53 research outputs found
Деградація земель у Калуському районі внаслідок сольового забруднення
Показано, що джерелами деградації ґрунтів внаслідок, їх засолення, є солевідвали
Домбровського кар’єру. Основними чинниками, що призводять до деградації є вітрова і
водна ерозія. Досліджено, що основну роль в засоленні ґрунтового покриву відіграють
процеси дифузії. Встановлено, що площа засолення (деградація) ґрунтів у декілька разів
перевищує площу солевідводів.Показано, что источниками деградации почв вследствие их засоления, являются
солеотвалы Домбровского карьера. Основными факторами, которые приводят к
деградации является ветровая и водная эрозия. Доказано, что основную роль в засолении
почвенного покрова играют процессы диффузии. Установлено, что площадь засоления
(деградация) почв в несколько раз превышает площадь солеотвалов.In the article is shown that the sources of land degradation occurs because of their salinity
and salt piles from Dombrowsky career. The main factors that lead to the degradation are wind
and water erosion. It is investigated that the main role in the salinity of soil processes play
diffusion. It is established that the area of salinity (degradation) of soil several times salt piles
are
Synergistic effects of putative Ca<sup>2+</sup>-binding sites of calmodulin in fungal development, temperature stress and virulence of <i>Aspergillus fumigatus</i>
In pathogenic fungi, calcium-calmodulin-dependent serine-threonine-specific phosphatase calcineurin is involved in morphogenesis and virulence. Therefore, calcineurin and its tightly related protein complexes are attractive antifungal drug targets. However, there is limited knowledge available on the relationship between in vivo Ca2+-binding sites of calmodulin (CaM) and its functions in regulating stress responses, morphogenesis, and pathogenesis. In the current study, we demonstrated that calmodulin is required for hyphal growth, conidiation, and virulence in the human fungal pathogen, Aspergillus fumigatus. Site-directed mutations of calmodulin revealed that a single Ca2+-binding site mutation had no significant effect on A. fumigatus hyphal development, but multiple Ca2+-binding site mutations exhibited synergistic effects, especially when cultured at 42 °C, indicating that calmodulin function in response to temperature stress depends on its Ca2+-binding sites. Western blotting implied that mutations in Ca2+-binding sites caused highly degraded calmodulin fragments, suggesting that the loss of Ca2+-binding sites results in reduced protein stability. Moreover, normal intracellular calcium homeostasis and the nuclear translocation of the transcriptional factor CrzA are dependent on Ca2+-binding sites of AfCaM, demonstrating that Ca2+-binding sites of calmodulin are required for calcium signalling and its major transcription factor CrzA. Importantly, in situ mutations for four Ca2+-binding sites of calmodulin resulted in an almost complete loss of virulence in the Galleria mellonella wax moth model. This study shed more light on the functional characterization of putative calcium-binding sites of calmodulin in the morphogenesis and virulence of A. fumigatus, which enhances our understanding of calmodulin biological functions in cells of opportunistic fungal pathogens.</p
Modeling and Simulation of Chemical Looping Combustion Using a Copper-Based Oxygen Carrier in a Double-Loop Circulating Fluidized Bed Reactor System
In this work, a computational fluid
dynamics simulator has been
developed for a novel double-loop circulating fluidized bed reactor
which is used for a chemical looping combustion process. The simulator
is implemented in an in-house code including the kinetic theory of
granular flow and reaction models. Methane is used as fuel, and copper
oxide-based particles are used as oxygen carrier. The process is configured
with an air reactor and a fuel reactor. The two reactors are modeled
and solved by a sequential approach. The connection between the two
reactors is realized through time-dependent inlet and outlet boundary
conditions. The model is validated with the experimental data obtained
in the current work. At a thermal input of 100 kW, a methane conversion
of 98% was achieved. For the cases studied in this work, temperature
is the most important factor for the reactor performance, followed
by the gas velocity and methane concentration of fuel. The increase
of the methane concentration could decrease the methane conversion,
which is due to the decrease of specific inventory. As the gas velocity
is increased, the residence time and the degree of gas–solid
contact decreases, causing a decrease in reactor performance. Besides
the effect of the single factor, the combination effect of the gas
velocity and methane concentration is also important to the reactor
performance
Highly Selective Fluorescence Turn-On Sensor for Fluoride Detection
Through click chemistry, triazole
and triazolium groups have been explored to recognize anions through
C–H···A<sup>–</sup> hydrogen-bonding
complexion. Herein, we demonstrate evidence of fluoride-induced deprotonation
of a C–H bond and its application in fluoride detection. The
combination of fluorene and triazolium units produced a highly selective
fluorescence turn-on prototype sensor for fluoride. The interactions
between the C–H bond and F<sup>–</sup> were studied
by fluorescence spectroscopy and <sup>1</sup>H NMR titrations. Test
papers were prepared to detect fluoride in aqueous media at concentrations
down to 1.9 ppm, important for estimating whether the fluoride concentration
in drinking water is at a safe level
Controlled Aggregation and Enhanced Two-Photon Absorption of a Water-Soluble Squaraine Dye with a Poly(acrylic acid) Template
Controlling the aggregation behavior
of organic dyes is important
for understanding and exploring supramolecular assembly utilizing
the specific characteristics of aggregation. Regulating J-aggregation
by electrostatic interactions between anionic polyelectrolytes and
cationic dyes has gained growing interest. Here, we report the formation
of J-aggregates of a water-soluble cationic squaraine dye, 4-(pyridinium-1-yl)butylbenzothiazolium
squaraine (<b>SQ</b>), using poly(acrylic acid) sodium salt
(PAA-Na) as a template. Electrostatic interactions between the PAA-Na
polyelectrolyte and the cationic <b>SQ</b> dye enhanced J-aggregation;
the absorbance of the resulting J-band with the polyelectrolyte template
was much sharper than the absorbance of the J-aggregate formed using
a high concentration of NaCl. Significantly, removal of the polyelectrolyte
PPA-Na template by the introduction of calcium ions, which can form
stronger ionic binding with carboxylate groups, dissociated J-aggregates,
freeing the <b>SQ</b> molecules back to unaggregated or lower
aggregate forms. To demonstrate the reversibility of the J-aggregate
formation cycle, an in situ experiment was conducted that showed 60%
reversibility of the second cycle. In addition, an enhancement by
ca. 23 times per repeat unit of the two-photon absorption (2PA) cross
section was observed at 920 nm for the polyelectrolyte template-<b>SQ</b> J-aggregate compared to unaggregated or lower aggregate <b>SQ</b>. These results suggest a prominent role of polyelectrolyte
templated <b>SQ</b> J-aggregation in the enhancement of 2PA
efficiency and provide a means of modulating supramolecular assembly
Bovine Serum Albumin Nanoparticles with Fluorogenic Near-IR-Emitting Squaraine Dyes
Two squaraine (SQ) dyes, N-propanesulfonate-benzothiazolium
squaraine
(<b>SQ-1</b>) and N-propanesulfonate-benzoindolium squaraine
(<b>SQ-2</b>), were synthesized with sulfonate groups to increase
water solubility. Both dyes are almost nonfluorescent in aqueous solution
with fluorescent quantum yields of 0.03, but exhibited fluorescence
enhancement after noncovalently binding with bovine serum albumin
(BSA). Upon addition of BSA, the fluorescence intensity increased
by ca. a factor of 10, along with a 10-fold extension in the fluorescence
lifetime. <b>SQ-1</b> and <b>SQ-2</b> interacted with
BSA efficiently and appeared to show a preference for binding at site
II, which involves combinational effects of electrostatic and hydrophobic
interactions. The fluorogenic squaraine dyes were then used to label
BSA, forming BSA-based nanoparticles (NPs) through noncovalent binding.
The resulting BSA-SQ NPs exhibited enhanced near-IR fluorescence and
reduced aggregation of the squaraine moiety. The BSA-SQ NPs were used
for cell incubation and bioimaging studies. Confocal fluorescent images
were obtained for HCT 116 cells incubated with the BSA-SQ NPs and
LysoSensor Green, demonstrating the utility of the NP probes for intracellular
imaging. This strategy ovecomes the generally low fluorescence emission
of SQ dyes in water and aggregation-reduced fluorescence, providing
a versatile strategy for sensing and imaging in biological environments
Ultralow-Power Near Infrared Lamp Light Operable Targeted Organic Nanoparticle Photodynamic Therapy
Tissue
penetration depth is a major challenge in practical photodynamic
therapy (PDT). A biocompatible and highly effective near infrared
(NIR)-light-absorbing carbazole-substituted BODIPY (<b>Car-BDP</b>) molecule is reported as a class of imaging-guidable deep-tissue
activatable photosensitizers for PDT. <b>Car-BDP</b> possesses
an intense, broad NIR absorption band (600–800 nm) with a remarkably
high singlet oxygen quantum yield (Φ<sub>Δ</sub> = 67%).
After being encapsulated with biodegradable PLA–PEG-FA polymers, <b>Car-BDP</b> can form uniform and small organic nanoparticles that
are water-soluble and tumor-targetable. Rather than using laser light,
such nanoparticles offer an unprecedented deep-tissue, tumor targeting
photodynamic therapeutic effect by using an exceptionally low-power-density
and cost-effective lamp light (12 mW cm<sup>–2</sup>). In addition,
these nanoparticles can be simultaneously traced in vivo due to their
excellent NIR fluorescence. This study signals a major step forward
in photodynamic therapy by developing a new class of NIR-absorbing
biocompatible organic nanoparticles for effective targeting and treatment
of deep-tissue tumors. This work also provides a potential new platform
for precise tumor-targeting theranostics and novel opportunities for
future affordable clinical cancer treatment
DataSheet1_Muscle transcriptome analysis provides new insights into the growth gap between fast- and slow-growing Sinocyclocheilus grahami.docx
Sinocyclocheilus grahami is an economically valuable and famous fish in Yunnan Province, China. However, given its slow growth (40 g/2 years) and large growth differences among individuals, its growth performance needs to be improved for sustainable future use, in which molecular breeding technology can play an important role. In the current study, we conducted muscle transcriptomic analysis to investigate the growth gaps among individuals and the mechanism underlying growth within 14 fast- and 14 slow-growth S. grahami. In total, 1,647 differentially expressed genes (DEGs) were obtained, including 947 up-regulated and 700 down-regulated DEGs in fast-growth group. Most DEGs were significantly enriched in ECM-receptor interaction, starch and sucrose metabolism, glycolysis/gluconeogenesis, pyruvate metabolism, amino acids biosynthesis and metabolism, peroxisome, and PPAR signaling pathway. Some genes related to glycogen degradation, glucose transport, and glycolysis (e.g., adipoq, prkag1, slc2a1, agl, pygm, pgm1, pfkm, gapdh, aldoa, pgk1, pgam2, bpgm, and eno3) were up-regulated, while some genes related to fatty acid degradation and transport (e.g., acox1, acaa1, fabp1b.1, slc27a1, and slc27a2) and amino acid metabolism (e.g., agxt, shmt1, glula, and cth) were down-regulated in the fast-growth group. Weighted gene co-expression network analysis identified col1a1, col1a2, col5a1, col6a2, col10a1, col26a1, bglap, and krt15 as crucial genes for S. grahami growth. Several genes related to bone and muscle growth (e.g., bmp2, bmp3, tgfb1, tgfb2, gdf10, and myog) were also up-regulated in the fast-growth group. These results suggest that fast-growth fish may uptake adequate energy (e.g., glucose, fatty acid, and amino acids) from fodder, with excess energy substances used to synthesize collagen to accelerate bone and muscle growth after normal life activities are maintained. Moreover, energy uptake may be the root cause, while collagen synthesis may be the direct reason for the growth gap between fast- and slow-growth fish. Hence, improving food intake and collagen synthesis may be crucial for accelerating S. grahami growth, and further research is required to fully understand and confirm these associations.</p
Direct Aqueous-Phase Synthesis of Sub-10 nm “Luminous Pearls” with Enhanced <i>in Vivo</i> Renewable Near-Infrared Persistent Luminescence
Near-infrared (NIR) persistent luminescence
nanoparticles (PLNPs),
possessing unique NIR PL properties, have recently emerged as important
materials for a wide variety of applications in chemistry and biology,
for which they must endure high-temperature solid-state annealing
reactions and subsequent complicated physical post-treatments. Herein,
we report on a first direct aqueous-phase chemical synthesis route
to NIR PLNPs and present their enhanced <i>in vivo</i> renewable
NIR PL. Our method
leads to monodisperse PLNPs as small as ca. 8 nm. Such sub-10 nm nanocrystals
are readily dispersed and functionalized, and can form stable colloidal
solutions in aqueous solution and cell culture medium for biological
applications. Under biotissue-penetrable red-light excitation, we
found that such nanocrystals possess superior renewable PL photoluminescence <i>in vitro</i> and <i>in vivo</i> compared to their
larger counterparts currently
made by existing methods. We believe that this solid-state-reaction-free
chemical approach overcomes the current key roadblock in regard to
PLNP development, and thus will pave the way to broad use of these
advanced miniature “luminous pearls” in photonics and
biophotonics
Palmitoylation of the Cysteine Residue in the DHHC Motif of a Palmitoyl Transferase Mediates Ca<sup>2+</sup> Homeostasis in <i>Aspergillus</i>
<div><p>Finely tuned changes in cytosolic free calcium ([Ca<sup>2+</sup>]<sub>c</sub>) mediate numerous intracellular functions resulting in the activation or inactivation of a series of target proteins. Palmitoylation is a reversible post-translational modification involved in membrane protein trafficking between membranes and in their functional modulation. However, studies on the relationship between palmitoylation and calcium signaling have been limited. Here, we demonstrate that the yeast palmitoyl transferase <i>Sc</i>Akr1p homolog, AkrA in <i>Aspergillus nidulans</i>, regulates [Ca<sup>2+</sup>]<sub>c</sub> homeostasis. Deletion of <i>akrA</i> showed marked defects in hyphal growth and conidiation under low calcium conditions which were similar to the effects of deleting components of the high-affinity calcium uptake system (HACS). The [Ca<sup>2+</sup>]<sub>c</sub> dynamics in living cells expressing the calcium reporter aequorin in different <i>akrA</i> mutant backgrounds were defective in their [Ca<sup>2+</sup>]<sub>c</sub> responses to high extracellular Ca<sup>2+</sup> stress or drugs that cause ER or plasma membrane stress. All of these effects on the [Ca<sup>2+</sup>]<sub>c</sub> responses mediated by AkrA were closely associated with the cysteine residue of the AkrA DHHC motif, which is required for palmitoylation by AkrA. Using the acyl-biotin exchange chemistry assay combined with proteomic mass spectrometry, we identified protein substrates palmitoylated by AkrA including two new putative P-type ATPases (Pmc1 and Spf1 homologs), a putative proton V-type proton ATPase (Vma5 homolog) and three putative proteins in <i>A</i>. <i>nidulans</i>, the transcripts of which have previously been shown to be induced by extracellular calcium stress in a CrzA-dependent manner. Thus, our findings provide strong evidence that the AkrA protein regulates [Ca<sup>2+</sup>]<sub>c</sub> homeostasis by palmitoylating these protein candidates and give new insights the role of palmitoylation in the regulation of calcium-mediated responses to extracellular, ER or plasma membrane stress.</p></div
- …