56 research outputs found

    Het gaat weer beter met de natuur in Nederland

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    In een Volkskrantinterview (22 mei 2009) poneerden de eerste drie auteurs de stelling, dat het weer beter gaat met de Nederlandse natuur. Aanleiding vormde de presentatie van de Monitor Duurzaam Nederland (CBS, 2009) waarbij het Planbureau concludeerde dat de biodiversiteit in ons land nog steeds achteruitholt. Dit artikel onderbouwt de stelling van 22 mei en is in feite een vervolg op een eerdere discussie, waarin de methodiek van het PBL werd gepresenteerd. Dit artikel gaat uit van de vraag hoe het gaat met de biodiversiteit en kijkt van daaruit naar de methode

    A novel small diameter nanotextile arterial graft is associated with surgical feasibility and safety and increased transmural endothelial ingrowth in pig

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    Globally, millions of patients are affected by myocardial infarction or lower limb gangrene/amputation due to atherosclerosis. Available surgical treatment based on vein and synthetic grafts provides sub-optimal benefits. We engineered a highly flexible and mechanically robust nanotextile-based vascular graft (NanoGraft) by interweaving nanofibrous threads of poly-L-lactic acid to address the unmet need. The NanoGrafts were rendered impervious with selective fibrin deposition in the micropores by pre-clotting. The pre-clotted NanoGrafts (4 mm diameter) and ePTFE were implanted in a porcine carotid artery replacement model. The fibrin-laden porous milieu facilitated rapid endothelization by the transmural angiogenesis in the NanoGraft. In-vivo patency of NanoGrafts was 100% at 2- and 4-weeks, with no changes over time in lumen size, flow velocities, and minimal foreign-body inflammatory reaction. However, the patency of ePTFE at 2-week was 66% and showed marked infiltration, neointimal thickening, and poor host tissue integration. The study demonstrates the in-vivo feasibility and safety of a thin-layered vascular prosthesis, viz., NanoGraft, and its potential superiority over the commercial ePTFE. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12951-022-01268-1

    Mortality in patients treated for tuberculous pericarditis in sub-Saharan Africa.

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    Tuberculous pericarditis is one of the most severe forms of extrapulmonary tuberculosis, causing death or disability in a substantial proportion of affected people.1,2 In Africa, the incidence of tuberculous pericarditis is rising as a result of the HIV epidemic.3 The effect of HIV infection on survival in patients with tuberculous pericarditis is unknown.2,4 Whereas some investigators have suggested that HIV-infected patients with tuberculous pericarditis have a similar outcome to non-infected cases,5 others have shown that there may be an increase in mortality in HIV associated with tuberculous pericarditis.2,6,7 We established a prospective observational study, the Investigation of the Management of Pericarditis in Africa (IMPI Africa) registry, to obtain current information on the diagnosis, management and outcome of patients with presumed tuberculous pericarditis living in sub-Saharan Africa, where the burden of HIV infection is the greatest in the world.4,8-10 In this paper, we report the mortality rate and its predictors during the 6 months of antituberculosis treatment among patients enrolled in the regis

    Clinical characteristics and initial management of patients with tuberculous pericarditis in the HIV era: the Investigation of the Management of Pericarditis in Africa (IMPI Africa) registry

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    BACKGROUND: The incidence of tuberculous pericarditis has increased in Africa as a result of the human immunodeficiency virus (HIV) epidemic. However, the effect of HIV co-infection on clinical features and prognosis in tuberculous pericarditis is not well characterised. We have used baseline data of the Investigation of the Management of Pericarditis in Africa (IMPI Africa) registry to assess the impact of HIV co-infection on clinical presentation, diagnostic evaluation, and treatment of patients with suspected tuberculous pericarditis in sub-Saharan Africa. METHODS: Consecutive adult patients in 15 hospitals in three countries in sub-Saharan Africa were recruited on commencement of treatment for tuberculous pericarditis, following informed consent. We recorded demographic, clinical, diagnostic and therapeutic information at baseline, and have used the chi-square test and analysis of variance to assess probabilities of significant differences (in these variables) between groups defined by HIV status. RESULTS: A total of 185 patients were enrolled from 01 March 2004 to 31 October 2004, 147 (79.5%) of whom had effusive, 28 (15.1%) effusive-constrictive, and 10 (5.4%) constrictive or acute dry pericarditis. Seventy-four (40%) had clinical features of HIV infection. Patients with clinical HIV disease were more likely to present with dyspnoea (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.4 to 7.4, P = 0.005) and electrocardiographic features of myopericarditis (OR 2.8, 95% CI 1.1 to 6.9, P = 0.03). In addition to electrocardiographic features of myopericarditis, a positive HIV serological status was associated with greater cardiomegaly (OR 3.89, 95% CI 1.34 to 11.32, P = 0.01) and haemodynamic instability (OR 9.68, 95% CI 2.09 to 44.80, P = 0.0008). However, stage of pericardial disease at diagnosis and use of diagnostic tests were not related to clinical HIV status. Similar results were obtained for serological HIV status. Most patients were treated on clinical grounds, with microbiological evidence of tuberculosis obtained in only 13 (7.0%) patients. Adjunctive corticosteroids were used in 109 (58.9%) patients, with patients having clinical HIV disease less likely to be put on them (OR 0.37, 95% CI 0.20 to 0.68). Seven patients were on antiretroviral drugs. CONCLUSION: Patients with suspected tuberculous pericarditis and HIV infection in Africa have greater evidence of myopericarditis, dyspnoea, and haemodynamic instability. These findings, if confirmed in other studies, may suggest more intensive management of the cardiac disease is warranted in patients with HIV-associated pericardial disease

    Spatial Clustering and Risk Factors for Malaria Infections and Marker of Recent Exposure to Plasmodium falciparum from a Household Survey in Artibonite, Haiti.

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    Targeting malaria interventions in elimination settings where transmission is heterogeneous is essential to ensure the efficient use of resources. Identifying the most important risk factors among persons experiencing a range of exposure can facilitate such targeting. A cross-sectional household survey was conducted in Artibonite, Haiti, to identify and characterize spatial clustering of malaria infections. Household members (N = 21,813) from 6,962 households were surveyed and tested for malaria. An infection was defined as testing positive for Plasmodium falciparum by either a conventional or novel highly sensitive rapid diagnostic test. Seropositivity to the early transcribed membrane protein 5 antigen 1 represented recent exposure to P. falciparum. Clusters were identified using SaTScan. Associations among individual, household, and environmental risk factors for malaria, recent exposure, and living in spatial clusters of these outcomes were evaluated. Malaria infection was detected in 161 individuals (median age: 15 years). Weighted malaria prevalence was low (0.56%; 95% CI: 0.45-0.70%). Serological evidence of recent exposure was detected in 1,134 individuals. Bed net use, household wealth, and elevation were protective, whereas being febrile, over age 5 years, and living in either households with rudimentary wall material or farther from the road increased the odds of malaria. Two predominant overlapping spatial clusters of infection and recent exposure were identified. Individual, household, and environmental risk factors are associated with the odds of individual risk and recent exposure in Artibonite; spatial clusters are primarily associated with household-level risk factors. Findings from serology testing can further strengthen the targeting of interventions

    Impact of a Plasmodium falciparum AMA1 Vaccine on Antibody Responses in Adult Malians

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    Apical Membrane Antigen 1 (AMA1) of Plasmodium falciparum merozoites is a leading blood-stage malaria vaccine candidate. Protection of Aotus monkeys after vaccination with AMA1 correlates with antibody responses.A randomized, controlled, double-blind phase 1 clinical trial was conducted in 54 healthy Malian adults living in an area of intense seasonal malaria transmission to assess the safety and immunogenicity of the AMA1-C1 malaria vaccine. AMA1-C1 contains an equal mixture of yeast-expressed recombinant proteins based on sequences from the FVO and 3D7 clones of P. falciparum, adsorbed on Alhydrogel. The control vaccine was the hepatitis B vaccine (Recombivax). Participants were enrolled into 1 of 3 dose cohorts (n = 18 per cohort) and randomized 2:1 to receive either AMA1-C1 or Recombivax. Participants in the first, second, and third cohorts randomized to receive AMA1-C1 were vaccinated with 5, 20 and 80 microg of AMA1-C1, respectively. Vaccinations were administered on days 0, 28, and 360, and participants were followed until 6 months after the final vaccination. AMA1-C1 was well tolerated; no vaccine-related severe or serious adverse events were observed. AMA1 antibody responses to the 80 microg dose increased rapidly from baseline levels by days 14 and 28 after the first vaccination and continued to increase after the second vaccination. After a peak 14 days following the second vaccination, antibody levels decreased to baseline levels one year later at the time of the third vaccination that induced little or no increase in antibody levels.Although the AMA1-C1 vaccine candidate was well-tolerated and induced antibody responses to both vaccine and non-vaccine alleles, the antibody response after a third dose given at one year was lower than the response to the initial vaccinations. Additionally, post-vaccination increases in anti-AMA1 antibody levels were not associated with significant changes in in vitro growth inhibition of P. falciparum.ClinicalTrials.gov NCT00343005

    Mortality in patients treated for tuberculous pericarditis in sub-Saharan Africa

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    Objective: To determine the mortality rate and its predictors in patients with a presumptive diagnosis of tuberculous pericarditis in sub-Saharan Africa. Design: Between 1 March 2004 and 31 October 2004, we enrolled 185 consecutive patients with presumed tuberculous pericarditis from 15 referral hospitals in Cameroon, Nigeria, and South Africa, and observed them during the 6-month course of antituberculosis treatment for the major outcome of mortality. This was an observational study, with the diagnosis and management of each patient left at the discretion of the attending physician. Using Cox regression, we have assessed the effect of clinical and therapeutic characteristics (recorded at baseline) on mortality during follow-up. Results: We obtained the vital status of 174 (94%) patients (median age 33; range 14-87 years). The overall mortality rate was 26%. Mortality was higher in patients who had clinical features of HIV infection than in those who did not (40% versus 17%, P=0.001). Independent predictors of death during follow-up were: (1) a proven non-tuberculosis final diagnosis (hazard ratio [HR] 5.35, 95% confidence interval 1.76 to 16.25), (2) the presence of clinical signs of HIV infection (HR 2.28, 1.14-4.56), (3) co-existent pulmonary tuberculosis (HR 2.33, 1.20-4.54), and (4) older age (HR 1.02, 1.01-1.05). There was also a trend towards an increase in death rate in patients with haemodynamic instability (HR 1.80, 0.90-3.58) and a decrease in those who underwent pericardiocentesis (HR 0.34, 0.10-1.19). Conclusion: A presumptive diagnosis of tuberculous pericarditis is associated with a high mortality in sub-Saharan Africans. Attention to rapid aetiological diagnosis of pericardial effusion and treatment of concomitant HIV infection may reduce the high mortality associated with the disease

    Beyond the Classroom Through the Paperless Mode

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    The development of technology in the modern world has necessitated the evolution of paperless classrooms. However, the transformation of educational technology and educational resources has not been able to keep pace with the growth of digital technology that we witnessed in the employment sector. Even today, textbooks and notebooks are widely used as primary teaching and learning tools in many universities across the Arabian Peninsula. The academic community has been making conscious moves to migrate into paperless classrooms in many higher education institutions across Oman through the increased application of computer and internet technology for instructional purposes. The digital mode of instruction can be considered as a conscious attempt to prepare and equip the learners for the paperless digital era. The theory and practice of paperless classrooms are analyzed critically in the first part. The second part of the paper is more specifically an observational analysis of the undergraduate students of Dhofar University and their engagement with digital devices in the classroom. The present educational scenario in the Arabian Peninsula in general and Dhofar University in particular demand a serious study of the concept of paperless classrooms to equip the students to look beyond the classrooms into the challenging avenues of employment opportunities. This study is an attempt to critically examine the paperless mode of education in Oman with special reference to the learners of English at Dhofar University, Salalah, Oman. The study finds that paperless classrooms are more dynamic, engaging and productive that will enable learners not only to develop autonomous learning, data collection and analysis, collaboration and teamwork in the classroom but also delimiting the geographical and time restrictions. Paperless classrooms equip learners with the technological skills that are in demand in the 21st-century for employability, e-business and eCommerce

    {4,6-Bis[(E)-1-methyl-2-(pyridin-2-ylmethylidene-κN)hydrazinyl-κN2]pyrimidine-κN1}dichloridocopper(II) methanol disolvate monohydrate

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    The title compound, [CuCl2(C18H18N8)]·2CH3OH·H2O, contains a pentacoordinated Cu(II) atom bonded to the tridentate 4,6-bis[(E)-1-methyl-2-(pyridin-2-ylmethylidene)hydrazinyl]pyrimidine ligand and two Cl atoms. The geometry around the CuII atom is distorted square-pyramidal. The molecules pack in the crystal structure via O—H...Cl, O—H...N, C—H...Cl and C—H...O hydrogen bonds, C—H...π and π–π interactions [centroid–centroid distances of the pyrimidine–pyridine and pyridine–pyridine interactions are 3.750 (3) and 3.850 (3) Å, respectively], forming sheet-like assemblies
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