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systemic filling pressure

Laurent Savale, Jason Weatherald, Xavier Jaïs, Constance Vuillard, Athénaïs Boucly, Mitja Jevnikar, David Montani, Olaf Mercier, Gerald Simonneau, Elie Fadel, Olivier Sitbon, Marc Humbert
Acute right heart failure in chronic precapillary pulmonary hypertension is characterised by a rapidly progressive syndrome with systemic congestion resulting from impaired right ventricular filling and/or reduced right ventricular flow output. This clinical picture results from an imbalance between the afterload imposed on the right ventricle and its adaptation capacity. Acute decompensated pulmonary hypertension is associated with a very poor prognosis in the short term. Despite its major impact on survival, its optimal management remains very challenging for specialised centres, without specific recommendations...
December 31, 2017: European Respiratory Review: An Official Journal of the European Respiratory Society
Brian Heiser, E B Okrasinski, Rebecca Murray, Kelly McCord
The initial negative pressures of evacuated blood collection tubes (EBCT) and their in vitro performance as a rigid closed-suction surgical drain (CSSD) reservoir has not been evaluated in the scientific literature despite being described in both human and veterinary texts and journals. The initial negative pressures of EBCT sized 3, 6, 10, and 15 mL were measured and the stability of the system monitored. The pressure-to-volume curve as either air or water was added and maximal filling volumes were measured...
November 13, 2017: Journal of the American Animal Hospital Association
Sara Magnani, Silvana Roberto, Gianmarco Sainas, Raffaele Milia, Girolamo Palazzolo, Lucia Cugusi, Virginia Pinna, Azzurra Doneddu, Seyed Alireza Hosseini Kakhak, Filippo Tocco, Giuseppe Mercuro, Antonio Crisafulli
This study was devised to investigate the effect of coronary artery disease (CAD) without overt signs of heart failure on the cardiovascular responses to muscle metaboreflex activation. We hypothesized that any CAD-induced pre-clinical systolic and/or diastolic dysfunction could impair hemodynamic response to the metaboreflex test. Twelve males diagnosed with CAD without any sign or symptoms of heart failure and 11 age-matched healthy controls (CTL) participated in the study. Subjects performed a post-exercise muscle ischemia (PEMI) test to activate the metaboreflex...
November 10, 2017: American Journal of Physiology. Heart and Circulatory Physiology
Jing Li, Pengfei Jiang, Wenliang Gao, Rihong Cong, Tao Yang
6H and 3C perovskites are important prototype structures in materials science. We systemically studied the structural evolution induced by the Sr(2+)-to-Ba(2+) substitution to the parent 6H perovskite Ba3ZnSb2O9. The 6H perovskite is only stable in the narrow range of x ≤ 0.2, which attributes to the impressibility of [Sb2O9]. The preference of 90° Sb-O-Sb connection and the strong Sb(5+)-Sb(5+) electrostatic repulsion in [Sb2O9] are competitive factors to stabilize or destabilize the 6H structure when chemical pressure was introduced by Sr(2+) incorporation...
November 9, 2017: Inorganic Chemistry
Heikki Huhta, Juulia Junno, Mervi Haapsamo, Tiina Erkinaro, Pasi Ohtonen, Lowell E Davis, A Roger Hohimer, Ganesh Acharya, Juha Rasanen
Fetal aortic isthmus (AoI) allows communication between left (LV) and right (RV) ventricular outputs and represents arterial watershed between the brachiocephalic (brain) and subdiaphragmatic (placenta) circulations. To understand the capability of AoI to maintain the balance between upper and lower body circulations, we performed a complete fetal ascending aorta occlusion in 9 chronically instrumented sheep at near term gestation. We hypothesized that the occlusion would significantly decrease LV output and concomitantly increase RV output in order to maintain adequate systemic cardiac output and perfusion pressure to the fetal brain circulation through retrograde filling of the AoI...
November 2, 2017: Experimental Physiology
Marco Voltolini, Abdelmoula Haboub, Shan Dou, Tae Hyuk Kwon, Alastair A MacDowell, Dilworth Y Parkinson, Jonathan Ajo-Franklin
Continuous improvements at X-ray imaging beamlines at synchrotron light sources have made dynamic synchrotron X-ray micro-computed tomography (SXR-µCT) experiments more routinely available to users, with a rapid increase in demand given its tremendous potential in very diverse areas. In this work a survey of five different four-dimensional SXR-µCT experiments is presented, examining five different parameters linked to the evolution of the investigated system, and tackling problems in different areas in earth sciences...
November 1, 2017: Journal of Synchrotron Radiation
Sarah M Friedrich, Jeffrey M Burke, Kelvin J Liu, Cornelius F Ivory, Tza-Huei Wang
In-line preconcentration techniques are used to improve the sensitivity of microfluidic DNA analysis platforms. The most common methods are electrokinetic and require an externally applied electric field. Here we describe a microfluidic DNA preconcentration technique that does not require an external field. Instead, pressure-driven flow from a fluid-filled microcapillary into a lower ionic strength DNA sample reservoir induces spontaneous DNA migration against the direction of flow. This migratory phenomenon that we call Molecular Rheotaxis initiates in seconds and results in a concentrated DNA bolus at the capillary orifice...
October 31, 2017: Nature Communications
David Tordrup, Christos Chouaid, Pim Cuijpers, William Dab, Johanna Maria van Dongen, Jaime Espin, Bengt Jönsson, Christian Léonard, David McDaid, Martin McKee, José Pereira Miguel, Anita Patel, Jean-Yves Reginster, Walter Ricciardi, Maureen Rutten-van Molken, Valentina Prevolnik Rupel, Tracey Sach, Franco Sassi, Norman Waugh, Roberto Bertollini
BACKGROUND: The importance of economic evaluation in decision making is growing with increasing budgetary pressures on health systems. Diverse economic evidence is available for a range of interventions across national contexts within Europe, but little attention has been given to identifying evidence gaps that, if filled, could contribute to more efficient allocation of resources. One objective of the Research Agenda for Health Economic Evaluation project is to determine the most important methodological evidence gaps for the ten highest burden conditions in the European Union (EU), and to suggest ways of filling these gaps...
October 30, 2017: International Journal of Technology Assessment in Health Care
Seok Hee Han, Seung-Ryong Kwon, Seol Baek, Taek-Dong Chung
Despite numerous reports on iontronic devices, there has been no whole circuit working in aqueous media including even power source. Herein, we introduce complete ionic circuits powered by reverse electrodialysis (RED) for the first time without employing any electronic components. The RED-driven polyelectrolyte diode successfully shows rectification behavior which is verified by monitoring dynamic ion distribution through fluorescence in real-time. We can also turn on and off the voltage applied to the circuit, and apply an arbitrary voltage by precisely manipulating the pressure imposed to an elastic connection tube filled with electrolyte...
October 25, 2017: Scientific Reports
Massimiliano Carassiti, Alessia Mattei, Rossella Quarta, Carlo Massaroni, Paola Saccomandi, Marco Tesei, Roberto Setola, Emiliano Schena
The detection of epidural space is usually performed by the technique of loss of resistance (LOR) without technological support, although there are few commercial options. We sought to design and develop a new noninvasive system able to detect the LOR without any changes to the conventional procedure. It allows detecting the LOR by a custom made algorithm. The system provides a visual and acoustic feedback when the LOR is detected. We optimized the detection algorithm and investigated the performance of the system during experiments on a custom simulator...
October 25, 2017: Artificial Organs
Ingelin Clausen, Lars Geir W Tvedt, Are Hellandsvik, Dag Kristian W Rognlien, Thomas Glott
An in vivo sensor system for direct measurement of pressure in the human urinary bladder is developed. The core component in the system is a small-sized and highly sensitive piezoresistive MEMS pressure sensor element integrated in a sensor catheter. The sensor catheter is wired to an external module for biasing, sampling, conversion and storage of sensor measurements. Our solution provides a target sensor placed directly into the urinary bladder and a reference sensor placed outside the bladder wall through a suprapubic and minimally invasive technique...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
H F Williams
This work makes proposals on the relationship between intracranial pressure (ICP) and hydrocephalus that changes over time with the evolution of the disease. This includes the cerebrospinal fluid (CSF) filling mechanism that leads to an increase in mode pressure if excess fluid volume exacerbates the obstructive process. Elevation in mode occurs because pressure in the central nervous system (CNS) represents a state of reduced flow, rather than an abnormality of volume. Diseases that cause elevated mode pressure by means of a primary edema can lead to hydrocephalus if there is sufficient time and obstruction to flow for the filling mechanism to act...
October 2017: Medical Hypotheses
Huimin Zhang, Juan Sun, Haiyang Zhang, Yuhua Zhu, Xujie Mao Xujie Mao, Fang Ai, Siyuan Tang, Rong Li
This paper aims to understand the blood pressure control status for hypertension patients, and discuss the relationship between social support, medication compliance and blood pressure for hypertensive patients. The survey objective was the hypertensive patients in chronic disease management system in Xinxiang city. The survey was conducted as the questionnaire survey filled by objectives. Social support rating scale and medication therapy compliance questionnaire was utilized to evaluate the patients' social support and medication therapy compliance...
July 2017: Pakistan Journal of Pharmaceutical Sciences
Xiaoyang Guo, Shigeki Tokita, Kento Yoshii, Hajime Nishioka, Junji Kawanaka
A simple and compact spectral-broadening system is presented that is based on a single-stage statically pressurized Ar filled hollow core fiber. By optimizing the inner diameter of the hollow core fiber, a bandwidth of 300 nm is obtained. This is the broadest bandwidth known to date with millijoule level energy near the 1-μm wavelength by a single stage gas filled hollow core fiber.
September 4, 2017: Optics Express
M Sherif El-Eskandarany, Ehab Shaban, Fahad Aldakheel, Abdullah Alkandary, Montaha Behbehani, M Al-Saidi
Storing hydrogen gas into cylinders under high pressure of 350 bar is not safe and still needs many intensive studies dedic ated for tank's manufacturing. Liquid hydrogen faces also severe practical difficulties due to its very low density, leading to larger fuel tanks three times larger than traditional gasoline tank. Moreover, converting hydrogen gas into liquid phase is not an economic process since it consumes high energy needed to cool down the gas temperature to -252.8 °C. One practical solution is storing hydrogen gas in metal lattice such as Mg powder and its nanocomposites in the form of MgH2...
October 16, 2017: Scientific Reports
Meng-Sheng Lee, I-Lun Tsai, Ching-Yao Tsai, Li-Lin Kuo, Shiow-Wen Liou, Lin-Chung Woung
Compared with conventional penetrating keratoplasty, Descemet's stripping automated endothelial keratoplasty (DSAEK) more effectively maintain global integrity and rapid vision rehabilitation with less ocular surface disorders in patients with endothelial dysfunction. Here, we report a case of a 76-year-old woman who experienced opacification of a hydrophilic intraocular lens (IOL) approximately 10 months after DSAEK. The patient with no history of systemic disease developed pseudophakic bullous keratopathy in the right eye 2 years after undergoing cataract surgery...
July 2017: Taiwan Journal of Ophthalmology
Mengrong Xu, Fei Yu, Jonathan Knight
We report the characteristics of a 1 W hollow-core fiber gas laser emitting CW in the mid-IR. Our system is based on an acetylene-filled hollow-core optical fiber guiding with low losses at both the pump and laser wavelengths and operating in the single-pass amplified spontaneous emission regime. Through systematic characterization of the pump absorption and output power dependence on gas pressure, fiber length, and pump intensity, we determine that the reduction of pump absorption at high pump flux and the degradation of gain performance at high gas pressure necessitate the use of increased gain fiber length for efficient lasing at higher powers...
October 15, 2017: Optics Letters
Shouvik Chatterjee, Jacob P Ruf, Haofei I Wei, Kenneth D Finkelstein, Darrell G Schlom, Kyle M Shen
In mixed-valent Kondo lattice systems, such as YbAl3, interactions between localized and delocalized electrons can lead to fluctuations between two different valence configurations with changing temperature or pressure. The impact of this change on the momentum-space electronic structure is essential for understanding their emergent properties, but has remained enigmatic. Here, by employing a combination of molecular beam epitaxy and in situ angle-resolved photoemission spectroscopy we show that valence fluctuations can lead to dramatic changes in the Fermi surface topology, even resulting in a Lifshitz transition...
October 11, 2017: Nature Communications
Saigen Naruse, Hiroyuki Shimada, Ryusaburo Mori
BACKGROUND: This study compared the postoperative outcomes of 27-gauge (G) and 25-G vitrectomy performed for the treatment of idiopathic epiretinal membrane (ERM). METHODS: The study design was single center, retrospective, interventional case series. Two hundred consecutive eyes that underwent primary vitrectomy for ERM (27-G vitrectomy in 100 eyes and 25-G vitrectomy in 100 eyes) were studied for 6 months. In all eyes, scleral tunnels were made using angle incisions, and air or gas exchange was performed...
October 10, 2017: BMC Ophthalmology
Wei Du, Dawei Liu, Yun Long, Xiaoting Wang
BACKGROUND: A vascular waterfall occurs when the critical closing pressure is greater than the mean systemic filling pressure. Because the waterfall phenomenon likely exists in the microcirculation, β1-receptor blockers such as esmolol could have some effect on microcirculation and vascular waterfall. OBJECTIVES: To determine whether a vascular waterfall exists during septic shock and to assess the effects of vasopressors and β-blockers on vascular waterfall. DESIGN: Sixteen mongrel dogs were mounted with ultrasonic flow probes to measure renal blood flow...
December 2017: Critical Care Medicine
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