A biomimetic (titin protein molecular structure) strategy is reported for preparing transparent and healable elastomers featuring supertoughness (345 MJ m−3) and high tensile strength (44 MPa) after ...self‐healing enabled by hierarchical (single, double, and quadruple) hydrogen‐bonding moieties in the polymer backbone. The rigid domain containing hierarchical H‐bonds formed with urethane, urea, and 2‐ureido‐41H‐pyrimidinone groups leads to a durable network structure that has enhanced mechanical properties and is also dynamic for rapid self‐healing. Healable polymers with hierarchical hydrogen‐bonding interactions show excellent recoverability and high energy dissipation owing to the durable interaction between polymer chains. This biomimetic strategy of using hierarchical hydrogen bonds as building blocks is an alternative approach for obtaining dynamic, strong, yet smart self‐healing polymers for heavy‐duty protection materials and wearable electronics.
Supertough self‐healing elastomers were constructed by a biomimetic synthetic strategy and control of the nanophase structure with hierarchical (single, double, quadruple) hydrogen‐bonding motifs. The successive dynamic interaction of the H‐bonds and increased chain mobility contribute to the self‐healing and supertough mechanical properties. The toughness after self‐healing reached 345 MJ m−3.
Elaborate design of highly active and stable catalysts from Earth-abundant elements has great potential to produce materials that can replace the noble-metal-based catalysts commonly used in a range ...of useful (electro)chemical processes. Here we report, for the first time, a synthetic method that leads to in situ growth of {2̅10} high-index faceted Ni3S2 nanosheet arrays on nickel foam (NF). We show that the resulting material, denoted Ni3S2/NF, can serve as a highly active, binder-free, bifunctional electrocatalyst for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Ni3S2/NF is found to give ∼100% Faradaic yield toward both HER and OER and to show remarkable catalytic stability (for >200 h). Experimental results and theoretical calculations indicate that Ni3S2/NF’s excellent catalytic activity is mainly due to the synergistic catalytic effects produced in it by its nanosheet arrays and exposed {2̅10} high-index facets.
Simultaneous realization of improved activity, enhanced stability, and reduced cost remains a desirable yet challenging goal in the search of oxygen evolution electrocatalysts in acid. Herein we ...report iridium‐containing strontium titanates (Ir‐STO) as active and stable, low‐iridium perovskite electrocatalysts for the oxygen evolution reaction (OER) in acid. The Ir‐STO contains 57 wt % less iridium relative to the benchmark catalyst IrO2, but it exhibits more than 10 times higher catalytic activity for OER. It is shown to be among the most efficient iridium‐based oxide electrocatalysts for OER in acid. Theoretical results reveal that the incorporation of iridium dopants in the STO matrix activates the intrinsically inert titanium sites, strengthening the surface oxygen adsorption on titanium sites and thereby giving nonprecious titanium catalytic sites that have activities close to or even better than iridium sites.
Iridium OER titanium: Iridium‐containing strontium titanate perovskites (Ir‐STO) are identified as active and stable, low‐iridium‐content electrocatalysts for the oxygen evolution reaction (OER) under acidic conditions. The iridium activates the previously inert titanium sites, making them nonprecious‐metal catalytic sites that have activities close to or even better than the Ir catalytic sites.
China is one of the countries with the highest incidence of gastric cancer. There are differences in epidemiological characteristics, clinicopathological features, tumor biological characteristics, ...treatment patterns, and drug selection between gastric cancer patients from the Eastern and Western countries. Non‐Chinese guidelines cannot specifically reflect the diagnosis and treatment characteristics for the Chinese gastric cancer patients. The Chinese Society of Clinical Oncology (CSCO) arranged for a panel of senior experts specializing in all sub‐specialties of gastric cancer to compile, discuss, and revise the guidelines on the diagnosis and treatment of gastric cancer based on the findings of evidence‐based medicine in China and abroad. By referring to the opinions of industry experts, taking into account of regional differences, giving full consideration to the accessibility of diagnosis and treatment resources, these experts have conducted experts’ consensus judgement on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes. This guideline uses tables and is complemented by explanatory and descriptive notes covering the diagnosis, comprehensive treatment, and follow‐up visits for gastric cancer.
Although a number of nonprecious materials can exhibit catalytic activity approaching (sometimes even outperforming) that of iridium oxide catalysts for the oxygen evolution reaction, their catalytic ...lifetimes rarely exceed more than several hundred hours under operating conditions. Here we develop an energy-efficient, cost-effective, scaled-up corrosion engineering method for transforming inexpensive iron substrates (e.g., iron plate and iron foam) into highly active and ultrastable electrodes for oxygen evolution reaction. This synthetic method is achieved via a desired corrosion reaction of iron substrates with oxygen in aqueous solutions containing divalent cations (e.g., nickel) at ambient temperature. This process results in the growth on iron substrates of thin film nanosheet arrays that consist of iron-containing layered double hydroxides, instead of rust. This inexpensive and simple manufacturing technique affords iron-substrate-derived electrodes possessing excellent catalytic activities and activity retention for over 6000 hours at 1000 mA cm
current densities.
Abstract
In general, giant flares (GFs) produced by magnetars have a very short-hard initial spike that is followed by a weak oscillatory phase. GFs from a nearby galaxy would appear as cosmic ...short-hard gamma-ray bursts (GRBs), such as GRB 200415A. In this paper, we search for GF-originated bursts in the Fermi GRB category and report GRB 210410A, which is presented with a very short-hard spike followed by an extended tail emission. In the
E
p,
z
−
E
iso
plane, GRB 210410A with a duration of
T
90
∼ 48 s differs from long GRBs, might be classified as a short GRB with a redshift of
z
∼ 0.28, and could be regarded as a GF with a distance of ∼2.7 Mpc. Here,
E
p,
z
,
E
iso
, and
L
iso
denote the rest-frame peak photon energy, the isotropic energy, and the isotropic luminosity of the burst, respectively. The radiation spectrum of GRB 210410A, similar to that of GRB 200415A, can be well fitted with a non-dissipative photospheric emission. However, GRB 210410A in the
E
p,
z
−
L
iso
plane is beyond the death line of cosmic GRBs for non-dissipated photospheric emission with a general initial size of the fireball. Since the
E
p,
z
−
L
iso
relation of GFs is far beyond the death line of cosmic GRBs, GRB 210410A may have originated from the same channel that produces GFs. We also perform the analysis and discuss both the highest photon energy event (4.2 GeV) and the extended tail emission in this burst.
ARID1A (the AT-rich interaction domain 1A, also known as BAF250a) is one of the most commonly mutated genes in cancer
. The majority of ARID1A mutations are inactivating mutations and lead to loss of ...ARID1A expression
, which makes ARID1A a poor therapeutic target. Therefore, it is of clinical importance to identify molecular consequences of ARID1A deficiency that create therapeutic vulnerabilities in ARID1A-mutant tumors. In a proteomic screen, we found that ARID1A interacts with mismatch repair (MMR) protein MSH2. ARID1A recruited MSH2 to chromatin during DNA replication and promoted MMR. Conversely, ARID1A inactivation compromised MMR and increased mutagenesis. ARID1A deficiency correlated with microsatellite instability genomic signature and a predominant C>T mutation pattern and increased mutation load across multiple human cancer types. Tumors formed by an ARID1A-deficient ovarian cancer cell line in syngeneic mice displayed increased mutation load, elevated numbers of tumor-infiltrating lymphocytes, and PD-L1 expression. Notably, treatment with anti-PD-L1 antibody reduced tumor burden and prolonged survival of mice bearing ARID1A-deficient but not ARID1A-wild-type ovarian tumors. Together, these results suggest ARID1A deficiency contributes to impaired MMR and mutator phenotype in cancer, and may cooperate with immune checkpoint blockade therapy.
The Indian-type mantle (i.e., above the north hemisphere reference line on the plot of 208Pb/204Pb vs. 206Pb/204Pb) has been considered as a “Southern Hemisphere” geochemical signature, whose origin ...remains enigmatic. The South China Sea is an extensional basin formed after rifting of the Euro-Asia continent in the Northern Hemisphere, however, the geochemical nature of the igneous crust remains unexplored. For the first time, IODP Expedition 349 has recovered seafloor basalts covered by the thick sediments in the Southwest sub-basin (Sites U1433 and U1434) and the East sub-basin (Site U1431). The Southwest sub-basin consists of enriched (E)-MORB type basalts, and the East sub-basin consists of both normal (N)-MORB-type and E-MORB-type basalts based on trace element compositions. The basalts of the two sub-basins are Indian-type MORBs based on Sr–Nd–Pb–Hf isotope compositions, and the Southwest sub-basin basalts show isotopic compositions (i.e., 206Pb/204Pb of 17.59–17.89) distinctly different from the East sub-basin (i.e., 206Pb/204Pb of 18.38–18.57), suggesting a sub-basin scale mantle compositional heterogeneity and different histories of mantle compositional evolution. Two different enriched mantle end-members (EM1 and EM2) are responsible for the genesis of the Indian-type mantle in the South China Sea. We have modeled the influences of Hainan mantle plume and lower continental crust based on Sr–Nd–Pb–Hf isotope compositions. The results indicate that the influence of Hainan plume can explain the elevated 206Pb/204Pb of the East sub-basin basalts, and the recycling of lower continental crust can explain the low 206Pb/204Pb of the Southwest sub-basin basalts. Based on the strong geochemical imprints of Hainan plume in the ridge magmatism, we propose that the Hainan plume might have promoted the opening of the South China Sea, during which the Hainan plume contributed enriched component to the sub-ridge mantle and caused thermal erosion and return of lower continental crust to the convective mantle. These results imply an in situ origin of the Indian-type mantle that can help understand the genesis of the “Southern Hemisphere” geochemical anomaly in the Northern Hemispheric extensional basin.
•An Indian-type mantle exists in the mantle source of the SCS.•The Indian-type mantle of the SCS can be explained by in situ geologic processes.•Lower continent crust and Hainan plume are involved in the mantle source of SCS.•Hainan plume played a role in promoting the opening of the SCS.
Splitting water to produce hydrogen requires the development of non-noble-metal catalysts that are able to make this reaction feasible and energy efficient. Herein, we show that cobalt pentlandite ...(Co9S8) nanoparticles can serve as an electrochemically active, noble-metal-free material toward hydrogen evolution reaction, and they work stably in neutral solution (pH 7) but not in acidic (pH 0) and basic (pH 14) media. We, therefore, further present a carbon-armoring strategy to increase the durability and activity of Co9S8 over a wider pH range. In particular, carbon-armored Co9S8 nanoparticles (Co9S8@C) are prepared by direct thermal treatment of a mixture of cobalt nitrate and trithiocyanuric acid at 700 °C in N2 atmosphere. Trithiocyanuric acid functions as both sulfur and carbon sources in the reaction system. The resulting Co9S8@C material operates well with high activity over a broad pH range, from pH 0 to 14, and gives nearly 100% Faradaic yield during hydrogen evolution reaction under acidic (pH 0), neutral (pH 7), and basic (pH 14) media. To the best of our knowledge, this is the first time that a transition-metal chalcogenide material is shown to have all-pH efficient and durable electrocatalytic activity. Identifying Co9S8 as the catalytically active phase and developing carbon-armoring as the improvement strategy are anticipated to give a fresh impetus to rational design of high-performance noble-metal-free water splitting catalysts.
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Utilization of self-healing nanocontainers with corrosion inhibitors is an efficient strategy for protecting metals from corrosion. However, self-healing coatings require the rapid ...release of these corrosion inhibitors to achieve an on-demand barrier on metal surface while avoiding unwanted leakage before the protective coatings are damaged. Herein, well-defined ZIF-7@BTA nanoparticles with approximately 30 wt% benzotriazole inhibitors are prepared via a ligand exchange approach. The as-synthesized ZIF-7@BTA nanoparticles can rapidly release the BTA inhibitor onto scratched areas on metal surfaces, providing 99.4% inhibition efficiency under acidic conditions. Moreover, only limited inhibitor of BTA molecules was leached out (less than 4%) in a neutral environment. Furthermore, the ZIF-7@BTA nanoparticles were further distributed in the polymer matrix to prepare the self-healing anticorrosion coatings for corrosion resistance enhancement in an acidic environment. Electrochemical impedance spectroscopy (EIS) analysis was utilized to characterize the corrosion resistance.
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