Absolute emission quantum yield determination of self-assembled mesoporous titania films grafted with a luminescent zinc complex

A luminescent zinc complex was successfully incorporated to mesostructured porous titania films through a grafting process. The resulting films show an intense blue-emission increasing with functionalization time. The emission quantum yield of these newly synthesized films was quantitatively and accurately determined by measurements carried by an integrating sphere.     

Microwave-assisted oxygenation of melt-processed bulk YBa2Cu3O7-δ ceramics

The properties (superconducting and non-superconducting) of YBa₂Cu₃O_7-δ bulk ceramics (YBCO) are strongly dependent on the oxygen deficiency, δ. Unfortunately, whether sintering or melt-processing is used to form the material, the final oxygen content is usually far from that which gives the optimum superconducting properties (δ≲0.1). Because of this, an additional oxygenation stage has to be carried out in which the material is heated and held at some elevated temperature (∼400–500 °C) for a significant time (often > 100 h) to allow oxygen to diffuse into the sample. Other diffusion-based processes (e.g. sintering) are known to be substantially enhanced in the presence of a microwave field, and it is reasonable to expect that the diffusion of oxygen into YBCO may also benefit from the application of such technology. The oxygenation of melt-processed YBCO using conventional and microwave-assisted heating has been compared. The diffusion coefficient at 400 and at 450 °C is shown to be enhanced by about 30% through the application of a high-frequency microwave field. Because the oxygenation time is inversely proportional to the diffusion coefficient, this represents a significant reduction in process time. The equilibrium value of the oxygen content is not affected by the application of a microwave field, and therefore the sample temperature must be the same for both microwave-assisted and conventional processing. Consequently, the observed enhancement is an example of a genuine non-thermal microwave effect. This revised version was published online in November 2006 with corrections to the Cover Date.     

Water effects on the bond strength of concrete/concrete adhesive joints

The paper discusses the experimental work by the authors investigating bond strength of epoxy adhesives and their efficiency when joining to concrete elements; the epoxies studied were those currently used in the construction industry. Flexural tests were undertaken to determine the mechanical properties of the exposed and the control specimens of three different epoxy adhesives. In addition, the water resistance of concrete/concrete epoxy joints was investigated by comparing bond strength with those of control samples; the maximum period of immersion was one month. A reduction in the glass transition temperature and the stiffness at short immersion time was found for all the adhesives employed, with a subsequent slight increase for prolonged immersion, while the effects on the strengths resulted almost proportional to their initial values. The effect of water on the adhesion of the joints was found to be significant, especially at longer immersion times; the bond strength of concrete–adhesive specimens reduced by 30% after one month of immersion in water.     

Problem-based medical education: development of a theoretical foundation and a science-based professional attitude

Problem-based learning, combined with early patient contact, integration between different subject areas, elements of multiprofessional education, and special emphasis on the development of communications skills has become the basis for the medical curriculum at the Faculty of Health Sciences in Link?ping. Critics have questioned the depth of the scientific and theoretical aspects of the curriculum. Through a series of specific measures in the organization of the curriculum and examinations, and due to the pedagogical principles involved per se, our claim is that students graduating at Link?ping do possess the required theoretical knowledge and a scientific attitude to the practice of medicine, at least equivalent to that obtained in a more conventional medical curriculum. One such specific measure is that all students perform one field study and two scientific studies during the course of the curriculum. An investigation of student opinions regarding the value of performing scientific projects of their own have shown that these projects have had a positive impact on the students' general scientific attitude and their willingness to engage in future scientific work. The specific skills acquired, as confirmed by oral examinations, were largely determined by the scientific nature of the chosen field of study. Our graduates have not yet progressed far enough in their careers for comparisons to be made on the basis of the Swedish Licensing Board Internship Examinations, but continuing evaluations of students, graduates and licensed doctors emerging from the curriculum will provide future evidence as to whether our present evaluation is correct.     

山上的"大房子"姜乐静的"潭南国小"

这是台湾921地震(1999年)后重建民间捐助的代表性案例,坐落在日月潭南边高山偏远地区,建筑师以布农族"家屋"的转化来重建这一村落学习"机构",以"大房子"意象作为基本的建构形式,也形成村落重建的精神方舟.建筑师诚恳地让山本身来造就了这大房子.     

How Can We Improve Vaccination Response in Old People? Part I: Targeting Immunosenescence of Innate Immunity Cells

Vaccination, being able to prevent millions of cases of infectious diseases around the world every year, is the most effective medical intervention ever introduced. However, immunosenescence makes vaccines less effective in providing protection to older people. Although most studies explain that this is mainly due to the immunosenescence of T and B cells, the immunosenescence of innate immunity can also be a significant contributing factor. Alterations in function, number, subset, and distribution of blood neutrophils, monocytes, and natural killer and dendritic cells are detected in aging, thus potentially reducing the efficacy of vaccines in older individuals. In this paper, we focus on the immunosenescence of the innate blood immune cells. We discuss possible strategies to counteract the immunosenescence of innate immunity in order to improve the response to vaccination. In particular, we focus on advances in understanding the role and the development of new adjuvants, such as TLR agonists, considered a promising strategy to increase vaccination efficiency in older individuals.     

Effects of sodium chloride and relative humidity on growth and sporulation of moulds isolated from cured fish

1. The aim of this study was to determine plasma levels of N-terminal atrial natriuretic peptide and atrial natriuretic peptide in normal subjects and in patients with essential hypertension, cardiac transplant and chronic renal failure, using radioimmunoassays directed towards the mid-portion pro-atrial natriuretic peptide (31-67) and pro-atrial natriuretic peptide (1-30) of the N-terminal atrial natriuretic peptide and atrial natriuretic peptide (99-126). The circulating form(s) of the immunoreactive N-terminal atrial natriuretic peptide in plasma extracts has been investigated using all three radioimmunoassays by means of gel filtration chromatography to further clarify the major immunoreactive molecular circulating form(s) of N-terminal atrial natriuretic peptide in man. 2. The plasma level (mean +/- SEM) of N-terminal pro-atrial natriuretic peptide (31-67) in the normal subjects was 547.2 +/- 32.7 pg/ml (n = 36) and was significantly elevated in patients with essential hypertension (730.2 +/- 72.3 pg/ml, P < 0.025, n = 39), in cardiac transplant recipients (3214.0 +/- 432.2 pg/ml, P < 0.001, n = 9) and in patients with chronic renal failure (3571.8 +/- 474.1 pg/ml, P < 0.001, n = 11). Plasma levels of N-terminal pro-atrial natriuretic peptide (1-30) and atrial natriuretic peptide were similarly elevated in the same patient groups when compared with the mean plasma values in the normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prosthetic valve endocarditis: superiority of surgical valve replacement versus medical therapy only

The objective of our study was to assess the long-term outcome of patients with prosthetic valve endocarditis. We used a multicenter, prospective, observational study design. Six university teaching hospitals with high volume cardiothoracic surgery participated. Seventy-four patients with prosthetic valve endocarditis as defined by explicit, objective criteria were selected for participation. All patients were followed up prospectively for 1 year. Thirty-one percent and 69% had development of endocarditis within 60 days of valve insertion ("early") and after 60 days ("late"), respectively. The most common causes were Staphylococcus epidermidis (40%), Staphylococcus aureus (20%), streptococcal species (18%), and aerobic gram-negative bacilli (11%). Physical signs of endocarditis (new or changing murmur, stigmata, emboli) were seen in 58%. At 6 months and 12 months, mortality was 46% and 47%, respectively. Surgical replacement of the infected valve led to significantly lower mortality (23%) as compared with medical therapy alone (56%), as assessed by both univariate and multivariate analyses (p < 0.05). Improved outcome was seen for the surgical group even when controlling for severity of illness at time of diagnosis. From these findings we conclude that accurate assessment of outcome in prosthetic valve endocarditis requires long-term follow-up of at least 6 months following diagnosis. Surgical therapy warrants greater scrutiny; evaluation in controlled clinical trials is appropriate.     

Recommendation of RILEM Technical Committee 250-CSM: Test method for Textile Reinforced Mortar to substrate bond characterization

Textile Reinforced Mortar (TRM), also known as Fabric Reinforced Mortar or Fabric Reinforced Cementitious Matrix, composites are an emerging technology for the external repair and strengthening of existing structures. For most applications, the effectiveness of the TRM reinforcement relies on its bond performance. This recommendation identifies the best practice to characterize the bond behaviour of TRM. A shear bond test method is proposed to determine the peak axial stress (associated with the maximum load that can be transferred from the structural member to the externally bonded TRM reinforcement), the stress–slip relationship and the failure mode that controls the TRM-to-substrate load transfer capacity. Guidelines on specimen manufacturing, experimental setup, test execution, and determination of test results are provided.     

Transplacental transfer and biotransformation studies of nicotine in the human placental cotyledon perfused in vitro

Our objective was to study the characteristics of transfer and biotransformation of nicotine in the human term placenta. Nicotine transfer was studied by dually perfusing an isolated cotyledon of the human placenta in vitro. Nicotine metabolism to cotinine was investigated in intact tissue during perfusion and in placental microsomal fractions. Following the addition of nicotine (40 ng/ml) to the maternal side of the placenta, distribution into placental tissue (0.43 +/- 0.13 ng/ml/min) was three times higher than transfer to the fetal side of the placenta (0.15 +/- 0.01 ng/ml/min). The steady-state maternal-to-fetal transfer of nicotine was approximately 90% that of antipyrine (a marker of flow-dependent transfer). There was no evidence of nicotine metabolism to cotinine by intact placental tissue or in microsomal fractions. The observation that nicotine readily crosses the human placenta with no evidence of metabolism suggests that nicotine has the potential to cause adverse affects on the developing fetus.