Image Retrieval Using Deep Convolutional Neural Networks and Regularized Locality Preserving Indexing Strategy

Convolutional Neural Networks (CNN) has been a very popular area in large scale data processing and many works have demonstrate that CNN is a very promising tool in many field, e.g., image classification and image retrieval. Theoretically, CNN features can become better and better with the increase of CNN layers. But on the other side more layers can dramatically increase the computational cost on the same condition of other devices. In addition to CNN features, how to dig out the potential information contained in the features is also an important aspect. In this paper, we propose a novel approach utilize deep CNN to extract image features and then introduce a Regularized Locality Preserving Indexing (RLPI) method which can make features more differentiated through learning a new space of the data space. First, we apply deep networks (VGG-net) to extract image features and then introduce Regularized Locality Preserving Indexing (RLPI) method to train a model. Finally, the new feature space can be generated through this model and then can be used to image retrieval.

Metabolic Pathway of Monounsaturated Lipids Revealed by In-Depth Structural Lipidomics by Mass Spectrometry

The study of lipid metabolism relies on the characterization of the lipidome,which is quite complex due to the structure variations of the lipid species.New analytical tools have been developed recently for characterizing fine structures of lipids,with C=C location identification as one of the major improvements.In this study,we studied the lipid metabolism reprograming by analyzing glycerol phospholipid compositions in breast cancer cell lines with structural specification extended to the C=C location level.Inhibition of the lipid desaturase,stearoyl-CoA desaturase 1,increased the proportion of n-10 isomers that are produced via an alternative fatty acid desaturase 2 pathway.However,there were different variations of the ratio of n-9/n-7 isomers in C18:1-containing glycerol phospholipids after stearoyl-CoA desaturase 1 inhibition,showing increased tendency in MCF-7 cells,MDA-MB-468 cells,and BT-474 cells,but decreased tendency in MDA-MB-231 cells.No consistent change of the ratio of n-9/n-7 isomers was observed in SK-BR-3 cells.This type of heterogeneity in reprogrammed lipid metabolism can be rationalized by considering both lipid desaturation and fatty acid oxidation,highlighting the critical roles of comprehensive lipid analysis in both fundamental and biomedical applications.

Antireflection Surfaces for Biological Analysis Using Laser Desorption Ionization Mass Spectrometry

Laser desorption ionization mass spectrometry(LDI-MS)is a primary tool for biological analysis.Its success relies on the use of chemical matrices that facilitate sof desorption and ionization of the biomolecules,which,however,also limits its application for metabolomics study due to the chemical interference by the matrix compounds.Te requirement for sample pretreatment is also undesirable for direct sampling analysis or tissue imaging.In this study,antirefection(AR)metal surfaces were investigated as sample substrates for matrix-free LDI-MS.Tey were prepared through ultrafast laser processing,with high light-to-heat energy conversion efciency.Te morphology and micro/nanostructures on the metal surfaces could be adjusted and optimized by tuning the laser fabrication process.Te super-high UV absorption at 97%enabled highly efcient thermal desorption and ionization of analytes.Te analytical performance for the matrix-free LDI was explored by analyzing a variety of biological compounds,including carbohydrates,drugs,metabolites,and amino acids.Its applicability for direct analysis of complex biological samples was also demonstrated by direct analysis of metabolites in yeast cells.

TRIM28 promotes the escape of gastric cancer cells from immune surveillance by increasing PD-L1 abundance

Immune checkpoint blockade(ICB)offers a new opportunity for treatment for gastric cancer(G.C.).Understanding the upstream regulation of immune checkpoints is crucial to further improve the efficacy of ICB therapy.Herein,using the CRISPR-Cas9-based genome-wide screening,we identified TRIM28 as one of the most significant regulators of PD-L1,a checkpoint protein,in G.C.cells.