324 research outputs found

    Non-uniform carrier density in Cd3_3As2_2 evidenced by optical spectroscopy

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    We report the detailed optical properties of Cd3_3As2_2 crystals in a wide parameter space: temperature, magnetic field, carrier concentration and crystal orientation. We investigate high-quality crystals synthesized by three different techniques. In all the studied samples, independently of how they were prepared and how they were treated before the optical experiments, our data indicate conspicuous fluctuations in the carrier density (up to 30%). These charge puddles have a characteristic scale of 100 μ\mum, they become more pronounced at low temperatures, and possibly, they become enhanced by the presence of crystal twinning. The Drude response is characterized by very small scattering rates (1\sim 1 meV) for as-grown samples. Mechanical treatment, such as cutting or polishing, influences the optical properties of single crystals, by increasing the Drude scattering rate and also modifying the high frequency optical response. Magneto-reflectivity and Kerr rotation are consistent with electron-like charge carriers and a spatially non-uniform carrier density.Comment: Accepted in Physical Review

    Multiple metachronus proliferative fasciitis occurring in different anatomic regions: a case report and review of the literature.

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    Proliferative fasciitis is a benign lesion that usually has a self-limited course and rarely recurs after excision. In the literature, the multifocal occurrence of PF in different anatomic sites has not been reported so far. In this report, we describe the clinical case of a 30-year-old woman with two metachronous proliferative fasciitis occurring firstly in the orbit and, after 18 months, in the forearm; we also review the available literature on this topic, outlining guidelines for therapy and the follow-up of these patients

    BSM W W production with a jet veto

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    We consider the impact on W W production of the unique dimension-six operator coupling gluons to the Higgs field. In order to study this process, we have to appropriately model the effect of a veto on additional jets. This requires the resummation of large logarithms of the ratio of the maximum jet transverse momentum and the invariant mass of the W boson pair. We have performed such resummation at the appropriate accuracy for the Standard Model (SM) background and for a signal beyond the SM (BSM), and devised a simple method to interface jet-veto resummations with fixed-order event generators. This resulted in the fast numerical code MCFM-RE, the Resummation Edition of the fixed-order code MCFM. We compared our resummed predictions with parton-shower event generators and assessed the size of effects, such as limited detector acceptances, hadronisation and the underlying event, that were not included in our resummation. We have then used the code to compare the sensitivity of W W and Z Z production at the HL-LHC to the considered higher-dimension operator. We have found that W W can provide complementary sensitivity with respect to Z Z, provided one is able to control theory uncertainties at the percent-level. Our method is general and can be applied to the production of any colour singlet, both within and beyond the SM

    Non-standard family histories and wellbeing at older ages

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    The life course approach emphasizes that health and wellbeing at older ages are influenced by experiences occurred in the previous stages of life. We contribute to the literature by focusing on the role of the non-standardness of family histories and argue that individuals who experienced non-standard trajectories have been exposed to social sanctions throughout their life course with negative long-term consequences on wellbeing. In our study, non-standardness of family histories is the extent an individual's family history differs from those of the others within reference groups, defined combining birth cohort, gender and country of residence. Family histories between age of 15 and 49 are analyzed using Sequence Analysis, thus accounting for events related to fertility and union formation (marriage and cohabitation) and dissolution, and their timing. Dissimilarities between family sequences are measured using optimal matching and are standardized within the reference groups. We use retrospective data from the seventh wave of the Survey of Health Ageing and Retirement in Europe (SHARE) and estimate linear regression models to assess the association between non-standardness of family histories and older people's life satisfaction. Quality of life and depressive symptoms are examined in additional analyses. A negative association is found between non-standardness of family histories and wellbeing, which is stronger for lower educated individuals and in Southern European countries. Results are consistent with the idea that uncommon family behaviors may have a long-term negative effect on wellbeing. Individual resources and a more tolerant societal context can reduce or eliminate the negative consequences of engaging in non-standard family behaviors

    Epidural blood patch in Trendelenburg position pre-medicated with acetazolamide to treat spontaneous intracranial hypotension

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    Background: Spontaneous intracranial hypotension (SIH) is characterized by orthostatic headache, diffuse pachymeningeal enhancement on brain magnetic resonance imaging (MRI) and low cerebrospinal fluid (CSF) pressure. Treatment ranges from conservative management, such as bed rest, overhydration and caffeine, to invasive procedures, such as the autologous epidural blood patch (EBP), computed tomography (CT)-guided fibrin glue injection at the site of the leak and open surgical intervention. EBP has emerged as the treatment of choice for SIH when initial conservative measures fail to bring relief. Methods: Forty-two patients with SIH were treated with lumbar autologous EBP in Trendelenburg position preceded by pre-medication with acetazolamide. Results: A complete recovery was obtained in all patients after one (90%), two (5%) or three (5%) EBPs. After EBP, two patients (5%) also performed evacuation of bilateral chronic subdural hematoma with mass effect. Conclusions: Spontaneous intracranial hypotension can be effectively cured by lumbar autologous EBP in Trendelenburg position pre-medicated with acetazolamide

    Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications

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    BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (VT) size was 500 ml, or 7 to 9 ml kg1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P < 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P < 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high VT and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome

    Extended Adjuvant Endocrine Treatment in Luminal Breast Cancers in the Era of Genomic Tests

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    In patients with early-stage endocrine receptor-positive (ER+) breast cancer (BC), adjuvant endocrine therapy (ET) for 5 years is the standard of care. However, for some patients, the risk of recurrence remain high for up to 15 years after diagnosis and extended ET beyond 5 years may be a reasonable option. Nevertheless, this strategy significantly increases the occurrence of side effects. Here we summarize the available evidence from randomized clinical trials on the efficacy and safety profile of extended ET and discuss available clinical and genomic tools helpful to select eligible patients in daily clinical practice

    EGFR/HER2 inhibitor AEE788 increases ER-mediated transcription in HER2/ER-positive breast cancer cells but functions synergistically with endocrine therapy

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    BACKGROUND: Cross-talk between receptor tyrosine kinases and the oestrogen receptor (ER) is implicated in resistance to endocrine therapy. We investigated whether AEE788 (a combined inhibitor of EGFR, HER2 and VEGFR) plus tamoxifen or letrozole enhanced the individual anti-tumour effects of these agents. METHODS: Breast cancer cell lines modelling endocrine-resistant and -sensitive disease were engineered to express aromatase (A) and examined using proliferation, western blotting and ER-alpha transcription assays. RESULTS: AEE788 enhanced the anti-proliferative effect of tamoxifen and letrozole in ER+ cell lines (MCF-7 2A, ZR75.1 A3 and BT474 A3). This associated with an elevated G1 arrest and nuclear accumulation of p27. It is noteworthy that AEE788 alone or in combination with endocrine therapy increased the expression of progesterone receptor (PGR) and TFF1 in BT474 A3 cells. This may indicate a mechanism of resistance to AEE788 in ER+/HER2(+) breast cancers. In a ZR75.1 A3 xenograft, AEE788 alone or in combination with tamoxifen provided no further benefit compared with letrozole. However, letrozole plus AEE788 produced a significantly greater inhibition of tumour growth compared with letrozole alone. CONCLUSION: These data suggest that AEE788 plus letrozole in breast cancer overexpressing HER2 may provide superior anti-tumour activity, compared with single agents. British Journal of Cancer (2010) 102, 1235-1243. doi: 10.1038/sj.bjc.6605641 www.bjcancer.com (C) 2010 Cancer Research U
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