We discuss the features involved in determining the titanium dioxide nanoparticle (TiO
NP) sizes in cosmetic samples via single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) in ...the millisecond-time resolution mode, and methods for considering the background signal. In the SP-ICP-MS determination of TiO
NPs in cosmetics, the background signal was recorded in each dwell time interval due to the signal of the Ti dissolved form in deionized water, and the background signal of the cosmetic matrix was compensated by dilution. A correction procedure for the frequency and intensity of the background signal is proposed, which differs from the known procedures due to its correction by the standard deviation above the background signal. Background signals were removed from the sample signal distribution using the deionized water signal distribution. Data processing was carried out using Microsoft Office Excel and SPCal software. The distributions of NP signals in cosmetic product samples were studied in the dwell time range of 4-20 ms. The limit of detection of the NP size (LOD
) with the proposed background signal correction procedure was 71 nm. For the studied samples, the LOD
did not depend on the threshold of the background signal and was determined by the sensitivity of the mass spectrometer.
A
bstract
In this paper we present the all-loop conjecture for integrands of Wilson line form factors, also known as reggeon amplitudes, in
N
=
4
SYM. In particular we present a new gluing operation ...in momentum twistor space used to obtain reggeon tree-level amplitudes and loop integrands starting from corresponding expressions for on-shell amplitudes. The introduced gluing procedure is used to derive the BCFW recursions both for tree-level reggeon amplitudes and their loop integrands. In addition we provide predictions for the reggeon loop integrands written in the basis of local integrals. As a check of the correctness of the gluing operation at loop level we derive the expression for LO BFKL kernel in
N
=
4
SYM.
In this paper, we propose the combined procedure of noble metal (NM) determination, including fire assay, acid digestion, and reversible dynamic sorptive preconcentration, followed by flow-injection ...ICP-MS. Reversible preconcentration of all NMs was carried out using micro-column packed new PVBC-VP sorbent and elution with a mixture of thiourea, potassium thiocyanate, and HCl, which recovers Pd, Ir, Pt, and Au by 95% and Ru, and Rh by 90%. The proposed procedure was approved using certified reference materials.
The gluing operation is an effective way to get form factors of both local and non-local operators starting from different representations of on-shell scattering amplitudes. In this paper it is shown ...how it works on the example of form factors of operators from stress-tensor operator supermultiplet in Grassmannian and spinor helicity representations.
Targeted delivery of anticancer drugs to brain tumors, especially glioblastoma multiforme, which is the most frequent and aggressive type, is one of the important objectives in nanomedicine. Vascular ...endothelial growth factor (VEGF) and its receptor type II (VEGFR2) are promising targets because they are overexpressed by not only core tumor cells but also by migrated glioma cells, which are responsible for resistance and rapid progression of brain tumors. The purpose of the present study was to develop the liposomal drug delivery system combining enhanced loading capacity of cisplatin and high binding affinity to glioma cells. This was achieved by using of highly soluble cisplatin analogue, cis-diamminedinitratoplatinum(II), and antibodies against the native form of VEGF or VEGFR2 conjugated to liposome surface. The developed drug delivery system revealed sustained drug release profile, high affinity to antigens, and increased uptake by glioma C6 and U-87 MG cells. Pharmacokinetic study on glioma C6-bearing rats revealed prolonged blood circulation time of the liposomal formulation. The above features enabled the present drug delivery system to overcome both poor pharmacokinetics typical for platinum formulations and low loading capacity typical for conventional liposomal cisplatin formulations.
Display omitted
► We used ICP-MS with microwave digestion for determination of REE in different rocks. ► Syenites, granodiorites and albitized granites are not digested in the MW at 210
°C. ► We ...explain this fact by the presence of stable saturated silicate–albite NaAlSi
3O
8. ► These rocks can be digested completely only by fusion with lithium metaborate.
Different methods of rock sample digestion for final analysis by ICP-MS technique are investigated. It is shown that only basic rocks can be quantitatively digested in a microwave (MW) field with the mixture of HF and HNO
3 acids at 210
°C for 60
min. The addition of HCl and H
3BO
3 provides complete digestion of andesites and some types of granites. Even at maximal temperature in the used MW oven of 210
°C syenites, granodiorites and albitized granites are not digested. These types of rocks are not digested in a closed Teflon autoclave for 16
h and can be digested only by fusion with lithium metaborate. The reason for such behavior is discussed. To avoid problems with the introduction of heavily acidic solutions after fusion in ICP the solutions were diluted. To compensate the loss of sensitivity due to the dilution step the REEs (Rare Earth Elements) pre-concentration using aminocarboxylic Pol-DETATA (diethyltriaminetetraacetate) sorbent was tested. The developed scheme is validated by the analysis of a wide range of reference rock materials.
The article describes the status of development of codes of new generation for the “PRORYV” Project by the end of 2019: twenty-five commercial-grade software products to justify design solutions and ...safety of power units with fast neutron reactors and liquid metal coolant (sodium and lead) in a closed nuclear fuel cycle. The developed system of codes is multi-physical and multi-scale that allows performing both calculations of the whole installations and high precision calculations of their individual elements. The developed codes offer unique features. Twelve developed codes have already been certified by Rostechnadzor, and six more have been submitted for certification. In addition to creating the software products, a large-scale work is being carried out to conduct experimental studies for code validation that meet modern requirements imposed by the codes: unique measurement techniques have been created; experimental data on flow characteristics of heavy liquid metal coolant (HLMC) in a fuel assembly simulator have been obtained, as well as of “gas-HLMC” interphase interaction after inert gas injection in HLMC and characteristics of heat exchange between the inert gas and HLMC. The results are already used for validation of system and CFD codes used in the “PRORYV” Project.
The reversible sorption preconcentration of noble metals (NMs) prior to their determination by inductively coupled plasma–mass spectrometry (ICP-MS) was investigated. Six new hypercrosslinked ...polystyrene sorbents were tested. The dependence of the degree of NMs sorption on the average degree of polymer network crosslinking and pore diameters was investigated. It was found that sorbents HP-100/6, HP-300/6 and HP-500/6 have low efficiency of NMs chlorocomplexes extraction. Among Stirosorb sorbents (Stirosorb-2, Stirosorb-514 and Stirosorb-584) the highest efficiency of the extraction of NMs’ chlorocomplexes has Stirosorb-514. Tributylamine (TBA), N-methylbenzylamine (MBA), N,N-dimethylbenzylamine (DMBA), N,N-dibenzylmetylamine (DBMA) were studied as the reagents for extraction of Ru, Rh, Pd, Ir, Pt and Au chlorocomplexes from hydrochloric acid solutions in the form of ion associates by reversed-phase mechanism. The reversible quantitative extraction of Ru, Pd, Pt and Au in system Stirosorb-514 – TBA – 1M HCl in ethanol as eluent was achieved. It was found that resulting eluates do not contain matrix components which may cause spectral interferences on the stage of NMs determination by ICP-MS. The found scheme of NMs reversible sorption was validated by the analysis of certified reference materials of basic and ultrabasic rocks GPt-5, GPt-6 and SARM-7. Good agreement between the measured NMs concentrations and the certified values was demonstrated. The achieved limits of detection for Ru, Pd, Pt and Au vary within 10−8–10−7wt% range.
Display omitted
•Six HP and Stirosorb sorbents for NMs' preconcentration were used for the first time.•Degree of polymer network crosslinking plays a critical role in the sorption efficiency.•The conditions of reversible extraction of Ru, Pd, Pt, Au on Stirosorb-514 were found.•The interferences from Cu and Ni in ICP-MS analysis of NMs are insignificant.
Tunable diode laser absorption spectroscopy (TDLAS) has become a proven method of rapid gas diagnostics. In the present review an overview of the state of the art of TDL-based sensors and their ...applications for measurements of temperature, pressure, and species concentrations of gas components in harsh environments is given. In particular, the contemporary tunable diode laser systems, various methods of absorption detection (direct absorption measurements, wavelength modulation based phase sensitive detection), and relevant algorithms for data processing that improve accuracy and accelerate the diagnostics cycle are discussed in detail. The paper demonstrates how the recent developments of these methods and algorithms made it possible to extend the functionality of TDLAS in the tomographic imaging of combustion processes. Some prominent examples of applications of TDL-based sensors in a wide range of practical combustion aggregates, including scramjet engines and facilities, internal combustion engines, pulse detonation combustors, and coal gasifiers, are given in the final part of the review.
•Overview of modern TDL-based sensors for combustion•TDL systems, methods of absorption detection and algorithms of data processing•Prominent examples of TDLAS diagnostics of the combustion facilities•Extension of the TDLAS on the tomographic imaging of combustion processes
A scheme of determination of As, Bi, Hg, Sb, Se and Te with photochemical generation of their volatile derivatives and inductively coupled plasma mass spectrometry (ICP-MS) detection was developed. ...The volatile compounds were produced using a novel photochemical reactor with direct contact of a sample with an ultraviolet (UV) lamp. Essential experimental parameters such as the concentrations of the reagents and the flow rates of the carrier gas and the sample were optimized. For each element, individual optimum values of these parameters were obtained. The detection limits in the optimal single element modes for As, Bi, Hg, Sb, Se and Te were 0.5, 13, 0.6, 0.3, 0.4 and 0.7 ng L−1 respectively. Compromise conditions were determined for simultaneous multielement analysis. The increase of the detection limit for each element in the multielement mode was experimentally estimated. The applicability of the proposed scheme was demonstrated by analysis of certified reference samples of water and fish muscle. Acceptable accuracy of determination of As, Se, Sb, Te and Hg in samples of local lake water was proved by spike recovery test. Possible matrix effects were screened using Placket-Berman design and further examined in detail.
Display omitted
•New photochemical vapor generator increased sensitivity of ICP-MS measurements.•The conditions of photochemical vapor generation differ for As, Bi, Hg, Sb, Se and Te.•Compromise conditions can be chosen for multielement ICP-MS determination of elements.
PDF
