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1.
Polymers (Basel) ; 12(3)2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32245077

RESUMO

The exploration of a new family of flexible and high-performance electromagnetic shielding materials is of great significance to the next generation of intelligent electronic products. In this paper, we report a simple magnetic-electrospinning (MES) method for the preparation of a magnetic flexible film, γ-Fe2O3 nanoparticle-embedded polymeric nanofibers. By introducing the extra magnetic field force on γ-Fe2O3 nanoparticles within composite fibers, the critical voltage for spinning has been reduced, along with decreased fiber diameters. The MES fibers showed increased strength for the magnetic field alignment of the micro magnets, and the attraction between them assisted the increase in fiber strength. The MES fibers show modifications of the magnetic properties and electrical conductivity, thus leading to better electromagnetic shielding performance.

2.
Nano Lett ; 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32227970

RESUMO

Increasing the power conversion efficiency (PCE) of colloidal quantum dot (CQD) solar cells has relied on improving the passivation of CQD surfaces, enhancing CQD coupling and charge transport, and advancing device architecture. The presence of hydroxyl groups on the nanoparticle surface, as well as dimers-fusion between CQDs-has been found to be the major source of trap states, detrimental to optoelectronic properties and device performance. Here, we introduce a CQD reconstruction step that decreases surface hydroxyl groups and dimers simultaneously. We explored the dynamic interaction of charge carriers between band-edge states and trap states in CQDs using time-resolved spectroscopy, showing that trap to ground-state recombination occurs mainly from surface defects in coupled CQD solids passivated using simple metal halides. Using CQD reconstruction, we demonstrate a 60% reduction in trap density and a 25% improvement in charge diffusion length. These translate into a PCE of 12.5% compared to 10.9% for control CQDs.

3.
Spine (Phila Pa 1976) ; 45(8): 504-511, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32224806

RESUMO

STUDY DESIGN: A retrospective study. OBJECTIVE: To assess the long-term results of zero-profile spacer for 3-level anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: Although widely used, there are still controversies about the long-term results of zero-profile spacer, especially in multilevel cases. METHODS: Cases received 3-level ACDF for cervical spondylotic myelopathy (CSM) using either zero-profile spacer (n = 27) (ZP Group), or plate and cages (n = 34) (PC Group), and with 5-year follow-up were reviewed. Neurological function and life quality were assessed by modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and Short-Form 36 (SF-36) score. Disc height, cervical lordosis, fusion rate, and surgical complications were observed. RESULTS: Neurological recovery and life quality improvement were similar in both groups. Disc height and cervical lordosis (C2-7 Cobb angle) were well restored after operations, but lost in both groups during follow-up. Loss of correction (LOC) in disc height was larger in ZP Group (11.38% vs 5.71%, P < 0.05) at 5-year follow-up. LOC of cervical lordosis in ZP group constantly grew from 11.28% to 48.13% during 5-year follow-up, significantly higher than that in the PC group (from 7.43% to 14.01%) (P < 0.05). The rate of postoperative dysphagia was no statistical difference between the two groups, and symptoms were all disappeared within 1 year. There were 10 levels of adjacent segment degeneration (1 in ZP Group, and 10 in PC Group, P = 0.02). Cage subsidence (11 of 81 levels, 13.58%) and screw migration (2 of 81 levels, 2.47%) were only observed in the ZP Group. The migrated screws in one case were surgically removed. Fusion was achieved in all cases. CONCLUSIONS: In long-term follow-up of 3-level ACDF for CSM, zero-profile spacer has the similar clinical results, but loss of correction of disc height and cervical alignment were significantly higher, compared with anterior plate and cages. LEVEL OF EVIDENCE: 3.

4.
J Am Chem Soc ; 2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-32150404

RESUMO

Metal halide perovskites show promise for light-emitting diodes (LEDs) owing to their facile manufacture and excellent optoelectronic performance, including high color purity and spectral stability, especially in the green region. However, for blue perovskite LEDs, the emission spectrum line width is broadened to over 25 nm by the coexistence of multiple reduced-dimensional perovskite domains, and the spectral stability is poor, with an undesirable shift (over 7 nm) toward longer wavelengths under operating conditions, degradation that occurs due to phase separation when mixed halides are employed. Here we demonstrate chloride insertion-immobilization, a strategy that enables blue perovskite LEDs, the first to exhibit narrowband (line width of 18 nm) and spectrally stable (no wavelength shift) performance. We prepare bromide-based perovskites and then employ organic chlorides for dynamic treatment, inserting and in situ immobilizing chlorides to blue-shift and stabilize the emission. We achieve sky-blue LEDs with a record luminance over 5100 cd/m2 at 489 nm, and an operating half-life of 51 min at 1500 cd/m2. By device structure optimization, we further realize an improved EQE of 5.2% at 479 nm and an operating half-life of 90 min at 100 cd/m2.

5.
Eur J Pharm Sci ; 148: 105319, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32205231

RESUMO

As one of the most promising drug delivery carriers, self-assembled DNA nanostructures are characterized of well-defined sizes, excellent biocompatibility, high drug loading and ability to control drug release. Studying the interactions between anticancer drugs and DNA nanostructures can help to associate microstructure-drug loading-release rate-therapeutic effect. Herein AS1411 aptamer-tethered DNA nanotrains (AS1411NTrs) were constructed and used as anthracyclines carrier with high payload for targeted delivery. The bindings of doxorubicin (DOX), epirubicin (EPI), and daunorubicin (DAU) to AS1411NTrs were investigated by isothermal titration calorimetry and fluorescence spectroscopy, and thermodynamic parameters were obtained. The high drug payload capacity of AS1411NTrs was verified by the large number of binding sites (~20). The binding mode was determined by differential scanning calorimetry and potassium iodide (KI) quenching experiments. The release experiment data showed that DNase I facilitated drug release and the release followed the first-order kinetic model. MTT cell viability assay demonstrated that the drug-loaded AS1411NTrs had significantly higher cytotoxicity against target HeLa cells than normal human liver L02 cells. These findings revealed that AS1411NTrs had high payload and targeted release capacity for DOX, EPI, and DAU. This result can provide a theoretical basis for constructing reasonable DNA nanostructures based on drug carriers.

6.
Bioorg Chem ; 99: 103749, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32220664

RESUMO

Fungal infections have become a serious medical problem due to the high infection rate and the frequent emergence of drug resistance. Ergosterol is an important structural component of the fungal cell membrane, its synthetases (squalene epoxidase (SE) and 14α-demethylase (CYP51)) are considered as the key points to block the ergosterol synthesis. In this study, we designed a series of dual-target arylamides derivatives based on the analysis of active sites (SE, CYP51). Subsequently, these target compounds were synthesized, and their antifungal activity was evaluated. Most of compounds demonstrate the potent antifungal activity against multiple Candida spp. and A. fum. In particular, the antifungal activities of compounds 10b and 11c are not only superior to positive control drugs, but also have significant inhibitory effects on drug-resistant fungi (C.alb. Strain100, C.alb. Strain103). Therefore, their action mechanism was further studied. Cellular uptake and electron microscopy observation showed that target compounds were able to enter fungal cytoplasmic region through free diffusion, and destroyed cell membrane structure. At the same time, preliminary mechanisms have demonstrated that they can affect the synthesis of ergosterol by inhibiting the activity of dual targets. It is worth noting that they also can exhibit excellent antifungal activity and low toxic side effects in vivo. Their ADMET properties and binding models were established will be useful for further lead optimization.

7.
Eur J Med Res ; 25(1): 2, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32178736

RESUMO

BACKGROUND: Acute coronary syndrome (ACS) is a serious type of cardiovascular diseases. This study aimed to investigate the expression patterns and clinical value of microRNA-145 (miR-145) in ACS patients, and further uncover the function of miR-145 in ACS rats. METHODS: Quantitative real-time PCR was used to estimate the expression of miR-145. Diagnostic value of miR-145 was evaluated, and its correlation with endothelial injury marker (vWF and H-FABP) and pro-inflammatory cytokines (IL-6 and TNF-α) was analyzed. Coronary artery ligation was adopted to construct the ACS rat model, and the effects of miR-145 on endothelial injury, inflammation and vascular endothelial cells (VECs) biological function were examined. RESULTS: Downregulated expression of miR-145 was found in the ACS serum samples compared with the healthy controls. The expression of miR-145 was proved to be a diagnostic biomarker and negatively correlated with vWF, H-FABP, IL-6 and TNF-α. The similar serum expression trends of miR-145 in ACS patients were also observed in the ACS rats, and the overexpression of miR-145 could decrease the elevated vWF, H-FABP, IL-6 and TNF-α in the animal model. Moreover, the upregulation of miR-145 in VECs led to promoted proliferation and migration. The bioinformatics prediction data and luciferase report results indicated that FOXO1 was a direct target of miR-145. CONCLUSIONS: In conclusion, it was hypothesized that serum decreased expression of miR-145 may serve as a potential diagnostic biomarker in ACS patients. Overexpression of miR-145 may improve the endothelial injury and abnormal inflammation through targeting FOXO1, indicating that miR-145 serves as a candidate therapeutic target of ACS.

8.
Adv Mater ; : e1906199, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32196136

RESUMO

Colloidal quantum dots (CQDs) are of interest in light of their solution-processing and bandgap tuning. Advances in the performance of CQD optoelectronic devices require fine control over the properties of each layer in the device materials stack. This is particularly challenging in the present best CQD solar cells, since these employ a p-type hole-transport layer (HTL) implemented using 1,2-ethanedithiol (EDT) ligand exchange on top of the CQD active layer. It is established that the high reactivity of EDT causes a severe chemical modification to the active layer that deteriorates charge extraction. By combining elemental mapping with the spatial charge collection efficiency in CQD solar cells, the key materials interface dominating the subpar performance of prior CQD PV devices is demonstrated. This motivates to develop a chemically orthogonal HTL that consists of malonic-acid-crosslinked CQDs. The new crosslinking strategy preserves the surface chemistry of the active layer beneath, and at the same time provides the needed efficient charge extraction. The new HTL enables a 1.4× increase in charge carrier diffusion length in the active layer; and as a result leads to an improvement in power conversion efficiency to 13.0% compared to EDT standard cells (12.2%).

9.
Arterioscler Thromb Vasc Biol ; : ATVBAHA119313830, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32160772

RESUMO

OBJECTIVE: Carotid bifurcation geometry has been believed to be a risk factor for the initiation of atherosclerosis because of its influence on hemodynamics. However, the relationships between carotid bifurcation geometry and plaque vulnerability are not fully understood. This study aimed to determine the association between carotid bifurcation geometry and plaque vulnerability using magnetic resonance vessel wall imaging. Approach and Results: A total of 501 carotid arteries with nonstenotic atherosclerosis were included from the cross-sectional, multicenter CARE II study (Chinese Atherosclerosis Risk Evaluation). Four standardized carotid bifurcation geometric parameters (bifurcation angle, internal carotid artery planarity, luminal expansion FlareA, and tortuosity Tort2D) were derived from time-of-flight magnetic resonance imaging. Presence of vulnerable plaque, which has intraplaque hemorrhage, large lipid-rich necrotic core, or disrupted luminal surface, was determined based on multicontrast carotid magnetic resonance vessel wall images. Vulnerable plaques (N=43) were found to occur at more distal locations (ie, near the level of flow divider) than stable plaques (N=458). Multivariable logistic regression shows that the luminal expansion FlareA (odds ratio, 0.45 [95% CI, 0.25-0.81]; P=0.008) was associated with plaque vulnerability after adjustment for age, sex, maximum wall thickness, plaque location, and other geometric parameters. CONCLUSIONS: Smaller luminal expansion at carotid bifurcation is associated with vulnerable plaque. The finding needs to be verified with longitudinal studies and the underlying mechanism should be further explored with hemodynamics measurement in the future.

11.
PLoS Genet ; 16(3): e1008678, 2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32203519

RESUMO

Plants have evolved strategies to avoid shade and optimize the capture of sunlight. While some species are tolerant to shade, plants such as Arabidopsis thaliana are shade-intolerant and induce elongation of their hypocotyl to outcompete neighboring plants. We report the identification of a developmental module acting downstream of shade perception controlling vascular patterning. We show that Arabidopsis plants react to shade by increasing the number and types of water-conducting tracheary elements in the vascular cylinder to maintain vascular density constant. Mutations in genes affecting vascular patterning impair the production of additional xylem and also show defects in the shade-induced hypocotyl elongation response. Comparative analysis of the shade-induced transcriptomes revealed differences between wild type and vascular patterning mutants and it appears that the latter mutants fail to induce sets of genes encoding biosynthetic and cell wall modifying enzymes. Our results thus set the stage for a deeper understanding of how growth and patterning are coordinated in a dynamic environment.

12.
J Chem Phys ; 152(5): 054903, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32035450

RESUMO

By using a graphics processing unit-accelerated parallel algorithm on a compute unified device architecture platform, we perform large-scale molecular dynamics simulations in a Lennard-Jones system to observe the entire crystallization process, including metastable stage, critical nuclei formation, and the stage of crystal growth. Although the intermediated precursors that play a role in determining the polymorphs are predominantly bcc ordered, the polymorph selection is rather different at different stages. The precursors that have a relatively high orientational order will be on average in a denser region than uniform liquids, but microscopically the crystal nucleation happens without a density change. The average density of nuclei first increases significantly, and then almost keeps independent on the crystallite size after the growing post-critical nucleus becomes large enough. With such a large enough system, the crystal growth rate is able to be calculated directly by doing a linear fit to the temporal evolution of growing crystallite size. The obtained value of the growth rate indicates that the actual crystal growth in the Lennard-Jones system where the crystal-liquid interface has several kinds of structures is possibly driven by both collision-controlled and diffusion-controlled mechanisms.

13.
Nanotechnology ; 31(22): 224002, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050177

RESUMO

MoO2 nanomaterials show a superior surface-enhanced Raman scattering (SERS) property due to their high concentration of free electrons and low resistivity. However, the physical process of semiconductor-based SERS is still elusive because there are many factors that affect the local electromagnetic field intensity and the subsequent Raman intensity of the molecules in close proximity to the semiconductor nanomaterials. Herein, we investigate the important contribution of surface morphology to molybdenum oxide SERS. The MoO3/MoO2 nanosheets (NSs) are synthesized by oxidizing MoO2 NS, and the surface roughness of MoO3 can be controlled through adjusting the oxidization time. Compared with the MoO2 NS before oxidization, the MoO3/MoO2 NSs exhibit a much stronger SERS signal, which favors their application as a SERS substrate to detect trace amounts of methylene blue molecules. The minimum detectable concentration is up to 10-9 M and the maximum enhancement factor is about 1.4 × 105. Meanwhile, excellent signal reproducibility is also observed using the MoO3/MoO2 NSs as the SERS substrate. A simulated electric field distribution shows that a stronger electric field enhancement is formed due to the lightning rod effect in the gap of corrugated MoO3 NSs. These results demonstrate that the surface topography of molybdenum oxide may play a more important role than their oxidation state in SERS signal enhancement.

14.
Odontology ; 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32016787

RESUMO

MIR4435-2HG has been characterized as an oncogenic lncRNA in several types of cancer, while its role in oral squamous cell carcinoma (OSCC, a major subtype of oral cancer) has not been characterized. We explored the functionality of MIR4435-2HG in OSCC and investigated its interactions with TGF-ß1. Blood samples were extracted from OSCC patients (n = 44) and healthy volunteers (n = 38), RT-qPCR, CCK-8, Transwell assays and western blot were performed in this study. The results showed that levels of MIR4435-2HG and TGF-ß1 in plasma were upregulated in OSCC. Across OSCC plasma samples, TGF-ß1 and MIR4435-2HG were significantly and positively correlated. Overexpression of MIR4435-2HG resulted in upregulated TGF-ß1 expression, while exogenous TGF-ß1 treatment had no effect on the expression of MIR4435-2HG. Overexpression of MIR4435-2HG and exogenous TGF-ß1 treatment led to promoted, while TGF-ß inhibitor led to inhibited migration, proliferation and invasion of cancer cells. Moreover, TGF-ß inhibitor led to reduced effects of overexpressing MIR4435-2HG. Therefore, MIR4435-2HG regulates the behaviors of OSCC cells by promoting the expression of TGF-ß1.

15.
Artigo em Inglês | MEDLINE | ID: mdl-32100941

RESUMO

Under the dual influences of high-intensity anthropogenic activity and climate change, wetland hydrologic connectivity (HC) has decreased significantly, resulting in severe wetland fragmentation, shrinking wetland area and degradation of hydrological functions. The result worsening disaster response to flood and drought. Dynamic change of wetland hydrologic connectivity is affected by a variety of driving factors. Many degraded wetlands have undergone hydrologic connectivity restoration measures. Recovery can improve the hydrologic connectivity pattern of degraded wetlands. Based on the knowledge of practitioners and the review of existing literature, it was found that recovery measures can be divided into structural recovery and functional recovery according to the specific recovery objects. However, the current method lacks a holistic analysis of the hydrologic connectivity pattern. To this end, this paper proposes a hydrologic network-water balance based hydrologic connectivity recovery and management framework that overcomes the limitations of single drive factor repair and local repair effects. This article is protected by copyright. All rights reserved.

16.
Br J Neurosurg ; : 1-5, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32003246

RESUMO

Purpose: Cases of allergy to large surgical implants have been reported. However, few studies have reported allergy to small titanium-containing implants (e.g. Zero-P device).Methods: We reported the case of a 51-year old male patient who underwent the anterior cervical discectomy and fusion (ACDF) procedure using a Zero-P device and exhibited allergic symptoms 1 month after the surgery.Results: The allergic symptoms included intermittent tingling and itches in the throat induced by speaking. Systemic rashes over the skin surface and congestion of the eyeball, and dysphagia were also present. Anti-allergic treatment did not resolve the symptoms. Patch tests revealed negative reactions to the rested reagents including titanium. Radiographic results showed solid bone fusion and no signs of chronic inflammation or hypotoxic infection in the surrounding tissues. Upon the patient's request, we removed the titanium screws and plate of the Zero-P device. No allergic reactions were observed after the surgery and at a 6-month follow-up.Conclusions: Even with a small implant such as the Zero-P device, allergy to titanium may still occur. This case demonstrated the need to screen for the presence of allergy to metals including titanium before the surgery.

17.
Mar Pollut Bull ; 151: 110801, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056596

RESUMO

We investigated the growth and nutrient uptake of Myriophyllum spicatum under different nutrient conditions and evaluated its implications for ecosystem services in an enclosed area of Jinshan. The specific growth rate ranged from 1.29%-4.37%/day, and the dissolved inorganic carbon and nitrogen, and phosphorus uptake rates were 1.30-1.62, 0.040-0.453, and 0.003-0.027 mg/(g∙day), respectively, under different nutrient conditions. The O2-production and carbon-sequestration efficiencies in the field were 154.30 and 1.25 mg/(g DW∙h), respectively. The average removal efficiencies of NH4+-N, NO3--N, NO2--N, and PO43--P were 43.05%, 97.03%, 64.26%, and 59.24%, respectively, in M. spicatum-cultivated areas compared with in the open sea. Harvesting of M. spicatum removed 12,936.87, 1289.97 and 114.81 kg of carbon, nitrogen, and phosphorus, respectively, from seawater in Jinshan in Nov, 2018. In conclusion, M. spicatum is a good candidate for integrated macrophyte/animal multi-trophic aquaculture in terms of nutrient extraction and economic diversification in low-salinity environments.


Assuntos
Ecossistema , Nitrogênio , Fósforo , Saxifragales , Animais , China , Nutrientes , Oceanos e Mares
18.
Neurotox Res ; 37(4): 1029-1035, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32026360

RESUMO

Hyperphosphorylated tau is an important pathological agent in Alzheimer's disease (AD). Tau effluxes from the brain to the blood could potentially stimulate the production of naturally occurring antibodies (NAbs). We aimed to investigate whether NAbs to tau (NAbs-tau) was generated in human blood and to figure out the alteration of plasma NAbs-tau level in AD patients. About 192 AD patients and 192 age-matched and non-demented controls (NC) were enrolled in the present study. Immunofluorescence staining and western blot assays were used to confirm the existence of NAbs-tau in human blood. The plasma level of NAbs-tau in NC and AD group was analyzed by ELISA. Immunofluorescence staining and western blot assays confirmed the existence of NAbs-tau in human blood. However, no significant difference in the plasma level of NAbs-tau was observed between NC and AD group. Furthermore, the plasma level of NAbs-tau had no significant correlation with MMSE scores. The present study confirmed that NAbs-tau exists in human blood but does not differ in level between the NC and AD group. Plasma NAbs-tau is not a reliable biomarker for AD.

20.
J Prosthet Dent ; 123(2): 290.e1-290.e8, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31902534

RESUMO

STATEMENT OF PROBLEM: The adhesion properties of modified cement-retained implant prostheses have not been elucidated. PURPOSE: The purpose of this in vitro study was to compare the adhesion strength and the flow conditions of the adhesives of 3 common modified cement-retained methods (MCRMs). MATERIAL AND METHODS: Four cement-retained methods were used: an occlusal hole for screw access (OH), a lingual hole for releasing the excess adhesive (LH), a resin replica for the titanium abutment (RR), and a control group (no holes and no resin trial abutments). Eight zirconia prostheses in each group were processed and cemented. The adhesion strength was examined by mechanical tensile experiments (MTE) in vitro. One-way ANOVA and the LSD post hoc tests were used to compare the results of the MTE (α=.05). The flow conditions of adhesives in the adhesion process were analyzed by computational fluid dynamics (CFD). CFD-Post 16.0 (ANSYS, Inc) was used to analyze the results of the CFD analyses. RESULTS: The adhesion strength of each group was 289.3 ±37.7 N in the LH group, 281.3 ±50.1 N in the OH group, 263.3 ±49.3 N in the RR group, and 239.2 ±29.4 N in the control group. A statistically significant difference is seen in the adhesion strength between the LH group and the control group (P=.025). The internal filling ratio of adhesives between the groups ranges from high to low in the order the LH group, the OH group, the RR group, and the control group. The amount of cervical overflow of adhesives between the groups ranges from less to more in the order the RR group, the OH group, the LH group, and the control group. CONCLUSIONS: MCRMs can effectively reduce the amount of cervical overflow of adhesives and improve the filling condition of the adhesive and its clearance to ensure the adhesion strength of the prostheses.


Assuntos
Dente Suporte , Implantes Dentários , Cimentos Dentários , Prótese Dentária Fixada por Implante , Análise do Estresse Dentário , Hidrodinâmica , Teste de Materiais , Resistência à Tração
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