Nano-Antennas Based on Silicon-Gold Nanostructures.

We experimentally realize nano-antennas based on hybrid silicon-gold nanoparticles (NPs). The silicon particles covered by clusters of small metal NPs are fabricated from a liquid phase under the effect of the laser irradiation. The complex nanoclusters containing both Si and Au components provide the enhancement of the near-field intensity and the resonant light scattering associated with excitation of multipole resonances in NPs. A strong sensitivity of the resonant light absorption to the hybrid particle size and material parameters is experimentally documented and theoretically discussed. The results demonstrate a high potentiality of the hybrid NPs for the realization of functional optical devices and metasurfaces.

Ultrastructural analysis of the central terminals of primary sensory neurones labelled by transganglionic transport of bandeiraea simplicifolia I-isolectin B4.

In this study the ultrastructural appearance of primary sensory neurones labelled by the injection of the plant lectin Bandeiraea simplicifolia I-isolectin B(4) (BSI-B(4)) into a peripheral nerve has been examined in the rat. Electron microscopy of the somata of retrogradely labelled neurones showed the lectin to be associated with the inner surface of cytoplasmic vesicles, supporting the premise that the uptake of BSI-B(4) into sensory neurones is by the process of receptor-mediated endocytosis. Light and electron microscopic analysis of the spinal cord revealed transganglionically transported lectin in unmyelinated axons in the dorsolateral funiculus and axon terminals concentrated mainly within lamina II of the dorsal horn. Detailed analysis of 1377 of these axon terminals revealed that the majority were glomerular in shape and surrounded by up to 14 other unlabelled profiles. These findings suggest that primary sensory neurones which transganglionically transport BSI-B(4) have a synaptic ultrastructure similar to that which has been previously reported for unmyelinated primary sensory neurones. Moreover, it appears that the axon terminals of these neurones are subjected to extensive modulation. Examination of the vesicle content of lectin labelled axon terminals revealed that the majority contained small agranular vesicles while large granular vesicles were observed only occasionally. These findings support the suggestion that the populations of neurones expressing binding sites for BSI-B(4) are fairly distinct from those containing neuroactive peptides. In conclusion, the results of the current study suggest that the lectin BSI-B(4) can be used as a histological marker for a subpopulation of small diameter primary sensory neurones and provide further evidence for the potential of this lectin as a useful tool in the study of pain.

Thalamic neuronal activity in rats with mechanical allodynia following contusive spinal cord injury.

Pain and allodynia following spinal cord injury are poorly understood and difficult to treat. Since there is evidence that supraspinal mechanisms are important in such pain, we have studied the role of the thalamus in an experimental model of spinal injury. Extracellular recordings were obtained from neurones of the thalamic nucleus ventralis postero-lateralis (VPL) in normal rats and those which had sustained a contusive spinal cord injury to the thoraco-lumbar junction 7 days previously. Behavioural testing with von Frey hairs established that 11 spinally injured rats showed exaggerated vocal responses to normally innocuous mechanical stimulation (allodynia) whereas eight were non-allodynic. Thalamic VPL neurones in spinally injured rats (both allodynic and non-allodynic) exhibited a dysrhythmia in that a significantly higher proportion fired spontaneously in an oscillatory mode when compared with neurones in uninjured rats. Thus this dysrhythmia was linked to spinal injury, not to allodynia. The evoked responses of VPL thalamic neurones to brushing the skin, however, were significantly elevated in allodynic rats when compared with those in uninjured rats and neuronal afterdischarges to these stimuli (which were absent in uninjured rats) were more common in allodynic than in non-allodynic rats. We have previously reported that a proportion of spinal neurones in allodynic spinally injured rats show increased evoked responses and afterdischarges following brushing the skin and hence the enhanced thalamic responses may reflect a greater spinal input. In view of the increasing evidence that thalamo-cortical rhythmical firing is linked to sensorimotor and cognitive brain functions, we propose that pain following brushing the skin results from an exaggerated spinal input being processed by a dysrhythmic thalamus. Thus both spinal and thalamic mechanisms may be important in the genesis of pain and allodynia following spinal cord injury.

Binding sites for the plant lectin Bandeiraea simplicifolia I-isolectin B(4) are expressed by nociceptive primary sensory neurones.

Circumstantial evidence suggests that binding sites for the plant lectin Bandeiraea simplicifolia I-isolectin B(4) are expressed by nociceptive primary sensory neurones. In order to test this hypothesis directly, we have used a combination of intracellular staining of functionally characterised primary sensory neurones and lectin binding. Consistent with the hypothesis, none of the low threshold primary sensory neurones we sampled expressed lectin binding sites, whilst a subpopulation of the nociceptive neurones did.

Understanding and leading the quad matrix: four generations in the workplace: the Traditional Generation, Boomers, Gen-X, Nexters.

Generational diversity is not new, but 4 generations working side by side has not occurred before. This climate of 4 generational workers offers challenges and opportunities for leaders. Leaders must show the opportunities of a diverse workforce and provide the encouragement and enthusiasm of working in a 4-generation environment. This article will define the 4 generations, the perspectives, values and motivations of each and the opportunity to tap into this rich tapestry.

Connexin expression patterns in human trophoblast cells during placental development.

This study focuses on the gap junction expression pattern in trophoblast cells during human placental development in vivo and in vitro. Investigations of cell-cell communication properties within the subpopulations of trophoblast responsible for invasion, placental growth and feto-maternal transport seem of special interest because the intercellular channels are believed to coordinate proliferation and differentiation processes. From all gap junction connexins (Cx) investigated (Cx26, Cx31, Cx32, Cx37, Cx40, Cx43), Cx40 was the only connexin clearly detected within the cytotrophoblast of human placenta, and was restricted to the extravillous trophoblast of cell islands and cell columns. Most intense staining was found in the juxtastromal area correlated to the proliferating extravillous trophoblast cells. Connexin protein expression was missing during trophoblast migration into the decidua but was re-expressed in trophoblast aggregates within the decidua. Cx40 expression decreased with progressing pregnancy and no connexins could be detected in villous or extravillous trophoblast of mature placentae. In parallel, isolated trophoblast cells of first and second trimester placentae revealed Cx40 expression and, in contrast to the situation in vivo, Cx43 was also found. In isolated cells of mature placentae, expression of both Cx40 and Cx43 transcripts was decreased to low levels and Cx40 immunoreactivity was absent. Cx43 protein, however, was still detectable in trophoblast cultures of term placentae. Our studies suggest that Cx40 is the characteristic channel for the proliferating cell population of cell islands and cell columns of first and second trimester placentae and isolated trophoblast and is probably involved in regulation and coordination of the invasive pathway.

3D reconstructions of neurofunctional structures for neuroimaging.

An improved method for computer-aided 3D reconstruction of neuroanatomical structures derived from intracranially fixed human brains is demonstrated. The embedded brains are cut into slices. The sliced surfaces are photographed. The outlines of the neuroanatomical structures are drawn onto transparencies which are scanned. The surfaces of the structures are 3D reconstructed with the triangulation method. The cortical structures of the human brain are complex, resulting in possible ambiguities for triangulation which must be solved interactively. These surface reconstructions allow for 3D visualization of the brain and its components comparable with intravital conditions found in clinical neuroimaging.

Relative contributions of voluntary apnoea, exposure to cold and face immersion in water to diving bradycardia in humans.

1. Diving or face immersion bradycardia is a well recognized but incompletely understood reflux which occurs in man and other mammals. 2. In order to investigate the contributions made by voluntary apnoea, face immersion in water and cold exposure, 18 normal subjects were exposed to these challenges separately and in various combination. 3. Tested individually, cold and apnoea caused significant reductions in heart beat (P < 0.01 and 0.002, respectively). Face immersion in thermoneutral water had no effect on heart rate. 4. The bradycardic effect of apnoea at maximal inspiration may be due to stimulation of pulmonary stretch receptors. 5. Cold exposure and voluntary apnoea applied simultaneously caused a summative effect but when tested with face immersion in water there was a synergistic response greater than the sum of individual responses. 6. The results confirm the bradycardic effect of apnoea and cold exposure, whereas immersion in thermoneutral water had little effect, a finding which has been disputed in the literature.

Embryological development of the arterial system of the forelimb in Tupaia.

BACKGROUND: The arterial system of the upper extremities in man shows drastic developmental changes and many individual variations related to interspecific variations in primates. The ontogenetic development in Tupaia was examined from the viewpoint of comparative embryology. METHODS: Histological specimens of 39 embryos were observed and reconstructed in three dimensions using a computer program. Four adult animals were dissected and examined with angiography to ascertain the end stage of development. RESULTS: At the proximal end of the upper arm the deep brachial artery appears first as a concomitant vessel with the radial nerve. It becomes reduced in size and is succeeded by the posterior circumflex humeral artery, which is accompanied initially by the axillary nerve and finally by the radial nerve. The main arterial passageway to the fingers consists of the brachial and interosseous arteries during early development. The superficial brachial artery and median artery are formed later, and their connection becomes the main route of blood supply for the finger arteries up to the adult stage. The ulnar artery is formed at the end of arterial development to form the ulnar end of the superficial palmar arch. The superficial antebrachial arteries are also recognized. CONCLUSIONS: All the arterial elements of the forelimb in Tupaia are observed in a variety of primates, including man, and the characteristics of Tupaia are thought to represent the primitive conditions of the common ancestor of tree shrews and primates.

Computer-assisted 3D-reconstruction and statistics of the limbic system. 1. Computer-assisted 3D-reconstruction of the hippocampal formation, the fornix, and the mamillary bodies.

The hippocampal formation of eight perfusion-fixed human brains was examined using new methods according to stereotactic and morphometric principles (macrovibratome and computer-aided 3D reconstruction). The reconstructions form part of a neuroanatomical reference system (NeuRef). This reference system allows for 3D visualisation of the brain and its components on a computer graphic workstation, as well as for the presentation of the union set based on a neuroanatomical structure taken from this sample of brains. This retrievable knowledge of neurofunctional systems is important for the preoperative planning of neurosurgeons and the adjustment of radiotherapy.

Computer-assisted 3D-reconstruction and statistics of the limbic system. 2. Spatial statistics of the hippocampal formation, the fornix, and the mammillary bodies.

A statistical method is described to show the distribution of neuroanatomical structures within a Cartesian coordinate system from any given number of examinations. The algorithm is based on polygons derived from the outlines of neuroanatomical structures in parallel canthomeatal-orientated cutting planes. These polygons are transformed in virtual voxels, rotated into the bicommissural coordinate system, and projected onto the three main planes of this coordinate system. Areas with the same probability for the structures examined are given in these planes. As an example this method is applied to the hippocampal formation and the results attained are shown.

[Three-dimensional reconstructions in neuroanatomy]. / Dreidimensionale Rekonstruktionen in der Neuroanatomie.

Computer-aided 3D reconstructions of neurofunctional systems and structures are generated as a reference for neuroimaging (CT, MRI, PET). The clinical application of these 3D reconstructions requires a coordinate system and conditions resembling the intravital neuroanatomy as far as possible. In this paper the neuroanatomical Reference System (NeuRef) of the Department of Neuroanatomy of Hannover Medical School is presented. This consists of methods to record brain structures from serial sections with minimal error (less than 1 mm) and to display 3D brain models derived from such a data base. In addition, NeuRef is able to generate sections through, for instance, the visual and pyramidal system and to transfer these data onto a corresponding CT image. Therefore, this method can serve as a diagnostic aid in neuroradiology, in operation planning, and radiotherapy. It can also be used in PACS.

[Schizophrenic patients in ambulatory treatment of a psychiatric hospital and in general practice of established psychiatrists]. / Schizophrene Patienten in ambulanter Behandlung eines psychiatrischen Krankenhauses und in Praxen niedergelassener Nervenärzte.

Two large samples of schizophrenic patients treated in a psychiatric hospital outpatient clinic (n = 108) and by psychiatrists in office practice (n = 265) are compared in regard to socio-demographic and illness characteristics, pharmacological treatment, tardive dyskinesia rate and psychopathological status--also with respect to results on an outcome-scale. For the outpatient clinic patients changes in hospitalization rates and duration of stay, together with predictors of psychosocial outcome dimensions are reported. The strongest differences between the samples are found in a more complicated course of illness for the outpatient clinic patients, which is interpreted as indication for a higher vulnerability. Against expectation, socio-demographic variables showed no significant differences.

[Doctor's-office blood pressure, home blood pressure, ergometry blood pressure and 24-hour blood pressure. The correlations with the echocardiographic parameters of heart muscle mass]. / Sprechstundenblutdruck, Heimblutdruck, Ergometer-Blutdruck und 24-Stunden-Blutdruck. Korrelationen mit echokardiographischen Parametern der Herzmuskelmasse.

In 62 untreated hypertensives (31 men, 31 women; median age 40 [17-57] years) blood pressures (BP) were measured in the doctor's office, at home (self-measured) and every 15 min during 24-hour monitoring (by portable automated oscillometry), the results being compared with echocardiographic measurements of ventricular septal thickness (VST), left ventricular muscle mass (LVM) and left ventricular mass index (LVMI), in 41 of them also during and 5 min after 100 W bicycle ergometry. In the total cohort, 24-hour values correlated better with diastolic VST (systolic: r = 0.706, P less than 0.00001; diastolic: r = 0.507, P less than 0.0001) than office BP (systolic: r = 0.381, P less than 0.01; diastolic: r = 0.177, not significant) and home BP (systolic: r = 0.477, P less than 0.0001; diastolic: r = 0.371, P less than 0.05). In the 41 exercised hypertensives the correlation with echocardiographic values was less close than with their 24-hour BP, but slightly better than with office and home BP. Systolic BP correlated better than diastolic BP with echocardiographic values. VST generally correlated better with BP than LVM and LVMI. It is concluded that (1) 24-hour BP values correlate more closely with LVM than any other noninvasive BP measurement; (2) VST is affected more by systolic than diastolic BP; and (3) VST more specifically reflects the influence of BP on myocardial structure than does LVM and LVMI.

Nocturnal hypertension in renal failure, haemodialysis and after renal transplantation.

Diurnal blood pressure variations in 20 patients with advanced renal failure, 20 patients on chronic haemodialysis, and 21 renal transplant recipients were compared with those of matched control groups without renal disease, using 24-h ambulatory blood pressure monitoring. Whereas the blood pressure during the day (from 8 a.m. to 8 p.m.) was roughly the same in the patients compared with their respective control groups, during the night (from 8 p.m. to 8 a.m.) it was substantially higher in all patient groups. The differences between the mean daytime and night-time values were significantly lower in the patients (P less than 0.05 to P less than 0.001). The nocturnal blood pressure decrease may be attenuated or even reversed in renal failure, in haemodialysis and after renal transplantation. In a proportion of these patients, 24-h ambulatory blood pressure monitoring showed an elevated nocturnal blood pressure, which may require some modification of treatment.

[Immunity of the populations of the USSR and East Germany to reference strains of influenza viruses and the characteristics of a new antigenic variant of the virus]. / Izuchenie immuniteta u naseleniia SSSR i GDR k étalonnym shtammam virusov grippa i kharakteristika novogo antigennogo varianta virusa.

In 1985, a new epidemic variant of influenza virus, A/Berlin/6/85 (H3N2) was isolated which differed antigenically from the reference A/Philippines/2/82 virus. The results of the study of population immunity in adults and children of the USSR and GDR to these virus variants confirm the data on the continuing drift of virus A (H3N2).