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1.
Int J Hyperthermia ; 36(1): 1233-1238, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31818163

RESUMO

Purpose: Adenomyosis is a relatively common disease among women of childbearing age. A minimally invasive alternative technique with low risks, faster recovery and decreased side effects is desired. We hypothesized that percutaneous microwave ablation (PMWA) under laparoscopic guidance would substantially reduce the risk of collateral thermal damage to the intestinal tract and relieve the pelvic adhesions. This study aimed to evaluate the feasibility, safety and efficacy of transvaginal ultrasound- and laparoscopy-guided PMWA for the treatment of adenomyosis.Materials and methods: From May 2015 to October 2017, a total of 70 patients with symptomatic adenomyosis who underwent transvaginal ultrasound- and laparoscopy-guided PMWA were included in this study. The technical efficacy and complications of PMWA were assessed. Meanwhile, the uterine volume, lesion volume, symptom severity score (SSS) and visual analog scale (VAS) score before PMWA and at 1, 6 and 12 months after PMWA were recorded.Results: PMWA was successfully performed with transvaginal ultrasound guidance and laparoscope assistance in all patients. No major complication was found after PMWA in any patients. The uterine volume, lesion volume, SSS and VAS were all decreased significantly at follow-up (p < .01).Conclusion: Transvaginal ultrasound- and laparoscopy-guided PMWA, which significantly decreased the uterine volume, lesion volume, SSS and VAS score, is a feasible minimally invasive technique for the treatment of adenomyosis.

2.
J Org Chem ; 84(22): 14892-14897, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31475536

RESUMO

Three new monoterpenoid indole alkaloids (MIAs), hunterines A-C (1-3), were isolated from Hunteria zeylanica. Compound 1 possesses a unique skeleton with an unprecedented azabicyclo[4.3.1]decane ring system. Compounds 2 and 3 are a pair of epimeric vobasinylindole alkaloid heterodimers. Their structures including absolute configurations were established by spectroscopic analyses, X-ray diffraction, computational calculation, and the modified Mosher's method. Plausible biogenetic pathways of 1-3 were also proposed. Alkaloid 1 showed moderate cytotoxic activity against the HepG2 cell line.

3.
Nat Commun ; 10(1): 2911, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266966

RESUMO

The stacking between nanosheets is an intriguing and inevitable phenomenon in the chemistry of nano-interfaces. Two-dimensional metal-organic framework nanosheets are an emerging type of nanosheets with ultrathin and porous features, which have high potential in separation applications. Here, the stacking between single-layer metal-organic framework nanosheets is revealed to show three representative conformations with tilted angles of 8°, 14°, and 30° for Zr-1, 3, 5-(4-carboxylphenyl)-benzene framework as an example. Efficient untwisted stacking strategy by simple heating is proposed. A detailed structural analysis of stacking modes reveals the creation of highly ordered sub-nanometer micropores in the interspacing of untwisted nano-layers, yielding a high-resolution separator for the pair of para-/meta-isomers over the twisted counterparts and commercial HP-5MS and VF-WAXMS columns. This general method is proven by additional nanosheet examples and supported by Grand Canonical Monte Carlo simulation. This finding will provide a synthetic route in the rational design of functionalities in two-dimensional metal-organic framework nanosheet.

4.
Angew Chem Int Ed Engl ; 58(28): 9464-9469, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31090132

RESUMO

The electrochemical N2 fixation, which is far from practical application in aqueous solution under ambient conditions, is extremely challenging and requires a rational design of electrocatalytic centers. We observed that bismuth (Bi) might be a promising candidate for this task because of its weak binding with H adatoms, which increases the selectivity and production rate. Furthermore, we successfully synthesized defect-rich Bi nanoplates as an efficient noble-metal-free N2 reduction electrocatalyst via a low-temperature plasma bombardment approach. When exclusively using 1 H NMR measurements with N2 gas as a quantitative testing method, the defect-rich Bi(110) nanoplates achieved a 15 NH3 production rate of 5.453 µg mgBi -1 h-1 and a Faradaic efficiency of 11.68 % at -0.6 V vs. RHE in aqueous solution at ambient conditions.

5.
J BUON ; 24(2): 709-714, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31128027

RESUMO

PURPOSE: Ovarian cancer causes considerable mortality in women across the globe. The limited availability of the efficient chemotherapeutic agents and associated side effects of the existing drugs forms a bottle neck in the treatment of ovarian cancer. In this study, the in vitro and in vivo anticancer activity of a plant derived lignan pinoresinol was investigated along with deciphering its mode of action. METHODS: The anticancer activity was evaluated by MTT cell viability assay and its effects on mitochondrial membrane potential loss was checked by flow cytometry. Effects on cell invasion were measured by Matrigel invasion assay, whereas effects on autophagy were evaluated by electron microscopy and Western blotting assay. Protein expressions of the phosphor (p)-MEK and p-ERK were measured by Western blot. RESULTS: Results revealed that Pinoresinol inhibits the growth of the ovarian SKOV-3 cancer cells and exhibits an IC50 of 20 µM. The anticancer effects were found to be due to the induction of autophagy which was associated with increase in the expression of LC3 II and Beclin and decrease in the expression of p62. Furthermore, pinoresinol also caused reduction in the mitochondrial membrane potential (MMP) of the SKOV-3 cells and inhibited their invasion capacity. The effects of pinoresinol were also investigated on the Raf/MEK/ERK signalling pathway and it was observed that pinoresinol inhibited the expression of phosphore (p)-MEK and p-ERK in a concentration-dependent manner. Finally, in vivo evaluation revealed that pinoresinol significantly inhibited the growth of xenografted tumors in mice, indicating the potential of pinoresinol in the treatment of ovarian cancer. CONCLUSIONS: Pinoresinol, as per the current study, has the potential to inhibit in vitro and in vivo cancer cell growth of SKOV-3 human ovarian cancer cells and as such could be a possible drug candidate for future research.


Assuntos
Autofagia/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Furanos/farmacologia , Lignanas/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Proteína Beclina-1/genética , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Proteínas Associadas aos Microtúbulos/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/genética , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Proteínas de Ligação a RNA/genética , Proteínas ras/genética
6.
Huan Jing Ke Xue ; 40(3): 1222-1235, 2019 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-31087969

RESUMO

This study was done to understand the diel variation and factors influencing the hydrochemistry of the Lijing River in different seasons. This is a typical medium river located at Guilin City in the Guangxi Zhuang Autonomous Region, SW China. The Shengli site was selected for this study. Two-day monitoring work with a high resolution rate logger and high frequency sampling at 2 hour intervals was conducted at the Shengli site of the Lijiang River in summer and autumn separately. Physical and hydrogeochemical parameters including pH, dissolved oxygen (DO), water temperature (T), electrical conductivity (EC), dissolved inorganic carbon (DIC), isotopes, and other chemical parameters were examined. The results show that:① the physical and hydrochemical parameters[T, pH, DO, SIC, EC, p (CO2)] and major ions (HCO3-, Ca2+) at the Shengli site displayed regular diel variation during monitoring. The data for T, pH, DO, and SIC increased in daylight and decreased at night, while the data for Ca2+, HCO3-, EC, and p (CO2) decreased in daylight and increased at night. ② The diurnal changes of nutrient elements (SO42-, NO3-, Cl-, Na+, Mg2+, and K+) at the Shengli site were mainly controlled by photosynthesis and respiration of aquatic plants, and showed the trend of decrease in daylight and increase at night. Due to the influence of a flood in mid-August 2017, the amount of diurnal variation in the nutrient element levels in summer was less than that in autumn. ③ The δ13CDIC increased in daylight and decreased at night both in summer and autumn, reflecting the influences of photosynthesis and precipitation. Under the influence of different root systems, soil microbial respiration intensity, and seasonal variation of river hydrological factors, the δ13CDIC in summer was generally lighter than that in autumn, with average values of -10.08‰ and -8.90‰, respectively. ④ The daily average fixation amount of karst carbon sink caused by aquatic plants was calculated to be 2.12 mmol·L-1 and 0.94 mmol·L-1 for Autumn and Summer, respectively. To sum up, there is a higher efficiency of karst carbon sink caused by aquatic plants in Autumn than that in Summer.

7.
Mol Biol Rep ; 46(3): 3451-3460, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31012026

RESUMO

An isolate (CanS-34A) of Aspergillus from a healthy plant of oilseed rape (Brassica napus) was identified based on morphological characterization and multi-locus phylogeny using the sequences of internal transcribed spacer (ITS)-5.8S rDNA region, BenA (for ß-tubulin), CaM (for calmodulin) and RPB2 (for RNA polymerase II). The results showed that CanS-34A belongs to Aspergillus capensis Hirooka et al. The antifungal metabolites produced by CanS-34A in potato dextrose broth (PDB) were extracted with chloroform. Three antifungal metabolites were isolated and purified from the chloroform extract of the PDB cultural filtrates of CanS-34A, and chemically identified as methyl dichloroasterrate, penicillither and rosellichalasin. They all showed antifungal activity against the plant pathogenic fungi Botrytis cinerea, Monilinia fructicola, Sclerotinia sclerotiorum and Sclerotinia trifoliorum with the EC50 values ranging from 2.46 to 65.00 µg/mL. To our knowledge, this is the first report about production of penicillither by Aspergillus and about the antifungal activity of methyl dichloroasterrate, penicillither and rosellichalasin against the four plant pathogenic fungi.


Assuntos
Aspergillus/classificação , Aspergillus/metabolismo , Brassica napus/microbiologia , Antifúngicos/metabolismo , Ascomicetos/genética , Aspergillus/genética , Aspergillus/isolamento & purificação , Testes de Sensibilidade Microbiana , Filogenia
8.
Adv Mater ; 31(19): e1900379, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30924206

RESUMO

Hardware implementation of artificial synaptic devices that emulate the functions of biological synapses is inspired by the biological neuromorphic system and has drawn considerable interest. Here, a three-terminal ferrite synaptic device based on a topotactic phase transition between crystalline phases is presented. The electrolyte-gating-controlled topotactic phase transformation between brownmillerite SrFeO2.5 and perovskite SrFeO3- δ is confirmed from the examination of the crystal and electronic structure. A synaptic transistor with electrolyte-gated ferrite films by harnessing gate-controllable multilevel conduction states, which originate from many distinct oxygen-deficient perovskite structures of SrFeOx induced by topotactic phase transformation, is successfully constructed. This three-terminal artificial synapse can mimic important synaptic functions, such as synaptic plasticity and spike-timing-dependent plasticity. Simulations of a neural network consisting of ferrite synaptic transistors indicate that the system offers high classification accuracy. These results provide insight into the potential application of advanced topotactic phase transformation materials for designing artificial synapses with high performance.

9.
Nat Commun ; 10(1): 1278, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30894539

RESUMO

Although single-atomically dispersed metal-Nx on carbon support (M-NC) has great potential in heterogeneous catalysis, the scalable synthesis of such single-atom catalysts (SACs) with high-loading metal-Nx is greatly challenging since the loading and single-atomic dispersion have to be balanced at high temperature for forming metal-Nx. Herein, we develop a general cascade anchoring strategy for the mass production of a series of M-NC SACs with a metal loading up to 12.1 wt%. Systematic investigation reveals that the chelation of metal ions, physical isolation of chelate complex upon high loading, and the binding with N-species at elevated temperature are essential to achieving high-loading M-NC SACs. As a demonstration, high-loading Fe-NC SAC shows superior electrocatalytic performance for O2 reduction and Ni-NC SAC exhibits high electrocatalytic activity for CO2 reduction. The strategy paves a universal way to produce stable M-NC SAC with high-density metal-Nx sites for diverse high-performance applications.

10.
Adv Mater ; 31(15): e1806781, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30803061

RESUMO

Efficient and selective dehydrogenation of formic acid is a key challenge for a fuel-cell-based hydrogen economy. Though the development of heterogeneous catalysts has received much progress, their catalytic activity remains insufficient. Moreover, the design principle of such catalysts are still unclear. Here, experimental and theoretical studies on a series of mono-/bi-metallic nanoparticles supported on a NH2 -N-rGO substrate are combined for formic acid dehydrogenation where the surface energy of a metal is taken as a relevant indicator for the adsorption ability of the catalyst for guiding catalyst design. The AuPd/NH2 -N-rGO catalyst shows record catalytic activity by reducing the energy barrier of rate controlling steps of formate adsorption and hydrogen desorption. The obtained excellent results both in experiments and simulations could be extended to other important systems, providing a general guideline to design more efficient catalysts.

11.
Cell Death Differ ; 26(5): 969-980, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30154445

RESUMO

Zygotic chromatin undergoes extensive reprogramming immediately after fertilization. It is generally accepted that maternal factors control this process. However, little is known about the underlying mechanisms. Here we report that maternal RAD9A, a key protein in DNA damage response pathway, is involved in post-zygotic embryo development, via a mouse model with conditional depletion of Rad9a alleles in oocytes of primordial follicles. Post-zygotic losses originate from delayed zygotic chromatin decondensation after depletion of maternal RAD9A. Pronucleus formation and DNA replication of most mutant zygotes are therefore deferred, which subsequently trigger the G2/M checkpoint and arrest development of most mutant zygotes. Delayed zygotic chromatin decondensation could also lead to increased reabsorption of post-implantation mutant embryos. In addition, our data indicate that delayed zygotic chromatin decondensation may be attributed to deferred epigenetic modification of histone in paternal chromatin after fertilization, as fertilization and resumption of secondary meiosis in mutant oocytes were both normal. More interestingly, most mutant oocytes could not support development beyond one-cell stage after parthenogenetic activation. Therefore, RAD9A may also play an important role in maternal chromatin reprogramming. In summary, our data reveal an important role of RAD9A in zygotic chromatin reprogramming and female fertility.

12.
Biochim Biophys Acta Mol Basis Dis ; 1865(1): 206-217, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30463689

RESUMO

Insulin resistance leads to myocardial contractile dysfunction and deranged autophagy although the underlying mechanism or targeted therapeutic strategy is still lacking. This study was designed to examine the impact of inhibition of the cytochrome P450 2E1 (CYP2E1) enzyme on myocardial function and mitochondrial autophagy (mitophagy) in an Akt2 knockout model of insulin resistance. Adult wild-type (WT) and Akt2-/- mice were treated with the CYP2E1 inhibitor diallyl sulfide (100 mg/kg/d, i.p.) for 4 weeks. Cardiac geometry and function were assessed using echocardiographic and IonOptix systems. Western blot analysis was used to evaluate autophagy, mitophagy, inducible NOS (iNOS), and the NLRP3 inflammasome, a multi-protein intracellular pattern recognition receptor complex. Akt2 deletion triggered insulin resistance, compromised cardiac contractile and intracellular Ca2+ property, mitochondrial ultrastructural damage, elevated O2- production, as well as suppressed autophagy and mitophagy, accompanied with elevated levels of NLRP3 and iNOS, the effects of which were significantly attenuated or ablated by diallyl sulfide. In vitro studies revealed that the NLRP3 activator nigericin nullified diallyl sulfide-offered benefit against Akt2 knockout on cardiomyocyte mechanical function and mitophagy (using Western blot and colocalization of GFP-LC3 and MitoTracker Red). Moreover, inhibition of iNOS but not mitochondrial ROS production attenuated Akt2 deletion-induced activation of NLRP3, substantiating a role for iNOS-mediated NLRP3 in insulin resistance-induced changes in mitophagy and cardiac dysfunction. In conclusion, these data depict that insulin resistance through CYP2E1 may contribute to the pathogenesis of myopathic changes including myocardial contractile dysfunction, oxidative stress and mitochondrial injury, possibly through activation of iNOS and NLRP3 signaling.


Assuntos
Cardiomiopatias/metabolismo , Citocromo P-450 CYP2E1/metabolismo , Resistência à Insulina/fisiologia , Miócitos Cardíacos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Autofagia , Citocromo P-450 CYP2E1/efeitos dos fármacos , Inibidores do Citocromo P-450 CYP2E1/farmacologia , Modelos Animais de Doenças , Inflamassomos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Contração Miocárdica , Miocárdio/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais
13.
ACS Appl Mater Interfaces ; 10(43): 37298-37306, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30339350

RESUMO

Driven by an ever-growing demand for environmentally compatible materials, the past two decades have witnessed the booming development in the field of piezoelectrics. To maximally explore the potential of lead-free piezoelectrics, chemical doping could be an effective approach, referenced from tactics adopted in lead-based piezoelectrics. Herein, we reveal the distinct role of manganese in a promising lead-free perovskite (K, Na)NbO3 (denoted by KNN) in comparison to that in market-dominating lead-based counterparts [Pb(Zr, Ti)O3, PZT]. In contrast to the scenario in PZT, manganese doping in KNN results in tremendously improved piezoelectric coefficient d33 by nearly 200%, whereas the same doping species in PZT deteriorates the d33 down to less than 30% of its original value. The result is rationalized from macroscopic and local electrical characterizations down to atomic-scale visualization. This study demonstrates that there is enormous space to further enhance piezoelectricity in lead-free systems because the chemical doping effect may completely differ in lead-containing and lead-free perovskites.

14.
J Am Chem Soc ; 140(37): 11705-11715, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30110545

RESUMO

Despite the recent surge of interest in inorganic lead halide perovskite nanocrystals, there are still significant gaps in their stability disturbance and the understanding of their destabilization, assembly, and growth processes. Here, we discover that polar solvent molecules can induce the lattice distortion of ligand-stabilized cubic CsPbI3, leading to the phase transition into orthorhombic phase, which is unfavorable for photovoltaic applications. Such lattice distortion triggers the dipole moment on CsPbI3 nanocubes, which subsequently initiates the hierarchical self-assembly of CsPbI3 nanocubes into single-crystalline nanowires. The systematic investigations and in situ monitoring on the kinetics of the self-assembly process disclose that the more amount or the stronger polarity of solvent can induce the more rapid self-assembly and phase transition. These results not only elucidate the destabilization mechanism of cubic CsPbI3 nanocrystals, but also open up opportunities to synthesize and store cubic CsPbI3 for their practical applications in photovoltaics and optoelectronics.

15.
Huan Jing Ke Xue ; 39(4): 1598-1607, 2018 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964984

RESUMO

The characteristics of heavy metal pollution in drinking water in the Liujiang river basin and its potential hazards on human health were investigated. In this study, the regular water-quality indices and the contents of metal elements Cd, As, Cr, Hg, Zn, Cu, Pb, Fe, and Mn in the Liujiang river and its main tributaries were detected from January to December of 2016. The health risks of drinking contaminated water were evaluated by the health risk assessment model recommended by the US EPA. The results showed that the concentrations of all of the aforementioned metal elements, except Hg, did not exceed the limits recommended by China's surface water environmental quality standard (GB 3838-2002). Pearson correlation analysis of the concentrations of metal elements indicated that Cd, Pb, As, and Fe may have similar sources, and Cu, Cr, Hg, and Zn may have source of diversity, while there was no significant correlation between the concentrations of metal elements and the pH value. The carcinogenic health risks posed by heavy metal elements in the Liujiang river basin in adults and children were 4.52E-04 a-1 and 5.91E-04 a-1, respectively, while the non-carcinogenic health risks were 8.96E-09 a-1 and 1.14E-08 a-1, respectively. The heavy metal elements in drinking water, on the basis of their average carcinogenic health risks, were ranked as Cr > As > Cd, and the risk levels ranged from 3.58E-06 to 1.21E-04 a-1; the risk values of Cr and As were higher than the maximum allowance levels recommended by ICRP (5.0×10-5 a-1). Simultaneously, the risk levels of the average non-carcinogenic health risks ranged from 3.53E-12 to 2.87E-09 a-1, and the range was lower than the maximum allowance levels recommended by EPA. Carcinogens, especially Cr and As, are the main causes of health risks in the aquatic environment of the Liujiang river basin, and should be prioritized as the main objects of aquatic environmental risk management in the Liujiang river basin.


Assuntos
Água Potável/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Adulto , Criança , China , Monitoramento Ambiental , Humanos , Medição de Risco , Rios
16.
Huan Jing Ke Xue ; 39(3): 1065-1075, 2018 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965450

RESUMO

In order to understand the temporal and spatial variations of major ions in water and their sources in the Lhasa River Basin, water samples were collected monthly at the hydrological station in the Lhasa River from August 2014 to July. The results show that HCO3- is the dominant anion in the water of the Lhasa River, which accounts for 68.73% of the anions, followed by SO42-. Ca2+ is the dominant cation, which accounts for 67.75% of the cations, followed by Mg2+. The pH values of the river water range between 8.31 and 8.90, with a mean of 8.59 throughout the year, generally showing alkaline water. The highest pH values occur in summer, which is probably due to the photosynthesis of aquatic plants and the growth of phytoplankton. Electrical conductivity (EC) varies between 155.0 and 257.0 µS·cm-1, with a mean of 210.5 µS·cm-1. Because of the frequent uplift of the Tibetan Plateau that enhanced the mechanical weathering of rocks and mineral dissolution, the total dissolved solid (TDS) concentration, at an average of 181.35 mg·L-1, is significantly higher than the average value of rivers around the world. The Lhasa River is recharged by surface runoff, so the concentrations of major ions in water are higher during winter, but lower in summer. An ion source analysis indicates that Ca2+, Mg2+, and HCO3- are mainly derived from chemical weathering of carbonate minerals, Cl-, SO42-, and NO3- are mainly affected by precipitation and rock weathering. Furthermore, the concentrations of major ions in the water have a negative correlation with the river discharge rate, which suggests there might be a dilution effect occurring during the rainy season.

17.
Zhongguo Zhong Yao Za Zhi ; 43(7): 1471-1475, 2018 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-29728039

RESUMO

To inverstigate the alkaloids from the twigs and leaves of Ervatamia pandacaqui, eleven known alkaloids were isolated by silica gel, Sephadex LH-20, and ODS column chromatography, as well as RP-HPLC. Their structures were elucidated by UV, IR, MS, and NMR spectral data as coronaridine (1), 3-oxocoronaridine (2), 19S-heyneanine (3), 19R-heyneanine (4), voacangine (5), 3-oxovoacangine (6), voacristine (7), 19-epi-voacristine (8), iso-voacangine (9), coronaridine 7-hydroxyindolenine (10), and voacangine 7-hydroxyindolenine (11). Compounds 1-11 were isolated from E. pandacaqui for the first time.


Assuntos
Alcaloides/análise , Apocynaceae/química , Cromatografia , Espectroscopia de Ressonância Magnética , Compostos Fitoquímicos/análise , Folhas de Planta/química , Plantas Medicinais/química
18.
Nat Mater ; 17(1): 49-56, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29180776

RESUMO

Erasable conductive domain walls in insulating ferroelectric thin films can be used for non-destructive electrical read-out of the polarization states in ferroelectric memories. Still, the domain-wall currents extracted by these devices have not yet reached the intensity and stability required to drive read-out circuits operating at high speeds. This study demonstrated non-destructive read-out of digital data stored using specific domain-wall configurations in epitaxial BiFeO3 thin films formed in mesa-geometry structures. Partially switched domains, which enable the formation of conductive walls during the read operation, spontaneously retract when the read voltage is removed, reducing the accumulation of mobile defects at the domain walls and potentially improving the device stability. Three-terminal memory devices produced 14 nA read currents at an operating voltage of 5 V, and operated up to T = 85 °C. The gap length can also be smaller than the film thickness, allowing the realization of ferroelectric memories with device dimensions far below 100 nm.

19.
Chem Commun (Camb) ; 54(11): 1307-1310, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29271429

RESUMO

Inspired by metabolic processes in biological systems, animal blood as a biowaste rich in biological enzymes with molecular Fe-N centers was successfully explored to produce an efficient electrocatalyst with single atomic Fe-N-C active sites for oxygen reduction reaction.

20.
BMC Urol ; 17(1): 99, 2017 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29084530

RESUMO

BACKGROUND: Calcifying nanoparticles (NPs) have been proven to be associated with a variety of pathological calcification and previously detected in semen samples from patients with testicular microlithiasis (TM). The present study was designed to test the hypothesis if human-derived NPs could invade the seminiferous tubules and induce TM phenotype. METHODS: The animals were divided into three groups. Normal saline (0.2 mL) was injected into the proximal right ductus deferens in group A as a control group. The experimental groups, B and C received Escherichia coli (106 cfu/mL, 0.2 mL) and human-derived NPs suspension (0.2 mL), respectively. Rats were euthanized in 2 batches at 2 and 4 weeks. Testicular pathology, ultrastructure and inflammatory mediators were assessed. RESULTS: Chronic inflammatory changes were observed at 2 weeks in both groups B and C. Moreover, the innermost layer of sperm cells were structurally impaired and a zone of concentrically layered collagen fibers around the human NPs body was formed in the lumen of the seminiferous tubule in group C only, in which TM phenotype of remarkable calcification surrounded by cellular debris within the seminiferous tubules was built at 4 weeks. CONCLUSIONS: The results obtained from our study suggested a potential pathogenic effect of NPs in the development of calcification within the seminiferous tubules, which should be addressed in the future studies.


Assuntos
Nanopartículas Calcificantes/efeitos adversos , Cálculos/etiologia , Túbulos Seminíferos/patologia , Doenças Testiculares/etiologia , Animais , Calcinose/etiologia , Cálculos/patologia , Modelos Animais de Doenças , Escherichia coli , Humanos , Inflamação/etiologia , Masculino , Camundongos , Microscopia Eletrônica de Varredura , Ratos , Ratos Sprague-Dawley , Doenças Testiculares/patologia , Testículo/patologia , Testículo/ultraestrutura
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