Ubiquitin Modification by the E3 Ligase/ADP-Ribosyltransferase Dtx3L/Parp9.

ADP-ribosylation of proteins is emerging as an important regulatory mechanism. Depending on the family member, ADP-ribosyltransferases either conjugate a single ADP-ribose to a target or generate ADP-ribose chains. Here we characterize Parp9, a mono-ADP-ribosyltransferase reported to be enzymatically inactive. Parp9 undergoes heterodimerization with Dtx3L, a histone E3 ligase involved in DNA damage repair. We show that the Dtx3L/Parp9 heterodimer mediates NAD+-dependent mono-ADP-ribosylation of ubiquitin, exclusively in the context of ubiquitin processing by E1 and E2 enzymes. Dtx3L/Parp9 ADP-ribosylates the carboxyl group of Ub Gly76. Because Gly76 is normally used for Ub conjugation to substrates, ADP-ribosylation of the Ub carboxyl terminus precludes ubiquitylation. Parp9 ADP-ribosylation activity therefore restrains the E3 function of Dtx3L. Mutation of the NAD+ binding site in Parp9 increases the DNA repair activity of the heterodimer. Moreover, poly(ADP-ribose) binding to the Parp9 macrodomains increases E3 activity. Dtx3L heterodimerization with Parp9 enables NAD+ and poly(ADP-ribose) regulation of E3 activity.

Defining the Macromolecules of Tomorrow through Synergistic Sustainable Polymer Research.

Transforming how plastics are made, unmade, and remade through innovative research and diverse partnerships that together foster environmental stewardship is critically important to a sustainable future. Designing, preparing, and implementing polymers derived from renewable resources for a wide range of advanced applications that promote future economic development, energy efficiency, and environmental sustainability are all central to these efforts. In this Chemical Reviews contribution, we take a comprehensive, integrated approach to summarize important and impactful contributions to this broad research arena. The Review highlights signature accomplishments across a broad research portfolio and is organized into four wide-ranging research themes that address the topic in a comprehensive manner: Feedstocks, Polymerization Processes and Techniques, Intended Use, and End of Use. We emphasize those successes that benefitted from collaborative engagements across disciplinary lines.

Improved Durability to SARS-CoV-2 Vaccine Immunity following Coimmunization with Molecular Adjuvant Adenosine Deaminase-1.

Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have demonstrated strong immunogenicity and protection against severe disease, concerns about the duration and breadth of these responses remain. In this study, we show that codelivery of plasmid-encoded adenosine deaminase-1 (pADA) with SARS-CoV-2 spike glycoprotein DNA enhances immune memory and durability in vivo. Coimmunized mice displayed increased spike-specific IgG of higher affinity and neutralizing capacity as compared with plasmid-encoded spike-only-immunized animals. Importantly, pADA significantly improved the longevity of these enhanced responses in vivo. This coincided with durable increases in frequencies of plasmablasts, receptor-binding domain-specific memory B cells, and SARS-CoV-2-specific T follicular helper cells. Increased spike-specific T cell polyfunctionality was also observed. Notably, animals coimmunized with pADA had significantly reduced viral loads compared with their nonadjuvanted counterparts in a SARS-CoV-2 infection model. These data suggest that pADA enhances immune memory and durability and supports further translational studies.

FATAL ACUTE HEMOLYSIS FOLLOWING TRIAZOLE THERAPY IN AFRICAN PENGUINS (SPHENISCUS DEMERSUS).

Aspergillosis is a major cause of morbidity and mortality in penguins, with triazole antifungal drugs being commonly used for prophylaxis and treatment. This report describes 15 cases of fatal hemolysis associated with liquid itraconazole and voriconazole formulations administered to African penguins (Spheniscus demersus) from four institutions. All penguins underwent stressful events (e.g. relocation, induced molt) and were administered commercial liquid itraconazole formulations or compounded voriconazole liquid suspension. Observed clinical signs in affected penguins prior to death included hyporexia, weight loss, lethargy, dyspnea, red-tinged droppings, and obtunded mentation. Intra- and extravascular hemolysis and hemoglobinuric nephrosis were the primary pathologic manifestations on postmortem examination. The concentration-dependent hemolytic potentials of itraconazole, voriconazole, and commercial and compounded vehicle suspensions were evaluated in vitro by exposing chicken whole blood as a surrogate for penguin blood. Hemoglobin content in blood plasma was then measured by spectrophotometry. Neither itraconazole nor voriconazole alone induced hemolysis in vitro. The vehicle ingredients sorbitol and hydromellose induced hemolysis, but not at predicted plasma levels in chicken erythrocytes, suggesting neither the azole antifungals nor their major vehicles alone were likely to contribute to hemolysis in vivo in these penguins. Potential mechanisms of toxicosis include generation of an unmeasured reactive metabolite causing hemolysis, preexisting erythrocyte fragility, or species-specific differences in hemolytic thresholds that were not assessed in the chicken erythrocyte model. More research is needed on the potential for toxicosis of azole antifungal drugs and carrier molecules in this and other avian species.

Angiostrongylus cantonensis Infection in Brown Rats (Rattus norvegicus), Atlanta, Georgia, USA, 2019-2022.

Rat lungworm (Angiostrongylus cantonensis), a zoonotic parasite invasive to the United States, causes eosinophilic meningoencephalitis. A. cantonensis harbors in rat reservoir hosts and is transmitted through gastropods and other paratenic hosts. We discuss the public health relevance of autochthonous A. cantonensis cases in brown rats (Rattus norvegicus) in Atlanta, Georgia, USA.

History of Veterinary Immunology in New Zealand.

Knowledge gained from veterinary immunology has played an important role in the control of microbial and parasitic diseases in New Zealand through the development and use of vaccines and diagnostic tests. In this article celebrating the 100th anniversary of the Journal, I follow the development of important discoveries in veterinary immunology which have led to major advances in the control of animal diseases.

Pandemic 1918 Influenza Virus Does Not Cause Lethal Infection in Rhesus or Cynomolgus Macaques.

The 1918 H1N1 influenza pandemic was among the most severe in history, taking the lives of approximately 50 million people worldwide, and novel prophylactic vaccines are urgently needed to prevent another pandemic. Given that macaques are physiologically relevant preclinical models of human immunology that have advanced the clinical treatment of infectious diseases, a lethal pandemic influenza challenge model would provide a stringent platform for testing new influenza vaccine concepts. To this end, we infected rhesus macaques and Mauritian cynomolgus macaques with highly pathogenic 1918 H1N1 influenza virus and assessed pathogenesis and disease severity. Despite infection with a high dose of 1918 influenza delivered via multiple routes, rhesus macaques demonstrated minimal signs of disease, with only intermittent viral shedding. Cynomolgus macaques infected via intrabronchial instillation demonstrated mild symptoms, with disease severity depending on the infection dose. Cynomolgus macaques infected with a high dose of 1918 influenza delivered via multiple routes experienced moderate disease characterized by consistent viral shedding, pulmonary infiltrates, and elevated inflammatory cytokine levels. However, 1918 influenza was uniformly nonlethal in these two species, demonstrating that this isolate is insufficiently pathogenic in rhesus and Mauritian cynomolgus macaques to support testing novel prophylactic influenza approaches where protection from severe disease combined with a lethal outcome is desired as a highly stringent indication of vaccine efficacy. IMPORTANCE The world remains at risk of an influenza pandemic, and the development of new therapeutic and preventative modalities is critically important for minimizing human death and suffering during the next influenza pandemic. Animal models are central to the development of new therapies and vaccine approaches. In particular, nonhuman primates like rhesus and cynomolgus macaques are highly relevant preclinical models given their physiological and immunological similarities to humans. Unfortunately, there remains a scarcity of macaque models of pandemic influenza with which to test novel antiviral modalities. Here, we demonstrate that even at the highest doses tested, 1918 influenza was not lethal in these two macaque species, suggesting that they are not ideal for the development and testing of novel pandemic influenza-specific vaccines and therapies. Therefore, other physiologically relevant nonhuman primate models of pandemic influenza are needed.

Differential pathogenesis of closely related 2018 Nigerian outbreak clade III Lassa virus isolates.

Nigeria continues to experience ever increasing annual outbreaks of Lassa fever (LF). The World Health Organization has recently declared Lassa virus (LASV) as a priority pathogen for accelerated research leading to a renewed international effort to develop relevant animal models of disease and effective countermeasures to reduce LF morbidity and mortality in endemic West African countries. A limiting factor in evaluating medical countermeasures against LF is a lack of well characterized animal models outside of those based on infection with LASV strain Josiah originating form Sierra Leone, circa 1976. Here we genetically characterize five recent LASV isolates collected from the 2018 outbreak in Nigeria. Three isolates were further evaluated in vivo and despite being closely related and from the same spatial / geographic region of Nigeria, only one of the three isolates proved lethal in strain 13 guinea pigs and non-human primates (NHP). Additionally, this isolate exhibited atypical pathogenesis characteristics in the NHP model, most notably respiratory failure, not commonly described in hemorrhagic cases of LF. These results suggest that there is considerable phenotypic heterogeneity in LASV infections in Nigeria, which leads to a multitude of pathogenesis characteristics that could account for differences between subclinical and lethal LF infections. Most importantly, the development of disease models using currently circulating LASV strains in West Africa are critical for the evaluation of potential vaccines and medical countermeasures.

Genome-wide screens uncover KDM2B as a modifier of protein binding to heparan sulfate.

Heparan sulfate (HS) proteoglycans bind extracellular proteins that participate in cell signaling, attachment and endocytosis. These interactions depend on the arrangement of sulfated sugars in the HS chains generated by well-characterized biosynthetic enzymes; however, the regulation of these enzymes is largely unknown. We conducted genome-wide CRISPR-Cas9 screens with a small-molecule ligand that binds to HS. Screening of A375 melanoma cells uncovered additional genes and pathways impacting HS formation. The top hit was the epigenetic factor KDM2B, a histone demethylase. KDM2B inactivation suppressed multiple HS sulfotransferases and upregulated the sulfatase SULF1. These changes differentially affected the interaction of HS-binding proteins. KDM2B-deficient cells displayed decreased growth rates, which was rescued by SULF1 inactivation. In addition, KDM2B deficiency altered the expression of many extracellular matrix genes. Thus, KDM2B controls proliferation of A375 cells through the regulation of HS structure and serves as a master regulator of the extracellular matrix.

Association Between the Modified Frailty Index and Outcomes Following Lobectomy.

INTRODUCTION: Elective thoracic surgery is safe in well-selected elderly patients. The association of frailty with postoperative morbidity in elective-lobectomy patients is understudied. We examined frailty as defined by abbreviated modified frailty index (mFI-5), mFI-11 in the thoracic surgery population, and the correlation between frailty and postoperative complications. METHODS: We studied outcomes of patients in two cohorts, 2010-2012 and 2013-2019, from the National Surgical Quality Improvement Program (NSQIP) database and used multivariable logistic regression models to predict all postoperative morbidity, mortality, and major morbidity. The mFI-5 could be calculated for all subjects (both 2010-2012, and 2013-2019); the mFI-11 could only be calculated for the 2010-2012 cohort. Patient frailty was defined as mFI≥3 (with either index). We used odds ratios (ORs) to examine associations of preoperative characteristics with postoperative complications and C-statistics to assess overall predictive power. RESULTS: Complications were less prevalent in the 2013-2019 cohort (17.9% versus 19.5%, P = 0.008). Open lobectomies were more common in the 2010-2012 cohort (53.9% versus 34.6%) and were strongly associated with postoperative morbidity and mortality (ORs >1.5) in both cohorts. Each frailty measure was associated with morbidity and mortality (ORs >1.4) after adjusting for other significant preoperative factors. Models on the 2010-2012 cohort had nearly identical C-statistics using the mFI-11 versus mFI-5 frailty indices (0.6142 versus 0.6139; P > 0.8). CONCLUSIONS: Frailty, as captured in the mFI-5, is a significant associated factor of postoperative morbidity and mortality following elective lobectomies. As a modifiable risk factor, frailty should be considered in surgical decision-making and when counseling patients regarding perioperative risks.

Toward an extreme-scale electronic structure system.

Electronic structure calculations have the potential to predict key matter transformations for applications of strategic technological importance, from drug discovery to material science and catalysis. However, a predictive physicochemical characterization of these processes often requires accurate quantum chemical modeling of complex molecular systems with hundreds to thousands of atoms. Due to the computationally demanding nature of electronic structure calculations and the complexity of modern high-performance computing hardware, quantum chemistry software has historically failed to operate at such large molecular scales with accuracy and speed that are useful in practice. In this paper, novel algorithms and software are presented that enable extreme-scale quantum chemistry capabilities with particular emphasis on exascale calculations. This includes the development and application of the multi-Graphics Processing Unit (GPU) library LibCChem 2.0 as part of the General Atomic and Molecular Electronic Structure System package and of the standalone Extreme-scale Electronic Structure System (EXESS), designed from the ground up for scaling on thousands of GPUs to perform high-performance accurate quantum chemistry calculations at unprecedented speed and molecular scales. Among various results, we report that the EXESS implementation enables Hartree-Fock/cc-pVDZ plus RI-MP2/cc-pVDZ/cc-pVDZ-RIFIT calculations on an ionic liquid system with 623 016 electrons and 146 592 atoms in less than 45 min using 27 600 GPUs on the Summit supercomputer with a 94.6% parallel efficiency.

Drivers and barriers of international migration of doctors to and from the United Kingdom: a scoping review.

BACKGROUND: Many high-income countries are heavily dependent on internationally trained doctors to staff their healthcare workforce. Over one-third of doctors practising in the UK received their primary medical qualification abroad. Simultaneously, an average of around 2.1% of doctors leave the UK medical workforce annually to go overseas. The aim of this study was to identify the drivers and barriers of international migration of doctors to and from the UK. METHODS: A scoping review was conducted. We searched EMBASE, MEDLINE, CINAHL, ERIC and BEI in January 2020 (updated October 2021). Grey literature and citation searching were also carried out. Empirical studies reporting on the drivers and barriers to the international migration of doctors to and from the UK published in the English language from 2009 to present were included. The drivers and barriers were coded in NVivo 12 building on an existing framework. RESULTS: 40 studies were included. 62% were quantitative, 18% were qualitative, 15% were mixed-methods and 5% were literature reviews. Migration into and out of the UK is determined by a variety of macro- (global and national factors), meso- (profession led factors) and micro-level (personal factors). Interestingly, many of the key drivers of migration to the UK were also factors driving migration from the UK, including: poor working conditions, employment opportunities, better training and development opportunities, better quality of life, desire for a life change and financial reasons. The barriers included stricter immigration policies, the registration process and short-term job contracts. CONCLUSIONS: Our research contributes to the literature by providing a comprehensive up-to-date review of the drivers and barriers of migration to and from the UK. The decision for a doctor to migrate is multi-layered and is a complex balance between push/pull at macro-/meso-/micro-levels. To sustain the UK's supply of overseas doctors, it is vital that migration policies take account of the drivers of migration particularly working conditions and active recruitment while addressing any potential barriers. Immigration policies to address the impact of Brexit and the COVID-19 pandemic on the migration of doctors to and from the UK will be particularly important in the immediate future. Trial registration PROSPERO CRD42020165748.

Reconstitution of the DTX3L-PARP9 complex reveals determinants for high-affinity heterodimerization and multimeric assembly.

Ubiquitination and ADP-ribosylation are post-translational modifications that play major roles in pathways including the DNA damage response and viral infection. The enzymes responsible for these modifications are therefore potential targets for therapeutic intervention. DTX3L is an E3 Ubiquitin ligase that forms a heterodimer with PARP9. In addition to its ubiquitin ligase activity, DTX3L-PARP9 also acts as an ADP-ribosyl transferase for Gly76 on the C-terminus of ubiquitin. NAD+-dependent ADP-ribosylation of ubiquitin by DTX3L-PARP9 prevents ubiquitin from conjugating to protein substrates. To gain insight into how DTX3L-PARP9 generates these post-translational modifications, we produced recombinant forms of DTX3L and PARP9 and studied their physical interactions. We show the DTX3L D3 domain (230-510) mediates the interaction with PARP9 with nanomolar affinity and an apparent 1 : 1 stoichiometry. We also show that DTX3L and PARP9 assemble into a higher molecular weight oligomer, and that this is mediated by the DTX3L N-terminal region (1-200). Lastly, we show that ADP-ribosylation of ubiquitin at Gly76 is reversible in vitro by several Macrodomain-type hydrolases. Our study provides a framework to understand how DTX3L-PARP9 mediates ADP-ribosylation and ubiquitination through both intra- and inter-subunit interactions.

Exploring recent patterns of migration of doctors to the United Kingdom: a mixed-methods study.

INTRODUCTION: A shortage of doctors is currently one of the biggest challenges faced by the healthcare workforce in the United Kingdom (UK). While plans are in place to increase the number of medical school places, in the short-term this gap will need to continue to be filled by the international recruitment of doctors. The aim of this study is to identify key factors that explain the patterns of migration of doctors to the UK, in order to aid the development of policies to recruit and retain a sustainable workforce. METHODS: We analysed General Medical Council (GMC) secondary data on the patterns of migration of internationally trained doctors (2009-2019). Qualitative interviews were conducted with 17 stakeholders by videoconferencing which were audio-recorded, transcribed and thematically analysed using NVivo. RESULTS: In 2019, 34.5% of UK doctors were trained internationally mainly in India, Pakistan, Italy, Nigeria, Greece, Romania and Egypt. Most new registrations by internationally trained doctors from 2009-2019 did not have a specialty at the time of initial registration (96.2% in 2019). Only a relatively small number of these doctors go on to gain specialist or GP registration (11.6% within 5 years and 27.2% within 10 years of registration). The stakeholder interviews highlighted training opportunities and career progression as the main drivers of migration. The barriers internationally trained doctors face regarding specialty training included differences between UK and destination health systems, systematic bias, bureaucracy and selection processes not being accessible. CONCLUSION: This study makes a contribution to the literature by identifying recent patterns in the migration of doctors to the UK. The UK's dependence on internationally trained doctors has important global implications as source countries are losing skilled health workers which is undermining their health systems. In keeping with the WHO Global Code on the International Recruitment of Healthcare Personnel, policymakers need to consider how to reduce the UK's reliance on internationally trained doctors, particularly from countries on the safeguard list whilst continuing the drive to increase medical school places. Additional support is required for internationally trained doctors, to ensure that they get on the training programmes they seek, enabling their career progression.

The Intersection between Alcohol use and Sexual Activity among Young Adult Male U.S. Service Members.

Aims: The current study explores drinking habits, preferences for alcohol use before sexual activity, and alcohol-related sexual behavior among young adult male active duty service members in the United States. Background: Hazardous alcohol use is a significant problem among United States military service members. Whereas the association between alcohol use and sexual assault is well documented in civilian samples, less is known regarding the intersection of alcohol use and sexual activity among soldiers. Objective: Descriptive statistics were utilized to summarize drinking habits, preferences for alcohol use before sexual activity, and alcohol-related sexual behavior. Methods: A sample of 338 active-duty male service members between the ages of 18 and 24 were recruited from a large military post in the Southeastern United States. Constructs were assessed using self-report surveys. Results: Participants reported consuming alcohol, on average, 5.6 times over the prior month. Average alcohol consumption was reported to be 7.8 beverages per drinking occasion. Participants reported engaging in heavy drinking an average of 2.9 times over the past 30 days. On average, service members reported a preference for 1.3 drinks before sexual activity. Furthermore, 75.2% of participants preferred to be sober during sex, and 82.1% preferred to engage in sexual activity with a sober partner. Approximately 14% of the sample reported using alcohol to improve their chances of having sex. Conclusion: These findings highlight high rates of alcohol use among soldiers. Nonetheless, young adult male soldiers report a preference for sexual activity while sober. Understanding the co-occurrence of alcohol use and sexual activity has the potential to inform the development of integrated alcohol and sexual assault prevention programs for service members.

Experimental Infection of Peromyscus Species Rodents with Sin Nombre Virus.

We demonstrate that 6 distinct Peromyscus rodent species are permissive to experimental infection with Sin Nombre orthohantavirus (SNV). Viral RNA and SNV antibodies were detected in members of all 6 species. P. leucopus mice demonstrated markedly higher viral and antibody titers than P. maniculatus mice, the established primary hosts for SNV.

Genomic analyses of the metastasis-derived prostate cancer cell lines LNCaP, VCaP, and PC3-AR.

BACKGROUND: The lymph node metastasis-derived LNCaP, the bone metastasis-derived PC3 (skull), and VCaP (vertebral) cell lines are widely used as preclinical models of human prostate cancer (CaP) and have been described in more than 19,000 publications. Here, we report on short-read whole-genome sequencing and genomic analyses of LNCaP, VCaP, and PC3 cells stably transduced with WT AR (PC3-AR). METHODS: LNCaP, VCaP, and PC3-AR cell lines were sequenced to an average depth of more than 30-fold using Illumina short-read sequencing. Using various computational methods, we identified and compared the single-nucleotide variants, copy-number profiles, and the structural variants observed in the three cell lines. RESULTS: LNCaP cells are composed of multiple subpopulations, which results in nonintegral copy number states and a high mutational load when the data is analyzed in bulk. All three cell lines contain pathogenic mutations and homozygous deletions in genes involved in DNA mismatch repair, along with deleterious mutations in cell-cycle, Wnt signaling, and other critical cellular processes. PC3-AR cells have a truncating mutation in TP53 and do not express the p53 protein. The VCaP cells contain a homozygous gain-of-function mutation in TP53 (p.R248W) that promotes cancer invasion, metastasis, and progression and has also been observed in prostate adenocarcinomas. In addition, we detect the signatures of chromothripsis of the q arms of chromosome 5 in both PC3-AR and VCaP cells, strengthening the association of TP53 inactivation with chromothripsis reported in other systems. CONCLUSIONS: Our work provides a resource for genetic, genomic, and biological studies employing these commonly-used prostate cancer cell lines.

Differential pathogenesis between Andes virus strains CHI-7913 and Chile-9717869in Syrian Hamsters.

Hantavirus cardiopulmonary syndrome (HCPS) is a severe respiratory disease caused by orthohantaviruses in the Americas with a fatality rate as high as 35%. In South America, Andes orthohantavirus (Hantaviridae, Orthohantavirus, ANDV) is a major cause of HCPS, particularly in Chile and Argentina, where thousands of cases have been reported since the virus was discovered. Two strains of ANDV that are classically used for experimental studies of the virus are Chile-9717869, isolated from the natural reservoir, the long-tailed pygmy rice rat, and CHI-7913, an isolate from a lethal human case of HCPS. An important animal model for studying pathogenesis of HCPS is the lethal Syrian golden hamster model of ANDV infection. In this model, ANDV strain Chile-9717869 is uniformly lethal and has been used extensively for pathogenesis, vaccination, and therapeutic studies. Here we show that the CHI-7913 strain, despite having high sequence similarity with Chile-9717869, does not cause lethal disease in Syrian hamsters. CHI-7913, while being able to infect hamsters and replicate to moderate levels, showed a reduced ability to replicate within the tissues compared with Chile-9717869. Hamsters infected with CHI-7913 had reduced expression of cytokines IL-4, IL-6, and IFN-γ compared with Chile-9717869 infected animals, suggesting potentially limited immune-mediated pathology. These results demonstrate that certain ANDV strains may not be lethal in the classical Syrian hamster model of infection, and further exploration into the differences between lethal and non-lethal strains provide important insights into molecular determinants of pathogenic hantavirus infection.Importance:Andes orthohantavirus (ANDV) is a New World hantavirus that is a major cause of hantavirus cardiopulmonary syndrome (HCPS, also referred to as hantavirus pulmonary syndrome) in South America, particularly in Chile and Argentina. ANDV is one of the few hantaviruses for which there is a reliable animal model, the Syrian hamster model, which recapitulates important aspects of human disease. Here we infected hamsters with a human isolate of ANDV, CHI-7913, to assess its pathogenicity compared with the classical lethal Chile-9717869 strain. CHI-7913 had 22 amino acid differences compared with Chile-9717869, did not cause lethal disease in hamsters, and showed reduced ability to replicate in vivo Our data indicate potentially important molecular signatures for pathogenesis of ANDV infection in hamsters and may lead to insights into what drives pathogenesis of certain hantaviruses in humans.

Use of In-Situ Simulation Based Clinical Systems Test of Thoracic Robotic Surgery Emergencies.

INTRODUCTION: With the advancement of robotic surgery, some thoracic surgeons have been slow to adopt to this new operative approach, in part because they are un-scrubbed and away from the patient while operating. Aiming to allay surgeon concerns of intra-operative emergencies, an insitu simulation-based clinical system's test (SbCST) can be completed to test the current clinical system, and to practice low-frequency, high-stakes clinical scenarios with the entire operating room (OR) team. METHODS: Six different OR teams completed an insitu SbCST of an intra-operative pulmonary artery injury during a robot-assisted thoracic surgery at a single tertiary care center. The OR team consisted of an attending thoracic surgeon, surgery resident, anesthesia attending, anesthesia resident, circulating nurse, and a scrub technician. This test was conducted with an entire OR team along with study observers and simulation center staff. Outcomes included the identified latent safety threats (LSTs) and possible solutions for each LST, culminating in a complete failure mode and effects analysis (FMEA). A Risk Priority Number (RPN) was determined for each LST identified. Pre- and post-simulation surveys using Likert scales were also collected. RESULTS: The six FMEAs identified 28 potential LSTs in four categories. Of these 28 LSTs, nine were considered high priority based on their Risk Priority Number (RPN) with seven of the nine being repeated multiple times. Pre- and post-simulation survey responses were similar, with the majority of participants (94%) agreeing that high fidelity simulation of intra-operative emergencies is helpful and provides an opportunity to train for high-stakes, low-frequency events. After completing the SbCST, more participants felt confident that they knew their role during an intra-operative emergency than their pre-simulation survey responses. All participants agreed that simulation is an important part of continuing education and is helpful for learning skills that are infrequently used. Following the SbCST, more participants agreed that they knew how to safely undock the da Vinci robot during an emergency. CONCLUSIONS: SbCSTs provide an opportunity to test the current clinical system with a low-frequency, high-stakes event and allow medical personnels to practice their skills and teamwork. By completing multiple SbCSTs, we were able to identify multiple LSTs within different OR teams, allowing for a broader review of the current clinical systems in place. The use of these SbCSTs in conjunction with debriefing sessions and FMEA completion allows for the most significant potential improvement of the current system. This study shows that SbCST with FMEA completion can be used to test current systems and create better systems for patient safety.

General, Rigorous Approach for the Treatment of Interfragment Covalent Bonds.

A generalized, projection-based transformation of the method-agnostic Fock operator in various ab initio fragment-based quantum chemistry methods has been developed for the treatment of interfragment covalent bonds. This transformation freezes the relevant localized molecular orbital associated with each interfragment bond, thereby restricting the variational subspace of the fragment wave functions, in order to maintain the proper physical characteristics of the involved covalent bonds. In addition, sets of orbitals that would lead to multiple occupancy of certain orbitals are explicitly removed from the variational space. The transformation is developed for the specific case of mutually orthonormal frozen and unfrozen orbitals within each fragment. The newly developed approach is then used to study model systems with two popular ab initio fragment-based methods, and the results of these calculations are compared to those obtained by existing methodologies. Analysis is focused on both quantitative and qualitative accuracy as well as computational scalability and stability. Other methods for which the developed formalisms are appropriate are outlined, and future extensions of the methods are discussed.