were three interior noise conditions: silence, air-conditioner noise, and irrelevant speech noise. Six exterior traffic noises (road, maglev, tram, metro, conventional inter-city train, and high-speed train) were merged with interior noise clips to create the combined noise stimuli. Forty subjects participated in the experiment to assess the acoustic environment in office spaces exposed to multiple noises. The results showed that both interior and exterior noise significantly affected acoustic comfort and noise disturbance. As for the exterior traffic noise, both the traffic noise source and the noise level were found to be influential on both attributes. More temporally fluctuating traffic noises, such as high-speed train noise, were found to have a greater negative effect on subjective evaluations. Meanwhile, the interior noise source was also found to influence evaluations of the sound environment. Compared to the single traffic noise condition, irrelevant speech noise significantly increased the negative impact of traffic noises, while the air-conditioner noise had a neutral effect. In addition, participants in offices with speech noise were less sensitive to the traffic noise level.

The goal of this study is to investigate the psychophysiological effects of traffic sounds in urban green spaces. In a laboratory experiment, psychological and physiological responses to four traffic sounds were measured, including road, conventional train, high-speed train, and tram. The findings demonstrated that traffic sounds had significant detrimental psychological and physiological effects. In terms of psychological responses, the peak sound level outperformed the equivalent sound level in determining the psychological impact of traffic sounds. The physiological effects of traffic sounds were shown to be significantly influenced by sound type and sound level. The physiological response to the high-speed train sound differed significantly from the other three traffic sounds. The physiological effects of road traffic sounds were found to be unrelated to the sound level. On the contrary, as for the railway sounds, the change in sound level was observed to have a significant impact on the participants’ physiological indicators.

Blast neurotrauma has been linked to impairments in higher-order cognitive functions, including memory, attention, and mood. Current literature is limited to a single overpressure exposure or repeated exposures at the same level of overpressure. In this study, a rodent model of primary blast neurotrauma was employed to determine the pressure at which acute and chronic neurological alterations occurred. Three pressure magnitudes (low, moderate and high) were used to evaluate injury thresholds. A biology shock tube (BST) was used to simulate shock waves with overpressures of 60 kPa, 90 kPa and 120 kPa respectively. Neurological behavior of the rats was assessed by the Multi-Conditioning System (MCS) at 1 d, 7 d, 28 d and 90 d after shock wave exposure. Serum dopamine (DA), 5-hydroxytryptamine (5-HT), brain-derived neurotrophic factor (BDNF) and gamma-aminobutyric acid (GABA) were measured at the same time points. The proteomic analysis was conducted to identify potentially vulnerable cellular and molecule targets of serum in the immediate post-exposure period. Results revealed that: (1) Anxiety-like behavior increased significantly at 1 d post-exposure in the medium and high overpressure (90 kPa, 120 kPa) groups, returned to baseline at 7 days, and anxiety-like behavior in the high overpressure groups re-emerged at 28 d and 90 d. (2) High overpressure (120 kPa) impaired learning and memory in the immediate post-exposure period. (3) The serum DA levels decreased significantly at 1 d post-exposure in the medium and high overpressure groups; The 5-HT levels decreased significantly at 1 d and 90 d in the high overpressure groups; The BDNF levels decreased significantly at 90 d in the high overpressure groups. (4) Proteomic analysis identified 38, 306, and 57 differentially expressed proteins in serum following low, medium and high overpressure exposures, respectively. Two co-expressed proteins were validated. Functional analysis revealed significant enrichment of 1121, 2096, and 1121 Gene Ontology (GO) items and 33, 47, and 26 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, indicating extensive molecular responses to overpressure in the early phase. These findings suggest that exposure, even at moderate levels, can induce persistent neurobehavioral and molecular alterations, highlighting the need for further research into the long-term consequences of blast neurotrauma.

The present study aims to explore the psychophysiological impact of different traffic sounds in office spaces. In this experiment, 30 subjects were recruited and exposed to different traffic sounds in a virtual reality (VR) office scene. The road traffic sound and three railway sounds (conventional train, high-speed train, and tram) with three sound levels (45, 55, and 65 dB) were used as the acoustic stimuli. Physiological responses, electrodermal activity (EDA) and heart rate (HR) were monitored throughout the experiment. Psychological evaluations under each acoustic stimulus were also measured using scales within the VR system. The results showed that both the psychological and the physiological responses were significantly affected by the traffic sounds. As for psychological responses, considerable adverse effects of traffic sounds were observed, which constantly increased with the increase in the sound level. The peak sound level was found to have a better performance than the equivalent sound level in the assessment of the psychological impact of traffic sounds. As for the physiological responses, significant effects of both the acoustic factors (sound type and sound level) and the non-acoustic factors (gender and exposure time) were observed. The relationship between sound level and physiological parameters varied among different sound groups. The variation in sound level hardly affected the participants’ HR and EDA when exposed to the conventional train and tram sounds. In contrast, HR and EDA were significantly affected by the levels of road traffic sound and high-speed train sound. Through a correlation analysis, a relatively weak correlation between the psychological evaluations and HR was found.

The Three Gorges Project is the largest water conservancy project in the world. To cope with the ecological problems of the subsidence zone in the Three Gorges Reservoir area, the Kaizhou water-level-regulating dam was built, forming a model of nested water conservancy projects. The Pengxi River Basin is affected not only by this project but also by human activities in the reservoir area and changes in the substratum and hydro-meteorology, which exert influences on the water connotation function and its ecological value through complex mechanisms. In addition, the response mechanism of the changes in the environment is unclear. Therefore, based on the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and a spatial interpolation method, in this study, two time nodes (2005 and 2018) before and after the operation of the nested water conservancy projects began were selected, and seven simulation scenarios with different water levels, precipitations, and temperatures were created to explore the evolution of the water conservation service function in the nested water conservancy project operation area under the complex changes in the environment. The results reveal that the operation of the water conservancy projects has had some influence on the water content, but the response of the water content function to the precipitation conditions has been more significant. In colder and rainier years, the water content was higher. In contrast, the lowest value occurred in a year with high temperatures and low rainfall. The highest and lowest values were quantitatively different. Therefore, the influences of the complex environmental factors on the regional water connotation service function deserve more attention. The results of this study provide a scientific basis for research on the ecological service function and the value of water conservation in the Three Gorges Reservoir subsidence zone and the nested operation area of the related water conservancy projects, as well as a data reference for the optimal allocation of regional water resources.

Street canyons are basic components of modern cities. Sound propagation in streets has been proven to be significantly affected by reflections from building façades. In this paper, an iterative model combining acoustic radiosity and the image source method (IMCRI) is proposed to investigate the effect of diffuse reflections on sound propagation in urban street canyons. By applying image patches, this model calculates both specular reflected components and diffuse reflected components in every reflection. The accuracy of this model is then validated with full-scale measured data from five actual streets with different scattering conditions. Good agreements of sound pressure level and reverberation time are found between the IMCRI and the measurements. The performance of the IMCRI is found to be superior to those of the existing energy models, especially for the reverberation time simulation.

Background: Blast traumatic brain injury (bTBI) can result in depression-like behaviors in the acute and chronic phases. SSRIs have been shown to significantly alleviate depression-like behaviors in animal models of traumatic brain injury (TBI) by increasing serotonin (5-HT) and brain-derived neurotrophic factor (BDNF) in the hippocampus. However, the therapeutic effects of SSRIs on depression caused by bTBI remain unclear. Objective: Therefore, this study was aimed at investigating the therapeutic effects of SSRIs on depression-like behaviors in bTBI models. Methods: We created a rat model to study mild TBI by subjecting rats to increased blast overpressures (BOP) and injecting fluoxetine and escitalopram SSRIs intraperitoneally for 28 days. Results: On day 14 post-BOP exposure, rats treated with SSRIs showed decreased depression-like behaviors. This finding was accompanied by higher 5-HT levels in the hippocampus and increased numbers of Nestin-positive cells in the dentate gyrus. Furthermore, rats treated with SSRIs exhibited increased pCREB and BDNF protein expression in the hippocampus on days 7, 14, and 28 after bTBI. Conclusions: Overall, our findings indicate that SSRI-induced recovery from depression-like behaviors after mild bTBI is associated with the upregulation of 5-HT levels, pCREB and BDNF expression, and neurogenesis in the hippocampus.

Urban parks are one of the most common spaces for social interactions in modern cities. The design of park spaces, especially space configuration, has significant influences on people’s social behaviors in parks. In this study, the associations between space configurational attributes and social interactions were investigated using space syntax theory. An observation analysis of social behaviors was carried out in two urban parks in Beijing, China. Nine space configurational attributes, including depth to the gate, depth to the main road, connectivity, normalized angular integration (NAIN), and normalized angular choice (NACH) with three radii, were calculated using a segment model. The variance analysis and regression analysis reveal the strong joint effect of space type, space scale factors, and space configurational attributes on social interaction behaviors in parks. The personal interaction group contained 23% of the total observed people involved in social interactions. Pathway length, zone area, and NACH-10K (NACH with a radius of 10,000 m) are positively associated with the number of people involved in personal interactions. For the social interaction group (77% of the total observed people), the space scale and depth to main city road were found to have a positive and negative influence on social interaction intensity.