1,346 research outputs found
3-(4-Chlorophenyl)-2-(diisopropylamino)-1-benzofuro[3,2-d]pyrimidin-4(3H)-one
In the molecule of the title compound, C22H22ClN3O2, the three fused rings of the benzofuro[3,2-d]pyrimidine system are almost coplanar. This ring system is oriented with respect to the substituted benzene ring at a dihedral angle of 79.05 (3)°. Intramolecular C—H⋯N hydrogen bonding results in the formation of a six-membered ring. In the crystal structure, π–π stacking interactions involving the furan, pyrimidinone and benzene rings are present [centroid-to-centroid distances in the range 3.258 (1)–3.870 (1) Å]
Determination of alpinetin glucuronidation activities in liver microsomes from different species using UFLC-ESI-MS
Alpinetin, a type of novel plant flavonoid derived from Alpinia katsumadai Hayata, has been demonstrated to exhibit multiple biochemical and pharmacological activities. The phenyl hydroxyl group existed in alpinetin is susceptible to the glucuronidation catalyzed by UDP-glucuronosyltransferase (UGT).
The aim of the present study is to develop a sensitive and specific ultra-fast liquid chromatography (UFLC)-mass spectrum (MS) method to determine the glucuronidation activity of alpinetin in the liver microsomes obtained from different species, including human liver microsomes (HLMs), rat liver microsomes (RLMs), mice liver microsomes (MLMs), and dog liver microsomes (DLMs). The alpinetin’s glucuronide was purified, and the structure was elucidated using 1H-NMR and 13C-NMR. The mass spectrometric detection was performed under selected ion monitoring (SIM) for alpinetin glucuronide at m/z 445 and 4-methylumbelliferyl-β-glucuronide (I.S.) at m/z 351. The assay exhibited linearity over the range 0.1- 60 μM for alpinetin glucuronide with the correlation coefficient of 0.9991. The intra- and inter-day precision was less than 5.3 %, with accuracy in the range 105.1-106.8 %. The developed method has been successfully applied to determine the glucuronidation of alpinetin, and the intrinsic clearance was calculated to be 2.51, 1.29, 0.23, and 1.27 mL/min/mg pro for HLM, RLM, MLM and DLM, respectively. The results obtained from this study are helpful to selection of animal models for pre-clinical pharmacokinetic study.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Rectal cancer patients with downstaging after neoadjuvant chemoradiotherapy and radical resection do not benefit from adjuvant chemotherapy
Background: Whether adjuvant chemotherapy is beneficial for rectal cancer patients who respond well to neoadjuvant chemoradiotherapy (NCRT) and undergo radical resection is controversial. This study aimed to assess the effect of adjuvant chemotherapy on the oncological outcomes of ypT0-2N0 rectal cancer patients after NCRT and radical resection, and identify the prognostic factors. Methods: The clinical and pathological data of rectal cancer patients with ypT0-2N0 who underwent NCRT and radical resection between January, 2010 and June, 2018 were collected and retrospectively analyzed. The oncological outcomes of the chemotherapy (chemo) group and the non-chemotherapy (non-chemo) group were compared. Multivariate analysis, using a Cox proportional hazard model, was performed to identify independent predictors of oncological outcome. Results: Of the 121 rectal cancer patients enrolled, 90 patients received postoperative adjuvant chemotherapy with no fewer than 3 cycles (the chemo group), and the other 31 patients with fewer than 3 cycles (the non-chemo group). There was no significant difference in the 5-year disease-free survival (DFS) or overall survival (OS) rates between the two groups (DFS: 79.1% vs. 82.9%, P=0.442; OS: 87.5% vs. 78.2%, P=0.667). cT4 is an independent risk factor for OS (HR =4.227, 95% CI: 1.128-15.838, P=0.02) and DFS (HR =4.878, 95% CI: 1.752-13.578). Preoperative consolidation chemotherapy with Capeox or FOLFOX after NCRT significantly improved the DFS rate (HR =0.212, 95% CI: 0.058-0.776, P=0.019). Conclusions: Rectal cancer patients with ypT0-2N0 who underwent NCRT and radical resection did not benefit significantly from postoperative adjuvant chemotherapy. For these patients, cT4 was an independent risk factor for OS and DFS. Preoperative consolidation chemotherapy with Capeox or FOLFOX after NCRT can significantly improve DFS
RbCa2Nb3O10 from X-ray powder data
Rubidium dicalcium triniobate(V), RbCa2Nb3O10, has been synthesized by solid-state reaction and its crystal structure refined from X-ray powder diffraction data using Rietveld analysis. The compound is a three-layer perovskite Dion–Jacobson phase with the perovskite-like slabs derived by termination of the three-dimensional CaNbO3 perovskite structure along the ab plane. The rubidium ions (4/mmm symmetry) are located in the interstitial space
EVALUATION OF THE ACUTE AND SUBCHRONIC TOXICITY OF Aster tataricus L. F.
Backgr ound: Aster tataricus L. f. is used as a traditional Chinese drug to relieve cough and asthma symptoms and to eliminate
phlegm. However, Aster tataricus L. f. possesses toxicity, and little systematic research has been conducted on its toxic effects in the
laboratory.
Methods and Materials: The acute group was administered 75% alcohol extract of Aster tataricus L. f. in a single dose. A
subchronic toxicity study was performed via daily oral administration of Aster tataricus L. f. at a dose of 0.34 g/kg body weight in
SD rats. The rats were divided into six groups: a petroleum ether extract (PEA) group, an ethyl acetate extract (EEA) group, an
n-butyl alcohol extract (NEA) group, a remaining lower aqueous phases (REA) group, a 75% alcohol extract (AEA) group and a
control group. Quantitative measurements of cytokines were obtained by fluorescence with a laser scanner using a Cy3 equivalent
dye.
Results: The LD50 of the 75% alcohol extract of Aster tataricus L. f. was 15.74 g/kg bw. In the subchronic toxicity study, no
significant differences were observed among groups in relative organ weights, urine traits, liver antioxidase levels, or cytokine levels.
However, significant sporadic differences were observed in body weight gains, haematology indices, biochemistry values, and
histopathology features in PEA, EEA group. In addition, sporadic changes in other groups in measures such as WBC, MCHC, CK,
ALP, AST, ALT, LDH, T-BIL, LDL-C, HDL-C, and TC were observed.
Conclusion: The toxicity study showed that Aster tataricus L. f. can produce toxic effects, mainly on the liver; much less on the
heart. The LD50 was 15.74 g/kg BW in mice, and the subchronic toxicity study, used a dosage of 0.34 g/kg/d.BW, showed that the
toxic components of Aster tataricus L. f. were mainly concentrated in the petroleum ether fraction, followed by the ethyl acetate
fraction, the n-butyl alcohol fraction, the lower aqueous phase and the 75% ethanol extracts
EMMNet: Sensor Networking for Electricity Meter Monitoring
Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters
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