Nederlandse wetgeving voor de sterilisatie van medische hulpmiddelen. Moderniseren of opheffen?

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Carbon Dots as a Fluorescence pH Nanosensor by Application of an Active Surface Preservation Strategy

In the environmental, industrial, and biomedical fields, pH monitorization is of the upmost importance. However, the most used type of pH sensors, glass pH-electrodes, still present limitations in their application in low volume samples and in cellular pH sensing, due to their size and invasive nature. Fluorescence-based sensors present a solution to such issues, providing a non-invasive solution to pH sensing. Herein, we report the rational development of carbon dots (CDs) as a pH nanosensor via an active surface preservation (ASP) method. Carbon dots (CDs) are carbon-based fluorescent nanoparticles with valuable properties such as high aqueous solubility, low cost and good biocompatibility, with remarkable fluorescence performance, been increasingly used as fluorescent nanosensors. Namely, these nanomaterials present advantages over molecular probes in terms of (photo)stability and water solubility, among others. By employing ASP strategies, the CDs will be prepared by using precursors with known active functional features. The ASP method allows the nanoparticles to retain the structural features of precursors, thus retaining their properties, without the need for costly and time-consuming post-synthesis functionalization procedures. In this work, we intend to provide a proof-of-concept of this type of strategy by utilizing the known pH-sensitivity of fluorescein to provide a pH-based response to CDs. The resulting CDs presented reversible response by fluorescence enhancement in the range of pH from 4 to 12. The nanoparticles exhibited excellent photostability, in different pH solutions. The studied CDs were also unaffected by, either variation of ionic strength or the presence of interferent species, while being compatible with human cancer cells. Finally, CDs were able to determine the pH of real samples. Thus, a selective pH fluorescent CDs-based nanosensor was developed.</jats:p

EEC Mineral Policy — Some Proposals for Change in the 1980s

SUMMARY The EEC perceives a mutuality of interest between itself and the Third World in the area of minerals. This was the basis for the introduction in the second Lomé Convention of several mineral?related instruments, including the Sysmin scheme, possible joint?financed mining projects, and a window for EIB lending to mining and energy. Of these, the Sysmin scheme was the most substantial, but its implementation so far has revealed a number of problems. In view of the very modest success of these measures, there is a need for new initiatives, particularly in three areas of potential mutual advantage: the promotion of exploration, emergency purchases of minerals from selected ACP states when prices are exceptionally low, and the encouragement of mineral revenue stabilisation funds. RESUMEN Política minera de la CEE. Algunas proposiciones de cambio para la décade de 1980 La CEE percibe la existencia de intereses mutuos entre ella y el Tercer Mundo en el área de los minerales. Esta fue la base para la introducción de varios instrumentos relativos a la minería en la Segunda Convención de Lomé, incluyendo el programa Sysmin, posibles proyectos mineros de financiamiento conjunto y una ventanilla para préstamos del BEI a la minería y la energía. El más sustancial de éstos fue el programa Sysmin, no obstante que hasta ahora su implementación ha revelado algunos problemas. El éxito muy modesto de estas medidas, demuestra la necesidad de nuevas iniciativas, especialmente en tres áreas de la mutua ventaja potencial: la promoción de exploraciones, el surgimiento de compras de minerales por parte de estados seleccionados del Africa, Caribe y Pacífico, cuando los precios son excepcionalmente bajos y, el fomento de fondos de estabilización de utilidades mineras. RÉSUMÉ La Polétique Minérale de la CEE — Quelques Propositions de Changements pour les années 80 La CEE entrevoit un intérêt mutuel entre elle et le Tiers?Monde dans le secteur des minéraux. Cela était à la base de l'introduction, lors de la deuxième Convention de Lomé, de plusieurs mécanismes relatifs aux minéraux, comprenant le plan Sysmin, d'éventuels projets d'exploitation minière conjointement financés, et une ouverture pour un prêt de la BIE à l'exploitation minière et à l'énergie. De tous, le plan Sysmin était le plus important, mais son exécution a jusqu'à présent soulevé quelques problèmes. Etant donné le succès très modeste de ces mesures, de nouvelles initiatives sont nécessaires, particulièrement dans trois domaines à avantage mutuel potentiel: la promotion de l'exploration, achats urgents de minéraux provenant d'une sélection d'états d'ACP à un moment où les prix sont exceptionnellement bas, et l'encouragement de fonds de stabilisation des revenus minéraux

Sistem Pendukung Pengambilan Keputusan Penentuan Biaya Pembangunan Rumah

Pengambilan keputusan pembangunan rumah adalah masalah yang komplek bukan masalah yang ringan, banyak orang yang merasa kesulitan dalam tahap perencanaan pembangunan rumah, baik itu dari segi pemilihan model, pemilihan bahan bangunan yang digunakan, dan penentuan anggaran atau biaya yang dibutuhkan. Sering kali terjadi biaya yang dikeluarkan tidak sesuai dengan anggaran pada rencana awal.Aplikasi Penentuan Biaya Pembangunan Rumah merupakan Sistem Pendukung Keputusan (SPK) yang dikembangkan dengan tahapan PADI, implementasi dengan bahasa pemrograman Delphi 7.Fasilitas yang diberikan dalam aplikasi Penentuan Biaya Pembangunan Rumah ini antara lain membantu para pengambil keputusan untuk mendapatkan informasi harga bahan bangunan, mendapatkan informasi volume pekerjaan, serta dapat mengambil keputusan yang tepat dalam pengeluaran biaya pembangunan rumah berdasarkan kriteria kelas bahan

Do early life cognitive ability and self-regulation skills explain socio-economic inequalities in academic achievement? An effect. decomposition analysis in UK and Australian cohorts

Socio-economic inequalities in academic achievement emerge early in life and are observed across the globe. Cognitive ability and “non-cognitive” attributes (such as self-regulation) are the focus of many early years’ interventions. Despite this, little research has compared the contributions of early cognitive and self-regulation abilities as separate pathways to inequalities in academic achievement. We examined this in two nationally representative cohorts in the UK (Millennium Cohort Study, n = 11,168; 61% original cohort) and Australia (LSAC, n = 3028; 59% original cohort). An effect decomposition method was used to examine the pathways from socio-economic disadvantage (in infancy) to two academic outcomes: ‘low’ maths and literacy scores (based on bottom quintile) at age 7–9 years. Risk ratios (RRs, and bootstrap 95% confidence intervals) were estimated with binary regression for each pathway of interest: the ‘direct effect’ of socio-economic disadvantage on academic achievement (not acting through self-regulation and cognitive ability in early childhood), and the ‘indirect effects’ of socio-economic disadvantage acting via self-regulation and cognitive ability (separately). Analyses were adjusted for baseline and intermediate confounding. Children from less advantaged families were up to twice as likely to be in the lowest quintile of maths and literacy scores. Around two-thirds of this elevated risk was ‘direct’ and the majority of the remainder was mediated by early cognitive ability and not self-regulation. For example in LSAC: the RR for the direct pathway from socio-economic disadvantage to poor maths scores was 1.46 (95% CI: 1.17–1.79). The indirect effect of socio-economic disadvantage through cognitive ability (RR = 1.13 [1.06–1.22]) was larger than the indirect effect through self-regulation (1.05 [1.01–1.11]). Similar patterns were observed for both outcomes and in both cohorts. Policies to alleviate social inequality (e.g. child poverty reduction) remain important for closing the academic achievement gap. Early interventions to improve cognitive ability (rather than self-regulation) also hold potential for reducing inequalities in children's academic outcomes

Evaluating Students' Perception of a Three-Dimensional Virtual World Learning Environment

Three-dimensional virtual environments have gained wide popularity due to improvement in graphic rendering technology and networking infrastructure. Many education institutions have been trying to leverage the potential of 3D virtual environments in their application in education. In this research, we aim to evaluate the students’ perception of virtual environments in teaching and learning activities. We set up a virtual classroom, where a short presentation was delivered to students through virtual projectors in Second Life, the most widely adopted 3D virtual environment. The students filled in a questionnaire after the class. We found that the students gave a statistically higher evaluation to 3D virtual environments in terms of satisfaction and enjoyment, while comparable scores between 3D and traditional learning environment in terms of concentration, perceived usefulness, and learning and understanding were obtained. Our results show that virtual learning environment is of great potential in e-learning. Some recommendations in using the virtual environment for learning activities are given.published_or_final_versio

Combined Experimental and Theoretical Investigation into the Photophysical Properties of Halogenated Coelenteramide Analogs

Marine Coelenterazine is one of the most well-known chemi-/bioluminescent systems, and in which reaction the chemi-/bioluminophore (Coelenteramide) is generated and chemiexcited to singlet excited states (leading to light emission). Recent studies have shown that the bromination of compounds associated with the marine Coelenterazine system can provide them with new properties, such as anticancer activity and enhanced emission. Given this, our objective is to characterize the photophysical properties of a previously reported brominated Coelenteramide analog, by employing a combined experimental and theoretical approach. To better analyze the potential halogen effect, we have also synthesized and characterized, for the first time, two new fluorinated and chlorinated Coelenteramide analogs. These compounds show similar emission spectra in aqueous solution, but with different fluorescence quantum yields, in a trend that can be correlated with the heavy-atom effect (F > Cl > Br). A blue shift in emission in other solvents is also verified with the F-Cl-Br trend. More relevantly, the fluorescence quantum yield of the brominated analog is particularly sensitive to changes in solvent, which indicates that this compound has potential use as a microenvironment fluorescence probe. Theoretical calculations indicate that the observed excited state transitions result from local excitations involving the pyrazine ring. The obtained information should be useful for the further exploration of halogenated Coelenteramides and their luminescent properties