Branch Fragments Research Articles

Structural Characterization, and Antioxidant, Hypoglycemic and Immunomodulatory Activity of Exopolysaccharide from Sanghuangporus sanghuang JM-1

Sanghuang as a medicinal fungus in China has a history of more than 2000 years, and is known as the “forest gold”. Most notably, the polysaccharides of Sanghuangporus sp. have attracted widespread attention due to their significant bioactivity in recent years. At present, extensive studies are being carried out on the extraction methods, structural characterization, and activity evaluation of polysaccharides. Here, we aimed to evaluate the structure and bioactivity of LEPS-1, an exopolysaccharide derived from the S. sanghuang JM-1 strain. The structure was elucidated by chromatography/spectral methods and hydrolyzation, and the solubility, the antioxidant activity, hypoglycemic activity and immunomodulatory activity were investigated. Results showed that LEPS-1 contained a →2)-α-Manp(1→6)-α-Galp(1→[2)-α-Manp(1→]n→2,6)-α-Manp(1→6,2)-α-Manp(1→3)-α-Manp(1→ backbone substituted at the O-6 and O-2 positions with side chains. These two branching fragments were β-Manp(1→. The molecular weight of LEPS-1 is 36.131 kDa. The results of biological activity analysis suggested that LEPS-1 was easily soluble in water, with reducing capability and DPPH radical scavenging capability. Furthermore, the IC50 values of LEPS-1 against α-amylase and α-glucosidase were 0.96 mg/mL and 1.92 mg/mL. LEPS-1 stimulated RAW264.7 cells to release NO, TNF-α and IL-6 with no cytotoxicity, showing potent potential for immunomodulatory activity. These findings describe a potential natural exopolysaccharide with medicinal value and a basis for the development of S. sanghuang exopolysaccharides.

Araucaria angustifolia and Picrasma crenata extracts as potential agents for the control of phytopathogenic fungi of agricultural interest

To expand knowledge about native species in southern Brazil, different types of extracts from the thin vinaceous bark of A. angustifolia and fragments of branches of P. crenata were evaluated. These were crushed and kept for fifteen days in contact with hydroalcoholic solutions at 70 % v/v and ethanolic (96 % v/v), seven days in the cold aqueous extract, and through the decoction process for 10 min. Afterward, they were evaluated at concentrations of 1.0 %, 2.5 %, 5.0 %, 10.0 %, and 20.0 % v/v on the mycelial development of the phytopathogenic fungi Colletotrichum gloeosporioides, Botrytis cinerea, and Sclerotinia sclerotiorum. The levels of phenolic compounds and total flavonoids were evaluated, and the alcoholic extracts of A. angustifolia had the highest total phenolic content. The main phenolic compounds identified in the P. crenata extract were resveratrol, followed by herperidin, rutin, ferulic acid, and kaempferol, and the main chemical compounds identified in the extracts of A. angustifolia were quercetin, rutin, ferulic acid, kaempferol, and gallic acid. A. angustifolia extracts and P. crenata, during the decoction, were more effective in controlling the phytopathogens C. gloeosporioides and B. cinerea from a concentration of 5 % v/v. The fungus S. sclerotiorum was moderately inhibited in hydroalcoholic extracts at 70 % v/v of P. crenata and A. angustifolia at 1.0 % and 2.5 % v/v concentrations. Effectively controlling these phytopathogenic fungi of agricultural importance confers importance on the conservation of these native species of socio-biodiversity in the Atlantic Forest in southern Brazil.

Effects of growth Medium, temperature and mycelium age on CHV-1 accumulation and transmission

Some mycoviruses such as Cryphonectria hypovirus 1 (CHV-1) have a potential application for biocontrol of Cryphonectria parasitica, the causal agent of chestnut blight, but little is known about the factors that regulate the fungus-virus interaction, especially when the concentration of the virus is low as it is usual in the wider environment in England. In this study, four CHV-1 infected isolate types of C. parasitica were tested for parameters relating to hypovirulence by inoculating onto potato dextrose agar (PDA), apples, and sweet chestnut branch fragments. Isolate L-6 (CHV-1 subtype I, haplotype E-5), together with the positive control isolate M784 (same haplotype), presented the highest hypovirulence values. The lowest hypovirulence was observed with isolate M784 previously kept in the cold at 8 °C, followed by isolate Db-1 (same haplotype but naturally mutated). The differences in hypovirulence were much more pronounced when inoculations took place using mycelial plugs taken from the edge of plate colonies as opposed to the centre of a colony. The same strains were used to further evaluate the effects of the growth medium (PDA or plant material), optimum and cold temperatures, and mycelium age (centre or edge plugs) on the respective virus concentration. Virus RNA was extracted and amplified by RT-PCR and the concentration of the CHV-1 DNA band (394 bp) measured. Virus concentration decreased when its host was growing on PDA when compared to its host growing on plant material. Virus concentration was reduced further if held in the cold temperature for 7 days, and the virus concentration decreased even further after an additional incubation period at 25 °C. Virus isolate L-6, sub-cultured from the colony centre, was the only one that recovered to its original concentration following incubation for 7 days on sweet chestnut wood fragments. The concentration of the virus was more stable in the centre of the plates than that found at the edge of a plate colony. Together with the expected 394 bp CHV-1 amplicon, another 90 bp band was occasionally simultaneously amplified using the same RT-PCR procedure. This band was quantified, and sequenced, finding no homologs. It is first time this satellite amplicon has been described and its concentration related with hypovirulence attributes of the virus infected C. parasitica, such as reduced fungal growth, and positive correlation with donor and recipient CHV-1 band load in donor-recipient transmission experiments. We discuss our findings in terms of previous parameters related to hypovirulence.

Middle Miocene (Serravallian) rhodoliths and coralline algal debris in carbonate ramps (Betic Cordillera, S Spain)

Serravallian (middle Miocene) coralline algal assemblages at the southern margin of the Guadalquivir Basin (southern Spain) occur as rhodoliths preserved in situ or very close to their growth habitats (autochthonous–parautochthonous assemblages) and also as reworked remains (allochthonous assemblages). The former assemblages consist of spherical rhodoliths built up by encrusting to warty plants and also of large fragments of branches, whereas the latter are mostly unrecognizable small fragments occurring in channeled packstone–grainstone beds. In both cases, the most abundant components are members of the order Hapalidiales (Mesophyllum roveretoi, Mesophyllum sp., Lithothamnion ramosissimum, and less frequently Phymatolithon group calcareum and Lithothamnion group corallioides). Laminar growths of Lithoporella minus and branches of Spongites group fruticulosus and Sporolithon sp. occur very rarely. There are also anecdotal records of Subterraniphyllum thomasii, extending its upper stratigraphic range up to the Serravallian in the western Tethys. The autochthonous–parautochthonous coralline algal assemblages formed in a middle ramp, at several tens of meters of water depth, as suggested by the dominance of Hapalidiales. The allochthonous assemblages represent fragments of coralline algae derived from the middle ramp and redeposited in deeper settings, most likely the outer ramp, due to storm-generated currents.

Firstever Breeding Record of Painted Stork along with Greater Adjutant Stork in the Flood Plains of Kosi River in Bhagalpur, Bihar, India

Painted stork (Mycteria leucocephela) is a large resident wetland bird of stork family- Ciconidae and has been categorized as near threatened. A new nesting colony of wild Painted stork, breeding along with Lesser (Leptoptilos javanicus) and Greater Adjutant stork (Leptoptilos dubius) have been observed on the same nesting tree (Kadamb- Anthocephalus cadamba) at Bagritola village of Kadwa panchayat located on the flood plains of the Kosi river in district of Bhagalpur, Bihar, India. In October, 2015, a single nest and three Painted storks were observed (of which one bird was seen incubating) on a Kadamb tree in the village Bagritola. This breeding site was studied from October, 2015 to March, 2020 to observe the detailed nesting and breeding behaviors. From October, 2015 onwards a significant increase in the number of nests of Painted storks was recorded at the same breeding site and the storks adopted 2-5 separate but closely situated kadamb trees for nesting. In the month of September, 2017, two adjacent Kadamb trees were adopted by the Lesser and Greater Adjutant storks for nesting and they built two nests (one on each) Kadamb tree. In October, 2017, Painted storks also started to build their nest on the same trees which were already occupied by the Adjutant storks. From 2018 onwards, no nests of Lesser adjutant stork were observed and the Painted storks were found to breed along with Greater adjutant storks only, till the end of the study period i.e. March, 2020. Similar to the other two stork species, both the male and female Painted storks were sharing the process of nest building, incubation, nursing and guarding the chicks by rotation. Fragments of old branches of nearby trees as well as from abandoned nests were used for building the nests which were cushioned with the leaves. The Painted storks were successfully breeding along with the Greater adjutant storks on the same nesting trees peacefully without any obvious disturbances. The breeding season of Painted storks was observed to continue between October to March and their incubation period was estimated to range between 27-30 days. The breeding season of Lesser adjutant stork was observed to continue between mid-August to Feb whereas of Greater adjutant stork was observed between September to March with slight variation of 6-10 days in Bihar, India.

Trends in the Transformation of Modern Law under the Influence of a New Stage of Scientific and Technological Progress

The article examines the trends of transformation of modern law under the influence of a technological breakthrough as a new stage of scientific and technological progress. The general trends of globalization and differentiation of law are highlighted, and the consequences of these trends, expressed in the growth of the number of complex branches of law that combine public and private interests, are considered. For the purpose of systematization, three main forms of globalization in law are identified: universalization, internationalization and integration. The analysis of the evolution of the legal system in the historical dimension allows to distinguish three stages of differentiation of modern law. At the first stage of the differentiation of law in the XX century, it was mainly expressed in the fragmentation of traditional branches of law. The second stage of the differentiation of law at the turn of the XX and XXI centuries is characterized by the intensive formation of complex mixed branches of law that join the institutions of public and private law for certain purposes of legal regulation. At the third, modern stage at the junction of the first and second decades of the XXI century. under the influence of scientific and technological progress, there is not only a further diversification and integration of traditional and new complex branches of law, but also a group of functional and instrumental branches of law. Th se branches of auxiliary law (due to its functional significance) determine the socio-legal technologies of regulation, implementation and development of law (for example, collision law, mediation law, digital law).The author puts forward the concept and reveals the system of branches of law of the new generation as the highest form of evolution of complex branches of law, justifies their special nature and significance in the system of law. The author also systematizes the branches of law of the new generation, taking into account the degree of their development in legal doctrine and law practice.Special attention is paid to digital law and bio-law, which most clearly indicate the impact of scientific and technological progress on law, as well as exposing the problem of the need for closer interaction of the principles and norms of law and ethics.

Banks fearing the drought? Liquidity hoarding as a response to idiosyncratic interbank funding dry-ups

We investigate whether idiosyncratic interbank funding shocks affecting a bank headquarters can trigger a liquidity hoarding reaction by their regional branches. Shock-affected branches of Brazilian banks increase liquid assets and cut lending in the shocks’ aftermath compared to non-affected branches within the same municipality, even in absence of a market-wide freeze. These effects increase in branches’ reliance on internal funding and vary depending on banks’ access to central bank emergency liquidity. Our findings suggest that the geographical fragmentation of branches’ funding limits their ability to offset idiosyncratic funding shocks.

Fungal Endophytes of Tahiti Lime (Citrus citrus × latifolia) and Their Potential for Control of Colletotrichum acutatum J. H. Simmonds Causing Anthracnose.

Colletotrichum acutatum is one of the causal agents of anthracnose in several crops, and of post-flowering fruit drop (PFD) in citrus and key lime anthracnose (KLA). The pathogen normally attacks flowers, causing lesions only in open flowers. Under very favorable conditions, however, it can also affect flower buds and small fruits, causing complete rotting of the fruit and a premature fall, resulting in major economic crop losses. We isolated endophytic fungi from Tahiti lime to evaluate its diversity, verify its antagonistic capacity against the phytopathogen Colletotrichum acutatum C-100 in dual tests, and evaluate the ability of various endophytic agents to control flowers with induced anthracnose. 138 fungal isolates were obtained from 486 fragments of branches, leaves, and fruit; from which 15 species were identified morphologically. A higher isolation frequency was found in branches and leaves, with a normal level of diversity compared to other citrus species. Of the 15 morphospecies, 5 were trialed against C. acutatum in antagonism tests, resulting in a finding of positive inhibition. 2 endophytic fungi from the antagonism tests demonstrated high inhibition of the phytopathogen, and were thus used in in vivo tests with Tahiti lime flowers, applied in a spore solution. Spore solutions of two molecularly identified species, Xylaria adscendens, and Trichoderma atroviride, reduced the lesions caused by the phytopathogen in these in vivo tests. The finding that these endophytes react antagonistically against C. acutatum may make them good candidates for further biological control research in an agroindustry that requires environmental sustainability.

Оцінювання запасів грубого деревного детриту у лісових екосистемах національного природного парку «Слобожанський»

Dead wood is an important component of forest ecosystems. It performs a number of environmental functions. Coarse woody debris includes standing dead trees, fallen dead trees, fragments of fallen trees (trunks), branches (fragments of branches), and rough tree roots. It is a substrate and habitat for living organisms, including a number of species of mosses, lichens, fungi, invertebrates, as well as birds and mammals. Woody detritus plays an important role in the biological cycle of substances and energy, and carbon deposition, is a source of nutrients. Therefore, the study of quantitative and qualitative features of dead wood, in particular on protected areas, is a considerable nowadays problem. The aim of the work is to estimate identified by forest inventory stocks of dead wood in forest ecosystems of Slobozhansky NNP by categories, as well as to analyze the distribution of its volumes in stands of dominant tree species and forest types. The estimation of coarse woody debris stocks was performed based on forest inventory data of Slobozhansky National Nature Park conducted by Ukrainian State Project Forestry Production association “Ukrderzhlisproekt”. Data from 493 forest stands of nine tree species were analyzed. The stock of the following fractions of coarse woody debris was studied: standing dead wood, fallen (downed) dead wood. Data analysis was performed using MS Excel 2016 software. It was found that the total area of forest stands in which standing or downed dead wood was found during forest inventory was 2149.8 ha, or 47.5% of the total forest area of NNP. The total stock of coarse woody debris was 19478 m3, more than 95% of which is concentrated in the stands of Scots pine (Pinus sylvestris L.) (78.8%) and pedunculate oak (Quercus robur L.) (16.6%). Standing dead wood prevailed (62.1%) fallen dead wood (37.9%) in the structure of dead wood volume. The volume of dead wood was in the range of 5–50 m3∙ha–1, and on average in studied forest ecosystems in which it was found was 9.1 m3∙ha–1. In Scots pine forest stands coarse woody debris was found on an area of 1703.5 hectares with total stock of 15355 m3, consists of standing dead trees (9952 m3, 64.8%) and fallen dead wood (5403 m3, 35.2%). The volume of dead wood in forest stands was 5–50 m3∙ha–1, on average – 9.0 m3∙ha–1. In pedunculate oak stands coarse wood debris was found on an area of 384.7 hectares with a total stock of 3224 m3, consists of standing dead wood (1469 m3, 45.6%) and fallen dead wood (1755 m3, 54.4%). The volume of dead wood in forest stands was 5–20 m3∙ha–1, on average – 8.4 m3∙ha–1.

Winds in the Lower Cloud Level on the Nightside of Venus from VIRTIS-M (Venus Express) 1.74 μm Images

The horizontal wind velocity vectors at the lower cloud layer were retrieved by tracking the displacement of cloud features using the 1.74 µm images of the full Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS-M) dataset. This layer was found to be in a superrotation mode with a westward mean speed of 60–63 m s−1 in the latitude range of 0–60° S, with a 1–5 m s−1 westward deceleration across the nightside. Meridional motion is significantly weaker, at 0–2 m s−1; it is equatorward at latitudes higher than 20° S, and changes its direction to poleward in the equatorial region with a simultaneous increase of wind speed. It was assumed that higher levels of the atmosphere are traced in the equatorial region and a fragment of the poleward branch of the direct lower cloud Hadley cell is observed. The fragment of the equatorward branch reveals itself in the middle latitudes. A diurnal variation of the meridional wind speed was found, as east of 21 h local time, the direction changes from equatorward to poleward in latitudes lower than 20° S. Significant correlation with surface topography was not found, except for a slight decrease of zonal wind speed, which was connected to the volcanic area of Imdr Regio.

Diversity of endophytic fungi in the leaflets and branches of Poincianella pyramidalis, an endemic species of Brazilian tropical dry forest

ABSTRACT Plants harbour diverse communities of fungal species in their internal compartments. Endophytic fungi help their hosts to establish, survive, and adapt to different environments. Here, we examined the diversity of endophytic fungi in the leaflets and branches of Poincianella pyramidalis, a plant species endemic to the Brazilian tropical dry forest (Caatinga). A total of 360 fragments of leaflets and branches were analysed and 189 endophytic fungi were isolated and distributed among 21 ascomycetous genera based on their ITS and LSU rDNA sequences. Diaporthe was the most frequently identified genus, followed by Didymella and Rhytidhysteron. The colonisation rate of plant fragments was higher in the branches (74 %) than in leaflets (14 %). The richness of the genera of endophytic fungi was also higher in the branches than in leaflets, whereas no difference was observed in endophyte diversity between the plant parts, based on Shannon-Wiener and Fisher alpha diversity indices. Our results indicate that endemic plant species from Brazilian dry forest, such as P. pyramidalis, are predominantly colonised by ascomycetous fungi, especially members of the class Dothideomycetes.

Occurrence of Ants (Hymenoptera: Formicidae) in both Leaf Litter and Twigs in Atlantic Forest

Twigs in the litter derived from the fragmentation of tree branches form one microhabitat, where entire colonies of ants, both leaf litter and arboreal species, can be found. The objective was to survey ant species that are presente in both the leaf litter and twigs simultaneously. We describe the nest type, the social structure of the colonies and the trophic guild membership of these species. Samples were collected from 10 preserved fragments of Brazilian Atlantic forest. We used Berlese funnels to collect leaf litter ants and manual collection for twig ants. We recorded 80 ant species; 60 species were in leaf litter samples and 35 species were in twigs. Of the total species, only 15 (20%) occurred simultaneously in the leaf litter and in twigs. Of these species, Gnamptogenys striatula, Pheidole sarcina, P. sospes and Solenopsis sp. 2 were the most frequent among leaf litter dwellers, and Myrmelachista catharinae was the most common arboreal species. Most of these belonged to generalista and predator guilds, with “polydomous nests” and colonies monogynous.

Rare bryozoans from the Gault Clay Formation (Lower Cretaceous, upper Albian) of Kent, England

Relatively few bryozoans have been recorded to date from the Gault Clay Formation of southern England, yet the Albian (late Early Cretaceous) age of this unit makes it potentially of importance in understanding the roots of the major radiations of cheilostome and cyclostome bryozoans during the Late Cretaceous. Two bryozoan genera are here described for the first time from the Gault Clay on the basis of single specimens from the upper part of this unit at Paddlesworth (Kent), recently discovered in the collection of the late Joe Collins. A colony of the cheilostome Wawalia crenulata that preserves the putative ancestrula reveals two novel features: a spiral pattern of early budding and the presence of pyrite-filled lacunae in the thick vertical walls of the zooids. The second bryozoan is a branch fragment of the erect eleid cyclostome genus Biforicula. Representing the oldest record of this genus, it is described as Biforicula collinsi sp. nov.

First Report of Colletotrichum siamense Causing Stem Tip Dieback of Sacha Inchi (Plukenetia volubilis) in China

Sacha inchi (Plukenetia volubilis L.), which belongs to the Euphorbiaceae family, was introduced into China in 2006. It is considered one of the most promising economic oilseed crops in China. A high content of polyunsaturated fatty acid, phytosterols, tocopherols, total carotenoids, and hydrophilic and lipophilic antioxidant capacities was found in the seeds of this plant with disease prevention potential (Chirinos et al. 2013). In 2018 to 2019, dieback characterized by progressive death of branches from tip was observed on the sacha inchi at the Danzhou campus of Hainan University. The disease incidence was nearly 100% in adult plants. In July 2018, six infected branches covered with Parafilm at both ends to reduce desiccation were collected, and 5-mm-long branch fragments were cut from the diseased and healthy borders. The branch fragments were surface disinfected in 2% sodium hypochlorite for 2 min, rinsed with sterile double distilled water for five to seven times, plated on potato dextrose agar (PDA) medium amended with 100 μg/ml of streptomycin, and incubated at 28°C for 5 days. Three pure isolates were obtained by transferring mycelial fragments from the margin of fungal colonies onto fresh PDA, and a representative isolate was DZJ-10. Colonies produced by isolates were dense, white to greyish aerial mycelium on PDA at 28°C for 7 days. The morphology of conidia was cylindrical, aseptate, with the average size 8.3 ± 1.1 × 2.7 ± 0.4 μm (50 conidia). To do molecular identification, three genes/genetic regions were amplified: the rDNA regions of the inner internal transcribed spacer (ITS) regions (primers ITS1/ITS4) (White et al. 1990), the actin gene (ACT; primers ACT-512F/ACT-783R) (Carbone and Kohn 1999), and the glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH; primers GDF/GDR) (Weir et al. 2012). The sequences were deposited in GenBank (accession nos. MT020423, MT029317, and MT029318). The sequences were blasted in GenBank. The sequence of ITS revealed 100% identity with Colletotrichum siamense ITS of KP703372 and KP703373 in GenBank, respectively. The ACT showed 100% similarity with C. siamense LC412418 and MK568557 accessions. And the GAPDH showed 99.59% identity with MK457189 and MH681394. The phylogenetic analysis of combined GAPDH, ITS, and ACT sequences performed in MEGA 6.0 using neighbor joining revealed that the isolates were C. siamense. The isolates are C. siamense based on morphological characters and multigene phylogeny (Ling et al. 2019; Prihastuti et al. 2009). For the pathogenicity test, the cut-stem inoculation technique was performed (Wang et al. 2020). The stem apex of each 2-month-old sacha inchi plant was cut above the node with a sharp scalpel. The open end of a 10- to 200-μl pipette tip was pushed into the margin of the 7-day-old C. siamense culture growing on PDA, and a mycelium plug was removed. The pipette tip containing the mycelium plug was immediately transferred onto the cut stem and pushed down to embed the stem into the medium and to secure the tip onto the stem. Nine plants were used for each isolate and the control, and the plants inoculated by PDA plugs were used as a control. All plants were placed in the greenhouse at 28°C and 80% relative humidity. Typical symptoms of plants infected by isolates were photographed after 18 days. C. siamense was reisolated from inoculated plants but not from the control plants. The experiment was repeated with similar results. To the authors’ knowledge, this report is the first to identify the pathogen of sacha inchi stem tip dieback as C. siamense in China. Our findings enriched the pathogen library of sacha inchi and paved the way for developing effective strategies to control the disease.

Late Quaternary Deep-Sea Corals (Anthozoa: Scleractinia) from the Argentine Continental Margin

Fossil deep-sea corals have been collected from dredges and sediment cores from the outer shelf and middle slope at the northern Argentine Continental Margin (37o–38o S). They have been identified as Flabellum ( F. ) thouarsii and Bathelia candida . Both species inhabit nowadays the outer shelf and the upper and middle slope of eastern South American coasts, but they had never been described as fossils. The integration of planktonic foraminiferal assemblages and one accelerator mass spectrometry 14C dating of a fragment of a coral branch belonging to B. candida allowed a precise biostratigraphic and geochronological control, indicating a Late Pleistocene age for the first fossil representatives of this species.

Effect of the impact of rigid rods on coffee fruit detachment efficiency by mechanical vibrations

The mechanization of field activities has been the response of coffee producers to the labor shortage, especially for fruit harvesting. The use of mechanical harvesters allows greater harvesting efficiency and ensures the economic viability of coffee plantations, which currently depend mainly on the reduction in production costs. The principle used for mechanized coffee harvesting is based on the principle of mechanical vibration. The objective of this studywas to analyze the dynamic behavior of the coffee fruit-peduncle-branch system under mechanical vibration and the impact of the vibrating rods on the fruit detachment process in association with this behavior. Fragments of coffee branches containing fruits in the unripe and ripe stages were used in this experiment. These samples were subjected to different frequencies (20, 30, 40, and 50 Hz) and amplitudes (0.002, 0.003, and 0.004 m). Another variableanalyzed was the form of vibration transmission to the fruits, with the vibrations being transmitted to the samples with or without the impact of the fiberglass rods. The fruit detachment efficiency increased as the ripening stage progressed from unripe to ripe. A higher detachment efficiency occurred with the increase in vibration frequency and amplitude because of the higher vibrational energy imposed on the fruit. The detachment efficiency was low when the vibration was transmitted without the impact of the rods. Conversely, the vibration in combination with impact achieved a mean detachment efficiency of approximately 90%.Key words: Coffee crop; dynamic behavior; harvester machine; mechanical harvesting.

Synthesis of in situ purified iron nanoparticles in an electrochemical and vibrating microreactor: study of ramified branch fragmentation by oscillating bubbles

We report on a novel concept of microreactor for the synthesis of metal nanoparticles (nP). The principle is to make grow by electrocrystallization long metallic ramified branches, made of metal nanocrystals, in a Hele-Shaw cell. The activation of an integrated vibrating element (PZT disk) induces the fragmentation of these fragile branches and so the nanocrystal release. One advantage is the possibility to flush the branches (and so the nP), prior to fragmentation, to avoid purification step. This principle is applied here to the synthesis of iron nP and focus is put on the branch fragmentation. High speed visualisations highlight the key role of H2 bubbles (co-formed during the branch growth). An effective fragmentation is obtained only using a square signal with which the initial bubbles coalesce. The resulting large bubbles exhibit shape oscillations and they induce microstreaming. This latter brings the branches close to bubble surface, where they are fragmented into fine particles. The required initial coalescence events are explained by a “dancing bubbles” effect made easier to achieve because initial small bubbles are excited at their resonance frequency by the sufficiently stiff signal steps. Transmission electron microscopy (TEM) reveals that dendritic particles, ∼ 2 μm long and ∼ 1 μm wide (broken secondary dendrites) with very high specific surface, and needle-like particles, ∼ 200 nm long and ∼ 20 nm in diameter (broken tertiary dendrites), are produced. A force balance, between the mechanical constraint applied by the fast flow near bubble surface and the material resistance, allows highlighting the key role of shape oscillations in the breakage of the dendrites.

Effect of Annealing Conditions on the Dissolution Process of Complex Carbonitrides in a V-Nb-Ti Microalloyed Steel

The present work has been undertaken to assess the evolution of dissolution process of large dendritic precipitates in a V-Nb-Ti microalloyed steel. The study was performed by reheating the samples at 1250°C, simulating the industrial reheating practices at laboratory scale and in situ, following industrial profile; afterwards the samples were quenched in 10%NaCl aqueous solution. The characterization of the material was carried out by scanning electron microscopy accompanied with dispersive energy spectrometry, and chemical analysis by inductively coupled plasma optical emission spectrometry. The results showed a partial dissolution of dendritic precipitates. This process ocurred by a progressive dissolving the Nb-rich shells formed over cuboidal particles and primary arm of well-faceted dendritic precipitates, and by fragmentation and spheroidization of secondary branches. These processes gave rise to spherical Nb rich precipitates and cuboidal particles at the reheating conditions used in this study. Both type of particles contain vanadium.

Quantitative LC-MS and MS/MS analysis of sialylated glycans modified by linkage-specific alkylamidation

Sialic acids (Sia) are involved in various biological and pathological processes, and are often found attached to non-reducing ends of glycans through either α2,3- or α2,6-linkages. To quantitatively analyze glycan structures with these linkage isoforms by liquid chromatography-mass spectrometry (LC-MS), we established a linkage-specific two-step alkylamidation method for N-glycans. Using this method, carboxyl groups of α2,3- and α2,6-linked Sia are derivatized with two kinds of alkylamines with different mass values in a linkage-specific manner, allowing products to be easily distinguished. The reaction efficiencies for di-, tri-, and tetra-sialyl PA-N-glycans were >94%, with few by-products. Mixtures of 2-aminopyridine (PA)-tagged N-glycans from human α1-acid glycoprotein were subjected to the method, and products were analyzed by LC-MS and MS/MS, and simultaneously monitored with a fluorescence detector. The relative content of Siaα2-3Gal and Siaα2-6Gal was estimated from the integrated fluorescence intensity of each peak. Moreover, MS/MS data clearly indicated characteristic B-ion fragments of N-glycan branches, such as the sialyl Lex sequence, with Sia linkage-specific alkylamidation, suggesting that this method also provides useful information of branch sequences. We optimized the method with the aim of (1) enabling high-throughput analysis and (2) maximizing the analysis of glycans from various types of samples, including highly heterogeneous glycans.

A new discovery of Chamaecyparis from the Lower Cretaceous of Inner Mongolia, North China and its significance

The fossil remains of Chamaecyparis Spach (Cupressaceae) were discovered in the Lower Cretaceous Guyang Formation of the Guyang Basin, Inner Mongolia, North China. The Guyang fossils are known from compressions-impressions of a foliated branch with an attached seed cone, a foliated vegetative branch fragment, an isolated seed cone and seeds. This is the first reliable fossil record of Chamaecyparis in China and is also the earliest member of Chamaecyparis currently known. The present fossils have been compared with living and some fossil Chamaecyparis species and they differ from them all. Therefore, the Guyang remains are provisionally identified as Chamaecyparis sp. because of the lack of diagnostic leaf cuticular characteristics. The presence of the Guyang fossils suggests that the genus Chamaecyparis might have originated in eastern Asia during the Early Cretaceous. Their discovery also suggests that Chamaecyparis sp. is possibly an ancestral taxon for the genus.