Silicon (Si)-based materials have the highest capacity among the investigated anode materials and have been recognized as one of the most promising materials for lithium-ion batteries. However, it is ...still a significant challenge to obtain good performance for practical applications due to the huge volume change during the electrochemical process. To date, the most successful strategy is to introduce other components into Si to form composite or alloy materials. In this review, the recent progress in Si-based materials utilized in lithium-ion batteries is reviewed in terms of composite systems, nano-structure designs, material synthesis methods, and electrochemical performances. The merits and disadvantages of different Si-based materials, the understanding of the mechanisms behind the performance enhancement as well as the challenges faced in Si anodes are also discussed. We are trying to present a full scope of the Si-based materials, and help understand and design future structures of Si anodes in lithium-ion batteries.
•The paper reviewed the merits of silicon-based anodes in lithium ion batteries.•The mechanisms were discussed from in-situ TEM and first-principles simulation.•The challenges faced in silicon-based anodes were analyzed and forecast.
A bifunctional squaramide‐catalyzed one‐pot three‐component Michael/Mannich‐Michael/cyclization sequential cascade reaction for the construction of bispirooxindole‐spirooxindoles was developed in ...good yields with excellent stereoselectivities (up to >20:1 dr, 99% ee). A series of original cinnamoyl‐3‐ylideneoxindoles have been applied to this sequential cascade strategy for the first time. This new strategy provides a process for the enantioselective construction of bispirooxindole‐spirooxindoles with seven stereocenters, of which three are quaternary spiro‐stereocenters.
Cholesterol is dynamically transported among organelles, which is essential for multiple cellular functions. However, the mechanism underlying intracellular cholesterol transport has remained largely ...unknown. We established an amphotericin B-based assay enabling a genome-wide shRNA screen for delayed LDL-cholesterol transport and identified 341 hits with particular enrichment of peroxisome genes, suggesting a previously unappreciated pathway for cholesterol transport. We show dynamic membrane contacts between peroxisome and lysosome, which are mediated by lysosomal Synaptotagmin VII binding to the lipid PI(4,5)P2 on peroxisomal membrane. LDL-cholesterol enhances such contacts, and cholesterol is transported from lysosome to peroxisome. Disruption of critical peroxisome genes leads to cholesterol accumulation in lysosome. Together, these findings reveal an unexpected role of peroxisome in intracellular cholesterol transport. We further demonstrate massive cholesterol accumulation in human patient cells and mouse model of peroxisomal disorders, suggesting a contribution of abnormal cholesterol accumulation to these diseases.
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•Genome-wide RNAi screen reveals 341 genes important for cholesterol transport•Lysosomal Syt7 binds peroxisomal PI(4,5)P2 to bridge the organelle contact•Organelle contacts mediate cholesterol transport from lysosome to peroxisome•Cholesterol is accumulated in cells and animal models of peroxisomal disorders
Lysosome forms dynamic membrane contacts with peroxisome, and cholesterol is transported from lysosome to peroxisome. Massive cholesterol accumulates in the cells from patients with peroxisomal disorders.
It is quite an important and challenging problem for change detection (CD) from heterogeneous remote sensing images. The images obtained from different sensors (i.e., synthetic aperture radar (SAR) & ...optical camera) characterize the distinct properties of objects. Thus, it is impossible to detect changes by direct comparison of heterogeneous images. In this article, a new unsupervised change detection (USCD) method is proposed based on image translation. The cycle-consistent adversarial networks (CycleGANs) are employed to learn the subimage to subimage mapping relation using the given pair (i.e., before and after the event) of heterogeneous images from which the changes will be detected. Then, we can translate one image (e.g., SAR) from its original feature space (e.g., SAR) to another space (e.g., optical). By doing this, the pair of images can be represented in a common feature space (e.g., optical). The pixels with close pattern values in the before-event image may have quite different values in the after-event image if the change happens on some ones. Thus, we can generate the difference map between the translated before-event image and the original after-event image. Then, the difference map is divided into changed and unchanged parts. However, these detection results are not very reliable. We will select some significantly changed and unchanged pixel pairs from the two parts with the clustering technique (i.e., <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula>-means). These selected pixel pairs are used to learn a binary classifier, and the other pixel pairs will be classified by this classifier to obtain the final CD results. Experimental results on different real datasets demonstrate the effectiveness of the proposed USCD method compared with several other related methods.
Obesity is a critical risk factor for hepatocellular carcinoma (HCC). However, it remains unknown whether inhibition of de novo lipid biosynthesis can suppress HCC. In this study, we blocked the ...sterol regulatory element‐binding protein (SREBP) pathway, one of the key determinants of lipid homeostasis, by ablating 78‐kDa cell‐surface glycoprotein or SREBP cleavage‐activating protein in hepatocytes, as well as by administering a chemical compound called betulin. We found that either genetically or pharmacologically inhibiting the SREBP pathway dramatically reduced diethylnitrosamine‐induced HCC progression by down‐regulating tumor‐promoting cytokines, including interleukin (IL)‐6, tumor necrosis factor alpha, and IL‐1β. Conclusion: Inhibition of de novo lipid biosynthesis by suppressing the SREBP pathway prevents HCC. This study identifies a previously underappreciated role of the SREBP pathway in HCC and suggests a novel metabolic strategy to control liver cancer. (Hepatology 2017;65:1936‐1947).
The security threats caused by the popularity of Unmanned Aerial Vehicles (UAVs) have received much attention. In this paper, a UAV detection and identification system based on WiFi signal and radio ...frequency (RF) fingerprint is proposed. The system firstly conducts UAV detection and after the UAV is detected, fractal dimension (FD), axially integrated bispectra (AIB), and square integrated bispectra (SIB) are extracted as UAV RF fingerprints due to their applicability and reliability. Furthermore, we propose weighted AIB and SIB fingerprints to identify UAVs. Since the high dimensionality of AIB and SIB features, the principal component analysis (PCA) algorithm is applied to reduce the dimensionality of these two features. Then the neighborhood component analysis (NCA) algorithm is utilized to weight the dimensions of the two features, AIB and SIB. The extracted UAV fingerprints are stored as training data and test data, respectively. Finally, machine learning algorithms are utilized to identify UAVs. The identification results are as follows: In the indoor scenario, the average identification accuracy of three features (FD, AIB, SIB) are 100%, 97.23%, and 96.11%, respectively. In outdoor scenario, the identification accuracy of three features are 100%, 95.00%, and 93.50%, respectively.
A series of readily available 2‐(2‐oxoindolin‐3‐yl)malononitriles bearing multiple active sites were first used in asymmetric catalytic synthesis, which have been successfully applied to develop a ...bifunctional squaramide‐catalyzed cascade Michael/cyclization reaction strategy. Various cyclopentene‐bispirooxindoles with three continuous stereocenters, two of which are quaternary spiro‐stereocenters, were constructed in good yields with excellent stereoselectivities (up to >20:1 dr, >99% ee).
Hedgehog (Hh) has been known as the only cholesterol-modified morphogen playing pivotal roles in development and tumorigenesis. A major unsolved question is how Hh signaling regulates the activity of ...Smoothened (SMO). Here, we performed an unbiased biochemical screen and identified that SMO was covalently modified by cholesterol on the Asp95 (D95) residue through an ester bond. This modification was inhibited by Patched-1 (Ptch1) but enhanced by Hh. The SMO(D95N) mutation, which could not be cholesterol modified, was refractory to Hh-stimulated ciliary localization and failed to activate downstream signaling. Furthermore, homozygous SmoD99N/D99N (the equivalent residue in mouse) knockin mice were embryonic lethal with severe cardiac defects, phenocopying the Smo−/− mice. Together, the results of our study suggest that Hh signaling transduces to SMO through modulating its cholesterylation and provides a therapeutic opportunity to treat Hh-pathway-related cancers by targeting SMO cholesterylation.
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•SMO is covalently modified by cholesterol on the Asp95 (D95) residue•Cholesterol modification of SMO is inhibited by Ptch1 and enhanced by Hh•SMO cholesterylation is essential for Hh signaling and embryonic development
Xiao et al. identify that SMO is covalently modified by cholesterol. This modification is regulated by Ptch1 and Hh and is essential for Hh signaling. It suggests that Hh signaling transduces to SMO through modulating its cholesterylation and that targeting SMO cholesterylation may provide a therapeutic approach to treat Hh-pathway-related cancers.
Bone morphogenetic protein 2 (BMP2), a member of the transforming growth factor-β (TGF-β) super-family, is one of the main chondrogenic growth factors involved in cartilage regeneration. BMP2 is ...known to induce chondrogenic differentiation in various types of stem cells in vitro. However, BMP2 also induces osteogenic differentiation and endochondral ossification in mesenchymal stem cells (MSCs). Although information regarding BMP2-induced chondrogenic and osteogenic differentiation within the same system might be essential for cartilage tissue engineering, few studies concerning these issues have been conducted. In this study, BMP2 was identified as a regulator of chondrogenic differentiation, osteogenic differentiation and endochondral bone formation within the same system. BMP2 was used to regulate chondrogenic and osteogenic differentiation in stem cells within the same culture system in vitro and in vivo. Any changes in the differentiation markers were assessed. BMP2 was found to induce chondrogenesis and osteogenesis in vitro via the expression of Sox9, Runx2 and its downstream markers. According to the results of the subcutaneous stem cell implantation studies, BMP2 not only induced cartilage formation but also promoted endochondral ossification during ectopic bone/cartilage formation. In fetal limb cultures, BMP2 promoted chondrocyte hypertrophy and endochondral ossification. Our data reveal that BMP2 can spontaneously induce chondrogenic differentiation, osteogenic differentiation and endochondral bone formation within the same system. Thus, BMP2 can be used in cartilage tissue engineering to regulate cartilage formation but has to be properly regulated for cartilage tissue engineering in order to retain the cartilage phenotype.
Background
In pancreatic cancer, methods to predict early recurrence (ER) and identify patients at increased risk of relapse are urgently required.
Purpose
To develop a radiomic nomogram based on MR ...radiomics to stratify patients preoperatively and potentially improve clinical practice.
Study Type
Retrospective.
Population
We enrolled 303 patients from two medical centers. Patients with a disease‐free survival ≤12 months were assigned as the ER group (n = 130). Patients from the first medical center were divided into a training cohort (n = 123) and an internal validation cohort (n = 54). Patients from the second medical center were used as the external independent validation cohort (n = 126).
Field Strength/Sequence
3.0T axial T1‐weighted (T1‐w), T2‐weighted (T2‐w), contrast‐enhanced T1‐weighted (CET1‐w).
Assessment
ER was confirmed via imaging studies as MRI or CT. Risk factors, including clinical stage, CA19‐9, and radiomic‐related features of ER were assessed. In addition, to determine the intra‐ and interobserver reproducibility of radiomic features extraction, the intra‐ and interclass correlation coefficients (ICC) were calculated.
Statistical Tests
The area under the receiver‐operator characteristic (ROC) curve (AUC) was used to evaluate the predictive accuracy of the radiomic signature in both the training and test groups. The results of decision curve analysis (DCA) indicated that the radiomic nomogram achieved the most net benefit.
Results
The AUC values of ER evaluation for the radiomics signature were 0.80 (training cohort), 0.81 (internal validation cohort), and 0.78 (external validation cohort). Multivariate logistic analysis identified the radiomic signature, CA19‐9 level, and clinical stage as independent parameters of ER. A radiomic nomogram was then developed incorporating the CA19‐9 level and clinical stage. The AUC values for ER risk evaluation using the radiomic nomogram were 0.87 (training cohort), 0.88 (internal validation cohort), and 0.85 (external validation cohort).
Data Conclusion
The radiomic nomogram can effectively evaluate ER risks in patients with resectable pancreatic cancer preoperatively, which could potentially improve treatment strategies and facilitate personalized therapy in pancreatic cancer.
Level of Evidence: 4
Technical Efficacy: Stage 4
J. Magn. Reson. Imaging 2020;52:231–245.
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