Functional outcome in dogs undergoing hemilaminectomy for thoracolumbar disc extrusion but without nociception > 96 h: A prospective study.

This prospective study investigated the functional recovery of surgically treated dogs with thoracolumbar intervertebral disc extrusion (IVDE) without deep pain perception (DPP) for > 96 h. Dogs (n = 36) with paraplegia secondary to thoracolumbar intervertebral disc extrusion with loss of deep pain perception ranging from 4 to 60 days were enrolled. All dogs underwent hemilaminectomy and fenestration of the affected intervertebral disc and postoperative follow-up was provided for a maximum of 180 days. Recovery of motor function was satisfactory (based on the owner's assessment) in 22 dogs, 61.1% (47.2% with DPP, and 13.9% without DPP) and unsatisfactory in 38.9% of cases (n = 14). Postoperative physiotherapy, preoperative anti-inflammatory drugs, and age had no effect on recovery. In this study, the longer the time taken to regain pain perception, the longer the recovery time. The median time to recovery was 30 days. A total of 47.2% of dogs with paraplegia and absence of DPP secondary to thoracolumbar IVDE lasting > 96 h, recovered functional ambulation after decompressive surgery.

Ballistic Graphene Cooper Pair Splitter.

We report an experimental study of a Cooper pair splitter based on ballistic graphene multiterminal junctions. In a two transverse junction geometry, namely the superconductor-graphene-superconductor and the normal metal-graphene-normal metal, we observe clear signatures of Cooper pair splitting in the local as well as nonlocal electronic transport measurements. Our experimental data can be very well described by our beam splitter model. These results open up possibilities to design new entangled state detection experiments using ballistic Cooper pair splitters.

Creation of equal-spin triplet superconductivity at the Al/EuS interface.

In conventional superconductors, electrons of opposite spins are bound into Cooper pairs. However, when the superconductor is in contact with a non-uniformly ordered ferromagnet, an exotic type of superconductivity can appear at the interface, with electrons bound into three possible spin-triplet states. Triplet pairs with equal spin play a vital role in low-dissipation spintronics. Despite the observation of supercurrents through ferromagnets, spectroscopic evidence for the existence of equal-spin triplet pairs is still missing. Here we show a theoretical model that reveals a characteristic gap structure in the quasiparticle density of states which provides a unique signature for the presence of equal-spin triplet pairs. By scanning tunnelling spectroscopy we measure the local density of states to reveal the spin configuration of triplet pairs. We demonstrate that the Al/EuS interface causes strong and tunable spin-mixing by virtue of its spin-dependent transmission.

Andreev bound states at spin-active interfaces.

Andreev bound states are ubiquitous in superconducting hybrid structures. They are formed near impurities, in Josephson junctions, in vortex cores and at interfaces. At spin-active superconductor-ferromagnet interfaces, Andreev bound states are formed due to spin-dependent scattering phases. Spin-dependent phase shifts are an important ingredient for the generation of triplet Cooper pairs in superconductor-ferromagnet hybrid structures. Spectroscopy of Andreev bound states is a powerful probe of superconducting order parameter symmetry, as well as spin-dependent interface scattering and the triplet proximity effect.This article is part of the theme issue 'Andreev bound states'.

Spin manipulation in nanoscale superconductors.

The interplay of superconductivity and magnetism in nanoscale structures has attracted considerable attention in recent years due to the exciting new physics created by the competition of these antagonistic ordering phenomena, and the prospect of exploiting this competition for superconducting spintronics devices. While much of the attention is focused on spin-polarized supercurrents created by the triplet proximity effect, the recent discovery of long range quasiparticle spin transport in high-field superconductors has rekindled interest in spin-dependent nonequilibrium properties of superconductors. In this review, the experimental situation on nonequilibrium spin injection into superconductors is discussed, and open questions and possible future directions of the field are outlined.

Observation of Thermoelectric Currents in High-Field Superconductor-Ferromagnet Tunnel Junctions.

We report on the experimental observation of spin-dependent thermoelectric currents in superconductor-ferromagnet tunnel junctions in high magnetic fields. The thermoelectric signals are due to a spin-dependent lifting of the particle-hole symmetry, and are found to be in excellent agreement with recent theoretical predictions. The maximum Seebeck coefficient inferred from the data is about -100 µV/K, much larger than commonly found in metallic structures. Our results directly prove the coupling of spin and heat transport in high-field superconductors.

Heating produced by therapeutic ultrasound in the presence of a metal plate in the femur of canine cadavers / Aquecimento gerado pelo ultrassom terapêutico em presença de placa óssea metálica no fêmur de cadáveres caninos

The present study aimed to assess the heat generated by a therapeutic ultrasound (TUS) in a metal bone plate and adjacent structures after fixation to the femur of canine cadavers. Ten pairs of hind limbs were used, and they were equally distributed between groups that were subjected to 1- and 3-MHz frequencies, with each frequency testing 1- and 2-W/cm² intensities. The right hind limb was defined as the control group (absence of the metal plate), and the left hind limb was the test group (presence of the metal plate). Therefore, the control groups (CG) were denominated CGI, using TUS with 1-MHz frequency and 1-W/cm² intensity; CGII, using 1-MHz frequency and 2-W/cm² intensity; CGIII, using 3-MHz frequency and 1-W/cm² intensity; and CGIV, using 3-MHz frequency and 2-W/cm² intensity. For each control group, its respective test group (TG) was denominated TGI, TGII, TGIII and TGIV. The TUS was applied to the lateral aspect of the thigh using the continuous mode and a 3.5-cm² transducer in a 6.25-cm² area for 2 minutes. Sensors were coupled to digital thermometers that measured the temperature in different sites before (t0) and after (t1) of the TUS application. The temperatures in t1 were higher in all tested groups. The intramuscular temperature was significantly higher (P<0.05) in the groups used to test the 3-MHz frequency in the presence of the metal plate. The therapeutic ultrasound in the continuous mode using frequencies of 1 and 3 MHz and intensities of 1 and 2 W/cm2 for 2 minutes caused heating of the metal plate and adjacent structures after fixation to the femur of canine cadavers...

O objetivo deste estudo foi avaliar o aquecimento gerado pelo ultrassom terapêutico (UST) na placa óssea metálica e estruturas adjacentes após a fixação no fêmur de cadáveres caninos. Foram utilizados dez pares de membros pélvicos, distribuídos igualmente entre os grupos que utilizaram as frequências de 1 e 3 MHz. Cada frequência testou as intensidades de 1 e 2 W/cm², sendo que o membro pélvico direito foi definido grupo controle (ausência da placa óssea metálica) e o membro pélvico esquerdo o grupo teste (presença da placa óssea metálica). Portanto, os grupos controles foram denominados GCI, com UST na frequência de 1 MHz e intensidade de 1 W/cm²; GCII, com 1 MHz e 2 W/cm²; GCIII, com frequência de 3 MHz e intensidade de 1 W/cm²; e GCIV, com 3 MHz e 2 W/cm². Para cada grupo controle, seu respectivo grupo teste foi denominado GTI, GTII, GTIII e GTIV. O UST foi aplicado na face lateral da coxa, utilizando o modo contínuo, transdutor de 3,5cm², em uma área de 6,25cm², durante dois minutos. Foram utilizados sensores acoplados a termômetros digitais que mediram a temperatura em diferentes locais antes (t0) e após (t1) a aplicação do UST. Pode-se verificar que as temperaturas em t1 foram maiores em todos os grupos testados. Os grupos que testaram a frequência de 3 MHz demonstraram que a temperatura intramuscular foi significativamente maior (P<0,05) na presença da placa óssea metálica. O ultrassom terapêutico no modo contínuo de 1 e 3 MHz e intensidades de 1 e 2 W/cm2 durante dois minutos promove o aquecimento da placa óssea metálica e estruturas adjacentes após a fixação no fêmur de cadáveres caninos...

Charge and spin transport in mesoscopic superconductors.

BACKGROUND: Non-equilibrium charge transport in superconductors has been investigated intensely in the 1970s and 1980s, mostly in the vicinity of the critical temperature. Much less attention has been paid to low temperatures and the role of the quasiparticle spin. RESULTS: We report here on nonlocal transport in superconductor hybrid structures at very low temperatures. By comparing the nonlocal conductance obtained by using ferromagnetic and normal-metal detectors, we discriminate charge and spin degrees of freedom. We observe spin injection and long-range transport of pure, chargeless spin currents in the regime of large Zeeman splitting. We elucidate charge and spin transport by comparison to theoretical models. CONCLUSION: The observed long-range chargeless spin transport opens a new path to manipulate and utilize the quasiparticle spin in superconductor nanostructures.

Long-range spin-polarized quasiparticle transport in mesoscopic Al superconductors with a Zeeman splitting.

We report on nonlocal transport in multiterminal superconductor-ferromagnet structures, which were fabricated by means of e-beam lithography and shadow evaporation techniques. In the presence of a significant Zeeman splitting of the quasiparticle states, we find signatures of spin transport over distances of several µm, exceeding other length scales such as the coherence length, the normal-state spin-diffusion length, and the charge-imbalance length. The relaxation length of the spin signal shows a nearly linear increase with magnetic field, hinting at a freeze-out of relaxation by the Zeeman splitting. We propose that the relaxation length is given by the recombination length of the quasiparticles rather than a renormalized spin-diffusion length.

Observation of Andreev bound states at spin-active interfaces.

We report on high-resolution differential conductance experiments on nanoscale superconductor-ferromagnet tunnel junctions with ultrathin oxide tunnel barriers. We observe subgap conductance features that are symmetric with respect to bias and shift according to the Zeeman energy with an applied magnetic field. These features can be explained by resonant transport via Andreev bound states induced by spin-active scattering at the interface. From the energy and Zeeman shift of the bound states, both the magnitude and sign of the spin-dependent interfacial phase shifts between spin-up and spin-down electrons can be determined. These results contribute to the microscopic insight into the triplet proximity effect at spin-active interfaces.

Temperatura de polimerização da resina acrílica odontológica na medula espinhal de ratos Wistar / Polymerization temperature of dental acrylic resin in the spinal cord of rats

Objetivou-se investigar se a temperatura de polimerização da resina acrílica odontológica ocasiona sinais neurológicos e alteração histológica na medula espinhal de ratos. Foram utilizados 48 ratos, Wistar, distribuídos em dois grupos denominados GI ou cimento ósseo (controle positivo) e GII ou resina acrílica odontológica. Cada grupo foi redistribuído em seis subgrupos, de acordo com a quantidade do composto, o tempo de pós-operatório e o local de aferição da temperatura. O cimento ósseo ou a resina acrílica odontológica foram moldados e colocados sobre as lâminas ósseas dorsais e os processos espinhosos das vértebras L1 e L2. A temperatura de polimerização do composto foi aferida a cada 10 segundos. A temperatura máxima de polimerização e a diferença entre a temperatura externa e a interna ao canal vertebral foram maiores nos subgrupos que receberam 10 gramas. Não foi observada alteração neurológica em nenhum dos animais deste estudo. Na análise histológica, foi observada reação inflamatória de intensidade variável na meninge e no parênquima medular. Pode-se concluir que a temperatura de polimerização da resina acrílica odontológica nas quantidades de um e 10 gramas provoca alterações histológicas na meninge e no parênquima medular, sem ocasionar sinais neurológicos em ratos.

The purpose of this study was to evaluate if the polymerization temperature of the dental acrylic leads to neurological signs and histological changes in the rat spinal cord. Forty eight rats were distributed in two groups: GI or bone cement (positive control) and GII or dental acrylic resin. Each group was redistributed in six subgroups according to compound quantity, postoperative period and location of temperature measurement. The bone cement or dental acrylic resin were molded and positioned on the bony lamina and the dorsal spinous processes of vertebrae L1 and L2. The polimerization temperature was measured every 10 seconds. The polymerization maximum temperature and the temperature difference between internal and external spinal canals were superior in subgroups that received 10 grams. There were no neurological deficits in any animal of this study. The histological analysis showed intensity variation of inflammatory reaction in the meninges and spinal cord parenchyma. The results demonstrate that the polymerization temperature of dental acrylic resin in quantity of 1 or 10 grams causes histological changes in the spinal cord parenchyma and meninges, without neurological deficits in rats.

Immediate physical therapy in dogs with rupture of the cranial cruciate ligament submitted to extracapsular surgical stabilization / Fisioterapia imediata em cães com ruptura do ligamento cruzado cranial submetidos à estabilização extracapsular

The study evaluated the influence of immediate physical therapy on the functional recovery of hind limbs of dogs with experimental cranial cruciate ligament rupture which underwent surgical extracapsular stabilization as well as to verify its interference in joint stability. Eight dogs were randomly divided into two groups: GI (control) (n=4) and GII (physical therapy) (n=4). The dogs in GII underwent the following therapeutic treatments in the postoperative period: cryotherapy, passive joint movement, massage, passive straightening, neuromuscular electrical stimulation, hydrotherapy (bath and aquatic mat) and therapeutic exercises. We performed evaluations of the thigh circumference, goniometry, X-ray, and knee stability (drawer test). Results did not demonstrate a significant difference between the groups nor between different post-operative times. Regarding gait analysis, we found that the 4 dogs in GI remained in degree 3 of lameness 45 and 90 days postoperatively. However, in GII, one dog remained in degree 3 45 and 90 days after surgery; one dog changed from degree 3 to 4 90 days after surgery and the other 2 dogs changed from degree 3 to 5 90 days after surgery. It is possible to conclude that dogs with CCL rupture that undergo immediate physical therapy demonstrate better results in regards to functional gait recovery. The therapeutic modalities used in the immediate post-operative period did not cause instability of the operated knee. Further studies are needed with a larger number of dogs to indicate the immediate physical therapy in dogs with CCL ligament rupture which underwent extracapsular stabilization.

Avaliou-se a influência da fisioterapia imediata na recuperação funcional do membro pélvico de cães com ruptura experimental do ligamento cruzado cranial (LCC) submetidos à estabilização cirúrgica extracapsular e verificou-se sua interferência na estabilidade articular. Foram utilizados oito cães distribuídos, aleatoriamente, em GI ou controle (n=4) e GII ou fisioterapia (n=4). Nos cães do GII, as modalidades terapêuticas empregadas no pós-operatório foram crioterapia, movimentação passiva da articulação, massagem, alongamento passivo, estimulação elétrica neuromuscular, hidroterapia (ducha e esteira aquática) e exercícios terapêuticos. Foram realizadas avaliações da circunferência da coxa, goniometria, radiografias e estabilidade do joelho (teste de gaveta) e os resultados não demonstraram diferença significativa entre os grupos e nos diferentes tempos de pós-operatório. Na análise da marcha, aos 45 dias, todos os cães do GI e do GII apresentaram grau 3 de claudicação. Aos 90 dias, quatros cães do GI permaneceram em grau 3 e no GII, um cão em grau 3, um em grau 4 e dois em grau 5. Conclui-se que cães com ruptura de LCC submetidos à fisioterapia imediata demonstraram melhores resultados quanto à recuperação funcional da marcha e as modalidades terapêuticas empregadas no pós-operatório imediato não ocasionaram instabilidade do joelho operado. Novas pesquisas são necessárias com um maior número de cães para poder indicar a fisioterapia imediata em cães com ruptura do ligamento cruzado cranial submetidos à estabilização cirúrgica extracapsular.

Recuperação funcional em cães com doença do disco intervertebral toracolombar sem percepção à dor profunda: 37 casos (2002-2010) / Functional recovery in dogs with thoracolumbar intervertebral disk disease without deep pain perception: 37 cases (2002-2010)

O objetivo deste trabalho foi avaliar a recuperação funcional de 37 cães com diagnóstico de doença do disco intervertebral (DDIV) toracolombar, sem percepção da dor profunda superior a 48 horas e não submetidos ao tratamento cirúrgico. Os dados identificados foram: raça, idade, sexo, localização da lesão, perda da percepção da dor profunda, duração dos sinais clínicos, recuperação funcional, retorno da percepção da dor profunda, recidivas, eutanásias ou morte. Foi observada recuperação funcional em 11 cães (55 por cento), sendo seis deles entre 30 e 60 dias após o início dos sinais clínicos. Dos onze cães que tiveram recuperação funcional satisfatória, dois (18 por cento) não tiveram retorno da percepção à dor profunda. Pode-se concluir que cães com diagnóstico de DDIV sem percepção à dor profunda superior a 48 horas e não submetidos ao tratamento cirúrgico podem apresentar recuperação funcional satisfatória e são necessários, no mínimo, 30 dias do início dos sinais clínicos para estabelecer um prognóstico quanto ao retorno dos movimentos voluntários.

The aim of this study was to evaluate functional recovery in 37 cases with diagnostic of thoracolumbar intervertebral disk disease in dogs without deep pain perception (more than 48 hours) and did not underwent surgical treatment from 2002 to 2010. The following data were obtained: Breed, age, sex, neuroanatomic localization, loss of deep pain perception, duration of clinical signs, functional recovery, deep pain recovery, recurrence and euthanasia or death. A satisfactory functional recovery was observed in 11 dogs (55 percent), mostly between 30-60 days after the beginning of the clinics signal (six dogs). Two of 11 dogs with satisfactory functional recovery did not recovered deep pain perception. The results showed that dogs with presumptive diagnoses of thoracolumbar intervertebral disk disease with more than 48 hours and that did not underwent surgical treatment are capable of a functional satisfactory recovery and should be waited 30 days after clinical signs begin to establish a prognosis on the recovery of voluntaries movements.

Surface stress-charge response of a (111)-textured gold electrode under conditions of weak ion adsorption.

We report a cantilever bending investigation into the variation of surface stress, f, with surface charge density, q, for (111)-textured thin films of gold in aqueous NaF and HClO 4. The graphs of f(q) are highly linear, and the surface stress-charge coefficients, d f/d q, are -1.95 V for 7 mM NaF and -2.0 V for 10 mM HClO 4 near the potential of zero charge. These values exceed some previously published experimental data by a factor of 2, but they agree with recent ab initio calculations of the surface stress-charge response of gold in vacuum.

Estimulação elétrica neuromuscular em cães com atrofia muscular induzida / Neuromuscular electric stimulation in dogs with induced muscle atrophy

Empregou-se a estimulação elétrica neuromuscular (EENM) de baixa freqüência no músculo quadríceps femoral de cães com atrofia induzida e avaliou-se a ocorrência de ganho de massa nessa musculatura. Foram utilizados oito cães com pesos entre 15 e 30kg, distribuídos aleatoriamente em dois grupos denominados de I ou controle e II ou tratado. A articulação femorotibiopatelar esquerda foi imobilizada por 30 dias pelo método de transfixação percutânea tipo II, com retirada de aparelho de imobilização após esse período. Decorridas 48 horas da remoção, foi realizada a EENM nos cães do grupo II, cinco vezes por semana, com intervalo de 24 horas cada sessão, pelo período de 60 dias. Foram avaliadas a circunferência da coxa, a goniometria do joelho, a análise clínica da marcha, as enzimas creatina-quinase (CK) e aspartato-amino-transferase (AST) e a morfometria das fibras musculares em cortes transversais do músculo vasto lateral colhido mediante biópsia muscular. A EENM foi empregada no músculo quadríceps femoral na freqüência de 50Hz, duração de pulso de 300 milisegundos e relação de tempo on/off de 1:2. Quanto à morfometria das fibras do músculo vasto lateral, no grupo tratado houve aumento significativo (P<0,05) da área transversal aos 90 dias em relação ao dia zero. A EENM de baixa freqüência ocasiona hipertrofia do músculo vasto lateral em cães após a imobilização rígida temporária da articulação do joelho.

Low frequency neuromuscular electrical stimulation (NMES) was used on the femoral quadriceps of dogs with induced muscular atrophy and the occurrence of gain in mass in these muscles was evaluated. Eight dogs from 15 to 30kg were randomly distributed in two groups named I, or control; and II, or treated. For the induction of muscular atrophy, the left femoral-tibial-patellar joint was immobilized for 30 days by percutaneous transfixation type II. After 30 days, the immobilization device was removed. The NMES treatment began 48 hours after the removal of the immobilization device of the dogs of group II, and it was carried out five times per week with an interval of 24 hours between each session, for 60 days. The following parameters were measured: thigh circumference, goniometry of the knee, clinical gait analysis, creatine kinase (CK) and aspartate aminotransferase (AST) enzymes, and morphometry of the muscular fibers in transversal cuts of the vastus lateralis muscle collected through muscular biopsy. The NMES was applied on the femoral quadriceps at a frequency of 50 Hz, with pulse duration of 300 milliseconds, and the on/off time was at a proportion of 1:2. Regarding the morphometry of the vastus lateralis fibers, a significant increase (P<0.05) in the transversal area of the treated group at 90 days was observed when compared with that identified at the time of immobilization. Thus, it can be concluded that low frequency NMES brings about hypertrophy of the vastus lateralis muscle in dogs after temporary rigid immobilization of the knee joint.

Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures.

We have measured the nonlocal resistance of aluminum-iron spin-valve structures fabricated by e-beam lithography and shadow evaporation. The sample geometry consists of an aluminum bar with two or more ferromagnetic wires forming point contacts to the aluminum at varying distances from each other. In the normal state of aluminum, we observe a spin-valve signal which allows us to control the relative orientation of the magnetizations of the ferromagnetic contacts. In the superconducting state, at low temperatures and excitation voltages well below the gap, we observe a spin-dependent nonlocal resistance which decays on a smaller length scale than the normal-state spin-valve signal. The sign, magnitude, and decay length of this signal are consistent with predictions made for crossed Andreev reflection.

[A questionnaire for assessment of "temprament in early childhood" as judged by parents]. / Ein Fragebogen zur Erfassung des "frühkindlichen Temperaments" im Elternurteil.

OBJECTIVES: This study assesses a German version of Rothbart's Infant Behavior Questionnaire for the internal consistency, inter-correlations and stability of the scales. Associations between the scales with maternal depression and anxiety are analyzed. METHODS: Independent samples of infants aged 6 to 8 months and 10 to 12 months (n = 149, respectively n = 109) and their mothers were studied. A longitudinal study of a sample of 101 mother-infant pairs was carried out at the infant's age of 4, 8 and 12 months. RESULTS: The internal consistency and independence of the five scales on the questionnaire are satisfactory. The stability coefficients correspond to a good degree to those of the American version of the IBQ scales. CONCLUSIONS: Thus a German version is now available that can be used in research and practice to measure the features of early childhood temperament by parental report.

Driving current through single organic molecules.

We investigate electronic transport through two types of conjugated molecules. Mechanically controlled break junctions are used to couple thiol end groups of single molecules to two gold electrodes. Current-voltage characteristics ( IVs) of the metal-molecule-metal system are observed. These IVs reproduce the spatial symmetry of the molecules with respect to the direction of current flow. We hereby unambiguously detect an intrinsic property of the molecule and are able to distinguish the influence of both the molecule and the contact to the metal electrodes on the transport properties of the compound system.

[Effects of significantly increased perinatal risks on developmental status in adolescence]. / Auswirkungen deutlich erhöhter Geburtsrisiken auf den Entwicklungsstand im Jugendalter.

In a 13-years-catamnesis a sample of 50 children with severe perinatal risks was assessed with regard to their physical, cognitive and behavioral development; selective drop-outs were analysed. In accordance with the results of other prospective studies there are deficits in visual-motor functioning, higher rates of somatic complaints, social withdrawal and attention deficits; a large number of these children attend special schools. The study presents predicative relations between risk factors of birth-time and the developmental status at youth. In comparison with typical single risks (e.g. gestational age or respiratory distress syndrome) a complex index for the perinatal risk, the so-called birth-optimality offers no substantial advantage. A significant influence of social factors is shown for school achievement. Children of fathers with higher educational level are attending schools of a higher grade. The combination of biological and social factors improves the reliability of developmental prognosis; the Mental Developmental Index of the Bayley Scales of Infant Development provides additional prognostic accuracy. For compensating developmental disadvantages especially parents with lower educational level should be informed about beneficial care. Even children of these families, who scored low in early cognitive assessments should receive early intervention or therapeutic support.