1,383 research outputs found
Adhesion Mechanism of Water Droplets on Hierarchically Rough Superhydrophobic Rose Petal Surface
Extremely hydrophobic surfaces, on which water droplets sit in a spherical shape leaving air entrapped into the roughness of the solid, are often called superhydrophobic. Hierarchically rough superhydrophobic surfaces that possess submicron scale fine structures combined with micron scale structures are generally more hydrophobic, and water droplet adhesion to those surfaces is lower in comparison with surfaces possessing purely micrometric structures. In other words, usually a fine structure on a superhydrophobic surface reduces liquid-solid contact area and water droplet adhesion. Here we show that this does not apply to a high-adhesive superhydrophobic rose petal surface. Contrary to the present knowledge, the function of the fine structure on the petal surface is to build up the high adhesion to water droplets. Understanding of the specific adhesion mechanism on the rose petal gives insight into an interesting natural phenomenon of simultaneous superhydrophobicity and high water droplet adhesion, but, in addition, it contributes to more precise comprehension of wetting and adhesion mechanisms of superhydrophobic surfaces overall
Amyloid myopathy: a diagnostic challenge
Amyloid myopathy (AM) is a rare manifestation of primary systemic amyloidosis (AL). Like inflammatory myopathies, it presents with proximal muscle weakness and an increased creatine kinase level. We describe a case of AL with severe, rapidly progressive myopathy as the initial symptom. The clinical manifestation and muscle biopsy were suggestive of inclusion body myositis. AM was not suspected until amyloidosis was seen in the gastric mucosal biopsy. The muscle biopsy was then re-examined more specifically, and Congo red staining eventually showed vascular and interstitial amyloid accumulation, which led to a diagnosis of AM. The present case illustrates the fact that the clinical picture of AM can mimic that of inclusion body myositis
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Eesti Arst 2021; 100(8):45
Income inequality, redistributive preferences and the extent of redistribution : An empirical application of optimal tax approach
We examine empirically the relationship between the extent of redistribution and the components of the Mirrlees framework, with a focus on inherent inequality and government's redistributive preferences. We have constructed our income distribution variables from the Luxembourg Income Study (LIS) database, which provides information on both factor and disposable incomes. Our redistributive preference measure is constructed using the optimal tax formula for which we have collected data from various sources. In addition to traditional linear specifications, we use flexible methods to allow nonlinearities because pre-specified functional forms are not easy to justify in empirical investigations of the optimal tax framework. We study 14 advanced countries for approximately four decades and find support for the Mirrlees model: There is a positive relationship between factor-income inequality and the extent of redistribution. We also find a link between our redistributive-preference measure and the extent of redistribution
Anticancer activity of the protein kinase C modulator HMI-1a3 in 2D and 3D cell culture models of androgen-responsive and androgen-unresponsive prostate cancer
Prostate cancer is one of the most common cancers in men. Although it has a relatively high 5-year survival rate, development of resistance to standard androgen-deprivation therapy is a significant clinical problem. Therefore, novel therapeutic strategies are urgently needed. The protein kinase C (PKC) family is a putative prostate cancer drug target, but so far no PKC-targeting drugs are available for clinical use. By contrast to the standard approach of developing PKC inhibitors, we have developed isophthalate derivatives as PKC agonists. In this study, we have characterized the effects of the most potent isophthalate, 5-(hydroxymethyl) isophthalate 1a3 (HMI-1a3), on three prostate cancer cell lines (LNCaP, DU145, and PC3) using both 2D and 3D cell culture models. In 2D cell culture, HMI-1a3 reduced cell viability or proliferation in all cell lines as determined by the metabolic activity of the cells (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay) and thymidine incorporation. However, the mechanism of action in LNCaP cells was different to that in DU145 or PC3 cells. In LNCaP cells, HMI-1a3 induced a PKC-dependent activation of caspase 3/7, indicating an apoptotic response, whereas in DU145 and PC3 cells, it induced senescence, which was independent of PKC. This was observed as typical senescent morphology, increased beta-galactosidase activity, and upregulation of the senescence marker p21 and downregulation of E2F transcription factor 1. Using a multicellular spheroid model, we further showed that HMI-1a3 affects the growth of LNCaP and DU145 cells in a 3D culture, emphasizing its potential as a lead compound for cancer drug development.Peer reviewe
Spinal cord injury during selective cerebral perfusion and segmental artery occlusion: an experimental study
OBJECTIVESSince selective cerebral perfusion (SCP) has been used in aortic arch surgical procedures, the core temperature during lower body circulatory arrest (LBCA) has been steadily rising. Simultaneously, the use of a frozen elephant trunk (FET) graft has been increasing. The safe period of LBCA in relation to spinal cord ischaemic tolerance in combination with segmental artery occlusion by the FET procedure has not been defined.METHODSSixteen pigs were assigned to undergo 65 (n = 10) or 90 min (n = 6) of SCP at 28°C with LBCA in combination with occlusion of the 8 uppermost segmental arteries in the thoracic (Th) aorta (15–20 cm FET, Th8-level). The follow-up period consisted of a 6-h intensive period and a 5-day observation period. Near-infrared spectroscopy of the collateral network was used to determine spinal cord oxygenation. The neurological status of the patients was evaluated daily, and the brain and the spinal cord were harvested for a histopathological analysis.RESULTSFive out of 6 pigs after 90 min and 1 out of 10 pigs after 65 min of LBCA died within 48 h of multiorgan failure. Of the survivors in the 65-min group, 6 out of 9 had paraparesis/paraplegia; the remaining 3 reached normal function. The lone survivor after 90 min of LBCA was paraplegic. Nadir near-infrared spectroscopy of the collateral network values at Th8 and Th10 were 34 (±5) and 39 (±4), and they were reached within 35 min of SCP in both groups.CONCLUSIONSAn extended FET graft with LBCA and SCP durations >65 min at 28°C results in a poor outcome.</p
Making species checklists understandable to machines : a shift from relational databases to ontologies
Abstract
Background
The scientific names of plants and animals play a major role in Life Sciences as information is indexed, integrated, and searched using scientific names. The main problem with names is their ambiguous nature, because more than one name may point to the same taxon and multiple taxa may share the same name. In addition, scientific names change over time, which makes them open to various interpretations. Applying machine-understandable semantics to these names enables efficient processing of biological content in information systems. The first step is to use unique persistent identifiers instead of name strings when referring to taxa. The most commonly used identifiers are Life Science Identifiers (LSID), which are traditionally used in relational databases, and more recently HTTP URIs, which are applied on the Semantic Web by Linked Data applications.
Results
We introduce two models for expressing taxonomic information in the form of species checklists. First, we show how species checklists are presented in a relational database system using LSIDs. Then, in order to gain a more detailed representation of taxonomic information, we introduce meta-ontology TaxMeOn to model the same content as Semantic Web ontologies where taxa are identified using HTTP URIs. We also explore how changes in scientific names can be managed over time.
Conclusions
The use of HTTP URIs is preferable for presenting the taxonomic information of species checklists. An HTTP URI identifies a taxon and operates as a web address from which additional information about the taxon can be located, unlike LSID. This enables the integration of biological data from different sources on the web using Linked Data principles and prevents the formation of information silos. The Linked Data approach allows a user to assemble information and evaluate the complexity of taxonomical data based on conflicting views of taxonomic classifications. Using HTTP URIs and Semantic Web technologies also facilitate the representation of the semantics of biological data, and in this way, the creation of more “intelligent” biological applications and services
Medulloblastoma, macrocephaly, and a pathogenic germline PTEN variant : Cause or coincidence?
Background Medulloblastomas (MBs) are a heterogeneous group of childhood brain tumors with four consensus subgroups, namely MBSHH, MBWNT, MBGroup 3, and MBGroup 4, representing the second most common type of pediatric brain cancer after high-grade gliomas. They suffer from a high prevalence of genetic predisposition with up to 20% of MBSHH caused by germline mutations in only six genes. However, the spectrum of germline mutations in MBSHH remains incomplete. Methods Comprehensive Next-Generation Sequencing panels of both tumor and patient blood samples were performed as molecular genetic characterization. The panels cover genes that are known to predispose to cancer. Results Here, we report on a patient with a pathogenic germline PTEN variant resulting in an early stop codon p.(Glu7Argfs*4) (ClinVar ID: 480383). The patient developed macrocephaly and MBSHH, but reached remission with current treatment protocols. Conclusions We propose that pathogenic PTEN variants may predispose to medulloblastoma, and show that remission was reached with current treatment protocols. The PTEN gene should be included in the genetic testing provided to patients who develop medulloblastoma at an early age. We recommend brain magnetic resonance imaging upon an unexpected acceleration of growth of head circumference for pediatric patients harboring pathogenic germline PTEN variants.Peer reviewe
Pharmacological Preconditioning with Diazoxide in the Experimental Hypothermic Circulatory Arrest Model
Background: Hypothermic circulatory arrest includes a remarkable risk for neurological injury. Diazoxide, a mitochondrial adenosine triphosphate-dependent potassium ion (K+ATP) channel opener, is known to have cardioprotective effects. We assessed its efficacy in preventing ischemic injury in a clinically relevant animal model. Methods: Eighteen piglets were randomized into a diazoxide group (n = 9) and a control group (n = 9). Animals underwent 60 minutes of hypothermic circulatory arrest at 18 degrees C. Diazoxide (5 mg/kg + 10 mL NaOH + 40 mL NaCl) was infused during the cooling phase. Metabolic and hemodynamic data were collected throughout the experiment. After 24-hour follow-up, whole brain, heart, and kidney biopsy specimens were collected for analysis. Results: Cerebellar Cytochrome-C and caspase-3 activation was higher in the control group (P = .02 and P = .016, respectively). Antioxidant activity tended to be higher in the diazoxide group (P = .099). Throughout the experiment, the oxygen consumption ratio was higher in the control animals (P-g = .04), as were the lactate levels (P-g = .02). Cardiac function tended to be better in diazoxide-treated animals. Conclusion: Diazoxide might confer neuroprotective effect as implied by the immunohistochemical analysis of the brain. Additionally, the circulatory effects of diazoxide were beneficial, supporting its neuroprotective effect.Peer reviewe
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