Search results for "Pressure"

P80Cannabinoid receptor CB2 prevents development of heart failure in a murine model of pressure overload

2014

Purpose: Cardiac adaptation to pressure overload is associated with inflammatory reaction, which untreated leads to myocardial fibrosis and heart failure. We have recently demonstrated that endogenous cannabinoids and the cannabinoid receptor 2 (CB2) are activated and associated with persistent inflammation in hypertrophic myocardium of patients with aortic valve stenosis. Therefore, we investigated the role of the CB2 in a mouse model of pressure overload. Methods: Transverse aortic constriction was performed in CB2-/--mice and their wildtype littermates (CB2+/+; n=8-12/group). Taqman® RT-qPCR analysis was performed after 3 and 7 days. After M-mode echocardiography and Millar® pressure-vol…

Thermal and high-pressure stability of purified polygalacturonase and pectinmethylesterase from four different tomato processing varieties

2006

Abstract Polygalacturonase (PG) and pectinmethylesterase (PME) were extracted and purified from four tomato varieties (Galeon, Malpica, Perfectpeel and Soto) used in the processing industry. The processing stability (thermal and high pressure) of PG and PME from the four varieties was analyzed, and they all showed the same behavior. PG was present in two isoforms, PG1 (inactivated at 90 °C, 5 min) and PG2 (inactivated at 65 °C, 5 min). In contrast, PG1s and PG2s showed the same pressure stability, both can be inactivated at room temperature in the pressure range of 300–500 MPa. On the other hand, purified PMEs could be thermally inactivated (5 min, 70 °C) but 50% of its activity remained af…

Strong enhancement of superconductivity at high pressures within the charge-density-wave states of2H−TaS2and2H−TaSe2

2016

We present measurements of the superconducting and charge density wave critical temperatures (Tc and TCDW) as a function of pressure in the transition metal dichalchogenides 2H-TaSe2 and 2H-TaS2. Resistance and susceptibility measurements show that Tc increases from temperatures below 1 K up to 8.5 K at 9.5 GPa in 2H-TaS2 and 8.2 K at 23 GPa in 2H-TaSe2. We observe a kink in the pressure dependence of TCDW at about 4 GPa that we attribute to the lock-in transition from incommensurate CDW to commensurate CDW. Above this pressure, the commensurate TCDW slowly decreases coexisting with superconductivity within our full pressure range.

Zur darstellung von phenolalkoholen aus phenolaldehyden mit wasserstoff/RANEY-nickel und aus phenolcarbonsäureestern mit LiAlH4

1963

Man kann Phenolaldehyde mit Wasserstoff/RANEY-Nickel entgegen Angaben in der Literatur auch bei Zimmertemperatur und Atmospharendruck zu Phenolalkoholen in guten Ausbeuten reduzieren. Die Reduktion von Phenolcarbonsaureestern mit LiAlH4 ist eine brauchbare Methode, um empfindliche und sonst nur schwer und mit geringen Ausbeuten erhaltliche Phenolalkohole mit verbesserter Ausbeute zu erhalten. It is possible to prepare phenol alcohols in good yields by reduction of phenol aldehydes with hydrogen in the presence of RANEY nickel and even at room temperature and normal pressure contrary to literature references. The reduction of phenol carboxylic acid esters by LiAlH4 is a suitable preparation …

1976

The phenomenon of “true cosolvency”, which has only recently been observed in the system acetone/diethyl ether/polystyrene (AC/DEE/PS), is investigated with regard to its pressure dependence and compared with the thermodynamic behaviour of the corresponding binary sub-systems. For the determination of the limits of complete solubility, a pressure apparatus was used which had been constructed, in order to measure the turbidity of fluids in the temperature range of −70 to +500°Cand in the pressure range of 1 to 4000 bar (105 to 4·108 Nm−2). The critical line observed for the system DEE/PS (MPS=20400) looks similar to that reported for AC/PS in the literature, i.e. the upper critical solution …

Technical characteristics can make the difference in a surgical linear stapler. Or not?

2015

Background Anastomotic leak (AL) after gastrointestinal surgery is a severe complication associated with relevant short- and long-term sequelae. Most of the anastomosis are currently performed with a surgical stapler that is required to have appropriate characteristics to guarantee good performances. The aim of our study was to evaluate, in the laboratory, pressure resistance and tensile strength of anastomosis performed with different surgical linear staplers, available in the market. Materials and methods We have been studying three linear staplers, with diverse cartridges and staple heights, of three different companies, used for gastrointestinal anastomosis and gastric or intestinal clo…

Transient reduction of the ocular perfusion pressure and the oscillatory potentials of the ERG

2005

Abstract Purpose. To evaluate the changes of the Oscillatory Potentials (OPs) of Electroretinogram (ERG) caused by short-term hypertension in human subjects, and their relationship with ocular perfusion pressure (OPP). Methods. Suction cup technique in 12 normal volunteers with OPs simultaneously recording. Results. Scotopic and photopic OPs were altered during OPP drop. Scotopic OPs showed more sensitiveness, with higher reduction (from 21% to 47%), when compared to the basal value, than in photopic recordings (from 14% to 34%). In both conditions, the relationship between OPP and OPs presented a steady amplitude before the trough after the +30 step, and rapid recovery after OPP normalisat…

The Role of Striated Sphincter Muscle in Urethral Closure Under Stress Conditions: An Experimental Study

1987

Decisive for urethral closure under stress is an increase in intraurethral pressure. This pressure increase is significantly affected by urethral tonus, passive pressure transmission and reflex pressure transmission. Approximately half of the urethral tonus is produced by the striated sphincter muscles (Rud et al. 1981; Tanagho 1979).

Electrochemical conversion of carbon dioxide in pressurized electrochemical cells

2019

To limit the negative effect of carbon dioxide as a greenhouse gas, an interesting approach is the utilization of Carbon Capture and Conversion (CCC) methodology, which is focused on the use of CO2 waste as a feedstock to produce added-value products by using the excess electric energy from renewable source [1]. In this framework, an increasing attention has been devoted to the electrochemical conversion of carbon dioxide to formic acid in water [2-3] or CO [1]. Since the main hurdle of the CO2 reduction from aqueous solution is the low CO2 solubility in water, in this work, the utilization of pressurized electrochemical cells is evaluated. The effect of various operating parameters, includ…

Electrochemical Abatement of Organic Pollutants in Water by Electro- Fenton with Natural Heterogeneous Catalysts Under Pressure

2020

In recent decades, electrochemical advanced oxidation processes (EAOPs) have proved as alternative technologies to conventional processes. Indeed, EAOPs can often allow to treat wastewater containing toxic and POPs. Among them, electro-Fenton (EF) is considered particularly promising for the treatment of recalcitrant organics, since it presents various advantages, including high abatements for many organic pollutants, simplicity of equipment and operations, relatively low cost and low consumption of chemicals. Recently, the utilization of some natural heterogeneous catalysts was proposed in order to avoid some disadvantages of the conventional EF process. In this frame, in this work EF proc…