Full-field calibration of color camera chromatic aberration using absolute phase maps

The refractive index of a lens varies for different wavelengths of light, and thus the same incident light with different wavelengths has different outgoing light. This characteristic of lenses causes images captured by a color camera to display chromatic aberration (CA), which seriously reduces image quality. Based on an analysis of the distribution of CA, a full-field calibration method based on absolute phase maps is proposed in this paper. Red, green, and blue closed sinusoidal fringe patterns are generated, consecutively displayed on an LCD (liquid crystal display), and captured by a color camera from the front viewpoint. The phase information of each color fringe is obtained using a four-step phase-shifting algorithm and optimum fringe number selection method. CA causes the unwrapped phase of the three channels to differ. These pixel deviations can be computed by comparing the unwrapped phase data of the red, blue, and green channels in polar coordinates. CA calibration is accomplished in Cartesian coordinates. The systematic errors introduced by the LCD are analyzed and corrected. Simulated results show the validity of the proposed method and experimental results demonstrate that the proposed full-field calibration method based on absolute phase maps will be useful for practical software-based CA calibration

Research progress in the treatment of bladder cancer based on nanotechnology

Bladder cancer is the most common malignant tumor in the urinary system. Currently, the clinical treatment options for bladder cancer mainly include surgery, chemotherapy, radiotherapy, immunotherapy, targeted therapy, photodynamic therapy, combination therapy, etc. The conventional treatment and administration strategies for bladder cancer primarily depend on the tumor stage and the extent of metastasis. However, in the process of non-surgical treatment, drugs lack specificity and targeting. Once the dosage is improperly controlled, drugs will damage normal cells when attacking cancer cells, which will lead to poor efficacy and multiple side effects. Nanomedicine is an emerging interdisciplinary field that utilizes nanomaterials and technologies in nanomedicine to provide disruptive technologies for traditional treatments, with advantages such as targeted delivery and high efficiency with low toxicity. Many nanotechnologies have become hot topics in clinical research in the field of medicine. Functionalized nanoparticles can actively or passively target specific cells within target organs, such as bladder cancer cells, by altering their surface properties, thereby enhancing drug delivery precision, reducing damage to normal cells, and improving treatment efficacy. This article provides an overview of the progress in classical and novel treatment approaches to bladder cancer, with a particular focus on the potential applications and future development directions of nanotechnology in the treatment of bladder cancer, providing important reference for personalized therapy and clinical translation in bladder cancer

Catalytic Mechanism Investigation of Lysine-Specific Demethylase 1 (LSD1): A Computational Study

Lysine-specific demethylase 1 (LSD1), the first identified histone demethylase, is a flavin-dependent amine oxidase which specifically demethylates mono- or dimethylated H3K4 and H3K9 via a redox process. It participates in a broad spectrum of biological processes and is of high importance in cell proliferation, adipogenesis, spermatogenesis, chromosome segregation and embryonic development. To date, as a potential drug target for discovering anti-tumor drugs, the medical significance of LSD1 has been greatly appreciated. However, the catalytic mechanism for the rate-limiting reductive half-reaction in demethylation remains controversial. By employing a combined computational approach including molecular modeling, molecular dynamics (MD) simulations and quantum mechanics/molecular mechanics (QM/MM) calculations, the catalytic mechanism of dimethylated H3K4 demethylation by LSD1 was characterized in details. The three-dimensional (3D) model of the complex was composed of LSD1, CoREST, and histone substrate. A 30-ns MD simulation of the model highlights the pivotal role of the conserved Tyr761 and lysine-water-flavin motif in properly orienting flavin adenine dinucleotide (FAD) with respect to substrate. The synergy of the two factors effectively stabilizes the catalytic environment and facilitated the demethylation reaction. On the basis of the reasonable consistence between simulation results and available mutagenesis data, QM/MM strategy was further employed to probe the catalytic mechanism of the reductive half-reaction in demethylation. The characteristics of the demethylation pathway determined by the potential energy surface and charge distribution analysis indicates that this reaction belongs to the direct hydride transfer mechanism. Our study provides insights into the LSD1 mechanism of reductive half-reaction in demethylation and has important implications for the discovery of regulators against LSD1 enzymes

Dystrophin Is a Tumor Suppressor in Human Cancers with Myogenic Programs

Many common human mesenchymal tumors, including gastrointestinal stromal tumor (GIST), rhabdomyosarcoma (RMS), and leiomyosarcoma (LMS), feature myogenic differentiation1–3. Here we report that intragenic deletion of the dystrophin-encoding and muscular dystrophy-associated DMD gene is a frequent mechanism by which myogenic tumors progress to high-grade, lethal sarcomas. Dystrophin is expressed in nonneoplastic and benign counterparts for GIST, RMS and LMS, and the DMD deletions inactivate larger dystrophin isoforms, including 427kDa dystrophin, while preserving expression of an essential 71kDa isoform. Dystrophin inhibits myogenic sarcoma cell migration, invasion, anchorage independence, and invadopodia formation, and dystrophin inactivation was found in 96%, 100%, and 62% of metastatic GIST, embryonal RMS, and LMS, respectively. These findings validate dystrophin as a tumor suppressor and likely anti-metastatic factor, suggesting that therapies in development for muscular dystrophies may also have relevance in treatment of cancer

Molecular Basis of NDM-1, a New Antibiotic Resistance Determinant

The New Delhi Metallo-β-lactamase (NDM-1) was first reported in 2009 in a Swedish patient. A recent study reported that Klebsiella pneumonia NDM-1 positive strain or Escherichia coli NDM-1 positive strain was highly resistant to all antibiotics tested except tigecycline and colistin. These can no longer be relied on to treat infections and therefore, NDM-1 now becomes potentially a major global health threat

Investigation of the Acetylation Mechanism by GCN5 Histone Acetyltransferase

The histone acetylation of post-translational modification can be highly dynamic and play a crucial role in regulating cellular proliferation, survival, differentiation and motility. Of the enzymes that mediate post-translation modifications, the GCN5 of the histone acetyltransferase (HAT) proteins family that add acetyl groups to target lysine residues within histones, has been most extensively studied. According to the mechanism studies of GCN5 related proteins, two key processes, deprotonation and acetylation, must be involved. However, as a fundamental issue, the structure of hGCN5/AcCoA/pH3 remains elusive. Although biological experiments have proved that GCN5 mediates the acetylation process through the sequential mechanism pathway, a dynamic view of the catalytic process and the molecular basis for hGCN5/AcCoA/pH3 are still not available and none of theoretical studies has been reported to other related enzymes in HAT family. To explore the molecular basis for the catalytic mechanism, computational approaches including molecular modeling, molecular dynamic (MD) simulation and quantum mechanics/molecular mechanics (QM/MM) simulation were carried out. The initial hGCN5/AcCoA/pH3 complex structure was modeled and a reasonable snapshot was extracted from the trajectory of a 20 ns MD simulation, with considering post-MD analysis and reported experimental results. Those residues playing crucial roles in binding affinity and acetylation reaction were comprehensively investigated. It demonstrated Glu80 acted as the general base for deprotonation of Lys171 from H3. Furthermore, the two-dimensional QM/MM potential energy surface was employed to study the sequential pathway acetylation mechanism. Energy barriers of addition-elimination reaction in acetylation obtained from QM/MM calculation indicated the point of the intermediate ternary complex. Our study may provide insights into the detailed mechanism for acetylation reaction of GCN5, and has important implications for the discovery of regulators against GCN5 enzymes and related HAT family enzymes

Novel processing routes for oxide cathode emission materials

An investigation has been carried out into the production of the alkaline earth carbonate and oxide powders and coatings suitable as cathode emission materials by the ethylenediaminetetraacetic acid (EDT A) gel method for potential application as cathode emission materials. The emission performance of thermionic cathodes coated with these materials has been measured, and found to give encouraging results, comparable with conventionally prepared oxide emission materials, despite the former having not been optimised. Amorphous gels of composition Ca-EDTA, Sr-EDTA, Ba-EDTA, [SrO.5 Bao.5J-EDTA and [SrO.5 Bao.5 Cao.05J-EDTA were successfully prepared from aqueous solutions of alkaline earth nitrates and EDT A. Subsequently, the thermal decomposition of the gels and the effects of temperature and atmospheres on the decomposition have been studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The gels and the powders derived from calcination of these gels at different temperatures have been characterised by Fourier transform infrared spectroscopy (FTIR) , X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) with X-ray energy dispersive (EDX) spectroscopy. Coatings prepared by dip-coating, spraying and electrophoretic deposition (EPD) from the EDT A-sols have been characterised by FTIR, XRI> and SEM techniques. In addition, an attempt was made to study the coating of the colloidal particles in the suspension of methanolethanediol- EDTA sol by electrochemical impedance spectroscopy

numericalstudyofsolidliquidtwophaseflowinstirredtankswithrushtonimpellerpredictionofcriticalimpellerspeed

The critical impeller speed, NJS, for complete suspension of solid particles in the agitated solid-liquid two-phase system in baffled stirred tanks with a standard Rushton impeller is predicted using the computational procedure proposed in Part Ⅰ. Three different numerical criteria are tested for determining the critical solid suspension. The predicted NJS is compared with those obtained from several empirical correlations. It is suggested the most reasonable criterion for determining the complete suspension of solid particles is the positive sign of simulated axial velocity of solid phase at the location where the solid particles are most difficult to be suspended