Modern microprocessor built from complementary carbon nanotube transistors.

Electronics is approaching a major paradigm shift because silicon transistor scaling no longer yields historical energy-efficiency benefits, spurring research towards beyond-silicon nanotechnologies. In particular, carbon nanotube field-effect transistor (CNFET)-based digital circuits promise substantial energy-efficiency benefits, but the inability to perfectly control intrinsic nanoscale defects and variability in carbon nanotubes has precluded the realization of very-large-scale integrated systems. Here we overcome these challenges to demonstrate a beyond-silicon microprocessor built entirely from CNFETs. This 16-bit microprocessor is based on the RISC-V instruction set, runs standard 32-bit instructions on 16-bit data and addresses, comprises more than 14,000 complementary metal-oxide-semiconductor CNFETs and is designed and fabricated using industry-standard design flows and processes. We propose a manufacturing methodology for carbon nanotubes, a set of combined processing and design techniques for overcoming nanoscale imperfections at macroscopic scales across full wafer substrates. This work experimentally validates a promising path towards practical beyond-silicon electronic systems.

Optimization of hybrid renewable-diesel power plants considering operational cost, battery degradation, and emissions.

Renewable energy sources have immense potential for enhancing environmental sustainability; however, addressing their intermittency and irregularity is vital for optimizing economic benefits within microgrids. Integrating renewable energy systems with energy storage presents a promising solution. This study introduces an innovative energy management system designed for hybrid renewable power stations, incorporating battery energy storage systems and diesel generators. By accounting for battery degradation costs associated with charge depth and lifespan, the study transforms long-term battery expenses into real-time operational costs. The optimization problem is formulated as a mixed integer linear programming framework with the objectives of minimizing operating costs, battery degradation costs, and pollutant gas emissions. Through diverse case studies reflecting various market profiles. The proposed approach demonstrates reductions in overall system costs.

Fabrication of crystalline silicon nanowires coated with graphene from graphene oxide on amorphous silicon substrate using excimer laser.

In this work, we report a single-step graphene-coated crystalline silicon nanowires (SiNWs) manufacturing technique. We report a one-step fabrication technique of SiNWscoated reduced graphene oxide using a krypton fluoride (KrF) excimer laser. The SiNWs have been manufactured by redistributing the silicon mass within the sample without etching any of the deposited amorphous silicon (a-Si) and then adding a synthesized graphene oxide suspension using the modified Hummers' method. The process is optimized to ensure that the graphene is completely reduced and that the crystalline nanowires are formed. In order to allow full control of the dimension of the generated nanowires, the properties of the excimer laser have been investigated. Additionally, graphene-coated Si nanowires have also been synthesized to be used for gas-sensing applications in the future. In this work, we are eviting the repetition of the previously published work by the same research group for the sake of brevity. But the reader can refer to the previously published work on the study of the effect of different parameters on the SiNWs growth like the study of the effect of changing the normalized frequency on the size of the grown SiNWs in terms of length and diameter as well as other parameters mentioned in the previously published work in the references.

The use of epinephrine infusion for the prevention of spinal hypotension during Caesarean delivery: A randomized controlled dose-finding trial.

BACKGROUND: This study aimed to compare three epinephrine doses for the prevention of spinal hypotension during Caesarean delivery. METHODS: This randomized controlled trial included full-term pregnant women undergoing elective Caesarean delivery under spinal anesthesia. The participants received prophylactic epinephrine infusions at rates of 0.01, 0.02, or 0.03 mcg/kg/min. Spinal hypotension (systolic blood pressure <80% of baseline) was managed with a 9-mg ephedrine bolus. The primary outcome was the incidence of spinal hypotension. Secondary outcomes included total ephedrine requirement, the incidence of severe spinal hypotension, excessive tachycardia and hypertension, and neonatal outcomes. RESULTS: The final analysis included 271 patients. The incidence of hypotension was lowest in the 0.03 mcg group (11/90 [12%]), followed by the 0.02 mcg (32/91 [35%]) and the 0.01 mcg (55/90 [61%]) groups (p < 0.001). The median ephedrine requirements (quartiles) were also the lowest in the 0.03 mcg group (0 [0-0] mg), followed by the 0.02 mcg (0 [0-9] mg) and the 0.01 mcg (9 [0-18] mg) groups. The incidence of severe hypotension was lower in the 0.03 mcg and 0.02 mcg groups than in the 0.01 mcg group (3/90 [3%], 5/91 [6%], and 15/90 [17%], respectively). The incidences of excessive tachycardia, hypertension, and neonatal outcomes were comparable among the groups. CONCLUSION: The use of epinephrine to prevent spinal hypotension during Caesarean delivery is feasible and effective. An initial dose of 0.03 mcg/kg/min produced the lowest incidence of hypotension compared to 0.02 mcg/kg/min and 0.01 mcg/kg/min doses. The three doses were comparable in terms of the incidence of tachycardia, hypertension, and neonatal outcomes. STUDY REGISTRATION: ClinicalTrials.gov Identifier: NCT05279703.

Ketamine-based Versus Fentanyl-based Regimen for Rapid-sequence Endotracheal Intubation in Patients with Septic Shock: A Randomised Controlled Trial.

Objective: The aim of this work is to compared ketamine-based versus fentanyl-based regimens for endotracheal intubation in patients with septic shock undergoing emergency surgery. Design: This was a randomised double-blinded controlled trial. Participants: Patients with septic shock on norepinephrine infusion scheduled for emergency surgery. Setting and Interventions: At induction of anaesthesia, patients were allocated into ketamine group (n=23) in which the participants received ketamine 1 mg/kg, and fentanyl group (n=19) in which the participants received fentanyl 2.5 mcg/ kg. Both groups received midazolam (0.05 mg/kg) and succinyl choline (1 mg/kg). Measurement: The primary outcome was mean arterial blood pressure. The secondary outcomes included: heart rate, cardiac output, and incidence of postintubation hypotension defined as mean arterial pressure ≤80% of baseline value. Results: Forty-two patients were available for final analysis. The mean blood pressure was higher in the ketamine group than in the fentanyl group at 1, 2 and 5 minutes after the induction of anaesthesia. Furthermore, the incidence of postinduction hypotension was lower in the ketamine group than in the fentanyl group (11 [47.8%] versus 16 [84.2%], P-value= 0.014). Other hypodynamic parameters, namely the heart rate and cardiac output, were comparable between both groups; and were generally maintained in relation to the baseline reading in each group. Conclusion: The ketamine-based regimen provided better hemodynamic profile compared to fentanyl-based regimen for rapid-sequence intubation in patients with septic shock undergoing emergency surgery.

Central Venous Catheter-Related Tachycardia in the Newborn: Case Report and Literature Review.

Central venous access is an important aspect of neonatal intensive care management. Malpositioned central catheters have been reported to induce cardiac tachyarrhythmia in adult populations and there are case reports within the neonatal population. We present a case of a preterm neonate with a preexisting umbilical venous catheter (UVC), who then developed a supraventricular tachycardia (SVT). This was initially treated with intravenous adenosine with transient reversion. Catheter migration was subsequently detected, with the UVC tip located within the heart. Upon withdrawal of the UVC and a final dose of adenosine, the arrhythmia permanently resolved. Our literature review confirms that tachyarrhythmia is a rare but recognised neonatal complication of malpositioned central venous catheters. We recommend the immediate investigation of central catheter position when managing neonatal tachyarrhythmia, as catheter repositioning is an essential aspect of management.