Engineering of molecularly imprinted cavity within 3D covalent organic frameworks: An innovation for enhanced extraction and removal of microcystins.

The scarcity of selective adsorbents for efficient extraction and removal of microcystins (MCs) from complex samples greatly limits the precise detection and effective control of MCs. Three-dimensional covalent organic frameworks (3D COFs), characterized by their large specific surface areas and highly ordered rigid structure, are promising candidates, but suffer from lack of specific recognition. Herein, we design to engineer molecularly imprinted cavities within 3D COFs via molecularly imprinted technology, creating a novel adsorbent with exceptional selectivity, kinetics and capacity for the efficient extraction and removal of MCs. As proof-of-concept, a new CC bond-containing 3D COF, designated JNU-7, is designed and prepared for copolymerization with methacrylic acid, the pseudo template L-arginine and ethylene dimethacrylate to yield the JNU-7 based molecularly imprinted polymer (JNU-7-MIP). The JNU-7-MIP exhibits a great adsorption capacity (156 mg g-1) for L-arginine. Subsequently, the JNU-7-MIP based solid-phase extraction coupled with high performance liquid chromatography-mass spectrometry achieves low detection limit of 0.008 ng mL-1, wide linear range of 0.025-100 ng mL-1, high enrichment factor of 186, rapid extraction of 10 min, and good recoveries of 92.4%-106.5% for MC-LR. Moreover, the JNU-7-MIP can rapidly remove the MC-LR from 1 mg L-1 to levels (0.26-0.35 µg L-1) lower than the WHO recommended limit for drinking water (1 µg L-1). This work reveals the considerable potential of 3D COF based MIPs as promising adsorbents for the extraction and removal of contaminants in complex real samples.

Recent advances in membrane technologies applied in oil-water separation.

Effective treatment of oily wastewater, which is toxic and harmful and causes serious environmental pollution and health risks, has become an important research field. Membrane separation technology has emerged as a key area of investigation in oil-water separation research due to its high separation efficiency, low costs, and user-friendly operation. This review aims to report on the advances in the research of various types of separation membranes around emulsion permeance, separation efficiency, antifouling efficiency, and stimulus responsiveness. Meanwhile, the challenges encountered in oil-water separation membranes are examined, and potential research avenues are identified.

Size-Dependent Deformation and Competition H-Bond Site-Induced Individual Fluorescence Response of a Single-Crystal Three-Dimensional Covalent Organic Framework.

Understanding the individual fluorescence response mechanism of covalent organic frameworks (COFs) at a single-crystal level is of great significance for the rational design of COF-based microsensors but unreachable because all previous COF-based sensors are performed with average fluorescence response behavior of various sized polycrystalline COFs. Herein, we design to explore the fluorescence response of a monodisperse single-crystal COF and further reveal the individual heterogeneity of the response mechanism. Three-dimensional single-crystal COF-301 (SCOF-301) with an intramolecular H-bond-induced excited-state intramolecular proton-transfer effect is selected as a proof-of-concept SCOF. With ethanol, benzene, and ammonia as model analytes, three different deformation and competition H-bond site-induced fluorescence response mechanisms related to crystal size are revealed. Small single particles of SCOF-301 (SSCOF-301) exhibit a more flexible structure, leading to the dominant role of deformation in the fluorescence response of small-sized SSCOF-301. The decreasing flexibility of SSCOF-301 with the increase of crystal size results in involvement of competition of the H-bond site to the fluorescence response besides deformation. Further increase of the crystal size makes the large-sized SSCOF-301 difficult to deform; thus, the competition of the H-bond site dominates the fluorescence response. This work provides a deep understanding of the individual fluorescence response mechanism of COFs to guide the design of a functional COF sensor with suitable size and mechanism for different structural analytes.

Contrast-enhanced ultrasound evaluation of renal perfusion before angioplasty and its predictive value for hypertension.

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) is a common disease in the elderly population. OBJECTIVE: The aim was to develop a contrast-enhanced ultrasound (CEUS)-based model for predicting post-angioplasty improvement in hypertension in patients with severe ARAS. METHODS: Thirty-five patients with severe ARAS (⩾ 70%) were included in this study, and 42 renal arteries received percutaneous transluminal renal arterial stenting. An optimal integral formula was developed from pre-interventional color-coded duplex sonography (CCDS) and CEUS parameters using least absolute shrinkage and selection operator (LASSO) regression and receiver operating characteristic (ROC) curve analysis. A model for predicting short-term hypertension improvement was established using the integral formula and clinical risk factors. Bootstrapping was used for internal validation. RESULTS: Two integral formulas, LASSO.CCDS and LASSO.CEUS, were established. ROC curves of the two integral formulas showed that LASSO.CEUS was the better formula for predicting hypertension improvement (AUC 0.816, specificity 78.6%). Univariate and multivariate regression analyses showed that duration of hypertension (OR 0.841, P= 0.027), diabetes (OR = 0.019, P= 0.010), and LASSO.CEUS (OR 7.641, P= 0.052) were predictors of short-term hypertension improvement after interventional therapy. Using LASSO.CEUS combined with clinical risk factors, the following prediction model was established: logit (short-term improvement in hypertension) = 1.879-0.173 × hypertension duration - 3.961 × diabetes + 2.034 × LASSO.CEUS (AUC 0.939). CONCLUSIONS: The model established using CEUS parameters and clinical risk factors could predict hypertension improvement after interventional therapy, but further research and verification are needed.

Pure Covalent-Organic Framework Membrane as a Label-Free Biomimetic Nanochannel for Sensitive and Selective Sensing of Chiral Flavor Substances.

Chiral flavor substances play an important role in the human perception of different tastes. Here, we report a pure covalent-organic framework (COF) membrane nanochannel in combination with a chiral gold nanoparticles (AuNPs) selector for sensing chiral flavor substances. The pure COF membrane with a proper pore size is selected as the nanochannel, while l-cysteine-modified AuNPs (l-Cys-AuNPs) are used as the chiral selector. l-Cys-AuNPs show stronger binding to the S-enantiomer than the R-enantiomer, causing current reduction to different degrees for the R- and S-enantiomer to achieve chiral sensing due to the synergistic effect of the size exclusion of the COF nanochannel and the chiral selectivity of l-Cys-AuNPs. The developed COF membrane nanochannel sensing platform not only allows an easy balance of the permeability and selectivity, which is difficult to achieve in traditional polymer membrane nanochannel sensors, but also exhibits better chiral performance than commercial artificial anodic aluminum oxide (AAO) nanochannel sensors. The developed nanochannel sensor is successfully applied for sensing flavor enantiomers such as limonene, propanediol, methylbutyric acid, and butanol with the enantiomer excess values of 55.2% (propanediol) and 72.4% (limonene) and the low detection limits of 36 (limonene) and 71 (propanediol) ng L-1. This study provides a new idea for the construction of nanochannel platforms based on the COF for sensitive and selective chiral sensing.

Single-cell data analysis of malignant epithelial cell heterogeneity in lung adenocarcinoma for patient classification and prognosis prediction.

Lung cancer is one of the leading causes of cancer-related death. Most advanced lung adenocarcinoma (LUAD) patients have poor survival because of drug resistance and relapse. Neglecting intratumoral heterogeneity might be one of the reasons for treatment insensitivity, while single-cell RNA sequencing (scRNA-seq) technologies can provide transcriptome information at the single-cell level. Herein, we combined scRNA-seq and bulk RNA-seq data of LUAD and identified a novel cluster of malignant epithelial cells - KRT81+ malignant epithelial cells - associated with worse prognoses. Further analysis revealed that the hypoxia and EMT pathways of these cells were activated to predispose them to differentiate into metastatic lung adenocarcinoma cells. Finally, we also studied the role of these tumor cells in the immune microenvironment and their role in the classification and prognosis prediction of lung adenocarcinoma patients.

Irreversible fluorine covalent organic framework based probe nanoelectrospray ionization mass spectrometry for direct and rapid determination of perfluoroalkyl carboxylic acids.

Probe nanoelectrospray ionization mass spectrometry (PESI-MS) is practically desirable for rapid and ultra-sensitive analysis of trace contaminants in environment, but limited with the stable and selective probe coating. Herein, we show the design and preparation of irreversible fluorine-based covalent organic framework (TFPPA-F4) covalently bonded probe to couple with ESI-MS (TFPPA-F4-PESI-MS) for direct and rapid determination of perfluoroalkyl carboxylic acids (PFCAs) in environmental water. Chemical bonding coating of irreversible crystalline TFPPA-F4 not only improved stability of the probe, but also offered accessible multiple interactions including hydrophobic, hydrogen bonding and F-F interactions to promote the kinetics and selectivity for PFCAs. The proposed TFPPA-F4-PESI-MS realized rapid determination of PFCAs (about 4 min) with low limits of detection of 0.06-0.88 ng L-1 and wide linear range of 1-5000 ng L-1 (R2 of 0.9982-0.9998). Recoveries for the spiked lake and pond water were 85.9-111.1 %. TFPPA-F4 based probe can maintain the extraction performance after 100 times of extraction. This work shows the great potential of the irreversible covalent organic framework based PESI-MS in rapid and ultra-sensitive determination of contaminants in environmental samples.

Effect of Rolling Process and Aging on the Microstructure and Properties of Cu-1.0Cr-0.1Zr Alloy.

In order to study the effect of the rolling process and aging on the microstructure evolution and mechanical and tribological properties of the material, room-temperature rolling (RTR), cryogenic rolling (CR), and deep cryogenic treatment after rolling (RTR + DCT) experiments were carried out on a Cu-1.0Cr-0.1Zr alloy by a large plastic deformation process. Alloy plates were aged at 550 °C for 60 min. Different rolling processes and aging treatments have different effects on the microstructure and properties of alloy plates. The alloy plate is rolled and deformed, and the grains change from equiaxed to layered. Compared with RTR and RTR + DCT treatment, CR can promote the precipitation of the Cr phase and the degree of grain fragmentation is greater. After aging treatment, the Cu-Zr mesophase compounds in the microstructure increased, the alloys treated with CR and RTR + DCT appeared to be partially recrystallized, and the number of twins in the CR alloy plate was significantly more than that of RTR + DCT. The ultimate tensile strength of the alloy plate reached 553 MPa and the hardness reached 170 HV after cryogenic rolling with 90% deformation, which indicates that CR treatment can further improve the physical properties of the alloy plate. After aging at 550 °C for 60 min, the RTR 90% + DCT alloy plate has a tensile strength of 498 MPa and an elongation of 47.9%, which is three times that of the as-rolled alloy plate. From the research on the tribological properties of alloy plates, we learned that the main wear mechanisms in the wear forms of CR and RTR + DCT alloy plates are adhesive wear and abrasive wear. Adhesive wear is dominant in the early stage, while abrasive wear is the dominant mechanism in the later stage of wear. The friction coefficient of the CR 90% alloy plate in the TD direction is close to 0.55, and the wear rate is 2.9 × 10-4 mm3/Nm, indicating that the CR treatment further improves the wear resistance of the alloy plates.

Integrating Ordered Two-Dimensional Covalent Organic Frameworks to Solid-State Nanofluidic Channels for Ultrafast and Sensitive Detection of Mercury.

Grafting specific recognition moieties onto solid-state nanofluidic channels is a promising way for selective and sensitive sensing of analytes. However, the time-consuming interaction between recognition moieties and analytes is the main hindrance to the application of nanofluidic channel-based sensors in rapid detection. Here, we show the integration of ordered two-dimensional covalent organic frameworks (2D COFs) to solid-state nanofluidic channels to achieve rapid, selective, and sensitive detection of contaminants. As a proof of concept, a thiourea-linked 2D COF (JNU-3) as the recognition unit is covalently bonded on the stable artificial anodic aluminum oxide nanochannels (AAO) to fabricate a JNU-3@AAO-based nanofluidic sensor. The rapid and selective interaction of Hg(II) with the highly ordered channels of JNU-3 allows the JNU-3@AAO-based nanofluidic sensor to realize ultrafast and precise determination of Hg(II) (90 s) with a low limit of detection (3.28 fg mL-1), wide linear range (0.01-100 pg mL-1), and good precision (relative standard deviation of 3.8% for 11 replicate determination of 10 pg mL-1). The developed method was successfully applied to the determination of mercury in a certified reference material A072301c (rice powder), real water, and rice samples with recoveries of 90.4-99.8%. This work reveals the great potential of 2D COFs-modified solid-state nanofluidic channels as a sensor for the rapid and precise detection of contaminants in complicated samples.

miR-489-3p promotes malignant progression of non-small cell lung cancer through the inactivation of Wnt/ß-catenin signaling pathway via regulating USP48.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the most prevalent form of lung cancer globally, with average age of cancer patients becoming younger gradually. It is of significance to gain a comprehensive understanding of molecular mechanism underlying NSCLC. METHODS: Quantitative polymerase chain reaction (qPCR) and western blot were applied to measure RNA and protein levels separately. Functional assays and western blot were performed to determine the effects of miR-489-3p and USP48 on cell growth, migration and epithelial-mesenchymal transition (EMT) in NSCLC. TOP/FOP flash luciferase reporter assay was carried out to detect the activity of Wnt pathway. Besides, qPCR, RNA pulldown and luciferase reporter assays were conducted to probe into the target gene of miR-489-3p. Immunoprecipitation-western blot (IP-western blot) analysis was implemented to assess the effect of USP48 on the ubiquitination of ß-catenin. RESULTS: miR-489-3p hampers NSCLC cell proliferation, migration and EMT in vitro and NSCLC tumorigenesis and metastasis in vivo. Additionally, miR-489-3p inactivates Wnt/ß-catenin signaling pathway and regulates USP48 to inhibit the ubiquitination of ß-catenin. Moreover, USP48 propels the development of NSCLC cells. CONCLUSIONS: The current study demonstrated that miR-489-3p promotes the malignant progression of NSCLC cells via targeting USP48, which might offer a new perspective into NSCLC treatment.

Engineering linkage as functional moiety into irreversible thiourea-linked covalent organic framework for ultrafast adsorption of Hg(II).

Development of novel functionalized covalent organic frameworks (COFs) as adsorbent for removal of mercury from environment is of great significance, but the conventional strategies for functionalizing COFs always sacrifice porous properties and suppress the exposure of functional sites, which goes against the rapid adsorption of Hg(II). Here, we show the rational design and preparation of the first thiourea-linked COFs via engineering the COFs linkage as functional moiety for ultrafast and selective adsorption of Hg(II). Two thiourea-linked COFs JNU-3 and JNU-4 were prepared via tautomerism reaction of 1,3,5-triformylphloroglucinol with 1,4-phenylenebis(thiourea) and 1,4-biphenylenebis(thiourea), respectively. The thiourea serves as not only linkage to connect the building block into irreversible crystalline structure, but also functional moiety to give no occupation of the COF pore and full exposure to Hg(II) with strong affinity, offering the JNU-3 and JNU-4 large adsorption capacity (960 and 561 mg g-1, respectively) and ultrafast kinetics (equilibrium time of 10 s) for Hg(II). The proposed strategy for the design of functional COFs with inherent linkage as functional moiety largely promotes the performance of COFs for diverse applications.

Clinical validation of the use of prototype software for automatic cartilage segmentation to quantify knee cartilage in volunteers.

BACKGROUND: The cartilage segmentation algorithms make it possible to accurately evaluate the morphology and degeneration of cartilage. There are some factors (location of cartilage subregions, hydrarthrosis and cartilage degeneration) that may influence the accuracy of segmentation. It is valuable to evaluate and compare the accuracy and clinical value of volume and mean T2* values generated directly from automatic knee cartilage segmentation with those from manually corrected results using prototype software. METHOD: Thirty-two volunteers were recruited, all of whom underwent right knee magnetic resonance imaging examinations. Morphological images were obtained using a three-dimensional (3D) high-resolution Double-Echo in Steady-State (DESS) sequence, and biochemical images were obtained using a two-dimensional T2* mapping sequence. Cartilage score criteria ranged from 0 to 2 and were obtained using the Whole-Organ Magnetic Resonance Imaging Score (WORMS). The femoral, patellar, and tibial cartilages were automatically segmented and divided into subregions using the post-processing prototype software. Afterwards, all the subregions were carefully checked and manual corrections were done where needed. The dice coefficient correlations for each subregion by the automatic segmentation were calculated. RESULTS: Cartilage volume after applying the manual correction was significantly lower than automatic segmentation (P < 0.05). The percentages of the cartilage volume change for each subregion after manual correction were all smaller than 5%. In all the subregions, the mean T2* relaxation time within manual corrected subregions was significantly lower than in regions after automatic segmentation (P < 0.05). The average time for the automatic segmentation of the whole knee was around 6 min, while the average time for manual correction of the whole knee was around 27 min. CONCLUSIONS: Automatic segmentation of cartilage volume has a high dice coefficient correlation and it can provide accurate quantitative information about cartilage efficiently without individual bias. Advances in knowledge: Magnetic resonance imaging is the most promising method to detect structural changes in cartilage tissue. Unfortunately, due to the structure and morphology of the cartilages obtaining accurate segmentations can be problematic. There are some factors (location of cartilage subregions, hydrarthrosis and cartilage degeneration) that may influence segmentation accuracy. We therefore assessed the factors that influence segmentations error.

A robust framework combined saliency detection and image recognition for garbage classification.

Using deep learning to solve garbage classification has become a hot topic in computer version. The most widely used garbage dataset Trashnet only has garbage images with a white board as background. Previous studies based on Trashnet focus on using different networks to achieve a higher classification accuracy without considering the complex backgrounds which might encounter in practical applications. To solve this problem, we propose a framework that combines saliency detection and image classification to improve the generalization performance and robustness. A saliency network Salinet is adopted to obtain the garbage target area. Then, a smallest rectangle containing this area is created and used to segment the garbage. A classification network Inception V3 is used to identify the segmented garbage image. Images of the original Trashnet are fused with complex backgrounds of the other saliency detection datasets. The fused and original Trashnet are used together for training to improve the robustness to noises and complex backgrounds. Compared with the image classification networks and classic target detection algorithms, the proposed framework improves the accuracy of 0.50% - 15.79% on the testing sets fused with complex backgrounds. In addition, the proposed framework achieves the best performance with a gain of 4.80% in accuracy on the collected actual dataset. The comparisons prove that our framework is more robust to garbage classification in complex backgrounds. This method can be applied to smart trash cans to achieve automatic garbage classification.

Aptamer Self-Assembly-Functionalized Nanochannels for Sensitive and Precise Detection of Chloramphenicol.

Sensitive and precise determination of chloramphenicol (CAP) is of great significance for human health due to its high risk in trace amounts. Solid-state artificial nanochannels are expected to be highly promising sensing devices owing to single-molecule sensitivity, target-specific selectivity, and portability. Herein, we report an aptamer self-assembly-functionalized artificial nanochannel-based sensor for highly sensitive and precise determination of CAP. Aptamer self-assembly (AAs) served as the specific recognition component and were in situ grown on the surface of stable anodic aluminum oxide (AAO) nanochannels to develop an AAs@AAO nanochannel-based sensor. Selective interaction with CAP led to the disassembly of AAs and sensitive current change of AAs@AAO nanochannels, allowing sensitive and precise sensing of CAP in complex food samples. The developed AAs@AAO nanochannel-based sensor showed a wide linear range from 0.32 to 1600 pg. mL-1, low limit of detection (LOD) of 0.1 pg. mL-1, high precision with relative standard deviation of 2.9%, and quantitative recoveries of 93.4-102.2% for CAP in milk, milk powder, and honey samples. This work proposes a versatile nanochannel-based platform for facile, sensitive, and precise sensing of hazardous residues in food samples.

A smart municipal waste management system based on deep-learning and Internet of Things.

A proof-of-concept municipal waste management system was proposed to reduce the cost of waste classification, monitoring and collection. In this system, we utilize the deep learning-based classifier and cloud computing technique to realize high accuracy waste classification at the beginning of garbage collection. To facilitate the subsequent waste disposal, we subdivide recyclable waste into plastic, glass, paper or cardboard, metal, fabric and the other recyclable waste, a total of six categories. Deep-learning convolution neural networks (CNN) were applied to realize the garbage classification task. Here, we investigate seven state-of-the-art CNNs and data pre-processing methods for waste classification, whose accuracies of nine categories range from 91.9 to 94.6% in the validation set. Among these networks, MobileNetV3 has a high classification accuracy (94.26%), a small storage size (49.5 MB) and the shortest running time (261.7 ms). Moreover, the Internet of Things (IoT) devices which implement information exchange between waste containers and waste management center are designed to monitor the overall amount of waste produced in this area and the operating state of any waste container via a set of sensors. According to monitoring information, the waste management center can schedule adaptive equipment deployment and maintenance, waste collection and vehicle routing plans, which serves as an essential part of a successful municipal waste management system.

Prevalence and Clinical Characteristics of Fabry Disease in Chinese Patients With Hypertrophic Cardiomyopathy.

BACKGROUND: The prevalence of Fabry disease (FD) in Chinese patients with hypertrophic cardiomyopathy (HCM) is unclear. We aimed to evaluate the prevalence, clinical characteristics, and outcomes of FD in Chinese patients with HCM. METHODS: Of 217 patients with HCM, FD probands were screened by next-generation sequencing at Fuwai Hospital. Medical data from α-galactosidase A activity, electrocardiography, echocardiography, coronary angiography, cardiac magnetic resonance, pathological examination, and follow up was analyzed. RESULTS: Two FD probands were observed (0.93% of patients with HCM), both of which were diagnosed with symptomatic obstructive HCM at 49 years of age. One proband had a GLA mutation (c.887T>C [p.M296T]) with a late-onset cardiac variant, which was characterized by dual ventricular hypertrophy and conduction disease with a permanent pacemaker. The other patient had a GLA mutation (c.758T>C [p.I253T]) with a classic phenotype and dual ventricular hypertrophy, atrioventricular block, renal failure, and recurrent cerebral infarction. Both probands had late gadolinium enhancement mainly in the basal segment of the inferolateral wall. Follow up revealed no exertional symptoms or outflow obstruction after surgical septal myectomy in the two probands, and stable renal function was observed after 6 months of migalastat therapy in the later one. A family study revealed six female carriers and three sudden cardiac deaths. CONCLUSIONS: FD is not uncommon in Chinese patients with HCM. Multiple organic involvement, dual ventricular hypertrophy, and conduction disease provide clinical clues for suspected FD, and early genetic screening is necessary. Surgical septal myectomy and migalastat improve the long-term prognosis of patients with FD.

The effect on ion channel of different protonation states of E90 in channelrhodopsin-2: a molecular dynamics simulation.

Channelrhodopsin-2 (ChR2) is a cationic channel protein that has been extensively studied in optogenetics. The ion channel is opened via a series of proton transfers and H-bond changes during the photocycle but the detailed mechanism is still unknown. Molecular dynamics (MD) simulations with enhanced sampling were performed on the dark-adapted state (i.e., D470) and two photocycle intermediates (P1 500 and P2 390) to study the proton transfer path of the Schiff base and the subsequent conformational changes. The results suggest there are two possible proton transfer pathways from the Schiff base to proton acceptors (i.e., E123 or D253), depending on the protonation of E90. If E90 is protonated in the P1 500 state, the proton on the Schiff base will transfer to E123. The polyene chain of 13-cis retinal tilts and opens the channel that detours the blocking central gate (CG) and forms a narrow channel through the transmembrane helices (TM) 2, 3, 6 and 7. In contrast, if E90 deprotonates after retinal isomerization, the primary proton acceptor is D253, and an almost-open channel through TM1, 2, 3 and 7 is generated. The channel diameter is very close to the experimental value. The potential mean force (PMF) suggests that the free energy is extremely low for ions passing through this channel.

High-Temperature Oxidation Behavior of a Cu-Bearing 17Cr Ferritic Stainless Steel.

The isothermal oxidation behavior of 17Cr-0.85Si-0.5Nb-1.2Cu ferritic stainless steel in air was studied from 850°C to 1050°C by analyzing its weight gain after oxidation. The kinetic curves were plotted using the oxidation weight-gain data, and the structure, surface morphology, and element distribution of the oxide films were analyzed by XRD, SEM, and EDS. The results showed that the oxidation kinetics curves at 850°C and 950°C followed a parabolic law, and a continuous and dense oxide film composed of Cr2O3 and MnCr2O4, FeCr2O4, and Cu-Cr rich spinel was formed, which reveals that the steel displayed good oxidation resistance. When the temperature was increased to 1050°C, the oxidation kinetics curves gradually changed from parabolic to linear after 40 h exposure, which indicated that the oxidation resistance significantly worsened. A lower oxidation resistance was observed at 1050°C due to the formation of a large amount of Fe2O3 on the surface and the volatilization of the inner Cr2O3 layer.