High Fasting Insulin Levels and Insulin Resistance May Be Linked to Idiopathic Recurrent Pregnancy Loss: A Case-Control Study

Objective. Patients with more than two spontaneous pregnancy losses are diagnosed with recurrent pregnancy loss. The aim of this study was to evaluate the IR (insulin resistance) in patients with idiopathic recurrent pregnancy loss. Material and Method. A single center, case control study was performed on one hundred eighteen women divided into case group (with at least two pregnancy losses, earlier than 20 weeks of gestation, and negative for the recurrent pregnancy loss testing) and control group (with at least one live birth, no pregnancy loss). FG (fasting glucose) and FI (fasting insulin) were determined for all patients. IR was evaluated by HOMA-IR index. Results. There were not significant differences between the mean age and BMI in cases and controls ( > 0.05). Fasting glucose was significantly higher in the control group (85.6 versus 79.8 < 0.01), but fasting insulin (15.24 versus 12.83, < 0.001) and HOMA-IR (2.98 versus 2.69, < 0.05) were significantly higher in the case group. Conclusion. In women with idiopathic recurrent pregnancy loss FI and IR are higher than those in women without spontaneous abortion

Ultrafast time-resolved photoluminescence from novel metal–dendrimer nanocomposites

We report the first results of ultra-fast enhanced light emission from gold– and silver–dendrimer nanocomposites. There is a fast (70 fs) fluorescence decay component associated with the metal nanocomposites. Anisotropy measurements show that this fast component is depolarized. The enhanced emission is suggestively due to local field enhancement in the elongated metal–dendrimer nanoparticles. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71043/2/JCPSA6-114-5-1962-1.pd

High Fasting Insulin Levels and Insulin Resistance May Be Linked to Idiopathic Recurrent Pregnancy Loss: A Case-Control Study

Objective. Patients with more than two spontaneous pregnancy losses are diagnosed with recurrent pregnancy loss. The aim of this study was to evaluate the IR (insulin resistance) in patients with idiopathic recurrent pregnancy loss. Material and Method. A single center, case control study was performed on one hundred eighteen women divided into case group (with at least two pregnancy losses, earlier than 20 weeks of gestation, and negative for the recurrent pregnancy loss testing) and control group (with at least one live birth, no pregnancy loss). FG (fasting glucose) and FI (fasting insulin) were determined for all patients. IR was evaluated by HOMA-IR index. Results. There were not significant differences between the mean age and BMI in cases and controls (). Fasting glucose was significantly higher in the control group (85.6 versus 79.8 ), but fasting insulin (15.24 versus 12.83, ) and HOMA-IR (2.98 versus 2.69, ) were significantly higher in the case group. Conclusion. In women with idiopathic recurrent pregnancy loss FI and IR are higher than those in women without spontaneous abortion

Ultrafast two-photon nonlinearities in CdSe near 1.5 mu m studied by interferometric autocorrelation

We have used interferometric autocorrelation measurements to study the femtosecond nonlinear optical properties of bulk CdSe crystals in the wavelength region just above the half gap wavelength of 1.42 μm. Between 1.42 and 1.55 μm, we measured an ultrafast third-order nonlinearity with nonlinear refractive index n 2 = 1.3 × 10 -13 cm 2/W -1. Detailed modeling of the autocorrelations revealed the influence of higher order effects due to free carriers generated by nonlinear absorption. We find that CdSe is an interesting alternative material to AlGaAs for applications in this technologically important wavelength region

Photon-number squeezing in a free-running quantum-well laser operating at 980 nm

We present intensity noise investigations of a free-running InGaAs quantum-well laser diode operating at 980 nm at room temperature. The laser had a threshold current of 17 mA. Photon-number squeezing was achieved for drive currents of 48 mA when the laser was operating on two dominant longitudinal modes. The degree of squeezing obtained was 9%, which was in reasonable agreement with the current-to-current efficiency of 11%. No squeezing was observed at 35 K

Interferometric autocorrelation measurements of ultrafast two-photon nonlinearities in CdSe

Bulk crystals of CdSe are studied to verify it as an alternative to AlGaAs in the 1.5 μm wavelength due to its half-gap energy of 0.875 eV and large nonlinear figure of merit. The pulses transmitted to the crystal are characterized by interferometric autocorrelation and spectral analysis. Detailed numerical modeling are used to identify the contributions of the different effects. Femtosecond pulses from an optical parametric oscillator, operating between 1.4 and 1.6 μm, are used. The nonlinear refractive index of 1.3×10-13 cm2/W compares favorably to AlGaAs and is suitable for a number of nonlinear applications

Single photon avalanche diodes (SPADs) for 1.5 µm photon counting applications

The paper reports on the design and characterization of InGaAs/InP single photon avalanche diodes (SPADs) for photon counting applications at wavelengths near 1.5 mm. It is shown how lower internal electric field amplitudes can lead to reduced dark count rates, but at the expense of degraded afterpulsing behaviour and larger timing jitter. Dark count rate behaviour provides evidence of thermally assisted tunnelling with an average thermal activation energy of ~0.14 eV between 150K and 220 K. Afterpulsing behaviour exhibits a structure-dependent afterpulsing activation energy, which quantifies how carrier de-trapping varies with temperature. SPAD performance simultaneously exhibits a dark count rate of 10 kHz at a detection efficiency of 20% with timing jitter of 100 ps at 200 K, and with appropriate performance tradeoffs, we demonstrate a 200K dark count rate as low as 3 kHz, a detection efficiency as high as 45%, and a timing jitter as low as 30 ps

Synthesis and third order nonlinear optics of a new soluble conjugated porphyrin polymer

The synthesis of a new soluble conjugated porphyrin polymer 4 is reported. The MALDI TOF mass spectrum shows the presence of oligomers with up to 13 repeat units and GPC gives a Mn of 53 kDa. The electronic absorption spectra of this polymer exhibit an intense Q band at 800 nm in solution and 853 nm in the solid state, demonstrating a high degree of conjugation. Electroabsorption spectroscopy shows that thin films of 4 have lower resonant third order NLO susceptibility than our previous conjugated porphyrin polymer 2, whereas closed z-scan measurements indicate that the off-resonance real susceptibility, at 1064 nm, is exceptionally large for both polymers (χ(3)R =-2 × 10-16 m2 V-2). Open z-scan measurements were also made at 1064 nm, demonstrating that the two polymers exhibit similar nonlinear absorption at this wavelength (β= 1 cm GW-1 at 0.2 mM concentration)