Clinical and prognostic aspects of adrenocortical neoplasms in childhood

BACKGROUND: A retrospective study of 54 children was undertaken to define the clinical presentation and secretory patterns of adrenal tumors and to evaluate the outcome of surgical resection and medical therapy. PROCEDURES: Different factors were studied in univariate and multivariate analysis by using the Cox proportional hazard model. RESULTS: Median age at diagnosis was 4 years. Boys and girls were affected equally. The disease was revealed by virilization (61%) or by a palpable mass (39%) with a 0.1-5.5 year delay from initial symptoms. At initial examination, we found that 76% of children were virilized. Ninety-four percent of the tested tumors secreted androgens, which were associated with glucocorticoids in 36%. Adrenal tumors in children were smaller than in adults. Half of them measured less than 10 cm. There were recurrences in 40% of children. The survival rate at 5 years was 49%, 70% if resection was microscopically complete and 7% if not (P < 0.001). CONCLUSIONS: In children, rare adrenal tumors have different diagnostic and prognostic characteristics than in adults; however, recurrences remain frequent. The efficacy of chemotherapy, mainly o,p'-DDD (Mitotane), remains to be evaluated in comparative trials.     

Small-signal analysis of 1.3-μm microcavity light-emittingdiodes

The modulation speed of 1.3-μm microcavity light-emitting diodes (MCLEDs) has been measured using a small-signal modulation analysis. A speed of 260 MHz using a 25-μm diameter sample at current density of 10 kA/cm² has been achieved. The carrier confinement has been calculated for several carrier densities in order to investigate the origin of the speed limitation. By comparing the performance of the 1.3-μm MCLEDs with that of the 990-nm devices we conclude that the limiting factor on the speed seems to be a lack of carrier confinement in the quantum wells and not a cavity effect     

Comparative behaviour of coal and maceral concentrates during artificial coalification

A series of experiments were performed in cold-seal autoclaves (confined-pyrolysis) to characterize the behaviour of individual macerais (vitrinite, inertinite, exinite) extracted from the same Lorraine Basin coal during artificial coalification. Rock-Eval pyrolysis, elemental analysis and weight loss determination provided the simple maturation indexes required. Emphasis was laid on the timing of hydrocarbon generation and on the possible similarities existing between inertinite and vitrinite of higher rank. Hydrocarbon potential and hydrocarbon yield were found to increase from inertinite to vitrinite and exinite, but similar mechanisms were involved during the thermal degradation of both inertinite and vitrinite.     

Kinematics of the pelvic girdle and the thoracic and lumbar segments in the course of the lateral inclinations and rotations of the spine

Physiological displacements of the trunk are the addition of these of the pelvic girdle and thoracic and lumbar spine segments. For a long time (3), this conjunction had been noticed but without numbered precisions. The purpose of this communication is to appreciate quantitatively, from a series of 16 subjects, the respective share of each components during lateral bending movements in the frontal plan and movements of rotation in the transverse plan. It results from this work that the pelvic girdle presents as reduced amplitude (4 degrees) in lateral bending on the other hand, displacement predominate to the level of thoracic spine (50 degrees). In rotation pelvic displacements are very important (30 degrees), while the spine so thoracic that lumbar has a weak participation (inferior to 5 degrees). Moderated abduction of hips increases by significant manner the motility of the pelvic girdle.     

Inventory on the dietary assessment tools available and needed in africa: a prerequisite for setting up a common methodological research infrastructure for nutritional surveillance,research, and prevention of diet-related non-communicable diseases

Objective: To carry out an inventory on the availability, challenges, and needs of dietary assessment (DA) methods in Africa as a pre-requisite to provide evidence, and set directions (strategies) for implementing common dietary methods and support web-research infrastructure across countries. Methods: The inventory was performed within the framework of the “Africa's Study on Physical Activity and Dietary Assessment Methods” (AS-PADAM) project. It involves international institutional and African networks. An inventory questionnaire was developed and disseminated through the networks. Eighteen countries responded to the dietary inventory questionnaire. Results: Various DA tools were reported in Africa; 24-Hour Dietary Recall and Food Frequency Questionnaire were the most commonly used tools. Few tools were validated and tested for reliability. Face-to-face interview was the common method of administration. No computerized software or other new (web) technologies were reported. No tools were standardized across countries. Conclusions: The lack of comparable DA methods across represented countries is a major obstacle to implement comprehensive and joint nutrition-related programmes for surveillance, programme evaluation, research, and prevention. There is a need to develop new or adapt existing DA methods across countries by employing related research infrastructure that has been validated and standardized in other settings, with the view to standardizing methods for wider use.     

Comparing the growth of a molecular semiconductor on amorphous and semi-crystalline polycarbonate substrates

Polymeric substrates are of importance in plastic electronics. However, polymeric surfaces can exhibit different morphologies depending on whether they are amorphous or semi-crystalline. This work focuses on the impact of the surface structure of bisphenol A polycarbonate substrates on the nucleation and growth of a p-type semi-conductor, namely zinc phthalocyanine (ZnPc). ZnPc films were deposited under high vacuum at different substrate temperatures on oriented semi-crystalline as well as amorphous substrates of PC. The oriented substrates of PC were prepared by a method combining mechanical rubbing and solvent induced crystallization: the substrates show a periodic and regular alternation of oriented crystalline lamellae. Grazing incidence X-ray diffraction shows that the crystalline lamellae of PC have a preferential (a, c) contact plane. Moreover, the substrates show a bilayer structure made of a 60 nm-thick semi-crystalline overlayer atop an amorphous underlayer. UV–vis spectroscopy shows that the polymorphism of the ZnPc films is not modified by the surface structure of the PC substrate (amorphous versus semi-crystalline). However, the statistical analysis of domain size and density versus substrate temperature T_s evidences different apparent activation energies of the growth mechanism. High Resolution Transmission Electron Microscopy suggests that twinning along a (2 ?1 0) plane accounts for the bifurcations of the in-plane b-axis direction of the ZnPc nanocrystals. On oriented substrates of PC, such bifurcations are partly suppressed by the nanocorrugation of the surface, resulting in larger apparent domain sizes and unidirectional in-plane orientation.     

Anisotropic loss of toughness with physical aging of work toughened polycarbonate

We have studied the response of mechanically toughened and physically aged polycarbonate primarily using Charpy impact and ultrasonic wave speed measurements. The toughening was conducted through plastic compression on as‐received PC. The Charpy impact tests showed anisotropic toughening, both in the absorbed energy and in the mode of fracture. The amount of toughening with plastic compression, even though anisotropic, is centered around the response of annealed and quenched samples, which represent the response of an unaged PC. There was an anisotropic drop in the toughness of some samples with aging. The time of this drop was uncorrelated in the different directions and disappeared for the highly toughened samples. This transition was bimodal and statistically distributed between either a fully ductile or a fully brittle failure. As the samples were prepared in a manner to remove induced residual stresses, this drop in toughening may be associated with an intrinsic anisotropic thermal aging of the deformed material. POLYM. ENG. SCI., 54:794–804, 2014. © 2013 Society of Plastics Engineers     

Nonuniform injection current induced unusual chirp behavior of afour-electrode bistable distributed Bragg reflector laser

A complete analysis of the chirp of a four-electrode bistable distributed Bragg reflector laser is given in theory and by experiment. Experimentally, the chirp investigation is realized by a Mach-Zehnder interferometer. In small-signal regime, the modulus and phase of 2β/m, frequency and amplitude modulation index ratio, is measured for different injection currents and shows an unusual behavior against the modulation frequency. A theoretical model including nonuniform injection current shows the same behavior of 2β/m against the modulation frequency and proves that the nonuniform carrier distribution inside the cavity is the origin of the specific behavior. The large-signal analysis provides a study of the instantaneous chirp behavior during optical switching     

Accroissement d’atténuation prévisible sur des fibres unimodales placées en atmosphère d’hydrogène

Behavior of GeO ₂ core doped, matched cladding singlemode fiber structures fitted for 1.3 μm and for 1.55 μmare studied at high temperature in hydrogen atmosphere. Loss increase prediction for submarine cables after 25 years at 3° C is less than 10 ^?4 dB/km at operating wavelengths.     

Immunochemical analysis of UMP kinase from Escherichia coli

Mono- and polyclonal antibodies directed against UMP kinase from Escherichia coli were tested with the intact protein or with fragments obtained by deletion mutagenesis. As detected in enzyme-linked immunosorbent assay tests, the carboxy-terminal quarter of UMP kinase is immunodominant. Polyclonal antibodies inhibited the enzyme activity with partial or total loss of allosteric effects exerted by UTP and GTP, respectively. These data indicate that the UTP and GTP binding sites in UMP kinase are only partially overlapping. One monoclonal antibody (44-2) recognized a linear epitope in UMP kinase between residues 171 and 180. A single substitution (D174N) in this segment of the enzyme abolished its interaction with the monoclonal antibody (44-2). Polyclonal antisera were used to identify UMP kinase in the bacterial proteome. The enzyme appears as a single spot on two-dimensional electrophoresis at a pI of 7.24 and an apparent molecular mass of 26 kDa. Immunogold labeling of UMP kinase in whole E. coli cells shows a localization of the protein near the bacterial membranes. Because the protein does not contain sequences usually required for compartmentalization, the aggregation properties of UMP kinase observed in vitro might play a role in this phenomenon. The specific localization of UMP kinase might also be related to its putative role in cell division.