5,702 research outputs found
Low-molecular-weight organic acids exuded by Mangrove (Kandelia candel (L.) Druce) roots and their effect on cadmium species change in the rhizosphere
Cadmium (Cd) accumulation has been found in large areas of estuaries due to emissions from municipal waste incinerators, car exhausts, residues from metalliferous mining and the smelting industry, and the use of sludge or urban composts, pesticides and fertilizers. In these areas, mangroves have been observed to possess a tolerance to high levels of Cd and it is hypothesized that low-molecular-weight organic acids (LMWOAs) produced at the soil-root interface (rhizosphere) may play an important role in the availability of Cd to these plants. Changes in both LMWOAs and Cd bioavailability, directly or indirectly related to the Cd stress were studied in the laboratory. A rhizobox technique was used for 6 months under growth in air-conditioned greenhouse with natural illumination and the relative humidity of 85%, the temperature ranging from 26 to 32 degrees C, in increasing Cd concentration stress conditions (0, 5, 10, 20, 30, 40 and 50 ppm). Six-month-old Kandelia candel (L.) Druce seedlings which grown in the rhizoboxes were selected to examine their root exudates. The results showed that monocarboxylic acids (formic, acetic, lactic, butyric and propionic acids), and di- and tricarbonxylic acids (maleic, fumaric, citric and L-tartaric acids) were found in root exudates. Citric, lactic and acetic acids being dominant took up 76.85-97.87% of the total LMWOAs in root exudations. Fumaric acid was only found where mangroves were growing on 20 ppm Cd. Root exudates reduced pH by 0.2-0.5 pH units in the rhizosphere compare to the bulk soil. The proportion of exchangeable Cd and Cd bound to carbonate had a positive correlation to total LMWOAs in the rhizosphere soil. Root exudates induced changes in soil Cd species under control conditions, consisting of lower exchangeable Cd compared with increasing stress. Results indicate that the measurement of LMWOAs may be included as early biomarkers in a plant bioassay to assess the phytotoxicity of Cd-contaminated soils on mangrove plants. (C) 2007 Elsevier B.V. All rights reserved
Kinase inhibit region of SOCS3 attenuates IL6-induced proliferation and astrocytic differentiation of neural stem cells via cross talk between signaling pathways
Aims: Efficiency of neural stem cells (NSCs) therapy for brain injury is restricted by astrogliosis around the damaged region, in which JAK2/STAT3 signaling plays a key role. The SOCS3 that can directly inhibit JAK/STAT3 pathway. Here, we investigated the effects of a fusion peptide that combined kinase inhibitory region (KIR) of SOCS3 and virus trans-activator of transcription (TAT) on biological behavior of cultured NSCs under inflammatory conditions. Methods: NSCs were isolated from embryonic brain of SD rats, TAT-KIR was synthesized, and penetration rate was evaluated by flow cytometry (FACS). CCK8, immunostaining, and FACS were used to detected of TAT-KIR on the proliferation of NSCs. The expressions of GFAP and β tubulin III positive cells induced by IL6 with/without TAT-KIR were examined by immunostaining and Western blotting to observe the NSCs differentiation, and the effect of TAT-KIR on signaling cross talk was observed by Western blotting. Results: Penetration rate of TAT-KIR into primary cultured NSCs was up to 94%. TAT-KIR did not affect the growth and viability of NSCs. It significantly reduced the NSCs proliferation that enhanced by IL-6 stimulation via blocking the cell cycle progression from the G0/G1 to S phase. In addition, TAT-KIR attenuated astrocytic differentiation and kept high level of neuronal differentiation derived from IL-6-induced NSCs. The fate of NSCs differentiation under inflammatory conditions was affected by TAT-KIR, which was associated with synchronous inhibition of STAT3 and AKT, while promoting JNK expression. Conclusion: TAT-KIR mimetic of SOCS3 could be a promising approach for brain repair via regulating the biological behaviors of exogenous NSCs
Multiphoton Interference in Quantum Fourier Transform Circuits and Applications to Quantum Metrology
© 2017 American Physical Society. Quantum Fourier transforms (QFTs) have gained increased attention with the rise of quantum walks, boson sampling, and quantum metrology. Here, we present and demonstrate a general technique that simplifies the construction of QFT interferometers using both path and polarization modes. On that basis, we first observe the generalized Hong-Ou-Mandel effect with up to four photons. Furthermore, we directly exploit number-path entanglement generated in these QFT interferometers and demonstrate optical phase supersensitivities deterministically
Speciation changes of cadmium in mangrove (Kandelia candel (L.)) rhizosphere sediments
The speciation distribution of cadmium (Cd) in mangrove (Kandelia candel (L.) Druce) rhizosphere sediment was investigated after different contents of Cd being loaded. The study results indicated that root induced changes of Cd bioavailability in the rhizosphere. Exchangeable and carbonate bound Cd in the rhizosphere sediments were lower than these in the bulk sediments, whilst an increase in Fe-Mn oxides bound and O.M/sulfide bound fractions occurred in the rhizosphere sediment. Increased levels of Cd in sediments resulted in higher Cd concentrations in mangrove plants, and the order of accumulation was: roots > hypocotyls > stems and leaves
Beliefs about the Minds of Others Influence How We Process Sensory Information
Attending where others gaze is one of the most fundamental mechanisms of social cognition. The present study is the first to examine the impact of the attribution of mind to others on gaze-guided attentional orienting and its ERP correlates. Using a paradigm in which attention was guided to a location by the gaze of a centrally presented face, we manipulated participants' beliefs about the gazer: gaze behavior was believed to result either from operations of a mind or from a machine. In Experiment 1, beliefs were manipulated by cue identity (human or robot), while in Experiment 2, cue identity (robot) remained identical across conditions and beliefs were manipulated solely via instruction, which was irrelevant to the task. ERP results and behavior showed that participants' attention was guided by gaze only when gaze was believed to be controlled by a human. Specifically, the P1 was more enhanced for validly, relative to invalidly, cued targets only when participants believed the gaze behavior was the result of a mind, rather than of a machine. This shows that sensory gain control can be influenced by higher-order (task-irrelevant) beliefs about the observed scene. We propose a new interdisciplinary model of social attention, which integrates ideas from cognitive and social neuroscience, as well as philosophy in order to provide a framework for understanding a crucial aspect of how humans' beliefs about the observed scene influence sensory processing
Expression, purification, and characterization of a novel Ca2+- and phospholipid-binding protein annexin B2
Annexin B2 (AnxB2) is a novel member of the annexin family of Ca2+- and phospholipid-binding proteins from Cysticercus cellulosae. To obtain highly pure AnxB2 with an easy and inexpensive purification approach, its cDNA was cloned into the prokaryotic expression vector pJLA503 and the translation initiation codon was immediately under the control of the inducible bacteriophage λ promoters PR and PL. After induction by shifting temperature, large amounts of non-fusion protein were produced in Escherichia coli in a soluble form. Then a novel purification method based on Ca2+-dependent phosphatidylserine (PS)-binding activity was established, whereby the purity of AnxB2 was increased to 98.7%. Western blot analysis showed that recombinant AnxB2 was specifically recognized by serum of pigs infected with cysticercosis. In vitro test showed that, the recombinant AnxB2 had anticoagulant activity and platelet binding activity. The expression, purification, and initial characterization of AnxB2 set an important stage for further characterization of the protein
First identification of excited states in Ba-117 using the recoil-beta-delayed proton tagging technique
Human Bocavirus NS1 and NS1-70 Proteins Inhibit TNF-α-Mediated Activation of NF-κB by targeting p65.
Human bocavirus (HBoV), a parvovirus, is a single-stranded DNA etiologic agent causing lower respiratory tract infections in young children worldwide. Nuclear factor kappa B (NF-κB) transcription factors play crucial roles in clearance of invading viruses through activation of many physiological processes. Previous investigation showed that HBoV infection could significantly upregulate the level of TNF-α which is a strong NF-κB stimulator. Here we investigated whether HBoV proteins modulate TNF-α-mediated activation of the NF-κB signaling pathway. We showed that HBoV NS1 and NS1-70 proteins blocked NF-κB activation in response to TNF-α. Overexpression of TNF receptor-associated factor 2 (TRAF2)-, IκB kinase alpha (IKKα)-, IκB kinase beta (IKKβ)-, constitutively active mutant of IKKβ (IKKβ SS/EE)-, or p65-induced NF-κB activation was inhibited by NS1 and NS1-70. Furthermore, NS1 and NS1-70 didn't interfere with TNF-α-mediated IκBα phosphorylation and degradation, nor p65 nuclear translocation. Coimmunoprecipitation assays confirmed the interaction of both NS1 and NS1-70 with p65. Of note, NS1 but not NS1-70 inhibited TNF-α-mediated p65 phosphorylation at ser536. Our findings together indicate that HBoV NS1 and NS1-70 inhibit NF-κB activation. This is the first time that HBoV has been shown to inhibit NF-κB activation, revealing a potential immune-evasion mechanism that is likely important for HBoV pathogenesis
Myofibrillogenesis regulator 1 (MR-1) is a novel biomarker and potential therapeutic target for human ovarian cancer
<p>Abstract</p> <p>Background</p> <p>Myofibrillogenesis regulator 1 (MR-1) is overexpressed in human cancer cells and plays an essential role in cancer cell growth. However, the significance of MR-1 in human ovarian cancer has not yet been explored. The aim of this study was to examine whether MR-1 is a predictor of ovarian cancer and its value as a therapeutic target in ovarian cancer patients.</p> <p>Methods</p> <p>Reverse-transcription polymerase chain reaction (PCR) and quantitative real-time PCR were used to detect MR-1 mRNA levels in tissue samples from 26 ovarian cancer patients and 25 controls with benign ovarian disease. Anti-MR-1 polyclonal antibodies were prepared, tested by ELISA and western blotting, and then used for immunohistochemical analysis of the tissue samples. Adhesion and invasion of 292T cells was also examined after transfection of a pMX-MR-1 plasmid. Knockdown of MR-1 expression was achieved after stable transfection of SKOV3 cells with a short hairpin DNA pGPU6/GFP/Neo plasmid against the MR-1 gene. In addition, SKOV3 cells were treated with paclitaxel and carboplatin, and a potential role for MR-1 as a therapeutic target was evaluated.</p> <p>Results</p> <p>MR-1 was overexpressed in ovarian cancer tissues and SKOV3 cells. 293T cells overexpressed MR-1, and cellular spread and invasion were enhanced after transfection of the pMX-MR-1 plasmid, suggesting that MR-1 is critical for ovarian cancer cell growth. Knockdown of MR-1 expression inhibited cell adhesion and invasion, and treatment with anti-cancer drugs decreased its expression in cancer cells. Taken together, these results provide the first evidence of the cellular and molecular mechanisms by which MR-1 might serve as a novel biological marker and potential therapeutic target for ovarian cancer.</p> <p>Conclusions</p> <p>MR-1 may be a biomarker for diagnosis of ovarian cancer. It may also be useful for monitoring of the effects of anti-cancer therapies. Further studies are needed to clarify whether MR-1 is an early diagnostic marker for ovarian cancer and a possible therapeutic target.</p
Enhanced Avidity Maturation of Antibody to Human Immunodeficiency Virus Envelope: DNA Vaccination with gp120-C3d Fusion Proteins
DNA vaccination can elicit both humoral and cellular immune responses and can confer protection against several pathogens. However, DNA vaccines expressing the envelope (Env) protein of human immunodeficiency virus (HIV) have been relatively ineffective at generating high titer, long-lasting, neutralizing antibodies in a variety of animal models. In this study, we report that fusion of Env and the complement component, C3d, in a DNA vaccine, enhances the titers of antibody to Env. Plasmids were generated that expressed a secreted form of Env (sgp120) from three isolates of HIV and these same forms fused to three tandem copies of the murine homologue of C3d (sgp120-3C3d). Analyses of titers and avidity maturation of the raised antibody indicated that immunizations with each of the sgp120-3C3d-expressing DNAs accelerated both the onset and the avidity maturation of antibody to Env. Originally published AIDS Research and Human Retroviruses, Vol. 17, No. 9, June 200
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