MFGE8 in exosomes derived from mesenchymal stem cells prevents esophageal stricture after endoscopic submucosal dissection in pigs.

BACKGROUND: Endoscopic submucosal dissection (ESD) is the current standard treatment for early-stage esophageal neoplasms. However, the postoperative esophageal stricture after extensive mucosal dissection remains a severe challenge with limited effective treatments available. In this study, we introduced a chitosan/gelatin (ChGel) sponge encapsulating the adipose mesenchymal stem cells (ADMSCs)-derived exosomes (ChGelMSC-Exo) for the prevention of esophageal stenosis after ESD in a porcine model. RESULTS: Pigs were randomly assigned into (1) ChGelMSC-Exo treatment group, (2) ChGelPBS group, and (3) the controls. Exosome treatments were applied immediately on the day after ESD as well as on day 7. Exosome components crucial for wound healing were investigated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and small RNA sequencing. ChGelMSC-Exo treatment significantly reduced mucosal contraction on day 21, with less fiber accumulation and inflammatory infiltration, and enhanced angiogenesis when compared with the control and ChGelPBS groups. The anti-fibrotic effects following MSC-Exo treatment were further found to be associated with the anti-inflammatory M2 polarization of the resident macrophages, especially within the M2b subset characterized by the reduced TGFß1 secretion, which sufficiently inhibited inflammation and prevented the activation of myofibroblast with less collagen production at the early stage after ESD. Moreover, the abundant expression of exosomal MFGE8 was identified to be involved in the transition of the M2b-macrophage subset through the activation of MFGE8/STAT3/Arg1 axis. CONCLUSIONS: Our study demonstrates that exosomal MFGE8 significantly promotes the polarization of the M2b-macrophage subset, consequently reducing collagen deposition. These findings suggest a promising potential for MSC-Exo therapy in preventing the development of esophageal stricture after near-circumferential ESD.

Enrichment-Sensing All-in-One Strategy Integrated in the La(OH)3-Au@AgNPs Substrate for Rapid Surface-Enhanced Raman Spectroscopy Analysis of Purine Components.

Improving the speediness of complex sample analysis has attracted much research interest in analytical science. In this work, an enrichment-sensing all-in-one strategy was presented for rapid surface-enhanced Raman spectroscopy (SERS) analysis of purine components by using the La(OH)3-Au@AgNPs nanocomposite. Two-dimensional (2D) La(OH)3 nanosheets with nanothickness and accessible active sites not only acted as efficient media for the rapid enrichment of analytes but also provided flat planes for the intensive decoration of Au@AgNPs nanoparticles to amplify the SERS signals of adsorbed analytes. The nanocomposite could realize the rapid enrichment-sensing of purine components in 1 min, including mercaptopurine, thioguanine, adenine, and purine. Subsequently, the surface adsorption behaviors were explored by density functional theory and the enhancement mechanisms were simulated by the finite-difference time-domain method. Moreover, the nanocomposite also exhibited good SERS performances with relative standard deviations (RSDs) of uniformity less than 6.5% (n = 23), RSDs of batch-to-batch stability less than 7.3% (n = 9), and long-term stability over 9 weeks with RSDs within 6.6%. Finally, the enrichment-sensing strategy was applied for the rapid SERS analysis of two projects: mercaptopurine in tablets and adenine in beers with detection limits of 6.0 and 0.76 µg/L and spiked recoveries of 90.9-100 and 84.2-101%, respectively. Benefiting from the high-performance enrichment medium and closely packed plasmonic nanoparticles, the enrichment-sensing all-in-one strategy possesses great potential for rapid on-site detection in food safety and pharmaceutical analysis.

All-in-One Preparation Strategy Integrated in a Miniaturized Device for Fast Analyses of Biomarkers in Biofluids by Surface Enhanced Raman Scattering.

Complex and tedious sample preparation processes have greatly limited rapid analyses of biological samples. In this work, an all-in-one sample preparation strategy based on a miniaturized gas membrane separation/oven ring enrichment (GMS/ORE) device was developed for efficient surface enhanced Raman scattering (SERS) analyses of trace biomarkers in biofluid samples. This strategy integrating gasification separation, liquid trapping, derivatization SERS activation, and coffee-ring enrichment could highly promote the efficiency of sample preparation. Meanwhile, the edges of membranes modified by the hydrophobic-infusing slippery liquid-induced uniform "coffee-ring" effect could significantly improve the sensitivity and stability for SERS quantification. By adapting proper derivatization approaches to the miniaturized GMS/ORE pretreatment, the matrix effects in samples could be prominently eliminated, and clear SERS responses could be obtained for the selective analyses of target biomarkers. The miniaturized GMS/ORE device was practically applied for SERS analyses of trace biomarkers in biofluids, including hydrogen sulfide in saliva samples, creatinine in serum samples, and sarcosine, creatinine, and dimethyl disulfide in urine samples. Accurate quantification of all biomarkers was achieved with recoveries of 89.5%-120.0%, and the contents found by GMS/ORE-SERS matched well with those found by corresponding chromatographic methods with relative errors from -8.6% to 9.3%. The miniaturized GMS/ORE device with multiple parallel processing units could simultaneously treat eight samples in one run with a total analysis time of 40 min. Such an efficient all-in-one strategy integrated on a miniaturized device possesses great potential for fast on-site/point-of-care detection in analytical science and clinical medicine.

Advanced materials on sample preparation for safety analysis of aquatic products.

Safety analysis of aquatic products has been a challenge in recent years due to the serious matrix interference, complex characteristics, and ultra-low content of analytes. Introducing advanced materials to sample preparation technique can greatly improve the extraction, enrichment, and separation for further qualification and quantification of target analytes by coupling with consequent analytical technologies. Based on this scope, this review is mainly introducing advanced materials on the sample preparation for safety analysis of aquatic products in the past decade. After introducing the importance of the corresponding advanced materials, advanced materials are used for the sample preparation and in the improvement of safety analysis result of aquatic products. Advanced materials for sample preparation of aquatic products were reviewed including carbon materials, metal organic frameworks, covalent organic frameworks, molecularly/ions imprinted polymers, etc. Then, applications of the advanced materials for the analysis of specific fishery analytes (antibiotics, anesthetic, preservatives, etc.) were briefly introduced. Conclusions and perspectives on advanced materials for sample preparation and safety analysis of aquatic products were also presented.

Bimetallic AgNPs@dopamine modified-halloysite nanotubes-AuNPs for adenine determination using surface-enhanced Raman scattering.

A bimetallic nanoparticles modified halloysite nanotubes (HNTs) hybrid was prepared by embedding AgNPs and modifying AuNPs on the inner or outer wall of dopamine-modified HNTs (DHNTs) in sequence. The resulting bimetallic AgNPs@DHNTs-AuNPs hybrid as surface-enhanced Raman scattering (SERS) substrate exhibited improved enhancement ability over monometallic AgNPs@DHNTs, and DHNTs-AuNPs substrates, with intensity ratios of about 48:1:9 (crystal violet) and 11:1:2 (p-phenylenediamine). The giant SERS effect of AgNPs@DHNTs-AuNPs substrate is probably attributed to the synergetic enhancement of the electromagnetic field (Au/Ag), optical plasmon force, molecular enrichment (HNTs), and charge transfer (NPs-dopamine-molecules). The sensitive and reproductive AgNPs@DHNTs-AuNPs substrate was applied for SERS determination of adenine with a linear range of 0.010-0.50 mg·L-1 and a detection limit of 2.2 µg·L-1. The SERS method enables the rapid determination of adenine in fish, chicken kidney and heart, and serum samples, with recoveries of 83.5-121.6% and relative standard deviations of 2.5-7.9%. The SERS substrate has high value for rapid analysis of food and biomarker determinations. Schematic illustration of the preparation of AgNPs@HNTs-AuNPs for SERS analysis of adenine in complex sample.

CoFe2O4@HNTs/AuNPs Substrate for Rapid Magnetic Solid-Phase Extraction and Efficient SERS Detection of Complex Samples All-in-One.

Fast and accurate practical sample detection is a great challenge in on-site detection. Herein, we developed a CoFe2O4@HNTs/AuNPs substrate for rapid and efficient magnetic solid-phase extraction (MSPE) surface-enhanced Raman scattering (SERS) detection of aromatic amines and nitrofuran in real samples all-in-one. Magnetic CoFe2O4 beads filled inside halloysite nanotubes (HNTs) can avoid aggregation of particles, endow the substrate with the rapid magnetic separation ability to simplify the pretreatment procedure, and reduce complex matrix interference. Meanwhile, outer surface AuNPs can generate electromagnetic enhancement and hot spots to amplify Raman signals of target molecules enriched/concentrated by HNTs. The CoFe2O4@HNTs/AuNPs substrate exhibited excellent SERS activity (high sensitivity, good reproducibility, and repeatability), pH stability (3.0-11.0), and good MSPE ability (fast magnetic enrichment/separation ability within 5 min). The CoFe2O4@HNTs/AuNPs MSPE SERS substrate can be applied for the determination of 4,4'-thioaniline and nitrofurantoin with a linear range of 0.054-21.7 mg/L and 0.05-1.0 mg/L, and the limits of detection were down to 0.026 mg/L and 0.014 mg/L, respectively. Furthermore, the enhancement factor (EF) of the substrate to 4,4'-thioaniline is up to 2.7 × 107. Besides, the substrate can realize practical SERS determination of trace 4,4-thioaniline in cosmetics and nitrofurantoin in fish feed and aquatic samples. The recoveries were varied from 71.6% to 103.6% for 4,4-thioaniline in hair dyes and 81.9% to 116.3% for nitrofurantoin in fish feed and aquatic samples, respectively. Such a robust and efficient MSPE SERS substrate possesses great potential in rapid detection (within 15 min) for a practical sample, and it also provides a methodology for the preparation of other HNTs-based composites.

Standing-type magnetically guided capsule endoscopy versus gastroscopy for gastric examination: multicenter blinded comparative trial.

AIM: To compare feasibility and safety after gastrointestinal checkup by standing-type magnetically controlled capsule endoscopy (SMCE) and conventional gastroscopy. METHODS: This was a prospective multicenter, blinded study that compared SMCE with gastroscopy in patients from April 2018 to July 2018. All patients first underwent SMCE and then subsequently had gastroscopy with i.v. anesthesia. We calculated the compliance rates of gastric lesion detection by SMCE using gastroscopy as the standard. Capsule retention rate, incidence of adverse events, and patient satisfaction were documented throughout the study. RESULTS: One hundred and sixty-one patients who completed SMCE and gastroscopy were included in the analysis. Positive compliance rate among SMCE and gastroscopy was 92.0% (95% CI: 80.77%-97.78%). Negative compliance rate was 95.5% (89.80%, 98.52%). Moreover, overall compliance rate was 94.41% (89.65%, 97.41%). Sixty-four pathological outcomes were identified. Of these 64 outcomes, 50 were detected by both procedures. The gastroscopy method neglected seven findings (such as five erosions, one polyp, and one ulcer). Furthermore, SMCE also overlooked seven lesions (i.e. one erosion, two polyps, one atrophy, and three submucosal tumors). Capsule retention or related adverse events were not reported. CONCLUSION: Standing-type magnetically controlled capsule endoscopy provides equivalent agreement with gastroscopy and may be useful for screening of gastric illnesses without any anesthesia.

LncRNA SNHG6 promotes chemoresistance through ULK1-induced autophagy by sponging miR-26a-5p in colorectal cancer cells.

BACKGROUND: Chemotherapy resistance is one of the main causes of recurrence in colorectal cancer (CRC) patients and leads to poor prognosis. Long noncoding RNAs (lncRNAs) have been reported to regulate chemoresistance. We aimed to determine the role of the lncRNA small nucleolar RNA host gene 6 (SNHG6) in CRC cell chemoresistance. METHODS: Cell drug sensitivity tests and flow cytometry were performed to analyze CRC cell chemoresistance. Animal models were used to determine chemoresistance in vivo, and micro RNA (miRNA) binding sites were detected by dual-luciferase reporter assays. Bioinformatics analysis was performed to predict miRNAs binding to SNHG6 and target genes of miR-26a-5p. SNHG6/miR-26a-5p/ULK1 axis and autophagy-related proteins were detected by qRT-PCR and western blotting. Furthermore, immunofluorescence was employed to confirm the presence of autophagosomes. RESULTS: SNHG6 enhanced CRC cell resistance to 5-fluorouracil (5-FU), promoted autophagy, inhibited 5-FU-induced apoptosis, and increased 5-FU resistance in vivo. Bioinformatics analysis showed that miR-26a-5p might bind to SNHG6 and target ULK1, and dual-luciferase reporter assays confirmed this activity. qRT-PCR and western blotting showed that SNHG6 was able to negatively regulate miR-26a-5p but correlated positively with ULK1. CONCLUSION: SNHG6 may promote chemoresistance through ULK1-induced autophagy by sponging miR-26a-5p in CRC cells.

Uniform arrangement of gold nanoparticles on magnetic core particles with a metal-organic framework shell as a substrate for sensitive and reproducible SERS based assays: Application to the quantitation of Malachite Green and thiram.

Magnetite (Fe3O4) spheres acting as a core were evenly decorated with gold nanoparticles (AuNPs) and coated with a shell of a metal organic framework (MOF) of type MIL-100(Fe). The resulting hybrid nanomaterial of type Fe3O4-Au@MIL-100(Fe) hybrid is shown to be a viable new SERS substrate. The integration of magnetic core, build-in plasmonic gold nanoparticles and a MOF shell endows the Fe3O4-Au@MIL-100(Fe) with highly efficient magnetic separation and enrichment ability, abundant interparticle hotspots, and significant chemical enhancement effect. This leads to a large enhancement, and greatly improved reproducibility of the SERS signals as shown for Malachite Green (MG) and the fungicide thiram. MG in solution can be quantified with a 50-fold lower detection limit (0.14 nM for peak at 1398 cm-1) and largely improved reproducibility (RSD = 9%, 1398 cm-1) when compared to the use of (a) AuNPs anchored on MIL-100(Fe) (RSD = 27%, 1186 cm-1), or (b) AuNPs embedded in MIL-100(Fe) (RSD = 36%, 1398 cm-1). The method was applied to the quantitation of MG and thiram in spiked water samples. The lower limits of detection are 4.4 nM for MG (1398 cm-1) and 15 nM for thiram (1380 cm-1), respectively, and signals' RSDs are 13% (1398 cm-1) and 5% (1380 cm-1) for MG and thiram, respectively. The substrate is recyclable. Graphical abstract Schematic illustration of the preparation and SERS molecule sensing application of Fe3O4-Au@MIL-100(Fe) hybrid. PMMA: poly(methacrylic acid; BPEI: branched poly(ethyleneimine); BTC: 1,3,5-tricarboxybenzene.

Au@Ag nanodome-cones array substrate for efficient residue analysis of food samples by surface-enhanced Raman scattering.

A bioinspired Au@Ag nanodome-cones array (Au@Ag NDCA) surface-enhanced Raman scattering (SERS) chip was developed for efficient residue analyses of food samples. The cicada wing inspired Au@Ag NDCA chip was fabricated by a bottom-up method, Au nanocones array was firstly grown onto nickel foil by displacement reaction and cetyltrimethylammonium bromide guidance growth, and then silver shell with controllable thickness was coated onto the Au nanocones array by magnetron sputtering. The Au@Ag NDCA chip exhibited good SERS performances with high enhancement factor of 1.2 × 108, good uniformity with relative standard deviation (RSD) less than 7.5% (n = 25), good inter-batch reproducibility with RSD less than 9.4% (n = 9), and long-term stability over 9 weeks. By adapting a minimized sample preparation, Au@Ag NDCA chip combined with a 96-well plate could realize high-throughput SERS analyses of 96 samples with average analysis time less than 10 min. The substrate was applied for quantitative analyses of two food projects. One was 6-benzylaminopurine auxin residue in sprout samples with detection limit of 38.8 µg/L, recoveries of 93.3-105.4% and RSDs of 1.5-6.5%, and the other was an edible spice of 4-amino-5,6-dimethylthieno (2,3-d) pyrimidin-2(1H)-one hydrochloride additive in beverage samples with detection limit of 18.0 µg/L, recoveries of 96.2-106.6% and RSDs of 3.5-7.9%. All the SERS results were well confirmed by conventional high-performance liquid chromatographic methods with relative errors less than 9.7%. The robust Au@Ag NDCA chip exhibited good analytical performances possessed great potential for convenient and reliable analyses of food quality and safety.

Advanced sample preparation techniques for rapid surface-enhanced Raman spectroscopy analysis of complex samples.

Surface-enhanced Raman spectroscopy (SERS) is a powerful and promising analytical technique for fast, non-destructive, and sensitive analysis of trace analytes. However, the serious matrix interference effect of complex sample is a bottleneck that limited rapid SERS analysis. Therefore, it is essential to introduce proper sample preparation techniques to address the limitation for advancing SERS analysis. With adaptable sample preparation techniques, target substances could be separated and purified from complex matrices, matrix interference effect could be eliminated/reduced, and finally pure SERS spectra could be obtained. However, the process of traditional sample preparation usually requires the tedious and time-consuming operation, large solvent consumption, high labor intensity, as well as low efficiency. Given that SERS is an ultrafast analytical technique, there is a great desire to develop advanced/modern sample preparation techniques for fast and efficient analysis of complex samples. To attract much attention and raise research enthusiasm on the beginning, recent development on advanced sample preparation techniques for rapid SERS analysis of complex sample was reviewed. (1) 'All-in-one' strategy for simultaneous separation, enrichment, and in-situ SERS detection. (2) Integrated strategy for high-speed pretreatment and high throughput analysis. (3) Derivatization strategy switches on the SERS activity of molecules with weak responses. (4) Field-assisted strategy for preconcentration acceleration. (5) Instrument combination strategy for online processing and real-time SERS analysis. Finally, conclusions and perspectives on future development were briefly discussed.

Study on the Strengthening Mechanism of Rare Earth Ce in Magnesium Alloys, Based on First-Principle Calculations and Electronegativity Theory.

Since the commercial applications of rare earth magnesium alloys are increasing gradually, there are considerable advantages to developing lower cost and higher performance magnesium alloys with high abundance rare earth (RE) elements. However, the alloying order of a matrix magnesium alloy is completely changed with the addition of RE elements. Therefore, further study of the strengthening mechanism of Ce element in magnesium alloys is required. In this work, the thermodynamic stability of the possible second phases in a Mg-Al-Mn-Ce multicomponent magnesium alloy were analyzed, based on first-principle calculations, and the precipitation sequence of the key RE phases was deduced as a consequence. Combined with Scanning Electron Microscope (SEM), X-ray Diffractometer (XRD), Energy Dispersive Spectrometer (EDS), and other experimental methods, it was investigated whether the preferentially precipitated second phases were the nucleation core of primary α-Mg. The complex alloying problem and strengthening mechanism in a multi-elemental magnesium alloy system were simplified with the aid of electronegativity theory. The results showed that the preferentially precipitated Al11Ce3 and Al10Ce2Mn7 phases could not be the nucleation core of primary α-Mg, and the grain refinement mechanism was such that the second phases at the grain boundary prevented the growth of magnesium grains. Moreover, the tensile test results showed that the reinforced structure, in which the Al-Ce phase was mixed with Mg-Al phase, was beneficial for improving the mechanical properties of magnesium alloys, at both ambient temperature and high temperature.

UiO-66 metal-organic frameworks/gold nanoparticles based substrates for SERS analysis of food samples.

Recently, metal-organic frameworks (MOFs) based substrates have shown great potential for the quantitative analysis of food samples by surface-enhanced Raman scattering (SERS) due to their unique properties. Herein, we developed two UiO-66 MOFs/gold nanoparticles (AuNPs) based substrates by self-assembly, including UiO-66/AuNPs suspension substrate and UiO-66(NH2)/AuNPs/Nylon-66 flexible membrane substrate, for quantitative analysis of complex food samples by SERS. UiO-66/AuNPs suspension substrate was prepared for SERS-based determination of a carcinogenic heterocyclic amine in barbecue meat. UiO-66(NH2)/AuNPs/Nylon-66 membrane substrate was fabricated for the simultaneous separation, enrichment, and in situ analysis of Sudan Red 7B in chilli products. The heterocyclic amine and Sudan dye in real samples could be detected and quantified with the recoveries of 82.3-110% and 84.5-114% and relative standard deviations (RSDs) of 3.1-11.0% and 1.9-5.6% (n = 3) by use of these two substrates, respectively. These two UiO-66/AuNPs based substrates combined molecular enrichment and SERS activity, achieving excellent analytical accuracy and widening SERS application in practical food safety analysis.

Nanoparticle-assembled bioadhesive coacervate coating with prolonged gastrointestinal retention for inflammatory bowel disease therapy.

A key challenge for the effective treatment of gastrointestinal diseases including inflammatory bowel disease is to develop an orally administered drug delivery system capable of prolonged retention in the gastrointestinal tract. Herein we report a bioadhesive liquid coacervate based on hydrogen bonding-driven nanoparticle assembly. Free from electrostatic interactions, our fluid nanoparticle-assembled coacervate demonstrates significant pH- and salt-independent structural stability and forms a physically adhesive coating on a large surface area of intestinal tract with an extended residence time of more than 2 days to mediate the sustained release of preloaded water-soluble small molecule drugs in vivo. The orally administered drug-laden nanoparticle-assembled coacervate significantly mitigates the symptoms of inflammatory bowel disease, restores the diversity of gut microbiota, reduces systemic drug exposure, and improves the therapeutic efficacy in a rat acute colitis model compared with the oral administration of the same amount of drug in solution form. We suggest that the nanoparticle-assembled coacervate provides a promising drug delivery platform for management and treatment of numerous gastrointestinal diseases where controlled drug release with extended residence time is desired.

4-Aminothiophenol capped halloysite nanotubes/silver nanoparticles as surface-enhanced Raman scattering probe for in-situ derivatization and selective determination of nitrite ions in meat product.

Halloysite nanotubes loaded with 4-aminothiophenol capped silver nanoparticles (mHNTs-AgNPs4-ATP) composite was synthesized as a sensitive surface-enhanced Raman scattering (SERS) probe for the determination of nitrite ions in sausage and pork luncheon meat. The as-prepared composite was characterized by transmission electron microscope, X-ray diffraction spectroscopy and Fourier transform infrared spectroscopy. The as-synthesized mHNTs-AgNPs4-ATP composite with evenly distribution of AgNPs can provide in-situ derivatization site for sensitive and selective SERS detection of nitrite ions. Under acid condition, the 4-ATP capped on the AgNPs can be transformed into p,p'-dimercaptoazobenzene (DMAB) through nitrite-triggered diazo reaction. This efficient nitrite-triggered reaction can be used to detect nitrite via the characteristic peaks of DMAB at 1143 cm-1, 1392 cm-1, and 1434 cm-1. This SERS method has a wide logarithmic range of 0.0069-6.9 mg L-1, with detection limit of 0.78, 3.4, 0.51 µg L-1 at the peak of 1143 cm-1, 1392 cm-1, and 1434 cm-1, respectively. Besides, this method can be applied to detect nitrite ions in sausage and pork luncheon meat with relative standard deviation less than 10.3%, and the results were consistent with that analyzed by UV-Vis method. This method has good potential in efficient detection of meat product in food safety.

Multifunctional magnetic sphere-MoS2@Au hybrid for surface-enhanced Raman scattering detection and visible light photo-Fenton degradation of aromatic dyes.

A ternary hybrid, MNPs-MoS2@Au, composed of gold nanoparticles (AuNPs) grown on a magnetic sphere (MNPs)-MoS2 microflower composite (MNPs-MoS2) was proposed for surface-enhanced Raman scattering (SERS) detection and visible-light photo-Fenton degradation of aromatic dyes. The hybrid was prepared by sequential solvothermal growth of MNPs and MoS2, and electroless deposition of AuNPs. A comparison of results revealed that the synergy among these components endowed the hybrid with a much higher SERS enhancement ability than MNPs, or MNPs@MoS2. The dosage of HAuCl4 and MNPs-MoS2 to prepare the hybrid greatly influenced the SERS activity of the hybrid. Under optimized conditions, quantitative SERS analysis of dyes including CV, MG, and MB was performed with a low detection limit (1 pM, 0.15 nM and 1 nM for CV, MG, and MB, respectively) and adequate reproducibility (RSDs were less than 6% and 11% for CV and MG, respectively). The hybrid could also serve as a visible light-active photo-Fenton catalyst for efficient degradation of aromatic dyes, and the decolorization of 20 mg/L RhB was 90% in 40 min in the presence of H2O2 because of a synergy mechanism among components confirmed by comparison experiment and first-order kinetics study. The multifunctional material prepared here possesses great values in SERS analysis, environmental monitoring, and restoration.

Recent progress on graphene-based substrates for surface-enhanced Raman scattering applications.

Since the intriguing and inspiring discovery of graphene-enhanced Raman scattering (GERS) in 2010, graphene and graphene-based substrates have attracted significant attention in both theoretical research and application exploration of surface-enhanced Raman scattering (SERS); this makes graphene-involved SERS a burgeoning area in many scientific branches. The introduction of graphene not only overcomes some intrinsic drawbacks of SERS, but also has a great synergistic effect with traditional noble metal nanoparticle enhancement substrates and thus greatly improves the sensing performance of SERS and largely expands its application area. To better learn about the recent progress in graphene-based SERS substrates and shed light on future research, an overview of graphene and graphene-based SERS substrates is presented herein. In this review, the role played by graphene in graphene-based SERS substrates is first summarized, and then, the classification and preparation methods of graphene-based substrates are presented, which are helpful for understanding the structure-property relationship. Furthermore, the SERS applications of graphene-based substrates in biomedical areas, including biomolecule detection, bio-imaging, cancer diagnosis and therapy and drug delivery, are highlighted. Other applications in hot-topic areas such as food safety and environmental monitoring are also briefly discussed. Finally, challenges and perspectives on the deficiencies, future development and achievements are presented.

Association between patient characteristics and magnetically controlled capsule endoscopy findings.

Background/Aim: Magnetically-controlled capsule endoscopy (MCE) is a potential option for the evaluation of gastric diseases in cases that are unsuited for conventional endoscopy, avoiding discomfort, sedation, and related complications. This retrospective study investigated associations between MCE findings and patient gender, age, and inpatient/outpatient status. Patients and Methods: The data of 580 consecutive patients who underwent MCE from 2015 to 2016 were analyzed. Data included age, gender, indication for MCE, inpatient/outpatient status, overall coverage of gastric anatomical landmarks, and comorbid conditions. Results: Compared with outpatients, inpatients had a higher rate of overall significant MCE findings (P = 0.014), polyp (P = 0.03), and ulceration (P = 0.003). MCE findings of the inpatient men and women were similar. Considering all patients, the percentage with ulceration was significantly higher in men than in women (P = 0.004), and men were younger (P < 0.001). Compared with younger patients, those aged ≥60 years had significantly higher rates of overall significant findings, mainly polyp and angiodysplasia. Conclusions: Compared with outpatients, the inpatients showed higher overall significant findings. Men undergoing MCE were younger than the women, and more likely to have ulcerations. Older patients, whether outpatient or inpatient, had higher rates of significant findings, mainly polyp and angiodysplasia.

[Quantum efficiency of the 5D0 level of Eu3+ at C2 site in cubic nanocrystalline Y2O3].

In the present the authors are trying to work out how the quantum efficiency depends on the nanocrystalline size. Cubic nanocrystalline Y2O3 : Eu3+ samples were prepared by chemical self-combustion. The bulk Y2O3 : Eu3+ was obtained by annealing the nanocrystalline at 1 000 degrees C for 2 h. The emission spectra, XRD and fluorescence decay showed that the emission intensities are increased and fluorescence decay becomes slow with an increase in particle diameter of the samples. Two routes were used to estimate the quantum efficiency of the 5D0 level of Eu3+ at C2 site. The quantum efficiencies of 5D0 level of Eu3+ at C2 site in the samples depend on the nanocrystalline sizes. Finally, a detailed discussion about these two approaches for estimating the quantum efficiencies was made.