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1.
Michael Lommel Vera Froese Moritz Sieber Marvin Jentzsch Tim Bierewirtz Ümit Hasirci Tim Rese Josef Seefeldt Sebastian Schimek Ulrich Kertzscher Christian Oliver Paschereit 《Indoor air》2021,31(6):1860-1873
The SARS-CoV-2 pandemic has created a great demand for a better understanding of the spread of viruses in indoor environments. A novel measurement system consisting of one portable aerosol-emitting mannequin (emitter) and a number of portable aerosol-absorbing mannequins (recipients) was developed that can measure the spread of aerosols and droplets that potentially contain infectious viruses. The emission of the virus from a human is simulated by using tracer particles solved in water. The recipients inhale the aerosols and droplets and quantify the level of solved tracer particles in their artificial lungs simultaneously over time. The mobile system can be arranged in a large variety of spreading scenarios in indoor environments and allows for quantification of the infection probability due to airborne virus spreading. This study shows the accuracy of the new measurement system and its ability to compare aerosol reduction measures such as regular ventilation or the use of a room air purifier. 相似文献
2.
Shamila Vibhushan Manuela Bratti Juan Eduardo Montero-Hernndez Alaa El Ghoneimi Marc Benhamou Nicolas Charles Eric Daugas Ulrich Blank 《International journal of molecular sciences》2021,22(1)
A sizable part (~2%) of the human genome encodes for proteases. They are involved in many physiological processes, such as development, reproduction and inflammation, but also play a role in pathology. Mast cells (MC) contain a variety of MC specific proteases, the expression of which may differ between various MC subtypes. Amongst these proteases, chymase represents up to 25% of the total proteins in the MC and is released from cytoplasmic granules upon activation. Once secreted, it cleaves the targets in the local tissue environment, but may also act in lymph nodes infiltrated by MC, or systemically, when reaching the circulation during an inflammatory response. MC have been recognized as important components in the development of kidney disease. Based on this observation, MC chymase has gained interest following the discovery that it contributes to the angiotensin-converting enzyme’s independent generation of angiotensin II, an important inflammatory mediator in the development of kidney disease. Hence, progress regarding its role has been made based on studies using inhibitors but also on mice deficient in MC protease 4 (mMCP-4), the functional murine counterpart of human chymase. In this review, we discuss the role and actions of chymase in kidney disease. While initially believed to contribute to pathogenesis, the accumulated data favor a more subtle view, indicating that chymase may also have beneficial actions. 相似文献
3.
Jasmin Kuhn Philipp M. Klein Nader Al Danaf Joel Z. Nordin Sren Reinhard Dominik M. Loy Miriam Hhn Samir El Andaloussi Don C. Lamb Ernst Wagner Yoshitsugu Aoki Taavi Lehto Ulrich Lchelt 《Advanced functional materials》2019,29(48)
Phosphorodiamidate morpholino oligomers (PMOs) are oligonucleotide analogs that can be used for therapeutic modulation of pre‐mRNA splicing. Similar to other classes of nucleic acid‐based therapeutics, PMOs require delivery systems for efficient transport to the intracellular target sites. Here, artificial peptides based on the oligo(ethylenamino) acid succinyl‐tetraethylenpentamine (Stp), hydrophobic modifications, and an azide group are presented, which are used for strain‐promoted azide‐alkyne cycloaddition conjugation with splice‐switching PMOs. By systematically varying the lead structure and formulation, it is determined that the type of contained fatty acid and supramolecular assembly have a critical impact on the delivery efficacy. A compound containing linolenic acid with three cis double bonds exhibits the highest splice‐switching activity and significantly increases functional protein expression in pLuc/705 reporter cells in vitro and after local administration in vivo. Structural and mechanistic studies reveal that the lipopeptide PMO conjugates form nanoparticles, which accelerate cellular uptake and that the content of unsaturated fatty acids enhances endosomal escape. In an in vitro Duchenne muscular dystrophy exon skipping model using H2K‐mdx52 dystrophic skeletal myotubes, the highly potent PMO conjugates mediate significant splice‐switching at very low nanomolar concentrations. The presented aminoethylene‐lipopeptides are thus a promising platform for the generation of PMO‐therapeutics with a favorable activity/toxicity profile. 相似文献
4.
Makrina A. Chairopoulou Fabian Kratzer Roland Gross Michael Herrmann Ulrich Teipel 《化学工程与技术》2020,43(5):904-912
Thermogravimetric analysis of a coccolith-containing biogenic broth showed a three-step degradation process. According to this system behavior, the biogenic broth was heated to specific temperatures and characterized in terms of its morphology, surface chemistry, and crystallinity. The elemental and organic composition of the treated samples was also evaluated and compared to the reference material. The presented results were acquired in an effort to exploit pretreatment scenarios for such a biogenic system that would improve and support a separation process. 相似文献
5.
OL Lopez RP Brenner JT Becker RF Ulrich F Boller ST DeKosky 《Canadian Metallurgical Quarterly》1997,48(6):1521-1525
We examined whether either psychotic features (e.g., delusions and hallucinations) or EEG abnormalities are associated with more rapid progression of Alzheimer's disease (AD). AD patients with psychosis have exhibited more EEG abnormalities than those without psychosis, and both abnormal EEG and psychosis have been noted to be predictors of functional and cognitive decline in AD. Ninety-five probable AD patients participating in a longitudinal study of dementia had an EEG and a semistructured psychiatric interview at baseline. Using EEG spectral analysis, we classified records as normal/abnormal based on the parasagittal mean frequency. Patients with abnormal EEGs were more functionally (e.g., Blessed Rating Scale for activities of daily living) and cognitively (e.g., Mini-Mental State) impaired than patients with normal EEG. AD patients with psychosis were only more functionally impaired than patients without psychosis. A two-factor analysis showed no interaction between abnormal EEG and psychosis. In addition, using a Cox proportional hazard model adjusted for age and education, the presence of an abnormal EEG or psychotic symptom at study entry was associated with higher risk of reaching severe cognitive and functional impairment during follow-up. Neither abnormal EEG nor the presence of psychosis predicted death. These results indicate that both abnormal EEG and psychosis are independent predictors of disease progression but not of physical survival. 相似文献
6.
A mixed mode digital/analog special purpose VLSI hardware implementation of an associative memory with neural architecture is presented. The memory concept is based on a matrix architecture with binary storage elements holding the connection weights. To enhance the processing speed analog circuit techniques are applied to implement the algorithm for the association. To keep the memory density as high as possible two design strategies are considered. First, the number of transistors per storage element is kept to a minimum. In this paper a circuit technique that uses a single 6-transistor cell for weight storage and analog signal processing is proposed. Second, the device precision has been chosen to a moderate level to save area as much as possible. Since device mismatch limits the performance of analog circuits, the impact of device precision on the circuit performance is explicitly discussed. It is shown that the device precision limits the number of rows activated in parallel. Since the input vector as well as the output vector are considered to be sparsely coded it is concluded, that even for large matrices the proposed circuit technique is appropriate and ultra large scale integration with a large number of connection weights is feasible. 相似文献
7.
Ulrich Buchenau 《Journal of Low Temperature Physics》2004,137(3-4):345-353
A recent hypothesis claims that the glass transition itself, though it is a very pronounced relaxation peak, is no separate relaxation process at all, but is just the breakdown of the shear modulus due to the weak elastic dipole interaction between all the quasi-independent relaxation centers of the glass. Two derivations are considered, one of them in terms of a breakdown of the shear modulus and the second in terms of a divergence of the shear compliance. Mechanical relaxation data from the literature for vitreous silica, glycerol, polymethylmethacrylate and polystyrene are found to be consistent with the first hypothesis. PACS numbers: 64.70.Pf 相似文献
8.
Interfacial hybridization kinetics of oligonucleotides immobilized onto fused silica surfaces 总被引:3,自引:0,他引:3
Jiang Zeng Amer Almadidy James Watterson Ulrich J. Krull 《Sensors and actuators. B, Chemical》2003,90(1-3):68-75
Fused silica optical fibers have been used in an intrinsic mode optical configuration as biosensors for fluorescence based detection of hybridization of nucleic acids. In this work, the kinetics of hybridization of single-stranded oligonucleotides that were covalently immobilized were studied. The probe DNA was dT20, and the target was Fluorescein-labeled non-complementary (dT20) or complementary (dA20) oligonucleotide. Chronofluorimetric monitoring of the adsorption and hybridization processes was used to investigate oligonucleotide films of different density, in different salt concentrations, at temperatures of 25 and 40 °C, with the concentration of the target DNA being 0.005–0.1 μM. Mathematical models based on first- and second-order Langmuir adsorption have been examined to describe both the adsorption and the hybridization processes. Experimental data were processed using the models, and the hybridization kinetics were calculated. Hybridization kinetics on these optical fiber DNA sensors was found to be up to three orders faster than results presented for a number of other experiments using different immobilization chemistries. 相似文献
9.
10.
Charbel Farhat Ulrich Hetmaniuk 《International journal for numerical methods in engineering》2002,54(9):1309-1332
We present a fictitious domain decomposition method for the fast solution of high‐frequency acoustic scattering problems characterized by a partially axisymmetric sound‐soft scatterer. We apply this method to the solution of various mockup submarine problems, and highlight its computational advantages and intrinsic parallelism. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献