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1.
Vascular endothelial growth factor A (referred to as VEGF) is implicated in colon cancer growth. Currently, the main accepted mechanism by which VEGF promotes colon cancer growth is via the stimulation of angiogenesis, which was originally postulated by late Judah Folkman. However, the cellular source of VEGF in colon cancer tissue; and, the expression of VEGF and its receptors VEGF-R1 and VEGF-R2 in colon cancer cells are not fully known and are subjects of controversy.  相似文献   
2.
Layered lithium–nickel–cobalt–manganese oxide (NCM) materials have emerged as promising alternative cathode materials owing to their high energy density and electrochemical stability. Although high reversible capacity has been achieved for Ni‐rich NCM materials when charged beyond 4.2 V versus Li+/Li, full lithium utilization is hindered by the pronounced structural degradation and electrolyte decomposition. Herein, the unexpected realization of sustained working voltage as well as improved electrochemical performance upon electrochemical cycling at a high operating voltage of 4.9 V in the Ni‐rich NCM LiNi0.895Co0.085Mn0.02O2 is presented. The improved electrochemical performance at a high working voltage at 4.9 V is attributed to the removal of the resistive Ni2+O rock‐salt surface layer, which stabilizes the voltage profile and improves retention of the energy density during electrochemical cycling. The manifestation of the layered Ni2+O rock‐salt phase along with the structural evolution related to the metal dissolution are probed using in situ X‐ray diffraction, neutron diffraction, transmission electron microscopy, and X‐ray absorption spectroscopy. The findings help unravel the structural complexities associated with high working voltages and offer insight for the design of advanced battery materials, enabling the realization of fully reversible lithium extraction in Ni‐rich NCM materials.  相似文献   
3.
Al is introduced into a compositionally graded cathode with average composition of Li[Ni0.61Co0.12Mn0.27]O2 (FCG61) whose Ni and Mn concentrations are designed to vary continuously within the cathode particle. The Al‐substituted full concentration gradient (Al‐FCG61) cathode is tested for 3000 cycles in a full‐cell, mainly to gauge its viability for daily charge/discharge cycles during the service life of electric vehicles (≈10 years). The Al‐substitution enables the Al‐FCG61 cathode to maintain 84% of its initial capacity even after 3000 cycles. It is demonstrated that the Al‐substitution strengthens the grain boundaries, substantiated by the mechanical strength data, thereby delaying the nucleation of microcracks at the phase boundaries which is shown to be the main reason for the cathode failure during long‐term cycling. It also shows that the Al‐substitution decreases the cation mixing and suppresses the deleterious formation of the secondary phase that likely initiates the microcracks. Unlike an NCA cathode, whose depth of discharge (DOD) must be limited to 60% for long‐term cycling, the proposed Al‐FCG61 cathode is cycled at 100% DOD for 3000 cycles to fully utilize its available capacity for maximum energy density and subsequent reduction in cost of the battery.  相似文献   
4.
The accumulation and perpetuation of viral pathogens over generations of clonal propagation in crop species such as sweetpotato, Ipomoea batatas, inevitably result in a reduction in crop yield and quality. This study was conducted at Bundaberg, Australia to compare the productivity of field‐derived and pathogen‐tested (PT) clones of 14 sweetpotato cultivars and the yield benefits of using healthy planting materials. The field‐derived clonal materials were exposed to the endemic viruses, while the PT clones were subjected to thermotherapy and meristem‐tip culture to eliminate viral pathogens. The plants were indexed for viruses using nitrocellulose membrane‐enzyme‐linked immunosorbent assay and graft‐inoculations onto Ipomoea setosa. A net benefit of 38% in storage root yield was realised from using PT materials in this study. Conversely, in a similar study previously conducted at Kerevat, Papua New Guinea (PNG), a net deficit of 36% was realised. This reinforced our finding that the response to pathogen testing was cultivar dependent and that the PNG cultivars in these studies generally exhibited increased tolerance to the endemic viruses present at the respective trial sites as manifested in their lack of response from the use of PT clones. They may be useful sources for future resistance breeding efforts. Nonetheless, the potential economic gain from using PT stocks necessitates the use of pathogen testing on virus‐susceptible commercial cultivars.  相似文献   
5.
The caudomedial nidopallium (NCM) of songbirds is a telencephalic area involved in the auditory processing and memorization of complex vocal communication signals. We used pure tone stimuli and multiunit electrophysiological recordings in awake birds to investigate whether the basic properties of song-responding circuits in NCM differ between canaries and zebra finches, two species whose songs are markedly different in their spectral and temporal organization. We found that the responses in zebra finch NCM are characterized by broad tuning and sustained responses that may facilitate the integration of zebra finch song syllables and call notes that are of long duration and have a broad harmonic structure. In contrast, we found that the responses in canary NCM show narrower tuning and less sustained responses over the time periods analyzed. These characteristics may contribute to enhanced processing of the narrow-band whistles, rapid trills, and steep frequency modulations that are prominent features of canary song. These species differences are much less pronounced in field L2, the direct thalamorecipient region that represents a preceding station in the central avian auditory pathway. NCM responses did not differ across sexes of either species, but field L2 did show wider tuning in zebra finch females relative to males. In sum, species differences in the response properties of NCM likely reflect selectivity for the acoustic elements of each species' vocal repertoire.  相似文献   
6.
应用Dot—ELISA检测PVX,PVY和PVS   总被引:7,自引:0,他引:7  
以NCM为固相载体、应用间接ELISA法测定了纯化的PVX、PVY和PVS;对接种的烟草,马铃薯块茎的芽、休眠块茎顶端的稀释度PVX分别为:1/20480-1/81920、1/5120;PVY分别为1/81920、1/20480和1/5120;PVS分别为1/81920-1/327680、1/20480-1/81920和1/5120-1/20480,和Cocktail-ELISA相关,检测PVX和  相似文献   
7.
Sulfogalactosylglycerolipid (SGG) is found in detergent-resistant lipid raft fractions isolated from sperm plasma membranes and has been shown to be important in sperm-egg adhesion. In order to provide more direct evidence for the association of sulfoglycolipids with lipid raft domains, we have examined the distribution of two sulfoglycolipids in supported membranes prepared from artificial lipid mixtures and cellular lipid extracts. Atomic force microscopy has been used to visualize the localization of SGG and sulfogalactosylceramide (SGC) in liquid-ordered domains in supported bilayers of ternary lipid mixtures comprised of dipalmitoylphosphatidylcholine, cholesterol and palmitoyldocosahexaenoylphosphatidylcholine. The localization of SGC/SGG in the liquid-ordered raft domains is demonstrated by changes in bilayer morphology in the presence of sulfoglycolipid, by selective antibody labeling of the domains with anti-SGC/SGG and by the effects of the cholesterol-sequestering agent, methyl-β-cyclodextrin, on the supported membranes. In addition, we use a combination of atomic force microscopy and immunofluorescence to show that supported bilayers made from lipids extracted from sperm anterior head plasma membranes (APM) and isolated APM vesicles exhibit small SGG-rich domains that are similar to those observed in bilayers of artificial lipid mixtures. The possible implications of these results for the involvement of SGG-rich lipid rafts in modulating sperm-egg interactions in vivo and the utility of model membranes for studying the behavior of lipid rafts are discussed.  相似文献   
8.
Songbirds rely on auditory processing of natural communication signals for a number of social behaviors,including mate selection,individual recognition and the rare behavior of vocal learning - the ability to learn vocalizations through imitation of an adult model,rather than by instinct.Like mammals,songbirds possess a set of interconnected ascending and descending auditory brain pathways that process acoustic information and that are presumably involved in the perceptual processing of vocal communication signals.Most auditory areas studied to date are located in the caudomedial forebrain of the songbird and include the thalamo-recipient field L (sub fields L1,L2 and L3),the caudomedial and caudolateral mesopallium (CMM and CLM,respectively) and the caudomedial nidopallium (NCM). This review focuses on NCM,an auditory area previously proposed to be analogous to parts of the primary auditory cortex in mammals.Stimulation of songbirds with auditory stimuli drives vigorous electrophysiological responses and the expression of several activity-regulated genes in NCM.Interestingly,NCM neurons are tuned to species-specific songs and undergo some forms of experience-dependent plasticity in-vivo .These activity-dependent changes may underlie long-term modifications in the functional performance of NCM and constitute a potential neural substrate for auditory discrimination.We end this review by discussing evidence that suggests that NCM may be a site of auditory memory formation and/or storage.  相似文献   
9.
10.
As a high‐capacity layered cathode material, Li[Ni0.8Co0.1Mn0.1]O2 (NCM811) has been one of the most felicitous candidates for utilization in the next generation of high‐energy lithium ion batteries (LIBs). Notwithstanding its superiority, there are some issues concerning its cyclability, rate capability, and thermal stability that need to be settled prior to its further practical application. It is believed that upon cycling, chemical, mechanical, and electrochemical stability of the cathode–electrolyte interface plays a key role in resolving these issues. Therefore, all the extensive efforts directed so far toward the optimization of NCM811 electrochemical performance are by some means in connection with the cathode–electrolyte interface. Herein, unique structural and electrochemical characteristics of NCM811 together with in‐depth understanding of its underlying bulk/surface degradation mechanism through cycling are reviewed. More importantly, for the first time, all compatible approaches thus far adopted to perfect the performance of NCM811 are exclusively and scrupulously addressed. Lastly, the most reasonable resolutions to accomplish a robust cathode–electrolyte interface, and consequently impeccable NCM811, along with proposed future research directions are presented.  相似文献   
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