Design of Long-Life Wireless Near-Field Hydrogen Gas Sensor.

A compact wireless near-field hydrogen gas sensor is proposed, which detects leaking hydrogen near its source to achieve fast responses and high reliability. A semiconductor-type sensing element is implemented in the sensor, which can provide a significant response in 100 ms when stimulated by pure hydrogen. The overall response time is shortened by orders of magnitude compared to conventional sensors according to simulation results, which will be within 200 ms, compared with over 25 s for spatial concentration sensors under the worst conditions. Over 1 year maintenance intervals are enabled by wireless design based on the Bluetooth low energy protocol. The average energy consumption during a single alarm process is 153 µJ/s. The whole sensor is integrated on a 20 × 26 mm circuit board for compact use.

Defluorinative alkylation of 1-trifluoromethyl alkenes with alkyl radicals derived from visible light-induced deoxygenation of xanthate salts: synthesis of gem-difluoroalkenes.

Catalyst- and metal-free difluoroallylation of alkyl precursors with trifluoromethyl alkenes for the synthesis of gem-difluoroalkenes is appealing and challenging. We herein describe a visible light-induced approach that enables deoxygenative difluoroallylation of abundant alcohols via xanthate salts with trifluoromethyl alkenes, where xanthate salts work as a photoreductant and an alkylating reagent, avoiding the use of external catalysts. This one-pot method can accommodate primary, secondary and tertiary alcohols with good functionality tolerance and be successfully applied to the late-stage functionalization of natural products and drugs.

TRIM58 functions as a tumor suppressor in colorectal cancer by promoting RECQL4 ubiquitination to inhibit the AKT signaling pathway.

BACKGROUND: This study aimed to investigate the underlying molecular mechanisms of TRIM58 in the development of colorectal cancer (CRC). CRC is one of the most common cancers of the digestive tract worldwide. The ubiquitin-proteasome system regulates many oncogenic or tumor-suppressive proteins. TRIM58, an E3 ubiquitin ligase and a member of the tripartite motif protein family, is a potential prognostic marker that indicates poor prognosis in cancer. Currently, the precise molecular mechanisms for the TRIM58-mediated CRC progression remain unclear. METHODS: To examine the effects of TRIM58 on cell viability, cell cycle progression, and apoptosis in CRC, Cell Counting Kit-8 and flow cytometry assays were employed. The AKT inhibitor LY294002 was used to examine the effects of AKT signaling on TRIM58-mediated cell viability, cell cycle progression, and apoptosis in CRC. Additionally, Co-IP and ubiquitination assays were used to examine the correlation between TRIM58 and RECQL4. RESULTS: TRIM58 overexpression inhibited CRC cell viability and promoted cell cycle arrest and apoptosis, in which the TRIM58 knockdown demonstrated inversed effects via the AKT signaling pathway. TRIM58 inhibited RECQL4 protein levels through its ubiquitin ligase activity, and RECQL4 overexpression inhibited TRIM58 overexpression-mediated CRC cell viability, cell cycle progression, and apoptosis. The downregulation of TRIM58 and upregulation of RECOL4 were observed in human CRC tissue, and TRIM58 demonstrated antitumor effects in CRC-induced tumor growth in a mouse model. CONCLUSIONS: TRIM58 acts as a tumor suppressor in CRC through the promotion of RECQL4 ubiquitination and inhibition of the AKT signaling pathway and may be investigated for the successful treatment of CRC.

Distribution Adaptation and Classification Framework Based on Multiple Kernel Learning for Motor Imagery BCI Illiteracy.

A brain-computer interface (BCI) translates a user's thoughts such as motor imagery (MI) into the control of external devices. However, some people, who are defined as BCI illiteracy, cannot control BCI effectively. The main characteristics of BCI illiterate subjects are low classification rates and poor repeatability. To address the problem of MI-BCI illiteracy, we propose a distribution adaptation method based on multi-kernel learning to make the distribution of features between the source domain and target domain become even closer to each other, while the divisibility of categories is maximized. Inspired by the kernel trick, we adopted a multiple-kernel-based extreme learning machine to train the labeled source-domain data to find a new high-dimensional subspace that maximizes data divisibility, and then use multiple-kernel-based maximum mean discrepancy to conduct distribution adaptation to eliminate the difference in feature distribution between domains in the new subspace. In light of the high dimension of features of MI-BCI illiteracy, random forest, which can effectively handle high-dimensional features without additional cross-validation, was employed as a classifier. The proposed method was validated on an open dataset. The experimental results show that that the method we proposed suits MI-BCI illiteracy and can reduce the inter-domain differences, resulting in a reduction in the performance degradation of both cross-subjects and cross-sessions.

Fabricating efficient and stable quasi-3D and 3D/2D perovskite solar cells with 2D-sheets connected by inorganic type ionic-bond.

In this work, we report a novel two-dimensional (2D) (SrBr)2PbI4perovskite layered architecture, which were formed by the reaction of strontium bromide (SrBr2), strontium iodide (SrI2) and lead iodide (PbI2). Formation of 2D (SrBr)2PbI4was verified by small angle XRD peak at 6.4°, which corresponds to the layer distance of 13.78 Å. The best one of solar cells fabricated with Quasi-3D perovskite, (SrBr)2FA59Pb60I181(n= 60), showed a power conversion efficiency (PCE) of 18.46% and retained 95% of the initial PCE at 1000 h in the dry air. Further, the 2D (SrBr)2PbI4as the surface passivation layer on the 3D FAPbI3perovskite greatly reduced the defects at the perovskite/Spiro-OMeTAD interface, and the corresponding solar cells with FAPbI3/(SrBr)2PbI43D/2D structure achieved a PCE of 22.14% and over 90% retention of the original PCE at 1000 h. In short, this work provides an example of inorganic complex cations that can form 2D perovskites and achieve perovskite solar cells with high PCE and stabilization at the same time.

Hyperuricemia prevalence in healthy subjects and its relationship with cardiovascular target organ damage.

BACKGROUND AND AIM: Heterogeneous results have been obtained in the relationship between Uric Acid (UA) and Target Organ Damage (TOD). In the present study we sought to assess the prevalence of hyperuricemia in healthy subjects as well as the role of UA in determining TOD. We evaluated vascular, cardiac and renal TODs in the whole population as well as sub-grouped by gender. METHODS AND RESULTS: As many as 379 blood donors participated at the present analysis. TOD was evaluated as Pulse Wave Velocity (PWV), Left Ventricular Mass Index (LVMI) and carotid Intima-Media Thickness (IMT). Hyperuricemia was defined with the classic cut-off (>7.0 in men and >6.0 mg/dL in women) but also with a most recently defined one (5.6 mg/dL for both sex). Hyperuricemia was present in 6.3% of the whole population (7.3% males, 2.8% females) considering the classic cut-off, while, with the recently identified one, it was present in 28.2% of the whole population (37.3% males, 4.7% females). Despite all the evaluated TODs significantly correlated with UA, linear multivariate regression analysis showed that none of them, except for GFR, displayed UA as a significant covariate. Similar figures were found also when both correlation and linear regression analyses were repeated in the two genders separately. CONCLUSIONS: Hyperuricemia is an important problem also in healthy subjects and its prevalence could further increase if lower cut-off will be used. In this specific population UA is significantly associated with renal impairment while this was not the case for cardiac and vascular damage.

Metabolic syndrome is related to vascular structural alterations but not to functional ones both in hypertensives and healthy subjects.

BACKGROUND AND AIMS: Metabolic Syndrome (MS) has been related to an impairment in arterial structural and functional properties with heterogeneous results. In this paper we focused on the effects of MS on arterial carotid-femoral PWV and common carotid IMT in two different populations, one of hypertensive patients and one of healthy controls. METHODS AND RESULTS: We enrolled 816 consecutive HT and 536 healthy controls. Vascular structural (IMT) and functional (PWV) properties were evaluated. NCEP-ATP-III criteria were used for diagnosis of MS. MS was diagnosed in 26.9% and 6.9% in hypertensive and control subjects, respectively. PWV was similar in controls with and without MS (7.7 ± 1.9 vs 7.6 ± 1.1 m/s, p = 0.69), while IMT was higher in controls with than those without MS (0.64 ± 0.18 vs 0.57 ± 0.13 mm, p = 0.02). Hypertensives with MS were older (57.9 ± 12.2 vs 52.7 ± 14.1 years, p < 0.001) and showed higher PWV (9.0 ± 2.3 vs 8.4 ± 2.1 m/s, p = 0.001) and IMT (0.72 ± 0.22 vs 0.65 ± 0.17 mm, p < 0.001) than those without MS, however at the age-adjusted analysis only the difference in IMT was confirmed (p = 0.007). Regression models showed that MS was an independent determinant of IMT in both controls (ß = 0.08, p = 0.03) and hypertensives (ß = 0.08, p = 0.01), but not of PWV either in controls (ß = 0.006, p = 0.886 and ß = 0.04, p = 0.19, respectively). CONCLUSIONS: the main finding of our work is that MS is a significant determinant of IMT while this is not the case for PWV. This result have been confirmed both in hypertensive subjects and in healthy controls.

Copper-catalyzed aerobic cyclizations of tetrahydroisoquinolines with bromoketones and alkenes for the synthesis of 5,6-dihydropyrrolo[2,1-a]isoquinolines.

A new copper-catalyzed oxidative cyclization protocol was developed for the synthesis of 5,6-dihydropyrrolo[2,1-a]isoquinolines via a three-component reaction of tetrahydroisoquinolines with bromoketones and electron-deficient alkenes with air as a terminal oxidant. A variety of functional groups survived under the reaction conditions and the target products were obtained in good yields. This reaction features such advantages as eco-friendly reaction conditions, a simplified operation process and a broad substrate scope.

CuBr-Catalyzed Aerobic Decarboxylative Cycloaddition for the Synthesis of Indolizines under Solvent-Free Conditions.

An efficient synthesis of diversified indolizine derivatives was developed via CuBr-catalyzed reaction of pyridines, methyl ketones and alkenoic acids under solvent-free conditions in oxygen atmosphere. This synthesis involves cascade processes of copper-catalyzed bromination of the methyl ketone, 1,3-dipolar cycloaddition of the pyridinium ylide with the alkenoic acid, followed by oxidative decarboxylation and dehydrogenative aromatization of the primary cycloadduct. By this protocol, a wide range of indoliznes with different substitution patterns were selectively prepared in one pot from simple substrates in good to excellent yields.

A Cu(ii)-promoted tandem decarboxylative halogenation and oxidative diamination reaction of 2-aminopyridines with alkynoic acids for the synthesis of 2-haloimidazo[1,2-a]pyridines.

A copper-promoted cascade decarboxylative halogenation and oxidative diamination reaction sequence of 2-aminopyridines with alkynoic acids has been developed for the synthesis of 2-haloimidazo[1,2-a]pyridines. In this reaction, two C-N bonds and one C-halogen bond are formed in one pot, generating the desired products in good yields. This is the first report on the synthesis of 2-haloimidazo[1,2-a]pyridine derivatives from alkynoic acids.

Metal-Free Tandem Oxidative Coupling of Primary Alcohols with Azoles for the Synthesis of Hemiaminal Ethers.

A novel metal-free tandem oxidative coupling process for the synthesis of hemiaminal ethers has been developed. This protocol could be applied for the C-N bond formation of electron-deficient trizoles, tetrazoles, carbazoles and indazoles with primary alcohols.

A Multifunctional Sensor in Ternary Solution Using Canonical Correlations for Variable Links Assessment.

Accurately measuring the oil content and salt content of crude oil is very important for both estimating oil reserves and predicting the lifetime of an oil well. There are some problems with the current methods such as high cost, low precision, and difficulties in operation. To solve these problems, we present a multifunctional sensor, which applies, respectively, conductivity method and ultrasound method to measure the contents of oil, water, and salt. Based on cross sensitivity theory, these two transducers are ideally integrated for simplifying the structure. A concentration test of ternary solutions is carried out to testify its effectiveness, and then Canonical Correlation Analysis is applied to evaluate the data. From the perspective of statistics, the sensor inputs, for instance, oil concentration, salt concentration, and temperature, are closely related to its outputs including output voltage and time of flight of ultrasound wave, which further identify the correctness of the sensing theory and the feasibility of the integrated design. Combined with reconstruction algorithms, the sensor can realize the content measurement of the solution precisely. The potential development of the proposed sensor and method in the aspect of online test for crude oil is of important reference and practical value.

Metal-Free Catalytic Approach for Allylic C-H Amination Using N-Heterocycles via sp(3) C-H Bond Activation.

A versatile metal-free synthesis of allylic N-heterocycles has been developed using a TBAI/TBHP oxidation system. This general protocol could be applied for the C-N bond formation of electron-deficient phthalimides, imidazoles, triazoles, and sulfonamides with cyclic and acylic olefins. The practical use of the method is demonstrated by the amidation of functionalized biologically active substrates.

Manganese catalysed sulfenylation of N-methyl amides with arenesulfonyl hydrazides.

A convenient oxidative sulfenylation method for the formation of various sulfenyl amides has been reported. Arenesulfonyl hydrazine as a sulfur source in the presence of a manganese salt can activate the sp(3) C-H bond of N-methyl amides through a free-radical pathway using di-tert-butyl peroxide (DTBP).

Palladium-catalyzed direct and regioselective C-H acyloxylation of indolizines.

A direct and regioselective C1-acyloxylation of indolizines was developed via palladium-catalyzed C-H functionalization. A series of indolizines were successfully acyloxylated at the C1 position with the tolerance of a broad range of functional groups. In this reaction, high regioselectivity was achieved in the absence of a directing group. This work represents the first example of indolizine acyloxylation via C-H activation.

Copper(II)-catalyzed carbon-carbon triple bond cleavage of internal alkynes for the synthesis of annulated indolizines.

Cleavage of C≡C bond in butynedioates via copper(II)-catalyzed reaction has been achieved, leading to the synthesis of benzo[f]pyrido[1,2-a]indole-6,11-diones in high yields by one-pot three-component reactions. In this unprecedented C≡C bond cleavage reaction of internal alkynes, both fragments from the alkyne are successively incorporated into the products.

Proteomic analysis of the response to NaCl stress of Lactobacillus bulgaricus.

Lactobacillus bulgaricus is commonly used in dairy products as a starter culture. Its viability during freeze-drying is of commercial interest. Here a significant (p < 0.05) improvement in survival rate of L. bulgaricus ATCC 11842 was achieved during freeze-drying when it was prestressed with 2 % (w/v) NaCl for 2 h in the late growth phase. To understand the mechanism of this stress-related viability improvement in L. bulgaricus, protein synthesis was analyzed by 2D difference gel electrophoresis. Nine protein spots were significantly altered by NaCl and were subsequently identified by peptide mass fingerprinting. The functions of the proteins included stress-related protein synthesis, amino acid biosynthesis, nucleotide biosynthesis, sugar metabolism, transport systems, and vitamin biosynthesis. These findings provide a considerable background regarding the NaCl stress response of L. bulgaricus.

EEG-DG: A Multi-Source Domain Generalization Framework for Motor Imagery EEG Classification.

Motor imagery EEG classification plays a crucial role in non-invasive Brain-Computer Interface (BCI) research. However, the performance of classification is affected by the non-stationarity and individual variations of EEG signals. Simply pooling EEG data with different statistical distributions to train a classification model can severely degrade the generalization performance. To address this issue, the existing methods primarily focus on domain adaptation, which requires access to the test data during training. This is unrealistic and impractical in many EEG application scenarios. In this paper, we propose a novel multi-source domain generalization framework called EEG-DG, which leverages multiple source domains with different statistical distributions to build generalizable models on unseen target EEG data. We optimize both the marginal and conditional distributions to ensure the stability of the joint distribution across source domains and extend it to a multi-source domain generalization framework to achieve domain-invariant feature representation, thereby alleviating calibration efforts. Systematic experiments conducted on a simulative dataset, BCI competition IV 2a, 2b, and OpenBMI datasets, demonstrate the superiority and competitive performance of our proposed framework over other state-of-the-art methods. Specifically, EEG-DG achieves average classification accuracies of 81.79% and 87.12% on datasets IV-2a and IV-2b, respectively, and 78.37% and 76.94% for inter-session and inter-subject evaluations on dataset OpenBMI, which even outperforms some domain adaptation methods. Our code is available at https://github.com/zxchit2022/EEG-DG for evaluation.

Copper(II)-catalyzed sequential C,N-difunctionalization of 1,4-naphthoquinone for the synthesis of benzo[f]indole-4,9-diones under base-free condition.

An efficient synthesis of benzo[f]indole-4,9-diones has been achieved by copper(II)-catalyzed naphthoquinone sequential C,N-difunctionalization reactions with ß-enaminones. New C-C and C-N bonds are easily formed in the reaction course. Copper(II) salt plays a dual role as Lewis acid and oxidative catalyst, and O2 acts as the terminal oxidant. The advantage of this reaction is the high atom economy with broad substrate scope and excellent yields. The reaction can be scaled up to using at least grams of substrates.

FBLPF-ABOW: An Effective Method for Blink Artifact Removal in Single-Channel EEG Signal.

OBJECTIVE: The latest development in low-cost single-channel Electroencephalography (EEG) devices is gaining widespread attention because it reduces hardware complexity. Discrete wavelet transform (DWT) has been a popular solution to eliminate the blink artifacts in EEG signals. However, the existing DWT-based methods share the same wavelet function among subjects, which ignores the individual difference. To remedy this deficiency, this article proposes a novel approach to eliminate the blink artifacts in single-channel EEG signals. METHODS: Firstly, the forward-backward low-pass filter (FBLPF) and a fixed-length window are used to detect blink artifact intervals. Secondly, the adaptive bi-orthogonal wavelet (ABOW) is constructed based on the most representative blink signal. Thirdly, these detected signals are filtered by ABOW-DWT. The DWT's decomposition depth is automatically chosen by a similarity-based method. RESULTS: Compared to eight state-of-the-art methods, experiments on semi-simulated and real EEG signals demonstrate the proposed method's superiority in removing the blink artifacts with less neural information loss. SIGNIFICANCE: To filter the blink artifacts in single-channel EEG signals, the innovative idea of constructing an adaptive wavelet function based on the signal characteristics rather than using the conventional wavelet is proposed for the first time.