Identifying materials with charge-spin physics using charge-spin susceptibility computed from first principles.

The authors present a quantity termed charge-spin susceptibility, which measures the charge response to spin degrees of freedom in strongly correlated materials. This quantity is simple to evaluate using both standard density functional theory and many-body electronic structure techniques, enabling comparison between different levels of theory. A benchmark on 28 layered magnetic materials shows that large values of charge-spin susceptibility correlate with unconventional ground states such as disordered magnets and unconventional superconductivity.

The epidemiology and functional outcomes of operative fixation of extracapsular proximal femoral fractures (AO 31-A) in young adults.

Proximal femoral fractures in adults under 50 years are not as common as in the elderly, but may have just as significant an impact. There is little in the literature describing the functional outcomes of fixation in this age group. Our aim was to assess the clinical and functional outcomes of operative management of extracapsular proximal femoral fractures (AO 31-A) in the young adult (<50 years). Consecutive skeletally mature patients <50 years undergoing operative fixation of these fractures were obtained from a prospective database over a 12-year period. Complications and mortality data were obtained from this database and case note review. Outcome scores were obtained via postal questionnaires. Eighty-eight patients were included in the study of which 74 (84%) had fixation with the dynamic hip screw. The mean age was 39 years (range 17-50) with a male preponderance (73.8%). Mean hospital stay was 14 days (range 2-94). Seventeen (19.3%) patients had died at a mean of 40 months from their operation date. The 1-year mortality was 4.5%. There were five complications (5.7%). SF-36 and EuroQol 5D scores showed that 5-10% had severe problems with a 20% decrease in quality of life compared to population norms. The biggest differences were in the physical function modalities. One-third had fair to poor hip function as assessed by the Oxford Hip Score. Though these injuries are relatively rare in this age group, they do have significant mortality and functional impairment reflecting a higher energy of injury rather than the frailty seen in the elderly.

Interaction-Driven Metal-Insulator Transition in Strained Graphene.

The question of whether electron-electron interactions can drive a metal to insulator transition in graphene under realistic experimental conditions is addressed. Using three representative methods to calculate the effective long-range Coulomb interaction between π electrons in graphene and solving for the ground state using quantum Monte Carlo methods, we argue that, without strain, graphene remains metallic and changing the substrate from SiO_{2} to suspended samples hardly makes any difference. In contrast, applying a rather large-but experimentally realistic-uniform and isotropic strain of about 15% seems to be a promising route to making graphene an antiferromagnetic Mott insulator.

The outcomes of displaced paediatric distal radius fractures treated with percutaneous Kirschner wire fixation: a review of 248 cases.

This study aimed to evaluate the effect of manipulation under anaesthesia (MUA) and Kirschner wire (K-wire) fixation of displaced, paediatric distal radius fractures on residual radiological angulation, displacement, and shortening, as well as functional outcomes, including complication rates. A retrospective review was conducted of all paediatric patients undergoing MUA and K-wire fixation for an extra-articular distal radius fracture over a period of 5 years. A total of 248 patients were included in the study with a mean age of 9.9 years (3-15). Mean follow-up was 6.6 weeks (4-156). There was a statistically significant increase in median dorsal angulation (p<0.0001) between initial post-operative and follow-up radiographs at the time of K-wire removal. The number of K-wires used did not have a significant effect on dorsal angulation (p=0.9015) at time of K-wire removal, nor did the use of an above or below elbow cast (p=0.3883). Seventeen patients required a further general anaesthetic (5 revision operations, 12 removal of migrated K-wires). Eighty-seven percentage of (215 patients) of patients had normal function at follow-up post-K-wire removal. Angulation at time of K-wire removal of more than 15° was significantly associated with reduced functional outcome (p=0.0377). A total of 41 patients (17%) had complications associated with K-wire use. We conclude that though K-wire fixation is an effective technique, it does not prevent re-angulation of the fracture and is associated with a significant complication rate. Given the remodelling potential and tolerance to deformity in children, surgeons should give careful thought before utilising this technique for all displaced or angulated paediatric distal radius fractures. If used, 1 K-wire with immobilisation in a below elbow cast is sufficient in most cases.

Construct validity of the anglicised FACE-Q skin cancer module.

OBJECTIVES: The FACE-Q Skin Cancer module is a patient-reported outcome measure (PROM) for facial skin cancer. It has been anglicised for the UK population and undergone psychometric testing using classical test theory. In this study, further evaluation of construct validity using Rasch measurement theory and hypothesis testing was performed. METHODS: Patients were prospectively recruited to the Patient-Reported Outcome Measures In Skin Cancer Reconstruction (PROMISCR) study and asked to complete the anglicised FACE-Q Skin Cancer module. The scalability and unidimensionality of the data were assessed with a Mokken analysis prior to Rasch analysis. Response thresholds, targeting, fit statistics, local dependency, and internal consistency were examined for all items and subscales. Four a priori hypotheses were tested to evaluate the convergent and divergent validity. We additionally hypothesised that the median 'cancer worry' score would be lower in post-operative than pre-operative patients. RESULTS: 239 patients self-completed the questionnaire between August 2017 and May 2019. Of the ten subscales assessed, five showed relative fit to the Rasch model. Unidimensionality was present for all five subscales, with most demonstrating ordered item thresholds and appropriate fit statistics. Two items in the 'cancer worry' subscale had either disordered or very close response thresholds. Subscales of the FACE-Q Skin Cancer module demonstrated convergent and divergent validity with relevant Skin Cancer Index comparators (p < 0.001). Median 'cancer worry' was lower in post-operative patients (44 vs 39, p < 0.001). CONCLUSION: The anglicised FACE-Q Skin Cancer module shows psychometric validity through hypothesis testing, and both classical and modern test theory.

Automated conversational agents for post-intervention follow-up: a systematic review.

BACKGROUND: Advances in natural language processing and other machine learning techniques have led to the development of automated agents (chatbots) that mimic human conversation. These systems have mainly been used in commercial settings, and within medicine, for symptom checking and psychotherapy. The aim of this systematic review was to determine the acceptability and implementation success of chatbots in the follow-up of patients who have undergone a physical healthcare intervention. METHODS: A systematic review of MEDLINE, MEDLINE In-process, EMBASE, PsychINFO, CINAHL, CENTRAL and the grey literature using a PRISMA-compliant methodology up to September 2020 was conducted. Abstract screening and data extraction were performed in duplicate. Risk of bias and quality assessments were performed for each study. RESULTS: The search identified 904 studies of which 10 met full inclusion criteria: three randomised control trials, one non-randomised clinical trial and six cohort studies. Chatbots were used for monitoring after the management of cancer, hypertension and asthma, orthopaedic intervention, ureteroscopy and intervention for varicose veins. All chatbots were deployed on mobile devices. A number of metrics were identified and ranged from a 31 per cent chatbot engagement rate to a 97 per cent response rate for system-generated questions. No study examined patient safety. CONCLUSION: A range of chatbot builds and uses was identified. Further investigation of acceptability, efficacy and mechanistic evaluation in outpatient care pathways may lend support to implementation in routine clinical care.

Response to Comment on "The role of electron-electron interactions in two-dimensional Dirac fermions".

Hesselmann et al question one of our conclusions: the suppression of Fermi velocity at the Gross-Neveu critical point for the specific case of vanishing long-range interactions and at zero energy. The possibility they raise could occur in any finite-size extrapolation of numerical data. Although we cannot definitively rule out this possibility, we provide mathematical bounds on its likelihood.

The role of electron-electron interactions in two-dimensional Dirac fermions.

The role of electron-electron interactions in two-dimensional Dirac fermion systems remains enigmatic. Using a combination of nonperturbative numerical and analytical techniques that incorporate both the contact and long-range parts of the Coulomb interaction, we identify the two previously discussed regimes: a Gross-Neveu transition to a strongly correlated Mott insulator and a semimetallic state with a logarithmically diverging Fermi velocity accurately described by the random phase approximation. We predict that experimental realizations of Dirac fermions span this crossover and that this determines whether the Fermi velocity is increased or decreased by interactions. We explain several long-standing mysteries, including why the observed Fermi velocity in graphene is consistently about 20% larger than values obtained from ab initio calculations and why graphene on different substrates shows different behaviors.

Tailoring sample-wide pseudo-magnetic fields on a graphene-black phosphorus heterostructure.

Spatially tailored pseudo-magnetic fields (PMFs) can give rise to pseudo-Landau levels and the valley Hall effect in graphene. At an experimental level, it is highly challenging to create the specific strain texture that can generate PMFs over large areas. Here, we report that superposing graphene on multilayer black phosphorus creates shear-strained superlattices that generate a PMF over an entire graphene-black phosphorus heterostructure with edge size of tens of micrometres. The PMF is intertwined with the spatial period of the moiré pattern, and its spatial distribution and intensity can be modified by changing the relative orientation of the two materials. We show that the emerging pseudo-Landau levels influence the transport properties of graphene-black phosphorus field-effect transistor devices with Hall bar geometry. The application of an external magnetic field allows us to enhance or reduce the effective field depending on the valley polarization with the prospect of developing a valley filter.

Functional outcome and complications following surgery for Dupuytren's disease: a multi-centre cross-sectional study.

Variables associated with recurrent Dupuytren's disease, or a 'diathesis', have been investigated, but those associated with functional outcome and complications are less well studied. Outcomes 1 or 5 years after an aponeurotomy, fasciectomy or dermofasciectomy were assessed by patient interview and examination at five UK centres. A total of 432 procedures were studied. The reoperation rate did not differ at 1 year ( p = 0.396, Chi-square test with Monte Carlo simulation), but was higher after aponeurotomy in the 5-year group (30%, versus 6% after fasciectomy and 0% after dermofasciectomy, p = 0.003, Chi square test with Monte Carlo simulation). Loss of function (DASH>15) did not differ between procedures at 5 years, even when reoperation and other variables were controlled. Diabetes, female gender and previous ipsilateral surgery were associated with poorer function in logistic regression analysis. The variables associated with poor function after treatments differ from diathesis variables. Aponeurotomy had lower complication rates than fasciectomy and dermofasciectomy. This may counterbalance the former's higher recurrence rate and explain why aponeurotomy demonstrated similar long-term functional outcome compared with excisional surgery in this study. LEVEL OF EVIDENCE: III.

Recovery, responsiveness and interpretability of patient-reported outcome measures after surgery for Dupuytren's disease.

This prospective cohort study investigated the responsiveness and interpretability of the Disabilities of the Arm, Shoulder and Hand (DASH) and Unité Rhumatologique des Affections de la Main (URAM) outcome measures for assessing recovery after fasciectomy and dermofasciectomy for Dupuytren's disease. DASH outcome scores at 1 year were significantly better than at 6 weeks, suggesting that recovery is not complete by 6 weeks. Of the 101 patients recruited to the DASH cohort, 71 completed preoperative, 6 week and 1 year postoperative DASH scores; 68 of them completed preoperative and 1 year postoperative DASH scores and an external anchor question. In the URAM cohort, 30/44 completed the preoperative and the 1 year postoperative URAM scores and the anchor question. The DASH score exhibited moderate responsiveness but poor interpretability on receiver operating characteristic curve analysis, such that a minimal important change could not be estimated. The URAM score showed acceptable responsiveness, and an MIC of 10.5 on receiver operating characteristic analysis. LEVEL OF EVIDENCE: II.

Bone SPECT-CT: An additional diagnostic tool for undiagnosed wrist pain.

Diagnosis of wrist pain can be difficult to determine with clinical examination and conventional imaging techniques alone. Bone SPECT-CT (single-photon emission tomography with computerized tomography) is a hybrid imaging technique that overlays functional bone scintigraphy in tomographic/3D mode with conventional CT. Data from the two modalities are complementary; areas of abnormal bone metabolism can be localized with anatomical precision, hitherto lacking in conventional bone scans, while structural information from the CT scan further embellishes the diagnostic information. Over the last 6 years, one surgeon (David Evans) has used bone SPECT and later bone SPECT-CT as an additional line of investigation. This is a series of 21 consecutive patients with wrist pain that could not be diagnostically resolved with the usual combination of history, examination, and conventional imaging, and therefore underwent bone SPECT-CT. Clinical and imaging findings, management, and outcomes of these cases are discussed to explore the potential role of this hybrid functional modality in hand and wrist surgical practice.

Minimal important changes and differences in elective hand surgery.

UNLABELLED: Minimal important changes and differences describe the smallest changes and differences between individuals that are relevant to patients following treatment. Minimal important differences may vary between conditions, treatments and lengths of follow-up, and can be calculated in different ways. Minimal important differences for elective hand surgery were reviewed. A total of 99 minimal important differences were identified in 29 articles. The conditions, treatments, outcome measures used and follow-up periods are discussed. The Disabilities of the Arm, Shoulder and Hand had the most estimates of minimal important differences, but these varied. The methods used in the included studies were reviewed and appraised. Most minimal important differences were calculated using retrospective anchors. Future research directions in this area are suggested. LEVEL OF EVIDENCE: II.

Dynamism in Dupuytren's contractures.

Dynamism of Dupuytren's contractures may occur if a contracture crosses over both the metacarpophalangeal (MCPJ) and proximal interphalangeal (PIPJ) joints of one finger. In this situation the extension deficit at one joint can be influenced by the position of the other. This may affect clinical measurements and introduce errors and bias into research using angular deformity as an endpoint. This study reports the dynamism encountered when measuring passive joint extension deficits in pre-operative contractures. Eighty-five digits with a contracture affecting the PIPJ or MCPJ and PIPJ on 72 hands from 70 patients were studied. Seventy-six digits showed dynamism at either the MCPJ or PIPJ (89%). Seventy-four showed dynamism at the PIPJ (87%). The mean dynamism observed was 6° at the MCPJ and 14° at the PIPJ. Previous Dupuytren's surgery to the finger did not influence the amount of dynamism seen. Dynamism is common and may be a source of error or bias in trials of Dupuytren's disease treatment.

What patients want from the treatment of Dupuytren's disease--is the Unité Rhumatologique des Affections de la Main (URAM) scale relevant?

Patients awaiting surgery for Dupuytren's contractures listed the problems from their Dupuytren's disease that had led them to request surgery and their relative priorities of the results of surgery. The listed problems were compared with the nine items comprising the Unité Rhumatologique des Affections de la Main (URAM) Dupuytren's disease-specific outcome measure. One hundred and ten patients reported 278 problems. Ninety-four different combinations of problems were provided by patients, and over half (55%) of the problems were not captured by items in the URAM scale. The long-term outcome from surgery was relatively more important to patients than speed of recovery. The URAM tool may not be relevant to patients in the UK, and further assessment of its face validity is required before it is used.

Tunable room-temperature ferromagnet using an iron-oxide and graphene oxide nanocomposite.

Magnetic materials have found wide application ranging from electronics and memories to medicine. Essential to these advances is the control of the magnetic order. To date, most room-temperature applications have a fixed magnetic moment whose orientation is manipulated for functionality. Here we demonstrate an iron-oxide and graphene oxide nanocomposite based device that acts as a tunable ferromagnet at room temperature. Not only can we tune its transition temperature in a wide range of temperatures around room temperature, but the magnetization can also be tuned from zero to 0.011 A m(2)/kg through an initialization process with two readily accessible knobs (magnetic field and electric current), after which the system retains its magnetic properties semi-permanently until the next initialization process. We construct a theoretical model to illustrate that this tunability originates from an indirect exchange interaction mediated by spin-imbalanced electrons inside the nanocomposite.