Evaluation of the uncertainty of molecular mass measurement by electrospray ionization mass spectrometry

Electrospray ionization (ES) is a novel method used in mass spectrometry (MS) for producing gas-phase ions from substances in solutions. Common practices for molecular mass estimation from ES spectra summarize the spectrum as a single peak giving no estimate of uncertainty or treat each peak as an independent molecular mass measurement. ES-MS data analysis showed that each peak in an ES spectrum does not always provide an independent measure of molecular mass. Underestimation of measurement uncertainty is a possible result. An elementary time series method, the Yule-Walker equations, was applied to molecular mass estimation from ES data.     

Specific bronchial provocation tests with flour in the diagnosis of occupational bronchial asthma

The gold standard in the diagnosis of occupational asthma is the specific bronchial provocation test (sBPT), but other diagnostic criteria have been proven to have a similar sensitivity, mainly in asthma due to high molecular weight compounds. In order to assess wether some clinical findings can predict the positive response to sBPT, we studied 37 subjects (14 millers and 23 bakers) with suspected occupational asthma who underwent sBPT with wheat flour dust (dust exposure in a small cabin: geometric mean 12.1 mg/m3 for up to 30 min). A positive response to sBPT (FEV1 > 20%) was elicited in 20 subjects (11 early, 4 late, and 5 dual responses). There was no significant difference between subjects with positive or negative sBPT as regards mean age, smoking, length of employment, duration of symptoms, atopy (skin positivity to one or more common allergens) and PD20FEV1 methacholine. The percentage of subjects with work-related symptoms was significantly higher in subjects with positive sBPT with respect to subjects with negative sBPT (81% versus 41.2%, p < 0.01 by chi 2 test); furthermore, FEV1 was significantly lower in subjects with positive sBPT. The percentage of positive skin response to wheat flour extract (mean wheal diameter > or = 3 mm) was mildly but not significantly higher in subjects with positive sBPT (68.4% versus 41.2%). None of the following clinical factors (age < 35 years, asthma symptoms pre-existing occupational exposure, non smokers, atopy and bronchial hyperresponsiveness to methacholine), alone or in combination, were associated with higher prevalence of positive sBPT. We conclude that the response to sBPT in subjects with suspected occupational asthma due to flour dust can not be adequately predicted by other clinical, allergologic and functional data. Therefore, sBPT with flour dust should always be performed in subjects with suspected occupational asthma.     

An expert decision support system for network routing: a case study

The paper presents a case study of the development of an expert decision support system which uses simple heuristic methods for fast determination of routes for simultaneous signals in a transmission network of limited capacity. It illustrates how heuristic solutions can be embodied in a model-based DSS and how the standard decision support literature, although intuitively appealing, provides little practical assistance in system construction or classification     

Effect of nimodipine on infectious brain edema in rabbits

AIM: To study the effect of nimodipine (Nim) on infectious brain edema (BE). METHODS: An infectious BE model was induced by injection of Bordetella pertussis suspension (BPS) into right internal carotid artery in rabbits. Eighteen rabbits were randomly divided into 3 groups (n = 6). Group BE: BPS (0.6 mL.kg-1) was given; group NS: normal saline was given as control; group Nim: 10 min after injection of BPS, Nim, 10 micrograms.kg-1, was injected i.v. as a bolus followed by continuous infusion of 0.75 microgram.kg-1.min-1. All the rabbits were kept under observation for 4 h. Evans blue staining was assessed; water, calcium, calmodulin (Cal), and sodium contents were determined in the right brain. RESULTS: Nim vs BE: water 82.2 +/- 1.0% vs 84.4 +/- 1.2 (P < 0.01); calcium 10.5 +/- 1.3 mmol.kg-1 dry tissue vs 17.5 +/- 1.4 (P < 0.01); Cal 15.9 +/- 1.8 mumol.kg-1 wet tissue vs 24.0 +/- 3.0 (P < 0.01); sodium 173 +/- 7 mmol.kg-1 dry tissue vs 275 +/- 38 (P < 0.05). No significant difference for Evans blue staining between the two groups. CONCLUSION: Nim had beneficial effect on the infectious BE.     

Benign breast changes and the risk for subsequent breast cancer: an update of the 1985 consensus statement. Cancer Committee of the College of American Pathologists

The Cancer Committee of the College of American Pathologists has prepared an update of the consensus statement on premalignant breast lesions and breast cancer risk that was originally published in the Archives of Pathology & Laboratory Medicine in 1986. The objective of this publication is to better define the relative breast cancer risk associated with specific histologic abnormalities by incorporating data derived from recent case-control studies. Explanatory notes are used to document and explain specific risk classifications. In addition to refining the degree of risk associated with individual lesions, such as fibroadenoma and atypical hyperplasia, this update includes a discussion of age-specific breast cancer risk and provides examples that can be used when counseling patients.     

Long-wavelength GaInNAs(Sb) lasers on GaAs

The boom in fiber-optic communications has caused a high demand for GaAs-based lasers in the 1.3-1.6-μm range. This has led to the introduction of small amounts of nitrogen into InGaAs to reduce the bandgap sufficiently, resulting in a new material that is lattice matched to GaAs. More recently, the addition of Sb has allowed further reduction of the bandgap, leading to the first demonstration of 1.5-μm GaAs-based lasers by the authors. Additional work has focused on the use of GaAs, GaNAs, and now GaNAsSb barriers as cladding for GaInNAsSb quantum wells. We present the results of photoluminescence, as well as in-plane lasers studies, made with these combinations of materials. With GaNAs or GaNAsSb barriers, the blue shift due to post-growth annealing is suppressed, and longer wavelength laser emission is achieved. Long wavelength luminescence out to 1.6 μm from GaInNAsSb quantum wells, with GaNAsSb barriers, was observed. In-plane lasers from these samples yielded lasers operating out to 1.49 μm, a minimum threshold current density of 500 A/cm² per quantum well, a maximum differential quantum efficiency of 75%, and pulsed power up to 350 mW at room temperature