Objective: To investigate the relationship between UGT1A1*6, UGT1A1*28, UGT1A1*60 and UGT1A1*93 polymorphisms and irinotecan-induced severe adverse reactions(grade 3-4 delayed diarrhea and neutropenia) in Chinese cancer patients. Methods: A total of 141 cancer patients treated with irinotecan were enrolled in this study. Peripheral venous blood was collected and genomic DNA was extracted. The genetic polymorphisms of UGT1A1*6, UGT1A1*28, UGT1A1*60 and UGT1A1*93 were analyzed by PCR and direct sequencing. The adverse reactions during chemotherapy were observed and recorded. The incidence of severe adverse reactions was compared among patients with different genotypes. Results: Among 141 patients, the cases with UGT1A1*6 GG, GA and AA genotypes were 71, 54 and 16, while those with UGT1A1*28 TA6/6, TA6/7 and TA7/7 genotypes were 105, 33 and 3, respectively. The cases with UGT1A1*60 AA, AC and CC genotypes were 52, 80 and 9, while those with UGT1A1*93 GG, GA and AA genotypes were 105, 32 and 4, respectively. The patients with grade 3-4 delayed diarrhea and neutropenia were 23 and 56, respectively. Multivariate logistic regression analysis showed that UGT1A1*6 and UGT1A1*60 genetic polymorphisms were independent factors influencing the occurrence of grade 3-4 delayed diarrhea. The risk of grade 3-4 delayed diarrhea in homozygous AA carriers of UGT1A1*6 increased 3.79 times compared with that in wild-type GG carriers (95%CI: 1.35-10.67). Moreover, the risk of grade 3-4 delayed diarrhea in homozygous CC carriers of UGT1A1*60 was 20.42 times compared with that in wild-type AA carriers (95%CI: 3.52-118.33). In addition, UGT1A1*28 genetic polymorphism was an independent factor of the occurrence of grade 3-4 neutropenia. The patients with homozygous TA7/7 carriers of UGT1A1*28 had an 1.61 times higher risk of grade 3-4 neutropenia compared with those with wild-type TA6/6 carriers (95%CI: 1.44-12.65). There was no correlation between UGT1A1*93 genetic polymorphism and severe adverse reactions caused by irinotecan. Conclusion: The cancer patients who carried UGT1A1*6, UGT1A1*28 and UGT1A1*60 gene polymorphisms have high risk of severe adverse events caused by irinotecan-based chemotherapy.
We have fabricated surface-enhanced Raman scattering (SERS) substrates based on arrays of silver nanoparticles grown on porous anodic alumina templates. Using this nanotechnology platform, label-free and high-speed detection of bacteria are achieved. SERS spectra of various bacteria including Staphylococcus Aureus (Gram-positive bacterium), Klebsiella Pneumoniae (Gram-negative bacterium), and Mycobacterium Smegmatis (Mycobacterium) were recorded. The highly reproducible SERS-based technological platform is capable of differentiating different kinds of bacteria by PCA, LDA, clustering analysis, and SVM methods, which provides promising opportunity for biosensing of clinical microbes.
Received 15 August 2012DOI:https://doi.org/10.1103/PhysRevLett.109.089902© 2012 American Physical Society
Fast replication of large-area femtosecond-laser-induced surface micro/nanostructures on plastic parts by injection molding is demonstrated. An STAVAX steel mold insert is irradiated by femtosecond laser pulses with linear or circular polarization to form periodic-like nanostructures or nanostructure-covered conical microstructures. It was then used for the process of thermal injection molding. The process provides high-volume manufacturing means to generate hydrophobic enhanced plastic parts, which is expected to be widely used in consumables and chemical/biomedical device industries.
The production of inexpensive, large-scale, uniform substrates for surface-enhanced Raman scattering (SERS) is a key to popularize its usage in chemical and biological detection. We demonstrate a flexible nano-imprinted hexagonally patterned SERS-active substrate. Its electromagnetic enhancement factor was optimized by the thickness adjustment of its silver over-coated film. The experimental data show a good correspondence with the theoretical prediction. Such substrate was shown to exhibit high uniformity and reproducibility with a variation of less than 2%, offering a potential of greatly exploiting such substrate in infield biocide monitoring.
The authors report experimental studies of surface-enhanced Raman scattering (SERS) of wurtzite-type GaN and ZnO crystalline samples covered with Ag-nanoparticles. The longitudinal optical phonons consistently exhibit unusually intense Raman enhancement in comparison with other phonons. The anomaly is interpreted by a proposed model based on a resonant Raman scattering process assisted by metal-induced gap states at the Ag/GaN and Ag/ZnO interfaces. This study suggests that SERS of lattice vibrations in inorganic semiconductors is sensitive to their propagation nature, providing a progressive perspective view on electron-mediated enhanced Raman scattering.
We report a way to assess the separation between a molecule and a metal surface on account of both Raman scattering and fluorescence intensities measured simultaneously. This approach has no need for an accurate quantity of molecules and bears 1 nm resolution. Its distance sensitivity is experimentally demonstrated in the case of dye molecules lying on a gold surface with a polymer spacer layer in between and is compared with theoretical prediction.
Investigating with pseudo-spectral time-domain method, we show that resonant scattering characteristics of Ag nanoparticle arrays are attributed to near-field surface magnetic field, instead of enhanced electric field induced by plasmonic coupling.
Crystals of FeSe0.88 and FeSeMn0.1 have been grown from KCl solutions. Crystals measuring 2−3 mm across and 0.1−0.3 mm thick grow with a hexagonal plate like habit. Powder X-ray diffraction (XRD) measurements show strong peaks corresponding to the tetragonal α-FeSe phase and weak hexagonal β-FeSe peaks in both cases. The plate side of the crystal is identified to be the (101) face of the tetragonal α-FeSe. Energy dispersive X-ray spectroscopic (EDS) measurements show that Mn substitutes for Fe. Both types of crystals show a superconducting transition at 8 K in the DC magnetization measurements and a broad resistive transition with zero resistance at 7.5 K with an onset at 11 K. Specific heat measurements also confirm bulk superconductivity in the crystals. Crystals could also be grown using KBr as a solvent.
The electronic structure single crystals of the new double perovskite Sr2YRu1−xCuxO6 (x = 0–0.05) has been investigated by x-ray absorption near-edge structure (XANES) spectroscopy. The Cu K-edge spectra show that Cu is incorporated as Cu1+ and Cu2+ in the crystals grown in air and in an oxygen atmosphere and Ru5+ is seen in the Ru K-edge spectra. The O K-edge and the Ru L3-edge spectra indicate an increase in the unoccupied states (hole concentration) as x is increased, accompanied by a lattice distortion from an increased O–Ru–O bond angle. These changes observed even with a small Cu addition are interpreted to result from the Cu 3d–O 2p hybridization as Cu replaces Ru in the octahedral sites.
We have examined a femtosecond pulse shaping phenomenon induced by self-organized Ag nanoparticle arrays. Significant pulse shortening was observed as plasmon resonance occurs between the array and femtosecond pulses.
The authors report the investigation of surface plasmon waves (SPW) generated by single nanohole and nanohole arrays. Scattering-type scanning near-field microscopy is used to directly observe near-field distribution. The images after Fourier transformation display characteristic patterns that match with the derived analytic formula. The correspondence helps to identify the role of the scanning tip in generating SPW, making possible of the removal of this tip-induced effect. This study provides a means to perform in-depth investigation on surface plasmon polaritons.
Single crystals of Sr2YRu1‐xCuxO6 with x=0 and x=0.1 were grown using PbO‐PbF2 based solutions at different temperatures in the range 1150–1350°C. The influence of Pb from the solutions and the Cu from the solid solutions of Sr2YRu1‐xCuxO6 on the resulting crystals was studied using microstructure and magnetic property measurements. The peaks in the powder X‐ray diffraction patterns and Raman spectra do not change in the case of x=0 crystals but shift in the presence of Cu. A diamagnetic transition indicative of superconductivity was observed in the presence of Cu and an antiferromagnetic behavior with x=0. Based on these results it is concluded that Pb may not be incorporated in the crystals and even if it does the influence is not observed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
This report presents an overview of our recent near-field investigation of both local and surface plasmon resonance (SPR) with a scattering-type scanning near-field optical microscope (s-SNOM) which has sub-10 nanometer resolution. With the ability to perform near-field optical experiments at multiple excitation wavelengths simultaneously, this instrument has recorded near-field intensity and phase images of a wide range of subwavelength plasmonic structures: single nanohole and nanoslit, circular and elliptical hole arrays, etc. The near-field results obtained with different excitation wavelengths were confirmed by numerical calculation and were made direct correspondence with far-field observations by comprehensive models. The multi-wavelength s-SNOM proves to be an essential tool to unravel many interesting plasmonic phenomena in nanometer scale. This work investigates the nature of subwavelength plasmon optics which potentially will play an important role in the development of many innovative highly efficient opto-electronic devices (light-emitting devices and solar cells) and highly sensitive sensors based on SPR and surface-enhanced Raman scattering.
We report a near-field study of the excitation and propagation of surface plasmon on ordered Ag elliptical hole arrays with a scattering-type scanning near-field optical microscope. Strong dipole-like local plasmon is identified at each individual hole from near-field optical intensity and phase images. The excitation of the local plasmon at the elliptical hole is found to follow polarization excitation constraint. The coherent superposition of these local plasmon waves to form an extended surface plasmon wave propagating to an adjacent hole array is observed directly. The near-field results are consistent with the results obtained from far-field extraordinary transmission measurements.
Single crystals of Sr2HoRu1−xCuxO6 (with x=0–0.2), measuring 2–3mm across have been grown from PbO–PbF2 based solutions in the temperature range of 1250–1150°C. The crystals exhibit octahedral morphology and belong to the monoclinic space group P21∕n. While Sr2HoRuO6 is found to be antiferromagnetic with weak ferromagnetism below 30K, the solid solutions containing Cu exhibit a diamagnetic transition at 31K which increases in magnitude and temperature with increasing Cu. Through a correlation of magnetic and calorimetric properties, these crystals are concluded to be spin-glass superconductors.
We present a numerical study of the electric field enhancement in the immediate vicinity of the apex of a conical silver tip and show that an optimal cone angle exists, allowing one to maximize the electric field. This angle depends on the tip length, the wavelength, as well as on the distance from the apex to the observation point. So both the angle and length of the tip can be considered as parameters to adjust the peak enhancement resonant position for a laser source wavelength. At the same time, reducing the cone angle does not ensure a concurrent increase in the electric field enhancement. A simple qualitative interpretation is proposed to explain this phenomenon based on competition of two mechanisms affecting the electric field near the tip apex. The results obtained show that the point-like dipole approximation is invalid for description of the field enhancement of a finite-size metal tip in the case of scattering-type near-field optical microscopy. One more conclusion is that the model of a sharp semi-infinite perfectly conducting tip is also not adequate in our case.
Uniform and highly surface-enhanced Raman spectroscopic (SERS)-active substrates have been fabricated using Ag nanoparticle arrays with unprecedented small tunable gaps. The dependence of the enhancing capability of the substrate on the gap size provides quantitative evidence for the collective SERS effect and confirms predictions of interparticle-coupling-induced Raman enhancement.