共查询到20条相似文献,搜索用时 31 毫秒
1.
Brozovic G Orsolic N Knezevic F Horvat Knezevic A Benkovic V Sakic K Borojevic N Dikic D 《Journal of applied genetics》2011,52(3):355-361
The aim of this study was to evaluate the genotoxicity of repeated exposure to isoflurane or halothane and compare it with
the genotoxicity of repeated exposure to cisplatin. We also determined the genotoxicity of combined treatment with inhalation
anaesthetics and cisplatin on peripheral blood leucocytes (PBL), brain, liver and kidney cells of mice. The mice were divided
into six groups as follows: control, cisplatin, isoflurane, cisplatin–isoflurane, halothane and cisplatin–halothane, and were
exposed respectively for three consecutive days. The mice were treated with cisplatin or exposed to inhalation anaesthetic;
the combined groups were exposed to inhalation anaesthetic after treatment with cisplatin. The alkaline comet assay was performed.
All drugs had a strong genotoxicity (P < 0.05 vs. control group) in all of the observed cells. Isoflurane caused stronger DNA damage on the PBL and kidney cells,
in contrast to halothane, which had stronger genotoxicity on brain and liver cells. The combination of cisplatin and isoflurane
induced lower genotoxicity on PBL than isoflurane alone (P < 0.05). Halothane had the strongest effect on brain cells, but in the combined treatment with cisplatin, the effect decreased
to the level of cisplatin alone. Halothane also induced the strongest DNA damage of the liver cells, while the combination
with cisplatin increased its genotoxicity even more. The genotoxicity of cisplatin and isoflurane on kidney cells were nearly
at the same level, but halothane caused a significantly lower effect. The combinations of inhalation anaesthetics with cisplatin
had stronger effects on kidney cells than inhalation anaesthetics alone. The observed drugs and their combinations induced
strong genotoxicity on all of the mentioned cells. 相似文献
2.
Isoflurane blocks glutamatergic excitatory transmission pre- and postsynaptically in crayfish muscle
M. Schramm J. Dudel 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1998,183(2):237-246
Crayfish neuromuscular junctions are good models for the α-amino-hydroxy-5-methyl-4-isoxazol-propionic acid-type of vertebrate
brain excitatory synapses. The action of a typical volatile anaesthetic, isoflurane, was studied on the excitatory postsynaptic
currents recorded with a perfused macropatch electrode. Isoflurane reduced quantal exitatory postsynaptic currents in amplitude,
in their rise time and in the decay time constant. Small such effects were elicited by <1 mmol · l−1 isoflurane, while the maximal isoflurane concentration of 7 mmol · l−1 reduced the amplitude to about a quarter and shortened the decay time constant even more, while the rise time was diminished
by about a quarter. This combination of effects is typical for an open channel block for which an approximate binding rate
constant of isoflurane of 6 · 105 mol−1l · s−1 and an unbinding rate of 10–100 s−1 is derived. In addition to this postsynaptic effect, isoflurane inhibited the release of transmitter quanta from the terminal,
for instance with 2.5 mmol · l−1 isoflurane by a factor of 7.3 ± 6.3 (SD). In the glutamatergic nerve terminals release is modulated by low glutamate concentrations
via a metabotropic autoreceptor which is blocked by the combination of 6-cyano-7-nitro-quinoxaline-2,3-dione and dl-2-amino-5-phosphor-valeric acid. This blocker combination also can prevent the inhibition of release by isoflurane, and it
may be suggested that isoflurane elicits inhibition of release through the metabotropic presynaptic glutamate receptors.
Accepted: 29 March 1998 相似文献
3.
Matsumoto S Murozono M Nagaoka D Matsuoka S Takeda A Narita H Watanabe S Isshiki A Watanabe Y 《Neurochemical research》2008,33(11):2302-2309
Volatile anesthetics isoflurane possibly improves the ischemic brain injury. However, its molecular actions are still unclear.
In ischemia, protein kinase C (PKC)γ and calcium/calmodulin dependent protein kinase II (CaMKII)-α are persistently translocated
from cytosol to cell membranes, and diminish these translocation suggested to be neuroprotective. We thus tested a hypothesis
that isoflurane inhibits PKCγ and CaMKII-α translocation after ischemic brain insults. C57Bl/6J male mice were made to inhale
1 or 2 MAC isoflurane, after which 3 or 5 min cerebral ischemia was induced by decapitation. The sampled cerebrum cortex was
then homogenized and centrifuged into crude synaptosomal fractions (P2), cytosolic fractions (S3), and particulate fractions
(P3). CaMKII-α and PKCγ levels of these fractions were analyzed by immunoblotting. PKCγ and CaMKII-α are translocated to synaptic
membrane from cytosol by cerebral ischemia, although isoflurane significantly inhibited such translocation. These results
may explain in part the cellular and molecular mechanisms of neuroprotective effects of isoflurane. 相似文献
4.
Biophysical studies of protein–anesthetic interactions using nuclear magnetic resonance (NMR) spectroscopy are often conducted
by the addition of micro amounts of neat inhaled anesthetic which yields much higher than clinically relevant (0.2–0.5 mM)
anesthetic concentrations. We report a 19F NMR technique to measure clinically relevant inhaled anesthetic concentrations from saturated aqueous solutions of these
anesthetics (halothane, isoflurane, sevoflurane, and desflurane). We use a setup with a 3-mm NMR tube (containing trifluoroacetic
acid as standard), coaxially inserted in a 5-mm NMR tube containing anesthetic solution under investigation. All experiments
are conducted in a 5-mm NMR probe. We also have provided standard curves for four inhaled anesthetics using NMR technique.
The standard curve for each of these anesthetics is helpful in determining the prerequisite amount of aqueous anesthetic solution
required to prepare clinically relevant concentrations for protein–anesthetic interaction studies.
Parts of the results to be presented at Society for Neuroscience meeting, 2008. 相似文献
5.
Mol S 《Biological trace element research》2011,143(2):974-982
Concentrations of selected metals were determined using ICP-MS in canned bonito, sardines and mackerel commercialized in Turkey.
Thirty samples and two different brands were sampled for each fish species. The minimum and maximum concentrations of trace
metals in canned bonito, sardines and mackerel were found as 0.000–34.742, 0.000–89.015, 0.000–28.725 mg/kg for iron, 2.388–26.620,
10.930–41.340, 4.778–29.270 mg/kg for zinc, 0.331–1.548, 0.599–2.242, 0.336–2.884 mg/kg for copper, 0.000–0.065, 0.000–0.113,
0.000–0.115 mg/kg for cadmium, 0.000–0.190, 0.000–0.158, 0.000–0.385 mg/kg for tin, 0.000–0.111, 0.000–0.223, 0.000–0.208 mg/kg
for mercury and 0.000–3.046, 0.000–2.875, 0.000–3.529 mg/kg for lead, respectively. These levels are similar those found in
other studies. Although the samples have concentrations within permissible limits for Zn, Cu, Sn and Hg, some of them contained
Fe, Cd and Pb above these limits. Periodical controls of metals in canned fish are essential both to protect human health
and to provide data on this subject. 相似文献
6.
E. I. Isaeva N. A. Mazurkova R. Ya. Podchernyayeva 《Applied Biochemistry and Microbiology》2011,47(8):723-729
Immunogenic properties of synthetic peptides corresponding to regions 122–133, 136–147, 154–164, and 314–328 of the heavy
chain (HA1) of A/Aichi/2/68 virus hemagglutinin were studied. Peptides 122–133 and 136–147 together form a nearly complete
antigenic determinant A, peptide 154–164 is a part of determinant B, and peptide 314–328 corresponds to the C-terminal HA1
fragment. In a model influenza A/Aichi/2/68 infection in CBA mice, a protective effect of conjugates of BSA with peptides
136–147 and 314–328 was shown. Immunization of animals with conjugates BSA-(136–147) and BSA-(314–328) in combination with
interferon inducers (larifan and ridostin) and a plant immunomodulator (immunomax) intensified the protection of mice against
the influenza infection. 相似文献
7.
Claire R. Quilter Sarah C. Blott Alan J. Mileham Nabeel A. Affara Carole A. Sargent Darren K. Griffin 《Mammalian genome》2002,13(10):588-594
A combination of FISH and RH mapping was used to study the evolution of sex chromosome genes in the pig. In total, 19 genes
were identified, including 3 PAR genes (STS, KAL, PRK). The gene order of the porcine X Chromosome (Chr) closely resembled
the human X Chr (PRK/STS/KAL–AMELX–EIF2s3X/ZFX–USP9X–DBX–SMCX), suggesting that the porcine X has undergone very little rearrangement
during evolution. For the porcine Y Chr, two linkage groups of 10 NRY genes were found, and the following order was established:
Ypter–(AMELY–EIF2S3Y/ZFY–USP9Y–DBY/UTY)–(TSPY–SMCY–UBE1Y–SRY)–CEN. This gene order showed greater conservation with the murine
Y than with the human Y Chr. In addition, all porcine Y Chr genes mapped to Yp, which is similar to the mouse and included
EIF2s3Y and UBE1Y, which are not present in humans. Interestingly, complete conservation of X/Y homologous gene order was
found between the pig X and Y Chrs, indicating that the porcine Y Chr has not undergone extensive reorganisation with respect
to the X. This suggests that the order of the X/Y homologous genes of the porcine X and Y Chrs may closely resemble the ancestral
gene order of the eutherian sex chromosomes. 相似文献
8.
Eighteen metals were estimated in the scalp hair samples from cancer patients (n = 111) and normal donors (n = 113). Nitric acid–perchloric acid wet digestion procedure was used for the quantification of the selected metals by flame
atomic absorption spectrophotometry. In the scalp hair of cancer patients, highest average levels were found for Ca (861 μg/g),
followed by Na (672 μg/g), Zn (411 μg/g), Mg (348 μg/g), Fe (154 μg/g), Sr (129 μg/g), and K (116 μg/g), whereas in comparison,
the dominant metals in the scalp hair of normal donors were Ca (568 μg/g), Zn (177 μg/g), Mg (154 μg/g), Fe (110 μg/g), and
Na (103 μg/g). The concentrations of Ca, Cd, Co, Cr, Fe, K, Mg, Mn, Na, Ni, Pb, Sb, Sr, and Zn were notably higher in the
hair of cancer patients as compared with normal donors, which may lead to a number of physiological disorders. Strong positive
correlations were found in Mn–Pb (0.83), Cd–Cr (0.82), Cd–Li (0.57), Fe–Pb (0.56), and Fe–Mn (0.55) in the hair of cancer
patients whereas Na–Cd, Li–Cr, Li–Co, Co–Cd, Li–Cd, Na–Co, Na–Li, Ca–Mg and Na–Cr exhibited strong relationships (r > 0.50) in the hair of normal donors. Principal Component Analysis (PCA) of the data revealed seven PCs, both for cancer
patients and normal donors, but with significantly different loadings. Cluster Analysis (CA) was also used to support the
PCA results. The study evidenced significantly different pattern of metal distribution in the hair of cancer patients in comparison
with normal donors. The role of trace metals in carcinogenesis was also discussed. 相似文献
9.
Bottaro Christina S. Kiceniuk Joe W. Chatt Amares 《Biological trace element research》1999,(1):149-166
Extractable organohalogens (EOX) are organic compounds that contain chlorine, bromine and/or iodine, which can be separated
from the matrix by liquid/liquid or liquid/solid extraction. A combination of instrumental neutron activation analysis (INAA)
and solvent extraction methods has been developed for the determination of EOX from the shrimpPandalus borealis. Levels of EOX were evaluated for spatial trends for shrimp caught in several areas off the Labrador coast, off the coast
of Nova Scotia, and off the coast of Maine. Muscle contained 1.09–6.05 Μg EOCl/g tissue and 105–498 Μg extractable organochlorine
(EOCl)/g lipid; 0.0607–0.288 Μg extractable organobromine (EOB)r/g tissue and 4.74-10.5 Μg EOBr/g lipid; and 0.014–0.048 Μg
extractable organoiodine (EOI)/g tissue and 1.03–1.76 Μg EOI/g lipid, respectively. The levels of EOC1 in roe were 1.60–12.34
Μg/g tissue and 39.0-146 Μg/g lipid. In roe, the EOBr levels were 0.707–1.03 Μg/g tissue and 6.96–13.5 Μg/g lipid; and EOI
levels were 0.123–0.349 Μg/g tissue and 1.42–4.11 Μg/g lipid. The EOCl, EOBr, and EOI levels in roe increased noticeably from
north to south along the coast of Labrador. Samples taken from the coast of Maine and from Canso Hole were typically higher
in EOCl levels than those taken from Labrador. The results for EOBr and EOI were in the same range as those from Labrador. 相似文献
10.
Mnemiopsis leidyi: larvae depend on microplankton (<200 µm) prey duringthe first few days following hatching until larvae are >0.5mm in length and can successfully capture and consume mesozooplanktonprey. Feeding and growth rates of newly hatched M. leidyi larvaewere measured in controlled laboratory experiments. When fednatural microplankton assemblages, newly hatched larvae consumedsignificant quantities of both autotrophic and heterotrophicprey, including diatoms, phototrophic, heterotrophic and mixotrophicdinoflagellates, euglenoid flagellates, aloricate and tintinnidciliates, and rotifers. Average per capita clearance rates were1.99–7.59 mL individual–1 h–1 ( = 4.01 mL individual–1 h–1; SD = 1.95)and total per capita ingestion was 0.01–4.70 µgC individual–1 day–1 x 102 ( = 0.83 µg C individual–1 day–1 x 102; SD =1.89). Larval growth rates were –0.13 to 0.56 mm individual–1day–1 (equivalent to –1.72 to 4.33 µg C individual–1day–1) over a range of larval sizes from 0.5 (<0.5µg C) to 5 mm (85 µg C). A diet consisting entirelyof microplankton prey supported larval growth for >2 weeks,and growth rate decreased when larvae reached 4–5 mm inlength, corresponding to the beginning of their morphologicaltransition from tentaculate to lobate feeding mode. The grossgrowth efficiency of larvae fed natural microplankton assemblageswas 3%. 相似文献
11.
Roles of complex gangliosides in the development of experimental autoimmune encephalomyelitis 总被引:1,自引:0,他引:1
We induced experimental autoimmune encephalomyelitis (EAE) inGM2/GD2 synthase knockout mice (GM2/GD2–/–), whichcannot synthesize complex gangliosides, such as GM1, GD1a, GD1b,GT1b, and GQ1b, to investigate the roles of complex gangliosidesin the pathogenesis of this disease. We used myelin-oligodendrocyteglycoprotein (MOG) as an immunogen. In active immunization EAE,the severity of clinical score was not different but the diseaseonset was significantly delayed in GM2/GD2–/– comparedwith those in wild-type mice. When we transferred MOG-reactiveT cells from GM2/GD2–/– or wild-type mice to wild-typemice, no significant differences were observed between the twogroups. In contrast, when we transferred MOG-reactive T cellsfrom wild-type mice to GM2/GD2–/– or to wild-typemice, the onset of EAE in GM2/GD2–/– mice was delayed.The recall response of MOG-specific T cells, the function ofantigen presenting cells, or the expression of several adhesionmolecules in the endothelium were not significantly differentbetween GM2/GD2–/– and wild-type mice. On the otherhand, quantitative analysis of cellular infiltration in thecentral nervous system (CNS) on day 9 of active immunizationEAE showed that the CD4+ cell number in the CNS isolated fromGM2/GD2–/– mice was significantly less than thatfrom wild-type mice. It indicated that the delayed onset ofEAE in GM2/GD2–/– mice was due to the delay of themigration of pathogenic T cells into the CNS. Thus, the complexgangliosides may be involved in the T cell–endothelialcell interaction in the pathogenetic process of EAE. 相似文献
12.
Jelena Arsenijević Slavica Ražić Zoran Maksimović Svetlana Đogo 《Central European Journal of Biology》2011,6(4):616-623
This paper brings out the results of the study on the levels of selected trace elements (Cu, Fe, Mn, Zn and Cr) in aerial
parts of Thymus pannonicus All. (Lamiaceae) and rhizosphere soil from twelve locations in Serbia. Prior to assays by flame and flameless atomic absorption
spectrometry, samples were subjected to microwave-assisted acid digestion. Real and potential acidity of soil samples were
also measured. Obtained results for soil samples, although slightly higher for some elements (Cu: 12.38–45.18 mg/kg; Fe: 22102–46193
mg/kg; Mn: 776.95–4901.27 mg/kg; Zn: 62.27–214.02 mg/kg; Cr: 48.86–69.13 mg/kg), were found to fit into biogeochemical background.
Element contents in plant samples differed depending on collecting site (Cu: 5.26–14.07 mg/kg; Fe: 25.92–1454.07 mg/kg; Mn:
89.29–278.25 mg/kg; Zn: 1.81–10.64 mg/kg; Cr: 1.11–3.51 mg/kg), which can be partly explainable by different nutrient availability
influenced by soil acidity. Zinc levels in T. pannonicus were below expected and seem to be strongly influenced by plant physiological properties. 相似文献
13.
We have determined the trace element composition of three mushrooms of Basidiomycetes, used in traditional Chinese medicine
using atomic absorption spectrophotometer (AAS). Metal concentrations in mushrooms were 203–401 mg/kg for iron, 22–51 mg/kg
for manganese, 84–116 mg/kg for zinc, 24.1–41.3 mg/kg for copper, 1.6–5.6 mg/kg for lead, 3.3–4.4 mg/kg for chromium, 9.3–11.5 mg/kg
for nickel, 0 mg/kg for vanadium, and 55.3–71 mg/kg for magnesium. The trace metal concentrations in mushrooms are hardly
affected by the ecosystem and soil where they grew, as well as by the mushroom species and trace metal species. The results
can be used to set new standards to control the quality of the three mushrooms of Basidiomycetes—Ganoderma lucidum, Coprinus comatus, and Grifola frondosa. 相似文献
14.
Mingming Zhu Joseph J. H. Ackerman Dmitriy A. Yablonskiy 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(6):701-710
Direct measurements of deep-brain and body-core temperature were performed on rats to determine the influence of cerebral
blood flow (CBF) on brain temperature regulation under static and dynamic conditions. Static changes of CBF were achieved
using different anesthetics (chloral hydrate, CH; α-chloralose, αCS; and isoflurane, IF) with αCS causing larger decreases
in CBF than CH and IF; dynamic changes were achieved by inducing transient hypercapnia (5% CO2 in 40% O2 and 55% N2). Initial deep-brain/body-core temperature differentials were anesthetic-type dependent with the largest differential observed
with rats under αCS anesthesia (ca. 2°C). Hypercapnia induction raised rat brain temperature under all three anesthesia regimes,
but by different anesthetic-dependent amounts correlated with the initial differentials—αCS anesthesia resulted in the largest
brain temperature increase (0.32 ± 0.08°C), while CH and IF anesthesia lead to smaller increases (0.12 ± 0.03 and 0.16 ± 0.05°C,
respectively). The characteristic temperature transition time for the hypercapnia-induced temperature increase was 2–3 min
under CH and IF anesthesia and ~4 min under αCS anesthesia. We conclude that both, the deep-brain/body-core temperature differential
and the characteristic temperature transition time correlate with CBF: a lower CBF promotes higher deep-brain/body-core temperature
differentials and, upon hypercapnia challenge, longer characteristic transition times to increased temperatures. 相似文献
15.
Progression age enhanced backward bifurcation in an epidemic model with super-infection 总被引:10,自引:0,他引:10
We consider a model for a disease with a progressing and a quiescent exposed class and variable susceptibility to super-infection.
The model exhibits backward bifurcations under certain conditions, which allow for both stable and unstable endemic states
when the basic reproduction number is smaller than one.
Received: 11 October 2001 / Revised version: 17 September 2002 /
Published online: 17 January 2003
Present address: Department of Biological Statistics and Computational Biology, 434 Warren Hall, Cornell University, Ithaca, NY 14853-7801
This author was visiting Arizona State University when most of the research was done.
Research partially supported by NSF grant DMS-0137687.
This author's research was partially supported by NSF grant DMS-9706787.
Key words or phrases: Backward bifurcation – Multiple endemic equilibria – Alternating stability – Break-point density – Super-infection – Dose-dependent
latent period – Progressive and quiescent latent stages – Progression age structure – Threshold type disease activation –
Operator semigroups – Hille-Yosida operators – Dynamical systems – Persistence – Global compact attractor 相似文献
16.
In this study, we performed a molecular docking and dynamics simulation for a benzoxazinone–human oxytocin receptor system to determine the possible hydrophobic and electrostatic interaction points in the dynamic complex. After the homology modeling, the ligand was docked into the putative active using AutoDock 3.05. After the application of energetic and structural filters, the complexes obtained were further refined with a simulated annealing protocol (AMBER8) to remove steric clashes. Three complexes were selected for subjection to the molecular dynamics simulation (5 ns), and the results on the occurrence of average anchor points showed a stable complex between the benzoxazinone derivative and the receptor. The complex could be used as a good starting point for further analysis with site-directed mutagenesis, or further computational research.
Figure The location of the ligands (complex B – blue; complex E – red; and complex F –
green) in the transmembrane regions (TM1 – red; TM2 – blue; TM3 – yellow; TM4
– purple; TM5 – orange; TM6 – cyan; TM7 – pink) of the hOTR. For clarity, the EC
and IC loops are not shown
Electronic Supplementary Material Supplementary material is available at 相似文献
17.
Alejandro A Nava-Ocampo Ferel T Aguirre-Garay Elvia Y Velázquez-Armenta Diana Moyao-García 《BMC anesthesiology》2001,1(1):1-8
Background
Infants usually respond differently to a neuromuscular relaxant compared to children or adults. Isoflurane is commonly used as an anesthetic gas in infants. In an RCT design, we investigated whether a dose of mivacurium 250 μg/kg results in faster onset of action than 200 μg/kg in infants under isoflurane anesthesia. Spontaneous recovery times and cardiovascular response were also evaluated. 相似文献18.
Isoflurane preconditioning uncouples mitochondria and protects against hypoxia-reoxygenation 总被引:1,自引:0,他引:1
Ljubkovic M Mio Y Marinovic J Stadnicka A Warltier DC Bosnjak ZJ Bienengraeber M 《American journal of physiology. Cell physiology》2007,292(5):C1583-C1590
Ischemic cardiac injury can be substantially alleviated by exposing the heart to pharmacological agents such as volatile anesthetics before occurrence of ischemia-reperfusion. A hallmark of this preconditioning phenomenon is its memory, when cardioprotective effects persist even after removal of preconditioning stimulus. Since numerous studies pinpoint mitochondria as crucial players in protective pathways of preconditioning, the aim of this study was to investigate the effects of preconditioning agent isoflurane on the mitochondrial bioenergetic phenotype. Endogenous flavoprotein fluorescence, an indicator of mitochondrial redox state, was elevated to 195 ± 16% of baseline upon isoflurane application in intact cardiomyocytes, indicating more oxidized state of mitochondria. Isoflurane treatment also elicited partial dissipation of mitochondrial transmembrane potential, which remained depolarized even after anesthetic withdrawal (tetramethylrhodamine fluorescence intensity declined to 83 ± 3 and 81 ± 7% of baseline during isoflurane exposure and washout, respectively). Mild uncoupling, with preserved ATP synthesis, was also detected in mitochondria that were isolated from animals that had been previously preconditioned by isoflurane in vivo, revealing its memory nature. These mitochondria, after exposure to hypoxia and reoxygenation, exhibited better preserved respiration and ATP synthesis compared with mitochondria from nonpreconditioned animals. Partial mitochondrial depolarization was paralleled by a diminished Ca2+ uptake into isoflurane-treated mitochondria, as indicated by the reduced increment in rhod-2 fluorescence when mitochondria were challenged with increased Ca2+ (180 ± 24 vs. 258 ± 14% for the control). In conclusion, isoflurane preconditioning elicits partial mitochondrial uncoupling and reduces mitochondrial Ca2+ uptake. These effects are likely to reduce the extent of the mitochondrial damage after the hypoxic stress. cardioprotection; uncoupling 相似文献
19.
The structures of ZnO graphene–like nanosheets (ZnOGLNS), i.e., ZnO aromatic–like (AL–ZnONS), naphthalene–like (NLL–ZnONS),
pyrene–like (PRL–ZnONS), coronene–like (CNL–ZnONS) and circumcoronene–like (CCL–ZnONS) and their oxygen adsorptions were obtained
using the B3LYP/LanL2DZ method. Adsorption energies of O2 on AL–ZnONS, NLL–ZnONS, PRL–ZnONS, CNL–ZnONS and CCL–ZnONS are reported. The bond strengths of the most inner Zn–O bonds
of ZnOGLNSs are in order: CCL–ZnONS > CNL–ZnONS > PRL–ZnONS. It was found that chemisorptions of O2 occur on the hydride atoms of zinc–hydride in the ZnOGLNSs. Physisorptions of O2 only occurring over the plane of ZnOGLNS were found. All the ZnOGLNSs are oxygen sensitive materials and would be developed
to be oxygen sensor based on electrical conductivity. 相似文献
20.
A pioneering limnological investigation was carried out in Bhutan in a small peat bog in the Trashiyangtse district (1950 m
above sea level) from February 2000 to January 2002. The sampled pond water had low transparency (55.0–95.0 cm), was typically
acidic (pH 5.69–6.58) with soft water (alkalinity, 11.0–36.0 mg/l; total hardness, 10.0–34.0 mg/l), and had low to moderate
specific conductivity (17.0–62.0 μS/cm). Further, moderate Na (2.0–6.8 mg/l), K (1.8–13.5 mg/l), sulphate (0.85–2.99 mg/l),
and silicate (2.5–15.0 mg/l) concentrations as well as low nutrient levels such as phosphate (0.006–0.170 mg/l) and nitrate
(0.003–0.180 mg/l) characterize the water in the peat bog. The recorded net plankton comprised 27 species of phytoplankton
and 49 species of zooplankton, with the latter indicating greater homogeneity and breaking down into Rotifera (23 species)
> Cladocera (13 species) > Rhizopoda (8 species) > Copepoda (3 species) > Ostracoda = Nematoda (1 species each). On the other
hand, the net plankton density ranged between 93 and 692 number/l (n/l) with numerical dominance by phytoplankton (68.5% ±
12%), of which Chlorophyceae were predominant (90 ± 63 n/l). Zooplankton showed moderately high diversity (2.745 ± 0.293)
and evenness (0.925 ± 0.049) and exhibited almost equal abundance of four recorded groups, namely Cladocera (20 ± 15 n/l)
> Rotifera (15 ± 6 n/l) > Copepoda (14 ± 7 n/l) > Rhizopoda (14 ± 4 n/l). While no significant impact of abiotic factors was
recorded on zooplankton density, rainfall alone was the most important factor that influenced net plankton and various groups
of phytoplankton. Comments on some comparative limnological attributes are also made with similar as well as different habitats
in the nearby Himalayan countries. 相似文献