Primary pancreatic non-Hodgkin''s lymphoma in a renal transplant recipient

Dormant preadipocytes isolated from adipose tissue are able to differentiate into adipocytes in vitro. A few adipogenic hormones (glucocorticoids or prostacyclin, IGF-I and insulin) are sufficient to trigger the differentiation program. In preadipose and adipose cells, glucocorticoids play a cardinal role by regulating the expression of numerous genes and by increasing the production of prostacyclin which acts as an intracrine/autocrine/paracrine effector. Fatty acids and metabolites (including prostacyclin) enhance adipocyte differentiation via the activation of nuclear peroxisome proliferator-activated receptors (PPARs). PPARs then modulate positively the expression of various lipid-related genes involved in triacylglycerol accumulation. These in vitro observations emphasize the importance of the hypothalamic-pituitary-adrenal axis and provide also a link which may take place in vivo between high-fat diets and the excess of adipose tissue development.     

Monolithic large-signal transimpedance amplifier for use in multi-gigabit, short-range optoelectronic interconnect applications

A novel large-signal transimpedance amplifier front-end, intended for monolithic integration with a Si p-i-n diode and employing HBT-CMOS technology for use in short-range optoelectronic interconnects is proposed. Simulated bandwidth and gain are >4 Gbits/s and 43 dB/spl Omega/, respectively, while driving a 100-fF load to TTL voltage levels.     

Predicting nonlinear electrical performance in single and multiplequantum-barrier varactors (QBV's) by the Monte Carlo technique

In this paper, nonlinear characterization and simulation of single and multiple quantum barrier varactors (QBV's) are obtained by using a multiparticle Monte Carlo simulator. The I-V relation is deduced directly from the equivalent charge variation and the bias voltage. The C-V characteristics are simply calculated from the width of the depletion region in a similar manner as for a parallel plate capacitor. The RF behavior is also simulated by modulating the voltage at 50 GHz and by performing an FFT of the current to study higher harmonic content of the QBV's. It is observed that only odd harmonics are generated and the current level of the third harmonic is about 10% of the injected signal current level. It is also shown that the use of multistack barriers can reduce the current density and the capacitance in accordance with the number of barriers in addition to increasing the breakdown voltage     

Intrinsic sinus node dysfunction in adolescence during anorexia nervosa

A seventeen year old girl with anorexia nervosa (32 kg; 165 cm) was admitted as an emergency after syncope with severe bradycardia resistant to atropine monitored over a one week period. Autonomic blockade confirmed the intrinsic character of the sinus node dysfunction with chronotropic incompetence on exercise. Secondarily, a Mobitz I second degree AVB was observed. A DDDR pacemaker was implanted with an excellent functional result. With a one year follow-up, the bradycardia persists but body weight has increased. The authors discuss the physiopathology of this case: in the literature, the classical bradycardia of anorexia nervosa is sensitive to vagolytic drugs and only exceptionally as intense as in this patient. Sinus node dysfunction is very rare in the young in the absence of congenital heart disease. It is possible that the bradycardia had become chronic in this case.     

Spray Pyrolysis Synthesized and ZnO–NiO Nanostructured Thin Films Analysis with Their Nanocomposites for Waveguiding Applications

Semiconductors - In this work, we have prepared ZnO, NiO, and nanocomposites ZnO–NiO thin films elaborated by the chemical method of spray pyrolysis on glass substrates at a temperature of...     

XBi4S7 (X = Mn,Fe): New Cost‐Efficient Layered n‐Type Thermoelectric Sulfides with Ultralow Thermal Conductivity

A new class of cost‐efficient n‐type thermoelectric sulfides with a layered structure is reported, namely MnBi₄S₇ and FeBi₄S₇. Theoretical calculations combined with synchrotron X‐ray/neutron diffraction analyses reveal the origin of their electronic and thermal properties. The complex low‐symmetry monoclinic crystal structure generates an electronic band structure with a mixture of heavy and light bands near the conduction band edge, as well as vibrational properties favorable for high thermoelectric performance. The low thermal conductivity can be attributed to the complex layered crystal structure and to the existence of the lone pair of electrons in Bi³⁺. This feature combined with the relatively high power factor lead to a figure of merit as high as 0.21 (700 K) in undoped MnBi₄S₇, making this material a promising n‐type candidate for low‐ and intermediate‐temperature thermoelectric applications.     

Relative efficiency of zinc oxide and zinc sulphate-enriched urea for spring wheat

Field experiments conducted at the Indian Agricultural Research Institute, New Delhi during 2005–2007 showed that the application of small amounts of zinc (Zn) in the form 0.5–2.0% of Zn-enriched urea significantly increased yield attributes, grain and straw yield, Zn concentrations in the grain and straw and Zn uptake by spring wheat. The agronomic and crop recovery efficiency of applied Zn decreased as the level of Zn-enrichment was increased from 0.5 to 2%. Zinc sulphate (ZnSO₄) and zinc oxide (ZnO) were equally effective in increasing the grain yield of wheat. Based on these results, we recommend the application of a 0.5–1.0% Zn enrichment of urea with ZnSO₄ or a 1.0% Zn-enrichment with ZnO.     

Mechanical properties of concrete with recycled coarse aggregate

This paper reports the results of an experimental study on some of the mechanical properties of recycled aggregate concrete (RAC) as compared to those of the conventional normal aggregate concrete (NAC). Ten mixes of concrete with target compressive cube strength ranging from 20 to 50 MPa were cast using normal or recycled coarse aggregates. The development of the cube compressive strength and the indirect shear strength at ages of 1, 3, 7, 14, 28 and 56 days, the compressive strength, the strains at maximum compressive stress and the modulus of elasticity tested by using concrete cylinders at 28 days are reported. The results show that the 28-day cube and cylinder compressive strength, and the indirect shear strength of recycled aggregate concrete were on the average 90% of those of natural aggregate concrete with the same mix proportions. For concrete with cylinder compressive strengths between 25 and 30 MPa, the modulus of elasticity of RAC was only 3% lower than that of NAC. The trends in the development of compressive and shear strength and the strain at peak stress in recycled aggregate concrete were similar to those in natural aggregate concrete.