Superlight pairs in face-centred-cubic extended Hubbard models with strong Coulomb repulsion.

The majority of fulleride superconductors with unusually high transition-temperature to kinetic-energy ratios have a face-centred-cubic (FCC) structure. We demonstrate that, within extended Hubbard models with strong Coulomb repulsion, paired fermions in FCC lattices have qualitatively different properties than pairs in other three-dimensional cubic lattices. Our results show that strongly bound, light, and small pairs can be generated in FCC lattices across a wide range of the parameter space. We estimate that such pairs can Bose condense at high temperatures even if the lattice constant is large (as in the fullerides).

Pityriasis rubra pilaris-like eruption following administration of the BNT163b2 (Pfizer-BioNTech) mRNA COVID-19 vaccine.

We describe a case of a pityriasis rubra pilaris (PRP)-like eruption occurring following administration of the Pfizer-Biontech mRNA COVID-19 vaccine, with worsening of the condition following the second dose. To our knowledge, this is the first reported case of a PRP-like eruption as a cutaneous adverse event of the Pfizer-Biontech mRNA COVID-19 vaccine.

Excimer laser assisted complex inferior vena cava filter retrieval: a single institution's experience over 6 years.

AIM: To investigate inferior vena cava (IVC) filter retrievals and the use of the excimer laser sheath to assist in complex cases. MATERIALS AND METHODS: Retrospective analysis was undertaken of 181 attempted filter retrievals over a 6 year period. Pre- and perioperative imaging was analysed from both standard retrieval and complex retrieval techniques. RESULTS: One hundred and eighty-one IVC filter retrievals were attempted: 130 (72%) standard retrievals were successful and 51 (28%) failed due to device endothelialisation. Forty (23%) cases then had subsequent successful complex retrieval under general anaesthetic. Eighteen (45%) cases were removed with the sling technique and 22 (55%) cases using the excimer laser dissection technique. Where preoperative venography/computed tomography (CT) demonstrated embedding of the filter feet versus filter apex, this was predictive of requiring dissection techniques versus sling technique (13/18 patients; p<0.05 chi-squared test). The difference in device indwelling time was statistically significant between the successful standard retrieval group (134 days) versus patients who failed standard retrieval and required complex techniques (243 days; p=0.00018). CONCLUSION: Standard retrieval techniques failed in 28% of cases. This correlated with devices that were indwelling for longer. When imaging demonstrated filter-feet endothelisation/perforation, this was predictive of requiring dissection techniques with the excimer laser.

Role of substrate induced electron-phonon interactions in biased graphitic bilayers.

Bilayers of graphitic materials have potential applications in field effect transistors (FETs). A potential difference applied between certain ionic bilayers made from insulating graphitic materials such as BN, ZnO and AlN could reduce gap sizes, turning them into useful semiconductors. On the other hand, opening of a small semiconducting gap occurs in graphene bilayers under applied field. The aim here is to investigate to what extent substrate induced electron-phonon interactions (EPIs) modify this gap change. We examine EPIs in several lattice configurations of graphitic bilayers, using a perturbative approach. The typical effect of EPIs on the ionic bilayers is an undesirable gap widening. The size of this gap change varies considerably with lattice structure and the magnitude of the bias. When bias is larger than the non-interacting gap size, EPIs have the smallest effect on the bandgap, especially in configurations with [Formula: see text] and AB structures. Thus careful selection of substrate, lattice configuration and bias strength to minimise the effects of EPIs could be important for optimising the properties of electronic devices. We use parameters related to BN in this article. In practice, the results presented here are broadly applicable to other graphitic bilayers, and are likely to be qualitatively similar in metal dichalcogenide bilayers such as MoS2, which are already of high interest for their use in FETs.

Effect of Treatment With Tabalumab, a B Cell-Activating Factor Inhibitor, on Highly Sensitized Patients With End-Stage Renal Disease Awaiting Transplantation.

B cell-activation factor (BAFF) is critical for B cell maturation. Inhibition of BAFF represents an appealing target for desensitization of sensitized end-stage renal disease (ESRD) patients. We conducted a Phase 2a, single-arm, open-label exploratory study investigating the effect of tabalumab (BAFF inhibitor) in patients with ESRD and calculated panel reactive antibodies (cPRAs) >50%. The treatment period duration was 24 weeks. Eighteen patients received tabalumab, at doses of 240-mg subcutaneous (SC) at Week 0 followed by 120-mg SC monthly for 5 additional months. Patients were followed for an additional 52 weeks. Immunopharmacologic effects were characterized through analysis of blood for HLA antibodies, BAFF concentrations, immunoglobulins, T and B cell subsets, as well as pre- and posttreatment tonsil and bone marrow biopsies. Significant reductions in cPRAs were observed at Weeks 16 (p = 0.043) and 36 (p = 0.004); however, absolute reductions were small (<5%). Expected pharmacologic changes in B cell subsets and immunoglobulin reductions were observed. Two tabalumab-related serious adverse events occurred (pneumonia, worsening of peripheral neuropathy), while the most common other adverse events were injection-site pain and hypotension. Three patients received matched deceased donor transplants during follow-up. Treatment with a BAFF inhibitor resulted in statistically significant, but not clinically meaningful reduction in the cPRA from baseline (NCT01200290, Clinicaltrials.gov).

Optimal interlayer hopping and high temperature Bose-Einstein condensation of local pairs in quasi 2D superconductors.

Both FeSe and cuprate superconductors are quasi 2D materials with high transition temperatures and local fermion pairs. Motivated by such systems, we investigate real space pairing of fermions in an anisotropic lattice model with intersite attraction, V, and strong local Coulomb repulsion, U, leading to a determination of the optimal conditions for superconductivity from Bose-Einstein condensation. Our aim is to gain insight as to why high temperature superconductors tend to be quasi 2D. We make both analytically and numerically exact solutions for two body local pairing applicable to intermediate and strong V. We find that the Bose-Einstein condensation temperature of such local pairs pairs is maximal when hopping between layers is intermediate relative to in-plane hopping, indicating that the quasi 2D nature of unconventional superconductors has an important contribution to their high transition temperatures.

Bias free gap creation in bilayer graphene.

For graphene to be utilized in the digital electronics industry the challenge is to create bandgaps of order 1 eV as simply as possible. The most successful methods for the creation of gaps in graphene are (a) confining the electrons in nanoribbons, which is technically difficult or (b) placing a potential difference across bilayer graphene, which is limited to gaps of around 300 meV for reasonably sized electric fields. Here we propose that electronic band gaps can be created without applying an external electric field, by using the electron-phonon interaction formed when bilayer graphene is sandwiched between highly polarisable ionic materials. We derive and solve self-consistent equations, finding that a large gap can be formed for intermediate electron-phonon coupling. The gap originates from the amplification of an intrinsic Coulomb interaction due to the proximity of carbon atoms in neighbouring planes.

Modelling of impaired cerebral blood flow due to gaseous emboli.

Bubbles introduced to the arterial circulation during invasive medical procedures can have devastating consequences for brain function but their effects are currently difficult to quantify. Here we present a Monte Carlo simulation investigating the impact of gas bubbles on cerebral blood flow. For the first time, this model includes realistic adhesion forces, bubble deformation, fluid dynamical considerations, and bubble dissolution. This allows investigation of the effects of buoyancy, solubility, and blood pressure on embolus clearance. Our results illustrate that blockages depend on several factors, including the number and size distribution of incident emboli, dissolution time and blood pressure. We found it essential to model the deformation of bubbles to avoid overestimation of arterial obstruction. Incorporation of buoyancy effects within our model slightly reduced the overall level of obstruction but did not decrease embolus clearance times. We found that higher blood pressures generate lower levels of obstruction and improve embolus clearance. Finally, we demonstrate the effects of gas solubility and discuss potential clinical applications of the model.

International field trials of pyrethroid-treated wood exposed to Coptotermes acinaciformis in Australia and Coptotermes formosanus (Isoptera: Rhinotermitidae) in China and the United States.

Coptotermes Wasmann is one of the most important genera of wood-destroying insect pests, both in its native and introduced countries. Pyrethroids are among the most widely used insecticides in wood preservation around the world. Consequently, they have often been evaluated against different species of Coptotermes. However, because various test methods have been used between countries, comparing results is problematic. These field trials, using a single aboveground method of exposure, assessed a range of retentions of two pyrethroids (bifenthrin and permethrin) in Pinus radiata D. Don sapwood against two species of Coptotermes in three countries to provide directly comparable results. Coptotermes acinaciformis (Froggatt) in Australia consumed the most nontreated wood, followed by Coptotermes formosanus Shiraki in China, then C. formosanus in the United States, although these data were not significantly different. Both termite species demonstrated a dose-response to wood treated with the two pyrethroids; less wood was consumed as retention increased. Overall, C. acinaciformis consumed relatively little of the treated wood. In comparison, C. formosanus consumed 20-90% of the wood treated at the lowest retentions of the pyrethroids evaluated. Results indicated that C. acinaciformis was more sensitive to pyrethroid toxicity/repellency compared with C. formosanus. Factors that may have influenced the results are discussed. However, using a single aboveground method of exposure across three countries, that suited both species of Coptotermes, made it possible to determine unambiguously the actual differences between the species in their tolerances to the two pyrethroid insecticides.

Bilayers of Rydberg atoms as a quantum simulator for unconventional superconductors.

In condensed matter, it is often difficult to untangle the effects of competing interactions, and this is especially problematic for superconductors. Quantum simulators may help: here we show how exploiting the properties of highly excited Rydberg states of cold fermionic atoms in a bilayer lattice can simulate electron-phonon interactions in the presence of strong correlation--a scenario found in many unconventional superconductors. We discuss the core features of the simulator, and use numerics to compare with condensed matter analogues. Finally, we illustrate how to achieve a practical, tunable implementation of the simulation using "painted spot" potentials.

Human papillomavirus typing of warts and response to cryotherapy.

BACKGROUND: Cutaneous warts are common and caused by a number of different types of human papillomaviruses (HPVs). OBJECTIVE: The aim of this study was to investigate the HPV types causing common warts and to determine any association between the HPV type and the duration of warts and response to cryotherapy. METHODS: Eighty wart samples from 76 immunocompetent patients were taken from warts by paring prior to cryotherapy and analysed by in situ hybridization (ISH) with HPV probes specific to HPV 1, 2, 3, 4, 7, 10 and 57 and PCR analysis using degenerate cutaneous HPV primers with subsequent DNA sequencing. Each patient's details, including site, duration and response of the wart to cryotherapy were recorded. Cryotherapy was performed at 2 week intervals for a maximum of 12 weeks. RESULTS: An HPV type was identified in 65 samples. The majority of warts (58 samples) were typed as HPV 2/27/57 by ISH and/or PCR. Three of the 18 samples that were HPV negative with ISH were HPV positive by PCR. Response to treatment did not correlate with HPV type, duration or location. In the 21 wart parings taken from patients aged 16 and under, response to treatment did not correlate with HPV type but warts of shorter duration were more likely to resolve with cryotherapy treatment than longer standing lesions. CONCLUSION: This study demonstrates that HPV type can be determined from wart parings. HPV-2 related viruses are the prevalent HPV types causing common warts on the hands and feet in this population.

Two cases of pustular toxic epidermal necrolysis.

Toxic epidermal necrolysis (TEN) is a life-threatening, immune-mediated reaction, characterized by severe cutaneous and mucosal blisters and erosions. It often presents with flu-like symptoms, followed by a maculopapular, urticarial, purpuric or erythema multiforme-like eruption, which then evolves into blisters and sheet-like erosions. Presentation with pustules, however, is not well described in the English literature, and may lead to delayed diagnosis. We present two unusual cases of TEN that initially presented with pustular lesions.

Endovascular techniques in palliative care.

Most palliative care patients will require multidisciplinary management to optimise symptom control. This overview will show that endovascular procedures are an important consideration in many cases. These procedures can be used primarily, or more commonly, as an adjunct to other therapy modalities. Catheter, wire and modern imaging technology allow interventional radiologists to treat a wide, and growing, spectrum of conditions. Percutaneous endovascular procedures allow for minimal discomfort and rapid recovery, ideal for palliative care patients. Many symptoms (or life-threatening conditions) can be treated with endovascular techniques. This discussion aims to demonstrate the increasing spectrum of endovascular interventions and review the evidence available. This overview cannot provide an exhaustive list of possible procedures, but covers most aspects and should reinforce the evidence base for intervention in this field. We have included a section on the technical aspects of endovascular intervention, including the use of sedoanalgesia, and post-embolisation syndrome. Embolisation of bleeding tumours, including bronchial artery embolisation and symptomatic renal tumour embolisation, is a fairly well-established technique. Embolisation of symptomatic skeletal metastases has shown good results. Covered stent grafting of ruptured or threatened arteries is an evolving field that has benefited from developments in stent graft technology and design. Symptomatic, unresectable liver tumours can be embolised with good results. Stent insertion in the superior vena cava produces dramatic relief of superior vena cava syndrome. Advanced malignancy predisposes to venous thrombosis; caval filtration is discussed together with venous thrombectomy.

Cross sectional analysis of respiratory symptoms in an injection drug user cohort: the impact of obstructive lung disease and HIV.

BACKGROUND: Injection drug use is associated with an increased risk of human immunodeficiency virus (HIV) infection and with obstructive lung diseases (OLD). Understanding how HIV and OLD may impact respiratory symptoms among injection drug users (IDUs) is important to adequately care for this high-risk population. We characterized the independent and joint effects of HIV and OLD on respiratory symptoms of a cohort of inner-city IDUs. METHODS: Demographics, risk behavior and spirometric measurements were collected from a cross-sectional analysis of the Acquired Immunodeficiency Syndrome Link to the IntraVenous Experience study, an observational cohort of IDUs followed in Baltimore, MD since 1988. Participants completed a modified American Thoracic Society respiratory questionnaire and the Medical Research Council (MRC) dyspnea score to assess respiratory symptoms of cough, phlegm, wheezing and dyspnea. RESULTS: Of 974 participants, 835 (86%) were current smokers and 288 (29.6%) were HIV-infected. The prevalence of OLD (FEV1/FVC < or = 0.70) was 15.5%, and did not differ by HIV status. OLD, but not HIV, was associated with increased frequency of reported respiratory symptoms. There was a combined effect of OLD and HIV on worsening of MRC scores. OLD and HIV were independently associated with an increased odds of reporting an MRC > or = 2 (OR 1.83 [95%CI 1.23-2.73] and 1.50 [95%CI 1.08-2.09], respectively). COPD, but not HIV, was independently associated with reporting an MRC >/= 3 (OR 2.25 [95%CI 1.43-3.54] and 1.29 [95%CI 0.87-1.91], respectively). CONCLUSIONS: While HIV does not worsen cough, phlegm or wheezing, HIV significantly increases moderate but not severe dyspnea in individuals of similar OLD status. Incorporating the MRC score into routine evaluation of IDUs at risk for OLD and HIV provides better assessment than cough, phlegm and wheezing alone.

Hair removal with the long-pulse alexandrite and long-pulse Nd:YAG lasers is safe and well tolerated in children.

BACKGROUND: Children with excessive hair may have severe psychological consequences. Laser hair removal in adults is known to be safe and well tolerated, but this is less well established in children. OBJECTIVE: To describe our experience with laser hair removal in children, and to investigate the safety and tolerability of this procedure in children. METHODS: The case records of 24 children aged < 16 years, who had received a minimum of three treatments for hair removal were analysed retrospectively. For patients with Fitzpatrick skin phototype II-IV, the lasers used were a long-pulse alexandrite (755 nm) with either continuous chilled-air cooling at fluences of 16-27 J/cm(2) or a long-pulse alexandrite with cryogen cooling at fluences of 16-32 J/cm(2). For patients with Fitzpatrick skin phototype IV-VI, lasers used were a long-pulse Nd:YAG (1064 nm) with a chilled contact sapphire tip at fluences of 20-35 J/cm(2) or a long-pulse Nd:YAG with cryogen cooling at fluences of 16-26 J/cm(2). RESULTS: Mean age at first treatment was 12.3 years. Diagnoses were constitutional hirsutism (14 patients), polycystic ovarian syndrome (five), congenital melanocytic naevus (two), generalized hypertrichosis (two) and naevoid hypertrichosis (one). One patient required a general anaesthetic, eight required topical anaesthetic cream, and 15 did not require any form of anaesthesia. Intolerable discomfort requiring adjustment in fluence was the only recorded side-effect, affecting two cases. There were no incidences of blistering, infection, dyspigmentation or scarring. CONCLUSION: When administered appropriately, laser hair removal is safe and well tolerated in children aged < 16 years.

Statistical physics of cerebral embolization leading to stroke.

We discuss the physics of embolic stroke using a minimal model of emboli moving through the cerebral arteries. Our model of the blood flow network consists of a bifurcating tree into which we introduce particles (emboli) that halt flow on reaching a node of similar size. Flow is weighted away from blocked arteries inducing an effective interaction between emboli. We justify the form of the flow weighting using a steady flow (Poiseuille) analysis and a more complicated nonlinear analysis. We discuss free flowing and heavily congested limits and examine the transition from free flow to congestion using numerics. The correlation time is found to increase significantly at a critical value and a finite-size scaling is carried out. An order parameter for nonequilibrium critical behavior is identified as the overlap of blockages' flow shadows. Our work shows embolic stroke to be a feature of the cerebral blood flow network on the verge of a phase transition.

Laser treatment of pigmented lesions in clinical practice: a retrospective case series and patient satisfaction survey.

Lasers are frequently used to treat pigmented skin lesions; however, there is little published data from routine clinical practice. We performed a retrospective review of patients treated between January 2003 and January 2004 to describe the patients, methods used and the clinical outcome. The long-term result was determined by a patient questionnaire. In total, 67 patients with 76 pigmented lesions were treated (22 males and 45 females, mean age 22 years); 27% had Fitzpatrick skin types IV-VI. The Q-switched Nd:YAG, and erbium:YAG lasers were used in 75% and 24% of cases, respectively, with an average of 5.4 treatments/patient. The physician-rated outcome at the end of treatment was 'very positive' in 45% and 'mostly positive' in 30% of cases. The patient-rated outcome at an average of 21 months post-treatment was 'excellent' in 29.5%, 'good' in 25%, and 'fair' in 22.7% of the 44 cases. About 50% of patients with the three most common lesions (congenital naevi, other/unspecified naevi and naevus of Ota) achieved good or excellent long-term results.