The malignant transformation of endometriosis: Is there a left lateral predisposition of ovarian clear cell and endometrioid carcinomas?

INTRODUCTION: Endometriosis affects 10% of women of reproductive age. There is evidence for a left lateral predisposition of endometriotic lesions and a 1.9-fold greater risk of ovarian cancer in endometriosis. The aim of this study is to determine whether a left lateral predisposition of ovarian clear-cell carcinoma (CCC) and endometrioid carcinoma (EC) exists. MATERIALS AND METHODS: A retrospective cohort study of all EC and CCC patients in Northern Ireland between March-2011 and June-2018. ANOVA was used to analyse preoperative prediction of stage, chi-squared (χ2) was used to compare left- and right-sided masses. Survival was estimated using Kaplan-Meier and log-rank test. A p-value <0.05 was considered significant. RESULTS: 158 patients were identified (95 EC, 55 CCC, 8 mixed). Mean age was 57.65 years with 69% presenting at stage 1. The mean CA125 was 559 U/mL (p = 0.850) and mean abdominal mass size was 14.12 cm (p = 0.732). The most common presenting symptom was an abdominal mass (37%). Despite 67% of patients having endometriosis on final pathology, only 8.9% had a known history pre-operatively. 51% of tumours were located on the left (p = 0.036). For unilateral tumours this was significant for EC (P = 0.002) but not for CCC (P = 0.555). The 1-, 3- and 5-year overall survival for all types/stages was 85%, 78% and 71% respectively. CONCLUSION: While CCC and EC are associated with endometriosis, only EC exhibits a left lateral predisposition. There is no association between preoperative CA125 or abdominal mass size and stage of disease.

Probing Nuclear Spin Effects on Electronic Spin Coherence via EPR Measurements of Vanadium(IV) Complexes.

Quantum information processing (QIP) has the potential to transform numerous fields from cryptography, to finance, to the simulation of quantum systems. A promising implementation of QIP employs unpaired electronic spins as qubits, the fundamental units of information. Though molecular electronic spins offer many advantages, including chemical tunability and facile addressability, the development of design principles for the synthesis of complexes that exhibit long qubit superposition lifetimes (also known as coherence times, or T2) remains a challenge. As nuclear spins in the local qubit environment are a primary cause of shortened superposition lifetimes, we recently conducted a study which employed a modular spin-free ligand scaffold to place a spin-laden propyl moiety at a series of fixed distances from an S = 1/2 vanadium(IV) ion in a series of vanadyl complexes. We found that, within a radius of 4.0(4)-6.6(6) Å from the metal center, nuclei did not contribute to decoherence. To assess the generality of this important design principle and test its efficacy in a different coordination geometry, we synthesized and investigated three vanadium tris(dithiolene) complexes with the same ligand set employed in our previous study: K2[V(C5H6S4)3] (1), K2[V(C7H6S6)3] (2), and K2[V(C9H6S8)3] (3). We specifically interrogated solutions of these complexes in DMF-d7/toluene-d8 with pulsed electron paramagnetic resonance spectroscopy and electron nuclear double resonance spectroscopy and found that the distance dependence present in the previously synthesized vanadyl complexes holds true in this series. We further examined the coherence properties of the series in a different solvent, MeCN-d3/toluene-d8, and found that an additional property, the charge density of the complex, also affects decoherence across the series. These results highlight a previously unknown design principle for augmenting T2 and open new pathways for the rational synthesis of complexes with long coherence times.

Synthetic Approach To Determine the Effect of Nuclear Spin Distance on Electronic Spin Decoherence.

Nuclear-electronic interactions are a fundamental phenomenon which impacts fields from magnetic resonance imaging to quantum information processing (QIP). The realization of QIP would transform diverse areas of research including accurate simulation of quantum dynamics and cryptography. One promising candidate for the smallest unit of QIP, a qubit, is electronic spin. Electronic spins in molecules offer significant advantages with regard to QIP, and for the emerging field of quantum sensing. Yet relative to other qubit candidates, they possess shorter superposition lifetimes, known as coherence times or T2, due to interactions with nuclear spins in the local environment. Designing complexes with sufficiently long values of T2 requires an understanding of precisely how the position of nuclear spins relative to the electronic spin center affects decoherence. Herein, we report the first synthetic study of the relationship between nuclear spin-electron spin distance and decoherence. Through the synthesis of four vanadyl complexes, (Ph4P)2[VO(C3H6S2)2] (1), (Ph4P)2[VO(C5H6S4)2] (2), (Ph4P)2[VO(C7H6S6)2] (3), and (Ph4P)2[VO(C9H6S8)2] (4), we are able to synthetically place a spin-laden propyl moiety at well-defined distances from an electronic spin center by employing a spin-free carbon-sulfur scaffold. We interrogate this series of molecules with pulsed electron paramagnetic resonance (EPR) spectroscopy to determine their coherence times. Our studies demonstrate a sharp jump in T2 when the average V-H distance is decreased from 6.6(6) to 4.0(4) Å, indicating that spin-active nuclei sufficiently close to the electronic spin center do not contribute to decoherence. These results illustrate the power of synthetic chemistry in elucidating the fundamental mechanisms underlying electronic polarization transfer and provide vital principles for the rational design of long-coherence electronic qubits.

Long Coherence Times in Nuclear Spin-Free Vanadyl Qubits.

Quantum information processing (QIP) offers the potential to create new frontiers in fields ranging from quantum biology to cryptography. Two key figures of merit for electronic spin qubits, the smallest units of QIP, are the coherence time (T2), the lifetime of the qubit, and the spin-lattice relaxation time (T1), the thermally defined upper limit of T2. To achieve QIP, processable qubits with long coherence times are required. Recent studies on (Ph4P-d20)2[V(C8S8)3], a vanadium-based qubit, demonstrate that millisecond T2 times are achievable in transition metal complexes with nuclear spin-free environments. Applying these principles to vanadyl complexes offers a route to combine the previously established surface compatibility of the flatter vanadyl structures with a long T2. Toward those ends, we investigated a series of four qubits, (Ph4P)2[VO(C8S8)2] (1), (Ph4P)2[VO(ß-C3S5)2] (2), (Ph4P)2[VO(α-C3S5)2] (3), and (Ph4P)2[VO(C3S4O)2] (4), by pulsed electron paramagnetic resonance (EPR) spectroscopy and compared the performance of these species with our recently reported set of vanadium tris(dithiolene) complexes. Crucially we demonstrate that solutions of 1-4 in SO2, a uniquely polar nuclear spin-free solvent, reveal T2 values of up to 152(6) µs, comparable to the best molecular qubit candidates. Upon transitioning to vanadyl species from the tris(dithiolene) analogues, we observe a remarkable order of magnitude increase in T1, attributed to stronger solute-solvent interactions with the polar vanadium-oxo moiety. Simultaneously, we detect a small decrease in T2 for the vanadyl analogues relative to the tris(dithiolene) complexes. We attribute this decrease to the absence of one nuclear spin-free ligand, which served to shield the vanadium centers against solvent nuclear spins. Our results highlight new design principles for long T1 and T2 times by demonstrating the efficacy of ligand-based tuning of solute-solvent interactions.

A One-Hole Cu4S Cluster with N2O Reductase Activity: A Structural and Functional Model for CuZ.

During bacterial denitrification, two-electron reduction of N2O occurs at a [Cu4(µ4-S)] catalytic site (CuZ*) embedded within the nitrous oxide reductase (N2OR) enzyme. In this Communication, an amidinate-supported [Cu4(µ4-S)] model cluster in its one-hole (S = 1/2) redox state is thoroughly characterized. Along with its two-hole redox partner and fully reduced clusters reported previously, the new species completes the two-electron redox series of [Cu4(µ4-S)] model complexes with catalytically relevant oxidation states for the first time. More importantly, N2O is reduced by the one-hole cluster to produce N2 and the two-hole cluster, thereby completing a closed cycle for N2O reduction. Not only is the title complex thus the best structural model for CuZ* to date, but it also serves as a functional CuZ* mimic.

Unexpected suppression of spin-lattice relaxation via high magnetic field in a high-spin iron(iii) complex.

A counterintuitive three-order of magnitude slowing of the spin-lattice relaxation rate is observed in a high spin qubit at high magnetic field via multifrequency pulsed electron paramagnetic resonance measurements.

Employing Forbidden Transitions as Qubits in a Nuclear Spin-Free Chromium Complex.

The implementation of quantum computation (QC) would revolutionize scientific fields ranging from encryption to quantum simulation. One intuitive candidate for the smallest unit of a quantum computer, a qubit, is electronic spin. A prominent proposal for QC relies on high-spin magnetic molecules, where multiple transitions between the many MS levels are employed as qubits. Yet, over a decade after the original notion, the exploitation of multiple transitions within a single manifold for QC remains unrealized in these high-spin species due to the challenge of accessing forbidden transitions. To create a proof-of-concept system, we synthesized the novel nuclear spin-free complex [Cr(C3S5)3](3-) with precisely tuned zero-field splitting parameters that create two spectroscopically addressable transitions, with one being a forbidden transition. Pulsed electron paramagnetic resonance (EPR) measurements enabled the investigation of the coherent lifetimes (T2) and quantum control (Rabi oscillations) for two transitions, one allowed and one forbidden, within the S = (3)/2 spin manifold. This investigation represents a step forward in the development of high-spin species as a pathway to scalable QC systems within magnetic molecules.

Influence of electronic spin and spin-orbit coupling on decoherence in mononuclear transition metal complexes.

Enabling the rational synthesis of molecular candidates for quantum information processing requires design principles that minimize electron spin decoherence. Here we report a systematic investigation of decoherence via the synthesis of two series of paramagnetic coordination complexes. These complexes, [M(C2O4)3](3-) (M = Ru, Cr, Fe) and [M(CN)6](3-) (M = Fe, Ru, Os), were prepared and interrogated by pulsed electron paramagnetic resonance (EPR) spectroscopy to assess quantitatively the influence of the magnitude of spin (S = (1)/2, (3)/2, (5)/2) and spin-orbit coupling (ζ = 464, 880, 3100 cm(-1)) on quantum decoherence. Coherence times (T2) were collected via Hahn echo experiments and revealed a small dependence on the two variables studied, demonstrating that the magnitudes of spin and spin-orbit coupling are not the primary drivers of electron spin decoherence. On the basis of these conclusions, a proof-of-concept molecule, [Ru(C2O4)3](3-), was selected for further study. The two parameters establishing the viability of a qubit are a long coherence time, T2, and the presence of Rabi oscillations. The complex [Ru(C2O4)3](3-) exhibits both a coherence time of T2 = 3.4 µs and the rarely observed Rabi oscillations. These two features establish [Ru(C2O4)3](3-) as a molecular qubit candidate and mark the viability of coordination complexes as qubit platforms. Our results illustrate that the design of qubit candidates can be achieved with a wide range of paramagnetic ions and spin states while preserving a long-lived coherence.

Brain parenchymal fraction predicts motor improvement following intensive task-oriented motor rehabilitation for chronic stroke.

BACKGROUND AND PURPOSE: Infarct volume and location have a weak relationship with motor deficit in patients with chronic stroke. Recent research has focused on the relationship between spared or seemingly "healthy" neural tissue and motor function. In this study we examined MRI scans of patients with chronic stroke to determine if characteristics of seemingly normal parenchyma could predict either response to different forms of upper extremity physical rehabilitation or to pre-treatment motor status. METHODS: Individuals with chronic stroke (ages 60.6 ± 11.9 years) and mild/moderate upper extremity hemiparesis were administered either CI therapy (n = 14) or a comparison therapy (n = 29). The patients were assessed prior to and following therapy with MRI scans and the Wolf Motor Function Test (WMFT) Performance Time measure. Total voxels in combined grey matter (GM) and white matter (WM) segments (parenchymal volume) were divided by total voxels in GM, WM, and cerebrospinal fluid segments (intracranial volume) to obtain the brain parenchymal fraction (BPF). RESULTS: BPF correlated with treatment gains on the WMFT (r(43) = -0.31, p = 0.04). Significant correlations between pre-treatment motor function and BPF were not observed. CONCLUSIONS: Individuals with greater BPFs after stroke show larger arm function gains after CI therapy, suggesting that reductions in volume of normal-appearing tissue may relate to ability to benefit from rehabilitation therapy in chronic stroke.

Electronic business in the home medical equipment industry.

This paper aims at developing electronic business solutions to increase value for the home medical equipment industry. First, an electronic strategic value chain model was developed for the home medical equipment industry. Second, electronic business solutions were mapped from this model. Third, the top 20 dominant companies in the home medical equipment industry were investigated to see the current adoption patterns of these electronic business solutions. The solutions will be beneficial to decision-makers in the information technology adoptions in the home medical equipment industry to increase the business values.

Synthesis and structure of solution-stable one-dimensional palladium wires.

One-dimensional metal wires are valuable materials because of their optical and electronic anisotropy, and they have potential utility in devices such as photovoltaic cells and molecular sensors. However, despite more than a century of research, only a few examples exist of well-defined one-dimensional (1D) metal wires that allow for the rational variation of conductivity. Herein we describe the first examples of 1D molecular wires supported by Pd-Pd bonds, the thin-film conductive properties of which can be altered by controlled molecular changes. Wires based on Pd(III) give semiconducting films with a modifiable bandgap, whereas wires based on Pd(2.5) give films that display metallic conductivity above 200 K: a metallic state has not been reported previously for any polymer composed of 1D metal wires. The wires are infinite in the solid state and maintain 1D structures in solution with lengths of up to 750 nm. Solution stability enables thin film coating, a requisite for device fabrication using molecular wires.