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1.
Stem Cells Dev ; 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111146

RESUMO

Neuroinflammation is associated with the pathogenesis of all types of neurological disease, in which microglial cells play a critical role. In response to disturbances in the microenvironment, microglia become activated and differentiate into either an M1 phenotype, which has a pro-inflammatory, damaging effect, or an M2 phenotype, which plays an anti-inflammatory and reparative role. Thus, modulating microglial polarization is a suitable strategy to treat neuroinflammatory disorders. Glial cell-derived neurotrophic factor (GDNF) is a neurotrophic mediator that exerts neuroprotective effects during neurological diseases. In this study, we predicted that adipose-derived stem cells (ADSCs) could produce GDNF and investigated the effects of GDNF on microglial M1/M2 polarization. Furthermore, we determined whether GDNF modulates microglial activation and polarization via the PI3K/AKT signaling pathway. We found that the secretion of inflammatory cytokines in lipopolysaccharide-stimulated microglia was downgrated, while the anti-inflammatory mediators in interleukin-4-stimulated microglia were upgrated obviously, following pretreatment with ADSCs or GDNF. In addition, GDNF produced by ADSCs inhibited the microglia M1 phenotype and promoted the M2 phenotype by upregulating the PI3K/ATK pathway. These results reveal that GDNF produced by ADSCs might be useful for the treatment of neuroinflammatory diseases.

2.
Talanta ; 212: 120760, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32113535

RESUMO

Time-gated luminescence (TGL) probes based on lanthanide complexes have appealed wide attention in the detection of biologically relevant analytes because of their inimitable photophysical properties. In this work, a TGL probe (TR-HOCl) based on intramolecular Förster resonance energy transfer (FRET) system for specific determination of hypochlorous acid (HOCl) was designed and synthesized, in which a rhodamine derivative (energy acceptor) was conjugated to a luminescent Tb3+ complex (energy donor). After reacting with HOCl, the Tb3+ emission of TR-HOCl at 540 nm declined while the rhodamine emission at 580 nm increased, which leaded to an increase of the TGL intensity ratio of rhodamine to Tb3+ complex (I560/I540) up to ~9-fold. The dose-dependent increase of I560/I540 gives a nice linearity in HOCl concentration range of 0.5-45 µM. The detection limit of for HOCl was determined to be 0.34 µM. Interestingly, the average luminescence lifetime of the Tb3+ emission decreased (from 588 µs to 254 µs) accompanied with the FRET process and the value gave a fine linearity to the variation of HOCl concentration. Additionally, TR-HOCl showed great selectivity for recognition of HOCl over other ROS, RNS, biothiols and other interference. These properties endow TR-HOCl to be conveniently applied for high accurate recognition of HOCl with ratiometric TGL and luminescence lifetime dual-signal output. Finally, TR-HOCl was successfully applied for the TGL determination of HOCl in HepG2 cells. The co-localization experiments of TR-HOCl with LysoSensor Green revealed the lysosome-localizing property of the probe in live cells. The study demonstrated that TR-HOCl could be a competent tool for investigating roles of HOCl in various physiological processes.

3.
Mikrochim Acta ; 187(3): 194, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32124079

RESUMO

A controllable approach for preparing a portable colloidal photonic crystal (CPC) array chip is presented. The approach was inspired by the confinement effect of nanoparticle self-assembly on patterned surface. Hydrophobic polydimethylsiloxane substrate with reproducible micro-region array was fabricated by soft-lithography. The substrate was employed as the patterned template for self-assembly of monodisperse polystyrene nanoparticles. The CPC units can be prepared in several minutes, and exhibit consistent reflection wavelength. By adjusting the size of polystyrene nanoparticles and the shape of micro-regions, CPC units with multiple structure, colors and geometries were obtained. The CPC array chip features fluorescence enhancement owing to the optical modulation capability of the periodic nanostructure of the self-assembled CPC. With the reflection wavelength (523 nm) of green CPC units overlapping the emission wavelength (520 nm, with excitation wavelength of 490 nm) of 6-carboxyfluorescein-labeled DNA probe, the fluorescence intensity increased more than 10-fold. For signal-amplified assay of adenosine, the concentration range of linear response was 5.0 × 10-5 mol L-1 to 1.0 × 10-3 mol L-1, and the limit of detection was 1.3 × 10-6 mol L-1. Because of the enhancement effect of photonic crystal, the fluorescence images were more readable from the CPC array chip, compared with those from the planar substrate. The chip has potential applications in multiplex determination with high-throughput via encoding strategy based on the tunable structure, color or geometric shape. Graphical abstractSchematic diagram of signal-enhanced fluorescent detection of adenosine based on the colloidal photonic crystal array chip (PDMS, polydimethylsiloxane; PS NPs, polystyrene nanoparticles; CPC, colloidal photonic crystal; GO, graphene oxide; FAM, 6-carboxyfluorescein).

4.
Molecules ; 25(5)2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32121474

RESUMO

Sensitive and selective detection of harmful gas is an important task in environmental monitoring. In this work, a gas sensor based on cataluminescence (CTL) for detection of acetaldehyde was designed by using nano-NiO as the sensing material. The sensor shows sensitive response to acetaldehyde at a relatively low working temperature of 200 °C. The linear range of CTL intensity versus acetaldehyde concentration is 0.02-2.5 mg/L, with a limit of detection of 0.006 mg/L at a signal-to-noise ratio of three. Mechanism study shows that electronically excited CO2 is the excited intermediate for CTL emission during the catalytic oxidation of acetaldehyde on the NiO surface. The proposed sensor has promising application in monitoring acetaldehyde in residential buildings and in the workplace.

5.
Sensors (Basel) ; 20(5)2020 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-32121408

RESUMO

Quick and effective detection of biothiols in biological fluids has gained increasing attention due to its vital biological functions. In this paper, a novel reversible fluorescence chemosensor (L-Cu2+) based on a benzocoumarin-Cu2+ ensemble has been developed for the detection of biothiols (Cys, Hcy and GSH) in human urine. The chemosensing ensemble (L-Cu2+) contains a 2:1 stoichiometry structure between fluorescent ligand L and paramagnetic Cu2+. L was found to exclusively bond with Cu2+ ions accompanied with a dramatic fluorescence quenching maximum at 443 nm and an increase of an absorbance band centered at 378 nm. Then, the in situ generated fluorescence sluggish ensemble, L-Cu2+, was successfully used as a chemosensor for the detection of biothiols with a fluorescence "OFF-ON" response modality. Upon the addition of biothiols, the decomplexation of L-Cu2+ led to the liberation of the fluorescent ligand, L, resulting in the recovery of fluorescence and absorbance spectra. Studies revealed that L-Cu2+ possesses simple synthesis, excellent stability, high sensitivity, reliability at a broad pH range and desired renewability (at least 5 times). The practical application of L-Cu2+ was then demonstrated by the detection of biothiols in human urine sample.

6.
Anal Chim Acta ; 1103: 156-163, 2020 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-32081180

RESUMO

Gasotransmitter hydrogen sulfide (H2S), produced enzymatically in body, has important functions in biological signaling and metabolic processes. An abnormal level of H2S expression is associated with different diseases, therefore, development of novel bioanalytical methods for rapid and effective detection of H2S in biological conditions is of great importance. In this work, we report the development of a new responsive nanosensor for ratiometric luminescence detection of H2S in aqueous solution and live cells. The nanosensor (Ru@FITC-MSN) was prepared by immobilizing a luminescent ruthenium(II) (Ru(II)) complex into a fluorescein isothiocyanate (FITC) conjugated water-dispersible mesoporous silica nanoparticle (MSN), showing dual emission bands at 520 nm (FITC) and 600 nm (Ru complex). The red luminescence of the formed Ru@FITC-MSN was quenched in the presence of Cu2+. The in-situ generated Ru-Cu@FITC-MSN responded to H2S rapidly and selectively, showing a linear ratiometric luminescence change in FITC and Ru(II) channels with the H2S concentration (0.5-4 µM). Limit of detection (LoD) and limit of quantification (LoQ) were determined to be 0.36 and 1.21 µM. Followed by investigation of cellular uptake processes, the utility of the nanosensor for ratiometric imaging of H2S in live cells and its capability to monitor H2S levels in inflammatory breast cancer cells were then demonstrated. This study provides a powerful approach for detection of highly reactive and unstable H2S biomolecules in live systems.

7.
Phys Rev Lett ; 124(1): 016402, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31976722

RESUMO

Spin-gapless semimetals (SGSMs), which generate 100% spin polarization, are viewed as promising semi-half-metals in spintronics with high speed and low consumption. We propose and characterize a new Z_{2} class of topological nodal line (TNL) in SGSMs. The proposed TNLSGSMs are protected by space-time inversion symmetry or glide mirror symmetry with two-dimensional (2D) fully spin-polarized nearly flat surface states. Based on first-principles calculations and effective model analysis, a series of high-quality materials with R3[over ¯]c and R3c space groups are predicted to realize such TNLSGSMs (chainlike). The 2D fully spin-polarized nearly flat surface states may provide a route to achieving equal spin pairing topological superconductivity as well as topological catalysts.

8.
Talanta ; 209: 120579, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892066

RESUMO

Sialic acid (SA) is a special monosaccharide widely distributed at the termini of sugar chains on the cell surface, and its expression level is closely connected with various biological and pathological processes. Therefore, accurate quantitative detection of SA on cancer cell surface is of great significance for clinical diagnosis and therapy. Here, we developed a whole-surface accessible method of accurate SERS quantification of SA level on a single cell, in which silver nanoparticles functionalized with 4-mercaptophenylboric acid and 4-mercaptobenzenitrile was used as the background-free SERS probe. The cyano group on the nanoprobe showed a unique Raman shift at 2232 cm-1, where most of the biological samples have no Raman response. Meanwhile, the boronic acid group had high specificity to SA molecules at physiological pH. The expression level of SA can be accurately quantitated on the basis of the CN Raman signal. The average number of expressed SA molecules on the surface of a single HeLa cell was 4.6 × 107. And SERS imaging of a single cell was achieved at 2232 cm-1 without biological interference. We evaluated SA expression level on the surface of different cancer cells and dynamically monitored SA expression under the influence of drugs. The proposed approach is accurate as well as sensitive for background-free quantification of SA on cell surface, which is promising for revealing the relationship between tumors and cell surface glycosylation.

9.
Colloids Surf B Biointerfaces ; 188: 110764, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31901687

RESUMO

Porous structures with highly dispersed and active catalytic sites are vital to improve the catalytic activity and stability of artificial enzyme-related catalytic reactions. Herein, a novel nanorod-like bimetal-organic framework serving as porous support and supplier of Co2+ and Cu2+ was used to prepare a beneficial porous metal oxide. By optimizing the calcination temperature, the composition of calcined product can be controlled and the nanorods with isolated and highly active CuCo2O4 nanoparticles were obtained. The porous CuCo2O4 nanorods exhibit a pH-dependent catalytic property, that is, they behave as oxidase in acid conditions and catalase in alkaline conditions. The CuCo2O4 nanorods perform dual-enzyme catalytic activity superior to monometallic oxides. What's more, compared with the reported Co3O4 nanoparticles, Co3O4/CuO hollow nanocage hybrids and NiCo2O4 mesoporous spheres, the porous CuCo2O4 nanorods show higher affinity to 3,3',5,5'-tetramethylbenzidine with a lower Km value. The superior dual-enzyme catalytic activities of CuCo2O4 nanorods benefit from the high catalytic activity of binary metal oxides and structural stability. After incubating in a wide range of pHs, temperatures and ionic strengths, the catalytic activity of CuCo2O4 nanorods can be maintained. The oxidase activity of CuCo2O4 nanorods can be inhibited in the presence of ascorbic acid, which can be applied in effective detection of ascorbic acid. This study opens a new path to prepare stable and highly active porous artificial enzymes.

10.
Br J Pharmacol ; 177(1): 93-109, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31444977

RESUMO

BACKGROUND AND PURPOSE: Considerable effort has recently been directed at developing multifunctional opioid drugs to minimize the unwanted side effects of opioid analgesics. We have developed a novel multifunctional opioid agonist, DN-9. Here, we studied the analgesic profiles and related side effects of peripheral DN-9 in various pain models. EXPERIMENTAL APPROACH: Antinociceptive effects of DN-9 were assessed in nociceptive, inflammatory, and neuropathic pain. Whole-cell patch-clamp and calcium imaging assays were used to evaluate the inhibitory effects of DN-9 to calcium current and high-K+ -induced intracellular calcium ([Ca2+ ]i ) on dorsal root ganglion (DRG) neurons respectively. Side effects of DN-9 were evaluated in antinociceptive tolerance, abuse, gastrointestinal transit, and rotarod tests. KEY RESULTS: DN-9, given subcutaneously, dose-dependently produced antinociception via peripheral opioid receptors in different pain models without sex difference. In addition, DN-9 exhibited more potent ability than morphine to inhibit calcium current and high-K+ -induced [Ca2+ ]i in DRG neurons. Repeated treatment with DN-9 produced equivalent antinociception for 8 days in multiple pain models, and DN-9 also maintained potent analgesia in morphine-tolerant mice. Furthermore, chronic DN-9 administration had no apparent effect on the microglial activation of spinal cord. After subcutaneous injection, DN-9 exhibited less abuse potential than morphine, as was gastroparesis and effects on motor coordination. CONCLUSIONS AND IMPLICATIONS: DN-9 produces potent analgesia with minimal side effects, which strengthen the candidacy of peripherally acting opioids with multifunctional agonistic properties to enter human studies to alleviate the current highly problematic misuse of classic opioids on a large scale.

11.
Biochem Biophys Res Commun ; 522(1): 133-137, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31757420

RESUMO

Number and molecular Brightness (N&B) analysis is a powerful method used to monitor protein aggregation in living cells. Here, we used the N&B method to characterize the unexpanded HTT protein oligomerization after the internalization of the mutant HTT (mHTT) which contains a CAG repeat extensions encoding for long polyglutamine (polyQ) proteins resulting in misfolding and aggregation. HEK cells expressing Htt25Q-mCherry proteins were infected with Htt97Q-EGFP aggregates, by cell to cell uptake, in cultured conditions resulting in an increasing population of dimers and tetramers compared to our controls. This study shows for the first time the impact of protein aggregation in the unexpanded Htt25Q-mCherry expressing cells that occurs from cell to cell transfer of the expanded Htt97Q-EGFP. These results signify the sporadic behavior of the polyQ inclusion that gives insight into the mechanism of protein dynamics as a consequence of secreted mHTT aggregates.

12.
Anal Bioanal Chem ; 412(3): 647-655, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31836924

RESUMO

In this work, simple, rapid, and low-cost multiplexed detection of tumor-related micro-RNAs (miRNAs) was achieved based on multi-color fluorescence on a microfluidic droplet chip, which simplified the complexity of light path to a half. A four-T-junction structure was fabricated to form uniform nano-volume droplet arrays with customized contents. Multi-color quantum dots (QDs) used as the fluorescence labels were encapsulated into droplets to develop the multi-path fluorescence detection module. We designed an integrated multiplex fluorescence resonance energy transfer system assisted by multiple QDs (four colors) and one quencher to detect four tumor-related miRNAs (miRNA-20a, miRNA-21, miRNA-155, and miRNA-221). The qualitative analysis of miRNAs was realized by the color identification of QDs, while the quantitative detection of miRNAs was achieved based on the linear relationship between the quenching efficiency of QDs and the concentration of miRNAs. The practicability of the multiplex detection device was further confirmed by detecting four tumor-related miRNAs in real human serum samples. The detection limits of four miRNAs ranged from 35 to 39 pmol/L was achieved without any target amplification. And the linear range was from 0.1 nmol/L to 1 µmol/L using 10 nL detection volume (one droplet) under the detection speed of 320 droplets per minute. The multiple detection system for miRNAs is simple, fast, and low-cost and will be a powerful platform for clinical diagnostic analysis. Graphical abstract.


Assuntos
Colorimetria/métodos , MicroRNAs/metabolismo , Microfluídica , Fluorescência , Humanos , Limite de Detecção
13.
Sci Total Environ ; 706: 136043, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31862589

RESUMO

The powder-based photocatalytic material is often difficult on wide application and then loaded on a matrix for separating conveniently from the liquid. Submerged photocatalysts may not take advantage of the light energy adequately. Thus, this boundedness may reduce their utilization and potentially cause the secondary pollution on the environment. In this paper, the micron-sized silica sphere is used as a floating substrate, and the visible-light-driven photocatalytic material iodine oxygen bismuth is prepared onto the hollow silica microspheres. The composite spheres as the visible-light-driven photocatalytic material have been characterized by XPS, XRD, SEM, EDX, PL, etc. It confirmed that BiOI combined on the SiO2 microsphere (mSiO2) by Bi-O-Si. The photogenerated electrons of the composite have a low probability of recombination and have a narrow band energy (1.82 eV). The composite was used to photodegrade diesel-containing wastewater and rhodamine B, and the superoxide group (·O2-) was found to be the main degradation active factor. And by GC-MS test, it is known that the superoxide group (·O2-) can degrade long-chain alkanes into short chains or form branches. Detailed studies on the acute exposure experiments of Vibrio qinghaiensis sp.-Q67 and zebrafish embryos showed that the composites can effectively reduce the toxicity of BiOI and mSiO2.

14.
Anal Chim Acta ; 1094: 106-112, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31761035

RESUMO

Endogenous hydrogen sulfide (H2S) exists in multiple physiological processes. In order to further understand the action mechanism of H2S in cells and human body, we proposed a smart surface-enhanced Raman scattering (SERS) nanoprobe, Au core-4-mercaptobenzonitrile-Ag shell nanoparticle (Au@4-MBN@Ag), for the detection of endogenous H2S in living cells based on the reaction between Ag shell and sulfide species. 4-MBN was selected as the SERS reporter to avoid interference from cellular molecules. With the sulfide concentration increasing, the Ag2S constantly formed, and consequently the SERS signal intensity of Au@4-MBN@Ag gradually decreased owing to the weaker SERS activity of Ag2S. With the nanoprobes, this method not only offers a high sensitivity for H2S detection at an nM level, but also achieves the goal of non-background analysis. It displays satisfactory anti-interference capability and a good linear relationship with sulfide concentration ranging from 50 nM to 500 µM, and an estimated detection limit is 0.14 nM. The Au@4-MBN@Ag nanoprobes were successfully applied to detect endogenous H2S in living HepG2 cells stimulated by pyridoxal 5-phosphate monohydrate. This work offers a potential analytical method in the related research of H2S physiological function.


Assuntos
Sulfeto de Hidrogênio/análise , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos , Linhagem Celular Tumoral , Ouro/química , Humanos , Insulina/farmacologia , Limite de Detecção , Fosfato de Piridoxal/farmacologia , Prata/química
15.
Sci Total Environ ; 699: 134355, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31520943

RESUMO

The present study investigated the reduction and carbonization behavior of perovskite-geikielite by using CH4-H2 gas mixture, which aimed to recycle the titanium resource in titanium-bearing blast furnace slag. Thermodynamic phase equilibrium analysis in the CaTiO3-CH4-H2, MgTiO3-CH4-H2 and CaTiO3-MgTiO3-CH4-H2 systems was performed by FactSage. The analysis indicated that CaTiO3 could be ultimately reduced and carbonized to TiCxOy by CH4-H2 gas mixture at temperature above 1300 °C, while the temperature for reduction of MgTiO3 was above 1200 °C. MgTiO3 is found to be reduced prior to CaTiO3 in the CaTiO3-MgTiO3-CH4-H2 systems. The reduction experiments of perovskite-geikielite were carried out in a temperature range of 1300 °C to 1450 °C in a flowing CH4-H2 atmosphere. Experimental results showed that perovskite-geikielite could be reduced completely to TiCxOy at 1400 °C and above after 8 h reduction, while geikielite was reduced prior to perovskite. The reduction and carbonization extent of samples increased with increasing time and temperature when in a low temperature range (below 1400 °C). However, a much higher temperature (above 1400 °C) would hinder further carbonization of TiCxOy for the production of deposited carbon. Addition of iron oxides to sample strongly facilitated the reduction reaction, and even promoted the reduction of titanium to be completed at only 1300 °C after 8 h reduction. The gas-solid reaction provided a low temperature method to reduce and carbonize perovskite and geikielite, and thus it provided a possible way to use titanium-bearing blast furnace slag.

16.
Langmuir ; 36(2): 520-533, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31886673

RESUMO

The adsorption of dye molecules is an important process for the photodegradation removal of dye pollutants. In this work, a semiconductor photocatalyst of Cr-doped ZnO nanorods (Cr-ZnO NRs) was synthesized, and its adsorption-photocatalysis synergy (APS) effect was investigated for anionic methyl orange (MO-) and cationic methylene blue (MB+). The detailed thermodynamic information (including adsorption maximum capacity qmax, adsorption equilibrium constant Kads and adsorption efficiency AE %) and dynamic information (including adsorption rate constant ka, degradation rate constant kd and degradation efficiency DE %) were obtained to evaluate the different reaction performances for MO- and MB+. With qmax(MB+) = 40.59 mg g-1 > qmax(MO-) = 15.95 mg g-1, ka(MB+) = 20.61 min-1 > ka(MO-) = 4.62 min-1, and AE(MB+) = 40% > AE(MO-) = 9%, Cr-ZnO NRs showed much superior adsorption performance for MB+ than MO-. With kd (MB+) = 0.0430 min-1 > kd (MO-) = 0.0014 min-1 and DE(MB+) = 98% > AE(MO-) = 20%, Cr-ZnO NRs also showed much superior photodegradation performance for MB+ than MO-. The APS mechanism of Cr-ZnO NRs is revealed to be multiple π-π interactions and stronger electrostatic attractions dominant for enhanced adsorption of MB+ and higher AE and more photocatalytic active species dominant for enhanced photodegradation of MB+. The APS was furthermore characterized and verified by zeta potential analysis, Fourier transform infrared investigation, and fluorescence imaging. The results indicate that Cr-ZnO NRs are promising adsorbent and photocatalyst candidates favorable for positive MB+ than negative MO-. Such an APS investigation can effectively help to improve the photodegradation treatment performance of photocatalysts for dye pollutant removal.

17.
Food Sci Biotechnol ; 28(5): 1475-1486, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31695946

RESUMO

This work focused on how roasting changed the chemical components of chili (Capsicum annuum L.) seeds and how it affected the stability of chili seed oils during storage. The oils from chili seeds before and after roasting treatments were stored at 63 °C for 30 days and then analyzed. Results showed that roasting changed the main sugars compositions and amino acid compositions (total content decreased from 15.9 to 7.4%), which confirmed that it could form brown pigments and volatile flavor compounds in pepper seeds after roasting. Compared with oil from unroasted seeds, oils from roasted seeds had greater oxidative stability and maintained greater antioxidant capacity during storage. These effects were possibly due to the synergistic of the neo-formed products by Maillard reaction, vitamin E, and other bioactive components. This investigation showed that roasting treatment could be considered as an appropriate method for extending the storage stability of chili seed oils.

18.
Anal Chem ; 91(24): 15826-15832, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31724393

RESUMO

ICP-MS is powerful in evaluating elemental species at the single-cell level, where high throughput/efficiency/precision are the keys for achieving statistically significant information based on massive data. We report an ultrahigh-throughput single-cell sampling system, consisting of a 3D spiral-helix tubing array to facilitate single-cell focusing into an orderly flow by inertial lift force and Dean drag force. The spiral-helix array ensures a superb single-cell sampling rate of 40 000 cells min-1 at a favorable temporal-spatial resolution of 41.55 ± 17.46 µm (distance between adjacent cells) or 0.97 ± 0.41 ms (time interval between adjacent cells). With a laboratory-made nebulization device, a cell measurement efficiency up to 42.1 ± 7.2% is achieved in ICP-MS assay. Analysis of Au nanoparticles (AuNPs) in living K562 cells after incubation illustrates obvious diversification of AuNPs among cells. The ultrahigh throughput and cell measurement efficiency generate massive data on single-cell assay, make statistical analysis more comprehensive, and enable interpreting extremely subtle differences among individual cells.

19.
Orthop Surg ; 11(6): 1101-1108, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31762217

RESUMO

OBJECTIVE: The purpose of this retrospective study was to evaluate the clinical and oncological results of combination treatment of short-term preoperative denosumab (the receptor activator of nuclear factor kappa-B ligand inhibitor) with surgery in unresectable or recurrent cases of giant cell tumor of the bone (GCTB). METHODS: Between 2016 and 2018, 11 eligible patients (1 man, 10 women, mean age 38.1 years) with grade 3 GCTB were treated with a combination of short-term (six doses) preoperative denosumab and surgery in a single institution. The clinical, radiological, and pathological alteration after the denosumab treatment were compared. The oncological results of the combination therapy were also recorded. Meanwhile, adverse effects or complications of denosumab, if any, were reported. RESULTS: The median follow-up time after surgical procedure was 30 months (range 13-45 months). After 3-4 denosumab injections, pain relief was observed in all patients. In two spine patients, the neurological status improved after four doses of treatment. Intraoperatively, the margin of the tumor became clear and the intensity of the tumor increased while the blood supply around and within the lesion decreased. Within the lesion, the typically soft and loose tissue were replaced by the tough and dense fibro-osseous tissue. The mean diameter of the lesion before and after treatment was 61.55 ± 22.49 mm and 51.81 ± 21.12 mm, respectively, and the T-score was 1.02 (P = 0.32). Variable calcification was observed at the periphery and within the lesion. A total of three patients experienced local recurrence in this study. In the resection group, only one extremity patient had soft tissue recurrence that was treated with en-bloc excision. In the curettage group, two of three sacral tumor patients had local occurrence. Both refused re-operation and restarted the monthly denosumab injection thereafter, and the lesions remained stable at the final follow up. Finally, no adverse effects or complications related to denosumab treatment were found. CONCLUSION: For the unresectable or recurrent GCTB cases, short-term (six doses) preoperative use of denosumab improved clinical symptoms, decreased the tumor size, and increased the tumor density. The changes in tumors, in turn, simplified the tumor removal manipulation and, subsequently, decreased the local recurrence for the resection surgery. For the curettage, the denosumab-induced changes had mixed impacts, and shorter term (fewer than six doses) usage may be more appropriate. Our six-dose regime was deemed safe, while the safety of long-term use remains unknown.

20.
Molecules ; 24(23)2019 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-31771216

RESUMO

In this work, we successfully developed a novel and sensitive gas sensor for the determination of trace acetophenone based on its cataluminescence (CTL) emission on the surface of nano-praseodymium oxide (nano-Pr6O11). The effects of working conditions such as temperature, flow rate, and detecting wavelength on the CTL sensing were investigated in detail. Under the optimized conditions, the sensor exhibited linear response to the acetophenone in the range of 15-280 mg/m3 (2.8-52 ppm), with a correlation coefficient (R2) of 0.9968 and a limit of detection (S/N = 3) of 4 mg/m3 (0.7 ppm). The selectivity of the sensor was also investigated, no or weak response to other compounds, such as alcohols (methanol, ethanol, n-propanol, iso-propanol, n-butanol), aldehyde (formaldehyde and acetaldehyde), benzenes (toluene, o-xylene, m-xylene, p-xylene), n-pentane, ethyl acetate, ammonia, carbon monoxide, carbon dioxide. Finally, the present sensor was applied to the determination of acetophenone in human exhaled breath samples. The results showed that the sensor has promising application in clinical breath analysis.

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