2,166 research outputs found

    Proton block of proton-activated TRPV1 current.

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    The TRPV1 cation channel is a polymodal nociceptor that is activated by heat and ligands such as capsaicin and is highly sensitive to changes in extracellular pH. In the body core, where temperature is usually stable and capsaicin is normally absent, H(+) released in response to ischemia, tissue injury, or inflammation is the best-known endogenous TRPV1 agonist, activating the channel to mediate pain and vasodilation. Paradoxically, removal of H(+) elicits a transient increase in TRPV1 current that is much larger than the initial H(+)-activated current. We found that this prominent OFF response is caused by rapid recovery from H(+) inhibition of the excitatory current carried by H(+)-activated TRPV1 channels. H(+) inhibited current by interfering with ion permeation. The degree of inhibition is voltage and permeant ion dependent, and it can be affected but not eliminated by mutations to acidic residues within or near the ion selectivity filter. The opposing H(+)-mediated gating and permeation effects produce complex current responses under different cellular conditions that are expected to greatly affect the response of nociceptive neurons and other TRPV1-expressing cells

    Understanding the influence of a contextual factor, stigma consciousness: a barrier for underrepresented students in engineering

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    The present study used Social Cognitive Career Theory (SCCT; Lent, Brown, & Hackett, 1994) to examine the influence of racial/ethnic stigma consciousness on persistence intention among 263 underrepresented racial/ethnic minority engineering students. Path analysis was used to test a model depicting relationships between contextual (i.e., racial/ethnic stigma consciousness, institution types) and person-cognitive (i.e., self-efficacy, positive and negative outcome expectations, persistence intention) variables as hypothesized in SCCT. Results indicated that both hypothesized indirect and direct structural models provided an excellent fit to the data, but the hypothesized indirect model showed better fit. Test of mediation was statistically significant for engineering self-efficacy, but not for positive and negative outcome expectations in the relations between racial/ethnic stigma consciousness and persistence intentions. Results of moderated mediation indicated a significant interaction of coping efficacy on racial/ethnic stigma consciousness on the indirect effect via engineering self-efficacy. A series of ANOVA and MANOVA were also conducted to determine whether demographic and contextual variables could explain racial/ethnic stigma consciousness, coping efficacy, and socio-cognitive variables (i.e., self-efficacy, positive and negative outcome expectations, persistence intentions) to pursue engineering degree. Suggestions for future research directions, clinical implications, and limitations are further provided.Includes bibliographical references

    Anti-oxidative and anti-neuroinflammatory effects of ethyl acetate extract fractions of Suaeda asparagoides MIq

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    Purpose: To evaluate the in vitro antioxidant and anti-neuroinflammatory effects of Suaeda asparagoides ethylacetate extract (SAE) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells.Methods: The antioxidative activity of SAE was evaluated by measuring 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity  spectrometrometrically. Cell viability was evaluated by 3-(4, 5- dimethylthiazol-2-yl)-2, 5- diphenyl-tetrazolium bromide (MTT) assay, while LPS-stimulated BV-2 microglia were used to study the expression and production of inflammatory mediators, including nitric oxide (NO), inducible NO synthase (iNOS) and tumor necrosis alpha (TNF-α).Results: Pretreatment with SAE prior to LPS treatment significantly inhibited excessive production of NO (p < 0.001 at 20, 40, 80 and 100 μg/mL) in a dose-dependent manner, and was associated with down-regulation of expression of inducible nitric oxide synthase (iNOS). SAE also suppressed the LPSinduced increase in TNF-α level (p < 0.01at concentrations of 40 and 80 μg/mL) in BV-2 cells. Furthermore, DPPH-generated free radicals were inhibited by SAE in a concentration-dependent manner.Conclusion: These results indicate that SAE possesses strong anti-oxidant properties, and inhibits excessive production of pro-inflammatory mediators, including NO, iNOS and TNF-α, in LPS-stimulated BV-2 cellsKeywords: Suaeda asparagoides, DPPH, Anti-inflammatory activity, Microglial cells, iNOS, TNF-

    Highly circularly polarized white light using a combination of white polymer light-emitting diode and wideband cholesteric liquid crystal reflector

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    We present a simple and intriguing device that generates highly circularly polarized white light. It comprises white polymer light-emitting diodes (WPLEDs) attached to a wideband cholesteric liquid crystal (CLC) reflector with a wide photonic bandgap (PBG) covering the visible range. The degree of circular polarization realized is very high over the visible range. The wide PBG was realized by introducing a gradient in pitch of the cholesteric helix by controlling the twisting power within the CLC medium. WPLEDs fabricated using a ternary (red, green, and blue) fluorescent polymer blend with the same moiety showed a low turn-on voltage, high brightness, high efficiency, and good color stability.open0

    In Vitro Chemosensitivity Using the Histoculture Drug Response Assay in Human Epithelial Ovarian Cancer

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    The choice of chemotherapeutic drugs to treat patients with epithelial ovarian cancer has not depended on individual patient characteristics. We have investigated the correlation between in vitro chemosensitivity, as determined by the histoculture drug response assay (HDRA), and clinical responses in epithelial ovarian cancer. Fresh tissue samples were obtained from 79 patients with epithelial ovarian cancer. The sensitivity of these samples to 11 chemotherapeutic agents was tested using the HDRA method according to established methods, and we analyzed the results retrospectively. HDRA showed that they were more chemosensitive to carboplatin, topotecan and belotecan, with inhibition rates of 49.2%, 44.7%, and 39.7%, respectively, than to cisplatin, the traditional drug of choice in epithelial ovarian cancer. Among the 37 patients with FIGO stage Ⅲ/Ⅳ serous adenocarcinoma who were receiving carboplatin combined with paclitaxel, those with carboplatin-sensitive samples on HDRA had a significantly longer median disease-free interval than patients with carboplatin- resistant samples (23.2 vs. 13.8 months, p<0.05), but median overall survival did not differ significantly (60.4 vs. 37.3 months, p=0.621). In conclusion, this study indicates that HDRA could provide useful information for designing individual treatment strategies in patients with epithelial ovarian cancer

    Is Further Treatment Necessary for Patellar Crepitus After Total Knee Arthroplasty?

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    Introduction: Posterior-stabilized (PS) TKA that sacrifice the cruciate ligaments improves pain and function in patients with advanced osteoarthritis. Patellar crepitus appears to be due to a spectrum of peripatellar fibrosynovial formations and is usually encountered after PS-TKA, which uniquely has an intercondylar box to accept the tibial post. Symptoms of patellar crepitus occur most commonly during terminal knee extension and occur usually from 3 to 9 months after PS-TKA, and in some cases, this phenomenon is symptomatic enough to warrant an arthroscopic procedure or open arthrotomy. The development of patellar crepitus after PS-TKA appears related to many factors such as femoral component design, surgical errors, increased postoperative knee flexion, and postoperative patellar baja, which are also responsible for patellar clunk syndrome

    Hybrid organic-inorganic light-emitting electrochemical cells using fluorescent polymer and ionic liquid blend as an active layer

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    We demonstrate enhanced device performance by using a blend of emissive polymer and mobile ionic liquid molecules in hybrid organic-inorganic polymeric light-emitting electrochemical cells with high air stability. The mobile anions and cations redistributed near each electrode/active layer interface make ohmic contacts, thereby enhancing current density and electroluminescence efficiency at relatively low operating voltage.open12

    Characterization of potential health promoting lipids in the co-products of de-flossed milkweed

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    The floss and oil of the common milkweed (Asclepias syriaca L.) seeds are currently used to produce comforters/pillows and skin care products, respectively. As an outcome of these products, copious quantities co-products (pressed seed meal and pod biomass) are disposed of each year despite the presence of potential health benefiting lipids. The objective of this project was to determine the feasibility of developing the lipid fraction from of these co-products for the fast growing dietary human health market. Although certain types of lipids were affected by the extraction solvent used (hexane and diethyl ether) as were overall amounts, analysis of the each extract showed novel lipid profiles with several potential health benefiting agents present at levels comparable to or exceeding those present in other typically consumed dietary oils or food systems (vitamin E, carotenoids, sterols and unsaturated free fatty acids, particularly the both omega 7-fatty acids)
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