ABSTRACT
Nanoscale periodic moiré patterns, for example those formed at the interface of a twisted bilayer of two-dimensional materials, provide opportunities for engineering the electronic properties of van der Waals heterostructures1-11. In this work, we synthesized the epitaxial heterostructure of 1T-TiTe2/1T-TiSe2 with various twist angles using molecular beam epitaxy and investigated the moiré pattern induced/enhanced charge density wave (CDW) states with scanning tunnelling microscopy. When the twist angle is near zero degrees, 2 × 2 CDW domains are formed in 1T-TiTe2, separated by 1 × 1 normal state domains, and trapped in the moiré pattern. The formation of the moiré-trapped CDW state is ascribed to the local strain variation due to atomic reconstruction. Furthermore, this CDW state persists at room temperature, suggesting its potential for future CDW-based applications. Such moiré-trapped CDW patterns were not observed at larger twist angles. Our study paves the way for constructing metallic twist van der Waals bilayers and tuning many-body effects via moiré engineering.
ABSTRACT
Strong electron correlation under two-dimensional limit is intensely studied in the transition metal dichalcogenides monolayers, mostly within their charge density wave (CDW) states that host a star of David period. Here, by using scanning tunneling microscopy and spectroscopy and density functional theory calculations with on-site Hubbard corrections, we study the VTe_{2} monolayer with a different 2sqrt[3]×2sqrt[3] CDW period. We find that the dimerization of neighboring Te-Te and V-V atoms occurs during the CDW transition, and that the strong correlation effect opens a Mott-like full gap at Fermi energy (E_{F}). We further demonstrate that such a Mott phenomenon is ascribed to the combination of the CDW transition and on-site Coulomb interactions. Our work provides a new platform for exploring Mott physics in 2D materials.
ABSTRACT
RNA-binding proteins (RBPs) dysfunction has been implicated in a number of diseases, and RBPs have traditionally been considered to be undruggable targets. Here, targeted degradation of RBPs is achieved based on the aptamer-based RNA-PROTAC, which consists of a genetically encoded RNA scaffold and a synthetic heterobifunctional molecule. The target RBPs can bind to their RNA consensus binding element (RCBE) on the RNA scaffold, while the small molecule can recruit E3 ubiquitin ligase to the RNA scaffold in a non-covalent manner, thereby inducing proximity-dependent ubiquitination and subsequent proteasome-mediated degradation of the target protein. Different RBPs targets, including LIN28A and RBFOX1, have been successfully degraded by simply replacing the RCBE module on the RNA scaffold. In addition, the simultaneous degradation of multiple target proteins has been realized by inserting more functional RNA oligonucleotides into the RNA scaffold.
Subject(s)
Proteins , Proteolysis Targeting Chimera , RNA , Proteasome Endopeptidase Complex/metabolism , Proteins/metabolism , Proteolysis , RNA/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitination , Aptamers, Nucleotide , Proteolysis Targeting Chimera/chemistryABSTRACT
BACKGROUND: MiRNAs can affect the radiosensitization of head and neck squamous cell carcinoma (HNSCC). We aimed to analyze the function of miR-125 family members in HNSCC using The Cancer Genome Atlas (TCGA) and determine their effect on radiation in laryngeal squamous cell cancer (LSCC). METHODS: First, we systematically analyzed the role of the miR-125 family in HNSCC using the TCGA database and found that miR-125a-5p is associated with radiotherapy. We then performed comprehensive enrichment analysis of miR-125a-5p and predicted target genes. Then, we performed transfection, cell proliferation assays, reverse transcription polymerase chain reaction, apoptosis assays, micronucleus tests, and western blotting on hep-2 cells selected with puromycin. RESULTS: MiR-125 family members exhibited significantly different expression in HNSCC. They were significantly associated with tumor-node-metastasis staging, clinical stages, and histological grades. Radiation therapy had a statistically effect on miR-125 family members, except miR-125a-3p. Moreover, miR-125a-5p was related to overall survival in LSCC. Thus, we predicted 110 target genes and seven hub genes of miR-125a-5p. The proliferation rate of cells transfected with lentivirus vector expressing miR-125a-5p was significantly reduced compared to the other groups. The radiation effect was enhanced in cells transfected with miR-125a-5p. The ratio of apoptotic cells transfected and exposed to X-rays (10 Gy) was distinctly higher than that of the Ad-control group. Western blotting analysis revealed that miR-125a-5p upregulated the apoptotic regulators P53 and rH2AX. Thus, miR-125a-5p may increase radiosensitivity in LSCC via upregulation of pro-apoptotic genes. CONCLUSIONS: MiR-125 family members could be prognostic biomarkers of HNSCC and improve HNSCC sensitivity to radiotherapy by activating P53. Upregulating miR-125a-5p via lentivirus vectors may be a novel strategy to strengthen the effect of radiotherapy on LSCC.
Subject(s)
Head and Neck Neoplasms , MicroRNAs , Humans , Squamous Cell Carcinoma of Head and Neck/genetics , Squamous Cell Carcinoma of Head and Neck/radiotherapy , Tumor Suppressor Protein p53/genetics , Cell Line, Tumor , MicroRNAs/genetics , Radiation Tolerance/genetics , Head and Neck Neoplasms/genetics , Head and Neck Neoplasms/radiotherapy , Gene Expression Regulation, Neoplastic , Cell Proliferation/geneticsABSTRACT
Lung adenocarcinoma (LUAD) is the most challenging neoplasm to treat in clinical practice. Ankyrin repeat domain 49 protein (ANKRD49) is highly expressed in several carcinomas; however, its pattern of expression and role in LUAD are not known. Tissue microarrays, immunohistochemistry, χ2 test, Spearman correlation analysis, Kaplan-Meier, log-rank test, and Cox's proportional hazard model were used to analyse the clinical cases. The effect of ANKRD49 on the LUAD was investigated using CCK-8, clonal formation, would healing, transwell assays, and nude mice experiment. Expressions of ANKRD49 and its associated downstream protein molecules were verified by real-time PCR, Western blot, immunohistochemistry, and/or immunofluorescence analyses. ANKRD49 expression was highly elevated in LUAD. The survival rate and Cox's modelling analysis indicated that there may be an independent prognostic indicator for LUAD patients. We also found that ANKRD49 promoted the invasion and migration in both in in vitro and in vivo assays, through upregulating matrix metalloproteinase (MMP)-2 and MMP-9 activities via the P38/ATF-2 signalling pathway Our findings suggest that ANKRD49 is a latent biomarker for evaluating LUAD prognosis and promotes the metastasis of A549 cells via upregulation of MMP-2 and MMP-9 in a P38/ATF-2 pathway-dependent manner.
Subject(s)
Adenocarcinoma of Lung , Lung Neoplasms , Muscle Proteins/metabolism , Activating Transcription Factor 2/metabolism , Adenocarcinoma of Lung/genetics , Adenocarcinoma of Lung/metabolism , Animals , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation , Gene Expression Regulation, Neoplastic , Lung Neoplasms/pathology , Matrix Metalloproteinase 9/metabolism , Mice , Mice, Nude , Signal TransductionABSTRACT
The efficient construction of cyclopropyl spiroindoline skeletons and the exploration of related follow-up synthetic transformations have elicited considerable interest amongst members of the chemistry community. Here, we describe a formal (2 + 1) annulation and three-component (1 + 1 + 1) cascade cyclisation via sulphur ylide cyclopropanation under mild conditions. The spiro-cyclopropyl iminoindoline moiety can be readily transformed into another medicinally interesting pyrrolo[3,4-c]quinoline framework through a novel rearrangement process.
Subject(s)
Sulfur , CyclizationABSTRACT
Described herein is the enantioselective synthesis of Hantzsch-type 1,4-dihydropyridines (DHPs), which are frequently contained in pharmaceuticals. Readily available symmetrical 1,4-DHPs were used as substrates, and the methyl group at the 2- or 6-position of the 1,4-DHP was selectively monobrominated by desymmetrizing enantioselective bromination. The inert C-H bond was converted into a versatile C-Br bond, which guaranteed the modification of the chiral 1,4-DHP derivatives with high efficiency. Furthermore, axially chiral 4-aryl pyridines were accessible by central-to-axial chirality conversion.
Subject(s)
Dihydropyridines , Catalysis , Dihydropyridines/chemistry , Halogenation , Phosphoric Acids , StereoisomerismABSTRACT
Asymmetric construction of α-carbolinones with easily available starting materials has recently attracted considerable attention from the synthesis community, and the development of effective catalysis for this target is in great demand. Here, a bifunctional Brønsted base catalyzed asymmetric [3 + 3] cyclization of indolin-2-imines and α,ß-unsaturated N-acylated succinimides was developed by using the strategy of noncovalent bonding catalysis. With this organocatalytic protocol, a variety of tetrahydro-α-carbolinones bearing different substituents were synthesized with up to 99% yield and up to 96:4 er.
ABSTRACT
The prevalence of Lynch syndrome (LS) varies significantly in different populations, suggesting that ethnic features might play an important role. We enrolled 3330 consecutive Chinese patients who had surgical resection for newly diagnosed colorectal cancer. Universal screening for LS was implemented, including immunohistochemistry for mismatch repair (MMR) proteins, BRAFV600E mutation test and germline sequencing. Among the 3250 eligible patients, MMR protein deficiency (dMMR) was detected in 330 (10.2%) patients. Ninety-three patients (2.9%) were diagnosed with LS. Nine (9.7%) patients with LS fulfilled Amsterdam criteria II and 76 (81.7%) met the revised Bethesda guidelines. Only 15 (9.7%) patients with absence of MLH1 on IHC had BRAFV600E mutation. One third (33/99) of the MMR gene mutations have not been reported previously. The age of onset indicates risk of LS in patients with dMMR tumors. For patients older than 65 years, only 2 patients (5.7%) fulfilling revised Bethesda guidelines were diagnosed with LS. Selective sequencing of all cases with dMMR diagnosed at or below age 65 years and only of those dMMR cases older than 65 years who fulfill revised Bethesda guidelines results in 8.2% fewer cases requiring germline testing without missing any LS diagnoses. While the prevalence of LS in Chinese patients is similar to that of Western populations, the spectrum of constitutional mutations and frequency of BRAFV600E mutation is different. Patients older than 65 years who do not meet the revised Bethesda guidelines have a low risk of LS, suggesting germline sequencing might not be necessary in this population.
Subject(s)
Colorectal Neoplasms, Hereditary Nonpolyposis/epidemiology , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , DNA Mismatch Repair/genetics , Mass Screening/methods , MutL Protein Homolog 1/genetics , Proto-Oncogene Proteins B-raf/genetics , Adult , Aged , Biomarkers, Tumor/genetics , China/epidemiology , Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis , DNA Copy Number Variations/genetics , Female , Genetic Predisposition to Disease/genetics , Germ-Line Mutation/genetics , Humans , Male , Middle Aged , PrevalenceABSTRACT
To reduce time delays during data collection and prolong the network lifetime in Wireless Rechargeable Sensor Networks (WRSNs), a type of high-efficiency data collection method based on Maximum Recharging Benefit (DCMRB) is proposed in this paper. According to the minimum number of the Mobile Data Collectors (MDCs), the network is firstly divided into several regions with the help of the Virtual Scan Line (VSL). Then, the MDCs and the Wireless Charging Vehicles (WCVs) are employed in each region for high efficient data collection and energy replenishment. In order to ensure the integrity of data collection and reduce the rate of packet loss, a speed adjustment scheme for MDC is also proposed. In addition, by calculating the adaptive threshold of the recharging request, those nodes with different energy consumption rates are recharged in a timely way that avoids their premature death. Finally, the limited battery capacity of WCVs and their energy consumption while moving are also taken into account, and an adaptive recharging scheme based on maximum benefit is proposed. Experimental results show that the energy consumption is effectively balanced in DCMRB. Furthermore, this can not only enhance the efficiency of data collection, but also prolong the network lifetime compared with the Energy Starvation Avoidance Online Charging scheme (ESAOC), Greedy Mobile Scheme based on Maximum Recharging Benefit (GMS-MRB) and First-Come First-Served (FCFS) methods.
ABSTRACT
A colorimetric and turn-on fluorescent probe 1 bearing triphenylamine-thiophene and dicyanovinyl groups has been synthesized and used to detect cyanide anion via a nucleophilic addition reaction. Probe 1 exhibited prominent selectivity and sensitivity towards CN- in aqueous media, even in the presence of other anions such as S2-, HS-, SO32-, S2O32-, S2O82-, I-, Br-, Cl-, F-, NO2-, N3-, SO42-, SCN-, HCO3-, CO32- and AcO-. Moreover, a low detection limit (LOD, 51 nM) was observed. In addition, good cell membrane permeability and low cytotoxicity to HeLa cells were also observed, suggesting its promising potential in bio-imaging.
Subject(s)
Colorimetry , Cyanides , Fluorescent Dyes , HeLa Cells , Humans , Spectrometry, FluorescenceABSTRACT
In the heart, glycosylation is involved in a variety of physiological and pathological processes. Cardiac glycosylation is dynamically regulated, which remains challenging to monitor in vivo. Here we describe a chemical approach for analyzing the dynamic cardiac glycome by metabolically labeling the cardiac glycans with azidosugars in living rats. The azides, serving as a chemical reporter, are chemoselectively conjugated with fluorophores using copper-free click chemistry for glycan imaging; derivatizing azides with affinity tags allows enrichment and proteomic identification of glycosylated cardiac proteins. We demonstrated this methodology by visualization of the cardiac sialylated glycans in intact hearts and identification of more than 200 cardiac proteins modified with sialic acids. We further applied this methodology to investigate the sialylation in hypertrophic hearts. The imaging results revealed an increase of sialic acid biosynthesis upon the induction of cardiac hypertrophy. Quantitative proteomic analysis identified multiple sialylated proteins including neural cell adhesion molecule 1, T-kininogens, and α2-macroglobulin that were upregulated during hypertrophy. The methodology may be further extended to other types of glycosylation, as exemplified by the mucin-type O-linked glycosylation. Our results highlight the applications of metabolic glycan labeling coupled with bioorthogonal chemistry in probing the biosynthesis and function of cardiac glycome during pathophysiological responses.
Subject(s)
Cardiomegaly/physiopathology , Myocytes, Cardiac/chemistry , N-Acetylneuraminic Acid/chemistry , Polysaccharides , Proteomics , Up-Regulation , Animals , Cardiac Imaging Techniques , Echocardiography, Doppler, Color , Membrane Glycoproteins/chemistry , Microscopy, Fluorescence , Polysaccharides/chemistry , Rats , Sialoglycoproteins/chemistryABSTRACT
Deep models, e.g., CNNs and Vision Transformers, have achieved impressive achievements in many vision tasks in the closed world. However, novel classes emerge from time to time in our ever-changing world, requiring a learning system to acquire new knowledge continually. Class-Incremental Learning (CIL) enables the learner to incorporate the knowledge of new classes incrementally and build a universal classifier among all seen classes. Correspondingly, when directly training the model with new class instances, a fatal problem occurs - the model tends to catastrophically forget the characteristics of former ones, and its performance drastically degrades. There have been numerous efforts to tackle catastrophic forgetting in the machine learning community. In this paper, we survey comprehensively recent advances in class-incremental learning and summarize these methods from several aspects. We also provide a rigorous and unified evaluation of 17 methods in benchmark image classification tasks to find out the characteristics of different algorithms empirically. Furthermore, we notice that the current comparison protocol ignores the influence of memory budget in model storage, which may result in unfair comparison and biased results. Hence, we advocate fair comparison by aligning the memory budget in evaluation, as well as several memory-agnostic performance measures. The source code is available at https://github.com/zhoudw-zdw/CIL_Survey/.
ABSTRACT
Urethral sphincter insufficiency following radical prostatectomy (RP) is a common cause of non-neurogenic stress urinary incontinence (SUI). Artificial urinary sphincter (AUS) insertion remains the standard of care for fit patients with SUI refractory to non-operative interventions. The proximal urethra is a common location for uncomplicated AUS placement. However, previous failed AUS, urethroplasty, or pelvic radiotherapy (RT) may compromise urethral tissue requiring technique modifications that optimise outcomes. In these situations, transcorporal cuff (TC) placement has been well described to facilitate continence restoration in men where there is no other feasible option other than urinary diversion or permanent incontinence. In the traditional TC approach, the procedure may be complicated by haematoma due to difficulty in completely closing the corporal defects behind the urethra. This narrated video demonstrates the tunical flap (TF) modification for transcorporal AUS implantation via a perineal and penoscrotal approach in patients with prior failed AUS placements secondary to urethral erosion. The TF technique for transcorporal AUS insertion provides circumferential reinforcement with tunica albuginea from the corpora cavernosa. Here, we show how this technique provides additional urethral support for compromised urethral tissue to help prevent cuff erosion. The TF preserves the corporal volume and does not limit candidacy for future penile prosthesis implantation. In our early results, there have been no postoperative haematoma formation with this technique.
ABSTRACT
Two-dimensional topological insulators hosting the quantum spin Hall effect have application potential in dissipationless electronics. To observe the quantum spin Hall effect at elevated temperatures, a wide band gap is indispensable to efficiently suppress bulk conduction. Yet, most candidate materials exhibit narrow or even negative band gaps. Here, via elegant control of van der Waals epitaxy, we have successfully grown monolayer ZrTe5 on a bilayer graphene/SiC substrate. The epitaxial ZrTe5 monolayer crystalizes in two allotrope isomers with different intralayer alignments of ZrTe3 prisms. Our scanning tunneling microscopy/spectroscopy characterization unveils an intrinsic full band gap as large as 254 meV and one-dimensional edge states localized along the periphery of the ZrTe5 monolayer. First-principles calculations further confirm that the large band gap originates from strong spin-orbit coupling, and the edge states are topologically nontrivial. These findings thus provide a highly desirable material platform for the exploration of the high-temperature quantum spin Hall effect.
ABSTRACT
PURPOSE: To compare bromfenac sodium 0.1%, fluorometholone 0.1% and dexamethasone 0.1% for the control of postoperative inflammation and prevention of cystoid macular edema (CME) after phacoemulsification. METHODS: Patients were randomized to receive bromfenac sodium 0.1% for 1 month (OBS1) or 2 months (OBS2), or fluorometholone 0.1% for 1 month (OFM) or dexamethasone 0.1% for 1 month (ODM). Best-corrected visual acuity, intraocular pressure, endothelial cell density, photon count value and retinal foveal thickness were measured. RESULTS: Mean photon count values were lower in the OBS1 and OBS2 groups compared with the ODM group during the first week. Bromfenac sodium cleared the ocular inflammation more rapidly than fluorometholone and dexamethasone. The foveal thickness was thinner in the second month and the incidence of CME was lower in the OBS1 and OBS2 groups compared with the OFM and ODM groups. CONCLUSION: Bromfenac sodium was more effective and safer than fluorometholone and dexamethasone as an anti-inflammatory, decreasing macular thickness and preventing CME in age-related cataract patients after cataract surgery.
Subject(s)
Benzophenones/administration & dosage , Bromobenzenes/administration & dosage , Dexamethasone/administration & dosage , Fluorometholone/administration & dosage , Macular Edema/prevention & control , Phacoemulsification/adverse effects , Uveitis/prevention & control , Aged , Aged, 80 and over , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Dose-Response Relationship, Drug , Drug Therapy, Combination , Female , Fluorescein Angiography , Follow-Up Studies , Fundus Oculi , Glucocorticoids/administration & dosage , Humans , Macular Edema/etiology , Male , Middle Aged , Ophthalmic Solutions , Postoperative Complications/prevention & control , Prospective Studies , Treatment Outcome , Uveitis/etiologyABSTRACT
An abnormal mechanical load is a pivotal inducer of endplate cartilage degeneration, which subsequently promotes intervertebral disc degeneration. Our previous study indicated that intermittent cyclic mechanical compression (ICMC) promotes endplate chondrocyte degeneration, but the mechanism underlying this effect is unclear. In this study, we investigated PTEN-induced kinase 1(PINK1) dependent mitophagy during ICMC-induced endplate chondrocyte degeneration. Furthermore, we determined whether NF-E2-related factor 2 (Nrf2) activation correlated with PINK1-dependent mitophagy regulation and increased oxidation resistance of endplate chondrocytes under ICMC application. First, we generated a mechanical compression-induced endplate chondrocyte degeneration model in vitro and in vivo. ICMC was found to promote endplate chondrocyte extracellular matrix degradation. PINK1-mediated mitophagy was suppressed in the ICMC-stimulated endplate chondrocytes, while increased mitochondrial reactive oxygen species generation suggested that mitophagy is involved in the protective effect of mechanical strain on endplate chondrocytes. Moreover, Nrf2 expression, interaction with Kelch-like ECH-associated protein (Keap1), and nuclear translocation were inhibited by ICMC. Nrf2 overexpression inhibited reactive oxygen species production and reversed ICMC-induced endplate chondrocyte degeneration. Transfection with PINK1 shRNA abolished this effect and partially blocked Nrf2-induced mitophagy. Our findings suggested that ICMC could inhibit the Nrf2/PINK1 signaling pathway to reduce the mitophagy levels which significantly promote oxidative stress and thereby endplate chondrocyte degeneration. Therapeutic regulation of the Nrf2/PINK1 signaling pathway may be an efficient anabolic strategy for inhibiting this process.
ABSTRACT
The itinerant ferromagnetism can be induced by a van Hove singularity (VHS) with a divergent density of states at Fermi level. Utilizing the giant magnified dielectric constant εr of SrTiO3(111) substrate with cooling, here we successfully manipulated the VHS in the epitaxial monolayer (ML) 1T-VSe2 film approaching to Fermi level via the large interfacial charge transfer, and thus induced a two-dimensional (2D) itinerant ferromagnetic state below 3.3 K. Combining the direct characterization of the VHS structure via angle-resolved photoemission spectroscopy (ARPES), together with the theoretical analysis, we ascribe the manipulation of VHS to the physical origin of the itinerant ferromagnetic state in ML 1T-VSe2. Therefore, we further demonstrated that the ferromagnetic state in the 2D system can be controlled through manipulating the VHS by engineering the film thickness or replacing the substrate. Our findings clearly evidence that the VHS can serve as an effective manipulating degree of freedom for the itinerant ferromagnetic state, expanding the application potentials of 2D magnets for the next-generation information technology.
Subject(s)
Asthma , Pulmonary Disease, Chronic Obstructive , Humans , Magnets , Cold TemperatureABSTRACT
The search for topological superconductivity (TSC) is currently an exciting pursuit, since non-trivial topological superconducting phases could host exotic Majorana modes. However, the difficulty in fabricating proximity-induced TSC heterostructures, the sensitivity to disorder and stringent topological restrictions of intrinsic TSC place serious limitations and formidable challenges on the materials and related applications. Here, we report a new type of intrinsic TSC, namely intrinsic surface topological superconductivity (IS-TSC) and demonstrate it in layered AuSn4 with Tc of 2.4 K. Different in-plane and out-of-plane upper critical fields reflect a two-dimensional (2D) character of superconductivity. The two-fold symmetric angular dependences of both magneto-transport and the zero-bias conductance peak (ZBCP) in point-contact spectroscopy (PCS) in the superconducting regime indicate an unconventional pairing symmetry of AuSn4. The superconducting gap and surface multi-bands with Rashba splitting at the Fermi level (EF), in conjunction with first-principle calculations, strongly suggest that 2D unconventional SC in AuSn4 originates from the mixture of p-wave surface and s-wave bulk contributions, which leads to a two-fold symmetric superconductivity. Our results provide an exciting paradigm to realize TSC via Rashba effect on surface superconducting bands in layered materials.