Search

Background Tumor necrosis factor receptor 2 (TNFR2) promotes tumor cell proliferation, activates immunosuppressive cells, and supports immune escape. However, its role in non‐small cell lung cancer (NSCLC) has not been reported. Methods Quantitative real‐time PCR and Western blotting were used to evaluate TNFR2 in three NSCLC cell lines (A549, H1299, H1975) and normal lung epithelial cells (BEAS‐2B). TNFR2 was evaluated in 71 tumor tissues and 25 adjacent normal lung tissues by immunohistochemistry and analyzed with respect to clinical parameters. Results The messenger RNA and protein levels of TNFR2 were significantly higher in A549, H1299, and H1975 cells than in BEAS‐2B cells (P

Background: Guan-Xin-Shu-Tong capsule (GXSTC) is a traditional Chinese medicine (TCM) that has been used to treat coronary heart disease (CHD) for many years in China. However, the holistic mechanism of GXSTC against CHD is still unclear. Therefore, the purpose of this paper was to systematically explore the mechanism of action GXSTC in the treatment of CHD rats using a metabolomics strategy.Methods: A CHD model was induced by ligation of the left anterior descending coronary artery (LAD). In each group, echocardiography was performed; the contents of creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate transaminase (AST) in serum were determined; and the myocardial infarct size was measured. The metabolites in plasma were analyzed by UHPLC-MS/MS-based untargeted metabolomics. Then, multivariate statistical analysis was performed to screen potential biomarkers associated with the GXSTC treatment in the LAD-induced rat CHD model. Finally, the MetaboAnalyst 4.0 platform was used for metabolic pathway enrichment analysis.Results: GXSTC was able to regulate the contents of CK, LDH and AST; restore impaired cardiac function; and significantly reduce the myocardial infarction area in model rats. Twenty-two biomarkers and nine metabolic pathways of GXSTC in the treatment of CHD were identified through UHPLC-MS/MS-based untargeted metabolomics analysis.Conclusion: GXSTC regulates metabolic disorders of endogenous components in LAD-induced CHD rats. The anti-CHD mechanism of GXSTC is mainly related to the regulation of amino acid, lipid and hormonal metabolism. This study provides an overall view of the mechanism underlying the action of GXSTC against CHD.

Composite sucker rods are widely used in oil fields because of light weight, high strength, and corrosion resistance. Bonded technology becomes the primary connection method of composites. However, the joints with composite sucker rods are prone to debone and fracture. The connected characteristics are less considered, so the failure mechanism of the joint is still unclear. Based on the cohesive zone model (CZM) and the Johnson-Cook constitutive model, a novel full-scale numerical model of the joint with composite sucker rod was established, and verified by pull-out experiments. The mechanical properties and slip characteristics of the joint were studied, and the damaged procession of the joint was explored. The results showed that: a) the numerical model was in good agreement with the experimental results, and the error is within 5%; b) the von Mises stress, shear stress, and interface stress distributed symmetrically along the circumferential path increased gradually from the fixed end to the loading end; c) the first-bonded interface near the loading end was damaged at first, followed by debonding of the second-bonded interface, leading to the complete shear fracture of the epoxy, and resulted in the debonding of the joint with composite sucker rod, which can provide a theoretical basis for the structural design and optimization of the joint. [ABSTRACT FROM AUTHOR]

Aims In heterantherous plants, 'division of labor' among structurally different stamens, i.e. pollinating and feeding functions, has been thought to reduce the evolutionary conflict of relying on pollen both as the carrier of male gametes and as the food for pollinators. The key to successful division of labor among different sets of stamens is the size match between stamens and legitimate pollinators, which results in the precise deposition of pollen onto specific locations on pollinator's body and facilitates cross pollination. However, the potential impact of small illegitimate insects that are ubiquitous during the pollination process on the plant reproduction in heterantherous species has been largely neglected in previous studies and never been demonstrated experimentally. Methods Here, we investigated the functions of three different types of stamens in Commelina communis. The pollinator visitation, pollen removal and deposition were compared among flowers with different types of anthers emasculated at two natural populations. Moreover, the mating systems of C. communis in wild populations were estimated using microsatellite markers. Important Findings Our data showed that the main floral visitors for C. communis at the two studied populations were small illegitimate bees rather than legitimate pollinators, accounting for 77.5 and 92.2% of total flower visits, respectively. Flower manipulations in C. communis demonstrated that the two types of brightly yellow stamens separately functioned as 'deceptive attraction' and 'feeding' functions. Although the brown inconspicuous stamens of C. communis with the largest amount of fertile pollen had the potential function in offering pollen for cross pollination, the high ratio of illegitimate visitation by small bees significantly affected the dispersal and deposition of pollen from the pollinating anthers, and subsequently decreased the levels of outcrossing (tm = 0.23-0.32) in wild populations. Our work further confirmed that the size match between pollinators and the floral morphology is the prerequisite to successfully fulfill the functional differentiation among different sets of stamens in heterantherous plants. Local high ratio of illegitimate visitation by size unmatched insects could significantly weaken the potential functions of heteranthery, affecting the dispersal and deposition of functional pollen in heterantherous plants and further the whole mating systems. [ABSTRACT FROM AUTHOR]

The roots and rhizomes of Smilax riparia (SR), called "Niu-Wei-Cai" in traditional Chinese medicine (TCM), are believed to be effective in treating gout symptoms. However, it is not clear if the active constituents and uricosuric mechanisms of S. riparia support its therapeutic activities. In this study, we isolated two steroidal glycosides named riparoside B and timosaponin J from the total saponins of S. riparia. We then examined if these two compounds were effective in reducing serum uric acid levels in a hyperuricemic mouse model induced by potassium oxonate. We found that the two steroidal glycosides possess potent uricosuric effect in hyperuricemic mice through decreasing renal mURAT1 mainly and inhibiting XOD activity in a certain extent, which contribute to the enhancement of uric acid excretion and attenuate hyperuricemia-induced renal dysfunction. Riparoside B and timosaponin J may have a clinical utility in treating gout and other medical conditions caused by hyperuricemia. [ABSTRACT FROM AUTHOR]

Demographic variation of gender expression among four natural populations and one cultivated in a monoecious species, Schisandra chinensis (Schisandraceae), was studied over three consecutive years in a bid to clarify its sexual system and to better understand reproductive strategies in monoecious plants. We found that gender expression was more variable in the natural populations than in the cultivated one. In the natural populations, plant size was positively correlated with flower production (total, male and female) but not with the female ratio, whereas shade intensity was negatively correlated with the female ratio. In the cultivated population, plant age was positively correlated with flower production and the female ratio within an age range. Hence, gender expression and reproductive output in Schisandra chinensis was found to be age-dependent. The female ratio varied with age; young and old plants had lower female ratios. Our study confirmed the sexual system in the species to be monoecy as opposed to dioecy, and supported the hypothesis that monoecious plants can regulate gender expression by altering quantities of pistillate and staminate flowers at the individual plant level to maximize fitness. [ABSTRACT FROM AUTHOR]

The duration of sexual phases in dichogamous plants are affected by many factors. Using both experimental and observational studies, we investigated natural patterns of pollen removal and deposition, visiting frequency of pollinators, patterns of nectar secretion, and effects of pollen removal and stigmatic pollen deposition on the duration of sexual phases in a protandrous plant, Glechoma longituba. We found that visiting frequency of pollinators correlated with the nectar secretion pattern. The nectar volume during the male phase was higher than during the female phase. In the morning, the main pollinator, the bee Anthophora plumipes, mainly foraged for nectar and showed no preference for flowers in male or female phase, despite male phase flowers producing higher amounts of nectar. However, in the afternoon, they changed their behavior and foraged mainly for pollen, and then showed a preference for flowers in male phase. Furthermore, the rates of pollen removal and stigmatic pollen deposition can affect the starting time and the duration of the female phase. When pollen removal and pollination rates are low due to scarcity of pollinator services, the sexual phase can be prolonged, leading to an overlap, and thereby enhance the chance for sexual reproduction through pollinator-facilitated self-pollination. We consider the variation of sexual phases in Glechoma longituba an adaptive mechanism prepared for both cross-pollination enhancement and reproductive assurance depending on the available pollination services. [ABSTRACT FROM AUTHOR]

Nickel is a potential neurotoxic pollutant. Oxidative stress is supposed to be involved in the mechanism underlying nickel-induced neurotoxicity. Melatonin has efficient protective effects against various oxidative damages in nervous system. The purpose of this study was to investigate whether melatonin could efficiently protect against neurotoxicity induced by nickel. Here, we exposed primary cultured cortical neurons and mouse neuroblastoma cell lines (neuro2a) to different concentrations of nickel chloride (NiCl2) (0.125, 0.25, 0.5, and 1 mm) for 12 hr or 0.5 mm NiCl2 for various periods (0, 3, 6, 12, and 24 hr). We found that nickel significantly increased reactive oxygen species production and caused the loss of cell viability both in cortical neurons and neuro2a cells. In addition, nickel exposure obviously inhibited the mitochondrial function, disrupted the mitochondrial membrane potential (ΔΨm), reduced ATP production, and decreased mitochondrial DNA (mtDNA) content. However, each of these oxidative damages was efficiently attenuated by melatonin pretreatment. These protective effects of melatonin may be attributable to its roles in reducing oxidative stress and improving mitochondrial function in nickel-treated nerve cells. Our results suggested that melatonin may have great pharmacological potential in protecting against the adverse effects of nickel in the nervous system. [ABSTRACT FROM AUTHOR]

The within-season modification or adjustment of sex expression was studied in the gynodioecious herb Glechoma longituba. The results from seven natural populations indicated that the seed sets of hermaphrodite ramets were relatively stable compared to those of female ramets. However, a negative correlation was detected between the seed set of female ramets and their frequency of occurrence in a population. Moreover, a negative correlation was also detected between the degree of gender modification in the late flowering period and the seed set in female ramets. Controlled experiments on both wild and cultivated plants indicated that the resource adjustment, presumably caused by flower removal or the hand pollination of flowers, in the early-middle flowering season could induce a greater degree of gender modification in later flowers from female to hermaphrodite and vice versa. However, the ranges of degree of gender modification were different between the two sex morphs, and the variation in females was greater than in hermaphrodites. This phenomenon could not be adequately explained based on the sequential adjustment of investment hypothesis which has been invoked in previous studies. We propose that the results of this study may provide a variation to the model of sequential adjustment of investment in serial flowering annual gynodioecious plants, including Glechoma longituba. We postulate that the variation of sex expression might be beneficial for the female in order to avoid pollen limitation and, further, to obtain a selective advantage. [ABSTRACT FROM AUTHOR]

Ion photon emission microscopy (IPEM) is a new ion-induced emission microscopy. It employs a broad ion beam with high energy and low fluence rate impinging on a sample. The position of a single ion is detected by an optical system with objective lens, prism, microscope tube and charge coupled device (CCD). A thin ZnS film doped with Ag ions is used as a luminescent material. Generation efficiency and transmission efficiency of photons in the ZnS(Ag) film created by irradiated Cl ions are calculated. A single Cl ion optical microscopic image is observed by high quantum efficiency CCD. The resolution of a single Cl ion given in this IPEM system is 6 μm. Several factors influencing the resolution are discussed. A silicon diode is used to collect the electrical signals caused by the incident ions. Effective and accidental coincidence of optical images and electronic signals are illustrated. A two-dimensional map of single event effect is drawn out according to the data of effective coincidence. [ABSTRACT FROM AUTHOR]

Yttria-stabilized zirconia (YSZ) is irradiated with 2.0-MeV Au2+ ions and 30-keV He+ ions. Three types of He, Au, Au + He (successively) ion irradiation are performed. The maximum damage level of a sequential dual ion beam implanted sample is smaller than single Au ion implanted sample. A comparable volume swelling is found in a sequential dual ion beam irradiated sample and it is also found in a single Au ion implanted sample. Both effects can be explained by the partial reorganization of the dislocation network into weakly damaged regions in the dual ion beam implanted YSZ. A vacancy-assisted helium trapping/diffusion mechanism in the dual ion beam irradiated condition is discussed. No phase transformation or amorphization behavior happens in all types of ion irradiated YSZ. [ABSTRACT FROM AUTHOR]

Background and Aims Most research on the widespread phenomenon of nectar robbing has focused on the effect of the nectar robbers behaviour on host-plant fitness. However, attention also needs be paid to the characteristics of host plants, which can potentially influence the consequences of nectar robbing as well. A system of three sympatric Corydalis species sharing the same nectar-robbing bumble-bee was therefore studied over 3 years in order to investigate the effect of nectar robbing on host reproductive fitness. Methods Three perennial species of Corydalis were studied in the Shennongjia Mountain area, central China. Observations were conducted on visitor behaviour and visitation frequencies of nectar-robbers and legitimate pollinators. Key Results The results indicated that the effect of nectar robbing by Bombus pyrosoma varied among species, and the three species had different mating systems. Seed set was thus influenced differentially: there was no effect on seed set of the predominantly selfing C. tomentella; for the facultative outcrossing C. incisa, nectar robbing by B. pyrosoma had a positive effect; and nectar robbing had a significant negative effect on the seed set of outcrossing C. ternatifolia. Conclusions A hypothesis is proposed that the type of host-plant mating system could influence the consequences of nectar robbing on host reproductive fitness. [ABSTRACT FROM AUTHOR]