New Innovation: Use of Flash Glucose Monitoring for Evaluating Glycaemic Variability, Patient Satisfaction and Clinical Utility in Pregnant Women with Diabetes

Aim

Application of Flash glucose monitoring (FGM) system to evaluate glycaemic variability (GV), patient satisfaction and clinical utility in pregnant women with diabetes.

Methods

This prospective study was conducted in a tertiary care teaching hospital on 70 pregnant women with diabetes where blood sugar levels were monitored by FGM and self-monitoring of blood glucose (SMBG).

Results

FGM generated 19,950 readings versus 1470 readings by SMBG over 3 days. Glucose values measured by FGM and SMBG had significant positive correlation (r > 0.89; p < 0.001). Significant difference (p < 0.001) was present between minimum glucose values by FGM (52.49 ± 15.42 mg/dl) and SMBG (72.74 ± 18.30 mg/dl). FGM (20.9%) was able to pick exact duration of hypoglycaemia, while one-third of this duration was missed by conventional SMBG (14.7%; p < 0.05). Hypoglycaemic episodes were observed in 92.9% women by FGM as compared to 45.7% by SMBG (p < 0.001). No significant difference was observed in maximum glucose level or duration of hyperglycaemia by both methods. FGM identified hyperglycaemia in 74% women vs. 52% by SMBG (p < 0.001). GV calculated by using MODD by FGM was 118.4 ± 52.4 mg/dl and by SMBG was 83.2 ± 53.2 mg/dl (p < 0.001). 100% women preferred AGP vs. SMBG.

Conclusion

This is the first study to evaluate FGM for GV and patient satisfaction in women with GDM. Significant correlation was observed in glucose values by FGM and SMBG. FGM was more sensitive in detecting GV and hypoglycaemic excursions as compared to SMBG. All women preferred FGM over SMBG. Use of FGM gave new insights in clinical management of challenging cases.

An atomic Fabry-Perot interferometer using a pulsed interacting Bose-Einstein condensate

We numerically demonstrate atomic Fabry-Perot resonances for a pulsed interacting Bose-Einstein condensate (BEC) source transmitting through double Gaussian barriers. These resonances are observable for an experimentally-feasible parameter choice, which we determined using a previously-developed analytical model for a plane matter-wave incident on a double rectangular barrier system. Through numerical simulations using the non-polynomial Schödinger equation-an effective one-dimensional Gross-Pitaevskii equation-we investigate the effect of atom number, scattering length, and BEC momentum width on the resonant transmission peaks. For [Formula: see text]Rb atomic sources with the current experimentally-achievable momentum width of [Formula: see text] [[Formula: see text]], we show that reasonably high contrast Fabry-Perot resonant transmission peaks can be observed using (a) non-interacting BECs, (b) interacting BECs of [Formula: see text] atoms with s-wave scattering lengths [Formula: see text] ([Formula: see text] is the Bohr radius), and (c) interacting BECs of [Formula: see text] atoms with [Formula: see text]. Our theoretical investigation impacts any future experimental realization of an atomic Fabry-Perot interferometer with an ultracold atomic source.

Orthorhombic crystal structure and oxygen deficient cluster distribution model for YBa2Cu3-xAlxO6+δ superconductor

Single crystal x-ray diffraction measurements on both as-grown as well as oxygenated single crystals of an aluminium doped high temperature superconductor YBa₂Cu_3−xAl_xO_6+δ revealed the crystal structure to be orthorhombic with space group Pmmm, in contrast to, tetragonal crystal structures corresponding to space group P4/mmm, previously reported for as-grown YBa₂Cu_3−xAl_xO_6+δ, and conflicting structures on oxygenated YBa₂Cu_3−xAl_xO_6+δ. The orthorhombic crystal structure was confirmed by powder x-ray diffraction that showed the presence of two peaks corresponding to (020) and (200) reflections associated with orthorhombic structures of space group Pmmm, instead of a single (200) reflection corresponding to tetragonal crystal structures with space group P4/mmm. All the as-grown crystals were found to be superconducting. An oxygen-vacancy cluster distribution model is proposed to explain the differences in the obtained magnetisation hysteresis loop and the broad superconducting transition temperature. The model proposes the existence of two oxygen deficient clusters of (Al-..-Cu-O-Cu)_n and (Cu-O-Cu-..)_n juxtaposed with each other whose number and size vary as the as-grown single crystals of YBa₂Cu_3−xAl_xO_6+δ are subjected to oxygenation. X-ray photoelectron spectroscopy measurements showed the existence of two distinct peaks in each of the spectrum of O, Cu, Y and Ba in YBa₂Cu_3−xAl_xO_6+δ crystals corresponding to the two different types of clusters. The relative intensities of each XPS peak was found to decrease in the oxygenated crystals as compared to the as-grown ones confirming the change in the number and size of clusters in the as-grown crystals after oxygenation.

Observation of short range ferromagnetic interactions and magnetocaloric effect in cobalt substituted Gd5Si2Ge2

Gd₅Si_2−xCo_xGe₂ compounds exhibit a strong correlation between their structure and magnetic properties showing Griffith's like phases and magnetocaloric effect.

Non-destructive shadowgraph imaging of ultra-cold atoms

An imaging system is presented that is capable of far-detuned non-destructive imaging of a Bose-Einstein condensate with the signal proportional to the second spatial derivative of the density. Whilst demonstrated with application to Rb85, the technique generalizes to other atomic species and is shown to be capable of a signal-to-noise of ∼25 at 1 GHz detuning with 100 in-trap images showing no observable heating or atom loss. The technique is also applied to the observation of individual trajectories of stochastic dynamics inaccessible to single shot imaging. Coupled with a fast optical phase locked loop, the system is capable of dynamically switching to resonant absorption imaging during the experiment.

Simultaneous Precision Gravimetry and Magnetic Gradiometry with a Bose-Einstein Condensate: A High Precision, Quantum Sensor

A Bose-Einstein condensate is used as an atomic source for a high precision sensor. A 5×10^{6}  atom F=1 spinor condensate of ^{87}Rb is released into free fall for up to 750 ms and probed with a T=130  ms Mach-Zehnder atom interferometer based on Bragg transitions. The Bragg interferometer simultaneously addresses the three magnetic states |m_{f}=1,0,-1⟩, facilitating a simultaneous measurement of the acceleration due to gravity with a 1000 run precision of Δg/g=1.45×10^{-9} and the magnetic field gradient to a precision of 120  pT/m.

Time-of-flight detection of ultra-cold atoms using resonant frequency modulation imaging

Resonant frequency modulation imaging is used to detect free falling ultra-cold atoms. A theoretical comparison of fluorescence imaging (FI) and frequency modulation imaging (FMI) is made, indicating that for low optical depth clouds, FMI accomplished a higher signal-to-noise ratio under conditions necessary for a 200 μm spatially resolved atom interferometer. A 750 ms time-of-flight measurement reveals near atom shot-noise limited number measurements of 2×10⁶ Bose-condensed Rb87 atoms. The detection system is applied to high precision spinor BEC based atom interferometer.

Fast machine-learning online optimization of ultra-cold-atom experiments

We apply an online optimization process based on machine learning to the production of Bose-Einstein condensates (BEC). BEC is typically created with an exponential evaporation ramp that is optimal for ergodic dynamics with two-body s-wave interactions and no other loss rates, but likely sub-optimal for real experiments. Through repeated machine-controlled scientific experimentation and observations our ‘learner’ discovers an optimal evaporation ramp for BEC production. In contrast to previous work, our learner uses a Gaussian process to develop a statistical model of the relationship between the parameters it controls and the quality of the BEC produced. We demonstrate that the Gaussian process machine learner is able to discover a ramp that produces high quality BECs in 10 times fewer iterations than a previously used online optimization technique. Furthermore, we show the internal model developed can be used to determine which parameters are essential in BEC creation and which are unimportant, providing insight into the optimization process of the system.