24 research outputs found

    Erratum: Micromachined Fabry-Pérot Interferometer with Embedded Nanochannels for Nanoscale Fluid Dynamics

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    In ref 1, the erroneous numbers are not discussed in detail, yet we briefly noted, p 349, the observation of an enhanced ﬿lling speed with respect to the Lucas Washburn equation...

    Micromachined Fabry-Perot interferometer with embedded nanochannels for nanoscale fluid dynamics

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    We describe a microfabricated Fabry-Pérot interferometer with nanochannels of various heights between 6 and 20 nm embedded in its cavity. By multiple beam interferometry, the device enables the study of liquid behavior in the nanochannels without using fluorescent substances. During filling studies of ethanol and water, an intriguing filling mode for partially wetting water was observed, tentatively attributed to the entrapment of a large amount of gas inside the channels

    Tunneling with dissipation and decoherence for a large spin

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    We present rigorous solution of problems of tunneling with dissipation and decoherence for a spin of an atom or a molecule in an isotropic solid matrix. Our approach is based upon switching to a rotating coordinate system coupled to the local crystal field. We show that the spin of a molecule can be used in a qubit only if the molecule is strongly coupled with its atomic environment. This condition is a consequence of the conservation of the total angular momentum (spin + matrix), that has been largely ignored in previous studies of spin tunneling.Comment: 4 page

    SARS-CoV-2 infects the human kidney and drives fibrosis in kidney organoids

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    Kidney failure is frequently observed during and after COVID-19, but it remains elusive whether this is a direct effect of the virus. Here, we report that SARS-CoV-2 directly infects kidney cells and is associated with increased tubule-interstitial kidney fibrosis in patient autopsy samples. To study direct effects of the virus on the kidney independent of systemic effects of COVID-19, we infected human-induced pluripotent stem-cell-derived kidney organoids with SARS-CoV-2. Single-cell RNA sequencing indicated injury and dedifferentiation of infected cells with activation of profibrotic signaling pathways. Importantly, SARS-CoV-2 infection also led to increased collagen 1 protein expression in organoids. A SARS-CoV-2 protease inhibitor was able to ameliorate the infection of kidney cells by SARS-CoV-2. Our results suggest that SARS-CoV-2 can directly infect kidney cells and induce cell injury with subsequent fibrosis. These data could explain both acute kidney injury in COVID-19 patients and the development of chronic kidney disease in long COVID

    The slipping rib syndrome: A case report

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    We present a case report and review of literature about slipping rib syndrome, a syndrome rarely recognized and often un or misdiagnosed. In literature there is no clear consensus about the diagnosis and treatment. We present a case of a 47 year old man who was diagnosed with slipping rib syndrome after a cycling incident 8 years ago. Also, we developed a flow chart according the diagnostic and therapeutic steps in the treatment of slipping rib syndrome. Central massage: Knowledge and treatment of the slipping rib syndrome can prevent chronic complaints and unnecessary comprehensive treatment

    Phenylglyoxal-based visualization of citrullinated proteins on Western blots

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    Contains fulltext : 152578.pdf (publisher's version ) (Open Access)Citrullination is the conversion of peptidylarginine to peptidylcitrulline, which is catalyzed by peptidylarginine deiminases. This conversion is involved in different physiological processes and is associated with several diseases, including cancer and rheumatoid arthritis. A common method to detect citrullinated proteins relies on anti-modified citrulline antibodies directed to a specific chemical modification of the citrulline side chain. Here, we describe a versatile, antibody-independent method for the detection of citrullinated proteins on a membrane, based on the selective reaction of phenylglyoxal with the ureido group of citrulline under highly acidic conditions. The method makes use of 4-azidophenylglyoxal, which, after reaction with citrullinated proteins, can be visualized with alkyne-conjugated probes. The sensitivity of this procedure, using an alkyne-biotin probe, appeared to be comparable to the antibody-based detection method and independent of the sequence surrounding the citrulline

    Micro evaporation electrolyte concentrator

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    The sensitivity of miniaturized chemical analysis systems depends most of the time on the obtainable detection limit. Concentrating the analyte prior to the detection system can enhance the detection limit. In this writing an analyte concentrator is presented that makes use of evaporation to increase the ion concentration of an electrolyte. The evaporation rate can be enhanced using forced convection. In order to control the evaporation rate a nitrogen flow is fed over a liquid channel covered with a hydrophobic vapor permeable membrane.Water vapor can pass through this membrane in contrast to water itself because of the hydrophobic nature of the membrane surface. An electrolyte conductivity detector is used to measure directly the concentration effect as a function of the nitrogen flow velocity. The influence of the convective nitrogen flow and the residence time of the analyte inside the concentrator are investigated in this paper. It is shown that the evaporation rate is enlarged with an increase in convective flow. The concentration effect is also enhanced when the residence time of the analyte inside the concentrator is increased. The higher concentration enhancement due to the longer residence time, however, results in an increase in water vapor present in the nitrogen flow. This results in a lower normalized evaporation rate when the available evaporation time is enlarged
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