Contribution of DEAF1 Structural Domains to the Interaction with the Breast Cancer Oncogene LMO4

The proteins LMO4 and DEAF1 contribute to the proliferation of mammary epithelial cells. During breast cancer LMO4 is upregulated, affecting its interaction with other protein partners. This may set cells on a path to tumour formation. LMO4 and DEAF1 interact, but it is unknown how they cooperate to regulate cell proliferation. In this study, we identify a specific LMO4-binding domain in DEAF1. This domain contains an unstructured region that directly contacts LMO4, and a coiled coil that contains the DEAF1 nuclear export signal (NES). The coiled coil region can form tetramers and has the typical properties of a coiled coil domain. Using a simple cell-based assay, we show that LMO4 modulates the activity of the DEAF NES, causing nuclear accumulation of a construct containing the LMO4-interaction region of DEAF1

Thienoisoindigo-Based Semiconductor Nanowires Assembled with 2-Bromobenzaldehyde via Both Halogen and Chalcogen Bonding

We fabricated nanowires of a conjugated oligomer and applied them to organic field-effect transistors (OFETs). The supramolecular assemblies of a thienoisoindigo-based small molecular organic semiconductor (TIIG-Bz) were prepared by co-precipitation with 2-bromobenzaldehyde (2-BBA) via a combination of halogen bonding (XB) between the bromide in 2-BBA and electron-donor groups in TIIG-Bz, and chalcogen bonding (CB) between the aldehyde in 2-BBA and sulfur in TIIG-Bz. It was found that 2-BBA could be incorporated into the conjugated planes of TIIG-Bz via XB and CB pairs, thereby increasing the pi - pi stacking area between the conjugated planes. As a result, the driving force for one-dimensional growth of the supramolecular assemblies via pi - pi stacking was significantly enhanced. TIIG-Bz/2-BBA nanowires were used to fabricate OFETs, showing significantly enhanced charge transfer mobility compared to OFETs based on pure TIIG-Bz thin films and nanowires, which demonstrates the benefit of nanowire fabrication using 2-BB

Functional Induction of the Cystine-Glutamate Exchanger System Xc- Activity in SH-SY5Y Cells by Unconjugated Bilirubin

We have previously reported that exposure of SH-SY5Y neuroblastoma cells to unconjugated bilirubin (UCB) resulted in a marked up-regulation of the mRNA encoding for the Na+ -independent cystine∶glutamate exchanger System Xc− (SLC7A11 and SLC3A2 genes). In this study we demonstrate that SH-SY5Y cells treated with UCB showed a higher cystine uptake due to a significant and specific increase in the activity of System Xc−, without the contribution of the others two cystine transporters (XAG− and GGT) reported in neurons. The total intracellular glutathione content was 2 folds higher in the cells exposed to bilirubin as compared to controls, suggesting that the internalized cystine is used for gluthathione synthesis. Interestingly, these cells were significantly less sensitive to an oxidative insult induced by hydrogen peroxide. If System Xc− is silenced the protection is lost. In conclusion, these results suggest that bilirubin can modulate the gluthathione levels in neuroblastoma cells through the induction of the System Xc−, and this renders the cell less prone to oxidative damage

Understanding acute ankle ligamentous sprain injury in sports

This paper summarizes the current understanding on acute ankle sprain injury, which is the most common acute sport trauma, accounting for about 14% of all sport-related injuries. Among, 80% are ligamentous sprains caused by explosive inversion or supination. The injury motion often happens at the subtalar joint and tears the anterior talofibular ligament (ATFL) which possesses the lowest ultimate load among the lateral ligaments at the ankle. For extrinsic risk factors to ankle sprain injury, prescribing orthosis decreases the risk while increased exercise intensity in soccer raises the risk. For intrinsic factors, a foot size with increased width, an increased ankle eversion to inversion strength, plantarflexion strength and ratio between dorsiflexion and plantarflexion strength, and limb dominance could increase the ankle sprain injury risk. Players with a previous sprain history, players wearing shoes with air cells, players who do not stretch before exercising, players with inferior single leg balance, and overweight players are 4.9, 4.3, 2.6, 2.4 and 3.9 times more likely to sustain an ankle sprain injury. The aetiology of most ankle sprain injuries is incorrect foot positioning at landing – a medially-deviated vertical ground reaction force causes an explosive supination or inversion moment at the subtalar joint in a short time (about 50 ms). Another aetiology is the delayed reaction time of the peroneal muscles at the lateral aspect of the ankle (60–90 ms). The failure supination or inversion torque is about 41–45 Nm to cause ligamentous rupture in simulated spraining tests on cadaver. A previous case report revealed that the ankle joint reached 48 degrees inversion and 10 degrees internal rotation during an accidental grade I ankle ligamentous sprain injury during a dynamic cutting trial in laboratory. Diagnosis techniques and grading systems vary, but the management of ankle ligamentous sprain injury is mainly conservative. Immobilization should not be used as it results in joint stiffness, muscle atrophy and loss of proprioception. Traditional Chinese medicine such as herbs, massage and acupuncture were well applied in China in managing sports injuries, and was reported to be effective in relieving pain, reducing swelling and edema, and restoring normal ankle function. Finally, the best practice of sports medicine would be to prevent the injury. Different previous approaches, including designing prophylactice devices, introducing functional interventions, as well as change of games rules were highlighted. This paper allows the readers to catch up with the previous researches on ankle sprain injury, and facilitate the future research idea on sport-related ankle sprain injury

Photo- and rubbing-alignable brush polyimides bearing three different chromophores

Three new photoreactive brush polyimides (PSPIs), each bearing a different type of chromophore (cinnamoyl (CA), 3-(2-furyl)acryloyl (FA), and methacryloyl (MA)) in their bristles (i.e., side groups), are successfully synthesized, and are found to produce good-quality films with smooth surfaces through conventional spin-casting and drying processes. These PSPI polymers are thermally stable up to 320 degrees C. This is the first quantitative investigation of the photoaligning and rubbing-aligning processabilities of PSPI polymer films, and of the abilities of the resultant films to control the orientation and anchoring of liquid-crystal (LC) molecules. The chromophores of both poly(1-cinnamoyloxy-2,4-phenylene hexafluoroisopropylidenediphthalimide) (6F-DAP-CA) and poly(1-3-(2-furyl)acryloyloxy-2,4-phenylene hexafluoroisopropylidenediphthalimide) (6F-DAP-FA) PSPIs are found to undergo photodimerization in thin films and, to a lesser extent, photoisomerization, resulting in insoluble, crosslinked films. The MA chromophores of 6F-DAP-MA PSPI are found to undergo photopolymerization in thin films, which might include photodimerization to a lesser extent, resulting in insoluble, crosslinked films. Thin films of the PSPI polymer chains are found to have excellent unidirectional orientation ability as a result of either photoexposure with linearly polarized UV light (LPUVL) or rubbing. Both the photoaligned and the rubbing-aligned polymer chains in the PSPI films are demonstrated to effectively induce the alignment of nematic LCs along their orientation directors by anisotropic interactions between the preferentially oriented polymer chain segments and the LCs. The contribution to LC alignment of the microgrooves developed in the rubbed films is found to be very low. The anchoring energies of the LCs on the photoaligned film surfaces are comparable to those on the rubbing-aligned film surfaces; the anchoring energies are found to be in the range 0.45-2.25 X 10(-5) J m(-2), and to depend on which film treatment process is used and which chromophore bristle is present. In summary, the new PSPIs reported in this paper are promising LC alignment-layer candidates with rubbing-free processing for the production of advanced LC-display (LCD) devices, including LCD televisions with large display areas.X1135sciescopu

Detailed investigation on factors governing liquid crystal alignment on rubbed polystyrene films

The molecular orientations and surface morphologies of rubbed films formed from atactic polystyrene (PS) samples with various molecular weights were investigated in detail. Previously unknown surface topography features were newly discovered in rubbed films, depending on molecular weights: submicroscale groove-like meandering structures composed of fine-grooves like pebbles in 10 nm are present, oriented perpendicular to the rubbing direction. The vinyl main chains, however, were preferentially oriented along the rubbing direction and the planes of the phenyl side groups were preferentially oriented perpendicular to the rubbing direction with para-directions that were positioned nearly normal to the film plane. Nematic liquid crystal (LC) molecules were found to always align on the rubbed PS surfaces along the orientation direction of the submicroscale grooves generated by rubbing. (c) 2006 Elsevier B.V. All rights reserved.X1112sciescopu

Rubbed films of isomeric poly (4-vinylpyridine) and poly(2-vinylpyridine): surface morphology, molecular orientation, and liquid crystal alignability

Films of poly(4-vinylpyridine) (P4VP) and poly(2-vinylpyridine) (P2VP) were characterized before and after they were rubbed with a rayon velvet, and their liquid crystal (LC) aligning abilities were investigated. Atomic force microscopy images showed that microgrooves developed along the rubbing direction in the surfaces of the rubbed films of both polymers. Retardation and linearly polarized infrared spectroscopy analyses revealed that in both polymers the vinyl backbones are oriented along the rubbing direction, while the pyridine side groups are oriented perpendicular to the rubbing direction; the para-directions of the pyridine rings in the P4VP film have a tilt angle of about 45 degrees in the plane perpendicular to the rubbing direction but the para-directions of the pyridine rings in the P2VP film align nearly in the film surface. These rubbed films were found to induce uniform, homogeneous LC alignment along the rubbing direction. Both LC alignments were, however, found to have low anchoring energies that are due to the inherently weak interactions of the LCs with the film surfaces. Moreover, LC cells prepared using these films were found to have only limited stability. These results lead to the conclusion that the microgrooves generated along the rubbing direction play a critical role in governing the alignment of LCs that weakly interact with the parallel oriented vinyl main chains in competition with the perpendicularly oriented pyridine side groups, despite their dimensions, which are larger than the LC molecules and thus limit their effectiveness. In addition, the zero degree pre-tilting behavior of the LCs on these films was investigated in detail, taking into account both the rubbing-induced orientations of the polymer segments and their anisotropic interactions with the LC molecules. (c) 2005 Elsevier Ltd. All rights reserved.X1111sciescopu

Realization of electrically stable organic field-effect transistors using simple polymer blended dielectrics

Organic field-effect transistors (OFETs) were fabricated using polymer blended gate dielectrics in an effort to enhance the electrical stability against a gate bias stress. A poly(melamine-co-formaldehyde) acrylated (PMFA) gate dielectric layer with great insulating properties was blended with polypentafluorostyrene (PFS), a type of hydrophobic fluorinated polymer. Although the overall electrical performance dropped slightly due to the rough and hydrophobic surfaces of the blend films, at the blend ratio (10%), the OFET's threshold voltage shift under a sustained gate bias stress applied over 3 h decreased remarkably compared with an OFET based on a PMFA dielectric alone. This behavior was attributed to the presence of the hydrophobic and electrically stable PFS polymer, which provided a low interfacial trap density between the gate dielectric and the semiconductor. A stretched exponential function model suggested that the energetic barrier to create trap states was high, and the distribution of energetic barrier heights was narrow in devices prepared with PFS. (C) 2015 Elsevier B.V. All rights reserved.X1196sciescopu

The Alignment of Liquid Crystals on the Film Surfaces of Soluble Aromatic Polyimides Bearing t-Butylphenyl and Trimethylsilylphenyl Side Groups

With the study goal of firstly elucidating the anisotropic interactions between oriented polymer chain segments and liquid crystal (LC) molecules, and secondly of determining the contributions of the chemical components of the polymer segments to the film surface topography, LC alignment, pretilt, and anchoring energy, we synthesized three dianhydrides, 1,4-bis(4'-t-butylphenyl)pyromellitic dianhydride (BBPD), 1,4-bis(4'-trimethylsilylphenyl)pyromellitic dianhydride (BTPD), and 2,2'-bis(4 ''-tert-butylphenyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride (BBBPAn), and a series of their organosoluble polyimides, BBPD-ODA, BBPD-NMA, BBPD-MDA, BTPD-FDA, and BBBPAn-FDA, which contain the diamines 4,4'-oxydianiline (ODA), 4,4'-methylenediamine (MDA), and 4,4'-(hexafluoroisopropylidene)dianiline (FDA). All the polyimides were determined to be positive birefringent polymers, regardless of the chemical components. Although all the rubbed polyimide films exhibited microgrooves which were created by rubbing process, the film surface topography varied depending on the polyimides. In all the rubbed films, the polymer chains were unidirectionally oriented along the rubbing direction. However, the degree of in-plane birefringence in the rubbed film varied depending on the polyimides. The rubbing-aligned polymer chains in the polyimide films effectively induced the alignment of nematic LCs along their orientation directors by anisotropic interactions between the preferentially oriented polymer chain segments and the LCs. The azimuthal and polar anchoring energies of the LCs ranged from 0.45x10(-4) - 1.37x10(-4) J/m(2) and from 0.86x10(-5) - 4.26x10(-5) J/m(2), respectively, depending on the polyimides. The pretilt angles of the LCs were in the range 0.10-0.62 degrees. In summary, the soluble aromatic polyimides, reported here are promising LC alignment layer candidates for the production of advanced LC display devices.X116sciescopuskc

Unusual alignment of liquid crystals on rubbed films of polyimides with fluorenyl side groups

We synthesized two polyimides (PIs), poly(4,4'-(9,9-fluorenyl) diphenylene cyclobutanyltetracarboximide) (CBDA-FDA) and poly(4,4'-(9,9-fluorenyl) diphenylene pyromellitimide) (PMDA-FDA), and investigated in detail the surface morphology, molecular orientation, and nematic liquid crystal (LC) alignments of rubbed CBDA-FDA and PMDA-FDA films. The rubbed CBDA-FDA film surface was found to contain microgrooves that run parallel to the rubbing direction, but was found to induce LC alignment perpendicular to the rubbing direction. In contrast, the rubbed PMDA-FDA film surface was found to contain unusual meandering microgrooves that run perpendicular to the rubbing direction; this is the first report of such structures on a rubbed PI film. The PMDA-FDA film surface was found to induce LC alignment parallel to the rubbing direction. Even though these two PI films have quite different groove structures and LC alignment behaviors, the polymer main chains in their surfaces lie in the film plane and are preferentially oriented along the rubbing direction, and the fluorenyl side groups lie in the out-of-plane and are preferentially oriented perpendicular to the rubbing direction. These LC alignment, anchoring energy, surface morphology, and polymer segmental orientation results indicate that LC alignments on the surfaces of rubbed PI films are determined by the interplay between the directionally anisotropic interactions of the LC molecules with the oriented polymer main chain segments, the oriented fluorenyl side groups, and the microgrooves. The directionally anisotropic interactions of the LC molecules with the oriented polymer chain segments were found to be much stronger than those with the directionally developed microgrooves. We conclude that CBDA-FDA and PMDA-FDA PIs are promising alignment layer materials for the fabrication of advanced LC display devices.X115354sciescopu