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41.
Julia N. Yakovleva Anna I. Lobanova Olga A. Panchenko Sergei A. Eremin 《International journal of environmental analytical chemistry》2013,93(11-12):851-863
Specific polyclonal antibodies towards acetochlor (2-chloro- N -(ethoxymethyl)- N -(2-ethyl-6-methylphenyl)acetamide) were obtained from rabbits immunized against a 3-mercaptopropionic acid derivative of acetochlor, covalently attached to bovine serum albumin. A polarization fluoroimmuoassay (PFIA) based on these antibodies was developed and optimized to detect acetochlor in water samples. The optimized PFIA had a detection limit of 9 µg/L, linear working range from 50 to 5500 µg/L and within-assay coefficient of variation less than 4%. Cross-reactivity studies demonstrated that these antibodies are capable of specific detection of acetochlor amongst structurally related chloroacetanilide herbicides. Assay cross-reactivity values were: alachlor 0%, metolachlor 2.4%, propachlor 0%, butachlor 0.2% and dimethachlor 0.5%. Five organic solvents commonly used in sample extraction were evaluated for their effect on acetochlor PFIA performance, and methanol and ethanol were found to be compatible with the assay up to 10% v/v. 相似文献
42.
Julia Woch Edyta Maachowska Kamil Korasiak Aneta Lipkiewicz Marcin Dubowik Justyna Chrobak Jolanta Iowska Piotr Przybysz 《Molecules (Basel, Switzerland)》2022,27(3)
Petroleum, synthetic, and natural waxes have been used as hydrophobic bases for dispersions intended for use as barrier coatings for packaging paper. Oil-in-water dispersions with alkaline pH were prepared by a two-step homogenization procedure containing paraffin wax, with various characteristics, the Fischer–Tropsch synthesis product or beeswax. The size of the dispersed particles determined by dynamic light scattering depended on the type of hydrophobic base used and was in the range of 350–440 nm. The ability of dispersion particles in aggregation driven by electrostatic attraction, evaluated by Zeta potential analysis by electrophoretic light scattering, was from −26 to −50 mV. Static multiply light scattering was used for 30 days of stability assessment and helped to select the dispersion with a Sarawax SX70 wax base as the most stable. Dispersions were further used for coating the backing of kraft paper by the Meyer rod method. Coated paper with an applied coating of 6 g/m2 had very good hydrophobic properties (Cobb60 < 4 g/m2), sufficient strength properties, and air permeation, which enabled its application as a packaging material. The dispersions based on Sarawax SX70 wax were evaluated as the best coating for Mondi ProVantage Kraftliner 125 g/m2 backing paper. Good hydrophobic properties and strength properties indicate the possibility of using the SX70-based wax dispersion coating as a replacement for PFAS coatings in some applications. 相似文献
43.
Margaux Fresnais Seda Karabulut Yasmin Abou Zeed Johannes Ungermann Julia Benzel Kristian W. Pajtler Stefan M. Pfister Walter E. Haefeli Jürgen Burhenne Rmi Longuespe 《Molecules (Basel, Switzerland)》2022,27(3)
Desorption/ionization mass spectrometry (DI-MS) approaches allow for the rapid quantification of drugs in biological matrices using assays that can be validated according to regulatory guidelines. However, specific adaptations must be applied to create reliable quantification methods, depending on the approach and instrumentation used. In the present article, we demonstrate the importance of the molecular weight, the fragmentation pattern, and the purity of the internal standard for the development of matrix-assisted laser desorption/ionization (MALDI)-ion mobility (IM)-tandem MS and MS/MS methods. We present preliminary results of method development for the quantification of selinexor in microdialysis fluids with a stable isotopically labeled internal standard. In addition, we discuss the selection of internal standards for MALDI-MS assays using different instrumentations. 相似文献
44.
Apoptolidin is a natural product that selectively induces apoptosis in several cancer cell lines. Apoptosis, programmed cell death, is a biological key pathway for regulating homeostasis and morphogenesis. Apoptotic misregulations are connected with several diseases, in particular cancer. The extrinsic way to apoptosis leads through death ligands and death receptors to the activiation of the caspase cascade, which results in proteolytic degradation of the cell architecture. The intrinsic pathway transmits signals of internal cellular damage to the mitochondrion, which loses its structural integrity, and forms an apoptosome that initiates the caspase cascade. Compounds which regulate apoptosis are of high medical significance. Many natural products regulate apoptotic pathways, and apoptolidin is one of them. The known synthetic routes to apoptolidin are described and compared in this Review. Selected further natural products which regulate apoptosis are introduced briefly. 相似文献
45.
Julia J. Chang Andrew Martin Chuanshen Du Alana M. Pauls Martin Thuo 《Angewandte Chemie (International ed. in English)》2020,59(38):16346-16351
Fabrication of bio‐templated metallic structures is limited by differences in properties, processing conditions, packing, and material state(s). Herein, by using undercooled metal particles, differences in modulus and processing temperatures can be overcome. Adoption of autonomous processes such as self‐filtration, capillary pressure, and evaporative concentration leads to enhanced packing, stabilization (jamming) and point sintering with phase change to create solid metal replicas of complex bio‐based features. Differentiation of subtle differences between cultivars of the rose flower with reproduction over large areas shows that this biomimetic metal patterning (BIOMAP) is a versatile method to replicate biological features either as positive or negative reliefs irrespective of the substrate. Using rose petal patterns, we illustrate the versatility of bio‐templated mapping with undercooled metal particles at ambient conditions, and with unprecedented efficiency for metal structures. 相似文献
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48.
Magnus Pauly Julia Krger Viola Duppel Corban Murphey James Cahoon Bettina V. Lotsch Paul A. Maggard 《Chemical science》2022,13(11):3187
The in-depth understanding of the reported photoelectrochemical properties of the layered carbon nitride, poly(triazine imide)/LiCl (PTI/LiCl), has been limited by the apparent disorder of the Li/H atoms within its framework. To understand and resolve the current structural ambiguities, an optimized one-step flux synthesis (470 °C, 36 h, LiCl/KCl flux) was used to prepare PTI/LiCl and deuterated-PTI/LiCl in high purity. Its structure was characterized by a combination of neutron/X-ray diffraction and transmission electron microscopy. The range of possible Li/H atomic configurations was enumerated for the first time and, combined with total energy calculations, reveals a more complex energetic landscape than previously considered. Experimental data were fitted against all possible structural models, exhibiting the most consistency with a new orthorhombic model (Sp. Grp. Ama2) that also has the lowest total energy. In addition, a new Cu(i)-containing PTI (PTI/CuCl) was prepared with the more strongly scattering Cu(i) cations in place of Li, and most closely matching with the partially-disorder structure in Cmc21. Thus, a complex configurational landscape of PTI is revealed to consist of a number of ordered crystalline structures that are new potential synthetic targets, such as with the use of metal-exchange reactions.The layered carbon nitride, poly(triazine imide), exhibits a complex configurational landscape for the coordination of cations within its intralayer cavities that has been elucidated for the first time. 相似文献
49.
Julia Lindberg Peter Saetre Seiji Nishino Emmanuel Mignot Elena Jazin 《BMC neuroscience》2007,8(1):34
Background
Narcolepsy causes dramatic behavioral alterations in both humans and dogs, with excessive sleepiness and cataplexy triggered by emotional stimuli. Deficiencies in the hypocretin system are well established as the origin of the condition; both from studies in humans who lack the hypocretin ligand (HCRT) and in dogs with a mutation in hypocretin receptor 2 (HCRTR2). However, little is known about molecular alterations downstream of the hypocretin signals. 相似文献50.
Julia Leitl Dr. Andrew R. Jupp Dr. Evi R. M. Habraken Verena Streitferdt Dr. Peter Coburger Dr. Daniel J. Scott Prof. Dr. Ruth M. Gschwind Prof. Dr. Christian Müller Dr. J. Chris Slootweg Prof. Dr. Robert Wolf 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(35):7788-7800
Salt metathesis of 1-methyl-2,4,6-triphenylphosphacyclohexadienyl lithium and chlorobis(pentafluorophenyl)borane affords a 1-phospha-7-bora-norbornadiene derivative 2 . The C≡N triple bonds of nitriles insert into the P−B bond of 2 with concomitant C−B bond cleavage, whereas the C≡C bonds of phenylacetylenes react with 2 to form λ4-phosphabarrelenes. Even though 2 must formally be regarded as a classical Lewis adduct, the C≡N and C≡C activation processes observed (and the mild conditions under which they occur) are reminiscent of the reactivity of frustrated Lewis pairs. Indeed, NMR and computational studies give insight into the mechanism of the reactions and reveal the labile nature of the phosphorus–boron bond in 2 , which is also suggested by detailed NMR spectroscopic studies on this compound. Nitrile insertion is thus preceded by ring opening of the bicycle of 2 through P−B bond splitting with a low energy barrier. By contrast, the reaction with alkynes involves formation of a reactive zwitterionic methylphosphininium borate intermediate, which readily undergoes alkyne 1,4-addition. 相似文献