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Comparative angioarchitectural formation seen in microvascular cast specimens of the fungiform papillae in the weaning period and adult rat tongue.

The purpose of this study was an attempt to identify the functional and comparative angioarchitectural differences between the sexes, and the developmental processes seen in microvascular cast specimens (MVCS) of the formation of the fungiform papillae (FuP) geometrically and regularly distributed on the anterodorsal surface in the weaning period and in the adult rat tongue. The basic microvascular structure seen in the MVCS of FuP of both the weaning and adult rat tongue consisted of several ascending (As. b) and descending branches (Ds. b) and a loop structure (L. st), and the cylindrical network structure of the L. st made up of the open-hole formation of the C form of the upper and lower microvascular structures. In the lateral view, the MVCS of FuP has a bamboo basket-like shape, and by means of the three-dimensional expansion of the surface area, effectively plays an assistant functional role in receiving the taste of foods and liquids. There were obviously no sex and morphological differences in the developmental process as to shape, but there was some difference between the weaning period and the adult rat in size in the MVCS of FuP.

Aging↗

Phylogenetics of the Thamnocalamus group and its allies (Gramineae: Bambusoideae): inference from the sequences of GBSSI gene and ITS spacer.

Phylogenetics of 33 species (35 species in the ITS analysis) of the Thamnocalamus group and its allies inferred from partial sequences of the nuclear GBSSI gene and from those of the nuclear ribosomal ITS spacer was discussed in the present paper. The analyses of two separate data and combined data sets were performed using the parsimony method. Two species from Arundinaria and Acidosasa were used as outgroups. All three analyses supported the monophyly of the Thamnocalamus group and its allies, which have pachymorph rhizomes and semelauctant synflorescences with three stamens. The two sampled species of Chimonocalamus were resolved as a strongly supported monophyletic group and as basal in the Thamnocalamus group and its allies in the ITS and combined analyses. The resolution of the Thamnocalamus group and its allies in the GBSSI-gene-based tree was generally poor, while the gene still identified some clades with strongly internal supports, i.e., the Chimonocalamus clade, the Ampelocalamus clade, the clade of Thamnocalamus spathiflorus and its variety, that of Fargesia porphyrea and Yushania bojieana, and the clade of Fargesia edulis and Fargesia fungosa. The topology resulting from the GBSSI and ITS combined data analysis had a better resolution than those from the two separate data sets. T. spathiflorus and its variety comprised another strongly supported basal clade and may be next to the Chimonocalamus clade. The positions of the African Thamnocalamus tessellatus and Arundinaria (Yushania) alpina, and the monotypic Chinese endemic Gaoligongshania were problematic. The Thamnocalamus group per se was resolved as polyphyletic. Most species of Fargesia and Yushania formed a group with no bootstrap support. This assemblage was heterogeneous according to the morphological characters and further investigation is needed. This study implicated that the current limitation of three genera of Thamnocalamus, Fargesia (incl. Borinda) and Yushania may not reflect the true phylogenetic relationships of the complex. The phylogenetic utility of GBSSI gene in closely related woody bamboos was also evaluated.

DNA, Plant↗

A case of fatal triazolam overdose.

A 57-year-old man was found dead lying down in a bamboo thicket. Moderate to severe petechiae were present on his conjunctivae, buccal mucosa, and laryngeal mucosa at autopsy. Cardiac chambers contained a normal volume of fluid blood. Moderate atherosclerosis and fatty liver were observed. No remarkable changes, other than congestion in other organs, were observed. Gas chromatographic screening of the stomach contents, blood and urine was positive for triazolam and alpha-hydroxytriazolam that were confirmed by gas chromatography-mass spectrometry. Blood concentrations of triazolam and free alpha-hydroxytriazolam were 62-251 and 10-66 ng/ml, respectively. A substantial amount of triazolam was detected in bile (1130 ng/ml), but not in urine. Free and total alpha-hydroxytriazolam concentrations were 3920 and 7050 ng/ml, respectively, in the bile and 3710 and 9670 ng/ml, respectively, in urine. Organs contained 216-583 ng/g triazolam. The concentration of free alpha-hydroxytriazolam in the kidney (246 ng/g) was higher than in any other organ. Free alpha-hydroxytriazolam was not detected in the liver. The concentrations of total alpha-hydroxytriazolam in the liver and kidney were 784 and 381 ng/g, respectively. Free to total ratios of alpha-hydroxytriazolam were 0.14-0.56 in fluid samples and 0.56-0.92 in tissue samples, except for the liver. A large quantity of triazolam (8.4 mg) remained in the stomach. The victim probably died of postural asphyxia caused by triazolam poisoning.

Anti-Anxiety Agents↗

Engaging the community in research: lessons learned from the malaria vaccine trial.

When staff of the Papua New Guinea Institute of Medical Research first went into Wosera in 1979, to try and interest the community into participating in malaria research, the traditional warning sign of crossed bamboo sticks constantly blocked their path as they tried to enter the villages. In 2003, the site is a thriving research centre, with many projects under its belt, a successfully executed malaria vaccine trial to its credit, and approximately 13000 people from 29 villages currently participating in demographic surveillance and various research projects. It has been a long road from community suspicion to sustainable community participation, and the field workers have learned many important lessons along the way that can be applicable to research programs in other disease-endemic areas.

Clinical Trials as Topic↗

Perfluorooctanesulfonate and periluorooctanoate in red panda and giant panda from China.

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) are important perfluorochemicals (PFCs) in various applications. Recently, it has been shown that these compounds are widespread in the environment, wildlife, and humans. The giant panda and the red panda belong to the order Carnivora, but are highly specialized as bamboo feeders. Both species are considered rare and endangered. In this study, we report for the first time on levels of PFOS and PFOA in serum of the giant panda and the red panda captured in zoos and animal parks from six provinces in China. PFOS was the predominant compound in all panda samples measured (ranging from 0.80 to 73.80 microg/L for red panda and from 0.76 to 19.00 microg/L for giant panda). The PFOA level ranged from 0.33 to 8.20 microg/L for red panda, and from 0.32 to 1.56 microg/L for giant panda. There was a positive significant correlation between concentrations of PFOS and PFOA in the serum obtained from pandas. No age- or sex- related differences were observed in concentrations of the fluorochemicals in panda sera. Greater concentrations of the fluorochemicals were found for those individuals collected from zoos near urbanized or industrialized areas than for other areas. These data combined with other reported data suggest that there are large differences in distribution of perfluorinated compounds in terrestrial animals.

Age Factors↗

Hydrogen uptake in boron nitride nanotubes at room temperature.

Hydrogen uptake capacities of 1.8 and 2.6 wt % were obtained on BN multiwalled nanotubes and bamboo-like nanotubes, respectively, under approximately 10 MPa at room temperature. The preliminary results show that chemical interactions mainly take place between hydrogen and BN. Taking into consideration the uniform semiconducting electronic property and ultimate stable chemical and thermal stability, BN nanotubes may exhibit some interesting possibilities in storing hydrogen. This will also provide some viewpoints on designing the carbon-based hydrogen storage system.

Journal Article↗

Large-scale synthesis of carbon nanotubes by an ethanol thermal reduction process.

The bamboo-shaped carbon nanotubes were synthesized on a large scale through an ethanol thermal reduction process, in which ethanol was used as the carbon source and magnesium was used as the reductant. The toxic or corrosive reagents have been completely avoided. Furthermore, Y-junction carbon nanotubes obtained from our experiment can be used as the building blocks of nanoelectronics. Because of the simplicity and high yield of this route, it may potentially be applied on the scale of industrial production.

Journal Article↗

Development of ochratoxin A during robusta (Coffea canephora) coffee cherry drying.

The occurrence and formation of ochratoxin A (OTA) in Robusta coffee was studied for three consecutive seasons under tropical conditions in Thailand. Sun drying of coffee cherries consistently led to OTA formation in the pulp and parchment (husks) of the cherries. In replicated trials, dried coffee beans (green coffee) were shown to contain on average OTA concentrations that were approximately 1% of those found in husks. OTA contamination of green coffee depended on cherry maturity, with green cherries being the least, and overripe cherries the most susceptible. Defects, and in particular the inclusion of husks, are the most important source of OTA contamination. OTA contamination occurred independently of whether cherries were placed on concrete, on bamboo tables, or on the ground. The study suggests that better raw material quality, an appropriate drying and dehulling procedure combined with a reduction of green coffee defects can effectively contribute to the reduction of OTA in green coffee.

Coffee↗

Antitumor agents. 134. New shiraiachrome-A- and calphostin-C-related perylene derivatives as cytotoxic and antiviral agents and inhibitors of protein kinase C.

Shiraiachrome-A and -B have been isolated from the mycelium of the Chinese bamboo fungus Shiraia bambusicola as the cytotoxic principles. A series of new perylene derivatives (7-27) related to Shiraiachrome-A and -B as well as Calphostin-C have been synthesized and evaluated for their cytotoxicity, antiviral activity, and inhibitory activity against protein kinase C. The results indicated that 11 and 12 are potent cytotoxic agents against HCT-8, RPMI-7951, and TE-671 solid tumor cells, whereas 24 and 26 demonstrated strong antiviral activity against HSV-1 and HSV-2. Compound 10 is an inhibitor of protein kinase C.

Animals↗

Distribution and structure of N atoms in multiwalled carbon nanotubes using variable-energy X-ray photoelectron spectroscopy.

We investigated the inhomogeneous distribution of concentration and electronic structure of the nitrogen (N) atoms doped in the multiwalled carbon nanotubes (CNTs) by variable-energy X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge structure, and electron energy-loss spectroscopy. The vertically aligned N-doped CNTs on the substrates were grown via pyrolysis of iron phthalocyanine (FePc), cobalt phthalocyanine (CoPc), and nickel phthalocyanine (NiPc) in the temperature range 750-1000 degrees C. They usually have a bamboo-like structure, and the diameter is in the range of 15-80 nm. As the photon energy of XPS increases from 475 to 1265 eV, the N content increases up to 8 atomic %, indicating a higher N concentration at the inside of nanotubes. We identified three typed N structures: graphite-like, pyridine-like, and molecular N(2). The pyridine-like N structure becomes significant at the inner walls. Molecular N(2) would exist as intercalated forms in the vicinity of hollow inside. The XPS valence band analysis reveals that the pyridine-like N structure induces the metallic behaviors. The CNTs grown using NiPc contain the higher content of pyridine-like structure compared to those grown using FePc and CoPc, so they exhibit more metallic properties.

Journal Article↗

X-ray absorption near edge structure study of BN nanotubes and nanothorns.

Two boron nitride (BN) nanostructures, the bamboo-like nanotubes and nanothorns where the nanosize h-BN layers are randomly stacked looking like thorns, were synthesized selectively via thermal chemical vapor deposition of B/B(2)O(3) under the NH(3) flow at 1200 degrees C. Electron energy-loss spectroscopy reveals the N-rich h-BN layers with a ratio of B/N = 0.75-0.85. Angle-resolved X-ray absorption near edge structure of these two N-rich nanostructures has been compared with that of h-BN microcrystals. The pi transition in the N K-edge shifts to the lower energy by 0.8-1.0 eV from that of h-BN microcrystals, and the second-order signals of N 1s electrons become significant. We suggest that the N enrichment would decrease the band gap of nanostructures from that of h-BN microcrystals. The Raman spectrum shows the peak broadening due to the defects of N-rich h-BN layers.

Journal Article↗

Thermal conductivity of nanostructured boron nitride materials.

We have measured the thermal conductivity of bulky pellets made of various boron nitride (BN)-based nanomaterials, including spherical nanoparticles, perfectly structured, bamboo-like nanotubes, and collapsed nanotubes. The thermal conductivity strongly depends on the morphology of the BN nanomaterials, especially on the surface structure. Spherical BN particles have the lowest thermal conductivity while the collapsed BN nanotubes possess the best thermoconductive properties. A model was proposed to explain the experimental observations based on the heat percolation passage considerations.

Journal Article↗

Synergism of C5N six-membered ring and vapor-liquid-solid growth of CN(x) nanotubes with pyridine precursor.

A series of bamboo-like CN(x)() nanotubes have been synthesized from pyridine precursor by chemical vapor deposition with bimetallic Fe-Co/gamma-Al(2)O(3) catalyst in the range of 550 approximately 950 degrees C. An unusual predomination of pyridinic nitrogen over graphitic nitrogen has been observed for the CN(x)() nanotubes with reaction temperature below 750 degrees C. The pyridinic nitrogen decreases and the graphitic nitrogen increases with rising reaction temperature. A synergism mechanism of C(5)N-six-membered-ring-based growth through surface diffusion and vapor-liquid-solid growth through bulk diffusion was accordingly deduced and schematically presented. This mechanism could not only explain our own experimental results, but also understand the CN(x)()-nanotube-related experimental phenomena in the literature, as well as be in accordance with the basic principle of diffusion kinetics. A promising route to the challenging topic for synthesizing regularly arranged C(5)N or high-N-content CN(x)() nanotubes has also been suggested.

Journal Article↗

4-Nitrobenzylamine partially intercalated into graphite powder and multiwalled carbon nanotubes: characterization using X-ray photoelectron spectroscopy and in situ atomic force microscopy.

We report the characterization of partial intercalation of 4-nitrobenzylamine (4-NBA) into edge-plane or edge-plane-like defect sites on the surface of both graphite powder and "bamboo-like" multiwalled carbon nanotubes (MWCNTs) using X-ray photoelectron spectroscopy (XPS). By comparing the XPS spectra of 4-NBA derivatized graphite powder and MWCNTs with that of graphite powder treated with benzylamine in a similar fashion, we conclude that benzylamine itself does not undergo partial intercalation. Using in situ atomic force microscopy, we are able to observe the partial intercalation of 4-NBA into an edge-plane-like "step" defect on the surface of a highly ordered pyrolytic graphite crystal in real time. Together these observations provide further evidence for the partial intercalation of 4-NBA and lead us to propose a new hypothesis to explain this phenomenon.

Journal Article↗

In situ investigations on organic foam films using neutron and synchrotron radiation.

We report on small-angle neutron scattering (SANS) and X-ray scattering (SAXS) investigations of foam films stabilized by sodium dodecyl sulfate. Previous measurements on dry foams (Axelos, M. A. V.; Boue, B. Langmuir 2003, 19, 6598) have shown the presence of spikes in the two-dimensional scattering data which suggest that the incident beam is reflected on some film surfaces. The latter interpretation is confirmed by new neutron studies performed on ordered ("bamboo") foams which allow selection of single films. In the first case, we show that the spikes of the scattered intensity can be obtained by reflection on two parts of the foam, namely, the films and the Plateau borders. With synchrotron radiation, first observations of distinct interference fringes have allowed an accurate determination of the film thickness. A comparison with X-ray and neutron data is made, opening a general discussion about the capabilities of small-angle scattering techniques for studying the microscopic properties of foam films.

Journal Article↗

Massive fabrication of free-standing one-dimensional Co/Pt nanostructures and modulation of ferromagnetism via a programmable barcode layer effect.

Massive fabrication of free-standing Co/Pt magnetic barcode nanowires with well-defined interfaces and layer thicknesses is obtained after freeing them from porous templates. Such barcodes display bamboo-like shapes with identical motifs either inside or out of the templates. The ferromagnetism of these barcode nanowires can be modulated easily depending on the cobalt segments and shape anisotropies. Further enhancements of the ferromagnetism of Co/Pt barcodes are also accomplished through interfacial alloying processes via a thermally induced phase transition.

Journal Article↗

Pterospora floridiensis, a new species of acephaline gregarine (Apicomplexa) from the maldanid polychaete Axiothella mucosa in St. Andrew Bay, Florida.

Pterospora floridiensis, a new species of acephaline gregarine from the body cavity of the bamboo worm Axiothella mucosa (Polychaeta: Maldanidae), is described. The gamont stage is distinctive and possesses a central cytoplasmic mass and two elongate trunks that bifurcate repeatedly and comprise approximately 60% of the total cell length. The gamont averages 198 (50-545) x 71 (25-180) microm (N= 45, 43) from the tip of the trunks to the anterior (the junctional site with the other gamont in syzygy). Gametocysts average 402 (297-545) x 304 (149-495) microm (N = 37). The oöcysts measure 22.5 (20.5-23.5) x 8.3 (7.0-10.0) microm (N = 30) and possess an internal capsule (average length = 13.9 microm, N = 30) containing the sporozoites and aliform wings on the epispore.

Animals↗

Nitrogen export from an agriculture watershed in the Taihu Lake area, China.

Temporal changes in nitrogen concentrations and stream discharge, as well as sediment and nitrogen losses from erosion plots with different land uses, were studied in an agricultural watershed in the Taihu Lake area in eastern China. The highest overland runoff loads and nitrogen losses were measured under the upland at a convergent footslope. Much higher runoff, sediment and nitrogen losses were observed under upland cropping and vegetable fields than that under chestnut orchard and bamboo forest. Sediment associated nitrogen losses accounted for 8-43.5% of total nitrogen export via overland runoff. N lost in dissolved inorganic nitrogen forms (NO(3-)-N + NH4+-N) accounted for less than 50% of total water associated nitrogen export. Agricultural practices and weather-driven fluctuation in discharge were main reasons for the temporal variations in nutrient losses via stream discharge. Significant correlation between the total nitrogen concentration and stream discharge load was observed. Simple regression models could give satisfactory results for prediction of the total nitrogen concentrations in stream water and can be used for better quantifying nitrogen losses from arable land. Nitrogen losses from the studied watershed via stream discharge during rice season in the year 2002 were estimated to be 10.5 kg N/ha using these simple models.

Agriculture↗