A simplified thermal analysis approach for power transistor rating in PWM-controlled DC/AC converters

A simplified dynamic thermal analysis approach is proposed for the estimation of the peak junction temperature in power IGBT transistors operating in pulse-width modulation (PWM) controlled DC/AC converters. This approach can be used for the rating of electron devices or heatsink systems in power circuit design, as it provides a direct analytical link, in terms of electrical and thermal device parameters and converter operating conditions between the case and the peak junction temperatures. In this way, by imposing a given upper limit on the junction temperature, indirect constraints on device size or load current or heatsink efficiency can easily be obtained. The approach is based on mild, pessimistic approximations on both the spectrum of dissipated power and on the dynamic thermal behavior of the device. The validity of such approximations has been verified by comparison with the results of accurate numerical simulations carried out by using measurement-based loss models. Possible ways of using this approach in a converter rating context are outlined in the paper, by considering different design scenario

A bolometric measurement of the antineutrino mass

High statistics calorimetric measurements of the beta spectrum of 187Re are being performed with arrays of silver perrhenate crystals operated at low temperature. After a modification of the experimental set-up, which allowed to substantially reduce the background of spurious counts and therefore to increase the sensitivity on the electron antineutrino mass, a new measurement with 10 silver perrhenate microbolometers is running since July 2002. The crystals have masses between 250 and 350 micrograms and their average FWHM energy resolution, constantly monitored by means of fluorescence X-rays, is of 28.3 eV at the beta end-point. The Kurie plot collected during 4485 hours x mg effective running time has an end-point energy of 2466.1 +/- 0.8{stat} +/- 1.5 {syst} eV, while the half lifetime of the decay is found to be 43.2 +/- 0.2{stat} +/- 0.1{syst} Gy. These values are the most precise obtained so far for 187Re. From the fit of the Kurie plot we can deduce a value for the squared electron antineutrino mass m(nu)^2 of 147 +/- 237{stat} +/- 90{syst} eV^2. The corresponding 90% C.L. upper limit for m(nu) is 21.7 eV.Comment: 3 pages, 3 figures. Submitted to Phys. Rev. Let

Milk Products in Bread Making

The topic was the usage of milk in bread making. Initial investigations in bread making using milk were aimed at learning how to prepare milk best suited for bread making and finding the proper quantities for optimum results. The convenience, economy, and uniformity of dry milk solids greatly increased their usage by bakers. These advantages have been further augmented by research and experimentation by the dry milk producers, which have resulted in a product which would appreciably improve bread quality. Milk may be altered both in physical and chemical properties by heating. The article goes on to give more information on milk usage in baking

Randomized placebo-controlled trial comparing desloratadine and montelukast in monotherapy and desloratadine plus montelukast in combined therapy for chronic idiopathic urticaria

BACKGROUND: H 1 -receptor antagonists are considered to be particularly effective in reducing pruritus, and they are therefore recommended as first-line treatment in patients with chronic idiopathic urticaria (CIU). Recently, antileukotriene receptors have been used in patients with CIU, either administered as monotherapy or combined with H 1 -receptor antagonists. OBJECTIVE: We compared the clinical efficacy of 5 mg of desloratadine administered once daily either as monotherapy or combined with a leukotriene antagonist, 10 mg of montelukast daily, and 10 mg of montelukast administered daily as monotherapy for the treatment of patients affected by CIU with placebo. METHODS: One hundred sixty patients aged 18 to 69 years (mean +/- SD, 43.9 +/- 13.4 years) with a history of moderate CIU were selected. A randomized, double-blind, double-dummy, placebo-controlled, parallel-group study design was used. Patients were treated with 5 mg of desloratadine once daily (n = 40), 10 mg of montelukast once daily (n = 40), 5 mg of desloratadine (n = 40) in the morning plus montelukast in the evening, or matched placebo (n = 40). Assessment of treatment efficacy was based on scores of daily cutaneous symptoms evaluated reflectively and instantaneously. RESULTS: Only the group treated with desloratadine as monotherapy or as combined therapy concluded the whole study. Twenty-seven of the 40 patients in the montelukast group and 35 of the 40 patients in the placebo group discontinued the treatment. As reflective evaluation, all groups showed significant differences compared with the placebo group in terms of total symptom score, number of hives, and size of largest hive. In addition to the pruritus, only the groups treated with desloratadine as monotherapy or combined therapy showed significant differences compared with those receiving placebo, whereas there were no differences between the montelukast and placebo groups. Finally, no differences were found between the desloratadine group and the desloratadine plus montelukast group. The instantaneous evaluation demonstrated similar results regarding the desloratadine group and the desloratadine plus montelukast group versus the placebo group, whereas there were no significant differences between the group treated with montelukast alone and the placebo group for pruritus and size of largest hive. No differences were found between the group treated with desloratadine alone and the desloratadine plus montelukast group. CONCLUSIONS: The results of this comparative study demonstrate that desloratadine is highly effective for the treatment of patients affected by CIU. In addition, the regular combined therapy of desloratadine plus montelukast does not seem to offer a substantial advantage with respect to desloratadine as monotherapy in patients affected by moderate CIU

Randomized placebo-controlled trial comparing fluticasone aqueous nasal spray in mono-therapy, fluticasone plus cetirizine, fluticasone plus montelukast and cetirizine plus montelukast for seasonal allergic rhinitis

BACKGROUND: Corticosteroids are considered to be particularly effective in reducing nasal congestion and are therefore recommended as first-line treatment in allergic rhinitis patients with moderate to severe and/or persistent symptoms. OBJECTIVE: We compared the clinical efficacy of fluticasone propionate aqueous nasal spray (FPANS) 200 microg given once daily, administered in mono-therapy or combined therapy with a H1 receptor antagonist (cetirizine, CTZ) or with a leukotriene antagonist (montelukast, MSK), and the combined therapy of CTZ plus MSK in the treatment of patients affected by allergic rhinitis to Parietaria during natural pollen exposure. In addition, we examined the effect of the treatment on eosinophil counts and eosinophil cationic protein (ECP) in nasal lavage performed at beginning of season, during season and at the end of the season. METHODS: One hundred patients aged 12-50 years (mean+/-SD 31.8+/-9.6) with a history of moderate to severe Parietaria pollen-induced seasonal allergic rhinitis were selected. A randomized, double-blind, double dummy, placebo (PLA)-controlled, parallel-group study design was used. Patients were treated FPANS 200 microg once daily (n=20) or with FPANS 200 microg once daily, plus CTZ (10 mg) in the morning (n=20), or with FPANS 200 microg once daily, plus MSK (10 mg) in the evening (n=20) or with CTZ (10 mg) in the morning plus MSK in the evening (n=20) or matched PLA (n=20). Assessment of efficacy was based on scores of daily nasal symptoms and on eosinophil counts and ECP in nasal lavage. RESULTS: All treatments showed significant differences (P<0.001) compared with PLA in terms of total symptom, rhinorrhea, sneezing and nasal itching scores. Concerning nasal congestion on waking and daily only the groups treated with FPANS in mono-therapy or in combined therapy showed significant differences compared with PLA. Comparing the group treated with FPANS alone and the groups treated with FPANS plus CTZ, we found significant differences for total symptom score (P=0.04) and for nasal itching (P=0.003). The comparison between FPANS plus CTZ and FPANS plus MSK showed significant difference for nasal itching (P=0.003). Finally, there were significant differences between the group treated with FPANS and the group treated with CTZ plus MSK for total symptom score (P=0.009), for nasal congestion on waking (P<0.001) and nasal congestion daily (P<0.001). Also the comparisons between the group treated with FPANS plus CTZ and the group treated with CTZ plus MSK demonstrated significant differences (P<0.001) for total symptom, for nasal congestion on waking and for nasal congestion on daily, for rhinorrhea (P=0.04) and for nasal itching (P=0.003) scores. Concerning the comparison between the group treated with FPANS plus MSK and the group treated with CTZ plus MSK we found significant differences for total symptom score (P=0.005), for nasal congestion on waking (P<0.001) and for nasal congestion on daily (P<0.001). No other differences were observed between the groups. Concerning blood eosinophil counts, significant differences were found between the treatments with FPANS in mono-therapy or in combined therapy with PLA group during and at the end of the season (P=0.0003 and P<0.0001, respectively). Concerning eosinophils and ECP in nasal lavage, all treatments showed significant differences (P<0.001) compared with PLA. Besides, there were significant differences (P<0.001) between the groups treated with FPANS alone or in combined therapy and the group treated with CTZ plus MSK. CONCLUSION: The results of this comparative study demonstrate that FPANS is highly effective for treating patients affected by allergic rhinitis, with efficacy exceeding that of CTZ plus MSK in combined therapy. In addition, the regular combined therapy of FPANS plus CTZ or plus MSK would not seem to offer substantial advantage with respect to FPANS in mono-therapy in patients affected by seasonal allergic rhinitis

Crossing of shears bands in196Pb

n/

Poly(adenosine diphosphate-ribose) polymerase 1 expression in malignant melanomas from photoexposed areas of the head and neck region.

Summary The family of the poly(adenosine diphosphate-ribose) polymerase (PARP) proteins is directly involved in genomic stability, DNA repair, and apoptosis by DNA damage. In this study, we evaluated the role of PARP-1 in melanoma and its prognostic importance. We studied by immunohistochemistry and Western blot analysis PARP-1 expression in a selected series of 80 primary melanoma of the head and neck region. The results were correlated with tumor thickness and patient’s outcome. A follow-up of at least 3 years was available. Fifteen cases of benign melanocytic nevi were used as controls. Normal melanocytes showed only scattered, focal nuclear positivity and were considered as negative for PARP-1 expression by immunohistochemistry (score, 0). Thirty cases of melanoma (37.5%) showed nuclear expression of PARP-1 in both radial and vertical growth phases. Western blot analysis showed the presence of a high signal for full-length PARP-1 only in the cases with high immunohistochemical (nuclear) expression of protein (score, ++/+++) in both radial and vertical growth phase. A significant correlation was present between PARP-1 expression in vertical growth phase and the thickness of tumor lesion ( P = .014); all but one tumor measuring less than 0.75 mm showed no or low PARP-1 expression. No correlation was found between PARP-1 expression in radial growth phase and tumor thickness ( P = .38, data not shown). These data suggest that PARP-1 overexpression is a potential novel molecular marker of aggressive cutaneous malignant melanoma and a direct correlation between PARP-1–mediated inhibition of the apoptosis and biologic behavior of cutaneous malignant melanoma

Similarity and differences in elderly patients with fixed airflow obstruction by asthma and by chronic obstructive pulmonary disease.

SummaryBackgroundEpidemiologic studies have demonstrated that elderly patients with fixed airflow obstruction can be affected by asthma or chronic obstructive pulmonary disease (COPD).MethodsWe studied 49 consecutive elderly outpatients, presenting fixed airflow obstruction, by clinical history (smoking), pulmonary function tests, blood gas analysis, and induced sputum.ResultsThe age was not different in patients with COPD (n=28) and asthma (n=21) (70.2±3.9 years vs. 69.6±3.7 years), also the degree of fixed airflow obstruction was similar (FEV1: 58.3±1.5% vs. 59.0±1.4% of predicted). Patients with asthma had significantly more eosinophils in peripheral blood (0.43±0.05×10−3μL vs. 0.27±0.1×10−3μL, P<0.0001), and in induced sputum (5.0% [(p25th and p75th) 5.0–6.0%] vs. 1.0% [(p25th and p75th) 0.01–1.0%]; P<0.0001), as well as serum ECP (18.6±4.9ng/mL vs. 7.7±4.7ng/mL, P<0.0001) and ECP in the induced sputum (31.6±2.9ng/mL vs. 5.6±4.9ng/mL, P<0.0001). Finally, in induced sputum the eosinophils EG2+ were higher in patients with asthma than in patients with COPD (40.5 [(p25th and p75th) 39.3–44.3] MFI vs. 3.9 [(p25th and p75th) 0–11.4] MFI, P<0.0001). They also had significantly higher diffusing capacity, and a greater reversibility to steroids, after 14-day course of therapy, whereas the reversibility to 400μg of salbutamol was similar.ConclusionDespite similar fixed airflow obstruction, elderly patients with asthma have distinct characteristics compared with patients with COPD