Problem of catheter-embolism following subclavian puncture

The catheterisation into the subclavian vein is important in the intensive therapy and for the prolonged parenteral nutrition. Numerous complications are described. In 300 catheterisations into the subclavian vein we observed 3 damages of catheters. The causes damages of catheters are investigated with the help of experiments. Recommendations to the prevention of the damage and the embolism of the subclavian catheters are given.     

Some methods for magnetometer zero-level determination

Zero-level determination is an important aspect of the processing of magnetometer observations made onboard spacecrafts. Due to the presence of instrument offset drift as well as magnetic fields produced by the spacecraft, such a zero-level determination requires in-flight methods in addition to preflight calibration. Two different such techniques have been studied, taking advantage of observations made by instruments other than the magnetometer. The first is based on measurements obtained by electron drift instruments, originally designed to measure electric fields. The authors discuss the applicability of such instruments to determine magnetometer offsets. The second method is based on particle pressure tensor measurements, where pressure anisotropy is used to determine the magnetic field direction     

Incommensurate phases in the system Ba2TiSi2O8-Ba2TiGe2O8

Incommensurate phases and phase transitions in fresnoite-type crystals: Ba₂TiSi₂O₈, Ba₂TiGe₂O₈, and compositions in the system Ba₂TiSi₂O₈-Ba₂TiGe₂O₈, are discussed.     

Dielectric behavior of single crystals near the (1-X) Pb(Mg1/3Nb2/3)O3-(x) PbTiO3 morphotropic phase boundary

Single crystals in the lead magnesium niobate-lead titanate-(1-x) Pb(Mg_1/3 Nb_2/3)O₃-(x) PbTiO₃ solid solution system were grown using a flux growth technique. Crystals over the compositional range of 0.3 ≤ ' ≤ 0.4 being near the rhombohedra1 (pseudo-cubic)-tetragonal morphotropic phase boundary were characterized. The dielectric behavior along the pseudo cubic [111] and [100] directions were measured as a function of temperature and frequency. The effect of poling was also examined.     

Therapy of soft tissue injuries--biological strategies

The traumatic soft tissue injury plays a central role in fracture healing. The knowledge of pathophysiological mechanisms has completely changed the management and therapy of injuries accompanied by soft tissue lesions. Treatment is aiming for prevention of the circle of hypoxia, microvascular perfusion disturbance, increased membrane permeability and potential infections. General therapeutic principles are decontamination, debridement, revascularisation and decompression. Modern methods of soft tissue treatment take these principles into consideration.     

Cr4+ lasers: present performance and prospects for newhost lattices

Cr-doped lasers, based on forsterite and YAG, provide broadly tunable power in the 1.25-μm and 1.45-μm regions. Performance data on tuning range, pumping, output power, and thermal management for these lasers is reviewed. Potential new crystals for Cr⁴⁺ should have heavy atoms to reduce lattice phonon frequencies, a distorted tetrahedral cage for the Cr⁴⁺ ion, and possibly an octahedral site for Cr³⁺. Possible materials include monticellite and diopside     

Synthesis of (±)-disparlure

A six-step, convergent synthesis has been developed for racemic (Z)-7,8-epoxy-2-methyloctadecane (disparlure), the sex pheromone of the gypsy moth. The key step is a Wittig reaction between 6-methylheptanal and triphenylundecylphosphonium bromide effected by potassium carbonate in the presence of a crown ether.     

Aortic rupture after blunt chest trauma. Rapid diagnosis using transesophageal echocardiography when radiographic and computed tomographic findings are unclear

HISTORY AND CLINICAL FINDINGS: A 37-year-old woman who was not wearing a seat-belt while driving a car had a head-on collision at 70 km/h. On arrival of the emergency physician she was awake and responsive but complained of pain with bruising over the sternum and the epigastrium. Pressure on the sternum was painful. Arterial pressure was 95/60 mm Hg, heart rate 112/min. On admission the heart sounds were unremarkable and peripheral pulses normal. Vesicular sounds were heard over both lungs. In addition to multiple facial abrasions voluntary movements were impaired and the right knee-joint was swollen. INVESTIGATIONS: The ECG showed sinus tachycardia (103 beats/min) with left axis deviation, but was otherwise unremarkable. Initially the haemoglobin was 12.6 g/dl with normal white cell and platelet counts. Clotting tests, serum transaminases, creatine kinase, lactate dehydrogenase and other routine laboratory tests were within normal limits. TREATMENT AND COURSE: Because the haemoglobin level had fallen to 7.7 g/dl within the first 4 hours erythrocytes concentrate was infused. The chest radiogram and subsequent computed tomography showed a mediastinal and paraaortic haematoma of unclear origin. Transoesophageal echocardiography (TEE) demonstrated rupture of the descending aorta with free floating intraluminal parts of the intima in the isthmal region, just distal to the origin of the left subclavian artery, which was not occluded. Colour Doppler echocardiography revealed abnormal flow into mediastinal and paraaortic tissues. At operation the echocardiographic findings were confirmed and part of the descending aorta was replaced by a 3 cm dacron tube during an aortic crossclamping time of 37 min. The patient was discharged after a postoperative stay of average length, during which her other injuries were treated. CONCLUSION: After blunt thoracic or deceleration trauma earliest possible TEE is indicated, because it can at once provide details of extent and degree of injury to heart and/or aorta.