Search

The present paper is concerned with the enhancement of robustness of an electrohydraulic servo motor operated using a sliding mode control scheme. A sliding mode control scheme combined with an asymptotic observer is useful as a means to depress chattering, but the mismatch of the parameters between the actual system and its observer model makes the transient estimation errors of states great, and the robustness is lowered. In this investigation, paying attention to the fact that the most dominant parameter of an electrohydraulic servo system is the inertia, an on-line inertia estimation method utilizing pressure sensors is developed. A new, gain scheduling type of observer, which is constructed using two linear observers and an estimate of the inertia, is presented. It is demonstrated that the robustness of an electrohydraulic servo motor is improved by using the proposed observer and that the robustnes s is more enhanced by varying the controller parameters according to the value of the estimate of the inertia. [ABSTRACT FROM AUTHOR]

Background: Transbronchial lung cryobiopsy is primarily used for diagnosing interstitial lung diseases and tumors, providing larger tissue samples with reduced tissue crushing than traditional biopsies. However, freezing during cryobiopsy may damage cells, potentially affecting diagnostic methods that require live cells, such as flow cytometry (FCM). We aimed to determine the extent of freezing-related cell damage in cryobiopsies using cells cultured in vitro., Methods: To investigate the relationship between freezing duration and sample volume, Jurkat cells underwent freezing for durations ranging from 2 to 6 s, with 1-s intervals, using either 1-mm- or 1.7-mm cryoprobes. FCM was conducted to assess both cell viability (2, 4, and 6 s) and cell-surface molecule expression (3 and 6 s) over varying freezing times. Additionally, we describe a clinical case involving a 70-year-old man suspected of malignant lymphoma, in which tissue samples were obtained via both forceps biopsy and cryobiopsy methods to compare the pathological and cytological features between the methods., Results: Harvested cell count increased with freezing duration, with a notable increase in viable cell percentage. Moreover, cells distant from the cryoprobe exhibited higher survival rates under milder freezing conditions. FCM revealed significantly higher marker expression levels in viable cryobiopsy samples than in non-viable samples. The clinical case demonstrated that cryobiopsy yields a significant proportion of live cells (>90%), with cytological findings consistent with those of non-frozen samples., Conclusions: Cryobiopsy may be beneficial for histopathological diagnosis, providing sufficient viable cells for FCM, and can be used for diagnosing malignant lymphomas and other pulmonary conditions., Competing Interests: Declaration of competing interest YM has received honoraria from AstraZeneca and GlaxoSmithKline. The other authors have no conflicts of interest., (Copyright © 2024 [The Author]. Published by Elsevier B.V. All rights reserved.)

A patient with late phase of COVID-19 pneumonia presented peripheral cystic features on chest computed tomography, which were spontaneously resolved with no antibiotic therapy or surgery. Physicians should pay attention to follow up the late phase of COVID-19 pneumonia for better understanding its progression and clinical course., Competing Interests: The author declares that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported., (© 2022 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd.)

The histidine (His)-to-Aspartate (Asp) phosphorelay is a paradigm of intracellular signaling systems through protein phosphorylation in both prokaryotes and eukaryotes. The fission yeast Schizosaccharomyces pombe has three histidine kinases (Phk1/Mak2, Phk2/Mak3, and Phk3/Mak1), together with two response regulators (Mcs4 and Prr1). The results of recent extensive studies suggested that these His-to-Asp phosphorelay components are involved in oxidative stress responses through the transcriptional regulation of several scavenger genes for toxic free radicals. It was also suggested that they were somehow implicated in control of both the mitotic and meiotic cell proliferations. Among these S. pombe His-to-Asp phosphorelay components, however, the function of Prr1 is less clear. We here characterized a mutant, named prr1-D418N, specifying an altered Prr1 protein that presumably acts as a gain-of-function (or constitutive-active) mutant, with special reference to sexual development. The mutant cells showed a striking phenotype in that they underwent mating even in a nitrogen-sufficient medium, under which conditions the wild-type cells hardly did so. Furthermore, the mutant cells underwent mating very rapidly in a nitrogen-deficient medium. Under anaerobic (or micro-aerobic) growth conditions, the wild-type cells were not capable of undergoing sexual development even in a nitrogen-deficient medium. The prr1-D418N cells underwent mating efficiently under such anaerobic growth conditions. Taken these together, it was suggested that the function of Prr1 is closely linked to the well-characterized signaling pathways for induction of the sexual development, in a way that this response regulator regulates a critical step of the initiation of meiosis through activating the transcription of ste11+, mam2+, and mei2+, in S. pombe.