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Polymorphonuclear neutrophils (PMN) contain multiple distinct secretory compartments that are sequentially mobilized during cell activation. Complement receptor type 1 (CR1) is a marker for a readily mobilizable secretory vesicle compartment, which can undergo exocytic fusion with the plasma membrane independently of secretion of traditional granule contents. The basis for the formation of these distinct compartments is incompletely understood. Primary and secondary granules are generated directly from the Golgi complex during different stages of development of the cell, obviating the need for sorting signals for proper packaging of their constituents. To determine whether the secretory vesicles are formed in a similar manner, we studied a stable rat basophilic leukemia cell line (RBL-CR1) transfected with a plasmid containing the cDNA of human CR1 driven by a viral promoter. The CR1 was present primarily intracellularly in small vesicles resembling the CR1 storage pools in resting PMN. Activation of RBL-CR1 resulted in translocation of intracellular CR1 to the plasma membrane, with mobilization requirements different from those of the classical RBL granules. Thus, in RBL-CR1, continuously synthesized CR1 is stored and upregulated in much the same way as in PMN. This suggests that differential timing of gene expression is not essential for proper storage of CR1 and that other sorting mechanisms are involved, which can be studied in RBL-transfectants. 相似文献
44.
The wear protecting properties of motor oils containing oil soluble polymethacrylates were investigated by means of measuring the wear of the crankshaft bearings of internal combustion machines. From this results follows that lube oils containing enough polymer (up to 12%) give lower wear than straight mineral oils of equal viscosity. That means that polymethacrylate has a wear protecting effect which is more efficient than the thickening effect of the polymer. The efficiency of this effect depends on polymer content and on the molecular weight of the polymer. Furthermore, the results clearly show that the wear protecting effect of the polymethacrylate is strongly influenced by the solving properties of the base oil. 相似文献
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In the last years the fabrication of micro components made from ceramic materials became more and more evident with respect to the pronounced chemical stability and the outstanding thermomechanical properties in comparison to plastics and metals. The aim of this work is the lithographic generation of ceramic microstructures avoiding an intermediate molding step using SU8 as pronounced sensitive resist matrix filled with fine ceramic powder in the submicron range. Focus of the research was to investigate the composite formation, patterning by x-ray lithography, developing, debinding and sintering to form stable ceramic parts. The addition of fine ceramic particles to low viscous liquids like SU8-10 leads to an increase of the viscosity. For a successful debinding and sintering a volume content of at least 40% ceramic is required resulting in a change of the viscosity from around 2 Pas up to a value of 1000 Pas at 25 °C and low shear rates. A modified casting procedure was developed for the formation of uniform resist films with a thickness around 300 m. Optimized exposure and development parameters allow the fabrication of good quality resist structures that can be further transformed into ceramic structures by sintering. Details of the work and results will be presented and discussed in this paper.At this point the authors would like to thank all people who supported this work. 相似文献
47.
Rümmeli MH Borowiak-Palen E Gemming T Pichler T Knupfer M Kalbác M Dunsch L Jost O Silva SR Pompe W Büchner B 《Nano letters》2005,5(7):1209-1215
In this letter, we show for the first time the use of metal oxides as catalysts in the synthesis of single-walled carbon nanotubes (SWCNTs) using laser ablation. Further, SWCNTs have been synthesized at low temperature (down to room temperature), where their nucleation cannot be explained via fullerene nucleation. The data point to a nucleation mechanism previously not identified, that places a stable oxidized ring as the root cause for the growth of SWCNTs. 相似文献
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M Jost D Schelker E Steinmann A Hoffmann F Burkart 《Canadian Metallurgical Quarterly》1982,112(45):1588-1591
The unipolar pulse generator systems were tested in 220 patients (96 VVIM, 97 VVIO, 27 physiological systems) to determine the incidence of sensing interference with muscle potentials. 23% exhibited oversensing, with a sex distribution of 32% for males and 15% for females. The interference was observed more often in VVIM pacemakers at nominal setting (35%) than in VVIO pacemakers (11%). In DDD pacemakers both inhibition and triggering of ventricular stimulation was observed. Among the 23 patients with persisting syncope or dizziness after implantation of the pacemaker, the symptoms were observed during physical activity only in 5. In these 5 the underlying arrhythmia was tachycardia in 3 and inhibition of the pacemaker by muscle potentials in only one patient. 相似文献
49.
A Palmowski WH Jost J Prudlo J Osterhage B K?smann K Schimrigk KW Ruprecht 《Canadian Metallurgical Quarterly》1995,4(6):355-362
Conservative therapy in cases of severe dysthyroid ophthalmopathy (DO) has not given satisfactory results. Since 1986, 51 patients (99 orbits) with marked DO have been treated by surgical decompression of the orbits. The procedure begins within the upper eyelid. The excision of the excessive skin and subcutaneous tissue is performed and eyelid fat is removed. In order to obtain the correction of the upper eyelid retraction, the levator aponeurosis is divided by 2-3 transverse incisions in its central part and Muller's muscle is sectioned at the level of its tarsal insertion. Through an incision in the lower eyelid, the posterior part of the orbital floor, the lateral orbit wall, as well as the periorbital and intraorbital fat are removed. Through an incision made over the medial margin of the orbit, the ethmoidal part of the medial orbital wall and the retrobulbar fat are removed. The periorbital periosteum should be incised at several sites. After operation all patients showed a significant reduction of exophthalmos (5-11 mm, 7.16 mm on average), significant reduction of intraocular pressure, marked improvement in ocular muscle function, as well as considerable reduction or disappearance of subjective symptoms. There was an improvement in vision in 68% patients who had impaired vision before the operation. There were no cases of subsequent impairment of vision or ocular motility. Mild relapse was recorded in three cases only and only one patient required unilateral reoperation. Strabismus surgery had to be performed in five patients due to unsatisfactory correction of double vision. It can be concluded that this method of orbital decompression gives very good functional and aesthetical long-term results. 相似文献
50.
Joana Silva Celso Alves Alice Martins Patrícia Susano Marco Simes Miguel Guedes Stephanie Rehfeldt Susete Pinteus Helena Gaspar Amrico Rodrigues Mrcia Ines Goettert Amparo Alfonso Rui Pedrosa 《International journal of molecular sciences》2021,22(4)
Parkinsons Disease (PD) is the second most common neurodegenerative disease worldwide, and is characterized by a progressive degeneration of dopaminergic neurons. Without an effective treatment, it is crucial to find new therapeutic options to fight the neurodegenerative process, which may arise from marine resources. Accordingly, the goal of the present work was to evaluate the ability of the monoterpenoid lactone Loliolide, isolated from the green seaweed Codium tomentosum, to prevent neurological cell death mediated by the neurotoxin 6-hydroxydopamine (6-OHDA) on SH-SY5Y cells and their anti-inflammatory effects in RAW 264.7 macrophages. Loliolide was obtained from the diethyl ether extract, purified through column chromatography and identified by NMR spectroscopy. The neuroprotective effects were evaluated by the MTT method. Cells’ exposure to 6-OHDA in the presence of Loliolide led to an increase of cells’ viability in 40%, and this effect was mediated by mitochondrial protection, reduction of oxidative stress condition and apoptosis, and inhibition of the NF-kB pathway. Additionally, Loliolide also suppressed nitric oxide production and inhibited the production of TNF-α and IL-6 pro-inflammatory cytokines. The results suggest that Loliolide can inspire the development of new neuroprotective therapeutic agents and thus, more detailed studies should be considered to validate its pharmacological potential. 相似文献