Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 51
Filter
Add more filters










Publication year range
1.
Entropy (Basel) ; 26(2)2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38392422

ABSTRACT

We investigate the effects of boost invariance breaking on the isotropization of pressure in the glasma, using a 3+1D glasma simulation. The breaking is attributed to spatial fluctuations in the classical color charge density along the collision axis. We present numerical results for pressure and energy density at mid-rapidity and across a wider rapidity region. It is found that, despite varying longitudinal correlation lengths, the behaviors of the pressure isotropizations are qualitatively similar. The numerical results suggest that, in the initial stage, longitudinal color electromagnetic fields develop, similar to those in the boost invariant glasma. Subsequently, these fields evolve into a dilute glasma, expanding longitudinally in a manner akin to a dilute gas. We also show that the energy density at mid-rapidity exhibits a 1/τ decay in the dilute glasma stage.

2.
Mar Pollut Bull ; 185(Pt A): 114327, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36356339

ABSTRACT

The presence of zinc (Zn), a vital element for algal physiological functions, coupled with the silicification of diatoms implies that it plays an integral role in the carbon and silicon cycles of the sea. In this study, we examined the effects of different pCO2 and Zn levels on growth rate, elemental compositions and silicification by Thalassiosira weissflogii. The results showed that under normal pCO2 (400 µatm), cultures of T. weissflogii were depressed for growth rate and silica incorporation rate, but encouraged for cellular silicon content, Si/C, Si/N, and sinking rate when Zn deficient (0.3 pmol L-1). However, cellular silicon and sinking rate of Zn-deficient and Zn-replete (25 pmol L-1) T. weissflogii were decreased and increased at higher pCO2 (800 µatm), respectively. Thus, acidification may affect diatoms significantly differently depending on the Zn levels of the ocean and then alter the biochemical cycling of carbon and silica.


Subject(s)
Diatoms , Diatoms/physiology , Silicon , Carbon Dioxide/metabolism , Hydrogen-Ion Concentration , Seawater/chemistry , Zinc/metabolism , Acids , Carbon/metabolism , Silicon Dioxide
3.
Ecotoxicol Environ Saf ; 243: 114017, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-36027715

ABSTRACT

Urea, nickel (Ni) and dissolved organic matter (DOM) from land varied with different sources have a great impact on the offshore ecosystem. The heterogeneity of Ni bioavailability and toxicity of Prorocentrum donghaiense influenced by DOM fractions incubated in urea was investigated in this study. On the occasion, chlorophyll (Chl a) concentration, growth rate, and photosynthesis parameters were monitored to track changes occurring in the test organism. Chl a concentration and photosynthesis parameters in the treatment of hydrophilic DOM (HPI) with Ni-free was significantly higher than that in the control treatment, and similar data were shown in the treatment of hydrophobic DOM(HPO)with the low Ni environment (0.17µmol L-1). However, the opposite phenomena were observed in the treatments of HPO with the higher Ni environment (over 170µmol L-1). Moreover, the EC50 of Ni for P.donghaiense incubated in HPO was relatively lower than that in HPI and control treatment, which implied that HPO elevated the toxicity of Ni. Therefore, the varied DOM compositions because of different origins, as a chelating agent and potential nutrient source in coastal waters, shows the significantly different bioavailability and toxicity of Ni with the increasing inputs of urea, which in turn influences the dynamics of phytoplankton.


Subject(s)
Dinoflagellida , Nickel , Biological Availability , Dissolved Organic Matter , Ecosystem , Nickel/toxicity , Urea
4.
Chemosphere ; 307(Pt 4): 136094, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35995200

ABSTRACT

Polystyrene (PS) is selected as a representative nanoplastic and persistent pollutant for its difficult degradation and wide application. The environmental risk assessment of PS is obstructed by the toxic dye-based fluorescent PS, which false positives could be induced by the leakage of dye. For high biocompatibility, low toxicity, hydrophilicity, good water dispersibility, strong fluorescent stability, graphene oxide quantum dots (o-CQDs) are selected and embedded into PS microspheres, i.e., o-CQDs@PS, by microemulsion polymerization and denoted as CPS. Meanwhile, the sizes of CPS, e.g., 100, 150, and 200 nm, could be controlled by optimizing the type and number of water-soluble initiators. The anti-interference, low toxicity, and in vivo fluorescent tracing of CPS are proven by the coexistence of metals (including Fe2+, Fe3+, K+, Ba2+, Al3+, Zn2+, Mg2+, Ca2+, and Na+) on the fluorescence intensity of CPS, the growth of Chlorella pyrenoidosa and Artemia cysts as aquatic phytoplankton and zooplankton cultured with CPS, and the transfer of CPS from water into brine shrimp. In the concentration range of 0.1-100 mg/L, CPS can be quantitatively determined, which is suitable for coastal water and wastewater treatment plants. Therefore, CPS with standard size is suitable as reference material of PS.


Subject(s)
Chlorella , Environmental Pollutants , Nanospheres , Quantum Dots , Animals , Artemia/metabolism , Environmental Pollutants/metabolism , Graphite , Microplastics , Polystyrenes/toxicity , Quantum Dots/toxicity , Water/metabolism
5.
J Agric Food Chem ; 70(31): 9769-9778, 2022 Aug 10.
Article in English | MEDLINE | ID: mdl-35895310

ABSTRACT

The high-carbohydrate, low-fat, low-protein (HC-LFP) and low-carbohydrate, high-fat, high-protein (LC-HFP) diets are the main dietary patterns worldwide. The influence of dietary patterns on bioavailable metals, gut microbes, and their interaction is still unknown. A biomimetic digestive tract with full functions is constructed to transform the diets into chyme, and the gut microbes are cultured with the corresponding chyme. The diet species-specificity in bioavailable metal content and the positive and negative correlations between bioavailable metals and microbial reproductions are disclosed. The safe dosage and maximum consumption are 369.5 and 858.6 g/d and 268.6 and 3119.0 g/d for LC-HFP and HC-LFP, respectively. When replacing HC-LFP with LC-HFP for 21 days, the bioavailability of Fe and Cr is increased 83.2% and 268.4%, respectively; the reproductions of harmful and benefical microbes are significantly increased and decreased. The prevalences of obesity, inflammation, septicemia, and cancer are increased, and then the risk of dietary pattern shift is disclosed.


Subject(s)
Gastrointestinal Microbiome , Carbohydrates , Diet, Fat-Restricted , Humans , Obesity , Risk Assessment
6.
Food Chem ; 373(Pt B): 131593, 2022 Mar 30.
Article in English | MEDLINE | ID: mdl-34838401

ABSTRACT

Nitrite is one of the most common carcinogens in daily food. Its simple, rapid, inexpensive, and in-field measurement is important for food safety, based on the requirements of the standard from Codex Alimentarius Commission and China. Using polyacrylonitrile (PAN) and thin layer silica gel (SG), p-aminophenylcyclic acid (SA) and naphthalene ethylenediamine hydrochloride (NEH), as carriers and chromogenic agents, respectively, PAN-NSS as nitrite color sensor is proposed. After fixing and protecting of SA and NEH with layer-upon-layer PAN, the validity period of the test paper can be prolonged from 7 days to more than 30 days. The reproducibility of PAN-NSS preparation is ensured by electrospinning. Combined with PAN-NSS, deep convolutional neural network (DCNN) and APP as a visual monitoring platform, which has the functions of rapid sampling, data processing and transmission, intuitive feedback, etc., and provides a fully integrated detection system for field detection.


Subject(s)
Colorimetry , Nitrites , China , Neural Networks, Computer , Reproducibility of Results
7.
J Hazard Mater ; 416: 126146, 2021 08 15.
Article in English | MEDLINE | ID: mdl-34492932

ABSTRACT

As worldwide edible fungi, Lentinula edodes and Agaricus bisporus accumulate both essential and harmful metals. Metal bioavailability is important for metal benefit-risk assessment. A full functional model of digestive tracts (including digestion, metabolism, and absorption) is established. Under the digestive tract functions, the bioaccessible and bioavailable metals are released from edible fungi and absorbed by intestinal tract, respectively. Based on bioavailable metal contents in the intestine, safe dosage and maximum consumption are 43.52 g/d and 248.7 g/d for Agaricus bisporu, 20.59/328.9 g/d (for males/ female) and 132.9 g/d for Lentinus edodes; V, Co, Ni, Cu, Zn, Se, Cr, Cd and Pb in Agaricus bisporus and Lentinula edodes are absorbed mainly in the large intestine; Fe is mainly absorbed in small intestine; edible fungi species-specificity in metal bioavailability is observed for As and Mn, which are mainly absorbed by small and large intestine for Agaricus bisporus and Lentinus edodes, respectively; and then metal toxicity on small and large intestine is disclosed. Metal benefit-risk is assessed by the content of monolayer liposome-extracted metal in the chyme from small and large intestine, which is controlled by the gastrointestinal functions, metal and edible fungi species.


Subject(s)
Agaricus , Metals, Heavy , Biological Availability , Biomimetics , Digestion , Environmental Monitoring , Female , Gastrointestinal Tract/metabolism , Humans , Metals, Heavy/analysis , Risk Assessment
8.
Environ Pollut ; 259: 113821, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31884212

ABSTRACT

Human-induced temperature changes influence coastal regions, both via thermal pollution and ocean warming, which exerts profound effects on the chemistry of metals and the physiology of organisms. However, it remains unknown whether the increased temperature of discharged water or ocean warming, as a result of climate change, lead to an increase of human health risks associated with the consumption of sea foods. In this study, the influence of temperature on metal accumulation by oysters was studied in individuals collected from a coastal area affected by the thermal water discharge of the Houshi Power Plant, China. The bioaccumulation factor (BAF) and oral bioavailability (OBA) of metals in oysters was determined. Elevated temperatures led to an increase in BAF for Cu, Zn, Hg, and Cd (p < 0.05), but no change was observed for As and Pb (p > 0.05). The OBA for Cd, As, and Pb correlated positively to elevated temperatures (p < 0.05). However, for Cu and Zn, OBA was negatively correlated with increasing temperature (p < 0.05). As, Pb, and Cd in the trophically available metal (defined as a sum of heat-stable proteins, heat-denaturable proteins, and organelles) was significantly elevated at the highest temperature seawater site (site A) compared to the lowest seawater site (site B). Thus, the irregular variation of OBA for each metal may be the result of variations in the subcellular distribution of metals and the protein quality influenced by the increased temperature. Moreover, the increased temperature and increased the hazard quotient values of As and Cd (p < 0.05 for As, n = 6, p < 0.05 for Cd, n = 6), which provided an indication of the potential risks of the consumption of oysters or other seafood to future warming under climate change scenarios.


Subject(s)
Metals, Heavy , Ostreidae , Water Pollutants, Chemical , Animals , Bioaccumulation , China , Environmental Monitoring , Humans , Oceans and Seas
9.
Phys Rev Lett ; 121(18): 182301, 2018 Nov 02.
Article in English | MEDLINE | ID: mdl-30444380

ABSTRACT

A fast charged particle crossing the boundary between chiral matter and vacuum radiates transition radiation. Its most remarkable features-the resonant behavior at a certain emission angle and the circular polarization of the spectrum-depend on the parameters of the chiral anomaly in a particular material or matter. Chiral transition radiation can be used to investigate the chiral anomaly in such diverse media as the quark-gluon plasma, Weyl semimetals, and axionic dark matter.

10.
Chemosphere ; 197: 57-64, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29331719

ABSTRACT

Exudates by marine phytoplankton and metals coexist in the seawater, but little is known about their interaction. In this study, cultures of Prorocentrum donghaiense Lu were grown in urea and ammonium, and then exposed to different Ni ion levels in order to study the effects of Ni ions on algal growth. The regulatory mechanisms of P. donghaiense Lu for coping with different Ni ion levels was investigating by characterizing dissolved organic carbon (DOC), carbohydrate and protein content released per cell, hydropathy properties (hydrophilic and hydrophobic fractions) and thiol compounds (cysteine-like or glutathione-like). Lower levels of Ni ions (pNi>10.0) significantly promoted the growth of P. donghaiense Lu when incubated in urea; however, the same was not true for P. donghaiense Lu cultivated in ammonium. An increased presence of hydrophobic fractions and thiol compounds (cysteine-like or glutathione-like compounds) induced by low Ni ions (pNi>10.0) in urea cultures suggest that the activation of cellular mechanisms in response to insufficient Ni ion stress enhances Ni bioavailability. Furthermore, the abundance of carbohydrates and proteins released by cells when exposed to higher Ni ions levels (from pNi = 10.0 to pNi = 8.0) both in urea and ammonium cultures suggests that algal cells may utilize exudate to complex Ni cations and reduce their toxicity. Therefore, it can be speculated that phytoplankton can produce large amounts of specific exudate, which may accelerate the metal bioavailability (insufficient levels) and reduce metal toxicity (excess levels) to maintain an equilibrium with metals in the environment.


Subject(s)
Dinoflagellida/metabolism , Nickel/metabolism , Water Pollutants, Chemical/metabolism , Biodegradation, Environmental , Biological Availability , Nitrogen/metabolism , Phytoplankton/metabolism , Seawater , Urea/metabolism
11.
Opt Express ; 25(21): 24861-24871, 2017 Oct 16.
Article in English | MEDLINE | ID: mdl-29041159

ABSTRACT

The chirality of photons plays a fundamental role in light-matter interactions. However, a limiting factor in photonic integrated circuits is the lack of a miniaturized component, which can distinguish the chirality in a low cost and integrated manner. Herein we numerically demonstrate a chirality-distinguishing beamsplitter that can address this challenge. It consists of an integrated polarization rotator and a linear polarization beamsplitter, which together can fulfill the task of distinguishing and splitting left- and right-handed quasi-circularly polarized modes on a chip with an ultra-broadband operation range from 1.45 µm to 1.65 µm. Owning to the reciprocity, the device can emit photons with selectable spin angular momentum depending on the chosen feeding waveguide. The device is compatible with complementary metal-oxide semiconductor technology and it may open up new avenues in the fields of on-chip nano-photonics, bio-photonics and quantum information science.

12.
Opt Express ; 25(10): 10972-10983, 2017 May 15.
Article in English | MEDLINE | ID: mdl-28788784

ABSTRACT

Gears are rotating machines, meshing with each other by teeth to transmit torque. Interestingly, the rotating directions of two meshing gears are opposite, clockwise and counterclockwise. Although this opposite handedness motion has been widely investigated in machinery science, the analogue behavior of light remains undiscovered. Here, we present a simple nanophotonic directional coupler structure which can generate two light beams with opposite handedness of polarization states-optical gears. Due to the abrupt phase shift effect and birefringence effect, the angular momentum (AM) states of photons vary with the propagation distance in two adjacent waveguides of the coupler. Thus, by the choice of coupling length, it is able to obtain two light beams with opposite handedness of polarization, confirming the appearance of optical gears. The full control in the handedness of output beams is achieved via tuning the relative phase between two orthogonal modes at the input port. Optical gears thus offer the possibility of exploring light-matter interactions in nanoscale, opening up new avenues in fields of integrated quantum computing and nanoscale bio-sensing of chiral molecules.

13.
Opt Express ; 24(25): 29216-29225, 2016 Dec 12.
Article in English | MEDLINE | ID: mdl-27958583

ABSTRACT

We propose and numerically investigate a gate-controlled on-chip graphene metasurface consisting of a monolayer graphene sheet and silicon photonic crystal-like substrate, to achieve an electrically-tunable induced transparency. The operation mechanism of the induced transparency of the on-chip graphene metasurface is analyzed. The tunable optical properties with different gate-voltages and polarizations have been discussed. Additionally, the spectral feature of the on-chip graphene metasurface as a function of the refractive index of the local environment is also investigated. The result shows that the on-chip graphene metasurface as a refractive index sensor can achieve an overall figure of merit of 8.89 in infrared wavelength range. Our study suggests that the proposed structure is potentially attractive as optoelectronic modulators and refractive index sensors.

14.
Aquat Toxicol ; 181: 22-28, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27810489

ABSTRACT

Nitrogen nutrients and nickel(Ni) are ubiquitous in aquatic environments, and they are important for primary production of ocean ecosystem. This study examined the interaction of nitrogen nutrients (specifically urea and nitrate) and Ni on chlorophyll (Chl a) concentration and photosynthesis parameters values of Prorocentrum donghaiense and Skeletonema costatum. The data presented here indicate that low concentration of Ni for P. donghaiense and S. costatum can enhance both Chl a concentration and photosynthesis parameters values when grown in urea containing environment. Despite this increase there was also an observed depression in both species tested when incubated in high concentration of Ni for P. donghaiense and S. costatum regardless of incubating in urea or nitrate. Additionally, EC50 values of Chl a and Fv/Fm for Ni at different time intervals were calculated in this study. These observations indicated that the Ni tolerance was higher in P. donghaiense as compared to S. costatum. The Ni tolerance of P. donghaiense incubated in urea was higher than that incubating in nitrate. The same phenomenon was not observed in S. costatum, which indicated that the influence of urea was dependent on the species investigated. Thus, urea input could impact Ni bioavailability and toxicity, and then affect the biodynamics thereafter.


Subject(s)
Nickel/toxicity , Nitrates/metabolism , Urea/metabolism , Water Pollutants, Chemical/toxicity , Biological Availability , Chlorophyll/metabolism , Chlorophyll A , Diatoms/drug effects , Diatoms/growth & development , Diatoms/metabolism , Dinoflagellida/drug effects , Dinoflagellida/growth & development , Dinoflagellida/metabolism , Ecosystem , Photosynthesis/drug effects , Water Pollutants, Chemical/chemistry
15.
Aquat Toxicol ; 181: 11-21, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27810488

ABSTRACT

Eutrophication and acidification have been the most concerned environmental problems in coastal ecosystem. However, their combined effect on coastal ecosystem function was unknown. Both diatom (Conticribra weissflogii) and dinoflagellate (Prorocentrum donghaiense) are used as coastal algal model. Seven parameters were determined for physiological function assessment, including cell density, chlorophyll a (Chl a), protein, malonaldehyde (MDA), superoxide dismutase, carbonic anhydrase (CA), and nitrate reductase (NR). The influence of nitrate (N) and phosphate (P) on MDA and CA in C. weissflogii was significant, and that on Chl a and protein in P. donghaiense were also significant. However, the influence of acidification on physiological functions was not significant. The effect of acidification could be intensified by coastal eutrophication. More importantly, the coexist influence of acidification and eutrophication on CA, NR and protein in C. weissflogii and MDA in P. donghaiense was significant. Both NR activity and Chl a content in P. donghaiense were positively correlated to N and P concentration when pH were 7.9 and 7.8, respectively. With simultaneous worsening of acidification and eutrophication, the cell growth of P. Donghaiense was accelerated more obviously than C. weissflogii, i.e., dinoflagellate was more adaptable than diatom, thus algal species distribution and abundance could be changed.


Subject(s)
Diatoms/growth & development , Dinoflagellida/growth & development , Eutrophication/physiology , Carbonic Anhydrases/metabolism , Chlorophyll/metabolism , Chlorophyll A , Diatoms/drug effects , Diatoms/metabolism , Dinoflagellida/drug effects , Dinoflagellida/metabolism , Ecosystem , Hydrogen-Ion Concentration , Malondialdehyde/metabolism , Nitrates/chemistry , Phosphates/chemistry , Superoxide Dismutase/metabolism , Water Pollutants, Chemical/toxicity
16.
Opt Express ; 24(19): 22169-76, 2016 Sep 19.
Article in English | MEDLINE | ID: mdl-27661951

ABSTRACT

We give the effective refractive index of graphene plasmonic waveguides with both linear and nonlinear effects based on the nonlinear cross-phase modulation, and address the effects of photo-induced refractive index change and absorption change. A non-resonant all-optical nonlinear graphene plasmonic switch with an ultra-compact size of 0.25 µm2 is proposed and numerically analyzed based on the dynamics of the photo-induced absorption change. The results show that the all-optical graphene plasmonic switch can realize a broad bandwidth over 5 THz, a potentially very high switching speed and an extinction ratio of 18.14 dB with the electric amplitude of the pump light of 1.5 × 107 V/m at the signal frequency of 28 THz. Our study could provide a possibility for future all-optical highly integrated optical components.

17.
Sensors (Basel) ; 16(9)2016 Sep 03.
Article in English | MEDLINE | ID: mdl-27598173

ABSTRACT

We review our works on Fabry-Perot (F-P) interferometric fiber-optic sensors with various applications. We give a general model of F-P interferometric optical fiber sensors including diffraction loss caused by the beam divergence and the Gouy phase shift. Based on different structures of an F-P cavity formed on the end of a single-mode fiber, the F-P interferometric optical sensor has been extended to measurements of the refractive index (RI) of liquids and solids, temperature as well as small displacement. The RI of liquids and solids can be obtained by monitoring the fringe contrast related to Fresnel reflections, while the ambient temperature and small displacement can be obtained by monitoring the wavelength shift of the interference fringes. The F-P interferometric fiber-optic sensors can be used for many scientific and technological applications.

18.
Rep Prog Phys ; 79(7): 076302, 2016 07.
Article in English | MEDLINE | ID: mdl-27275776

ABSTRACT

The hot and dense matter generated in heavy-ion collisions may contain domains which are not invariant under P and CP transformations. Moreover, heavy-ion collisions can generate extremely strong magnetic fields as well as electric fields. The interplay between the electromagnetic field and triangle anomaly leads to a number of macroscopic quantum phenomena in these P- and CP-odd domains known as anomalous transports. The purpose of this article is to give a pedagogical review of various properties of the electromagnetic fields, the anomalous transport phenomena, and their experimental signatures in heavy-ion collisions.

20.
Sci Rep ; 6: 24959, 2016 04 22.
Article in English | MEDLINE | ID: mdl-27102332

ABSTRACT

Nanophotonic waveguides are the building blocks of integrated photonics. To date, while quarter-wave plates (QWPs) are widely used as common components for a wide range of applications in free space, there are almost no reports of Integratable QWPs being able to manipulate the angular momentum (AM) of photons inside nanophotonic waveguides. Here, we demonstrate two kinds of Integratable QWPs respectively based on the concept of abrupt phase change and birefringence effect. The orientation of the equivalent optical axis of an Integratable QWP is designable. Remarkably, a combination of two integratable QWPs with different equivalent optical axes leads to an integrated system that performances one-way AM conversion. Moreover, this system can be used as a point source that can excite different patterns on a metal surface via directional excitation of surface plasmon polaritons (SPP). These results allow for the control of AM of light in nanophotonic waveguides, which are crucial for various applications with limited physical space, such as on-chip bio-sensing and integrated quantum information processing.

SELECTION OF CITATIONS
SEARCH DETAIL
...