A Meta-Analysis Comparing Endoscopic Ultrasound-guided Fine-needle Aspiration With Endoscopic Ultrasound-guided Fine-needle Biopsy.

BACKGROUND: The superiority between endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is still a debate. The purpose of this meta-analysis was to compare the diagnostic value and safety of these 2 needles in sampling of all solid lesions and separately pancreatic lesions. MATERIALS AND METHODS: PubMed, EMBASE, and the Cochrane library were searched for randomized controlled studies that reported the comparison of FNA and FNB in solid mass. Outcome measures included diagnostic accuracy, number of needle passes, diagnostic adequacy, presence of tissue cores, and adverse events. Standard error, upper and lower confidence intervals at 95% confidence interval for the risk were obtained using Review Manager Version 5.3 which was also used to generate forest plots for pooled analysis. The random or fixed effect model was applied depending on the heterogeneity ( I2 ). RESULTS: Eighteen randomized control trial studies with a total of 2718 patients (1141 patients with EUS-FNA, 1108 with EUS-FNB, and remaining 469 patients were sampled with both needles alternatively) were included in the meta-analysis.FNB group has relatively good diagnostic accuracy relative risk (RR): 0.94, 0.92-0.97; P =0.0002), diagnostic adequacy (RR: 0.95, 0.9-1.0; P =0.04) and high quality histologic yield compared (RR: 0.77, 0.64-0.93; P =0.007) with the FNA group in solid gastrointestinal lesions, and the number of needle passes to obtain sufficient tissue (mean difference: 0.54, 0.45-0.64; P <0.00001) was lower in the FNB group. For solid pancreatic disease only, there was no difference in diagnostic accuracy (RR: 0.97, 0.93-1.01, P =0.13) or quality histologic yield (RR: 0.60, 0.29-1.23; P =0.16). The rate of adverse events (RR: 1.04, 0.48-2.29; P =0.92) did not significantly differ between FNA and FNB groups. CONCLUSIONS: In solid gastrointestinal lesions, FNB is associated with a relatively better diagnostic adequacy, diagnostic adequacy and tissue cores rates, and less number of needle passes. For solid pancreatic disease only, there is no difference in diagnostic accuracy or tissue cores rates.

Spatial distribution and pollution assessment of heavy metals in the surface sediments of the Bohai and Yellow Seas.

A total of 141 surface sediments were collected and analyzed for their geochemistry, total organic carbon, and grain size to assess the heavy metal pollution in the Bohai and Yellow Seas. The enrichment factor (EF) and geoaccumulation index (Igeo) of Cu, Pb, Zn, Cr, Cd, Ni, As, and Hg were calculated to assess anthropogenic contamination, and the results suggest that moderate Pb, Cd, and As contamination occurs in the study area. Sediment quality guidelines were applied to assess the adverse biological effects of these metals. The spatial distribution of the mean Effects Range-Median quotient for the vast majority of the study area is between 0.1 and 0.5, indicating low impact and potential negative biological effects. Multivariate analysis indicates that Cu, Pb, Zn, Cr, and Ni resulted primarily from lithogenic sources, whereas As, Cd, and Hg were mainly attributed to anthropogenic sources.

The versatile colour gamut of coatings of plasmonic metal nanoparticles.

We have investigated the colour gamut of coatings produced by the growth of plasmonically-active coatings of cap-shaped Au or Ag nanoparticles on a transparent substrate. The control of colour and spectral selectivity that can be obtained by the manipulation of the rates of nucleation and growth were explored using a combination of experiment and calculation. In our experimental work the Au nanoparticles were grown in situ using a wet chemical electroless plating technique while the Ag nanoparticles were produced by physical vapour deposition. The optical properties were numerically simulated using the discrete dipole approximation. The resulting measured or calculated transmission spectra were mapped to the CIE L-a -b colour space. The aspect ratio of the nanoparticles was the primary factor in determining the colours in both cases. However, increasing the nucleation rate of the particles resulted in them becoming more closely packed, which also red-shifted the optical extinction peak of the structure due to interactions of their near-fields. This caused an enhancement in the blue component of the transmitted light. Coatings of Ag particles had a significantly wider and brighter colour gamut than those of Au.

In situ organization of gold nanorods on mixed self-assembled-monolayer substrates.

A method is described for assembling gold nanorods, end-to-end, into long chains attached on top of a mixed self-assembled monolayer that has been functionalized with streptavidin. Methods to prepare chains of nanorods in colloidal suspension have been reported by others, but our protocol offers a way to directly form such structures on a substrate. The rods are spaced approximately 5 nm apart in the resulting chains, which extend for over a micrometer in length. The assembly and morphology of the nanorod structures were characterized by surface plasmon resonance spectroscopy, as well as by scanning electron microscopy and scanning probe microscopy. Structures of this type could conceivably serve as plasmonic waveguides in future nanodevices.

Dipole-dipole plasmon interactions in gold-on-polystyrene composites.

Red-shifting of the optical absorption spectra of aggregates of gold nanoparticles by dipole-dipole interactions is of considerable interest, both for theoretical reasons and because the phenomenon can be potentially exploited in various applications. A convenient and practical way to control the effect is to assemble the aggregated ensemble of n gold nanoparticles on the outer surface of larger dielectric spheres. Here, we show by experiment and calculation how the spectra of these structures can be systematically morphed from that of isolated gold particles, through the regime of broad absorption dominated by particle-particle interactions, and finally to the limiting case of a continuous nanoshell. The experimental data were produced using the process of deposition-precipitation, which provides a facile method to decorate polystyrene microspheres with gold nanoparticles. There is no need for prior functionalization of the microsphere surface in our method of deposition-precipitation. Calculations were carried out using a code based on the discrete dipole approximation (DDA). The spectra were dominated by three effects. These were a peak absorption at about 540 nm produced by the conventional plasmon resonance of spherical gold nanoparticles, a broad absorption in the range 600-900 nm caused by diverse dipole-dipole interactions between particles, which strengthened as the number of attached gold particles increased and finally, when n was large, an absorption peak due to the onset of nanoshell-like resonances. The experimental spectra could be successfully fitted by spectra calculated using combinations of these effects.