Electrochemically Driven para-Selective C(sp2)-H Alkylation Enabled by Activation of Alkyl Halides without Sacrificial Anodes.

With alkyl halides (I, Br, Cl) as a coupling partner, an electrochemically driven strategy for para-selective C(sp2)-H alkylation of electron-deficient arenes (aryl esters, aldehydes, nitriles, and ketones) has been achieved to access diverse alkylated arenes in one step. The reaction enables the activation of alkyl halides in the absence of sacrificial anodes, achieving the formation of C(sp2)-C(sp3) bonds under mild electrolytic conditions. The utility of this protocol is reflected in high site selectivity, broad substrate scope, and scalable.

Development of a sensitive direct competitive chemiluminescent enzyme immunoassay for gentamicin based on the construction of a specific single-chain variable fragment-alkaline phosphatase fusion protein.

A sensitive chemiluminescent enzyme immunoassay (CLEIA) was established for the determination of gentamicin (GEN) residue levels in animal tissue. This assay is based on a fusion protein of single-chain variable fragment (scFv) and alkaline phosphatase (AP). Initially, VL and VH derived from anti-gentamicin monoclonal antibody were linked by a short peptide to construct a scFv. Subsequently, the constructed scFv sequence was accessed into the pLIP6/GN vector, and a soluble scFv-AP fusion protein was generated. The scFv-AP fusion protein was used to develop a direct competitive CLEIA (dcCLEIA) for the determination of gentamicin. In the dcCLEIA, the half inhibitory concentration (IC50) and limit of detection (LOD) were 1.073 ng/mL and 0.380 ng/mL, respectively. The average recoveries of gentamicin spiked in animal tissue samples ranged from 78% to 96%. These results showed a strong correlation with ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The above results suggest that the anti-GEN scFv-AP fusion protein is suitable for detecting gentamicin residues in edible animal tissues.

Fabrication of a large computer-generated hologram with high diffraction efficiency and high accuracy by scanning homogenization etching.

The diffraction efficiency, defined as the ratio of diffracted power to incident power, is one of the key working indicators for a computer-generated hologram (CGH). The CGH with high diffraction efficiency could suppress stray light and eliminate ghost images, thus improving interferometric performance in aspherical testing of low-reflectivity or large off-axis distance surfaces. However, the high-efficiency CGH is hard to precisely fabricate by traditional reactive ion etching and focusing ion beam, because it requires high etching depth with a high uniformity and sub-nanometric roughness in the glass, especially in the fabrication of a large CGH with an aperture of up to 300 mm. In this study, fabrication of the above-mentioned CGH was demonstrated via what we believe to be a new method called scanning homogenization etching (SHE), in which the ion source with a Gaussian energy distribution accurately scans the glass surface to realize homogenization etching. Different from controlling dwell time at each etching point, this paper proposes to control the scanning rate to achieve not only uniform but also quantitative depth removal in a single scan. Moreover, the depth errors in deep etching across the whole glass surface can be remarkably reduced due to homogenization effects introduced by multiple scanning etching. Finally, the target etching depth of 692.3 nm with an etching uniformity of 2.2% in the etching of a 300 mm CGH was achieved. The roughness of the etched and unetched area both have Ra values of 0.3 nm. The diffraction efficiency of working order is 39.998%, achieving 98.6% of the theoretical diffraction efficiency. In addition, the SHE is not limited by the aperture of the ion source, so it can achieve even larger diffractive optical elements with high diffraction efficiency and high accuracy.

Electrochemically Driven C4-Selective Decyanoalkylation of Cyanopyridines with Unactivated Alkyl Bromides Enabling C(sp3)-C(sp2) Coupling.

With cyanopyridines and alkyl bromides as coupling partners, an electrochemically driven C4-selective decyanoalkylation has been established to access diverse 4-alkylpyridines in one step. The reaction proceeds through the single electron reduction/radical-radical coupling tandem process under mild electrolytic conditions, achieving the cleavage of the C(sp2)-CN bond and the formation of C(sp3)-C(sp2). The practicality of this protocol is illustrated by no sacrificial anodes, a broad substrate scope, and gram-scale synthesis.

Elimination of surface/subsurface defects on additively manufactured AlSi10Mg mirrors through nano-second laser irradiation.

Metal mirrors have attracted increasing attention for satisfying the growing demands for high-performance optics in airborne and spaceborne remote sensing systems. Additive manufacturing has enabled the development of metal mirrors with reduced weight and improved strength. AlSi10Mg is the most widely used metal for additive manufacturing. Diamond cutting is an effective method for obtaining nanometer-scale surface roughness. However, the surface/subsurface defects of additively manufactured AlSi10Mg deteriorate the surface roughness. Conventionally, AlSi10Mg mirrors used in near-infrared and visible systems are plated with NiP layers to improve the surface polishing performance; however, this leads to the bimetallic bending because of the different coefficients of thermal expansion between the NiP layers and AlSi10Mg blanks. In this study, a method of nanosecond-pulsed laser irradiation is proposed to eliminate the surface/subsurface defects of AlSi10Mg. The microscopic pores, unmolten particles and two-phase microstructure of the mirror surface were eliminated. The mirror surface exhibited better polishing performance, and it could be smoothly polished to a nanometer-scale surface roughness. The mirror exhibits strong temperature stability owing to the elimination of the bimetallic bending caused by the NiP layers. It is expected that the mirror surface fabricated in this study can satisfy the requirements for near-infrared or even visible applications.

Production of high affinity monoclonal antibody and development of indirect competitive chemiluminescence enzyme immunoassay for gentamicin residue in animal tissues.

To determine gentamicin residues in animal tissues, a monoclonal antibody (Mab) was produced and a sensitive indirect competitive chemiluminescent enzyme immunoassay (icCLEIA) was developed. At first, gentamicin was conjugated with bovine serum albumin as immunogens which were used to immunize BALB/c mice. Then, an anti-gentamicin Mab was prepared by hybridoma technology. Finally, a sensitive icCLEIA was developed with an 50% inhibition concentration (IC50) of 0.067 ng/mL for gentamicin. The limit of detection of the icCLEIA was 0.002 ng/mL. The cross reactivity of the Mab with structural analogues were<0.01%. The recoveries of gentamicin ranged from 80 to 101% and coefficient of variation was <6.4% in pork and fish samples. Samples were detected by UPLC-MS/MS for evaluating reliability of the icCLEIA. The results suggested that the prepared anti-gentamicin Mab can be used for rapid and convenient immunoassays to detect gentamicin residues in animal tissues.

Cathodic Carbonyl Alkylation of Aryl Ketones or Aldehydes with Unactivated Alkyl Halides.

An efficient cathodic carbonyl alkylation of aryl ketones or aldehydes with unactivated alkyl halides has been realized through the electrochemical activation of iron. The protocol is believed to include a radical-radical coupling or nucleophilic addition process, and the formation of ketyl radicals and alkyl radicals has been demonstrated. The protocol provides various tertiary or secondary alcohols by the formation of intermolecular C-C bonds under safe and mild conditions, is scalable, consumes little energy, and exhibits a broad substrate scope.

Curvature effect-based modeling and experimentation of the material removal in polishing optical surfaces using a flexible ball-end tool.

Optical surfaces with high quality have been widely applied in high-tech industries for their excellent performances. To precision manufacture those surfaces efficiently and effectively, various machining technologies involved become extremely crucial. As one of the promising ultra-precision machining technologies, inflated or solid elastic tool polishing has attracted more attention for its own superiority. However, there is still lack of understanding on material removal mechanisms especially with the consideration of curvature effect, and it is of great importance to determine the surface quality and form control in ultra-precision polishing process. In this paper, originating from the famous macro-scale Preston equation, the curvature effect-based material removal model in polishing using a flexible ball-end tool has been developed successfully on the basis of two key sub-models, one is the generic model of effective relative velocity and the other refers to the semi-experimental contact pressure model. A series of spot polishing experiments subsequently are conducted on concave surfaces with a curvature radius range from 75 mm to 225 mm. The experimentally measured section profiles of polishing spots do match well with the predicted data, which verifies the effectiveness of the proposed material removal model. On the measured polishing spots, it is also observed that there have two nonuniform material removal phenomena, one is analyzed along the central axis and the other is discussed by two regions symmetrical about the central axis. Compared with the effective relative velocity, it is found that, the contact pressure is more sensitive to curvature effect by investigating the variation of maximum removal depth within a broader curvature radius range from 75 mm to 1000 mm. This study can provide a valuable foundation for polishing optical surfaces with deterministic removal.

Fringe projection profilometry method with high efficiency, precision, and convenience: theoretical analysis and development.

Fringe projector profilometry (FPP) is an important three-dimensional (3D) measurement technique, especially when high precision and speed are required. Thus, theoretical interrogation is critical to provide deep understanding and possible improvement of FPP. By dividing an FPP measurement process into four steps (system calibration, phase measurement, pixel correspondence, and 3D reconstruction), we give theoretical analysis on the entire process except for the extensively studied calibration step. Our study indeed reveals a series of important system properties, to the best of our knowledge, for the first time: (i) in phase measurement, the optimal and worst fringe angles are proven perpendicular and parallel to epipolar line, respectively, and can be considered as system parameters and can be directly made available during traditional calibration, highlighting the significance of the epipolar line; (ii) in correspondence, when two sets of fringes with different fringe orientations are projected, the highest correspondence precision can be achieved with arbitrary orientations as long as these two orientations are perpendicular to each other; (iii) in reconstruction, a higher reconstruction precision is given by the 4-equation methods, while we notice that the 3-equation methods are almost dominatingly used in literature. Based on these theoretical results, we propose a novel FPP measurement method which (i) only projects one set of fringes with optimal fringe angle to explicitly work together with the epipolar line for precise pixel correspondence; (ii) for the first time, the optimal fringe angle is determined directly from the calibration parameters, instead of being measured; (iii) uses 4 equations for precise 3D reconstruction but we can remove one equation which is equivalent to an epipolar line, making it the first algorithm that can use 3-equation solution to achieve 4-equation precision. Our method is efficient (only one set of fringe patterns is required in projection and the speed is doubled in reconstruction), precise (in both pixel correspondence and 3D reconstruction), and convenient (the computable optimal fringe angle and a closed-form 3-equation solution). We also believe that our work is insightful in revealing fundamental FPP properties, provides a more reasonable measurement for practice, and thus is beneficial to further FPP studies.

Classification and Prognostic Characteristics of Hepatocellular Carcinoma Based on Glycolysis Cholesterol Synthesis Axis.

Background: Liver hepatocellular carcinoma (LIHC) is among the most frequent causes of cancer-related death across the world with a considerably poor prognosis. The current study targeted providing a new type of LIHC from the perspective of the glycolysis/cholesterol synthesis axis, predicting its prognostic characteristics, and exploring the potential role and mechanism of the glycolysis/cholesterol synthesis axis in the occurrence and development of LIHC. Methods: Based on the two expression profile data and clinical information of LIHC in The Cancer Genome Atlas (TCGA) database and hepatocellular carcinoma database (HCCDB), as well as glycolysis/cholesterol-related genes from the Molecular Signatures Database (MSigDB), unsupervised consistent clustering method was used to identify molecular subtypes. In addition, the differential genes were identified by limma package, and then the gene set was enriched, analyzed, and annotated by WebGestaltR package. At the same time, the immune infiltration analysis of tumor samples was carried out using the ESTIMATE to evaluate the tumor immune score of the samples. Finally, the differences in clinical characteristics among molecular subtypes were measured using univariate and multivariate Cox analyses. Results: According to the median standardized expression levels of glycolysis/cholesterol production genes, samples were divided into four groups (molecular subtypes): Quiescent group, Glycolysis group, Cholesterol group, and Mixed group. Significant prognostic differences were observed among the four groups. In both TCGA and HCCDB18 datasets, the prognosis of subtype Mixed was the worst, while Quiescent had a good prognosis. Cell cycle and oncogenic pathways were significantly enriched in the Mixed group. In addition, glycolysis and cholesterol production gene expressions were related to the prognostic LIHC subtype classification genes' expression levels. Conclusion: Metabolic classification regarding glycolysis and cholesterol production pathways provided new insights into the biological aspects of LIHC molecular subtypes and might help to develop personalized therapies for unique tumor metabolic profiles.

Challenges and strategies in high-accuracy manufacturing of the world's largest SiC aspheric mirror.

In the process of manufacturing the world's largest silicon carbide (SiC) aspheric mirror, the primary difficulties are mirror blank preparation, asphere fabrication, and testing, as well as cladding and coating. Specifically, the challenges include the homogeneity of the complicated structure casting, accuracy and efficiency of the fabrication process, print-through effect, fidelity and precision of test procedure, stress and denseness of cladding process, the dynamic range of interferometric measurement, and air turbulence error due to the long optical path. To break through such a barrier of difficulties, we proposed the water-soluble room temperature vanishing mold and gel casting technology, homogeneous microstructure reaction-formed joint technology, nano-accuracy efficient compound fabrication, gravity unloading technology, high-denseness low-defect physical vapor deposition (PVD) Si-cladding technology, test data fusion method, and time-domain averaging method, etc. Based on the proposed technologies and methods, we have accomplished the world's largest SiC aspheric mirror with a size of ⌀4.03 m. The impressive performance of the SiC aspheric mirror is validated by the characteristics of the fabricated SiC aspheric mirror. The aerial density of the SiC blank is less than 120 kg/m2, surface shape test accuracy is better than 6 nm RMS, thickness inhomogeneity of the cladding layer is less than 5%, and the final surface figure error and roughness are 15.2 nm RMS and 0.8 nm RMS, respectively.

Electrochemically induced Markovnikov-type selective hydro/deuterophosphonylation of electron-rich alkenes.

The regioselective hydro/deuterophosphonylation of electron-rich alkenes with P(O)H compounds has been realized via a metal-free electrochemically induced strategy, accessing various Markovnikov-type adducts in high yields. A series of monodeuterated organophosphorus compounds with high deuterium (D) incorporation are subsequently obtained by adding D2O as the D source. The protocol features broad substrate scope, low energy consumption, high atom economy, and scalability. Monodeuterated organophosphoric acids can be synthesized via late-stage transformation.

Integrative analysis of the characteristic of lipid metabolism-related genes for the prognostic prediction of hepatocellular carcinoma.

BACKGROUND: Dysregulation of lipid metabolism is implicated in the progression of hepatocellular carcinoma (HCC). We therefore investigated the molecular characteristics of lipid-metabolism-related genes in HCC. METHODS: Multi-dimensional bioinformatics analysis was conducted to comprehensively identify the lipid metabolism-related genes (LMRGs) from public databases, as well as the clinical information, immune features, and biological characteristics of HCC. The IMGR were then used to classify HCC into molecular phenotypes. Six lipid metabolism-related genes sets with the potential to predict the prognosis of HCC patients were identified. RESULTS: A total of 770 HCC patients with complete clinical information and corresponding 776 LMRGs were downloaded from 3 databases. Univariate cox and non-negative matrix factorization analyses were used to classify HCC patients into 2 clusters. This molecular classification was associated with overall survival, clinical characteristics, and immune cells. The biological function of the differentially expressed LMRGs in the 2 clusters showed the genes associated with tumor-related metabolism pathways. A combination of multivariate/univariate cox regression and least absolute shrinkage and selection operator analyses were conducted to build a 6 LMRGs signature (6-IS) to predict the prognosis of HCC. The 6-IS signature was found to be an independent prognostic factor. Performance of the 6-IS prognostic signature was verified in a validation set and compared with an external data set. Results revealed the 6-IS signature could effectively predict the prognosis of patients with HCC. CONCLUSIONS: This study provides new insights into the role of LMRG in the pathogenesis of HCC and presents a novel prognostic signature 6-IS monitoring the clinical course of HCC.

Design and Fabrication of Extremely Lightweight Truss-Structured Metal Mirrors.

Three-dimensional printing, also called additive manufacturing (AM), offers a new vision for optical components in terms of weight reduction and strength improvement. A truss, which is a triangulated system of members that are structured and connected in such a way that they mainly bear axial force, is commonly used in steel structures to improve stiffness and reduce weight. Combining these two technologies, an extremely lightweight truss-structured mirror was proposed. First, the finite element analyses (FEA) on surface shape deviation and modal properties were carried out. Results showed that the mirrors had sufficient stiffness and a high weight reduction of up to 85%. In order to verify their performance, the truss-structured mirror blanks were fabricated with AM technology. After that, both the preprocessing and the postprocessing of the mirrors were carried out. The results show that without NiP coating, a surface shape deviation of 0.353λ (PV) and 0.028 λ (RMS) (λ = 632.8 nm) with a roughness of Ra 2.8 nm, could be achieved. Therefore, the truss-structured mirrors in this study have the characteristics of being extremely lightweight and having improved stiffness as well as strong temperature stability.

Cathodic Regioselective Coupling of Unactivated Aliphatic Ketones with Alkenes.

A regioselective coupling of aliphatic ketones with alkenes has been realized by cathodic reduction. This reaction enables the formation of ketyl radicals and the activation of challenging alkenes under mild electrolysis conditions, providing an effective protocol for accessing diverse tertiary alcohols with substrate-dependent regioselectivity. The practicability of this reaction is demonstrated by scale-up experiments. The hydrogen source for the products, the migration isomerization of allylarenes, and the applicability of internal alkenes are demonstrated by control experiments.

Anodic C(sp3)-H Acyloxylation of Indolin-3-ones Enabled by Oxidant-Free Cross-Dehydrogenative C(sp3)-O Coupling.

An efficient anodic C(sp3)-H acyloxylation protocol has been established via intermolecular cross-dehydrogenative C(sp3)-O coupling. The protocol provides various C2-acyloxy indolin-3-ones without the addition of metal catalysts and external oxidants because indolin-3-ones can be directly oxidized at the anode. The effective application of several medical drugs and the realization of the gram-scale experiment have proven the practicality of this protocol.

CircRNA MFACR Is Upregulated in Myocardial Infarction and Downregulates miR-125b to Promote Cardiomyocyte Apoptosis Induced by Hypoxia.

ABSTRACT: Circular RNA (circRNA) MFACR promotes cardiomyocyte death that leads to myocardial infarction (MI). This study aimed to explore the role of MFACR in MI. T-qPCRs were performed to measure the expression levels of MFACR and miR-125b in plasma samples from both MI patients (n = 61) and healthy controls (n = 61). MFACR or miR-125b was overexpressed in AC16 cells (cardiomyocytes) to explore the interaction between them. Methylation of miR-125b gene in cells with the overexpression of MFACR was detected by methylation-specific PCR. Cell apoptosis after transfections was detected by cell apoptosis assay. MI model was constructed to further demonstrate the effect of MFACR in vivo. We found that MFACR was upregulated in MI and inversely correlated with miR-125b. In AC16 cells, hypoxia treatment increased the expression levels of MFACR and decreased the expression levels of miR-125b. In AC16 cells, overexpression of MFACR decreased the expression levels of miR-125b and increased the methylation of miR-125b gene. Under hypoxia treatment, overexpression of MFACR increased AC16 cell apoptosis, and overexpression of miR-125b decreased cell apoptosis. In addition, overexpression of miR-125b reversed the effects of overexpression of MFACR on cell apoptosis both in vivo and in vitro.

Antibacterial chitosan composite films with food-inspired carbon spheres immobilized AgNPs.

The cumulative toxicity of AgNPs has limited their application in food packaging. As such, the quest for AgNPs should focus on controlling their release to reduce the cumulative toxicity. Here, two kinds of green hydrothermal carbonized methods were used to treat sulfhydryl-modified chitosan to obtain two kinds of carbon spheres/AgNPs (Glutinous rice sesameballs-like AgNPs-SMCS and dragon fruit-like SMCS-Ag), which exhibited good stability and high immobilization efficiency for AgNPs, and the release of total Ag from AgNPs-SMCS and SMCS-Ag were only about 5.63% and 3.59% after 14 days, respectively. Subsequently, they were added into chitosan separately to prepare chitosan-based films. Two carbon spheres/AgNPs regulated the microstructure of chitosan-based films because of the electrostatic interaction and the micro-nanometer filling behavior, thus further immobilized the AgNPs. Importantly, the films presented good antibacterial activity and excellent safety. These results will provide a theoretical basis for the green and safe design of AgNPs antibacterial agent.

Stress-induced deformation of the coating on large lightweight freeform optics.

Large aperture, lightweight optics are frequently utilized in modern optical systems. However, despite the use of advanced techniques for developing their materials, fabrication, and mechanical structure, the coatings placed on the substrates induce slight lattice mismatches and increase the thin film stress on polished surfaces. This significantly distorts nano-accuracy optical surfaces, especially on lightweight freeform surfaces. In this study, we construct a finite element model (FEM) and a ray tracing model to estimate the impact of the stress-induced deformation of the coating on a 1.5m class lightweight silicon carbine (SiC) mirror with a freeform surface. Our simulation results are within 10% deviation from the experimental results, and the deformation texture map matches these results as well. We discuss several possible strategies to overcome stress-induced deformation, including fabrication pre-compensation, lightweight structure redesign, and an inverse print-through effect.

Honeycomb-like structure-tunable chitosan-based porous carbon microspheres for methylene blue efficient removal.

Chitosan (CS) can be used for the preparation of carbon materials with different morphologies due to its excellent properties, but there are no reports on its spherical morphology. In this study, a feasible step-by-step strategy was proposed to fabricate nitrogen-containing chitosan-based porous carbon microspheres (CPCM) in HCl and KOH. The unique spherical morphology and honeycomb-like porous structure of CPCM were accurately regulated. A great quantity of micro/mesopores endowed CPCM an ultra-high specific surface area up to 2463.9 m2 g-1. Moreover, CPCM exhibited an ultra-high maximum adsorption capacity up to 1599.03 mg g-1 for methylene blue (MB), meanwhile the adsorption process was in well agreement with the Langmuir isotherm and pseudo-second-order kinetic models. It was simultaneously a favorable reusable adsorbent with high regenerative capacity. The high dye adsorption properties suggest that chitosan can be a promising candidate for sewage treatment in the form of carbon microspheres.