2,032 research outputs found

    Extremal Problems in Bergman Spaces and an Extension of Ryabykh's Theorem

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    We study linear extremal problems in the Bergman space ApA^p of the unit disc for pp an even integer. Given a functional on the dual space of ApA^p with representing kernel kAqk \in A^q, where 1/p+1/q=11/p + 1/q = 1, we show that if the Taylor coefficients of kk are sufficiently small, then the extremal function FHF \in H^{\infty}. We also show that if qq1<q \le q_1 < \infty, then FH(p1)q1F \in H^{(p-1)q_1} if and only if kHq1k \in H^{q_1}. These results extend and provide a partial converse to a theorem of Ryabykh.Comment: 16 pages. To appear in the Illinois Journal of Mathematic

    Recovery of renal function in liver transplant alone versus combined liver kidney transplantation: analysis from the NHSBT UK registry

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    Introduction and Aims: Recovery of renal function after liver transplantation is strongly influenced by pretransplant degree and duration of renal insufficiency, despite imprecise methods for measuring renal dysfunction. Indications for combined liver-kidney transplantation (CLKT) have been defined, but these are still under debate and hepatorenal syndrome (HRS) is a particularly challenging condition given the hardly predictable spontaneous improvement with liver transplant alone (LTA). Methods: We analysed data of 6035 patients (Jan 2001-Dec 2012) from NHSBT UK Transplant Registry. Renal function at 1 years after transplantation was compared between CLKT and LTA with stratification on the basis of glomerular filtration rate (eGFR) at transplant (KDIGO Guidelines) and treatment with renal replacement therapy (RRT). Renal function post-transplantation was classified as eGFR &gt;60, between 59-30 and &lt;30 ml/min/1.73m2, the latter identified as non recovery of renal function. Univariate and multivariable analysis were performed. Results: 5912 patients (98.0%) underwent liver transplant alone (LTA) and 123 (2.0%) patients received a CLKT. 305 (5.2%) of the LTA group were on RRT at time of transplantation, compared to 72 (58.5%) of the CKLT group. No patient with a MELD score &lt;20 received RRT before transplant. No patients with eGFR ≥60 mL/min/1.73m2 received CLKT. 27% of patients receiving CLKT were diagnosed with pre-transplant glomerular/tubular kidney disease, 39% with polycystic disease and 34% were not specified. LTA patients on RRT were more frequently presenting ascites ( p&lt;0.001), variceal bleeding ( p=0.002), higher MELD score ( p&lt;0.001), higher INR ( p&lt;0.001) and bilirubin at transplant ( p&lt;0.001), suggesting the occurrence of HRS (data not available). Patients on RRT experience a significant difference of renal function recovery at 1 year post-transplant when receiving LTA versus CLKT, with the latter group experiencing a higher percentage of non-recovery ( p=0.001; table 1). This difference was not detected for other eGFR stratifications.The univariate analysis identified recipient age &gt;50 years, female gender, RRT in patients with MELD &gt;20, polycystic disease and diabetes as predictive factors for non-recovery of renal function in patients undergoing LTA. In a multivariable model including all clinically relevant variables simultaneously, the independent predictors of renal function non-recovery were female gender (HR 2.76; 95% CI 1.52-4.99, p=0.001), RRT in patients with MELD &gt;20 (HR 3.62; 95% CI 1.44-9.08, p=0.006) and diabetes (HR 2.55; 95% CI 1.38-4.73, p=0.003). Conclusions: Recovery of renal function post-LTA is acceptable for patients with different stratifications of eGFR pre-transplant. RRT, female gender and diabetes may suggest to perform CLKT

    Utilization of Raman spectroscopy to identify breast cancer from the water content in surgical samples containing blue dye

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    This is the final version. Available on open access from Wiley via the DOI in this record. Data availability: The data that support the findings of this study are available from the corresponding author upon reasonable request.Breast conserving surgery (BCS) for breast cancer aims for optimal oncological results with minimal tissue excision. Positive margins due to insufficient resection results in significant numbers of patients requiring re‐excision, which could be resolved with intra‐operative margin analysis (IMA). High wavenumber (HWN) Raman Spectroscopy (RS) examines the difference in protein/lipid environment and water content in tissues. Fluorescence from haemoglobin and blue dye surgical pigments (commonly present in excised breast tissue) can confound HWN RS. We present a Raman system with 785 nm excitation laser and indium gallium arsenide camera capable of quantifying changes in water content in different environments (protein‐rich and lipid‐rich) by measuring the water/total area ratio (W/TAR) of the HWN spectrum. We demonstrate that haemoglobin and blue dye do not adversely affect water content analysis by the W/TAR calculation. Measurement of paired tumour/non‐tumour human breast tissue specimens showed the biochemical differences between tissues, and spectral analysis with W/TAR demonstrated large differences in water content and that our Raman system can accurately differentiate between tumour and non‐tumour tissue, even in the presence of surgical pigments. This provides proof of principle that this Raman system is suitable for further investigation with a view to providing IMA in the clinical environment.National Institute for Health Research (NIHR)Engineering and Physical Sciences Research Council (EPSRC

    Impact of ENSO 2016-17 on regional climate and malaria vector dynamics in Tanzania

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    Large scale modes of climate variability, including the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), have been shown to significantly impact mosquito-borne diseases in the Tropics, including malaria. However, the mechanistic cascade from ENSO and the IOD, to induced changes in regional climate and ultimately mosquito abundance and behaviour is poorly understood. Mosquito population dynamics, behaviour and their potential to transmit disease are all sensitive to micro-climatic conditions. The warm phase of ENSO (El Niño) tends to be associated with increased precipitation and outbreaks of various vector-borne diseases, while the cold phase (La Niña) can cause drought during the short rains over East Africa. The sensitivity of Anopheles mosquito population dynamics and host-seeking behaviour to ENSO and to the resulting micro-climatic conditions, were investigated in the Kilombero Valley in Tanzania. From June 2016 to September 2017, changes in the timing and intensity of the rainy seasons and temperature due to the ENSO 2016–17 were observed. Mosquitoes were collected using Centres for Disease Control and Prevention (CDC) light traps indoors and mosquito electrocuting traps in- and outdoors. Changes in abundance and biting behaviour of Anopheles arabiensis and Anopheles funestus were correlated with climate and micro-climate. The impacts of El Niño on climate and mosquito abundance were not clear. However, the study area experienced a drought due to La Niña during which both vector species declined significantly. An. arabiensis densities stayed more stable at higher temperatures and were found in higher numbers outdoors with respect to An. funestus. For both species, indoor temperature and season determined their host-seeking location, with higher temperatures and the wet season driving them outside. The study confirmed the influence of ENSO and micro-climate on malaria vector abundance and host-seeking behaviour, generating hypotheses for predicting the impact of future ENSO on malaria risk and vector control. Our observation of higher outdoor biting during warmer conditions indicates that indoor vector control strategies may become proportionally less effective during this time

    Application of the speed-duration relationship to normalize the intensity of high-intensity interval training

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    The tolerable duration of continuous high-intensity exercise is determined by the hyperbolic Speed-tolerable duration (S-tLIM) relationship. However, application of the S-tLIM relationship to normalize the intensity of High-Intensity Interval Training (HIIT) has yet to be considered, with this the aim of present study. Subjects completed a ramp-incremental test, and series of 4 constant-speed tests to determine the S-tLIM relationship. A sub-group of subjects (n = 8) then repeated 4 min bouts of exercise at the speeds predicted to induce intolerance at 4 min (WR4), 6 min (WR6) and 8 min (WR8), interspersed with bouts of 4 min recovery, to the point of exercise intolerance (fixed WR HIIT) on different days, with the aim of establishing the work rate that could be sustained for 960 s (i.e. 4×4 min). A sub-group of subjects (n = 6) also completed 4 bouts of exercise interspersed with 4 min recovery, with each bout continued to the point of exercise intolerance (maximal HIIT) to determine the appropriate protocol for maximizing the amount of high-intensity work that can be completed during 4×4 min HIIT. For fixed WR HIIT tLIM of HIIT sessions was 399±81 s for WR4, 892±181 s for WR6 and 1517±346 s for WR8, with total exercise durations all significantly different from each other (P&#60;0.050). For maximal HIIT, there was no difference in tLIM of each of the 4 bouts (Bout 1: 229±27 s; Bout 2: 262±37 s; Bout 3: 235±49 s; Bout 4: 235±53 s; P&#62;0.050). However, there was significantly less high-intensity work completed during bouts 2 (153.5±40. 9 m), 3 (136.9±38.9 m), and 4 (136.7±39.3 m), compared with bout 1 (264.9±58.7 m; P&#62;0.050). These data establish that WR6 provides the appropriate work rate to normalize the intensity of HIIT between subjects. Maximal HIIT provides a protocol which allows the relative contribution of the work rate profile to physiological adaptations to be considered during alternative intensity-matched HIIT protocols

    An observational prospective study of topical acidified nitrite for killing methicillin-resistant Staphylococcus aureus (MRSA) in contaminated wounds

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    Background Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Findings Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Conclusions Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue

    New Chiral Phases of Superfluid 3He Stabilized by Anisotropic Silica Aerogel

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    A rich variety of Fermi systems condense by forming bound pairs, including high temperature [1] and heavy fermion [2] superconductors, Sr2RuO4 [3], cold atomic gases [4], and superfluid 3He [5]. Some of these form exotic quantum states having non-zero orbital angular momentum. We have discovered, in the case of 3He, that anisotropic disorder, engineered from highly porous silica aerogel, stabilizes a chiral superfluid state that otherwise would not exist. Additionally, we find that the chiral axis of this state can be uniquely oriented with the application of a magnetic field perpendicular to the aerogel anisotropy axis. At suffciently low temperature we observe a sharp transition from a uniformly oriented chiral state to a disordered structure consistent with locally ordered domains, contrary to expectations for a superfluid glass phase [6].Comment: 6 pages, 4 figure, and Supplementary Informatio
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