Cluster Amplitudes and Their Interplay with Self-Consistency in Density Functional Methods.

Density functional theory (DFT) provides convenient electronic structure methods for the study of molecular systems and materials. Regular Kohn-Sham DFT calculations rely on unitary transformations to determine the ground-state electronic density, ground state energy, and related properties. However, for dissociation of molecular systems into open-shell fragments, due to the self-interaction error present in a large number of density functional approximations, the self-consistent procedure based on the this type of transformation gives rise to the well-known charge delocalization problem. To avoid this issue, we showed previously that the cluster operator of coupled-cluster theory can be utilized within the context of DFT to solve in an alternative and approximate fashion the ground-state self-consistent problem. This work further examines the application of the singles cluster operator to molecular ground state calculations. Two approximations are derived and explored: i) A linearized scheme of the quadratic equation used to determine the cluster amplitudes. ii) The effect of carrying the calculations in a non-self-consistent field fashion. These approaches are found to be capable of improving the energy and density of the system and are quite stable in either case. The theoretical framework discussed in this work could be used to describe, with an added flexibility, quantum systems that display challenging features and require expanded theoretical methods.

Cluster Amplitudes and Their Interplay with Self-Consistency in Density Functional Methods.

The front cover artwork is provided by the Mosquera group at Montana State University, Bozeman. The image shows theoretical elements involved in the density-functional calculations that are free of spurious fractional charges. Read the full text of the Research Article at 10.1002/cphc.202200592.

Slippery Paraelectric Transition-Metal Dichalcogenide Bilayers.

Traditional ferroelectrics undergo thermally induced phase transitions whereby their structural symmetry increases. The associated higher-symmetry structure is dubbed paraelectric. Ferroelectric transition-metal dichalcogenide bilayers have been recently shown to become paraelectric, but not much has been said of the atomistic configuration of such a phase. As discovered through numerical calculations that include molecular dynamics here, their paraelectricity can only be ascribed to a time average of ferroelectric phases with opposing intrinsic polarizations, whose switching requires macroscopically large areas to slip in unison.

Theoretical quantum model of two-dimensional propagating plexcitons.

When plasmonic excitations of metallic interfaces and nanostructures interact with electronic excitations in semiconductors, new states emerge that hybridize the characteristics of the uncoupled states. The engendered properties make these hybrid states appealing for a broad range of applications, ranging from photovoltaic devices to integrated circuitry for quantum devices. Here, through quantum modeling, the coupling of surface plasmon polaritons and mobile two-dimensional excitons such as those in atomically thin semiconductors is examined with emphasis on the case of strong coupling. Our model shows that at around the energy crossing of the dispersion relationships of the uncoupled species, they strongly interact and polariton states-propagating plexcitons-emerge. The temporal evolution of the system where surface plasmon polaritons are continuously injected into the system is simulated to gain initial insight on potential experimental realizations of these states. The results show a steady state that is dominated by the lower-energy polariton. The study theoretically further establishes the possible existence of propagating plexcitons in atomically thin semiconductors and provides important guidance for the experimental detection and characterization of such states for a wide range of optoelectronic technologies.

Understanding the Origin of Enhanced Piezoelectric Response in PVDF Matrices with Embedded ZnO Nanoparticles, from Polarizable Molecular Dynamics Simulations.

The pervasive use of portable electronic devices, powered from rechargeable batteries, represents a significant portion of the electricity consumption in the world. A sustainable and alternative energy source for these devices would require unconventional power sources, such as harvesting kinetic/potential energy from mechanical vibrations, ultrasound waves, and biomechanical motion, to name a few. Piezoelectric materials transform mechanical deformation into electric fields or, conversely, external electric fields into mechanical motion. Therefore, accurate prediction of elastic and piezoelectric properties of materials, from the atomic structure and composition, is essential for studying and optimizing new piezogenerators. Here, we demonstrate the application of harmonic-covalent and reactive force fields (FF), Dreiding and ReaxFF, respectively, coupled to the polarizable charge equilibration (PQEq) model for predicting the elastic moduli and piezoelectric response of crystalline zinc oxide (ZnO) and polyvinylidene difluoride (PVDF). Furthermore, we parametrized the ReaxFF atomic interactions for Zn-F in order to characterize the interfacial effects in hybrid PVDF matrices with embedded ZnO nanoparticles (NPs). We capture the nonlinear piezoelectric behavior of the PVDF-ZnO system at different ZnO concentrations and the enhanced response that was recently observed experimentally, between 5 and 7 wt % ZnO concentrations. From our simulation results, we demonstrate that the origin of this enhancement is due to an increase in the total atomic stress distribution at the interface between the two materials. This result provides valuable insight into the design of new and improved piezoelectric nanogenerators and demonstrates the practical value of these first-principles based modeling methods in materials science.

Partially-oxidized phosphorene sensor for the detection of sub-nano molar concentrations of nitric oxide: a first-principles study.

The development of new techniques or instruments for detecting and accurately measuring biomarker concentrations in living organisms is essential for early diagnosis of diseases, and for tracking the effectiveness of treatments. In chronic diseases, such as asthma, precise phenotyping can help predict the response of patients to treatments and reduce the risk of complications. Fractional exhaled nitric oxide (FeNO) is a positive biomarker for eosinophilic asthma in humans, and it can be directly detected in the respiratory tract, at very low and volatile concentrations, which makes real-time measurement a challenge. This work describes the first-principles design and characterization of a molecular- and back-gated electronic field-effect transistor device for the detection and measurement of ultra-low FeNO concentrations (pM-nM) from a person' s exhaled breath, as a cost-efficient alternative to the slower and more expensive techniques based on off-line sputum characterization via mass spectrometry. The proposed device uses a partially oxidized phosphorene semiconducting channel material for FeNO detection, allowing nM L-1 concentration measurements of this analyte in an array configuration with an effective sensing surface area of 8.775 µm2, which results in a predicted limit of detection (LOD) of 19 nM L-1. In spite of the limited stability of phosphorene in oxygen-rich and humid environments, the proposed device would be practical for mobile applications with disposable sensors.

Proximity Band Structure and Spin Textures on Both Sides of Topological-Insulator/Ferromagnetic-Metal Interface and Their Charge Transport Probes.

The control of recently observed spintronic effects in topological-insulator/ferromagnetic-metal (TI/FM) heterostructures is thwarted by the lack of understanding of band structure and spin textures around their interfaces. Here we combine density functional theory with Green's function techniques to obtain the spectral function at any plane passing through atoms of Bi2Se3 and Co or Cu layers comprising the interface. Instead of naively assumed Dirac cone gapped by the proximity exchange field spectral function, we find that the Rashba ferromagnetic model describes the spectral function on the surface of Bi2Se3 in contact with Co near the Fermi level EF0, where circular and snowflake-like constant energy contours coexist around which spin locks to momentum. The remnant of the Dirac cone is hybridized with evanescent wave functions from metallic layers and pushed, due to charge transfer from Co or Cu layers, a few tenths of an electron-volt below EF0 for both Bi2Se3/Co and Bi2Se3/Cu interfaces while hosting distorted helical spin texture wounding around a single circle. These features explain recent observation of sensitivity of spin-to-charge conversion signal at TI/Cu interface to tuning of EF0. Crucially for spin-orbit torque in TI/FM heterostructures, few monolayers of Co adjacent to Bi2Se3 host spectral functions very different from the bulk metal, as well as in-plane spin textures (despite Co magnetization being out-of-plane) due to proximity spin-orbit coupling in Co induced by Bi2Se3. We predict that out-of-plane tunneling anisotropic magnetoresistance in Cu/Bi2Se3/Co vertical heterostructure can serve as a sensitive probe of the type of spin texture residing at EF0.

Zirconium(IV)-Benzene Phosphonate Coordination Polymers: Lanthanide and Actinide Extraction and Thermal Properties.

Coordination polymers with different P/(Zr + P) molar ratios were prepared by combining aqueous solutions of Zr(IV) and benzenephosphonate derivatives. 1,3,5-Benzenetrisphosphonic acid (BTP) as well as phosphonocarboxylate derivatives in which carboxylate substitutes one or two of the phosphonate groups were chosen as the building blocks. The precipitates obtained on combining the two solutions were not X-ray amorphous but rather were indicative of poorly ordered materials. Hydrothermal treatment did not alter the structure of the materials produced but did result in improved crystalline order. The use of HF as a mineralizing agent during hydrothermal synthesis resulted in the crystallization of at least three relatively crystalline phases whose structure could not be determined owing to the complexity of the diffraction patterns. Gauging from the similarity of the diffraction patterns of all the phases, the poorly ordered precipitates and crystalline materials appeared to have similar underlying structures. The BTP-based zirconium phosphonates all showed a higher selectivity for lanthanides and thorium compared with cations such as Cs(+), Sr(2+), and Co(2+). Substitution of phosphonate groups by carboxylate groups did little to alter the pattern of selectivity implying that selectivity in the system was entirely determined by the -POH group with little influence from the -COOH groups. Samples with the highest phosphorus content showed the highest extraction efficiencies for lanthanide elements, especially the heavy lanthanides such as Dy(3+) and Ho(3+) with separation factors of around four with respect to La(3+). In highly acid solutions (4 M HNO3) there was a pronounced variation in extraction efficiency across the lanthanide series. In situ, nonambient diffraction was performed on ZrBTP-0.8 loaded with Th, Ce, and a complex mixture of lanthanides. In all cases the crystalline Zr2P2O7 pyrophosphate phase was formed at ∼800 °C demonstrating the versatility of this structure.

Racial and socioeconomic disparities in the treatment of unruptured intracranial aneurysms: A county hospital experience.

BACKGROUND: With increasing prevalence of unruptured intracranial aneurysms (UIAs), there is a need to provide appropriate management. Several studies have suggested that minorities in the United States have limited access to non-invasive imaging leading to increased presentation of aneurysmal subarachnoid hemorrhages (aSAHs). Given our medical institution's commitment to ensuring racial equality within our health care system, we chose to analyze our practice to assess the utilization of care provided by our neuroendovascular team. We hypothesized that given our diverse neuroendovascular care team along with our dedication to equity in healthcare, that we would find no difference in care provided to minority patients versus white patients who presented with UIAs. METHODS: We conducted a retrospective electronic medical record-based review of all patients with UIAs (n = 140) between September 2010 and June 2022 treated at a county hospital. Data regarding age at the time of treatment, gender, race, insurance type and aneurysm location were obtained. RESULTS: Of the 140 patients that underwent treatment, 54 % of patients were from the Black/Hispanic group and 46 % were from the white/non-Hispanic group. Commercial/private insurance was more common among White/NonHispanic patients (57.7 % vs 51.4 %) whereas Medicaid or uninsured status was more common among Black/Hispanic patients (25.7 % vs 15.4 %), although these differences were not statistically significant. CONCLUSION: Building a diverse neuroendovascular physician team with intentionality to equity in healthcare, and providing appropriate funding and resources to facilities used by marginalized populations, such as safety-net institutions, can mitigate minority patients' limited access to intracranial aneurysmal care.

Percutaneous treatment of lumbar synovial cysts with bleomycin: A case report.

Lumbar synovial cysts (LSC) that protrude into the spinal canal can cause lower back pain, neurogenic claudication, and radiculopathy. Often diagnosed in the elderly population (typically ∼60 years of age) with a slight preponderance for females, their underlying etiology is thought to be due to degeneration of the adjacent facet joint, with the most common location at the level of L4-L5. Treatment of LSC can be conservative (with NSAIDs and physical therapy), percutaneous (with rupture), or surgically (with decompression with or without fusion). Percutaneous treatment of LSC involves rupturing the cyst by injecting it with steroids and local anesthetics. Although this option is less invasive than surgery, multiple studies have documented recurrence with this method and patients eventually undergoing surgical intervention. In this report, we document a case where a patient who presented with a symptomatic LSC underwent successful percutaneous treatment with bleomycin.

Prevention and cure of murine C. difficile infection by a Lachnospiraceae strain.

We sought to better understand how intestinal microbiota confer protection against Clostridioides difficile (C. difficile) infection (CDI). We utilized gnotobiotic altered Schaedler flora (ASF) mice, which lack the abnormalities of germfree (GF) mice as well as the complexity and heterogeneity of antibiotic-treated mice. Like GF mice, ASF mice were highly prone to rapid lethal CDI, without antibiotics, while very low infectious doses resulted in chronic CDI. Administering such chronic CDI mice an undefined preparation of Clostridia lowered C. difficile levels by several logs. Importantly, such resolution of CDI was associated with colonization of Lachnospiraceae. Fractionation of the Clostridia population to enrich for Lachnospiraceae led to the appreciation that its CDI-impeding property strongly associated with a specific Lachnospiraceae strain, namely uncultured bacteria and archaea (UBA) 3401. UBA3401 was recalcitrant to being propagated as a pure culture but could be maintained in ASF mice, wherein it comprised up to about 50% of the intestinal microbiota, which was sufficient to generate a high-quality genomic sequence of this bacterium. Sequence analysis and ex vivo study of UBA3401 indicated that it had the ability to secrete substance(s) that directly impeded C. difficile growth. Moreover, in vivo administration of UBA3401/ASF feces provided strong protection to C. difficile challenge. Thus, UBA3401 may contribute to and/or provide a means to study microbiota-mediated CDI resistance.

Safety and efficacy of endovascular versus microsurgical treatment of unruptured wide-necked middle cerebral artery aneurysms: a propensity score-matched analysis of the NeuroVascular Quality Initiative Quality Outcomes Database Cerebral Aneurysm Registry.

OBJECTIVE: Unruptured, wide-necked middle cerebral artery (WN-MCA) aneurysms have traditionally been considered ideal candidates for microsurgery (MS), although endovascular treatment (EVT) has dramatically increased in popularity with the advent of novel devices such as intrasaccular flow disruptors. The purpose of this study was to evaluate the safety and efficacy of MS versus EVT for unruptured WN-MCA aneurysms. METHODS: The NeuroVascular Quality Initiative Quality Outcomes Database (NVQI-QOD) Cerebral Aneurysm Registry, a multiinstitutional, prospectively collected procedural database, was queried for cases of unruptured WN-MCA aneurysms treated with MS or EVT between 2015 and 2022. A wide neck was defined as an aneurysm neck ≥ 4 mm or a dome/neck ratio ≤ 2. Demographics and aneurysm characteristics were queried. Propensity score matching (PSM) was utilized to match aneurysm size, number of aneurysms treated, patient age, and aneurysm status. Safety outcomes were evaluated including intraoperative and postoperative complication rates. Aneurysm occlusion status and clinical outcomes using the modified Rankin Scale (mRS) score at discharge and the last follow-up were also assessed. RESULTS: Of 671 unruptured MCA aneurysms, 319 were wide necked. Thirty cases were excluded, as the aneurysm had been previously treated. Two hundred eighty-nine operations (203 EVT, 86 MS) in 282 patients satisfied inclusion criteria. After PSM, there were 86 operations in each group for analysis. The mean aneurysm width was 5.0 (EVT) versus 4.9 mm (MS; p = 0.285). Safety data showed similar intraoperative (7.0% EVT vs 3.5% MS, p = 0.496) and postoperative (4.7% vs 7%, p = 0.746) complication rates. The MS patients were more likely to have complete aneurysm occlusion at discharge (90.4% vs 58.8%, p < 0.001). In a limited subset of patients (52.9%) for whom outcome data were available, the EVT patients were more likely to have an mRS score 0 at discharge (50/59 [84.7%] vs 29/54 [53.7%], p < 0.0003] and at the last follow-up (36/55 [65.5%] vs 13/36 [36.1%], p = 0.006). CONCLUSIONS: This study describes a large, modern cohort of propensity score-matched patients who underwent treatment of unruptured WN-MCA aneurysms. Safety data on intraoperative and postoperative complication rates were similar in both treatment groups. MS was more likely to result in complete aneurysm occlusion at discharge. In a subset of patients with available outcome data, EVT was associated with better functional outcomes at discharge and the last follow-up. Given the lack of complete follow-up data and rates of retreatment, these results should be interpreted cautiously.

Review and Proposal for a Classification System of Soft Robots Inspired by Animal Morphology.

The aim of this article is to propose a bio-inspired morphological classification for soft robots based on an extended review process. The morphology of living beings that inspire soft robotics was analyzed; we found coincidences between animal kingdom morphological structures and soft robot structures. A classification is proposed and depicted through experiments. Additionally, many soft robot platforms present in the literature are classified using it. This classification allows for order and coherence in the area of soft robotics and provides enough freedom to expand soft robotics research.

Urinary bladder retention secondary to intranasal administration of oxymetazoline "Afrin" for intra-arterial chemotherapy.

Selective ophthalmic artery infusion of chemotherapy (SOAIC) has emerged as the standard of care for retinoblastoma (RB). Intranasal oxymetazoline (INO), Afrin, is often intraoperatively administered adjunctively to optimize flow to the orbit. There has been one report to date that suggests the adjunctive use of INO has led to systemic side effects. To our knowledge, this is the first documented case of INO causing urinary retention in a patient undergoing SOAIC, and the recommended treatment.

A Proposal of Bioinspired Soft Active Hand Prosthesis.

Soft robotics have broken the rigid wall of interaction between humans and robots due to their own definition and manufacturing principles, allowing robotic systems to adapt to humans and enhance or restore their capabilities. In this research we propose a dexterous bioinspired soft active hand prosthesis based in the skeletal architecture of the human hand. The design includes the imitation of the musculoskeletal components and morphology of the human hand, allowing the prosthesis to emulate the biomechanical properties of the hand, which results in better grips and a natural design. CAD models for each of the bones were developed and 3D printing was used to manufacture the skeletal structure of the prosthesis, also soft materials were used for the musculoskeletal components. A myoelectric control system was developed using a recurrent neural network (RNN) to classify the hand gestures using electromyography signals; the RNN model achieved an accuracy of 87% during real time testing. Objects with different size, texture and shape were tested to validate the grasping performance of the prosthesis, showing good adaptability, soft grasping and mechanical compliance to object of the daily life.

Peritoneal and retroperitoneal anatomy and its relevance for cross-sectional imaging.

It is difficult to identify normal peritoneal folds and ligaments at imaging. However, infectious, inflammatory, neoplastic, and traumatic processes frequently involve the peritoneal cavity and its reflections; thus, it is important to identify the affected peritoneal ligaments and spaces. Knowledge of these structures is important for accurate reporting and helps elucidate the sites of involvement to the surgeon. The potential peritoneal spaces; the peritoneal reflections that form the peritoneal ligaments, mesenteries, and omenta; and the natural flow of peritoneal fluid determine the route of spread of intraperitoneal fluid and disease processes within the abdominal cavity. The peritoneal ligaments, mesenteries, and omenta also serve as boundaries for disease processes and as conduits for the spread of disease.

Thermal properties of single-layer MoS2-WS2 alloys enabled by machine-learned interatomic potentials.

Two-dimensional (2D) quantum materials are poised to transform conventional electronics for a wide spectrum of applications that will encompass chemical sciences. For the study of thermal transport in single-layer (1L) or multi-layer transition metal dichalcogenides (TMDs), this work explores the combination of density functional theory (DFT) and algorithmic training for the generation of a moment tensor potential (MTP) that models 1L-MoS2, 1L-WS2 and their alloys, and demonstrates a synergy of theoretical techniques that is anticipated to play an important role in the field. From a high-performance computing perspective, these yield very convenient inter-atomic (or inter-molecular in other contexts) potentials that are useful to predict the response of quantum materials to thermal perturbations, or other driving forces. We show that our trained MTP functions successfully describe vibrational properties of the systems, and their thermal conductivities. The trained potential displays consistent agreement with DFT calculations, as well as the Stillinger-Weber (SW) potential. We also find that the thermal conductivity of the 2D alloys is little affected by sulfur vacancies. This is a behavior that may aid the fine-tuning of material's thermal properties for heat management and energy storage and conversion applications.

Effect of surface oxidation on the electronic transport properties of phosphorene gas sensors: a computational study.

The potential for phosphorene-based devices has been compromised by the material's fast degradation under ambient conditions. Its tendency to fully oxidize under O2-rich and humid environments, leads to the loss of its appealing semiconducting properties. However, partially-oxidized phosphorene (po-phosphorene), has been demonstrated to remain stable over significantly longer periods of time, thereby enabling its use in sensing applications. Here, we present a computational study of po-phosphorene-based gas sensors, using the Density-Functional-based Tight Binding (DFTB) method. We show that DFTB accurately predicts the bandgap for the pristine material and po-phosphorene, the electronic transport properties of po-phosphorene at different surface oxygen concentrations, and the appropriate trends in Density-of-States (DOS) contributions caused by adsorbed gas molecules, to demonstrate its potential application in the development of gas sensors. Results are compared against the more traditional and expensive Density Functional Theory (DFT) method using generalized gradient approximation (GGA) exchange-correlation functionals, which significantly underestimates the material's bandgap.

Mid-term follow-up of staged bilateral internal carotid artery aneurysm treatment with Pipeline embolization.

BACKGROUND: Endovascular treatment of large complex morphology aneurysms is challenging. High recanalization rates have been reported with techniques such as stent-assisted coiling and balloon-assisted coiling. Flow diverter devices have been introduced to improve efficacy outcomes and recanalization rates. Thromboembolic complications and in-device stenosis are certainly more worrisome when treatment of bilateral internal carotid arteries has been performed. This study aimed to report our experience with mid-term imaging follow-up of staged bilateral Pipeline embolization device placement for the treatment of bilateral internal carotid artery aneurysms. METHODS: We reviewed the clinical, angiographic, and follow-up imaging data in all consecutive patients treated with bilateral internal carotid artery aneurysms who underwent elective Pipeline embolization. RESULTS: Six female patients were treated, harboring a total of 13 aneurysms. Of these, 60% were asymptomatic. Diplopia and headache were the most common symptoms. The most common location was the paraclinoid segment (6/13), including by cavernous segment (4/13) and ophthalmic segment (2/13). Successful delivery of the device was achieved in 12 cases. Difficult distal access precluded the deployment of the device in one case. The treatment was always staged with at least eight weeks' difference between the two procedures. All aneurysm necks were covered completely. There were no periprocedural complications. Angiographic follow-up ranged between 3 and 12 months, and computed tomography angiogram follow-up ranged between 2 and 24 months. Complete aneurysm occlusion was achieved in all cases. CONCLUSION: In our series, Pipeline deployment for the treatment of bilateral internal carotid artery aneurysms in a staged fashion is safe and feasible. Mid-term imaging follow-up showed permanent occlusion of all the treated aneurysms.