An investigation was carried out into laboratory practical skills development and students' specific challenges in transition from laboratory chemistry at Chinese High School (HS) to a fully English ...style university laboratory course. To the best of our knowledge this is the first study of its type investigating practical laboratory skills for a TransNational Education (TNE) Chemistry BSc (3 + 1) degree programme between the United Kingdom (UK) and the People's Republic of China (PRC). Internationalization of such courses have become popular in recent years. The two universities in this study are Nanjing Tech University (NJTech) and the University of Sheffield (UoS). Our study is exploratory with the aim to determine the level of practical laboratory skills the NJTech students gained from High School and the challenges they encountered as they joined a UK degree laboratory programme delivered in English. For this international study, a mixed-methods approach was followed using qualitative inductive and deductive methodologies. Using open-ended questions it was found that particular challenges in the transition were around the lack of prior laboratory experience and the development of many new skills, laboratory notebook documentation, laboratory safety, and studying laboratory chemistry in a second language. Students welcomed these challenges and felt they were developing into professional chemists. Specific recommendations are made for international TNE degrees with laboratory programmes, particularly for those students who progress from Chinese High School through the Chinese GaoKao system into a western university chemistry laboratory programme. The scaffolded/structured curriculum design allowed for total and successful integration of the NJTech with the Sheffield home students during the final year of their BSc in Chemistry. After graduation, having gained high class degrees and becoming fluent in English many of the students progressed into Industry, and onto Masters or PhD programmes in the UK and throughout the world, suggesting internationalisation of students on our TNE programme was successful.
The discovery of functional MRI (fMRI), with the first papers appearing in 1992, gave rise to new categories of data that drove the development of new signal-processing strategies. Workers in the ...field were confronted with image time courses, which could be reshuffled to form pixel time courses. The waveform in an active pixel time-course was determined not only by the task sequence but also by the hemodynamic response function. Reference waveforms could be cross-correlated with pixel time courses to form an array of cross-correlation coefficients. From this array of numbers, colorized images could be created and overlaid on anatomical images. An early paper from the authors' laboratory is extensively reviewed here (Bandettini et al., 1993. Magn. Reson. Med. 30:161–173). That work was carried out using the vocabulary of vector algebra. Cross-correlation methodology was central to the discovery of functional connectivity MRI (fcMRI) by Biswal et al. (1995. Magn. Reson. Med. 34:537–541). In this method, a whole volume time course of images is collected while the brain is nominally at rest and connectivity is studied by cross-correlation of pixel time courses.
Toward discovery science of human brain function Biswal, Bharat B; Mennes, Maarten; Zuo, Xi-Nian ...
Proceedings of the National Academy of Sciences - PNAS,
03/2010, Volume:
107, Issue:
10
Journal Article
Peer reviewed
Open access
Although it is being successfully implemented for exploration of the genome, discovery science has eluded the functional neuroimaging community. The core challenge remains the development of common ...paradigms for interrogating the myriad functional systems in the brain without the constraints of a priori hypotheses. Resting-state functional MRI (R-fMRI) constitutes a candidate approach capable of addressing this challenge. Imaging the brain during rest reveals large-amplitude spontaneous low-frequency (<0.1 Hz) fluctuations in the fMRI signal that are temporally correlated across functionally related areas. Referred to as functional connectivity, these correlations yield detailed maps of complex neural systems, collectively constituting an individual's "functional connectome." Reproducibility across datasets and individuals suggests the functional connectome has a common architecture, yet each individual's functional connectome exhibits unique features, with stable, meaningful interindividual differences in connectivity patterns and strengths. Comprehensive mapping of the functional connectome, and its subsequent exploitation to discern genetic influences and brain-behavior relationships, will require multicenter collaborative datasets. Here we initiate this endeavor by gathering R-fMRI data from 1,414 volunteers collected independently at 35 international centers. We demonstrate a universal architecture of positive and negative functional connections, as well as consistent loci of inter-individual variability. Age and sex emerged as significant determinants. These results demonstrate that independent R-fMRI datasets can be aggregated and shared. High-throughput R-fMRI can provide quantitative phenotypes for molecular genetic studies and biomarkers of developmental and pathological processes in the brain. To initiate discovery science of brain function, the 1000 Functional Connectomes Project dataset is freely accessible at www.nitrc.org/projects/fcon_1000/.
The Gordon coupler was introduced for use in EPR experiments at liquid helium temperatures. It provides an evanescent wave incident on the iris of a microwave resonator. Match of power incident on ...the coupler to the resonator is obtained by variation of the amplitude of an evanescent wave that arises from displacement of a dielectric wedge in a tapered waveguide. Reduced microphonics from helium bubbling was reported. The Gordon coupler was subsequently extended from cavity resonators to loop-gap resonators, initially at helium temperatures but later for aqueous samples. Plastics with low dielectric constants, usually Teflon, were used. Here, we extend the Gordon coupler for application in X-band five-loop–four-gap resonators using fused quartz, sapphire, or rutile dielectrics, noting that the size of the coupler can then be commensurate with dimensions of dielectric loop-gap resonators as well as dielectric tube resonators. Finite-element modeling of electromagnetic fields has been carried out, and use of a capacitive iris that interfaces with the Gordon coupler reduces pulling of the resonant frequency when matching the resonator.
Display omitted
•Single crystal rutile can give 6 times the X-band EPR resonator efficiency of an LGR.•A factor of two higher saturable EPR signal for aqueous sample sizes near 400 nL.•Dielectric in ...the inner loop of an LGR can perform similarly to a DR.•Experimental results are compared with analytic theory and finite element simulations.•Polycrystalline rutile has background signals that make it unsuitable for EPR use.
The performance of a metallic microwave resonator that contains a dielectric depends on the separation between metallic and dielectric surfaces, which affects radio frequency currents, evanescent waves, and polarization charges. The problem has previously been discussed for an X-band TE011 cylindrical cavity resonator that contains an axial dielectric tube (Hyde and Mett, 2017). Here, a short rutile dielectric tube inserted into a loop-gap resonator (LGR) at X-band, which is called a dielectric LGR (dLGR), is considered. The theory is developed and experimental results are presented. It was found that a central sample loop surrounded by four “flux-return” loops (i.e., 5-loop–4-gap) is preferable to a 3-loop–2-gap configuration. For sufficiently small samples (less than 1 µL), a rutile dLGR is preferred relative to an LGR both at constant Λ (B1/Pl) and at constant incident power. Introduction of LGR technology to X-band EPR was a significant advance for site-directed spin labeling because of small sample size and high Λ. The rutile dLGR introduced in this work offers further extension to samples that can be as small as 50 nL when using typical EPR acquisition times.
Autobiography of James S. Hyde Hyde, James S.
Applied magnetic resonance,
12/2017, Volume:
48, Issue:
11-12
Journal Article
Peer reviewed
Open access
The papers, book chapters, reviews, and patents by James S. Hyde in the bibliography of this document have been separated into EPR and MRI sections and within each section by topics. Within each ...topic, publications are listed chronologically. A brief summary is provided for each patent listed. A few publications and patents that do not fit this schema have been omitted. This list of publications is preceded by a scientific autobiography that focuses on selected topics that are judged to have been of most scientific importance. References to many of the publications and patents in the bibliography are made in the autobiography.
The alpha-2-adrenoreceptor agonist, medetomidine, which exhibits dose-dependent sedative effects and is gaining acceptance in small-animal functional magnetic resonance imaging (fMRI), has been ...studied. Rats were examined on the bench using the classic tail-pinch method with three infusion sequences: 100 μg/kg/h, 300 μg/kg/h, or 100 μg/kg/h followed by 300 μg/kg/h. Stepping the infusion rate from 100 to 300 μg/kg/h after 2.5 h resulted in a prolonged period of approximately level sedation that cannot be achieved by a constant infusion of either 100 or 300 μg/kg/h. By stepping the infusion dosage, experiments as long as 6 h are possible. Functional MRI experiments were carried out on rats using a frequency dependent electrical stimulation protocol—namely, forepaw stimulation at 3, 5, 7, and 10 Hz. Each rat was studied for a four-hour period, divided into two equal portions. During the first portion, rats were started at a 100 μg/kg/h constant infusion. During the second portion, four secondary levels of infusion were used: 100, 150, 200, and 300 μg/kg/h. The fMRI response to stimulation frequency was used as an indirect measure of modulation of neuronal activity through pharmacological manipulation. The frequency response to stimulus was attenuated at the lower secondary infusion dosages 100 or 150 μg/kg/h but not at the higher secondary infusion dosages 200 or 300 μg/kg/h. Parallel experiments with the animal at rest were carried out using both electroencephalogram (EEG) and functional connectivity MRI (fcMRI) methods with consistent results. In the secondary infusion period using 300 μg/kg/h, resting-state functional connectivity is enhanced.
The hypothesis is made that the dispersion electron paramagnetic resonance (EPR) spectrum can yield a higher signal-to-noise ratio than the absorption spectrum in diagnostic examinations if phase ...noise in the bridge is under control. The rationale for this hypothesis is based on the observation that the dispersion spectrum becomes more intense than the absorption spectrum at high incident powers. The rationale is dependent on optimization of high microwave efficiency (Λ; mT/W
1/2
) and low-quality factor (
Q
-value) sample resonators as well as the use of microwave sources with reduced phase noise. Microwave frequencies from 1.2 to 94 GHz are considered. Although the dispersion display appears to be observable with an adequate signal-to-noise ratio for most EPR research initiatives, a weakness of microwave bridges for studies at high incident microwave power was identified. Spurious leakage of incident microwave power through the circulator, thereby bypassing the probe leading to the resonator, can result in a decreased signal-to-noise ratio in both absorption and dispersion because of phase noise. For dispersion EPR with low
Q
-value sample resonators, this leakage is the primary contributor to phase noise at the receiver. In this work, we focus on the design of microwave reflection bridges and discuss possible methods to ameliorate this source of noise.
The stretched exponential function (SEF) was used to analyze and interpret saturation recovery (SR) electron paramagnetic resonance (EPR) data obtained from spin-labeled porcine eye-lens membranes. ...This function has two fitting parameters: the characteristic spin–lattice relaxation rate (
T
1str
−1
) and the stretching parameter (
β
), which ranges between zero and one. When
β
=1, the function is a single exponential. It is assumed that the SEF arises from a distribution of single exponential functions, each described by a
T
1
value. Because
T
1
−1
s are determined primarily by the rotational diffusion of spin labels, they are a measure of membrane fluidity. Since
β
describes the distribution of
T
1
−1
s, it can be interpreted as a measure of membrane heterogeneity. The SEF was used to analyze SR data obtained from intact cortical and nuclear fiber cell plasma membranes extracted from the eye lenses of 2-year-old animals and spin labeled with phospholipid and cholesterol analogs. The lipid environment sensed by these probe molecules was found to be less fluid and more heterogeneous in nuclear membranes than in cortical membranes. Parameters
T
1str
−1
and
β
were also used for a multivariate K-means cluster analysis of stretched exponential data. This analysis indicates that SEF data can be assigned accurately to clusters in nuclear or cortical membranes. In future work, the SEF will be applied to analyze data from human eye lenses of donors with differing health histories.
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