Decreased flow-mediated dilation in healthy Chinese adolescent with a family history of type 2 diabetes.

BACKGROUND: Endothelial dysfunction appears early in the development of cardiovascular disease and is associated with type 2 diabetes. We, therefore, tested the hypothesis that endothelial dysfunction is already present in healthy Chinese adolescent participants at risk of type 2 diabetes and associates with physical activity. METHODS: We investigated the flow-mediated dilation in 65 first-degree relatives (normal tension, normal glucose tolerance) and 62 age-, sex- and BMI-matched controls without a family history of type 2 diabetes by ultrasound. Physical activity level was assessed using the Global Physical Activity Questionaire and type 2 diabetes family history through self-reporting. The association between physical activity and flow-mediated dilation was evaluated by Pearson correlations and multiple regressions in adolescents with or without a family history of type 2 diabetes. RESULTS: Female adolescents display better flow-mediated dilation than males. Adolescents with a family history of type 2 diabetes had significantly impaired flow-mediated dilation than healthy controls. Among the parameter detection in the blood, the flow-mediated dilation is only positively associated with high-density lipoprotein cholesterol level, but not others. Interestingly, flow-mediated dilation is positively corrected with physical activity scores in both the male and female adolescents, while slightly impaired but not significant in adolescents with a family history of type 2 diabetes. CONCLUSION: Studies in adolescents are important to understand the early pathogenesis of type 2 diabetes. Findings of this investigation suggest that family history of type 2 diabetes may play a role in regulating the vascular function in Chinese adolescents. Given the impaired flow-mediated dilation in individuals with family history and the effects of physical activity in improved flow-mediated dilation, people with a family history of type 2 diabetes may need higher physical activity levels to attenuate their susceptibility to impaired flow-mediated dilation.

Lignans and Phenylethanoid Glycosides from the Aerial Parts of Pogostemon cablin.

Two new lignans (1-2) and a new octaketide (12), together with twenty-nine known compounds (3-11, 13-32) were isolated and identified from the aerial part of Pogostemon cablin. Their chemical structures were revealed mainly through NMR and MS data. The absolute configuration of 1 and 2 was deduced by comparing its experimental CD with the calculated ECD spectra. The inhibitory activities of the isolated compounds on LPS-stimulated nitric oxide (NO) production in RAW 264.7 cells were investigated. At a concentration of 25 µM, compounds 1 and 11 showed approximately equal NO inhibitory effects to that of aminoguanidine.

(-)-α-Bisabolol Alleviates Atopic Dermatitis by Inhibiting MAPK and NF-κB Signaling in Mast Cell.

(-)-α-Bisabolol (BIS) is a sesquiterpene alcohol derived mostly from Matricaria recutita L., which is a traditional herb and exhibits multiple biologic activities. BIS has been reported for treatment of skin disorders, but the effect of BIS on anti-atopic dermatitis (AD) remains unclear. Therefore, we investigated the effects of BIS on 2,4-dinitrochlorobenzene (DNCB)-induced AD in BALB/c mice and the underlying mechanism in Bone Marrow-Derived Mast Cells (BMMCs). Topical BIS treatment reduced AD-like symptoms and the release of interleukin (IL)-4 without immunoglobulin (Ig)-E production in DNCB-induced BALB/c mice. Histopathological examination revealed that BIS reduced epidermal thickness and inhibited mast cells in the AD-like lesions skin. Oral administration of BIS effectively and dose-dependently suppressed mast-cell-mediated passive cutaneous anaphylaxis. In IgE-mediated BMMCs, the levels of ß-hexosaminidase (ß-hex), histamine, and tumor necrosis factor (TNF)-α were reduced by blocking the activation of nuclear factor-қB (NF-қB) and c-Jun N-terminal kinase (JNK) without P38 mitogen activated protein (P38) and extracellular regulated protein kinases (Erk1/2). Taken together, our experimental results indicated BIS suppresses AD by inhibiting the activation of JNK and NF-κB in mast cells. BIS may be a promising therapeutic agent for atopic dermatitis and other mast-cell-related diseases.

Electronic structure of triangular M3 (M = B, Al, Ga): nonclassical three-center two electron π bond and σ delocalization.

The small molecule clusters have received more and more attention due to their widespread applications in chemical insulators, explosives, semiconductors and the high energy density materials industry. The electron deficiency of group IIIA elements endows their clusters with interesting properties. In this work, the electronic structures of M3 (M = B, Al, Ga) have been investigated by means of a complete active space self-consistent field (CASSCF) method. The nature of the chemical bond has been analyzed using the quantum theory of atoms in molecules (QTAIM) and electron localization function (ELF) analyses. The following conclusions can be drawn: in M3 (M = B, Al, Ga) clusters, two π electrons are shared by three atoms forming a 3c-2e delocalization π bond. Going from B3 to Al3 to Ga3, more and more electrons move from the bond pair to the outside of the M atom, which leads to a gradual enhancement of the delocalization of σ electrons. Aromaticity and the adaptive natural density partitioning (AdNDP) analyses reveal the existence of the 3c-2e π bond and delocalization of σ electrons in the studied systems.

Sensing-Based Dynamic Spectrum Sharing in Integrated Wireless Sensor and Cognitive Satellite Terrestrial Networks.

This paper presents a cognitive satellite communication based wireless sensor network, which combines the wireless sensor network and the cognitive satellite terrestrial network. To address the conflict between the continuously increasing demand and the spectrum scarcity in the space network, the cognitive satellite terrestrial network becomes a promising candidate for future hybrid wireless networks. With the higher transmit capacity demand in satellite networks, explicit concerns on efficient resource allocation in the cognitive network have gained more attention. In this background, we propose a sensing-based dynamic spectrum sharing scheme for the cognitive satellite user, which is able to maximize the ergodic capacity of the satellite user with the interference of the primary terrestrial user below an acceptable average level. Firstly, the cognitive satellite user monitors the channel allocated to the terrestrial user through the wireless sensor network; then, it adjusts the transmit power based on the sensing results. If a terrestrial user is busy, the satellite user can access the channel with constrained power to avoid deteriorating the communication quality of the terrestrial user. Otherwise, if the terrestrial user is idle, the satellite user allocates the transmit power based on its benefit to enhance the capacity. Since the sensing-based dynamic spectrum sharing optimization problem can be modified into a nonlinear fraction programming problem in perfect/imperfect sensing conditions, respectively, we solve them by the Lagrange duality method. Computer simulations have shown that, compared with the opportunistic spectrum access, the proposed method can increase the channel capacity more than 20 % for P a v = 10 dB in a perfect sensing scenario. In an imperfect sensing scenario, P a v = 15 dB and Q a v = 5 dB, the optimal sensing time achieving the highest ergodic capacity is about 2.34 ms when the frame duration is 10 ms.

Efficient Wideband Spectrum Sensing with Maximal Spectral Efficiency for LEO Mobile Satellite Systems.

The usable satellite spectrum is becoming scarce due to static spectrum allocation policies. Cognitive radio approaches have already demonstrated their potential towards spectral efficiency for providing more spectrum access opportunities to secondary user (SU) with sufficient protection to licensed primary user (PU). Hence, recent scientific literature has been focused on the tradeoff between spectrum reuse and PU protection within narrowband spectrum sensing (SS) in terrestrial wireless sensing networks. However, those narrowband SS techniques investigated in the context of terrestrial CR may not be applicable for detecting wideband satellite signals. In this paper, we mainly investigate the problem of joint designing sensing time and hard fusion scheme to maximize SU spectral efficiency in the scenario of low earth orbit (LEO) mobile satellite services based on wideband spectrum sensing. Compressed detection model is established to prove that there indeed exists one optimal sensing time achieving maximal spectral efficiency. Moreover, we propose novel wideband cooperative spectrum sensing (CSS) framework where each SU reporting duration can be utilized for its following SU sensing. The sensing performance benefits from the novel CSS framework because the equivalent sensing time is extended by making full use of reporting slot. Furthermore, in respect of time-varying channel, the spatiotemporal CSS (ST-CSS) is presented to attain space and time diversity gain simultaneously under hard decision fusion rule. Computer simulations show that the optimal sensing settings algorithm of joint optimization of sensing time, hard fusion rule and scheduling strategy achieves significant improvement in spectral efficiency. Additionally, the novel ST-CSS scheme performs much higher spectral efficiency than that of general CSS framework.

Energy-Efficient Optimal Power Allocation in Integrated Wireless Sensor and Cognitive Satellite Terrestrial Networks.

This paper proposes novel satellite-based wireless sensor networks (WSNs), which integrate the WSN with the cognitive satellite terrestrial network. Having the ability to provide seamless network access and alleviate the spectrum scarcity, cognitive satellite terrestrial networks are considered as a promising candidate for future wireless networks with emerging requirements of ubiquitous broadband applications and increasing demand for spectral resources. With the emerging environmental and energy cost concerns in communication systems, explicit concerns on energy efficient resource allocation in satellite networks have also recently received considerable attention. In this regard, this paper proposes energy-efficient optimal power allocation schemes in the cognitive satellite terrestrial networks for non-real-time and real-time applications, respectively, which maximize the energy efficiency (EE) of the cognitive satellite user while guaranteeing the interference at the primary terrestrial user below an acceptable level. Specifically, average interference power (AIP) constraint is employed to protect the communication quality of the primary terrestrial user while average transmit power (ATP) or peak transmit power (PTP) constraint is adopted to regulate the transmit power of the satellite user. Since the energy-efficient power allocation optimization problem belongs to the nonlinear concave fractional programming problem, we solve it by combining Dinkelbach's method with Lagrange duality method. Simulation results demonstrate that the fading severity of the terrestrial interference link is favorable to the satellite user who can achieve EE gain under the ATP constraint comparing to the PTP constraint.

Extracting rate changes in transcriptional regulation from MEDLINE abstracts.

BACKGROUND: Time delays are important factors that are often neglected in gene regulatory network (GRN) inference models. Validating time delays from knowledge bases is a challenge since the vast majority of biological databases do not record temporal information of gene regulations. Biological knowledge and facts on gene regulations are typically extracted from bio-literature with specialized methods that depend on the regulation task. In this paper, we mine evidences for time delays related to the transcriptional regulation of yeast from the PubMed abstracts. RESULTS: Since the vast majority of abstracts lack quantitative time information, we can only collect qualitative evidences of time delays. Specifically, the speed-up or delay in transcriptional regulation rate can provide evidences for time delays (shorter or longer) in GRN. Thus, we focus on deriving events related to rate changes in transcriptional regulation. A corpus of yeast regulation related abstracts was manually labeled with such events. In order to capture these events automatically, we create an ontology of sub-processes that are likely to result in transcription rate changes by combining textual patterns and biological knowledge. We also propose effective feature extraction methods based on the created ontology to identify the direct evidences with specific details of these events. Our ontologies outperform existing state-of-the-art gene regulation ontologies in the automatic rule learning method applied to our corpus. The proposed deterministic ontology rule-based method can achieve comparable performance to the automatic rule learning method based on decision trees. This demonstrates the effectiveness of our ontology in identifying rate-changing events. We also tested the effectiveness of the proposed feature mining methods on detecting direct evidence of events. Experimental results show that the machine learning method on these features achieves an F1-score of 71.43%. CONCLUSIONS: The manually labeled corpus of events relating to rate changes in transcriptional regulation for yeast is available in https://sites.google.com/site/wentingntu/data. The created ontologies summarized both biological causes of rate changes in transcriptional regulation and corresponding positive and negative textual patterns from the corpus. They are demonstrated to be effective in identifying rate-changing events, which shows the benefits of combining textual patterns and biological knowledge on extracting complex biological events.

A method for the quantitative analysis of Lycium barbarum polysaccharides (LBPs) using Fourier-transform infrared spectroscopy (FTIR): From theoretical computation to experimental application.

Lycium barbarum polysaccharides (LBPs) is one of the most important active substances in Lycium barbarum (LB). It is a challenge to quantitatively determine the content due to their complex structures and lack of suitable reference standard in practice. In this study, a quantitative analysis method of LBPs in LB was established based on Fourier-transform infrared spectroscopy (FTIR). The stretching vibration of CO on the pyranose ring of saccharide at 921 cm-1 was selected as the characteristic absorption band by theoretical calculation, which can't be impacted by the preparation methods and interfered by the component monosaccharides. The molecular weight CRM of dextran (Mw 63.3 kDa) served as the reference standard. The introducing internal standard (KSCN) can obtain a good precision (RSD = 1.10 %) and effectively compensate for the analysis errors caused by the environment, quality loss and uneven distribution during the tablet pressing processes. The methodological verification suggested that the method had good accuracy according to the recovery rate (96.61 %-105.45 %) and the blank recovery (92.39 %-99.37 %), respectively. The LOD and LOQ of CRMD were 0.10 mg and 0.32 mg, respectively. The polysaccharide content of LB from 24 different regions (0.50-2.54 %) and 10 batches of LB extracts (7.09-10.56 %) determined by the developed method less than the ones using phenol-sulfuric acid assay (1.95 %-4.83 % for LB and 9.83-15.53 % for extracts, respectively). The established method based on FTIR could be served as a supplement to phenol-sulfuric acid assay and a rapid quantitative assay for polysaccharides products. In additional, this study provided a new idea for the quantitative analysis of plant polysaccharides.

Explore public concerns about environmental protection on Sina Weibo: evidence from text mining.

The increasingly serious problem of ecological environmental pollution warns the importance of human environmental protection behavior. However, public attention to environmental protection plays an important role in solving environmental problems. Therefore, in order to explore the environmental concerns of Chinese residents, the trends in time and space, the relationship between online retweets, and the extraction of environmental concerns, this study analyzed the data of Sina Weibo users and their comments on related posts. At the same time, we used the text mining analysis method to analyze the social media text data, and the results are as follows. In that analysis of concern about environmental protection, women show a stronger attitude and willingness to protect the environment than men, and the public in economically developed areas is more concerned. In order to further investigate the public's environmental concerns, this study also utilized the PageRank algorithm to further study the forwarding relationships between users. The study found that celebrities and some good media organizations can attract environmental attention. Finally, we use pyLDAvis technology to visualize and analyze popular environmental themes and propose reasonable countermeasures and suggestions to enhance public environmental awareness based on the research results.

Structural Dimension Exploration and Measurement Scale Development of Employee Involution in China's Workplace Field.

The phenomenon of workplace involution has attracted ample attention. How to make employees treat their work with the correct attitude and behavior and improve their work performance has become a realistic proposition. This study uses a combination of qualitative and quantitative research methods, with the help of grounded theory, to conduct an exploratory study on the structural dimensions of employee involution in the Chinese workplace and, on this basis, to develop and test the measurement scale. The research results show that employee involution is a multi-dimensional construct with rich connotations, including four dimensions: inefficient busyness, exhaustion of innovation, promotion anxiety, and internal competition. The measurement scale consists of four factors and 13 items. The factor analysis results showed that the developed scale's reliability and validity reached an ideal level. To a certain extent, this study promotes the recognition and attention of various types of organizations at all levels to involution. The research conclusions provide theoretical guidance for employees to get rid of the involution crisis and will motivate managers to formulate better intervention measures to prevent and reduce workplace involution.

Eighteen structurally diversified sesquiterpenes isolated from Pogostemon cablin and their inhibitory effects on nitric oxide production.

Five new sesquiterpenes, namely, guaianes A-E (1-5), including one novel carbon skeleton guaiane-type sesquiterpene derivatives (1), together with thirteen known compounds (6-18), were isolated from the aerial parts of Pogostemon cablin (Blanco.) Benth. Their chemical structures were mainly established through the relative spectroscopic data, while the absolute configurations of compounds 1-5 were elucidated on the base of single-crystal X-ray diffraction analysis and electronic circular dichroism (ECD) calculations. All compounds were tested for their inhibiting effects on NO production in LPS-stimulated BV2 microglia cells as well as the cell viabilities. The results showed that compounds 2-16 and 18 possessed moderately anti-inflammatory activities at a concentration of 50 µM.

How do environmental values impact green product purchase intention? The moderating role of green trust.

Environmental values are key factors influencing consumers' purchase intentions and improving consumers' willingness to buy green products is crucial for the sustainable development of ecological environments. Based on environmental values and green product trust, the present study classified environmental values into egoistic, altruistic, and biospheric values and discussed the influence mechanisms of environmental values on green product purchase intention. On this basis, the study verified the mediating role of environmental concern and the moderating role of green trust on the relationship between environmental concern and green product purchase intention. The research results revealed that (1) altruistic and biospheric values had a significant positive impact on green product purchase intention, while egoistic values had a negative impact on green product purchase intention; (2) environmental concern had a partial mediating effect on the relationship between environmental values and green product purchase intention; and (3) green trust had a positive moderating effect on the relationship between environmental concern and green product purchase intention. The present study expanded on the existing research on green product purchase intention driven by values, and the conclusions provided theoretical guidance for green marketing by enterprises and the establishment of customers' trust in the green attributes of products.

Enhanced catalytic performance of a PdO catalyst prepared via a two-step method of in situ reduction-oxidation.

A supported PdO nanocatalyst prepared by a facile in situ reduction process followed by an oxidation step showed significantly enhanced activity for the removal of pollutants from natural gas vehicles. The excellent catalytic performance is mainly due to high dispersion of the uniform PdO nanoparticles generated during the novel two-step method.

Liver fibrosis evaluation by ARFI and APRI in chronic hepatitis C.

AIM: To explore the value of liver fibrosis assessment by acoustic radiation force impulse (ARFI) and the AST/PLT ratio index (APRI) in chronic hepatitis C patients. METHODS: One hundred and twenty eight patients with chronic hepatitis C were examined using ARFI elastometry and APRI, calculated according to known formulae. The gold standard of liver biopsy was referred; ROC curve analysis was used to assess all ARFI and APRI values. The corresponding cut-off values, sensitivities, and specificities were calculated and compared. In addition, the correlation of liver fibrosis stages in chronic hepatitis C patients with ARFI measurements and APRI were also tested to evaluate significant data. RESULTS: The values of ARFI in S1-S4 were 1.23 ± 0.34 m/s, 1.48 ± 0.43 m/s, 2.06 ± 0.45 m/s, and 2.30 ± 0.87 m/s. The values of APRI in S1-S4 were 0.31 ± 0.45 m/s, 0.28 ± 0.38 m/s, 0.58 ± 0.59 m/s and 0.65 ± 0.34 m/s. ARFI (r = 0.649, P < 0.05) showed a better correlation with liver fibrosis stages in chronic hepatitis C than APRI (r = 0.478, P < 0.05). The areas under the ROC curves for ARFI and APRI were 0.775 and 0.721 for stages ≥ S2, 0.901 and 0.787 for stages ≥ S3, and 0.792 and 0.780 for S = 4, respectively. CONCLUSION: Both ARFI and APRI could evaluate liver fibrosis stages in chronic hepatitis C. ARFI is more accurate than the APRI index.