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Calculations to determine the electrostatic potential of the iron storage protein ferritin, using the human H-chain homopolymer (HuHF), reveal novel aspects of the protein. Some of the charge density correlates well with regions previously identified as active sites in the protein. The three-fold channels, the putative ferroxidase sites, and the nucleation sites all show expectedly negative values of the electrostatic potential. However, the outer entrance to the three-fold channels are surrounded by regions of positive potential, creating an electrostatic field directed toward the interior cavity. This electrostatic gradient provides a guidance mechanism for cations entering the protein cavity, indicating the three-fold channel as the major entrance to the protein. Pathways from the three-fold channels, indicated by electrostatic gradients on the inner surface, lead to the ferroxidase center, the nucleation center and to the interior entrance to the four-fold channel. Six glutamic acid residues at the nucleation site give rise to a region of very negative potential, surrounding a small positively charged center due to the presence of two conserved arginine residues, R63, in close proximity (4.9 A), suggesting that electrostatic fields could also play a role in the nucleation process. A large gradient in the electrostatic potential at the 4-fold channel gives rise to a field directed outward from the internal cavity, indicating the possibility that this channel functions to expel cations from inside the protein. The 4-fold channel could therefore provide an exit pathway for protons during mineralization, or iron leaving the protein cavity during de-mineralization.

Human liver fatty acid binding protein (hL-FABP) has been reported to act as an intracellular shuttle of lipid molecules, playing a central role in systemic metabolic homeostasis. The involvement of hL-FABP in the transport of bile salts has been postulated but scarcely investigated. Here we describe a thorough NMR investigation of glycocholate (GCA) binding to hL-FABP. The protein proved able to bind a single molecule of GCA in contrast with the 1:2 stoichiometry observed with fatty acids. GCA was found to occupy the large internal cavity of hL-FABP without requiring major conformational rearrangements of the protein backbone but leading to an increased stability, similar to that estimated for the hL-FABP:oleate complex. Fast time scale dynamics appeared not significantly perturbed in the presence of ligands. Slow motions, at variance with other proteins of the family, were retained or enhanced upon binding and consistent with a requirement of structural plasticity for promiscuous recognition. Fil: Favretto, F.. Universita Di Verona; Italia Fil: Assfalg, M.. Universita Di Verona; Italia Fil: Gallo, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina Fil: Cicero, D. O.. Fundación Instituto Leloir; Argentina. Universita Di Roma; Italia Fil: D' Onofrio, M. D.. Universita Di Verona; Italia Fil: Molinari, H.. Laboratorio NMR, ISMAC-CNR ; Italia

BACKGROUND: Excessive absorption of cobalt has been associated with cases of dilated cardiomyopathy in the past, but it is unclear whether occupationally exposed populations are at risk. OBJECTIVE: To assess the possible relationship between occupational exposure to cobalt and incipient signs of dilated cardiomyopathy. METHODS: A cross-sectional survey was conducted in a cobalt production facility in Belgium constituting one of the largest occupational populations worldwide (n=256 male workers). Exposure to cobalt was assessed by measuring urinary cobalt concentration (µg/gcreat), reflecting recent exposure, and by computing an integrated exposure index (µg/gcreat×years), reflecting long-term exposure. The effect on the myocardium was investigated by echocardiography and electrocardiography, and dose-effect relations with cobalt exposure were traced by multiple regression analysis. RESULTS: No dose-effect relationship between exposure to cobalt and parameters reflecting dilated cardiomyopathy was found in a population of workers characterised by a median recent cobalturia of 4 µg/gcreat and a median long-term cobalturia of 100 µg/gcreat×years. A reduction in the dimensions of the left ventricular internal cavity was associated with recent exposure to cobalt. CONCLUSIONS: Occupational exposure to cobalt does not appear associated with incipient signs of dilated cardiomyopathy within the gradient of exposure recorded in this population.

The light received by source stars in microlensing events may be significantly polarized if both an efficient photon scattering mechanism is active in the source stellar atmosphere and a differential magnification is therein induced by the lensing system. The best candidate events for observing polarization are highly magnified events with source stars belonging to the class of cool, giant stars {in which the stellar light is polarized by photon scattering on dust grains contained in their envelopes. The presence in the stellar atmosphere of an internal cavity devoid of dust produces polarization profiles with a two peaks structure. Hence, the time interval between them gives an important observable quantity directly related to the size of the internal cavity and to the model parameters of the lens system.} We show that {during a microlensing event} the expected polarization variability can solve an ambiguity, that arises in some cases, related to the binary or planetary lensing interpretation of the perturbations observed near the maximum of the event light-curve. We consider a specific event case for which the parameter values corresponding to the two solutions are given. Then, assuming a polarization model for the source star, we compute the two expected polarization profiles. The position of the two peaks appearing in the polarization curves and the characteristic time interval between them allow us to distinguish between the binary and planetary lens solutions., Comment: In press on Physica Scripta (IOPscience), 2013

In recent years there has been an outburst of interest regarding the employment of nanoparticles for biomedical applications. Among the different types, such as metallic, organic, biological and hybrid systems, virus based nanoparticles have become a popular field of research. Viruses are able to form organized structures by molecular self assembly of repetitive building blocks, which implies non covalent interactions of protein monomers to form the quaternary structure of viral capsids. Plant virus based systems, in particular, are among the most advanced and exploited for their potential use as bioinspired structured nanomaterials and nanovectors. Plant viruses have a size particularly suitable for nanoscale applications and can offer several advantages. In fact, they are structurally uniform, robust, biodegradable and easy to produce. Moreover, many are the examples regarding functionalization of plant virus based nanoparticles by means of modification of their external surface and by loading cargo molecules into their internal cavity. This plasticity in terms of nanoparticles engineering is the ground on which multivalency, payload containment and targeted delivery can be fully exploited. This review aims primarily to summarize the most important plant virus based nanoparticles systems through their recent applications in biomedicine, such as epitope display for vaccine development and targeted delivery for diagnosis or therapy. In addition, their production in the most commonly used plant propagation and expression systems will be also reviewed. © 2013 Bentham Science Publishers.

A new sorediate lichen, Menegazzia hypernota Bjerke, is described from New Zealand. This new species is characterised by convex, crescent‐shaped to fabi‐form soralia that are occasionally associated with perforations; apothecia with 2‐spored asci; the small perforations; the numerous secondary lobules; the presence of inconspicuous, yellow spots in the internal cavity; and fumarprotocetraric acid as principal medullary constituent. Menegazzia caliginosa, a species associated with M. hypernota, is reported for the first time from the Auckland Islands.

In this paper are presented the results of a research program on comparative test procedures on epoxy materials, in the presence of internal partial discharges under varied thermal working conditions. These studies involved only two materials. New data on other materials, filled and unfilled, are presented and analyzed. The time to breakdown of specimens subjected to 25 kV sinusoidal voltage under different testing temperatures is examined. A modified version of the CIGRE test cell, Method I, is used to obtain specimens with an hemispherical internal cavity geometry between embedded electrodes. This arrangement permits very high signal to noise ratio values and thereby fully exploits the recent digital techniques based on pulse amplitude analysis and off-line treatment of recorded data. Finally, different discharge mechanisms, governing the aging activity of cavities at 20 and 80/spl deg/C respectively, were observed. >

The article analyzes the forces acting on the inline cleaning units of new design, operating on a bailer principle. In this case all cleaning products are collected in the internal cavity of the cleaning unit, which eliminates the formation of the ground plug and can significantly reduce the friction of the cleaning unit on the inner surface of the pipeline. The moving of the cleaning units of the given design within the space of a curved steel pipeline is investigated, the solution of the obtained equations and their analysis related to pipeline submerged crossing are shown.

To overcome the problem of cleanliness in the laser's internal cavity, a glass cavity design for a Nd:glass slab amplifier was proposed, which uses UV-stop quartz glass for its main structure.The design of the main structure of the glass cavity and the sealing are optimized, and metal-coated surfaces are used to prevent light from escaping.The cleanliness of the stainless steel cavity of the slab amplifier of the SG-II-UP laser and the glass cavity of a 100 slab amplifier were compared; the cleanliness of the glass cavity was found to be 70% better than that of the stainless cavity. Further, advanced system analysis program was used to simulate the designed amplifier, with the pumping ratio of the Nd:glass in the glass cavity being increased by 8.84%.Thus, the glass cavity decreases the production of aerosols and enhances the pumping ratio of the Nd∶glass.

Aim : The aim of the study is to compare the occurance of internal void in composite restorations using different incremental techniques. Objective: The main objective of this study is to compare the occurance of internal voids in tooth restored with composite using different incremental techniques. Background : Dental composite resins are the most frequently used direct tooth-colored restorative materials restoring cervical lesions. Adaptation of the restorative materials to cavity margins , internal cavity surfaces and presence of voids are crucial for long -term performance of restoration. It comprises the strength of the restoration. Reason : It is of utmost importance to find out which incremental technique of composite restoration results in minimum voids.

Este reporte trata sobre ambientes de dormir de majás (Cuniculus paca, Linnaeus, 1766). El estudio fue llevado a cabo entre agosto del 2006 y abril del 2007 y está basado en observaciones detalladas. Los resultados indican que este roedor utiliza como ambientes de dormir los huecos en tierra o en troncos de árboles caídos. Cada uno de estos ambientes contaba con dos o más orificios y una cavidad interna para el "sueño diurno". Generalmente uno de los orificios era de uso habitual y el resto para la fuga circunstancial. De acuerdo a su forma, número de orificios y ubicación en el piso del bosque, los ambientes de dormir fueron clasificados hasta en cuatro tipos; de ellos, el tipo A fue el más común. Los resultados también indican mayor concentración de ambientes de dormir en bosque de galería de inundación temporal. This report deals with paca sleeping dens (Cuniculus paca Linnaeus, 1766). The study was conducted between August 2006 and April 2007 and is based on detailed observations. Results indicate that this rodent uses holes in the ground or in fallen trees as sleeping dens. Each of these sleeping dens had two or more orifices and an internal cavity for the "diurnal sleep". Typically, one orifice was for common use and the rest for the circumstantial escape. According to their form, their localization in the ground, and the number and location of orifices, sleeping dens were classified into four types, of which type A was the most common. The results also indicate a greater concentration of sleeping dens in temporary flooded gallery forest.

An experimental and theoretical investigation of the Nigerian slit gong is reported. It is shown that in tuning the gong the artisan ensures that the frequencies of the two lowest mechanical resonances are nearly coincident with the frequencies of two of the acoustic resonances of the internal cavity. Four possible tuning parameters are identified and the effects of changing these parameters are discussed.

Attaching peripheral amide groups to the backbone of cyclic aromatic oligoamides 1 leads to new macrocycles 2 that show drastically changed behavior including modest yields of formation and no tendency to aggregate while maintaining a rigid backbone and a defined, guest-binding internal cavity.

Alternative use of the X-ray test to evaluate seed quality has become increasingly diverse. This study was performed primarily to establish experimental procedures and verify the effectiveness of the X-ray test to detect damage or abnormalities in bell pepper (Capsicum annuum) seed structure associated with germination. Five seed lots each of hybrids Reinger and Sentinel were used. Two hundred seeds per lot were exposed to durations and intensities of X-radiation and visually classified into four categories according to the proportion between the area occupied by the embryo and endosperm in relation to the total cavity area in the internal seed structure, e.g. 0, < 50%, 50-75% and 100%. The last category was subdivided into two others based on the occurrence of morphological abnormalities. Seed samples obtained from different X-ray categories were then submitted to germination test at 25ºC for 14 days and subsequently compared with results of the X-ray analysis. Exposure to a 10 kV radiation for 260 s was the most suitable X-ray dose for visualizing seed structure. Seeds in which the area of the internal cavity occupied by the embryo and endosperm varied from 50-75% produced abnormal seedlings or did not germinate. Full seeds (100% of the internal cavity area occupied) with abnormal structure usually originated defective seedlings. As a consequence, the classification of bell pepper seeds according to the proportion occupied by the seed content (embryo + endosperm) allowed a reliable estimation of the degree of seed physical integrity based on X-ray analysis and its association with germination performance.

In order to maximize stealth, most new military fighter/attack aircraft are designed to carry weapons internally. Associated wind tunnel testing of stores inside an internal bomb bay or cavity can be problematic due to the use of a sting or strut to place the simulated store in the desired position inside the internal cavity. Since aft mounted stings are usually not feasible, a strut mounted sting is typically used for determination of moments on a simulated store in an internal cavity. However, these strut devices can impact store freestream aerodynamics. A study was completed to see if computational fluid dynamics could be used to identify the potential impact on the strut on store aerodynamics.

The exclusive self-sorting observed in the self-assembly process between tetraurea benzyl calix[4]pyrroles and tetraurea tolyl calix[4]arene to afford unprecedented hybrid dimeric capsules with polar interiors is described. The coencapsulation of a solvent molecule with an organic guest yields four particle aggregates in which the guests are confined and restricted into single hemispheres due to the polar requirements of the internal cavity.

Ferritin is the protein whose function is to store iron that the cell does not require immediately for metabolic processes, thereby protecting against the toxic effects of free Fe2+. Ferritin therefore plays a crucial role in iron metabolism as well as in the development of some diseases, especially those related to the presence of free Fe2+ and toxic hydroxyl radicals. In addition, ferritin is itself a catalytic bionanoparticle. Its internal cavity can be used as a nanoreactor to produce non-native metallic nanoparticles. Moreover, its external protein shell can be chemically modified, allowing ferritin to be used as a precursor for a library of metallic nanoparticles, some which may have potential applications in biomedicine, especially as multimodal imaging probes. This article presents a brief overview of the evidence for the role of native ferritin in some diseases, as well as the potential of some synthetic ferritins – in which a non-native inorganic material has been introduced into the cavity and/or the external shell has been modified – in the field of nanobiomedicine.

An asymmetric character of the internal cavities provided by novel cage-type cyclophanes, two triaza[3.3.3]paracyclophanes linked with three chiral bridging components, was clarified by means of circular dichroism (CD) spectroscopy and a computer-aided molecular modeling study based on molecular mechanics conformational search.

Hydrogen bonding to anions drives the helical folding of an indolocarbazole oligomer, thus resulting in an internal cavity with six NHs and two OHs for binding sulfate with high selectivity.

The pre-sacral vertebrae of most sauropod dinosaurs were surrounded by interconnected, air-filled diverticula, penetrating into the bones and creating an intricate internal cavity system within the vertebrae. Computational finite-element models of two sauropod cervical vertebrae now demonstrate the mechanical reason for vertebral pneumaticity. The analyses show that the structure of the cervical vertebrae leads to an even distribution of all occurring stress fields along the vertebrae, concentrated mainly on their external surface and the vertebral laminae. The regions between vertebral laminae and the interior part of the vertebral body including thin bony struts and septa are mostly unloaded and pneumatic structures are positioned in these regions of minimal stress. The morphology of sauropod cervical vertebrae was influenced by strongly segmented axial neck muscles, which require only small attachment areas on each vertebra, and pneumatic epithelia that are able to resorb bone that is not mechanically loaded. The interaction of these soft tissues with the bony tissue of the vertebrae produced lightweight, air-filled vertebrae in which most stresses were borne by the external cortical bone. Cervical pneumaticity was therefore an important prerequisite for neck enlargement in sauropods. Thus, we expect that vertebral pneumaticity in other parts of the body to have a similar role in enabling gigantism.

Dual-energy x-ray absorptiometry (DEXA), the technique most widely used to assess skeletal integrity, is routinely performed on cadaveric tissue to ensure that the bone mineral densities (BMD) of the test specimens are representative of the target patient population for a particular orthopaedic device [1]. It is well established that DEXA-BMD measurements are sensitive to the amount of fat and other soft tissue present in the region of interest [2]. Recognizing that the removal of perivertebral soft tissue may affect DEXA-BMD readings of in vitro cadaveric specimens, biomechanics researchers have used various “torso surrogates” to simulate the removed tissue and x-ray attenuation. These include: 1) submersion of spinal sections in a physiological saline bath, 2) surrounding spinal sections with gel-filled packs, and 3) packing rice-filled bags around spinal sections and within the internal cavity of eviscerated torsos [3, 4]. It is unknown whether these inter-study differences in technique affect in vitro DEXA measurements. Given the prevalence of soft tissue artifacts in vivo, the goal of this study is to examine the sensitivity of in vitro DEXA-BMD to the quantity and composition of soft tissue surrogates. This work is the first step in a broader study to develop a set of best practices for DEXA scanning of cadaveric tissue.Copyright © 2009 by ASME

Este reporte contiene información acerca de los ambientes de dormir, estructura poblacional y el impacto de la caza del majas (Cuniculus paca Linnaeus, 1766). Está basado en observaciones de madrigueras, censos por transectos y registros de caza. Encontramos que cada ambiente de dormir tenía de uno a tres orificios para el acceso y salida, uno a cuatro orificios para la fuga circunstancial y una cavidad interna para el “sueño diurno”. Del total de ambientes examinados, 67% estaban localizados entre 0 y 60 m respecto a los cuerpos de agua, pero algunos también fueron encontrados más allá de los 100 m. De la población extraída por los cazadores, 74% fueron adultos y solamente 4% correspondieron a los infantes. La presión de caza anual fue estimada en 0,4 individuos/km2 y la densidad para el área en general en 6,2 individuos/km2. Finalmente, el modelo de cosecha indica que la caza de esta especie es sostenible en la cuenca del río Alto Itaya., This report contains information about sleeping dens, population structure and the impact of hunting of the paca (Cuniculus paca Linnaeus, 1766). It is based in sleeping den observations, transect censuses and hunt- ing records. We found that each sleeping den has one to three orifices for regular access and way out, one to four orifices for circumstantial escape, and an internal cavity for the diurnal sleep. Of the total sleeping dens inspected, 67% where located between 0 and 60 m from water bodies, but some were also found as far as 100 m away. Of the population extracted by hunters, 74% were adults and only 4% were infants. The annual hunting pressure was estimated at 0,4 individuals/ km2 and the population density for the overall area at 6,2 individuals/ km2. Finally, the harvest model suggests that hunting of the paca is sustainable in Alto Itaya river basin.

The shape of things to come: Aromatic oligohydrazide macrocycles with planar backbones enforced by three-center hydrogen bonds are formed in high yield from monomeric diacid chlorides and dihydrazides. Macrocycles consisting of six meta-linked pyridine and benzene residues have an internal cavity of about 10 A diameter, while those with alternating meta- and para-linked benzene residues are larger and contain multiple convergent sites (see picture).

International audience; General odorant-binding proteins (GOBPs) are believed to transport a wide range of volatile hydrophobic molecules across the aqueous sensillum lymph towards olfactory receptors in insects. GOBPs are involved in the first step of odorant recognition, which has a great impact in agriculture and in insect-mediated human disease control. We report here the first structural study of a GOBP, the honeybee ASP2, in complex with a small hydrophilic ligand. The overall fold of the NMR structure of ASP2 consists in the packing of six ?-helices creating an internal cavity and closely resembles that of the related pheromone-binding proteins (PBPs). The predominantly hydrophobic internal cavity of ASP2 provides additional possible interactions (?-stacking, electrostatic contact) for ligand binding. We also show that the internal cavity of ASP2 has the ability to bind ligands of different structures and properties, including a hydrophobic component of the floral scent (2-isobutyl-3-methoxypyrazine, IBMP) and a small hydrophilic ligand. We further demonstrate that IBMP binds ASP2 with two stable alternative conformations inside the ASP2 binding pocket. The 15N NMR relaxation study suggests that significant backbone mobility occurs at the ligand entry site at the millisecond rate, which likely plays a role in the recognition and the uptake/release mechanism of ligands by ASP2. We propose that the broad ligand specificity of GOBPs compared with PBPs is conferred by the cumulative effects of weak non-specific protein/ligand interactions and of enhanced protein internal dynamics at the ligand entry site.

Left ventricular internal cavity dimensions (LVID) were determined from radionuclide ventriculographic (RNVG) studies using a spatial calibration algorithm and visually defined edges and were compared to the results from two-dimensional echocardiography. Routine clinical cases were used with no additional views and no attenuation or scatter correction. In an initial set of 21 patients, mean RNVG LVID was 5.7 +/- 1.1 (mean +/- 1 S.D.) cm compared to 5.3 +/- 1.0 cm for echocardiography. In a prospective validation of the regression equations derived in the initial set of patients, regression-corrected RNVG results were within 5 mm of those determined echocardiographically in 18/22 patients and the mean LVID values were the same. Quantitative estimation of LVID by RNVG is simple, rapid, and reproducible. Systematic overestimation of dimensions compared to echocardiography can be corrected using a regression equation.

Immunohistochemical staining was applied together with the multicolor fluorescent scheme to demonstrate the amylase activity for polysaccharide hydrolysis in stored or starved aerobic granules that are in substrate deficiency. If sufficient nutrients were present, alpha-amylase and beta-amylase were found close to the surface layer of the original granules. Following storage or starvation during which most external nutrients were depleted, the alpha-amylase and beta-amylase were distributed over the entire granule interior, suggesting endogenous respiration at the core of the granule. In particular, the fluorescent intensities of alpha-amylase and beta-amylase were enriched 5-20 microm from the edge of the internal cavity, suggesting the strong correlation between polysaccharide hydrolysis and the formation of interior cavities. The secreted amylase was located near the living cells, suggesting that the polysaccharide hydrolysis is restricted to local environment that occurs near the functional strains. Internal hydrolysis within the core, for the case of both proteins and polysaccharides should correspond in principle to the loss of granule stability.

Unraveling the factors that control the conformation of molecular chains is of great interest both for understanding the shape of biological molecular strands and for designing artificial ones that adopt desired forms. Thus, a variety of artificial folding codons have been identified that enforce the formation, among others, of helices, strands, and loops, the major emphasis being on the shape of the foldamer. We report herein the synthesis and study of a family of foldamers and macrocycles based on the 1,8-naphthyridine and pyrimidine units, whose internal cavity is large enough to accommodate ionic substrates, and focus on the impact of guest binding within a cylindrical environment. Interestingly, the binding event within these large oligomers is translated to the outside of the receptors and affects the interaction of the overall complexes with the outside world. For instance, alkali cations bind to the one-turn helices and macrocycles to promote fibril formation and aggregation. Also, polyammonium su...

ties in elastic solids," J. Elasticity, 16, No. 2, 201-211 (1986). 12. R. Hill, "An invariant treatment of interfacial discontinuities in elastic composites," in: Mechanics of a Continuous Medium and Kindred Analysis Problems [in Russian], (1972), pp. 596-604. 13. N. Laws, "On interfacial discontinuities in elastic composites," J. Elasticity, ~, No. 2, 227-235 (1975). 14. T. Mura, Micromechanics of Defects in Solids, Martinus Nijhoff Publ., The Hague (1982). 15. K. Yamazaki and J. Oda, "Optimum shape of elastic inclusion in infinite elastic solid under triaxial stress field," Comput. Mech. 86: Theory and Appl. Proc. Int. Conf., Tokyo, May 25-29, 1986, Vol. 2, X/83-X/89 (1986).

The increase in left ventricular (LV) end-diastolic volume has recently been shown to explain more than 70% of the increase in stroke volume during upright exercise in endurance athletes. As the end-diastolic volume enhancement not could be explained by an increase in axial cavity length an augmentation in LV short-axis diameters is to be expected. To investigate LV end-diastolic geometrical alterations during exercise, 15 endurance athletes were examined using contrast exercise echocardiography. LV end-diastolic short-axis diameters were made from apical views at several LV cavity levels. From upright rest to upright exercise the LV end-diastolic internal cavity measurements increased significantly. During exercise, the LV cavity became geometrically more spherical with the largest increase in the LV end-diastolic short-axis cavity diameters in the mid and apical parts of the left ventricle. The LV internal long axis showed significant increase from rest to exercise but the absolute increase was small.

The potency of flagellated cells of Halisarca dujardini (Halisarcida, Demospongiae) larvae from the White Sea (Arctic) was investigated experimentally during metamorphosis. Two types of experiments were conducted. First, larvae were maintained in Ca 2þ free seawater (CFSW) until the internal cells were released outside through the opening of the posterior pole. These larvae that only composed of flagellated cells (epithelial larvae) werethenreturnedtoseawater(SW)toobservetheirmeta- morphosis. The posterior aperture closed before they set- tled on a substratum and started a metamorphosis similar to intact larvae. Secondly, epithelial larvae were, first, fur- ther treated in CFSW and then mechanically dissociated. Separated cells or groups of cells were returned to SW, where they constituted large friable conglomerates. After 12-17 h in SW, flagellated cells showed the first steps of de- differentiation, and regional differentiation was noticeable within conglomerates after approximately 24-36 h. Exter- nal cells differentiated into pinacocytes while internal cells kept their flagella and became united in a layer. Within 48-72 h, internal cells of the conglomerates formed spheri- cal or ovoid clusters with an internal cavity bearing flag- ella. These clusters further fused together in a rhagon con- taining one or two large choanocyte chambers. The sequence of cellular processes in epithelial larvae and in flagellated cell conglomerates was similar. Previous obser- vations indicating the totipotentiality of larval flagellated cells during normal metamorphosis of H. dujardini are thus confirmed. J. Morphol. 268:529-536, 2007. 2007 Wiley-Liss, Inc.

Ionic liquids can reversibly absorb large amounts of molecular SO(2) gas under ambient conditions with the gas captured in a restricted configuration, possibly allowing SO(2) to probe the internal cavity structures in ionic liquids besides being useful for SO(2) removal in pollution control.

Plant LTP1 are small helical proteins stabilized by four disulfide bridges and are characterized by the presence of an internal cavity, in which various hydrophobic ligands can be inserted. Recently, we have determined the solution structure of the recombinant tobacco LTP1_1. Unexpectedly, despite a global fold very similar to the structures already known for cereal seed LTP1, its binding properties are different: Tobacco LTP1_1 is able to bind only one monoacylated lipid, whereas cereal LTP1 can bind either one or two. The 3D structure of tobacco LTP1_1 revealed the presence of a hydrophobic cluster, not observed on cereal LTP1 structures, which may hinder one of the two entrances of the cavity defined for wheat LTP1. To better understand the mechanism of lipid entrance for tobacco LTP1_1 and to define the regions of the protein monitoring the accessibility of the cavity, we have complemented our structural data by the study of the internal dynamics of tobacco LTP1_1, using (15)N magnetic relaxation rate data and MD simulations at room and high temperatures. This work allowed us to define two regions of the protein experiencing the largest motions. These two regions delineate a portal that opens up during the simulation constituting a unique entrance of the hydrophobic cavity, in contrast with wheat LTP1 where two routes were detected. The hydrophobic interactions resulting from a few point mutations are strong enough to completely block the second portal so that the accessibility of the cavity is restricted to one entrance, explaining why this particular LTP1 binds only one lipid molecule.

Insight into basic principles of cation transport through ''molecular channels'', and especially details of the related fundamental H2O vehicle function, could be obtained via Li-7 NMR studies of the Li+ uptake/release processes by the unique porous nanocapsule [{(Mo-VI)(Mo5O21)-O-VI(H2O)(6)}(12) {(Mo2O4)-O-V(SO4)}(30)](72-) which behaves as a semi-permeable inorganic membrane open for H2O and small cations; channel traffic as well as internal cavity distribution processes show a strong dependence on ''environmental'' effects such as exerted by solvent properties, the amount of water present, and competing complexing ligands, and end up in a complex equilibrium situation as in biological leak channels.

A supramolecular copper-aqua-crown ether complex, [Cu(II)(H2O)4(dibenzo-24-crown-8]2+ (1c) is stabilized with a Lindqvist-type polyoxometalate anion, [Mo(VI)6O19]2- (1a), in an ion-pair compound [Cu(II)(H2O)4(dibenzo-24-crown-8][Mo(VI6O19] identical with [1c][1a] identical with 1. In the crystal, 1c and 1a assemble to a chainlike structure in which each polyoxoanion 1a is sandwiched by two 1c cations. 1c is a structurally characterized dibenzo-24-crown-8 (a larger-cavity crown ether) supramolecular complex that shows encapsulation of a small cation at the center of its internal cavity, and compound 1 represents a unique example of a first-row transition metal-crown ether inclusion complex that interacts with a polyoxometalate anion.

The MRI/FLAIR sequence is being used for the diagnosis of strokes. The bleeding area shows a high intensity in most cases. However, a doctor must check each image which can take a lot of time. We found that in this process a skilled doctor typically checks the gap area (internal cavity) of the brain to give a diagnosis. This fact is confirmed by a questionnaire of several neuro surgeons. In order to extract the gap area, we utilize a region growing method and a 2D deformable model. We also improve the preciseness by eliminating high intensity areas near the bulb of the brain. Finally, we calculate the degree of riskfactor by counting pixels with high intensity in the gap area. From our experience, we found that the histogram of strokes had a similar pattern, and it could be used for diagnosis of strokes. Finally, we visualize the distribution of the bleeding area of the stroke, and evaluate the results in several ways.

The A4 collaboration at the Institut fur Kernphysik, University of Mainz, is conducting experiments on single-spin asymmetries in the elastic electron–nucleon-scattering which require polarized beams. In order to measure the absolute beam polarization, we have installed a Compton backscattering polarimeter in front of the target, using for the first time the internal cavity concept. A maximum intra-cavity intensity of 90 W has been measured, and in August 2003, first backscattered photons have been detected. Recently, first Compton asymmetries have been measured.

Why bovine odorant-binding protein (OBPb), among OBP family, assumes a dimeric structure has been unclear. Here we clarified, by measuring the fluorescence of intrinsic tryptophan and tyrosine residues of intact OBPb and OBPb whose C-terminal 10 amino acids were deleted, that odorant enters the central pocket formed by the dimerization when OBPb first encounters odorant, and odorant with high affinity with OBPb subsequently enters the internal cavity (suggested binding site), releasing the pre-bound odorant. The internal cavity-bound odorant can be released by the binding of other odorants at another internal cavity or at the central pocket, depending on the binding odorants. Due to this mechanism enabled by the dimerization, OBPb is more reactive than other monomeric OBPs.

Foram conduzidos dois experimentos em Mossoró para avaliar o desempenho de híbridos de melão do grupo inodorus. Em ambos experimentos, foram utilizados delineamentos experimentais em blocos completos casualizados com três repetições. O primeiro experimento foi constituído de dez híbridos Pele de Sapo e o segundo de cinco híbridos de melão do tipo Amarelo e quatro Pele de Sapo. Avaliou-se a produtividade, peso médio do fruto, cavidade interna, espessura da polpa, índice de formato, aparências externa e interna, perda de peso, teor de sólidos solúveis, firmeza da polpa e concentração da produção. No primeiro experimento o híbrido PS RDR destacou-se como o mais promissor, com alta produtividade, alto teor de sólidos solúveis, elevada firmeza de polpa e boa aparência interna e externa. No segundo experimento, os melões do tipo Amarelo diferiram dos melões Pele de Sapo nas características avaliadas. Os híbridos 'Gold Mine' e 'AMR GLDX' tiveram as melhores performances entre os melões tipo Amarelo e o híbrido 'PS 07' entre os melões do tipo Pele de Sapo. Two experiments were carried out in Mossoró, Rio Grande do Norte State, Brazil, to evaluate the performance of melon hybrids of the inodorus group. The experimental design was a randomized complete blocks with three replications. In the first experiment ten 'Piel del Sapo" hybrids were evaluated and in the second five hybrids of Valenciano type of melon and four 'Piel del Sapo' hybrids were evaluated. Evaluations of yield, average fruit weight, format index, internal cavity, pulp thickness, external and intern appearance, weight loss, total soluble solids, pulp firmness and yield concentration, were done. In the first experiment, the hybrid 'PS RDR' was the most promising with high fruit yield and total soluble solids content, better pulp firmness besides good appearance. The Valenciano type of melons differed from 'Piel del Sapo' type of melons for the assessed characteristics. The hybrids 'Gold Mine' and 'AMR GLDX' had the best performance among the Valenciano type and the hybrid 'PS 07' was the best among the 'Piel del Sapo' melons.

The behavior of sucking disks, used to stabilize human tissue during surgeries, was investigated using conventional plastic sucking disks. The contact load to control a sustainable tangential load was calculated from the pressure and area of the internal cavity and the normal load. We observed an interesting phenomenon wherein the more the disk was pulled, the more it was pressed against the counter-surface. We also investigated the maximum tangential frictional force for several pre-loads applied perpendicularly to clarify the potential for sticking. We found that higher the pre-load, the lower was the maximum tangential friction force obtained.Copyright © 2005 by ASME

The pH-driven opening and closure of beta-lactoglobulin EF loop, acting as a lid and closing the internal cavity of the protein, has been studied by molecular dynamics (MD) simulations and free energy calculations based on molecular mechanics/Poisson-Boltzmann (PB) solvent-accessible surface area (MM/PBSA) methodology. The forms above and below the transition pH differ presumably only in the protonation state of residue Glu89. MM/PBSA calculations are able to reproduce qualitatively the thermodynamics of the transition. The analysis of MD simulations using a combination of MM/PBSA methodology and the colony energy approach is able to highlight the driving forces implied in the transition. The analysis suggests that global rearrangements take place before the equilibrium local conformation is reached. This conclusion may bear general relevance to conformational transitions in all lipocalins and proteins in general.

This study was conducted on ‘Tombul’ hazelnut growing at four elevations (0-50 m, 100-150 m, 200-250 m and 300-350 m) in Persembe (Ordu/ Northern Turkey) province in 1999 and 2000 years. Sixteen traits (oil, protein and ash contents as chemical; nut weight, nut size, shell thickness, kernel weight, kernel size, percent kernel, internal cavity, shriveled kernels, good kernels as physical; pH, organic matter, phosphorus and potassium in soil) were examined at each elevation. Interrelationships among important soil, nut and kernel characteristics were examined. There were significant correlation and interrelationships among the traits. The correlation between oil-nut size, oil- protein positively; protein-kernel size, protein- shriveled kernel negatively; organic matter- shell thickness, organic matter-good kernel negatively; pH- shell thickness, pH-good kernel negatively; good kernel-shell thickness positively; shriveled kernel-kernel weight, shriveled kernel-percent kernel negatively; internal cavity-nut weight positively and internal cavity-nut size negatively; percent kernel-kernel weight, percent kernel-kernel size positively; kernel size-kernel weight positively, and kernel weight-nut weight positively were significant. Significant differences among elevations were observed for shell thickness, ash content in kernel, and pH value in soil. The highest coefficients of variation were observed for phosphorus, shriveled kernels, potassium, internal cavity and organic matter, respectivelyEste estudio ha sido realizado en la avellana ’Tombul’ que crece en cuatro elevaciones (0-50 m, 100-150 m, 200-250 m y 300- 350 m) en la provincia de Persembe (Ordu/ Norte de Turquía) en los años 1999 y 2000. Dieciséis rasgos (contenido en aceite, proteína y ceniza como características químicas; peso, tamaño y grosor de cáscara, peso, tamaño y porcentaje del grano, cavidad interna, granos arrugados y granos buenos como características físicas; pH, materia orgánica, fósforo y potasio en el suelo) han sido examinados en cada elevación. Las correlaciones entre características importantes del suelo, de la cáscara y del grano fueron examinadas. Las correlaciones fueron significativas positivamente entre tamaño de la cáscara-aceite, y aceite-proteína; negativamente entre proteína-tamaño grano, y proteína-grano arrugado; negativamente entre materia orgánica-grosor de cáscara, y materia orgánica-grano bueno; negativamente entre pH-grosor de cáscara, y pH-grano bueno; positivamente ente grano bueno-grosor de cáscara; negativamente entre grano arrugadopeso del grano, y grano arrugado-porcentaje del grano; positivamente entre cavidad interna-peso de cáscara y negativamente entre cavidad interna-tamaño de cáscara; positivamente ente porcentaje del grano- peso del grano, y porcentaje del grano-tamaño del grano; positivamente entre tamaño del grano-peso del grano, y peso de cáscara-peso del grano. Diferencias significativas entre elevaciones han sido observadas para el grosor de cáscara, el contenido de ceniza en el grano, y pH en el suelo. Los coeficientes de variación más altos han sido observados para el fósforo, granos arrugados, potasio, cavidad interna y materia orgánica, respectivamente.

The vault is a large 13 MDa ribonucleoprotein particle that is present in abundant copy numbers and has a nearly ubiquitous distribution among eukaryotic cells. The strong conservation of morphology and composition of the vault across species is an indication of an important cellular function, and recently vaults have been implicated in multidrug resistance in certain cancer cells. We have published several cryo-electron microscopy structural studies of the vault isolated from rat and knockout mice. The structures reveal a large internal cavity in the vault and suggest a role for the particle in either macromolecular transport or sequestration. Here we present our latest results on the structure of recombinantly produced vaultlike particles with various protein compositions.

The multistep kinetics of ligand binding to myoglobin is investigated at variable pressure (0.1 – 190 MPa) and temperature (180 – 300 K). The amplitude of the geminate rebinding process increases with pressure corresponding to a smaller escape fraction of ligands into the solvent. High pressures may alter the accessibility of internal cavities in the protein and specific ligand pathways.

Background: To test the diagnostic potential of the SonoHeart, a battery-powered hand-held ultrasound imaging device, in an outpatient clinic setting. Methods: A total of 114 patients with a variety of cardiac diseases were examined by 2 independent cardiologists with the hand-held device using the standard echocardiographic system (SE) as a reference. Global right ventricular (RV) and left ventricular (LV) function (scored as normal, mildly to moderately, or severely reduced) and internal cavity dimensions were assessed. Regional wall motion of 6 segments using a 2-point score (1 = normal wall motion, 2=abnormal wall motion) was evaluated in 34 patients on-line. Results: There was a good agreement between the 2 imaging devices for evaluation of global LV (93%) and RV function (99%), regional wall motion (90%), dimensions of the LV (99%) and the RV (99%), and the left (96%) and right atria (99%). Furthermore, SonoHeart identified hypertrophic cardiomyopathy, pericardial effusion, and abnormalities of valves. Conclusion: The SonoHeart device allows rapid and accurate diagnosis, whenever needed in the outpatient clinic. (J Am Soc Echocardiogr 2002;15:80-5.)

Uteroglobin (UTG) forms a fascinating homodimeric structure that binds small- to medium-sized ligands through an internal hydrophobic cavity, located at the interface between the two monomers. Previous studies have shown that UTG fold is not limited to the UTG/CC10 family, whose sequence/structure relationships are highlighted here, but can be extended to the cap domain of Xanthobacter autotrophicus haloalkane dehalogenase. We show here that UTG fold is adopted by several other cap domains within the alpha/beta hydrolase family, making it a well-suited "geode" structure allowing it to sequester various hydrophobic molecules. Additionally, some data about a new crystal form of oxidized rabbit UTG are presented, completing previous structural studies, as well as results from molecular dynamics, suggesting an alternative way for the ligand to reach the internal cavity.

The hydration of intestinal fatty acid binding protein (IFABP) in apo-form and complexed with palmitate, oleate, and 1-anilino-8-naphthalene sulfonate (ANS) has been studied by water 17O and 2H magnetic relaxation dispersion (MRD) measurements. These ligands bind in a large internal cavity, displacing most of the crystallographically identified cavity water molecules. Unlike most other proteins, IFABP gives rise to MRD profiles with two dispersion steps. The low-frequency dispersion yields a correlation time of 7 ns at 300 K, matching the known tumbling time of IFABP. The dispersion amplitude requires only three (apo) or four (holo) long-lived and ordered water molecules (residence time 0.01-4 μs at 300 K). Comparison of MRD profiles from the different complexes indicates that the displaced cavity water molecules are short-lived. The few long-lived (>10 ns) water molecules required by the MRD data are tentatively assigned to crystallographic hydration sites on the basis of accessibility, positional order, and H-bonding. The amplitude of the high-frequency dispersion corresponds to 10-20 moderately ordered water molecules, with a correlation time of ca. 1 ns that may reflect a transient opening of the cavity required for exchange with external water.