34 research outputs found
Dopaminergic Neurons in Zona Incerta Drives Appetitive Self-Grooming
Dopaminergic (DA) neurons are known to play a key role in controlling behaviors. While DA neurons in other brain regions are extensively characterized, those in zona incerta (ZITH or A13) receive much less attention and their function remains to be defined. Here it is shown that optogenetic stimulation of these neurons elicited intensive selfâgrooming behaviors and promoted place preference, which can be enhanced by training but cannot be converted into contextual memory. Interestingly, the same stimulation increased DA release to periaqueductal grey (PAG) neurons and local PAG antagonism of DA action reduced the elicited selfâgrooming. In addition, A13 neurons increased their activity in response to various external stimuli and during natural selfâgrooming episodes. Finally, monosynaptic retrograde tracing showed that the paraventricular hypothalamus represents one of the major upstream brain regions to A13 neurons. Taken together, these results reveal that A13 neurons are one of the brain sites that promote appetitive selfâgrooming involving DA release to the PAG
13.4 % Efficiency from All-Small-Molecule Organic Solar Cells Based on a Crystalline Donor with Chlorine and Trialkylsilyl Substitutions
How to simultaneously achieve both high open-circuit voltage (Voc) and high short-circuit current density (Jsc) is a big challenge for realising high power conversion efficiency (PCE) in all-small-molecule organic solar cells (all-SM OSCs). Herein, a novel small molecule (SM)-donor, namely FYSMâSiCl, with trialkylsilyl and chlorine substitutions was designed and synthesized. Compared to the original SM-donor FYSMâH, FYSMâSi with trialkylsilyl substitution showed a decreased crystallinity and lower highest occupied molecular orbital (HOMO) level, while FYSMâSiCl had an improved crystallinity, more ordered packing arrangement, significantly lower HOMO level, and predominant âface-onâ orientation. Matched with a SM-acceptor Y6, the FYSMâSiCl-based all-SM OSCs exhibited both high Voc of 0.85 V and high Jsc of 23.7 mA cmâ2, which is rare for all-SM OSCs and could be attributed to the low HOMO level of FYSMâSiCl donor and the delicate balance between high crystallinity and suitable blend morphology. As a result, FYSMâSiCl achieved a high PCE of 13.4 % in all-SM OSCs, which was much higher than those of the FYSMâH- (10.9 %) and FYSMâSi-based devices (12.2 %). This work demonstrated a promising method for the design of efficient SM-donors by a side-chain engineering strategy via the introduction of trialkylsilyl and chlorine substitutions
Identification of an immunogenic DKK1 long peptide for immunotherapy of human multiple myeloma
Dickkopf-1 (DKK1), broadly expressed by tumor cells from human multiple myeloma (MM) and other cancers but absent from most normal tissues, may be an ideal target for immunotherapy. Our previous studies have shown that DKK1 (peptide)-specific cytotoxic T lymphocytes can effectively lyse primary MM cells in vitro. To develop DKK1-based vaccines that can be easily and inexpensively made and used by all patients, we identified a DKK1 long peptide (LP), DKK13-76-LP, that contains 74 amino acids and epitopes that can potentially bind to all major MHC class I and II molecules. Using HLA-A*0201- and HLA-DR*4-transgenic mouse models, we found that DKK1-specific CD4+ and CD8+ T cell responses, detected by DKK1 short peptide (P20 and P66v)-HLA-A*0201 tetramer staining and cytotoxic assay for CD8+ T cells or by CSFE dilution and IFN-a; secretion for CD4+ T cells respectively, can be induced in vivo by immunizing mice with the DKK13-76-LP. In addition, DKK13-76-LP also induced anti-DKK1 humoral immunity in the transgenic mice and the DKK1 antibodies were functional. Finally, DKK13-76-LP stimulated human blood T cells ex vivo to generate DKK1-specific CD4+ and CD8+ T cell responses from eight out of ten MM patients with different MHC backgrounds. The generated DKK1-specific CD8+ cells efficiently lysed autologous MM cells from these patients. Thus, these results confirm the immunogenicity of the DKK13-76-LP in eliciting DKK1-specific CD4+ and CD8+ T cell responses in vitro and in vivo, and suggest that the DKK13-76-LP can be used for immunotherapy of MM and other cancers
Nano-Ferrite Near-Field Microwave Imaging for In-Body Applications
In recent years, nanotechnology has become indispensable in our lives, especially in the medical field. The key to nanotechnology is the perfect combination of molecular imaging and nanoscale probes. In this paper, we used iron oxide nanoparticles as a nanoprobe because it is widely used in clinical MRI and other molecular imaging techniques. We built our own experimental environment and used absorbing materials during the whole experiment to avoid electromagnetic interference with the surroundings. Moreover, we repeated the experiment many times to exclude the influence of contingency. Hence, the experimental data we obtained were relatively precise and persuasive. Finally, the results demonstrated that the iron oxide nanoparticles were appropriate for use as contrast agents in biological imaging
Aridification in the Asian Interior Recorded by Mineral Assemblages in Tarim Basin since the Late Miocene and Its Link to Global Cooling
Understanding climate change during the relatively warm Pliocene, as compared to the present, offers significant potential for understanding future global consequences of rising atmospheric CO2. Sensitivity differences among various climate proxies lead to divergent interpretations of the driving mechanisms of inland aridification. Minerals as a paleoclimatic indicator with high water-sensitivity can provide effective support for reconstructing climate evolution and clearly understanding driving mechanisms in extremely arid regions. Here we present results of mineral analyses from lacustrineâfluvial Neogene sediments in the eastern Tarim Basin. Evaporite minerals are composed principally of calcite, dolomite, and gypsum, with minor amounts of ankerite and celestite. Clay minerals are dominated by illite and chlorite. We find that evaporite minerals and illite reflect regional climate change through time, and specifically determine the following: (1) climate in the Tarim Basin during the late Miocene was relatively humid, with alternating dry and wet periods from 6.86~5.58 Ma; (2) immediately following that interval, aridification increased rapidly, with reduced regional precipitation that accelerated the shrinkage of the lake; (3) from 4.4 Ma to 3.62 Ma, regional precipitation increased slightly but afterwards, aridification resumed: the climate there has been extremely dry since about 2.7 Ma. Our results show that the climate in the Tarim Basin has followed a global cooling trend since the late Miocene, and suggest that the effect of uplift in the Tibetan Plateau is a secondary influence
A Nearly Zero-Strain Li-Rich Rock-Salt Oxide with Multielectron Redox Reactions as a Cathode for Li-Ion Batteries
Li-rich oxide cathodes are drawing increasing attention as next-generation cathode materials for the development of high-energy-density Li-ion batteries due to their strikingly high capacities. However, transition-metal migration, irreversible structural phase transformations, and the irreversible release of oxygen are responsible for rapid capacity and voltage decay. This study reports a Li-rich cation-ordered rock-salt oxide LixV0.4Ti0.4O2(LVTO, x = 0.97/1.2) with space group Fd3ÂŻ m that delivers a high capacity of over 250 mAh g-1and capacity retention up to 89% after 50 cycles. A comprehensive experimental analysis confirms that the capacity can be attributed to the reversible V3+/V5+multielectron cationic redox reactions and a minor contribution from reversible anionic redox reactions. Importantly, LVTO exhibits nearly zero-strain behavior upon (dis)charge cycling cycles, which is associated with reversible V migration from octahedral to tetrahedral sites. Our results demonstrate that Li-rich rock-salt oxide LVTO could be a promising cobalt-free cathode material for Li-ion batteries
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Highly reversible Li 2 RuO 3 cathodes in sulfide-based all solid-state lithium batteries
The practical application of high-capacity lithium-rich cathode materials in lithium-ion batteries has been largely restricted by severe side reactions with electrolytes. Herein, we report a highly stable lithium-rich Li2RuO3 cathode by forming a passivating solid electrolyte interphase at the interface with a sulfide solid electrolyte such as Li6PS5Cl in all-solid-state lithium batteries (ASSLBs), which efficiently suppresses serious parasitic interfacial reactions and fast-increasing interfacial impedance normally observed in liquid electrolytes. The exceptionally high interfacial stability of the Li2RuO3/sulfide electrolyte interface contributes to a high reversible capacity of 257 mA h gâ1 of Li2RuO3 at 0.05C rate, and unprecedented cycling stability with 90% capacity retention after 1000 cycles at 1C rate. Comprehensive experimental characterizations and first-principles calculations disclose that electronically insulating interfacial reaction products forming at the interface between the Li2RuO3 cathode and Li6PS5Cl facilitate the formation of a stable and passivating interphase and block the continuous side reactions. Importantly, reversible oxygen redox activity of Li2RuO3 is well-maintained in this configuration of ASSLBs even after 600 cycles, thus the common voltage decay of the Li-rich material is also significantly reduced. These new discoveries demonstrate the critical role of interface design for achieving prolonged cycling stability of lithium-rich cathode materials
Tailoring the redox-active transition metal content to enhance cycling stability in cation-disordered rock-salt oxides
Lithium-excess cation-disordered rock-salt oxides (DRXs) are investigated intensively as cathode materials for future lithium-ion batteries combining cationic and anionic redox reactions. However, the lattice oxygen redox can cause severe oxygen release resulting in rapid capacity fading. Here, we investigate a series of xLi(2)TiO(3)-(1 - x)LiMnO2 (0 <= x <= 1) materials and find that only Li1.2Mn0.4Ti0.4O2 (x = 0.4) and Li1.1Mn0.7Ti0.2O2 (x = 0.2) can form phase-pure DRXs, which both deliver high capacity (250 mAh g(-1)). The newly discovered Li1.1Mn0.7Ti0.2O2 DRX exhibits remarkably high capacity retention of 84.4% after 20 cycles compared to only 60.8% for Li1.2Mn0.4Ti0.4O2. Our result indicates that the irreversible oxygen loss is reduced by raising the Mn content. Theoretical calculations further reveal that increasing the redox-active Mn content from Li1.2Mn0.4Ti0.4O2 to Li1.1Mn0.7Ti0.2O2 causes the orbitals near the Fermi level to change from O(2)p non-bonding (Li-O-Li unhybridized orbitals) to (Mn-O)* antibonding bands, exhibiting a high O-O aggregation barrier, preventing O-2 release and resulting in sustained capacity retention. Hence, these new findings demonstrate that regulating oxygen redox by tailoring the redox-active transition metal content is an effective strategy to enhance the cycling stability of DRXs