Harris lines (HL; also known as “growth arrest lines” or “transverse radiopaque lines”) are horizontal sclerotic lines formed in the metaphyseal or diaphyseal part of long bones, usually visualized ...using X-ray images. Among the factors that may lead to a temporary arrest of bone growth (and thus—to HL deposition), the most commonly mentioned are nutritional disorders (malnutrition, protein, vitamin, and mineral deficiencies), a history of smallpox, pneumonia or other diseases, food poisoning, or alcohol abuse. The position of the HL is related to the period of incidence of physiological stress inhibiting bone growth, which enables the estimation of the age at which the subject was exposed to it. Such information can be valuable in the study on archeological populations; therefore, various methods have been developed to determine the age of HL deposition. In this review, six known methods for calculating the age of HL origin are presented and compared: Allison/McHenry, Hunt and Hatch, Clarke, Hummert and van Gerven, and Maat and Byers’ methods. In addition, the authors propose here a modification to the last method in order to enable calculations on non-adult bones.
Purpose
The purpose of the present study was to investigate the feasibility of developing a fast non-destructive at-line transmission Raman spectroscopy (TRS) method for core tablet potency and ...content uniformity (CU) as part of a real-time release testing (RTRt) control strategy.
Methods
The effects of tablet hardness and weight (thickness), API particle size, and concentration were studied by using a novel experimental design called generalized subset designs (GSDs). A subset of 28 experiments plus three replicate center points were selected for a total of 31 experiments. Matrix effects included tablets with active pharmaceutical ingredient (API) at seven concentration levels (14 to 26%
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), and API particle size (17 to 71 μm), tablet weight (275 to 328 mg), and tablet hardness (8 to 16 SCU) at two levels.
Results
Three calibration models were developed, by using partial least squares (PLS) and different preprocessing conditions (model nos. 1 to 3). In model no. 1, all matrix effects were excluded. This model showed high potency prediction errors (RMSEP of 10.0%). When all matrix variations were included in the multivariate calibration according to the GSD as shown in model nos. 2 and 3, the prediction accuracy was greatly improved (RMSEP 2.56 and 1.74% respectively). The statistical significance of the tablet weight, hardness, and API particle size in the %Recovery (TRS vs. the reference HPLC method) was investigated by using MODDE Pro (Sartorius Stedim Data Analytics). Statistically significant effects were identified if the calculated
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value was ≤ 0.05. The main effect hardness, the cross-term hardness×particle size, and the quadratic term cal level×cal level showed to be statistically significant. However, these effects had a very small impact on tablet prediction accuracy (± 1.0%
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) well within the intermediate precision of the method.
Conclusion
A non-destructive TRS method for core tablet potency and CU was fully validated, following ICH Q2 and EMEA NIR guidelines. The applicability of the method to process development batches was demonstrated and compared to a previously developed and validated NIR method.
Apoptosis is the main driver of cell death in bioreactor suspension cell cultures during the production of biopharmaceuticals from animal cell lines. It is known that apoptosis also has an effect on ...the quality and quantity of the expressed recombinant protein. This has raised the importance of studying apoptosis for implementing culture optimization strategies. The work here describes a novel approach to obtain near real time data on proportion of viable, early apoptotic, late apoptotic and necrotic cell populations in a suspension CHO culture using automated sample preparation in conjunction with flow cytometry. The resultant online flow cytometry data can track the progression of apoptotic events in culture, aligning with analogous manual methodologies and giving similar results. The obtained near-real time apoptosis data are a significant improvement in monitoring capabilities and can lead to improved control strategies and research data on complex biological systems in bioreactor cultures in both academic and industrial settings focused on process analytical technology applications.
Solid-phase extraction (SPE) is a good strategy for overcoming the low sensitivity of capillary electrophoresis (CE). Here, we present a critical review of applications of coupling between SPE and CE ...reported between 2000 and March 2007. We highlight selected developments and advances and focus on various combinations of these two techniques, which include at-line, in-line and on-line modes of SPE–CE. We discuss the advantages and the drawbacks of the different set-ups and methodologies. We also outline novel trends in SPE–CE coupling.
Sorbent preconcentration offers good strategies to overcome the poor detection limits of capillary electrophoresis (CE). The present review focuses on the recent trends of the coupling between ...sorbent preconcentration techniques, namely solid-phase extraction (SPE) and solid-phase microextraction (SPME), to capillary electrophoresis (CE). Special attention is given to their environmental and biological application. We also discuss the most important advantages and disadvantages of the different methodologies and briefly outline the new trends of the coupling between sorbent preconcentration and CE.
Chemokine receptors belong to the class of G protein-coupled receptors and are important in the host defense against infections and inflammation. However, aberrant chemokine signaling is linked to ...different disorders such as cancer, central nervous system and immune disorders, and viral infections Scholten DJ et al. (2012) Br J Pharmacol 165(6):1617–1643. Modulating the chemokine receptor function provides new ways of targeting specific diseases. Therefore, discovery and development of drugs targeting chemokine receptors have received considerable attention from the pharmaceutical industry in the past decade. Along with that, the determination of bioactivities of individual metabolites derived from lead compounds towards chemokine receptors is crucial for drug selectivity, pharmacodynamics, and potential toxicity issues. Therefore, advanced analytical methodologies are in high demand. This study is aimed at the optimization of a new analytical method for metabolic profiling with parallel bioaffinity assessment of CXCR3 ligands of the azaquinazolinone and piperazinyl-piperidine class and their metabolites. The method is based on mass spectrometric (MS) identification after liquid chromatographic (LC) separation of metabolic mixtures. The bioaffinity assessment is performed “at-line” via high-resolution nanofractionation onto 96-well plates allowing direct integration of radioligand binding assays. This new method enables identification of metabolites from lead compounds with associated estimation of their individual bioaffinity. Moreover, the identification of the metabolite structures via accurate mass measurements and MS² allows the identification of liable metabolic “hotspots” for further lead optimization. The efficient combination of chemokine receptor ligand binding assays with analytical techniques, involving nanofractionation as linking technology, allows implementation of comprehensive metabolic profiling in an early phase of the drug discovery process.
In theory, heat production rates are very well suited for analysing and controlling bioprocesses on different scales from a few nanolitres up to many cubic metres. Any bioconversion is accompanied by ...a production (exothermic) or consumption (endothermic) of heat. The heat is tightly connected with the stoichiometry of the bioprocess via the law of Hess, and its rate is connected to the kinetics of the process. Heat signals provide real-time information of bioprocesses. The combination of heat measurements with respirometry is theoretically suited for the quantification of the coupling between catabolic and anabolic reactions. Heat measurements have also practical advantages. Unlike most other biochemical sensors, thermal transducers can be mounted in a protected way that prevents fouling, thereby minimizing response drifts. Finally, calorimetry works in optically opaque solutions and does not require labelling or reactants. It is surprising to see that despite all these advantages, calorimetry has rarely been applied to monitor and control bioprocesses with intact cells in the laboratory, industrial bioreactors or ecosystems. This review article analyses the reasons for this omission, discusses the additional information calorimetry can provide in comparison with respirometry and presents miniaturization as a potential way to overcome some inherent weaknesses of conventional calorimetry. It will be discussed for which sample types and scientific question miniaturized calorimeter can be advantageously applied. A few examples from different fields of microbiological and biotechnological research will illustrate the potentials and limitations of chip calorimetry. Finally, the future of chip calorimetry is addressed in an outlook.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, EMUNI, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK
Environmental and process control applications have needs for sensors that operate continuously or repeatedly, making them applicable to batch measurement and flowing product stream measurement. ...Additionally, for lactose monitoring in dairy-processing plants, the sensors must have sufficient flexibility to handle a wide range of substrate concentration and be resilient to withstand wide pH excursions brought about by frequent exposure to clean-in-place chemicals that happen without any warning. This paper describes the development and trialling of an at-line lactose biosensor that meets the needs of the dairy industry for loss monitoring of lactose in dairy-processing plants by the combination of a third-generation enzyme biosensor with a sequential injection analyser. Results, both from grab sample analysis and an at-line factory prototype, are shown from their operation when installed at a Fonterra dairy factory (New Zealand) during the 2011–2012 season. Previous sensor fabrication methods were converted to a single-step process, and the flow-through cell was adapted to bubble-free operation. The lactose concentration in wastewater-processing streams was successfully monitored by taking and analysing samples every 2–3 min, semi-continuously, for 3 months by an unskilled operator. The Fonterra site flushes approximately 100–300,000 L of wastewater per hour from its lactose plant. In the 2011–2012 season, the daily mean lactose content of this wastewater varied significantly, from 0.0 to 8.0 %
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(0–233,712 μM) and equated to substantial total losses of lactose over a 6-month period. These lactose losses represent lost saleable or useable product.
The Ising spin glass model on Bethe-like lattices (cactus lattices) is studied using replicas in the presence of a magnetic field. Parisi's order parameter function and the de Almeida–Thouless (AT) ...line are obtained close to the spin glass transition temperature. The results are compared with those for the Bethe lattice to see the effects of loops. The slope of the order parameter function diminishes considerably for both lattices compared with that for the Sherrington–Kirkpatrick (SK) model. The loci of the AT line for the cactus lattices and the Bethe lattice are above and below that for the SK model, respectively.
In the present work, we consider the dependence of the viscosity of polyamide 66 (PA66) as a function of both temperature and pressure. Measurements were carried out using a standard capillary ...rheometer to evaluate the effect of temperature and the corresponding shift factor of viscosity data. The pressure influence was accounted for by employing an at-line rheometer equipped with a counter-pressure cell, the so-called enhanced exit pressure method. Time-temperature-pressure superposition was applied to obtain the viscosity master curve. Interestingly, PA66 displays an unusual increase of the pressure coefficient as a function of temperature. On the contrary, previous studies on nonpolar liquids or polymers for which polar interactions are relatively weak indicated that the sensitivity to pressure, measured by the so-called Barus parameter, is a decreasing function of the temperature. Thus, we attribute the peculiar behavior of PA66 to the strong polar interactions which are present and which may dominate the viscosity at relatively low temperatures and would be less dominant at higher temperatures.
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