Variational Pair-Density Functional Theory: Dealing with Strong Correlation at the Protein Scale

Multiconfigurational pair-density functional theory (MC-PDFT) offers a promising solution to the challenges faced by traditional density functional theory (DFT) in addressing molecular systems containing transition metals, open-shells, or strong correlations in general. By utilizing both the density and on-top pair-density, MC-PDFT can make use of a more flexible multiconfigurational wave function to capture the necessary static correlation, while the pair-density functional also includes the effect of dynamic correlation. So far, MC-PDFT has been used after a multiconfigurational self-consistent field (MCSCF) step, using the orbitals and configuration interaction coefficients from the converged MCSCF wave function to compute PDFT energies and properties. Here, instead, we propose to perform a direct optimization of the wave function using the pair-density functionals, resulting in a variational formulation of MC-PDFT. We derive the expressions for the wave function gradient and illustrate their similarity to standard MCSCF equations. Furthermore, we illustrate the accuracy on a set of singlet-triplet gaps as well as dissociation curves. Our findings highlight one of MC-PDFT's standout features: a reduced dependency on the active space size compared to conventional multiconfigurational wave function methodologies. Additionally, we show that the computational cost of MC-PDFT is potentially lower than MCSCF and often on-par with standard Kohn-Sham DFT, which is demonstrated by performing a MC-PDFT calculation of the entire ferredoxin protein with 1447 atoms and nearly 12 000 basis functions.

Separating the components of an abdominal wall fellowship

Complex abdominal wall reconstruction is an emerging subspecialty yet, despite the abundance of abdominal wall hernias requiring treatment and the increasing complexity of this type of surgery, there are few opportunities for surgeons to gain subspecialist training in this field. In this paper we discuss the need for focused training in complex abdominal wall reconstruction, outline some of the problems that may be hindering the availability of such opportunities and propose potential solutions to these issues.

Multiconfigurational Pair-Density Functional Theory Is More Complex than You May Think

Multiconfigurational pair-density functional theory (MC-PDFT) is a promising way to describe both strong and dynamic correlations in an inexpensive way. The functionals in MC-PDFT are often "translated" from standard spin density functionals. However, these translated functionals can in principle lead to "translated spin densities" with a nonzero imaginary component. Current developments so far neglect this imaginary part by simply setting it to zero. In this work, we show how this imaginary component is actually needed to reproduce the correct physical behavior in a range of cases, especially low-spin open shells. We showcase the resulting formalism on both local density approximation and generalized gradient approximation functionals and illustrate the numerical behavior by benchmarking a number of singlet-triplet splittings (ST gaps) of organic diradicals and low-lying excited states of some common organic molecules. The results demonstrate that this scheme improves existing translated functionals and gives more accurate results, even with minimal active spaces.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

Quality of amoxicillin/clavulanic acid oral formulations for intended veterinary use in the UK, Malaysia, Serbia and Thailand

OBJECTIVES

Amoxicillin/clavulanate is the most commonly used oral antimicrobial drug in companion animals. The objective of the study was to detect types and frequency of deficits in the quality of veterinary oral formulations of amoxicillin/clavulanate in various countries.

MATERIALS AND METHODS

In a prospective study with purposive sampling, amoxicillin/clavulanate tablet formulations for canine use were collected in four countries (wholesalers or veterinary practice) and shipped to a central bioanalytical laboratory. Twenty-four samples were collected from the UK (nine), Malaysia (nine), Serbia (four) and Thailand (two), yielding 18 different formulations (10 veterinary). Packaging inspection, tablet disintegration and content assay were conducted (validated high-performance liquid chromatography with ultra-violet detection); content was acceptable when within the 90% to 120% pre-specified range (US Pharmacopeia).

RESULTS

Secondary packaging was present for 13 of 24 samples and primary packaging integrity was verified for all but one sample. Amoxicillin trihydrate/potassium clavulanate label ratio was 4:1, except for three formulations (2:1). Tablet dose strength ranged from 250 to 625 mg. All formulations contained both analytes. For amoxicillin, two of 24 samples were out of specification with 72.8% (Malaysia) and 82.3% (Thailand) of labelled content. For clavulanate, four of 24 samples were out of specification with 46.9% (Serbia), 79.0% (UK), 84.3% (Serbia) and 86.5% (Thailand) of labelled content. One formulation (Thailand) failed for both analytes.

CLINICAL SIGNIFICANCE

Antimicrobial formulations of substandard quality have negative consequences for efficacy in patients and potentially promote antimicrobial resistance. There was evidence of substandard formulations in all countries, not only for amoxicillin but especially for clavulanate; this could compromise equitable access to acceptable quality essential veterinary medicines worldwide.

Local anaesthetic for pain post rubber band ligation of haemorrhoids: a prospective, single-blinded randomised controlled trial

BACKGROUND

Rubber band ligation (RBL) is a widely accepted intervention for the treatment of haemorrhoids. However, post procedure pain is a common complaint. The aim of this study was to determine whether the addition of local anaesthetic (LA) to the haemorrhoid pedicle base, post RBL, aids in reducing early post-procedure pain. Additionally, to compare perceived perianal numbness, oral analgesia usage and total consumption, and adverse events.

METHODS

This study was a prospective, single-blinded randomised controlled trial. Patients were recruited from colorectal clinics in two Australian hospitals between 2018-2019. Patients randomised to the intervention (LA) group received 2mls bupivacaine 0.5% with adrenaline 1:200,000 to each haemorrhoid base. Patients in the control group were not administered LA. Pain scores were recorded over 48 h using visual analogue scales. Analgesia consumption was documented and other secondary objectives were recorded dichotomously (yes/no).

RESULTS

At 1 h post-procedure, patient reported pain scores were significantly lower in the LA group compared to the control group (p = 0.04). There were no significant differences in pain scores between the groups at 4, 24 or 48 h. Additionally, there were no significant differences between groups with respect to oral analgesia usage, perianal numbness or adverse events.

CONCLUSIONS

LA to the haemorrhoid pedicle post RBL may significantly reduce early post procedure pain without any increased risk of adverse effects.

Complex Linear Response Functions for a Multiconfigurational Self-Consistent Field Wave Function in a High Performance Computing Environment

We present novel developments for the highly efficient evaluation of complex linear response functions of a multiconfigurational self-consistent field (MCSCF) wave function as implemented in MultiPsi. Specifically, expressions for the direct evaluation of linear response properties at given frequencies using the complex polarization propagator (CPP) approach have been implemented, within both the Tamm-Dancoff approximation (TDA) and the random phase approximation (RPA). Purely real algebra with symmetric and antisymmetric trial vectors in a shared subspace is used wherein the linear response equations are solved. Two bottlenecks of large scale MC-CPP calculations, namely, the memory footprint and computational time, are addressed. The former is addressed by limiting the size of the subspace of trial vectors by using singular value decomposition (SVD) on either orbital or CI subspaces. The latter is addressed using an efficient parallel implementation as well as the strategy of dynamically adding linear response equations at near-convergence to neighboring roots. Furthermore, a novel methodology for decomposing MC-CPP spectra in terms of intuitive orbital excitations in an approximate fashion is presented. The performance of the code is illustrated with several numerical examples, including the X-ray spectrum of a molecule with nearly one hundred atoms. Additionally, for X-ray spectroscopy, the effect of including or excluding the core orbital in the active space on small covalent metal complexes is discussed.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

7-Steps medication reviews: analysis of medicine changes in acute medical wards

Introduction

In Northern Ireland, medication errors cause 20 patient deaths, lead to around 800 non-elective hospital admissions and cost £1.9 million annually.1 The iSIMPATHY (implementing Stimulating Innovation in the Management of Polypharmacy and Adherence Through the Years) project is an EU-funded partnership between Scotland, Ireland and Northern Ireland delivering medication reviews using the 7-Steps medication review tool and asking ‘what matters to you?’ 2 The iSIMPATHY 7-Steps review is a new research study in Northern Ireland.

Aim

To identify medicine changes made by an independent prescribing pharmacist during 7-Steps medication reviews.

Method

Medication reviews were delivered on acute medical wards in the Northern Health and Social Care Trust. No patients were excluded from reviews, however reviews were targeted at patients aged 50 years and older and resident in a care home, approaching the end of their lives, prescribed 10 or more medicines or on high-risk medication. Data on medication changes made during 192 medication reviews was collected and analysed to identify the numbers and types of medicines stopped, started and doses altered. Ethical approval was not required, an approved Data Protection Impact Assessment was in place.

Results

Mean number of medicines per patient pre- and post-review were 12.2 and 12.3 respectively. Medicines were stopped in 49% of patients, dose decreased in 36%, changed to a more appropriate medicine in 15%, dose increased in 15% and new medicines started in 55%. Medicines stopped included opioids and gabapentenoids (18%), nutritional and electrolyte supplements (15%), items for comfort (9%), antidepressants (including amitriptyline for pain) (10%), antihypertensives and diuretics (8%), bladder anticholinergics and mirabegron (5%), laxatives (4%), betahistine (3%), quinine (2%). Dose decreases were made for analgesics including opioids (28%), PPI/H2RA (23%), anticoagulants (13%), statins and fibrates (6%), antihypertensives (6%), benzodiazepines and z-drugs (5%), antidiabetics (3%). Dose increases were made for anticoagulants and items for comfort (both 26%), laxatives (24%), pancreatin (15%), nutritional and electrolyte supplements (9%). Medicines started included nutritional and electrolyte supplements (45%), medicines for comfort (19%), laxatives (15%), nicotine replacement (7%), PPI/H2RA (2%), bisphosphonates (2%).

Discussion/Conclusion

The 7-STEPS medicine reviews led to important medicine changes while the number of medicines following review remained the same. The person-centred, holistic approach facilitated identification and actioning of the medicine changes that mattered to individual patients. Stopped and decreased dose medicines included high risk medicines, those likely to cause adverse effects or high anticholinergic burden and medicines no longer needed or effective for the individual. Medicine doses were increased for high risk medicines, to ensure sufficient nutritional, electrolyte and enzyme replacement and items for comfort for example constipation. Importantly, unmet therapeutic needs were identified and new medicines were prescribed to address these needs, for example, acid suppressants, bisphosphonates, anticoagulants, statins, antidiabetics, nicotine replacement therapy and for patient’s comfort including pain relief. Limitations include results may not be reflective of all hospital patients as set in an acute setting and through the iSIMPATHY project.

References

1. Transforming medication safety in Northern Ireland, Department of Health 2022. Available from: https://www.health-ni.gov.uk/sites/default/files/publications/health/Transforming-medication-safety-in-Northern-Ireland_1.pdf

2. iSimpathy. Making Medication Personal. 2022. Available from: https://www.isimpathy.eu/

Symptom burden and health-related quality of life in moderate to severe chronic rhinosinusitis with nasal polyposis

Background: Chronic rhinosinusitis with nasal polyposis (CRSwNP) affects up to 4% of individuals. Common symptoms include nasal congestion/obstruction, nasal discharge, facial pain, and reduced sense of smell. This study describes patient- and physician-reported CRSwNP symptom burden and health-related quality of life (HRQOL) in a real-world clinical setting. Methods: This multinational, geographically diverse, point-in-time survey invited physicians to evaluate 5 consecutive adults with confirmed bilateral moderate to severe CRSwNP (consecutive sampling) plus the next 2 patients with recurrent nasal polyps and ≥1 surgery for polyp removal (oversampling). Patients’ and physicians’ surveys were assessed in the entire consecutive sample and by categories of physician-determined CRSwNP severity, and by categories of asthma comorbidity (total sample). Patients’ and physicians’ responses were compared in a matched sample. Results: The total sample of 1,782 patients comprised 1,296 (72.7%) from consecutive sampling and 486 (27.3%) from oversampling. Among the consecutive sample (mean age, 46.9 years), 1,122 (86.6%) had moderate and 174 (13.4%) had severe CRSwNP. Of 1,697 patients from total sampling with known asthma status, 708 (41.7%) had asthma and 989 (58.3%) did not. Patients’ self-reported symptom frequency, severity, and burden on HRQOL worsened with increasing CRSwNP severity and comorbid asthma. Physicians underreported prevalence, severity, and impact of symptoms on daily activities compared with patients (matched sample). Conclusion: Patients and physicians from real-world settings both described a considerable burden of CRSwNP, but physicians consistently reported fewer and less severe symptoms than patients. This suggests a more patient-centric view is needed when assessing CRSwNP symptom burden and HRQOL.

OC-022 MAINTAINING AN ELECTIVE ABDOMINAL WALL RECONSTRUCTION SERVICE DURING THE COVID 19 PANDEMIC

Aim

Elective surgery services suffered significantly due to the COVID-19 pandemic. The aim of this study was to analyse the impact and outcomes of abdominal wall reconstruction (AWR) performed during the COVID-19 pandemic, assessing safety and sustainability.

Material and Methods

A retrospective review of all patients undergoing AWR in a single NHS trust, multiple surgeons, between 23rd March 2020 and 22rd March 2022, the 2 years following U.K. Government imposed lockdown, was undertaken and compared with the pre-pandemic AWR activity. Procedures were initially undertaken at a cold site and when demonstrated to be safe, main site operating restarted. The primary outcome was 90 day mortality, secondary outcomes of COVID-19 infection within 7 days, length of stay, critical care requirement, and complication rate.

Results

In the study period, 173 patients underwent AWR, compared with 99 cases in a single year preceding lockdown. 90 day mortality rate was zero. No patients returned positive COVID tests to the trust within 7 days of AWR, and no patients were readmitted for COVID related symptoms. Critical care admission was required in 7 patients, 3 of these were planned admissions pre-operatively. The surgical site occurrence rate was 9.8% (17), infection 5.8% (10), seroma 2.3% (4) and haematoma 1.7% (3). There were no recurrences reported, with follow up ranging between 1 and 18 months.

Conclusion

Continuing AWR services during the COVID pandemic is feasible and safe. Peri-operative COVID infection rates are low, critical care requirements minimal, and there is no impact on patient morbidity or mortality.

P-135 FIRST EXPERIENCE WITH A NEW CLOSED INCISION NEGATIVE PRESSURE WOUND THERAPY, PREVENA™, IN ABDOMINAL WALL RECONSTRUCTION PATIENTS

Aim

Surgical site infection (SSI) contributes a significant proportion of post operative morbidity in patients undergoing abdominal wall reconstruction (AWR). Prevena™ closed incision negative pressure wound therapy (ciNPT) has been demonstrated to reduce SSI rates in the elective and emergency laparotomy setting. However, there is no evidence for Prevena™ use in AWR patients. The aim of this study was to assess the safety and feasibility of Prevena™ in AWR patients.

Materials and Method

Patients undergoing AWR at a single trust were selected at random to receive Prevena™. This was applied to the incision under sterile conditions, a continuous pressure of -125mmHg was applied for 7 days. The primary outcome measure was SSI, with secondary outcomes of 90 day mortality, complications and length of stay.

Results

10 patients received ciNPT in the study period, 8 female 2 male, mean BMI was 34.5. All patients had a Rives-Stoppa repair, with 2 patients also requiring bilateral transversus abdominal release (TAR). A vertical panniculectomy with umboplasty was used in 7 cases, fleur-de-lys panniculectomy with umboplasty in 2 cases, and a single case approached via transverse panniculectomy. There were no deaths within 90 days, median length of stay was 4 days. There was a single SSI managed with oral antibiotics, not requiring admission.

Conclusion

Prevena™ has been shown to reduce SSI rates in other patient cohorts and this small series demonstrates it is feasible and safe to use in the AWR setting. Larger studies are required to demonstrate SSI rate reduction in AWR patients.

Magnetic circular dichroism within the Algebraic Diagrammatic Construction scheme of the polarisation propagator up to third order

We present an implementation of the B term of Magnetic Circular Dichroism within the Algebraic Diagrammatic Construction (ADC) scheme of the polarization propagator and its Intermediate State Representation. As illustrative results, the MCD spectra of the ADC variants ADC(2), ADC(2)-x and ADC(3) of the molecular systems uracil, 2-thiouracil, 4-thiouracil, purine, hypoxanthine 1,4-naphthoquinone, 9,10-anthraquinone and1-naphthylamine are computed and compared with results obtained using the Resolution-of-Identity Coupled-Cluster Singles and Approximate Doubles (RICC2) method, literature TD-DFT results, and available experimental data.

Reading a preoperative CT scan to guide complex abdominal wall reconstructive surgery

Computed tomography (CT) scanning is the imaging modality of choice when planning the overall management and operative approach to complex abdominal wall hernias. Despite its availability and well-recognised benefits there are no guidelines or recommendations regarding how best to read or report such scans for this application. In this paper we aim to outline an approach to interpreting preoperative CT scans in abdominal wall reconstruction (AWR). This approach breaks up the interpretive process into 4 steps-concentrating on the hernia or hernias, any complicating features of the hernia(s), the surrounding soft tissues and the abdominopelvic cavity as a whole-and was developed as a distillation of the authors' collective experience. We describe the key features that should be looked for at each of the four steps and the rationale for their inclusion.

Laparoscopic colorectal resections during the COVID-19 pandemic - business as usual?

INTRODUCTION

To analyse the outcomes of major colorectal resections performed during the COVID-19 pandemic, to assess safety and explore all precautionary measures.

METHOD

All patients who underwent major elective colorectal resections at St Helens and Knowsley Teaching Hospital NHS Trust between 24th March 2020 (the date that the Royal Colleges of Surgery produced their guidelines re operating during the pandemic) and 17th April 2020 were analysed from a prospectively maintained database. The primary outcome was 7-day mortality and secondary outcomes were the development of a positive COVID-19 test consequent to hospital stay and the overall complication rate.

RESULTS

In this 24 day time frame 27 patients (17 males) underwent elective colorectal resections at St Helens and Knowsley NHS Trust. The median age was 69 (41-84) years and median ASA was 2 (1-3). The median Body Mass Index was 30 (21-40.7). Twenty-five patients underwent surgery for cancer and two patients had urgent resections for low-grade sepsis secondary to diverticular colovesical fistulae. 24 patients underwent laparoscopic colorectal resections and 3 patients underwent planned open surgery. 7-day mortality was 0%, and no patients/staff contracted COVID-19 during the post-operative period. The overall complication rate was 14.8%. At a median follow-up of 29 (17-44) days via telephone, there have been no reported COVID-19 related symptoms in any of these patients.

CONCLUSION

Our experience demonstrated that it was possible to undertake laparoscopic colorectal resections despite the COVID-19 pandemic posing a major threat to humanity, providing that adequate and stringent precautions are undertaken.

A mathematical framework for modelling 3D cell motility: applications to glioblastoma cell migration

The collection of 3D cell tracking data from live images of micro-tissues is a recent innovation made possible due to advances in imaging techniques. As such there is increased interest in studying cell motility in 3D in vitro model systems but a lack of rigorous methodology for analysing the resulting data sets. One such instance of the use of these in vitro models is in the study of cancerous tumours. Growing multicellular tumour spheroids in vitro allows for modelling of the tumour microenvironment and the study of tumour cell behaviours, such as migration, which improves understanding of these cells and in turn could potentially improve cancer treatments. In this paper, we present a workflow for the rigorous analysis of 3D cell tracking data, based on the persistent random walk model, but adaptable to other biologically informed mathematical models. We use statistical measures to assess the fit of the model to the motility data and to estimate model parameters and provide confidence intervals for those parameters, to allow for parametrization of the model taking correlation in the data into account. We use in silico simulations to validate the workflow in 3D before testing our method on cell tracking data taken from in vitro experiments on glioblastoma tumour cells, a brain cancer with a very poor prognosis. The presented approach is intended to be accessible to both modellers and experimentalists alike in that it provides tools for uncovering features of the data set that may suggest amendments to future experiments or modelling attempts.

Ab Initio Excited-State Electronic Circular Dichroism Spectra Exploiting the Third-Order Algebraic-Diagrammatic Construction Scheme for the Polarization Propagator

Excited-state rotatory strengths are reported for the first time at a correlated ab initio level, here with the algebraic diagrammatic construction scheme of the polarization propagator up to the third order. To demonstrate the capabilities of this computational approach, the gas phase S₁ electronic circular dichroism spectra of the bicyclic ketones (1R)-camphor, (1R)-norcamphor, and (1R)-fenchone have been calculated at the ADC(3) level of theory. Furthermore, the solution excited-state spectra of the energetically lowest conformer of R-(+)-1,1'-bi(2-naphthol) have been computed with inclusion of a polarizable continuum model at the ADC(2) level of theory.

Efficient implementation of isotropic cubic response functions for two-photon absorption cross sections within the self-consistent field approximation

Within the self-consistent field approximation, computationally tractable expressions for the isotropic second-order hyperpolarizability have been derived and implemented for the calculation of two-photon absorption cross sections. The novel tensor average formulation presented in this work allows for the evaluation of isotropic damped cubic response functions using only ∼3.3% (one-photon off-resonance regions) and ∼10% (one-photon resonance regions) of the number of auxiliary Fock matrices required when explicitly calculating all the needed individual tensor components. Numerical examples of the two-photon absorption cross section in the one-photon off-resonance and resonance regions are provided for alanine-tryptophan and 2,5-dibromo-1,4-bis(2-(4-diphenylaminophenyl)vinyl)-benzene. Furthermore, a benchmark set of 22 additional small- and medium-sized organic molecules is considered. In all these calculations, a quantitative assessment is made of the reduced and approximate forms of the cubic response function in the one-photon off-resonance regions and results demonstrate a relative error of less than ∼5% when using the reduced expression as compared to the full form of the isotropic cubic response function.