In recent years, there has been a growing awareness of the potential health benefits of the natural environment for human well-being. Given the fast-paced nature of contemporary lifestyles, research ...into the use of virtual environments as a means to provide various seasonal landscapes has gained increasing importance.
The aim of this study is to investigate the impact of different sensory modes on the preferences and therapeutic effects of virtual autumn landscapes on university campuses.
In this study, 320 participants, with an average age of 21.11 years (±1.21 years), were exposed to virtual environments featuring autumn color landscapes and bare tree landscapes using visual, auditory, and combined conditions. A control group was included for comparison. Differences in participants' physiological indicators (EEG, heart rate) and psychological measures (POMS, PANAS, SVS, ROS) were analyzed, with the use of the Holm correction (P < 0.05).
(1) Autumn virtual landscapes with color had a superior therapeutic effect. (2) There were significant differences in the therapeutic effects of different sensory modes within the same season's landscape categories, suggesting that incorporating additional sensory dimensions may enhance therapeutic outcomes.
Based on the study's findings, we recommend that when designing therapeutic environments, attention should be given to seasonal variations and the integration of various sensory modes to optimize therapeutic results.
The protective effects of kaempferol against reactive oxygen species (ROS)-induced hemolysis and its antiproliferative activity on human cancer cells were evaluated in this study. Kaempferol ...exhibited strong cellular antioxidant ability (CAA) with a CAA value of 59.80 ± 0.379 μM of quercetin (QE)/100 μM (EC50 = 7.74 ± 0.049 μM). Pretreatment with kaempferol significantly attenuated the ROS-induced hemolysis of human erythrocyte (87.4% hemolysis suppressed at 100 μg/mL) and reduced the accumulation of toxic lipid peroxidation product malondialdehyde (MDA). The anti-hemolytic activity of kaempferol was mainly through scavenging excessive ROS and preserving the intrinsic antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GPx) activities in normal levels. Additionally, kaempferol showed significant antiproliferative activity on a panel of human cancer cell lines including human breast carcinoma (MCF-7) cells, human stomach carcinoma (SGC-7901) cells, human cervical carcinoma (Hela) cells and human lung carcinoma (A549) cells. Kaemperol induced apoptosis of MCF-7 cells accompanied with nuclear condensation and mitochondria dysfunction.
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•Kaempferol exhibited strong cellular antioxidant ability by scavenging the accumulation of ROS.•Pretreatment with kaempferol significantly attenuated the ROS-induced hemolysis.•Kaempferol preserved the activities of antioxidant enzymes to normal levels.•Kaempferol showed significant antiproliferative activity against several human cancer cells.•Kaempferol induced apoptosis of MCF-7 cells through the mitochondrial pathway.
Brachymystax tsinlingensis Li is a threatened fish species endemic to China. With the problems of environmental factors and seeding breeding diseases, it is important to further improve the ...efficiency of seeding breeding and the basis of resource protection. This study investigated the acute toxicity of copper, zinc and methylene blue (MB) on hatching, survival, morphology, heart rate (HR) and stress behaviour of B. tsinlingensis. Eggs (diameter: 3.86 ± 0.07 mm, weight: 0.032 ± 0.004 g) of B. tsinlingensis were selected randomly from artificial propagation and developed from eye‐pigmentation‐stage embryos to yolk‐sac stage larvae (length: 12.40 ± 0.02 mm, weight: 0.03 ± 0.001 g) and exposed to different concentrations of Cu, Zn and MB for 144 h in a series of semi‐static toxicity tests. The acute toxicity tests indicated that the 96‐h median lethal concentration (LC50) values of the embryos and larvae were 1.71 and 0.22 mg l−1 for copper and 2.57 and 2.72 mg l−1 for zinc, respectively, whereas the MB LC50 after 144‐h exposure for embryos and larvae were 67.88 and 17.81 mg l−1, respectively. The safe concentrations of copper, zinc and MB were 0.17, 0.77 and 6.79 mg l−1 for embryos and 0.03, 0.03 and 1.78 mg l−1 for larvae, respectively. Copper, zinc and MB treatments with concentrations greater than 1.60, 2.00 and 60.00 mg l−1, respectively, led to a significantly low hatching rate and significantly high embryo mortality (P < 0.05), and copper and MB treatments with concentrations greater than 0.2 and 20 mg l−1 led to significantly high larvae mortality (P < 0.05). Exposure to copper, zinc and MB resulted in developmental defects, including spinal curvature, tail deformity, vascular system anomalies and discolouration. Moreover, copper exposure significantly reduced the HR of larvae (P < 0.05). The embryos exhibited an obvious change in behaviour, converting from the normal behaviour of emerging from the membrane head first to emerging tail first, with probabilities of 34.82%, 14.81% and 49.07% under copper, zinc and MB treatments, respectively. The results demonstrated that the sensitivity of yolk‐sac larvae to copper and MB was significantly higher than that of embryos (P < 0.05) and that B. tsinlingensis embryos or larvae might be more resistant to copper, zinc and MB than other members of the Salmonidae family, which benefits their resource protection and restoration.
摘要
秦岭细鳞鲑 (Brachymystax tsinlingensis Li, 1966)是我国特有濒危陆封型冷水鱼类，随着环境改变和苗种培育疾病等问题突显，为进一步提高其苗种培育效率及资源保护范围，本研究随机挑选经人繁的同批次秦岭细鳞鲑受精卵 (卵径为3.86±0.07 mm，卵质量为0.032±0.004 g)，采用半静态方式对其胚胎眼色素出现期至卵黄囊仔鱼期 (全长为12.40±0.02 mm，体质量为0.03±0.001 g)进行不同浓度的铜离子、锌离子和亚甲基蓝暴露试验，实验周期为144 h。结果显示，铜和锌分别对秦岭细鳞鲑胚胎和仔鱼的96 h LC50值为1.71mg/L和0.22 mg/L，2.57 mg/L和2.80 mg/L；亚甲基蓝对其胚胎和仔鱼的144h LC50值分别是68.86 mg/L和17.81 mg/L。重金属铜、锌，亚甲基蓝对秦岭细鳞鲑胚胎及仔鱼的安全浓度 (safe concentration，SC)分别为0.17mg/L，0.77 mg/L和6.89 mg/L，0.03 mg/L，0.03 mg/L和1.78 mg/L。当重金属铜、锌和亚甲基蓝的浓度分别高于1.60 mg/L，2.00 mg/L和60.00 mg/L时，秦岭细鳞鲑胚胎孵化率显著降低、胚胎死亡率显著升高(P<0.05)，而当铜和亚甲基蓝浓度高于0.20 mg/L和20.00 mg/L导致仔鱼死亡率显著升高(P<0.05)。重金属铜、锌和亚甲基蓝暴露可导致秦岭细鳞鲑胚胎和仔鱼发育缺陷，包括脊柱弯曲、尾巴畸形、血管系统缺陷和异常色素沉着等。此外，铜暴露显著降低秦岭细鳞鲑仔鱼的心率(P<0.05)。秦岭细鳞鲑胚胎暴露于重金属铜、锌，及亚甲基蓝时都表现出明显规避现象，即由正常情况下的头部破膜转变为尾部破膜，其累积概率分别为34.82%，14.81%和49.07%。研究结果表明，秦岭细鳞鲑卵黄囊期仔鱼对铜和亚甲基蓝的敏感度显著高于胚胎期(P<0.05)，且秦岭细鳞鲑胚胎和仔鱼对重金属铜、锌和亚甲基蓝的耐受性高于鲑科其它种鱼类，该研究结果可为秦岭细鳞鲑的疾病治疗和环境耐受性提供基础数据，有利于其资源保护和恢复。
Pericyclic reactions are powerful transformations for the construction of carbon-carbon and carbon-heteroatom bonds in organic synthesis. Their role in biosynthesis is increasingly apparent, and ...mechanisms by which pericyclases can catalyse reactions are of major interest
. 4+2 cycloadditions (Diels-Alder reactions) have been widely used in organic synthesis
for the formation of six-membered rings and are now well-established in biosynthesis
. 6+4 and other 'higher-order' cycloadditions were predicted
in 1965, and are now increasingly common in the laboratory despite challenges arising from the generation of a highly strained ten-membered ring system
. However, although enzyme-catalysed 6+4 cycloadditions have been proposed
, they have not been proven to occur. Here we demonstrate a group of enzymes that catalyse a pericyclic 6+4 cycloaddition, which is a crucial step in the biosynthesis of streptoseomycin-type natural products. This type of pericyclase catalyses 6+4 and 4+2 cycloadditions through a single ambimodal transition state, which is consistent with previous proposals
. The 6+4 product is transformed to a less stable 4+2 adduct via a facile Cope rearrangement, and the 4+2 adduct is converted into the natural product enzymatically. Crystal structures of three pericyclases, computational simulations of potential energies and molecular dynamics, and site-directed mutagenesis establish the mechanism of this transformation. This work shows how enzymes are able to catalyse concerted pericyclic reactions involving ambimodal transition states.
The famous Kibble-Zurek mechanism offers us a significant clue to study quantum phase transitions out of equilibrium. Here, we investigate an intriguing phenomenon of a spin-orbit coupled ...Bose-Einstein condensate by quenching the Raman coupling strength from a high-symmetry phase (nonmagnetic phase) to a low-symmetry phase (magnetic phase). When crossing the critical point, the fluctuation of momentum distribution leads to delayed bifurcation structures. Simultaneously, the domain information emerges in momentum space. Moreover, the universal scalings of spatiotemporal dynamics are extracted from the fluctuations and domains, which manifests homogeneous and inhomogeneous Kibble-Zurek power laws at different timescales. Our work demonstrates a paradigmatic study on the inhomogeneous Kibble-Zurek mechanism.
Herein, a highly regioselective propargylic benzylation with propargylic carbonates and benzyl 1,4-dihydropyridine derivatives was developed
via
a photoredox/palladium dual-catalyzed process, which ...represents a novel catalytic model for non-terminal propargylic functionalization. The reaction showed excellent regioselectivity and functional group compatibility. A radical coupling mechanism between the propargylic radical and benzyl radical was proposed.
The developed photo/palladium dual catalytic system provided a novel route to internal propargylic benzylation products. A radical coupling mechanism between the propargylic radical and benzyl radical was proposed.
The health of rolling bearing is of great importance for the normal operation of rotating machinery. The fault diagnosis process can be roughly summarized as signal processing, feature extraction, ...and fault classification. In this paper, a novel feature extraction and fault diagnosis method with fractional order back-propagation neural network is put forward. The new sine cosine algorithm optimized variational mode decomposition is performed on vibration signals, and the fault feature vectors are selected and built by singular value decomposition. Inspired by the fractional order calculus, a fractional order back-propagation neural network is employed to realize fault classification. The capability of the developed fault diagnosis algorithm is comprehensively evaluated via benchmark bearing data. The experimental results demonstrate that the designed method substantially extracts bearing defect features, increases classification accuracy and efficiency, and also outperforms existing algorithms.
An international panel including patients, clinicians, researchers, acupuncture and surgery trialists, statisticians, and experts in clinical epidemiology and methodology have developed new guidance ...for randomised controlled trials in acupuncture. It addresses the most prevalent and critical concerns of current acupuncture trials and will help funding agencies, trial registers, and journal editors to evaluate the relevance, importance, and quality of submitted trial proposals and completed trials
The Floquet engineering opens the way to create new topological states without counterparts in static systems. Here, we report the experimental realization and characterization of new anomalous ...topological states with high-precision Floquet engineering for ultracold atoms trapped in a shaking optical Raman lattice. The Floquet band topology is manipulated by tuning the driving-induced band crossings referred to as band inversion surfaces (BISs), whose configurations fully characterize the topology of the underlying states. We uncover various exotic anomalous topological states by measuring the configurations of BISs that correspond to the bulk Floquet topology. In particular, we identify an unprecedented anomalous Floquet valley-Hall state that possesses anomalous helical-like edge modes protected by valleys and a chiral state with high Chern number.
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