fluid mechanics

Penn State University is developing a pediatric total artificial heart (pTAH) as a bridge-to-transplant device that supports infants and small children with single ventricle anomalies or biventricular heart failure to address high waitlist mortality rates for patients with severe congenital heart disease. Two issues with mechanical circulatory support devices are thrombus formation and thromboembolic events. This in vitro study characterizes flow within Penn State's pTAH under physiological operating conditions...

BACKGROUND: Short-term acid-base effects of 0.9% saline solution infusion are not well described. Aim of this study was to assess the effects of a fluid challenge with 0.9% saline in critically ill patients according to the Stewart's approach, which allows a precise determination of acid base equilibrium. METHODS: In 40 mechanically ventilated critically ill patients, acid-base variables according to Stewart's approach were measured before and after 30 minutes from the infusion of 0...

Secondary brain injury (SBI) occurs with a lag of several days post-bleeding in patients with aneurysmal subarachnoid hemorrhage (aSAH) and is a strong contributor to mortality and long-term morbidity. aSAH-SBI coincides with cell-free hemoglobin (Hb) release into the cerebrospinal fluid. This temporal association and convincing pathophysiological concepts suggest that CSF-Hb could be a targetable trigger of SBI. However, sparse experimental evidence for Hb's neurotoxicity in vivo defines a significant research gap for clinical translation...

PURPOSE: The high efficacy of flow diverters (FD) in the case of wide-neck aneurysms is well demonstrated, yet new challenges have arisen because of reported posttreatment failures and the growing number of new generation of devices. Our aim is to present a measurement-supported in silico workflow that automates the virtual deployment and subsequent hemodynamic analysis of FDs. In this work, the objective is to analyze the effects of FD deployment variability of two manufacturers on posttreatment flow reduction...

This work seeks to generate new knowledge about the mechanisms underlying the protective effects of cranberry against urinary tract infections (UTI). Using Caco-2 cells grown in Transwell inserts as an intestinal barrier model, we found that a cranberry-derived digestive fluid (containing 135 ± 5 mg of phenolic compounds/L) increased transepithelial electrical resistance with respect to control (ΔTEER = 54.5 Ω cm2 ) and decreased FITC-dextran paracellular transport by about 30%, which was related to the upregulation of the gene expression of tight junction (TJ) proteins (i...

A 55-year-old male with acute pericarditis presented with low-pressure cardiac tamponade (LPCT) unresponsive to volume infusion. Subsequent pericardiocentesis resulted in hemodynamic improvement and unmasking of pericardial constriction. This case provides illustrative hemodynamic tracings of LPCT. Additionally, the presence of concurrent pericardial constriction that may indicate a plausible underlying mechanism for the blunted responsiveness to fluid expansion in LPCT. The underlying physiologic processes and the associated hemodynamic tracings are discussed...

There is a need to develop new and versatile fabrication methods to achieve efficient mixing of fluids in microfluidic channels using microstructures. This work presents a new technique that combines stereolithography (SLA) and pulsed laser ablation (PLA) to manufacture a straight micromixer for uniform mixing of two samples. Computational fluid dynamics (CFD) simulation is performed to deeply understand the physical mechanisms of the process. The results suggest that this new optical technique holds the potential to become a versatile hybrid technique for manufacturing remarkable mixing microfluidic devices...

INTRODUCTION: The Lifei Decoction (LD) is a commonly utilized Chinese medicine for the treatment of sepsis and bronchial inflammation. However, its therapeutic potential in chronic obstructive pulmonary disease (COPD) remains unknown. Therefore, the objective of this study was to investigate the therapeutic efficacy and underlying mechanism of LD in a mouse model of COPD induced by cigarette smoke (CS) combined with lipopolysaccharide (LPS). METHODS: Hematoxylin-eosin (H&E) staining was employed to observe the pathological alterations in lung tissue, while ELISA was utilized for the detection of levels of inflammatory factors in both lung tissue and bronchoalveolar lavage fluid (BALF)...

PURPOSE: Uveitis is a heterogenous group of inflammatory eye disease for which current cytokine-targeted immune therapies are effective for only a subset of patients. We hypothesized that despite pathophysiologic nuances that differentiate individual disease states, all forms of eye inflammation might share common mechanisms for immune cell recruitment. Identifying these mechanisms is critical for developing novel, broadly acting therapeutic strategies. DESIGN: Experimental study...

Transporter research primarily relies on the canonical substrates of well-established transporters. This approach has limitations when studying transporters for the low-abundant micromolecules, such as micronutrients, and may not reveal physiological functions of the transporters. While d-serine, a trace enantiomer of serine in the circulation, was discovered as an emerging biomarker of kidney function, its transport mechanisms in the periphery remain unknown. Here, using a multi-hierarchical approach from body fluids to molecules, combining multi-omics, cell-free synthetic biochemistry, and ex vivo transport analyses, we have identified two types of renal d-serine transport systems...

BACKGROUND: Calycosin, a flavonoid compound extracted from Astragalus membranaceus, has shown anti-asthma benefits in house dust mite-induced asthma. Recent studies have suggested that innate-type cells, including group 2 innate lymphoid cells (ILC2s) and macrophages, serve as incentives for type 2 immunity and targets for drug development in asthma. This work focuses on the effects of calycosin on the dysregulated ILC2s and macrophages in allergic asthma. METHODS: In vivo, the asthmatic mouse model was established with ovalbumin (OVA) sensitization and challenge, and calycosin was intraperitoneally administered at doses of 20 and 40 mg/kg...

OBJECTIVE: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with significant mortality rates. The role of Fcgr2b in the pathogenesis of ALI/ARDS is not fully elucidated. This study aimed to investigate the functions of Fcgr2b in ALI/ARDS and explore its underlying mechanisms. METHODS: Methods: In this study, rat models of ARDS and pulmonary microvascular endothelial cell (PMVEC) injury models were established through the administration of lipopolysaccharide (LPS)...

This work, in a pioneering approach, attempts to build a biometric system that works purely based on the fluid mechanics governing exhaled breath. We test the hypothesis that the structure of turbulence in exhaled human breath can be exploited to build biometric algorithms. This work relies on the idea that the extrathoracic airway is unique for every individual, making the exhaled breath a biomarker. Methods including classical multi-dimensional hypothesis testing approach and machine learning models are employed in building user authentication algorithms, namely user confirmation and user identification...

Neuroinflammation, blood-brain barrier (BBB) dysfunction, neuron and glia injury/death and myelin damage are common central nervous system (CNS) pathologies observed in various neurological diseases and injuries. Serine protease inhibitor (Serpin) clade A member 3n (Serpina3n), and its human orthologue SERPINA3, is an acute-phase inflammatory glycoprotein secreted primarily by the liver into the bloodstream in response to systemic inflammation. Clinically, SERPINA3 is dysregulated in brain cells, cerebrospinal fluid and plasma in various neurological conditions...

INTRODUCTION: Malignant ascites indicates ovarian cancer progression and predicts poor clinical outcome. Various ascites components induce an immunosuppressive crosstalk between tumor and immune cells, which is poorly understood. In our previous study, imbalanced electrolytes, particularly high sodium content in malignant ascites, have been identified as a main immunosuppressive mechanism that impaired NK and T-cell activity. METHODS: In the present study, we explored the role of high concentrations of ascites proteins and immunoglobulins on antitumoral NK effector functions...

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, commonly known as COVID-19, has been associated with various neurological complications. However, the mechanisms underlying these neurological manifestations remain incompletely understood. We present a case of a 63-year-old male who was admitted to the intensive care unit with severe COVID-19 pneumonia. Following recovery from respiratory symptoms, he was found to have weakness in the limbs. Months later, he also developed altered mental status, hallucinations, and behavioral changes...

The constituent ions of calcium phosphate in body fluids are in the supersaturated state and tend to form minerals physiologically or pathologically. Inorganic pyrophosphate (PPi) has been considered as one of the most important inhibitors against the formation of calcium phosphate minerals. However, serum PPi concentrations in humans are maintained at a level of several μmol/L, and its effectiveness and mechanism for mineralization inhibition remain ambiguous. Therefore, this work studied the mineralization process in an aqueous solution, explored the effective inhibitory concentration of PPi by titration, and characterized the species during the reactions...

Oscillations, a highly conserved brain function across mammalian species, are pivotal in brain physiology and pathology. Traumatic brain injury (TBI) often leads to subacute and chronic brain oscillatory alterations associated with complications like post-traumatic epilepsy (PTE) in patients and animal models. Our recent work longitudinally recorded local field potential from the contralateral hippocampus of 12 strains of recombinant inbred Collaborative Cross (CC) mice alongside classical laboratory inbred C57BL/6J mice after lateral fluid percussion injury...

INTRODUCTION: We investigate pathological correlates of plasma phosphorylated tau 181 (p-tau181 ), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) across a clinically diverse spectrum of neurodegenerative disease, including normal cognition (NormCog) and impaired cognition (ImpCog). METHODS: Participants were NormCog (n = 132) and ImpCog (n = 461), with confirmed β-amyloid (Aβ+/-) status (cerebrospinal fluid, positron emission tomography, autopsy) and single molecule array plasma measurements...

BACKGROUND AND OBJECTIVE: Malignant ascites (MA) is common in patients with advanced cancer, and about 60% of patients with MA experience distressing symptoms. In addition, MA has been identified as a poor prognostic factor, therefore, making the management of MA an important issue. We aimed to review literature describing MA provide a narrative synthesis of relevant studies. METHODS: A literature search of articles published between 1971 and May 2023 was performed in PubMed, and Cochrane library using the words "ascites/malignant ascites" and the theme of each section...