Two-dimensional (2D) materials have been studied extensively as monolayers, vertical or lateral heterostructures. To achieve functionalization, monolayers are often patterned using soft lithography ...and selectively decorated with molecules. Here we demonstrate the growth of a family of 2D materials that are intrinsically patterned. We demonstrate that a monolayer of PtSe
can be grown on a Pt substrate in the form of a triangular pattern of alternating 1T and 1H phases. Moreover, we show that, in a monolayer of CuSe grown on a Cu substrate, strain relaxation leads to periodic patterns of triangular nanopores with uniform size. Adsorption of different species at preferred pattern sites is also achieved, demonstrating that these materials can serve as templates for selective self-assembly of molecules or nanoclusters, as well as for the functionalization of the same substrate with two different species.
Topological materials with exotic quantum properties are promising candidates for quantum spin electronics. Different classes of topological materials, including Weyl semimetal, topological ...superconductor, topological insulator and Axion insulator, etc., can be connected to each other via quantum phase transition. For example, it is believed that a trivial band insulator can be twisted into topological phase by increasing spin-orbital coupling or changing the parameters of crystal lattice. With the results of LDA calculation and measurement by angle-resolved photoemission spectroscopy (ARPES), we demonstrate in this work that the electronic structure of SrSn2As2 single crystal has the texture of band inversion near the critical point. The results indicate the possibility of realizing topological quantum phase transition in SrSn2As2 single crystal and obtaining different exotic quantum states.
In recent decades, wintertime sea surface temperatures off the eastern coast of China have steadily increased. The warming is accompanied by on‐coast wind convergence across East China Sea and by ...stronger northeasterly wind which is spatially inhomogeneous being greatest in the Taiwan Strait. Strong winds favor more frequent cross‐shelf currents and vigorous spreading of heat from the Kuroshio, which warms the coastal sea in a positive feedback loop. The process also weakens the East Asian winter monsoon over eastern China, contributing to its decoupling from the recent rebound of the Siberian High.
Key Points
Recent warming off coastal China is accompanied by stronger northeasterly wind
Stronger winter monsoon spreads heat from Kuroshio producing air‐sea response
The increased wind is detached from the recent rebound of the Siberian High
Although significant advances have recently been made in the diagnosis and treatment of cervical carcinoma, the long-term survival rate for advanced cervical cancer remains low. Therefore, an urgent ...need exists to both uncover the molecular mechanisms and identify potential therapeutic targets for the treatment of cervical cancer. MicroRNAs (miRNAs) have important roles in cancer progression and could be used as either potential therapeutic agents or targets. miR-506 is a component of an X chromosome-linked miRNA cluster. The biological functions of miR-506 have not been well established. In this study, we found that miR-506 expression was downregulated in approximately 80% of the cervical cancer samples examined and inversely correlated with the expression of Ki-67, a marker of cell proliferation. Gain-of-function and loss-of-function studies in human cervical cancer, Caski and SiHa cells, demonstrated that miR-506 acts as a tumor suppressor by inhibiting cervical cancer growth in vitro and in vivo. Further studies showed that miR-506 induced cell cycle arrest at the G1/S transition, and enhanced apoptosis and chemosensitivity of cervical cancer cell. We subsequently identified Gli3, a hedgehog pathway transcription factor, as a direct target of miR-506 in cervical cancer. Furthermore, Gli3 silencing recapitulated the effects of miR-506, and reintroduction of Gli3 abrogated miR-506-induced cell growth arrest and apoptosis. Taken together, we conclude that miR-506 exerts its anti-proliferative function by directly targeting Gli3. This newly identified miR-506/Gli3 axis provides further insight into the pathogenesis of cervical cancer and indicates a potential novel therapeutic agent for the treatment of cervical cancer.
Amelogenesis imperfecta (AI) is a diverse group of inherited diseases featured by various presentations of enamel malformations that are caused by disturbances at different stages of enamel ...formation. While hypoplastic AI suggests a thickness defect of enamel resulting from aberrations during the secretory stage of amelogenesis, hypomaturation AI indicates a deficiency of enamel mineralization and hardness established at the maturation stage. Mutations in ENAM, which encodes the largest enamel matrix protein, enamelin, have been demonstrated to cause generalized or local hypoplastic AI. Here, we characterized 2 AI families with disparate hypoplastic and hypomaturation enamel defects and identified 2 distinct indel mutations at the same location of ENAM, c588+1del and c.588+1dup. Minigene splicing assays demonstrated that they caused frameshifts and truncation of ENAM proteins, p.Asn197Ilefs*81 and p.Asn197Glufs*25, respectively. In situ hybridization of Enam on mouse mandibular incisors confirmed its restricted expression in secretory stage ameloblasts and suggested an indirect pathogenic mechanism underlying hypomaturation AI. In silico analyses indicated that these 2 truncated ENAMs might form amyloid structures and cause protein aggregation with themselves and with wild-type protein through the added aberrant region at their C-termini. Consistently, protein secretion assays demonstrated that the truncated proteins cannot be properly secreted and impede secretion of wild-type ENAM. Moreover, compared to the wild-type, overexpression of the mutant proteins significantly increased endoplasmic reticulum stress and upregulated the expression of unfolded protein response (UPR)–related genes and TNFRSF10B, a UPR-controlled proapoptotic gene. Caspase, terminal deoxynucleotidyl transferase UTP nick-end labeling (TUNEL), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays further revealed that both truncated proteins, especially p.Asn197Ilefs*81, induced cell apoptosis and decreased cell survival, suggesting that the 2 ENAM mutations cause AI through ameloblast cell pathology and death rather than through a simple loss of function. This study demonstrates that an ENAM mutation can lead to generalized hypomaturation enamel defects and suggests proteinopathy as a potential pathogenesis for ENAM-associated AI.
Submicron aerosol particles (PM1) were measured in-situ using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer during the summer 2009 Field Intensive Study at Queens College in New York, ...NY. Organic aerosol (OA) and sulfate are the two dominant species, accounting for 54% and 24%, respectively, of the total PM1 mass. The average mass-based size distribution of OA presents a small mode peaking at ~150 nm (Dva) and an accumulation mode (~550 nm) that is internally mixed with sulfate, nitrate, and ammonium. The diurnal cycles of both sulfate and OA peak between 01:00–02:00 p.m. EST due to photochemical production. The average (±σ) oxygen-to-carbon (O/C), hydrogen-to-carbon (H/C), and nitrogen-to-carbon (N/C) ratios of OA in NYC are 0.36 (±0.09), 1.49 (±0.08), and 0.012 (±0.005), respectively, corresponding to an average organic mass-to-carbon (OM/OC) ratio of 1.62 (±0.11). Positive matrix factorization (PMF) of the high resolution mass spectra identified two primary OA (POA) sources, traffic and cooking, and three secondary OA (SOA) components including a highly oxidized, regional low-volatility oxygenated OA (LV-OOA; O/C = 0.63), a less oxidized, semi-volatile SV-OOA (O/C = 0.38) and a unique nitrogen-enriched OA (NOA; N/C = 0.053) characterized with prominent CxH2x + 2N+ peaks likely from amino compounds. Our results indicate that cooking and traffic are two distinct and mass-equivalent POA sources in NYC, together contributing ~30% of the total OA mass during this study. The OA composition is dominated by secondary species, especially during high PM events. SV-OOA and LV-OOA on average account for 34% and 30%, respectively, of the total OA mass. The chemical evolution of SOA in NYC appears to progress with a continuous oxidation from SV-OOA to LV-OOA, which is further supported by a gradual increase of O/C ratio and a simultaneous decrease of H/C ratio in total OOA. Detailed analysis of NOA (5.8% of OA) presents evidence that organic nitrogen species such as amines might have played an important role in the atmospheric processing of OA in NYC, likely involving both acid-base chemistry and photochemistry. In addition, analysis of air mass trajectories and satellite imagery of aerosol optical depth (AOD) indicates that the high potential source regions of secondary sulfate and aged OA are mainly located in regions to the west and southwest of the city.
Aim
To investigate whether the timing of root canal treatment (primary aim) or other endodontic parameters (secondary aim) is associated with the survival probability of autotransplanted third ...molars, using a nationwide population‐based database.
Methodology
A total of 1811 third molars autotransplanted between 2000 and 2013 met the inclusion criteria and were followed until the end of 2016. The teeth were classified into three groups on the basis of timing between root canal treatment and the autotransplantation: preoperative, extraoral and postoperative treatment groups. Univariate and multivariate Cox proportional hazards models were used to estimate the association between the timing of root canal treatment and the risk of tooth extraction after autotransplantation.
Results
Of the 1811 autotransplanted third molars, 462 were extracted, yielding a 17‐year survival probability of 0.578. The survival probability of autotransplanted teeth that received postoperative root fillings after 17 years was 0.583, which was significantly higher than the 0.434 and 0.566 for teeth that received preoperative and extraoral root fillings, respectively (P = 0.0013). After adjustment for potential confounding factors, teeth that received postoperative root fillings were associated with a significantly lower tooth extraction hazard ratio (HR) compared with those that received extraoral root fillings (adjusted HR, 1.43; 95% confidence interval CI, 1.14–1.78) and those that received preoperative root fillings (adjusted HR, 2.13; 95% CI, 1.19–3.82). Furthermore, the use of a rubber dam during postoperative root filling was associated with a significantly lower extraction rate after autotransplantation (adjusted HR, 0.54; 95% CI, 0.43–0.69).
Conclusions
Postoperative root canal treatment resulted in a significantly lower extraction rate than did preoperative or extraoral root canal treatment amongst autotransplanted third molars during a mean follow‐up period of 8.33 years. Rubber dam use is recommended during postoperative root canal treatment to improve the outcomes of autotransplantation.
The open-cell porous Ti-6Al-4V structure, intended to be applied as replacement for human cortical and cancellous bone, are fabricated by selective laser melting (SLM). The computer aided design ...(CAD) was used to design porous structures in various porosity levels from 40% to 80% and with pore sizes from 600 to 1000 μm, in order to fit the bone-tissue in-growth. The SLM porous samples with 40% to 70% porosity matched well with the CAD structure, but the 80% porosity one was found to be difficult to achieve the design. In comparison with the CAD structures and the SLM samples, there are minor discrepancies in terms of pore size and ligament width, mainly a result of laser beam broadening. To achieve more precise SLM porous morphologies, further reduction of powder size and laser beam diameter would be necessary. The measured data on the Young's modulus and yield strength of the SLM porous samples can be roughly estimated by the Gibson and Ashby model. The sample with 67% porosity was found to match best with human bone, with Young's modulus of 15 GPa and yield stress of 129 MPa, preventing from the risk of stress shielding effect.
•The porous Ti-6Al-4V foams are prepared by selective laser melting.•Minor discrepancies between CAD and SLM are due to laser beam broadening.•The 67% porosity sample matches with human bone avoiding stress shielding effect.
High-energy photons from the Crab Nebula
The Crab Nebula contains a pulsar that excites the surrounding gas to emit high-energy radiation. The combination of the pulsar's youth and nearby location ...makes the nebula the brightest gamma-ray source in the sky. The LHAASO Collaboration report observations of this source at energies of tera– to peta–electron volts, extending the spectrum of this prototypical object. They combine these data with observations at lower energies to model the physics of the emission process. The multiwave-length data can be explained by a combination of synchrotron radiation and inverse Compton scattering.
Science
, abg5137, this issue p.
425
Detection of the Crab Nebula at peta–electron volt energies constrains the gamma-ray emission mechanism.
The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar’s rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10
−4
to 1.1 peta–electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta–electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron’s size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta–electron volt electrons, 2.5 × 10
36
ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta–electron volt protons to the production of the highest-energy gamma rays.
Purpose
Numerous biomarkers of diabetic kidney disease (DKD) are associated with renal prognosis but head-to-head comparisons are lacking. This study aimed to examine the association of soluble tumor ...necrosis factor receptor type 1 (sTNFR1), fibroblast growth factor 21 (FGF-21), endocan, N-terminal pro-brain natriuretic peptide (NT-pro-BNP), and renal outcomes of patients with or without clinical signs of DKD.
Methods
A total of 312 patients were enrolled in a prospective observational study that excluded individuals with estimated glomerular filtration rates (eGFR) < 30 mL/min/1.73 m
2
. Composite renal outcomes included either a > 30% decline in eGFR and worsening albuminuria or both from consecutive tests of blood/urine during a 3.5-year follow-up period.
Results
Higher sTNFR1 and FGF-21, rather than endocan and NT-pro-BNP, levels were associated with renal outcomes but the significance was lost after adjusting for confounders. However, sTNFR1 levels ≥ 9.79 pg/dL or FGF-21 levels ≥ 1.40 pg/dL were associated with renal outcomes after adjusting for the confounders (hazard ration HR 2.76, 95% confidence interval CI 1.36–5.60,
p
= 0.005 for sTNFR1 level; HR 1.95, 95% CI 1.03–3.69,
p
= 0.03 for FGF-21 level). The combination of both levels exhibited even better association with renal outcomes than did either one alone (adjusted HR 4.45, 95% CI 1.86–10.65,
p
= 0.001). The results were consistent among patients with preserved renal function and normoalbuminuria.
Conclusion
Both sTNFR1 and FGF-21 levels were associated with renal outcomes of in patients with type 2 diabetes, and the combination of the abovementioned markers exhibits better predictability.
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