Sharing visual secrets in single image random dot stereograms.

Visual cryptography schemes (VCSs) generate random and meaningless shares to share and protect secret images. Conventional VCSs suffer from a transmission risk problem because the noise-like shares will raise the suspicion of attackers and the attackers might intercept the transmission. Previous research has involved in hiding shared content in halftone shares to reduce these risks, but this method exacerbates the pixel expansion problem and visual quality degradation problem for recovered images. In this paper, a binocular VCS (BVCS), called the (2,n)-BVCS, and an encryption algorithm are proposed to hide the shared pixels in the single image random dot stereograms (SIRDSs). Because the SIRDSs have the same 2D appearance as the conventional shares of a VCS, this paper tries to use SIRDSs as cover images of the shares of VCSs to reduce the transmission risk of the shares. The encryption algorithm alters the random dots in the SIRDSs according to the construction rule of the (2,n)-BVCS to produce nonpixel-expansion shares of the BVCS. Altering the dots in a SIRDS will degrade the visual quality of the reconstructed 3D objects. Hence, we propose an optimization model that is based on the visual quality requirement of SIRDSs to develop construction rules for a (2,n)-BVCS that maximize the contrast of the recovered image in the BVCS.

Image size invariant visual cryptography for general access structures subject to display quality constraints.

Conventional visual cryptography (VC) suffers from a pixel-expansion problem, or an uncontrollable display quality problem for recovered images, and lacks a general approach to construct visual secret sharing schemes for general access structures. We propose a general and systematic approach to address these issues without sophisticated codebook design. This approach can be used for binary secret images in non-computer-aided decryption environments. To avoid pixel expansion, we design a set of column vectors to encrypt secret pixels rather than using the conventional VC-based approach. We begin by formulating a mathematic model for the VC construction problem to find the column vectors for the optimal VC construction, after which we develop a simulated-annealing-based algorithm to solve the problem. The experimental results show that the display quality of the recovered image is superior to that of previous papers.

Hyaluronic acid inhibits the glial scar formation after brain damage with tissue loss in rats.

BACKGROUND: Brain tissue scarring (gliosis) was believed to be the major cause of epileptic focus after brain injury, and prevention of scarring could reduce the incidence of seizure. We tried the HA coating onto the cortical brain defect of Spraque-Dawley rats to reduce the marginal glial scarring. METHODS: A 4 x 2 x 2 mm(3) cortical defect was created in the brain of Spraque-Dawley rats. Three percent HA gel was coated onto the lesion for the experimental groups and normal saline solutions for the control groups. The brain was retrieved 4, 8, and 12 weeks after treatment. The brains were then sectioned and processed for H&E and GFAP staining, and the thickness of the scarring and the number of GFAP+ cells were analyzed. RESULTS: The thickness of cutting marginal gliosis was significantly decreased in the HA groups. The 12-week HA group showed the smallest thickness of gliosis, whereas the 12-week control group exhibited the largest thickness of gliosis. The significant difference in the thickness of gliosis was also noted between the HA and the control groups 8 weeks after treatment. The number of GFAP+ cells was also significantly decreased in the HA groups when compared to the respective control group 4, 8, and 12 weeks after the surgery. CONCLUSION: The results support the hypothesis that HA inhibits glial scarring not only by decreasing the thickness of gliosis but also by reducing the number of the glial cells. Furthermore, our results suggest that HA might be used to reduce glial scar formation in central nervous system surgery, which subsequently prevents the post-operation or posttraumatic seizure incidence.

Biochemical alteration in cerebrospinal fluid precedes behavioral deficits in Parkinsonian rats induced by 6-hydroxydopamine.

BACKGROUND: Parkinson's disease, affecting at least 1% of population older than 65 years, is the most common neurodegenerative movement disorder. Up to now, no evidence has demonstrated that biochemical changes in CSF occur preceding the onset of Parkinson's symptoms. In this study, we tested the hypothesis that biochemical changes in CSF precede behavioral deficits in Parkinsonian animals. METHODS: We infused different doses of 6-OHDA into the MFB of rats bilaterally and examined the animals' movement behaviors, biochemical alterations in CSF, and dopaminergic neuronal number in the SNpc 1 week later. RESULTS: Our results indicated that animals with over 70% dopaminergic neuronal loss in the SNpc exhibited behavioral bradykinesia and rigidity, and a decrease of HVA in CSF. In contrast, animals with about 42% dopaminergic neuronal loss in the SNpc showed normal movement behaviors, but displayed a drastic decline of HVA in CSF. Furthermore, the number of dopaminergic neurons in the SNpc was positively correlated with the HVA level in CSF. CONCLUSIONS: Our findings demonstrate that biochemical alteration in CSF foreruns behavioral deficits and the HVA level in CSF is positively correlated with the number of dopaminergic neurons in the SNpc of Parkinsonian rats induced by 6-OHDA. Our results strongly suggest that additional studies are needed to evaluate usefulness of monitoring the HVA level in CSF for early detection of the loss of dopaminergic neurons in the SNpc that precedes the onset of Parkinsonian symptoms in humans.

Putative alternative trans-splicing of leukocyte adhesion-GPCR pre-mRNAs generates functional chimeric receptors.

The EGF-TM7 receptors, a subfamily of adhesion-GPCRs mostly restricted to leukocytes, are known to express multiple functional protein isoforms through extensive alternative cis-splicing. Here, we demonstrate that EGF-TM7 pre-mRNAs also undergo the rare trans-splicing, leading to the generation of functional chimeric receptors. RT-PCR and in silico analyses of EMR2 transcripts identified unique fragments containing the EGF-like motif 3 of a closely related EGF-TM7 gene, CD97, in addition to the alternative cis-spliced products. The sequence swapping is restricted to the EGF-3 exon, generating unique EMR2(1-2-3*-5) and EMR2(1-2-3*-4-5) molecules, which are functional in ligand-binding as the wild-type EMR2(1-2-3-4-5) and CD97(1-2-3-4-5) receptors. Our results suggest that human leukocytes employ trans-splicing as well as cis-splicing to increase the repertoire of functional adhesion-GPCRs.

Structural variations in novel silver(I) complexes with bitopic pyrazole/n-heterocyclic carbene ligands.

The synthesis and structural characterization of several new silver complexes of L (L = a bidendate ligand of pyrazole and N-heterocyclic carbene) are described. The result shows that the choice of counterions, N-substitutions of L, and reaction conditions are crucial which lead to a variety of structural motifs, including novel metallomacrocycles [Ag2(mu-L)2]2+ with or without Ag...Ag close contact, a mononuclear [AgL2]+ complex, and a [LAg(NO3)]n coordination polymer. In particular, the nonbonding Ag...Ag distance and the overall geometry of the metallomacrocycles are controllable with different N-substitutions and counterions. All these complexes have been determined by X-ray diffraction. The solid-state aggregates are retained in solution as supported by the electrospray mass spectroscopic studies.