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1.
Soft Matter ; 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32159200

RESUMO

The exploitation and utilization of renewable clean energy is of great significance to the sustainable development of society. Electrokinetic energy conversion (EKEC) based on micro/nanochannels is expected to provide immense potential for ocean energy harvesting, self-powered micro/nanodevices, and small portable power supplies through converting environmental energy into electrical energy. Herein, aiming to get a deeper understanding of EKEC based on micro/nanochannels, several classic theoretical models and corresponding calculation equations are introduced briefly. For high efficiency energy conversion, it is essential to clearly discuss the interface properties between the inner surface of the channel and the bulk electrolyte solution. Therefore, we put forward soft interface designs of solid-liquid and liquid-liquid interfaces, and summarize their recent progress. In addition, the different applications of EKEC, harvesting from environmental energy, are further discussed. We hope that this review will attract more scientists' attention to transform the experimental results of EKEC systems in the lab into available products on shelves.

2.
J Mol Biol ; 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32061929

RESUMO

Impaired protein homeostasis and accumulation of damaged or abnormally modified protein are common disease mechanisms in many neurodegenerative disorders, including Parkinson's disease (PD). As one of the major degradation pathways, autophagy plays a pivotal role in maintaining effective turnover of proteins and damaged organelles in cells. Several decades of research efforts led to insights into the potential contribution of impaired autophagy machinery to α-synuclein accumulation and the degeneration of dopaminergic neurons, two major features of PD pathology. In this review, we summarize recent pathological, genetic, and mechanistic findings that link defective autophagy with PD pathogenesis in human patients, animals, and cellular models and discuss current challenges in the field.

3.
Fitoterapia ; 141: 104469, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31917301

RESUMO

Two new cyclonerane sesquiterpenes, (10E)-isocyclonerotriol (1) and (10Z)-isocyclonerotriol (2), and one new isocoumarin derivative, trichophenol A (3), were isolated from Trichoderma citrinoviride A-WH-20-3, an endophyte from the marine red alga Laurencia okamurai. Their structures and relative configurations were assigned by spectroscopic techniques, highlighted by using Sarotti's DP4+ sheet to confirm the cyclopentane ring. The absolute configuration of 1 was established by comparison of experimental and calculated specific rotation data. Compounds 1 and 2 represent the first occurrence of ring-isomerized cycloneranes. Compound 3 is the first 3-phenylisocoumarin derivative from Trichoderma and features inhibition of several marine-derived bacteria and phytoplankton species.

4.
Science ; 367(6475): 272-277, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31949075

RESUMO

One great challenge in understanding the history of life is resolving the influence of environmental change on biodiversity. Simulated annealing and genetic algorithms were used to synthesize data from 11,000 marine fossil species, collected from more than 3000 stratigraphic sections, to generate a new Cambrian to Triassic biodiversity curve with an imputed temporal resolution of 26 ± 14.9 thousand years. This increased resolution clarifies the timing of known diversification and extinction events. Comparative analysis suggests that partial pressure of carbon dioxide (Pco2) is the only environmental factor that seems to display a secular pattern similar to that of biodiversity, but this similarity was not confirmed when autocorrelation within that time series was analyzed by detrending. These results demonstrate that fossil data can provide the temporal and taxonomic resolutions necessary to test (paleo)biological hypotheses at a level of detail approaching those of long-term ecological analyses.

5.
ACS Nano ; 14(2): 2465-2474, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31994870

RESUMO

The development of liquid gating membrane (LGM) systems with tunable multiphase selectivity and antifouling properties is limited by the mechanical stability of the membrane materials. The mechanical integrity of most polymeric membranes can be compromised by deformation under harsh operating conditions (elevated temperatures, corrosive environments, foulants, etc.), ultimately leading to their failure. Here, a facile electrochemical approach to the fabrication of multifunctional metal-based liquid gating membrane systems is presented. The membrane porosity, pore size, and membrane surface roughness can be tuned from micro- to nanometer scale, enabling function under a variety of operating conditions. The prepared LGMs demonstrate controllable gas-liquid selectivity, superior resistance to corrosive conditions and fouling chemicals, and significant reduction of the transmembrane pressure required for the separation process, resulting in lower energy consumption. The stability of the gating liquid is confirmed experimentally through sustained fouling resistance and further supported by the interfacial energy calculations. The mechanically robust metal-based membrane systems reported in this study significantly extend the operating range of LGMs, prompting their applications in water treatment processes such as wastewater treatment, degassing, and multiphase separation.

6.
Int J Biol Macromol ; 145: 620-633, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31883893

RESUMO

Herbal medicines are frequently used for the prevention and treatment of obesity and obesity-related disorders. Our preliminary screening showed that St. John's Wort (SJW) displayed potent inhibition on pancreatic lipase (PL), a key hydrolase responsible for lipid digestion and absorption in mammals. Herein, the inhibition potentials and inhibitory mechanism of SJW extract and its major constituents on PL were fully investigated by a set of in vitro and in silico studies. The results clearly demonstrated that the naphthodianthrones, biflavones and most of flavonoids in SJW displayed strong to moderate inhibition on PL. Among all tested natural compounds, two naphthodianthrones (hypericin and pseudohypericin) and one biflavone (I3,II8-biapigenin) isolated from SJW exhibited potent PL inhibition activity, with the IC50 values of <1 µM. Inhibition kinetics analyses showed that hypericin, pseudohypericin and I3,II8-biapigenin inhibited PL via a mixed manner, while molecular dynamics simulations revealed that three newly identified PL inhibitors could bind on PL at both the catalytic cavity and the interface between colipase and the C-terminal domain of PL. Collectively, our findings suggested that part of major constituents in SJW displayed potent PL inhibition activities, which could be used as lead compounds for the development of novel PL inhibitors.

7.
Small ; : e1905318, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31793747

RESUMO

Fluidic flow behaviors in microfluidics are dominated by the interfaces created between the fluids and the inner surface walls of microchannels. Microchannel inner surface designs, including the surface chemical modification, and the construction of micro-/nanostructures, are good examples of manipulating those interfaces between liquids and surfaces through tuning the chemical and physical properties of the inner walls of the microchannel. Therefore, the microchannel inner surface design plays critical roles in regulating microflows to enhance the capabilities of microfluidic systems for various applications. Most recently, the rapid progresses in micro-/nanofabrication technologies and fundamental materials have also made it possible to integrate increasingly complex chemical and physical surface modification strategies with the preparation of microchannels in microfluidics. Besides, a wave of researches focusing on the ideas of using liquids as dynamic surface materials is identified, and the unique characteristics endowed with liquid-liquid interfaces have revealed that the interesting phenomena can extend the scope of interfacial interactions determining microflow behaviors. This review extensively discusses the microchannel inner surface designs for microflow control, especially evaluates them from the perspectives of the interfaces resulting from the inner surface designs. In addition, prospective opportunities for the development of surface designs of microchannels, and their applications are provided with the potential to attract scientific interest in areas related to the rapid development and applications of various microchannel systems.

8.
Zhongguo Zhong Yao Za Zhi ; 44(14): 3010-3014, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31602847

RESUMO

The Dao-di herbs are recognized as high-quality Chinese medicines with good medicinal properties. The factors of their growth environment affects the quality of Dao-di herbs. Choosing the right place to produce,rationally planting appropriate local medicinal materials,and improving the quality and yield of authentic medicinal materials are prerequisites for ensuring the steady development of Chinese medicine industry. In this paper,a knowledge model of the relationship between organic medicinal materials and growth environment factors was constructed by integrating the dataset of environmental factors of medicinal materials,and a knowledge base was constructed to provide a decision for the study of suitable medicinal materials under different environmental conditions. Based on this,it is expected to provide a platform for further research on the relationship between the medicinal properties of medicinal herbs and environmental factors.


Assuntos
Asteraceae/crescimento & desenvolvimento , Bases de Dados Factuais , Ecossistema , Plantas Medicinais/crescimento & desenvolvimento , Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa
9.
Chem Asian J ; 14(23): 4262-4267, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31584745

RESUMO

The oxidative contraction of α-formal ketone to form continuous all carbon chiral centers promoted by H2 O2 is widely used in natural product total synthesis. Typically, using this transformation, chiral cyclic ketones are obtained as the major products and ring-opening products as the minor products. Herein, DFT calculations have been used to investigate the detailed reaction mechanism and chemoselectivity. In addition, with the widely accepted mechanism of H2 O2 -promoted transformation, our systematic investigation with various explicit-solvent-model calculations for the first time shows that H2 O and H2 O2 are comparable at catalyzing the rate-determining step of this reaction, which emphasis the importance of solvent effect in such transformations. It is found that both the less ring-constrain and a later transition state in an exothermic reaction account for the origin why the reaction favors ring-contraction pathway rather than ring-opening one. By a comprehensive analysis for the substituted groups, it has been disclosed that the steric effects of the substituted groups on R2 and R3 contribute to the selectivity with larger steric hindrance favoring the chiral cyclic products. Moreover, the electronic effects on R1 but not R3 affect the selectivity with electron-donating groups leading to the cyclic products. Based on our calculations, some predictions for higher selectivity have been made.

10.
Nanoscale Res Lett ; 14(1): 268, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31388778

RESUMO

In this report, we locally modulate the doping type in the n-AlGaN layer by proposing n-AlGaN/p-AlGaN/n-AlGaN (NPN-AlGaN)-structured current spreading layer for AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs). After inserting a thin p-AlGaN layer into the n-AlGaN electron supplier layer, a conduction band barrier can be generated in the n-type electron supplier layer, which enables the modulation of the lateral current distribution in the p-type hole supplier layer for DUV LEDs. Additionally, according to our studies, the Mg doping concentration, the thickness, the AlN composition for the p-AlGaN insertion layer and the NPN-AlGaN junction number are found to have a great influence on the current spreading effect. A properly designed NPN-AlGaN current spreading layer can improve the optical output power, external quantum efficiency (EQE), and the wall-plug efficiency (WPE) for DUV LEDs.

11.
Nanomaterials (Basel) ; 9(7)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31266235

RESUMO

Terahertz (THz) radiation has received much attention during the past few decades for its potential applications in various fields, such as spectroscopy, imaging, and wireless communications. To use terahertz waves for data transmission in different application systems, the efficient and rapid modulation of terahertz waves is required and has become an in-depth research topic. Since the turn of the century, research on metasurfaces has rapidly developed, and the scope of novel functions and operating frequency ranges has been substantially expanded, especially in the terahertz range. The combination of metasurfaces and semiconductors has facilitated both new opportunities for the development of dynamic THz functional devices and significant achievements in THz modulators. This paper provides an overview of THz modulators based on different kinds of dynamic tunable metasurfaces combined with semiconductors, two-dimensional electron gas heterostructures, superconductors, phase-transition materials, graphene, and other 2D material. Based on the overview, a brief discussion with perspectives will be presented. We hope that this review will help more researchers learn about the recent developments and challenges of THz modulators and contribute to this field.

12.
Heliyon ; 5(7): e02027, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31360785

RESUMO

This study succeeded to prepare three pure phases of Mn2O3, Mn3O4 beside one of the best cathode materials, spinel LiMn2O4. LiMn2O4 with high phase purity and crystallinity was synthesized by a facile, cost effective and one step synthesis method. The structure and morphology of the powders were studied in detail by means of X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM) and surface area. The X-ray diffraction shows that the post-annealing process reveals the formation of pure crystalline spinel LiMn2O4 with small particle size and lower lattice strain. The thermogravimetric analysis threw the light on the role of the evaporation technique in producing LiMn2O4 by following the different phases on the thermal performance of the precursor. The morphological characterization shows the clear appearance of the octahedral particles of LiMn2O4 calcined at high temperature with microporous nanosized structure. Electrochemical testing of the as prepared spinel at 900 °C showed promising results in terms of high initial capacity and good cycle stability. The as prepared spinel sample shows also good rate performance.

13.
iScience ; 19: 93-100, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31357171

RESUMO

Conventional printing is worth revisiting because of its established procedures in meeting the surging demand of manufacturing printed electronics, 3D products, etc. However, one goal in penetrating printing into these is to control pattern transfer with no limitation of wettability. Here we introduce a miscible liquid-liquid transfer printing mechanism that can synchronize material preparation and material patterning with desirable properties including limitless selection of raw materials, corrosion resistance, no wetting constraint, and ability to prepare large-area defect-free materials for multi-function applications. Theoretical modeling and experiments demonstrate that donor liquid could be used to make patterns within the bulk of a receiver material, allowing the obtained intrinsically patterned functional materials to be resistant to harsh conditions. Different from current liquid printing technologies, this printing approach enables stable and defect-free material preparation and is expected to prove useful in flexible display, soft electronics, 4D printing, and beyond.

14.
Opt Express ; 27(12): A643-A653, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31252844

RESUMO

In this work, the size-dependent effect for InGaN/GaN-based blue micro-light emitting diodes (µLEDs) is numerically investigated. Our results show that the external quantum efficiency (EQE) and the optical power density drop drastically as the device size decreases when sidewall defects are induced. The observations are owing to the higher surface-to-volume ratio for small µLEDs, which makes the Shockley-Read-Hall (SRH) non-radiative recombination at the sidewall defects not negligible. The sidewall defects also severely affect the injection capability for electrons and holes, such that the electrons and holes are captured by sidewall defects for the SRH recombination. Thus, the poor carrier injection shall be deemed as a challenge for achieving high-brightness µLEDs. Our studies also indicate that the sidewall defects form current leakage channels, and this is reflected by the current density-voltage characteristics. However, the improved current spreading effect can be obtained when the chip size decreases. The better current spreading effect takes account for the reduced forward voltage.

15.
Methods Mol Biol ; 1985: 383-389, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31069747

RESUMO

Nonaqueous capillary electrophoresis (NACE) is an effective method for chiral separation. Many polyol derivatives (e.g., D-(+)-xylose, lactobionic acid, diacetone-D-mannitol, L-sorbose, and D-gluconic acid δ-lactone) can react with boric acid in methanol to produce polyol derivative-boric acid complexes which can be utilized as chiral selectors of enantioseparations. The enantiomers of more than a dozen basic analytes can be resolved under the optimized NACE using these chiral selectors.


Assuntos
Ácidos Bóricos/química , Eletroforese Capilar/métodos , Polímeros/química , Acetona/química , Dissacarídeos/química , Manitol/química , Estereoisomerismo
16.
Neurobiol Learn Mem ; 161: 106-114, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30954674

RESUMO

We have previously reported cognitive impairments in both young and old mice, particularly in female mice expressing mouse Arg-61 apoE, with a point mutation to mimic the domain interaction feature of human apoE4, as compared to the wildtype mouse (C57BL/6J) apoE. In this study, we further evaluated water maze performance in the female Arg-61 mice at an additional time point and then investigated related hippocampal cyto-architecture in these young female Arg-61 apoE mice vs. the wildtype mice. The results of behavioral performance consistently support our previous report that the young female Arg-61 apoE showed cognitive impairment versus C57BL/6J at the same age. The cyto-architectural results showed that volume of the granular cell layer (GCL) was significantly larger in both 5- and 10-month old Arg-61 apoE mice versus C57BL/6J mice. While the number of newborn calretinin-positive neurons was greater in the sub-granular zone (SGZ) in 5-month old Arg-61 mice, this number dropped significantly in 10-month old Arg-61 mice to a lower level than in age-matched C57BL/6J mice. In addition, the amyloid ß species was significantly higher in 5-month old Arg-61 mice versus age-matched C57BL/6J mice. In conclusion, impaired cognitive functions in female Arg-61 apoE mice appear correlated with larger GCL volume and higher calretinin-positive cell number and suggest a compensatory cellular response that may be related to amyloid beta perturbations early in life. Therefore this study suggests a novel cyto-architectural mechanism of apoE4-dependent pathologies and increased susceptibility of APOEε4 subjects to Alzheimer's disease.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Apolipoproteínas E/genética , Calbindina 2/metabolismo , Disfunção Cognitiva , Hipocampo , Neurogênese , Fatores Etários , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Animais , Comportamento Animal/fisiologia , Disfunção Cognitiva/genética , Disfunção Cognitiva/fisiopatologia , Modelos Animais de Doenças , Feminino , Hipocampo/citologia , Hipocampo/metabolismo , Hipocampo/patologia , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Neurogênese/genética , Neurogênese/fisiologia , Memória Espacial/fisiologia
17.
J Exp Med ; 216(5): 1182-1198, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-30940720

RESUMO

Subclinical hypothyroidism is associated with cardiovascular diseases, yet the underlying mechanism remains largely unknown. Herein, in a common population (n = 1,103), TSH level was found to be independently correlated with both carotid plaque prevalence and intima-media thickness. Consistently, TSH receptor ablation in ApoE -/- mice attenuated atherogenesis, accompanied by decreased vascular inflammation and macrophage burden in atherosclerotic plaques. These results were also observed in myeloid-specific Tshr-deficient ApoE -/- mice, which indicated macrophages to be a critical target of the proinflammatory and atherogenic effects of TSH. In vitro experiments further revealed that TSH activated MAPKs (ERK1/2, p38α, and JNK) and IκB/p65 pathways in macrophages and increased inflammatory cytokine production and their recruitment of monocytes. Thus, the present study has elucidated the new mechanisms by which TSH, as an independent risk factor of atherosclerosis, aggravates vascular inflammation and contributes to atherogenesis.

18.
Cancer Lett ; 454: 146-157, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-30978442

RESUMO

Metabolic abnormality is one of the hallmarks of cancer cells, and limiting material supply is a potential breakthrough approach for cancer treatment. Increasing researchers have been involved in the study of glioma cell metabolism reprogramming since the significance of IDH1 was confirmed in glioma. However, the molecular mechanisms underlying metabolic reprogramming induced by methionine deprivation regulates glioma cell proliferation remain unclear. Here we demonstrated that methionine deprivation inhibited glioma cell proliferation via downregulating interleukin 1 receptor antagonist (IL1RN) both in vitro and in vivo, methionine deprivation or knocking down IL1RN induced glioma cell cycle arrest. Moreover, we confirmed that IL1RN is a tumor associated gene and its expression is negatively correlated with the survival time of glioma patients. Altogether these results demonstrate a strong rationale insight that targeting amino acid metabolism such as methionine deprivation/IL1RN related gene therapy may offer novel direction for glioma treatment.

19.
Electrophoresis ; 40(16-17): 2029-2040, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30968445

RESUMO

Two dimensional nanomaterials including graphene, hexagonal boron-nitride, molybdenum disulfide, etc., provide immense potentials for separation applications. However, the tradeoff between selectivity and permeability in choosing 2D nanomaterial-based membrane is inevitable, limiting the progress on separation efficiency for mass industrial applications. To target these issues, versatile strategies such as the rational design of predefined interlayer channels, membrane nanopores, and reasonable functionalization, as well as new mechanisms have been emerged. In this review, we introduce the recent progress on separation mechanisms of 2D nanomaterial-based membranes with different structures (including the interlayer channels type and the membrane nanopores type) and their inner surface functionalization. Moreover, the interface designs are discussed, in terms of employing dynamic liquid-liquid/liquid-gas interfaces, to advance the selectivity and permeability of the membranes. We further discuss the variety of separation applications based on 2D nanomaterial-based membranes. The authors hope this review will inspire the active interest of many scientists in the area of the development and application of membrane science.

20.
J Int Med Res ; 47(5): 1927-1935, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30832523

RESUMO

OBJECTIVE: Acute gout is a painful, inflammatory arthritis that features a rapidly escalating inflammatory response resulting from the formation of monosodium urate crystals in the affected joint space. Previously, we found that Chuanhu anti-gout mixture (CAGM) had similar effects as colchicine against gout in the clinic. Subsequently, to improve its effectiveness and efficacy, we modified the original formulation of CAGM. The current study evaluated the effectiveness of the modified formulation in mice. METHODS: Potassium oxonate (PO) was used to establish a mouse model of hyperuricemia. Plasma levels of uric acid and creatine were determined using the respective test kits. Hepatic xanthine oxidase (XOD) expression was examined by enzyme-linked immunosorbent assay. To explore the underlying mechanism, renal urate transporter 1 (URAT1) mRNA levels were evaluated by quantitative real-time PCR. Allopurinol and benzbromarone were used as reference drugs. RESULTS: The original CAGM and its modified high-dose formulation significantly reduced serum uric acid and creatine levels in hyperuricemic mice. In addition, the CAGM-treated groups displayed lower mRNA levels of hepatic XOD and renal URAT1. CONCLUSIONS: CAGM and its modified formulation significantly ameliorated PO-induced hyperuricemia in mice, which might be partially attributable to reductions of hepatic XOD and renal URAT1 levels.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Hiperuricemia/tratamento farmacológico , Rim/fisiopatologia , Substâncias Protetoras/uso terapêutico , Animais , Creatinina/sangue , Hiperuricemia/sangue , Hiperuricemia/induzido quimicamente , Hiperuricemia/genética , Masculino , Camundongos , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismo , Proteínas de Transporte de Cátions Orgânicos/genética , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Ácido Oxônico , Substâncias Protetoras/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ácido Úrico/sangue , Xantina Oxidase/metabolismo
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