763 research outputs found
Centrality, system size and energy dependences of charged-particle pseudo-rapidity distribution
Utilizing the three-fireball picture within the quark combination model, we
study systematically the charged particle pseudorapidity distributions in both
Au+Au and Cu+Cu collision systems as a function of collision centrality and
energy, 19.6, 62.4, 130 and 200 GeV, in full pseudorapidity
range. We find that: (i)the contribution from leading particles to
distributions increases with the decrease of the collision
centrality and energy respectively; (ii)the number of the leading particles is
almost independent of the collision energy, but it does depend on the nucleon
participants ; (iii)if Cu+Cu and Au+Au collisions at the same
collision energy are selected to have the same , the resulting of
charged particle distributions are nearly identical, both in the
mid-rapidity particle density and the width of the distribution. This is true
for both 62.4 GeV and 200 GeV data. (iv)the limiting fragmentation phenomenon
is reproduced. (iiv) we predict the total multiplicity and pseudorapidity
distribution for the charged particles in Pb+Pb collisions at TeV. Finally, we give a qualitative analysis of the
and as function of
and from RHIC to LHC.Comment: 12 pages, 8 figure
Soil texture and microorganisms dominantly determine the subsoil carbonate content in the permafrost-affected area of the Tibetan Plateau
Under climate warming conditions, storage and conversion of soil inorganic carbon (SIC) play an important role in regulating soil carbon (C) dynamics and atmospheric CO2 content in arid and semi-arid areas. Carbonate formation in alkaline soil can fix a large amount of C in the form of inorganic C, resulting in soil C sink and potentially slowing global warming trends. Therefore, understanding the driving factors affecting carbonate mineral formation can help better predict future climate change. Till date, most studies have focused on abiotic drivers (climate and soil), whereas a few examined the effects of biotic drivers on carbonate formation and SIC stock. In this study, SIC, calcite content, and soil microbial communities were analyzed in three soil layers (0–5 cm, 20–30 cm, and 50–60 cm) on the Beiluhe Basin of Tibetan Plateau. Results revealed that in arid and semi-arid areas, SIC and soil calcite content did not exhibit significant differences among the three soil layers; however, the main factors affecting the calcite content in different soil layers are different. In the topsoil (0–5 cm), the most important predictor of calcite content was soil water content. In the subsoil layers 20–30 cm and 50–60 cm, the ratio of bacterial biomass to fungal biomass (B/F) and soil silt content, respectively, had larger contributions to the variation of calcite content than the other factors. Plagioclase provided a site for microbial colonization, whereas Ca2+ contributed in bacteria-mediated calcite formation. This study aims to highlight the importance of soil microorganisms in managing soil calcite content and reveals preliminary results on bacteria-mediated conversion of organic to inorganic C
Quantitative measurement of cell membrane receptor internalization by the nanoluciferase reporter: Using the G protein-coupled receptor RXFP3 as a model
AbstractNanoluciferase (NanoLuc) is a newly developed small luciferase reporter with the brightest bioluminescence to date. In the present work, we developed NanoLuc as a sensitive bioluminescent reporter to measure quantitatively the internalization of cell membrane receptors, based on the pH dependence of the reporter activity. The G protein-coupled receptor RXFP3, the cognate receptor of relaxin-3/INSL7, was used as a model receptor. We first generated stable HEK293T cells that inducibly coexpressed a C-terminally NanoLuc-tagged human RXFP3 and a C-terminally enhanced green fluorescent protein (EGFP)-tagged human RXFP3. The C-terminal EGFP-tag and NanoLuc-tag had no detrimental effects on the ligand-binding potency and intracellular trafficking of RXFP3. Based on the fluorescence of the tagged EGFP reporter, the ligand-induced RXFP3 internalization was visualized directly under a fluorescence microscope. Based on the bioluminescence of the tagged NanoLuc reporter, the ligand-induced RXFP3 internalization was measured quantitatively by a convenient bioluminescent assay. Coexpression of an EGFP-tagged inactive [E141R]RXFP3 had no detrimental effect on the ligand-binding potency and ligand-induced internalization of the NanoLuc-tagged wild-type RXFP3, suggesting that the mutant RXFP3 and wild-type RXFP3 worked independently. The present bioluminescent internalization assay could be extended to other G protein-coupled receptors and other cell membrane receptors to study ligand–receptor and receptor–receptor interactions
Simulation study of factors influencing oil yield during cold pressing of rapeseed
Objective: This study aimed to investigate the factors influencing the oil yield of rapeseed during pressing in a double screw oil press. Methods: To simulate the pressing process of rapeseed and to explore the effects of two factors, the speed of the press screw and the porosity, on the oil yield. Results: The oil yield of rapeseed was linearly related to the porosity, and a larger porosity, was associated with a lower oil yield. Moreover, the oil yield was negatively related to the speed of the press screw. Conclusion: The oil yield of rapeseed was highest when the porosity was 0.45 with the speed of pressing screw at 20 r/min
Učinak glicerola i glukoze na povećanje biomase, udjela lipida i topljivih ugljikohidrata u miksotrofnoj kulturi alge Chlorella vulgaris
Biodiesel-derived glycerol is a promising substrate for mixotrophic cultivation of oleaginous microalgae, which can also reduce the cost of microalgal biodiesel. The objective of this study is to investigate the potential of using glycerol and glucose as a complex carbon substrate to produce microalgal biomass and biochemical components, such as photosynthetic pigments, lipids, soluble carbohydrates and proteins by Chlorella vulgaris. The results show that C. vulgaris can utilize glycerol as a sole carbon substrate, but its effect is inferior to that of the mixture of glycerol and glucose. The effect of glycerol and glucose could enhance the algal cell growth rate, biomass content and volumetric productivity, and overcome the lower biomass production on glycerol as the sole organic carbon source in mixotrophic culture medium. The utilization of complex organic carbon substrate can stimulate the biosynthesis of lipids and soluble carbohydrates as the raw materials for biodiesel and bioethanol production, and reduce the anabolism of photosynthetic pigments and proteins. This study provides a promising niche for reducing the overall cost of biodiesel and bioethanol production from microalgae as it investigates the by-products of algal biodiesel production and algal cell hydrolysis as possible raw materials (lipids and carbohydrates) and organic carbon substrates (soluble carbohydrates and glycerol) for mixotrophic cultivation of microalgae.Glicerol dobiven iz biodizela može se upotrijebiti za uzgoj miksotrofnih mikroalgi iz kojih se proizvodi ulje, te za smanjenje troškova proizvodnje biodizela. Svrha je ovoga rada bila ispitati mogućnost primjene glicerola i glukoze u složenoj hranjivoj podlozi za uzgoj alge Chlorella vulgaris, te proizvodnju biomase i biokemijskih sastojaka, kao što su fotosintetski pigmenti, lipidi, topljivi ugljikohidrati i proteini. Rezultati potvrđuju da se alga Chlorella vulgaris može uzgojiti na glicerolu kao jedinom izvoru ugljika, iako su bolji rezultati postignuti uzgojem na podlozi s glicerolom i glukozom. Stopa rasta, prinos biomase i volumetrijska produktivnost alge povećani su primjenom podloge s glicerolom i glukozom, u usporedbi s podlogom koja sadržava samo glukozu kao organski izvor ugljika. Uporabom složene hranjive podloge može se ubrzati biosinteza lipida i topljivih ugljikohidrata (sirovina za proizvodnju biodizela i bioetanola), te usporiti sinteza fotosintetskih pigmenata i proteina. U radu je ispitana mogućnost primjene nusproizvoda dobivenih proizvodnjom biodizela i hidrolizom algi te podloga s organskim izvorima ugljika (topljivi ugljikohidrati i glicerol) kao sirovina (izvor lipida i ugljikohidrata) za proizvodnju miksotrofnih mikroalgi, radi smanjenja ukupnih troškova proizvodnje biodizela i bioetanola
Molecular identification and food source inference of constructive plants, native to the Ophiocordyceps sinensis habitat
Ophiocordyceps sinensis is a precious and effectual Traditional Chinese Medicine, native to Tibetan Plateau. Its development originated from parasitization of Hirsutella sinensis to Hepialus larvae, which was deemed to be of great importance including feeding food habit. Hereby in the present, study on food resource plants and their molecular identification technique were performed by some methods such as vegetation investigation, morphological taxonomy, sequence alignment, phylogenetic inference, primer design and correlation analysis and so on. In consequence, molecular identification system of constructive plants native to the O. sinensis habitat was established, and then feeding food habit of Hepialus pui larvae and its correlation with genesis mechanism of O. sinensis were preliminarily analyzed and discussed. It is very significant for phylogenetic systematicbotany research of plateau plants on a relative large scale, and it is the first time to study feeding food habit of Hepialus larvae and its related infected process on the molecular level.Keywords: Phylogenetic inference, molecular identification, constructive plant, Ophiocordyceps sinensis, Hepialus pu
Centrality dependence of spectra for identified hadrons in Au+Au and Cu+Cu collisions at GeV
The centrality dependence of transverse momentum spectra for identified
hadrons at midrapidity in Au+Au collisions at GeV is
systematically studied in a quark combination model. The
spectra of , , and in
different centrality bins and the nuclear modification factors () for
these hadrons are calculated. The centrality dependence of the average
collective transverse velocity for the hot and dense quark matter
is obtained in Au+Au collisions, and it is applied to a relative smaller Cu+Cu
collision system. The centrality dependence of spectra and
the for , and in Cu+Cu collisions at
GeV are well described. The results show that is only a function of the number of participants and it is
independent of the collision system.Comment: 7 pages, 6 figure
Efficacy and Safety of Transglutaminase-Induced Corneal Stiffening in Rabbits
Purpose: To evaluate the biomechanical efficacy and safety of in vivo microbial transglutaminase (Tgases)-induced corneal crosslinking in a rabbit model.
Methods: A total of 34 white New Zealand rabbits were divided into two groups, a biochemistry group and a photochemistry group. The right eye of every rabbit was treated and left eyes served as negative controls. In the biochemistry group, a 1 U/mL solution of crosslinking agent microbial Tgases (Tgases CXL) was applied to the corneal surface, while in the photochemistry group, clinical ultraviolet A-riboflavin crosslinking (UVA/RF CXL) was used. Efficacy and safety evaluated on the 14th day after the procedures. Twelve pairs of corneal strips were harvested from the eyes of 12 euthanized rabbits in every group, and uniaxial tensile tests were performed to evaluate ex vivo biomechanical effects. The CXL-treated eye to its corresponding untreated eye ratio of tangent modulus were calculated. Another five pairs of corneal button were excised from euthanized animals in every group for corneal stroma and endothelium staining to evaluate changes in keratocyte distribution and endothelial cell damage.
Results: In tensile tests, tangent modulus was statistically higher in the Tgases CXL groups under 1.0 MPa (26.59 +/- 4.54 vs. 21.47 +/- 4.72 MPa, P = 0.04) and 1.5 MPa (29.75 +/- 5.01 vs. 20.47 +/- 6.63 MPa, P = 0.00). The tangent modulus ratio of Tgases group (1.72 +/- 1.0 vs. 1.05 +/- 0.22, P = 0.04) was significantly higher than that of UVA/RF under 1.5-MPa stress. The distribution of keratocytes in the corneal stroma and the morphologies of endothelial cells were similar in Tgases CXL-treated and untreated corneas. However, in the UVA/RF CXL group, keratocytes in the anterior half of stromal thickness were lost, and clear endothelial cell apoptosis was observed.
Conclusions: Tgases-CXL effectively stiffened the cornea and caused no damage to the endotheliumand keratocytes in the cornea. This crosslinking method could be useful as a next-generation treatment for corneal ectasia and could replace CXL of photochemistry
N′-(2-Chlorobenzylidene)-3,4,5-trimethoxybenzohydrazide methanol solvate
In the title compound, C17H17ClN2O4·CH4O, the dihedral angle between the benzene ring planes is 5.29 (6)°. Intermolecular N—H⋯O and O—H⋯O hydrogen bonds link the molecules into a chain along the a axis
Kilonovae and Optical Afterglows from Binary Neutron Star Mergers. II. Optimal Search Strategy for Serendipitous Observations and Target-of-opportunity Observations of Gravitational Wave Triggers
In the second work of this series, we explore the optimal search strategy for serendipitous and gravitational-wave-triggered target-of-opportunity (ToO) observations of kilonovae and optical short-duration gamma-ray burst (sGRB) afterglows from binary neutron star (BNS) mergers, assuming that cosmological kilonovae are AT2017gfo-like (but with viewing-angle dependence) and that the properties of afterglows are consistent with those of cosmological sGRB afterglows. A one-day cadence serendipitous search strategy with an exposure time of ∼30 s can always achieve an optimal search strategy of kilonovae and afterglows for various survey projects. We show that the optimal detection rates of the kilonovae (afterglows) are ∼0.3/0.6/1/20 yr−1 (∼50/60/100/800 yr−1) for Zwicky the Transient Facility (ZTF)/Multi-channel Photometric Survey Telescope (Mephisto)/Wide Field Survey Telescope (WFST)/Large Synoptic Survey Telescope (LSST), respectively. A better search strategy for SiTian than the current design is to increase the exposure time. In principle, a fully built SiTian can detect ∼7(2000) yr−1 kilonovae (afterglows). Population properties of electromagnetic (EM) signals detected by serendipitous observations are studied in detail. For ToO observations, we predict that one can detect ∼11 yr−1 BNS gravitational wave (GW) events during the fourth observing run (O4) by considering an exact duty cycle of the third observing run. The median GW sky localization area is expected to be ∼10 deg2 for detectable BNS GW events. For O4, we predict that ZTF/Mephisto/WFST/LSST can detect ∼5/4/3/3 kilonovae (∼1/1/1/1 afterglows) per year, respectively. The GW detection rates, GW population properties, GW sky localizations, and optimistic ToO detection rates of detectable EM counterparts for BNS GW events at the Advanced Plus, LIGO Voyager, and ET&CE eras are detailedly simulated in this paper
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