128 resultados para Padding.


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In this Letter, an unambiguous synthetic strategy is reported for the preparation of enantiomerically purecis-5-halo-piperazic acid derivatives in single diastereoisomer form. Contrary to the recent report by Shin and co-workers (Chem. Lett. 2001, 1172), in which it is claimed that the Ph3P and N-chlorosuccinimide (NCS)-mediated chlorination of (3R,5S)-trans-N(1),N(2)-di-t-Boc-5-hydroxy-piperazic acid derivative 1proceeds with retention of configuration at C(5) to give 2, we now show that this and related Ph3P-mediated halogenations all occur with SN2 inversion at the alcohol center, as is customary for such reactions. Specifically, we demonstrate that the (3R,5S)-trans-5-Cl-piperazic acid derivative 2 claimed by Shin and co-workers (Chem. Lett. 2001, 1172) is in actual fact the chlorinated (3S,5R)-enantiomer 6, which must have been prepared from the cis-(3S,5S)-alcohol 3, a molecule whose synthesis is not formally described in the Shin paper. We further show here that the cis-(3R,5R)-5-Cl-Piz 13 claimed by Shin and co-workers inChem. Lett. 2001, 1172, is also (3S,5R)-trans-5-Cl-Piz 6. Authentic 13 has now been synthesized by us, for the very first time, here. Since Lindsley and Kennedy have recently utilized the now invalid Shin and co-workers’ retentive Ph3P/NCS chlorination procedure on 1 in their synthetic approach to piperazimycin A (Tetrahedron Lett. 2010, 51, 2493), it follows that their claimed 5-Cl-Piz-containing dipeptide 25 probably has the alternate structure 26, where the 5-Cl-Piz residue has a 3,5-cis-configuration. The aforementioned stereochemical misassignments appear to have come from a mix-up of starting materials by Shin and co-workers (Chem. Lett. 2001, 1172), and an under-appreciation of the various steric and conformational effects that operate in N(2)-acylated piperazic acid systems, most especially rotameric A1,3-strain. The latter has now been unambiguously delineated and defined here under the banner of the A1,3-rotamer effect.

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Background

Although the General Medical Council recommends that United Kingdom medical students are taught ‘whole person medicine’, spiritual care is variably recognised within the curriculum. Data on teaching delivery and attainment of learning outcomes is lacking. This study ascertained views of Faculty and students about spiritual care and how to teach and assess competence in delivering such care.

Methods

A questionnaire comprising 28 questions exploring attitudes to whole person medicine, spirituality and illness, and training of healthcare staff in providing spiritual care was designed using a five-point Likert scale. Free text comments were studied by thematic analysis. The questionnaire was distributed to 1300 students and 106 Faculty at Queen’s University Belfast Medical School.

Results

351 responses (54 staff, 287 students; 25 %) were obtained. >90 % agreed that whole person medicine included physical, psychological and social components; 60 % supported inclusion of a spiritual component within the definition. Most supported availability of spiritual interventions for patients, including access to chaplains (71 %), counsellors (62 %), or members of the patient’s faith community (59 %). 90 % felt that personal faith/spirituality was important to some patients and 60 % agreed that this influenced health. However 80 % felt that doctors should never/rarely share their own spiritual beliefs with patients and 67 % felt they should only do so when specifically invited. Most supported including training on provision of spiritual care within the curriculum; 40-50 % felt this should be optional and 40 % mandatory. Small group teaching was the favoured delivery method. 64 % felt that teaching should not be assessed, but among assessment methods, reflective portfolios were most favoured (30 %). Students tended to hold more polarised viewpoints but generally were more favourably disposed towards spiritual care than Faculty. Respecting patients’ values and beliefs and the need for guidance in provision of spiritual care were identified in the free-text comments.

Conclusions

Students and Faculty generally recognise a spiritual dimension to health and support provision of spiritual care to appropriate patients. There is lack of consensus whether this should be delivered by doctors or left to others. Spiritual issues impacting patient management should be included in the curriculum; agreement is lacking about how to deliver and assess.

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PURPOSE Potentially inappropriate prescribing (PIP) is common in older people and can result in increased morbidity, adverse drug events, and hospitalizations. The OPTI-SCRIPT study (Optimizing Prescribing for Older People in Primary Care, a cluster-randomized controlled trial) tested the effectiveness of a multifaceted intervention for reducing PIP in primary care.

METHODS We conducted a cluster-randomized controlled trial among 21 general practitioner practices and 196 patients with PIP. Intervention participants received a complex, multifaceted intervention incorporating academic detailing; review of medicines with web-based pharmaceutical treatment algorithms that provide recommended alternative-treatment options; and tailored patient information leaflets. Control practices delivered usual care and received simple, patient-level PIP feedback. Primary outcomes were the proportion of patients with PIP and the mean number of potentially inappropriate prescriptions. We performed intention-to-treat analysis using random-effects regression.

RESULTS All 21 practices and 190 patients were followed. At intervention completion, patients in the intervention group had significantly lower odds of having PIP than patients in the control group (adjusted odds ratio = 0.32; 95% CI, 0.15–0.70; P = .02). The mean number of PIP drugs in the intervention group was 0.70, compared with 1.18 in the control group (P = .02). The intervention group was almost one-third less likely than the control group to have PIP drugs at intervention completion, but this difference was not significant (incidence rate ratio = 0.71; 95% CI, 0.50–1.02; P = .49). The intervention was effective in reducing proton pump inhibitor prescribing (adjusted odds ratio = 0.30; 95% CI, 0.14–0.68; P = .04).

CONCLUSIONS The OPTI-SCRIPT intervention incorporating academic detailing with a pharmacist, and a review of medicines with web-based pharmaceutical treatment algorithms, was effective in reducing PIP, particularly in modifying prescribing of proton pump inhibitors, the most commonly occurring PIP drugs nationally.

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The characterization of complex cellular responses to diverse stimuli can be studied by the use of emerging chip-based technologies.

The p53 pathway is critical to maintaining the integrity of the genome in multicellular organisms. The p53gene is activated in response to DNA damage and encodes a transcription factor [1], which in turn activates genes that arrest cell growth and induce apoptosis, thereby preventing the propagation of genetically damaged cells. It is the most important known tumor suppressor gene: perhaps half of all human neoplasms have mutations in p53, and there is a remarkable concordance between oncogenic mutation and the loss of p53 transcriptional activity [2]. There is also compelling experimental evidence that loss of p53 function (by whatever means) is one of the key oncogenic steps in human cells, along with altered telomerase activity and expression of mutant ras [3]. So far, however, relatively few of the genes regulated by p53 have been identified and it is not even known how many binding sites there are for p53 in the genome, although an estimate based on the incidence of the canonical p53 consensus binding site (four palindromic copies of the sequence 5'-PuPuPuGA/T-3', where Pu is either purine) in a limited region suggests there may be as many as 200 to 300, possibly representing the same number of p53-responsive genes [4]. This makes the p53 response an attractive target for the emerging techniques for global analysis of gene expression, and two recent reports [5,6] illustrate the ways in which these techniques can be used to elucidate the spectrum of genes regulated by this key transcription factor. Vogelstein and colleagues [5] have used serial analysis of gene expression (SAGE) to identify 34 genes that exhibit at least a 10-fold upregulation in response to inducible expression of p53; Tanaka et al. [6] have used differential display to identify p53R2, a homolog of ribonuclease reductase small subunit (R2) as a target gene, thereby for the first time implicating p53 directly in the repair of DNA damage.

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The rotational state of asteroids is controlled by various physical mechanisms including collisions, internal damping and the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect. We have analysed the changes in magnitude between consecutive detections of ∼ 60,000 asteroids measured by the PanSTARRS 1 survey during its first 18 months of operations. We have attempted to explain the derived brightness changes physically and through the application of a simple model. We have found a tendency toward smaller magnitude variations with decreasing diameter for objects of 1 < D < 8 km. Assuming the shape distribution of objects in this size range to be independent of size and composition our model suggests a population with average axial ratios 1: 0.85 ± 0.13: 0.71 ± 0.13, with larger objects more likely to have spin axes perpendicular to the orbital plane.

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In this paper we study the well-posedness for a fourth-order parabolic equation modeling epitaxial thin film growth. Using Kato's Method [1], [2] and [3] we establish existence, uniqueness and regularity of the solution to the model, in suitable spaces, namelyC0([0,T];Lp(Ω)) where  with 1<α<2, n∈N and n≥2. We also show the global existence solution to the nonlinear parabolic equations for small initial data. Our main tools are Lp–Lq-estimates, regularization property of the linear part of e−tΔ2 and successive approximations. Furthermore, we illustrate the qualitative behavior of the approximate solution through some numerical simulations. The approximate solutions exhibit some favorable absorption properties of the model, which highlight the stabilizing effect of our specific formulation of the source term associated with the upward hopping of atoms. Consequently, the solutions describe well some experimentally observed phenomena, which characterize the growth of thin film such as grain coarsening, island formation and thickness growth.

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This study evaluated the effect of an industrial scale continuous flow microwave volumetric heating system in comparison to conventional commercial scale pasteurisation for the processing of tomato juice in terms of physicochemical properties, microbial characteristics and antioxidant capacity. The effect against oxidative stress in Caco-2 cells, after in vitro digestion was also investigated. Physicochemical and colour characteristics of juices were very similar between technologies and during storage. Both conventional and microwave pasteurisation inactivated microorganisms and kept them in low levels throughout storage. ABTS+ values, but not ORAC, were higher for the microwave pasteurised juice at day 0 however no significant differences between juices were observed during storage. Juice processed with the microwave system showed an increased cytoprotective effect against H2O2 induced oxidation in Caco-2 cells. Organoleptic analysis revealed that the two tomato juices were very similar. The continuous microwave volumetric heating system appears to be a viable alternative to conventional pasteurisation.

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Retinal angiogenesis is tightly regulated to meet oxygenation and nutritional requirements. In diseases such as proliferative diabetic retinopathy and neovascular age-related macular degeneration, uncontrolled angiogenesis can lead to blindness. Our goal is to better understand the molecular processes controlling retinal angiogenesis and discover novel drugs that inhibit retinal neovascularization. Phenotype-based chemical screens were performed using the ChemBridge DiversetTM library and inhibition of hyaloid vessel angiogenesis in Tg(fli1:EGFP) zebrafish. 2-[(E)-2-(Quinolin-2-yl)vinyl]phenol, (quininib) robustly inhibits developmental angiogenesis at 4–10 μM in zebrafish and significantly inhibits angiogenic tubule formation in HMEC-1 cells, angiogenic sprouting in aortic ring explants, and retinal revascularization in oxygen-induced retinopathy mice. Quininib is well tolerated in zebrafish, human cell lines, and murine eyes. Profiling screens of 153 angiogenic and inflammatory targets revealed that quininib does not directly target VEGF receptors but antagonizes cysteinyl leukotriene receptors 1 and 2 (CysLT1–2) at micromolar IC50 values. In summary, quininib is a novel anti-angiogenic small-molecule CysLT receptor antagonist. Quininib inhibits angiogenesis in a range of cell and tissue systems, revealing novel physiological roles for CysLT signaling. Quininib has potential as a novel therapeutic agent to treat ocular neovascular pathologies and may complement current anti-VEGF biological agents.

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γ-Ray sources are among the most fundamental experimental tools currently available to modern physics. As well as the obvious benefits to fundamental research, an ultra-bright source of γ-rays could form the foundation of scanning of shipping containers for special nuclear materials and provide the bases for new types of cancer therapy.

However, for these applications to prove viable, γ-ray sources must become compact and relatively cheap to manufacture. In recent years, advances in laser technology have formed the cornerstone of optical sources of high energy electrons which already have been used to generate synchrotron radiation on a compact scale. Exploiting the scattering induced by a second laser, one can further enhance the energy and number of photons produced provided the problems of synchronisation and compact γ-ray detection are solved.

Here, we report on the work that has been done in developing an all-optical and hence, compact non-linear Thomson scattering source, including the new methods of synchronisation and compact γ-ray detection. We present evidence of the generation of multi-MeV (maximum 16–18 MeV) and ultra-high brilliance (exceeding 1020 photons s−1mm−2mrad−2 0.1% BW at 15 MeV) γ-ray beams. These characteristics are appealing for the paramount practical applications mentioned above.

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Background: Staff in palliative care settings perform emotionally demanding roles which may lead to psychological distress including stress and burnout. Therefore, interventions have been designed to address these occupational risks.

Aim: To investigate quantitative studies exploring the effectiveness of psychosocial interventions that attempt to improve psychological wellbeing of palliative care staff.

Design: A systematic review was conducted according to methodological guidance from UK Centre for Reviews and Dissemination.

Data sources: A search strategy was developed based on the initial scans of palliative care studies. Potentially eligible research articles were identified by searching the following databases: CINAHL, MEDLINE (Ovid), PsycINFO and Web of Science. Two reviewers independently screened studies against pre-set eligibility criteria. To assess quality, both researchers separately assessed the remaining studies using the Quality Assessment Tool for Quantitative Studies.

Results: A total of 1786 potentially eligible articles were identified – nine remained following screening and quality assessment. Study types included two randomised controlled trials, two non-randomised controlled trial designs, four one-group pre–post evaluations and one process evaluation. Studies took place in the United States and Canada (5), Europe (3) and Hong Kong (1). Interventions comprised a mixture of relaxation, education, support and cognitive training and targeted stress, fatigue, burnout, depression and satisfaction. The randomised controlled trial evaluations did not improve psychological wellbeing of palliative care staff. Only two of the quasi-experimental studies appeared to show improved staff wellbeing although these studies were methodologically weak.

Conclusion: There is an urgent need to address the lack of intervention development work and high-quality research in this area.

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El Proyecto “Caracterización del sector Transporte; marítimo, fluvial y aéreo, como un factor importante para el perfil logístico en Colombia” es un trabajo que tiene como objeto elaborar un documento, que proporcione toda la información necesaria para comprender y analizar el sector a tratar, teniendo en cuenta los factores que influyeron en el proceso de conformación en cada uno de los sistemas de transporte, dando así un punto de partida para entender la situación actual y las posibles fallas a lo largo de todo el proceso logístico que este implica.

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Anonymous web browsing is an emerging hot topic with many potential applications for privacy and security. However, research on low latency anonymous communication, such as web browsing, is quite limited; one reason is the intolerable delay caused by the current dominant dummy packet padding strategy, as a result, it is hard to satisfy perfect anonymity and limited delay at the same time for web browsing. In this paper, we extend our previous proposal on using prefetched web pages as cover traffic to obtain perfect anonymity for anonymous web browsing, we further explore different aspects in this direction. Based on Shannon’s perfect secrecy theory, we formally established a mathematical model for the problem, and defined a metric to measure the cost of achieving perfect anonymity. The experiments on a real world data set demonstrated that the proposed strategy can reduce delay more than ten times compared to the dummy packet padding methods, which confirmed the vast potentials of the proposed strategy.

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Anonymous web browsing is a hot topic with many potential applications for privacy reasons. The current dominant strategy to achieve anonymity is packet padding with dummy packets as cover traffic. However, this method introduces extra bandwidth cost and extra delay. Therefore, it is not practical for anonymous web browsing applications. In order to solve this problem, we propose to use the predicted web pages that users are going to access as the cover traffic rather than dummy packets. Moreover, we defined anonymity level as a metric to measure anonymity degrees, and established a mathematical model for anonymity systems, and transformed the anonymous communication problem into an optimization problem. As a result, users can find tradeoffs among anonymity level and cost. With the proposed model, we can describe and compare our proposal and the previous schemas in a theoretical style. The preliminary experiments on the real data set showed the huge potential of the proposed strategy in terms of resource saving.

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Secondary Schools have been involved in Gender Based Violence (GBV) Prevention Education for many years. What, when and how this is done has always been difficult to assess. Programs come and go as governments react to public concerns and teachers and schools are expected to implement initiatives that are often reactions to public outcries. Teachers decide what they will teach and how they will teach it.  Last year I returned to work on a new initiative after a near 20-year break. I was surprised by the lack of change that had taken place over this period. There was still a lack of focus in schools, teachers were still reluctant to teach about it and ‘best practice’ appeared to be little different to that developed and implemented twenty years earlier. 

The purpose of this paper is to discuss the experience of teachers and students involved in a pilot of the Respectful Relationships curriculum materials trialled in Victoria in 2010. Using data collected from teachers and students as part of research to update the materials this paper explores the usefulness of the materials for teaching about GBV in secondary schools.

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Plasma treatment is an emerging surface modification technique that alters dye uptake of wool without using chemicals or water for pre-treatment. Padding is an established continuous dyeing technique known for its efficient use of water, time and energy. This study combined these two techniques for colouration of wool fabric using two natural dyes derived from the Acacia plant family. The investigation focused on the effects of plasma treatment and obtaining unique patterning effects. Helium (100%) and a mixture of helium and nitrogen (95%/5%) were used as the plasma gases under atmospheric conditions. Plasma treated wool fabric was padded with the above natural dyes. Copper sulphate and ferrous sulphate were applied on the dyed fabric as mordant yielding neutral shades of beige and grey respectively. Up to a 30% enhancement of dye adsorption on plasma treated wool substrate was observed as compared to untreated sample for both gases used. This higher adsorption indicates the hydrophilic character of the natural dyes used. Key performance parameters such as fastness to washing, rubbing and light were tested and found to be satisfactory. A single process tone-on-tone pattern was achieved by controlling the plasma exposure of treated area. This study concluded that a merger of natural dyes with modern plasma treatment and padding techniques for wool colouration was feasible.