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Background Patent ductus arteriosus in preterm neonates leads to significant morbidity. Surgery is indicated when pharmacological treatment fails or is contraindicated, but the optimal timing remains unclear.Methods We retrospectively studied all 41 preterm neonates with symptomatic ductus arteriosus who underwent ligation between 1988 and 2009. We compared early complications rates and late neurological outcomes of patients operated on before 21 days of age with these operated on later.Results The median gestational age at birth was 26 weeks (range 23–31 weeks) and median weight at birth was 930?g (range 510–1500?g); 34 (82.9%) received pharmacological treatment before surgery. Fourteen (34.1%) patients underwent surgical closure before 21 days of age and 27 (65.9%) after 21 days. The 2 groups did not differ significantly in gestational age and weight at birth, but those operated on after 21 days received significantly more pharmacological treatment cycles. Patients in the early closure group had shorter intubation times: median 23 days (range 13–35 days) vs. 43 days (range 27–84 days; p?

AbstractBackgroundThe aim of this study was to evaluate the surgical treatment of complex aortic coarctation using partial cardiopulmonary bypass to increase the spinal cord protection.MethodsA total of 15 patients (age range from 7 to 48 years) underwent coarctation repair through a left posterolateral thoracotomy with cardiopulmonary bypass. Cannulation was performed via the descending aorta and the main pulmonary artery. In all, six surgeries were performed under hypothermic circulatory arrest and nine repairs were performed under mild hypothermia. The clinical outcome regarding the development of restenosis, as well as major neurologic complication, was studied.ResultsThere was no mortality. None of the patients developed paraplegia. Of the 15 patients, two developed a recurrent stenosis at the proximal anastomosis between the aortic arch and the aortic prothesis at a mean follow-up of 5.5 years. In the remaining 13 patients, echocardiography and magnetic resonance imaging showed no evidence of a significant gradient.ConclusionComplex aortic coarctation without hypoplasia of the proximal aortic arch and intra-cardiac anomalies can be repaired with low mortality and neurologic morbidity via a left thoracotomy using cardiopulmonary bypass. The use of cardiopulmonary bypass goes along with a low risk of spinal cord and lower body ischaemia and provides a sufficient amount of time for the anastomoses.

Increased pulmonary blood flow in patients with left-to-right shunt has been shown to be associated with alterations in prostacyclin-synthesis. There are limited data with respect to the plasma cAMP in patients with elevated pulmonary artery pressure due to left-to-right shunt. We hypothesized that plasma cAMP might be influenced by pulmonary blood flow or pressure in patients with left-to-right shunt.

The uncoupled Continuous Time Random Walk (CTRW) in one space-dimension and under power law regime is splitted into three distinct random walks: (rw1), a random walk along the line of natural time, happening in operational time; (w2), a random walk along the line of space, happening in operational time; (rw3), the inversion of (rw1), namely a random walk along the line of operational time, happening in natural time. Via the general integral equation of CTRWand appropriate rescaling, the transition to the diffusion limit is carried out for each of these three random walks. Combining the limits of (rw1) and (rw2) we get the method of parametric subordination for generating particle paths, whereas combination of (rw2) and (rw3) yields the subordination integral for the sojourn probability density in space - time fractional diffusion.

AbstractBackgroundIntra-cardiac repair of congenital cardiac diseases in children with left?right shunt is often associated with acute elevation of pulmonary artery pressure following cardiopulmonary bypass. We studied the correlation between the Glu298Asp polymorphism of the endothelial nitric oxide synthase gene and pulmonary hypertension in children with congenital cardiac diseases.Methods and resultsA total of 80 children with congenital cardiac diseases at a median age of 3.8 years, ranged 0.1?36.2 years, and 136 controls were enrolled. Most patients presented with significant left-to-right shunt ? pulmonary-to-systemic blood flow of 2.8, with a range from 0.6 to 7.5. In all, 40 out of 80 children showed pulmonary hypertension with mean pressure of 42, ranged 26?82, millimetres of mercury. Thirty-one out of 40 children underwent intra-cardiac repair and 15 out of 31 operated patients were found to have an acute elevation of pulmonary artery pressure after cardiopulmonary bypass. The Glu298Asp polymorphism was identified using polymerase chain reaction and restriction fragment length polymorphism. Both in patients and in controls, the genotype distribution corresponded to the Hardy?Weinberg equilibrium. The gene frequency for Glu298Glu, Glu298Asp and Asp298Asp was not different in the control group compared to the patients (Armitage trend test: p = 0.37). The endothelial nitric oxide synthase polymorphism was related to acute post-operative elevation of pulmonary artery pressure (genotypic frequency 53.3 versus 25%; Armitage trend test: p = 0.038). In addition, the allelic frequency of the Glu298Asp was related to post-operative pulmonary hypertension (Fischer?s exact test: p = 0.048). The positive predictive value was 71.43%.ConclusionPatients with left-to-right shunt are more likely to develop acute elevation of pulmonary artery pressure after cardiopulmonary bypass when presenting with the Glu298Asp polymorphism of the gene endothelial nitric oxide synthase. This could be used as a genetic marker for the predisposition for the development of pulmonary hypertension after intra-cardiac repair.

In a Fontan circuit the mechanisms involved in control of cardiac output at rest and during exercise differ significantly from normal. The classical model presumes an unlimited preload which is not available in the Fontan circuit. This review critically analyses the role of contractility, heart rate, and afterload and highlights the importance of pulmonary vascular resistance (PVR) in determining adequate preload and, therefore, cardiac output in these patients. A conceptual model of the determinants of cardiac output in Fontan patients is presented.

Ventricular dysfunction is frequently encountered in Fontan patients. Cardiologists and cardiac surgeons have, therefore, mainly focused on preservation of cardiac function, limiting the early volume overload as much as possible both in magnitude and duration. This resulted in improved cardiac function but, in some patients, also in poor pulmonary artery (PA) growth which in turn resulted in a poor final Fontan circuit. The volume requirements for optimal growth and development of the ventricle and the lungs are different and divergent. Avoiding overload of the ventricle is important, but excessive protection from volume overload may not be necessary and may result in PA hypoplasia, which in turn will severely affect the Fontan circuit.

AbstractBackgroundWe present a group of infants and children with pulmonary arterial sling and tracheal stenosis. In some of the patients, the anomalously located pulmonary artery had previously been reimplanted, but without simultaneous repair of the trachea.MethodsFrom 1992 to 2007, we reimplanted the left pulmonary artery in 13 children with a pulmonary arterial sling. Their median age was 8 months, with a range from 1 to 72 months. We also performed tracheal resection with end-to-end anastomosis, or complex tracheal reconstructions. In 5 patients, the reoperation was indicated because of persistent tracheal stenosis not treated initially at first correction of the arterial sling. All patients presented with stridor and respiratory distress. Cardiac catheterization, bronchoscopy and multidetecting computer tomography angiography were performed in all cases prior to the operation. All operations were performed under cardiopulmonary bypass.ResultsThere was no operative or late mortality. The patients were extubated under bronchoscopic control. The mean period of intubation was 18 plus or minus 8 days, and the average follow-up was 8 plus or minus 4 years. The patients showed no signs of tracheal re-stenosis clinically or on bronchoscopy. The group of the patients under reoperations, however, required longer periods of intubation and hospitalization.ConclusionOur experience demonstrates that, in patients with a pulmonary arterial sling, any associated tracheal stenosis should be explored at the initial operation, since decompression of the trachea by reimplanting the anomalously located pulmonary artery fails to provide relief. The funnel trachea, if present, undergoes progressive stenosis, and will require surgical repair. The use of cardiopulmonary bypass permitted extensive mobilization of the tracheobronchial tree, and allowed us to perform a tension-free anastomotic reconstruction of the trachea.

We studied the effect of chronic endothelin A receptor blockade by atrasentan on the pulmonary endothelin-1 system and vascular endothelial growth factor (VEGF) expression in piglets with high pulmonary blood flow. Twenty-five 4-week-old piglets with high pulmonary blood flow were randomized to three groups: sham operated (n = 8), placebo (water) (n = 7), or treatment with atrasentan (2 mg/kg per day) (n = 10). After 3 months, mean pulmonary arterial pressure (PAP) was higher in the placebo group than in the sham group [18 ± 2 mm Hg versus 14 ± 1 mm Hg; P< 0.05 (ANOVA)]. Atrasentan treatment was associated with lower cardiac output, PAP (14 ± 1 mm Hg), and medial wall thickness of pulmonary arteries (diameter: 50-150 μM) compared with placebo [13.6 ± 3.0% versus 18.1 ± 4.2%; P< 0.05 (ANOVA)]. Quantitative real-time polymerase chain reaction for endothelin-1, endothelin B receptor, and endothelin-converting enzyme-1 mRNA in lung tissue did not differ. However, immunostaining as well as mRNA for VEGF were lower in atrasentan-treated animals (relative gene expression: atrasentan versus placebo: 0.8 ± 0.3 versus 1.5 ± 0.3; P= 0.009). Atrasentan treatment effectively reduces medial hypertrophy in piglets with chronic pulmonary hyperperfusion. Chronic endothelin A receptor blockade by atrasentan may interfere with the expression of VEGF.

Family presence during cardiopulmonary resuscitation in children is an emerging practice. Although many hospitals allow this practice, there is scant research on physician attitudes and opinions and on physician views about training for resident physicians.

AbstractEin Terahertz-Time-Domain-Spektroskopie- (THz-TDS-) System mit elektrooptischem Detektor auf der Basis von ZnTe wird vorgestellt. Als Laserquelle dient ein Ti:Sa-Laser, der Laserpulse mit einer Dauer von ca. 10 fs bei einer zentralen Wellenlänge von 800 nm liefert. Durch Optimierung des Detektionsverfahrens wurde mit nur 25 mW Laserleistung ein Signal-Rausch-Verhältnis (SNR) von größer als 103erzielt. Die aufgenommenen Spektren bekannter Substanzen weisen materialspezifische Absorptionslinien auf und erlauben deren eindeutige Erkennung.

Mutations of the bone morphogenetic protein receptor II (BMPR2) gene on chromosome 2q33 can cause familial primary pulmonary hypertension (PPH) and may occur in 26% adult patients with sporadic disease. Other disease-related genes have been localized to chromosomes 2q31 (PPH2) and 12q13 (ALK1). The genetic background in affected children remains unclear. Thirteen children (age at diagnosis, 6 mo to 13 y; mean, 5.6 ± 3.9 y) with invasively confirmed PPH were screened for BMPR2mutations using denaturing HPLC and sequence analysis. In addition, all children were scanned for BMPR2deletions by Southern blot analysis. Pulmonary artery pressure was assessed using echocardiography at rest and during exercise in 57 family members of six infants. The six families were subjected to linkage analysis. None of the 13 children had a BMPR2mutation or deletion. Linkage to chromosome 2 or 12 could not be confirmed in any of the families investigated. In all assessed families, both parents of the index patient and/or members of both branches revealed an abnormal pulmonary artery systolic pressure (PASP)-response to exercise. PPH in children may have a different genetic background than in adults. We postulate a recessive mode of inheritance in a proportion of infantile cases.

In this review, we discuss current concepts in the pathogenesis and management of pulmonary hypertension affecting infants and children, with special focus on left-to-right shunting, bronchopulmonary dysplasia, and primary pulmonary hypertension.In patients of these ages, functional aspects, such as an imbalance between vasoconstricting and vasodilating mechanisms, and morphological alterations of the vessel wall, contribute to the pulmonary hypertension. In the past decades, strategies have emerged for treatment that are targeted at the pathophysiological basis. Thus, in patients with left-to-right shunting and pulmonary hypertension after intra-cardiac repair, treatment with nitric oxide has been introduced effectively, while treatment with prostanoids, such as iloprost, is under investigation. In patients with pulmonary hypertension and bronchopulmonary dysplasia, therapeutic strategies focus on the underlying chronic lung disease and use of vasodilators. The pathogenesis of primary pulmonary hypertension in children remains as yet unclear, although treatment with prostanoids has proven effectively to improve the long-term prognosis.

A considerable amount of the constituents in wastewater of the pulp and paper mill industry is not biodegradable. As an alternative to the usual coagulation, flocculation, and sedimentation of the substances, the combination of ozonation and a subsequent biological treatment step has been proposed. Ozonation in combination with microbiological treatment was employed to remove ligninsulfonic acid and refractory organic substances from the effluent of a paper mill wastewater treatment plant. Laboratory experiments showed that ligninsulfonic acid was converted into low‐molecular‐weight acids which were biodegradable.

Increasing worldwide demand for mammalian cell production capacity will likely be partially satisfied by a greater use of higher volumetric productivity perfusion processes. An important additional component of any perfusion system is the cell retention device that can be based on filtration, sedimentation, and/or acoustic technologies. A common concern with these systems is that pumping and transient exposure to suboptimal medium conditions may damage the cells or influence the product quality. A novel air‐backflush mode of operating an acoustic cell separator was developed in which an injection of bioreactor air downstream of the separator periodically returned the captured cells to the reactor, allowing separation to resume within 20 s. This mode of operation eliminated the need to pump the cells and allows the selection of a residence time in the separator depending on the sensitivity of the cell line. The air‐backflush mode of operating a 10L acoustic separator was systematically tested at 107cells/mL to define reliable ranges of operation. Consistent separation performance was obtained for wide ranges of cooling airflow rates from 0 to 15 L/min and for backflush frequencies between 10 and 40 h−1. The separator performance was optimized at a perfusion rate of 10 L/day to obtain a maximum separation efficiency of 92 ± 0.3%. This was achieved by increasing the power setting to 8 W and using duty cycle stop and run times of 4.5 and 45 s, respectively. Acoustic cell separation with air backflush was successfully applied over a 110 day CHO cell perfusion culture at 107cells/mL and 95% viability.

Acoustic cell retention devices have provided a practical alternative for up to 50 L/day perfusion cultures but further scale-up has been limited. A novel temperature-controlled and larger-scale acoustic separator was evaluated at up to 400 L/day for a 10⁷ CHO cell/mL perfusion culture using a 100-L bioreactor that produced up to 34 g/day recombinant protein. The increased active volume of this scaled-up separator was divided into four parallel compartments for improved fluid dynamics. Operational settings of the acoustic separator were optimized and the limits of robust operations explored. The performance was not influenced over wide ranges of duty cycle stop and run times. The maximum performance of 96% separation efficiency at 200 L/day was obtained by setting the separator temperature to 35.1°C, the recirculation rate to three times the harvest rate, and the power to 90 W. While there was no detectable effect on culture viability, viable cells were selectively retained, especially at 50 L/day, where there was a 5-fold higher nonviable washout efficiency. Overall, the new temperature-controlled and scaled-up separator design performed reliably in a way similar to smaller-scale acoustic separators. These results provide strong support for the feasibility of much greater scale-up of acoustic separations. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 438–444, 2002.

No abstracts.

We consider the operator M of convolving a function g supported in the finite interval [-1,1] with the Hankel function [image omitted] . We derive a characterization of the range of M, considered as an operator on LP([ - 1,1]), in terms of the Hilbert transform. This characterization can be used as a starting point for solving the integral equation Mg=f with f contained in the range of M. The characterization of the range of M is obtained by applying contour integration methods in the complex plane and it can be expected that by applying such techniques also the ranges of other integral operators can be characterized

Both secundum atrial septal defect (ASD) and patent foramen ovale (PFO) have been closed interventionally using several different occluding devices. At a single institution we strived for interventional occlusion of interatrial communications using the Amplatzer device exclusively. During a study period of 22 months, we studied 48 patients ranging in age from 1 to 48 years with an ASD (n = 45) or a PFO (n = 3). Successful implantation of an Amplatzer device was possible in 92% of the patients, and 95% of these patients had a complete early closure of their defect. There were no complications related to the procedure. We conclude that interventional closure of interatrial communications with the Amplatzer device is feasible and safe for selected patients.

KININGHAM, R. B., and D. W. GORENFLO. Weight loss methods of high school wrestlers. Med. Sci. Sports Exerc., Vol. 33, No. 5, 2001, pp. 810–813.

Asymmetrical dimethyl-l-arginine (ADMA) is an endogenous inhibitor of nitric oxide synthase. We hypothesized that plasma levels of ADMA could be increased in patients with congenital heart disease and pulmonary hypertension. Cardiac catheterization was performed in 20 children and young adults with congenital heart disease with a median age of 10 years (range, 4 months to 33 years). The patients were assigned to group I (high flow, low pressure; n 14) when Qp/Qs was 1.5 or greater and the mean PAP was less than 25 mm Hg or to group II (high pressure, high resistance; n 6) when the mean PAP was greater than 25 mm Hg and Rp/Rs was greater than 0.3. Blood samples were taken from pulmonary vein or left ventricle. ADMA was measured by high-performance liquid chromatography. In addition, levels of ADMA were measured in peripheral venous blood obtained from eight control patients. Levels of ADMA in control patients (median, 0.21 M/l; range, 0.08–0.27 M/l) did not differ from levels obtained in group I (median, 0.30 M/l; range, 0.06–0.49) M/l). Patients in group II showed increased plasma levels of ADMA (median, 0.55; range, 0.25–0.79) (p < 0.01). Inhibition of nitric oxide synthase by increased levels of ADMA might contribute to pulmonary hypertension in patients with congenital heart disease.

A process for the large-scale production of 4-hydroxyvalerate (4HV)-containing biopolyesters with a new monomer composition was developed by means of high-cell-density cultivation applying recombinant strains of Pseudomonas putida and Ralstonia eutropha, harboring the PHA-biosynthesis genes phaC and phaE of Thiocapsa pfennigii. Cell densities of about 20 g/L revealing a PHA content of 52% (w/w) and a molar fraction of 4HV of up to 15.4 mol % were obtained by a two-stage fed-batch cultivation process at a 25-L scale using octanoic acid during the growth phase and levulinic acid for the accumulation of 4HV-containing polyesters. Besides 4HV the polyester contained significant amounts of both 3-hydroxybutyric acid (3HB) and 3-hydroxyvaleric acid (3HV) and traces of 3-hydroxyhexanoic acid (3HHx) and 3-hydroxyoctanoic acid (3HO). With glucose or gluconic acid as the growth substrate, the components of the polyester could be reduced to mainly 3HV and 4HV with only a negligible fraction of 3HB, resulting in a polyester with a new composition. Scale-up of the cultivation process to a 500-L scale was successfully performed, resulting in the production of these polyesters at a pilot plant scale. Short-term shifts in temperature and pH resulted in the formation of cell agglomerates of about 50−100 μm by which the effectiveness of the semicontinuous centrifugation process was drastically increased. Washing of the freeze-dried cells with boiling methanol significantly shortened the extraction process and resulted in a polyester of higher purity. The physical and mechanical properties of these copolyesters were characterized by means of size exclusion chromatography, dynamic mechanical analysis, differential scanning calorimetry, stress−strain measurements, and measurements of the viscosity of the solution. The copolyesters were cast into films, spun to fibers, or processed into test bars by melt spinning and injection molding, respectively. They revealed an almost entirely amorphous structure and consequently were sticky and lacked strength. However they showed high thermal stability and an unusually high elongation at break of about 200%; the molecular weights (Mw) were between 2.0 × 10⁵ and 3.3 × 10⁵ g/mol. It was shown that 4HV-containing polyesters belong to the class of thermoplastic elastomeres.

The pulmonary arterial smooth muscle cell (SMC) cytoskeleton was studied in tissue from 36 piglets aged from within 5 min of birth to 21 d of age, and in 8 adults. An additional 16 piglets were made pulmonary hypertensive by exposure to hypobaric hypoxia (50.8 kPa) for 3 d. In conduit intrapulmonary elastic arteries α, β and γ actin, the 204, 200 and 196 kDa myosin heavy chain (MHC) isoforms and vinculin were localised by immunohistochemistry. The total actin content, the proportion of monomeric to filamentous α and γ actin and changes in the proportions of the MHC isoforms were determined biochemically. Dividing SMCs were localised and quantified using Ki‐67. We found a transient reduction in immunohistochemical expression of γ actin, 204 kDa MHC isoform and vinculin at 3 and 6 d in the inner media, associated with a transient increase in Ki‐67 labelling. The actin content also decreased at 3 and 6 d (P< 0.05), but there was a postnatal, permanent increase in monomeric actin, first the α then the γ isoform. The relative proportions of the MHC isoforms did not change between birth and adulthood in elastic pulmonary arteries but in muscular arteries the 200 kDa isoform increased between 14 d and adulthood. Pulmonary hypertension prevented both the immunohistochemical changes and the postnatal burst of SMC replication and prevented the transient postnatal reduction in actin content. These findings suggest that rapid remodelling of the actin cytoskeleton is an essential prerequisite of a normal postnatal fall in pulmonary vascular resistance.

AbstractEndothelin-1 (ET-1), with its vasoconstrictive and proliferation-stimulating effects, could play a role in the pathogenesis of primary pulmonary hypertension. We investigated the relationship between the ET-1 like immunoreactivity and the ET-receptor density, the grade of the pulmonary vasculopathy, and properties of the pulmonary circulation in patients with pulmonary hypertension due to congenital heart disease.Twenty-six patients with a median age of 1 year and 1 month (6 weeks–17 years–9 months) were assigned to group I (n = 15) with a pulmonary to systemic flow ratio (Qp/Qs) ≥ 1.5 and a pulmonary to systemic resistance ratio (Rp/Rs) ≤ 0.3 (“high flow–low resistance group”) and to group II (n = 11) with a Qp/Qs < 1.5 and an Rp/Rs > 0.3 (“low flow–high resistance group”).Patients belonging to group II showed a higher ETA-receptor density in lung arteries (p < 0.05) and parenchyma (p < 0.01) than patients in group I. Patients with the highest ET-1 like immunoreactivity in lung artery walls also showed a trend towards a higher ETA-receptor density. The ETB-receptor expression was low and not related to any of the above factors.Our results suggest that the paracrine lung ET-1 system is up-regulated in pediatric patients with secondary pulmonary hypertension associated with congenital heart disease.

Background.Despite the proven success of national efforts such as the Special Supplementary Food Program for Women, Infants, and Children (WIC) to curb childhood iron deficiency anemia (IDA) in the United States, aggregate programmatic data may not accurately represent the experience of particularly high risk groups, such as the children of adolescent mothers of low socio-economic status.

The problem of heating a homogeneous half-space by radiation from outside across the plane boundary is considered. Newtonian heating means that the heat flux across the boundary is proportional to the difference of outside temperature and interior boundary temperature. The outside temperature is assumed to be constant and positive, the initial inside temperature is zero everywhere. The problem is onedim ensional in space. The temporal evolution of the inward boundary temperature obeys an Abel integral equation of second kind for whose explicit solution three methods are described (one by Laplace transform , the other two by infinite series defining the Mittag-Leffler function of index 1/2). The explicit solution facilitates discussion of its qualitative properties. Finally, the general Abel integral equation of second kind is treated by Mittag-Leffler functions.

A two-stage aerobic fed-batch process for the biotechnological production of polyesters containing 4-hydroxyvaleric acid (4HV) and medium-chain-length hydroxyalkanoic acids by a recombinant strain of Pseudomonas putida was developed in mineral salts medium with octanoic and levulinic acid as carbon sources at a 15-L scale. The cells were first grown to high densities on octanoic acid at a pH between 7 and 8 and at a temperature of 30 °C. Accumulation conditions were induced in the second stage by nitrogen starvation at pH 7.0 and at 35 or 37 °C while levulinic acid was continuously supplied. At the end of the accumulation phase, 4HV-containing polyesters, contributing up to 50% (w/w) of the cellular dry weight, were cast into films after extraction with chloroform and precipitation with ethanol, and were spun to fibers. The unprocessed as well as the processed polyesters were characterized with respect to their molecular weight and their thermal, rheological, and mechanical properties. These polyesters showed a distinctly elastomeric behavior resulting from the low content of medium chain-length hydroxyalkanoic acids. The polyester revealed an extremely high elongation at break of approximately 1000%; the molecular weights (Mw) were between 3.3 × 10⁵ and 9.4 × 10⁵ g/mol and decreased during the melt spinning process.

One of the most fundamental challenges facing the Republic of the Marshall Islands is changing regional organization, with population and economic resources becoming increasingly concentrated at two urban centers. Present national planning objectives focus upon developing the means to accommodate these centers. But such development strategies often encounter difficulties, for centralization on the order currently found in the Marshalls has neither historic nor sociocultural precedent. In this study regional change in the Marshall Islands is examined in terms of demographic development, and regional evolution assessed through complementary statistical measures of spatial autocorrelation, point-to-point temporal association, and spatio-temporal association. It is concluded that the current regional imbalance in population and human resources in the Marshalls represents a significant break from past trends which may well be unsustainable. Alternative regional planning strategies are suggested which appeal to the historic and sociocultural foundations of the area.

Heat transfer with pool boiling of hexane was measured for single plain and finned steel tubes with great diameter and very rough, sandblasted surface. The results show that the heat transfer coefficients calculated for the outer surfaces of both tubes are higher in the case of the finned tube at high heat fluxes, and gradually diminish down to the values of the plain tube until natural convection without bubble formation has been reached. Additional measurements using a plain tube with much smaller diameter but identical surface treatment indicate that great differences of the tube diameter influence the increase of the heat transfer coefficient with heat flux significantly, the relative pressure dependence and the absolute values of the heat transfer coefficient at intermediate heat fluxes, however, are concerned on a smaller scale.

Regular exercise has been associated with numerous health benefits. In response, the promotion of regular exercise for patients has become a recommended component of preventive health care. The extent to which primary care physicians encourage their patients to exercise and the factors associated with exercise promotion are not well elucidated. We surveyed the attitudes and practices of 63 family physicians and 63 internists regarding exercise promotion to patients. We evaluated the associations between demography, cognition, belief, and behavior with exercise promotion. Several factors were associated with physicians’ recommending exercise to their patients. A logistic regression model suggests that physicians who have a follow-up plan, who have been in practice over 10 years, who exercise themselves, and who estimate that more than 10% of their patients exercise encourage exercise in >50% of their patients.

Bacterial poly(hydroxyalkanoate)s (PHA) are a complex class of polyesters, and almost one hundred different constituents are currently known. Unfortunately, most of these constituents only occur in the polyesters if specific precursor substrates are provided as carbon source. Recently, however, bacteria and mutants were isolated, which synthesize PHA exhibiting an interesting composition from simple unrelated substrates obtainable from renewable resources provided by the agriculture. This contribution will provide an example how PHA based on 4‐hydroxyvaleric acid can be obtained from bulk chemicals. In addition, some aspects of our current knowledge on the physiological and molecular basis of PHA biosynthesis will be provided.

The paper is devoted to the study of the properties of the special functions generalizing the Mittag-Leffler type functions. The order and type of such entire functions are evaluated and recurrence relations are given. Connections with hypergeometric functions are discussed and differentiation formulae are proved.

We show that the singular values σm of the fractional integration operator of order α0 acting from weighted L2 spaces of functions defined on the interval (-1,1) or (0,∞) may, in both cases, have asymptotics m-α or m-α/2, as m→∞, depending on the specific choice of weight functions. Some questions of singular value decompositions are also investigated for Riesz potential operators in weighted L2 spaces of functions defined on Rn.

A modification of the mikusinski operational caculus is used to obtain explicit solution of some classes of integral equations of the second kind of abel type .inparticular the solution of the generalized abel equation [image omitted]  with the riemann-liouville fractional integral opereator [image omitted]  is expressed in terms of the mittag-leffler function of several variables.

The integral equation [image omitted]  where 0<α<1, is considered under appropriate assumptions on K: For the approximate equation Au ≈ g regularization schemes are developed: (i) in Lp,(ii) in the space of functions of bounded variation, (iii) in the space of functions that are Hölder continuous of order γ where 0 <γ<1. The extra information is in case in case ,in case (i)[image omitted] , in case (ii)Var [image omitted] , in case (iii) [image omitted] .

Pulmonary vascular findings in infants with bronchopulmonary dysplasia (BPD) are inconsistent. We compared five infants who fulfilled histologic criteria of BPD (group I; survival up to 1 month) with five controls who died of severe neonatal infection without having been ventilated. Nine infants who survived up to 7 months also fulfilled clinical criteria of BPD (group II). These were compared with three term infants who died of nonpulmonary causes. Lung slices were examined qualitatively and by quantitative histomorphometry. The influence of oxygen concentration and positive pressure ventilation on arterial density was studied. Arterial concentration in group I [2.43 (0.63) vessels/mm2, mean ± SD] increased significantly compared with the controls [1.64 (0.49) vessels/mm2, mean ± SD]. Most infants in group II who had cor pulmonale at autopsy had decreased arterial density when compared with normal term infants. Postmortem pulmonary angiography was also consistent with this finding. Total oxygen dose was the factor with the greatest influence on reduced arterial density. Relative wall thickness of vessels less than 75 μm in diameter was not significantly reduced in group I (p > .05). Infants from group II with cor pulmonale had an increased wall thickness compared with their controls. The proportion of fully muscularized arteries less than 100 μm in diameter was reduced in group I but increased in group II. We conclude that the reduction of cross-sectional perfusion area and abnormal muscularization of more peripheral vessels are important in the pathogenesis of pulmonary hypertension in infants with BPD.