360 research outputs found
Methanol-to-Olefins Catalysis with Hydrothermally Treated Zeolite SSZ-39
Zeolite SSZ-39 is evaluated for catalyzing the methanol-to-olefins (MTO) reaction. By steaming NH_4âSSZ-39, Al can be removed from framework positions, resulting in an increase in framework-Si/AlT and thus a lowered active acid site density. The Si/Al_T ratios can be controlled by the steaming temperatures. SSZ-39 steamed at 750 °C, with preserved pore volume and morphology, is an excellent MTO catalyst, as high, stable olefin selectivities, long time-on-stream activity, and low alkane production are observed. Moreover, interesting propylene/ethylene/butylene ratios of 2.8/1/1.1 are obtained, likely related to the shape of the AEI cage. By Cu^(2+)-exchanging SSZ-39, evidence is provided to show that Al_T sites in close proximity (high AlT density) produce the unwanted effects (higher alkane-make and carbonaceous deposits) in nonsteamed materials during MTO
Collagen content and distribution in the normal and transplanted human heart: A postmortem quantitative light microscopic analysis
Endomyocardial biopsies in heart transplant patients offer the opportunity to study the myocardial interstitium in the context of myocardial function. For that purpose endomyocardial biopsies should reliably reflect the composition of the entire myocardium. We determined whether the collagen content in the subendocardial region of the right side of the interventricular septum (site of right ventricular endomyocardial biopsy), in 16 normal and 30 transplanted human hearts, is representative for the entire myocardium. Moreover we determined whether or not the mean collagen content of the myocardium is altered along with the posttransplantation survival time and which factors might contribute to the development of interstitial myocardial fibrosis. Transmural sections of the right and left ventricular free wall and interventricular septum were stained with Sirius red, which specifically stains collagen fibers. Collagen in the subendocardial region and central parts of the myocardium was quantified using a digital image analyzer. In normal hearts the mean collagen content of the subendocardial region of the right side of the interventricular septum (site of right ventricular endomyocardial biopsy) correlates well with the mean collagen content of the right ventricular wall and the center of the interventricular septum, but it does not reliably reflect the mean collagen content of the left ventricular free wall. In transplanted hearts the collagen content at the site of right ventricular endomyocardial biopsy correlates highly with the mean collagen content of the entire myocardium. In transplanted hearts the increase in collagen content is a result mainly of an increase in collagen of the left ventricular free wall. We conclude that in heart transplant patients, right ventricular endomyocardial biopsies have potential value in the analysis of the causes of left ventricular dysfunction. In transplanted human hearts, the posttransplantation survival time correlates positively with the collagen content, and this is attributable mainly to an increase in the collagen of the left ventricular free wall
Immunomagnetic t-lymphocyte depletion (ITLD) of rat bone marrow using OX-19 monoclonal antibody
Graft versus host disease (GVHD) may be abrogated and host survival prolonged by in vitro depletion of T lymphocytes from bone marrow (BM) prior to allotransplantation. Using a mouse anti-rat pan T-lymphocyte monoclonal antibody (0Ă19) bound to monosized, magnetic, polymer beads, T lymphocytes were removed in vitro from normal bone marrow. The removal of the T lymphocytes was confirmed by flow cytometry. Injection of the T-lymphocyte-depleted bone marrow into fully allogeneic rats prevents the induction of GVHD and prolongs host survival. A highly efficient technique of T-lymphocyte depletion using rat bone marrow is described. It involves the binding of OX-19, a MoAb directed against all rat thy-mocytes and mature peripheral T lymphocytes, to monosized, magnetic polymer spheres. Magnetic separation of T lymphocytes after mixing the allogeneic bone marrow with the bead/OX-19 complex provides for a simple, rapid depletion of T lymphocytes from the bone marrow. In vitro studies using flow cytometry and the prevention of GVHD in a fully allogeneic rat bone marrow model have been used to demonstrate the effectiveness of the depletion procedure. © 1989 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
Recommended from our members
Readability of Ebola Information on Websites of Public Health Agencies, United States, United Kingdom, Canada, Australia, and Europe
Public involvement in efforts to control the current Ebola virus disease epidemic requires understandable information. We reviewed the readability of Ebola information from public health agencies in non-Ebola-affected areas. A substantial proportion of citizens would have difficulty understanding existing information, which would potentially hinder effective health-seeking behaviors
An ex-ante analysis of transport impacts of a distance-based heavy goods vehicle charge in the Netherlands
In 2017, the newly installed Dutch government announced in its coalition agreement to introduce a distance-based heavy goods vehicle charge, similar to the charges levied in other European countries. To study the possible transport impacts, we applied available models and methods in preparation for the introduction of this truck charge in the Netherlands in 2023, in order to present decision information to the government on different aspects of the charge. In this paper we present the analysis of different implementation scenarios for a distance-based truck charge. Different behavioural responses can be expected in terms of freight transport demand, mode choice, logistic efficiency, and route choice. Many studies however lack sufficient detail to properly describe the impact of road charges for HGV on OD flows and freight traffic. In our contribution we explore the bandwidth of impacts of different pricing schemes, using strategic transport models for freight demand and traffic assignment, with detailed modal split and route choice models, ensuring a proper representation of generalsed transport costs. We explain how we use available transport models in an overarching analytical framework to make a comprehensive impact assessment of the different responses, and to decompose the impacts on the different responses. Final impacts are quantified in terms of freight demand (spatial pattern of transport flows), modal split and traffic flows (route choice, and congestion).
Depending on the pricing scenario the tonne kilometres decrease by 0.4%â4.8% on average. The modal shift impacts are stronger on longer transport distances: this is explained both by the larger impact of a distance-based charge on these routes, and by higher substitution possibilities to barge or rail. The results indicate that the overall impacts of the introduction of the different charging alternatives are moderate. However, the network impacts at local level can be substantial due to the impact of re-routing of truck trips to avoid charge
First report of Soybean Mosaic Virus in commercially grown soybean in the Netherlands
In July 2020, plants with crinkled, chlorotic, occasionally necrotic leaves, typical for Soybean Mosaic Virus (SMV), were observed in eight soybean fields (Glycine max L.) in Flevoland, The Netherlands (Supp. Fig. 1). Disease incidence varied from 5-50% and the plants affected often occurred in small or extensive patches. Leaves from several symptomatic plants were sampled from each of two fields planted with soybean variety Green Shell or Summer Shell. Total RNA was extracted from one plant leaf sample per field using InviTrap Spin Plant RNA Mini Kit (Invitek, Germany). One-tube RT-PCRs employing potyvirus generic primers P9502 and CPUP (Van der Vlugt et al, 1999) and SMV-specific primers SMV-dT (5'-TTTTTTTTTTTTTTTAGGACAAC-3') and SMV-Nib-Fw (5'-CAAGGATGARTTTAAGGAG-3') combined with Sanger sequencing confirmed the presence of SMV in all leaf samples. To exclude the presence of other agents in the samples, total RNA from each cultivar was used in standard Illumina library preparation with ribosomal RNA depletion followed by sequencing on an Illumina NovaSeq6000 (paired-end, 150 bp) which yielded 66,579,158 reads (Summer Shell) and 223,953,206 reads (Green Shell). After quality trimming in CLC Genomics Workbench 20.0.4 (CLC-GWB; Qiagen, Hilden), four million reads were randomly sampled for de novo assembly. Contigs over 500 nucleotides (nts) in length with a minimum of 500 reads were annotated by BLASTn against NCBI GenBank. This identified one contig of 9,883 nts (6,233,397 reads) in Summer Shell and one contig of 9,727 nts (3,139,927 reads) in Green Shell with clear homology to SMV (E-value = 0.0). No other viruses were identified in the datasets. Reference assemblies against the SMV reference sequence (NC_002634) mapped 24,090,763 reads (36.2%) for Summer Shell and 175,459,637 reads (78.3%) for Green Shell. Extracted consensus sequences for SMV in both soybean cultivars were 9,584 nts long (excluding the poly-A tail). Sequence data from the de novo and reference assemblies were combined into consensus sequences which showed over 98% overall nt sequence identity to NC_002634 and 99.6% to each other. Both consensus sequences were deposited in GenBank under accession numbers MW822167 (SMV-Summer Shell) and MW822168 (SMV-Green Shell). In addition, the presence of SMV in the field samples was confirmed with an inoculation assay. Leaf samples from both fields were ground in phosphate buffer (0.1M, pH 7.2) and inoculated on cotyledons and first expanded leaves of soybean plants (unknown cv.) 12 days post-germination. Plants showed veinal chlorosis in systemic leaves from 12 days post-inoculation, which developed into veinal necrosis. SMV infections were confirmed by RT-PCR in systemic, chlorotic leaf samples of all symptomatic plants using the SMV-specific primers described above. To our knowledge, this is the first report of SMV in The Netherlands. As soybean is a relatively new but expanding crop in this country, information about emerging diseases is highly relevant. SMV can be transmitted via seeds and aphids, where seeds can serve as primary source of virus inoculum (Cui et al., 2011; Hartman et al., 2016; Hajimorad et al., 2018). Weeds and non-commercial plants can also serve as origin of SMV, particularly in subsequent growing seasons, although this virus infects a limited host range of six plant families (Cui et al., 2011; Hill & Whitham, 2014). Special monitoring would be advised for the recurrence and possible damage by SMV in Dutch soybean fields
The effect of trastuzumab on cardiac function in patients with HER2-positive metastatic breast cancer and reduced baseline left ventricular ejection fraction
We investigated the effect of trastuzumab on cardiac function in a realâworld historic cohort of patients with HER2âpositive metastatic breast cancer (MBC) with reduced baseline left ventricular ejection fraction (LVEF). Thirtyâseven patients with HER2âpositive MBC and baseline LVEF of 40% to 49% were included. Median LVEF was 46% (interquartile range [IQR] 44%â48%) and median followâup was 18âmonths (IQR 9â34âmonths). During this period, the LVEF did not worsen in 24/37 (65%) patients, while 13/37 (35%) patients developed severe cardiotoxicity defined as LVEF 5%âpoints below baseline) in 3/13 (23%) patients and irreversible (defined as absolute LVEF increase 5%âpoints below baseline) in 3/13 (23%) patients. Likelihood of reversibility was numerically higher in patients who received cardioâprotective medications (CPM), including ACEâinhibitors, betaâblockers and angiotensineâ2 inhibitors, compared to those who did not receive any CPM (71% vs 13%, PÂ =Â .091). Sixtyâfive percent of patients who received trastuzumab for HER2âpositive MBC did not develop severe cardiotoxicity during a median followâup of 18âmonths, despite having a compromised baseline LVEF. If severe cardiotoxicity occurred, it was at least partly reversible in more than twoâthirds of the cases. Risks and benefits of trastuzumab use should be balanced carefully in this vulnerable population
The challenges of communicating research evidence in practice: perspectives from UK health visitors and practice nurses
<p>Background: Health practitioners play a pivotal role in providing patients with up-to-date evidence and health information. Evidence-based practice and patient-centred care are transforming the delivery of healthcare in the UK. Health practitioners are increasingly balancing the need to provide evidence-based information against that of facilitating patient choice, which may not always concur with the evidence base. There is limited research exploring how health practitioners working in the UK, and particularly those more autonomous practitioners such as health visitors and practice nurses working in community practice settings, negotiate this challenge. This research provides a descriptive account of how health visitors and practice nurses negotiate the challenges of communicating health information and research evidence in practice.</p>
<p>Methods: A total of eighteen in-depth telephone interviews were conducted in the UK between September 2008 and May 2009. The participants comprised nine health visitors and nine practice nurses, recruited via adverts on a nursing website, posters at a practitioner conference and through recommendation. Thematic analysis, with a focus on constant comparative method, was used to analyse the data.</p>
<p>Results: The data were grouped into three main themes: communicating evidence to the critically-minded patient; confidence in communicating evidence; and maintaining the integrity of the patient-practitioner relationship. These findings highlight some of the daily challenges that health visitors and practice nurses face with regard to the complex and dynamic nature of evidence and the changing attitudes and expectations of patients. The findings also highlight the tensions that exist between differing philosophies of evidence-based practice and patient-centred care, which can make communicating about evidence a daunting task.</p>
<p>Conclusions: If health practitioners are to be effective at communicating research evidence, we suggest that more research and resources need to be focused on contextual factors, such as how research evidence is negotiated, appraised and communicated within the dynamic patient-practitioner relationship.</p>
- âŠ