<p>I skolan använder sig lärare av skriftliga prov som ett av underlagen vid betygssättning, men det finns dåliga och bra prov. Ett bra prov utvärderar det som avses. Kan det vara så att betyg på skriftliga prov i dagens skola grundas på annat än vad som avses i betygskriterierna? För att granska detta gjordes en kvalitativ samstämmighetsanalys av autentiska prov och betygskriterier gällande organisk kemi, kemi b på gymnasiet. Till detta användes Blooms reviderade taxonomi. Undersökningen ämnade visa om skriftliga prov i var konstruerade på sådant vis att eleverna tilläts visa på kvalitéer som motsvarar Väl Godkänt (VG) och Mycket Väl Godkänt (MVG). En kompletterande enkätundersökning genomfördes med avsikten att ta reda på ifall lärarna använder sig av skriftliga prov för att bedöma VG och MVG. De skriftliga proven i vår undersökning och betygskriterierna för VG och MVG visar mycket dålig samstämmighet. De skriftliga proven betonar en lägre kognitiv nivå än betygskriterierna. Samtidigt visar enkätundersökningen att de skriftliga proven endast är en av flera underlag vid betygssättning.</p>

<p>Johan Afzelius held the chair in chemistry at Uppsala University 1784-1820. His predecessor was the reputable Torbern Bergman, one of Afzelius’ students the famous Jacob Berzelius. The published scientific production of Afzelius is very limited. Afzelius has been described as with no interest of chemistry, reluctant to scientific innovations and as an opponent to the new "antiflogistic" chemistry. Also, he is believed to have given Jacob Berzelius hard times when Berzelius studied in Uppsala.</p><p>The study suggests that the judgement of Johan Afzelius should be revised. It appears that the above description of Afzelius is to be regarded as an artefact. So, Afzelius, besides being devoted to mineralogy, was keen at chemistry, interested in scientific innovations, and from 1799 on no opponent to the new chemistry.</p>

<p>A colloid of magnesium hydroxide is used to stabilize droplets of monomers before suspension polymerisation. The characteristics of precipitated magnesium hydroxide changes significantly during the first hours. The viscosity is high and flucctuating at first but decreases and becomes low and stable after a few hours. When the colloid ages the primary particles agglomerate into larger particles which increases in size by time due to, among other things, Oswald ripening and aggregation. This can cause problems with poor reproducibility in the production. Therefore, the purpose of this study was finding a way to age the colloid without an increase in particle size and without changing any other features. Several experiments were made to optimize the precipitation procedure and to find out what parameters that are most important. The results showed that the stirring rate and colloidal concentration have big influence.</p><p>Small amounts of chemicals that modifies the surface of the colloid was added. This made the particle size near constant over time and the colloid was aged for two months without increasing in size or changing other properties. This was confirmed by making microspheres that had the same characteristics as microspheres made with a fresh colloid.</p>

<p>Quality is the main focus in management of all laboratories. Accurate results of the analyses are not only determined by the analytical procedure but also by preanalytical factors. In the total analytical process of clinical specimens, there are many possible preanalytical sources of error. Monetoring of temperature on test samples of the transport boxes is one way to reduce the mistakes in the preanalytical phase.</p><p>In this study, four laboratories from primary health care were invited to participate. The temperature has been measured on test samples of the transport boxes being delivered to the laboratory.</p><p>In three cases the temperature remained within the limits, but in the fourth case the temperature varied more than the allowed interval. Mistakes found in the preanalytical phase, especially in the handling and processing in the process before complete distribution of test samples to laboratory. This suggests that good communication and cooperation among the personnel is the key to improvement of the laboratory quality.</p>

<p>The Heck reaction is one of the most appreciated methods for carbon-carbon bond formation. Due to its mildness and ability to be tuned by additives, it often leaves few alternative competitive reactions. It has also proven easy to develop the reaction conditions in an environmentally benign direction. Through the introduction of palladium chelating groups in olefinic precursors for the Heck reaction, it has been possible to direct the substitution in the following Heck arylation in favor of the terminal position with good regioselectivity. In this thesis, the concept has been utilized to produce a small array of drug-like compounds at useful yields under fast microwave-enhanced conditions utilizing the thermostable Herrmanns palladacycle. During the last decade, this, together with other palladacycles has become commonly employed as precatalyst for the Heck reaction. However, there have been conflicting opinions regarding the mechanisms governing its catalytic effect. A Pd^II-Pd^IV catalytic cycle has been suggested to be operative, in contrast to the classical Pd⁰-Pd^II cycle. In order to clarify the presence of such a mechanism, a set of Heck reactions was performed with the advent of different palladium precatalysts (classical and palladacycles), which revealed that the regiochemicαal substitution pattern is highly conserved, regardless of which precatalyst was employed, and thus, the same mechanism seems to be operative. This is also supported by data from ESI-MS investigations where all the reactions investigated gave rise to the same set of oxidative addition complexes. A crafted route to 3-aryl-1,2-cyclohexandiones has been developed in which 1,2-cyclohexandione is produced <i>is situ</i> from 2,3-epoxycyclohexanone, followed by Heck arylation. A diverse array of aryl bromides encompassing electron-rich, electron-poor, neutral and sterically hindered repressentatives has been successfully utilized to produce the corresponding products at useful yields.The intramolecular Heck reaction offers a route to quaternary carbonic centersand is being increasingly exploited in synthetic endeavors. However, the use of electron-rich olefinic precursors is only reported in a few cases. The implementation of one capto-dative and five electron-rich olefins has therefore been successfully subjected to Heck reaction conditions rendering the corresponding spiro compounds.</p>

The Lattrell-Dax method of nitrite-mediated substitution of carbohydrate triflates is an efficient method to generate structures of inverse configuration. In this study, the effects of the neighboring group on the Lattrell-Dax inversion were explored. A new carbohydrate/anion host-guest system was discovered and the ambident reactivity of the nitrite anion was found to cause a complicated behavior of the reaction. It has been demonstrated that a neighboring equatorial ester group plays a highly important role in this carbohydrate epimerization reaction, restricting the nitrite N-attack, thus resulting in O-attack only and inducing the formation of inversion compounds in good yields. Based on this effect, efficient synthetic routes to a range of carbohydrate structures, notably β-D-mannosides and β-D-talosides, were designed by use of double parallel and double serial inversion. A supramolecularly activated, triggered cascade reaction was also developed. This cascade reaction is triggered by a deprotonation process that is activated by anions. It was found that the anions can activate this reaction following their hydrogen bonding tendencies to the hydroxyl group in aprotic solvents. / QC 20100709

The ability to create surfaces with well-defined chemical properties is a major research field. One possibility to do this is to design peptides that bind with a specific secondary structure to silica nanoparticles. The peptides discussed in this thesis are constructed to be random coil in solution, but are “forced” to become helical when adsorbed to the particles. The positively charged side-chains on the peptides strongly disfavor an ordered structure in solution due to electrostatic repulsion. When the peptides are introduced to the particles these charges will strongly favor the structure because of ion pair bonding between the peptide and the negatively charged nanoparticles. The peptide-nanoparticle system has been thoroughly investigated by systematic variations of the side-chains. In order to determine which factors that contributes to the induced structure, several peptides with different amino acid sequences have been synthesized. Factors that have been investigated include 1) the positive charge density, 2) distribution of positive charges, 3) negative charge density, 4) increasing hydrophobicity, 5) peptide length, and 6) by incorporating amino acids with different helix propensities. Moreover, pH dependence and the effect of different nanoparticle curvature have also been investigated. It will also be shown that the system can be modified to incorporate a catalytic site that is only active when the helix is formed. This research will increase our understanding of peptide-surface interactions and might be of importance for both nanotechnology and medicine.

Infrared spectroscopy detects molecular vibrations and assesses the properties of molecules and their environment. It is a powerful technique to detect ligand induced changes in biomolecules as it has distinct signals and provides different levels of structural information. An addition of a dialysis accessory to attenuated total reflection infrared spectroscopy makes this technique more universal for ligand binding studies. It facilitates to study ligand binding of substrates, activators, inhibitors and ions to macromolecules as well as effect of pH, ionic strength or denaturants on the structure of macromolecules, which play an important role in drug development. This method was tested with two proteins cyt c and calcium ATPase. We studied phosphoenol pyruvate (PEP) in different ionization states by infrared spectroscopy combined with theoretical analysis. Theoretical calculations helped to assign the bands. The infrared spectrum of labeled PEP and infrared measurement in D2O also helped in band assignment. We used the method dialysis accessory to attenuated total reflection infrared spectroscopy to investigate the binding of PEP and Mg2+ to pyruvate kinase (PK), where conformational changes of PK were revealed upon binding of PEP and Mg2+. Isotopic labeled PEP helped to assign and evaluate the infrared absorption bands. The difference spectrum of bound and free PEP indicates specific interactions between ligand and protein. The quantitative evaluation revealed that the enzyme environment has little influence on the P-O bond strengths, which are weakened by less than 3% upon binding. The carboxylate absorption bands indicate shortening of the C-O bond by as little as 1.3 pm. The binding of PEP to PK in presence of monovalent cations K+ and Na+ showed that the binding interactions are very similar. / doctoral

Syftet med detta arbete är att ta reda hur eleverna upplever skolans undervisning inom ämnesområdet naturvetenskap. Vad har de för upplevelse av sin naturkunskapsundervisning och ligger den i fas med hur den borde se ut med tanke på de mål som finns uppsatta i dessa ämnen? Då jag varit ute på praktik, fältstudier, vikarierat eller mött elever på annat sätt, har jag fått uppfattningen av att många elever inte har den kunskap de borde ha i NO för den aktuella årskursen, och det är då tankarna till detta arbete har väckts. Genom en enkät- studie har jag fått ta del av ca 100 elevers syn på sin NO- undervisning. Dessa resultat har jag kopplat till min litteraturstudie där jag lyft fram de didaktiska frågorna vad, hur och varför. Jag kopplar även resultatet till de kursplaner som finns i berörda ämnen. Då vi är inne på både ett nytt årtusende och nytt århundrade är det även dags att se på hur de pedagogiska tankarna kan komma att se ut i framtiden och jag presenterar några tankar som är aktuella. Detta arbete väcker många tankar till liv vad gäller undervisning inom NO- ämnena och genom dessa tankar har jag utvecklat mig själv i min yrkesroll.

This thesis deals with the synthesis and characterisation of a series of dinuclear manganese complexes. Their ability to donate electrons to photo-generated ruthenium(III) has been investigated in flash photolysis experiments followed by EPR-spectroscopy. These experiment shows several consecutive one-electron transfer steps from the manganese moiety to ruthenium(III), that mimics the electron transfer from the oxygen evolving centre in photosystem II. The redox properties of these complexes have been investigated with electro chemical methods and the structure of the complexes has been investigated with different X-ray techniques. Structural aspects and the effect of water on the redox properties have been shown. One of the manganese complexes has been covalently linked in a triad donor-photosensitizer-acceptor (D–P–A) system. The kinetics of this triad has been investigated in detail after photo excitation with both optical and EPR spectroscopy. The formed charge separated state (D––P–A+) showed an unusual long lifetime for triad based on ruthenium photosensitizers. The thesis also includes a study of manganese-salen epoxidation reactions that we believe can give an insight in the oxygen transfer mechanism in the water oxidising complex in photosystem II.