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We carried out nanoimprinting lithography on solution-processed tin oxide (SnO) film for use as a liquid crystal (LC) alignment layer, for which we used a parallel configuration. To transfer the nanostructures onto the SnO film, we conducted an experiment according to curing, from which fine nanostructures on the SnO film were obtained at a curing temperature of 200 °C. These acted as a guide for the arrangement of the LC molecules and induced geometric restriction which minimized elastic distortion energies, and so the LC molecules could be aligned in the direction of the nanostructures. The LC alignment state was investigated using polarized optical microscopy, and the pre-tilt angle was measured using a crystal rotation method. With high thermal endurance and drastically low power consumption, the nano patterned SnO was shown to be a promising candidate for LC applications. The nanopatterning process combined with nanoimprinting lithography and solution-processed inorganic materials exhibited the possibility of broadening the features of nanostructure-mounted applications, including LC devices.

A styrene-butadiene-styrene (SBS) block copolymer was utilized to fabricate the wrinkle pattern in accordance with the buckling theory, and ion-beam (IB) irradiation was applied to induce surface r...

We investigated the wrinkle formation on ion-beam (IB)-irradiated substrates coated with the thermoplastic elastomer styrene-b-isoprene-b-styrene (SIS) and demonstrate a relation of the wrinkle str...

We present a simple and economically convenient method to fabricate nanopatterned ZnO films by imprinting lithography and use them for the layer alignment of liquid crystal (LC) displays. First, a one-dimensional nanopattern was obtained by laser interference lithography on a silicon wafer, and the silicon mold replica was transferred onto a flexible polydimethylsiloxane (PDMS) sheet for conformal patterning. The so-obtained PDMS mold was then applied on a ZnO film spin-coated on a glass substrate. During the imprinting process, the temperature was controlled from 100 to 250 °C to observe the transferring morphologies of the ZnO film; the nanopattern was successfully transferred at annealing temperatures of 200 and 250 °C because the ZnO film at the sol state filled the cavities of the PDMS nanopattern and solidified, forming a negative replica of the nanopattern. The direction of the nanopatterned ZnO film served as a guide for aligning the LC molecules on the LC surface at the centimeter scale and, due to their elastic characteristics and group behavior, propagating their directional states in the LC bulk. The resulting LC cell exhibited an enhanced electro-optical performance and high thermal endurance above 180 °C. The geometry of the alignment layer increased the electric field on the ZnO film and showed reduced threshold voltage. In addition, since flexible devices are generally based on polyimide, which imidized at around 200 °C, the relatively low annealing temperatures of our fabricated nanopatterned ZnO film allow it to be mounted on such devices without any deterioration of the underlying thermoplastic substrate. Therefore, nanopatterned ZnO has a considerable potential for advanced LC displays.

Intestinal stem cells (ISCs) at the crypt base contribute to intestinal homeostasis through a balance between self-renewal and differentiation. However, the molecular mechanisms regulating this homeostatic balance remain elusive. Here we show that the matricellular protein CCN1/CYR61 coordinately regulates ISC proliferation and differentiation through distinct pathways emanating from CCN1 interaction with integrins αvβ3/αvβ5. Mice that delete Ccn1 in Lgr5+ ISCs or express mutant CCN1 unable to bind integrins αvβ3/αvβ5 exhibited exuberant ISC expansion and enhanced differentiation into secretory cells at the expense of absorptive enterocytes in the small intestine, leading to nutrient malabsorption. Analysis of crypt organoids revealed that through integrins αvβ3/αvβ5, CCN1 induces NF-κB-dependent Jag1 expression to regulate Notch activation for differentiation and promotes Src-mediated YAP activation and Dkk1 expression to control Wnt signaling for proliferation. Moreover, CCN1 and YAP amplify the activities of each other in a regulatory loop. These findings establish CCN1 as a novel niche factor in the intestinal crypts, providing new insights into how matrix signaling exerts overarching control of ISC homeostasis.

Intestinal stem cells (ISCs) at the crypt base contribute to intestinal homeostasis through a balance between self-renewal and differentiation. However, the molecular mechanisms regulating this homeostatic balance remain elusive. Here we show that the matricellular protein CCN1/CYR61 coordinately regulates ISC proliferation and differentiation through distinct pathways emanating from CCN1 interaction with integrins αvβ3/αvβ5. Mice that delete Ccn1 in Lgr5 + ISCs or express mutant CCN1 unable to bind integrins αvβ3/αvβ5 exhibited exuberant ISC expansion and enhanced differentiation into secretory cells at the expense of absorptive enterocytes in the small intestine, leading to nutrient malabsorption. Analysis of crypt organoids revealed that through integrins αvβ3/αvβ5, CCN1 induces NF-κB-dependent Jag1 expression to regulate Notch activation for differentiation and promotes Src-mediated YAP activation and Dkk1 expression to control Wnt signaling for proliferation. Moreover, CCN1 and YAP amplify the activities of each other in a regulatory loop. These findings establish CCN1 as a niche factor in the intestinal crypts, providing insights into how matrix signaling exerts overarching control of ISC homeostasis.

This study compressed the conventional two-step process of brush coating and orientation for liquid crystal (LC) alignment layer manufacturing into a one-step process. Surface modification and LC alignment were performed by brush coating with a tin oxide solution prepared via the solgel process at different curing temperatures. The effect of the curing temperature on atomic bonds was analyzed through x-ray photoelectron spectroscopy, the physical morphology of the film surface was characterized by scanning electron microscopy and atomic force microscopy, and the LC alignment of the brush-coated tin oxide film was verified via polarized optical microscopy and pretilt angle measurements. The shear stress generated during the brush coating process formed a partial groove structure; the resulting anisotropy aligned the LC molecules homogeneously. The brush-coated film showed excellent LC orientation properties, confirming the potential of the proposed and efficient fabrication process as a new orientation technology.

We demonstrated uniform LC alignment on IB-irradiated aluminium tin oxide (AlSnO) by controlling the annealing temperature. Physico-chemical analyses were carried out to determine the surfa...

The characteristics of ion beam (IB) irradiated polyethylene glycol (PEG) films were analyzed to determine their potential use as a liquid crystal (LC) alignment layer. The transmittance of...

We investigated the surface modification induced by the ion-beam (IB) irradiation of a polyethylene glycol (PEG) film and its liquid crystal (LC) alignment characteristics. The X-ray photoe...

Ultra-violet nanoimprint lithography was utilized to transfer a one-dimensional nano pattern onto a hydrophilic ultra-violet cured polymer surface for use in liquid crystal displays. A master mold with the one-dimensional nano pattern was initially constructed using laser interference lithography, which is a fast and maskless process that can be employed over a large area. The UV cured polymer showed a hydrophilic characteristic, and was used as a homogeneous alignment layer. The nano-patterned ultra-violet polymer successfully aligned the liquid crystal molecules without defects. Additionally, the liquid crystal cell was characterized by high thermal stability due to the high thermal endurance of UV cured polymer. Therefore, the proposed ultra-violet nanoimprint lithography technique is beneficial for advanced liquid crystal devices with high brightness and resolution with numerous switching components that require a high thermal cost.

We investigated the wrinkle formation on ion-beam (IB)-irradiated substrates coated with the thermoplastic elastomer styrene

We studied the change of the surface and liquid crystal (LC) alignment characteristics of Polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-graft-maleic anhydride (SEBS-g-MA) film according to ion beam (IB) irradiation. Atomic force microscopy (AFM) analysis revealed that IB irradiation reduces peaks and creates a wrinkled structure. X-ray photoelectron spectroscopy (XPS) analysis revealed that IB irradiation disintegrates the C–C bonds and makes C–O bonds, creating a dipole-dipole interaction, which improves the LC alignment characteristics. Through polarized optical microscopy (POM) analysis, it was found that the best LC alignment characteristics can be obtained after 120 s of IB irradiation. It was found that the anisotropy caused by the ion beam contributed more to the liquid crystal alignment in homogeneous direction than the one caused by the wrinkle structure.

Liquid crystal (LC) alignment characteristics were investigated using a solution-derived lanthanum-doped zinc oxide (La:ZnO) film that was exposed to various intensities of ion-beam (IB) irradiation. At an IB intensity of 1700 eV, uniform and homogeneous LC alignment was achieved, as revealed by cross-polarized optical microscopy and pre-tilt angle measurement. Field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) were used to verify that the IB irradiation induced physical and chemical surface reformation of the La:ZnO film that relate to LC alignment. FE-SEM and AFM revealed that the IB irradiation reformed the existing surface structure into a new structure with an altered surface roughness. The XPS results showed that the van der Waals force with anchoring energy increased as the IB intensity increased, and this profoundly affected the state of LC alignment. The capacitance-voltage (C-V) hysteresis curve was measured as ...

We report uniform and homogeneous liquid crystal (LC) alignment using ion beam (IB)-irradiated poly(styrene-maleic anhydride) (SMA) films as an alignment layer when the IB incidence angle is controlled. The molecular polarity on the SMA surface increased with IB irradiation, especially at an incidence angle of 30°, resulting in strong van der Waals forces between the LC molecules and the surface. Atomic force microscopy and X-ray photoelectron spectroscopy were used to determine the LC alignment mechanism. Chemical structure analysis indicated that the orientation of LC molecules was due to van der Waals forces and selective breaking of C–C bonds by IB irradiation. The potential application of SMA substrates as alignment layers for display devices was further supported by their higher thermal stability (220 °C) compared with that of conventional rubbed SMA (160 °C) and rubbed polyimide (160 °C). Therefore, LC cells with IB-irradiated SMA are potential candidates for alternative alignment layers in LC applications.

In this study, UV nanoimprint lithography (NIL) was conducted with a hybrid mixture of tin oxide and a UV-curable polymer to fabricate 1-D nanostructures on a thin film. It was confirmed through chemical and physical surface analyses that a hybrid thin film with high-resolution nanostructures had been successfully fabricated. In particular, nanostructures with an amplitude of 49.354 nm and a wavelength of 0.768 μm, which are the most similar to the mold used, were achieved at 3 min UV exposure time. Afterward, they were applied to a liquid crystal (LC) device as an alignment layer, with which uniform and homogeneous LC alignment were achieved due to the anisotropic characteristics and geometric restrictions caused by fabricated nano structures. In addition, a high thermal budget was obtained due to the thermal endurance of the hybrid thin films with an LC alignment performance of a UV exposure time of 3 min. Furthermore, the electro-optical performance under this condition was superior to LC devices with conventional rubbed polyimide layers From the results, it was determined that using the UV-NIL process on a hybrid mixture of tin oxide and a UV-curable polymer created high-resolution 1-D nano structures on films that can be used this as LC alignment layers with strong potential for high-quality LC applications.

We present the fabrication of an anisotropic structure on a polyurethane (PU) film for aligning liquid crystal (LC) molecules with ion beam (IB) irradiation at an incident angle. The obtained aniso...

We present a low-overhead ransomware-proof SSD, called Ran-somBlocker (RBlocker). RBlocker provides 100% full protections against all possible ransomware attacks by delaying every data deletion until no attack is guaranteed. To reduce storage overheads of the delayed deletion, RBlocker employs a time-out based backup policy. Based on the fact that ransomware must store encrypted version of target files, early deletions of obsolete data are allowed if no encrypted write was detected for a short interval. Otherwise, RBlocker keeps the data for an interval long enough to guarantee no attack condition. For an accurate in-line detection of encrypted writes, we leverages entropy-and CNN-based detectors in an integrated fashion. Our experimental results show that RBlocker can defend all types of ransomware attacks with negligible overheads. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from permissions@acm.org. DAC ’19, June 2’6, 2019, Las Vegas, NV, USA © 2019 Association for Computing Machinery.

We demonstrated homogeneous liquid crystal (LC) alignment on Nickel Oxide (NiO) films subjected to ion beam (IB) irradiation. Uniform LC alignment was achieved at high IB intensity values of 1200 and 1800 eV. To determine the mechanism of LC alignment following IB irradiation, physicochemical analysis was performed using atomic force microscopy and X-ray photoelectron spectroscopy. IB irradiation with high intensity increases uniformity of the surface, and IB irradiation induces the formation of oxygen vacancies and increases the NiO (Ni2+) phase components. Hence, both of the smooth surface and the strong van der Waals interactions between the NiO film and the LC molecules provides the LC molecules with a stable anchor on the surface, leading to uniform LC alignment on NiO films after IB irradiation. IB-irradiated NiO exhibited a high transparency of 85% in the visible light range as compared with the 83% average transmittance of conventional polyimide, which makes the IB-irradiated NiO alignment layer attractive in display devices.

We report an investigation of poly(styrene–maleic anhydride) (SMA) films as liquid crystal (LC) alignment layers fabricated by ion-beam (IB) irradiation. We confirmed that SMA-deposited LC cells have superior optical properties by measuring the transmittance and phase differences. Using an IB-irradiated SMA film for the alignment layer, we could confirm that uniform and homogeneous LC alignment was achieved, yielding extremely high-performance nematic liquid crystal (NLC) systems. The LC alignment mechanism was determined by X-ray photoelectron spectroscopy. IB irradiation caused chemical modifications that led to strong van der Waals forces between LCs and the modified SMA surface, thereby inducing uniform LC alignment. Moreover, the IB-irradiated SMA films exhibited good electro-optical characteristics. Therefore, these IB-irradiated SMA films are suitable as alternative alignment layers for LC display applications.

Surface wrinkling method is used to fabricate a 1-dimensional nanostructure. The structure is transferred to an ultraviolet cured polymer which is used as an alignment layer. The anisotropic geometry serves as a guide for aligning liquid crystal molecules uniformly without defects. The TN-LC cell showed a successful LC switching, with a response time of 20.5 ms, and a threshold voltage of 2.00 V. It also exhibited high thermal stability above 180°C. The proposed UV-cured polymers with 1-D nano wrinkle geometry can be a candidate for alternative alignment techniques, for advanced liquid crystal devices with high thermal budgets.