176 research outputs found
Continuous radial flow chromatography of proteins
A continuous radial flow chromatography (CRFC) system consisting of an annular
packed bed between two rotating concentric porous stainless steel cylinders was constructed
and tested. The protein feed, wash buffer and elution buffer are applied simultaneously
at different fixed angular positions at the periphery of the rotating bed and flow
radially inwards. The target protein is bound in the feed zone and eluted in the elution
zone while unbound protein flows through the feed zone. Continuity equations for fixed
bed radial flow chromatography were extended to model the CRFC by including angular displacement
terms, and solved using finite difference methods. Film diffusion at the resin particle
boundary and pore diffusion within the resin particle was described by an overall mass
transfer coefficient and a multicomponent Langmuir isotherm was used to describe protein
absorption onto the resin particle. To verify the model, a solution containing 0.53 mg ml21
lactoferrin and 1.6 mg ml21 bovine serum albumin (BSA) was applied at 5 ml min21 to a
220-ml CRFC system packed with DEAE Sepharose Fast Flow ion exchange resin, with
abed speed of 0.02 rpm. The proteins were separated into lactoferrin of 68% purity (74% recovery)
and BSA of 94%purity (85% recovery). Experimental data were used to find values for the
parameters in the model proposed
Developmentally appropriate transitional care during the Covid-19 pandemic for young people with juvenile-onset rheumatic and musculoskeletal diseases : the rationale for a position statement
Background
The importance of developmentally appropriate transitional care in young people with juvenile-onset rheumatic and musculoskeletal disease is well recognised. The Paediatric Rheumatology European Society (PReS) / European League Against Rheumatism (EULAR) Taskforce has developed international recommendations and standards for transitional care and a growing evidence base supports the positive benefits of such care. However, there is also evidence that universal implementation has yet to be realised. In 2020, against this background the COVID-19 pandemic arrived with significant impact on all our lives, young and old, patient, public and professional alike. The unfortunate reality of the pandemic with potential for unfavourable outcomes on healthcare provision during transition was acknowledged by the PReS working groups in a position statement to support healthcare professionals, young people and their caregivers.
Aim
The aim of this review is to present the literature which provides the rationale for the recommendations in the PReS Position Statement.
Summary
The following areas are specifically addressed: the prime importance of care coordination; the impact of the pandemic on the various aspects of the transition process; the importance of ensuring continuity of medication supply; the pros and cons of telemedicine with young people; ensuring meaningful involvement of young people in service development and the importance of core adolescent health practices such as routine developmental assessment psychosocial screening and appropriate parental involvement during transitional care
A Systematic Review and Meta-analysis of Psychosocial Interventions to Reduce Drug and Sexual Blood Borne Virus Risk Behaviours Among People Who Inject Drugs
Opiate substitution treatment and needle exchanges have reduced blood borne virus (BBV) transmission among people who inject drugs (PWID). Psychosocial interventions could further prevent BBV. A systematic review and meta-analysis examined whether psychosocial interventions (e.g. CBT, skills training) compared to control interventions reduced BBV risk behaviours among PWID. 32 and 24 randomized control trials (2000-May 2015 in MEDLINE, PsycINFO, CINAHL, Cochrane Collaboration and Clinical trials, with an update in MEDLINE to December 2016) were included in the review and meta-analysis respectively. Psychosocial interventions appear to reduce: sharing of needles/syringes compared to education/information (SMD ?0.52; 95% CI ?1.02 to ?0.03; I2 = 10%; p = 0.04) or HIV testing/counselling (SMD ?0.24; 95% CI ?0.44 to ?0.03; I2 = 0%; p = 0.02); sharing of other injecting paraphernalia (SMD ?0.24; 95% CI ?0.42 to ?0.06; I2 = 0%; p < 0.01) and unprotected sex (SMD ?0.44; 95% CI ?0.86 to ?0.01; I2 = 79%; p = 0.04) compared to interventions of a lesser time/intensity, however, moderate to high heterogeneity was reported. Such interventions could be included with other harm reduction approaches to prevent BBV transmission among PWID
The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour
Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect
A constructive study of the module structure of rings of partial differential operators
The purpose of this paper is to develop constructive versions of Stafford's theorems on the module structure of Weyl algebras A n (k) (i.e., the rings of partial differential operators with polynomial coefficients) over a base field k of characteristic zero. More generally, based on results of Stafford and Coutinho-Holland, we develop constructive versions of Stafford's theorems for very simple domains D. The algorithmization is based on the fact that certain inhomogeneous quadratic equations admit solutions in a very simple domain. We show how to explicitly compute a unimodular element of a finitely generated left D-module of rank at least two. This result is used to constructively decompose any finitely generated left D-module into a direct sum of a free left D-module and a left D-module of rank at most one. If the latter is torsion-free, then we explicitly show that it is isomorphic to a left ideal of D which can be generated by two elements. Then, we give an algorithm which reduces the number of generators of a finitely presented left D-module with module of relations of rank at least two. In particular, any finitely generated torsion left D-module can be generated by two elements and is the homomorphic image of a projective ideal whose construction is explicitly given. Moreover, a non-torsion but non-free left D-module of rank r can be generated by r+1 elements but no fewer. These results are implemented in the Stafford package for D=A n (k) and their system-theoretical interpretations are given within a D-module approach. Finally, we prove that the above results also hold for the ring of ordinary differential operators with either formal power series or locally convergent power series coefficients and, using a result of Caro-Levcovitz, also for the ring of partial differential operators with coefficients in the field of fractions of the ring of formal power series or of the ring of locally convergent power series. © 2014 Springer Science+Business Media
Looking to peripheral river islands in Brazil to develop an urban island water metabolism perspective.
Across Brazil, including the water rich Amazon region, access to safe drinking water remains a challenge and rainwater harvesting has gained credibility as a technological solution. Complementing a more techno-centric approach, this practice paper analyses initial findings from an 'immersion' that was undertaken in August 2017 on Paquetå and surrounding islands located on the periphery of Belém (Schiffer and Swan, 2018), through the proposed urban island water metabolism framework. As such, the research draws on the 'urban metabolism' concept which can be described as socio-technical, socio-economic, socio-political and socio-ecological flows including water resources, people and information in, out and within the urban environment (Currie and Musango, 2016; Kennedy, Cuddihy and Engel-Yan, 2007). Here this has been adapted to 'urban island water metabolisms'. The research highlights the value of more holistic and situated understanding of water systems in urban island contexts including: the role of intra-island networks that operate beyond municipal borders; accessibility in the contexts of ever changing water levels; and seasonal dimensions. The paper recommends longer-term and comparative research to further the understanding of the specific needs and challenges for water management in these peripheral contexts and to strengthen the urban island water metabolism concept
Latitudinal gradient of nestedness and its potential drivers in stream detritivores
Understanding what mechanisms shape the diversity and composition of biological assemblages across broad-scale gradients is central to ecology. Litter-consuming detritivorous invertebrates in streams show an unusual diversity gradient, with α-diversity increasing towards high latitudes but no trend in γ -diversity. We hypothesized this pattern to be related
to shifts in nestedness and several ecological processes shaping their assemblages (dispersal, environmental filtering and competition). We tested this hypothesis, using a global dataset, by examining latitudinal trends in nestedness and several indicators of the above processes along the latitudinal gradient. Our results suggest that strong environmental filtering and low dispersal in the tropics lead to often species-poor local detritivore assemblages, nested in richer regional assemblages. At higher latitudes, dispersal becomes stronger, disrupting the nested assemblage structure and resulting in local assemblages that are generally more species-rich and non-nested subsets of the regional species pools. Our results provide
evidence that mechanisms underlying assemblage composition and diversity of stream litter-consuming detritivores shift
across latitudes, and provide an explanation for their unusual pattern of increasing α-diversity with latitude. When we repeated these analyses for whole invertebrate assemblages of leaf litter and for abundant taxa showing reverse or no diversity gradients we found no latitudinal patterns, suggesting that function-based rather than taxon-based analyses of assemblages may help elucidate the mechanisms behind diversity gradients
The mammalian gene function resource: The International Knockout Mouse Consortium
In 2007, the International Knockout Mouse Consortium (IKMC) made the ambitious promise to generate mutations in virtually every protein-coding gene of the mouse genome in a concerted worldwide action. Now, 5 years later, the IKMC members have developed highthroughput gene trapping and, in particular, gene-targeting pipelines and generated more than 17,400 mutant murine embryonic stem (ES) cell clones and more than 1,700 mutant mouse strains, most of them conditional. A common IKMC web portal (www.knockoutmouse.org) has been established, allowing easy access to this unparalleled biological resource. The IKMC materials considerably enhance functional gene annotation of the mammalian genome and will have a major impact on future biomedical research
PeriĂłdicos cientĂficos na America Latina: tĂtulos em Acesso Aberto indexados no ISI e SCOPUS
Continuous radial flow chromatography of proteins
A continuous radial flow chromatography (CRFC) system consisting of an annular
packed bed between two rotating concentric porous stainless steel cylinders was constructed
and tested. The protein feed, wash buffer and elution buffer are applied simultaneously
at different fixed angular positions at the periphery of the rotating bed and flow
radially inwards. The target protein is bound in the feed zone and eluted in the elution
zone while unbound protein flows through the feed zone. Continuity equations for fixed
bed radial flow chromatography were extended to model the CRFC by including angular displacement
terms, and solved using finite difference methods. Film diffusion at the resin particle
boundary and pore diffusion within the resin particle was described by an overall mass
transfer coefficient and a multicomponent Langmuir isotherm was used to describe protein
absorption onto the resin particle. To verify the model, a solution containing 0.53 mg ml21
lactoferrin and 1.6 mg ml21 bovine serum albumin (BSA) was applied at 5 ml min21 to a
220-ml CRFC system packed with DEAE Sepharose Fast Flow ion exchange resin, with
abed speed of 0.02 rpm. The proteins were separated into lactoferrin of 68% purity (74% recovery)
and BSA of 94%purity (85% recovery). Experimental data were used to find values for the
parameters in the model proposed
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