Lidar thermometry using two-line atomic fluorescence.

In this work, Scheimpflug lidar has been combined with the thermometric technique two-line atomic fluorescence, to carry out stand-off, spatially resolved temperature measurements. Indium atoms were seeded into a modified Perkin-Elmer-burner and two tunable single-mode diode lasers with their wavelengths tuned to 410.17 and 451.12 nm were used to excite the seeded atoms. The fluorescence signal was collected using both a line-scan detector and a two-dimensional intensified CCD camera. One-dimensional flame temperature profiles were measured at different heights above a porous-plug burner, located at a distance of 1.5 m from the lidar system. The technique was also used to demonstrate two-dimensional temperature measurements in the same flame. The accuracy of the measured temperature was found to be limited mainly by uncertainty in the spectral overlap between the laser emission and the indium atom absorption spectrum as well as uncertainty in laser power measurements. With the constraint that indium can be introduced into the measurement volume, it is anticipated that the developed measurement concept could constitute a valuable tool, allowing in situ spatially resolved thermometry in intractable industrial applications, sufferings from limited optical access, thus requiring remote single-optical-port sensing.

The spatial variation of O3, NO, NO2 and NO x and the relation between them in two Swedish cities.

Ozone and nitrogen oxides (NO x ) are air pollutants with known associations to adverse health effects on humans. Few studies have simultaneously measured ozone and nitrogen oxides with high spatial resolution. The main aim of this paper was to assess the levels and variation of ground-level ozone, NO2 and NO x in two Swedish cities. An additional aim was to describe the levels of these pollutants within and between three different types of measurement sites (regional background, urban background and traffic sites) and within and between different measurement periods of the year. Three weekly sampling campaigns of NO x and ozone were conducted simultaneously at 20 sites in two Swedish regions using Ogawa badges. Ozone was measured at 20 additional sites in each area. The median ozone concentration for all measurements was statistically significantly higher in Malmö (67 µg/m3) compared to Umeå (56 µg/m3), and in both cities, ozone levels were highest in April. Measurement period was a more important factor for describing the variation in ozone concentrations than the type of measurement site. The levels of NO2 and NO x were statistically significantly higher in the Malmö area (8.1 and 12 µg/m3) compared to the Umeå area (4.5 and 8.9 µg/m3). The levels were generally highest at the sites categorized as traffic, while the variability between different seasons was sparse.

Choices Behind Numbers: a Review of the Major Air Pollution Health Impact Assessments in Europe.

PURPOSE OF REVIEW: The aim of this review is to identify the key contextual and methodological differences in health impact assessments (HIA) of ambient air pollution performed for Europe. We limited our review to multi-country reviews. An additional aim is to quantify some of these differences by applying them in a HIA template in three European cities. RECENT FINDINGS: Several HIAs of ambient air pollution have been performed for Europe, and their key results have been largely disseminated. Different studies have, however, come up with substantial differences in attributed health effects. It is of importance to review the background contributing to these differences and to quantify their importance for decision makers who will use them. We identified several methodological differences that could explain the discrepancy behind the number of attributable deaths or years of life lost. The main differences are due to the exposure-response functions chosen, the ways of assessing air pollution levels, the air pollution scenarios and the study population. In the quantification part, we found that using risk estimates from the European Study of Cohorts for Air Pollution Effects (ESCAPE) instead of the American Cancer Society (ACS) study could nearly double the attributable burden of ambient air pollution. This study provides some insights into the differential results in previously published HIAs on air pollution in Europe. These results are important for stakeholders in order to make informed decisions.

The effect of cytidine diphosphate choline on in vivo lung mechanics in premature newborn rabbits.

The influence of CDP-choline on neonatal lung adaptation was studied in premature rabbit neonates, delivered on day 28 of gestation. We found that the administration of CDP-choline (200 mg/kg body wt) at birth has a moderately beneficial effect on the respiratory frequency, dynamic lung compliance, and expiratory lung resistance. Since this effect was obtained within 60 min, and since the phospholipid content of the alveolar wash was similar on experimental and control animals, we concluded that the observed improvement in lung mechanics was probably not mediated by increased synthesis or release of surfactant phospholipids.

Efficacy of stellate ganglion block: a clinical study with bupivacaine.

BACKGROUND AND OBJECTIVES: When administering stellate ganglion blocks (e.g., to pain patients), it may be essential to know whether the sympathetic block is complete. The aim of the present study was to study the efficacy of stellate ganglion blocks using different concentrations and volumes of local anesthetic and different sites of injection. METHODS: Fifty-four stellate ganglion blocks (cervicothoracic sympathetic blocks) were performed for relief of chronic pain in 30 patients, all with a pre-block palmar skin temperature 32 degrees C or lower. Bupivacaine in random combinations of concentration (high, 5 mg/ml; low, 2.5 mg/ml), volume (high, 15-20 ml; low, 5-10 ml), and site of injection (C6 or C7) was used. The efficacy of these combinations was assessed by registering the following changes in effector organ activity: (1) observed signs (e.g., Horner's syndrome: miosis, ptosis, enophthalmos, and reddening of the sclera) and (2) objective measurements of changes in skin temperature, skin blood flow (laser Doppler flowmetry), skin resistance response, and in skin resistance level. RESULTS: Only 15 of 54 blocks met four of the five criteria for an effective block: a Horner's syndrome in combination with an increased skin temperature (to > or = 34 degrees C), increased skin blood flow ( > or = 50%), and completely abolished skin resistance response on both the radial and the ulnar sides of the blocked hand. Only six of those 54 met all five criteria: they also had an increase ( > or = 13%) in skin resistance level on the radial and ulnar sides. Injection toward C7 instead of injection toward C6, and high concentration instead of low, seemed to be more advantageous, whereas volume seemed to be of less importance. A relationship between pre-block skin temperature and the rise in temperature during the block was found. CONCLUSIONS: It was difficult to achieve a block that met all five established criteria. When assessing the efficacy of a stellate ganglion block, it is essential to evaluate the effects on vasoconstrictor and sudomotor fibers.

Effects of epidural bupivacaine or mepivacaine on somatosensory evoked potentials and skin resistance responses.

OBJECTIVE: The main purpose of this study was to compare the depth of neural block in lumbar epidural analgesia using either 20 mg/ml mepivacaine or 5 mg/ml bupivacaine. METHODS: Sixteen healthy patients were randomly divided to receive blindly either 17.5 ml mepivacaine (median, 15-20) or 17.5 ml bupivacaine (median, 14-20) for lumbar epidural analgesia. Afferent block was assessed by somatosensory evoked potentials (SEPs) during electrical stimulation of cutaneous sensory nerves at the T10, L1, L4, and L5 dermatomes. Efferent block was assessed by skin resistance responses (SRRs) recorded from the hand (C6), T12-L1, and foot (L5). RESULTS: Upper level of analgesia (pin-prick, cold) was T4 (T1-11) in the mepivacaine group and T4-5 (T2-9) in the bupivacaine group. In the mepivacaine group, SEPs were abolished in seven of eight cases at the T10 stimulation level and in five of eight cases at the L1 level. In the bupivacaine group, SEPs were abolished in two of eight cases at the T10 level and in three of eight cases at the L1 level. At the L4 and L5 levels, SEPs were only slightly changed in both groups. In the mepivacaine group, SRRs were completely or almost completely blocked (0-35% of control values) in all of eight cases at both the T12-L1 level and in the foot. Corresponding values for bupivacaine were six of seven and five of eight, respectively. Skin resistance responses in the foot and hand were significantly (p less than 0.05) lower in cases with abolished SEPs at the T10 stimulation level compared with those cases with preserved (although reduced) SEPs. CONCLUSIONS: Twenty mg/ml mepivacaine produces a more complete neural block than 5 mg/ml bupivacaine. The responsiveness of the afferent and efferent limbs of the nervous system was blocked in a similar manner as was shown by depression of the SEPs and SRRs.

Laser Doppler perfusion imager (LDPI)--for the assessment of skin blood flow changes following sympathetic blocks.

A laser Doppler perfusion imager (LDPI) for evaluation of skin blood flow is presented and its use illustrated in two cases with a presumptive diagnosis of reflex sympathetic dystrophy (RSD) treated with local anesthetic sympathetic blocks. Among the advantages are the good spatial resolution over the area measured (12 x 12 cm) and that measurements can be done without contact with the skin. Generating a complete image takes 4.5 min but if higher temporal resolution is needed continuous measurements at one point are possible by use of another software routine.

Carcinoembryonic antigen in amniotic fluid.

Carcinoembryonic antigen (CEA), a substance which is known to occur in high amounts in the fetal gut and also in certain tumors of the gastrointestinal tract, has been demonstrated in amniotic fluids from different stages of pregnancy. Radioimmunoassays of CEA in amniotic fluids of 91 normal pregnancies showed a decrease from a mean of 53 ng/ml at 19 weeks to 25 ng/ml at the end of gestation. The CEA activity in amniotic fluid was eluted in the same volume as a standard 125I-CEA on a Sephadex G200 column. Amniotic fluid therefore contains CEA similar in molecular weight to the CEA purified from liver metastases of colonic cancer. Among 17 cases of abnormal pregnancies, CEA elevations were observed in five with anomalous fetuses.

Elevated levels of alfa fetoprotein in maternal serum and amniotic fluid in two cases of spina bifida.

Therapeutic abortions were performed in two cases of spina bifida which were diagnosed by determination of the lafa fetoprotein levels in the amniotic fluid and maternal serum.