Macromolecular crowding effect is critical for maintaining SIRT1's nuclear localization in cancer cells

<p>SIRT1 is a principle class III histone deacetylase which exhibits versatile functions in stress response, development, and pathological processes including cancer. Although SIRT1 deacetylates a wide range of nuclear and cytoplasmic proteins, its subcellular localization in cancer cells has been controversial. In this study, we uncovered the inconsistent reports about SIRT1 subcellular localization is partially due to different analysis approaches. While immunofluorescence and live cell imaging reveal a predominant nuclear localization of SIRT1, conventional cell fractionation often results in a severe leaking of SIRT1 into the cytoplasm. Such a leakage is mainly caused by loss of cytoplasmic macromolecular crowding effect as well as hypotonic dwelling during the isolation of the nuclei. We also developed an improved cell fractionation procedure which maintains SIRT1 in its original subcellular localization. Analyzing a variety of human cancer cell lines using this approach and other methods demonstrate that SIRT1 predominantly localizes to the nucleus in cancer cells.</p

PbS Quantum Dots Capped with Amorphous ZnS for Bulk Heterojunction Solar Cells: The Solvent Effect

In this study, two distinct structures of PbS quantum dots (QDs) are produced with amorphous ZnS as the capping material by successive ionic layer adsorption and reaction. With methanolic solution, spherical PbS QDs (∼5 nm) are embedded in the ZnS matrix (i.e., embedding structure), exhibiting relatively large distance between the QDs. With aqueous solution, irregularly shaped PbS QDs (<3 nm) blend intimately with the ZnS medium (i.e., blending structure), showing indiscernible QD spacing. This is attributed to a relatively low reactivity of Pb²⁺ ions in water, suppressing quantum dot growth in the mesopores. Bulk heterojunction of mesoporous TiO₂ substrate filled up with the blending configuration shows superior photovoltaic performance to the embedding architecture, because of the small QD size and close distance between the QDs

Ultralong, Small-Diameter TiO₂ Nanotubes Achieved by an Optimized Two-Step Anodization for Efficient Dye-Sensitized Solar Cells

An optimized two-step anodization is developed to fabricate ultralong, small-diameter TiO₂ nanotubes, that is, with tube length of up to 31 μm and pore diameter of about 35 nm in this work. This overcomes the length limitation of small diameter tubes that usually presents in conventional one-step anodization. The small tubes with lengths of 23 μm yield a conversion efficiency of 5.02% in dye-sensitized solar cells under nonoptimized conditions

Evolution of Oxyhalide Crystals under Electron Beam Irradiation: An in Situ Method To Understand the Origin of Structural Instability

The oxyhalides have attracted growing interest because of their excellent photocatalytic performance. However, their structural instability hampers further development toward practical applications, a major challenge of current concerns. It is appealing to figure out the origin of structural instability and guide the design of advanced oxyhalide crystals for efficient photocatalysis. In this study, the decomposition of BiOCl crystals, a typical oxyhalide, is triggered by electron beam irradiation and investigated in situ by transmission electron microscopy. The results indicate that the instability originates from the unique layered structure of BiOCl crystals; the interlayer van der Waals bonds are easily broken under electron beam irradiation via the assistance of hydroxyl groups. This facilitates the formation of O/Cl-deficient BiO_1–<i>x</i>Cl_1–<i>y</i> species, Bi metal nanoparticles, and nanobubbles (gaseous substance) that are confined between the adjacent layers. Surface reconstruction would be an effective way to stabilize the oxyhalide crystals

Evolution of Oxyhalide Crystals under Electron Beam Irradiation: An in Situ Method To Understand the Origin of Structural Instability

The oxyhalides have attracted growing interest because of their excellent photocatalytic performance. However, their structural instability hampers further development toward practical applications, a major challenge of current concerns. It is appealing to figure out the origin of structural instability and guide the design of advanced oxyhalide crystals for efficient photocatalysis. In this study, the decomposition of BiOCl crystals, a typical oxyhalide, is triggered by electron beam irradiation and investigated in situ by transmission electron microscopy. The results indicate that the instability originates from the unique layered structure of BiOCl crystals; the interlayer van der Waals bonds are easily broken under electron beam irradiation via the assistance of hydroxyl groups. This facilitates the formation of O/Cl-deficient BiO_1–<i>x</i>Cl_1–<i>y</i> species, Bi metal nanoparticles, and nanobubbles (gaseous substance) that are confined between the adjacent layers. Surface reconstruction would be an effective way to stabilize the oxyhalide crystals

Evolution of Oxyhalide Crystals under Electron Beam Irradiation: An in Situ Method To Understand the Origin of Structural Instability

The oxyhalides have attracted growing interest because of their excellent photocatalytic performance. However, their structural instability hampers further development toward practical applications, a major challenge of current concerns. It is appealing to figure out the origin of structural instability and guide the design of advanced oxyhalide crystals for efficient photocatalysis. In this study, the decomposition of BiOCl crystals, a typical oxyhalide, is triggered by electron beam irradiation and investigated in situ by transmission electron microscopy. The results indicate that the instability originates from the unique layered structure of BiOCl crystals; the interlayer van der Waals bonds are easily broken under electron beam irradiation via the assistance of hydroxyl groups. This facilitates the formation of O/Cl-deficient BiO_1–<i>x</i>Cl_1–<i>y</i> species, Bi metal nanoparticles, and nanobubbles (gaseous substance) that are confined between the adjacent layers. Surface reconstruction would be an effective way to stabilize the oxyhalide crystals

Evolution of Oxyhalide Crystals under Electron Beam Irradiation: An in Situ Method To Understand the Origin of Structural Instability

The oxyhalides have attracted growing interest because of their excellent photocatalytic performance. However, their structural instability hampers further development toward practical applications, a major challenge of current concerns. It is appealing to figure out the origin of structural instability and guide the design of advanced oxyhalide crystals for efficient photocatalysis. In this study, the decomposition of BiOCl crystals, a typical oxyhalide, is triggered by electron beam irradiation and investigated in situ by transmission electron microscopy. The results indicate that the instability originates from the unique layered structure of BiOCl crystals; the interlayer van der Waals bonds are easily broken under electron beam irradiation via the assistance of hydroxyl groups. This facilitates the formation of O/Cl-deficient BiO_1–<i>x</i>Cl_1–<i>y</i> species, Bi metal nanoparticles, and nanobubbles (gaseous substance) that are confined between the adjacent layers. Surface reconstruction would be an effective way to stabilize the oxyhalide crystals

Large-Scale, Uniform, and Superhydrophobic Titania Nanotubes at the Inner Surface of 1000 mm Long Titanium Tubes

Large-scale and mass production of uniform nanostructured materials has been a growing challenge. Anodic titania nanotubes have been widely employed in various applications, which are usually demonstrated with limited size and planar geometry. In this study, a coaxial electrochemical anodization approach is explored and reported. With this method, uniform titania nanotube arrays are produced at the inner surface of titanium tubular electrodes of 1000 mm in length and 10 mm in diameter, in good contrast to the nonuniform nanotubes attained with a conventional anodizing scheme. Such an approach is cost-effective and energy-efficient. It is also capable of processing other valve metals possible for anodization and even longer tubular substrates. The wetting property of the resulting nanotube arrays is further tailored, with a maximum contact angle of 166° for water and 163° for glycerol, exhibiting a superhydrophobic feature. An equation is derived to compute the intrinsic contact angle of a spherical droplet on an asymmetric tubular substrate, based on measurable apparent contact angle, droplet radius, and tube radius. Such a superhydrophobic tube with a sliding angle of <3° is promising to be applied in drag reduction, condensation heat transfer, microfluidics, etc

Large-Scale, Uniform, and Superhydrophobic Titania Nanotubes at the Inner Surface of 1000 mm Long Titanium Tubes

Large-scale and mass production of uniform nanostructured materials has been a growing challenge. Anodic titania nanotubes have been widely employed in various applications, which are usually demonstrated with limited size and planar geometry. In this study, a coaxial electrochemical anodization approach is explored and reported. With this method, uniform titania nanotube arrays are produced at the inner surface of titanium tubular electrodes of 1000 mm in length and 10 mm in diameter, in good contrast to the nonuniform nanotubes attained with a conventional anodizing scheme. Such an approach is cost-effective and energy-efficient. It is also capable of processing other valve metals possible for anodization and even longer tubular substrates. The wetting property of the resulting nanotube arrays is further tailored, with a maximum contact angle of 166° for water and 163° for glycerol, exhibiting a superhydrophobic feature. An equation is derived to compute the intrinsic contact angle of a spherical droplet on an asymmetric tubular substrate, based on measurable apparent contact angle, droplet radius, and tube radius. Such a superhydrophobic tube with a sliding angle of <3° is promising to be applied in drag reduction, condensation heat transfer, microfluidics, etc

Large-Scale, Uniform, and Superhydrophobic Titania Nanotubes at the Inner Surface of 1000 mm Long Titanium Tubes

Large-scale and mass production of uniform nanostructured materials has been a growing challenge. Anodic titania nanotubes have been widely employed in various applications, which are usually demonstrated with limited size and planar geometry. In this study, a coaxial electrochemical anodization approach is explored and reported. With this method, uniform titania nanotube arrays are produced at the inner surface of titanium tubular electrodes of 1000 mm in length and 10 mm in diameter, in good contrast to the nonuniform nanotubes attained with a conventional anodizing scheme. Such an approach is cost-effective and energy-efficient. It is also capable of processing other valve metals possible for anodization and even longer tubular substrates. The wetting property of the resulting nanotube arrays is further tailored, with a maximum contact angle of 166° for water and 163° for glycerol, exhibiting a superhydrophobic feature. An equation is derived to compute the intrinsic contact angle of a spherical droplet on an asymmetric tubular substrate, based on measurable apparent contact angle, droplet radius, and tube radius. Such a superhydrophobic tube with a sliding angle of <3° is promising to be applied in drag reduction, condensation heat transfer, microfluidics, etc