62 research outputs found

    Methodology of calculation of construction and hydrodynamic parameters of a foam layer apparatus for mass-transfer processes

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    Промислова реалізація методу стабілізації газорідинного шару дозволяє значно розширити галузь застосування пінних апаратів і відкриває нові можливості інтенсифікації технологічних процесів з одночасним створенням маловідходних технологій. У статті встановлені основні параметри, що впливають на гідродинаміку пінних апаратів, розглянуті основні конструкції та режими роботи пінних апаратів. Виявлено зв'язок гідродинамічних параметрів. Розглянуто гідродинамічні закономірності пінного шару. Вказані фактори, що впливають на процес масообміну, як в газовій, так і в рідкій фазах. Проведений аналіз ряду досліджень показав, що перспективним напрямком інтенсифікації процесу масообміну є розробка апаратів з трифазним псевдозрідженим шаром зрошуваної насадки складних форм із сітчастих матеріалів. Отже, необхідне проведення спеціальних досліджень гідродинамічних режимів роботи апарату з сітчастою насадкою і визначенням параметрів, що впливають на швидкість переходу насадки з одного режиму в інший.Industrial implementation of the stabilization method of the gas-liquid layer can significantly expand the field of use of foaming apparatus and opens up new opportunities for intensifying technological processes with the simultaneous creation of low-waste technologies. The article establishes the basic parameters influencing the hydrodynamics of foam apparatus, considers the basic constructions and operating modes of foam apparatus. The connection of hydrodynamic parameters is revealed. The hydrodynamic laws of the foam layer are considered. The indicated factors affecting the process of mass transfer, both in the gas and in the liquid phases. The conducted analysis of a number of studies showed that the perspective direction of intensification of the mass transfer process is the development of apparatuses with a three-phase fluidized bed of an irrigated nozzle of complex forms with mesh materials

    Management of cardiac health in trastuzumab-treated patients with breast cancer: updated United Kingdom National Cancer Research Institute recommendations for monitoring

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    More women are living with and surviving breast cancer, because of improvements in breast cancer care. Trastuzumab (Herceptin®▾) has significantly improved outcomes for women with HER2-positive tumours. Concerns about the cardiac effects of trastuzumab (which fundamentally differ from the permanent myocyte loss associated with anthracyclines) led to the development of cardiac guidelines for adjuvant trials, which are used to monitor patient safety in clinical practice. Clinical experience has shown that the trial protocols are not truly applicable to the breast cancer population as a whole, and exclude some women from receiving trastuzumab, even though they might benefit from treatment without long-term adverse cardiac sequelae. Consequently, five oncologists who recruited patients to trastuzumab trials, some cardiologists with whom they work, and a cardiovascular lead general practitioner reviewed the current cardiac guidelines in the light of recent safety data and their experience with adjuvant trastuzumab. The group devised recommendations that promote proactive pharmacological management of cardiac function in trastuzumab-treated patients, and that apply to all patients who are likely to receive standard cytotoxic chemotherapy. Key recommendations include: a monitoring schedule that assesses baseline and on-treatment cardiac function and potentially reduces the overall number of assessments required; intervention strategies with cardiovascular medication to improve cardiac status before, during, and after treatment; simplified rules for starting, interrupting and discontinuing trastuzumab; and a multidisciplinary approach to breast cancer care

    Differentiating Embryonic Stem Cells Pass through ‘Temporal Windows’ That Mark Responsiveness to Exogenous and Paracrine Mesendoderm Inducing Signals

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    BACKGROUND: Mesendoderm induction during embryonic stem cell (ESC) differentiation in vitro is stimulated by the Transforming Growth Factor and Wingless (Wnt) families of growth factors. PRINCIPAL FINDINGS: We identified the periods during which Bone Morphogenetic Protein (BMP) 4, Wnt3a or Activin A were able to induce expression of the mesendoderm marker, Mixl1, in differentiating mouse ESCs. BMP4 and Wnt3a were required between differentiation day (d) 1.5 and 3 to most effectively induce Mixl1, whilst Activin A induced Mixl1 expression in ESC when added between d2 and d4, indicating a subtle difference in the requirement for Activin receptor signalling in this process. Stimulation of ESCs with these factors at earlier or later times resulted in little Mixl1 induction, suggesting that the differentiating ESCs passed through 'temporal windows' in which they sequentially gained and lost competence to respond to each growth factor. Inhibition of either Activin or Wnt signalling blocked Mixl1 induction by any of the three mesendoderm-inducing factors. Mixing experiments in which chimeric EBs were formed between growth factor-treated and untreated ESCs revealed that BMP, Activin and Wnt signalling all contributed to the propagation of paracrine mesendoderm inducing signals between adjacent cells. Finally, we demonstrated that the differentiating cells passed through 'exit gates' after which point they were no longer dependent on signalling from inducing molecules for Mixl1 expression. CONCLUSIONS: These studies suggest that differentiating ESCs are directed by an interconnected network of growth factors similar to those present in early embryos and that the timing of growth factor activity is critical for mesendoderm induction

    Brachyury and Related Tbx Proteins Interact with the Mixl1 Homeodomain Protein and Negatively Regulate Mixl1 Transcriptional Activity

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    Mixl1 is a homeodomain transcription factor required for mesoderm and endoderm patterning during mammalian embryogenesis. Despite its crucial function in development, co-factors that modulate the activity of Mixl1 remain poorly defined. Here we report that Mixl1 interacts physically and functionally with the T-box protein Brachyury and related members of the T-box family of transcription factors. Transcriptional and protein analyses demonstrated overlapping expression of Mixl1 and Brachyury during embryonic stem cell differentiation. In vitro protein interaction studies showed that the Mixl1 with Brachyury associated via their DNA-binding domains and gel shift assays revealed that the Brachyury T-box domain bound to Mixl1-DNA complexes. Furthermore, luciferase reporter experiments indicated that association of Mixl1 with Brachyury and related T-box factors inhibited the transactivating potential of Mixl1 on the Gsc and Pdgfrα promoters. Our results indicate that the activity of Mixl1 can be modulated by protein-protein interactions and that T-box factors can function as negative regulators of Mixl1 activity

    Gendered dimensions of obesity in childhood and adolescence

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    BACKGROUND: The literature on childhood and adolescent obesity is vast. In addition to producing a general overview, this paper aims to highlight gender differences or similarities, an area which has tended not to be the principal focus of this literature. METHODS: Databases were searched using the terms 'obesity' and 'child', 'adolescent', 'teenager', 'youth', 'young people', 'sex', 'gender', 'masculine', 'feminine', 'male', 'female', 'boy' and 'girl' (or variations on these terms). In order to limit the potential literature, the main focus is on other reviews, both general and relating to specific aspects of obesity. RESULTS: The findings of genetic studies are similar for males and females, and differences in obesity rates as defined by body mass index are generally small and inconsistent. However, differences between males and females due to biology are evident in the patterning of body fat, the fat levels at which health risks become apparent, levels of resting energy expenditure and energy requirements, ability to engage in certain physical activities and the consequences of obesity for the female reproductive system. Differences due to society or culture include food choices and dietary concerns, overall physical activity levels, body satisfaction and the long-term psychosocial consequences of childhood and adolescent obesity. CONCLUSION: This review suggests differences between males and females in exposure and vulnerability to obesogenic environments, the consequences of child and adolescent obesity, and responses to interventions for the condition. A clearer focus on gender differences is required among both researchers and policy makers within this field

    Determinants of willingness to receive healthy lifestyle advice in the context of cancer screening

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    Background: Providing lifestyle advice at cancer screening may help reduce the cancer burden attributable to health-related behaviour. We examined determinants of willingness to receive advice about several behavioural cancer risk factors. Methods: A population-based sample of English adults eligible for cancer screening (n = 1221) completed items on willingness to receive lifestyle advice. Sociodemographic, psychological (risk perceptions, cancer risk factor awareness) and behavioural factors were used to predict interest in advice about diet, weight, physical activity, smoking and alcohol consumption. Results: Two thirds (62–67%) reported interest in advice about diet, weight, and physical activity; 17% were willing to receive advice about smoking, and 32% about alcohol consumption. Willingness to receive advice was higher in those not adhering to guidelines for weight, physical activity, smoking and alcohol consumption (all p < 0.01). Non-White ethnicity was associated with interest in advice about diet, physical activity and smoking (all p < 0.01). Willingness to receive advice about diet, weight, physical activity and alcohol consumption increased with greater recognition of cancer risk factors (all p < 0.01). Conclusions: Willingness to receive lifestyle advice at cancer screening was high, suggesting this context may provide an opportunity to support behaviour change. Increasing awareness of cancer risk factors may facilitate interest in lifestyle advice

    Advances in structure elucidation of small molecules using mass spectrometry

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    The structural elucidation of small molecules using mass spectrometry plays an important role in modern life sciences and bioanalytical approaches. This review covers different soft and hard ionization techniques and figures of merit for modern mass spectrometers, such as mass resolving power, mass accuracy, isotopic abundance accuracy, accurate mass multiple-stage MS(n) capability, as well as hybrid mass spectrometric and orthogonal chromatographic approaches. The latter part discusses mass spectral data handling strategies, which includes background and noise subtraction, adduct formation and detection, charge state determination, accurate mass measurements, elemental composition determinations, and complex data-dependent setups with ion maps and ion trees. The importance of mass spectral library search algorithms for tandem mass spectra and multiple-stage MS(n) mass spectra as well as mass spectral tree libraries that combine multiple-stage mass spectra are outlined. The successive chapter discusses mass spectral fragmentation pathways, biotransformation reactions and drug metabolism studies, the mass spectral simulation and generation of in silico mass spectra, expert systems for mass spectral interpretation, and the use of computational chemistry to explain gas-phase phenomena. A single chapter discusses data handling for hyphenated approaches including mass spectral deconvolution for clean mass spectra, cheminformatics approaches and structure retention relationships, and retention index predictions for gas and liquid chromatography. The last section reviews the current state of electronic data sharing of mass spectra and discusses the importance of software development for the advancement of structure elucidation of small molecules

    Oral abstracts of the 21st International AIDS Conference 18-22 July 2016, Durban, South Africa

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    The rate at which HIV-1 infected individuals progress to AIDS is highly variable and impacted by T cell immunity. CD8 T cell inhibitory molecules are up-regulated in HIV-1 infection and associate with immune dysfunction. We evaluated participants (n=122) recruited to the SPARTAC randomised clinical trial to determine whether CD8 T cell exhaustion markers PD-1, Lag-3 and Tim-3 were associated with immune activation and disease progression.Expression of PD-1, Tim-3, Lag-3 and CD38 on CD8 T cells from the closest pre-therapy time-point to seroconversion was measured by flow cytometry, and correlated with surrogate markers of HIV-1 disease (HIV-1 plasma viral load (pVL) and CD4 T cell count) and the trial endpoint (time to CD4 count <350 cells/μl or initiation of antiretroviral therapy). To explore the functional significance of these markers, co-expression of Eomes, T-bet and CD39 was assessed.Expression of PD-1 on CD8 and CD38 CD8 T cells correlated with pVL and CD4 count at baseline, and predicted time to the trial endpoint. Lag-3 expression was associated with pVL but not CD4 count. For all exhaustion markers, expression of CD38 on CD8 T cells increased the strength of associations. In Cox models, progression to the trial endpoint was most marked for PD-1/CD38 co-expressing cells, with evidence for a stronger effect within 12 weeks from confirmed diagnosis of PHI. The effect of PD-1 and Lag-3 expression on CD8 T cells retained statistical significance in Cox proportional hazards models including antiretroviral therapy and CD4 count, but not pVL as co-variants.Expression of ‘exhaustion’ or ‘immune checkpoint’ markers in early HIV-1 infection is associated with clinical progression and is impacted by immune activation and the duration of infection. New markers to identify exhausted T cells and novel interventions to reverse exhaustion may inform the development of novel immunotherapeutic approaches

    The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

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    Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy
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