DIPOLE-DIPOLE OPERATOR IN ANGULAR MOMENTUM BASIS: A COMPLEMENTARY STUDY IN NUCLEARMAGNETICRESONANCE. The relationship between the magnetic dipole-dipole potential energy function and its quantum analogue is presented in this work. It is assumed the reader is familiar with the classical expression of the dipolar interaction and has basic knowledge of the quantum mechanics of angular momentum. Except for these two points only elementary steps are involved.
Methodology/Principal Findings: Rats were randomized into five groups (n = 7 each group). Propofol and isoflurane were administered to two groups each, for 2 or 6 h. The control group received no anesthesia. Brains were removed directly after anesthesia. Hydrophilic compounds were extracted from excised whole brains and measured by proton nuclearmagneticresonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of the metabolite profiles. Data were visualized by plotting principal component (PC) scores. In the plots, each point represents an individual sample. The propofol and isoflurane groups were clustered separately on the plots, and this separation was especially pronounced when comparing the 6-h groups. The PC scores of the propofol group were clearly distinct from those of the control group, particularly in the 6-h group, whereas the difference in PC scores was more subtle in the isoflurane group and control groups.
NUCLEARMAGNETICRESONANCE. The literature carries many theories about the mechanism of action of local anesthetics (LA). We can highlight those focusing the direct effect of LA on the sodium channel protein and the ones that consider the interaction of anesthetic molecules with the lipid membrane phase. The interaction between local anesthetics and human erythrocyte membranes has been studied by 1 H and 31 P nuclearmagneticresonance spectroscopy. It was found that lidocaine (LDC) and
mais aumentadas devido ao efeito NOE (“Nuclear Overhauser Enhancement”). Como este aumento é proporcional ao número de hidrogênios ligados diretamente, os diferentes carbonos da molé- cula sofrerão diferentes variações de intensidade em virtude do NOE. Outra contribuição importante para esta distorção surge dos diferentes tempos de relaxação apresentados pelos diferentes car- bonos na molécula, levando à perda de intensidade durante o expe- rimento devido à saturação. Estas são as principais fontes de distorções que impedem a integração de espectros de RMN de 13 C
etc, sofrem este fenômeno. Um spin nuclear se comporta como um dipolo magnético, que tende a se alinhar ao campo magné- tico aplicado. O magnetismo de um núcleo é descrito em ter- mos de sua constante giromagnética γ, que é proporcional à razão entre o momento magnético nuclear µ e o momento an- gular de spin nuclear I 2 :
Carbonaceous pitches are used as raw materials in advanced carbon products. This work aims at combining solvent extraction methodology with low field nuclearmagneticresonance relaxometry technique in order to characterize heated-treated samples of petroleum pitches. The T 1 relaxation times showed two distinct domains: one was referring to the aromatic region and the other one was attributed to mesophase. The results also evidenced that the 1 H NMR
By different solvent extractions and chromatographic techniques an antibacterial constituent was isolated from leaves of Cassia alata Linn. Infra red spectroscopy, mass spectroscopy and nuclearmagneticresonance studies showed that the isolated compound was chemically 3,4 dihydroxy cinnamic acid. In vitro antibacterial activity of 3,4 dihydroxy cinnamic acid was studied against four Gram-positive and four Gram-negative bacteria using disc diffusion method. Minimum inhibitory concentration (MIC) of 3,4 dihydroxy cinnamic acid was also recorded against those bacteria by serial dilution technique. Kanamycin was used as positive control. Results showed that 3,4 dihydroxy cinnamic acid had antibacterial activity against the tested bacteria.
The goal of the present study was to determine the potential use of thermal analysis for the measurement of the light crude oil (LCO) content of standard biodiesel mixtures. Standard samples of biodiesel/LCO blends were prepared with different ratios of biodiesel; LCO: 1:0 (biodiesel only), 1:3, 1:1, 3:1, 0:1 (LCO only). Thermogravimetry (TG) and differential scanning calorimetry were used to determine the usefulness of thermal analysis for quantification of the LCO in the mixtures. Proton nuclearmagneticresonance ( 1 H NMR) spectroscopy was also used to confirm the composition of the samples. It was found that thermogravimetric curves were
X-ray and computerized axial tomography of the cervi- cal spine showed lytic lesions between C2 and C3. The nuclearmagneticresonance imaging (NMR) showed signs suggestive of spondylodiscitis in C2-C3 associated with the presence of a massive epidural abscess compressing the ventral surface of the spinal cord, as well as involvement of paravertebral and prevertebral soft tissues (Figure 1). Bone scintigraphy ruled out an expansive tumor process and conirmed the NMR indings.
in spite of their great utility in compatibility studies, are still under used in pharmaceutical tests, like solid state nuclearmagneticresonance (ssNMR) and a special technique of thermal analysis called thermo-optical analysis (TOA). Therefore, solid state nuclearmagneticresonance, Fourier- transformed infrared spectroscopy, differential scanning
Three of the isolated metabolites are previously unreported azaphilones and were named mycoleptones A, B, and C (2, 4, and 5). Mycoleptone A (2) was isolated as a yellow powder, and the complete structural characterization was carried out by nuclearmagneticresonance (NMR) spectroscopy, high- resolution mass spectrometry (HRMS), electronic circular dichroism (ECD) spectroscopy, time-dependent density func- tional theory (TD-DFT) calculations, and single-crystal X-ray diﬀraction studies (Figure 2). The UV spectrum of 2 displays maximum absorptions at 254 nm (log ε 2.90) and 361 nm (log ε 2.83), revealing the presence of an extended conjugated system, characteristic of azaphilones. Compound 2 displays similar 1 H and 13 C NMR spectra to austdiol, 8,9 with the
A phytochemical investigation of the roots of Krameria tomentosa A. St.-Hil. led to the isolation of five neolignans, two of them with novel structures [1,1’-(E)-propenyl-4-methoxy- 3,4’-oxyneolignan (ottomentosa) and 2-(2’-hydroxy-4’,6’-dimethoxyphenyl)benzofuran- 5-carboxylic acid (sobraline)] and three known compounds [eupomatenoid 6, dihydrocarinatidin and 2-(2’,4’-dihydroxyphenyl)-5-(E)-propenylbenzofuran]. The structural characterization of the compounds isolated was established based on infrared spectroscopy, mass spectrometry, one- and two-dimensional nuclearmagneticresonance, along with comparison with spectral data described in the literature.
parity (oddness or evenness) of a given cyclic permutation. A classical algorithm requires two que- ries to the black-box. We show that a quantum algorithm can solve the problem with a single query. Even though the problem that the algorithm solves is not crucial, the algorithm is interesting in that it makes use of a single qudit, which means that neither entanglement nor any other correlation plays a role. Moreover, we present an experimental demonstration of this algorithm using a room temperature nuclearmagneticresonance (NMR) quadrupolar setup.
Abstract. The main purpose of this article is to review the theoretical prerequisites of nuclearmagneticresonance (NMR) application in tasks of search and exploration of hy- drocarbon deposits. The identification peculiarities of hydro- carbon deposits in a weak magnetic field of the Earth were analysed. The necessity of using highly directional antennas for providing greater sounding depths as well as the use of absorption spectra of the sought-for minerals as sounding signals were identified and justified. A variant of practical implementation of such a system was examined and exam- ples of practical application of the innovative NMR technol- ogy were provided.
A furanoditerpene-enriched fraction was obtained from the fruits of Pterodon emarginatus and submitted to semipreparative high performance liquid chromatography (HPLC). Two new furanoditerpenes, 6α,19β-diacetoxy-7β,14β-dihydroxyvouacapan and 6α-acetoxy- 7β,14β-dihydroxyvouacapan, in addition to the known compound methyl 6α-acetoxy- 7β-hydroxyvouacapan-17β-oate were obtained. Compound structures were determined by 1D and 2D nuclearmagneticresonance (NMR) experiments and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). The major compound methyl 6α-acetoxy-7β-hydroxyvouacapan-17β-oate was evaluated against promastigote forms of Leishmania amazonensis and L. braziliensis, presenting the concentration which causes lysis on 50% of parasites IC 50 < 30 µg mL -1 .