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1.
Sex Med ; 12(1): qfae014, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38500665

ABSTRACT

Background: The traditional audiovisual sexual stimulation (AVSS) test may experience limitations including low erectile response rate and lack of unified diagnostic criteria. Aim: We aimed to explore the clinical value of AVSS with virtual reality (VR-AVSS) test in assessing erectile function and diagnosing erectile dysfunction (ED). Methods: Participants 18 to 60 years of age were screened for analysis in 3 clinical centers from June 2020 to March 2022. Demographic data, 5-item International Index of Erectile Function (IIEF-5), erectile hardness score (EHS), and self-reported symptom questions were collected. The ED patients and control patients were confirmed according to the IIEF-5 and EHS. All subjects watched a 60-minute erotic video by VR device during RigiScan recording. The parameters including tip average rigidity, tip effective erectile duration (duration of rigidity ≥60%, tip effective erectile duration), base average rigidity, and base effective erectile duration were evaluated. Outcomes: The main outcome of interest was the application of VR immersion technology to improve the traditional AVSS test. Results: A total of 301 ED cases and 100 eligible control patients were included for final analysis. Compared with control patients, ED cases had significantly lower IIEF-5 scores, EHS, positive response rate, and erectile rigidity and duration. The positive response rate of ED and control patients were 75.5% and 90.9%, respectively. The cutoff points of tip average rigidity, tip effective erectile duration, base average rigidity, and base effective erectile duration were 40.5% (sensitivity: 77.6%, specificity: 70.2%; P < .001), 4.75 minutes (sensitivity: 75.9%, specificity: 75.4%; P < .001), 48.5% (sensitivity: 77.6%, specificity: 75.1%; P < .001), and 7.75 minutes (sensitivity: 79.3%, specificity: 75.7%; P < .001). Clinical Implications: The technological superiority of VR will enable the VR-AVSS immersion test to be a more accurate detection than traditional AVSS modes. Strengths and Limitations: Our study applied VR immersion technology to establish the standard operation procedure for the AVSS test, which could effectively reduce the interference of adverse factors and minimize the detecting errors. However, the test data only included positive response subjects, so the true erectile status of men with a negative response to the AVSS test cannot be obtained. Conclusions: The VR-AVSS test can effectively improve the diagnostic accuracy of ED. The average rigidity and effective erectile duration were the optimal diagnostic parameters for excluding ED.

2.
Curr Urol ; 18(1): 30-33, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38505155

ABSTRACT

Objectives: To assess the effect of redo inferior pubectomy on the management of complicated pelvic fracture urethral injury (PFUI) in patients with a history of failed anastomotic urethroplasty. Materials and methods: We retrospectively reviewed all patients receiving redo anastomotic urethroplasty with redo inferior pubectomy for failed PFUI between January 2010 and December 2021. Patients with incomplete data and those who were lost to follow-up were excluded. Successful urethroplasty was defined as the restoration of a uniform urethral caliber without stenosis or leakage and further intervention. Functional results, including erectile function and urinary continence, were evaluated. Descriptive statistical analyses were then performed. Results: Thirty-one patients were included in this study. Among them, concomitant urethrorectal fistula occurred in 2 patients, and concomitant enlarged bladder neck occurred in 1. The stenosis site was the bulbomembranous urethra in 2 patients and the prostatomembranous urethra in 29. The mean length of urethral stenosis in all patients was 3.1 cm (range, 2.0-5.0 cm). After a mean follow-up of 34.6 months, the final success rate was 96.8%. The incidence of erectile dysfunction reached 77.4% (24/31). Normal continence was achieved in 27 (87.1%) patients. One patient developed urinary incontinence of grade II requiring urinary pads because of an enlarged bladder neck. According to the Clavien-Dindo classification, postoperative complications of grade I occurred in 7 patients and grade II in 4. Conclusions: Repeat anastomotic urethroplasty with repeat inferior pubectomy provides reliable success rates for failed PFUI. In complicated cases, it should be known and mastered.

3.
Opt Express ; 32(4): 4876-4886, 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-38439228

ABSTRACT

The conventional orthogonality of Laguerre-Gaussian (LG) beams is widely recognized and serves as the fundamental basis for mode division multiplexing utilizing LG beams as channels. However, this conventional orthogonality holds true only when two LG beams share the same axis. Whether non-coaxial LG beams, with parallel axes separated by a distance, are orthogonal to each other remains an open question. To address this issue and reveal the orthogonality of non-coaxial LG beams, we analytically derive the projection of one LG beam onto another. This projection exhibits a helical phase and a rotationally symmetric amplitude with dark rings present. These dark rings indicate that two non-coaxial LG beams are indeed orthogonal to each other when their axes are appropriately separated. Furthermore, any pair of non-coaxial LG beams within a set also exhibit orthogonality when their axes are fixed at a certain separation distance. This novel form of orthogonality predicts an innovative compound multiplexing technique that simultaneously combines mode and space, enabling more efficient packing of multiple LG beams within a single transmission aperture while maintaining parallel and closely spaced beam axes.

4.
Eur J Med Chem ; 269: 116296, 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38467086

ABSTRACT

Steroid hybrids have emerged as a type of advantageous compound as they could offer improved pharmacological and pharmaceutical properties. Here, we report a series of novel peptide-dehydroepiandrosterone hybrids, which would effectively induce endoplasmic reticulum stress (ERS) and lead to apoptosis with outstanding in vitro and in vivo anti-melanoma effects. The lead compound IId among various steroids conjugated with peptides and pyridines showed effective in vivo activity in B16 xenograft mice: in medium- and high-dose treatment groups (60 and 80 mg/kg), compound IId would significantly inhibit the growth of tumours by 98%-99% compared to the control group, with the highest survival rate as well. Further mechanism studies showed that compound IId would damage the endoplasmic reticulum and upregulate the ERS markers C/EBP homologous protein (CHOP) and glucose-regulated protein 78 (GRP78), which could further regulate caspase and Bcl-2 family proteins and lead to cell apoptosis. The compound IId was also proven to be effective in inhibiting B16 cell migration and invasion.


Subject(s)
Apoptosis , Endoplasmic Reticulum , Humans , Mice , Animals , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum Stress , Peptides/pharmacology , Dehydroepiandrosterone/metabolism , Dehydroepiandrosterone/pharmacology
5.
Bioresour Technol ; 395: 130403, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38295958

ABSTRACT

L-Valine, a branched-chain amino acid with diversified applications, is biosynthesized with α-acetolactate as the key precursor. In this study, the metabolic flux in Klebsiella oxytoca PDL-K5, a Risk Group 1 organism producing 2,3-butanediol as the major fermentation product, was rearranged to L-valine production by introducing exogenous L-valine biosynthesis pathway and blocking endogenous 2,3-butanediol generation at the metabolic branch point α-acetolactate. After further enhancing L-valine efflux, strengthening pyruvate polymerization and selecting of key enzymes for L-valine synthesis, a plasmid-free K. oxytoca strain VKO-9 was obtained. Fed-batch fermentation with K. oxytoca VKO-9 in a 7.5 L fermenter generated 122 g/L L-valine with a yield of 0.587 g/g in 56 h. In addition, repeated fed-batch fermentation was conducted to prevent precipitation of L-valine due to oversaturation. The average concentration, yield, and productivity of produced L-valine in three cycles of repeated fed-batch fermentation were 81.3 g/L, 0.599 g/g, and 3.39 g/L/h, respectively.


Subject(s)
Klebsiella oxytoca , Lactates , Valine , Klebsiella oxytoca/genetics , Klebsiella oxytoca/metabolism , Bioreactors , Fermentation , Butylene Glycols/metabolism , Metabolic Engineering
6.
Langmuir ; 40(1): 474-479, 2024 Jan 09.
Article in English | MEDLINE | ID: mdl-38149797

ABSTRACT

Photoresponsive materials enable dynamic remote control of their fundamental properties. The incorporation of photochromic molecules in nanoporous metal-organic frameworks (MOFs) provides a unique opportunity to tailor the material properties, including the interaction between the MOF host and guest molecules in the pores. Here, a MOF film of type HKUST-1 with embedded hexaarylbiimidazole (HABI), undergoing reversible light-induced reactions between the stable dimer state and the metastable radical state, is presented. The switching between the dimer and radical form is shown by infrared, UV-vis, and electron paramagnetic resonance (EPR) spectroscopy. By transient uptake experiments with ethanol and methanol as probe molecules, we show that the dimer-radical switching impacts the host-guest interaction and, in particular, modifies the uptake amount and diffusion coefficient of the guest molecules. For ethanol, the diffusion slows down by 75%. This research presents the first MOF material with photoswitchable (meta)stable dimer and radical molecules, and it contributes to the advancement of photoresponsive nanoporous materials.

7.
World J Stem Cells ; 15(7): 734-750, 2023 Jul 26.
Article in English | MEDLINE | ID: mdl-37545755

ABSTRACT

BACKGROUND: Haploid embryonic stem cells (haESCs) have been established in many species. Differentiated haploid cell line types in mammals are lacking due to spontaneous diploidization during differentiation that compromises lineage-specific screens. AIM: To derive human haploid neural stem cells (haNSCs) to carry out lineage-specific screens. METHODS: Human haNSCs were differentiated from human extended haESCs with the help of Y27632 (ROCK signaling pathway inhibitor) and a series of cytokines to reduce diploidization. Neuronal differentiation of haNSCs was performed to examine their neural differentiation potency. Global gene expression analysis was con-ducted to compare haNSCs with diploid NSCs and haESCs. Fluorescence activated cell sorting was performed to assess the diploidization rate of extended haESCs and haNSCs. Genetic manipulation and screening were utilized to evaluate the significance of human haNSCs as genetic screening tools. RESULTS: Human haESCs in extended pluripotent culture medium showed more compact and smaller colonies, a higher efficiency in neural differentiation, a higher cell survival ratio and higher stability in haploidy maintenance. These characteristics effectively facilitated the derivation of human haNSCs. These human haNSCs can be generated by differentiation and maintain haploidy and multipotency to neurons and glia in the long term in vitro. After PiggyBac transfection, there were multiple insertion sites in the human haNSCs' genome, and the insertion sites were evenly spread across all chromosomes. In addition, after the cells were treated with manganese, we were able to generate a list of manganese-induced toxicity genes, demonstrating their utility as genetic screening tools. CONCLUSION: This is the first report of a generated human haploid somatic cell line with a complete genome, proliferative ability and neural differentiation potential that provides cell resources for recessive inheritance and drug targeted screening.

8.
Polymers (Basel) ; 15(5)2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36904497

ABSTRACT

Recent studies have shown that introducing fluorinated groups into polyimide (PI) molecules can effectively reduce the dielectric constant (Dk) and dielectric loss (Df) of PIs. In this paper, 2,2'-bis[4-(4-aminophenoxy) phenyl]-1,1',1',1',3,3',3'-hexafluoropropane (HFBAPP), 2,2'-bis(trifluoromethyl)-4,4'-diaminobenzene (TFMB), diaminobenzene ether (ODA), 1,2,4,5-Benzenetetracarboxylic anhydride (PMDA), 3,3',4,4'-diphenyltetracarboxylic anhydride (s-BPDA) and 3,3',4,4'-diphenylketontetracarboxylic anhydride (BTDA) were selected for mixed polymerization to find the relationship between the structure of PIs and dielectric properties. Firstly, different structures of fluorinated PIs were determined, and were put into simulation calculation to learn how structure factors such as fluorine content, the position of fluorine atom and the molecular structure of diamine monomer affect the dielectric properties. Secondly, experiments were carried out to characterize the properties of PI films. The observed change trends of performance were found to be consistent with the simulation results, and the possible basis of the interpretation of other performance was made from the molecular structure. Finally, the formulas with the best comprehensive performance were obtained respectively. Among them, the best dielectric properties were 14.3%TFMB/85.7%ODA//PMDA with dielectric constant of 2.12 and dielectric loss of 0.00698.

9.
Sci Adv ; 9(13): eadg1645, 2023 Mar 29.
Article in English | MEDLINE | ID: mdl-36989366

ABSTRACT

The catalytic dearomative cycloaddition of bicyclic heteroaromatics including benzofurans and indoles provides rapid access to functionalized heterocyclic molecules. Because of the inherent stereoelectronic differences, the furan or pyrrole nucleus is more prone to dearomative cycloaddition than the benzene ring. Here, we realized a geometry-based differentiation approach for achieving C6-C7 and C7-C7a regioselectivity. The rotationally restricted σ bond at C7 position respectively placed the C6-C7 and C7-C7a sites of benzofurans or indoles in an optimal spatial orientation toward the axially chiral heterodiene, thus affording two enantioenriched polycyclic compounds from a single racemic heterobiaryl atropisomers. Calculation results of density functional theory interpreted the mechanism of this parallel kinetic resolution. The bioactivity of the dearomatized products was evaluated in cancer cell lines with certain compounds exhibiting interesting biological activities.

10.
Angew Chem Int Ed Engl ; 62(20): e202218052, 2023 May 08.
Article in English | MEDLINE | ID: mdl-36808409

ABSTRACT

Molecular machines and responsive materials open a plethora of new opportunities in nanotechnology. We present an oriented crystalline array of diarylethene (DAE)-based photoactuators, arranged in a way to yield an anisotropic response. The DAE units are assembled, together with a secondary linker, into a monolithic surface-mounted metal-organic framework (SURMOF) film. By Infrared (IR) and UV/Vis spectroscopy as well as by synchrotron X-ray diffraction, we show that the light-induced extension changes of the molecular DAE linkers multiply to yield mesoscopic and anisotropic length changes. Due to the special architecture and substrate-bonding of the SURMOF, these length changes are transferred to the macroscopic scale, leading to the bending of a cantilever and performing work. This research shows the potential of assembling light-powered molecules into SURMOFs to yield photoactuators with a directed response, presenting a path to advanced actuators.

11.
Pharmacology ; 108(2): 138-146, 2023.
Article in English | MEDLINE | ID: mdl-36516801

ABSTRACT

INTRODUCTION: Voltage-gated Kv7/M potassium channels play an essential role in the control of membrane potential and neuronal excitability. Fangchinoline, a bisbenzylisoquinoline alkaloid, displays extensive biological activities including antitumor, anti-inflammatory, and antihypertension effects. In this study, we investigated the effects of fangchinoline on Kv7/M channels. METHODS: A perforated whole-cell patch technique was used to record Kv7 currents from HEK293 cells and M-type currents from mouse dorsal root ganglion (DRG) neurons. RESULTS: Fangchinoline inhibited Kv7.2/Kv7.3 currents in a concentration-dependent manner, with an IC50 of 9.5 ± 1.2 µM. Fangchinoline significantly inhibited Kv7.1, Kv7.2, Kv7.3, Kv7.4, and Kv7.3/Kv7.5 channels without selective effects. Furthermore, fangchinoline significantly slowed the activation of Kv7.1-Kv7.5 channels and inhibited native M-channel currents of DRG neurons. CONCLUSION: Taken together, our findings indicate that fangchinoline concentration-dependently inhibited Kv7/M channel currents.


Subject(s)
Benzylisoquinolines , Humans , Mice , Animals , HEK293 Cells , Membrane Potentials , Benzylisoquinolines/pharmacology , KCNQ2 Potassium Channel , KCNQ3 Potassium Channel
12.
Opt Express ; 30(24): 44132-44140, 2022 Nov 21.
Article in English | MEDLINE | ID: mdl-36523095

ABSTRACT

The Newton's rings are interference patterns with concentric rings, and Newton's rings experiment is one of the most famous classic optics experiments. Here, we show that if we use a vortex beam, we can obtain generalized Newton's rings. Unlike traditional Newton's rings, the generalized ones are no longer concentric rings but spiral arms, and fork-shaped dislocations appear in spiral arms. More interesting, we reveal that both the number of spiral arms and the number of fork-shaped dislocations are equal to the value of topological charge of incident vortex beams. Our theoretical results are demonstrated experimentally. This novel interference pattern can be used for measuring the topological charge of vortex beams.

13.
Transl Androl Urol ; 11(11): 1486-1494, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36507487

ABSTRACT

Background: Glycated serum albumin (GSA) is an early glycosylation product that participates in diabetic vascular complications. This study examined the role of GSA in early damage to the corpus cavernosum and the involved mechanisms. Methods: Nine 8-week-old male Sprague-Dawley (SD) rats (250-300 g) were divided into the control (saline vehicle, n=3) and GSA (200 µg/kg, n=6) groups. The corpus cavernosum tissues were harvested. Phosphorylated and non-phosphorylated connexin 43 (Cx43), endothelial nitric oxide synthase (eNOS), phosphatidylinositol 3-kinase (PI3K), and serine-threonine kinase (Akt) were tested by immunohistochemistry and western blotting. Human umbilical vein endothelial cells (HUVECs) overexpressing Cx43 were used to analyze the Cx43 phosphorylation sites (S368, S262, Y265, S255, and S279/282) using western blotting. Results: The expression of phosphorylated Cx43 in the penis was significantly lower in GSA-treated rats than in controls. The expression levels of p-Cx43, p-eNOS, p-PI3K, and p-Akt were significantly decreased in HUVECs exposed to GSA in dose- and time-dependent manners. The most significant impact on all four proteins was observed with 1 µg/mL of GSA for 12 h. Phosphorylation at the S368, S262, Y265, S255, and S279/282 sites of Cx43 was downregulated by GSA, and S368 was the most significantly suppressed phosphorylation site compared with the other sites. Conclusions: GSA decreases the expression of p-Cx43 in the corpus cavernosum of rats. This effect might be also related to the decreased phosphorylation of p-eNOS, p-PI3K, and p-Akt, as well as by the downregulation of phosphorylation at the S368 site.

14.
Materials (Basel) ; 15(22)2022 Nov 14.
Article in English | MEDLINE | ID: mdl-36431500

ABSTRACT

In this paper, a new aromatic diamine monomer 4,4'-(2,6-naphthalenediyl)bis[benzenamine]) (NADA) was synthesized and a series of modified PI films containing naphthalene ring structure obtained by controlling the molar ratio of NADA monomer, ternary polymerization with 4,4'-oxydianiline (ODA), and pyromellitic dianhydride (PMDA). The effects of the introduction of the naphthalene ring on the free volume and various properties of PI were investigated by molecular dynamic simulations. The results show that the comprehensive properties of the modified films are all improved to some extent, with 5% thermal weight loss temperature (Td5%) of 569 °C, glass transition temperature (Tg) of 381 °C, tensile strength of 96.41 MPa, and modulus of elasticity of 2.45 GPa. Dielectric property test results show that the dielectric constant (Dk) of the film at 1 MHz is reduced from 3.21 to 2.82 and dielectric loss (Df) reduced from 0.0091 to 0.0065. It is noteworthy that the PI-1 dielectric constant is reduced from 3.26 to 3.01 at 10 GHz with only 5% NADA doping, which is expected to yield the best ratio and provide the possibility of industrial production.

15.
Medicine (Baltimore) ; 101(46): e31930, 2022 Nov 18.
Article in English | MEDLINE | ID: mdl-36401438

ABSTRACT

Spinal cord injury is a severe central nervous system injury that results in the permanent loss of motor, sensory, and autonomic functions below the level of injury with limited recovery. The pathological process of spinal cord injury includes primary and secondary injuries, characterized by a progressive cascade. Secondary injury impairs the ability of the mitochondria to maintain homeostasis and leads to calcium overload, excitotoxicity, and oxidative stress, further exacerbating the injury. The defective mitochondrial function observed in these pathologies accelerates neuronal cell death and inhibits regeneration. Treatment of spinal cord injury by preserving mitochondrial biological function is a promising, although still underexplored, therapeutic strategy. This review aimed to explore mitochondrial-based therapeutic advances after spinal cord injury. Specifically, it briefly describes the characteristics of spinal cord injury. It then broadly discusses the drugs used to protect the mitochondria (e.g., cyclosporine A, acetyl-L-carnitine, and alpha-tocopherol), phenomena associated with mitochondrial damage processes (e.g., mitophagy, ferroptosis, and cuproptosis), mitochondrial transplantation for nerve cell regeneration, and innovative mitochondrial combined protection therapy.


Subject(s)
Spinal Cord Injuries , Humans , Mitochondria/pathology , Oxidative Stress
16.
mBio ; 13(6): e0262422, 2022 12 20.
Article in English | MEDLINE | ID: mdl-36218368

ABSTRACT

Pseudomonas aeruginosa is an important opportunistic pathogen that is lethal to cystic fibrosis (CF) patients. Glycerol generated during the degradation of phosphatidylcholine, the major lung surfactant in CF patients, could be utilized by P. aeruginosa. Previous studies have indicated that metabolism of glycerol by this bacterium contributes to its adaptation to and persistence in the CF lung environment. Here, we investigated the metabolic mechanisms of glycerol and its important metabolic intermediate glycerol 3-phosphate (G3P) in P. aeruginosa PAO1. We found that G3P homeostasis plays an important role in the growth and virulence factor production of P. aeruginosa PAO1. The G3P accumulation caused by the mutation of G3P dehydrogenase (GlpD) and exogenous glycerol led to impaired growth and reductions in pyocyanin synthesis, motilities, tolerance to oxidative stress, and resistance to kanamycin. Transcriptomic analysis indicates that the growth retardation caused by G3P stress is associated with reduced glycolysis and adenosine triphosphate (ATP) generation. Furthermore, two haloacid dehalogenase-like phosphatases (PA0562 and PA3172) that play roles in the dephosphorylation of G3P in strain PAO1 were identified, and their enzymatic properties were characterized. Our findings reveal the importance of G3P homeostasis and indicate that GlpD, the key enzyme for G3P catabolism, is a potential therapeutic target for the prevention and treatment of infections by this pathogen. IMPORTANCE In view of the intrinsic resistance of Pseudomonas aeruginosa to antibiotics and its potential to acquire resistance to current antibiotics, there is an urgent need to develop novel therapeutic options for the treatment of infections caused by this bacterium. Bacterial metabolic pathways have recently become a focus of interest as potential targets for the development of new antibiotics. In this study, we describe the mechanism of glycerol utilization in P. aeruginosa PAO1, which is an available carbon source in the lung environment. Our results reveal that the homeostasis of glycerol 3-phosphate (G3P), a pivotal intermediate in glycerol catabolism, is important for the growth and virulence factor production of P. aeruginosa PAO1. The mutation of G3P dehydrogenase (GlpD) and the addition of glycerol were found to reduce the tolerance of P. aeruginosa PAO1 to oxidative stress and to kanamycin. The findings highlight the importance of G3P homeostasis and suggest that GlpD is a potential drug target for the treatment of P. aeruginosa infections.


Subject(s)
Cystic Fibrosis , Pseudomonas Infections , Humans , Pseudomonas aeruginosa/genetics , Glycerol/metabolism , Virulence Factors/genetics , Cystic Fibrosis/microbiology , Anti-Bacterial Agents/metabolism , Kanamycin/metabolism , Oxidoreductases/metabolism , Pseudomonas Infections/microbiology
17.
Nanomaterials (Basel) ; 12(18)2022 Sep 06.
Article in English | MEDLINE | ID: mdl-36144881

ABSTRACT

Due to its unique physical and chemical properties, MXene has recently attracted much attention as a promising candidate for wastewater treatment. However, the low water permeation flux of MXene membrane remains a challenge that has not been fully solved. In this study, attapulgite was used to increase the flux of MXene membrane through a facile one-pot method, during which the MXene nanosheets were self-assembled while being intercalated by the attapulgite nanorods to finally form the composite membranes. Under optimal conditions, an increase of water permeation flux of 97.31% could be observed, which was attributed to the broadened nano-channel upon the adequate intercalation of attapulgite nanorods. Its permeation flux and rejection rate for methylene blue (MB) were further studied for diverse applications. In contrast to bare MXene, the permeation flux increased by 61.72% with a still high rejection rate of 90.67%, owing to the size rejection. Overcoming a key technique barrier, this work successfully improved the water permeability of MXene by inserting attapulgite nanorods, heralding the exciting prospects of MXene-based lamellar membrane in dye wastewater treatment.

18.
Acc Chem Res ; 55(19): 2780-2795, 2022 10 04.
Article in English | MEDLINE | ID: mdl-36121104

ABSTRACT

Atropisomers, arising from conformational restriction, are inherently chiral due to the intersecting dissymmetric planes. Since there are numerous applications of enantiopure atropisomers in catalyst design, drug discovery, and material science, the asymmetric preparation of these highly prized molecules has become a flourishing field in synthetic chemistry. A number of catalysts, synthetic procedures, and novel concepts have been developed for the manufacture of the atropisomeric molecules. However, due to the intrinsic properties of different types of atropisomers featuring biaryl, hetero-biaryl, or non-biaryl architectures, only very few methods pass the rigorous inspection and are considered generally applicable. The development of a broadly applicable synthetic strategy for various atropisomers is a challenge. In this Account, we summarize our recent studies on the enantioselective synthesis of atropisomers using the vinylidene ortho-quinone methides (VQMs) as pluripotent intermediates.The most appealing features of VQMs are the disturbed aromaticity and axial chirality of the allene fragment. At the outset, the applications of VQMs in organic synthesis have been neglected due to their principal liabilities: ephemeral nature, extraordinary reactivity, and multireaction sites. The domestication of this transient intermediate was demonstrated by in situ catalytic asymmetric generation of VQMs, and the reactivity and selectivity were fully explored by judiciously modifying precursors and tuning catalytic systems. A variety of axially chiral heterocycles were achieved through five-, six-, seven- and nine-membered ring formation of VQM intermediates with different kinds of branched nucleophilic functional groups. The axially chiral C-N axis could be constructed from VQM intermediates via N-annulation or desymmetrization of preformed C-N scaffolds. We take advantage of the high electrophilicity of VQMs toward a series of sulfur and carbon based nucleophiles leading to atropisomeric vinyl arenes. Furthermore, chiral helical compounds were realized by cycloaddition or consecutive annulation of VQM intermediates. These achievements demonstrated that the VQMs could work as a nuclear parent for the collective synthesis of distinct and complex optically active atropisomers. Recently, we have realized the isolation and structural characterization of the elusive VQMs, which were questioned as putative intermediates for decades. The successful isolation of VQMs provided direct evidence for their existence and an unprecedented opportunity to directly investigate their reactivity. The good thermal stability and reserved reactivity of the isolated VQMs demonstrated their great potential as synthetic reagents and expanded the border of VQM chemistry.


Subject(s)
Indolequinones , Carbon , Indolequinones/chemistry , Stereoisomerism , Sulfur
19.
Int J Biol Macromol ; 218: 1-8, 2022 Oct 01.
Article in English | MEDLINE | ID: mdl-35792312

ABSTRACT

Polycaprolactone (PCL) nanofibers have become an ideal material for bone tissue engineering due to a series of advantages. Considering the clinical treatment of bone defects, in addition to meeting the golden standard, PCL based nanofibers also need to be multifunctional to anti-inflammatory, antibacterial properties, and enhance the bone regeneration and repair. Herein, we successfully developed the multifunctional PCL/LIG/ZIF-8 composite nanofibers by loading ZIF-8 on electrospun PCL/lignin (PCL/LIG) nanofibers. The prepared composite nanofibers exhibit fairly good wettability and acceptable degradation rate, as well as excellent antioxidative stress and antibacterial properties originating from the incorporated LIG and loaded ZIF-8. Moreover, owing to the synergistic effect of LIG and ZIF-8, the composite nanofibers present excellent osteogenic differentiation, which can be verified in biomineralization experiments and real-time quantitative polymerase chain reaction. These results indicate that the PCL/LIG/ZIF-8 composite nanofibers, as potential healthcare candidate, have a promising applied in the treatment of bone defects.


Subject(s)
Nanofibers , Anti-Bacterial Agents/therapeutic use , Lignin , Nanofibers/therapeutic use , Osteogenesis , Polyesters , Tissue Engineering/methods , Tissue Scaffolds
20.
J Integr Plant Biol ; 64(8): 1531-1542, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35652263

ABSTRACT

Arabidopsis MITOGEN-ACTIVATED PROTEIN KINASE3 (MAPK3 or MPK3) and MPK6 play important signaling roles in plant immunity and growth/development. MAPK KINASE4 (MKK4) and MKK5 function redundantly upstream of MPK3 and MPK6 in these processes. YODA (YDA), also known as MAPK KINASE KINASE4 (MAPKKK4), is upstream of MKK4/MKK5 and forms a complete MAPK cascade (YDA-MKK4/MKK5-MPK3/MPK6) in regulating plant growth and development. In plant immunity, MAPKKK3 and MAPKKK5 function redundantly upstream of the same MKK4/MKK5-MPK3/MPK6 module. However, the residual activation of MPK3/MPK6 in the mapkkk3 mapkkk5 double mutant in response to flg22 pathogen-associated molecular pattern (PAMP) treatment suggests the presence of additional MAPKKK(s) in this MAPK cascade in signaling plant immunity. To investigate whether YDA is also involved in plant immunity, we attempted to generate mapkkk3 mapkkk5 yda triple mutants. However, it was not possible to recover one of the double mutant combinations (mapkkk5 yda) or the triple mutant (mapkkk3 mapkkk5 yda) due to a failure of embryogenesis. Using the clustered regularly interspaced short palindromic repeats (CRISPR) - CRISPR-associated protein 9 (Cas9) approach, we generated weak, N-terminal deletion alleles of YDA, yda-del, in a mapkkk3 mapkkk5 background. PAMP-triggered MPK3/MPK6 activation was further reduced in the mapkkk3 mapkkk5 yda-del mutant, and the triple mutant was more susceptible to pathogen infection, suggesting YDA also plays an important role in plant immune signaling. In addition, MAPKKK5 and, to a lesser extent, MAPKKK3 were found to contribute to gamete function and embryogenesis, together with YDA. While the double homozygous mapkkk3 yda mutant showed the same growth and development defects as the yda single mutant, mapkkk5 yda double mutant and mapkkk3 mapkkk5 yda triple mutants were embryo lethal, similar to the mpk3 mpk6 double mutants. These results demonstrate that YDA, MAPKKK3, and MAPKKK5 have overlapping functions upstream of the MKK4/MKK5-MPK3/MPK6 module in both plant immunity and growth/development.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Gene Expression Regulation, Plant , MAP Kinase Kinase Kinase 5/metabolism , Mitogen-Activated Protein Kinases/genetics , Mitogen-Activated Protein Kinases/metabolism , Pathogen-Associated Molecular Pattern Molecules/metabolism , Plant Development , Plant Immunity/genetics
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