The slopes of sub-barrier heavy-ion fusion excitation functions shed light on the dynamics of quantum tunnelling.

Quantum tunnelling plays a crucial role in heavy-ion fusion reactions at sub-barrier energies, especially in the context of nuclear physics and astrophysics. The nuclear structure of the colliding nuclei and nucleon transfer processes represent intrinsic degrees of freedom. They are coupled to the relative ion motion and, in general, increase the probability of tunnelling. The influence of couplings to nucleon transfer channels relatively to inelastic excitations, on heavy-ion fusion cross sections, is one of the still open problems in this field. We present a new analysis of several systems, based on the combined observation of the energy-weighted excitation functions E σ in relation to their first energy derivatives d ( E σ ) / d E . The relation between d ( E σ ) / d E and E σ removes the basic differences due to the varying Coulomb barrier when comparing different systems. We show that, depending on the nuclear structure and/or the presence of strong transfer channels, this representation reveals characteristic features below the barrier. The possible presence of cross section oscillations makes this analysis less clear for light- or medium-light systems.

Pathway for the Production of Neutron-Rich Isotopes around the N=126 Shell Closure.

Absolute cross sections for isotopically identified products formed in multinucleon transfer in the (136)Xe+(198)Pt system at ∼8 MeV/nucleon are reported. The isotopic distributions obtained using a large acceptance spectrometer demonstrated the production of the "hard-to-reach" neutron-rich isotopes for Z<78 around the N=126 shell closure far from stability. The main contribution to the formation of these exotic nuclei is shown to arise in collisions with a small kinetic energy dissipation. The present experimental finding corroborates for the first time recent predictions that multinucleon transfer reactions would be the optimum method to populate and characterize neutron-rich isotopes around N=126 which are crucial for understanding both astrophysically relevant processes and the evolution of "magic" numbers far from stability.

Rat visceral yolk sac cells: viability and expression of cell markers during maternal diabetes.

The function of the visceral yolk sac (VYS) is critical for embryo organogenesis until final fetal development in rats, and can be affected by conditions such as diabetes. In view of the importance of diabetes during pregnancy for maternal and neonatal health, the objective of this study was to assess fetal weight, VYS cell markers, and viability in female Wistar rats (200-250 g) with induced diabetes (alloxan, 37 mg/kg) on the 8th gestational day (gd 8). At gd 15, rats from control (n=5) and diabetic (n=5) groups were anesthetized and laparotomized to remove the uterine horns for weighing of fetuses and collecting the VYS. Flow cytometry was used for characterizing VYS cells, and for determining mitochondrial activity, cell proliferation, DNA ploidy, cell cycle phases, and caspase-3 activity. Fetal weight was reduced in the diabetic group. Expression of the cell markers CD34, VEGFR1, CD115, CD117, CD14, CCR2, CD90, CD44, STRO-1, OCT3/4, and Nanog was detected in VYS cells in both groups. In the diabetic group, significantly decreased expression of CD34 (P<0.05), CCR2 (P<0.001), and OCT3/4 (P<0.01), and significantly increased expression of CD90 (P<0.05), CD117 (P<0.01), and CD14 (P<0.05) were observed. VYS cells with inactive mitochondria, activated caspase-3, and low proliferation were present in the rats with diabetes. Severe hyperglycemia caused by maternal diabetes had negative effects on pregnancy, VYS cell viability, and the expression of cell markers.

Neutron pair transfer in (60)Ni+(116)Sn far below the Coulomb barrier.

An excitation function of one- and two-neutron transfer channels for the ^{60}Ni+^{116}Sn system has been measured with the magnetic spectrometer PRISMA in a wide energy range, from the Coulomb barrier to far below it. The experimental transfer probabilities are well reproduced, for the first time with heavy ions, in absolute values and in slope by microscopic calculations which incorporate nucleon-nucleon pairing correlations.

Fusion hindrance for a positive-q-value system (24)Mg+(30)Si.

Measurements of the excitation function for the fusion of (24)Mg+(30)Si (Q=17.89 MeV)have been extended toward lower energies with respect to previous experimental data. The S-factor maximum observed in this large, positive-Q-value system is the most pronounced among such systems studied thus far. The significance and the systematics of an S-factor maximum in systems with positive fusion Q values are discussed. This result would strongly impact the extrapolated cross sections and reaction rates in the carbon and oxygen burnings and, thus, the study of the history of stellar evolution.

Avaliação da técnica de arteriografia renal guiada por fluoroscopia em suínos / Description of the fluoroscopy-guided renal arteriography in swine

The fluoroscopy-guided renal arteriography was evaluated in order to be used as an auxiliary method in investigations and as a way to experimentally induce kidney diseases in swine. The technique was effective to obtain sharp images as well as to determine the area of renal irrigation. Despite its easiness, trained professionals are required to perform it.

Lifetime measurements of the neutron-rich N = 30 isotones 50Ca and 51Sc: orbital dependence of effective charges in the fp shell.

The lifetimes of the first excited states of the N = 30 isotones (50)Ca and (51)Sc have been determined using the Recoil Distance Doppler Shift method in combination with the CLARA-PRISMA spectrometers. This is the first time such a method is applied to measure lifetimes of neutron-rich nuclei populated via a multinucleon transfer reaction. This extends the lifetime knowledge beyond the f_{7/2} shell closure and allows us to derive the effective proton and neutron charges in the fp shell near the doubly magic nucleus (48)Ca, using large-scale, shell-model calculations. These results indicate an orbital dependence of the core polarization along the fp shell.

Muscular dystrophy-related quantitative and chemical changes in adenohypophysis GH-cells in golden retrievers.

Duchenne muscular dystrophy (DMD) is a recessive X-linked lethal condition which affects a boy in every 3300 births. It is caused by the absence of dystrophin, a protein occurring especially within the musculoskeletal system and in neurons in specific regions of the central nervous system (CNS). Growth hormone (GH) inhibition is believed to decrease the severity of DMD and could perhaps be used in its treatment. However, the underlying pathological mechanism is not known. The golden retriever muscular dystrophy dog (GRMD) represents an animal model in the study of DMD. In this paper we investigated the morphological aspects of the adenohypophysis as well as the total number and size of GH-granulated cells using design-based stereological methods in a limited number of dystrophic and healthy golden retrievers. GH-cells were larger (32.4%) in dystrophic dogs than in healthy animals (p=0.01) and they occupied a larger portion (62.5%) of the adenohypophysis volume (p=0.01) without changes in either adenohypophysis volume (p=0.893) or total number of GH-granulated cells (p=0.869). With regard to ultrastructure, granulated cells possessed double-layer electron-dense granules which were evenly distributed in the cytosol. Furthermore, these granules in dystrophic animals occupied a larger proportion of GH-granulated cell volume (66.9%; p=0.008) as well as of all GH-cells in the whole pars distalis of adenohypophysis (77.3%; p=0.035), albeit IGF-1 serum concentration was lower in severe cases. This suggests difficulties in the GH secretion that might possibly be associated to dystrophin absence. In contrast to earlier reports, our data suggest that a lower IGF-1 concentration may be more related to a severe, as opposed to a benign, clinical form of muscular dystrophy.

Sex-related macrostructural organization of the deer's brachial plexus.

We describe the morphological organization of the deer brachial plexus in order to supply data to veterinary neuroclinics and anaesthesiology. The deer (Mazama gouazoubira) brachial plexus is composed of four roots: three cervical (C6, C7 and C8) and one thoracic (T1). Within each sex group, no variations are observed between the left and the right brachial plexus, though sex-related differences are seen especially in its origin. The origin of axillary and radial nerves was: C6, C7, C8 and T1 in males and C8-T1 (radial nerve) and C7, C8 and T1 (axillary nerve) in females; musculocutaneous nerve was: C6-C7 (males) and C8-T1 (females); median and ulnar nerves was: C8-T1 (males) and T1 (females); long thoracic nerve was: C7 (males) and T1 (females); lateral thoracic nerve was: C6, C7, C8 and T1 (males) and T1 (females); thoracodorsal nerve was: C6, C7, C8 and T1 (males) and C8-T1 (females); suprascapular nerve was: C6-C7 (males) and C6 (females) and subscapular nerve was: C6-C7 (males) and C7 (females). This study suggests that in male deer the origin of the brachial plexus is more cranial than in females and the origin of the brachial plexus is slightly more complex in males, i.e. there is an additional number of roots (from one to three). This sexual dimorphism may be related to specific biomechanical functions of the thoracic limb and electrophysiological studies may be needed to shed light on this morphological feature.

Unilateral ganglionectomy technique on the sheep"s cranial cervical ganglion as a support for morphofunctional and quantitative studies

The article has no abstract.

Gross anatomic organization of the capybara's (Hydrochaeris hydrochaeris) brachial plexus.

The innervation of the capybara thoracic limb was characterized. The following nerves were observed constituting the right and left brachial plexus: n. dorsalis scapulae (C4 and C5; C4, C5 and C6) which innervates the m. serratus ventralis cervicis and m. rhomboideus; n. suprascapularis (C4, C5 and C6; C5, C6 and C7) supplying the m. supraspinatus and the m. infraspinatus; cranial and caudal nn. subscapulares (C5 and C6; C5, C6 and C7) innervating the m. subscapularis; n. axillaris (C5 and C6; C6, C7 and C8) which supplies the m. triceps brachii (caput mediale); n. radialis (C6, C7, C8 and T1; C6, C7 and C8) which innervates the m. triceps brachii (caput longum and caput mediale) and the m. extensor carpi radialis, m. extensor digitorum communis, m. extensor digitorum lateralis; n. medianus joined to the n. musculocutaneus (C6, C7, C8 and T1; C6, C7 and C8) supplying the m. biceps brachii, m. flexor carpi radialis and m. coracobrachialis; n. ulnaris (C6, C7, C8 and T1; C6, C7 and C8) leading to the m. flexor carpi radialis, the m. flexor carpi ulnaris and the m. flexor digitorum superficialis; n. thoracodorsalis (C6, C7, C8 and T1; C6, C7 and C8) supplying the m. latissimus dorsi; n. thoracicus lateralis (C8, T1; C7, C8, T1) which innervates m. pectoralis profundus (caudal portion); n. thoracicus longus (C6, C7; C7, C8) which is distributed to the m. serratus ventralis thoracis. A communication between the n. radialis and n. ulnaris was observed at the left brachial plexus.