521 research outputs found

    Secondhand smoke exposure induces Raf/ERK/MAPK-mediated upregulation of cerebrovascular endothelin ETA receptors

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    <p>Abstract</p> <p>Background</p> <p>Cigarette smoking enhances the risk of stroke. However, the underlying molecular mechanisms are largely unknown. The present study established an <it>in vivo </it>rat secondhand cigarette smoking (SHS) model and examined the hypothesis that SHS upregulates endothelin receptors with increased cerebrovascular contraction <it>via </it>the Raf/extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway.</p> <p>Results</p> <p>Rats were exposed to SHS for up to 8 weeks. The cerebral artery vasoconstriction was recorded by a sensitive myograph. The mRNA and protein expressions for endothelin receptors in cerebral arteries were studied by real-time PCR and Western blot. Compared to fresh air exposed rats, cerebral arteries from SHS rats exhibited stronger contractile responses (<it>P </it>< 0.05) mediated by endothelin type A (ET<sub>A</sub>) receptors. The expressions of mRNA and protein for ET<sub>A </sub>receptors in the cerebral arteries from SHS rats were higher (<it>P </it>< 0.05) than that in control. SHS did not affect endothelin type B (ET<sub>B</sub>) receptor-mediated contractions, mRNA or protein levels. The results suggest that SHS upregulates ET<sub>A</sub>, but not ET<sub>B </sub>receptors <it>in vivo</it>. After SHS exposure, the mRNA levels of Raf-1 and ERK1/2, the protein expression of phosphorylated (p)-Raf-1 and p-ERK1/2 were increased (<it>P </it>< 0.05). Raf-1 inhibitor, GW5074 suppressed the enhanced ET<sub>A </sub>receptor-mediated contraction, mRNA and protein levels induced by SHS. In addition, GW5074 inhibited the SHS-caused increased mRNA and phosphorylated protein levels of Raf-1 and ERK1/2, suggesting that SHS induces activation of the Raf/ERK/MAPK pathway.</p> <p>Conclusions</p> <p>SHS upregulates cerebrovascular ET<sub>A </sub>receptors <it>via </it>the Raf/ERK/MAPK pathway, which provides novel understanding of mechanisms involved in SHS-associated stroke.</p

    Does online media attention improve China’s green fund performance?

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    This study investigates the relationship between online media attention and the performance of China’s green funds. The results show that increased media attention can boost the performance of green funds in the short term, however, this effect is short-lived. The mechanism of short-term positive effects may be due to increased media attention leading to larger purchases, which may undermine funds’ long-term performance. In particular, online media attention has a greater impact on larger and older funds. Moreover, it indicates that media attention reduces the returns of individual investor-dominated funds, but has little effect on institutional investor-dominated funds

    Breeding response of transcript profiling in developing seeds of Brassica napus

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    <p>Abstract</p> <p>Background</p> <p>The upgrading of rapeseed cultivars has resulted in a substantial improvement in yield and quality in China over the past 30 years. With the selective pressure against fatty acid composition and oil content, high erucic acid- and low oil-content cultivars have been replaced by low erucic acid- and high oil-content cultivars. The high erucic acid cultivar Zhongyou 821 and its descendent, low erucic acid cultivar Zhongshuang 9, are representatives of two generations of the most outstanding Chinese rapeseed cultivars (<it>B. napus</it>) developed the past 2 decades. This paper compares the transcriptional profiles of Zhongshuang 9 and Zhongyou 821 for 32 genes that are principally involved in lipid biosynthesis during seed development in order to elucidate how the transcriptional profiles of these genes responded to quality improvement over the past 20 years.</p> <p>Results</p> <p>Comparison of the cultivar Zhongyou 821 with its descendent, Zhongshuang 9, shows that the transcriptional levels of seven of the 32 genes were upregulated by 30% to 109%, including <it>FAD3</it>, <it>ACCase, FAE1</it>, <it>GKTP</it>, <it>Caleosin</it>, <it>GAPDH</it>, and <it>PEPC</it>. Of the 32 genes, 10 (<it>KAS3, β-CT, BcRK6, P450, FatA, Oleosin, FAD6, FatB, α-CT </it>and <it>SUC1</it>) were downregulated by at least 20% and most by 50%. The <it>Napin </it>gene alone accounted for over 75% of total transcription from all 32 genes assessed in both cultivars. Most of the genes showed significant correlation with fatty acid accumulation, but the correlation in ZS9 was significantly different from that in ZY821. Higher <it>KCR2 </it>activity is associated with higher C16:0, C18:0, and C18:2 in both cultivars, lower C22:1 and total fatty acid content in ZY821, and lower 18:1 in ZS9.</p> <p>Conclusion</p> <p>This paper illustrates the response of the transcription levels of 32 genes to breeding in developing rapeseed seeds. Both cultivars showed similar transcription profiles, with the <it>Napin </it>gene predominantly transcribed. Selective pressure for zero erucic acid, low glucosinolate, high oleic acid and high oil content, as well as high yield, resulted in higher <it>FAD3</it>, <it>ACCase, FAE1</it>, <it>GKTP</it>, <it>Caleosin</it>, <it>GAPDH</it>, and <it>PEPC </it>expression levels and lower <it>KAS3, β-CT, BcRK6, P450, FatA, Oleosin, FAD6, FatB, α-CT </it>and <it>SUC1 </it>expression levels. It also resulted in altered relationships between these genes during storage accumulation in seed development.</p

    The MLH1 2101C>A (Q701K) variant increases the risk of gastric cancer in Chinese males

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    <p>Abstract</p> <p>Background</p> <p>Gastric cancer is one of the most common cancers affecting East Asians, and <it>MLH1 </it>could play a critical role during tumorigenesis in this condition.</p> <p>Methods</p> <p>Samples from 236 Chinese patients suffering from gastric cancer were screened for <it>MLH1 </it>germline mutations. Carrier frequencies of the mutations were compared between gastric cancer patients and 240 cancer-free controls. Bioinformatic analysis was used to predict the effect of these mutations on protein function and mRNA splicing.</p> <p>Results</p> <p>Six <it>MLH1 </it>sequence alterations were identified in gastric cancer patients including two promoter region substitutions, -93G>A and -28A>G, and four missense mutations 649C>T (R217C), 655A>G (I219V), 1151T>A (V384D) and 2101C>A (Q701K). Compared with the <it>MLH1 </it>2101CC genotype, the 2101CA genotype was associated with a risk of gastric cancer (OR = 8.42, 95% CI = 1.04-68.06) in males. Furthermore, the <it>MLH1 </it>2101C>A mutant was predicted by <it>in silico </it>analysis to affect exon splicing ability. Immunohistochemistry of one index patient carrying the <it>MLH1 </it>2101C>A mutation demonstrated a loss of MLH1 protein and normal expression of MSH2 and E-cadherin. No significant differences were demonstrated between cases and controls for the other five <it>MLH1 </it>variants but the data indicated an ethnic difference in the frequency of these variations between Eastern Asians and Western populations.</p> <p>Conclusions</p> <p>An ethnic-specific <it>MLH1 </it>mutation spectrum occurred in Chinese gastric cancer patients. The <it>MLH1 </it>2101C>A mutation could be a marker for susceptibility to gastric cancer, particularly in males.</p

    Plane Double-Layer Structure of AC@S Cathode Improves Electrochemical Performance for Lithium-Sulfur Battery

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    Due to the high theoretical specific capacity of lithium-sulfur batteries, it is considered the most promising electrochemical energy storage device for the next generation. However, the development of lithium-sulfur battery has been restricted by its low cycle efficiency and low capacity. We present a Plane double-layer structure of AC@S cathode to improve the electrochemical performance of lithium-sulfur batteries. The battery with this cathode showed good electrochemical performance. The initial discharge capacity of the battery with the structure of AC@S cathode could reach 1,166 mAhg−1 at 0.1 C. After 200 cycles, it still remains a reversible capacity of 793 mAh g−1 with a low fading rate of 0.16% per cycle. Furthermore, the batteries could hold a discharge capacity of 620 mAh g−1 after 200 cycles at a typical 0.5 C rate. The improvement of electrochemical performance is attributed to that the polysulfide produced during charge/discharge can be better concentrated in the cathode by the planar double-layer structure, thus reducing the loss of sulfur

    Transplantation of Ciliary Neurotrophic Factor-Expressing Adult Oligodendrocyte Precursor Cells Promotes Remyelination and Functional Recovery after SpinalCord Injury

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    Demyelination contributes to the dysfunction after traumatic spinal cord injury (SCI). We explored whether the combination of neurotrophic factors and transplantation of adult rat spinal cord oligodendrocyte precursor cells (OPCs) could enhance remyelination and functional recovery after SCI. Ciliary neurotrophic factor (CNTF) was the most effective neurotrophic factor to promote oligodendrocyte (OL) differentiation and survival of OPCs in vitro. OPCs were infected with retroviruses expressing enhanced green fluorescent protein (EGFP) or CNTF and transplanted into the contused adult thoracic spinal cord 9 d after injury. Seven weeks after transplantation, the grafted OPCs survived and integrated into the injured spinal cord. The survival of grafted CNTF-OPCs increased fourfold compared with EGFP-OPCs. The grafted OPCs differentiated into adenomatus polyposis coli (APC+) OLs, and CNTF significantly increased the percentage of APC+ OLs from grafted OPCs. Immunofluorescent and immunoelectron microscopic analyses showed that the grafted OPCs formed central myelin sheaths around the axons in the injured spinal cord. The number of OL-remyelinated axons in ventrolateral funiculus (VLF) or lateral funiculus (LF) at the injured epicenter was significantly increased in animals that received CNTF-OPC grafts compared with all other groups. Importantly, 75% of rats receiving CNTF-OPC grafts recovered transcranial magnetic motor-evoked potential and magnetic interenlargement reflex responses, indicating that conduction through the demyelinated axons in VLF or LF, respectively, was partially restored. More importantly, recovery of hindlimb locomotor function was significantly enhanced in animals receiving grafts of CNTF-OPCs. Thus, combined treatment with OPC grafts expressing CNTF can enhance remyelination and facilitate functional recovery after traumatic SCI

    The ethical dimension of management ownership in China

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    Management ownership has ethical consequences because it has an interest alignment effect or an entrenchment effect. In this paper, we investigate the ethical consequences of management ownership in China using accounting conservatism as the direct measure of entrenchment and alignment between shareholders and managers. We argue and find that the ethical effect of management ownership differs significantly in firms with different ultimate controlling shareholders. Specifically, management ownership in non-state-owned enterprises (NSOEs) has an alignment effect, while management ownership has less of an alignment effect in state-owned enterprises than in NSOEs. These results show that the ethical consequences of management ownership are moderated by the nature of ultimate controlling ownership

    Political connections and tax-induced earnings management: Evidence from China

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    We use the occasion of a change in tax policy that raised the tax rate for many of the listed companies in China to examine tax-induced earnings management (TEM) from the perspective of political connections. We find that when the tax rate increased, only those affected firms with politically connected management engaged in TEM. This suggests that, in addition to motivation for managing earnings, capability of influencing tax authorities is also an important determinant of TEM. We also find that TEM helped the firms with politically connected management to reduce their tax burden
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