Detecting Trivariate Associations in High-Dimensional Datasets.

Detecting correlations in high-dimensional datasets plays an important role in data mining and knowledge discovery. While recent works achieve promising results, detecting multivariable correlations especially trivariate associations still remains a challenge. For example, maximal information coefficient (MIC) introduces generality and equitability to detect bivariate correlations but fails to detect multivariable correlation. To solve the problem mentioned above, we proposed quadratic optimized trivariate information coefficient (QOTIC). Specifically, QOTIC equitably measures dependence among three variables. Our contributions are three-fold: (1) we present a novel quadratic optimization procedure to approach the correlation with high accuracy; (2) QOTIC exceeds existing methods in generality and equitability as QOTIC has general test functions and is applicable in detecting multivariable correlation in datasets of various sample sizes and noise levels; (3) QOTIC achieved both higher accuracy and higher time-efficiency than previous methods. Extensive experiments demonstrate the excellent performance of QOTIC.

Hough Transform-Based Large Dynamic Reflection Coefficient Micro-Motion Target Detection in SAR.

Special phase modulation of SAR echoes resulted from target rotation or vibration, is a phenomenon called the micro-Doppler (m-D) effect. Such an effect offers favorable information for micro-motion (MM) target detection, thereby improving the performance of the synthetic aperture radar (SAR) system. However, when there are MM targets with large differences in reflection coefficient, the weak reflection components will be difficult to be detected. To find a solution to this problem, we propose a novel algorithm. First, we extract and detect the strongest reflection component. By removing the strongest reflection component from the original azimuth echo one by one, we realize the detection of reflection components sequentially, from the strongest to the weakest. Our algorithm applies to detecting MM targets with different reflection coefficients and has high precision of parameter estimation. The results of simulation and field experiments verify the advantages of the algorithm.

Cooperative Catalysis-Enabled Asymmetric α-Arylation of Aldehydes Using 2-Indolylmethanols as Arylation Reagents.

A catalytic asymmetric α-arylation of aldehydes using 2-indolylmethanols as arylation reagents has been established. This reaction was enabled by a cooperative catalytic system consisting of a gold complex, a Brønsted acid, and a chiral amine, which have a synergistic effect in the reaction process. By using this strategy, a series of α-arylation products of aldehydes were generated in overall acceptable yields and good enantioselectivities (up to 69%, 91:9 er). The control experiments demonstrated that the addition of PPh3AuCl as a gold complex was helpful to improve the yield, and trifluoroacetic acid as a Brønsted acid played a crucial role in the reaction by promoting the generation of carbocation and chiral enamine intermediates, which are two key intermediates of the asymmetric α-arylation reaction. In addition, the enantioselectivity of the reaction was mainly controlled by the chiral amine catalyst via forming a chiral enamine intermediate. This reaction has not only provided a useful protocol for catalytic asymmetric α-arylation of aldehydes but also enriched the research contents of 2-indolylmethanol-involved reactions and asymmetric cooperative catalysis.

Metal-Catalyzed Oxa-[4+2] Cyclizations of Quinone Methides with Alkynyl Benzyl Alcohols.

An oxa-[4+2] cyclization of quinone methides with alkynyl benzyl alcohols has been realized in the presence of a metal catalyst, and the reaction afforded spiroacetal products in overall high yields (up to 99%) and good diastereoselectivities (up to >95:5 dr). By carrying out the reaction under gold catalysis and utilizing alkynyl benzyl alcohols as electron-rich reaction partners, this approach provides a useful strategy for settling the challenges in oxa-[4+2] cyclization of para-quinone methide derivatives. This reaction serves as a good example for metal-catalyzed oxa-[4+2] cyclizations of quinone methides. In addition, it also offers a useful method for the construction of spiroacetal skeletons.

Enantioselective Construction of Cyclopenta[b]indole Scaffolds via the Catalytic Asymmetric [3 + 2] Cycloaddition of 2-Indolylmethanols with p-Hydroxystyrenes.

The catalytic asymmetric [3 + 2] cycloaddition of 2-indolylmethanols to p-hydroxystyrenes was established in the presence of a chiral phosphoramide, and this reaction provided chiral cyclopenta[b]indole scaffolds in generally high yields and with good enantioselectivities (up to 98% yield, 99:1 er). The control experiments demonstrated that the dual hydrogen-bonding activation mode of the chiral catalyst toward the two substrates played an important role in the reaction. In addition, the large-scale reaction indicated that this catalytic asymmetric [3 + 2] cycloaddition could be scaled up for the synthesis of chiral cyclopenta[b]indole derivatives.

Radical Deaminative ipso-Cyclization of 4-Methoxyanilines with 1,7-Enynes for Accessing Spirocyclohexadienone-Containing Cyclopenta[c]quinolin-4-ones.

A new C-center radical-triggered bicyclization cascade of N-tethered 1,7-enynes for forming 28 examples of biologically interesting spirocyclohexadienone-containing cyclopenta[c]quinolin-4-ones with two all-carbon quaternary stereocenters has been established under mild conditions. The in situ generated diazonium salts from 4-methoxyanilines and t-BuONO are served as 4-methoxyphenyl precursors without additional oxidant, enabling 6-exo-dig cyclization/5-exo-trig ipso-cyclization to construct three new C-C bonds through metal-free dearomatization. The reaction also features broad substrate scope, annulation efficiency, and high functional group tolerance.

Automatic schizophrenic discrimination on fNIRS by using complex brain network analysis and SVM.

BACKGROUND: Schizophrenia is a kind of serious mental illness. Due to the lack of an objective physiological data supporting and a unified data analysis method, doctors can only rely on the subjective experience of the data to distinguish normal people and patients, which easily lead to misdiagnosis. In recent years, functional Near-Infrared Spectroscopy (fNIRS) has been widely used in clinical diagnosis, it can get the hemoglobin concentration through the variation of optical intensity. METHODS: Firstly, the prefrontal brain networks were constructed based on oxy-Hb signals from 52-channel fNIRS data of schizophrenia and healthy controls. Then, Complex Brain Network Analysis (CBNA) was used to extract features from the prefrontal brain networks. Finally, a classier based on Support Vector Machine (SVM) is designed and trained to discriminate schizophrenia from healthy controls. We recruited a sample which contains 34 healthy controls and 42 schizophrenia patients to do the one-back memory task. The hemoglobin response was measured in the prefrontal cortex during the task using a 52-channel fNIRS system. RESULTS: The experimental results indicate that the proposed method can achieve a satisfactory classification with the accuracy of 85.5%, 92.8% for schizophrenia samples and 76.5% for healthy controls. Also, our results suggested that fNIRS has the potential capacity to be an effective objective biomarker for the diagnosis of schizophrenia. CONCLUSIONS: Our results suggested that, using the appropriate classification method, fNIRS has the potential capacity to be an effective objective biomarker for the diagnosis of schizophrenia.

Base-Promoted [4 + 1]/[3 + 1 + 1] Bicyclization for Accessing Functionalized Indeno[1,2-c]furans.

A novel three-component bicyclization strategy for the metal-free synthesis of densely functionalized indeno[1,2-c]furans with generally good yields has been established from readily accessible o-phthalaldehydes (OPA), isocyanides, and α-diazoketones. The reaction pathway involves aldol-type addition, 1,2-hydride shift, 5-exo-trig cyclization, and 1,4-addition as well as an oxo-5-exo-dig cyclization sequence, resulting in continuous multiple bond-forming events including C-C and C-O bonds to rapidly build up functional oxo-heterocycles.

Metal-Free Radical Haloazidation of Benzene-Tethered 1,7-Enynes Leading to Polyfunctionalized 3,4-Dihydroquinolin-2(1H)-ones.

A new cascade three-component haloazidation of benzene-tethered 1,7-enynes for the formation of biologically interesting azidylated 3,4-dihydroquinolin-2(1H)-ones has been achieved under mild and metal-free conditions using TMSN3 as a N3 source and NIS (or NBS or NCS) as a halogen source. The reaction pathway involves in situ-generated azidyl radical-triggered α,ß-conjugated addition/6-exo-dig cyclization/radical coupling sequence, resulting in successive multiple bond-forming events, including carbon-nitrogen, carbon-carbon, and carbon-halogen bonds to rapidly construct complex heterocyclic molecules. Furthermore, the resulting products would be useful building blocks in the discovery of lead compounds and other biologically interesting N3-containing heterocycles.

DDQ-Mediated Three-Component Dioxygenation of Alkenes.

A new DDQ-mediated three-component dioxygenation of alkenes has been established, providing a direct and metal-free access toward densely functionalized 4,5-dichloro-3-hydroxyphthalonitrile derivatives with generally good to excellent yields under mild conditions. During this process, DDQ plays dual roles as both a dehydrogenation reagent and a coupling partner, enabling oxidative coupling to form two C-O functionalities in a highly atom-economy fashion.

Synthesis of Allenyl Sulfones via a TBHP/TBAI-Mediated Reaction of Propargyl Alcohols with Sulfonyl Hydrazides.

A new TBHP/TBAI-mediated reaction of propargyl alcohols with sulfonyl hydrazides in the presence of HOAc has been established, in which a wide variety of allenyl sulfones were obtained in moderate to excellent yields. Mechanistic studies indicate that this transformation involves HOAc-promoted sulfonohydrazide intermediate formation, sequential C-O, C-N, and N-S bond cleavage, and C-S bond formation. Significantly, this sulfonohylation proceeds in a radical process and shows highly functional group compatibility and excellent regioselectivity, with a short reaction time and inexpensive reagents.

Base-promoted transannulation of heterocyclic enamines and 2,3-epoxypropan-1-ones: regio- and stereoselective synthesis of fused pyridines and pyrroles.

Base-promoted transannulation of heterocyclic enamines and 2,3-epoxypropan-1-ones has been successfully achieved, providing a new access to structurally diverse fused pyridines and pyrroles with excellent regio- and stereoselectivity. Treatment with N-aryl 4-aminofuran-2(5H)-ones and 2,3-epoxypropan-1-ones under microwave heating resulted in functional furo[3,2-b]pyridines in good yields. The N-aryl 4-aminopyrrol-2(5H)-ones bearing an electron-withdrawing group engaged in the reaction afforded pyrrolo[3,2-b]pyridines, whereas their counterparts with an electron-neutral or an electron-donating group underwent a different reaction pathway to form pyrrolo[3,2-b]pyrroles through C-C bond cleavage.

Domino reaction of arylglyoxals with pyrazol-5-amines: selective access to pyrazolo-fused 1,7-naphthyridines, 1,3-diazocanes, and pyrroles.

New multicomponent domino reactions of arylglyoxals with pyrazol-5-amines have been established, providing selective access to unprecedented pyrazolo-fused 1,7-naphthyridines, 1,3-diazocanes, and pyrroles (up to 52 examples). The unreported dipyrazolo-fused 1,7-naphthyridines were regioselectively synthesized through a special double [3 + 2 + 1] heteroannulation accompanied by direct C-C formation between two electrophilic sites of arylglyoxals. The unusual [3 + 3 + 1 + 1] cyclization resulted in 20 examples of novel dipyrazolo-fused 1,3-diazocanes, whereas pyrrolo[2,3-c]pyrazoles were obtained in good yields by varying arylglyoxals 1 and pyrazol-5-amines 2 in the ratio 1:2. Mechanisms of formation of these three new types of heterocycles are also proposed.

Organocatalytic chemo- and regioselective oxyarylation of styrenes via a cascade reaction: remote activation of hydroxyl groups.

The first organocatalytic oxyarylation of styrenes has been established through a cascade of vinylogous Michael addition/alkoxyl transfer reactions of o- or p-hydroxylstyrenes with quinone imine ketals. The process leads to a highly chemo- and regioselective oxyarylation of styrenes and provides access to m-alkylated anilines in generally high yields and excellent diastereoselectivity (up to 99% yield, >95:5 dr). An investigation of the reaction pathway revealed that the existence and position of the hydroxyl group of styrene played crucial roles in the cascade reaction, suggesting that the two reactants were simultaneously activated by binaphthyl-derived phosphoric acid via hydrogen bonding interactions and long-distance conjugative effects. In addition, the activating group of the hydroxyl functionality in the products can be easily removed or transformed, demonstrating the applicability and utility of this strategy in styrene oxyarylation and in the synthesis of styrene-based compounds.

Sensitive fluorescence detection of miRNA-124 in cardiomyocytes under oxidative stress using a nucleic acid probe.

MicroRNAs (miRNAs) are small noncoding RNAs of 18-25 bases. miRNAs are also important new biomarkers that can be used for disease diagnosis in the future. Studies have shown that miR-124 levels are significantly elevated during acute myocardial infarction (AMI) and play a key role in the cardiovascular system. A variety of methods have been established to detect myocardial infarction-related miRNAs. However, most require complex miRNA extraction and isolation, and these methods are virtually undetectable when RNA levels are low in the sample. It may lead to biased results. Thus, it is necessary to develop a technique that can detect miRNA without extracting it, which means that intracellular detection is of great significance. Here, we improved the traditional silicon spheres and obtained a biosensor that could effectively capture and detect specific noncoding nucleic acids through the layer-by-layer assembly method. The sensor is protected by hyaluronic acid so it can successfully escape the lysosome into the cell and achieve detection. With the help of a full-featured microplate reader, we determined that the detection limit of the biosensor could reach 1 fM, meeting the needs of intracellular detection. At the same time, we prepared an oxidative stress cardiomyocyte infarction model and successfully captured the overexpressed miR-124 in the infarcted cells to achieve in situ detection. This study could provide a new potential tool to develop miRNAs for sensitive diagnosis in AMI, and the proposed strategy implies its potential for biomedical research.

A multi-source heterogeneous medical data enhancement framework based on lakehouse.

Obtaining high-quality data sets from raw data is a key step before data exploration and analysis. Nowadays, in the medical domain, a large amount of data is in need of quality improvement before being used to analyze the health condition of patients. There have been many researches in data extraction, data cleaning and data imputation, respectively. However, there are seldom frameworks integrating with these three techniques, making the dataset suffer in accuracy, consistency and integrity. In this paper, a multi-source heterogeneous data enhancement framework based on a lakehouse MHDP is proposed, which includes three steps of data extraction, data cleaning and data imputation. In the data extraction step, a data fusion technique is offered to handle multi-modal and multi-source heterogeneous data. In the data cleaning step, we propose HoloCleanX, which provides a convenient interactive procedure. In the data imputation step, multiple imputation (MI) and the SOTA algorithm SAITS, are applied for different situations. We evaluate our framework via three tasks: clustering, classification and strategy prediction. The experimental results prove the effectiveness of our data enhancement framework.

Detecting overlapping protein complexes in PPI networks based on robustness.

BACKGROUND: Recently, large data sets of protein-protein interactions (PPI) which can be modeled as PPI networks are generated through high-throughput methods. And locally dense regions in PPI networks are very likely to be protein complexes. Since protein complexes play a key role in many biological processes, detecting protein complexes in PPI networks is one of important tasks in post-genomic era. However, PPI networks are often incomplete and noisy, which builds barriers to mining protein complexes. RESULTS: We propose a new and effective algorithm based on robustness to detect overlapping clusters as protein complexes in PPI networks. And in order to improve the accuracy of resulting clusters, our algorithm tries to reduce bad effects brought by noise in PPI networks. And in our algorithm, each new cluster begins from a seed and is expanded through adding qualified nodes from the cluster's neighbourhood nodes. Besides, in our algorithm, a new distance measurement method between a cluster K and a node in the neighbours of K is proposed as well. The performance of our algorithm is evaluated by applying it on two PPI networks which are Gavin network and Database of Interacting Proteins (DIP). The results show that our algorithm is better than Markov clustering algorithm (MCL), Clique Percolation method (CPM) and core-attachment based method (CoAch) in terms of F-measure, co-localization and Gene Ontology (GO) semantic similarity. CONCLUSIONS: Our algorithm detects locally dense regions or clusters as protein complexes. The results show that protein complexes generated by our algorithm have better quality than those generated by some previous classic methods. Therefore, our algorithm is effective and useful.

A novel three-component [5 + 1] heterocyclization leading to 2-azafluorenone synthesis and its polyfunctionalizations.

An efficient methodology for the synthesis of new and highly functionalized 2-azafluorenones via a three-component domino reaction involving C1-aryl acylation, C3-thiolation, and C4-cyanation has been developed. This domino reaction enables successful assembly of three new sigma bonds including a C-S bond and a C-N bond in a one-pot operation. Features of this strategy include the mild condition, convenient one-pot operation, and short reaction periods (15-30 min).

A novel domino strategy for forming poly-substituted quaternary imidazoles through a Cs2CO3-promoted aryl migration process.

A new domino strategy for the synthesis of highly functionalized quaternary imidazole derivatives via [3 + 2] heterocyclization, involving aryl migration and ring-opening of oxirane, has been developed. This domino reaction enables the successful assembly of three new sigma bonds including two C-N bonds in a simple operation. Features of this strategy include the mild conditions, convenient operation, and short reaction periods (15-20 min).

Online bridge crack monitoring with smart film.

Smart film crack monitoring method, which can be used for detecting initiation, length, width, shape, location, and propagation of cracks on real bridges, is proposed. Firstly, the fabrication of the smart film is developed. Then the feasibility of the method is analyzed and verified by the mechanical sensing character of the smart film under the two conditions of normal strain and crack initiation. Meanwhile, the coupling interference between parallel enameled wires of the smart film is discussed, and then low-frequency detecting signal and the custom communication protocol are used to decrease interference. On this basis, crack monitoring system with smart film is designed, where the collected crack data is sent to the remote monitoring center and the cracks are simulated and recurred. Finally, the monitoring system is applied to six bridges, and the effects are discussed.