Nuclear transfer and cloning

Ultraviolet-induced erythema is now recognized as an important clinical marker for skin cancer risk. People with a history of repeated erythematous exposures to sunlight are more likely to develop both melanoma and nonmelanoma skin cancers. Is erythema the most important thing we need to be concerned about in terms of protecting the public from the harmful effects of sunlight? What do we know about UV-induced erythema, and why is it a powerful influence on skin cancer risk?     

Continuous active T-gate travelling-wave transistor

In the letter experimental results are presented which show that a continuous active gate travelling-wave transistor (TWT) can be used for medium power applications in a wide bandwidth. To reduce the gate resistance, a T-gate configuration has been chosen. This allows one to extend the frequency bandwidth of such a device. Simulations have been performed using small- and large-signal models taking in addition the parasitic capacitances into account. A distributed Schottky diode has been used to adjust the phase synchronisation and therefore to achieve flat gain.<>     

Influence of GMPLS on network providers' operational expenditures: a quantitative study

GMPLS is promoted as a major technology for the automation of network operations. It is often claimed to allow the reduction of operational expenses. However, detailed analysis and quantitative evaluation of the changes induced by such technologies is very rare. In this article we quantify the cost reduction potential of GMPLS. We present a detailed analysis and modeling of traditional operator processes. We also develop a model for the expected changed processes when using GMPLS and identify the differences quantitatively. A survey with major telecom operators has been done, and the process models have been verified and parameterized. This allowed quantitative evaluations of the OPEX changes with GMPLS. The results show that, depending on the network operator's processes, different impacts can be expected. As an overall result we could verify that a reduction on the order of 50 percent of OPEX can be expected for most operational models.     

Acute Meckel's diverticulum in a senior patient

Meckel's diverticulum is the most common congenital abnormality of the intestinal tract, occurring in 2% of autoptic studies. The case of an 85-year-old man referred to the Emergency Surgery Unit for intestinal obstruction and lower gastrointestinal tract bleeding is reported. Surgical exploration revealed a complicated Meckel's diverticulum full of coproliths, immersed in pus and blood. Examination of the resected diverticulum showed necrotic diverticulitis in the absence of ectopic gastric or pancreatic tissues.     

Clearance of technetium 99m N-NOET in normal, ischemic-reperfused, and membrane-disrupted myocardium

BACKGROUND: Technetium 99m-labeled bis(N-ethoxy, N-ethyl dithiocarbamato) nitrido technetium(v) (99mTcN-NOET) is a new neutral cardiac perfusion imaging agent that has been shown to have very high uptake and retention in vitro. The purpose of this study was to determine the clearance kinetics of 99mTcN-NOET in control, ischemic-reperfused, and membrane-disrupted myocardium. METHODS AND RESULTS: After a 100 microCi (3.7 x 10(6) Bq) bolus of 99mTcN-NOET was injected, myocardial clearance was monitored for 1 hour by the use of a sodium iodide detector in 30 isolated, Krebs-Henseleit (KH) perfused rat hearts. Seven hearts were used as controls (group 1). In seven ischemic-reperfused hearts, tracer administration and uptake was followed by 30 minutes of no flow and 1 hour of reflow (group 2). In six additional ischemic-reperfused hearts, tracer administration was followed by deprivation of flow for 1 hour followed by 1 hour of reflow (group 3). Six hearts were perfused with a 0.5% Triton X-100 KH perfusate for 1 hour (group 4). Four hearts were perfused with KH for 10 minutes, followed by cyanide for 10 minutes (group 5). This cycle was repeated three times. Activities remaining in each heart at the end of each experiment were quantitated, and activity at peak uptake was calculated. The 99mTcN-NOET myocardial clearance was near linear in the control (0.6 +/- 0.4) and both ischemic-reperfused groups with virtually no fractional clearance (1.2% +/- 0.6% and 2.1% +/- 0.6%, respectively; p = NS). In the Triton X-100 membrane-disrupted hearts, clearance was substantial (94.2% +/- 4.0%; p < 0.0001 compared with the control and ischemic-reperfused groups). Cyanide treatment produced rapid clearance, which was arrested by a return to the standard KH perfusate. Peak uptake as a percentage of injected dose was 74.9% +/- 1.4% for all groups combined. CONCLUSION: Thus 99mTcN-NOET has extremely high myocardial retention after 1 hour in normal myocardium and is not significantly affected by ongoing myocardial ischemia or reperfusion injury in this model. Clearance is increased markedly in extreme conditions of membrane disruption. These data are consistent with the concept that 99mTc-NOET is localized predominantly in or on cell membranes. 99mTcN-NOET is a promising, new myocardial perfusion imaging agent that exhibits a stable myocardial distribution in the setting of acute developing injury.     

Active immunological enhancement of sarcoma 180 in splenectomized Swiss mice

Maximal enhancement of tumor growth was obtained in Swiss mice, with or without spleen, inoculated with S180 within a subcutaneously implanted glass cylinder and pretreated with soluble tumor antigen.     

Plasma concentrations of ethynyl oestradiol and norethindrone after oral administration to women

Rapid vasicular resistance adjustments in the brain and in the circle of Willis have been continuously measured and enhanced by signal averaging methods. Naftidrofuryl, a drug chemically similar to local anesthetics and to beta adrenergic blocking agents, increases local CBF by reducing resistance in brain and in extracerebral supply arteries. It has also been reported to affect brain metabolism. Other similar drugs merit study for potential effects on CBF and brain metabolism which may be useful in treatment.     

Variations in Allelochemical Composition of Leachates of Different Organs and Maturity Stages of <Emphasis Type="Italic">Pinus halepensis</Emphasis>

We investigated changes in the occurrence of allelochemicals from leachates of different Pinus halepensis organs taking into account the stages of pine stand age (i.e., young  < 15-years-old, middle age ± 30-years, and old  > 60-years-old). GC-MS analysis of aqueous extracts revealed approx. 59 components from needles and roots. The major constituents were divided into different phytochemical groups—phenolics (50%), fatty acids (44%), and terpenoids. Further analyses were carried out to characterize the distribution of allelochemicals in different organs and P. halepensis successional stages. Roots and needles had two distinct chemical profiles, while needle leachates were composed mainly of oxygenated terpenoids (e.g., α-eudesmol, α-cadinol, and α-terpineol). Roots mainly contained fatty acids. Needles from young pine stands had the highest content of monoterpenes, suggesting their role as potential allelochemicals that could help young pine stands to establish. Pooling the different functional chemical groups showed that needles and, to a lesser extent, old roots, had higher chemical diversity than the roots of young and medium-aged pines. The highest diversity in phenolic constituents and fatty acids was in young needles (D_chem = 2.38). Finally, caffeic acid, a compound that has allelopathic properties was found in aqueous extracts at high concentrations in both young needles and old roots. The role of this compound in mediation of biological interactions in P. halepensis ecosystem functioning is discussed.     

Mutual coupling between slots printed at the back of ellipticaldielectric lenses

This paper presents calculations of the mutual admittance between two slots on a ground plane that are the primary feed of an elliptical dielectric lens antenna. This admittance may also be regarded as the basic constituent of a Galerkin method of moments formulation for the analysis of more complex feeding arrangements of slot antennas and coplanar waveguide circuits, it is found that the contribution of the reflection mechanisms inside the lens significantly affects the mutual admittance especially for H-plane coupling