1. The effects of graded intravenous infusions of sodium nitroprusside on resting blood pressure and heart rate and on the reflex changes in these variables evoked by a standardized Valsalva manoeuvre were studied in six normal subjects. The effects of nitroprusskle on the above variables were also studied after pretreatment with captopril, to allow assessment of the role of angiotensin 11. 2. ...

Leak detection in transmission pipelines is important for safe operation of pipelines. The probability of leaks may be occurred at any time and location, therefore pipeline leak detection systems play a key role in minimization of the occurrence of leaks probability and their impacts. Today there are many available assortments of modern technologies in the domain of leak detection. This paper p...

OBJECTIVE To evaluate and discuss etiopathology, clinical manifestations and surgical outcome of a rare subset of unruptured aneurysm of the sinus of Valsalva which erodes into the interventricular septum. METHODS Between 1989 and 1995, seven cases of unruptured aneurysm of the sinus of Valsalva eroding into the interventricular septum underwent surgical correction at the King Edward VII Memo...

A retrospective analysis of 632 infants with hyaline membrane disease admitted to this regional intensive care nursery between 1 July 1974 and 31 December 1982 showed that 387 (61%) received mechanical ventilation. The ventilator pressures at the time the first air leak was detected were available from the records of 120 of 154 (78%) of the infants who sustained pulmonary air leak. There was a ...

OBJECTIVES Although uncommon, prolonged postoperative air leaks are a troublesome complication of lung surgery. This study was performed to determine if buttressing pulmonary staple lines would reduce air leakage at varying airway pressures, and if there was a difference between buttressing materials. METHODS Using cadaver lungs, the development of air leak from staple lines was evaluated at ...

We have compared ease of insertion, oropharyngeal leak pressure, directly measured pharyngeal mucosal pressure and anatomical position (assessed fibreoptically) for the size 4 and size 5 laryngeal mask airway (LMA) in 20 male and 20 female patients. Microchip pressure sensors were attached to the LMA at locations corresponding to the piriform fossa, hypopharynx, base of the tongue, lateral and ...

BACKGROUND The effects of epidural needle design, angle, and bevel orientation on cerebrospinal fluid leak after puncture have not been reported. The impact of these factors on leak rate was examined using a dural sac model. Dural trauma was examined using scanning electron microscopy. METHODS Human cadaveric dura, mounted on a cylindrical model, was punctured with epidural needles using a mi...

The cardiac output has been measured during the immediate post-Valsalva maneuver recovery period in normal subjects, patients with clinically significant mitral stenosis, and patients with alterations of the autonomic nervous system. When compared with the resting value, it was found that normal subjects had a decrease in cardiac output during the immediate post-Valsalva recovery period, while ...

OBJECT The incidence of cerebrospinal fluid (CSF)-related complications after intradural spinal tumor (IST) surgery is high and reported in up to 18% of patients. However, no efficient way to prevent those complications has been reported so far. Treating these complications may require prolonged bed rest, re-exploration, external lumbar drain, use of antibiotics, and possible precipitation of o...

An elastomeric seal may leak by elastic deformation without any material damage. We describe elastic leak using a theoretical model, and watch a seal deform and leak using a transparent experimental setup. The elastomer seals the fluid by forming contact with surroundinghardmaterials. As the fluid pressure increases, the contact stress also increases but not as much. When the fluid pressure sur...