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The oil in hydropower station catchment wells is a source of water pollution which can cause the downstream river to become polluted. Timely detection of oil can effectively prevent the expansion of oil leakage and has important significance for protecting water sources. However, the poor environment and insufficient light on the water surface of catchment wells make oil pollution detection difficult, and the real-time performance is poor. To address these problems, this paper proposes a catchment well oil detection method based on the global relation-aware attention mechanism. By embedding the global relation-aware attention mechanism in the backbone network of Yolov5s, the main features of oil are highlighted and the minor information is suppressed at the spatial and channel levels, improving the detection accuracy. Additionally, to address the problem of partial loss of detail information in the dataset caused by the harsh environment of the catchment wells, such as dim light and limited area, single-scale retinex histogram equalization is used to improve the grayscale and contrast of the oil images, enhancing the details of the dataset images and suppressing the noise. The experimental results show that the accuracy of the proposed method achieves 94.1% and 89% in detecting engine oil and turbine oil pollution, respectively. Compared with the Yolov5s, Faster R-CNN, SSD, and FSSD detection algorithms, our method effectively reduces the problems of missing and false detection, and has certain reference significance for the detection of oil pollution on the water surface of catchment wells.

A Chinese yam polysaccharide possess a triple helix structure and has hypoglycemic activity. The mechanism of regulating blood glucose may be related to the PI3K/Akt signaling pathway in the livers of diabetic mice.

Purple sweet potato Ipomoea batatas (L.) has long been used as a medicine and a food. It contains various bioactive substances such as polysaccharides, anthocyanins, and flavonoids. Purple sweet potato polysaccharides are known to have anti-oxidant, anti-tumor, and immunomodulatory functions. Nevertheless, studies on the structural characterization of purple sweet potato polysaccharides and their ability to prevent non-alcoholic fatty liver disease (NAFLD) have rarely been reported.A novel polysaccharide (PSPP-A) was extracted and isolated from purple sweet potato, and its structural characteristics and preventive effects on NAFLD were investigated. The results indicated that PSPP-A was composed of l-rhamnose, d-arabinose, d-galactose, d-glucose, and d-glucuronic acid with molar ratios of 1.89:8.45:1.95:1.13:1. Its molecular weight was 2.63 × 10The novel polysaccharide, PSPP-A, mainly contains arabinose, which has certain preventive effects on NAFLD. This study provides a theoretical basis for further elucidating the hepatoprotective effect of purple sweet potatoes as a functional food. © 2022 Society of Chemical Industry.

Tibet is an area in China with a high incidence of stroke, typically attributed to hypobaric hypoxia. The present study aimed to observe the neuronal injury of ischemic stroke after hypobaric hypoxia and explore the mechanism by which N-methyl-D-aspartate receptor (NMDAR) and its downstream pathways are involved. This study employed a hypobaric chamber to imitate high altitude at 4000 m. After hypoxia, the middle cerebral artery occlusion (MCAO) model was used to mimic ischemic stroke. Behavioral tests and measurements of infarct area were used to observe neuronal injuries. The expression of NMDAR, Ca2+/calmodulin-dependent protein kinase II (CaMKII) and phosphorylated CaMKII (Threonine 286) (P-CaMKII) was tested by western blot, and hematological tests were used to count the number of red blood cells (RBCs) and hemoglobin. Compared with the plain+MCAO group, the neurological deficit scores and infarct area of rats in the 4000 m + MCAO group were all decreased, and the protein expression of NMDAR, CaMKII and P-CaMKII was reduced. Compared with the plain group, the numbers of RBCs, hemoglobin and hematocrit were increased in the 4000 m group; compared with the 4000 m groups, the three indexes were increased in the 4000 m + MCAO groups. The neuronal injuries after hypoxia were not more serious than those in rats enduring ischemia and reperfusion in plain. The underlying mechanisms were related to the decreased expression of NMDAR and CaMKII; furthermore, the increased numbers of RBCs and hemoglobin may be crucial mechanisms for the incidence and development of ischemic stroke at high altitude.

Docosahexaenoic acid (DHA) has been studied for many years owing to its protective effect on the decline in brain function. DHA intake reduces the risk of Alzheimer's disease (AD) and decreases amyloid deposition; however, the underlying molecular mechanism has not been completed elucidated. In this study, the effect of DHA on the cognitive function of amyloid precursor protein (APP)/PS1 in wild-type mice and its related mechanism were investigated. Results from the Morris water maze test showed that DHA improved learning and memory function in mice. Moreover, DHA reduced neuronal damage in mice brains, as determined using Nissl staining. Unsaturated fatty acid levels in the brain of mice increased (p < 0.01) after DHA administration and saturated fatty acid levels decreased (p < 0.01). The deposition of amyloid-beta (Aβ) plaques and tau protein neurofibrillary tangles was significantly inhibited. The mechanism of action of DHA was attributed to the upregulation of the expression of β-secretase (BACE)2, which competed with BACE1 to cleave APP, thus decreasing the production of extracellular Aβ fragments (p < 0.01). The expression level of insulin-degrading enzyme was not significantly different. The expression of N-methyl-D-aspartate receptors was further downregulated and the phosphorylation of glycogen synthase kinase-3β and tau protein was inhibited (p < 0.01). These data indicated that DHA could protect cognitive function in mice by reducing Aβ plaque formation and decreasing tau phosphorylation levels.

High ammonia concentration hinders the efficient treatment of antibiotic production wastewater (APW). Developing effective ammonia oxidation wastewater treatment strategies is an ideal approach for facilitating APW treatment. Compared with traditional nitrification strategies, the partial nitrification process is more eco-friendly, less energy-intensive, and less excess sludge. The primary limiting factor of the partial nitrification process is increasing ammonia-oxidizing bacteria (AOB) while decreasing nitrite-oxidizing bacteria (NOB). In this study, an efficient AOB microbiota (named AF2) was obtained via enrichment of an aerobic activated sludge (AS0) collected from a pharmaceutical wastewater treatment plant. After a 52-day enrichment of AS0 in 250 mL flasks, the microbiota AE1 with 69.18% Nitrosomonas microorganisms was obtained. Subsequent scaled-up cultivation in a 10 L fermenter led to the AF2 microbiota with 59.22% Nitrosomonas. Low concentration of free ammonia (FA,42.01 mg L

Docosahexaenoic acid (DHA) has attracted plenty of interest in the prevention of neurodegenerative diseases. Although the beneficial effects of DHA on the central nervous system function are recognized, more information on the molecular mechanisms involved in its neuroprotective effects is required. The present study aimed to evaluate the effects of DHA on the function of mitochondria, neurite growth-related proteins signaling pathway, and neural signal transmission. In this study, PC12 cells were treated with H

Existence of cantharidin (CTD) in blister beetles is a significant ecological adaptive mechanism that defends against predators and regulates courtship and mating behaviors. To better understand CTD biosynthetic information as well as its biology and pharmacology, we assembled a genome of 151.88 Mb for Epicauta chinensis using PacBio sequencing technology. Gene annotation yielded 249,238 repeats, 527 non-coding RNAs and 12,520 protein-coding genes. Compared to other 11 insects, expansions of gene families in E. chinensis for most core gene families likely associated with environmental adaptation, such as chemoreception, immunity, and detoxification. We further annotated P450s and immune-related genes, a total of 117 putative P450s comprising 7 CYP2, 67 CYP3, 36 CYP4, and 7 mitochondrial P450s and 281 immune-related genes were identified. Comparative analysis of the insect immune repertoires indicated presence of immune genes detected only from Coleopteran insects such as MD2-like. This suggested a lineage-specific gene evolution for Coleopteran insects. Based on the gene family evolution analysis, we identified two probable candidate genes including CYP4TT1 and phytanoyl-CoA dioxygenase for CTD biosynthesis. The high-quality reference genome of E. chinensis provides the genetic basis for further investigation of CTD biosynthesis and in-depth studies of the development and evolution of blister beetles.

In the present work, Zn-incorporated TiO2 coatings are prepared through a one-step micro-arc oxidation (MAO) method on a grade 4 pure titanium with the addition of either Na2Zn-EDTA solution or ZnO nanoparticles (NPs) as Zn sources. The microstructural features of both Zn-incorporated TiO2 coatings were systematically examined. It is revealed that different Zn sources result in significant difference of phase component, chemical state, composition and morphology between the resultant Zn-incorporated MAO coatings. Zn species could be present as ZnO and Zn(OH)2 in the coating when Na2Zn-EDTA was used as Zn source whereas the presence of ZnO nano-clusters is obvious on the coating surface with ZnO NPs as Zn source. The addition of ZnO NPs during the MAO process also leads to a lower Zn content of the resultant coating, which is more defective with increased thickness in comparison to that of Na2Zn-EDTA. Further, antibacterial property and osteogenic activity of both Zn-incorporated coatings were examined. Both Zn-incorporated coatings exhibit favourable bacterial inhibition ability and bone formability, suggesting the successful synthesis of bifunctional coatings through the facile one-step micro-arc oxidation method.

Equalizers are common microwave devices often used to improve the problem of unsatisfactory signal amplitudefrequency characteristics in microwave systems. This paper briefly introduces the basic principles of the equalizer, and brings up the equalizer designing method: based on the uneven signal amplitude-frequency characteristics, use the theoretical analysis to design the initial value, and perform computer simulation optimization, and develop the X-band microstrip equalizer. The test results show that the equalizer's equalization in the working frequency band is about 4dB, and the input and output standing wave coefficient is less than 1.5, which meets the system's designing requirements for equalization, standing waves and miniaturization.

Urban space is vital to contemporary urban life. However, the digital era has had an enduring impact on global urban space. The vitality of many physical urban spaces has been declining, with many of their functions replaced by online activities. It has become crucial to theoretically reconsider the key elements of the attractiveness of urban space and to find an effective practical measurement to improve urban space vitality. Therefore, this paper applies an interdisciplinary view of sociology and urban planning, raising an explanatory framework to show that the major determinant of urban space vitality has shifted to “spatial social interaction”, which is derived from people's social needs. Based on this assumption, this paper further presents various factors of spatial social interaction and constructs a quantitative model. In addition, it verifies the model through an empirical analysis of OCT Loft in Shenzhen, China. In the process, the interaction parameters of typical spaces are calculated and compared with the actual situation and shows a positive correlation. The construction of the theoretical framework and preliminary verification are expected to provide insights into the worldwide revitalization of urban space and to help in the preevaluation of related designs.

The objective of this experiment was to learn more about the genetic mechanisms influencing calyx persistence in Korla fragrant pear (Pyrus sinkiangensis Yu). Flowers were collected from fragrant pear trees at three flowering stages. High-throughput small RNA sequencing profiles of sepals and ovaries with persistent calyx (S_e and S_z, respectively) were compared with those of sepals and ovaries with deciduous calyx (T_e and T_z, respectively). A total of 46 known miRNAs belonging to 33 families and 102 novel miRNAs were identified through high-throughput sequencing. There were 51 differentially expressed miRNAs in S_z vs T_z and 31 differentially expressed miRNAs in S_e vs T_e. Eleven miRNAs were differentially expressed in both comparisons. The expression patterns of eight miRNAs were validated by quantitative reverse transcription real-time PCR (qRT-PCR). A total of 263 target genes were predicted for the differentially expressed miRNAs. The target genes were correlated with various transcription factors (psi-miR156p/x－SPL, psi-miR172i－AP2/SAUR, psi-miR160a－ARF, psi-miR396a/b－GRF, psi-miR164a－NAC and psi-miR159c－MYB) and other related proteins. GO analysis showed that the differentially expressed miRNAs were involved in regulating various biological processes, plant hormone and auxin response, lignin metabolic process, DNA binding, intracellular membrane-bounded organelle and membrane-bounded organelle. KEGG pathway analysis showed that the differentially expressed miRNAs were mainly related to steroid biosynthesis, starch and sucrose metabolism, and galactose metabolism.

MicroRNAs play important roles in the regulation of gene expression in plants and animals. However, little information is known about the action mechanism and function of fungal microRNA-like RNAs (milRNAs). In this study, combining deep sequencing, molecular and histological assays, milRNAs and their targets in the phytopathogenic fungus Valsa mali were isolated and identified. A critical milRNA, Vm-milR16, was identified to adaptively regulate the expression of virulence genes. Fourteen isolated milRNAs showed high expression abundance. Based on the assessment of a pathogenicity function of these milRNAs, Vm-milR16 was found to be a critical milRNA in V. mali by regulating sucrose non-fermenting 1 (VmSNF1), 4,5-DOPA dioxygenase extradiol (VmDODA), and a hypothetical protein (VmHy1). During V. mali infection, Vm-milR16 is downregulated, while its targets are upregulated. Overexpression of Vm-milR16, but not mutated Vm-milR16, significantly reduces the expression of targets and virulence of V. mali. Furthermore, deletion of VmSNF1, VmDODA and VmHy1 significantly reduce virulence of V. mali. All three targets seem to be essential for oxidative stress response and VmSNF1 is required for expression of pectinase genes during V. mali-host interaction. Our results demonstrate Vm-milRNAs contributing to the infection of V. mali on apple trees by adaptively regulating virulence genes.

The objective of the study was to learn more about some newly identified miRNAs related to calyx persistence in Korla fragrant pear (Pyrus sinkiangensis Yu). Small RNAs were subjected to high-throughput sequencing after extraction from the ovaries and sepals of flowers with either a deciduous or a persistent calyx. Differentially expressed miRNAs were screened, and 73 new miRNAs were obtained. Twenty of these new miRNAs were selected to further validate all of the new miRNAs. Their mature miRNAs were cloned and identified, the secondary structures of the precursor miRNAs (pre-miRNAs) were analysed, and then qRT-PCR analysis was conducted. The results showed that the mature sequences of nine new miRNAs (novel_miRNA) in different samples were consistent with the results of high-throughput sequencing. Overall, this study improved current methods for the molecular cloning and identification of fruit tree miRNA. Nine new miRNA types were identified. This study laid a good foundation for elucidating the...

In this paper, a plasmonic nano-sensor is proposed in semicircle cavity waveguide, the transmission characteristics of the new structure are analyzed by the finite-difference time-domain method. Dual plasmon-induced transparency (PIT) phenomenon is emerged in the semicircle cavity coupled with bus waveguide, which is resulted from the destructive interference superposition of the reflected and transmitted waves from cavity resonator. High sensitivity and figure of merit (FOM) based on PIT in the resonator has been investigated in detail. The sensitivity of the proposed model is about 2000 nm/RIU and its maximum FOM is up to 85370. In addition, dual PIT peaks are found by changing the structure parameters. The simple structure with such high sensitivity and FOM provide potential implications in nano-sensing field.

In this study, the corrosion behavior of 7075-T6 aluminum alloy in a high salinity environment containing Aspergillus niger was investigated using high-performance liquid chromatography tandem mass spectrometry, gas chromatography, surface analysis and electrochemical measurement. Results demonstrated that uniform and localized corrosion rates of the alloy in the presence of A. niger were approximately 3.7 and 22.4 times, respectively, of that in the absence A. niger. This higher corrosion rate was attributed to accelerated anode and cathode reactions from the actions of A. niger biofilm. Additionally, organic acid corrosion caused by the presence of A. niger was confirmed to be the main cause for the corrosion of aluminum alloy.

The wastewater of vitamin B2 (VB2) production treated after anaerobic digesters contains high total nitrogen (TN) and low organic carbon. To efficiently remove nitrogen pollution in the wastewater, one lab-scale anaerobic ammonium oxidation (anammox) bioreactor was designed. Synthetic wastewater and proper conditions were used to startup the anammox process in the bioreactor. The stoichiometric parameters of the bioreactor showed that anammox process was successfully established during operation. Evaluation of the bioreactor with real VB2 wastewater suggested that the bioreactor can efficiently remove nitrogen pollution at low organic carbon situation. The optimal state of total nitrogen loading rate (TNLR) and the highest total nitrogen removal efficiency (TNRE) of the bioreactor were 0.35 kg/(m3·d) and 75%, respectively. The microbiota run at day 112 (named VBM112) was significantly different with the microbiotas of the two inoculation cultures. At the phylum level, the most abundant phylum was Proteobacteria in the inoculation culture, while Bacteroidetes was the most abundant phylum in VBM112. At the genus level, the composition of nitrogen removal related microbes significantly increased in VBM112. Especially, the anammox bacteria Candidatus Kuenenia increased from 0% of the inoculation culture to 2.2% of VBM112. The analyses of running parameters and microbiota profiles confirmed the well establishment of one lab-scale anammox bioreactor, which might be helpful for future full-scale VB2 wastewater treatment startup.

The humanoid end effector has a better performance when grabbing irregular objects. Compared to a full-drive dexterous robot hand, the underactuated gripper has a more compact structure, simpler control, and good self-adaptive ability, it can be applied to different shapes of objects. However, in some cases, improper design will lead to uneven grasping force, and it will not be able to grasp firmly or even have ejection phenomenon. So the optimization of the geometrical parameters is of great importance. In this paper, according to the designed three-degrees-of-freedom link-type underactuated manipulator, the mechanical model under grasping state is deduced by the principle of virtual work. Setting the average degree of grasping force as the optimization goal, the size and angle of pressure have been optimized by using MATLAB genetic algorithm toolbox and several suitable results have been obtained.

Active contour models (ACM) based on level set method (LSM) are widely used in image segmentation. However, the classical edge-based models always extract some unnecessary objects or noise, and they lack robustness in segmenting weak boundary. In this paper, a method to constrain the evolution of contour is proposed. Firstly, extracting objects with a known topology (such as k connected objects) is viewed a sparse representation problem under a set of basis functions. According to sparse representation, a set of basis function is obtained with label operator to represent every connected region. Then, the corresponding energy functional model which views noise and non-objects as redundancy is defined based on basis functions. Furthermore, through the defined basis functions, a novel edge-stop term is designed and integrated into geometric active contour models. Experiments demonstrate that the proposed method improves the robust performances of ACM. On the other hand, the proposed method does not introduce any extra parameter.

The application of microsatellites has been development with the continuous expansion of space missions in resents years. The microsatellites have several characteristics such as light weight, small size and low cost. The platform flotation table is one of the simulation ways on the ground. With the continuous development of space technology, satellite ground simulation platform flotation table as a key technology which attracts lots of researchers. In this paper, the highspeed nozzle has been analyzed based on the research of Laval nozzle. The state of shock waves can be researched by the Laval nozzle and the air speed from the nozzle can be calculated. The flow field of the high speed nozzle has been simulation by the FLUENT software. The nozzle mode has been built by the GAMBIT and the model is meshed in structured grid. The simulation result shows that the air in the nozzle has many speeds in different place. The stable speeds are 390 m/s and 150m/s in the larynx and trailing end position.The maximum are reached into the nozzle and the speed is 578m/s, which is deviated from the theoretical analysis. At the constant pressure of 4 bar, the mass of nozzle flow is 0.000318758 kg/s. The mass of outlet flow is 0.000318798 kg/s, and the calculation error is 10-8. The thrust of the nozzle is also stable at 3ms, and its stability value is 50.1 mN. The maximum force of the outlet is 176 mN before the nozzle reaches stability. The simulation result can guided for the nozzle design and itis more significance for the high precision control and measurement of nozzles.

Alzheimer's disease (AD) chiefly characterizes a progressively neurodegenerative disorder of the brain, and eventually leads to irreversible loss of intellectual abilities. The β-amyloid (Aβ)-induced neurodegeneration is believed to be the main pathological mechanism of AD, and Aβ production inhibition or its clearance promotion is one of the promising therapeutic strategies for anti-AD research. Here, we report that the natural product arctigenin from Arctium lappa (L.) can both inhibit Aβ production by suppressing β-site amyloid precursor protein cleavage enzyme 1 expression and promote Aβ clearance by enhancing autophagy through AKT/mTOR signaling inhibition and AMPK/Raptor pathway activation as investigated in cells and APP/PS1 transgenic AD model mice. Moreover, the results showing that treatment of arctigenin in mice highly decreased Aβ formation and senile plaques and efficiently ameliorated AD mouse memory impairment strongly highlight the potential of arctigenin in anti-AD drug discovery.

This paper proposes a high performance frequency synthesizer system featured by ultra-broadband, low phase noise. In order to achieve frequency synthesizer covering 0.4∼18GHz with 10MHz step, two PLL (Phase Locked Loop), mixer, microwave switch, multiplier, frequency divider, and band-pass filter are been used. The three-section frequency VCO is use to generate 4.5∼9GHz frequency signal. The 0.4∼0.45GHz frequency signal is obtained by division of 4.5∼9GHz frequency signal, and the 9∼18GHz signal is obtained by frequency doubler of 4.5∼9GHz frequency signal. The frequency synthesizer's output power level is −50dBm∼0dBm, the phase noise is better than −85dBc/Hz@1KHz, and the suppression to spurious is better than −55dBc.

Background The objective of this study was to increase understanding about genetic mechanisms affecting calyx persistence in Korla fragrant pear (Pyrus brestschneideri Rehd). Flowers were collected at early bloom, full bloom, and late bloom. The RNA was extracted from the flowers and then combined according to calyx type. Transcriptome and digital gene expression (DGE) profiles of flowers, ovaries, and sepals with persistent calyx (SC_hua, SC_ep, and SC_zf, respectively) were compared with those of flowers, ovaries, and sepals with deciduous calyx (TL_hua, TL_ep, and TL_zf, respectively). Temporal changes in the expression of selected genes in floral organs with either persistent or deciduous calyx were compared using real-time quantitative PCR (qRT-PCR). Results Comparison of the transcriptome sequences for SC_hua and TL_hua indicated 26 differentially expressed genes (DEGs) with known relationship to abscission and 10 DEGs with unknown function. We identified 98 MYB and 21 SPL genes from the assembled unigenes. From SC_zf vs TL_zf, we identified 21 DEGs with known relationship to abscission and 18 DEGs with unknown function. From SC_ep vs TL_ep, 12 DEGs with known relationship to abscission were identified along with 11 DEGs with unknown function. Ten DEGs were identified by both transcriptome sequencing and DGE sequencing. Conclusions More than 50 DEGs were observed that were related to calyx persistence in Korla fragrant pear. Some of the genes were related to cell wall degradation, plant hormone signal transduction, and stress response. Other DEGs were identified as zinc finger protein genes and lipid transfer protein genes. Further analysis showed that calyx persistence in Korla fragment pear was a metabolic process regulated by many genes related to cell wall degradation and plant hormones. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2470-3) contains supplementary material, which is available to authorized users.

LBVS of 12480 in-house compounds, followed by HTRF assay, resulted in one nonsteroidal compound (11) with antagonistic activity against FXR (69.01 ± 11.75 μM). On the basis of 11, 26 new derivatives (12a-z) were designed and synthesized accordingly. Five derivatives (12f-g, 12p, 12u, and 12y) showed better antagonistic activities against FXR than compound 11. Remarkably, the most potent derivative, 12u (8.96 ± 3.62 μM), showed antagonistic capability approximately 10 times and 8-fold higher than that of the control (GS) and the starting compound 11, respectively. 12u was further confirmed to have high binding affinity with FXRαLBD, FXR specificity over six other nuclear receptors, and potent antagonistic activity against FXR in two cell testing platforms. 12u strongly suppressed the regulating effects of CDCA on FXR target genes. The therapeutic potential of 12u was identified by lowering the contents of triglyceride and cholesterol in human hepatoma HepG2 cells and in the cholesterol-fed C57BL/6 mices.

Retinoic X receptor (RXR) is a promising target for drug discovery against cancer and metabolic syndromes. Here, we identified a specific RXRα antagonist, danthron, from the traditional Chinese medicine rhubarb. Danthron repressed all tested RXRα-involved response element transcription, including the RXRE, PPRE, FXRE, and LXRE. Results from native PAGE and isothermal titration calorimetry (ITC)-based assays indicated that danthron bound to the tetrameric RXRα-LBD in a specific stoichimetric ratio, and such a binding could influence the corepressor SMRT affinity to the receptor. Additionally, a unique tetrameric structure of the apo-RXRα ligand-binding domain (LBD) was determined, which exhibited a larger tetramer interface and different ligand-binding pocket size compared with the one previously reported. Together with the biochemical and biophysical results, the determined crystal structure of danthron-soaked RXRα-LBD suggested a new mechanism for danthron antagonism to tetrameric RXRα. Moreover, the in vivo efficient improvement of insulin sensitivity by danthron was observed in diet-induced obese (DIO) mice. Thus, our findings were expected to supply new insights into the structural basis of RXRα antagonist for its further potential therapeutic application.

Aim: To investigate the inhibitory effect of the natural product Leukamenin F on liver fibrosis and explore its potential underlying mech - anisms. Methods: Carbon tetrachloride (CCl4)-treated mouse model in vivo and in hepatic stellate cells (HSC) in vitro were used. The effect on CCl4-induced liver fibrosis was studied using histochemical and biochemical analysis, while the inhibition on HSC was assessed using cell proliferation/apoptosis assay and collagen I production using real-time PCR. The inhibitory effects of Leukamenin F on Akt/mTOR/ p70S6K and TGFβ/Smad pathways was studied using Western blot and cell image analysis. Results: Leukamenin F (0.1-1 mg/kg, ip, q.d.×28) significantly reduced α-SMA and collagen specific Sirius red staining areas in CCl 4 -treated mouse livers. This compound at 1-2 µmol/L dose-dependently inhibited α-SMA expression, cell proliferation and type I procol- lagen mRNA expression in activated HSC. Furthermore it inhibited the Akt/mTOR/p70S6K pathway and suppressed TGFβ -induced Smad2/Smad3 phosphorylation and nuclear translocation in HSC. Conclusion: Our results demonstrated that Leukamenin F could attenuate CCl4-induced liver fibrogenesis in mice as an efficient inhibi - tor against both HSC proliferation and ECM production. This natural product provides a valuable structural hint for the development of anti-liver fibrosis reagents.

In view of photoacoustic spectroscopy theory, the relationship between weak photoacoustic signal and gas concentration is described. The studies, on the principle of Duffing oscillator for identifying state transition as well as determining the threshold value, have proven the feasibility of applying the Duffing oscillator in weak signal detection. An improved differential Duffing oscillator is proposed to identify weak signals with any frequency and ameliorate the signal-to-noise ratio. The analytical methods and numerical experiments of the novel model are introduced in detail to confirm its superiority. Then the signal detection system of weak photoacoustic based on differential Duffing oscillator is constructed, it is the first time that the weak signal detection method with differential Duffing oscillator is applied triumphantly in photoacoustic spectroscopy gas monitoring technology.

Alzheimer's disease (AD) characterizes a progressive neurodegenerative disorder of the brain, while AD patients are afflicted with irreversible loss of neurons and further the intellectual abilities including memory and reasoning. One of the typical hallmarks of AD is the deposition of senile plaque that is contributed mainly by amyloid-beta (Abeta), whose production is initiated by beta-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1). Inhibition of BACE1 is thereby regarded as an attractive strategy for anti-AD drug discovery. Here, we reported that the natural product 2,2',4'-trihydroxychalcone (TDC) from Glycyrrhiza glabra functioned as a specific non-competitive inhibitor against BACE1 enzyme, and potently repressed beta-cleavage of APP and production of Abeta in human embryo kidney cells-APPswe cells. Moreover, the amelioration ability of this compound against the in vivo memory impairment was further evaluated by APP-PS1 double transgenic mice model. It is discovered that treatment of 9 mg/kg/day of TDC could obviously decrease Abeta production and Abeta plaque formation, while efficiently improve the memory impairment based on Morris water maze test. Our findings thus demonstrated that the natural product TDC as a new BACE1 inhibitor could ameliorate memory impairment in mice, and is expected to be potentially used as a lead compound for further anti-AD reagent development.

Level set is an important method in image segmentation, and some models based on level set method have obtained great success, such as Chan and Vese (C-V) and its convex formulation, local binary fitting (LBF) model. However, these models have two drawbacks to be simultaneously solved. One is the non-convexity of energy functional; the other difficulty is segmenting objects in the background of inhomogeneous intensity. In order to simultaneously cope with these shortcomings, a fuzzy level set energy functional model is proposed. Firstly, a fuzzy factor is introduced in the original LBF model to describe the intensity inhomogeneity. Besides, the edge information is also integrated into the proposed model to improve the robustness of extracting objects. Finally, a regularisation optimisation method is introduced to obtain the global minimisation. Experimental results confirm the proposed method is robust to initialisation and could segment objects with inhomogeneous intensity.

Alzheimer’s disease (AD) is a progressively neurodegenerative disease that eventually leads to the irreversible loss of neurons and intellectual abilities, including cognition and memory. AD has become the most common cause of dementia in aged people, and the ill-defined pathogenesis of AD is seriously impeding the current drug discovery against this disease. To date, there is still a lack of etiologically therapeutic drugs for AD, although some symptomatic treatments have been successfully developed. The β-amyloid (Aβ)-induced neurodegeneration is determined as the main pathogenesis of AD, and by targeting the regulation of Aβ in production inhibition or clearance promotion, many active agents have been designed potentially for AD treatment, but no drug has yet been approved in clinical use. Actually, AD has a complex pathogenic mechanism that involves multiple aberrant signaling genes and pathways, and the idea of ‘single target’ for anti-AD drug research is thus full of challenges. Recently, with a deep understanding of AD pathogeneses and the development of advanced pharmacological techniques, ‘multiple target’-based strategy has been widely applied for the drug discovery against this disease, and many promising results have been achieved. Here, we review the recent multitarget strategies for the drug discovery in the treatment of AD by focusing on the involvement of Aβ regulation.