1In the pseudogap state of the high−T c copper-oxide (cuprate) superconductors [1], angle-resolved photoemission (ARPES) measurements have seen an Fermi arc, i.e., an open-ended gapless section in the large Fermi surface [2,3,4,5,6,7,8], rather than a closed loop expected of an ordinary metal. This is all the more puzzling because Fermi pockets (small closed Fermi surface features) have been suggested from recent quantum oscillation measurements [9,10,11,12,13,14]. The Fermi arcs have worried the high−T c community for many years because they cannot be understood in terms of existing theories. Theorists came up with a way out in the form of conventional Fermi surface pockets associated with competing order, with a back side that is for detailed reasons invisible by photoemission [15]. Here we report ARPES measurements of La-Bi2201 that give direct evidence of the Fermi pocket.The charge carriers in the pocket are holes and the pockets show an unusual dependence upon doping, namely, they exist in underdoped but not overdoped samples. A big surprise is that these Fermi pockets appear to coexist with the Fermi arcs. This coexistence has not been expected theoretically and the understanding of the mysterious pseudogap state in the high-T c cuprate superconductors will rely critically on understanding such a new finding.The high resolution Fermi surface mapping (Fig. 1a) on the underdoped La-Bi2201 UD18K sample using VUV laser reveals three Fermi surface sheets with low spectral weight (labeled as LP, LS and LPS in Fig. 1a) in the covered momentum space, in addition to the prominent main Fermi surface (LM). One particular Fermi surface sheet LP crosses the main band LM, forming an enclosed loop, an Fermi pocket, near the nodal region. Quantitative Fermi surface data measured from both VUV laser (Fig. 2a) and Helium discharge lamp ( (Fig. 2a) and HP band observed in Helium lamp measurement (Fig. 2b) are intrinsic; they can not be attributed to any of the umklapp bands or shadow bands (Fig. 2c). The location of the three bands can be well connected by the same superlattice vector, indicating that the HP and LPS bands correspond to the first order umklapp bands of the main Fermi pocket LP. The shape 2 and area of the Fermi pockets are also consistent in these two independent measurements, making a convincing case on the presence of the Fermi pocket. We note that in both the laser (Fig. 2a) and Helium lamp (Fig. 2b and SFig. 2 in the Supplementary) measurements, all the observed bands except for the "Fermi pocket bands" can be assigned by only one regular superstructure wavevector (0.24,0.24). The presence of additional superstructure, which would give rise to new bands, appears to be unlikely because there is no indication of such additional bands observed in our measurements.The Fermi pocket is observed both in the normal state and superconducting state, as shown in Fig. 3 for the La-Bi2201 UD18K sample. Moreover, its location, shape and area show little change with temperature (Figs. 3a and 3f). Below T c , the openi...

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Alcoholic liver injury, known as the most general result of chronic alcohol intake, is induced by inflammatory responses, which is activated by intestine-derived endotoxins formed from intestinal dysbiosis. The hepatoprotective activity of rice bran phenolic extract (RBPE) on ethanol-fed mice was investigated for the first time in this study, and the underlying mechanism was explored from gut microbiota, barrier function, and hepatic inflammation. Mice were fed an alcohol-containing liquid diet alone or in mixture with RBPE for 8 weeks. RBPE treatment mitigated ethanol-induced liver damage, evidenced by the declined lipid profile levels and hepatic function markers. Moreover, ethanol intake induced intestinal microbiota dysbiosis, which was attenuated by RBPE supplementation. RBPE treatment improved the alcohol-induced decrease in the expression of ZO-1, Claudin-1, Claudin-4, and Reg3g, revealing the ameliorative effect of RBPE on intestinal barrier dysfunction. Furthermore, RBPE treatment repressed the alcohol-induced trigger of the hepatic endotoxin–TLR4–NF-κB pathway, followed by the mitigated liver inflammation. The findings indicate that RBPE supplementation ameliorates intestinal microbiota dysbiosis and barrier dysfunction, inactivates the endotoxin–TLR4–NF-κB pathway, and represses inflammatory responses in liver, and therefore, intake of RBPE or brown rice may be an effective way to mitigate alcoholic liver injury.

Water-dispersible Fe(3)O(4) nanoparticles have been prepared by a simple solution method, in which the particle size (3-11 nm) can be tuned by simply adjusting the reaction temperature and time; the formation mechanism of Fe(3)O(4) nanoparticles is proposed and their low cytotoxicity has also been proved.

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Development of versatile, chemically tunable photocages for photoactivated chemotherapy (PACT) represents an excellent opportunity to address the technical drawbacks of conventional photodynamic therapy (PDT) whose oxygen-dependent nature renders it inadequate in certain therapy contexts such as hypoxic tumors. As an alternative to PDT, oxygen free mechanisms to generate cytotoxic reactive oxygen species (ROS) by visible light cleavable photocages are in demand. Here, we report the detailed mechanisms by which the small molecule blebbistatin acts as a one-photon blue light-gated or twophoton near-infrared light-gated photocage to directly release a hydroxyl radical (•OH) in the absence of oxygen. By using femtosecond transient absorption spectroscopy and chemoselective ROS fluorescent probes, we analyze the dynamics and fate of blebbistatin during photolysis under blue light. Waterdependent photochemistry reveals a critical process of water-assisted protonation and excited state intramolecular proton transfer (ESIPT) that drives the formation of short-lived intermediates, which surprisingly culminates in the release of •OH but not superoxide or singlet oxygen from blebbistatin. CASPT2//CASSCF calculations confirm that hydrogen bonding between water and blebbistatin underpins this process. We further determine that blue light enables blebbistatin to induce mitochondria-dependent apoptosis, an attribute conducive to PACT development. Our work demonstrates blebbistatin as a controllable photocage for •OH generation and provides insight into the potential development of novel PACT agents.

Photodynamic therapy (PDT) is a new technology using photodynamic effect for disease diagnosis and treatment. It is a two-step technique involving the uptake of a photosensitizer by cancer tissue followed by light irradiation that excites the photosensitizer to produce highly reactive oxygen species, the latter execute apoptosis of cancerous cells. As a second-generation of photosensitizers, phthalocyanine demonstrates higher absorption in the 650-800 nm range and short tissue accumulation compared to their first generation. However, many potent phthalocyanine photosensitizers are hydrophobic and poorly water-soluble, which limit their therapeutic applications. As a result, advanced delivery systems and different strategies are called for to improve the effectiveness of PDT. Facts have proved that using nanoparticles as carries of photosensitizers is a very promising route. Nanoparticles have the potentials to increase photosensitizers' aqueous solubility, bioavailability and stability, and deliver photosensitizers to the target tissues. This article reviewed the commonly-used nanoparticles, including colloid gold, quantum dots, paramagnetic nanoparticles, silica-based materials, polymer-based nanoparticles, as potential delivery systems for phthalocyanine photosensitizers, and summarized the improved biological functions of phthalocyanine photosensitizers in PDT.