Effect of in-flight particle behavior on the morphology of flame sprayed Er2O3 splats

The morphology and microstructure of splats impact the comprehensive capability of a new coating methodology called chelate flame spraying (CFS). This study addresses the quantitative characterization of the spread morphologies of flame sprayed Er₂O₃ splats directly deposited under different spray conditions on aluminum alloy substrates with a mirror finish. The influence of the in-flight particle temperature and velocity, carrier gas type, and carrier gas ratio on the solidification mechanism of molten droplets was investigated. Image analysis methods were employed to identify single splats from the morphology observed with field-emission scanning electron microscopy (FE-SEM). In addition, Er₂O₃ films were synthesized on an Al–Mg alloy (A5052) substrate using N₂ or O₂ as the carrier gas. When O₂ was used as the carrier gas, 109-μm-thick films were deposited on the A5052 substrate. The cross-sectional porosity of the films was 3.8%. In contrast, films with 101-μm thickness were synthesized on the A5052 substrate when N₂ was used as the carrier gas. The cross-sectional porosity of these films was 13.8%. The results showed that the carrier gas type (N₂) and carrier gas ratio had a significant effect on the flattening behavior of the molten droplets. A spraying method combined with multidimensional modes is proposed to control the morphology of the splats.     

Thermoelectric properties of β-FeSi2 with B4C and BN dispersion by mechanical alloying

The B₄C- and BN-dispersed -FeSi₂ thermoelectric materials were synthesized by mechanical alloying and subsequent hot pressing. The effects of the B₄C and BN dispersion on the thermoelectric properties, such as Seebeck coefficient, electrical resistivity and thermal conductivity etc., of the -FeSi₂ were investigated. For the sample with B₄C and BN addition, a larger amount of the residual phase was detected in the X-ray diffraction patterns than the sample without addition. In the case of the BN addition, the Seebeck coefficient was enhanced by BN addition above 700 K, and the electrical resistivity also increased with increasing amount of BN. This is considered to result from doping of a small amount of B into the phase due to partial decomposition of the BN phase. The fine dispersion of BN particles in the phase matrix was quite effective for reducing the thermal conductivity as compared to the B₄C addition over the entire temperature range. The figure of merit, Z, of the -FeSi₂ was significantly enhanced by BN addition.     

A method for calculating the electromagnetic noise of a motor-driven thin blade fan

An urgent need exists to develop a method of predicting the noise level of a blade fan attached to a motor shaft. To satisfy this requirement, we developed a method for calculating the sound generated when a rotating blade is excited by the torque pulsation of a motor. The sound pressure values calculated by the new method for a rotating blade were found to correspond well with experimentally measured ones.     

Role of Stripes in Spin and Charge Dynamics of Underdoped La2−x Sr x CuO4

We investigate the electronic states of underdoped La _2–x Sr _x CuO ₄ (LSCO) by using a microscopic model, i.e., t-t-t-J model, containing charge stripes. The numerically exact diagonalization calculation is employed on small clusters. The physical properties observed in the angle-resolved photoemission and optical conductivity experiments are consistently explained in the model with vertical stripes, but not diagonal ones. These results demonstrate a crucial role of the vertical stripes in underdoped LSCO.     

Effect of anti-IL-4 and anti-IL-5 antibodies on allergic airway hyperresponsiveness in mice

In order to study the role of IL-4 and IL-5 in allergen-induced airway hyperresponsiveness in mice, the effect of the combined administration of anti-IL-4 and anti-IL-5 monoclonal antibodies (mAbs) on IgE response, airway inflammation and airway hyperresponsiveness was studied in sensitized Balb/c mice. Three inhalations of antigen caused an increase in the number of eosinophils in bronchoalveolar lavage fluid and in airway responsiveness to acetylcholine, with a significant elevation in the serum antigen-specific IgE level. Anti-IL-4 mAb inhibited IgE production but did not affect airway eosinophilia or hyperresponsiveness. Moreover, anti-IL-5 mAb inhibited airway eosinophilia but did not affect IgE production or airway hyperresponsiveness. The combined administration of anti-IL4 and anti-IL-5 mAbs, however, inhibited IgE antibody production, airway eosinophilia and hyperresponsiveness. These results suggest that inhibitory action of IL-4 and IL-5 in combination can effectively suppress the onset of antigen-induced airway hyperresponsiveness in mice.     

Endothelin converting enzyme inhibitor protects development of right ventricular overload and medial thickening of pulmonary arteries in rats with monocrotaline-induced pulmonary hypertension

We evaluated the effects of FR901533, endothelin converting enzyme inhibitor, on development of right ventricular overload and medial thickening of pulmonary arteries in rats with monocrotaline-induced pulmonary hypertension. Pulmonary hypertension was induced by a single injection of monocrotaline (80 mg/kg). Twenty-four hours later (day 1), continuous subcutaneous injection of FR901533 (100 mg/kg/day) was started. Right ventricular systolic pressure, mass ratio of right ventricle to left ventricle, right ventricular wall thickness, right ventricular myocardial fiber diameter, percent medial thickness, and percent smooth muscle area in pulmonary arteries were significantly less in rats that received FR901533 than in the control with monocrotaline on day 28. Both immunoreactivities of endothelin-1 in pulmonary arteries and plasma endothelin-1 levels were observed significantly less in rats treated with FR901533 than in the control with monocrotaline. There were significant increased immunoreactivities of endothelin-B receptor in pulmonary arteries in rats that received FR901533 as compared with those in the control with monocrotaline. FR901533 (100 mg/kg/day), protected the development of right ventricular overload and medial thickening of pulmonary arteries in a rat model of pulmonary hypertension.     

Smoke extract stimulates lung epithelial cells to release neutrophil and monocyte chemotactic activity

Inflammatory cells accumulate within the lungs of cigarette smokers. Current concepts suggest that these cells can induce protease-antiprotease and/or oxidant-antioxidant imbalance(s), which may damage the normal lung alveolar and interstitial structures. Because type II pneumocytes line the alveolar space, and because the inflammatory cells migrate and reside at the alveolus, we postulated that the type II pneumocytes might release chemotactic activity for neutrophils and monocytes in response to smoke extract. To test this hypothesis, A549 cells were cultured and the supernatant fluids were evaluated for the neutrophil and monocyte chemotactic activity (NCA and MCA) by a blind-well chamber technique. A549 cells released NCA and MCA in response to smoke extract in a dose- and time-dependent manner (P < 0.05). Checkerboard analysis showed that the activity was chemotactic. Partial characterization of NCA and MCA revealed that the activity was partly heat labile, trypsin sensitive, and ethyl acetate extractable. Lipoxygenase inhibitors and cycloheximide inhibited the release of NCA and MCA. Molecular sieve column chromatography showed multiple peaks for both NCA and MCA. NCA was inhibited by anti-human-interleukin (IL)-8 antibody, granulocyte colony-stimulating factor (G-CSF) antibody, or leukotriene (LT)B4 receptor antagonist. Monocyte chemoattractant protein (MCP)-1 antibody or LTB4 receptor antagonist inhibited MCA. Immunoreactive IL-8, G-CSF, MCP-1, and LTB4 significantly increased in the supernatant fluids in response to smoke extract. These data suggest that the type II pneumocytes may release NCA and MCA and modulate the inflammatory cell recruitment into the lung.     

Inhibition of intimal hyperplasia after vein grafting by in vivo transfer of human senescent cell-derived inhibitor-1 gene

OBJECTIVE: To define the distribution and determinants of cardiovascular disease events among participants undergoing long-term antihypertensive therapy, and to stratify them into risk groups on the basis of pretreatment clinical profiles. DESIGN: A prospective cohort study of participants in a worksite-based antihypertensive treatment program in New York city (1973-1994). PATIENTS: We studied 8690 systematically treated patients who had at least 6 months of follow-up (average of 5.7 years) and, at entry, had had a systolic blood pressure of > or = 160 mmHg or a diastolic blood pressure of > or = 95 mmHg (after 1992 > or = 140/90 mmHg), or had been being administered antihypertensive medication. MAIN OUTCOME MEASURES: Blood pressure and incidence of morbid and mortal cardiovascular events. RESULTS: Blood pressure control (to 140 +/- 3/87 +/- 7 mmHg) was achieved by the first year and maintained through 18 years of therapy. In nearly 50,000 person-years of follow-up, there were 468 cardiovascular disease events [myocardial infarction including revascularization (282), strokes (93), congestive heart failure (30) and other cardiovascular deaths (63)]. Deaths from cardiovascular disease events accounted for 68% of all deaths. Myocardial infarction was most common throughout, but congestive heart failure incidence surpassed stroke incidence after 10 years. A scheme for risk stratification was constructed after analysis of the independent association of baseline factors and incident cardiovascular events. Upon the basis of ease of ascertainment and their demonstrated associations with occurrence of cardiovascular disease during treatment, we selected five pretreatment factors (history of heart attack, stroke, diabetes, age > or = 55 years and pulse pressure > or = 60 mmHg) to stratify patients into four groups. Those with no risk factor had a low risk (n=2999), those with one had a moderate risk (3042), those with two had a high risk (2237), and those with three or more had a very high risk (412). Overall, the unadjusted rates of incidence of cardiovascular disease events per 1000 person-years for patients in very high and low risk groups differed by factors of six and 14 for men and women, respectively. CONCLUSION: These results demonstrate that long-term control of blood pressure can be achieved in a general population. Nevertheless, cardiovascular disease events still accounted for most morbidity and mortality among these 'recovered' hypertensive patients. At entry, on the basis of readily identifiable characteristics, it was possible to stratify patients according to likelihood of subsequent events occurring despite control of blood pressure. This scheme could provide the basis for targeting more aggressive therapy where the potential for further cardioprotection is greatest.     

Three patients with insulin-treated diabetes and senile dementia of Alzheimer''s type

Caught between the successes of modern psychopharmacology, the requests of suffering patients for quick relief, and the shortsightedness of many third-party payers, psychodynamic psychotherapy might seem to be on the ropes. It is, however, thriving and providing crucial help to many individuals for whom medication and brief counseling are insufficient. Meanwhile, many more who could benefit from psychotherapy do not have an opportunity to do so. Although psychodynamic psychotherapy originated and developed within a medical framework, it has minimal visibility on the current medical scene, and many physicians have been provided with little meaningful information about it. This article is intended to give physicians a general idea of what psychodynamic psychotherapy is and how it works.