Pseudospin-resolved transport spectroscopy of the Kondo effect in a double quantum dot.

We report measurements of the Kondo effect in a double quantum dot, where the orbital states act as pseudospin states whose degeneracy contributes to Kondo screening. Standard transport spectroscopy as a function of the bias voltage on both dots shows a zero-bias peak in conductance, analogous to that observed for spin Kondo in single dots. Breaking the orbital degeneracy splits the Kondo resonance in the tunneling density of states above and below the Fermi energy of the leads, with the resonances having different pseudospin character. Using pseudospin-resolved spectroscopy, we demonstrate the pseudospin character by observing a Kondo peak at only one sign of the bias voltage. We show that even when the pseudospin states have very different tunnel rates to the leads, a Kondo temperature can be consistently defined for the double quantum dot system.

[Detection of pyrogenic exotoxin SpeA, SpeB and SpeC genes in Chilean streptococci isolates and their association with clinical manifestations]. / Detección de los genes de las exotoxinas pirogénicas SpeA, SpeB y SpeC en cepas chilenas de Streptococcus pyogenes y su asociación con la clínica.

BACKGROUND: The virulence of Streptococcus pyogenes is determined by a variety of structural molecules, toxins and complex enzymes. Pyrogenic exotoxins cause fever, erythematous reactions, cytotoxic and immunological effects. AIM: To assess the frequency of speA, SpeB and SpeC genes in Chilean Streptococcus pyogenes strains and their association with the invasiveness of infections. MATERIAL AND METHODS: The genes for pyrogenic exotoxins SpeA, SpeB and SpeC were determined by polymerase chain reactions in 114 strains of group A Streptococcus pyogenes isolated from Chilean patients with invasive or non invasive infections. RESULTS: The gene for SpeA was present in 30.7% of isolates, the gene for SpeB was present in 69.3% and the gen for SpeC in 44.7% of isolates. The gene for SpeA was present in 20 of 33 invasive infections and in 15 of 81 non invasive infections (p < 0.0001). On the contrary, the gene for SpeC was present in 11 of 33 invasive infections and in 41 of 81 non invasive infections (p < 0.05). The frequency of speB was similar in invasive and non invasive infections. CONCLUSIONS: There is a clear relationship between the presence of SpeA genes and the severity of infections caused by Streptococcus pyogenes.

Organ transplantation in the mirror of the recent world-wide legislation.

Transplantation constitutes a rapidly changing field for medicolegal law-markers. Until two or three decades ago there were no laws governing organ transplants, and at least some of these processes fell within the realm of human experimentation. An extensive legislative work has been accomplished since then in order to catch up with the expeditious scientific progress. Transplantation is a definite medical process which requires a definite legal response. No wonder that some issues are dealt with by national laws in similar manners. Nevertheless, practice makes perfect, and recent legislations have gained experience and drawn their lessons from the former ones. The present review will analyze the guidelines concerning a few substantial issues, like distribution of organs, costs and donations, the removal-when and how allowed, and restrictions and conditions of removal. These and other issues have recently been formed by the following legislatures: Argentine, Canada, Columbia, Finland, France, India, Italy, Krygystan, Mexico, Peru, Portugal, Romania, Russia, USA and by the Council of Europe.

[Cerebral hemorrhage in migraine]. / Hémorragies cérébrales au cours de la migraine.

We report a case of intracerebral hemorrhage which occurred during a migraine in a 62 year-old woman who had migraine since the age of 20. The patient was normotensive. The angiograms were normal. Cerebral hemorrhage in migraine appears to be very rare: we found 6 reported cases that were compared with our own. The hypothesis of recirculation in an infarcted tissue and the possible role of dissecting aneurysms are examined.

Medical decisions under uncertainty.

The court applies the criteria of the reasonable doctor and common practice in order to consider the behaviour of a defendant physician. The meaning of our demand that the doctor expects that his or her acts or omissions will bring about certain implications is that, according to the present circumstances and subject to the limited knowledge of the common practice, the course of certain events or situations in the future may be assumed in spite of the fog of uncertainty which surrounds us. The miracles and wonders of creation are concealed from us, and we are not aware of the way and the nature of our bodily functioning. Therefore, there seems to be no way to avoid mistakes, because in several cases the correct diagnosis cannot be determined even with the most advanced application of all information available. Doctors find it difficult to admit that they grope in the dark. They wish to form clear and accurate diagnoses for their patients. The fact that their profession is faced with innumerable and unavoidable risks and mistakes is hard to swallow, and many of them claim that in their everyday work this does not happen. They should not content themselves by changing their style. A radical metamorphosis is needed. They should not be tempted to formulate their diagnoses in 'neutral' statements in order to be on the safe side. Uncertainty should be accepted and acknowledged by the profession and by the public at large as a human phenomenon, as an integral part of any human decision, and as a clear characteristic of any legal or medical diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

On patient's rights.

A committee appointed by the World Health Organization was given the task of formulating a Declaration on the Rights of Patients. A member of this committee outlines the main guidelines formulated in the Declaration and discusses its utility in the struggle for patients' rights in general.

Israeli drug cases: field research.

This survey describes the general traits of drug-related crimes, the offenders and the judicial decisions. But statistics do not cure. Ways must be sought to discover the hidden powers that drive the drug phenomenon.

Human rights in medicine and law.

Human rights are discussed in the context of the technological advances in modern medicine and the complex sociological settings in which major issues, such as accessibility, availability, costs and quality and health care, scarce resources, and shifting values, have led to reconsideration of the present systems. Rights in the field of medicine and law are discussed in general, and patients' rights in particular.

On cross-examination of expert witnesses.

Cross-examination is a very powerful weapon in court trials. Its success is measured by the final effect on the problem of proof. It can elicit favourable facts to one's case and also show that the witness is not worthy of credence or that his evidence is unacceptable. However pointless and endless cross-examination may prejudice the court against the case. A single question may make an opening for a flood of evidence. One unnecessary question may destroy a series of valuable answers and the whole case. There are occasions when silence is golden. A number of pertinent examples are cited to illustrate the values and pitfalls of cross-examination.

Role of roots in regulating the growth rate and cytokinin content in leaves.

The role of roots in the enhancement of cytokinin content and leaf growth of Phaseolus vulgaris plants after decapitation and partial defoliation was investigated. Partial excision of the roots of plants which were decapitated above the primary leaf node resulted in a reduction of leaf growth and soluble proteins accumulation in the primary leaves. Roots excision was done at time of decapitation and repeated 8 days later. Endogenous cytokinins, known to be involved in enhancing shoot growth, accumulated in the leaves and stems of decapitated and partially defoliated plants. Lower levels of cytokinins were detected in the leaves of decapitated plants with only a partial root system. The level of cytokinins in the roots of decapitated plants was reduced by partial root excision. The growth and accumulation of cytokinins in leaves were, however, not totally suppressed by removing a large proportion of the roots. At the commencement of the experiment the stem had a higher cytokinin content than both the leaves and roots. This suggests that the stem could be an alternative source of cytokinins to the leaves. The cytokinin complement in the leaves of decapitated plants is not identical to that in the roots. It appears that cytokinins supplied by the roots are metabolized in the leaves, or that alternatively certain cytokinins are synthesized in the leaves themselves.

Regulation of Photosynthetic Activity in the Primary Leaves of Bean (Phaseolus vulgaris L.) by Materials Moving in the Water-conducting System.

Endogenous factors which determine the photosynthetic capacity of the leaf were studied in the fully expanded, primary leaves of young seedings of bean (cv. Bulgarian). Following removal of the shoot above the primary leaf node and excision of all axillary buds, the primary leaves increased in area and thickness, in chlorophyll content, in levels of soluble protein, and in the specific activity of ribulose-1,5-bisphosphate carboxylase. Plants in which phloem continuity was disrupted by heat-girdling of the stem, between the shoot above the primary leaf node and the organs below, did not exhibit similar increases, whereas the shoot above the girdle continued to grow for several days. Plants in which all developing trifoliate leaves were excised as soon as they became macroscopic exhibited an increase in their photosynthetic activity, area, and thickness, while their main stem and (leafless) branches made considerable growth. Transpiration from the primary leaves was the same in decapitated plants as in the heat-girdled ones, although in the latter it accounted for only about 30% of total transpiration.The photosynthetic capacity of the primary leaves is not controlled by source/sink relationship of photosynthates, but rather by the pattern of distribution of factors carried from the roots to the leaves in the transpiration stream.