Hydroformylation of olefins is widely used in the chemical industry due to its versatility and the ability to produce valuable aldehydes with 100% atom economy. Herein, a hybrid phosphate promoter was found to efficiently promote rhodium-catalyzed hydroformylation of styrenes under remarkably mild conditions with high regioselectivities. Preliminary mechanistic studies revealed that the weak coordination between the Rhodium and the P=O double bond of this pentavalent phosphate likely induced exceptional reactivity and high ratios of branched aldehydes to linear products.
View Article and Find Full Text PDFBiomimetics (Basel)
March 2024
Biological fish exhibit a remarkably broad-spectrum visual perception capability. Inspired by the eye arrangement of biological fish, we design a fish-like binocular vision system, thereby endowing underwater bionic robots with an exceptionally broad visual perception capacity. Firstly, based on the design principles of binocular visual field overlap and tangency to streamlined shapes, a fish-like vision system is developed for underwater robots, enabling wide-field underwater perception without a waterproof cover.
View Article and Find Full Text PDFBiological fish exhibit remarkable adaptability and exceptional swimming performance through their powerful and flexible bodies. Therefore, designing a continuum flexible body is significantly important for the development of a robotic fish. However, it is still challenging to replicate these functions of a biological body due to the limitations of actuation and material.
View Article and Find Full Text PDFAquatic animals such as fish and cetaceans can actively modulate their body stiffness with muscle to achieve excellent swimming performance under different situations. However, it is still challenging for a robotic swimmer with bionic propulsion mode to dynamically adjust its body stiffness to improve the swimming speed due to the difficulties in designing an effective stiffness adjustment structure. In this paper, based on the special torque mode of a motor, we propose an active variable stiffness control method for a robotic dolphin to pursue better swimming speed.
View Article and Find Full Text PDFPurpose: To assess the consistency of Ovarian-Adnexal Reporting and Data System (O-RADS) lexicon interpretation between senior and junior sonologists and to investigate its impact on O-RADS classification and diagnostic performance.
Methods: We prospectively studied 620 patients with adnexal lesions, all of whom underwent transvaginal or transrectal ultrasound performed by a senior sonologist (R1) who selected the O-RADS lexicon description and O-RADS category for the lesion after the examination. Meanwhile, the junior sonologist (R2) analyzed the images retained by R1 and divided the lesion in the same way.
Spirodiphosphines have been successfully applied in various asymmetric catalytic transformations. However, controlling the coordinating conformations by the direct displacement of the spiro atom remains elusive. Herein, we report the application of Si-centered spirodiphosphine (Si-SDP) ligands in the enantioselective hydrosilylation/cyclization of 1,6-enynes.
View Article and Find Full Text PDFBiomimetics (Basel)
April 2023
Bionic robots possess inherent advantages for underwater operations, and research on motion control and intelligent decision making has expanded their application scope. In recent years, the application of reinforcement learning algorithms in the field of bionic underwater robots has gained considerable attention, and continues to grow. In this paper, we present a comprehensive survey of the accomplishments of reinforcement learning algorithms in the field of bionic underwater robots.
View Article and Find Full Text PDFThe palladium-catalyzed intramolecular hydroaminocarbonylation of 2-(1-methylvinyl)aniline derivatives has been achieved using dppp (1,3-bis(diphenylphosphino)propane) as a ligand under hydrogen-free conditions. The reaction involves the generation of an active palladium hydride species with a catalytic amount of TsOH. This amide bond formation reaction was applied to the synthesis of various 4-substituted 3,4-dihydroquinolone derivatives with both high yield and regioselectivity.
View Article and Find Full Text PDFNatural product dimers have intriguing structural features and often have remarkable pharmacological activities. We report here two uncommon marine gorgonian-derived symmetric dimers, weizhouochrones A () and B (), with indenone-derived monomers, that were isolated from the coral collected from the South China Sea. These dimers are difficult targets for structure elucidation that solely relies upon conventional NMR data such as NOEs and -couplings.
View Article and Find Full Text PDFFront Cardiovasc Med
January 2022
Objective: To evaluate the feasibility of 9. 4-T postmortem MRI (pm-MRI) for assessment of major congenital heart defects (CHD) cases terminated in the early stage of gestation.
Methods: Fetuses with CHD detected by the detailed first-trimester ultrasound scan and terminated before 18 gestational weeks were recruited between January 2018 and June 2020.
We report the room-temperature Pd-catalyzed methoxy-carbonylation with high branched selectivity using a new class of bisphosphine-picolinamide ligands. Systematic optimization of ligand structures and reaction conditions revealed the significance of both the picolinamide and bisphosphine groups in the ligand backbone. This strategic design of ligand was leveraged to deliver various α-substituted acrylates in good to excellent yields.
View Article and Find Full Text PDFObjective: To assess the feasibility of fetoscopy-guided bipolar umbilical cord coagulation for selective fetal reduction in complicated monochorionic diamniotic (MCDA) twin pregnancies.
Methods: MCDA twins undergoing fetoscopy-guided bipolar cord coagulation (BCC) were enrolled prospectively between December 2015 to March 2020 in a fetal medicine center.
Results: Twenty-three cases undergoing fetoscopy-guided BCC were finally analyzed, including 11 cases for type 2 selective intrauterine growth restriction, 4 cases for twin-twin transfusion syndrome, and 8 cases for a severe discordant anomaly.
Single-atom Rh catalysts present superior activity relative to homogeneous catalyst in olefins hydroformylation, yet with limited success in regioselectivity control. In the present work, we develop a phosphorus coordinated Rh single-atom catalyst with nanodiamond as support. Benefiting from this unique structure, the catalyst exhibits excellent activity and regioselectivity in hydroformylation of arylethylenes with wide substrate generality, i.
View Article and Find Full Text PDFObjective: To present the experience on prenatal features of 17q12 microdeletion and microduplication syndromes.
Materials And Methods: Prenatal chromosomal microarray analysis (CMA) were conducted between January 2015 and December 2018 at a single Chinese tertiary medical centre. Information of cases identified with 17q12 microdeletion or microduplication syndromes were retrospectively collected.
Purpose: To summarize the outcomes of different surgical treatment modalities for cesarean scar pregnancy (CSP) at a single institution over 8 years.
Methods: A case series of patients diagnosed with CSP who were admitted to Nanjing Drum Tower Hospital from January 2011 to December 2018 was retrospectively studied. Medical records of all the patients were carefully reviewed.
Background: Viral myocarditis (VMC) is a type of cardiac inflammation that is generally caused by coxsackievirus B3 (CVB3) infection. Several MicroRNAs (miRNAs) are known to play crucial roles in VMC pathogenesis. MiR-15 is reportedly associated with myocardial injury, inflammatory responses and viral infection.
View Article and Find Full Text PDFBenzoxepane derivatives were designed and synthesized, and one hit compound emerged as being effective in vitro with low toxicity. In vivo, this hit compound ameliorated both sickness behavior through anti-inflammation in LPS-induced neuroinflammatory mice model and cerebral ischemic injury through anti-neuroinflammation in rats subjected to transient middle cerebral artery occlusion. Target fishing for the hit compound using photoaffinity probes led to identification of PKM2 as the target protein responsible for anti-inflammatory effect of the hit compound.
View Article and Find Full Text PDFIntrauterine adhesion (IUA) is a common cause of uterine infertility and one of the most severe clinical features is endometrial fibrosis namely endometrial scarring for which there are few cures currently. Blocked angiogenesis is the main pathological change in the scarred endometrium. The fibroblast growth factor 2 (bFGF), a member of FGF family, is usually applied to promote healing of refractory ulcer and contributes to angiogenesis of tissues.
View Article and Find Full Text PDFObjective: To explore the value of strain elastography as an early predictor of long-term prognosis in patients with locally advanced cervical cancers treated with concurrent chemoradiotherapy (CCRT).
Methods: Strain elastography examinations were performed on 45 patients with locally advanced cervical cancers at 3 time points: prior to CCRT, and at 1 and 2 weeks after the start of CCRT. The maximum tumor diameter (D), strain ratio (SR), and their percentage changes (ΔD and ΔSR) were calculated to predict long-term prognosis.
Two new highly oxygenated ergostane-type sterols (1, 2) together with one known related compound sinugrandisterol A (3) were isolated from the soft coral Sinularia sp. collected from the water area near the Xisha Islands, South China Sea. Their structures were elucidated on the basis of detailed spectroscopic analysis, chemical transformations, and by comparison with those reported in literature.
View Article and Find Full Text PDFFour new cembranoids (1-4) were isolated from the extracts of a soft coral collected from the sea area near Xisha Island, South China Sea. The structures of these compounds were determined mainly by spectroscopic analyses, with the absolute configuration of 1 being established by X-ray diffraction analysis. In bioassay, compounds 1 and 3 displayed moderate inhibitory activity against Aβ aggregation (20.
View Article and Find Full Text PDFThree new polyoxygenated diterpenes (1, 3 and 4) of eunicellin-type, namely, 8-n-butyryl-litophynol A, 6-keto-litophynol B and 6-epi-litophynol B, respectively, together with two related known ones (2 and 5), were isolated from the soft coral Cladiella krempfi collected off the Weizhou island, Guangxi Zhuang Autonomous Region, China. The structures of the new compounds were elucidated by extensive spectroscopic analysis and chemical correlation. In bioassay, all the new compounds displayed moderate anti-inflammatory effects.
View Article and Find Full Text PDFObjective: To estimate the potential value of fetal assessment for the cardiac axis (CAx) and V-sign angle (VSA) in the first trimester in the prediction of fetal major cardiac defects.
Methods: A cohort study was conducted from December 2015 to June 2016. Patients with singleton pregnancies and crown-rump length from 45 to 84 mm were recruited to undergo nuchal translucency sonography.