Stress effect on magnetoimpedance (MI) in amorphous wires at GHz frequencies and application to stress-tunable microwave composite materials

The effect of tensile stress on magnetoimpedance (MI) in CoMnSiB amorphous wires at microwave frequencies (0.5-3 GHz) is investigated both experimentally and theoretically. In the presence of the dc bias magnetic field of the order of the anisotropy field, the impedance shows very large and sensitive change when the wire is subjected to a tensile stress: 100% and 60% per 180 MPa for frequencies 500 MHz and 2.5 GHz, respectively. It is demonstrated that this behavior owes mainly to the directional change in the equilibrium magnetization caused by the applied stress and field, which agrees well with the theoretical results for the surface impedance. This stress effect on MI is proposed to use for creating microwave stress-tunable composite materials containing short magnetic wires. The analysis of the dielectric response from such materials shows that depending on the stress level in the material, the dispersion of the effective permittivity can be of a resonant or relaxation type with a considerable change in its values (up to 100% at 600 MPa). This media can be used for structural stress monitoring by microwave contrast imaging

Magnetostatic bias in multilayer microwires: theory and experiments

The hysteresis curves of multilayer microwires consisting of a soft magnetic nucleus, intermediate non-magnetic layers, and an external hard magnetic layer are investigated. The magnetostatic interaction between magnetic layers is proved to give rise to an antiferromagnetic-like coupling resulting in a magnetostatic bias in the hysteresis curves of the soft nucleus. This magnetostatic biasing effect is investigated in terms of the microwire geometry. The experimental results are interpreted considering an analytical model taking into account the magnetostatic interaction between the magnetic layers.Comment: 6 pages, 7 figure

Comparative study of vascular arterial reactivity in several mammal species: 1. Reactivity of the arterial smooth muscle to vasoconstrictor agents

Vascular reactivity is one of the three pillars on which lies the regulation of arterial pressure in living organisms. Arterial pressure is one of the main determinants of the activity state of various organs and systems both in healthy and in pathologically-altered states. The present study aims at identifying similarities and differences between the resistance arteries belonging from various mammal species that are most involved in veterinary practice: rats, cats, dogs and horses. The arterial fragments harvested from animals dead due to various clinical and traumatic conditions unrelated to vascular pathology were normalized using a newly-introduced system of quantification, the force index system. This has been calculated using the wet-weight parameter and the force generated after administration of various pharmacological agents that cause vasoconstriction. The artery fragments were fitted in organ baths using the Krebs-Henseleit saline, thermostated at 37° C and bubbled with a mixture of 95% O2 and 5%CO2. Vascular endothelium was either kept or removed using gentle rubbing with moist filter paper. Control of endothelial removal was made both functionally, using carbachol (synthetic derivative of acetylcholine) and microscopically, after testing. The force generated was measured using isometric force transducers coupled to a computerized acquisition system. The pharmacological vasoconstricting agents used were phenylephrine (synthetic derivative of epinephrine), KCl (potassium chloride 40-80 mM, as depolarizing agent) angiotensin II, and vasopressin. The results were statistically investigated using the t-test and ANOVA testing. The preliminary results show a dependence of the force generated an the amount of muscle present in the various species from which the arteries were taken, a specifically increased response of feline-derived arteries to angiotensin and a specifically increased response of canine-derived arteries to vasopressin. These results will be used as controls for further testing in various pathological conditions and for various other pharmacological agents used in the therapy of vascularly-induced pathological states

An observational retrospective evaluation of 79 young men with long-term adverse effects after use of finasteride against androgenetic alopecia

Concern regarding adverse effects of finasteride is increasing. We aimed to determine the type and frequency of symptoms in men having long-term sexual and non-sexual side effects after finasteride treatment (a condition recently called post-finasteride syndrome, PFS) against androgenetic alopecia (AGA). Subjects were recruited at the Urology Unit of the Trieste University-Hospital, and from a dedicated website. Out of 79 participants, 34% were white Italians, mean age was 33.4\ua0\ub1\ua07.60\ua0years, mean duration of finasteride use was 27.3\ua0\ub1\ua033.21\ua0months; mean time from finasteride discontinuation was 44.1\ua0\ub1\ua034.20\ua0months. Symptoms were investigated by an ad hoc 100 questions' questionnaire, and by validated Arizona Sexual Experience Scale (ASEX) and Aging Male Symptom Scale (AMS) questionnaires. By ASEX questionnaire, 40.5% of participants declared getting and keeping erection very difficult, and 3.8% never achieved; reaching orgasm was declared very difficult by 16.5%, and never achieved by 2.5%. By the ad hoc questionnaire, the most frequent sexual symptoms referred were loss of penis sensitivity (87.3%), decreased ejaculatory force (82.3%), and low penile temperature (78.5%). The most frequent non-sexual symptoms were reduced feeling of life pleasure or emotions (anhedonia) (75.9%); lack of mental concentration (72.2%), and loss of muscle tone/mass (51.9%). We contributed to inform about symptoms of PFS patients; unexpectedly loss of penis sensitivity was more frequent than severe erectile dysfunction and loss of muscle tone/mass was affecting half of the subjects. Further studies are necessary to investigate the pathophysiological and biochemical pathways leading to the post-finasteride syndrome

Current applications of 3d printing in neurosurgery

Medical implications of 3-dimensional (3D) printing technology have progressed with increasingly used especially in surgical fields. 3D printing techniques are practical and anatomically accurate methods of producing patient specific models for medical education, surgical planning, training and simulation, and implants production for the assessment and treatment of neurosurgical diseases. This article presents the main directions of 3D printing models application in neurosurgery

Problems in diagnosis and surgical treatment of the retroperitoneal non-pancreatogenic phlegmons

Catedra de Chirurgie, FEC MF, Universitatea de Stat de Medicină și Farmacie ”N. Testemițanu”, Chișinău, Moldova, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Supurațiile ale spațiului retroperitoneal sunt o problemă medico-chirurgicală neobișnuită cu un tablou clinic vag, care prezintă o provocare în aprecierea diagnosticului. Debutul insidios și evoluție ocultă ale acestei patologii sunt urmate de un diagnostic întârziat și drenaj neadecvat, astfel pentru flegmon retroperitoneal sunt caracteristice morbiditatea și mortalitatea considerabile. Anterior au fost publicate studii privind detaliile anatomice ale spațiilor extraperitoneale, dar mai puțina atenție a fost acordată metodelor de diagnostic și tehnicilor chirurgicale de drenaj. Prezentăm o trecere în revistă a 15 de cazuri de inflamații suruprative retroperitoneale nonpancreatogene care s-au manifestat ca entitate clinică principală. În aspect etiologic pacienții s-au repartizat în 5 grupe: psoitele purulente – 4, abcesele retroperitoneale apendiculare - 4, perinefritele purulente - 3, colecții retroperitoneale în urma osteolizei - 3 (ostemielita hematogenă, postraumatică, tuberculoza osoasă), hematom postraumatic retroperitoneal infectat – 1 caz. Trei pacienți (16,7 %) au decedat în perioada postoperatorie precoce. Complicații au survenit la 40 % pacienți. Letalitatea și rata înaltă de complicații au fost asociate cu perioada îndelungată de la debut până la diagnostic pozitiv (> 5 zile) și cu hemocultura pozitivă. Există o corelație între tipuri de complicații și sursa de infecție retroperitoneală. Computer tomografia este metoda cea mai informativă în diagnosticul supurațiilor abdominale extraperitoneale. În cazuri selecte drenajul ecoghidat poate fi folosit ca un gest chirurgical inițial. Descriem tehnica operatorie în dependență de topografia procesului purulent retroperitoneal. Este propus un plan de diagnostic și tratament pentru fiecare grup etiologic.Retroperitoneal space inflammation is an unusual surgical problem with vague clinical presentation, which presents a diagnostic challenge. An insidious onset and occult evolution of illness marked by diagnostic delay, inadequate drainage, and considerable morbidity and mortality is common. Papers regarding anatomic detailing of the extraperitoneal spaces have been published, but less attention has been focused on diagnostic and drainage techniques.We report an analysis of 15 cases of retroperitoneal suppurations which acted as main clinical manifestation. According to etiology of inflammation patients were distributed into 5 groups: psoas abscesses – 4 cases, retroperitoneal appendical abscesses – 4 cases, purulent perinephritis -3, retroperitoneal collections caused by osteolysis – 3 patients (hematogenic, posttraumatic or tuberculous) and one case of infected posttraumatic hematoma.Three patients (16,7 %) died in the early postoperative period. Rate of complications was 40 %. High lethality and postoperative morbidity were associated with positive blood cultures and delayed diagnosis (> 5 days). There is a correlation between the type of complications and etiology of the retroperitoneal phlegmon. Computed tomography is the most informative diagnostic method for the extraperitoneal purulent collections. Echoguided drainage in selected cases appears to be a useful initial approach. The operative technique dependent on the retroperitoneal purulent collection topography is described. A diagnostic and treatment plan is proposed for each etiologic group

Experimentally increased brood size accelerates actuarial senescence and increases subsequent reproductive effort in a wild bird population

The assumption that reproductive effort decreases somatic state, accelerating ageing, is central to our understanding of life-history variation. Maximal reproductive effort early in life is predicted to be maladaptive by accelerating ageing disproportionally, decreasing fitness. Optimality theory predicts that reproductive effort is restrained early in life to balance the fitness contribution of reproduction against the survival cost induced by the reproductive effort. When adaptive, the level of reproductive restraint is predicted to be inversely linked to the remaining life expectancy, potentially resulting in a terminal effort in the last period of reproduction. Experimental tests of the reproductive restraint hypothesis require manipulation of somatic state and subsequent investigation of reproductive effort and residual life span. To our knowledge the available evidence remains inconclusive, and hence reproductive restraint remains to be demonstrated. We modulated somatic state through a lifelong brood size manipulation in wild jackdaws and measured its consequences for age-dependent mortality and reproductive success. The assumption that lifelong increased brood size reduced somatic state was supported: Birds rearing enlarged broods showed subsequent increased rate of actuarial senescence, resulting in reduced residual life span. The treatment induced a reproductive response in later seasons: Egg volume and nestling survival were higher in subsequent seasons in the increased versus reduced broods' treatment group. We detected these increases in egg volume and nestling survival despite the expectation that in the absence of a change in reproductive effort, the reduced somatic state indicated by the increased mortality rate would result in lower reproductive output. This leads us to conclude that the higher reproductive success we observed was the result of higher reproductive effort. Our findings show that reproductive effort negatively covaries with remaining life expectancy, supporting optimality theory and confirming reproductive restraint as a key factor underpinning life-history variation

Polymerization in Magnetic Field. XIX. Thermal Behavior of the Copolymers of Methyl Methacrylate with Glycidyl Methacrylate Synthesized in the Magnetic Field Presence

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‘The International Teacher Leadership project,’ a case of international action research.

Copyright CARNThe paper arises from the International Teacher Leadership project, a research and development project involving researchers and practitioners in 14 European countries. The paper provides a conceptual exploration of the idea of teacher leadership and its role in educational reform, central to which is the idea that teachers, regardless of their level of power and organisational position, can engage in the leadership of enquiry-based development activity aimed at influencing their colleagues and embedding improved practices in their schools. The paper provides an outline of the project’s methodology which builds on that used in the Carpe Vitam Leadership for Learning project (Frost, 2008a). It is a form of collaborative action research which is highly developmental and discursive. It seeks to identify principles, strategies and tools that can be applied in a range of cultural settings. The paper includes a thematic analysis of the cultural contexts and policy environments of the participating countries in order to identify the obstacles to teacher leadership and to inform the nature of the support strategies employed

Our experience in surgical treatment of intraorbital tumors

Orbital tumors are complex lesions representing a great challenge for the neurosurgeons and ophthalmologist.Methods: We analyse the database for 57 patients who underwent surgery for the treatment of orbital tumors at our institution between 2001 and 2010. Data from clinical notes, surgical reports, and radiological findings were extracted for the statistical analysis.Results: Predominant symptoms were exophthalmos (68%), visual disturbance (42%) and ocular mobility limitation (37%). The most used surgical approache was superior orbitotomy. Orbital tumors histopathological results showed that hemangiomas were the most common tumors type (35%). Malignant tumors accounted for 23% of cases. Total resection of tumors was achieved in 78% of patients.Conclusion: Surgical treatment could be considered an optimal treatment option for most of the orbital tumor. A better imaging anatomy analysis of the orbit correlated with good surgical skills is needed to overcome the pitfalls of intraorbital surgery