High Frequency Electrochemical Nanopolishing of Alpha Titanium

Product miniaturization is an ever increasing customer demand in aerospace, bio-medical, defense and electronics industries. These microparts play a vital role and are required to abide by stringent norms set forth by various quality control agencies. To maintain their functionality over a period of time, they are made of special engineering materials rather than silicon as commonly used in microelectronics. Lithography, etching, embossing, electroplating, laser machining and other micro manufacturing techniques have been employed traditionally to manufacture microcomponents; however, these techniques would be expensive, cause surface damage, or produce a very rough surface. Electrochemical polishing is capable of machining/polishing any conducting material while holding close dimensional tolerances. This research develops a high frequency electrochemical nanopolishing technique for commercially pure alpha titanium. An alcohol and salt based electrolyte was used with direct current as well as alternating current on alpha titanium plate. For both current types, optimal surface roughness R_(a) ~ 300 nm was obtained on poly grained surface using interferometry and ~ 2 nm within a single grain by atomic force microscopy. Comparable results were obtained by other researchers with 30-120 nm R_(a) for titanium and titanium alloys. Linear regression models were developed to predict the surface roughness. The surface roughness predicted by the models was found to be within 26% of the measured values

Trajectory Energy Management Systems for eVTOL Vehicles: Modeling, Simulation and Testing

Presented at AIAA AVIATION Forum 2022The rise of electric aircraft propulsion methods, the increased use of automated and integrated flight control systems, and the envisioned use of personal Vertical Takeoff and Landing (VTOL) vehicles in urban environments lead to novel technical and regulatory challenges for aircraft manufacturers, certification authorities and operators. The combination of electric propulsion, where energy reserves and powertrain performance are highly sensitive to the environment, and VTOL, where the aircraft cannot simply glide to an emergency landing, generates the need for Trajectory Energy Management (TEM). The TEM task involves the manipulation of flight and propulsion controls to achieve a planned flight profile. The TEM system must provide the pilot or automated control system with guidance cues to achieve a planned flight profile, to maintain an energy-optimal trajectory, to avoid deviations from the flight plan causing increases in energy and power consumption, and to mitigate the risk of energy completion. As the pilot must manage both the energy source and flight dynamics energy state, the TEM system must provide sufficient information to the pilot, so that the pilot can perform the mission. This research is intended to define some requirements for energy management such that the pilot can safely accomplish an intended profile and land with enough energy reserves. These requirements must be defined based on prototype algorithm development, simulation results, and flight test data

A calcineurin–Hoxb13 axis regulates growth mode of mammalian cardiomyocytes

10.1038/s41586-020-2228-6Nature5827811271-27

BRD4 Promotes DNA Repair and Mediates the Formation of TMPRSS2-ERG Gene Rearrangements in Prostate Cancer.

BRD4 belongs to the bromodomain and extraterminal (BET) family of chromatin reader proteins that bind acetylated histones and regulate gene expression. Pharmacological inhibition of BRD4 by BET inhibitors (BETi) has indicated antitumor activity against multiple cancer types. We show that BRD4 is essential for the repair of DNA double-strand breaks (DSBs) and mediates the formation of oncogenic gene rearrangements by engaging the non-homologous end joining (NHEJ) pathway. Mechanistically, genome-wide DNA breaks are associated with enhanced acetylation of histone H4, leading to BRD4 recruitment, and stable establishment of the DNA repair complex. In support of this, we also show that, in clinical tumor samples, BRD4 protein levels are negatively associated with outcome after prostate cancer (PCa) radiation therapy. Thus, in addition to regulating gene expression, BRD4 is also a central player in the repair of DNA DSBs, with significant implications for cancer therapy

A Simplified Cost-Utility Analysis of Inpatient Flap Monitoring after Microsurgical Breast Reconstruction and Implications for Hospital Length of Stay.

BACKGROUND:The number of free flap take-backs and successful salvages following microsurgical breast reconstruction decreases as time from surgery increases. As a result, the cost of extended inpatient monitoring to achieve a successful flap salvage rises rapidly with each postoperative day. This study introduces a simplified cost-utility model of inpatient flap monitoring and identifies when cost-utility exceeds the thresholds established for other medical treatments. METHODS:A retrospective review of a prospectively maintained database was performed of patients who underwent microsurgical breast reconstruction to identify flap take-back and salvage rates by postoperative day. The number of patients and flaps that needed to be kept on an inpatient basis each day for monitoring to salvage a single failing flap was determined. Quality-of-life measures and incremental cost-effectiveness ratios for inpatient flap monitoring following microsurgical breast reconstruction were calculated and plotted against a $100,000/quality-adjusted life-year threshold. RESULTS:A total of 1813 patients (2847 flaps) were included. Overall flap take-back and salvage rates were 2.4 percent and 52.3 percent, respectively. Of the flaps taken back, the daily take-back and salvage rates were 56.8 and 60.0 percent (postoperative day 0 to 1), 13.6 and 83.3 percent (postoperative day 2), 11.4 and 40.0 percent (postoperative day 3), 9.1 and 25.0 percent (postoperative day 4), and 9.1 and 0.0 percent (\u3epostoperative day 4), respectively. To salvage a single failing flap each day, the number of flaps that needed to be monitored were 121 (postoperative day 0 to 1), 363 (postoperative day 2), 907 (postoperative day 3), 1813 (postoperative day 4), and innumerable for days beyond postoperative day 4. The incremental cost-effectiveness ratio of inpatient flap monitoring begins to exceed a willingness-to-pay threshold of$100,000/quality-adjusted life-year by postoperative day 2. CONCLUSION:The health care cost associated with inpatient flap monitoring following microsurgical breast reconstruction begins to rise rapidly after postoperative day 2

Creation of spliced vein conduit using microvascular anastomotic coupler.

The single-segment great saphenous vein continues to be a conduit of choice for lower extremity arterial bypass. In patients without an adequate continuous segment of great saphenous vein, a spliced vein graft may be used as an alternative. Creating a spliced vein conduit can be technically challenging and time consuming. We present a technique of creating a spliced vein conduit by using a microvascular anastomotic coupler

The IFN response in bats displays distinctive ifn-stimulated gene expression kinetics with atypical RNASEL induction

10.4049/jimmunol.1701214Journal of Immunology2001209-21

Vein grafting your way out of trouble: Examining the utility and efficacy of vein grafts in microsurgery.

INTRODUCTION: There is limited data on the indications, outcomes, and associated complications with use of interpositional vein grafts (IVG) in microsurgery. This study sought to critically examine and update the utility of this microsurgical technique. METHODS: All microsurgical cases at a single institution from 2005 to 2011 were examined for use of IVGs in the primary procedure or during take back or salvage attempts. We examined the cohort overall and performed a subgroup analysis by timing of initial IVG. RESULTS: In the study period, 1718 patients underwent 2368 free flaps. 51 IVGs were utilized in 38 patients (2.2%) and 38 flaps (1.6%). Eight (42.1%) of the primary procedure IVGs (n = 19) were planned preoperatively. Nine total flap losses (24%) occurred when IVGs were utilized, 89% of which occurred in the take back cohort (p = 0.02). However, planned IVG had a 100% success rate, and IVG utilized in the primary procedure overall had a 95% success rate. Importantly, A significantly higher rate of thrombotic events was noted in all primary cases where IVGs were utilized (p = 0.005). CONCLUSIONS: This study demonstrates that IVGs can be utilized in primary free flap reconstructions with success rates exceeding 95%. However, in salvage procedures, the use of vein grafts does not approach the same rate of success likely due to multiple factors. Yet when utilized appropriately with thrombectomy and resection of the thrombosed vessel to healthy intima, IVGs can provide an important tool for flap salvage. LEVEL OF EVIDENCE: prognostic/risk category, level II