Спосіб фіксації гістологічних блоків для виготовлення багатоплощинних зрізів мозочка

В статье описывается способ фиксации гистологических блоков для изготовления многоплоскостных срезов мозжечка, который можно также использовать для гистологического изучения других тканей. Дано подробное описание способа. Обоснованы преимущества его применения. Приведены графические изображения.In article the fixation mode of histological block for preparation of multiplane sections of cerebellum is described. The positive characteristics are well-grounded

Uncovering a neurological protein signature for severe COVID-19

Coronavirus disease of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has sparked a global pandemic with severe complications and high morbidity rate. Neurological symptoms in COVID-19 patients, and neurological sequelae post COVID-19 recovery have been extensively reported. Yet, neurological molecular signature and signaling pathways that are affected in the central nervous system (CNS) of COVID-19 severe patients remain still unknown and need to be identified. Plasma samples from 49 severe COVID-19 patients, 50 mild COVID-19 patients, and 40 healthy controls were subjected to Olink proteomics analysis of 184 CNS-enriched proteins. By using a multi-approach bioinformatics analysis, we identified a 34-neurological protein signature for COVID-19 severity and unveiled dysregulated neurological pathways in severe cases. Here, we identified a new neurological protein signature for severe COVID-19 that was validated in different independent cohorts using blood and postmortem brain samples and shown to correlate with neurological diseases and pharmacological drugs. This protein signature could potentially aid the development of prognostic and diagnostic tools for neurological complications in post-COVID-19 convalescent patients with long term neurological sequelae

Electrolyte Effects on the Stability of Ni−Mo Cathodes for the Hydrogen Evolution Reaction

\u3cp\u3eWater electrolysis to form hydrogen as a solar fuel requires highly effective catalysts. In this work, theoretical and experimental studies are performed on the activity and stability of Ni-Mo cathodes for this reaction. Density functional theory studies show various Ni-Mo facets to be active for the hydrogen evolution reaction, Ni segregation to be thermodynamically favorable, and Mo vacancy formation to be favorable even without an applied potential. Electrolyte effects on the long-term stability of Ni-Mo cathodes are determined. Ni-Mo is compared before and after up to 100 h of continuous operation. It is shown that Ni-Mo is unstable in alkaline media, owing to Mo leaching in the form of MoO 4 2- , ultimately leading to a decrease in absolute overpotential. It is found that the electrolyte, the alkali cations, and the pH all influence Mo leaching. Changing the cation in the electrolyte from Li to Na to K influences the surface segregation of Mo and pushes the reaction towards Mo dissolution. Decreasing the pH decreases the OH - concentration and in this manner inhibits Mo leaching. Of the electrolytes studied, in terms of stability, the best to use is LiOH at pH 13. Thus, a mechanism for Mo leaching is presented alongside ways to influence the stability and make the Ni-Mo material more viable for renewable energy storage in chemical bonds. \u3c/p\u3

A proteomics perspective at human circulating cells

This thesis describes both the development and the implementation of novel strategies of mass spectrometry based proteomics used to characterize and investigate human primary circulating immune cells. The studies were performed to gain better insights into protein constituents of these cells and to explore the option of using these cells for obtaining clinically relevant biomarkers. One of these projects involved finding potential biomarkers in circulating cells for coronary artery disease. Contrary to most protein based biomarker studies that target easily accessible patient material which are substantially hampered by dynamic range issues in protein abundance, we investigated circulating cells that should in theory hold disease state specific biochemical information with a more favorable dynamic range. This yielded a total of 2440 quantified proteins of which 62 proteins initially were revealed as significantly different. However upon closer inspection unavoidable and variable contamination of plasma, erythrocyte and leukocyte components became apparent, which could be traced back to the individual patient level. We presented that correlating the quantitative patient/control study with reported quantitative proteomes of potential contaminating cells allows for filtering of false positive biomarkers into the verification phase. Also, a novel method for identifying the platelet releasate was introduced based on a reversed releasate proteomics approach to unambiguously and quantitatively determine the platelets released from activated platelets against a resting platelet background. Using this strategy we were able to quantitatively discriminate the released proteins from uncontrolled lysis products. Monitoring the copy numbers of roughly 4500 platelet proteins it became apparent that following a full stimulation only 124 proteins were significantly released. The released proteins span a concentration range of at least 5 orders of magnitude. Secretion of several of these proteins were confirmed by ELISA analysis. The released proteins were highly enriched in exhibiting the known secretion tags, among them some known high abundant factors. Besides the well-known secreted proteins many novel low abundant proteins could be identified. The proteomes of neutrophil, eosinophil and basophil granulocytes are quantitatively characterized and compared. At present no comprehensive proteomes are available for these 3 granulocytes that are to some extent similar but have diverging roles as well. For each of these cell types a comprehensive proteome was identified and quantified, exposing many novel specific proteins for these three granulocyte types. A first step was taken to find the similarities between neutrophils, eosinophils and basophils, as well as to expose the proteins that may be involved in their diverging roles

Cathodic Electrodeposition of Ni−Mo on Semiconducting NiFe2 O4 for Photoelectrochemical Hydrogen Evolution in Alkaline Media

Photocathodes for hydrogen evolution from water were made by electrodeposition of Ni−Mo layers on NiFe2O4 substrates, deposited by spin coating on F:SnO2‐glass. Analysis confirmed the formation of two separate layers, without significant reduction of NiFe2O4. Bare NiFe2O4 was found to be unstable under alkaline conditions during (photo)electrochemistry. To improve the stability significantly, the deposition of a bifunctional Ni−Mo layer through a facile electrodeposition process was performed and the composite electrodes showed stable operation for at least 1 h. Moreover, photocurrents up to −2.1 mA cm−2 at −0.3 V vs. RHE were obtained for Ni−Mo/NiFe2O4 under ambient conditions, showing that the new combination functions as both a stabilizing and catalytic layer for the photoelectrochemical evolution of hydrogen. The photoelectrochemical response of these composite electrodes decreased with increasing NiFe2O4 layer thickness. Transient absorption spectroscopy showed that the lifetime of excited states is short and on the ns timescale. An increase in lifetime was observed for NiFe2O4 of large layer thickness, likely explained by decreasing the defect density in the primary layer(s), as a result of repetitive annealing at elevated temperature. The photoelectrochemical and transient absorption spectroscopy results indicated that a short charge carrier lifetime limits the performance of Ni−Mo/NiFe2O4 photocathodes

Template-Free Nanostructured Fluorine-Doped Tin Oxide Scaffolds for Photoelectrochemical Water Splitting

The synthesis and characterization of highly stable and conductive F:SnO2 (FTO) nanopyramid arrays are investigated, and their use as scaffolds for water splitting is demonstrated. Current densities during the oxygen evolution reaction with a NiFeOx catalyst at 2 V vs reversible hydrogen electrode were increased 5-fold when substituting commercial FTO (TEC 15) by nanostructured FTO scaffolds. In addition, thin α-Fe2O3 films (∼50 nm thick) were employed as a proof of concept to show the effect of our nanostructured scaffolds during photoelectrochemical water splitting. Double-layer capacitance measurements showed a drastic increase of the relative electrochemically active surface area for the nanostructured samples, in agreement with the observed photocurrent enhancement, whereas UV–vis spectroscopy indicates full absorption of visible light at wavelengths below 600 nm

Human CD62Ldim neutrophils identified as a separate subset by proteome profiling and in vivo pulse-chase labeling

During acute inflammation, 3 neutrophil subsets are found in the blood: neutrophils with a conventional segmented nucleus, neutrophils with a banded nucleus, and T-cell-suppressing CD62Ldim neutrophils with a high number of nuclear lobes. In this study, we compared the in vivo kinetics and proteomes of banded, mature, and hypersegmented neutrophils to determine whether these cell types represent truly different neutrophil subsets or reflect changes induced by lipopolysaccharide (LPS) activation. Using in vivo pulse-chase labeling of neutrophil DNA with 6,6-2H2-glucose, we found that 2H-labeled banded neutrophils appeared much earlier in blood than labeled CD62Ldim and segmented neutrophils, which shared similar label kinetics. Comparison of the proteomes by cluster analysis revealed that CD62Ldim neutrophils were clearly separate from conventional segmented neutrophils despite having similar kinetics in peripheral blood. Interestingly, the conventional segmented cells were more related at a proteome level to banded cells despite a 2-day difference in maturation time. The differences between CD62Ldim and mature neutrophils are unlikely to have been a direct result of LPS-induced activation, because of the extremely low transcriptional capacity of CD62Ldim neutrophils and the fact that neutrophils do not directly respond to the low dose of LPS used in the study (2 ng/kg body weight). Therefore, we propose CD62Ldim neutrophils are a truly separate neutrophil subset that is recruited to the bloodstream in response to acute inflammation. This trial was registered at www.clinicaltrials.gov as #NCT01766414

Template-Free Nanostructured Fluorine-Doped Tin Oxide Scaffolds for Photoelectrochemical Water Splitting

The synthesis and characterization of highly stable and conductive F:SnO2 (FTO) nanopyramid arrays are investigated, and their use as scaffolds for water splitting is demonstrated. Current densities during the oxygen evolution reaction with a NiFeOx catalyst at 2 V vs reversible hydrogen electrode were increased 5-fold when substituting commercial FTO (TEC 15) by nanostructured FTO scaffolds. In addition, thin α-Fe2O3 films (∼50 nm thick) were employed as a proof of concept to show the effect of our nanostructured scaffolds during photoelectrochemical water splitting. Double-layer capacitance measurements showed a drastic increase of the relative electrochemically active surface area for the nanostructured samples, in agreement with the observed photocurrent enhancement, whereas UV–vis spectroscopy indicates full absorption of visible light at wavelengths below 600 nm

Electrolyte Effects on the Stability of Ni-Mo Cathodes for the Hydrogen Evolution Reaction

Water electrolysis to form hydrogen as a solar fuel requires highly effective catalysts. In this work, theoretical and experimental studies are performed on the activity and stability of Ni−Mo cathodes for this reaction. Density functional theory studies show various Ni−Mo facets to be active for the hydrogen evolution reaction, Ni segregation to be thermodynamically favorable, and Mo vacancy formation to be favorable even without an applied potential. Electrolyte effects on the long‐term stability of Ni−Mo cathodes are determined. Ni−Mo is compared before and after up to 100 h of continuous operation. It is shown that Ni−Mo is unstable in alkaline media, owing to Mo leaching in the form of MoO42−, ultimately leading to a decrease in absolute overpotential. It is found that the electrolyte, the alkali cations, and the pH all influence Mo leaching. Changing the cation in the electrolyte from Li to Na to K influences the surface segregation of Mo and pushes the reaction towards Mo dissolution. Decreasing the pH decreases the OH− concentration and in this manner inhibits Mo leaching. Of the electrolytes studied, in terms of stability, the best to use is LiOH at pH 13. Thus, a mechanism for Mo leaching is presented alongside ways to influence the stability and make the Ni−Mo material more viable for renewable energy storage in chemical bonds

Human CD62L(dim) Neutrophils Identified as a Separate Subset by Proteome Profiling and In Vivo Pulse-Chase Labelling

During acute inflammation three neutrophil subsets are found in the blood: neutrophils with a conventional segmented nucleus, neutrophils with a banded nucleus and T-cell-suppressing CD62L(dim) neutrophils with a high number of nuclear lobes. In this study (clinicaltrials.gov NCT01766414) we compared the in vivo kinetics and proteomes of banded, mature and hypersegmented neutrophils to determine whether these cell types represent truly different neutrophil subsets or reflect changes induced by LPS activation. Using in vivo pulse-chase labelling of neutrophil DNA with 6,6-(2)H2-glucose, we found that (2)H-labelled banded neutrophils appeared much earlier in blood than labelled CD62L(dim) and segmented neutrophils, which shared similar label kinetics. Comparison of the proteomes by cluster analysis revealed that CD62L(dim) neutrophils were clearly separate from conventional segmented neutrophils despite having similar kinetics in peripheral blood. Interestingly, the conventional segmented cells are more related at a proteome level to banded cells despite a two days difference in maturation time. The differences between CD62L(dim) and mature neutrophils are unlikely to be a direct result of LPS-induced activation, due to the extremely low transcriptional capacity of CD62L(dim) neutrophils and the fact that neutrophils do not directly respond to the low dose of LPS used in the study (2ng/kg bodyweight). Therefore, we propose CD62L(dim) neutrophils to be a truly separate neutrophil subset that is recruited to the bloodstream in response to acute inflammation