Systematic evaluation of matrix effects in hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry.

Reversed phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) is the gold standard technique in bioanalysis. However, hydrophilic interaction chromatography (HILIC) could represent a viable alternative to RPLC for the analysis of polar and/or ionizable compounds, as it often provides higher MS sensitivity and alternative selectivity. Nevertheless, this technique can be also prone to matrix effects (ME). ME are one of the major issues in quantitative LC-MS bioanalysis. To ensure acceptable method performance (i.e., trueness and precision), a careful evaluation and minimization of ME is required. In the present study, the incidence of ME in HILIC-MS/MS and RPLC-MS/MS was compared for plasma and urine samples using two representative sets of 38 pharmaceutical compounds and 40 doping agents, respectively. The optimal generic chromatographic conditions in terms of selectivity with respect to interfering compounds were established in both chromatographic modes by testing three different stationary phases in each mode with different mobile phase pH. A second step involved the assessment of ME in RPLC and HILIC under the best generic conditions, using the post-extraction addition method. Biological samples were prepared using two different sample pre-treatments, i.e., a non-selective sample clean-up procedure (protein precipitation and simple dilution for plasma and urine samples, respectively) and a selective sample preparation, i.e., solid phase extraction for both matrices. The non-selective pretreatments led to significantly less ME in RPLC vs. HILIC conditions regardless of the matrix. On the contrary, HILIC appeared as a valuable alternative to RPLC for plasma and urine samples treated by a selective sample preparation. Indeed, in the case of selective sample preparation, the compounds influenced by ME were different in HILIC and RPLC, and lower and similar ME occurrence was generally observed in RPLC vs. HILIC for urine and plasma samples, respectively. The complementary of both chromatographic modes was also demonstrated, as ME was observed only scarcely for urine and plasma samples when selecting the most appropriate chromatographic mode.

Emergent patterns of social organization in captive Cercocebus torquatus: Testing the GrooFiWorld agent-based model

We empirically applied the GrooFiWorld agent-based model (Puga-González et al. 2009) in a group of captive mangabeys (Cercocebus torquatus). We analysed several measurements related to aggression and affiliative patterns. The group adopted a combination of despotic and egalitarian behaviours resulting from the behavioural flexibility observed in the Cercopithecinae subfamily. Our study also demonstrates that the GrooFiWorld agent-based model can be extended to other members of the Cercopithecinae subfamily generating parsimonious hypotheses related to the social organization.

The ESRg matrix for strong field d5 systems

This review has tried to collect and correlate all the various equations for the g matrix of strong field d5 systems obtained from different basis sets using full electron and hole formalism calculations. It has corrected mistakes found in the literature and shown how the failure to properly take in symmetry boundary conditions has produced a variety of apparently inconsistent equations in the literature. The review has reexamined the problem of spin-orbit interaction with excited t4e states and finds that the earlier reports that it is zero in octahedral symmetry is not correct. It has shown how redefining what x, y, and z are in the principal coordinate system simplifies, compared to previous methods, the analysis of experimental g values with the equations.

Qualidade de medições em química analítica. Estudo de caso: determinação de cádmio por espectrofotometria de absorção atômica com chama

Calculation of uncertainty of results represents the new paradigm in the area of the quality of measurements in laboratories. The guidance on the Expression of Uncertainty in Measurement of the ISO / International Organization for Standardization assumes that the analyst is being asked to give a parameter that characterizes the range of the values that could reasonably be associated with the result of the measurement. In practice, the uncertainty of the analytical result may arise from many possible sources: sampling, sample preparation, matrix effects, equipments, standards and reference materials, among others. This paper suggests a procedure for calculation of uncertainties components of an analytical result due to sample preparation (uncertainty of weights and volumetric equipment) and instrument analytical signal (calibration uncertainty). A numerical example is carefully explained based on measurements obtained for cadmium determination by flame atomic absorption spectrophotometry. Results obtained for components of total uncertainty showed that the main contribution to the analytical result was the calibration procedure.

The governmental organization's role in railway freight market's liberalization -building knowledge through Swedish and Polish operators' experiences

Globalization has increased transport aggregates’ demand. Whilst transport volumes increase, ecological values’im portance has sharpened: carbon footprint has become a measure known world widely. European Union together with other communities emphasizes friendliness to the environment: same trend has extended to transports. As a potential substitute for road transport is noted railway transport, which decreases the congestions and lowers the emission levels. Railway freight market was liberalized in the European Union 2007, which enabled new operators to enter the markets. This research had two main objectives. Firstly, it examined the main market entry strategies utilized and the barriers to entry confronted by the operators who entered the markets after the liberalization. Secondly, the aim was to find ways the governmental organization could enhance its service towards potential railway freight operators. Research is a qualitative case study, utilizing descriptive analytical research method with a normative shade. Empirical data was gathered by interviewing Swedish and Polish railway freight operators by using a semi-structured theme-interview. This research provided novel information by using first-hand data; topic has been researched previously by utilizing second-hand data and literature analyses. Based on this research, rolling stock acquisition, needed investments and bureaucracy generate the main barriers to entry. The research results show that the mostly utilized market entry strategies are start-up and vertical integration. The governmental organization could enhance the market entry process by organizing courses, paying extra attention on flexibility, internal know-how and educating the staff.

Intracellular membrane trafficking in Osteoclasts The role of direct Rab protein – Rac 1 interactions in the targeting of intracellular vesicles

Osteoclasts are cells responsible for bone resorption. These cells undergo extensive membrane re-organization during their polarization for bone resorption and form four distinct membrane domains, namely the ruffled border, the basolateral membrane, the sealing zone and the functional secretory domain. The endocytic/biosynthetic pathway and transcytotic route(s) are important for the resorption process, since the endocytic/biosynthetic pathway brings the specific vesicles to the ruffled border whereas the transcytotic flow is believed to transport the degraded bone matrix away from the resorption lacuna to the functional secretory domain. In the present study, we found a new transcytotic route from the functional secretory domain to the ruffled border, which may compensate membrane loss from the ruffled border during the resorption process. We also found that lipid rafts are essential for the ruffled border-targeted late endosomal pathways. A small GTP-binding protein, Rab7, has earlier been shown to regulate the late steps of the endocytic pathway. In bone-resorbing osteoclasts it is involved in the formation of the ruffled border, which displays several features of late endosomal membranes. Here we discovered a new Rab7-interacting protein, Rac1, which is another small GTP-binding protein and binds to the GTP-form of Rab7 in vitro. We demonstrated further that Rab7 colocalizes with Rac1 at the fusion zone of the ruffled border in bone-resorbing osteoclasts. In other cell types, such as fibroblast-like cells, this colocalization is mainly perinuclear. Because Rac1 is known to control the actin cytoskeleton through its effectors, we suggest that the Rab7-Rac1 interaction may mediate late endosomal transport between microtubules and microfilaments, thus enabling endosomal vesicles to switch tracks from microtubules to microfilaments before their fusion to the ruffled border. We then studied the role of Rab-Rac1 interaction in the slow recycling pathway. We revealed that Rac1 also binds directly to Rab11 and to some other but not all Rab-proteins, suggesting that Rab-Rac1 interaction could be a general regulatory mechanism to direct the intracellular vesicles from microtubule mediated transport to actin filament mediated transport and vice versa. On the basis of our results we thus propose a new hypothesis for these GTPases in the regulation of intracellular membrane flow.

Finite-temperature T matrix in a real-time formalism

A generalized off-shell unitarity relation for the two-body scattering T matrix in a many-body medium at finite temperature is derived, through a consistent real-time perturbation expansion by means of Feynman diagrams. We comment on perturbation schemes at finite temperature in connection with an erroneous formulation of the Dyson equation in a paper recently published.

Developing A Knowledge Management Process Model for Internal IT Organization, Case: Stora Enso Oyj, Corporate IT

The objectives of this Master’s Thesis were to find out what kind of knowledge management strategy would fit best an IT organization that uses ITIL (Information Technology Infrastructure Library) framework for IT Service Management and to create a knowledge management process model to support chosen strategy. The empirical material for this research was collected through qualitative semi-structured interviews of a case organization Stora Enso Corporate IT. The results of the qualitative interviews indicate that codification knowledge management strategy would fit best for the case organization. The knowledge management process model was created based on earlier studies and a literature of knowledge management. The model was evaluated in the interview research and the results showed that the created process model is realistic, useful, and it responds to a real life phenomenon.

Development and validation of a dissolution test for primaquine/polyethylene oxide matrix tablets

A simple, precise, specific, repeatable and discriminating dissolution test for primaquine (PQ) matrix tablets was developed and validated according to ICH and FDA guidelines. Two UV assaying methods were validated for determination of PQ released in 0.1 M hydrochloric acid and water media. Both methods were linear (R²>0.999), precise (R.S.D.<1.87%) and accurate (97.65-99.97%). Dissolution efficiency (69-88%) and equivalence of formulations (f2) was assessed in different media and apparatuses (basket/100 rpm and paddle/50 rpm) tested. Discriminating condition was 900 mL aqueous medium, basket at 100 rpm and sampling times at 1, 4 and 8 h. Repeatability (R.S.D.<2.71%) and intermediate precision (R.S.D.<2.06%) of dissolution method were satisfactory.

EVALUATION OF A BUFFERED SOLID PHASE DISPERSION PROCEDURE ADAPTED FOR PESTICIDE ANALYSES IN THE SOIL MATRIX

An evaluation of the pesticides extracted from the soil matrix was conducted using a citrate-buffered solid phase dispersion sample preparation method (QuEChERS). The identification and quantitation of pesticide compounds was performed using gas chromatography-mass spectrometry. Because of the occurrence of the matrix effect in 87% of the analyzed pesticides, the quantification was performed using matrix-matched calibration. The method's quantification limits were between 0.01 and 0.5 mg kg-1. Repeatability and intermediate precision, expressed as a relative standard deviation percentage, were less than 20%. The recoveries in general ranged between 62% and 99%, with a relative standard deviation < 20%. All the responses were linear, with a correlation coefficient (r) ≥0.99.

Development of Collaborative Product Structure Management

The purpose of this thesis is to develop an environment or network that enables effective collaborative product structure management among stakeholders in each unit, throughout the entire product lifecycle and product data management. This thesis uses framework models as an approach to the problem. Framework model methods for development of collaborative product structure management are proposed in this study, there are three unique models depicted to support collaborative product structure management: organization model, process model and product model. In the organization model, the formation of product data management system (eDSTAT) key user network is specified. In the process model, development is based on the case company’s product development matrix. In the product model framework, product model management, product knowledge management and design knowledge management are defined as development tools and collaboration is based on web-based product structure management. Collaborative management is executed using all these approaches. A case study from an actual project at the case company is presented as an implementation; this is to verify the models’ applicability. A computer assisted design tool and the web-based product structure manager, have been used as tools of this collaboration with the support of the key user. The current PDM system, eDSTAT, is used as a piloting case for key user role. The result of this development is that the role of key user as a collaboration channel is defined and established. The key user is able to provide one on one support for the elevator projects. Also the management activities are improved through the application of process workflow by following criteria for each project milestone. The development shows effectiveness of product structure management in product lifecycle, improved production process by eliminating barriers (e.g. improvement of two-way communication) during design phase and production phase. The key user role is applicable on a global scale in the company.

Electron migration in DNA matrix: an electron transfer reaction

This paper brings an active and provocative area of current research. It describes the investigation of electron transfer (ET) chemistry in general and ET reactions results in DNA in particular. Two DNA intercalating molecules were used: Ethidium Bromide as the donor (D) and Methyl-Viologen as the acceptor (A), the former intercalated between DNA bases and the latter in its surface. Using the Perrin model and fluorescence quenching measurements the distance of electron migration, herein considered to be the linear spacing between donor and acceptor molecule along the DNA molecule, was obtained. A value of 22.6 (± 1.1) angstroms for the distance and a number of 6.6 base pairs between donor and acceptor were found. In current literature the values found were 26 angstroms and almost 8 base pairs. DNA electron transfer is considered to be mediated by through-space interactions between the p-electron-containing base pairs.

Pk-yrityksen layout-suunnittelu ohutlevytuoteteollisuudessa

Diplomityössä käsitellään omistajanvaihdon myötä tapahtuvaa yritysten yhdentymistä pkt- sektorilla. Tutkimuksen tarkoituksena oli suunnitella layout uuteen halliin sekä suunnitella muuttoprosessi kokonaisuudessaan. Tutkimuksessa käsiteltiin koneiden siirron lisäksi myös yritysten yhdentymistä ja yritysfuusiota. Ratkaisumalleja haettiin kirjallisuudesta, tuotannon seuraamisesta ja edellisistä muutoista syntyneistä kokemuksista. Työn aikana kartoitettiin yritysten nykytilanne ja etsittiin siellä olevat parantamista vaativat kohdat. Lisäksi selvitettiin yritysten tuotanto layout -suunnittelua varten. Layoutin tekemisen runkona käytettiin Mutherin -layoutkaaviota. Tietojen pohjalta tehtiin kolme erillistä mallia, joista hyötyarvomatriisia hyväksi käyttäen valittiin yksi. Lisäksi yritysten yhdentymisen työkirjan avulla tehtiin lista tarvittavista toimenpiteistä ennen muuttoa sekä muuton jälkeen. Tutkimuksessa käsiteltiin myös yrityksen ohjelmainvestointeja sekä levytyökeskuksen että laserleikkauskoneen nestaukseen. Lisäksi työssä käsiteltiin myös uusia koneinvestointeja ja uutta organisaatiokaaviota.