Improving SERS-based readout strategy for biomarker detecting immunoassays

Detection and monitoring of disease biomarkers increases probability of successful disease treatment. Surface enhanced Raman scattering (SERS) has several advantages over conventional readout strategies utilized in detecting immunoassays. SERS provides a method for chemical characterization based on molecular vibrational spectra. Raman signals are typically weak and need to be enhanced. This can be done using plasmons in nanoparticles of noble metals, we use gold (Au). Molecules with known spectra, Raman reporter molecules (RRM), can be adsorbed to Au nanoparticles. This enhances the Raman signal of the RRM when illuminated by a laser of optimal wavelength. Adding antibodies to nanoparticles modified with this method can then provide a means for finding hard to detect disease biomarkers. The focus of this research is the effects to the Raman signal by varying the nanoparticle modification process. We look at the effects of adding PEG molecules to Au nanoparticles and how Raman signals are affected by the laser used to take measurements. RRM type, nanoparticle size, and PEG amounts were varied. Consecutive measurements show how Raman signals change over time. We have interpreted Raman signal changes as plasmon-driven conversion of RRMs as well as desorption of RRMs from the surface of AuNP and photodamage. We also observed catalytic photoconversion of both NBT and ABT to diazobenzene suggesting that AuNP can act as catalysts in complex reactions. Additionally, we discovered a novel pathway of converting amine substituted benzene to carbon wires as indicated by appearance of the Raman peak at 2130 cm-1

Surface-Enhanced Raman Scattering-Based Immunoassay Technologies for Detection of Disease Biomarkers

Detection of biomarkers is of vital importance in disease detection, management, and monitoring of therapeutic efficacy. Extensive efforts have been devoted to the development of novel diagnostic methods that detect and quantify biomarkers with higher sensitivity and reliability, contributing to better disease diagnosis and prognosis. When it comes to such devastating diseases as cancer, these novel powerful methods allow for disease staging as well as detection of cancer at very early stages. Over the past decade, there have been some advances in the development of platforms for biomarker detection of diseases. The main focus has recently shifted to the development of simple and reliable diagnostic tests that are inexpensive, accurate, and can follow a patient’s disease progression and therapy response. The individualized approach in biomarker detection has been also emphasized with detection of multiple biomarkers in body fluids such as blood and urine. This review article covers the developments in Surface-Enhanced Raman Scattering (SERS) and related technologies with the primary focus on immunoassays. Limitations and advantages of the SERS-based immunoassay platform are discussed. The article thoroughly describes all components of the SERS immunoassay and highlights the superior capabilities of SERS readout strategy such as high sensitivity and simultaneous detection of a multitude of biomarkers. Finally, it introduces recently developed strategies for in vivo biomarker detection using SERS

Изменение агрохимических свойств и вертикального распределения 137cs в аллювиальной почве в зависимости от реабилитационных мероприятий

As a result of the accident at the Chernobyl nuclear power plant and the loss of artificial. radionuclides, there was a decrease in the area of fodder land capable of producing feed that meets radiation standards. The use of rehabilitation measures contributes to the return of lost lands to agricultural. circulation, however, the issues of changing the fertility and behavior of 137Cs in al. luvial. soil are not well understood. Therefore, the aim of the study was to study the transformation of soil fertility under the influence of rehabilitation measures and the behavior of 137Cs in the soil profile of floodplain meadows. It was found that the use of floodplain meadows as hayfields does not change the agrochemical. indicators of the fertility of al. luvial. soil. A radical. and superficial. improvement with the introduction of mineral. fertilizers increased the content of nutrients in the soil. It was established that at the initial. stage of the rehabilitation of radioactively contaminated floodplain meadows it is necessary to carry out a radical. improvement (the use of deep two-tier plowing), due to this there is a maximum decrease in concentration in the root-inhabited layer of al. luvial. soil. At the initial. stage of the study, the largest part of 137Cs was in a layer of 0-5 cm of al. luvial. soil, a uniform distribution of the radionuclide to a depth of 20 cm occurred after 21 years, and the application of mineral. fertilizer contributed to the equal. ization of the specific activity of 137Cs in layers of 0-5 and 5-10 cm. The application of radical. and surface improvement with the introduction of mineral. fertilizer enhanced the equal. ization of the concentration of 137Cs Рin the layers 0-5, 5-10, 10-15 and 15-20 cm. 137Cs  migration to the root layer of the soil from the underlying layers was reveal. ed due to an increase in the mass of grass cover under the influence of increasing doses of mineral. fertilizer.в результате аварии на Чернобыльской АЭС и выпадению искусственных радионуклидов произошло уменьшение площадей кормовых угодий способных производить корма отвечающих радиационным нормативам. Применение реабилитационных мероприятий способствует возврату потерянных земель в сельскохозяйственный оборот, однако вопросы изменения плодородия и поведения 137Cs в аллювиальной почве недостаточно изучены. Поэтому цель исследования изучить трансформацию почвенного плодородия под действием реабилитационных мероприятий и особенности поведения 137Cs в профиле почв пойменных лугов. В результате исследований выявили, что использование пойменного луга в качестве сенокоса не меняет агрохимические показатели плодородия аллювиальной почвы. Коренное и поверхностное улучшение с внесением минерального удобрения увеличивало содержание элементов питания в почве. Установили, что в начальный этап реабилитации радиоактивно загрязненных пойменных лугов необходимо проводить коренное улучшение (применение глубокой двухъярусной вспашки), за счет этого происходит максимальное снижение концентрации в корнеобитаемом слое аллювиальной почвы. На начальном этапе исследования наибольшая часть 137Cs находилась в слое 0-5 см аллювиальной почвы, по прошествии 21 года произошло равномерное распределение радионуклида до глубины 20 см, а внесение минерального удобрения способствовало выравниванию удельной активности 137Cs в слоях 0-5 и 5-10 см. Применение коренного и поверхностного улучшения с внесением минерального удобрения усиливало выравнивание концентрации 137Cs в слоях 0-5, 5-10, 10-15 и 15-20 см. Выявлена миграция 137Cs в корнеобитаемый слой почвы из нижележащих слоев за счет увеличения массы травостоя под действием возрастающих доз минерального удобрения

Incorrect storage of medicines and potential for cost savings

Objective Incorrect storage and handling of refrigerated medicines may result in destruction of medicines and financial loss for hospitals. At the Medicine Information Centre we receive and answer queries on drug-related issues. In this study we aimed to investigate and quantify savings made following advice supplied by the Medicine Information Centre in reply to queries regarding the incorrect storage of refrigerated medicines.Methods A retrospective study was conducted by systematically reviewing each drug when the cold chain had been impaired, in order to determine whether the drug could continue to be used, possibly with a shortened expiry date. Thus, by examining all cases of incorrect storage, the value of drugs that pharmacists advised could be used despite a broken cold chain, could be estimated.Results The Medicine Information Centre dealt with 171 cases concerning incorrect storage in 2013. Data show that advice from Medicine Information Centre pharmacists resulted medicine cost savings of DKK 13 million (approx. €1.7 million) in hospitals in the Capital Region for that year.Conclusions Substantial savings can be made by seeking the advice of a team of information pharmacists regarding the incorrect storage of medicines

Radiation from Comoving Poynting Flux Acceleration

We derive analytic formulas for the radiation power output when electrons are accelerated by a relativistic comoving kinetic Poynting flux, and validate these analytic results with Particle-In-Cell simulations. We also derive analytically the critical frequency of the radiation spectrum. Potential astrophysical applications of these results are discussed. A quantitative model of gamma-ray bursts based on the breakout of kinetic Poynting flux is presented.Comment: 30 pages 8 figures, resubmitted to ApJ, replaces earlier preprint titled "Radiation from Kinetic Poynting Flux Acceleration" (arXiV:0704.1843); most of the paper has been rewritte

Distribution of Cu, Ni, Zn, Mn, Cr, Cd, Pb, Co, Mo, As in alluvial soils of floodplain landscapes of the Sozh river basin

The studies were carried out in the western part of the Bryansk Region in the landscapes of the Sozh River basin (Iput’ River, tributary of the 1st order, south of the village of Perevoz; River Besed', tributary of the 1st order, northwest of the village of Baturovka; River Unecha, tributary 2nd order, west of the village of Lopatny). The aim of this work is to study the features of the vertical and horizontal distribution of the gross content of Cu, Ni, Zn, Mn, Cr, Cd, Pb, Co, Mo, As in the alluvial soils of floodplain landscapes. The selection of soil samples for the determination of the gross content of trace elements was carried out in subsystems of the floodplain landscape, different in geomorphology and hydrology, by the method of soil springs. Each key soil plot was a full-profile soil pit and four reconnaissance pits. Samples were taken from the walls of the cuts every 5 cm, mixed and averaged by the quartering method. The gross content of trace elements was determined by the atomic absorption method, after preliminary decomposition of the samples with a mixture of concentrated nitric and hydrofluoric acids using a microwave system. Variations in the content of trace elements in the layers of alluvial soils were assessed using the coefficient of variation. To characterize the degree of concentration or dispersion of trace elements in soils, the concentration clarke was calculated. As a result of the research, it was found that the vertical distribution of trace elements in the 0–20 cm layer is determined by their chemical properties and the genesis of the soils of the floodplain subsystems, and can be uniform, decreasing/increasing with depth or with concentration in separate layers. Clarke concentrations of microelements and their content increase in the direction from the riverbed to the near-terrace subsystem of the floodplain. Concentrations of elements in the soils of floodplain landscapes do not exceed the clarke value. The exceptions are Cr, Zn and Cu in the soil of the near-terrace subsystem of the river Unecha, Cd – in the soil of the central subsystem of the river Besed’, as well as Cu and Cd – in the soil of the near-terrace subsystem of the river Besed’. An excess of the clarke value for some elements may indicate their anthropogenic origin

UV/Optical Emission Accompanying Gamma-ray Burst

We discuss the possible simultaneously UV/optical emission accompanying Gamma-ray bursts (GRBs). We show that as long as the intrinsic spectrum of GRB can extend to $\sim$10 GeV or higher, there is a large amount of relativistic $e^\pm$ pairs generated due to the annihilation of the soft $\gamma-$rays with the very energetic photons, which dominates over the electrons/positrons associated with the fireball, no matter the fireball is highly magnetized or not (For the highly magnetized fireball, the magnetic field is ordered, the high linear polarization of the multi-wavelength emission is expected). We find that these $e^\pm$ pairs can power an UV flash with $m\simeq 12-13{\rm th}$ magnitude, and the corresponding optical emission can be up to $m_{\rm R}\simeq15-16{\rm th}$ magnitude. Such bright UV emission can be detected by the upcoming satellite Swift, planned for launch in early 2004. The behavior of the optical-UV spectrum ($F_{\nu}\propto \nu^{5/2}$) differs significantly from that of the reverse shock emission ($F_{\nu}\propto \nu^{-\beta/2}$, $\beta \simeq 2.2$), which is a signature of the emission accompanying with GRB. The mild optical emission can be detected with the ROTSE-IIIa telescope system, if the response to the GRB alert is fast enough.Comment: 5 pages, no figures. MNRAS in pres