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1.
Inorg Chem ; 63(17): 7705-7713, 2024 Apr 29.
Article in English | MEDLINE | ID: mdl-38620065

ABSTRACT

Herein, three In(III)-based metal-organic frameworks (In-MOFs) with different degrees of interpenetration (DOI), namely In-MOF-1, In-MOF-2, and In-MOF-3, constructed by In3+ and Y-shaped ligands 4,4',4″-s-triazine-2,4,6-triyltribenzoate (H3TATB), are successfully synthesized through the ionothermal/solvothermal method. Subsequently, three novel In-MOFs, including noninterpenetration polycatenation, 2-fold interpenetrated, and 4-fold interpenetrated structure, are employed as the platform for systematically investigating the separation efficiency of CO2/N2, CO2/CH4, and CO2/CH4/N2 mixture gas system. Among them, In-MOF-2 shows the highest CO2 uptake capacities at 298 K and simultaneously possesses the low adsorption enthalpy of CO2 (26.4 kJ/mol at low coverage), a feature desirable for low-energy-cost adsorbent regeneration. The CO2/N2 (v: v = 15/85) selectivity of In-MOF-2 reaches 37.6 (at 298 K and 1 bar), also revealing outstanding selective separation ability from flue gases and purifying natural gas, affording a unique robust separation material as it has moderate DOI and pore size. In-MOF-2 shows exceptional stability and feasibility to achieve reproducibility. Aperture adjustment makes In-MOF-2 a versatile platform for selectively capturing CO2 from flue gases or purifying natural gas.

2.
Environ Sci Pollut Res Int ; 31(17): 26141-26152, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38491241

ABSTRACT

Agricultural wastes, comprising cotton straw and livestock manure, can be effectively managed through aerobic co-composting. Nevertheless, the quality and microbial characteristics of co-composting products from different sources remain unclear. Therefore, this study utilized livestock manure from various sources in Xinjiang, China, including herbivorous sheep manure (G), omnivorous pigeon manure (Y), and pigeon-sheep mixture (GY) alongside cotton stalks, for a 40-day co-composting process. We monitored physicochemical changes, assessed compost characteristics, and investigated fungal community. The results indicate that all three composts met established composting criteria, with compost G exhibiting the fastest microbial growth and achieving the highest quality. Ascomycota emerged as the predominant taxon in three compost products. Remarkably, at the genus level, the biomarker species for G, Y, and GY are Petromyces and Cordyceps, Neurospora, and Neosartorya, respectively. Microorganisms play a pivotal role in organic matter degradation, impacting nutrient composition, demonstrating significant potential for the decomposition and transformation of compost components. Redundancy analysis indicates that potassium, total organic carbon, and C:N are key factors influencing fungal communities. This study elucidates organic matter degradation in co-composting straw and livestock manure diverse sources, optimizing treatment for efficient agricultural waste utilization and sustainable practices.


Subject(s)
Composting , Mycobiome , Animals , Sheep , Soil/chemistry , Manure/microbiology , Livestock , Gossypium
3.
Diagn Microbiol Infect Dis ; 108(4): 116172, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38340483

ABSTRACT

BACKGROUND: Tuberculosis (TB) infection remains a crucial global health challenge, with active tuberculosis (ATB) representing main infection source. MicroRNA (miRNA) has emerged as a potential diagnostic tool in this context. This study aims to identify candidate miRNAs for ATB diagnosis and explore their possible mechanisms. METHODS: Differentially expressed miRNAs in ATB were summarized in qualitative analysis. The diagnostic values of miRNAs for ATB subtypes were assessed by overall sensitivity, specificity, and area under the curve. Additionally, we conducted enrichment analysis on miRNAs and target genes. RESULTS: Over 100 differentially expressed miRNAs were identified, with miR-29 family being the most extensively studied. The miR-29 family demonstrated sensitivity, specificity, and area under the curve of 80 %, 80 % and 0.86 respectively for active pulmonary TB (PTB). The differentially expressed miR-29-target genes in PTB were enriched in immune-related pathways. CONCLUSIONS: The miR-29 family exhibits good diagnostic value for active PTB and shows association with immune process.


Subject(s)
MicroRNAs , Tuberculosis, Pulmonary , Tuberculosis , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Biomarkers , Tuberculosis/diagnosis , Tuberculosis, Pulmonary/diagnosis
4.
J Hazard Mater ; 468: 133794, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38368686

ABSTRACT

The tailings soil originating from an abandoned sulfur-iron mine in Sichuan Province, China, exhibits elevated concentrations of heavy metals (HMs) and possesses limited soil conservation capacity. Variability soil particle size fractions (PSFs) contributes to an increased risk of HMs ion migration. Existing research on HMs behavior has focused on the bulk soil scale, resulting in a dearth of comprehensive information concerning different particle sizes and colloid scales. We collected soil samples from upstream source (XWA), migration path (XWB), and downstream farmland (XWC) of an abandoned tailing and categorized into sand, silt, clay, colloid and dissolved, respectively. The investigation primarily aimed to elucidate the solid-liquid distribution trade-off strategies of soil HMs along migration pathway. Results show that PSFs composition predominantly influences HMs solid-liquid distribution. In the mining area, large particles serve as the principal component for HMs enrichment. However, along the migration pathway, the proportion of highly mobile fine particles increases, shifting HMs from solid to liquid phase. Furthermore, inorganic elements such as Mg, Al, and Fe influence on HMs distribution within PSFs through various reactions, whereas organic matter and glomalin-related soil protein (GRSP) also exert regulatory roles. Increasing the proportion of large particles can reduce the risk of HMs migration.

5.
Sci Total Environ ; 896: 166146, 2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37595914

ABSTRACT

Plant Volatile components are an ecological adaptation mechanism of plants that can reflect species differences and environment information where it is located. The alpine shrub Rosa sericea complex consists of several allied species, which are morphologically similar and difficult to distinguish, they are typical distribution along the elevation in the Himalayas and the Transverse Ranges. We selected two typical areas to find that the different species could be distinguished by their "green leaf volatile components" (GLV) composition as well as their geographical location, and it was evident that species with glands had higher sesquiterpene content. Correlation analysis revealed the relation between volatile components and ecology factors (climate factors, soil factors, phyllospheric microorganisms). Our study adds a new perspective and basis for the environmental adaptations of different species in the alpine shrub Rosa sericea complex from a chemical ecology perspective.


Subject(s)
Rosa , Species Specificity , Plant Leaves , Soil
6.
Biometrics ; 79(2): 1520-1533, 2023 06.
Article in English | MEDLINE | ID: mdl-34965306

ABSTRACT

''For how many days during the past 30 days was your mental health not good?" The responses to this question measure self-reported mental health and can be linked to important covariates in the National Health and Nutrition Examination Survey (NHANES). However, these count variables present major distributional challenges: The data are overdispersed, zero-inflated, bounded by 30, and heaped in 5- and 7-day increments. To address these challenges-which are especially common for health questionnaire data-we design a semiparametric estimation and inference framework for count data regression. The data-generating process is defined by simultaneously transforming and rounding (star) a latent Gaussian regression model. The transformation is estimated nonparametrically and the rounding operator ensures the correct support for the discrete and bounded data. Maximum likelihood estimators are computed using an expectation-maximization (EM) algorithm that is compatible with any continuous data model estimable by least squares. star regression includes asymptotic hypothesis testing and confidence intervals, variable selection via information criteria, and customized diagnostics. Simulation studies validate the utility of this framework. Using star regression, we identify key factors associated with self-reported mental health and demonstrate substantial improvements in goodness-of-fit compared to existing count data regression models.


Subject(s)
Mental Health , Models, Statistical , Humans , Nutrition Surveys , Self Report , Computer Simulation
7.
J Environ Manage ; 317: 115471, 2022 Sep 01.
Article in English | MEDLINE | ID: mdl-35751270

ABSTRACT

Terrestrial mosses are promising species to study concerning metal deposition, absorption, and soil fertility as moss biocrusts. However, acrocarpous moss, as a kind of terrestrial mosses, has not yet been well understood, both in environmental monitoring and ecological application, especially exposed to an abandoned pyrite mining. Herein, we investigated the concentrations of different heavy metals in soil underlying acrocarpous moss Campylopus schmidii at three distances from an abandoned pyrite mine tailings (0.5, 1, 2 km) by sampling analysis, as well as the accumulation properties of heavy metals in different parts of mosses and soil nutrients under intact mosses and moss-free layers. The results indicated that the soil we researched was heavily polluted by Cr, Cu, and Cd, which was 4.46, 4.18, and 1.77 times higher than the standard of risk screening values for soil environment quality in China. And there was a marked difference in the concentrations and distribution of heavy metals in mosses, with higher concentrations of Cr, Cu, Ni and Pb mainly in the ageing parts. In addition, mosses can effectively promote soil fertility. Compared with the bare soil without the moss layer, the total organic matter and total potassium concentrations of the soil covered by the intact moss layer were significantly increased, by 113.91% and 186.08% respectively. Correlation analysis indicated that similar pollution sources for Zn, Cd, Cu, and Pb, and the concentrations of these heavy metals in soil connected with the distance from the source of pollution. Overall, we expected that these findings could assess the greater potential of single native dominant moss species C.schmidii to act as biomonitors in specific pyrite mine tailings characterized by barren soil with strong acids (pH < 4.0) and polymetallic pollution. Meanwhile, our results revealed may serve as a possibility reference for similar areas and is recommended for developing a vegetative cover utilizing local acrocarpous mosses to achieve greening of degraded tailings in the future, as well as environmental management and protection.


Subject(s)
Bryophyta , Metals, Heavy , Soil Pollutants , Cadmium/analysis , China , Environmental Biomarkers , Environmental Monitoring/methods , Iron , Lead/analysis , Metals, Heavy/analysis , Risk Assessment , Soil/chemistry , Soil Pollutants/analysis , Sulfides
8.
Environ Res ; 208: 112621, 2022 05 15.
Article in English | MEDLINE | ID: mdl-34990612

ABSTRACT

Soil microbes play crucial roles in biochemical and geochemical processes in contaminated arable ecosystems. However, what factors determine the assembling process of soil bacterial community under multiple heavy metal (loid)s (HMs) stress and how communities respond to geochemical changes have rarely been understood. Therefore, a number of contaminated soils were sampled to explore the interactions among geochemical parameters, HMs and innate bacterial community. The results showed that soil biochemical activities were inhibited obviously with the increase of HMs. Significant differences were observed in bacterial composition and abundance in studied areas, with Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteria and Firmicutes governing the bacterial community structure. Redundancy analysis and variation partition analysis revealed that about 67.33% of the variation in bacterial assemblages could be explained by physiochemical parameters (21.59%), biochemical parameters (11.64%), toxic metal (loid)s (9.11%) and the interaction effect of these variables (24.99%), among which total-arsenic and moisture were the main factors. Spearman correlation analysis also demonstrated that dehydrogenase, moisture and TOC have a positive correlation with bacterial community structure with As-Cd-Pb gradient. Altogether, this study would provide a comprehensive relationship between major environmental factors and bacterial assemblages, which could offer some baseline data to investigate the mechanisms of how communities respond to physiochemical changes.


Subject(s)
Metals, Heavy , Soil Pollutants , Bacteria , Ecosystem , Metals, Heavy/analysis , Metals, Heavy/toxicity , Soil/chemistry , Soil Microbiology , Soil Pollutants/analysis , Soil Pollutants/toxicity
9.
Sci Total Environ ; 808: 151995, 2022 Feb 20.
Article in English | MEDLINE | ID: mdl-34856269

ABSTRACT

Miscanthus floridulus is a plant with high biomass and heavy metal tolerance, which is a good candidate for phytoremediation. It is essential to explore how to improve its remediation ability, especially the rhizosphere ecological characteristics which are significant for phytoremediation efficiency. Therefore, the heavy metals accumulation of M. floridulus, rhizosphere soil physicochemical properties, enzyme activities, and bacterial community of different distances from the tailing were measured, focusing on the relationship between phytoremediation ability and rhizosphere ecological characteristics. The results show that the stronger the phytoremediation ability is, the better is the soil environment, and the higher the coverage with plants. Soil rhizosphere environment and the phytoremediation ability are shaped by heavy metals. Rhizosphere microecology may regulate phytoremediation by improving soil nutrients and enzyme activities, alleviating heavy metal toxicity, changing rhizosphere microbial community structure, increasing beneficial microbial abundance, promoting heavy metals accumulation by plants. This study not only clarified the relationship between rhizosphere ecological factors, but also elucidated the phytoremediation regulatory mechanism. Some of microbial taxa might developed as biological bioinoculants, providing the possibility to promote the growth of plants with ecological restoration ability and improve the phytoremediation efficiency.


Subject(s)
Metals, Heavy , Soil Pollutants , Biodegradation, Environmental , Metals, Heavy/analysis , Rhizosphere , Soil , Soil Microbiology , Soil Pollutants/analysis
10.
Appl Ergon ; 99: 103638, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34768226

ABSTRACT

Advanced driver assistance systems (ADAS) can enhance road safety by sending warning signals to drivers. Multimodal signals are gaining attention in ADAS warning design because they offer redundant information that facilitates human-system communication. However, no consensus has been reached on which multimodal design offers optimal benefit to road safety. Icons iconically map the real world and are associated with fast recognition and response time. Therefore, this study aims to investigate whether visual and auditory icons will benefit the effectiveness of audiovisual multimodal warnings. Thirty-two participants (16 females) experienced four types of unimodal warnings (high and low mapping visual warnings and high and low mapping auditory warnings) and four types of audiovisual warnings (high mapping visual + high mapping auditory warning, low mapping visual + low mapping auditory warning, high mapping visual + low mapping auditory warning, and low mapping visual + high mapping auditory warning) in simulated driving conditions. Visual warnings are presented in a head-up display. Results showed that multimodal warnings outperformed unimodal warnings (i.e., modality effect). We found mapping effect in audiovisual warnings, but only high mapping auditory constituents benefited warning effectiveness. Eye movement results revealed that the high mapping constituents might distract drivers from the road. This study adds evidence that multimodal warnings can offer extra benefits to drivers and high mapping auditory signals should be included in multimodal warning design to achieve better driving performance.


Subject(s)
Accidents, Traffic , Automobile Driving , Attention , Computer Simulation , Eye Movements , Female , Humans , Reaction Time
11.
Sci Total Environ ; 802: 149899, 2022 Jan 01.
Article in English | MEDLINE | ID: mdl-34464792

ABSTRACT

A mass of tailings left by mineral exploitation have caused serious environmental pollution. Although many studies have shown that soil microorganisms have the potential to remediate environmental pollution, the interaction mechanism between microorganisms and the surrounding environment of tailings is still unclear. In this study, 15 samples around pyrite mine tailing were collected to explore the ecological effects of environmental factors on bacterial community. The results showed that most of the samples were acidic and contaminated by multiple metals. Cadmium (Cd), copper (Cu), nickel (Ni) migrated and accumulated to into downstream farmlands while chromium (Cr) was the opposite. Proteobacteria, Chloroflex and Actinobacteria were the dominant phyla. Soil pH, total phosphorus (TP), total nitrogen (TN), available potassium (AK), available phosphorus (AP), the bacteria abundance and diversity all gradually increased with the increase of the distance from the tailing. Invertase, acid phosphatase, total organic carbon (TOC), pH, TP and Cr were the main influencing factors to cause the variation of bacterial community. This work could help us to further understand the changes in soil microbial communities around pollution sources.


Subject(s)
Metals, Heavy , Soil Pollutants , China , Environmental Monitoring , Environmental Pollution , Metals, Heavy/analysis , Soil , Soil Microbiology , Soil Pollutants/analysis , Soil Pollutants/toxicity
12.
Nanomaterials (Basel) ; 11(8)2021 Jul 23.
Article in English | MEDLINE | ID: mdl-34443717

ABSTRACT

Optically transparent polyimide (PI) films with good dielectric properties and long-term sustainability in atomic-oxygen (AO) environments have been highly desired as antenna substrates in low earth orbit (LEO) aerospace applications. However, PI substrates with low dielectric constant (low-Dk), low dielectric dissipation factor (low-Df) and high AO resistance have rarely been reported due to the difficulties in achieving both high AO survivability and good dielectric parameters simultaneously. In the present work, an intrinsically low-Dk and low-Df optically transparent PI film matrix, poly[4,4'-(hexafluoroisopropylidene)diphthalic anhydride-co-2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane] (6FPI) was combined with a nanocage trisilanolphenyl polyhedral oligomeric silsesquioxane (TSP-POSS) additive in order to afford novel organic-inorganic nanocomposite films with enhanced AO-resistant properties and reduced dielectric parameters. The derived 6FPI/POSS films exhibited the Dk and Df values as low as 2.52 and 0.006 at the frequency of 1 MHz, respectively. Meanwhile, the composite films showed good AO resistance with the erosion yield as low as 4.0 × 10-25 cm3/atom at the exposure flux of 4.02 × 1020 atom/cm2, which decreased by nearly one order of magnitude compared with the value of 3.0 × 10-24 cm3/atom of the standard PI-ref Kapton® film.

13.
Ecotoxicol Environ Saf ; 220: 112368, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-34082243

ABSTRACT

A field investigation on the content of heavy metals in soils and dominant plants was conducted in three sites (A<0.5 km, B<1.0 km, C<1.5 km) with different distances of mine tailings. The spatial distribution of heavy metals and the accumulation in plants were compared, and the candidate species for ecosystem restoration were selected. The results indicated that the soil was polluted by chromium (Cr), Cadmium (Cd), copper (Cu), nickel (Ni) in varying degrees, which is 2.07, 2.60, 1.79, and 4.49 times higher than the Class-Ⅱ standard in China. The concentrate of Ni, Cd, and Zinc (Zn) increased, while Cr, Lead (Pb), and Cu decreased with the distance from the mine tailings. 73 species (34 families) were found and mainly herbaceous plants. The concentrate of Cd, Cu, Cr, and Ni in 29 dominant plants were measured and 66.67%, 21.43%, 100%, 47.62% plants exceeded the normal concentration range. Based on the comparative analysis of heavy metal content, bioconcentration factor, and translocation factor in plants, Polygonum capitatum has good phytoextraction ability, Boehmeria nivea, Chrysanthemum indicum, Miscanthus floridulus, Conyza canadensis, Rubus setchuenensis, Senecio scandens, and Arthraxon hispidus showed remarkable phytostabilization abilities of Cr, Cd, Ni, and Cu, which can be used as potential phytoremediation candidate.


Subject(s)
Metals, Heavy/metabolism , Mining , Plants/metabolism , Soil Pollutants/metabolism , Bioaccumulation , Biodegradation, Environmental , China , Metals, Heavy/analysis , Plants/classification , Soil/chemistry , Soil Pollutants/analysis
14.
J Hazard Mater ; 416: 125814, 2021 08 15.
Article in English | MEDLINE | ID: mdl-33866290

ABSTRACT

Pleurotus has great potential for heavy metal mycoremediation. Using comparative transcriptome analysis, the response of Pleurotus ostreatus and Pleurotus cornucopiae under Cd contamination was evaluated. P. ostreatus and P. cornucopia accumulated 0.34 and 0.46 mg/g Cd in mycelium, respectively. Cd removal elevated with its concentration elevation, which reached 56.47% and 54.60% for P. ostreatus and P. cornucopia with Cd at 20 mg/L. Low-level Cd (≤ 1 mg/L) had no significant influence on either fungus, while varied response was observed under high-level Cd. 705 differentially expressed genes (DEGs) were identified in P. cornucopia at Cd1 and Cd20, whereas 12,551 DEGs in P. ostreatus. Differentially regulated functional categories and pathways were also identified. ATP-binding cassette transporters were involved in Cd transport in P. cornucopia, whereas the endocytosis and phagosome pathways were more enhanced in P. ostreatus. 26 enzymes including peroxisomal enzymes catalase and superoxide dismutase were upregulated in P. ostreatus, whereas only cytosolic catalase was overexpressed in P. cornucopia, suggesting their different Cd detoxification pathways. Also, the mitogen-activated protein kinase signaling pathway involved in Cd resistance in both species instead of glutathione metabolism, although more active in P. ostreatus. These findings provided new insight into the molecular mechanism of mycoremediation and accumulator screening.


Subject(s)
Pleurotus , Cadmium/toxicity , Catalase , Gene Expression Profiling , Pleurotus/genetics
15.
Nanomaterials (Basel) ; 11(1)2021 Jan 08.
Article in English | MEDLINE | ID: mdl-33435592

ABSTRACT

For the development of spacecraft with long-servicing life in low earth orbit (LEO), high-temperature resistant polymer films with long-term atomic oxygen (AO) resistant features are highly desired. The relatively poor AO resistance of standard polyimide (PI) films greatly limited their applications in LEO spacecraft. In this work, we successfully prepared a series of novel AO resistant PI composite films containing nanocaged polyhedral oligomeric silsesquioxane (POSS) components in both the PI matrix and the fillers. The POSS-containing PI matrix film was prepared from a POSS-substituted aromatic diamine, N-[(heptaisobutyl-POSS)propyl]-3,5-diaminobenzamide (DABA-POSS) and a common aromatic diamine, 4,4'-oxydianline (ODA) and the aromatic dianhydride, pyromellitic dianhydride (PMDA) by a two-step thermal imidization procedure. The POSS-containing filler, trisilanolphenyl POSS (TSP-POSS) was added with the fixed proportion of 20 wt% in the final films. Incorporation of TSP-POSS additive apparently improved the thermal stability, but decreased the high-temperature dimensional stable nature of the PI composite films. The 5% weight loss temperature (T5%) of POSS-PI-20 with 20 wt% of DABA-POSS is 564 °C, and its coefficient of linear thermal expansion (CTE) is 81.0 × 10-6/K. The former is 16 °C lower and the latter was 20.0 × 10-6/K higher than those of the POSS-PI-10 film (T5% = 580 °C, CTE = 61.0 × 10-6/K), respectively. POSS components endowed the PI composite films excellent AO resistance and self-healing characteristics in AO environments. POSS-PI-30 exhibits the lowest AO erosion yield (Es) of 1.64 × 10-26 cm3/atom under AO exposure with a flux of 2.51 × 1021 atoms/cm2, which is more than two orders of magnitude lower than the referenced PI (PMDA-ODA) film. Inert silica or silicate passivation layers were detected on the surface of the PI composite films exposed to AO.

16.
Polymers (Basel) ; 12(12)2020 Nov 30.
Article in English | MEDLINE | ID: mdl-33265995

ABSTRACT

The relatively poor atomic-oxygen (AO) resistance of the standard polyimide (PI) films greatly limits the wide applications in low earth orbit (LEO) environments. The introduction of polyhedral oligomeric silsesquioxane (POSS) units into the molecular structures of the PI films has been proven to be an effective procedure for enhancing the AO resistance of the PI films. In the current work, a series of POSS-substituted poly (pyromellitic anhydride-4,4'-oxydianiline) (PMDA-ODA) films (POSS-PI) with different POSS contents were synthesized via a POSS-containing diamine, N-[(heptaisobutyl-POSS)propyl]-3,5-diaminobenzamide (DABA-POSS). Subsequently, the effects of the molecular structures on the thermal, tensile, optical, and especially the AO-erosion behaviors of the POSS-PI films were investigated. The incorporation of the latent POSS substituents decreased the thermal stability and the high-temperature dimensional stability of the pristine PI-0 (PMDA-ODA) film. For instance, the PI-30 film with the DABA-POSS content of 30 wt% in the film exhibited a 5% weight loss temperature (T5%) of 512 °C and a coefficient of linear thermal expansion (CTE) of 54.6 × 10-6/K in the temperature range of 50-250 °C, respectively, which were all inferior to those of the PI-0 film (T5% = 574 °C; CTE = 28.9 × 10-6/K). In addition, the tensile properties of the POSS-containing PI films were also deteriorated, to some extent, due to the incorporation of the DABA-POSS components. The tensile strength (TS) of the POSS-PI films decreased with the order of PI-0 > PI-10 > PI-15 > PI-20 > PI-25 > PI-30, and so did the tensile modulus (TM) and the elongations at break (Eb). PI-30 showed the TS, TM, and Eb values of 75.0 MPa, 1.55 GPa, and 16.1%, respectively, which were all lower than those of the PI-0 film (TS = 131.0 MPa, TM = 1.88 GPa, Eb = 73.2%). Nevertheless, the incorporation of POSS components obviously increased the AO resistance of the PI films. All of the POSS-PI films survived from the AO exposure with the total fluence of 2.16 × 1021 atoms/cm2, while PI-0 was totally eroded under the same circumstance. The PI-30 film showed an AO erosion yield (Es) of 1.1 × 10-25 cm3/atom, which was approximately 3.67% of the PI-0 film (Es = 3.0 × 10-24 cm3/atom). Inert silica or silicate passivation layers were detected on the surface of the POSS-PI films after AO exposure, which efficiently prevented the further erosion of the under-layer materials.

17.
IEEE Trans Biomed Circuits Syst ; 14(4): 903-917, 2020 08.
Article in English | MEDLINE | ID: mdl-32746358

ABSTRACT

Electrochemical micro-sensors made of nano-graphitic (NG) carbon materials could offer high sensitivity and support voltammetry measurements at vastly different temporal resolutions. Here, we implement a configurable CMOS biochip for measuring low concentrations of bio-analytes by leveraging these advantageous features of NG micro-sensors. In particular, the core of the biochip is a discrete-time ∆Σ modulator, which can be configured for optimal power consumption according to the temporal resolution requirements of the sensing experiments while providing a required precision of ≈ 13 effective number of bits. We achieve this new functionality by developing a design methodology using the physical models of transistors, which allows the operating region of the modulator to be switched on-demand between weak and strong inversion. We show the application of this configurable biochip through in-vitro measurements of dopamine with concentrations as low as 50 nM and 200 nM at temporal resolutions of 100 ms and 10 s, respectively.


Subject(s)
Electrochemical Techniques/instrumentation , Graphite/chemistry , Lab-On-A-Chip Devices , Dopamine/analysis , Equipment Design , Nanostructures/chemistry , Semiconductors
18.
ACS Omega ; 5(25): 15620-15630, 2020 Jun 30.
Article in English | MEDLINE | ID: mdl-32637838

ABSTRACT

The electronic and vibrational structures of trinickel metal string complexes [Ni3(dpa)4X2]1-,0,1+ (X = Cl, NCS) were investigated using both theoretical calculations and spectroscopic methods. We used the density functional theory (DFT) method B3LYP*-D3, including less exact exchange energy and the van der Waals interaction of metal ions, to obtain the geometries and vibrational structures, which were found to be in excellent agreement with the experimental data. The ground state of Ni3(dpa)4X2 is an antiferromagnetic (AF) singlet state, and the next state is a quintet state, which was detected using temperature-dependent Raman spectroscopy under a magnetic field. The vibrational structure of the quintet state is nearly identical to that of the AF state, according to the measured Raman spectra, except that the stretching of Ni-Cl is blue-shifted from 282.5 cm-1 in the AF state to 283.8 cm-1 in the quintet state. Two oxidized Ni3 complexes were found to have [Ni3]7+ cores, the doublet [Ni3(dpa)4]3+ without axial ligands and the quartet [Ni3(dpa)4X2]+. Complex [Ni3(dpa)4X2]-, which was produced from a reduction reaction by gold nanoparticles at room temperature, consists of a quartet state as the ground state and a doublet state lying nearby.

19.
Chem Commun (Camb) ; 56(59): 8285-8288, 2020 Jul 28.
Article in English | MEDLINE | ID: mdl-32573592

ABSTRACT

Broadband near-infrared CuInS2/ZnS quantum dots with up to 94.8% quantum yield were synthesized with fast precursor decomposition leading to monomer conversion improvement. In the mini-LED package, the device showed high power efficiency and stability was also demonstrated with a penetration test and vein imaging showing its potential biomedical application in the theranostics field.

20.
ACS Omega ; 4(3): 5327-5334, 2019 Mar 31.
Article in English | MEDLINE | ID: mdl-31459703

ABSTRACT

The facet-dependent redox reactions of diruthenium metal-string complexes by gold nanoparticles (AuNPs) are explored by using the surface-enhanced Raman scattering (SERS) technique. Gold nano-rhombic dodecahedrons (AuRDs), gold nanocubes (AuNCs), and gold octahedrons (AuOhs) with exclusive facets {110}, {100}, and {111}, respectively, were synthesized. These AuNPs linked face-to-face by metal-string complexes Ru2M(dpa)4Cl2 (dpa = dipyridyl amino, M = Ni, Cu) with chloride axial ligands serve as both SERS substrates and reducing agents in the reactions. We employ the diruthenium core in these complexes with multiple redox states to study the reduction ability of varied AuNP facets upon plasmonic excitation. In Ru2Ni(dpa)4Cl2, the Ru-Ru stretching mode νRu-Ru str. lies at 327 cm-1 on the SERS substrate AuOh, but this band shifts to 313 cm-1 on the AuRD and AuNC. The diruthenium moiety was reduced to [Ru2]4+ by the AuRD facet {110} and the AuNC {100}. The gold nanorods in the solution prepared with metal-string complexes bridging head-to-head on {111} facets were used for the SERS substrate. The SERS curves of the complexes in these self-assembled head-to-head rods display νRu-Ru str. at 327 cm-1, which is assigned to having an [Ru2]5+ core. Hence, facets {110} and {100} have a reduction reactivity greater than that of {111}. In Ru2Cu(dpa)4Cl2, the νRu-Ru str. is observed to lie at 312 cm-1 on AuRD, but shifts to 320 cm-1 on the AuNC and AuOh. In the latter cases, the diruthenium moiety was reduced to having a charge of 4+ with electronic configuration π*2δ*2, whereas the former case band at 312 cm-1 with a weaker Ru-Ru bonding is also attributed to [Ru2]4+ but with electron configuration π*4. π*4 lies at an energy greater than π*2δ*2. The electrochemical SERS spectra of diruthenium complexes were recorded to verify their oxidation states. Conclusively, these results yield the reduction reactivity of the following facet: {110} > {100} > {111}. According to the results of the redox reactions, the valence states of the diruthenium metal-string complexes are verified. In the [Ru2] n+ core, n = 4 π*4, 4 π*2δ*2, 5 π*2δ*, and 6 π*δ*, and the νRu-Ru str. is 312, 320, 327, and 337 cm-1, respectively.

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