Defining the Structural Consequences of Mechanism-Based Inactivation of Mammalian Cytochrome P450 2B4 Using Resonance Raman Spectroscopy

In view of the potent oxidizing strength of cytochrome P450 intermediates, it is not surprising that certain substrates can give rise to reactive species capable of attacking the heme or critical distal-pocket protein residues to irreversibly modify the enzyme in a process known as mechanism-based (MB) inactivation, a result that can have serious physiological consequences leading to adverse drug−drug interactions and toxicity. While methods exist to document the attachment of these substrate fragments, it is more difficult to gain insight into the structural basis for the altered functional properties of these modified enzymes. In response to this pressing need to better understand MB inhibition, we here report the first application of resonance Raman spectroscopy to study the inactivation of a truncated form of mammalian CYP2B4 by the acetylenic inhibitor 4-(tert-butyl)phenylacetylene, whose activated form is known to attach to the distal-pocket T302 residue of CYP2B4

Coherent Electron Transport by Adiabatic Passage in an Imperfect Donor Chain

Coherent Tunneling Adiabatic Passage (CTAP) has been proposed as a long-range physical qubit transport mechanism in solid-state quantum computing architectures. Although the mechanism can be implemented in either a chain of quantum dots or donors, a 1D chain of donors in Si is of particular interest due to the natural confining potential of donors that can in principle help reduce the gate densities in solid-state quantum computing architectures. Using detailed atomistic modeling, we investigate CTAP in a more realistic triple donor system in the presence of inevitable fabrication imperfections. In particular, we investigate how an adiabatic pathway for CTAP is affected by donor misplacements, and propose schemes to correct for such errors. We also investigate the sensitivity of the adiabatic path to gate voltage fluctuations. The tight-binding based atomistic treatment of straggle used here may benefit understanding of other donor nanostructures, such as donor-based charge and spin qubits. Finally, we derive an effective 3 × 3 model of CTAP that accurately resembles the voltage tuned lowest energy states of the multi-million atom tight-binding simulations, and provides a translation between intensive atomistic Hamiltonians and simplified effective Hamiltonians while retaining the relevant atomic-scale information. This method can help characterize multi-donor experimental structures quickly and accurately even in the presence of imperfections, overcoming some of the numeric intractabilities of finding optimal eigenstates for non-ideal donor placements

Band Structure, Phase transitions and Semiconductor Analogs in One-Dimensional Solid Light Systems

The conjunction of atom-cavity physics and photonic structures (``solid light'' systems) offers new opportunities in terms of more device functionality and the probing of designed emulators of condensed matter systems. By analogy to the canonical one-electron approximation of solid state physics, we propose a one-polariton approximation to study these systems. Using this approximation we apply Bloch states to the uniformly tuned Jaynes-Cummings-Hubbard model to analytically determine the energy band structure. By analyzing the response of the band structure to local atom-cavity control we explore its application as a quantum simulator and show phase transition features absent in mean field theory. Using this novel approach for solid light systems we extend the analysis to include detuning impurities to show the solid light analogy of the semiconductor. This investigation also shows new features with no semiconductor analog.Comment: 7 page

Error Rate of the Kane Quantum Computer CNOT Gate in the Presence of Dephasing

We study the error rate of CNOT operations in the Kane solid state quantum computer architecture. A spin Hamiltonian is used to describe the system. Dephasing is included as exponential decay of the off diagonal elements of the system's density matrix. Using available spin echo decay data, the CNOT error rate is estimated at approsimately 10^{-3}.Comment: New version includes substantial additional data and merges two old figures into one. (12 pages, 6 figures

The Design and Rationale of a Multicenter Real-World Trial: The Southeastern Collaboration To Improve Blood Pressure Control in the US Black Belt – Addressing the Triple Threat

BACKGROUND: Impoverished African Americans (AA) with hypertension face poor health outcomes. PURPOSE: To conduct a cluster-randomized trial testing two interventions, alone and in combination, to improve blood pressure (BP) control in AA with persistently uncontrolled hypertension. METHODS: We engaged primary care practices serving rural Alabama and North Carolina residents, and in each practice we recruited approximately 25 AA adults with persistently uncontrolled hypertension (mean systolic BP \u3e140 mmHg over the year prior to enrollment plus enrollment day BP assessed by research assistants ≥140/90 mmHg). Practices were randomized to peer coaching (PC), practice facilitation (PF), both PC and PF (PC + PF), or enhanced usual care (EUC). Coaches met with participants from PC and PC + PF practices weekly for 8 weeks then monthly over one year, discussing lifestyle changes, medication adherence, home monitoring, and communication with the healthcare team. Facilitators met with PF and PC + PF practices monthly to implement ≥1 quality improvement intervention in each of four domains. Data were collected at 0, 6, and 12 months. RESULTS: We recruited 69 practices and 1596 participants; 18 practices (408 participants) were randomized to EUC, 16 (384 participants) to PF, 19 (424 participants) to PC, and 16 (380 participants) to PC + PF. Participants had mean age 57 years, 61% were women, and 56% reported annual income \u3c$20,000. LIMITATIONS: The PF intervention acts at the practice level, possibly missing intervention effects in trial participants. Neither PC nor PF currently has established clinical reimbursement mechanisms. CONCLUSIONS: This trial will fill evidence gaps regarding practice-level vs. patient-level interventions for rural impoverished AA with uncontrolled hypertension

Implications of Electronics Constraints for Solid-State Quantum Error Correction and Quantum Circuit Failure Probability

In this paper we present the impact of classical electronics constraints on a solid-state quantum dot logical qubit architecture. Constraints due to routing density, bandwidth allocation, signal timing, and thermally aware placement of classical supporting electronics significantly affect the quantum error correction circuit's error rate. We analyze one level of a quantum error correction circuit using nine data qubits in a Bacon-Shor code configured as a quantum memory. A hypothetical silicon double quantum dot quantum bit (qubit) is used as the fundamental element. A pessimistic estimate of the error probability of the quantum circuit is calculated using the total number of gates and idle time using a provably optimal schedule for the circuit operations obtained with an integer program methodology. The micro-architecture analysis provides insight about the different ways the electronics impact the circuit performance (e.g., extra idle time in the schedule), which can significantly limit the ultimate performance of any quantum circuit and therefore is a critical foundation for any future larger scale architecture analysis.Comment: 10 pages, 7 figures, 3 table

Practice Facilitation and Peer Coaching for Uncontrolled Hypertension Among Black Individuals: A Randomized Clinical Trial

IMPORTANCE: Rural Black participants need effective intervention to achieve better blood pressure (BP) control. OBJECTIVE: Among Black rural adults with persistently uncontrolled hypertension attending primary care clinics, to determine whether peer coaching (PC), practice facilitation (PF), or both (PCPF) are superior to enhanced usual care (EUC) in improving BP control. DESIGN, SETTING, AND PARTICIPANTS: A cluster randomized clinical trial was conducted in 69 rural primary care practices across Alabama and North Carolina between September 23, 2016, and September 26, 2019. The participating practices were randomized to 4 groups: PC plus EUC, PF plus EUC, PCPF plus EUC, and EUC alone. The baseline EUC approach included a laptop for each participating practice with hyperlinks to participant education on hypertension, a binder of practice tips, a poster showing an algorithm for stepped care to improve BP, and 25 home BP monitors. The trial was stopped on February 28, 2021, after final data collection. The study included Black participants with persistently uncontrolled hypertension. Data were analyzed from February 28, 2021, to December 13, 2022. INTERVENTIONS: Practice facilitators helped practices implement at least 4 quality improvement projects designed to improve BP control throughout 1 year. Peer coaches delivered a structured program via telephone on hypertension self-management throughout 1 year. MAIN OUTCOMES AND MEASURES: The primary outcome was the proportion of participants in each trial group with BP values of less than 140/90 mm Hg at 6 months and 12 months. The secondary outcome was a change in the systolic BP of participants at 6 months and 12 months. RESULTS: A total of 69 practices were randomized, and 1209 participants\u27 data were included in the analysis. The mean (SD) age of participants was 58 (12) years, and 748 (62%) were women. In the intention-to-treat analyses, neither intervention alone nor in combination improved BP control or BP levels more than EUC (at 12 months, PF vs EUC odds ratio [OR], 0.94 [95% CI, 0.58-1.52]; PC vs EUC OR, 1.30 [95% CI, 0.83-2.04]; PCPF vs EUC OR, 1.02 [95% CI, 0.64-1.64]). In preplanned subgroup analyses, participants younger than 60 years in the PC and PCPF groups experienced a significant 5 mm Hg greater reduction in systolic BP than participants younger than 60 years in the EUC group at 12 months. Practicewide BP control estimates in PF groups suggested that BP control improved from 54% to 61%, a finding that was not observed in the trial\u27s participants. CONCLUSIONS AND RELEVANCE: The results of this cluster randomized clinical trial demonstrated that neither PC nor PF demonstrated a superior improvement in overall BP control compared with EUC. However, PC led to a significant reduction in systolic BP among younger adults