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21.
Abstract

The title compounds (4b-d) together with the benzothiazolines (5b-d) have been obtained by a reaction between 2,2′-dithiodianiline (1) and β-keto esters (2b-d). The reaction between 1 and the β-keto ester 2a gives 1,4-benzothiazine 3a in addition to the benzothiazoline 5a.

It has been established that the 1,4-benzothaizines 4b-d undergo an acid-catalysed thermal rearrangement involving a [1,3] shift of the sulfur atom, giving rise to the isomeric 1,4-benzothiazines 3b-d.  相似文献   
22.
Highlights? IL-17 is involved in many inflammatory diseases ? Directed evolution of IL-17A receptor results in improved IL-17A affinity ? The engineered receptors efficiently inhibit IL-17A induced cytokine secretion ? Engineered receptor promotes the recovery of psoriasis plaques in mouse model  相似文献   
23.
The cholecystokinin-2 receptor (CCK-2R) is overexpressed in several human cancers but displays limited expression in normal tissues. For this reason, it is a suitable target for developing specific radiotracers. In this study, a nastorazepide-based ligand functionalized with a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelator (IP-001) was synthesized and labelled with indium-111. The radiolabeling process yielded >95% with a molar activity of 10 MBq/nmol and a radiochemical purity of >98%. Stability studies have shown a remarkable resistance to degradation (>93%) within 120 h of incubation in human blood. The in vitro uptake of [111In]In-IP-001 was assessed for up to 24 h on a high CCK-2R-expressing tumor cell line (A549) showing maximal accumulation after 4 h of incubation. Biodistribution and single photon emission tomography (SPECT)/CT imaging were evaluated on BALB/c nude mice bearing A549 xenograft tumors. Implanted tumors could be clearly visualized after only 4 h post injection (2.36 ± 0.26% ID/cc), although a high amount of radiotracer was also found in the liver, kidneys, and spleen (8.25 ± 2.21%, 6.99 ± 0.97%, and 3.88 ± 0.36% ID/cc, respectively). Clearance was slow by both hepatobiliary and renal excretion. Tumor retention persisted for up to 24 h, with the tumor to organs ratio increasing over-time and ending with a tumor uptake (1.52 ± 0.71% ID/cc) comparable to liver and kidneys.  相似文献   
24.
Melissopalynology, antioxidant capacity and mineral and toxic element contents were analyzed in eight types of Hungarian honeys. Based on color, two groups were distinguished: light honeys comprised acacia, amorpha, phacelia and linden honeys; while dark honeys included sunflower, chestnut, fennel and sage honeys, with 100 to 300 and 700 to 1500 mAU, respectively. The unifloral origin of each sample was supported using pollen analysis. The absorbance of honey correlated positively with antioxidant capacity determined by three different methods (TRC, DPPH, ORAC), and also with mineral content. The exception was the light amber linden honey with significantly higher K content and antiradical activity than other light honeys. The Mn, Zn and Fe contents were the highest in chestnut, sunflower and fennel honeys, respectively. The black meadow sage honey performed best regarding the content of other elements and antioxidant activity. The concentrations of several toxic elements were below the detection limit in the samples, indicating their good quality. The principal component analysis (PCA) revealed correlations between different antioxidant assays and minerals, and furthermore, confirmed the botanical authentication of the honeys based on the studied parameters. To our best knowledge, the present study is the first to provide a complex analysis of quality parameters of eight unifloral Hungarian honeys.  相似文献   
25.
The tetrahedral, shape‐persistent molecule 1 4+, containing four pyridylpyridinium units connected through a central carbon atom, exhibits unexpected photophysical properties including a substantially redshifted absorption (2350 cm?1) and a very strong fluorescence (Φem=40 %), compared with the monomer 2 + (Φem=0.4 %). Density functional theory calculations on the structure and spectroscopic properties of 1 4+ and 2 + show that exciton interactions, homoconjugation, and orbital nature account for the observed differences in their photophysical properties. The protonated tetramer binds four cucurbit[7]uril molecules and the host/guest interactions can be controlled by chemical (acid/base) as well as redox stimuli.  相似文献   
26.
In this study, imidacloprid, a systemic insecticide, currently having a specified European Commission MRL value for vine leaves (2 mg kg−1), was applied on a Lebanese vineyard under different commercial formulations: as a soluble liquid (SL) and water dispersible granules (WDG). In Lebanon, many commercial formulations of imidacloprid are subject to the same critical good agricultural practice (cGAP). It was, therefore, important to verify the variability in dissipation patterns according to matrix nature and formulation type. Random samplings of grapes and vine leaves were performed starting at 2 days until 18 days after treatment. Residue extractions were performed according to the QuEChERS method and the analytical determination using liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS). The SL formulation yielded significantly higher initial deposit than the WDG formulation on grapes and vine leaves. The formulation type did not significantly affect the dissipation rates; the estimated half-lives in grapes and vine leaves were 0.5 days for all imidacloprid formulations. No pre-harvest intervals were necessary on grapes. PHIs of 3.7 days for the SL formulation and 2.8 days for the WDG formulation were estimated on vine leaves. The results showed that the type of formulation and the morphological and physiological characteristics of the matrix had an effect on the initial deposits, and thus residue levels, but not on the dissipation patterns.  相似文献   
27.
28.
Six different racemates of the profen family were used as analytes in order to test the chiral selector properties of three members of a new class of cyclodextrin derivatives, hemispherodextrins (HMs), in capillary electrophoresis. In addition to experiments carried out to separate each enantiomeric pair one by one, other experiments were carried out on samples containing all six enantiomeric pairs. Electropherograms were obtained either by adding a single HM to the background electrolyte (BGE), or a binary mixture of HMs. The results obtained confirm the excellent chiral selector properties of the HMs, and furthermore show that these compounds can also be used for achiral selection. When mixing different HMs, a complementary effect in chiral selectivity is observed, which, in our opinion, deserves further study.  相似文献   
29.

Background  

The polysialylated neuronal cell adhesion molecule (PSA-NCAM) is considered a marker of developing and migrating neurons and of synaptogenesis in the immature vertebrate nervous system. However, it persists in the mature normal brain in some regions which retain a capability for morphofunctional reorganization throughout life. With the aim of providing information relevant to the potential for dynamic changes of specific neuronal populations in man, this study analyses the immunohistochemical occurrence of PSA-NCAM in the human trigeminal ganglion (TG) and brainstem neuronal populations at prenatal and adult age.  相似文献   
30.
The reaction between 2-aminothiophenol 1 and acetylenic nitriles or esters 2a-d leads to the vinyl thio-ethers 3a-d. The conversion of 3 into benzothiazoles 8 and/or 1,4-benzothiazines 9 , in boiling dimethyl sulfoxide, has been achieved. A possible pathway involving benzothiazolines 5 as key intermediates is suggested.  相似文献   
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