Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 511
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Clin Otolaryngol ; 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32058675

RESUMO

OBJECTIVES: To evaluate the clinical efficacy of a high-efficiency air purifier in patients with allergic rhinitis. DESIGN: We conducted a randomized, double-blind, clinical controlled trial with active and inactive versions of an air purifier. Our study included patients with allergic rhinitis who were sensitive to Artemisia pollen and treatment of the indoor environment using air filtration at night. We evaluated the clinical efficacy of indoor air filtration during the Artemisia pollen scattering season in Yulin City in Shangxi Province, China. SETTING: The First Hospital of Yulin. (Yulin City, Shanxi Province, China). PARTICIPANTS: A total of 90 patients with allergic rhinitis who were sensitive to allergens of Artemisia pollen were randomly assigned to one of two groups in equal numbers. MAIN OUTCOME MEASURES: The primary outcome measure was the difference in visual analog scale scores from baseline. Secondary outcomes were changes from baseline in nasal symptoms, allergy symptom scores, responses to the Rhinoconjunctivitis Quality of Life Questionnaire, Epworth Sleepiness Scale scores, and tolerability scores for the air purifier. RESULTS: Based on the allergy symptom score, we found significant differences in rhinitis symptoms between the groups who used the active versus the inactive air purifier. CONCLUSIONS: The results of our investigation demonstrated the health benefits of particle filtration.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32078224

RESUMO

Immobilization of compartmentalized microscale objects in three-dimensional hydrogels provides a step towards the modular assembly of soft functional materials with tunable architectures and distributed functionalities. Here we use a combination of micro-compartmentalization, immobilization and modularization to fabricate and assemble hydrogel-based micro-reactor assemblies comprising millions of functionalized polysaccharide-polynucleotide coacervate droplets. The heterogeneous hydrogels can be structurally fused by interfacial crosslinking and coupled as input and output modules to implement a UV-induced photocatalytic/ peroxidation nanoparticle/ DNAzyme reaction cascade that generates a spatiotemporal fluorescence read-out depending on the droplet number density, intensity of photo-energization and chemical flux. Our approach offers a route to heterogeneous hydrogels with endogenous reactivity and reconfigurable architecture, and provides a step towards the development of soft modular materials with programmable functionality.

3.
Medicine (Baltimore) ; 99(1): e18489, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31895782

RESUMO

BACKGROUND: In a multitude of previous studies, Chlamydia trachomatis (CT) plays an important role in the occurrence of ectopic pregnancy (EP). However, the predictive value of CT infections in the occurrence of EP has not been estimated worldwide. We thus evaluated, by means of a meta-analysis, the current status of the association between CT infections with EP and the potential predictive value of CT infections in EP. METHODS: We evaluated studies performed between the database construction time and August 2018 published in PubMed, the Cochrane Library, EMBASE, and the Web of Science (SCI). The relationship between CT and EP was calculated based upon the predetermined entry criteria for control group selection and the original data. The related articles were analyzed using a random-effects model, and the heterogeneity of the studies was assessed using the I index. Data were analyzed with the STATA 12.0 software. RESULTS: Twenty-five studies that recruited 11960 patients were included in the present meta-analysis, and the relation of CT infections with EP were assessed. The association between CT infections and EP risk showed an odds ratio (OR) of 3.03, with a 95% confidence interval (CI) of 2.37 to 3.89. Our results showed that there was a statistically significant difference between the intervention and control groups. The prevalence of CT infections in EP was then calculated by a subgroup analysis: African (OR, 2.22; 95% CI, 1.14-4.31), European (OR, 3.16; 95% CI, 2.10-4.47), North American (OR, 3.07; 95% CI, 1.78-5.31), and Asian (OR, 3.39; 95% CI, 1.95-5.90). CONCLUSIONS: From the results of numerous studies conducted on different continents, this meta-analysis showed a clear association between EP and prior CT infections, that is, CT infections increase the risk of EP occurrence.


Assuntos
Infecções por Chlamydia/epidemiologia , Gravidez Ectópica/epidemiologia , Adulto , Chlamydia trachomatis , Feminino , Humanos , Razão de Chances , Gravidez , Gravidez Ectópica/etiologia , Prevalência , Fatores de Risco , Sensibilidade e Especificidade
4.
Adv Mater ; : e1907491, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31984560

RESUMO

The effectiveness of commercial bone adhesives is known to be hampered by the weak efficacy of cell ingrowth. The strategy of macropore-forming, especially bioactive macropores, holds considerable promise to circumvent this problem, thereby promoting fracture healing. Herein, a class of bioactive glass-involved macropore-embedded bone adhesives is developed, which is capable of facilitating the migration of bone-derived mesenchymal stromal cells into the adhesive layer and differentiation into osteocytes. The integration of bioactive glass-particle-encapsulated porogens in the bone adhesives is key to this approach. A robust instant bonding on the bone adhesive and a high efficiency of bone regeneration on a mouse skull are observed, both of which are vital for clinical applications and personalized surgical procedures. This work represents a general strategy to design biomaterials with high cell-ingrowth efficacy.

6.
Telemed J E Health ; 26(1): 114-125, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30994407

RESUMO

Background: Teleconsultation plays an increasingly important role to solve the health care problem in rural areas around the world. Teleconsultation resource optimization has become a new research topic. Materials and Methods: Given the complex teleconsultation process was difficult to be described by mathematical methods, a queuing simulation model was developed based on the data and teleconsultation empirical flow of Henan Telemedicine Center of China (HTCC) and we used kernel density estimation to solve the problem of arrival rate and service rate of teleconsultation. The data obtained from HTCC included 21,295 teleconsultation records over a 1-year period (February 27, 2016-March 25, 2017). Results: The average waiting time (WT) that primary hospitals requested for teleconsultation was obtained by simulation and compared with empirical average WT to verify this model. We found that Department of Internal Medicine (DIM) WT was the highest and we searched the optimized combination of teleconsultation rooms and DIM experts by sensitivity analyses. Conclusions: The existing resource allocation was not optimal and the hospital managers can improve it to reduce the hospitals' operating costs and the patients' waiting costs. We suggested that the teleconsultation rooms needed at least four and the DIM experts could increase from three to four.

7.
Spectrochim Acta A Mol Biomol Spectrosc ; 227: 117534, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31685424

RESUMO

Two novel ruthenium(II) polypyridyl complexes, namely, [Ru(dmp)2(CAPIP)](ClO4)2 (Ru(II)-1) and [Ru(dmp)2(CFPIP)](ClO4)2 (Ru(II)-2), which respectively contain (E)-2-(2-(furan-2-yl)vinyl)-1H-imidazo[4,5-f][1,10]phen-anthroline (CAPIP) and (E)-2-(4-fluorostyryl)-1H-imidazo[4,5-f][1,10]phenanthroline. (CFPIP), were first designed and characterized (dmp = 2,9-dimethyl-1,10-phenanthroline). DNA binding experiments indicated that Ru(II) complexes interact with CT DNA through intercalative mode. In addition, the complexes Ru(II)-1 and Ru(II)-2, showed remarkable cell cytotoxicity, giving the respective IC50 values of 4.1 ±â€¯1.4 µM and 6.1 ±â€¯1.4 µM on the A549 cancer cells. These values indicated higher activity than CAPIP, CFPIP, cisplatin (8.2 ±â€¯1.4 µM) and other corresponding Ru(II) polypyridyl complexes. Furthermore, the Ru(II) complexes could arrive the cytoplasm through the cell membrane and accumulate in the mitochondria. Significantly, complexes Ru(II)-1 and Ru(II)-2 induced A549 cells apoptosis was mediated by increase of ROS levels and dysfunction of mitochondria, and resulted in cell cycle arrest and increased anti-migration activity on A549 cells. Overall, these results indicated that complexes Ru(II)-1 and Ru(II)-2 could be suitable candidates for further investigation as a chemotherapeutic agent in the treatment of tumors.

8.
Chem Commun (Camb) ; 56(4): 595-598, 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31830150

RESUMO

We herein present a new family of crown ether-based covalent organic frameworks (CE-COFs) for the first time. The CE-COFs show excellent phase-transfer catalytic performance in various nucleophilic substitution reactions.

9.
Dev Comp Immunol ; 103: 103511, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31580833

RESUMO

ß-defensin is a cationic host defense peptide actively participating in host innate immune response against pathogens. In teleost fish, ß-defensin exhibits a diversity in genotypes and functions. Herein, a ß-defensin homolog (PaBD) was identified from ayu, Plecoglossus altivelis, showing multiple tissues' upregulation against Vibrio anguillarum challenge. In vivo experiments revealed that intraperitoneal injection of chemically synthesized mature PaBD (mPaBD) increased the survival rate of V. anguillarum-infected ayu, accompanied by reduced bacterial load and decreased tissue mRNA levels of tumor necrosis factor α (PaTNF-α) and interleukin 1ß (PaIL-1ß). However, in vitro, mPaBD showed weak bactericidal activity against V. anguillarum. Interestingly, mPaBD enhanced phagocytosis, intracellular bacterial killing, and respiratory burst of ayu monocytes/macrophages (MO/MΦ). Moreover, it inhibited mRNA levels of PaIL-1ß and PaTNF-α in MO/MФ upon V. anguillarum infection. In conclusion, PaBD protects ayu against V. anguillarum challenge not only through its direct antibacterial ability, but also through its immunomodulation in MO/MΦ.

10.
J Am Chem Soc ; 142(1): 70-74, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31840513

RESUMO

Covalent organic frameworks (COFs) are an emerging class of crystalline porous organic polymers with potential for innovative applications. Here we report the use of COFs as precursors for the fabrication of well-defined tubular nanomaterials. A proof-of-concept study is presented for the controllable fabrication of organic nanotubes through selective disassembly of two-dimensional heteropore COFs. Two dual-pore COFs are constructed based on orthogonal reactions. Each COF possesses two different kinds of pores, which are formed by linking all-hydrzaone-bonded nanopores with boroxines. Selectively hydrolyzing boroxine rings in the COFs while keeping hydrazone linkages untouched gives rise to organic nanotubes with diameters and shapes corresponding to the nanochannels of the COFs.

11.
Biomed Pharmacother ; 121: 109566, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31698268

RESUMO

Oxidative stress is a crucial pathogenic factor in osteoporosis. Autophagy is a cellular self-digestion process that can selectively remove damaged organelles under oxidative stress, and thus presents a potential therapeutic target against osteoporosis. Monotropein is an iridoid glycoside which can increase osteoblastic bone formation and be applied for medicinal purpose in China. The aim of this work is to investigate whether autophagy participates the protection effects of monotropein in osteoblasts under oxidative stress and the possible mechanism of such involvement. Here, monotropein was capable of inhibiting the H2O2-induced reactive oxygen species generation in osteoblasts. Monotropein induced autophagy and protected osteoblasts from cytotoxic effects of H2O2, as assessed by viability assays, apoptosis and western blotting. Moreover, it significantly attenuated H2O2-evoked oxidative stress as measured by malondialdehyde, catalase, and superoxide dismutase levels. Importantly, monotropein reduced the phosphorylation of protein kinase B (Akt), mammalian target of rapamycin (mTOR) and its two downstream proteins (p70S6K and 4EBP1). The autophagy level increased in osteoblasts treated with monotropein as represented by an increased in both Beclin1 expression and the LC3-II/LC3-I ratio. However, the Akt activator (SC79) and mTOR activator (MHY1485) suppressed the autophagy level induced by monotropein in H2O2-treated cells. Consequently, the antioxidant effects of monotropein were mediated, at least in part, by enhancing autophagy through the Akt/mTOR pathway. These results suggested that monotropein might be a promising candidate for osteoporosis treatment.

12.
Int J Biol Macromol ; 145: 325-331, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31843609

RESUMO

Structural modification of starch using efficient α-amylases to improve its properties is an established method in the starch industry. In our previous research, the novel maltogenic α-amylase CoMA that catalyzes multi-molecular reactions has been identified. In this study, the impact of CoMA on the structure and retrogradation properties of potato starch was evaluated. CoMA cleaves internal starch chains to change the proportion of amylose and amylopectin in starch. Following treatment, visible pores and microporous on the surface of starch granules were observed from SEM analysis. CoMA modification led to increased insoluble blue complex formation and hydrolysis to shorten the outer chains, which was found to reduce the development rate of starch according to network interactions from the dynamic rheological analysis. Furthermore, maltose accumulation with water competition was also deduced to be involved in the inhibition of retrogradation. Its activities in the cleavage of internal starch granules, shortening of outer chains of starch, and maltose formation make CoMA a powerful agent for the inhibition of starch retrogradation with a very low effective dose of 0.5 mg/kg, which may find potential applications in the starch processing industry.

13.
Org Biomol Chem ; 18(3): 530-537, 2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31854422

RESUMO

A phosphine-mediated deoxygenative condensation of 1,2-dicarbonyl compounds such as aroylformates, α-diketones, and isatins with arylazocarboxylates has been developed for a facile synthesis of N-aryl-N-acyl hydrazones in moderate to excellent yields under very mild conditions. Mechanistic investigation based on 31P NMR tracking experiments unveils that the reaction is initiated with the in situ formation of the modified Huisgen zwitterions from arylazocarboxylates and PPh3 and proceeds via a nitrogen to nitrogen ester group migration process. This study also represents the first exploration of the reactivity patterns of the modified Huisgen zwitterions derived from arylazocarboxylates toward electrophiles such as 1,2-dicarbonyl compounds.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31697230

RESUMO

A novel bacterium, designated TRM 44457T, belonging to the genus Streptomyces, was isolated from soil sampled in cotton fields in Xinjiang, PR China. Comparative 16S rRNA gene sequence analysis indicated that strain TRM 44457T was phylogenetically most closely related to Streptomyces laurentii LMG 19959T (99.38 % sequence similarity); however, strain TRM 44457T had a relatively low DNA-DNA relatedness value with S. laurentii LMG 19959T as determined by calculating the average nucleotide identity value (84.42 %). Strain TRM 44457T possessed ll-diaminopimelic acid as the diagnostic cell-wall diamino acid, MK-9 (H6) and MK-9 (H10) as the major menaquinone. The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphotidylinositol, phosphatidylinositol mannosides and an unidentified phospholipid. The major fatty acids were anteiso-C15:0, iso-C16:0, anteiso-C17:0, iso-C15:0, C16:0, iso-C17:0, cyclo-C17:0 and anteiso-C17:1ω9c. The genomic DNA G+C content was 72.6 mol%. Based on the evidence from this polyphasic study, strain TRM 44457T represents a novel species of the Streptomyces, for which the name Streptomyces roseicoloratus is proposed. The type strain is TRM 44457T (=KCTC 39904T=CCTCC AA 2016040T).

15.
Micromachines (Basel) ; 10(11)2019 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-31744264

RESUMO

The stretchable sensor has been considered as the most important component in a wearable device. However, it is still a great challenge to develop a highly sensitive textile-based strain sensor with good flexibility, excellent skin affinity, and large dynamic range. Herein, polypyrrole (PPy) was immobilized on a stretchable textile knitted by polyester and spandex via low-temperature interfacial polymerization to prepare a conductive strain sensor for human motion and respiration measurements. Scanning electron microscopy, Fourier transform infrared spectrometry, and thermal gravimetric data verify that a thin layer of PPy has been successfully coated on the textile with a high density and very uniform distribution. The resistance of the as-prepared textile is 21.25 Ω/cm2 and the PPy-coated textile could be used as an electric conductor to light up a LED lamp. Moreover, the textile could tolerate folding at an angle of 180° and 500 times of bending-twisting cycles without significant changes on its resistance. A negative correlation between the resistance change and the applied strain is observed for the textile-based sensor in the strain ranging from 0 to 71% with the gauge factor of -0.46. After more than 200 cycles of stretching-releasing under the strain of 26%, there is no obvious alteration on the sensing responses. The sensors were attached on volunteers' body or clothes for the real-time measurement of human motions and respiration, demonstrating that the textile-based sensor could sensitively detect finger, elbow, and knee bending and differentiate deep, normal, and fast breath. This work may provide an approach to uniform and dense coating conductive polymers on textiles for highly sensitive and stretchable sensors, which possess great potentials in practical applications for real-time monitoring human motions and physiological signs.

16.
Nat Commun ; 10(1): 4609, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601815

RESUMO

Constructing two-dimensional (2D) polymers with complex tessellation patterns via synthetic chemistry makes a significant contribution not only to the understanding of the emergence of complex hierarchical systems in living organisms, but also to the fabrication of advanced hierarchical materials. However, to achieve such tasks is a great challenge. In this communication we report a facile and general approach to tessellate 2D covalent organic frameworks (COFs) by three or four geometric shapes/sizes, which affords 2D COFs bearing three or four different kinds of pores and increases structural complexity in tessellations of 2D polymers to a much higher level. The complex tessellation patterns of the COFs are elucidated by powder X-ray diffraction studies, theoretical simulations and high-resolution TEM.

17.
Angew Chem Int Ed Engl ; 58(49): 17758-17763, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31584748

RESUMO

Two different artificial predation strategies are spatially and temporally coupled to generate a simple tit-for-tat mechanism in a ternary protocell network capable of antagonistic enzyme-mediated interactions. The consortium initially consists of protease-sensitive glucose-oxidase-containing proteinosomes (1), non-interacting pH-sensitive polypeptide/mononucleotide coacervate droplets containing proteinase K (2), and proteinosome-adhered pH-resistant polymer/polysaccharide coacervate droplets (3). On receiving a glucose signal, secretion of protons from 1 triggers the disassembly of 2 and the released protease is transferred to 3 to initiate a delayed contact-dependent killing of the proteinosomes and cessation of glucose oxidase activity. Our results provide a step towards complex mesoscale dynamics based on programmable response-retaliation behavior in artificial protocell consortia.

18.
R Soc Open Sci ; 6(8): 190182, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31598231

RESUMO

Three novel core-shell nanostructured composites SiO2@ANA-Si-Tb, SiO2@ANA-Si-Tb-L (L = second ligand) with SiO2 as the core and terbium organic complex as the shell were successfully synthesized. The core and shell were connected together by covalent bonds. The terbium ion was coordinated with organic ligand-forming terbium organic complex in the shell layer. The organosilane (HOOCC5H4NN(CONH(CH2)3Si(OCH2CH3)3)2 (abbreviated as ANA-Si) was used as the first ligand and 1,10-phenanthroline (phen) or 2-thenoyltrifluoroacetone (TTA) was used as the second ligand. Furthermore, silica-modified SiO2@ANA-Si-Tb@SiO2, SiO2@ANA-Si-Tb-L@SiO2 core-shell-shell nanostructured composites were also synthesized by sol-gel chemical route, which involved the hydrolysis and polycondensation processes of tetraethoxysilane (TEOS) using cetyltrimethyl ammonium bromide (CTAB) as a surface-active agent. An amorphous silica shell was coated around the SiO2@ANA-Si-Tb, SiO2@ANA-Si-Tb-L core-shell nanostructured composites. The core-shell and core-shell-shell nanostructured composites exhibited excellent luminescence in the solid state. Meanwhile, an improved luminescent stability property of the core-shell-shell nanostructured composites was observed for the aqueous solution. This type of core-shell-shell nanostructured composites exhibited bright luminescence, high stability and good solubility, which may present potential applications in the fields of optoelectronic devices, bio-imaging, medical diagnosis and study on the structure of function composite materials.

19.
Mikrochim Acta ; 186(11): 691, 2019 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-31605264

RESUMO

Cobalt-doped nanoporous carbon (Co-NPC) with dodecahedral shape was pyrolytically synthesized and applied as a sorbent and matrix for the enrichment and analysis of small molecules by surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS). Extremely low detection limits were accomplished for cetyltrimethylammonium bromide (1 fg·mL-1), and Rhodamine B (1 fg·mL-1) in water, and Malachite Green and its metabolite in fish blood and fish extracts (pg·mL-1 concentrations). Graphical abstract Schematic representation of cobalt-doped nanoporous carbons (Co-NPCs) applied as SALDI matrix for analysis of toxic contaminants in fish and receipt papers. The Co-NPCs have a high desorption/ionization efficiency and low limit of detection.

20.
Sci Rep ; 9(1): 13065, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31506509

RESUMO

The novel submicro-spheres SiO2@LaPO4:Eu@SiO2 with core-shell-shell structures were prepared by connecting the SiO2 submicro-spheres and the rare earth ions through an organosilane HOOCC6H4N(CONH(CH2)3Si(OCH2CH3)3 (MABA-Si). The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (IR). It is found that the intermediate shell of the submicro-spheres was composed by LaPO4:Eu nanoparticles with the size of about 4, 5-7, or 15-34 nm. A possible formation mechanism for the SiO2@LaPO4:Eu@SiO2 submicro-spheres has been proposed. The dependence of the photoluminescence intensity on the size of the LaPO4:Eu nanoparticles has been investigated. The intensity ratios of electrical dipole transition 5D0 → 7F2 to magnetic dipole transition 5D0 → 7F1 of Eu3+ ions were increased with decreasing the size of LaPO4:Eu nanoparticles. According to the Judd-Ofelt (J-O) theory, when the size of LaPO4:Eu nanoparticles was about 4, 5-7 and 15-34 nm, the calculated J-O parameter Ω2 (optical transition intensity parameter) was 2.30 × 10-20, 1.80 × 10-20 and 1.20 × 10-20, respectively. The increase of Ω2 indicates that the symmetry of Eu3+ in the LaPO4 lattice was gradually reduced. The photoluminescence intensity of the SiO2@LaPO4:Eu@SiO2 submicro-spheres was unquenched in aqueous solution even after 15 days.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA