Double quantum dot with tunable coupling in an enhancement-mode silicon metal-oxide semiconductor device with lateral geometry

We present transport measurements of a tunable silicon metal-oxide-semiconductor double quantum dot device with lateral geometry. Experimentally extracted gate-to-dot capacitances show that the device is largely symmetric under the gate voltages applied. Intriguingly, these gate voltages themselves are not symmetric. Comparison with numerical simulations indicates that the applied gate voltages serve to offset an intrinsic asymmetry in the physical device. We also show a transition from a large single dot to two well isolated coupled dots, where the central gate of the device is used to controllably tune the interdot coupling.Comment: 4 pages, 3 figures, to be published in Applied Physics Letter

Association between duration of controlled ovarian stimulation and live birth rate in women undergoing In Vitro Fertilization: a SART CORS analysis

Background: In-Vitro Fertilization (IVF) treatment involves synchronization of multiple time-sensitive events, most of which are rate-limiting too. Controlled ovarian stimulation (COS) is one such event. The reproductive outcomes based on the duration of COS (d-COS) in a fresh, IVF embryo transfer (ET) are not well established and therefore, remains largely uncertain. Objective: To evaluate the association between d-COS and live birth rate (LBR) in women undergoing a fresh IVF-ET using autologous oocytes. Methods: A retrospective cohort study was conducted using a US nationwide IVF register – SARTCORS (Society for Assisted Reproductive Technology Clinic Outcomes Reporting System). From a total of 93,889 cycles, we included 56,666 fresh, autologous, IVF - ET treatment cycles from January 2014 through December 2015, with follow-up until October 2016. Adjusted odds and risk ratio with 95% confidence intervals were estimated while controlling for multiple demographic factors and other potential confounders. Variables and outcomes: The primary exposure variable was d-COS defined as the difference in days between gonadotrophin administration and oocyte retrieval. The primary outcome measure was live birth following a fresh IVF-ET. Secondary outcome measures included biochemical pregnancy rate, miscarriage rate, implantation rate and clinical pregnancy rate. Results: A total of 56,666 treatment cycles (mean [SD] age of 33.9 [4.47], BMI of 26.1 [6.02], AMH value of 2.19 [3.37]), and a baseline FSH value of 7.62 [3.49]) underwent a fresh IVF-ET. The LBR after a combined analysis for all ages and all protocols was 44.2 % (n = 25043). In the combined analysis, there was a statistically significant decrease in the live birth rate with LBR with d-COS beyond 10 days. The adjusted OR (95% CI) of LBR for a woman who had 11, 12, 13 and ≥14 days of COS, compared to optimal duration of 10 days was 0.97 (0.87-0.99), 0.94 (0.8-1), 0.83 (0.77-0.89) and 0.73 (0.68-0.79) respectively. The AOR (95% CI) of miscarriage rates for a woman who had 11, 12, 13 and ≥14 days of COS, compared to referent was 1.12 (1-1.26), 0.99 (0.87-1.12), 1.03 (0.90 -1.17) and 1.04 (0.90 - 1.2) respectively. With increasing d-COS, the implantation rate (IR) and clinical pregnancy rate (CPR) also showed a decreasing trend, as with other reproductive outcomes. The RR (95% CI) for implantation rate in a woman who had 11, 12, 13 and ≥14 days of COS, compared to referent was 0.97 (0.93-1), 0.97 (0.93-1.01), 0.91 (0.87-0.95) and 0.86 (0.82-0.9). The adjusted OR (95% CI) of CPR for a woman who had 11, 12, 13 and ≥14 days of COS, compared to referent was 0.95 (0.89-1.01), 0.93 (0.87-0.99), 0.8 (0.75-0.86) and 0.7 (0.65-0.75) respectively. Conclusions and Relevance: In this nationwide cohort study of women undergoing fresh IVF-ET using autologous oocytes, controlled ovarian stimulation lasting approximately 10-days was associated with an optimal live birth rate

Medically relevant ElectroNeedle technology development.

ElectroNeedles technology was developed as part of an earlier Grand Challenge effort on Bio-Micro Fuel Cell project. During this earlier work, the fabrication of the ElectroNeedles was accomplished along with proof-of-concept work on several electrochemically active analytes such as glucose, quinone and ferricyanide. Additionally, earlier work demonstrated technology potential in the field of immunosensors by specifically detecting Troponin, a cardiac biomarker. The current work focused upon fabrication process reproducibility of the ElectroNeedles and then using the devices to sensitively detect p-cresol, a biomarker for kidney failure or nephrotoxicity. Valuable lessons were learned regarding fabrication assurance and quality. The detection of p-cresol was accomplished by electrochemistry as well as using fluorescence to benchmark ElectroNeedles performance. Results from these studies will serve as a guide for the future fabrication processes involving ElectroNeedles as well as provide the groundwork necessary to expand technology applications. One paper has been accepted for publication acknowledging LDRD funding (K. E. Achyuthan et al, Comb. Chem. & HTS, 2008). We are exploring the scope for a second paper describing the applications potential of this technology

Effect of endometrial thickness on live birth rates in fresh and frozen embryo transfers in women under 38 years of age

Many IVF clinics use endometrial thickness as a predictive factor for IVF outcomes, as research has shown a positive association between endometrial thickness and favorable IVF outcomes. A thickness of 6-8 mm is often used as a cut-off in for the decision of whether or not to transfer an embryo in both fresh and frozen cycles. However, prior studies investigating the relationship between a thin endometrium and IVF outcomes have overwhelmingly been performed in fresh cleavage stage embryo transfers. Given the recent trend toward the transfer of frozen blastocyst transfers, we aimed to determine whether endometrial thickness predicts live birth in both fresh and frozen blastocyst stage single embryo transfers

Enhancement mode double top gated MOS nanostructures with tunable lateral geometry

We present measurements of silicon (Si) metal-oxide-semiconductor (MOS) nanostructures that are fabricated using a process that facilitates essentially arbitrary gate geometries. Stable Coulomb blockade behavior free from the effects of parasitic dot formation is exhibited in several MOS quantum dots with an open lateral quantum dot geometry. Decreases in mobility and increases in charge defect densities (i.e. interface traps and fixed oxide charge) are measured for critical process steps, and we correlate low disorder behavior with a quantitative defect density. This work provides quantitative guidance that has not been previously established about defect densities for which Si quantum dots do not exhibit parasitic dot formation. These devices make use of a double-layer gate stack in which many regions, including the critical gate oxide, were fabricated in a fully-qualified CMOS facility.Comment: 11 pages, 6 figures, 3 tables, accepted for publication in Phys. Rev.