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1.
J Org Chem ; 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32383591

RESUMO

In this article, a high-yield method for the synthesis of sulfonyl 9-fluorenylidenes is described, which consists of a one-pot straightforward three-step synthetic route, including (i) CuBr2-mediated α-bromination of o-arylacetophenone, (ii) sequential nucleophilic substitution of the resulting α-bromo o-arylacetophenone with sodium sulfinate (RSO2Na), and (iii) the CuBr2-mediated intramolecular Friedel-Crafts cyclizative dehydration. A plausible mechanism is proposed and discussed. This protocol provides a highly effective regio- and stereoselective annulation via the formation of one carbon-carbon (C-C) bond and one carbon-sulfur (C-S) bond.

2.
J Org Chem ; 85(8): 5651-5659, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32208623

RESUMO

Amberlyst 15-controlled one-pot easy-operational intermolecular cyclocondensation of substituted piperidines with arylaldehydes provides diversified 3,5-diarylmethylpyridines in high to excellent yields under refluxing toluene conditions. The uses of various acidic solid supports and reaction solvents are investigated for facile and efficient transformation. A plausible mechanism has been proposed.

3.
Sci Total Environ ; 713: 136710, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32019045

RESUMO

Nonylphenols (NPs) are endocrine-disrupting compounds commonly found in the environment and a number of food products. In this study, we constructed a probabilistic risk framework incorporating a Bayesian inference of exposure level in foodstuffs in conjunction with effect analysis of reproduction and renal disease. Our objective was to contrast the risk of dietary exposure to NPs among individuals in various age groups, with a particular focus on fertile females. In this study, seafood presented relatively high NP concentrations; however, seafood accounts for only a small proportion of the total food intake of most individuals. Rice was shown to make the largest contribution to NP daily intake among males and females in most age groups. Chicken made the largest contribution in the 12-16 and 16-18 year age groups. The mean average daily dose of NPs tended to decrease with age, regardless of gender. The estimated distribution of hazard quotients of <1 in all groups means that the risk of reproductive or renal abnormalities due to dietary exposure to NPs is negligible within most of the Taiwanese population. Nonetheless, preschoolers (3-6-year-olds) appear to be more vulnerable to NPs than do individuals in other age groups. There has been growing concern among researchers concerning the neurotoxic effects of NPs on offspring via maternal exposure. We recommend conducting a comprehensive assessment of exposure to NPs via multiple exposure routes, particularly among fertile women and preschoolers.


Assuntos
Fenóis/toxicidade , Teorema de Bayes , Exposição Dietética , Disruptores Endócrinos , Feminino , Humanos , Masculino
4.
J Org Chem ; 85(2): 1033-1043, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31804066

RESUMO

In this paper, an easy-operational, high-yielding method for the gram-scale synthesis of 3-sulfonyl flavanones is described by a one-pot straightforward POCl3 mediated intermolecular (5 + 1) annulation of the ß-ketosulfones with an o-hydroxyaryl group (dual nucleophile) and arylaldehydes (dual electrophile) in refluxing toluene for 3 h. A plausible mechanism is proposed and discussed. This protocol provides a highly effective annulation via one carbon-oxygen (C-O) and one carbon-carbon (C-C) bond formations.

5.
J Org Chem ; 84(18): 11699-11723, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31465690

RESUMO

In this paper, we developed facile and high-yield synthetic routes for the preparation of 2-sulfonyl indenes and indanes, including: (i) Amberlyst-15-promoted Knoevenagel reaction of ß-ketosulfones and arylaldehydes in refluxing toluene; (ii) Grignard reagent (R'MgBr) or reducing reagent (NaBH4) promoted regio- and/or stereocontrolled 1,4-addition or 1,4-/1,2-reduction of the resulting sulfonyl chalcones in THF or MeOH/THF at 25 °C; and then (iii) Amberlyst-15 mediated intramolecular Friedel-Crafts annulation of the corresponding ß-ketosulfones or ß-hydroxysulfones in toluene at reflux. This present method describes a highly efficient (3 + 2) annulation via the formation of two carbon-carbon (C-C) bonds. The DFT calculations were utilized to rationalize the regioselectivity of the addition reaction.

6.
Biomed J ; 42(2): 124-130, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31130248

RESUMO

BACKGROUND: Ankylosing spondylitis (AS) is an inflammatory autoimmune disorder that manifested with sacroiliitis at its early stage and developed extensive inflammation with syndesmophytes of the lumbar, thoracic and cervical spines at its later stage. In the present study, we characterized the trunk isometric strength in patients with AS with different disease severity, defined by the radiological images. METHODS: In a cross-sectional study conducted in a university-affiliated hospital, thirty-eight male AS patients (23 in the early AS group whose radiological findings showed no syndesmophyte, Modified Stoke Ankylosing Spinal Score (m-SASSS <3); and 15 in the syndesmophyte group, m-SASSS ≥24), and 22 healthy controls were recruited. All subjects received assessments of maximum isometric strength of trunk flexor and extensor muscles at a variety of trunk postures measured by an isokinetic device. RESULTS: Under all examined trunk postures, the syndesmophyte AS patient group had the lowest isometric trunk muscle strength among the three groups. The flexion/extension ratio, defined by the ratio between isometric trunk flexor and extensor strengths, was highest among the three groups. CONCLUSIONS: Trunk muscle strength significantly decreases in patients with syndesmophyte AS. The decrease of trunk muscle is inhomogeneous, which is more profound in extensor than in flexor muscles.


Assuntos
Debilidade Muscular/fisiopatologia , Músculo Esquelético/fisiopatologia , Coluna Vertebral/fisiopatologia , Espondilite Anquilosante/fisiopatologia , Adulto , Estudos Transversais , Feminino , Humanos , Inflamação/fisiopatologia , Masculino , Pessoa de Meia-Idade , Radiografia/métodos
7.
Front Neurorobot ; 13: 3, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30814945

RESUMO

Study design: Case series. Background: Robot-assisted rehabilitation mediated by exoskeletal devices is a popular topic of research. The biggest difficulty in the development of rehabilitation robots is the consideration of the clinical needs. This study investigated the usability of a novel cable-driven exoskeletal robot specifically designed for hand rehabilitation. Methods: The study consists of three steps, including prototype development, spasticity observation, and usability evaluation. First, we developed the prototype robot DexoHand to manipulate the patient's fingers based on the clinical needs and the cable-driven concept established in our previous work. Second, we applied DexoHand to patients with different levels of spasticity. Finally, we obtained the system usability scale (SUS) and assessed its usability. Results: Two healthy subjects were recruited in the pre-test, and 18 patients with stroke and four healthy subjects were recruited in the formal test for usability. The total SUS score obtained from the patients and healthy subjects was 94.77 ± 2.98 (n = 22), indicating an excellent level of usability. The satisfaction score was 4.74 ± 0.29 (n = 22), revealing high satisfaction with DexoHand. The tension profile measured by the cables showed the instantaneous force used to manipulate fingers among different muscle tone groups. Conclusions: DexoHand meets the clinical needs with excellent usability, satisfaction, and reliable tension force monitoring, yielding a feasible platform for robot-assisted hand rehabilitation.

8.
Org Lett ; 21(6): 1832-1836, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30788972

RESUMO

In this paper, a novel and efficient route for the synthesis of α,ß-bis-sulfonyl arylketones via an NH2OH-HCl-mediated intermolecular umpolung α-methylsulfonylation of α-sulfonyl ketones with methylsulfoxides is described. A plausible mechanism is proposed and discussed. Various reaction conditions for this efficient, one-pot, environmentally friendly transformation were investigated.

9.
J Org Chem ; 84(1): 443-449, 2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30547592

RESUMO

In this work, a concise route for the synthesis of sulfonyl dibenzo-oxabicyclo[3.3.1]nonanes by a two-step route is described, including (i) NaBH4/LiCl-mediated reduction of 3-sulfonyl-2-benzylchromen-4-ones and (ii) sequential BF3·OEt2-mediated intramolecular annulation of the resulting 3-sulfonyl-2-benzylchroman-4-ols. A plausible mechanism is proposed and discussed herein. This protocol provides a highly effective stereocontrolled aryl-hydroxyl Friedel-Crafts-type cross-coupling to construct the tetra- or pentacyclic bridged framework. The use of various reaction conditions is investigated for an efficient transformation.

10.
J Org Chem ; 84(1): 326-337, 2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30537830

RESUMO

Temperature-controlled intermolecular desulfonylative condensation of α-sulfonyl o-hydroxyacetophenones with 2-formyl azaarenes (pyridines and quinolones) provides azaaryl (pyridyl and quinolyl) aurones and flavones under warming and refluxing toluene reaction conditions via the formation of the intermediate of sulfonyl chroman-4-one. The uses of various solvents are investigated for facile and efficient transformation. A plausible mechanism is proposed.

11.
J Org Chem ; 83(12): 6798-6804, 2018 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-29788719

RESUMO

The stereocontrolled reduction of 3-sulfonyl chromen-4-ones by two synthetic methods, NaBH4/LiCl and Pd/C/H2, provides two kinds of 3-sulfonyl chroman-4-ols with three contiguous chiral centers under different reaction conditions. The use of various reaction conditions is investigated for efficient transformation.

12.
PM R ; 10(10): 1119-1121, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29550415

RESUMO

Posttraumatic syringomyelia with an initial presentation of involuntary movement is rare. We describe a 25-year-old patient who sustained complete traumatic spinal cord injury at the thoracic level and presented with rhythmic neck muscle spasms and upper limb muscle myoclonic jerks 1 month after trauma. Magnetic resonance imaging revealed syrinx formation between C3 and T1. Lumbar-peritoneal shunt and decompression were performed. The symptoms completely disappeared after surgery. This report highlights that rhythmic neck muscle spasms and upper limb muscle myoclonic jerks can be the initial and only manifestations of syringomyelia. LEVEL OF EVIDENCE: V.


Assuntos
Laminectomia/métodos , Mioclonia/diagnóstico , Espasmo/diagnóstico , Traumatismos da Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/cirurgia , Siringomielia/etiologia , Acidentes de Trânsito , Adulto , Vértebras Cervicais/lesões , Vértebras Cervicais/cirurgia , Diagnóstico Diferencial , Fixação de Fratura/métodos , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Músculos do Pescoço/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Siringomielia/diagnóstico por imagem
13.
Clin Respir J ; 12(2): 563-571, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27727525

RESUMO

INTRODUCTION: In the pathogenesis of asthma, an imbalance between helper T (Th) 1/Th2 and Th17/Treg cells is believed to play a key role in asthmatic inflammatory responses. Some studies indicated that zinc deficiency increases inflammatory factor production and worsens asthma. However, the effects of zinc on T cell profiles to reduce inflammatory response remain unclear. OBJECTIVES: We investigated the beneficial effects of zinc on isolated cell populations and cytokine levels from patients with asthma. METHODS: Thirty-six individuals Dermatophagoides pteronyssinus (Der p)-allergic and 31 healthy subjects were enrolled in the study, and peripheral blood mononuclear cells (PBMCs) were collected. Harvested PBMCs were stimulated with recombinant Der p antigen in the presence or absence of zinc sulfate (25 µM or 50 µM) for 48 h. Cell surface markers and intracellular cytokine levels were examined by flow cytometry. The pro-inflammatory factors in plasma and culture supernatants were measured by commercial enzyme-linked immunosorbent assay. RESULTS: Zinc sulfate dramatically reduced the proportions of Th2 and Th17 cells, but increased that of Th1 and Treg cells. Zinc sulfate also markedly reduced the levels of interleukin (IL)-4 and IL-17, but increased the levels of IFN-γ. CONCLUSIONS: Zinc ameliorates the imbalance in T cell profiles and could be a potential adjuvant therapy for Der p-induced allergic hypersensitivity.


Assuntos
Asma/imunologia , Citocinas/metabolismo , Linfócitos T Reguladores/efeitos dos fármacos , Sulfato de Zinco/farmacologia , Adulto , Análise de Variância , Antígenos de Dermatophagoides/imunologia , Asma/sangue , Asma/fisiopatologia , Estudos de Casos e Controles , Células Cultivadas , Citocinas/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Testes de Função Respiratória , Índice de Gravidade de Doença , Linfócitos T Reguladores/imunologia , Adulto Jovem
14.
Sci Rep ; 7(1): 12701, 2017 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-28983102

RESUMO

Selective-area growth (SAG) of single-crystal wurtzite GaN nanorods (NRs) directly onto Si(001) substrates with un-etched native SiOx amorphous layer, assisted by a patterning TiNx mask fabricated by nanosphere lithography (NSL), has been realized by reactive magnetron sputter epitaxy (MSE). The GaN NRs were grown vertically to the substrate surface with the growth direction along c-axis in the well-defined nano-opening areas. A 5-step structural and morphological evolution of the SAG NRs observed at different sputtering times depicts a comprehensive growth model, listed in sequence as: formation of a polycrystalline wetting layer, predominating c-axis oriented nucleation, coarsening and coalescence of multi-islands, single NR evolution, and finally quasi-equilibrium crystal shape formation. Room-temperature cathodoluminescence spectroscopy shows a strong GaN bandedge emission with a uniform luminescence across the NRs, indicating that the SAG NRs are grown with high quality and purity. In addition, single-longitudinal-mode lasing, attributed to well-faceted NR geometry forming a Fabry-Pérot cavity, was achieved by optical pumping, paving a way for fabricating high-performance laser optoelectronics using MSE.

15.
J Org Chem ; 82(13): 7077-7084, 2017 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-28616981

RESUMO

In this article, a facile two-step and one-pot synthetic route for the preparation of substituted aryl dihydronaphthalenes starting from 2-allylbenzaldehydes via Grignard 1,2-addition and Bi(OTf)3-catalyzed intramolecular olefinic cyclization has been developed. A five-membered ring indene skeleton is also prepared via olefin isomerization, 1,2-addition followed by cyclization. Some key structures are determined using single-crystal X-ray crystallography. A possible mechanism is presented herein.

16.
Nanomaterials (Basel) ; 7(4)2017 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-28383488

RESUMO

Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new "paradigm shift" non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs) with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD) and chemical bath deposition (CBD) as used by the Cu(In,Ga)Se2 (CIGS) thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase.

17.
J Org Chem ; 82(6): 3317-3326, 2017 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-28248498

RESUMO

In this work, we developed a concise synthetic route for the synthesis of polysubstituted naphthalenes starting from commercially available isovanillin and its derivatives. Reaction with styryl bromide via O-styrylation, Claisen rearrangement, ene reaction, and O-alkylation occurred in high yields. The key structures were confirmed by single-crystal X-ray diffraction.

18.
Sci Rep ; 7: 42962, 2017 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-28256529

RESUMO

In this research, nano-ring light-emitting diodes (NRLEDs) with different wall width (120 nm, 80 nm and 40 nm) were fabricated by specialized nano-sphere lithography technology. Through the thinned wall, the effective bandgaps of nano-ring LEDs can be precisely tuned by reducing the strain inside the active region. Photoluminescence (PL) and time-resolved PL measurements indicated the lattice-mismatch induced strain inside the active region was relaxed when the wall width is reduced. Through the simulation, we can understand the strain distribution of active region inside NRLEDs. The simulation results not only revealed the exact distribution of strain but also predicted the trend of wavelength-shifted behavior of NRLEDs. Finally, the NRLEDs devices with four-color emission on the same wafer were demonstrated.

19.
Org Lett ; 19(6): 1358-1361, 2017 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-28257215

RESUMO

Intramolecular annulation of o-carbonyl allylbenzenes was achieved to construct novel nitrated [6,6,6]tricycles having an acetal or ketal motif in good yields. The expeditious one-step nitration route provides 4 or 5 new bond formations, including 2 or 3 C-N bonds and 2 C-O bonds. The structural framework of benzobicycle [3.3.1] is confirmed by X-ray crystallographic analysis. A plausible mechanism is proposed.

20.
Org Lett ; 19(7): 1870-1873, 2017 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-28332839

RESUMO

CuI/DMSO-mediated intramolecular cycloacetalization/ketalization of o-carbonyl allylbenzenes has been achieved for constructing [6,6,5]-tricycles having a ketal motif in good yields. The expeditious one-step route provides a three C-O bond formation. The key products with the structural framework of a benzofused dioxabicyclo[3.2.1]octane core have been confirmed by X-ray crystallographic analysis. Synthesis of dihydroisocoumarin has been studied.

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