Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 11
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Analytical chemistry 31 (1959), S. 1084-1086 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Analytical chemistry 31 (1959), S. 176-178 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Analytical chemistry 49 (1977), S. 508-510 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Analytical chemistry 20 (1948), S. 547-555 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 9844-9854 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: In switched-angle spinning spectroscopy (SAS) a sample is spun about different angles, β, relative to the magnetic field, during various periods of the experiment. In the present work, SAS is combined with two-dimensional exchange spectroscopy in order to correlate carbon-13 chemical shift tensors of the carbonyl (1) and hydroxyl (2) carbons of tropolone. Experiments were performed on a sample enriched to 25 at. % in each of these sites (at different molecules). At this level of enrichment the dominant exchange mechanism between the two sites involves spin diffusion. The experiment consists of a preparation period during which the sample spins at the magic angle and the magnetization of one of the sites is quenched by means of a selective pulse sequence. During the rest of the experiment the sample spins with its axis away from the magic angle except for a short period just before the detection where the axis is switched to the magic angle in order to select the magnetization to be detected. Experiments were performed for all four possible combinations of the initial and final magnetizations, thus providing chemical shift correlations between carbons 1,1′, 2, and 2′ in the two magnetically inequivalent (but symmetry related) molecules in the unit cell. Combining these results with the known crystal structure of tropolone (neglecting a small tilt between the perpendicular to the molecular plane and the crystallographic c-axis) provides information on the orientation and magnitude of the chemical shift tensors of the two types of carbons. The principal values (in ppm) are σ1xx=65, σ1yy=33, σ1zz=−98, σ2xx=77, σ2yy=17, and σ2zz=−94. Assuming σzz to be perpendicular to the molecular plane, the orientations of the σyy's are 12° off the C1=0 bond (toward the hydroxyl carbon) for carbon 1 and 10° off the C3=C2 bond (away from the carbonyl carbon) for carbon 2. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 1852-1864 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Slow, large-amplitude chain motions play an important role in determining the macroscopic mechanical properties of polymers. Although such motions have been studied quantitatively by two-dimensional (2D) nuclear magnetic resonance (NMR) exchange experiments, overlapping anisotropic patterns hamper spectral analysis, and limit applications. Variable angle correlation spectroscopy (VACSY) has proven useful in resolving such problems for rapidly spinning samples by separating anisotropic spectral patterns according to isotropic chemical shifts. In a previous study [J. Am. Chem. Soc. 115, 4825 (1993)], we described a three-dimensional (3D) NMR experiment that incorporates the VACSY method and a hop of the rotor axis to correlate the isotropic chemical shifts to 2D anisotropic exchange patterns. The hop of the rotor axis, however, presents experimental difficulties and limits the range of motional rates that may be studied. We present in this paper a new 3D VACSY exchange experiment that obtains the same correlations without the need for the rotor axis hop. A series of 2D exchange spectra are recorded with the sample spinning at different rotation axis angles. Then using the scaling of the anisotropic frequency at the different angles, we construct the data onto a 3D matrix so that a Fourier transformation directly yields the desired correlations. The technique is applied to 13C exchange NMR to study the slow molecular motion of ordered isotactic polypropylene.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Pediatric anesthesia 5 (1995), S. 0 
    ISSN: 1460-9592
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Twenty ASA 1 children, one to six years old, weighing 10–20 kg, scheduled for a combination of general and caudal anaesthesia received at random midazolam 0.2, 0.4, or 0.6 mg·kg−1 or NaCl 0.9% (control group) intranasally. Drug or NaCl 0.9% were administered in one nostril, after inhalation induction of anaesthesia, intubation without relaxant and caudal anaesthesia. Spontaneous respiration was via a circle system and fresh gas flow of 61·min−1 (N2O/O2= 2:1), PEEP 5 cm H2O, endtidal halothane 0.4%.Immediately before and 2, 5, 8, 12, 16, 20, 30, 60 and 120 min after application of the drug 2.5 ml blood was sampled for plasma levels of midazolam. Endtidal CO2, respiratory rate, and oxygen saturation were recorded as long as the children were intubated. Endtidal CO2 and respiratory rate showed no statistical difference between the groups at any time, however, in the group receiving 0.6 mg·kg−1, -endtidal CO2 increased significantly from 5.3 kPa (41 mm Hg) at the start to 5.9 kPa (45.5 mm Hg) after 30 min. Plasma levels of midazolam were detected 2 min after application in 10 of 15 patients. Median peak levels were found between 12 and 16 min. Medians of peak plasma levels showed no statistical difference between the three groups (0.2 mg·kg−1:111 ng·ml−1, 0.4 mg·kg−1:136 ng·ml−1, 0.6 mg·kg−1:277 ng·ml−1). After 30, 60 and 120 min medians of midazolam plasma concentration were significantly higher in the group 0.6 mg·kg−1.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 99 (1995), S. 11989-11993 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Industrial and engineering chemistry 15 (1943), S. 91-95 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Industrial & engineering chemistry 28 (1936), S. 682-683 
    ISSN: 1520-5045
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...