A Catalyst-Free Synthesis of Phosphinic Amides Using <i>O</i>‑Benzoylhydroxylamines

A practical approach for the synthesis of phosphinic amides via the coupling of secondary phosphine oxides (SPOs) with <i>O</i>-benzoyl­hydroxyl­amines has been reported. Simply heating the mixture of SPOs and <i>O</i>-benzoylhydroxylamines in the presence of K₂CO₃ gave the phosphinic amides in moderate to excellent yields under an open air system. This method provides a practical and catalyst-free method for the synthesis of various synthetically valuable phosphinic amides

LC–MS/MS Quantitation of Esophagus Disease Blood Serum Glycoproteins by Enrichment with Hydrazide Chemistry and Lectin Affinity Chromatography

Changes in glycosylation have been shown to have a profound correlation with development/malignancy in many cancer types. Currently, two major enrichment techniques have been widely applied in glycoproteomics, namely, lectin affinity chromatography (LAC)-based and hydrazide chemistry (HC)-based enrichments. Here we report the LC–MS/MS quantitative analyses of human blood serum glycoproteins and glycopeptides associated with esophageal diseases by LAC- and HC-based enrichment. The separate and complementary qualitative and quantitative data analyses of protein glycosylation were performed using both enrichment techniques. Chemometric and statistical evaluations, PCA plots, or ANOVA test, respectively, were employed to determine and confirm candidate cancer-associated glycoprotein/glycopeptide biomarkers. Out of 139, 59 common glycoproteins (42% overlap) were observed in both enrichment techniques. This overlap is very similar to previously published studies. The quantitation and evaluation of significantly changed glycoproteins/glycopeptides are complementary between LAC and HC enrichments. LC–ESI–MS/MS analyses indicated that 7 glycoproteins enriched by LAC and 11 glycoproteins enriched by HC showed significantly different abundances between disease-free and disease cohorts. Multiple reaction monitoring quantitation resulted in 13 glycopeptides by LAC enrichment and 10 glycosylation sites by HC enrichment to be statistically different among disease cohorts

Engineering Interconnected Nanofluidic Channel in a Hydrogel Supernetwork toward K⁺ Ion Accelerating Transport and Efficient Sensing

Ion transportation via the mixed mechanisms of hydrogels underpins ultrafast biological signal transmission in nature, and its application to the rapid and sensitive sensing detection of human specific ions is of great interest for the field of medical science. However, current research efforts are still unable to achieve transmission results that are comparable to those of bioelectric signals. Herein, 3D interconnected nanochannels based on poly(pyrrole-co-dopamine)/poly(vinyl alcohol) (P(Py-co-DA)/PVA) supernetwork conductive hydrogels are designed and fabricated as stimuli-responsive structures for K+ ions. Distinct from conventional configurations, which exhibit rapid electron transfer and permeability to biosubstrates, interconnected nanofluidic nanochannels collaborated with the P(Py-co-DA) conductive polymer in the supernetwork conductive hydrogel significantly improve conductivity (88.3 mS/cm), ion transport time (0.1 s), and ion sensitivity (74.6 mV/dec). The faster ion response time is attributed to the synergism of excellent conductivity originating from the P(Py-co-DA) polymer and the electronic effect in the interconnected nanofluidic channels. Furthermore, the supernetwork conductive hydrogel demonstrates K+ ion selectivity relative to other cations in biofluids such as Na+, Mg2+, and Ca2+. The DFT calculation indicates that the small solvation energy and low chemical transfer resistance are the main reasons for the excellent K+ ion selectivity. Finite element analysis (FEA) simulations further support these experimental results. Consequently, the P(Py-co-DA)/PVA supernetwork conductive hydrogels enriched with the 3D interconnected nanofluidic channels developed in this work possess excellent sensing of K+ ions. This strategy provides great insight into efficient ion sensing in traditional biomedical sensing that has not been explored by previous researchers

Additional file 1 of Alterations and correlations in dental plaque microbial communities and metabolome characteristics in patients with caries, periodontitis, and comorbid diseases

Supplementary Material

Phototriggered Mechanical Movement in A Bipyridinium-based Coordination Polymer Powered by Electron Transfer

Photomechanical movement with a morphological deformation has been achieved in the crystalline state of a bipyridinium-based coordination polymer. The engine “heart” is the electron-deficient bipyridinium core sandwiched by electron-rich phenylcarboxylate components. The decorrelation of the CT state triggered by PET reaction in the engine “heart” promotes the occurrence of this mechanical movement

Multi-Direction-Tunable Three-Dimensional Meta-Atoms for Reversible Switching between Midwave and Long-Wave Infrared Regimes

We introduce an electromechanically tunable metasurface composed of an array of three-dimensional nanosplit-rings for reversible and large-range changes of optical characteristics in infrared (IR) regime. When a current is induced or withdrawn, each nanosplit ring in the surface can deform in multi directions and consequently become a closed (OFF) or an open (ON) state. Theoretical and experimental results manifest that, as the metasurface is dynamically manipulated between the ON and OFF states, the corresponding resonance absorption will reversibly switch between the long wave (around 10.4 μm) and midwave (around 6.3 μm) IR regimes, two key IR spectral windows, and the reversible relative reflection changes can reach up to 95%

Trend of total cost as the demand satisfaction rate changes.

<p>Trend of total cost as the demand satisfaction rate changes.</p

Pd-Catalyzed Chemoselective Catellani <i>Ortho</i>-Arylation of Iodopyrroles: Rapid Total Synthesis of Rhazinal

A Pd-catalyzed chemoselective Catellani reaction of iodopyrroles was developed. The rare chemoselectivity between two different aryl halides was realized by optimizing the kinetics of the different steps of this multicomponent process. The new developed method led to the rapid synthesis of rhazinal in a highly efficient manner

A Comprehensive Study on Metal Triflate-Promoted Hydrogenolysis of Lactones to Carboxylic Acids: From Synthetic and Mechanistic Perspectives

Direct hydrogenolysis of lactone to carboxylic acid (i.e., hydrogenolysis of the C_alkoxy–O bond with the carbonyl group untouched) is generally difficult, as the current strategies employing Brønsted acids as the catalyst usually require harsh conditions such as a high temperature and a high H₂ pressure. Herein, we report a developed solvent-free catalytic transformation, in which W­(OTf)₆ is believed to promote the hydrogenolysis process. This strategy could efficiently hydrogenate lactones to carboxylic acids under extra mild conditions (e.g., a reaction temperature of <150 °C and 1 atm of H₂) and showed a broad substrate scope. In addition, the catalytic protocol can be further applied to the hydrogenolysis of polyhydroxyalkanoate, as a renewable polymer, to the corresponding straight-chain carboxylic acids. An extensive mechanistic study was subsequently performed, and the density functional theory calculations revealed a reaction pattern, including the complete cleavage of the CO bond with the assistance of the W­(OTf)₆ catalyst. Moreover, the key intermediate created in the mechanism, as an oxonium with an OTf moiety, was successfully detected by electrospray ionization mass spectra. Through a comparison with the Brønsted acid-catalyzed system, the study confirmed that the existence of the OTf moiety can significantly lower the barriers associated with the rearrangement and elimination processes. Meanwhile, emphasis was placed on the critical role that the anion plays, as well as the fact that the anion effect is directly related to the chemoselectivity

Rescue materials flow chart for the government-enterprises joint reserves mode.

<p>Rescue materials flow chart for the government-enterprises joint reserves mode.</p