Tetracyclic nitrile
19a and ester
19b, exhibiting the ABC core of cephalotaxine
1a, were prepared through KH-induced cyclization of thioimides
14a and
14b, respectively. This new ring-closure ...methodology proved to be particularly efficient: thus nitrile
19a was obtained in only 7 steps with a 17 % overall yield from commercially available, inexpensive safrole
2.
Construction of the ABC core of cephalotaxine, starting from safrole. An efficient ring-closure of thioimides.
We report a case of a 57-yr-old woman with a complaint of dysphagia of 2-wk duration. She had rheumatoid arthritis and had been taking 10 mg of prednisone and 2 mg of lorazepam daily for 2 yr. ...Radiologic examination showed partial retention of barium sulfate in the pharynx, which was confirmed by scintigraphic examination of the oral and pharyngeal phases of swallowing. This retention was about 47% of the volume swallowed. The benzodiazepine was withdrawn, and 2 wk later she had no symptoms. We repeated the scintigraphic study, and it showed no retention. We conclude that chronic ingestion of benzodiazepine may cause dysphagia.
Two-dimensional (2D) materials occupy noteworthy place in nanophotonics providing for subwavelength light confinement and optical phenomena dissimilar to those of their bulk counterparts. In the ...mid-infrared, graphene-based heterostructures and van der Waals crystals of hexagonal boron nitride (hBN) overwhelmingly concentrate the attention by exhibiting real-space nano-optics from plasmons, phonon-polaritons and hybrid plasmon phonon-polaritons quasiparticles. Here we present the mid-infrared nanophotonics of talc, a natural atomically flat layered material, and graphene-talc (G-talc) heterostructures using broadband synchrotron infrared nano-spectroscopy. We achieve wavelength tuning of the talc resonances, assigned to in- and out-of-plane vibrations by changing the thickness of the crystals, which serves as its infrared fingerprints. Moreover, we encounter coupling of the graphene plasmons polaritons with surface optical phonons of talc. As in the case of the G-hBN heterostructures, this coupling configures hybrid surface plasmon phonon-polariton modes causing 30 % increase in intensity for the out-of-plane mode, blue-shift for the in-plane mode and we have succeeded in altering the amplitude of such hybridization by varying the gate voltage. Therefore, our results promote talc and G-talc heterostructures as appealing materials for nanophotonics, like hBN and G-hBN, with potential applications for controllably manipulating infrared electromagnetic radiation at the subdiffraction scale.
Forty-five patients with systemic lupus erythematosus (SLE) underwent a cross-sectional study to evaluate intestinal secretory immunity. Peroral jejunal biopsy with histologic and immunohistochemical ...assessment of the mucosa were carried out in the patients and in 12 healthy volunteers. It was observed that an altered pattern of immunoglobulin-bearing plasma cells distributed in the lamina propria and complementary components were invariably present, mainly in the patients with active disease. The basement membrane of the intestinal crypt epithelium exhibited immunoglobulin and complementary deposits, similar to the lupus band test. None of the immunologic findings correlated with the medical treatment and with the peripheral blood analysis. The local changes in humoral immunity in patients with SLE did not correlate with gastrointestinal symptoms and may reflect the systemic effects of the disease.
In cellular networks, communication among mobile devices is accomplished through base stations (fixed antennas). A base station allocates communication channels whenever a mobile device (a cell ...phone, for example) in its coverage area requests communication with some other device (mobile or fixed). With the rapidly growing number of mobile devices, the use of communication channels available in cellular networks needs to be optimized. To efficiently optimize the use of communication channels in cellular networks dynamic (on-the-fly) channel allocation may be used, using algorithms for that purpose; however such algorithms demand previous knowledge of the number of mobile devices in the area of coverage of a given base station. In this paper, we propose a strategy to support dynamic channel allocation in cellular networks by predicting the number of mobile devices in the area covered by a base station at any given moment. The proposed strategy is based on an indexing mechanism for mobile objects. The results obtained through experiments prove the efficiency of the proposed strategy
To report the case of a woman with a diagnosis of grade II (low grade) parosteal osteosarcoma with the occurrence of myocardial metastasis 13 years after resection, and to present a review of the ...existing literature on the subject.
Description of the case and review of the literature.
The review leads to the conclusion that the occurrence of metastasis from parosteal osteosarcoma can occur in up to 38% of the cases, in spite of its relatively low aggressiveness. However, myocardial metastasis of a parosteal osteosarcoma is an event that was not found in the literature.
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