Novel protocols for P300-based brain-computer interfaces

The oddball protocol is often used in brain-computer interfaces (BCIs) to induce P300 ERPs, although, recently, some issues have been shown to detrimentally effect its performance. In this paper, we study a new periodic protocol and explore whether it can compete with the standard oddball protocol within the context of a BCI mouse. We found that the new protocol consistently and significantly outperforms the standard oddball protocol in relation to information transfer rates (33 bits/min for the former and 22 bits/min for the latter, measured at 90% accuracy) as well as P300 amplitudes. Furthermore, we performed a comparison of two periodic protocols with two less conventional oddball-like protocols that reveals the importance of the interactions between task and sequence in determining the success of a protocol.     

Ultra-Fine Grained Degradable Magnesium for Biomedical Applications

通过对工业纯镁以及ZM21合金的性能测试研究了镁合金在可降解生物医学中的应用,讨论了等径角挤压制备超细晶以及温挤压对材料性能的影响。晶粒细化导致合金材料压缩强度明显提高,强烈的初始变形织构导致粗晶镁合金拉伸强度高于压缩。等径角挤压能够减弱织构的影响,使不同合金塑性流变行为获得改变。材料腐蚀性能主要受化学成分、晶粒大小以及先前变形诱导晶格畸变程度的综合影响。等径角挤压细化晶粒、增大晶格缺陷密度在一定程度上制衡了材料的腐蚀性能。同时弥散分布的第二相粒子的增加对于点蚀发展有着积极的作用。     

Effect of long‐term exposure of silver nanoparticles on growth indices,hematological and biochemical parameters and gonad histology of male goldfish (Carassius auratus gibelio)

Studying the impact of emerging pollutants such as nanoparticles is necessary to reveal the adverse effect. In this study, the effects of silver nanoparticles (Ag‐NPs) on hematological, biochemical, and gonad histopathological indices of male goldfish were examined. Sublethal toxicity were calculated based on acute toxicity and three dosages were selected. Live specimen of Carassius auratus gibelio larval were treated in 1, 2, and 3 ppm Ag‐NP with one control group. Blood and tissue samples were extracted after 6 months exposure to sublethal concentrations. Results showed that Ag‐NPs have reduced growth rate and effected on all blood indices significantly. Biochemical analysis revealed that Ag‐NPs significantly reduced blood glucose and total protein than in comparison to the control group and caused significantly differences in the concentrations of serum cholesterol (p < .05). Furthermore, histological observation of intestine after 6 months exposure showed definite alterations in tissue and maximum hypertrophy injuries were found after long‐term exposure to 3 ppm Ag‐NPs concentration. In addition, indicated that long‐term exposure to Ag‐NPs postponed sexual maturity in male gibel carp.     

Antagonizing S1P3 Receptor with Cell-Penetrating Pepducins in Skeletal Muscle Fibrosis

S1P is the final product of sphingolipid metabolism, which interacts with five widely expressed GPCRs (S1P_1-5). Increasing numbers of studies have indicated the importance of S1P₃ in various pathophysiological processes. Recently, we have identified a pepducin (compound KRX-725-II) acting as an S1P₃ receptor antagonist. Here, aiming to optimize the activity and selectivity profile of the described compound, we have synthesized a series of derivatives in which Tyr, in position 4, has been substituted with several natural aromatic and unnatural aromatic and non-aromatic amino acids. All the compounds were evaluated for their ability to inhibit vascular relaxation induced by KRX-725 (as S1P₃ selective pepducin agonist) and KRX-722 (an S1P₁-selective pepducin agonist). Those selective towards S1P₃ (compounds V and VII) were also evaluated for their ability to inhibit skeletal muscle fibrosis. Finally, molecular dynamics simulations were performed to derive information on the preferred conformations of selective and unselective antagonists.     

TRPM2 Oxidation Activates Two Distinct Potassium Channels in Melanoma Cells through Intracellular Calcium Increase

Tumor microenvironments are often characterized by an increase in oxidative stress levels. We studied the response to oxidative stimulation in human primary (IGR39) or metastatic (IGR37) cell lines obtained from the same patient, performing patch-clamp recordings, intracellular calcium ([Ca²⁺]_i) imaging, and RT-qPCR gene expression analysis. In IGR39 cells, chloramine-T (Chl-T) activated large K⁺ currents (KROS) that were partially sensitive to tetraethylammonium (TEA). A large fraction of KROS was inhibited by paxilline—a specific inhibitor of large-conductance Ca²⁺-activated BK channels. The TEA-insensitive component was inhibited by senicapoc—a specific inhibitor of the Ca²⁺-activated KCa3.1 channel. Both BK and KCa3.1 activation were mediated by an increase in [Ca²⁺]_i induced by Chl-T. Both KROS and [Ca²⁺]_i increase were inhibited by ACA and clotrimazole—two different inhibitors of the calcium-permeable TRPM2 channel. Surprisingly, IGR37 cells did not exhibit current increase upon the application of Chl-T. Expression analysis confirmed that the genes encoding BK, KCa3.1, and TRPM2 are much more expressed in IGR39 than in IGR37. The potassium currents and [Ca²⁺]_i increase observed in response to the oxidizing agent strongly suggest that these three molecular entities play a major role in the progression of melanoma. Pharmacological targeting of either of these ion channels could be a new strategy to reduce the metastatic potential of melanoma cells, and could complement classical radio- or chemotherapeutic treatments.     

Nitric Oxide: From Gastric Motility to Gastric Dysmotility

It is known that nitric oxide (NO) plays a key physiological role in the control of gastrointestinal (GI) motor phenomena. In this respect, NO is considered as the main non-adrenergic, non-cholinergic (NANC) inhibitory neurotransmitter responsible for smooth muscle relaxation. Moreover, many substances (including hormones) have been reported to modulate NO production leading to changes in motor responses, further underlying the importance of this molecule in the control of GI motility. An impaired NO production/release has indeed been reported to be implicated in some GI dysmotility. In this article we wanted to focus on the influence of NO on gastric motility by summarizing knowledge regarding its role in both physiological and pathological conditions. The main role of NO on regulating gastric smooth muscle motor responses, with particular reference to NO synthases expression and signaling pathways, is discussed. A deeper knowledge of nitrergic mechanisms is important for a better understanding of their involvement in gastric pathophysiological conditions of hypo- or hyper-motility states and for future therapeutic approaches. A possible role of substances which, by interfering with NO production, could prove useful in managing such motor disorders has been advanced.     

Block copolymer morphologies in dye-sensitized solar cells: probing the photovoltaic structure-function relation

We integrate mesostructured titania arrays into dye-sensitized solar cells by replicating ordered, oriented one-dimensional (1D) columnar and three-dimensional (3D) bicontinuous gyroid block copolymer phases. The solar cell performance, charge transport, and recombination are investigated. We observe faster charge transport in 1D "wires" than through 3D gyroid arrays. However, owing to their structural instability, the surface area of the wire arrays is low, inhibiting the solar cell performance. The gyroid morphology, on the other hand, outperforms the current state-of-the-art mesoporous nanoparticle films.