Impact of SARS-CoV-2 infection on patients with myasthenia gravis: a retrospective study in a Chinese population.

Background And Purpose: Myasthenia gravis (MG) is characterized by fluctuating muscle weakness due to immune-mediated damage to acetylcholine receptors. Viral infections can exacerbate symptoms of muscle weakness, and the clinical status of patients with MG may influence the outcomes of such infections. Here, we identified factors of symptom exacerbation, severe SARS-CoV-2 infection, and pneumonia in patients with MG who are infected with SARS-CoV-2.

Relationship between the morphology of the posterior pole of the eyeball and changes in choroidal structure and blood flow in myopia.

Background: The eyeball axial length (AL) is an important biological indicator of myopia, which has been widely studied. However, little research has been conducted on the relationship between eye shape and fundus structural changes in myopia. This study aimed to analyze the relationship between the shape of the posterior pole of the eye, and choroidal characteristics by comparing with the relationship between AL and choroidal characteristics.

Synergistic effect between biochar and nitrate fertilizer facilitated arsenic immobilization in an anaerobic contaminated paddy soil.

Nitrate nitrogen fertilizer was usually used to mitigate arsenic (As) release and mobilization in the anaerobic contaminated paddy soil. However, the effect of the interplay between nitrate fertilizer and biochar on As availability as well as the involved mechanism were poorly understood. Herein, the effects and mechanisms of biochar, nitrate fertilizer, and biochar-based nitrate fertilizer on the availability of As in the contaminated paddy soil were investigated via a microcosm incubation experiment.

Enhanced-electrochemiluminescence biosensor for detecting miRNA-21 based on a CuO-mediated click reaction and catalytic hairpin self-assembly.

MicroRNAs (miRNAs) are closely associated with cancer and have been considered cancer biomarkers. Herein, we propose an electrochemiluminescence (ECL) biosensor for detecting miRNA-21 based on target-induced catalytic hairpin self-assembly (CHA) and CuO-mediated azide-alkyne cycloaddition. Two hairpin DNAs were employed: one was immobilized on magnetic beads (HP2) and another was labeled with CuO (HP1-CuO).

Measurement of the Tilt Angle of the Optic Disc Using Spectral-Domain Optical Coherence Tomography and Related Factors in Myopia.

Purpose: This study presents a novel, three-dimensional method for measuring the tilt angle of the tilted optic disc (TOD) using spectral-domain optical coherence tomography (SD-OCT) and investigates the correlation between ocular-related parameters and TOD.

Methods: We included the right eyes of 243 healthy young individuals, categorized by axial length. We measured the ovality index (OI) and dihedral angle (DA) using SD-OCT infrared ray fundus photographs and high-resolution cross-sectional images of the optic disc, respectively.

A novel ratiometric electrochemical biosensing strategy based on T7 exonuclease-assisted homogenous target recycling coupling hairpin assembly-triggered double-signal output for the multiple amplified detection of miRNA.

A novel ratiometric electrochemical biosensing strategy based on T7 exonuclease (T7 Exo)-assisted homogenous target recycling coupling hairpin assembly triggered dual-signal output was proposed for the accurate and sensitive detection of microRNA-141 (miRNA-141). Concretely, in the presence of target miRNA, abundant signal transduction probes were released via the T7 Exo-assisted homogenous target recycling amplification, which could be captured by the specially designed ferrocene-labeled hairpin probe (Fc-H1) on -electrode interface and triggered the nonenzymatic catalytic hairpin assembly (Fc-H1 + MB-H2) to realize the cascade signal amplification and dual-signal output. Through such a conformational change process, the electrochemical signal of Fc (IFc) and MB (IMB) is proportionally and substantially decreased and increased.

Enzyme-free and triple-amplified electrochemical sensing of 8-hydroxy-2'-deoxyguanosine by three kinds of short pDNA-driven catalyzed hairpin assemblies followed by a hybridization chain reaction.

A sensitive and enzyme-free electrochemical aptasensor was constructed for the sensing of 8-hydroxy-2'-deoxyguanosine (8-OH-dG). In the process of constructing the aptasensor, triple signal amplification strategies were introduced to enhance the sensitivity. First, every aptamer/pDNA complex immobilized on magnetic beads could release three kinds of pDNAs when 8-OH-dG was introduced, which caused three-fold magnification of the target.

An ultrasensitive luminol cathodic electrochemiluminescence probe with highly porous Pt on ionic liquid functionalized graphene film as platform for carcinoembryonic antigen sensing.

The low-potential electrochemiluminescence (ECL) sensors based on cathodic light emission of luminol have caused more and more concerns due to their good stability and reproducibility. In this work, highly porous platinum (Pt) nanostructures on ionic liquid functionalized graphene film (GR-IL/pPt) were prepared as platform to construct a label-free ECL sensor for the detection of carcinoembryonic antigen (CEA). Due to their good biocompatibility, excellent electrocatalytic activity and highly porous structure, the as-prepared GR-IL/pPt composites benefited amplified cathodic ECL signal of luminol and high loading density of the CEA antibody.

A versatile label-free electrochemical biosensor for circulating tumor DNA based on dual enzyme assisted multiple amplification strategy.

A versatile label-free electrochemical biosensor based on dual enzyme assisted multiple amplification strategy was developed for ultrasensitive detection of circulating tumor DNA (ctDNA). The biosensor consists of a triple-helix molecular switch (THMS) as molecular recognition and signal transduction probe, ribonuclease HII (RNase HII) and terminal deoxynucleotidyl transferase (TdT) as dual enzyme assisted multiple amplification accelerator. The presence of target ctDNA could open THMS and trigger RNase HII-assisted homogenous target recycling amplification to produce substantial signal transduction probe (STP).

Perylenetetracarboxylic acid and carbon quantum dots assembled synergistic electrochemiluminescence nanomaterial for ultra-sensitive carcinoembryonic antigen detection.

It is important to design a nice electrochemiluminescence (ECL) biological nanomaterial for fabricating sensitive ECL immunosensor to detect tumor markers. Most reported ECL nanomaterial was decorated by a number of mono-luminophore. Here, we report a novel ECL nanomaterial assembled by dual luminophores perylenetetracarboxylic acid (PTCA) and carbon quantum dots (CQDs).

A novel "signal-on/off" sensing platform for selective detection of thrombin based on target-induced ratiometric electrochemical biosensing and bio-bar-coded nanoprobe amplification strategy.

A novel dual-signal ratiometric electrochemical aptasensor for highly sensitive and selective detection of thrombin has been designed on the basis of signal-on and signal-off strategy. Ferrocene labeled hairpin probe (Fc-HP), thrombin aptamer and methyl blue labeled bio-bar-coded AuNPs (MB-P3-AuNPs) were rationally introduced for the construction of the assay platform, which combined the advantages of the recognition of aptamer, the amplification of bio-bar-coded nanoprobe, and the ratiometric signaling readout. In the presence of thrombin, the interaction between thrombin and the aptamer leads to the departure of MB-P3-AuNPs from the sensing interface, and the conformation of the single stranded Fc-HP to a hairpin structure to take the Fc confined near the electrode surface.

A novel sandwiched electrochemiluminescence immunosensor for the detection of carcinoembryonic antigen based on carbon quantum dots and signal amplification.

In this study, a novel sandwiched electrochemiluminescence (ECL) immunosensor for the detection of carcinoembryonic antigen (CEA) was developed. The nanocomposite of polydopamine and Ag nanoparticles (PDA-AgNPs) was prepared by the redox reaction between Ag and dopamine. This nanocomposite not only provided an effective matrix for the immobilization of primary antibody (Ab) but also enhanced the conductivity of the electrode.

Highly sensitive electrochemical biosensor based on nonlinear hybridization chain reaction for DNA detection.

In the present work we demonstrated an ultrasensitive detection platform for specific DNA based on nonlinear hybridization chain reaction (HCR) by triggering chain-branching growth of DNA dendrimers. HCR was initiated by target DNA (tDNA) and finally formed dendritic structure by self-assembly. The electrochemical signal was drastically enhanced by capturing multiple catalytic peroxidase with high-ordered growth.

Synthesis of chiral aminophosphines from chiral aminoalcohols via cyclic sulfamidates.

Protic aminophosphines with multiple chiral centers were synthesized in good yields and high purity by the nucleophilic ring-opening of N-protected cyclic sulfamidates with metal phosphides, followed by hydrolysis and deprotection. This synthetic approach is clean, scalable, and high yielding. The method provides an efficient alternative route for the synthesis of chiral aminophosphines.

Aminophosphine ligands R(2)P(CH(2))(n)NH(2) and ruthenium hydrogenation catalysts RuCl(2)(R(2)P(CH(2))(n)NH(2))(2).

The aminophosphine ligands R(2)P(CH(2))(2)NH(2) and R(2)P(CH(2))(3)NH(2) (R = Ph, (i)Pr, (t)Bu) were isolated in good to excellent yields from the reaction of LiPR(2) with Cl(CH(2))(2)N(TMS)(2) and Cl(CH(2))(3)N(TMS)(2), respectively, followed by hydrolysis. This approach allows fine tuning of the ligands' stereoelectronic properties through the variation of the substituents on the phosphine. The aminophosphine ligands were used to prepare the ruthenium complexes RuCl(2)(R(2)P(CH(2))(2)NH(2))(2) and RuCl(2)(R(2)P(CH(2))(3)NH(2))(2) by reacting a 2:1 mixture of the respective ligand and [RuCl(2)(cod)](n) in an appropriate solvent.

Highly active iridium catalysts for the hydrogenation of ketones and aldehydes.

The pressure hydrogenation capabilities of the iridium pincer complexes IrH2Cl[((i)Pr2PC2H4)2NH] (1) and IrH3[((i)Pr2PC2H4)2NH] (2) are described and compared to related results obtained previously in transfer hydrogenation. Complex 1 was shown to act as a convenient air-stable entry point to the active catalyst 2, in the presence of base and hydrogen gas. The catalysts are active in a range of solvents, including CH2Cl2 and CHCl3, in contrast to related ruthenium systems.

Codon usage in mitochondrial genomes: distinguishing context-dependent mutation from translational selection.

We analyze the frequencies of synonymous codons in animal mitochondrial genomes, focusing particularly on mammals and fish. The frequencies of bases at 4-fold degenerate sites are found to be strongly influenced by context-dependent mutation, which causes correlations between pairs of neighboring bases. There is a pattern of excess of certain dinucleotides and deficit of others that is consistent across large numbers of species, despite the wide variation of single-nucleotide frequencies among species.

Electrochemical performance of 8-hydroxy-2'-deoxyguanosine and its detection at poly(3-methylthiophene) modified glassy carbon electrode.

8-Hydroxy-2'-deoxyguanosine (8-OH-dG) has attracted enormous attention in recent years because it has been acknowledged as a typical biomarker of oxidative DNA damage. In this paper, the electrochemical performance of 8-OH-dG at the poly(3-methylthiophene) (P3MT) modified glassy carbon electrode (GCE) was investigated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The conducting polymer P3MT can effectively decrease the oxidation peak potential of 8-OH-dG and greatly enhance its peak current.

Highly selective and sensitive determination of dopamine using a Nafion/carbon nanotubes coated poly(3-methylthiophene) modified electrode.

A poly(3-methylthiophene) modified glassy carbon electrode coated with Nafion/single-walled carbon nanotubes film was fabricated and used for highly selective and sensitive determination of dopamine. The hybrid film surface of the modified electrode was characterized by scanning electrochemical microscopy (SECM) and the results indicated that the carbon nanotubes were dispersed uniformly on the conductive polymer. The experimental results suggest that the hybrid film modified electrode combining the advantages of poly(3-methylthiophene), carbon nanotubes with Nafion exhibits dramatic electrocatalytic effect on the oxidation of dopamine (DA) and results in a marked enhancement of the current response.

Linear and star-shaped polynuclear Ru(II) complexes of 2-(2'-pyridyl)benzimidazolyl derivatives: syntheses, photophysical properties and red light-emitting devices.

Two new star-shaped ligands with a 1,3,5-triphenylbenzene core, tmpb (1,3,5-tris[p-2-(2'-pyridyl)benzimidazolylphenyl]benzene), and a 2,4,6-tris(p-biphenyl)-1,3,5-triazine core, tmbt (2,4,6-tris[p-2-(2'-pyridyl)benzimidazolylbiphenyl]-1,3,5-triazine), have been synthesized. Their corresponding trinuclear Ru(II) complexes [Ru3(tmpb)(bpy)6](PF6)6 (3) and [Ru3(tmpt)(bpy)6](PF6)6 (4) have been obtained. Two dinuclear linear Ru(II) complexes with previously reported ligands bmb (1,4-bis[2-(2'-pyridyl)benzimidazolyl]benzene) and bmbp (4,4'-bis[2-(2'-pyridyl)benzimidazolyl]biphenyl) and formulae [Ru2(bmb)(bpy)4](PF6)4 (1) and [Ru2(bmbp)(bpy)4](PF6)4 (2) have also been synthesized.

Phosphorescent Cu(I) complexes of 2-(2'-pyridylbenzimidazolyl)benzene: impact of phosphine ancillary ligands on electronic and photophysical properties of the Cu(I) complexes.

Four mononuclear Cu(I) complexes of 2-(2'-pyridyl)benzimidazolylbenzene (pbb) with four different ancillary phosphine ligands PPh(3), bis[2-(diphenylphosphino)phenyl]ether (DPEphos), bis(diphenylphosphino)ethane (dppe), and bis(diphenylphosphinomethyl)diphenylborate (DPPMB) have been synthesized. The crystal structures of [Cu(pbb)(PPh(3))(2)][BF(4)] (1), [Cu(pbb)(dppe)][BF(4)] (2), [Cu(pbb)(DPEphos)][BF(4)] (3), and the neutral complex [Cu(pbb)(DPPMB)] (4) were determined by single-crystal X-ray diffraction analyses. The impact of the phosphine ligands on the structures of the copper(I) complexes was examined, revealing that the most significant impact of the phosphine ligands is on the P-Cu-P bond angle.