With the dramatic increase in nanotechnologies, it has become probable that biological systems will be exposed to excess of nanoparticles (NPs). However, the impact of NPs on plants remains to be ...explored. The aim of this research was to determine the effects of ZnO NPs on tomato (
Solanum lycopersicum
L.) plants. Plant growth, photosynthetic characteristics, chlorophyll fluorescence parameters, and activities of antioxidative enzymes were measured in 35-d-old plants. The ZnO NP treatments significantly inhibited tomato root and shoot growth, decreased the content of chlorophylls
a
and
b
, and reduced photosynthetic efficiency and some other chlorophyll fluorescence parameters in a concentration-dependent manner. However, the supernatant of ZnO NP suspensions did not affect growth of tomato, despite the presence of small amounts of Zn
2+
. Taken together, these results suggest that toxic effects on tomato plants were from ZnO NPs, not from Zn
2+
released into the solution; toxicity was likely caused by reduced chlorophyll content and damaged photochemical system, which in turn limited photosynthesis and led to the reduction in biomass accumulation. Also, ZnO NPs enhanced the transcription of genes related to antioxidant capacity, suggesting that ZnO NPs could enhance the defence response by increasing activities of antioxidant enzymes.
We calculated the organic matter to organic carbon mass ratios (OM/OC mass ratios) in PM2.5 collected from 14 Chinese cities during summer and winter of 2003 and analyzed the causes for their ...seasonal and spatial variability. The OM/OC mass ratios were calculated two ways. Using a mass balance method, the calculated OM/OC mass ratios averaged 1.92 ± 0.39 year-round, with no significant seasonal or spatial variation. The second calculation was based on chemical species analyses of the organic compounds extracted from the PM2.5 samples using dichloromethane/methanol and water. The calculated OM/OC mass ratio in summer was relatively high (1.75 ± 0.13) and spatially-invariant due to vigorous photochemistry and secondary organic aerosol (OA) production throughout the country. The calculated OM/OC mass ratio in winter (1.59 ± 0.18) was significantly lower than that in summer, with lower values in northern cities (1.51 ± 0.07) than in southern cities (1.65 ± 0.15). This likely reflects the wider usage of coal for heating purposes in northern China in winter, in contrast to the larger contributions from biofuel and biomass burning in southern China in winter. On average, organic matter constituted 36% and 34% of Chinese urban PM2.5 mass in summer and winter, respectively. We report, for the first time, a high regional correlation between Zn and oxalic acid in Chinese urban aerosols in summer. This is consistent with the formation of stable Zn oxalate complex in the aerosol phase previously proposed by Furukawa and Takahashi (2011). We found that many other dicarboxylic acids were also highly correlated with Zn in the summer Chinese urban aerosol samples, suggesting that they may also form stable organic complexes with Zn. Such formation may have profound implications for the atmospheric abundance and hygroscopic properties of aerosol dicarboxylic acids.
Abstract
The electronic instabilities in CsV
3
Sb
5
are believed to originate from the V 3
d
-electrons on the kagome plane, however the role of Sb 5
p
-electrons for 3-dimensional orders is largely ...unexplored. Here, using resonant tender X-ray scattering and high-pressure X-ray scattering, we report a rare realization of conjoined charge density waves (CDWs) in CsV
3
Sb
5
, where a 2 × 2 × 1 CDW in the kagome sublattice and a Sb 5
p
-electron assisted 2 × 2 × 2 CDW coexist. At ambient pressure, we discover a resonant enhancement on Sb
L
1
-edge (2
s
→5
p
) at the 2 × 2 × 2 CDW wavevectors. The resonance, however, is absent at the 2 × 2 × 1 CDW wavevectors. Applying hydrostatic pressure, CDW transition temperatures are separated, where the 2 × 2 × 2 CDW emerges 4 K above the 2 × 2 × 1 CDW at 1 GPa. These observations demonstrate that symmetry-breaking phases in CsV
3
Sb
5
go beyond the minimal framework of kagome electronic bands near van Hove filling.
The microstructure significantly influences the mechanical properties of metals and alloys. Herein, we present a novel approach to tailoring the mechanical properties of a CoCrNi medium-entropy alloy ...by controlling nanotwin-HCP lamellae and annealing twins. It has been observed that the dislocations, three-dimensional nanotwins and Lomer-Cottrell locks, induced by equal channel angular pressing, synergistically strengthened the CoCrNi alloy. The nanotwin-HCP composite lamellae, induced by post-deformation annealing at 500 °C, resulted in high strength of 1.5 GPa and a strain of 4.1%. A superior combination of high strength (~ 1 GPa) and excellent ductility (~ 45%) has been obtained by further decorating the microstructure through producing annealing twins in recrystallized micro-sized grains. The present study presents the strengthening mechanisms and provides a generic approach to obtain the desirable mechanical properties of the alloys via microstructural optimization.
The use of X-ray computed tomography (CT), exploiting both synchrotron and laboratory sources, has grown significantly over the last decade, driven primarily by improvements in spatial resolution, ...reduction in acquisition time and the increasing availability of laboratory X-ray CT systems. It is now able to provide highly accurate three-dimensional (3D) inspections of fibre architectures, manufacturing defects and in-service damage accumulation non-destructively, allowing the user to examine cross-sections that would previously have required laborious and skilled mechanical sectioning with the potential for inducing damage or loss of material. Further, by repeated acquisition of 3D images, it has opened new opportunities for time-lapse studies. This feature article reviews the technical aspects relating to the X-ray CT imaging of composites such as obtaining sufficient contrast, examination of thin panels, sample size/resolution issues, quantification of damage and defects, and image-based modelling. The capability of X-ray CT to provide important information is considered across applications ranging from manufacturing processes, through tensile and compression loading to fatigue and impact damage. The complementary advantages of laboratory and synchrotron X-ray CT are examined with a view to identify new opportunities and challenges.
Blood loss during liver surgery is found to be correlated with central venous pressure (CVP). The aim of the current retrospective study is to find out the cutoff value of CVP and stroke volume ...variation (SVV), which may increase the risk of having intraoperative blood loss of more than 100 mL during living liver donor hepatectomies.
Twenty-seven adult living liver donors were divided into 2 groups according to whether they had intraoperative blood loss of less (G1) or more than 100 mL (G2). The mean values of the patients' CVP and SVV at the beginning of the transaction of the liver parenchyma was used as the cutoff point. Its correlation to intraoperative blood loss was evaluated using the χ2 test; P < .001 was regarded as significant.
The cutoff points of CVP and SVV were 8 mm Hg and 13% respectively. The odds ratio of having blood loss exceeding 100 mL was 91.25 (P < .001) and 0.36 (P < .001) for CVP and SVV, respectively.
CVP less than 5 mm Hg, as suggested by most authors, is not always clinical achievable. Our results show that a value of less than 8 mm Hg or SVV 13% is able to achieve a minimal blood loss of 100 mL during parenchyma transaction during a living donor hepatectomy. Measurements used to lower the CVP or increased SVV in our serial were intravenous fluids restriction and the use of a diuretic.
•Blood loss in liver surgery is found to be correlated with central venous pressure (CVP).•A CVP less than 5 mm Hg is suggested in the literature.•A CVP less than 5 mm Hg as suggested by most authors is not always clinically achievable. Our results show that a CVP of less than 8 mm Hg or an SVV of 13% can achieve minimal blood loss of 100 mL during parenchyma transactions in living donor hepatectomy.
We have performed high-resolution angle-resolved photoemission spectroscopy on Fe-based superconductor LiFeAs (T(c)=18 K). We reveal multiple nodeless superconducting (SC) gaps with 2Δ/k(B)T(c) ...ratios varying from 2.8 to 6.4, depending on the Fermi surface (FS). We also succeeded in directly observing a gap anisotropy along the FS with magnitude up to ~30%. The anisotropy is fourfold symmetric with an antiphase between the hole and electron FSs, suggesting complex anisotropic interactions for the SC pairing. The observed momentum dependence of the SC gap offers an excellent opportunity to investigate the underlying pairing mechanism.
Cosmological models in which dark matter consists of cold elementary particles predict that the dark halo population should extend to masses many orders of magnitude below those at which galaxies can ...form
. Here we report a cosmological simulation of the formation of present-day haloes over the full range of observed halo masses (20 orders of magnitude) when dark matter is assumed to be in the form of weakly interacting massive particles of mass approximately 100 gigaelectronvolts. The simulation has a full dynamic range of 30 orders of magnitude in mass and resolves the internal structure of hundreds of Earth-mass haloes in as much detail as it does for hundreds of rich galaxy clusters. We find that halo density profiles are universal over the entire mass range and are well described by simple two-parameter fitting formulae
. Halo mass and concentration are tightly related in a way that depends on cosmology and on the nature of the dark matter. For a fixed mass, the concentration is independent of the local environment for haloes less massive than those of typical galaxies. Haloes over the mass range of 10
to 10
solar masses contribute about equally (per logarithmic interval) to the luminosity produced by dark matter annihilation, which we find to be smaller than all previous estimates by factors ranging up to one thousand
.
To isolate and identify a benefic bacterium, Bacillus subtilis E20, from natto (fermented soybeans), and incorporate it into shrimp feed to promote shrimp growth performance. A protease-producing ...bacterium, E20, isolated from natto was identified as B. subtilis by an API 50 CHB kit and the 16S rDNA sequence. B. subtilis E20 was able to grow at a broad range of temperatures (10-50°C), pH values (5-10), and NaCl levels (0-9%). The best culture conditions for B. subtilis E20 to produce the protease were 40°C, a pH of 6-8 and 0% NaCl. No shrimp died after being injected with B. subtilis E20 up to 10⁹ colony-forming units (CFU) per shrimp. Bacillus subtilis E20 was incorporated in diets at the levels of 0 (control), 10⁶, 10⁷, and 10⁸ CFU kg⁻¹ for shrimp grow-out culture, and results showed that after feeding on B. subtilis E20-containing diets (10⁸ CFU kg⁻¹ of diet), shrimp had excellent growth performance and production compared to the control because protease activities in the digestive tract were improved by B. subtilis E20. Bacillus subtilis E20 isolated from natto is a great protease producer and is able to improve shrimp growth performance through increasing the digestibility of food. Results suggest that B. subtilis E20 is a potential candidate for use as a probiotic to improve shrimp growth performance, and consequently reduce feed costs.
We report the first genome-wide association study in 1000 bipolar I patients and 1000 controls, with a replication of the top hits in another 409 cases and 1000 controls in the Han Chinese ...population. Four regions with most strongly associated single-nucleotide polymorphisms (SNPs) were detected, of which three were not found in previous GWA studies in the Caucasian populations. Among them, SNPs close to specificity protein 8 (SP8) and ST8 α-N-acetyl- neuraminide α-2,8-sialyltransferase (ST8SIA2) are associated with Bipolar I, with P-values of 4.87 × 10(-7) (rs2709736) and 6.05 × 10(-6) (rs8040009), respectively. We have also identified SNPs in potassium channel tetramerization domain containing 12 gene (KCTD12) (rs2073831, P=9.74 × 10(-6)) and in CACNB2 (Calcium channel, voltage-dependent, β-2 subunit) gene (rs11013860, P=5.15 × 10(-5)), One SNP nearby the rs1938526 SNP of ANK3 gene and another SNP nearby the SNP rs11720452 in chromosome 3 reported in previous GWA studies also showed suggestive association in this study (P=6.55 × 10(-5) and P=1.48 × 10(-5), respectively). This may suggest that there are common and population-specific susceptibility genes for bipolar I disorder.
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