A Novel Design of a Low Temperature Preamplifier for Pulsed NMR Experiments of Dilute 3He in Solid 4He

Huan, Chao; Kim, S. S.; Phelps, L.; Xia, J. S.; Candela, D.; Sullivan, N. S.

doi:10.1007/s10909-009-9984-x

Cited by 10 publications

(5 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In metabolomic analysis 1 H NMR has the advantage of having simple sample preparation, being fast, non-selective and a non-destructive technique, providing global information in a single analysis but also can allow structural characterisation (Gilard et al, 2010). New advances in instrumentation such as use of cryogenic probes (Kovacs et al, 2005;Kang et al, 2008), capillary probes (Hu et al, 2008) and preamplifier components (Huan et al, 2010) together with the use of one and two dimensional strategies enable the identification and quantification of multiple samples at molar concentrations in far shorter times (>15 min) (Lewis et al, 2007). However, despite these advances one main drawback with NMR is the limit of sensitivity when compared to techniques such as mass spectrometry (10 −9 and 10 −11 mol in comparison with 10 −19 ) (Pan and Raftery, 2007).…”

Section: Nmr For Fingerprinting and Metabolomicsmentioning

confidence: 99%

The potential of metabolic fingerprinting as a tool for the modernisation of TCM preparations

Sheridan

Krenn

Jiang

et al. 2012

Journal of Ethnopharmacology

View full text Add to dashboard Cite

A vast majority Chinese herbal medicines (CHM) are traditionally administered as individually prepared water decoctions (tang) which are rather complicated in practice and their dry extracts show technological problems that hamper straight production of more convenient application forms. Modernised extraction procedures may overcome these difficulties but there is lack of clinical evidence supporting their therapeutic equivalence to traditional decoctions and their quality can often not solely be attributed to the single marker compounds that are usually used for chemical extract optimisation. As demonstrated by the example of the rather simple traditional TCM formula Danggui Buxue Tang, both the chemical composition and the biological activity of extracts resulting from traditional water decoction are influenced by details of the extraction procedure and especially involve pharmacokinetic synergism based on co-extraction. Hence, a more detailed knowledge about the traditional extracts' chemical profiles and their impact on biological activity is desirable in order to allow the development of modernised extracts that factually contain the whole range of compounds relevant for the efficacy of the traditional application. We propose that these compounds can be identified by metabolomics based on comprehensive fingerprint analysis of different extracts with known biological activity. TCM offers a huge variety of traditional products of the same botanical origin but with distinct therapeutic properties, like differentially processed drugs and special daodi qualities. Through this variety, TCM gives an ideal field for the application of metabolomic techniques aiming at the identification of active constituents.

show abstract

Section: Nmr For Fingerprinting and Metabolomicsmentioning

confidence: 99%

The potential of metabolic fingerprinting as a tool for the modernisation of TCM preparations

Sheridan

Krenn

Jiang

et al. 2012

Journal of Ethnopharmacology

View full text Add to dashboard Cite

show abstract

“…The coils were isolated from the sample cell and allowed to float independently from the sample temperature which was monitored using a carbon resistor calibrated against a 3 He melting curve thermometer. The NMR signals at these concentrations are very weak and to improve the signalto-noise ratio we used a low temperature RF preamplifier that could operate in a strong applied magnetic field [12]. Even with this preamplifier signal averaging up to five days per data point was needed to realize an adequate signal-to-noise ratio.…”

mentioning

confidence: 99%

NMR Study of the Dynamics ofHe3Impurities in the Proposed Supersolid State of SolidHe4

Huan

Yin

et al. 2011

Phys. Rev. Lett.

Self Cite

View full text Add to dashboard Cite

“…An anomalous peak is also seen in the sound attenuation [6]. These results suggest that the dynamical properties of the 4 He lattice play an important role in these two anomalous responses and we therefore carried out NMR experiments [7,8] to study the microscopic dynamics for samples at the very low 3 He concentrations (x 3 ≤ 25 ppm) for which the NCRIFs are still clearly visible.…”

Section: Introductionmentioning

confidence: 94%

Nuclear Spin Relaxation of Very Dilute 3He impurities in Solid 4He

Kim,

Huan,

Yin

et al. 2012

Preprint

Self Cite

View full text Add to dashboard Cite

We report measurements of the nuclear spin-lattice and spin-spin relaxation times of very dilute 3 He in solid 4 He in the temperature range 0.01 ≤ T ≤ 0.5 K for densities where anomalies have been observed in torsional oscillator and shear modulus measurements. We compare the results with the values of the relaxation times reported by other observers for higher concentrations and the theory of Landesman that takes into account the elastic properties of the 4 He lattice. A sharp increase in the magnitude of the nuclear spin-lattice relaxation times compared to the the classical Landesman theory is observed close to the temperatures where the torsional and shear modulus anomalies are observed. The NMR results suggest that the tunneling of 3 He impurities in the atomic-scale elastic distortion is affected by the same processes that give rise to the macroscopic elastic dissipation anomalies.

show abstract

A Novel Design of a Low Temperature Preamplifier for Pulsed NMR Experiments of Dilute 3He in Solid 4He

Cited by 10 publications

References 10 publications

The potential of metabolic fingerprinting as a tool for the modernisation of TCM preparations

The potential of metabolic fingerprinting as a tool for the modernisation of TCM preparations

NMR Study of the Dynamics ofHe3Impurities in the Proposed Supersolid State of SolidHe4

Nuclear Spin Relaxation of Very Dilute 3He impurities in Solid 4He

Contact Info

Product

Resources

About