Publications by authors named "Weimin Sun"

161 Publications

Arsenic and antimony co-contamination influences on soil microbial community composition and functions: Relevance to arsenic resistance and carbon, nitrogen, and sulfur cycling.

Environ Int 2021 Apr 1;153:106522. Epub 2021 Apr 1.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China. Electronic address:

Microorganisms can mediate arsenic (As) and antimony (Sb) transformation and thus change the As and Sb toxicity and mobility. The influence of As and Sb on the innate microbiome has been extensively characterized. However, how microbial metabolic potentials are influenced by the As and Sb co-contamination is still ambiguous. In this study, we selected two contrasting sites located in the Shimen realgar mine, the largest realgar mine in Asia, to explore the adaptability and response of the soil microbiome to As and Sb co-contamination and the impact of co-contamination on microbial metabolic potentials. It is observed that the geochemical parameters, including the As and Sb fractions, were the driving forces that reshaped the community composition and metabolic potentials. Bacteria associated with Bradyrhizobium, Nocardioides, Sphingomonas, Burkholderia, and Streptomyces were predicted to be tolerant to high concentrations of As and Sb. Co-occurrence network analysis revealed that the genes related to C fixation, nitrate/nitrite reduction, N fixation, and sulfate reduction were positively correlated with the As and Sb fractions, suggesting that As and Sb biogeochemical cycling may interact with and benefit from C, N, and S cycling. The results suggest that As and Sb co-contamination not only influences As-related genes, but also influences other genes correlated with microbial C, N, and S cycling.
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http://dx.doi.org/10.1016/j.envint.2021.106522DOI Listing
April 2021

Bacteria responsible for antimonite oxidation in antimony-contaminated soil revealed by DNA-SIP coupled to metagenomics.

FEMS Microbiol Ecol 2021 Mar 31. Epub 2021 Mar 31.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.

Antimony (Sb), the analog of arsenic (As), is a toxic metalloid that poses risks to the environment and human health. Antimonite (Sb(III)) oxidation can decrease Sb toxicity, which contributes to the bioremediation of Sb contamination. Bacteria can oxidize Sb(III), but the current knowledge regarding Sb(III)-oxidizing bacteria (SbOB) is limited to pure culture studies, thus underestimating the diversity of SbOB. In this study, Sb(III)-oxidizing microcosms were set up using Sb-contaminated rice paddies as inocula. Sb(III) oxidation driven by microorganisms was observed in the microcosms. The increasing copies and transcription of the arsenate-oxidizing gene, aioA, in the microcosms during biotic Sb(III) oxidation indicated that microorganisms mediated Sb(III) oxidation via the aioA genes. Furthermore, a novel combination of DNA-SIP and shotgun metagenomic was applied to identify the SbOB and predict their metabolic potential. Several putative SbOB were identified, including Paracoccus, Rhizobium, Achromobacter, and Hydrogenophaga. Furthermore, the metagenomic analysis indicated that all of these putative SbOB contained aioA genes, confirming their roles in Sb(III) oxidation. These results suggested the concept of proof of combining DNA-SIP and shotgun metagenomics directly. In addition, the identification of the novel putative SbOB expands the current knowledge regarding the diversity of SbOB.
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http://dx.doi.org/10.1093/femsec/fiab057DOI Listing
March 2021

Investigation of the antimony fractions and indigenous microbiota in aerobic and anaerobic rice paddies.

Sci Total Environ 2021 Jun 26;771:145408. Epub 2021 Jan 26.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China. Electronic address:

The accumulation of antimony (Sb) by rice is a severe threat to exposed populations. Previous studies demonstrated that, compared to flooded (anaerobic) water management, dry cultivation management (aerobic) could substantially decrease As, an analog of Sb, uptake by rice. However, the effects of different water management strategies on the accumulation of Sb by rice are less understood. It is proposed that microorganisms play an important role in regulating Sb mobility in rice paddies. Hence, the current study compared the microbial communities in rice paddies receiving different water management, i.e., flooded (anaerobic) and dry (aerobic)) rice cultivation. Significant decrease in Sb uptake by rice, in both the roots and grains, was observed under the aerobic compared to the anaerobic conditions. This could partially be attributed to the differences in the microbial communities as shaped by the redox environment. In aerobic soils, the gene responsible for Sb oxidation (i.e., aioA) was significantly, while in anaerobic soils the gene responsible for Sb reduction (i.e., arrA) was enriched, suggesting that variation in redox conditions may trigger different microbial responses. Accordingly, geochemical analysis indicated that accumulation of Sb(III) was only observed under anaerobic conditions, but not under aerobic conditions. The environment-microbe interactions were distinct between the two treatments with a greater number of interactions between Sb fractions and the microbial assemblage under anaerobic conditions, while Eh was the most influential geochemical parameter under aerobic conditions. Finally, the presence of a core microbiome under the two conditions suggested the possibility of microorganisms that support rice growth, nutrition, and health. The reduction of Sb in rice grain significantly decreases Sb exposure to the residents in Sb contaminated regions, and should be considered for future rice cultivation practices.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145408DOI Listing
June 2021

Influence of probe geometry on the characteristics of optical fiber gas-liquid two-phase flow measurement signals.

Appl Opt 2021 Feb;60(6):1660-1666

A conical tip-shaped plastic optical fiber sensor for gas-liquid flow measurement is described. Experimental results show that a distinctive spike signal occurs before the output signal when using a conventional conical fiber probe, whereas this spike signal was greatly suppressed when a cleaved probe is used. A full simulation is implemented based on a three-dimensional ray-tracing method providing a means of comparison with theoretical analysis. The results show that an appropriately cleaved tip provides a promising method of enhancing the bubble measurement signal-to-noise ratio.
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http://dx.doi.org/10.1364/AO.414041DOI Listing
February 2021

Efficient reduction of antimony by sulfate-reducer enriched bio-cathode with hydrogen production in a microbial electrolysis cell.

Sci Total Environ 2021 Feb 8;774:145733. Epub 2021 Feb 8.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China.

Bio-cathode Microbial electrolysis cell (MEC) is a promising and eco-friendly technology for concurrent hydrogen production and heavy metal reduction. However, the bioreduction of Antimony (Sb) in a bio-electrochemical system with H production is not explored. In this study, two efficient sulfate-reducing bacterial (SRB) strains were used to investigate the enhanced bioreduction of sulfate and Sb with H production in the MEC. SRB Bio-cathode MEC was developed from the microbial fuel cell (MFC) and operated with an applied voltage of 0.8 V. The performance of the SRB bio-cathode was confirmed by cyclic voltammetry, linear sweep voltammetry and electrochemical impedance spectroscopy. SRB strains of BY7 and SR10 supported the synergy reduction of sulfate and Sb by sulfide metal precipitation reaction. Hydrogen gas was the main product of SRB bio-cathode, with 86.9%, and 83.6% of H is produced by SR10 and BY7, respectively. Sb removal efficiency reached up to 88.2% in BY7 and 96.3% in SR10 with a sulfate reduction rate of 92.3 ± 2.6 and 98.4 ± 1.6 gmd in BY7 and SR10, respectively. The conversion efficiency of Sb (V) to Sb (III) reached up to 70.1% in BY7 and 89.2% in SR10. It was concluded that the total removal efficiency of Sb relies on the amount of sulfide concentration produced by the sulfate reduction reaction. The hydrogen production rate was increased up to 1.25 ± 0.06 (BY7) and 1.36 ± 0.02 m H/(m·d) (SR10) before addition of Sb and produced up to 0.893 ± 0.03 and 0.981 ± 0.02 mH/(m·d) after addition of Sb. The precipitates were characterized by X-ray diffraction and X-ray photoelectron spectroscopy, which confirmed Sb (V) was reduced to SbS.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145733DOI Listing
February 2021

Profiling of Microbial Communities in the Sediments of Jinsha River Watershed Exposed to Different Levels of Impacts by the Vanadium Industry, Panzhihua, China.

Microb Ecol 2021 Feb 12. Epub 2021 Feb 12.

School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China.

The mining, smelting, manufacturing, and disposal of vanadium (V) and associated products have caused serious environmental problems. Although the microbial ecology in V-contaminated soils has been intensively studied, the impacted watershed ecosystems have not been systematically investigated. In this study, geochemistry and microbial structure were analyzed along ~30 km of the Jinsha River and its two tributaries across the industrial areas in Panzhihua, one of the primary V mining and production cities in China. Geochemical analyses showed different levels of contamination by metals and metalloids in the sediments, with high degrees of contamination observed in one of the tributaries close to the industrial park. Analyses of the V4 hypervariable region of 16S rRNA genes of the microbial communities in the sediments showed significant decrease in microbial diversity and microbial structure in response to the environmental gradient (e.g., heavy metals, total sulfur, and total nitrogen). Strong association of the taxa (e.g., Thauera, Algoriphagus, Denitromonas, and Fontibacter species) with the metals suggested selection for these potential metal-resistant and/or metabolizing populations. Further co-occurrence network analysis showed that many identified potential metal-mediating species were among the keystone taxa that were closely associated in the same module, suggesting their strong inter-species interactions but relative independence from other microorganisms in the hydrodynamic ecosystems. This study provided new insight into the microbe-environment interactions in watershed ecosystems differently impacted by the V industries. Some of the phylotypes identified in the highly contaminated samples exhibited potential for bioremediation of toxic metals (e.g., V and Cr).
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http://dx.doi.org/10.1007/s00248-021-01708-9DOI Listing
February 2021

Stable-isotope probing coupled with high-throughput sequencing reveals bacterial taxa capable of degrading aniline at three contaminated sites with contrasting pH.

Sci Total Environ 2021 Jun 27;771:144807. Epub 2021 Jan 27.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China. Electronic address:

The biodegradation of aniline is an important process related to the attenuation of aniline pollution at contaminated sites. Aniline contamination could occur in various pH (i.e., acidic, neutral, and alkaline) environments. However, little is known about preferred pH conditions of diverse aniline degraders at different sites. This study investigated the active aniline degraders present under contrasting pH environments using three aniline-contaminated cultures, namely, acidic sludge (ACID-S, pH 3.1), neutral river sediment (NEUS, pH 6.6), and alkaline paddy soil (ALKP, pH 8.7). Here, DNA-based stable isotope probing coupled with high-throughput sequencing revealed that aniline degradation was associated with Armatimonadetes sp., Tepidisphaerales sp., and Rhizobiaceae sp. in ACID-S; Thauera sp., Zoogloea sp., and Acidovorax sp. in NEUS; Delftia sp., Thauera sp., and Nocardioides sp. in ALKP. All the putative aniline-degrading bacteria identified were present in the "core" microbiome of these three cultures; however, only an appropriate pH may facilitate their ability to metabolize aniline. In addition, the biotic interactions between putative aniline-degrading bacteria and non-direct degraders showed different characteristics in three cultures, suggesting aniline-degrading bacteria employ diverse survival strategies in different pH environments. These findings expand our current knowledge regarding the diversity of aniline degraders and the environments they inhabit, and provide guidance related to the bioremediation of aniline contaminated sites with complex pH environments.
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http://dx.doi.org/10.1016/j.scitotenv.2020.144807DOI Listing
June 2021

Inhibition of ULK1 promotes the death of leukemia cell in an autophagy irrelevant manner and exerts the antileukemia effect.

Clin Transl Med 2021 Jan;11(1):e282

The Second Affiliated Hospital, The State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Guangzhou, China.

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http://dx.doi.org/10.1002/ctm2.282DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7803353PMC
January 2021

Solar-driven, self-sustainable electrolysis for treating eutrophic river water: Intensified nutrient removal and reshaped microbial communities.

Sci Total Environ 2021 Apr 24;764:144293. Epub 2020 Dec 24.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China. Electronic address:

River ecosystems are the most important resource of surface freshwater, but they have frequently been contaminated by excessive nutrient input of nitrogen (N) and phosphorus (P) in particular. An efficient and economic river water treatment technology that possesses the capacity of simultaneous N and P removal is urgently required. In this study, a solar-driven, self-sustainable electrolytic treatment was conducted in situ to intensify N and P removal from eutrophic river water. Solar panel was applied to provide the electrolysis setups with energy (voltage 10 ± 0.5 V), and the current density was controlled to be 0.06 ± 0.02 mA cm. Results indicated that the average removal efficiencies of total N (TN) and total P (TP) under electrolysis conditions reached 72.4 ± 11.7 and 13.8 ± 5.3 mg m d, which were 3.7- and 4.7-fold higher compared to untreated conditions. Enhanced TN removal mainly reflected the abatement of nitrate N (NO-N) (80.6 ± 4.1%). The formation of ferric ions through the electro-dissolution of the sacrificial iron anode improved TP removal by coprecipitation with SPS. Combined high-throughput sequencing and statistical analyses revealed that electrolysis significantly reshaped the microbial communities in both the sediment-water interface and suspended sediment (SPS), and hydrogenotrophic denitrifiers (e.g., Hydrogenophaga) were highly enriched under electrolysis conditions. These findings indicated that in situ electrolysis is a feasible and effective technology for intensified nutrient removal from river water.
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http://dx.doi.org/10.1016/j.scitotenv.2020.144293DOI Listing
April 2021

Highly sensitive strain sensor based on a long-period fiber grating with chain-shaped structure.

Appl Opt 2020 Nov;59(33):10278-10282

In this paper, a novel chain-shaped long-period fiber grating (CS-LPFG) for strain measurement is investigated and experimentally demonstrated. This structure is achieved by polishing periodic slant planes on a single-mode fiber with a high-frequency laser. The chain-shaped structures improved the strain sensitivity of the sensor while shortening the length of the sensing unit. Experimental results show that the strain sensitivity of CS-LPFG is 34.8 pm/µε in the range of 0-650 µε, and the total length of the sensing unit is significantly reduced to 7.5 mm. Meanwhile, the temperature-strain cross talk is 1.6 µε/°C, which is much lower than that of most fiber strain sensors.
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http://dx.doi.org/10.1364/AO.404861DOI Listing
November 2020

Microbiome-environment interactions in antimony-contaminated rice paddies and the correlation of core microbiome with arsenic and antimony contamination.

Chemosphere 2021 Jan 3;263:128227. Epub 2020 Sep 3.

Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou, 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, 510650, China. Electronic address:

Mining activities of antimony (Sb) and arsenic (As) typically result in severe environmental contamination. These contaminants accumulate in rice and thus threaten the health of local residents, who consume Sb- and As-enriched rice grains. Microorganisms play a critical role in the transformation and transportation of Sb and As in paddy soil. Thus, an understanding of the microbiology of contaminated sites would promote the production of safe agricultural products. In this study, six Sb- and As-contaminated rice fields near an active Sb-mining area were investigated. The Sb and As concentrations of all samples were elevated compared to the background level in China. Nitrate, total As, total Sb, and Fe(III) were the major determinants of the microbial community structure. Seven bacterial taxa (i.e. Bradyrhizobium, Bryobacter, Candidatus Solibacter, Geobacter, Gemmatimonas, Halingium, and Sphingomonas) were identified as the core microbiome. These taxa were strongly correlated with the As and Sb contaminant fractions and likely to metabolize As and Sb. Results imply that many soil microbes can survival in the Sb/As contaminated sites.
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http://dx.doi.org/10.1016/j.chemosphere.2020.128227DOI Listing
January 2021

Root microbiome assembly of As-hyperaccumulator Pteris vittata and its efficacy in arsenic requisition.

Environ Microbiol 2020 Nov 3. Epub 2020 Nov 3.

State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.

The assemblage of root-associated microorganisms plays important roles in improving their capability to adapt to environmental stress. Metal(loid) hyperaccumulators exhibit disparate adaptive capability compared to that of non-hyperaccumulators when faced with elevated contents of metal(loid)s. However, knowledge of the assemblage of root microbes of hyperaccumulators and their ecological roles in plant growth is still scarce. The present study used Pteris vittata as a model plant to study the microbial assemblage and its beneficial role in plant growth. We demonstrated that the assemblage of microbes from the associated bulk soil to the root compartment was based on their lifestyles. We used metagenomic analysis and identified that the assembled microbes were primarily involved in root-microbe interactions in P. vittata root. Notably, we identified that the assembled root microbiome played an important role in As requisition, which promoted the fitness and growth of P. vittata. This study provides new insights into the root microbiome and potential valuable knowledge to understand how the root microbiome contributes to the fitness of its host.
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http://dx.doi.org/10.1111/1462-2920.15299DOI Listing
November 2020

Thallium shifts the bacterial and fungal community structures in thallium mine waste rocks.

Environ Pollut 2021 Jan 27;268(Pt A):115834. Epub 2020 Oct 27.

Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China. Electronic address:

Thallium (Tl) is a highly toxic metalloid and is considered a priority pollutant by the US Environmental Protection Agency (EPA). Currently, few studies have investigated the distribution patterns of bacterial and fungal microbiomes in Tl-impacted environments. In this study, we used high-throughput sequencing to assess the bacterial and fungal profiles along a gradient of Tl contents in Tl mine waste rocks in southwestern China. Our results showed that Tl had an important, but different influence on the bacterial and fungal diversity indices. Using linear regression analysis, we furtherly divided the dominant bacterial and fungal groups into three distinct microbial sub-communities thriving at high, moderate, and low levels of Tl. Furthermore, our results also showed that Tl is also an important environmental variable that regulates the distribution patterns of ecological clusters and indicator genera. Interestingly, the microbial groups enriched in the samples with high Tl levels were mainly involved in metal and nutrient cycling. Taken together, our results have provided useful information about the responses of bacterial and fungal groups to Tl contamination.
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http://dx.doi.org/10.1016/j.envpol.2020.115834DOI Listing
January 2021

V Reduction by spp. in Vanadium Mine Tailings.

Environ Sci Technol 2020 11 30;54(22):14442-14454. Epub 2020 Oct 30.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.

Vanadium (V) is an important metal with critical industrial and medical applications. Elevated V contamination, however, can be a threat to the environment and human health. Microorganisms can reduce the more toxic and mobile V to the less toxic and immobile V, which could be a detoxification and energy metabolism strategy adopted by V-reducing bacteria (VRB). The limited understanding of microbial responses to V contamination and the mechanisms for V reduction, however, hamper our capability to attenuate V contamination. This study focused on determining the microbial responses to elevated V concentration and the mechanisms of V reduction in V tailings. The bacterial communities were characterized and compared between the V tailings and the less contaminated adjacent mineral soils. Further, V-reducing enrichments indicated that bacteria associated with , a genus belonging to the family , were potentially responsible for V reduction. Retrieved metagenome-assembled genomes (MAGs) suggested that the spp. encoded genes (, , and ) were responsible for V reduction. Additionally, spp. was metabolically versatile and could use both organic and inorganic electron donors. The metabolic versatility of spp. may be important for its ability to flourish in the V tailings.
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http://dx.doi.org/10.1021/acs.est.0c05328DOI Listing
November 2020

Optical fiber sensor based on a cholesteric liquid crystal film for mixed VOC sensing.

Opt Express 2020 Oct;28(21):31872-31881

This paper proposes a novel cholesteric liquid crystal (CLC) film-based dual-probe fiber sensor to monitor volatile organic compound (VOC) gas. The sensor consists of a 2×2 multimode fiber coupler, in which the two output fiber ends are covered by two types of CLC films (CLCF) with different pitches. It can be observed that the reflection peak wavelengths of CLCs shift to the red side as the VOC gas concentration increases. The sensitivities of the two CLCFs are 8.435 nm·L/mmol and 14.867 nm·L/mmol to acetone, 14.586 nm·L/mmol and 29.303 nm·L/mmol to ethanol, respectively. In addition, the dependence of the peak wavelength shift of CLCF on the total concentration of the acetone and ethanol mixed gas at different mixing ratios is measured. The linear relationships between the peak shift of CLCFs, the total mixed gas concentration and acetone/ethanol ratio are calculated using the least-squares method. Therefore, this proposed dual-probe fiber optic sensor can distinguish the concentrations of acetone and ethanol in a mixed gas of acetone and ethanol.
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http://dx.doi.org/10.1364/OE.405627DOI Listing
October 2020

Few-mode fiber-embedded long-period fiber grating for simultaneous measurement of refractive index and temperature.

Appl Opt 2020 Oct;59(29):9248-9253

A few-mode fiber (FMF)-embedded long-period fiber grating is proposed as a sensor for simultaneous measurement of refractive index and temperature. Periodically embedding the FMFs induces the local refractive index modulation to achieve a compact sensor size and obtains a low insertion loss. The simulated results show that the two resonance dips have opposite waveguide dispersion coefficients. Therefore, they show different refractive indices and temperature sensitivities in the experiment. At the same time, the spectral characteristics of double-resonance dips provides a condition for simultaneous measurement of two parameters. By monitoring wavelength shift of the two dips, the simultaneous measurement of refractive index and temperature is easily realized.
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http://dx.doi.org/10.1364/AO.401444DOI Listing
October 2020

Investigation of the characteristics of a fiber-optic gas-liquid two-phase flow sensor.

J Opt Soc Am A Opt Image Sci Vis 2020 Oct;37(10):1687-1694

A laboratory-prepared wedge-shaped fiber probe using step-index multimode plastic optical fiber was described and tested in a lab-scale gas-liquid flow generator. A three-dimensional model was established in order to fully simulate the process of bubble piercing by the optical fiber probe. A theoretical analysis of the luminous intensity distribution of the light transmission in the process of bubble piercing was undertaken under conditions of different relative positions between the fiber probe and the bubble axis. Using this analytical method, it was possible to accurately define the range of the central region of the bubble where the presignal appeared.
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http://dx.doi.org/10.1364/JOSAA.401823DOI Listing
October 2020

Estimation of various radiological parameters associated with radioactive contents emanating with fly ash from Sahiwal coal-fuelled power plant, Pakistan.

Environ Monit Assess 2020 Oct 20;192(11):715. Epub 2020 Oct 20.

Optical Fibre Sensors Research Centre, University of Limerick, Castletroy, Limerick, V94 T9PX, Ireland.

The release of natural radioactive materials with the emission of fly ash as a result of coal burning in power generation plants is considered amongst the sources that elevate the technologically environmental radioactivity level. This research mainly concerns the assessment of various radiological parameters including excess lifetime cancer risk due to natural radioactive contents associated with fly ash emitted to the surrounding environment from the stack of 1320 Mw Sahiwal coal-fuelled power generation plant (CFPP). For this purpose, fifty-four soil samples were collected in a radius of 4 Km from CFPP and a highly background radiation-shielded HPGe system is used to measure radioactivity in the collected samples. The activity concentrations of radium-226, potassium-40, and thorium-232 in collected samples was found to be in the range of 20 to 138, 43 to 860, and 27 to 127 Bq/kg with average values of 66, 409, and 67 Bq/kg respectively. Activity concentrations of radium-226 and thorium-232 were observed significantly higher than UNSCEAR reported typical global average values. A significant decrease in the level of the aforementioned radionuclides in the collected soil samples was observed with increasing distance from the power plant, which is a clear indication for the elevation of radioactivity concentrations in the surrounding environment as a result of the operation of the CFPP. To assess the radiation dose delivered to the occupational workers and inhabitants living next to Sahiwal CFPP, absorbed γ-dose rate (D), outdoor annual effective dose rate (E), and excess lifetime cancer risk (ELCR) were estimated and these were found higher than the UNSCEAR recommended values of 59 nGy/h, 0.07 mSv/y, and 2.9 × 10 respectively. The outcome of this first systematic study is the assessment of potential radiological health risk to the occupational workers as well as the inhabitants living in the proximity of this CFPP.
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http://dx.doi.org/10.1007/s10661-020-08669-5DOI Listing
October 2020

Microbial adaptation in vertical soil profiles contaminated by an antimony smelting plant.

FEMS Microbiol Ecol 2020 Oct;96(11)

Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, P.R. China.

Antimony mining has resulted in considerable pollution to the soil environment. Although studies on antinomy contamination have been conducted, its effects on vertical soil profiles and depth-resolved microbial communities remain unknown. The current study selected three vertical soil profiles (0-2 m) from the world's largest antimony mining area to characterize the depth-resolved soil microbiota and investigate the effects of mining contamination on microbial adaptation. Results demonstrated that contaminated soil profiles showed distinct depth-resolved effects when compared to uncontaminated soil profiles. As soil depth increased, the concentrations of antimony and arsenic gradually declined in the contaminated soil profiles. Acidobacteria, Chloroflexi, Proteobacteria and Thaumarchaeota were the most variable phyla from surface to deep soil. The co-occurrence networks were loosely connected in surface soil, but obviously recovered and were well-connected in deep soil. The metagenomic results indicated that microbial metabolic potential also changed with soil depth. Genes encoding C metabolism pathways were negatively correlated with antimony and arsenic concentrations. Abundances of arsenic-related genes were enriched by severe contamination, but reduced with soil depth. Overall, soil depth-resolved characteristics are often many meters deep and such effects affected the indigenous microbial communities, as well as their metabolic potential due to different contaminants along vertical depths.
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http://dx.doi.org/10.1093/femsec/fiaa188DOI Listing
October 2020

Fiber micro-tip temperature sensor based on cholesteric liquid crystal.

Opt Lett 2020 Sep;45(18):5209-5212

This Letter proposes and demonstrates a novel, miniature fiber-tip temperature sensor with a tapered hollow capillary tube (HCT) filled with glycerin and dye-doped cholesteric liquid crystal (CLC). The function of glycerin is to provide a surface anchoring force to control the uniform orientation of CLC molecules, so that the CLC in the tapered HCT can be considered as a mirrorless photonic bandgap (PBG) microcavity. An unambiguously identifiable PBG mode single peak appears in the emission spectra of the sensor. The CLC-based fiber-tip temperature sensor has a temperature sensitivity of -9.167/, and the figure of merit can reach 67.4. This sensor offers key features and advantages, including compactness, unambiguous identifiability, and biocompatibility, which can satisfy requirements of temperature measurement in various temperature sensing application fields and has great potential for biochemical detection at cell level. In addition, the CLC was integrated into the optical fiber terminal, and the PBG mode is excited, collected and transmitted by the multimode fiber coupler, which is reported for the first time, to the best of our knowledge.
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http://dx.doi.org/10.1364/OL.402473DOI Listing
September 2020

Pyridoxine induces monocyte-macrophages death as specific treatment of acute myeloid leukemia.

Cancer Lett 2020 11 26;492:96-105. Epub 2020 Aug 26.

The Second Affiliated Hospital, The State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Guangzhou, 510260, PR China. Electronic address:

Acute myeloid leukemia (AML) is an aggressive hematological malignancy that gradually develops resistance to current chemotherapy treatments. The available chemotherapy drugs show serious non-specific cytotoxicity to healthy normal cells, resulting in relapse and low survival rates. Natural small molecules with less toxicity and high selectivity for AML are urgently needed. In this study, we confirmed that pyridoxine (vitamin B6) selectively induces monocyte macrophages to undergo programmed cell death in two different modes: caspase-3-dependent apoptosis in U937 cells or GSDME-mediated pyroptosis in THP-1 cells. Further molecular analysis indicated that blocking the caspase pathway could switch the death to MLKL-dependent necroptosis and subsequent extensive inflammatory response. Pyridoxine also delayed the disease progression in a THP-1 leukemia mouse model. In addition, it induced the death of primary AML cells from AML patients by activating caspase-8/3. Overall, our results identify pyridoxine, a low-toxicity natural small molecule, as a potential therapeutic drug for AML treatment.
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http://dx.doi.org/10.1016/j.canlet.2020.08.018DOI Listing
November 2020

Aggregation kinetics of diesel soot nanoparticles in artificial and human sweat solutions: Effects of sweat constituents, pH, and temperature.

J Hazard Mater 2021 02 5;403:123614. Epub 2020 Aug 5.

Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangzhou, Guangdong, 510650, China; Agricultural Environmental Protection and Rural Energy Station, Department of Agriculture and Rural Affairs of Guangdong Province, Guangzhou, Guangdong, 510500, China.

Soot nanoparticles (SNPs) are airborne contaminants that could potentially penetrate skin, but their aggregation after contact with sweat may lower their health risks. This study investigated SNP aggregation kinetics in 4 artificial sweat standards and 21 human sweat samples. Effects of sweat inorganic (NaCl, NaHPO, and NaHPO) and organic (L-histidine, lactic acid, and urea) constituents, pH, temperature, and concentrations were examined. Results showed that SNP aggregation rates in 4 standards followed American Association of Textile Chemists and Colorists (AATCC) > British Standard (EN) > International Standard Organization (ISO) pH 5.5 > ISO pH 8.0, and could be described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The aggregation rates increased with concentrations of SNPs, inorganic salts, L-histidine, and lactic acid, decreased with increasing pH and concentration of urea, and were weakly influenced by temperature. Systematic characterizations revealed SNP adsorption for organic sweat constituents. SNPs aggregated rapidly to ∼1000 nm in AATCC, but remained stable in ISO pH 8.0 and > 14/21 human sweat fluids over 20 min. The SNP aggregation rates correlated negatively with pH (r = -0.531*) and |ζ potential| (r = -0.464*) of human sweat samples. Sweat evaporation could promote aggregation of SNPs, hence lowering their potential harm via dermal exposure.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123614DOI Listing
February 2021

Investigation of the Ecological Roles of Putative Keystone Taxa during Tailing Revegetation.

Environ Sci Technol 2020 09 25;54(18):11258-11270. Epub 2020 Aug 25.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China.

Metal contamination released from tailings is a global environmental concern. Although phytoremediation is a promising remediation method, its practice is often impeded by the adverse tailing geochemical conditions, which suppress biological activities. The ecosystem services provided by indigenous microorganisms could alter environmental conditions and facilitate revegetation in tailings. During the process, the keystone taxa of the microbial community are assumed an essential role in regulating the community composition and functions. The identity and the environmental functions of the keystone taxa during tailing revegetation, however, remain unelucidated. The current study compared the microbial community composition and interactions of two contrasting stibnite (SbS) tailings, one revegetated and one unvegetated. The microbial interaction networks and keystone taxa were significantly different in the two tailings. Similar keystone taxa were also identified in other revegetated tailings, but not in their corresponding unvegetated tailings. Metagenome-assembled genomes (MAGs) indicated that the keystone taxa in the revegetated tailing may use both organic and inorganic energy sources (e.g., sulfur, arsenic, and antimony). They could also facilitate plant growth since a number of plant-growth-promoting genes, including phosphorus solubilization and siderophore production genes, were encoded. The current study suggests that keystone taxa may play important roles in tailing revegetation by providing nutrients, such as P and Fe, and promoting plant growth.
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http://dx.doi.org/10.1021/acs.est.0c03031DOI Listing
September 2020

All fiber compact bending sensor with high sensitivity based on a multimode fiber embedded chirped long-period grating.

Opt Lett 2020 Aug;45(15):4172-4175

We investigated and prepared a chirped long-period grating for high sensitivity bending measurement. The novel fiber structure is composed of the multimode fiber (MMF) with fixed length and gradually longer single-mode fiber using the continuous splicing method. The powerful ability of refractive index modulation in the MMF renders the miniaturization of the sensor. The total length of the sensor is 3.45 mm. Chirped period arrangement is adopted to improve the bending sensitivity. Through numerical calculation, the chirp coefficient is determined, and the clear resonance peaks are obtained using the wavelength scanning. The experimental results of several samples show that the maximum bending sensitivity is 53.68/ at 0-1.803. With the advantages of small size and high sensitivity, the sensor is especially suitable for bending sensing with a micro-structure.
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http://dx.doi.org/10.1364/OL.396301DOI Listing
August 2020

Compact fiber strain sensor fabricated by a CO laser.

Opt Lett 2020 Aug;45(15):4156-4159

In this Letter, a novel, to the best of our knowledge, parallel inclined planes long period fiber grating (PIP-LPFG) for strain measurement is proposed. This structure is fabricated by a high frequency laser, which has polished periodic parallel inclined planes on a single mode fiber (SMF). Refractive index modulation (RIM) over a large area on the surface of the SMF significantly shortens the total length of the grating, and the structure of parallel inclined planes efficiently enhance the strain sensitivity of PIP-LPFG. Experimental results show that this LPFG with a miniature length of 3.9 mm has a good repeatability and stability of strain response, which can reach to 116 pm/µε in the dynamic range of 0-425 µε. Meanwhile, the temperature sensitivity of PIP-LPFG is 54.7 pm/°C in the dynamic range of 30-170°C.
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http://dx.doi.org/10.1364/OL.391593DOI Listing
August 2020

Correction: A liquid-crystal-based immunosensor for the detection of cardiac troponin I.

Analyst 2020 08;145(17):5951

Key Lab of In-fiber Integrated Optics, Ministry Education of China, Harbin Engineering University, Harbin 150001, China.

Correction for 'A liquid-crystal-based immunosensor for the detection of cardiac troponin I' by Chunli Xia et al., Analyst, 2020, 145, 4569-4575, DOI: 10.1039/D0AN00425A.
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http://dx.doi.org/10.1039/d0an90078hDOI Listing
August 2020

Multi-foci metalens for terahertz polarization detection.

Opt Lett 2020 Jul;45(13):3506-3509

We propose a reflective terahertz (THz) metalens with four focal points for polarization detection of THz beams. The metalens is composed of -shaped resonators with spatially variant orientations, a reflective gold layer, and a dielectric spacer between them. The polarization states of the focal points include left circular polarization, right circular polarization, an incident polarization state, and a polarization state whose major axis is rotated /4 in comparison with that of the incident polarization. The handedness, ellipticity, and major axis of the polarization state can be determined based on the light intensities of the focal points. The uniqueness of the designed device renders this technique very attractive for applications in compact THz polarization detection and information processing.
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http://dx.doi.org/10.1364/OL.395580DOI Listing
July 2020

Energy and environmental impact assessment of a passive remediation bioreactor for antimony-rich mine drainage.

Environ Sci Pollut Res Int 2020 Oct 25;27(28):35040-35050. Epub 2020 Jun 25.

National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China.

Industrial processes, such as smelting and mining, lead to antimony (Sb) contamination, which poses an environmental and human health risk. In this study, the energy consumption and environmental impacts of a passive biological treatment system were quantitatively evaluated using life cycle assessment (LCA), and the results were compared with that of an adsorption purification system. The results showed that the biosystem had a lower energy consumption compared with the adsorption system, with an energy savings of 27.39%. The environmental impacts of the bioreactor were also lower regarding acidification, ecotoxicity, carcinogens, climate change, resource depletion, and respiratory effects. The construction resulted in the most energy consumption (99%) for the passive bioreactor. Therefore, adopting environmentally friendly construction materials could make the biosystem a more energy-efficient option. Results demonstrated that the bioreactor in this research can have great potential for Sb mine drainage applications in terms of energy savings and environmental remediation without diminishing performance. The study findings can be useful for deciding the most energy effective process for mine drainage remediation. In addition, the identification of the energy and environmental impacts of the processes provide valuable information for the design of future systems that consume less materials and utilize new construction materials.
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http://dx.doi.org/10.1007/s11356-020-09816-8DOI Listing
October 2020

Characterization of Nitrate-Dependent As(III)-Oxidizing Communities in Arsenic-Contaminated Soil and Investigation of Their Metabolic Potentials by the Combination of DNA-Stable Isotope Probing and Metagenomics.

Environ Sci Technol 2020 06 2;54(12):7366-7377. Epub 2020 Jun 2.

Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China.

Arsenite (As(III)) oxidation has important environmental implications by decreasing both the mobility and toxicity of As in the environment. Microbe-mediated nitrate-dependent As(III) oxidation (NDAO) may be an important process for As(III) oxidation in anoxic environments. Our current knowledge of nitrate-dependent As(III)-oxidizing bacteria (NDAB), however, is largely based on isolates, and thus, the diversity of NDAB may be underestimated. In this study, DNA-stable isotope probing (SIP) with C-labeled NaHCO as the sole carbon source, amplicon sequencing, and shotgun metagenomics were combined to identify NDAB and investigate their NDAO metabolism. As(III) oxidation was observed in the treatment amended with nitrate, while no obvious As(III) oxidation was observed without nitrate addition. The increase in the gene copies of in the nitrate-amended treatment suggested that As(III) oxidation was mediated by microorganisms containing the genes. Furthermore, diverse putative NDAB were identified in the As-contaminated soil cultures, such as , , , and Burkholderiales-related bacteria. Metagenomic analysis further indicated that most of these putative NDAB contained genes for As(III) oxidation and nitrate reduction, confirming their roles in NDAO. The identification of novel putative NDAB expands current knowledge regarding the diversity of NDAB. The current study also suggests the proof of concept of using DNA-SIP to identify the slow-growing NDAB.
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http://dx.doi.org/10.1021/acs.est.0c01601DOI Listing
June 2020