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A new operation has been developed to remove unmarked DNA strands from surfaces for use in multiple-word DNA computing.

By employing solid-state high-resolution 13C nuclear magnetic resonance (NMR), we found that the helicaljump motion of crystalline poly(ethylene oxide) (PEO) segments onlyexists for the PEO3/LiF3SO3complexeswith the molecular weights of PEO larger than 2 × 103g mol–1, and the helical jump rate increases withincreasing the molecular weight of PEO. It is demonstrated that thehelical jump rate of crystalline PEO segments depends on the relativecontent and chain mobility of the amorphous structures for PEO–alkalimetal salt complexes. The sufficient amount of amorphous phase isthe necessary condition for the helical jump motion to happen, andthe chain motion in the amorphous phase might be the driving forcefor the helical jump motion of the crystalline PEO segments. On thebasis of the above recognition, we tend to believe that the helicaljump motion is corresponding to the movement of an entire PEO chainembedded in the crystallites. [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) is a disease that is characterized by a rapid decline in renal function and has a relatively high incidence in hospitalized patients. Sepsis, renal hypoperfusion, and nephrotoxic drug exposure are the main causes of AKI. The major therapy measures currently include supportive treatment, symptomatic treatment, and kidney transplantation. These methods are supportive treatments, and their results are not satisfactory. Fortunately, many new treatments that markedly improve the AKI therapy efficiency are emerging. These include antioxidant therapy, ferroptosis therapy, anti-inflammatory therapy, autophagy therapy, and antiapoptotic therapy. In addition, the development of nanotechnology has further promoted therapeutic effects on AKI. In this review, we highlight recent advances in the development of nanocarriers for AKI drug delivery. Emphasis has been placed on the latest developments in nanocarrier modification and design. We also summarize the applications of different nanocarriers in AKI treatment. Finally, the advantages and challenges of nanocarrier applications in AKI are summarized, and several nanomedicines that have been approved for clinical trials to treat diverse kidney diseases are listed.

Triboelectric nanogenerator (TENG) has been demonstrated as a sustainable energy utilization method for waste mechanical energy and self-powered system. However, the charge dissipation of frictional layer materials in a humid environment severely limits their stable energy supply. In this work, a new method is reported for preparing polymer film as a hydrophobic negative friction material by solution blending poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) and polyvinyl chloride (PVC), doping with titanium dioxide (TiO 2 ) nanoparticles, and further surface patterning modification. The P-TENG composed of the PVDF-HFP/PVC/TiO 2 composite film with optimized hydrophobic performance (WCA = 124°) achieved an output voltage of 235 V and a short-circuit current of 35 μA, which is approximately three times that of the bare PVDF-HFP-based TENG. Under charge excitation, the transferred charge of the P-TENG can reach 35 nC. When the external load resistance is 5.5 MΩ, the output peak power density can reach 1.4 W m -2 . Meanwhile, the hydrophobic surface layer with a rough surface structure enables the device to overcome the influence of water molecules on charge transfer in a humid environment, quickly recover, and maintain a high output. The P-TENG can effectively monitor finger flexibility and strength and realize real-time evaluation of the exercise state and hand fatigue of the elderly and rehabilitation trainers. It has broad application prospects in self-powered intelligent motion sensing, soft robotics, human-machine interaction, and other fields.

Aqueous electrochemical coupling reactions, which enable the green synthesis of complex organic compounds, will be a crucial tool in synthetic chemistry. However, a lack of informed approaches for screening suitable catalysts is a major obstacle to its development. Here, we propose a pioneering electrochemical reductive coupling reaction toward direct electrosynthesis of oxime from NO x and aldehyde. Through integrating experimental and theoretical methods, we screen out the optimal catalyst, i.e., metal Fe catalyst, that facilitates the enrichment and C-N coupling of key reaction intermediates, all leading to high yields (e.g., ∼99% yield of benzaldoxime) for the direct electrosynthesis of oxime over Fe. With a divided flow reactor, we achieve a high benzaldoxime production of 22.8 g h -1 g cat -1 in ∼94% isolated yield. This work not only paves the way to the industrial mass production of oxime via electrosynthesis but also offers references for the catalyst selection of other electrochemical coupling reactions.

Nitrogen dioxide (NO 2 ) is an active species of exhaust gas recirculation gas, and it has a significant impact on the autoignition and combustion processes of fuels. This study presented a comprehensive investigation of the effect of NO 2 on the combustion characteristics of the n -butanol/biodiesel dual fuel. Experiments were conducted on a single-cylinder engine with 0, 100, 200, and 400 v/v ppm NO 2 addition at two fuel injection ratios. The findings of the experiments indicated that adding NO 2 resulted in an earlier start of heat release and an increase in peak in-cylinder pressure as compared to experiments where no NO 2 was added. The evolutions of n -butanol, biodiesel, and OH radicals were evaluated using the computational fluid dynamics software coupled with the n -butanol-biodiesel-NO 2 mechanism. The results revealed that when 400 v/v ppm NO 2 was added, the consumption of n -butanol and biodiesel occurred earlier, and the formation of OH radicals was approximately an order of magnitude higher before the biodiesel was injected. Furthermore, reaction rate and flux analyses were performed to understand the effect of NO 2 addition on the reaction process. When NO 2 was added, 35% of the HO 2 radicals reacted with NO which converted from NO 2 via the reaction NO + HO 2 ⇌ NO 2 + OH, promoting the formation of OH radicals in the reaction system. The addition of NO 2 can also enhance the consumption of CH 3 radicals via the reaction CH 3 + HO 2 ⇌ CH 3 O + OH., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

The combination of Cu and Ag presents a promising way to steer the CO 2 reduction products through regulating the surface active sites. However, the difficulty in forming the CuAg alloy with a controllable atomic ratio impedes the in-depth understanding of the structure-activity relationship of CuAg catalysts. Herein, we use E-beam evaporation to synthesize a series of CuAg films with uniform distribution and controllable stoichiometry to reveal the real reaction mechanism on CuAg for the electrochemical CO 2 reduction process. Compared with Cu, the Cu 1- x Ag x ( x = 0.05-0.2) alloy showed an apparent suppression of HCOOH and the ratio between C 2 liquid products (e.g., ethanol and acetate) and C 1 liquid product (HCOOH) is also increased. Operando synchrotron radiation Fourier transform infrared spectroscopy results suggest that the introduction of Ag into the Cu phase can significantly strengthen the absorbed *CO and *OCCO intermediates and suppress the O-C-O intermediates. This research provides a reliable way to inhibit the generation of HCOOH and enhance the production of liquid C 2 products during CO 2 RR and presents a guideline for the future manipulation of copper catalysts by alloying.

Uncariae Ramulus Cum Uncis, known as "Gou-Teng" in Chinese, is derived mainly from the dried hook-bearing stems of Uncaria rhynchophylla . Quantitative determination of monoterpenoid indole alkaloids is critical for controlling its quality. In the present study, a rapid, accurate, and precise method was developed for the simultaneous quantitation of four characteristic components, namely, rhynchophylline ( 1 ), isorhynchophylline ( 2 ), corynoxeine ( 3 ), and isocorynoxeine ( 4 ), through 1 H NMR spectrometry techniques. This method was performed on a 600 MHz NMR spectrometer with optimized acquisition parameters for performing quantitative experiments within 14 min. The highly deshielded signal of NH was at δ H 10-11 in the aprotic solvent DMSO- d 6 , which enables satisfactory separation of the signals to be integrated. Validation of the quantitative method was also performed in terms of specificity, linearity, sensitivity, accuracy, and precision. The method is linear in the concentration range of 25-400 μg/mL. The lower limit of quantification is 25 μg/mL. The intra- and interday relative standard deviation across three validation runs over the entire concentration range is less than 2.51%. The accuracy determined at three concentrations was within ±4.4% in terms of relative error. The proposed qNMR method was demonstrated to be a powerful tool for quantifying the alkaloids in traditional Chinese medicines (TCMs) due to its unique advantages of high precision, rapid analysis, and nonrequirement of standard compounds for calibration curve preparation. Moreover, qNMR represents a feasible alternative to high-performance liquid chromatography-based methods for the quality control of TCMs., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

We present a strategy of self-nanocavity confinement for substantially boosting the superior electrochemical hydrogen peroxide (H 2 O 2 ) selectivity for conductive metal-organic framework (MOF) materials. By using operando synchrotron radiation X-ray adsorption fine structure and Fourier transform infrared spectroscopy analyses, the dissociation of key *OOH intermediates during the oxygen reduction reaction (ORR) is effectively suppressed over the self-nanocavity-confined X-Ni MOF (X = F, Cl, Br, or I) catalysts, contributing to a favorable two-electron ORR pathway for highly efficient H 2 O 2 production. As a result, the as-prepared Br-confined Ni MOF catalyst significantly promotes H 2 O 2 selectivity up to 90% in an alkaline solution, evidently outperforming the pristine Ni MOF catalyst (40%). Moreover, a maximal faradic efficiency of 86% with a high cumulative H 2 O 2 yield rate of 596 mmol g catalyst -1 h -1 for electrochemical H 2 O 2 generation is achieved by the Br-confined Ni MOF catalyst.

Synthesis of the unconventional phase of noble metal nanocrystals may create new opportunities in exploring intriguing physicochemical properties but remains challenging. In the research field of thin film growth, the interface strain offers a general driving force to stabilize the metastable phase of epitaxial film. Herein we extend this concept to the field of noble metal nanocrystals and report the solution synthesis of metastable face-centered tetragonal Au that has not been discovered before. The successful synthesis relies on the formation of intermetallic AuCu 3 @Au core-shell structure, where the interface strain stabilizes the metastable fct Au overlayer. Compared with the face-centered cubic Au counterpart, the metastable fct Au shows greatly improved catalytic activity toward CO 2 reduction to CO. The density functional theory calculations and spectroscopic studies reveal that the metastable fct Au upshifts the d -band center, which lowers the energy barrier of key intermediate COOH* formation and thus facilitates the reaction kinetics.

Glycogen, a randomly branched glucose polymer, provides energy storage in organisms. It forms small β particles which in animals bind to form composite α particles, which give better glucose release. Simulations imply β particle size is controlled only by activities and sizes of glycogen biosynthetic enzymes and sizes of polymer chains. Thus, storing more glucose requires forming more β particles, which are expected to sometimes form α particles. No α particles have been reported in bacteria, but the extraction techniques might have caused degradation. Using milder glycogen extraction techniques on Escherichia coli, transmission electron microscopy and size-exclusion chromatography showed α particles, consistent with this hypothesis for α-particle formation. Molecular density and size distributions show similarities with animal glycogen, despite very different metabolic processes. These general polymer constraints are such that any organism which needs to store and then release glucose will have similar α and β particle structures: a type of convergent evolution.

Highly efficient oxygen evolution driven by abundant sunlight is a key to realize overall water splitting for large-scale conversion of renewable energy. Here, we report a strategy for the interfacial atomic and electronic coupling of layered CoOOH and BiVO 4 to deactivate the surface trapping states and suppress the charge-carrier recombination for high photoelectrochemical (PEC) water oxidation activity. The successful synthesis of a 3D ultrathin-CoOOH-overlayer-coated coral-like BiVO 4 photoanode effectively tailors the migration route of photocarriers on the semiconductor/liquid interface to realize a great increase of ∼200% in the photovoltage relative to bare BiVO 4 , consequently decreasing the corresponding onset potential of PEC water splitting from 0.60 to 0.20 V RHE . As a result, the unique CoOOH/BiVO 4 photoanode could efficiently perform PEC water oxidation in a neutral aqueous solution (pH = 7) with a high photocurrent density of 4.0 mA/cm 2 at 1.23 V RHE and a prominent quantum efficiency of 65% at 450 nm. Electronic structural characterizations and theoretical calculations reveal that the combination of layered CoOOH and BiVO 4 forming interfacial oxo-bridge bonding could greatly eliminate surface trapping states and promote the direct transfer of photogenerated holes from the valence band to the surface water redox potential for water oxidation.

Developing efficient and durable oxygen evolution electrocatalyst is of paramount importance for the large-scale supply of renewable energy sources. Herein, we report the design of significant surface hydrophilicity based on cobalt oxyhydroxide (CoOOH) nanosheets to greatly improve the surface hydroxyl species adsorption and reaction kinetics at the Helmholtz double layer for high-efficiency water oxidation activity. The as-designed CoOOH-graphene nanosheets achieve a small surface water contact angle of ∼23° and a large double-layer capacitance (C dl ) of 8.44 mF/cm 2 and thus could evidently strengthen surface species adsorption and trigger electrochemical oxygen evolution reaction (OER) under a quite low onset potential of 200 mV with an excellent Tafel slope of 32 mV/dec. X-ray absorption spectroscopy and first-principles calculations demonstrate that the strong interface electron coupling between CoOOH and graphene extracts partial electrons from the active sties and increases the electron state density around the Fermi level and effectively promotes the surface intermediates formation for efficient OER.

Direct and efficient photocatalytic water splitting is critical for sustainable conversion and storage of renewable solar energy. Here, we propose a conceptual design of two-dimensional C 3 N 4 -based in-plane heterostructure to achieve fast spatial transfer of photoexcited electrons for realizing highly efficient and spontaneous overall water splitting. This unique plane heterostructural carbon ring (C ring )-C 3 N 4 nanosheet can synchronously expedite electron-hole pair separation and promote photoelectron transport through the local in-plane π-conjugated electric field, synergistically elongating the photocarrier diffusion length and lifetime by 10 times relative to those achieved with pristine g-C 3 N 4 . As a result, the in-plane (C ring )-C 3 N 4 heterostructure could efficiently split pure water under light irradiation with prominent H 2 production rate up to 371 μmol g -1 h -1 and a notable quantum yield of 5% at 420 nm.

Outstanding magnetic properties are highly desired for two-dimensional ultrathin semiconductor nanosheets. Here, we propose a phase incorporation strategy to induce robust room-temperature ferromagnetism in a nonmagnetic MoS2 semiconductor. A two-step hydrothermal method was used to intentionally introduce sulfur vacancies in a 2H-MoS2 ultrathin nanosheet host, which prompts the transformation of the surrounding 2H-MoS2 local lattice into a trigonal (1T-MoS2) phase. 25% 1T-MoS2 phase incorporation in 2H-MoS2 nanosheets can enhance the electron carrier concentration by an order, introduce a Mo(4+) 4d energy state within the bandgap, and create a robust intrinsic ferromagnetic response of 0.25 μB/Mo by the exchange interactions between sulfur vacancy and the Mo(4+) 4d bandgap state at room temperature. This design opens up new possibility for effective manipulation of exchange interactions in two-dimensional nanostructures.

According to Yang Shao-Horn's principle, CoSe2 is a promising candidate as an efficient, affordable, and sustainable alternative electrocatalyst for the oxygen evolution reaction, owing to its well-suited electronic configuration of Co ions. However, the catalytic efficiency of pure CoSe2 is still far below what is expected, because of its poor active site exposure yield. Herein, we successfully overcome the disadvantage of insufficient active sites in bulk CoSe2 by reducing its thickness into the atomic scale rather than any additional modification (such as doping or hybridizing with graphene or noble metals). The positron annihilation spectrometry and XAFS spectra provide clear evidence that a large number of VCo″ vacancies formed in the ultrathin nanosheets. The first-principles calculations reveal that these VCo″ vacancies can serve as active sites to efficiently catalyze the oxygen evolution reaction, manifesting an OER overpotential as low as 0.32 V at 10 mA cm(-2) in pH 13 medium, which is superior to the values for its bulk counterparts as well as those for the most reported Co-based electrocatalysts. Considering the outstanding performance of the simple, unmodified ultrathin CoSe2 nanosheets as the only catalyst, further improvement of the catalytic activity is expected when various strategies of doping or hybridizing are used. These results not only demonstrate the potential of a notable, affordable, and earth-abundant water oxidation electrocatalyst based on ultrathin CoSe2 nanosheets but also open up a promising avenue into the exploration of excellent active and durable catalysts toward replacing noble metals for oxygen electrocatalysis.