Coupled atomistic spin-lattice simulations of ultrafast demagnetization in 3d ferromagnets

Despite decades of research, the role of the lattice and its coupling to the magnetisation during ultrafast demagnetisation processes is still not fully understood. Here we report on studies of both explicit and implicit lattice effects on laser induced ultrafast demagnetisation of bcc Fe and fcc Co. We do this using atomistic spin- and lattice dynamics simulations following a heat-conserving three-temperature model. We show that this type of Langevin-based simulation is able to reproduce observed trends of the ultrafast magnetization dynamics of fcc Co and bcc Fe. The parameters used in our models are all obtained from electronic structure theory, with the exception of the lattice dynamics damping term, where a range of parameters were investigated. It was found that while the explicit spin-lattice coupling in the studied systems does not impact the demagnetisation process notably, the lattice damping has a large influence on the details of the magnetization dynamics. The dynamics of Fe and Co following the absorption of a femtosecond laser pulse are compared with previous results for Ni and similarities and differences in the materials' behavior are analysed. For all elements investigated so far with this model, we obtain a linear relationship between the value of the maximally demagnetized state and the fluence of the laser pulse , which is in agreement with experiments. Moreover, we demonstrate that the demagnetization amplitude is largest for Ni and smallest for Co. This holds over a wide range of the reported electron-phonon couplings, and this demagnetization trend is in agreement with recent experiments.

Prospective Longitudinal Assessment of Quality of Life After Stereotactic Ablative Radiotherapy for Oligometastases: Analysis of the Population-based SABR-5 Phase II Trial

AIMS

To evaluate longitudinal patient-reported quality of life (QoL) in patients treated with stereotactic ablative radiotherapy (SABR) for oligometastases.

MATERIALS AND METHODS

The SABR-5 trial was a population-based single-arm phase II study of SABR to up to five sites of oligometastases, conducted in six regional cancer centres in British Columbia, Canada from 2016 to 2020. Prospective QoL was measured using treatment site-specific QoL questionnaires at pre-treatment baseline and at 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after treatment. Patients with bone metastases were assessed with the Brief Pain Inventory (BPI). Patients with liver, adrenal and abdominopelvic lymph node metastases were assessed with the Functional Assessment of Chronic Illness Therapy-Abdominal Discomfort (FACIT-AD). Patients with lung and intrathoracic lymph node metastases were assessed with the Prospective Outcomes and Support Initiative (POSI) lung questionnaire. The two one-sided test procedure was used to assess equivalence between the worst QoL score and the baseline score of individual patients. The mean QoL at all time points was used to determine the trajectory of QoL response after SABR. The proportion of patients with 'stable', 'improved' or 'worsened' QoL was determined for all time points based on standard minimal clinically important differences (MCID; BPI worst pain = 2, BPI functional interference score [FIS] = 0.5, FACIT-AD Trial Outcome Index [TOI] = 8, POSI = 3).

RESULTS

All enrolled patients with baseline QoL assessment and at least one follow-up assessment were analysed (n = 133). On equivalence testing, the patients' worst QoL scores were clinically different from baseline scores and met MCID (BPI worst pain mean difference: 1.8, 90% confidence interval 1.19 to 2.42]; BPI FIS mean difference: 1.68, 90% confidence interval 1.15 to 2.21; FACIT-AD TOI mean difference: -8.76, 90% confidence interval -11.29 to -6.24; POSI mean difference: -4.61, 90% confidence interval -6.09 to -3.14). However, the mean FIS transiently worsened at 9, 18 and 21 months but eventually returned to stable levels. The mean FACIT and POSI scores also worsened at 36 months, albeit with a limited number of responses (n = 4 and 8, respectively). Most patients reported stable QoL at all time points (range: BPI worst pain 71-82%, BPI FIS 45-78%, FACIT-AD TOI 50-100%, POSI 25-73%). Clinically significant stability, worsening and improvement were seen in 70%/13%/18% of patients at 3 months, 53%/28%/19% at 18 months and 63%/25%/13% at 36 months.

CONCLUSIONS

Transient decreases in QoL that met MCID were seen between patients' worst QoL scores and baseline scores. However, most patients experienced stable QoL relative to pre-treatment levels on long-term follow-up. Further studies are needed to characterise patients at greatest risk for decreased QoL.

Predictors of Quality of Life Decline in Patients with Oligometastases treated with Stereotactic Ablative Radiotherapy: Analysis of the Population-Based SABR-5 Phase II Trial

AIMS

Most patients experience stable quality of life (QoL) after stereotactic ablative radiotherapy (SABR) treatment for oligometastases. However, a subset of patients experience clinically relevant declines in QoL on post-treatment follow-up. This study aimed to identify risk factors for QoL decline.

MATERIALS AND METHODS

The SABR-5 trial was a population-based single-arm phase II study of SABR to up to five sites of oligometastases. Prospective QoL was measured using treatment site-specific tools at pre-treatment baseline and 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after treatment. The time to persistent QoL decline was calculated as the time from SABR to the first decline in QoL score meeting minimum clinically important difference with no improvement to baseline score on subsequent assessments. Univariable and multivariable logistic regression analyses were carried out to determine factors associated with QoL decline.

RESULTS

One hundred and thirty-three patients were included with a median follow-up of 32 months (interquartile range 25-43). Thirty-five patients (26%) experienced a persistent decline in QoL. The median time until persistent QoL decline was not reached. The cumulative incidence of QoL decline at 2 and 3 years were 22% (95% confidence interval 14.0-29.6) and 40% (95% confidence interval 28.0-51.2), respectively. In multivariable analysis, disease progression (odds ratio 5.23, 95% confidence interval 1.59-17.47, P = 0.007) and adrenal metastases (odds ratio 9.70, 95% confidence interval 1.41-66.93, P = 0.021) were associated with a higher risk of QoL decline. Grade 3 or higher (odds ratio 3.88, 95% confidence interval 0.92-16.31, P = 0.064) and grade 2 or higher SABR-associated toxicity (odds ratio 2.24, 95% confidence interval 0.85-5.91, P = 0.10) were associated with an increased risk of QoL decline but did not reach statistical significance.

CONCLUSIONS

Disease progression and adrenal lesion site were associated with persistent QoL decline following SABR. The development of grade 3 or higher toxicities was also associated with an increased risk, albeit not statistically significant. Further studies are needed, focusing on the QoL impact of metastasis-directed therapies.

Exploring HIV disease indicators at MDR-TB treatment initiation in South Africa

BACKGROUND: Understanding relationships between HIV and multidrug-resistant TB (MDR-TB) is crucial for ensuring successful MDR-TB outcomes.METHODS: We used a cross-sectional analysis to evaluate sociodemographic and clinical characteristics as correlates of antiretroviral therapy (ART) use, having an HIV viral load (VL) result, and HIV viral suppression in a cross-sectional sample of people with HIV (PWH) and MDR-TB enrolled in a cluster-randomized trial of nurse case management to improve MDR-TB outcomes.RESULTS: Among 1,479 PWH, the mean age was 37.1 years; 809 (54.7%) were male, and 881 (59.6%) were taking ART. Housing location, employment status, and CD4 count differed significantly between those taking vs. those not taking ART. Among the 881 taking ART, 681 (77.3%) had available HIV VL results. Housing location, CD4 count, and prior history of TB differed significantly between those with and without a VL result. Among the 681 with a VL result, 418 (61.4%) were virally suppressed. Age, education level, CD4 count, TB history, housing location, and ART type differed significantly between those with and without viral suppression.CONCLUSION: PWH presenting for MDR-TB treatment with a history of TB, taking a protease inhibitor, or living in a township may risk poor MDR-TB outcomes.

Evaluation of Patient-Specific Quality Control (QC) for Markerless Dynamic Tumor Tracking (MDTT) Deliveries

PURPOSE/OBJECTIVE(S)

To report on the patient-specific QC for MDTT for liver and lung tumors treated using the dome-of-liver/diaphragm as a surrogate for the target position and compare to the QC of conventional fiducial-based tracking.

MATERIALS/METHODS

Vero4DRT is a linear accelerator that has a gimbal-mounted waveguide and collimation system allowing the radiation beam to perform dynamic tumor tracking based on a patient's respiratory motion. A correlation model is built between an external IR marker placed on the chest and an internal structure, which may be implanted fiducial surrogates or in the case of MDTT, an anatomic landmark. During treatment an orthogonal kV image pair is taken every second. The auto detected internal structure position versus the predicted position is recorded in treatment log files. Five IMRT tracking plans were delivered to two commercial motion phantoms with in-house additions for patient-specific tracking QC. For point dose measurements, a 0.6cc farmer chamber was placed inside the dynamic tracking phantom which contains fiducials for fiducial-based tracking delivery and an anatomic landmark for MDTT. For 2D dose distribution measurements, a radiographic film insert for the Quasar Respiratory Motion Phantom was constructed. The phantom contains both fiducials and has a liver-dome shape at one end to facilitate MDTT. Both motion platforms were interfaced with software that enabled patient-specific respiratory motion traces acquired during a 4DCT scan. Each plan was delivered three times on each phantom: 1) in static mode, 2) during fiducial-based tracking, and 3) during MDTT. Chamber measurements taken during static and tracked delivery were compared to the average chamber dose from the treatment planning software (TPS). Film distributions measured during tracked deliveries were compared to the static film distribution using gamma analysis with FILMQA PRO software. Finally, dynamic tracking treatment statistics, extracted from log files, were compared between fiducial and markerless tracking deliveries.

RESULTS

All chamber measurements resulted in dose differences <2.5% compared with the TPS. Dose differences between fiducial-based and MDTT were 0.26% on average (range 0.03-0.62%). For film dose map analysis, gamma pass rates were >95% for all plans for all tracking methods. The average gamma pass rate for 3%/3mm was 99.4% (fiducial-based) vs 98.4% (markerless). For 2%/2mm, the average gamma pass rate was 96.4% (fiducial-based tracking) vs 95.6% (MDTT). Dynamic treatment statistics from logs files reported an average 3D absolute deviation from predicted position of 0.52mm (±0.24) for fiducial tracking and 1.19mm (±0.50) for MDTT.

CONCLUSION

Both fiducial-based and MDTT plans meet passing criteria for patient-specific QC. 3D absolute deviation of detected versus predicted position are larger for MDTT compared to fiducial tracking, however no significant impact on dose delivery was measured.

Prospective Longitudinal Assessment of Quality of Life after Stereotactic Ablative Radiotherapy for Oligometastases: Analysis of the Population-Based SABR-5 Phase II Trial

PURPOSE/OBJECTIVE(S)

To evaluate longitudinal patient-reported quality of life (QoL) in patients treated with stereotactic ablative radiotherapy (SABR) for oligometastases.

MATERIALS/METHODS

The SABR-5 trial was a population-based single-arm phase II study of SABR to up to 5 sites of oligometastases, conducted in 6 regional cancer centers in British Columbia from 2016 to 2020. Prospective QoL was measured using treatment site-specific QoL questionnaires at pre-treatment baseline and 3, 6, 9, 12, 15, 18, 21, 24, 30, and 36 months after treatment. Patients with bone metastases were assessed with the Brief Pain Inventory (BPI). Patients with liver, adrenal, and abdominopelvic lymph node metastases were assessed with the Functional Assessment of Chronic Illness Therapy-Abdominal Discomfort (FACIT-AD). Patients with lung and intrathoracic lymph node metastases were assessed with the Prospective Outcomes and Support Initiative (POSI) lung questionnaire. The two one-sided test procedure was used to assess equivalence between the worst QoL score and baseline score of individual patients. Mean QoL at all time points was used to determine the trajectory of QoL response after SABR. The proportion of patients with "stable," "improved," or "worsened" QoL was determined for all time points based on standard minimal clinically important differences (MCID; BPI worst pain = 2, BPI Functional Interference Score [FIS] = 0.5, FACIT-AD Trial Outcome Index [TOI] = 8, POSI = 3).

RESULTS

All enrolled patients with baseline QoL assessment and at least 1 follow-up assessment were analyzed (n = 135). On equivalence testing, patients' worst QoL scores were clinically different from baseline scores and met MCID (BPI worst pain mean difference: 1.8, 90% CI [1.19 to 2.42]; BPI FIS mean difference: 1.68, 90% CI [1.15 to 2.21]; FACIT-AD TOI mean difference: -8.76, 90% CI [-11.29 to -6.24]; POSI mean difference: -4.61, 90% CI [-6.09 to -3.14]). However, the mean FIS transiently worsened at 9, 18 and 21 months but eventually returned to stable levels. The mean FACIT and POSI scores also worsened at 36 months, albeit with a limited number of responses (n = 4 and 8, respectively). The majority of patients reported stable QoL at all time points (range: BPI worst pain 71-82%, BPI FIS 45-78%, FACIT-AD TOI 50-100%, POSI 25-73%). Clinically significant stability, worsening, and improvement were seen in 70%/13%/18% of patients at 3 months, 53%/28%/19% at 18 months and 63%/25%/13% at 36 months.

CONCLUSION

SABR in the oligometastatic setting can lead to transient decreases in QoL. However, most patients experienced stable QoL relative to pre-treatment levels on long-term follow-up. Further studies are needed to characterize patients at greatest risk for decreased QoL.

"Living like an empty gas tank with a leak": Mixed methods study on post-acute sequelae of COVID-19

BACKGROUND

The burden and presentation of post-acute sequela of SARS-CoV-2 infection (PASC) are a developing major public health concern.

OBJECTIVES

To characterize the burden of PASC in community-dwelling individuals and understand the experiences of people living with PASC.

METHODS

This mixed-methods study of COVID-19 positive community-dwelling persons involved surveys and in-depth interviews. Main outcome was self-report of possible PASC symptoms 3 weeks or longer after positive COVID-19 test. In-depth interviews were guided by a semi-structured interview guide with open-ended questions and probes based on emerging literature on PASC and the impact of COVID-19.

RESULTS

With a survey response rate of 70%, 442 participants were included in this analysis, mean (SD) age 45.4 (16.2) years, 71% female, 12% Black/African American. Compared to those with no PASC symptoms, persons who reported PASC symptoms were more likely to be older (mean age: 46.5 vs. 42; p = 0.013), female (74.3% vs. 61.2%; p = 0.010), to have pre-existing conditions (49.6% vs. 34%; p = 0.005), and to have been hospitalized for COVID-19 (14.2% vs. 2.9%; p = 0.002). About 30% of the participants experienced severe fatigue; the proportion of persons reporting severe fatigue was 7-fold greater in those with PASC symptoms (Adjusted Prevalence Ratio [aPR] 6.73, 95%CI: 2.80-16.18). Persons with PASC symptoms were more likely to report poor quality of life (16% vs. 5%, p<0.001) and worse mental health functioning (Mean difference: -1.87 95%CI: -2.38, -1.37, p<0.001). Themes from in-depth interviews revealed PASC was experienced as debilitating.

CONCLUSIONS

In this study, the prevalence of PASC among community-dwelling adults was substantial. Participants reported considerable coping difficulties, restrictions in everyday activities, invisibility of symptoms and experiences, and impediments to getting and receiving PASC care.

Combating Stigma in the Era of Monkeypox-Is History Repeating Itself?

ABSTRACT

Men who have sex with men (MSM) and people with HIV (PWH) perceive, internalize, and experience significant stigma from family members, health care providers, and community members because of their sexual behaviors. The current monkeypox (MPX) outbreak is affecting both communities. The pandemic has spread to 89 countries with more than 31,000 confirmed cases, and global agencies are concerned about how the disease is portrayed in the media. This article will introduce MPX and its associated stigmas, providing a brief theoretical perspective on adaptive behaviors and nursing interventions to mitigate stigma. This is followed by a case-based description of the current experiences of an MSM with MPX. We will discuss stigma prevention strategies from an adaptation and mitigation perspective. We conclude with how nurses can contribute to stigma prevention for individuals with MPX.

Monkeypox Virus Outbreak 2022: Key Epidemiologic, Clinical, Diagnostic, and Prevention Considerations

ABSTRACT

Monkeypox is a zoonotic infection that manifests as dermatologic lesions that may be painful or pruritic and can appear on the face, trunk, extremities, genitals, and mucosal surfaces. In 2022, cases of monkeypox increased exponentially and it was declared a public health emergency by the World Health Organization and the U.S. Department of Health and Human Services. Unlike previous monkeypox outbreaks, the current situation has disproportionately affected men who have sex with men and seems to be associated with lower mortality. Options for treatment and prevention are limited. The distribution and availability of vaccines and antivirals has posed challenges for patients, clinicians, and public health systems. Early recognition and management of persons with monkeypox is critical in controlling the spread of this infection. This article reviews key features of monkeypox and highlights current recommendations for clinical management, prevention, and considerations for persons with HIV. Implications for public health and nursing are discussed.

Genome-wide analysis of mitochondrial DNA copy number reveals loci implicated in nucleotide metabolism, platelet activation, and megakaryocyte proliferation

Mitochondrial DNA copy number (mtDNA-CN) measured from blood specimens is a minimally invasive marker of mitochondrial function that exhibits both inter-individual and intercellular variation. To identify genes involved in regulating mitochondrial function, we performed a genome-wide association study (GWAS) in 465,809 White individuals from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the UK Biobank (UKB). We identified 133 SNPs with statistically significant, independent effects associated with mtDNA-CN across 100 loci. A combination of fine-mapping, variant annotation, and co-localization analyses was used to prioritize genes within each of the 133 independent sites. Putative causal genes were enriched for known mitochondrial DNA depletion syndromes (p = 3.09 × 10-15) and the gene ontology (GO) terms for mtDNA metabolism (p = 1.43 × 10-8) and mtDNA replication (p = 1.2 × 10-7). A clustering approach leveraged pleiotropy between mtDNA-CN associated SNPs and 41 mtDNA-CN associated phenotypes to identify functional domains, revealing three distinct groups, including platelet activation, megakaryocyte proliferation, and mtDNA metabolism. Finally, using mitochondrial SNPs, we establish causal relationships between mitochondrial function and a variety of blood cell-related traits, kidney function, liver function and overall (p = 0.044) and non-cancer mortality (p = 6.56 × 10-4).

Reframing Intersectional Stigma for a South African Context Integrating Tuberculosis, HIV and Poverty Stigmas

ABSTRACT

Intersectionality is closely intertwined with Black feminism within the context of the United States. As a result, intersectionality is often overlooked in non-Western contexts where racial homogeneity may reduce some of the impact of race on marginalization. This article will look at intersectional stigma from the South African context using the tuberculosis/HIV (TB/HIV) treatment environment in South Africa to exemplify intersectionality's versatility as an analytic method outside of the United States. We will use colonial history and contemporary research to reframe intersectionality considering a new set of stigmatized identities, including HIV stigma, TB stigma, and poverty stigma, to create a situation-specific framework adapted from a model by Bulent Turan and colleagues.

Evaluating Integrated Care for People Living With HIV and Multidrug-Resistant Tuberculosis in South Africa: A Case-Based Approach Using the Chronic Care Model

ABSTRACT

In South Africa, tuberculosis (TB) and multidrug-resistant TB (MDR-TB) frequently occur in people living with HIV. World Health Organization guidelines recommend the integration of MDR-TB and HIV care but, in practice, fully integrated care is difficult to achieve. In this article, we use five elements of the Chronic Care Model as a framework for evaluating a case of integrated MDR-TB/HIV care and to highlight opportunities for nurses to improve care delivery and patient outcomes. We apply the Chronic Care Model framework to a concrete example by examining the case of a 33-year-old man who developed MDR-TB treatment failure while concurrently taking a powerful new MDR-TB antiretroviral therapy regimen for his HIV.

Risk factors for poor engagement in drug-resistant TB care in South Africa: a systematic review

BACKGROUND

Metrics of poor patient engagement, including missed appointments, treatment interruption, sub-optimal medication adherence, and loss to follow-up, have been linked to poor clinical multidrug-resistant TB (MDR-TB) outcomes. Understanding the risk factors for poor patient engagement is necessary to improve outcomes and control TB. This review synthesizes the risk factors for poor patient engagement in MDR-TB treatment across South Africa.

DESIGN

A systematic review of five databases (PubMed, Embase, CINAHL, Cochrane, and Web of Science) was conducted, covering articles published between 2010 and 2020. Articles were included if they provided information about risk factors associated with poor engagement among adults (⩾15 years) in treatment for MDR-TB in South Africa. Reviews, editorials, abstracts, and case studies were excluded.

RESULTS

Six studies met the inclusion criteria. Male sex and younger age were the most consistently identified risk factors for poor engagement; however, there was a lack of consistency in the choice of covariates, measurement of the variables, analytic methods, and significant factors associated with poor engagement between studies. Alcohol use, substance use, living with HIV, pulmonary TB site, and ethnicity were all identified as risk factors in at least one included study, while formal housing and steady employment were found to be protective.

CONCLUSION

The available literature offers little cohesive data to address poor patient engagement in this population. Further research needs to focus on identifying and addressing risk factors for poor patient engagement. This is particularly salient within the context of newer all-oral and short-course MDR-TB treatment regimens.

Identification of IgG1 isotype phosphorylcholine antibodies for the treatment of inflammatory cardiovascular diseases

BACKGROUND

Phosphorylcholine (PC) is an important pro-inflammatory damage-associated molecular pattern. Previous data have shown that natural IgM anti-PC protects against cardiovascular disease. We aimed to develop a monoclonal PC IgG antibody with anti-inflammatory and anti-atherosclerotic properties.

METHODS

Using various techniques PC antibodies were validated and optimized. In vivo testing was performed in a femoral artery cuff model in ApoE3*Leiden mice. Safety studies are performed in rats and cynomolgus monkeys.

RESULTS

A chimeric anti-PC (PC-mAb(T15), consisting of a human IgG1 Fc and a mouse T15/E06 Fab) was produced, and this was shown to bind specifically to epitopes in human atherosclerotic tissues. The cuff model results in rapid induction of inflammatory genes and altered expression of genes associated with ER stress and choline metabolism in the lesions. Treatment with PC-mAb(T15) reduced accelerated atherosclerosis via reduced expression of endoplasmic reticulum stress markers and CCL2 production. Recombinant anti-PC Fab fragments were identified by phage display and cloned into fully human IgG1 backbones creating a human monoclonal IgG1 anti-PC (PC-mAbs) that specifically bind PC, apoptotic cells and oxLDL. Based on preventing macrophage oxLDL uptake and CCL2 production, four monoclonal PC-mAbs were selected, which to various extent reduced vascular inflammation and lesion development. Additional optimization and validation of two PC-mAb antibodies resulted in selection of PC-mAb X19-A05, which inhibited accelerated atherosclerosis. Clinical grade production of this antibody (ATH3G10) significantly attenuated vascular inflammation and accelerated atherosclerosis and was tolerated in safety studies in rats and cynomolgus monkeys.

CONCLUSIONS

Chimeric anti-PCs can prevent accelerated atherosclerosis by inhibiting vascular inflammation directly and through reduced macrophage oxLDL uptake resulting in decreased lesions. PC-mAb represents a novel strategy for cardiovascular disease prevention.

Accuracy of Double Contrast Barium Enema and Sigmoideoscopy in the Detection of Polyps in Patients with Diverticulosis

The sensitivity between double contrast barium enema (DCBE) and sigmoideoscopy in diagnosing neoplastic lesions in the sigmoid colon was compared in patients with diverticulosis. In 52 patients with severe diverticulosis (≥15 diverticulas) the DCBE detected one out of 4 polyps found by sigmoideoscopy. In the remaining 54 patients with mild diverticulosis (<15 diverticulas) DCBE detected 7 out of 10 polyps found by sigmoideoscopy. Successful bowel preparation did not influence the outcome of the DCBE. Sigmoideoscopy was incomplete in 17 (16%) of the patients; females were more difficult to examine than males (p= 0.012), as were those with a previous pelvic operation (p= 0.032). We conclude that neither DCBE nor sigmoideoscopy alone is sufficient to detect all neoplastic lesions in the sigmoid colon in patients with sigmoid diverticulosis of the colon.

Local dynamics of topological magnetic defects in the itinerant helimagnet FeGe

Chiral magnetic interactions induce complex spin textures including helical and conical spin spirals, as well as particle-like objects such as magnetic skyrmions and merons. These spin textures are the basis for innovative device paradigms and give rise to exotic topological phenomena, thus being of interest for both applied and fundamental sciences. Present key questions address the dynamics of the spin system and emergent topological defects. Here we analyse the micromagnetic dynamics in the helimagnetic phase of FeGe. By combining magnetic force microscopy, single-spin magnetometry and Landau–Lifschitz–Gilbert simulations we show that the nanoscale dynamics are governed by the depinning and subsequent motion of magnetic edge dislocations. The motion of these topologically stable objects triggers perturbations that can propagate over mesoscopic length scales. The observation of stochastic instabilities in the micromagnetic structure provides insight to the spatio-temporal dynamics of itinerant helimagnets and topological defects, and discloses open challenges regarding their technological usage.

Topological defects may strongly influence the evolution of a materials' micromagnetic structure whilst their manipulation forms the basis for emerging technological concepts. Here, the authors study the depinning and motion of magnetic edge dislocations in the domain structure of helimagnetic FeGe.

High spatial resolution, low-noise Brillouin dynamic gratings reflectometry based on digital pulse compression

Digital pulse compression was used to enhance the performance of optical time-domain reflectometry, employing Brillouin dynamic gratings (BDGs) in polarization-maintaining fibers. The fundamental and unique issues in BDG field-reflection are addressed, and rules for proper selection of the coding and detection techniques are formulated. While coding in BDG applications generally requires coherent processing of the reflection, conditions are established for use of direct detection. A 256-bit Golay complementary unipolar probe code is used to demonstrate an eightfold signal-to-noise ratio enhancement in the measurement of the Brillouin gain spectrum (BGS), with a spatial resolution of 2 cm and a full-BGS acquisition rate of 133⅓ kHz, resulting in an equivalent reduction in the estimation error of small Brillouin frequency shifts.

Effects of multiple ascending doses of the glucagon receptor antagonist PF-06291874 in patients with type 2 diabetes mellitus

AIMS

To assess the pharmacokinetics, pharmacodynamics, safety and tolerability of multiple ascending doses of the glucagon receptor antagonist PF-06291874 in patients with type 2 diabetes mellitus (T2DM).

METHODS

Patients were randomized to oral PF-06291874 or placebo on a background of either metformin (Part A, Cohorts 1-5: 5-150 mg once daily), or metformin and sulphonylurea (Part B, Cohorts 1-2: 15 or 30 mg once daily) for 14-28 days. A mixed-meal tolerance test (MMTT) was administered on days -1 (baseline), 14 and 28. Assessments were conducted with regard to pharmacokinetics, various pharmacodynamic variables, safety and tolerability. Circulating amino acid concentrations were also measured.

RESULTS

PF-06291874 exposure was approximately dose-proportional with a half-life of ∼19.7-22.7 h. Day 14 fasting plasma glucose and mean daily glucose values were reduced from baseline in a dose-dependent manner, with placebo-corrected decreases of 34.3 and 42.4 mg/dl, respectively, at the 150 mg dose. After the MMTT, dose-dependent increases in glucagon and total glucagon-like peptide-1 (GLP-1) were observed, although no meaningful changes were noted in insulin, C-peptide or active GLP-1 levels. Small dose-dependent increases in LDL cholesterol were observed, along with reversible increases in serum aminotransferases that were largely within the laboratory reference range. An increase in circulating gluconeogenic amino acids was also observed on days 2 and 14. All dose levels of PF-06291874 were well tolerated.

CONCLUSION

PF-06291874 was well tolerated, has a pharmacokinetic profile suitable for once-daily dosing, and results in reductions in glucose with minimal risk of hypoglycaemia.

Systematic review: the financial burden of surgical complications in patients with ulcerative colitis

BACKGROUND

Patients undergoing colectomy for ulcerative colitis (UC) may experience complications associated with reduced quality of life (QoL), and maybe a considerable economic burden to healthcare systems. Appreciation of these burdens is important to evaluate the cost effectiveness of newer interventions for UC vs. colectomy.

AIM

To identify data representing resource utilisation or costs of complications arising from colorectal procedures in patients with UC, and data representing patient QoL, as reported by health state utility values (HSUVs).

METHODS

Embase, MEDLINE and The Cochrane Library were searched for studies (1995-2014) reporting resource use/costs of surgical complications, and HSUVs data in adult patients with UC, undergoing colorectal procedures. Conference proceedings (January 2011-January 2014) were hand-searched.

RESULTS

Twelve studies reported resource use/costs, and three reported HSUVs data in patients with UC experiencing surgical complications. Additional mean costs of postoperative complications ranged from $18 650/patient with complications at a 6-month follow-up (46% incidence) to $34 714/patient with complications over a 5-year period (49% incidence). Pouchitis, pouch failure and small bowel obstruction carried the greatest burden. Marked reductions in HSUVs were observed for patients with UC experiencing surgical complications, vs. patients with UC in a remission state.

CONCLUSIONS

There is a paucity of well reported studies on resource use/cost, and QoL burden of surgical complications in patients with UC. However, surgical complications represent a substantial burden both in terms of cost and of quality of life, with reoperations, physician fees, additional in-patient hospital stays and infertility treatment being the main cost drivers.

Comparison between MRI and CT in prediction of peritoneal carcinomatosis index (PCI) in patients undergoing cytoreductive surgery in relation to the experience of the radiologist

BACKGROUND

To compare CT and MRI for peritoneal carcinomatosis index (PCI) assessment and to compare assessments made by the radiologist based on their experiences.

METHOD AND MATERIALS

MRI and CT of abdomen and pelvis were performed on 39 prospectively followed by surgery directly. Two blinded radiologists with different experience levels evaluated PCI separately on different occasions on 19 cases initially and later on the remaining 20. The agreement between the radiologists' assessment and surgical findings in total and per site were recorded.

RESULTS

Total PCI: The experienced radiologist was able to assess total tumor burden correctly on both CT and MRI (kappa = 1.0). For the inexperienced radiologist the assessment was better on CT (kappa = 0.73) compared to MRI (kappa = 0.58). Different sites: The experienced radiologist showed high agreement with kappa = 0.77 for MRI and 0.80 for CT. Corresponding figures were 0.39 and 0.60 for the inexperienced radiologist. For the second phase the agreement levels increased for the inexperienced radiologist increased to 0.80 and 0.70, respectively.

CONCLUSION

CT and MRI are equal when read by experienced radiologist. CT shows better results when read by an inexperienced radiologist compared to MRI, however the results of the latter can easily be improved.

Magnetic properties of Fe(x)Co(1-x) nanochains on Pt(1 1 1) surfaces

The magnetic properties of FexCo1-x nanochains on Pt(1 1 1) were studied using the first-principles real-space linear muffin-tin orbital-atomic sphere approximation (RS-LMTO-ASA) method within the density functional theory. The relative amounts of Fe and Co atoms in a chosen nanochain were varied and several possible arrangements of the atomic species were taken into account. The results of the exchange interaction demonstrates ferromagnetic coupling for the nanowires. Our calculations of Fe and Co average magnetic moments reveal a large enhancement of both spin and orbital moments compared to Fe-Co films deposited on a Pt(1 1 1) surface. The trend for the orbital moments with respect to stoichiometry differs from all previous higher-dimensional Fe-Co alloys on Pt(1 1 1) studies.

Interatomic exchange interactions for finite-temperature magnetism and nonequilibrium spin dynamics

We derive ab inito exchange parameters for general noncollinear magnetic configurations, in terms of a multiple scattering formalism. We show that the general exchange formula has an anisotropiclike term even in the absence of spin-orbit coupling, and that this term is large, for instance, for collinear configuration in bcc Fe, whereas for fcc Ni it is quite small. We demonstrate that keeping this term leads to what one should consider a biquadratic effective spin Hamiltonian even in the case of collinear arrangement. In noncollinear systems this term results in new tensor elements that are important for exchange interactions at finite temperatures, but they have less importance at low temperature. To illustrate our results in practice, we calculate for bcc Fe magnon spectra obtained from configuration-dependent exchange parameters, where the configurations are determined by finite-temperature effects. Our theory results in the same quantitative results as the finite-temperature neutron scattering experiments.

The MutSβ complex is a modulator of p53-driven tumorigenesis through its functions in both DNA double-strand break repair and mismatch repair

Loss of the DNA mismatch repair (MMR) protein MSH3 leads to the development of a variety of tumors in mice without significantly affecting survival rates, suggesting a modulating role for the MutSβ (MSH2-MSH3) complex in late-onset tumorigenesis. To better study the role of MSH3 in tumor progression, we crossed Msh3(-/-) mice onto a tumor predisposing p53-deficient background. Survival of Msh3/p53 mice was not reduced compared with p53 single mutant mice; however, the tumor spectrum changed significantly from lymphoma to sarcoma, indicating MSH3 as a potent modulator of p53-driven tumorigenesis. Interestingly, Msh3(-/-) mouse embryonic fibroblasts displayed increased chromatid breaks and persistence of γH2AX foci following ionizing radiation, indicating a defect in DNA double-strand break repair (DSBR). Msh3/p53 tumors showed increased loss of heterozygosity, elevated genome-wide copy-number variation and a moderate microsatellite instability phenotype compared with Msh2/p53 tumors, revealing that MSH2-MSH3 suppresses tumorigenesis by maintaining chromosomal stability. Our results show that the MSH2-MSH3 complex is important for the suppression of late-onset tumors due to its roles in DNA DSBR as well as in DNA MMR. Further, they demonstrate that MSH2-MSH3 suppresses chromosomal instability and modulates the tumor spectrum in p53-deficient tumorigenesis and possibly has a role in other chromosomally unstable tumors as well.