Microfluidic electrochemical cell for in situ structural characterization of amorphous thin-film catalysts using high-energy X-ray scattering.

Porous, high-surface-area electrode architectures are described that allow structural characterization of interfacial amorphous thin films with high spatial resolution under device-relevant functional electrochemical conditions using high-energy X-ray (>50 keV) scattering and pair distribution function (PDF) analysis. Porous electrodes were fabricated from glass-capillary array membranes coated with conformal transparent conductive oxide layers, consisting of either a 40 nm-50 nm crystalline indium tin oxide or a 100 nm-150 nm-thick amorphous indium zinc oxide deposited by atomic layer deposition. These porous electrodes solve the problem of insufficient interaction volumes for catalyst thin films in two-dimensional working electrode designs and provide sufficiently low scattering backgrounds to enable high-resolution signal collection from interfacial thin-film catalysts. For example, PDF measurements were readily obtained with 0.2 Šspatial resolution for amorphous cobalt oxide films with thicknesses down to 60 nm when deposited on a porous electrode with 40 µm-diameter pores. This level of resolution resolves the cobaltate domain size and structure, the presence of defect sites assigned to the domain edges, and the changes in fine structure upon redox state change that are relevant to quantitative structure-function modeling. The results suggest the opportunity to leverage the porous, electrode architectures for PDF analysis of nanometre-scale surface-supported molecular catalysts. In addition, a compact 3D-printed electrochemical cell in a three-electrode configuration is described which is designed to allow for simultaneous X-ray transmission and electrolyte flow through the porous working electrode.

Resolving the Chemically Discrete Structure of Synthetic Borophene Polymorphs.

Atomically thin two-dimensional (2D) materials exhibit superlative properties dictated by their intralayer atomic structure, which is typically derived from a limited number of thermodynamically stable bulk layered crystals (e.g., graphene from graphite). The growth of entirely synthetic 2D crystals, those with no corresponding bulk allotrope, would circumvent this dependence upon bulk thermodynamics and substantially expand the phase space available for structure-property engineering of 2D materials. However, it remains unclear if synthetic 2D materials can exist as structurally and chemically distinct layers anchored by van der Waals (vdW) forces, as opposed to strongly bound adlayers. Here, we show that atomically thin sheets of boron (i.e., borophene) grown on the Ag(111) surface exhibit a vdW-like structure without a corresponding bulk allotrope. Using X-ray standing wave-excited X-ray photoelectron spectroscopy, the positions of boron in multiple chemical states are resolved with sub-angström spatial resolution, revealing that the borophene forms a single planar layer that is 2.4 Å above the unreconstructed Ag surface. Moreover, our results reveal that multiple borophene phases exhibit these characteristics, denoting a unique form of polymorphism consistent with recent predictions. This observation of synthetic borophene as chemically discrete from the growth substrate suggests that it is possible to engineer a much wider variety of 2D materials than those accessible through bulk layered crystal structures.

Antibiotic treatment for uncomplicated and mild complicated diverticulitis: outpatient treatment for everyone.

PURPOSE: Antibiotic treatment is the treatment of choice for uncomplicated diverticulitis (uD) and can be performed for mild complicated diverticulitis (mcD). In several cases, outpatient treatment (OT) can be undertaken. This study assessed the 1-month failure rate of OT for uD/mcD compared to inpatient treatment (IT), and identified predictive factors for treatment failure. METHODS: All consecutive patients (2006-2012) diagnosed with uD/mcD by CT scan were retrospectively analyzed. Acute uD was defined as absence of the following: abscess, fistula, extraluminal contrast, pneumoperitoneum, and need for immediate percutaneous drainage/surgery. Acute mcD was defined as complicated diverticulitis with abscess <4 cm or pneumoperitoneum <2 cm. All patients received antibiotherapy. Treatment failure was defined as (re)hospitalization the first month after treatment onset or need of drainage/surgery during hospitalization. All patients were contacted using a standardized questionnaire. RESULTS: Out of 540 uD/mcD, IT was offered to 369 patients (68%) and OT to 171 patients (32%). The IT group had higher median age, more women, higher median Charlson Index, more severe median Ambrosetti score, longer median time in the emergency room, and higher median CRP. Response rates to the questionnaire were 56% (IT) vs. 62% (OT), p = 0.18. Failure rates were 32% in IT vs. 10% in OT group, p < 0.01. Among the uD/mcD patients, admission/CT time between midnight and 6 AM, Ambrosetti score of 4, and free air around the colon were risk factors for failure. CONCLUSIONS: Outpatient treatment for uncomplicated/mild complicated diverticulitis is feasible and safe. Prognostic factors of failure necessitating closer follow-up were admission/CT time, Ambrosetti score of 4, and free air around the colon.

Liquid Water- and Heat-Resistant Hybrid Perovskite Photovoltaics via an Inverted ALD Oxide Electron Extraction Layer Design.

Despite rapid advances in conversion efficiency (>22%), the environmental stability of perovskite solar cells remains a substantial barrier to commercialization. Here, we show a significant improvement in the stability of inverted perovskite solar cells against liquid water and high operating temperature (100 °C) by integrating an ultrathin amorphous oxide electron extraction layer via atomic layer deposition (ALD). These unencapsulated inverted devices exhibit a stable operation over at least 10 h when subjected to high thermal stress (100 °C) in ambient environments, as well as upon direct contact with a droplet of water without further encapsulation.

Low-Temperature Atomic Layer Deposition of MoS2 Films.

Wet chemical screening reveals the very high reactivity of Mo(NMe2 )4 with H2 S for the low-temperature synthesis of MoS2 . This observation motivated an investigation of Mo(NMe2 )4 as a volatile precursor for the atomic layer deposition (ALD) of MoS2 thin films. Herein we report that Mo(NMe2 )4 enables MoS2 film growth at record low temperatures-as low as 60 °C. The as-deposited films are amorphous but can be readily crystallized by annealing. Importantly, the low ALD growth temperature is compatible with photolithographic and lift-off patterning for the straightforward fabrication of diverse device structures.

Impact of Video Education on Influenza Vaccination in Pregnancy.

OBJECTIVE: Despite influenza vaccination being an integral part of prenatal care, vaccination rates remain low. To evaluate the impact of pre-visit video education on patients' vaccination health beliefs and vaccination rate. STUDY DESIGN: From November 2013-January 2014 unvaccinated patients seen for routine prenatal carewere randomized into 2 study groups: pre-visit vaccination video education or control. Pre- and post-video health beliefs were assessed on a 5-point scale, and unvaccinated participants were subsequently interviewed by phone. RESULTS: In 105 randomized participants, intervention positively influenced health beliefs, as demonstrated by differences in mean pre- versus post-video scores for intervention versus control: vaccination may harm mother (difference = -0.05, p = 0.009) and baby (difference = -0.44, p = 0.015), and vaccination can protect mother (difference = 0.49, p = 0.003) and baby (difference = 0.59, p = 0.001). Vaccination rates were 28% intervention and 25% control (p = 0.70). Provider recommendation was associated with vaccination (47% if recommended vs. 12% if not, p < 0.001). Phone interviews revealed susceptibility, to influenza and vaccine safety as primary reasons for remaining unvaccinated. CONCLUSION: Video education positively influenced vaccination health beliefs without impacting vaccination rates. Physician's recommendation was strongly associated with participant's decision to become vaccinated and may be most effective when emphasizing influenza vaccination's protective impact on the newborn,.

Templating sub-10 nm atomic layer deposited oxide nanostructures on graphene via one-dimensional organic self-assembled monolayers.

Molecular-scale control over the integration of disparate materials on graphene is a critical step in the development of graphene-based electronics and sensors. Here, we report that self-assembled monolayers of 10,12-pentacosadiynoic acid (PCDA) on epitaxial graphene can be used to template the reaction and directed growth of atomic layer deposited (ALD) oxide nanostructures with sub-10 nm lateral resolution. PCDA spontaneously assembles into well-ordered domains consisting of one-dimensional molecular chains that coat the entire graphene surface in a manner consistent with the symmetry of the underlying graphene lattice. Subsequently, zinc oxide and alumina ALD precursors are shown to preferentially react with the functional moieties of PCDA, resulting in templated oxide nanostructures. The retention of the original one-dimensional molecular ordering following ALD is dependent on the chemical reaction pathway and the stability of the monolayer, which can be enhanced via ultraviolet-induced molecular cross-linking.

Ambient-processable high capacitance hafnia-organic self-assembled nanodielectrics.

Ambient and solution-processable, low-leakage, high capacitance gate dielectrics are of great interest for advances in low-cost, flexible, thin-film transistor circuitry. Here we report a new hafnium oxide-organic self-assembled nanodielectric (Hf-SAND) material consisting of regular, alternating π-electron layers of 4-[[4-[bis(2-hydroxyethyl)amino]phenyl]diazenyl]-1-[4-(diethoxyphosphoryl) benzyl]pyridinium bromide) (PAE) and HfO2 nanolayers. These Hf-SAND multilayers are grown from solution in ambient with processing temperatures ≤150 °C and are characterized by AFM, XPS, X-ray reflectivity (2.3 nm repeat spacing), X-ray fluorescence, cross-sectional TEM, and capacitance measurements. The latter yield the largest capacitance to date (1.1 µF/cm(2)) for a solid-state solution-processed hybrid inorganic-organic gate dielectric, with effective oxide thickness values as low as 3.1 nm and have gate leakage <10(-7) A/cm(2) at ±2 MV/cm using photolithographically patterned contacts (0.04 mm(2)). The sizable Hf-SAND capacitances are attributed to relatively large PAE coverages on the HfO2 layers, confirmed by X-ray reflectivity and X-ray fluorescence. Random network semiconductor-enriched single-walled carbon nanotube transistors were used to test Hf-SAND utility in electronics and afforded record on-state transconductances (5.5 mS) at large on:off current ratios (I(ON):I(OFF)) of ~10(5) with steep 150 mV/dec subthreshold swings and intrinsic field-effect mobilities up to 137 cm(2)/(V s). Large-area devices (>0.2 mm(2)) on Hf-SAND (6.5 nm thick) achieve mA on currents at ultralow gate voltages (<1 V) with low gate leakage (<2 nA), highlighting the defect-free and conformal nature of this nanodielectric. High-temperature annealing in ambient (400 °C) has limited impact on Hf-SAND leakage densities (<10(-6) A/cm(2) at ±2 V) and enhances Hf-SAND multilayer capacitance densities to nearly 1 µF/cm(2), demonstrating excellent compatibility with device postprocessing methodologies. These results represent a significant advance in hybrid organic-inorganic dielectric materials and suggest synthetic routes to even higher capacitance materials useful for unconventional electronics.

Chemically resolved interface structure of epitaxial graphene on SiC(0001).

Atomic-layer 2D crystals have unique properties that can be significantly modified through interaction with an underlying support. For epitaxial graphene on SiC(0001), the interface strongly influences the electronic properties of the overlaying graphene. We demonstrate a novel combination of x-ray scattering and spectroscopy for studying the complexities of such a buried interface structure. This approach employs x-ray standing wave-excited photoelectron spectroscopy in conjunction with x-ray reflectivity to produce a highly resolved chemically sensitive atomic profile for the terminal substrate bilayers, interface, and graphene layers along the SiC[0001] direction.

In-situ probe of gate dielectric-semiconductor interfacial order in organic transistors: origin and control of large performance sensitivities.

Organic thin film transistor (OTFT) performance is highly materials interface-dependent, and dramatic performance enhancements can be achieved by properly modifying the semiconductor/gate dielectric interface. However, the origin of these effects is not well understood, as this is a classic "buried interface" problem that has traditionally been difficult to address. Here we address the question of how n-octadecylsilane (OTS)-derived self-assembled monolayers (SAMs) on Si/SiO(2) gate dielectrics affect the OTFT performance of the archetypical small-molecule p-type semiconductors P-BTDT (phenylbenzo[d,d]thieno[3,2-b;4,5-b]dithiophene) and pentacene using combined in situ sum frequency generation spectroscopy, atomic force microscopy, and grazing incidence and reflectance X-ray scattering. The molecular order and orientation of the OTFT components at the dielectric/semiconductor interface is probed as a function of SAM growth mode in order to understand how this impacts the overlying semiconductor growth mode, packing, crystallinity, and carrier mobility, and hence, transistor performance. This understanding, using a new, humidity-specific growth procedure, leads to a reproducible, scalable process for highly ordered OTS SAMs, which in turn nucleates highly ordered p-type semiconductor film growth, and optimizes OTFT performance. Surprisingly, the combined data reveal that while SAM molecular order dramatically impacts semiconductor crystalline domain size and carrier mobility, it does not significantly influence the local orientation of the overlying organic semiconductor molecules.

Solution-deposited organic-inorganic hybrid multilayer gate dielectrics. Design, synthesis, microstructures, and electrical properties with thin-film transistors.

We report here on the rational synthesis, processing, and dielectric properties of novel layer-by-layer organic/inorganic hybrid multilayer dielectric films enabled by polarizable π-electron phosphonic acid building blocks and ultrathin ZrO(2) layers. These new zirconia-based self-assembled nanodielectric (Zr-SAND) films (5-12 nm thick) are readily fabricated via solution processes under ambient atmosphere. Attractive Zr-SAND properties include amenability to accurate control of film thickness, large-area uniformity, well-defined nanostructure, exceptionally large electrical capacitance (up to 750 nF/cm(2)), excellent insulating properties (leakage current densities as low as 10(-7) A/cm(2)), and excellent thermal stability. Thin-film transistors (TFTs) fabricated with pentacene and PDIF-CN(2) as representative organic semiconductors and zinc-tin-oxide (Zn-Sn-O) as a representative inorganic semiconductor function well at low voltages (<±4.0 V). Furthermore, the TFT performance parameters of representative organic semiconductors deposited on Zr-SAND films, functionalized on the surface with various alkylphosphonic acid self-assembled monolayers, are investigated and shown to correlate closely with the alkylphosphonic acid chain dimensions.

Mental illness related disparities in diabetes prevalence, quality of care and outcomes: a population-based longitudinal study.

BACKGROUND: Health care disparity is a public health challenge. We compared the prevalence of diabetes, quality of care and outcomes between mental health clients (MHCs) and non-MHCs. METHODS: This was a population-based longitudinal study of 139,208 MHCs and 294,180 matched non-MHCs in Western Australia (WA) from 1990 to 2006, using linked data of mental health registry, electoral roll registrations, hospital admissions, emergency department attendances, deaths, and Medicare and pharmaceutical benefits claims. Diabetes was identified from hospital diagnoses, prescriptions and diabetes-specific primary care claims (17,045 MHCs, 26,626 non-MHCs). Both univariate and multivariate analyses adjusted for socio-demographic factors and case mix were performed to compare the outcome measures among MHCs, category of mental disorders and non-MHCs. RESULTS: The prevalence of diabetes was significantly higher in MHCs than in non-MHCs (crude age-sex-standardised point-prevalence of diabetes on 30 June 2006 in those aged ≥20 years, 9.3% vs 6.1%, respectively, P < 0.001; adjusted odds ratio (OR) 1.40, 95% CI 1.36 to 1.43). Receipt of recommended pathology tests (HbA1c, microalbuminuria, blood lipids) was suboptimal in both groups, but was lower in MHCs (for all tests combined; adjusted OR 0.81, 95% CI 0.78 to 0.85, at one year; and adjusted rate ratio (RR) 0.86, 95% CI 0.84 to 0.88, during the study period). MHCs also had increased risks of hospitalisation for diabetes complications (adjusted RR 1.20, 95% CI 1.17 to 1.24), diabetes-related mortality (1.43, 1.35 to 1.52) and all-cause mortality (1.47, 1.42 to 1.53). The disparities were most marked for alcohol/drug disorders, schizophrenia, affective disorders, other psychoses and personality disorders. CONCLUSIONS: MHCs warrant special attention for primary and secondary prevention of diabetes, especially at the primary care level.

The impact of mental illness on potentially preventable hospitalisations: a population-based cohort study.

BACKGROUND: Emerging evidence indicates an association between mental illness and poor quality of physical health care. To test this, we compared mental health clients (MHCs) with non-MHCs on potentially preventable hospitalisations (PPHs) as an indicator of the quality of primary care received. METHODS: Population-based retrospective cohort study of 139,208 MHCs and 294,180 matched non-MHCs in Western Australia from 1990 to 2006, using linked data from electoral roll registrations, mental health registry (MHR) records, hospital inpatient discharges and deaths. We used the electoral roll data as the sampling frame for both cohorts to enhance internal validity of the study, and the MHR to separate MHCs from non-MHCs. Rates of PPHs (overall and by PPH category and medical condition) were compared between MHCs, category of mental disorders and non-MHCs. Multivariate negative binomial regression analyses adjusted for socio-demographic factors, case mix and the year at the start of follow up due to dynamic nature of study cohorts. RESULTS: PPHs accounted for more than 10% of all hospital admissions in MHCs, with diabetes and its complications, adverse drug events (ADEs), chronic obstructive pulmonary disease (COPD), convulsions and epilepsy, and congestive heart failure being the most common causes. Compared with non-MHCs, MHCs with any mental disorders were more likely to experience a PPH than non-MHCs (overall adjusted rate ratio (ARR) 2.06, 95% confidence interval (CI) 2.03-2.09). ARRs of PPHs were highest for convulsions and epilepsy, nutritional deficiencies, COPD and ADEs. The ARR of a PPH was highest in MHCs with alcohol/drug disorders, affective psychoses, other psychoses and schizophrenia. CONCLUSIONS: MHCs have a significantly higher rate of PPHs than non-MHCs. Improving primary and secondary prevention is warranted in MHCs, especially at the primary care level, despite there may be different thresholds for admission in people with established physical disease that is influenced by whether or not they have comorbid mental illness.

Vaccination in pregnancy: A call to all providers for help.

Vaccination in pregnancy is an important part of maternity care, but maternal immunization rates continue to be below national benchmarks. Influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccinations have been shown to be safe and provide important protections to pregnant women, the fetus, and neonates. Although obstetrician-gynecologists provide the bulk of pregnancy care, general internists and medical specialists have frequent clinical encounters with maternity patients and should assist in immunization education and administration.

Use of Immediate Postpartum Long-Acting Reversible Contraception Before and After a State Policy Mandated Inpatient Access.

OBJECTIVE: To assess the rate of immediate postpartum long-acting reversible contraceptive (LARC) use in a multihospital health care system 2 years before and after the policy was implemented, and to assess factors associated with LARC use and repeat pregnancy rates within 12 months after delivery. METHODS: We conducted a retrospective chart review of all patients giving birth at three Cleveland Clinic Ohio hospitals from July 1, 2015, to June 30, 2019. We reviewed the inpatient medication reconciliation to identify the LARC initiation rate. We compared all patients who received inpatient postpartum LARC to a 1:3 matched sample of patients who did not receive LARC, matched by delivery date and location, to identify patient characteristics associated with LARC use. The electronic medical record (Epic) was reviewed to identify new pregnancies occurring within 12 months postdelivery. RESULTS: We identified 17,848 deliveries prepolicy and 18,555 deliveries postpolicy. Immediate postpartum LARC was used by 0.5% (monthly range 0-2.1%) of patients prepolicy and 11.6% (monthly range 8.3-15.4%) of patients postpolicy. Levonorgestrel intrauterine devices (IUDs) were used by 56.5%, implants by 29.1%, and copper IUDs by 14.5% of LARC users. Characteristics associated with LARC use included younger age, public insurance, non-White race, Hispanic or Latina ethnicity, higher body mass index, sexually transmitted infection in pregnancy, and tobacco use. Long-acting reversible contraceptive users had a lower rate of repeat pregnancy at 12 months postpartum compared with the non-LARC group (1.9% vs 3.6%, P<.001). CONCLUSION: Immediate postpartum LARC use increased after a state policy change mandated universal access and was associated with decreased pregnancy rates in the first year postdelivery.

Thermal Atomic Layer Deposition of Gold: Mechanistic Insights, Nucleation, and Epitaxy.

An in situ microbalance and infrared spectroscopic study of alternating exposures to Me2Au(S2CNEt2) and ozone illuminates the organometallic chemistry that allows for the thermal atomic layer deposition (ALD) of gold. In situ quartz crystal microbalance (QCM) studies resolve the nucleation delay and island growth of Au on a freshly prepared aluminum oxide surface with single cycle resolution, revealing inhibition for 40 cycles prior to slow nucleation and film coalescence that extends over 300 cycles. In situ infrared spectroscopy informed by first-principles computation provides insight into the surface chemistry of the self-limiting half-reactions, which are consistent with an oxidized Au surface mechanism. X-ray diffraction of ALD-grown gold on silicon, silica, sapphire, and mica reveals consistent out-of-plane oriented crystalline film growth as well as epitaxially directed in-plane orientation on closely lattice-matched mica at a relatively low growth temperature of 180 °C. A more complete understanding of ALD gold nucleation, surface chemistry, and epitaxy will inform the next generation of low-temperature, nanoscale, textured depositions that are applicable to high surface area supports.

Tracking-A Flexible Obstetrics and Gynecology Residency Curriculum.

Residency programs across the United States are searching for ways to improve surgical skills and operative experiences in obstetrics and gynecology residencies. We developed an obstetrics and gynecology residency program that offers a flexible curriculum, referred to as tracking, to address these needs. Curriculum content was developed using a modified Delphi method, using input from experts in medical education and obstetrics and gynecology. Outcome data were collected on trainees who graduated between 2016 and 2019, including postgraduate fellowship placement and our residents' achievement of surgical minimum requirements based on procedure logs. Trainees from this program have consistently exceeded minimal surgical requirements in all areas, regardless of tracking preference. Since the beginning of the program in 2012, more than 60% of graduates have matriculated into fellowships. Flexible curricula, such as tracking, offer one approach to a changing climate of medicine. The ability to offer flexible, focused, and individualized training is an approach with great potential to produce graduates who excel in all areas of obstetrics and gynecology while sharpening skills specific to their areas of interest.

Measuring Dipole Inversion in Self-Assembled Nano-Dielectric Molecular Layers.

A self-assembled nanodielectric (SAND) is an ultrathin film, typically with periodic layer pairs of high-k oxide and phosphonic-acid-based π-electron (PAE) molecular layers. IPAE, having a molecular structure similar to that of PAE but with an inverted dipole direction, has recently been developed for use in thin-film transistors. Here we report that replacing PAE with IPAE in SAND-based thin-film transistors induces sizable threshold and turn-on voltage shifts, indicating the flipping of the built-in SAND polarity. The bromide counteranion (Br-) associated with the cationic stilbazolium portion of PAE or IPAE is of great importance, because its relative position strongly affects the electric dipole moment of the organic layer. Hence, a set of X-ray synchrotron measurements were designed and performed to directly measure and compare the Br- distributions within the PAE and IPAE SANDs. Two trilayer SANDs, consisting of a PAE or IPAE layer sandwiched between an HfOx and a ZrOx layer, were deposited on the SiOx surface of Si substrates or periodic Si/Mo multilayer substrates for X-ray reflectivity and X-ray standing wave measurements, respectively. Along with complementary DFT simulations, the spacings, elemental (Hf, Br, and Zr) distributions, molecular orientations, and Mulliken charge distributions of the PAE and IPAE molecules within each of the SAND trilayers were determined and correlated with the dipole inversion.

Mechanistic understanding of tungsten oxide in-plane nanostructure growth via sequential infiltration synthesis.

Tungsten oxide (WO3-x) nanostructures with hexagonal in-plane arrangements were fabricated by sequential infiltration synthesis (SIS), using the selective interaction of gas phase precursors with functional groups in one domain of a block copolymer (BCP) self-assembled template. Such structures are highly desirable for various practical applications and as model systems for fundamental studies. The nanostructures were characterized by cross-sectional scanning electron microscopy, grazing-incidence small/wide-angle X-ray scattering (GISAXS/GIWAXS), and X-ray absorption near edge structure (XANES) measurements at each stage during the SIS process and subsequent thermal treatments, to provide a comprehensive picture of their evolution in morphology, crystallography and electronic structure. In particular, we discuss the critical role of SIS Al2O3 seeds toward modifying the chemical affinity and free volume in a polymer for subsequent infiltration of gas phase precursors. The insights into SIS growth obtained from this study are valuable to the design and fabrication of a wide range of targeted nanostructures.

An original valveless artificial heart providing pulsatile flow tested in mock circulatory loops.

PURPOSE: We present the test bench results of a valveless total artificial heart that is potentially compatible with the pediatric population. METHODS: The RollingHeart is a valveless volumetric pump generating pulsatile flow. It consists of a single spherical cavity divided into 4 chambers by 2 rotating disks. The combined rotations of both disks produce changes in the volumes of the 4 cavities (suction and ejection). The blood enters/exits the spherical cavity through 4 openings that are symmetrical to the fixed rotation axis of the first disk.Mock circulatory system: The device pumps a 37% glycerin solution through 2 parallel circuits, simulating the pulmonary and systemic circulations. Flow rates are acquired with a magnetic inductive flowmeter, while pressure sensors collect pressure in the left and right outflow and inflow tracts.In vitro test protocol: The pump is run at speeds ranging from 20 to 180 ejections per minute. The waveform of the pressure generated at the inflow and outflow of the 4 chambers and the flow rate in the systemic circulation are measured. RESULTS: At an ejection rate of 178 min-1, the RollingHeart pumps 5.3 L/min for a systemic maximal pressure gradient of 174 mmHg and a pulmonary maximal pressure gradient of 75 mmHg. The power input was 14 W, corresponding to an efficiency of 21%. CONCLUSIONS: The RollingHeart represents a new approach in the domain of total artificial heart. This preliminary study endorses the feasibility of a single valveless device acting as a total artificial heart.