A cryogenic spin-torque memory element with precessional magnetization dynamics.

We present a study of precessional magnetization switching in orthogonal spin-torque spin-valve devices at low temperatures. The samples consist of a spin-polarizing layer that is magnetized out-of-the film plane and an in-plane magnetized free and reference magnetic layer separated by non-magnetic metallic layers. We find coherent oscillations in the switching probability, characterized by high speed switching (~200 ps), error rates as low as 10-5 and decoherence effects at longer timescales (~1 ns). Our study, which is conducted over a wide range of parameter space (pulse amplitude and duration) with deep statistics, demonstrates that the switching dynamics are likely dominated by the action of the out-of-plane spin polarization, in contrast to in-plane spin-torque from the reference layer, as has been the case in most previous studies. Our results demonstrate that precessional spin-torque devices are well suited to a cryogenic environment, while at room temperature they have so far not exhibited coherent or reliable switching.

Large fluctuations and singular behavior of nonequilibrium systems.

We present a general geometrical approach to the problem of escape from a metastable state in the presence of noise. The accompanying analysis leads to a simple condition, based on the norm of the drift field, for determining whether caustic singularities alter the escape trajectories when detailed balance is absent. We apply our methods to systems lacking detailed balance, including a nanomagnet with a biaxial magnetic anisotropy and subject to a spin-transfer torque. The approach described within allows determination of the regions of experimental parameter space that admit caustics.

Multidisciplinary approach for the study of an Egyptian coffin (late 22nd/early 25th dynasty): combining imaging and spectroscopic techniques.

This paper demonstrates that an educated methodology based on both non-invasive and micro invasive techniques in a two-step approach is a powerful tool to characterize the materials and stratigraphies of an Egyptian coffin, which was restored several times. This coffin, belonging to a certain Mesiset, is now located at the Museo Civico Archeologico of Bologna (inventory number MCABo EG 1963). Scholars attributed it to the late 22nd/early 25th dynasty by stylistic comparison. The first step of the diagnostic approach applied imaging techniques on the whole surface in order to select measurements spots and to unveil both original and restored areas. Images and close microscopic examination of the polychrome surface allowed selecting representative areas to be investigated in situ by portable spectroscopic techniques: X-ray Fluorescence (XRF), Fiber Optic Reflectance Spectroscopy (FORS) and Fourier Transform Infrared spectroscopy (FTIR). After the analysis of the results coming from the first step, very few selected samples were taken to clarify the stratigraphy of the polychrome layers. The first step, based on the combination of imaging and spectroscopic techniques in a totally non-invasive modality, is quite unique in the literature on Egyptian coffins and enabled us to reveal many differences in the ground layer's composition and to identify a remarkable number of pigments in the original and restored areas. This work offered also a chance to check the limitations of the non-invasive approach applied on a complex case, namely the right localization of different materials in the stratigraphy and the identification of binding media. Indeed, to dissolve any remaining doubts on superimposed layers belonging to different interventions, it was necessary to sample few micro-fragments in some selected areas and analyze them prepared as cross-sections. The original ground layer is made of calcite, while the restored areas show the presence of either a mixture of calcite and silicates or a gypsum ground, overlapped by lead white. The original pigments were identified as orpiment, cinnabar and red clay, Egyptian blue and green copper based pigments. Some other pigments, such as white lead, Naples yellow, cerulean blue and azurite were only found in the restored areas.

Sulfated K5 Escherichia coli polysaccharide derivatives inhibit human immunodeficiency type-1 (HIV-1) infection: candidate microbicides to prevent sexual HIV transmission.

The ideal microbicide must fulfill a number of criteria including a broad and potent activity against transmission of HIV and other sexually transmitted agents in the absence of toxicity and inflammation. We have described that derivatives of K5 polysaccharide from Escherichia coli inhibit HIV entry in target cells. K5 derivatives have a structure that resembles that of heparin, but they are devoid of the anticoagulant activity typical of heparin. Moreover, in contrast to heparin, they inhibit a broad spectrum of HIV-1 laboratory-adapted and primary isolates that use either CCR5 or CXCR4 or both coreceptors in terms of their infection and replication in primary CD4+ lymphocytes and monocytes-derived macrophages (MDM). Therefore, these compounds could be developed as candidate microbicides for preventing sexual HIV transmission, a predominant modality of HIV spreading in both the developed and underdeveloped world.

[Beta-agonists: new perspective in the treatment of asthma?]. / Beta-agonistas una nueva perspectiva en el tratamiento del asma?

Beta-agonists (beta 2) are the first treatment for acute asthma. Metered dose inhalers are preferable to nebulizers. During regular treatment, long-acting beta 2 show better results than sabutamol. Clinically relevant antiinflammatory activity has not been demonstrated. During regular treatment, tolerance to bronchodilator effects has not been detected but decrease of bronchoprotective effect is seen. These findings do not show clinical relevance. Short or long-acting beta 2 remain an appropriate and reliable treatment option for patients with asthma. Salmeterol and formoterol show similar action and adverse effects. The most rational treatment strategy seems to be: a) use inhaled steroids as the first and main regular treatment; b) when doses higher than 1,000-1,200 mcg/d of BCM or BUD are required, try long-acting beta-agonists; c) if that treatment is not effective enough, continue to increase inhaled steroid doses to identify patients responsive to higher doses.

Amotosalen photochemical inactivation of severe acute respiratory syndrome coronavirus in human platelet concentrates.

A novel human coronavirus causing severe acute respiratory syndrome (SARS) emerged in epidemic form in early 2003 in China and spread worldwide in a few months. Every newly emerging human pathogen is of concern for the safety of the blood supply during and after an epidemic crisis. For this purpose, we have evaluated the inactivation of SARS-coronavirus (CoV) in platelet concentrates using an approved pathogen inactivation device, the INTERCEPT Blood System. Apheresis platelet concentrates (APCs) were inoculated with approximately 10(6) pfu mL(-1) of either Urbani or HSR1 isolates of SARS-CoV. The inoculated units were mixed with 150 microm amotosalen and illuminated with 3 J cm(-2) UV-A light. The viral titres were determined by plaque formation in Vero E6 cells. Mixing SARS-CoV with APC in the absence of any treatment decreased viral infectivity by approximately 0.5-1 log10. Following photochemical treatment, SARS-CoV was consistently inactivated to the limit of detection in seven independent APC units. No infectious virus was detected after treatment when up to one-third of the APC unit was assayed, demonstrating a mean log10-reduction of >6.2. Potent inactivation of SARS-CoV therefore extends the capability of the INTERCEPT Blood System in inactivating a broad spectrum of human pathogens including recently emerging respiratory viruses.

Thoracic extension of hydatid cysts of the liver.

Of a total of 77 patients affected by hydatid cysts of the liver observed between 1983 and 1988, we examined a group of 25 patients with cysts that had migrated into the thorax. The main characteristic of these patients was the hydatid hepatic cyst, which was situated in the right hepatic lobe in every patient, involving one or more right hemithoracic structures. In 24 patients, there were different combinations of symptoms, but only ten were thoracic. In those with advanced intrathoracic evolution of the hydatid cyst, we not only found a destruction of the hemidiaphragm, but also the presence of pleural effusion, empyema, atelectasis and multiple pleural hydatidosis caused by the development of a cystic fistula in the pleural cavity. Analysis of these instances allowed us to see that ultrasonograms of the liver and roentgenograms of the thorax are often the most sensitive and reliable diagnostic procedures for showing the intrathoracic evolution of the cyst. We believe that the surgical treatment must be carried out with simultaneous right thoracoabdominal access, which, besides exposing the thoracic lesions, also permits adequate treatment of the hepatic hydatid cyst and the possible associated biliary complications.

Indications and results for splenectomy for beta thalassemia in two hundred and twenty-one pediatric patients.

To determine the advantages and complications of splenectomy in the treatment of beta thalassemia, 221 splenectomies for thalassemia performed upon pediatric patients from 1971 to 1982 are evaluated. There were 125 boys and 96 girls with a mean age of 8.2 +/- 2.5 years at the time of the operation. Sixty-one other patients who underwent splenectomy for other diseases served as the controls. Early and late complications after splenectomy are considered with a follow-up study of ten years. Hemoglobin (Hb) value, transfusional quotients and mean of transfused blood previous to surgical treatment are matched with the same parameters evaluated during the follow-up period. The effect of treatment with salicylates and dipyridamole upon the incidence of early complications after operation is analyzed. The postoperative complications in patients with thalassemia were 43.4 versus 3.2 per cent (p less than 0.01) registered in control patients. Late complications occurred with an incidence of 10.7 per cent and were due principally to sepsis. Six patients died of sepsis during the follow-up period, but the mortality rate for sepsis in the patients we studied was significantly lower than that reported by others in 73 instances of splenectomy for beta thalassemia. Blood consumption dropped from 270 +/- 99 to 155 +/- 31 milliliters per kilogram per year postoperatively (p less than 0.01) and Hb levels rose from 9.7 +/- 1.3 to 11.2 +/- 0.7 grams per milliliter. These results suggest that, even though splenectomy for beta thalassemia causes a relevant incidence of complications and fatalities, surgical treatment permits an improvement in the quality of the lives of patients with beta thalassemia and significantly reduces blood consumption. Prophylactic antibiotic therapy can reduce the incidence of sepsis, as was observed in the patients we studied.

Beta-agonistas una nueva perspectiva en el tratamiento del asma? / [Beta-agonists: new perspective in the treatment of asthma?]

Beta-agonists (beta 2) are the first treatment for acute asthma. Metered dose inhalers are preferable to nebulizers. During regular treatment, long-acting beta 2 show better results than sabutamol. Clinically relevant antiinflammatory activity has not been demonstrated. During regular treatment, tolerance to bronchodilator effects has not been detected but decrease of bronchoprotective effect is seen. These findings do not show clinical relevance. Short or long-acting beta 2 remain an appropriate and reliable treatment option for patients with asthma. Salmeterol and formoterol show similar action and adverse effects. The most rational treatment strategy seems to be: a) use inhaled steroids as the first and main regular treatment; b) when doses higher than 1,000-1,200 mcg/d of BCM or BUD are required, try long-acting beta-agonists; c) if that treatment is not effective enough, continue to increase inhaled steroid doses to identify patients responsive to higher doses.