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The properties and stability of nonlinear dust-ion-acoustic waves are examined in dusty plasma environment such as Titan ionosphere. The plasma is composed of warm collisional negatively charged dust grains, positive ions contain source terms, and Maxwellian electrons. Based on the one-dimensional version of the standard reductive perturbation technique, the nonlinear waves are described by a complex Ginzburg-Landau (CGL) equation. Using a factorization method, the CGL equation is solved to obtain different nonlinear solutions in the form of a localized electrostatic potential pulse such as rogue, bright, and shock-like solutions. At certain plasma parameters, the rogue wave turns into a bright soliton or other nonlinear wave forms. The influence of various plasma configuration parameters, such as wave number k, relative temperatures σ e , coefficients of plasma ionization frequency H 2 , relative dust density δ d , and collision frequency ν on electrostatic nonlinear wave characteristics (amplitude and width) has been examined. The stability of the envelope soliton solution from the CGL equation has been investigated. Our results will be useful in understanding the dynamics of nonlinear excitations in Titan ionosphere where the dust grains have been well established in recent years by Cassini mission. [ABSTRACT FROM AUTHOR]

The propagation properties of various nonlinear electrostatic structures, namely, soliton, shocklike, periodic, and explosive waves, are explored in a collision-less, magnetized, multi-component plasma relevant to Venus' ionospheric plasma. According to the spacecraft in-situ measurements, the ionosphere (at altitudes ∼ 200–1000 km) primarily consists of hydrogen ( H + ) and oxygen ( O + ) ions as well as Maxwellian electrons. The nonlinear dynamics of these structures are described by the nonlinear Zakharov-Kuznetsov equation. The G ′ / G -expansion technique is employed to obtain a class of travelling wave solutions to describe the nonlinear structures of interest. The influence of plasma parameters on the basic features of these waves is discussed. The results show that the ions concentration and temperature affect the basic features (phase velocity, amplitude, and width) of the pulses. Moreover, it is found that the ionosphere supports both subsonic and supersonic compressive ion-acoustic waves. [ABSTRACT FROM AUTHOR]

The proliferation of dust-acoustic nonlinear electrostatic waves in dusty plasma bound to nonthermal electrons and trapped nonthermal ions have been studied. The fluid hydrodynamic equations for dust fluid combined with appropriate electrons and ions distributions have been used to derive an evolution equation called a nonlinear Schrödinger equation. The rogue wave solution of the latter is used to describe a bright envelope soliton that can transform to Rossby structure at certain magnetic field strength and directional cosine. This work provides a theoretical aspects of Rossby waves, bright envelope soliton, and rogue waves on different spatial in the context of Earth magnetosphere. [ABSTRACT FROM AUTHOR]

The non-linear propagation of different kinds of ion-acoustic waves (IAWs) in multi-component plasma involving proton beam, positive ions and isothermal electrons has been studied. Using the derivative expansion method of basic equations, namely the hydrodynamic and Poisson equations, they are reduced to a single evolution equation of the non-linear Schrödinger (NLS)-type equation. By applying this model to plasma formed in Earth's magnetosphere, different waves can be predicted that express the properties of the plasma. Using the separating variables method and the G ′ / G -expansion method, we derived the exact analytical solutions to the evolution equation by using different solution regions in which non-linear waves are defined. A comparison has been made between the solutions describing the differential equation in each region in which the solution can appear using the data on the Earth's magnetosphere in the study by Alotaibi et al. (2021). [ABSTRACT FROM AUTHOR]

Cerebral injuries can trigger stress-related cardiomyopathy. The extent of cerebral injury and the involvement of the insular cortex influence the incidence and extent of myocardial injury (MI), and drugs with proven neuroprotective and cardioprotective properties such as levosimendan might be beneficial. This hypothesis was addressed in a rat model of transient middle cerebral artery occlusion. Transient brain ischemia was induced for 60 min by intraluminal occlusion of the middle cerebral artery in 40 male Wistar rats. Treatment with levosimendan (24 µg/kg) was started briefly before reperfusion. Hemodynamic parameters were recorded and cerebral and MI quantified after 24 h. Levosimendan treatment significantly reduced cerebral infarct size in the cortex, but not in the striatal and insular regions. However, its effects on survival (28 vs. 45 %), incidence of MI (8 vs. 33 %) as indicated by a troponin I (sTnI) threshold of 4.8 µg/L and large insular infarcts of ≥10 mm (23 vs. 50 %) failed to reach statistical significance. Blood pressure demonstrated significant differences related to insular infarct size during reperfusion. Levosimendan demonstrated no relevant effects on markers of MI (sTnI = 1.5 ± 2.8 vs. 5.3 ± 7.2 µg/L, P = 0.121). Insular infarct size could be identified as the only predictor of MI (odds ratio = 1.86, P = 0.037). In conclusion, the current investigation confirmed insular infarct size as a predictor of MI and source of hemodynamic compromise, but failed to demonstrate an effect of levosimendan on MI trigged by brain ischemia. A hardly protectable insular region might explain this. [ABSTRACT FROM AUTHOR]

Introduction: Hernia repair with prosthetic meshes represents one of the most common surgical procedures in the field of surgery. This intervention is always associated with an ensuing inflammatory response, angiogenesis and fibrotic encapsulation forming a foreign body granuloma (FBG) around the mesh fibres. Several studies have described this inflammatory reaction by characterising inflammatory cell infiltrate around the FBG after mesh explantation. However, very little is known about the real-time progression of such an inflammatory response. The aim of this study was to investigate the feasibility of monitoring the ongoing inflammatory response to mesh implantation using bioluminescence in vivo. Materials and methods: Three luciferase transgenic mice strains (FVB/N-Tg(Vegfr2-luc)-Xen, BALB/C-Tg(NFκB-RE-luc)-Xen and Tg(INS/EpRE-Luc)T20Rbl) were used. Mice were anaesthetized with 2 % isoflurane, and two incisions were made on the left and right sides of the abdomen of the mice. A 1-cm propylene mesh was implanted subcutaneously in the right incision wound of each mouse, and the left wound served as control. Two hundred microliters of D-luciferin was injected into the mice, and bioluminescence measurements were done prior to the surgical intervention and subsequently every 3 days. After mesh explantation, histological analysis was done. Statistical analysis was done using prism GraphPad software. Results: Bioluminescence results revealed different time points of maximum signal for the different mice strains. VEGFR2 gene expression peaked on day 6, NFkB on day 12 and ARE on day 3 post mesh implantation. We also observed much higher bioluminescent signal around the FBG surrounding the mesh as compared to the control wound, with p < 0.05 for all the different mice strains. Conclusion: Our results prove the possibility of monitoring the inflammatory reaction after mesh implantation in vivo using bioluminescence signal release. This provides a novel method of accessing and accurately describing the ongoing inflammatory response over a given period of time. [ABSTRACT FROM AUTHOR]

Middle cerebral artery occlusion (MCAO) models have become well established as the most suitable way to simulate stroke in experimental studies. The high variability in the size of the resulting infarct due to filament composition, rodent strain and vessel anatomy makes the setup of such models very complex. Beside controllable variables of homeostasis, the choice of anesthetics and the grade of ischemia and reperfusion played a major role for extent of neurological injury. Transient MCAO was induced during either isoflurane or ketamine/xylazine (ket/xyl) anesthesia with simultaneously measurement of cerebral blood flow (CBF) in 60 male Wistar rats (380-420 g). Neurological injury was quantified after 24 h. Isoflurane compared with ket/xyl improved mortality 24 h after MCAO (10 vs. 50 %, p = 0.037) and predominantly led to striatal infarcts (78 vs. 18 %, p = 0.009) without involvement of the neocortex and medial caudoputamen. Independent of anesthesia type, cortical infarcts could be predicted with a sensitivity of 67 % and a specificity of 100 % if CBF did not exceed 35 % of the baseline value during ischemia. In all other cases, cortical infarcts developed if the reperfusion values remained below 50 %. Hyperemia during reperfusion significantly increased infarct and edema volumes. The cause of frequent striatal infarcts after isoflurane anesthesia might be attributed to an improved CBF during ischemia (46 ± 15 % vs. 35 ± 19 %, p = 0.04). S-100β release, edema volume and upregulation of IL- 6 and IL- 1β expression were impeded by isoflurane. Thus, anesthetic management as well as the grade of ischemia and reperfusion after transient MCAO demonstrated important effects on neurological injury. [ABSTRACT FROM AUTHOR]

To assess the effect of the perfusion pressure (PP) during machine perfusion (MP) on the preservation quality of kidney grafts, we compared mean PPs of 25 and 30 mmHg using a porcine autotransplantation model. After assessment of the microcirculation, animals underwent left nephrectomy. Thereafter, kidneys were washed out followed by 20 h of MP at 25 mmHg (MP25, n = 7) or 30 mmHg (MP30, n = 7) using a novel MP system for hypothermic pulsatile perfusion. After MP preservation, the contralateral kidneys were removed and the preserved kidneys heterotopically autotransplanted. Ten minutes after reperfusion, the microcirculation was reassessed. Seven days posttransplant, animals were euthanized and the kidney grafts removed for histological analysis. MP using a mean PP of 25 mmHg resulted in higher capillary blood flow after reperfusion. In the MP30 group, 6 out of 7 animals survived, whereas in the MP25 group all animals survived. Overall, improvement in recovery of renal function and a better preservation of structural integrity were seen in the MP25 group compared to the MP30 group. Using a novel system for hypothermic MP, a mean PP of 25 mmHg is preferred over a mean PP of 30 mmHg. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the radiographic and biological effects of different polyurethane nasolacrimal duct stents in an animal model. Fifteen polyurethane nasolacrimal duct stents ( n = 5 mushroom-type stents, n = 5 newly designed S-shaped TearLeader stents without hydrophilic coating, and n = 5 S-shaped TearLeader stents with hydrophilic coating) were implanted in the nasolacrimal ducts of eight unaffected New Zealand rabbits. One nasolacrimal system served as control. Clinical and radiographic follow-up was performed at 1-, 2-, and 4-week intervals, then after a 3-month interval, after which the animals were euthanized. All stents were implanted without major periprocedural complications. The stents proved to be patent by the end of the procedure. During follow-up, all mushroom-type stents were occluded at 4 weeks. None of these stents opened to forced irrigation. Clinically, all rabbits demonstrated severe dacryocystitis. Three out of five TearLeader stents without hydrophilic coating were blocked at 4 weeks; one out of five was open to irrigation. Best results were observed in the stent group with hydrophilic coating. Follow-up dacryocystography demonstrated patent stents in nasolacrimal ducts of all animals after 4 weeks. In only one of five cases, the coated stent became partially occluded after 2 months. These animals were free of clinical symptoms. After 3 months, at least three out of five stents still opened to forced irrigation and only one stent was completely blocked. Dislocation of the stents was not observed. Refinement of the stent surface and stent design improves the results of nasolacrimal duct stenting in this animal model. Implantation of hydrophilic-coated S-shaped stents is highly superior to conventional mushroom-type stents and noncoated stent types. Hydrophilic coating seems to prevent foreign-body reactions, resulting in maximized stent patency. [ABSTRACT FROM AUTHOR]

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The observed escape of ions from the ionosphere of Titan suggests a potential role of the solar wind in the interaction with the upper atmospheric layers. We investigate such a plausible scenario using a hydrodynamic fluid approach for the plasma expansion in the upper ionosphere of Titan, combining (Maxwellian) electrons and three different species of positive ions which interact with the solar wind electrons and protons. Using a self-similar transformation, a numerical analysis is performed to solve the basic equations and characterize the plasma density, velocity, and electric potential during the expansion. It is found that increasing the solar wind proton number density leads to a reduction of the ion escape, while the effect of electrons is opposite stimulating the ion escape. Moreover, the expansion domain does not change for more energetic protons. The heavier ions play the leading role in controlling the ion escape, i.e. by comparison with CH 5 + ions, C2H 5 + ions appear to have more influence in the loss from Titan ionosphere. For a higher temperature contrast between ions and electrons, the depletion rate of the density increases and the ions move faster, leading to a higher ionic loss. [ABSTRACT FROM AUTHOR]

Chest trauma has a significant relevance on outcome after severe trauma. Clinically, impaired lung function typically occurs within 72 hours after trauma. However, the underlying pathophysiological mechanisms are still not fully elucidated. Therefore, we aimed to establish an experimental long-term model to investigate physiological, morphologic and inflammatory changes, after severe trauma. Male pigs (sus scrofa) sustained severe trauma (including unilateral chest trauma, femur fracture, liver laceration and hemorrhagic shock). Additionally, non-injured animals served as sham controls. Chest trauma resulted in severe lung damage on both CT and histological analyses. Furthermore, severe inflammation with a systemic increase of IL-6 (p = 0.0305) and a local increase of IL-8 in BAL (p = 0.0009) was observed. The pO2/FiO2 ratio in trauma animals decreased over the observation period (p < 0.0001) but not in the sham group (p = 0.2967). Electrical Impedance Tomography (EIT) revealed differences between the traumatized and healthy lung (p < 0.0001). In conclusion, a clinically relevant, long-term model of blunt chest trauma with concomitant injuries has been developed. This reproducible model allows to examine local and systemic consequences of trauma and is valid for investigation of potential diagnostic or therapeutic options. In this context, EIT might represent a radiation-free method for bedside diagnostics. [ABSTRACT FROM AUTHOR]

A new approach to understand the electron/hole interfaced plasma in GaN high electron mobility transistors (HEMTs). A quantum hydrodynamic model is constructed to include electrons/holes degenerate pressure, Bohm potential, and the exchange/correlation effect and then reduced to the nonlinear Schrödinger equation (NLSE). Numerical analysis of the latter predicts the rough (in)stability domains, which allow for the rogue waves to occur. Our results might give physical solution rather than the engineering one to the intrinsic problems in these high frequency/power transistors. [ABSTRACT FROM AUTHOR]