Experimental Evidence of a Twofold Electromagnetic Enhancement Mechanism of Surface-Enhanced Raman Scattering

The electromagnetic enhancement mechanism is a major contributor to surface-enhanced Raman scattering enhancements, which are a direct consequence of the roughness present on noble metal surfaces. The electromagnetic enhancement mechanism is a twofold phenomenon that involves the enhancement of both the incident excitation and scattered Raman fields. In this paper, we report a direct observation of the double-enhancement mechanism using a Ag nanorod array/SiO₂ dielectric layer/Ag mirror multilayer thin-film “local plasmon resonator”. The effect of light interference was controlled by adjusting the film thickness of the SiO₂ phase control layer (PCL), and the absorption rate in the Raman scattering wavelength range was tuned from 90 to 0%. In addition to the characteristic Raman peak of an aqueous solution of 4, 4-bipyridine, the background of the Raman scattering spectrum was also enhanced. By examining the relationship between the background Raman emission and the absorption spectrum, we demonstrated that the intensity of the background emission is closely related to the surface-enhanced Raman scattering (SERS) enhancement. We further illustrated that the Raman scattered field and background were enhanced when the absorption was high in the wavelength range of the scattering field. The present results not only suggest that the PCL layer may increase the intensity of plasmon-mediated broadband emission but also provide us with sufficient evidence for a twofold SERS enhancement mechanism

One-Step Synthesis of Copper and Cupric Oxide Particles from the Liquid Phase by X-Ray Radiolysis Using Synchrotron Radiation

The deposition of copper (Cu) and cupric oxide (Cu4O3, Cu2O, and CuO) particles in an aqueous copper sulfate (CuSO4) solution with additive alcohol such as methanol, ethanol, 2-propanol, and ethylene glycol has been studied by X-ray exposure from synchrotron radiation. An attenuated X-ray radiation time of 5 min allows for the synthesis of Cu, Cu4O3, Cu2O, and CuO nano/microscale particles and their aggregation into clusters. The morphology and composition of the synthesized Cu/cupric oxide particle clusters were characterized by scanning electron microscopy, scanning transmission electron microscopy, and high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy. Micro-Raman spectroscopy revealed that the clusters comprised cupric oxide core particles covered with Cu particles. Neither Cu/cupric oxide particles nor their clusters were formed without any alcohol additives. The effect of alcohol additives is attributed to the following sequential steps: photochemical reaction due to X-ray irradiation induces nucleation of the particles accompanying redox reaction and forms a cluster or aggregates by LaMer process and DLVO interactions. The procedure offers a novel route to synthesize the Cu/cupric oxide particles and aggregates. It also provides a novel additive manufacturing process or lithography of composite materials such as metal, oxide, and resin

Tailoring coupling of light to local plasmons by using Ag nanorods/structured dielectric/mirror sandwiches

The optical properties of the sandwich of Ag nanorod array (NRA)/structured dielectric layer/Ag mirror have been investigated theoretically and experimentally, where the structured dielectric layer has stacked sublayers of an anisotropic nanocolumnar layer and a uniform layer. The functions of the nanocolumnar and the uniform sublayers are to control shape of the Ag nanorods and to tune optical path length inside the sandwich, respectively. Calculations based on a simple model by treating the NRAs as uniform effective media indicate that the antireflection condition is realized by changing the thickness of the dielectric layer and that the Ag nanorods absorb most of the incident light. The designed structures have been successfully fabricated by taking advantages of the dynamic oblique-angle deposition technique. Under the experimental antireflection condition, Raman scattering measured on the Ag NRA in the near infrared region exhibits significant enhancement. This indicates that the local electric field close to the Ag nanorods can be controlled by the interference of light in the nanostructured sandwiches

Associations among Preoperative Malnutrition, Muscle Loss, and Postoperative Walking Ability in Intertrochanteric Fractures: A Retrospective Study

Sarcopenia and malnutrition are increasing in older adults and are reported risk factors for functional impairment after hip fracture surgery. This study aimed to investigate the associations between skeletal muscle mass loss, malnutrition, and postoperative walking ability in patients with hip fracture. We retrospectively reviewed patients who underwent intertrochanteric fracture surgery at our institute. The psoas muscle index, controlling nutritional status score, and functional ambulation category (FAC) were used to evaluate skeletal muscle mass, nutritional status, and walking ability, respectively. Six months after surgery, walking ability was assessed as either “gait disturbance” or “independent gait”. Multivariate binomial logistic regression analysis, with skeletal muscle mass, nutritional status, and other factors, was used to predict the risk of being assigned to the gait disturbance group. This study included 95 patients (mean age, 85.2 years; 70 women). Sixty-six patients had low skeletal muscle mass, 35 suffered from malnutrition, and 28 had both. Malnutrition and low skeletal muscle mass were significantly associated with postoperative gait disturbance (FAC < 3). Preoperative low skeletal muscle mass and malnutrition were risk factors for postoperative poor walking ability. Further preventive interventions focusing on skeletal muscle mass and nutritional status are required

Determining Response to Treatment for Drug-Induced Bronchocentric Granulomatosis by the Forced Oscillation Technique

Anti-tumor necrosis factor alpha (TNFα) therapy is widely used to treat various inflammatory conditions. Paradoxically, there are several case reports describing the development of bronchocentric granulomatosis treated with TNFα inhibitors, and it is difficult to determine the effect of treatment using conventional spirometry because the lesions are located in small airways. However, it has been reported that the forced oscillation technique (FOT) is useful in the evaluation of small airway disease in bronchial asthma or chronic obstructive pulmonary disease. We performed the FOT to determine the effect of treatment on bronchocentric granulomatosis and found it to be useful. We report the case of a 55-year-old female with ulcerative colitis who was treated with golimumab and who developed bronchocentric granulomatosis as a sarcoid-like reaction to golimumab. She was successfully treated with prednisone, and the treatment efficacy was confirmed by the FOT. The FOT may be useful in the evaluation of small airway disease in bronchocentric granulomatosis. This case may help inform clinicians of the usefulness of the FOT to assess small airway disease in various diseases

Clinical responses to EGFR-tyrosine kinase inhibitor retreatment in non-small cell lung cancer patients who benefited from prior effective gefitinib therapy: a retrospective analysis

<p>Abstract</p> <p>Background</p> <p>Gefitinib was the first epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) approved for the treatment of advanced non-small cell lung cancer (NSCLC). Few treatment options are available for NSCLC patients who have responded to gefitinib treatment and demonstrated tumor progression. The present study was conducted to evaluate the efficacy and toxicity of the 2^ndEGFR-TKI administration.</p> <p>Methods</p> <p>We retrospectively analyzed 11 patients who had obtained a partial response (PR) or stable disease (SD) with gefitinib treatment and were re-treated with EGFR-TKI after failure of the initial gefitinib treatment.</p> <p>Results</p> <p>Three patients (27%) were treated with gefitinib as the 2^ndEGFR-TKI, and 8 patients (73%) received erlotinib. Only one patient (9%) showed PR, 7 (64%) achieved SD, and 3 (27%) had progressive disease. The disease control rate was 73% (95% CI, 43% - 91%) and the median progression-free survival was 3.4 months (95% CI, 2 - 5.2). The median overall survival from the beginning of the 2^ndEGFR-TKI and from diagnosis were 7.3 months (95% CI, 2.7 - 13) and 36.7 months (95% CI, 23.6 - 43.9), respectively. No statistical differences in PFS or OS were observed between gefitinib and erlotinib as the 2^ndEGFR-TKI (PFS, P = 0.23 and OS, P = 0.052). The toxicities associated with the 2^ndEGFR-TKI were generally acceptable and comparable to those observed for the initial gefitinib therapy.</p> <p>Conclusions</p> <p>Our results indicate that a 2^ndEGFR-TKI treatment can be an effective treatment option for gefitinib responders.</p

Clinical responses to EGFR-tyrosine kinase inhibitor retreatment in non-small cell lung cancer patients who benefited from prior effective gefitinib therapy: a retrospective analysis

<p>Abstract</p> <p>Background</p> <p>Gefitinib was the first epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) approved for the treatment of advanced non-small cell lung cancer (NSCLC). Few treatment options are available for NSCLC patients who have responded to gefitinib treatment and demonstrated tumor progression. The present study was conducted to evaluate the efficacy and toxicity of the 2^ndEGFR-TKI administration.</p> <p>Methods</p> <p>We retrospectively analyzed 11 patients who had obtained a partial response (PR) or stable disease (SD) with gefitinib treatment and were re-treated with EGFR-TKI after failure of the initial gefitinib treatment.</p> <p>Results</p> <p>Three patients (27%) were treated with gefitinib as the 2^ndEGFR-TKI, and 8 patients (73%) received erlotinib. Only one patient (9%) showed PR, 7 (64%) achieved SD, and 3 (27%) had progressive disease. The disease control rate was 73% (95% CI, 43% - 91%) and the median progression-free survival was 3.4 months (95% CI, 2 - 5.2). The median overall survival from the beginning of the 2^ndEGFR-TKI and from diagnosis were 7.3 months (95% CI, 2.7 - 13) and 36.7 months (95% CI, 23.6 - 43.9), respectively. No statistical differences in PFS or OS were observed between gefitinib and erlotinib as the 2^ndEGFR-TKI (PFS, P = 0.23 and OS, P = 0.052). The toxicities associated with the 2^ndEGFR-TKI were generally acceptable and comparable to those observed for the initial gefitinib therapy.</p> <p>Conclusions</p> <p>Our results indicate that a 2^ndEGFR-TKI treatment can be an effective treatment option for gefitinib responders.</p

Supramolecular networks stabilise and functionalise black phosphorus

The limited stability of the surface of black phosphorus (BP) under atmospheric conditions is a significant constraint on the exploitation of this layered material and its few layer analogue, phosphorene, as an optoelectronic material. Here we show that supramolecular networks stabilised by hydrogen bonding can be formed on BP, and that these monolayer-thick films can passivate the BP surface and inhibit oxidation under ambient conditions. The supramolecular layers are formed by solution deposition and we use atomic force microscopy to obtain images of the BP surface and hexagonal supramolecular networks of trimesic acid and melamine cyanurate (CA.M) under ambient conditions. The CA.M network is aligned with rows of phosphorus atoms and forms large domains which passivate the BP surface for more than a month, and also provides a stable supramolecular platform for the sequential deposition of 1,2,4,5-tetrakis(4-carboxyphenyl)benzene to form supramolecular heterostructures