Low Dimensional Nanostructure-Assisted Long-Range Surface Plasmon Resonance Sensors With High Figure of Merit.

Long-range surface plasmon resonance (LRSPR) sensors have been extensively studied by virtue of their extremely narrow full width at half maxima (FWHM) characteristics, but their low sensitivity remains an important factor limiting the figure of merit (FOM), making the sensors have difficulties in detecting small refractive index changes accurately. To address this problem, this paper proposes and demonstrates a low dimensional nanostructure (Au nanospheres, WS2) assisted LRSPR sensor to achieve an effective enhancement of the sensor interfaced electric field and thus improve the sensitivity. The performance parameters of the two sensors are compared with the LRSPR sensor by finite element method analysis, and the results showed that the assistance of the low dimensional nanostructure has a positive effect on the sensor. The first refractive index sensing experiment of the WS2-assisted LRSPR sensor was realized with a 25.47% increase in sensitivity and a 7.13% increase in FOM simultaneously, and the Au nanospheres-assisted LRSPR sensor with a 29.23% increase in sensitivity and a 15.95% increase in FOM simultaneously. The introduction of low dimensional nanostructures provides a flexible and effective means of sensitization for LRSPR sensors, making the plasmon resonance sensors combine high sensitivity, narrow FWHM and high FOM, which have promising applications in biochemical sensing.

Research advances on surface plasmon resonance biosensors.

The surface plasmon resonance (SPR) phenomenon is of wide interest due to its sensitivity to changes in surface refractive index for the label-free, highly sensitive and rapid detection of biomarkers. This paper reviews research progress on SPR biosensors modified with different substrate structures and surface materials, surface plasmon resonance imaging (SPRI), and SPR-enhanced electrochemiluminescent (ECL) biosensors for applications in biosensing in the last five years. This paper focuses on the research on the application of the SPR phenomenon in the field of bio-detection, reviews the sensing characteristics of SPR biosensors with substrate structures of prisms, gratings, and optical fibers, and summarizes and analyzes the sensitivity and interference resistance of SPR sensors with surface modification of different materials (high-refractive index dielectric films, metallic micro- and nanostructures, and surface antifouling materials). Considering that imaging is an important tool for biomedical detection, this paper reviews the research progress on SPRI technology in the field of biomedical detection. In addition, this paper also reviews the research progress on SPR-enhanced ECL biosensors in the field of biosensing. Finally, this paper provides an outlook on the development trends of biosensing technology in terms of portable high-precision SPR sensors, reduction of self-loss of thin film materials, optimization of image processing techniques and simplification of electrode modification for ECL sensors.

Promoting neurogenesis in hippocampal dentate gyrus of chronic unpredictable stress-induced depressive-like rats with paeoniflorin.

Hippocampal neurogenesis plays an important role in the onset and treatment of depressive disorders. Previous studies suggest that paeoniflorin could be used as an antidepressant for treating rats subjected to chronic unpredictable stress. In this study, the effects of paeoniflorin on neurogenesis in the hippocampus dentate gyrus and potential mechanism of action are further investigated in chronic unpredictable stress-induced rat. Results suggest that paeoniflorin markedly increased both sucrose consumption and the number of 5-bromo-2-deoxyuridine-positive cells in the dentate gyrus of chronic unpredictable stress-induced rats, and the ratio of co-expressed 5-bromo-2-deoxyuridine and glial fibrillary acidic protein-positive cells, but exerted no significant effect on the ratio of co-expressed 5-bromo-2-deoxyuridine and neuronal nuclei-positive cells. Compared with the vehicle group, a significant increase was detected in the number of brain-derived neurotrophic factor-positive cells and the expression of brain-derived neurotrophic factor mRNA in the hippocampus of the paeoniflorin-treated group. According to the results, paeoniflorin promoted neural stem cell proliferation, their differentiation into astrocytes, and neurogenesis in the hippocampal dentate gyrus of chronic unpredictable stress-induced rats. Apart from enhancing the protein expression and gene transcription of brain-derived neurotrophic factor, it also activated the expression of tropomyosin receptor kinase B (a high-affinity receptor of brain-derived neurotrophic factor). This suggests that paeoniflorin might promote neurogenesis in the hippocampus dentate gyrus of chronic unpredictable stress-induced rats and act as an antidepressant by regulating the brain-derived neurotrophic factor-tropomyosin receptor kinase B signaling pathway.

Therapeutic mechanisms of single Chinese medicine herb or their extracts for extrahepatic obstructive jaundice.

Obstructive jaundice (OJ) is classified as extrahepatic OJ or intrahepatic OJ. Extrahepatic OJ is attributed to a variety of intricate etiological factors. Research has begun with Chinese medicine (CM), which can be used as an adjunctive therapy for extrahepatic OJ. Particular attention has been paid to the therapeutic effects and their mechanisms of single CM herb and relevant extracts. The roles of single CM or their extracts during adjunctive therapy for extrahepatic OJ have been described briefly. This review focuses on the effects and their mechanisms of relevant herbal medicines.

Antidepressant-like effects of paeoniflorin on the behavioural, biochemical, and neurochemical patterns of rats exposed to chronic unpredictable stress.

We have previously demonstrated that the total glycosides of peony exert antidepressant-like effects in animal models. Paeoniflorin is the main active glycoside of peony. The purpose of this study was to evaluate the antidepressant-like effects of paeoniflorin in a rat model of chronic unpredictable stress (CUS) and its active mechanisms. The results showed that CUS-exposed rats exhibited depressive-like behaviour with reduced weight, low motor activity as well as reduced consumption of sucrose, biochemical changes with increased concentrations of corticosterone and adrenocorticotropic hormone and neurochemical changes with reduced monoamine neurotransmitter levels. Paeoniflorin treatment markedly increased sucrose consumption and decreased serum corticosterone and adrenocorticotropic hormone levels in the CUS-treated rats. Furthermore, paeoniflorin treatment significantly attenuated CUS-induced reductions in noradrenaline, serotonin and its metabolite 5-hydroxyindoleacetic acid as well as CUS-induced increases in the ratio between the latter two factors. These results suggest that the modulation of the hypothalamic-pituitary-adrenal axis and up-regulation of serotonergic and noradrenergic systems are important mechanisms underlying the antidepressant-like effects of paeoniflorin in CUS-treated rats.

Mechanistic study on the antidepressant-like effect of danggui-shaoyao-san, a chinese herbal formula.

Danggui-Shaoyao-San (DSS), a famous Chinese herbal formula, has been widely used in the treatment of various diseases. Previous studies have shown that DSS produces antidepressant-like effect in rodents. This study aims to investigate the mechanism(s) underlying the antidepressant-like action of DDS. The results showed that DSS treatment significantly antagonized reserpine-induced ptosis in mice. In addition, DSS treatment significantly increased sucrose consumption in chronic unpredictable stress- (CUS-) treated mice. DSS treatment also markedly attenuated CUS-induced decreases in noradrenaline and dopamine concentrations in mouse brain. Furthermore, DSS treatment significantly reversed CUS-induced increase in serum malondialdehyde (MDA) content and decrease in serum superoxide dismutase (SOD) activity in mice. The results suggest that the antidepressant-like activity of DSS is probably mediated by the modulation of central monoamine neurotransmitter systems and the reduction of oxidative stress.

Protective effects of paeoniflorin against corticosterone-induced neurotoxicity in PC12 cells.

Neuroprotection has been proposed as one of the acting mechanisms of antidepressants. Paeoniflorin, a monoterpene glycoside, has been reported to display antidepressant-like effects in animal models of behavioural despair. The present study aimed to examine the protective effect of paeoniflorin treatment on corticosterone-induced neurotoxicity in cultured rat pheochromocytoma (PC12) cells. Paeoniflorin was shown to elevate cell viability, decrease levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) in corticosterone-treated PC12 cells. Paeoniflorin also reversed the reduced nerve growth factor (NGF) mRNA level caused by corticosterone in PC12 cells. The results suggest that paeoniflorin exerts a neuroprotective effect on corticosterone-induced neurotoxicity in PC12 cells, at least in part, via the inhibition of oxidative stress and the up-regulation of NGF expression. This neuroprotective effect may be one of the action pathways that accounts for the in vivo antidepressant activity of paeoniflorin.