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1.
J Nanosci Nanotechnol ; 21(2): 1184-1189, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33183460

RESUMO

Acute lung injury (ALI) is a critical illness but have not effective therapeutic modalities currently where recent studies have revealed anti-inflammatory pleiotropic effects and plaque stabilizing effects of statins so the purpose of this work is preparation of simvastatin loaded nanostructured lipid carriers (simvastatin-NLCs) and investigation of its efficacy in lung injury mice. The simvastatin- NLCs was prepared by thermal melting-low temperature curing method and the quality evaluation was performed with particle size distribution, encapsulation efficiency, and drug loading. Sixty C57BL/6 mice were divided into three experimental groups: blank group model group and simvastatin treated group. Simvastatin was administered intraperitoneally immediately after the LPS injection in animals of the treated group at a dose of 20 mg/kg/day. Lung injury degree and the protective effects of simvastatin against LPS-induced lung injury were assessed at the time-points of 24, 48, and 72 h post injection, and the in vivo efficacy of simvastatin-NLCs on mice was investigated. The average particle size of simvastatin-NLCs was (102.1±42.2) nm, the encapsulation efficiency was (94.6±2.5)%, and the drug loading was (5.78±0.57)%. After 24 hours of administration, the data shows that simvastatin-NLCs inhibit the levels of IL-6 and TNF-α inflammatory factor in the lungs of mice.

2.
Anal Chim Acta ; 1135: 64-72, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33070860

RESUMO

Alkaline phosphatase (ALP), which converts the phosphate group (-PO4) in the substrate to the hydroxyl group (-OH), is a useful tool in the biological analysis, a good indicator of dissolved inorganic phosphorus levels and an important biomarker for several diseases. In conventional designs for ALP detection, both the interferent with a -PO4 and the target with a -OH will go into the sensing path and give out the undesired background and the desired signal respectively. This limited the sensitivity of the method and required the complicated design to achieve a satisfying limit of detection (LOD) of ALP. Here, we provided a new sensing strategy for ALP detection design. We designed a path-choice-based biosensor with two DNA tracks in which ALP works as the switch to guide the reaction path of lambda exonuclease (λ exo). The path-choice character enlarged the difference between signal and background by separating the interferent removing path and the target sensing path. The substrate preference of ALP and λ exo was studied to optimize the structure of DNA tracks. The path-choice-based biosensor achieved simple, fast (30 min), sensitive (LOD 0.014 U L-1) and selective detection of the activity of ALP. The method has been applied to detect the activity of ALP in cell lysates, which shows the potential application in ALP-related biological research.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33010216

RESUMO

PURPOSE: To investigate the application and value of intraoperative computed tomography (CT) in the surgical management of temporomandibular joint (TMJ) ankylosis. PATIENTS AND METHODS: Patients who underwent surgery of TMJ ankylosis with the aid of intraoperative CT scan from July 2016 to December 2018 were retrospectively studied. Demographics, type of ankylosis, surgical method, intraoperative CT scan time, radiographic evidence, the CT-directed revision rate, and clinical outcomes were analyzed. RESULTS: Four patients (5 sides) were successfully operated with the aid of intraoperative CT imaging, and CT-directed revisions were made in 3 of them during surgery. The average time spent in CT scanning was (10.2 ± 3.3) minutes. No surgical complications were noted, and a good satisfaction rate (with an average maximum mouth opening of 38.8 mm and no recurrence during the follow-up period) was obtained. CONCLUSIONS: Intraoperative CT scanning is a helpful tool in the evaluation of the radiographic result of TMJ ankylosis, and a real-time revision could be made. It increased the precision and safety of the surgery of TMJ ankylosis.

4.
J Trauma Acute Care Surg ; 89(6): 1092-1098, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32925581

RESUMO

BACKGROUND: Invasive mechanical ventilation (IMV) is a lifesaving strategy for critically ill patients with coronavirus disease 2019 (COVID-19). We aim to report the case series of critical patients receiving IMV in Wuhan and to discuss the timing of IMV in these patients. METHODS: Data of 657 patients admitted to emergency intensive care unit of Zhongnan Hospital and isolated isolation wards of Wuhan Union Hospital from January 1 to March 10, 2020, were retrospectively reviewed. All medical records of 40 COVID-19 patients who required IMV were collected at different time points, including baseline (at admission), before receiving IMV, and before death or hospital discharge. RESULTS: Among 40 COVID-19 patients with IMV, 31 died, and 9 survived and was discharged. The median age was 70 years (interquartile range [IQR], 62-76 years), and nonsurvivors were older than survivors. The median period from the noninvasive mechanic ventilation (NIV) or high-flow nasal cannula oxygen therapy (HFNC) to intubation was 7 hours (IQR, 2-42 hours) in IMV survivors and 54 hours (IQR, 28-143 hours) in IMV nonsurvivors. We observed that, when the time interval from NIV/HFNC to intubation was less than 50 hours (about 2 calendar days), together with Acute Physiology and Chronic Health Evaluation II (APACHE II) score of less than 10 or pneumonia severity index (PSI) score of less than 100, mortality can be reduced to 60% or less. Prolonged interval from NIV/HFNC to intubation and high levels of APACHE II and PSI before intubation were associated with higher mortality in critically ill patients. Multiple organ damage was common among these nonsurvivors in the course of treatment. CONCLUSION: Early initial intubation after NIV/HFNC might have a beneficial effect in reducing mortality for critically ill patients meeting IMV indication. Considering APACHE II and PSI scores might help physicians in decision making about timing of intubation for curbing subsequent mortality. LEVEL OF EVIDENCE: Therapeutic, level V.

5.
J Cell Mol Med ; 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32746503

RESUMO

Sulfiredoxin 1 (SRXN1) is a pivotal regulator of the antioxidant response in eukaryotic cells. However, the role of SRXN1 in hepatocellular carcinoma (HCC) is far from clear. The present study aims to elucidate whether SRXN1 participates in tumorigenesis and metastasis of HCC and to determine the molecular mechanisms. We found that SRXN1 expression was up-regulated in HCC tissue samples and correlated with poor prognosis in HCC patients. We also observed that SRXN1 knockdown by transient siRNA transfection inhibited HCC cell proliferation, migration and invasion. Overexpression of SRXN1 increased HCC cell migration and invasion. B-cell translocation gene 2 (BTG2) was identified as a downstream target of SRXN1. Mechanistic studies revealed that SRXN1-depleted reactive oxygen species (ROS) modulated migration and invasion of HCC cells. In addition, the ROS/p65/BTG2 signalling hub was found to regulate the epithelial-mesenchymal transition (EMT), which mediates the pro-metastasis role of SRXN1 in HCC cells. In vivo experiments showed SRXN1 promotes HCC tumour growth and metastasis in mouse subcutaneous xenograft and metastasis models. Collectively, our results revealed a novel pro-tumorigenic and pro-metastatic function of SRXN1 in HCC. These findings demonstrate a rationale to exploit SRXN1 as a therapeutic target effectively preventing metastasis of HCC.

6.
Chem Commun (Camb) ; 56(62): 8794-8797, 2020 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-32618975

RESUMO

A wedge-like tool was established to finely and bidirectionally regulate the displacement rate of toehold-mediated strand displacement. This novel tool is very robust in terms of sequence generality and is compatible with most of the current DNA nanodevices based on traditional toehold reactions.

9.
J Am Chem Soc ; 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32130002

RESUMO

Harvesting solar energy for catalytic conversion of CO2 into valuable chemical fuels/feedstocks is an attractive yet challenging strategy to realize a sustainable carbon-cycle utilization. Homogeneous catalysts typically exhibit higher activity and selectivity as compared with heterogeneous counterparts, benefiting from their atomically dispersed catalytic sites and versatile coordination structures. However, it is still a "black box" how the coordination and electronic structures of catalysts dynamically evolve during the reaction, forming the bottleneck for understanding their reaction pathways. Herein, we demonstrate to track the mechanistic pathway of photocatalytic CO2 reduction using a terpyridine nickel(II) complex as a catalyst model. Integrated with a typical homogeneous photosensitizer, the catalytic system offers a high selectivity of 99% for CO2-to-CO conversion with turnover number and turnover frequency as high as 2.36 × 107 and 385.6 s-1, respectively. We employ operando and time-resolved X-ray absorption spectroscopy, in combination with other in situ spectroscopic techniques and theoretical computations, to track the intermediate species of Ni catalyst in the photocatalytic CO2 reduction reaction for the first time. Taken together with the charge dynamics resolved by optical transient absorption spectroscopy, the investigation elucidates the full mechanistic reaction pathway including some key factors that have been often overlooked. This work opens the "black box" for CO2 reduction in the system of homogeneous catalysts and provides key information for developing efficient catalysts toward artificial photosynthesis.

10.
Neurosci Lett ; 723: 134829, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32057920

RESUMO

Spinal cord injury (SCI) triggers pronounced inflammatory responses that are accompanied by neuronal disruption and functional deficits. SCI treatment remains an unmet clinical need. Emerging evidence suggests that riluzole may exert a neuroprotective effect due to its anti-inflammatory properties. However, details of the underlying mechanisms remain poorly defined. The polarization of microglial/macrophages has an important role in neuroinflammation. Here, we examined whether riluzole can exert a neuroprotective effect after acute SCI, and whether this effect is associated with changes in microglia/macrophages polarization. Riluzole (4 mg/kg) or vehicle were injected intraperitoneally (i.p.) in female rats immediately following SCI and repeated for 7 consecutive days (b.i.d.). Compared with vehicle treatment, riluzole-treated SCI rats showed significant higher locomotor scores (Basso, Beattie, and Bresnahan score, Inclined Plane test score, n = 18/group). Riluzole-treated rats also developed smaller spinal cavities, showed higher levels of myelin basic protein (MBP) and neurofilament (NF)200 immunoreactivities, and lower levels of proinflammatory cytokines in the spinal cord at 7 days post-SCI. Immunofluorescence study revealed more CD206+ cells and less iNOS+ cells in the injured spinal cord of riluzole-treated SCI rats, as compared to vehicle control. Using real-time PCR, we found that riluzole upregulated the mRNA levels of M2 markers, but downregulated that of M1 markers, as compared to the vehicle treatment. Current findings suggest that systemic administration of riluzole after acute SCI facilitated motor function recovery and inhibited inflammatory responses, which may be associated with polarization of M2 microglia/macrophages.

11.
ACS Appl Mater Interfaces ; 12(4): 4638-4648, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31903738

RESUMO

Three noncovalently fused-ring electron acceptors (FOC6-IC, FOC6-FIC, and FOC2C6-2FIC) are synthesized. Single crystals of FOC6-IC and FOC2C6-2FIC are prepared, and structure analyses reveal that the molecular backbone can be planarized via the formation of the intramolecular noncovalent interactions. These acceptor molecules can be packed closely in the solid state via π-π stacking and static interactions between the central phenylene unit and the terminal group with a distance of 3.3-3.4 Å. Besides, multiple intermolecular noncovalent interactions can be observed in the single crystal structure of the fluorinated acceptor FOC2C6-2FIC, which help increase the crystallinity of acceptors and the charge mobility of the blends. Photovoltaic devices based on FOC2C6-2FIC give a power conversion efficiency of 12.36%, higher than 12.08% for FOC6-FIC and 10.80% for FOC6-IC.

12.
Phys Chem Chem Phys ; 21(41): 22831-22838, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31608904

RESUMO

Lead halide perovskite quantum dots (PQDs) have recently been proposed as a scalable and color-tunable quantum source, but their slow spontaneous emission creates a mismatch with high-speed nanophotonic devices. Here, we demonstrate fast and bright emission in PQD films coupled to silver nanowire networks (NWKs), in which polyvinyl alcohol (PVA) is used as a spacer to regulate the lossy characteristics of the plasmonic cavity. Compared with bare quartz, the PVA substrate shows a considerable enhancement effect on the apparent emission intensity, but a reduction in the emission rate of PQD excitons. The efficient NWK-PQD coupling generates an increase in the emission intensity of a factor of 6.0 (average 3.4) and simultaneously a 2.4-fold (average 1.9) enhancement in the emission rate. However, an opposite PVA spacer thickness dependence for Purcell factor and quantum yield is observed, indicating that the fast and bright emission would be a trade-off between the Purcell-enhanced radiative rate and large metal loss. These results are believed to provide fundamental guidance on plasmonic cavity design for perovskite-based nanophotonic devices.

13.
J Phys Chem B ; 123(43): 9180-9186, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31609605

RESUMO

Crystal growth of N2 hydrate in a three-phase system consisting of N2 hydrate, liquid water, and gaseous N2 was performed by molecular dynamics simulation at 260 K. Pressure influence on hydrate growth was evaluated. The kinetic properties including the growth rates and cage occupancies of the newly formed hydrate and the diffusion coefficient and concentration of N2 molecules in liquid phase were measured. The results showed that the growth of N2 hydrate could be divided into two stages where N2 molecules in gas phase had to dissolve in liquid phase and then form hydrate cages at the liquid-hydrate interface. The diffusion coefficient and concentration of N2 in liquid phase increased linearly with increasing pressure. As the pressure rose from 50 to 100 MPa, the hydrate growth rate kept increasing from 0.11 to 0.62 cages·ns-1·Å-2 and then dropped down to around 0.40 cages·ns-1·Å-2 once the pressure surpassed 100 MPa. During the hydrate formation, the initial sII N2 hydrate phase set in the system served as a template for the subsequent growth of N2 hydrate so that no new crystal structure was found. Analysis on the cage occupancies revealed that the amount of cages occupied by two N2 molecules increased evidently when the pressure was above 100 MPa, which slowed down the growth rate of hydrate cages. Additionally, a small fraction of defective cages including two N2 molecules trapped in 51265 cages and three N2 molecules trapped 51268 cages was observed during the hydrate growth.

14.
Exp Ther Med ; 18(1): 296-304, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31258665

RESUMO

The present study investigated the relationship between connexin 43 (Cx43) expression in alveolar type II epithelial cells (ATII) and alveolar air-blood barrier permeability, and the effect of microRNA-206 (miR-206) on the expression of Cx43 in sepsis-induced acute lung injury. For the in vivo study, rats were divided into the sham, caecum ligation and perforation (CLP), CLP+Cx43 inhibitors (Cx43-In) and CLP+miR-206 analogs (miR-206-Mi) groups. CLP method was used to prepare an acute lung injury model of sepsis. Following successful modeling, lung tissue was collected for hematoxylin and eosin (HE) staining, and the wet to dry weight ratio (W/D) and protein content in bronchoalveolar lavage fluid (BALF) were detected. Cx43 expression in lung tissue was determined by immunohistochemistry and western blot analysis. Additionally, miR-206 and Cx43 expression levels in lung tissue were detected by reverse transcription-quantitative polymerase chain reaction. Rat ATII cells were cultured in Transwells plates to form monolayers, then treated with Cx43 mRNA inhibitors or miR-206 analogs. The cell monolayers were then stimulated with lipopolysaccharide and their permeability was evaluated by detecting fluorescein-labeled dextran at the lower chamber of the Transwells. The dual luciferase reporter gene assay was used to investigate whether miR-206 targeted the 3' untranslated region of Cx43 mRNA to regulate Cx43 expression, thereby regulating the permeability of the alveolar air-blood barrier. Results demonstrated that the CLP method induced damage to the alveolar structure, thickened the alveolar wall, caused hyperemia and hemorrhage in the pulmonary interstitium and caused infiltration of inflammatory cells. Edema in the pulmonary interstitium and alveolar space, exudation of neutrophilic granulocyte and pink edema fluid in alveolar cavities were also observed. W/D ratio, the BALF protein content, and expression of Cx43mRNA and Cx43 were increased significantly, whilst miR-206 expression decreased compared with the control group. The lung tissue inflammatory response was attenuated, and the W/D ratio and BALF protein content decreased in the Cx43-In and miR-206-Mi groups compared with the CLP group. Moreover, Cx43 mRNA and protein expression were decreased significantly in the Cx43-In and miR-206-Mi groups. In addition, the dual luciferase reporter gene assay determined that the untranslated region of Cx43 mRNA had a complementary sequence to miR-206. Of note, Cx43 mRNA expression in the miR-206-Mi group was not significantly decreased in vitro. In conclusion, the increase in ATII cell Cx43 expression during sepsis-induced acute lung injury resulted in an increase in the permeability of the alveolar air-blood barrier. miR-206 targeted the Cx43 mRNA 3'untranslated region to downregulate Cx43 expression, which further improved the permeability of the alveolar air-blood barrier.

15.
J Phys Chem B ; 123(29): 6200-6211, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31259553

RESUMO

Amyloid fibrillation by hen egg white lysozyme (HEWL) under the influences of two common surfactants, sodium dodecyl sulfate (SDS) and Triton X-100 (TX-100), was investigated with atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. Detailed AFM investigations indicated that both SDS and TX-100 were able to induce some significant morphological changes of HEWL amyloid fibrils. Both SDS and TX-100 could induce a morphological change which was characterized with alternating fibril regions with increased thicknesses along the fibril axis. In addition, TX-100 was also able to induce a morphological change which was characterized with fibril branching. In contrast, the positively charged cetyltrimethylammonium bromide displayed no such effect as compared with the negatively charged SDS and the nonionic TX-100. These intriguing modulation effects of SDS and TX-100 on amyloid fibrillation were hypothesized to be due to surfactant-induced surface-catalyzed secondary nucleation owing to the noncovalent interaction between the surfactants and HEWL. The proposed hypothesis was further supported by FTIR spectroscopic investigation, which demonstrated the formation of a SDS-amyloid fibril complex and TX-100-amyloid fibril complex. Detailed FTIR analysis suggested that the tail group of SDS associated with amyloid fibrils is more disordered similar to that of SDS in aqueous solution, while the headgroup of SDS appears to interact with amyloid fibrils strongly similar to that of SDS in the solid state, and the ether groups of TX-100 associated with amyloid fibrils experienced a different microenvironment as compared with that of neat TX-100. Additional control experiments with FTIR spectroscopy revealed that the interactions of SDS/TX-100 with HEWL amyloid fibrils were different from those of SDS/TX-100 with HEWL amorphous aggregates. In addition, the ß-sheet structures of the HEWL amyloid fibrils were found to be increased due to the influences of SDS and TX-100. Our work provides new insight into the modulation effects of surfactants on amyloid fibrillation.

16.
Angew Chem Int Ed Engl ; 58(34): 11860-11867, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31183943

RESUMO

Although progress has been made to improve photocatalytic CO2 reduction under visible light (λ>400 nm), the development of photocatalysts that can work under a longer wavelength (λ>600 nm) remains a challenge. Now, a heterogeneous photocatalyst system consisting of a ruthenium complex and a monolayer nickel-alumina layered double hydroxide (NiAl-LDH), which act as light-harvesting and catalytic units for selective photoreduction of CO2 and H2 O into CH4 and CO under irradiation with λ>400 nm. By precisely tuning the irradiation wavelength, the selectivity of CH4 can be improved to 70.3 %, and the H2 evolution reaction can be completely suppressed under irradiation with λ>600 nm. The photogenerated electrons matching the energy levels of photosensitizer and m-NiAl-LDH only localized at the defect state, providing a driving force of 0.313 eV to overcome the Gibbs free energy barrier of CO2 reduction to CH4 (0.127 eV), rather than that for H2 evolution (0.425 eV).

17.
J Am Chem Soc ; 141(20): 8093-8097, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31063363

RESUMO

The precision of array of laser applications and manipulation on smaller scales are limited by the so-called 200 nm wall, and breakthroughs rely on the discovery of new materials with transparency and phase matchability in the ultraviolet and deep ultraviolet region. Herein, we discover an unprecedented alignment of the asymmetric non-π-conjugated species [PO3F] in NaNH4PO3F·H2O, which allows the best uniform P-F bond orientation that generates a remarkable enhancement of the (010) in-plane anisotropy that yields the largest birefringence (obv.: 0.053) to date in the phosphate and fluorophosphate families. The substance produces second harmonic generation lasers through direct frequency doubling with incident Yb:KGW femtosecond lasers on an as-synthesized (010) wafer with a size of 14 × 10 × 2.1 mm3. According to the calculated refractive index dispersion curve, the shortest second-harmonic generation (SHG) wavelength is estimated to be 194 nm, the shortest among phosphates and monofluorophosphate. These insights may help to design other high-performance non-π-conjugated deep-UV nonlinear optical materials.

19.
Molecules ; 24(7)2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30965674

RESUMO

The isonitrile (NC) group has been shown to be a promising infrared probe for studying the structure and dynamics of biomolecules. However, there have been no systematic studies performed on the NC group as an infrared probe, when it is bonded to an indole ring. Here, we systematically study the NC stretching mode of two model compounds, 5-isocyano-1H-indole (5ICI) and 5-isocyano-1-methyl-1H-indole (NM5ICI), using Fourier transform infrared (FTIR) spectroscopy. The NC stretching frequency is shown to be strongly dependent on the polarizability of protic solvents and the density of hydrogen-bond donor groups in the solvent when NC is bonded to an indole ring. Infrared pump⁻probe studies of 5ICI in DMSO and in EtOH further support that the NC stretching mode could be used as a site-specific infrared probe for local environments when NC is bonded to an indole ring.


Assuntos
Indóis/química , Solventes/análise , Ligação de Hidrogênio , Raios Infravermelhos , Estrutura Molecular , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
20.
Nanoscale ; 11(14): 6737-6746, 2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30907396

RESUMO

Hybrid nanostructures comprising conjugated polymers (CPs) and plasmonic metals show excellent performance in light harvesting. However, the energy transfer mechanism of the CP film to nearby metal nanoparticles, especially knowledge of the characteristic distance, is still unclear. Here, quenching of the emission of a CP film in proximity to a monolayer of graphene-nanodot-supported silver nanoparticles (GND-Ag NPs) is investigated. Uniform Ag NPs with D = 3.2 nm were grown on GNDs in situ under mild light irradiation, and a series of bilayer structures of GND-Ag NPs/CPs were constructed by spin-coating blue, green and red light-emitting poly(9,9-dioctylfluorene) (PFO), poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) and poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV),respectively, on top of the GND-Ag NP plane. The spacer distance was controlled by the layers of assembled polyelectrolytes. Both steady and transient photoluminescence (PL) spectra showed emission quenching of the bilayer structures, providing the maximum efficiency of 99% for the F8BT films. The surface density of GND-Ag NPs and the spacer distance-dependent PL quenching data were analyzed within the plasmonic resonant energy transfer model, and the extracted characteristic distances are 6 nm, 3 nm and 10 nm for the PFO, F8BT and MEH-PPV systems, respectively. Current-sensing atomic force microscopy shows that the GND-Ag NPs/F8BT film exhibits enhanced electrical conductivity. These results are believed to be important for the development of plasmonic enhanced polymer photovoltaics and photocatalysis.

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