Inter-annual and spatial variations of air-sea CO fluxes and acidification mechanism in the coastal waters of Qingdao, China during 2011-2019.

The interplay of global climate change and anthropogenic activities has significantly affected the carbon cycle in coastal ocean environments. Consequently, further investigation into the carbonate system, carbon source and sink processes, and acidification mechanisms is essential. This study examined the surface carbonate system offshore of Qingdao, utilizing data from nine spring cruises in 2011-2019.

Pyrolysis-Free Synthesis of Synergistic Single-Atom/Nanocluster Electrocatalysts for Hydrogen Evolution.

Constructing catalysts that simultaneously contain single atom/metal nanocluster active sites is a promising strategy to enhance the original catalytic behavior and accelerate the catalysis involving multi-electron reactions or multi-intermediates. Herein, the pyrolysis-free synthetic method is developed to integrate single atoms and nanoclusters towards highly satisfactory catalytic performances for both acidic and alkaline hydrogen electrocatalysis. The controllable pyrolysis-free strategy allows the precise modulation of the active centers, realizing the optimization of the adsorption energy and the regulation of the synergistic active components.

Atomically precise copper clusters with dual sites for highly chemoselective and efficient hydroboration.

The hydroboration of alkynes into vinylboronate esters is a vital transformation, but achieving high chemoselectivity of targeted functional groups and an appreciable turnover number is a considerable challenge. Herein, we develop two dynamically regulating dual-catalytic-site copper clusters (CuNC and CuNC) bearing N-heterocyclic thione ligands that endow CuNC and CuNC catalysts with performance. In particular, the performance of microcrystalline CuNC in hydroboration is characterized by a high turnover number (77786), a high chemoselectivity, high recovery and reusability under mild conditions.

An activatable red emitting fluorescent probe for monitoring vicinal dithiol protein fluctuations in a stroke model.

Vicinal dithiol proteins (VDPs) facilitate cellular redox homeostasis, modulate protein synthesis and participate in post-translational modifications through the dynamic equilibrium of dithiol and disulfide bonds. Herein, an activatable red emitting fluorescent probe, VDP-red, is developed for detecting VDPs. With the aid of this probe, we have discovered for the first time a reduction in the levels of reduced VDPs in a stroke mouse model.

Satellite Pd Single-Atom Embraced AuPd Alloy Nanoclusters for Enhanced Hydrogen Evolution.

The fabrication of hybrid active sites that synergistically contain nanoclusters and single atoms (SAs) is vital for electrocatalysts to achieve excellent activity and durability. Herein, we develop a ligand-assisted pyrolysis strategy using nanoclusters (AuPd(SCHPh)) with alloy cores and protected ligands to build AuPd cluster sites embraced by satellite Pd SAs. In the thermal drive control process, different thermodynamic properties of the alloy atoms and the confinement effects of organic ligands allow for the mild spillover of the single-component metal Pd, resulting in the formation of AuPd alloy nanoclusters tightly encompassed by isolated Pd atoms.

Dual-Functional Fluorescent Probe in the Diagnosis of Liver Injury and the Evaluation of Drug Therapy with Double Signal Amplification.

Viscosity and polarity are crucial microenvironmental parameters within cells, intimately linked to the physiological activities of organisms. We constructed and synthesized an innovative dual-functional fluorescent probe, DHBP. In the green channel, the fluorescence signal notably intensifies with decreasing environmental polarity, while in the red channel, fluorescence signal amplification occurs due to the collaborative effects of viscosity and polarity, resulting in more pronounced changes.

A NIR Dual-Channel Fluorescent Probe for Fluctuations of Intracellular Polarity and HO and Its Applications for the Visualization of Inflammation and Ferroptosis.

Hydrogen peroxide and polarity are closely related to many physiological activities and pathological processes. However, near-infrared fluorescent probes that are sensitive to both HO and polarity are still scarce. Herein, we developed the first dual-channel near-infrared fluorescent probe NBO, with an AIE effect, enabling simultaneous monitoring of HO and polarity.

Holistic insights into carbon nanotubes and MXenes as a promising route to bio-sensing applications.

Essential biosensor use has become increasingly important in drug discovery and recognition, biomedicine, food safety, security, and environmental research. It directly contributed to the development of specialized, reliable diagnostic instruments known as biosensors, which use biological sensing components. Traditional biosensors have poor performance, so scientists need to develop advanced biosensors with promising selectivity, sensitivity, stability, and reusability.

Spin and dielectric transitions promoted by dimerization of anionic radical stacks and volume-conserving motion of cations in an ion-pair compound.

Demonstrating the mechanism of a structural phase transition (SPT) is significantly important for guiding the precise design of new phase transition materials. Herein, an ion-pair compound [DPIm][Ni(mnt)] (1, DPIm = 1,3-dipropylimidazolium and mnt = maleonitriledithiolate) has been obtained and thoroughly characterized through microanalysis, spectral, and thermal analysis techniques. The [Ni(mnt)] anions form columnar stacks, featuring one-dimensional (1D) = ½ spin chains.

Asymmetric Büchner reaction and arene cyclopropanation via copper-catalyzed controllable cyclization of diynes.

The asymmetric Büchner reaction and related arene cyclopropanations represent one type of the powerful methods for enantioselective dearomatization. However, examples of asymmetric Büchner reactions via a non-diazo approach are quite scarce, and the related arene cyclopropanation based on alkynes has not been reported. Herein, we disclose an asymmetric Büchner reaction and the related arene cyclopropanation by copper-catalyzed controllable cyclization of N-propargyl ynamides via vinyl cation intermediates, leading to chiral tricycle-fused cycloheptatrienes and benzonorcaradienes in high yields and enantioselectivities.

Toward 95.5% Efficient Red Emissive Carbon Dots: Oxidation State Enhancing Radiative Electron-Transition of Indole Fluorophore.

Red fluorescence carbon dots (CDs) are promising for diverse applications and have attracted tremendous research interest. However, it is still challenging to achieve red fluorescence CDs with high fluorescence quantum yields (QYs > 50%). Herein, three kinds of red fluorescence CDs with QYs of 53.

Novel Ternary System for Electrochemiluminescence Biosensor and Application toward Pb Assay.

This study constructed an electrochemiluminescence (ECL) biosensor for ultrasensitive detection of Pb in a ternary system by employing DNAzyme. The ternary system is composed of a potassium-neutralized perylene derivative (KPTC) as the ECL emitter, KSO as the coreactant, and neodymium metal-organic frameworks (Nd-MOFs) as the coreaction accelerators. Nd-MOFs immobilize DNAzymes and enhance the luminescence intensity of the KPTC/KSO system.

Access to Alkenyl Cyclobutanols by Ni-Catalyzed Regio- and Enantio-Selective syn-Hydrometalative 4-exo-trig Cyclization of Alkynones.

Enantioselective synthesis of (spiro)cyclobutane derivatives poses significant challenges yet holds promising applications for both synthetic and medicinal chemistry. We report here a nickel-catalyzed asymmetric syn-hydrometalative 4-exo-trig cyclization of 1,4-alkynones to synthesize alkenyl cyclobutanols with a tetrasubstituted stereocenter. This strategy features a broad substrate scope, delivering a variety of trifluoromethyl-containing rigid (spiro)carbocycle skeletons in good yields with high enantioselectivities (up to 84 % yield and 98.

Streamlining RNA Aptamer Selection via Unique Molecular Identifiers and High-Throughput Sequencing.

Aptamers are valuable tools for applications such as cell imaging, drug delivery, and therapeutics. RNA aptamers, in particular, exhibit complex structural diversity and flexibility, affording higher affinity and specificity, broader target recognition, and easier chemical modification compared with DNA aptamers. However, traditional selection methods for RNA aptamers are time-consuming and involve numerous rounds of screening, thus limiting their widespread application.

Asymmetric one-carbon ring expansion of diverse N-heterocycles via copper-catalyzed diyne cyclization.

One-carbon ring expansion reaction of N-heterocycles has gained particular attention in the past decade because this method allows for the conversion of readily available N-heterocycles into potentially useful complex ring-expanded N-heterocycles, which are inaccessible by traditional methods. However, the catalytic asymmetric variant of this reaction has been rarely reported to date. Herein, we disclose an enantioselective one-carbon ring expansion reaction through chiral copper-catalyzed diyne cyclization, leading to the practical, atom-economic and divergent assembly of an array of valuable chiral N-heterocycles bearing a quaternary stereocenter in generally good to excellent yields with excellent enantioselectivities (up to >99% ee).

Nitrogen oxides emissions from coastal wetland sediments: Experimental assessment of the influence of vegetation and nitrogen input.

Nitrogen oxides (NO = NO + NO) have essential impacts on global climate and the environment, making it essential to study the contribution of wetland-generated NO to environmental problems. With exogenous nitrogen input from anthropogenic activities, wetland sediments become active emission hotspots for NO. In this study, we conducted field experiments in a typical salt marsh wetland to measure nitric oxide (NO, the primary component of NO from sediments) exchange fluxes in both mudflat and vegetated sediments.

Selective and Orally Bioavailable c-Met PROTACs for the Treatment of c-Met-Addicted Cancer.

c-Met is an attractive therapeutic target in multiple tumors. Previous studies have discovered some effective proteolysis-targeting chimeras (PROTACs) able to degrade c-Met; however, the structure-activity relationship (SAR), degradation selectivity, and pharmacokinetic profiles of c-Met PROTACs have, to date, remained largely unknown. Herein, through extensive SAR studies on various warheads, linkers, and E3 ligase ligands, a novel potent c-Met PROTAC was identified.

Carbonylative Cyclization of 2-Iodofluorobenzenes and 2-Aminophenols with Recyclable Palladium-Complexed Dendrimers on SBA-15: One-Pot Synthesis of Dibenzoxazepinones.

A novel, efficient, and practical route to dibenzoxazepinones has been developed through a one-pot heterogeneous palladium-catalyzed aminocarbonylation/aromatic nucleophilic substitution (SAr) sequence starting from readily available 2-iodofluorobenzenes and 2-aminophenols. The carbonylative cyclization reaction proceeds smoothly in dimethyl sulfoxide (DMSO) at 120 °C with 1,8-diazabicyclo(5.4.

Isomerization of Covalent Organic Frameworks for Efficiently Activating Molecular Oxygen and Promoting Hydrogen Peroxide Photosynthesis.

Constitutional-isomerized covalent organic frameworks (COFs), constructed by swapping monomers around imine bonds, have attracted attention for their distinct optoelectronic properties, which significantly impact photocatalytic performance. However, limited research has delved into the inherent relationship between isomerization and the enhancement of HO photosynthesis. Herein, a pair of isomeric COFs linked by imine bonds (PB-PT-COF and PT-PB-COF) is synthesized, and it is proved that isomeric COFs exhibit different rate-determining steps in the generation process of HO, resulting in a twofold increase in photocatalytic efficiency.