Novel Route to Produce Hydrocarbons from Woody Biomass Using Molten Salts

[Image: see text] The thermochemical decomposition of woody biomass has been widely identified as a promising route to produce renewable biofuels. More recently, the use of molten salts in combination with pyrolysis has gathered increased interest. The molten salts may act as a solvent, a heat transfer medium, and possibly also a catalyst. In this study, we report experimental studies on a process to convert woody biomass to a liquid hydrocarbon product with a very low oxygen content using molten salt pyrolysis (350–450 °C and atmospheric pressure) followed by subsequent catalytic conversions of the liquids obtained by pyrolysis. Pyrolysis of woody biomass in molten salt (ZnCl(2)/NaCl/KCl with a molar composition of 60:20:20) resulted in a liquid yield of 46 wt % at a temperature of 450 °C and a molten salt/biomass ratio of 10:1 (mass). The liquids are highly enriched in furfural (13 wt %) and acetic acid (14 wt %). To reduce complexity and experimental issues related to the production of sufficient amounts of pyrolysis oils for further catalytic upgrading, model studies were performed to convert both compounds to hydrocarbons using a three-step catalytic approach, viz., (i) ketonization of acetic acid to acetone, (ii) cross-aldol condensation between acetone and furfural to C(8)–C(13) products, followed by (iii) a two-stage catalytic hydrotreatment of the latter to liquid hydrocarbons. Ketonization of acetic acid to acetone was studied in a continuous setup over a ceria–zirconia-based catalyst at 250 °C. The catalyst showed no signs of deactivation over a period of 230 h while also achieving high selectivity toward acetone. Furfural was shown to have a negative effect on the catalyst performance, and as such, a separation step is required after pyrolysis to obtain an acetic-acid-enriched fraction. The cross-aldol condensation reaction between acetone and furfural was studied in a batch using a commercial Mg/Al hydrotalcite as the catalyst. Furfural was quantitatively converted with over 90% molar selectivity toward condensed products with a carbon number between C(8) and C(13). The two-stage hydrotreatment of the condensed product consisted of a stabilization step using a Ni-based Picula catalyst and a further deep hydrotreatment over a NiMo catalyst, in both batch setups. The final product with a residual 1.5 wt % O is rich in (cyclo)alkanes and aromatic hydrocarbons. The overall carbon yield for the four-step approach, from pinewood biomass to middle distillates, is 21%, assuming that separation of furfural and acetic acid after the pyrolysis step can be performed without losses

Einzelmolekulare Untersuchungen von T-Zell Aktivierung

Abweichender Titel nach Übersetzung der Verfasserin/des VerfassersZusammenfassung in deutscher SpracheCD 4+ T Lymphozyten sind in der Lage, geringste Mengen an pathogenen Peptiden, die von speziellen Antigen-präsentierenden Zellen (APC) präsentiert werden, zu erkennen. Nach der erfolgreichen Erkennung des krankhaften Peptids folgt die Initialisierung der T Zell Aktivierung, welche mit großen strukturellen Veränderungen und Calzium Ausschüttung einhergeht. Den wichtigsten Proteinkomplex stellt der T Zell Rezeptor (TCR) dar, da er für die Unterscheidung zwischen ungefährlichen und krankhaften Peptiden verantwortlich ist. Der T Zell Rezeptor bindet an das Peptid, das im peptide major histocompatibility complex (pMHC) an der Oberfläche der APC präsentiert wird. Diese Interaktion zwischen TCR und pMHC ist aktueller Gegenstand kontroversieller Diskussionen in der Immunologie. Das Ziel dieser Diplomarbeit war ein tieferes Verständnis der Interaktion zwischen TCR und pMHC auf Einzelmolekülniveau zu erlangen. Dabei wurden Erkenntnisse über die Interaktion von einzelnen pMHC mit TCR mittels single molecule Förster resonance energy transfer (smFRET) Ereignissen, Immobilisierungen und Diffusionskonstanten von verschiedenen Peptiden im pMHC Komplex unter aktivierenden und nicht-aktivierenden Bedingungen gewonnen. Die Korrelation zwischen smFRET und Immobilisierungen konnte zeigen, dass die direkte Interaktion von pMHC und TCR kürzer ist, als die dazugehörige Immobilisierung. Darüberhinaus wurden Diffusionskonstanten von verschiedenen Peptiden im pMHC Komplex und einem fluoreszenzmarkierten Cholesterol als Negativkontrolle unter und neben der T Zelle gemessen und verglichen. Hierbei wurde demonstriert, dass die Moleküle unterhalb der T Zelle nicht nur langsamer diffundieren, sondern auch immobilisiert werden - im Gegensatz zu Molekülen neben der T Zelle. Mit dieser Arbeit konnten weitere Einblicke in die Interaktion von T Zell Rezeptor mit pMHC gewonnen werden.CD4+ T lymphocytes are capable of detecting low amounts of pathogenic peptides presented by antigen presenting cells (APC). The initial T cell activation upon successful recognition goes along with large structural changes and internal Calcium signalling. The crucial protein complex in the discrimination between different self and pathogenic peptides is the T cell receptor (TCR). It binds to its counterpart on the antigen presenting cell (APC), the peptide carrying major histocompatibility complex (pMHC). Binding dynamics between TCR and pMHC are highly debated in the immunological community. The main goal of this master thesis was to probe the interaction of the TCR with the pMHC on a single molecule level, with the latter being embedded in a synthetic lipid bilayer membrane. To this end, dwell times of single molecule Förster resonance energy transfer (smFRET) events, times of immobilisations and diffusion constants of various pMHCs under activating and non-activating conditions were determined. By comparing smFRET with immobilisation data, it was possible to show, that the direct TCR-pMHC interaction lasts shorter than the corresponding immobilisation time. Furthermore, diffusion constants of various pMHC variants and a fluorescently labelled cholesterol-analogue under and adjacent to the T cell synapse were compared with each other. Thereby, it was feasible to demonstrate, that molecules in the interface of the T cell and the synthetic antigen presenting cell (APC) not only immobilized but in addition exhibited a reduced diffusion constant. Diffusion constants of pMHCs under activating and non-activating conditions - realized by a high versus a very low density of pMHC molecules - were compared, which also revealed differences in the diffusion performance. Taken together, presented studies allowed for a deeper insight in the interaction of the TCR with the pMHC.7

Molecules / Line Scan Raman Microspectroscopy for Label-Free Diagnosis of Human Pituitary Biopsies

Pituitary adenomas are neoplasia of the anterior pituitary gland and can be subdivided into hormone-producing tumors (lactotroph, corticotroph, gonadotroph, somatotroph, thyreotroph or plurihormonal) and hormone-inactive tumors (silent or null cell adenomas) based on their hormonal status. We therefore developed a line scan Raman microspectroscopy (LSRM) system to detect, discriminate and hyperspectrally visualize pituitary gland from pituitary adenomas based on molecular differences. By applying principal component analysis followed by a k-nearest neighbor algorithm, specific hormone states were identified and a clear discrimination between pituitary gland and various adenoma subtypes was achieved. The classifier yielded an accuracy of 95% for gland tissue and 8499% for adenoma subtypes. With an overall accuracy of 92%, our LSRM system has proven its potential to differentiate pituitary gland from pituitary adenomas. LSRM images based on the presence of specific Raman bands were created, and such images provided additional insight into the spatial distribution of particular molecular compounds. Pathological states could be molecularly differentiated and characterized with texture analysis evaluating Grey Level Cooccurrence Matrices for each LSRM image, as well as correlation coefficients between LSRM images.(VLID)491681

Novel Route to Produce Hydrocarbons from Woody Biomass Using Molten Salts

The thermochemical decomposition of woody biomass has been widely identified as a promising route to produce renewable biofuels. More recently, the use of molten salts in combination with pyrolysis has gathered increased interest. The molten salts may act as a solvent, a heat transfer medium, and possibly also a catalyst. In this study, we report experimental studies on a process to convert woody biomass to a liquid hydrocarbon product with a very low oxygen content using molten salt pyrolysis (350-450 °C and atmospheric pressure) followed by subsequent catalytic conversions of the liquids obtained by pyrolysis. Pyrolysis of woody biomass in molten salt (ZnCl2/NaCl/KCl with a molar composition of 60:20:20) resulted in a liquid yield of 46 wt % at a temperature of 450 °C and a molten salt/biomass ratio of 10:1 (mass). The liquids are highly enriched in furfural (13 wt %) and acetic acid (14 wt %). To reduce complexity and experimental issues related to the production of sufficient amounts of pyrolysis oils for further catalytic upgrading, model studies were performed to convert both compounds to hydrocarbons using a three-step catalytic approach, viz., (i) ketonization of acetic acid to acetone, (ii) cross-aldol condensation between acetone and furfural to C8-C13products, followed by (iii) a two-stage catalytic hydrotreatment of the latter to liquid hydrocarbons. Ketonization of acetic acid to acetone was studied in a continuous setup over a ceria-zirconia-based catalyst at 250 °C. The catalyst showed no signs of deactivation over a period of 230 h while also achieving high selectivity toward acetone. Furfural was shown to have a negative effect on the catalyst performance, and as such, a separation step is required after pyrolysis to obtain an acetic-acid-enriched fraction. The cross-aldol condensation reaction between acetone and furfural was studied in a batch using a commercial Mg/Al hydrotalcite as the catalyst. Furfural was quantitatively converted with over 90% molar selectivity toward condensed products with a carbon number between C8and C13. The two-stage hydrotreatment of the condensed product consisted of a stabilization step using a Ni-based Picula catalyst and a further deep hydrotreatment over a NiMo catalyst, in both batch setups. The final product with a residual 1.5 wt % O is rich in (cyclo)alkanes and aromatic hydrocarbons. The overall carbon yield for the four-step approach, from pinewood biomass to middle distillates, is 21%, assuming that separation of furfural and acetic acid after the pyrolysis step can be performed without losses

Morpho-Molecular Metabolic Analysis and Classification of Human Pituitary Gland and Adenoma Biopsies Based on Multimodal Optical Imaging

Pituitary adenomas count among the most common intracranial tumors. During pituitary oncogenesis structural, textural, metabolic and molecular changes occur which can be revealed with our integrated ultrahigh-resolution multimodal imaging approach including optical coherence tomography (OCT), multiphoton microscopy (MPM) and line scan Raman microspectroscopy (LSRM) on an unprecedented cellular level in a label-free manner. We investigated 5 pituitary gland and 25 adenoma biopsies, including lactotroph, null cell, gonadotroph, somatotroph and mammosomatotroph as well as corticotroph. First-level binary classification for discrimination of pituitary gland and adenomas was performed by feature extraction via radiomic analysis on OCT and MPM images and achieved an accuracy of 88%. Second-level multi-class classification was performed based on molecular analysis of the specimen via LSRM to discriminate pituitary adenomas subtypes with accuracies of up to 99%. Chemical compounds such as lipids, proteins, collagen, DNA and carotenoids and their relation could be identified as relevant biomarkers, and their spatial distribution visualized to provide deeper insight into the chemical properties of pituitary adenomas. Thereby, the aim of the current work was to assess a unique label-free and non-invasive multimodal optical imaging platform for pituitary tissue imaging and to perform a multiparametric morpho-molecular metabolic analysis and classification

Combination of High-Resolution Optical Coherence Tomography and Raman Spectroscopy for Improved Staging and Grading in Bladder Cancer

We present a combination of optical coherence tomography (OCT) and Raman spectroscopy (RS) for improved diagnosis and discrimination of different stages and grades of bladder cancer ex vivo by linking the complementary information provided by these two techniques. Bladder samples were obtained from biopsies dissected via transurethral resection of the bladder tumor (TURBT). As OCT provides structural information rapidly, it was used as a red-flag technology to scan the bladder wall for suspicious lesions with the ability to discriminate malignant tissue from healthy urothelium. Upon identification of degenerated tissue via OCT, RS was implemented to determine the molecular characteristics via point measurements at suspicious sites. Combining the complementary information of both modalities allows not only for staging, but also for differentiation of low-grade and high-grade cancer based on a multivariate statistical analysis. OCT was able to clearly differentiate between healthy and malignant tissue by tomogram inspection and achieved an accuracy of 71% in the staging of the tumor, from pTa to pT2, through texture analysis followed by k-nearest neighbor classification. RS yielded an accuracy of 93% in discriminating low-grade from high-grade lesions via principal component analysis followed by k-nearest neighbor classification. In this study, we show the potential of a multi-modal approach with OCT for fast pre-screening and staging of cancerous lesions followed by RS for enhanced discrimination of low-grade and high-grade bladder cancer in a non-destructive, label-free and non-invasive way