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1.
Science ; 369(6506): 918-919, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32820111

Assuntos
Coloides
2.
Water Res ; 182: 116012, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32730996

RESUMO

Nanoparticle and microplastic (colloid) transport behaviors impact strategies for groundwater protection and remediation. Complex colloid transport behaviors of anionic nano- and micro-sized colloids have been previously elucidated via independent experiments in chemically-cleaned and amended granular media with grain sizes in the range of fine to coarse sand (e.g., 200-1000 µm). Such experiments show that under conditions where a repulsive barrier was present in colloid-collector interactions (unfavorable conditions), the distribution of retained colloids down-gradient from their source deviates from the exponential decrease expected from compounded loss across a series of collectors (grains). Previous experiments have not examined the impact of colloid size or granular media grain size on colloid distribution down-gradient from their source, particularly in streambed-equilibrated granular media. To address this gap, a field transport experiment in constructed wetland stream beds to distances up to 20 m were conducted for colloids ranging in size from micro to nano (60 nm-7 µm) in streambed-equilibrated pea gravel and sand (4200 and 420 µm mean grain sizes, respectively). All colloid sizes showed non-exponential (hyper-exponential) distributions from source, over meter scales in pea gravel versus cm scales reported for fine sand. Colloids in the ca. 1 µm size range were most mobile, as expected from mass transfer to surfaces and interaction with nanoscale heterogeneity. The distance over which non-exponential colloid distribution occurred increased with media grain size, which carries implications for the potential mechanism driving non-exponential colloid distribution from source, and for strategies to predict transport.


Assuntos
Nanopartículas , Plásticos , Coloides , Microplásticos , Tamanho da Partícula , Porosidade
3.
Nat Commun ; 11(1): 3658, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32694613

RESUMO

Biological systems organize multiple hierarchical structures in parallel, and create dynamic assemblies and functions by energy dissipation. In contrast, emerging artificial non-equilibrium self-assembling systems have remained relatively simplistic concerning hierarchical design, and non-equilibrium multi-component systems are uncharted territory. Here we report a modular DNA toolbox allowing to program transient non-equilibrium multicomponent systems across hierarchical length scales by introducing chemically fueled molecular recognition orchestrated by reaction networks of concurrent ATP-powered ligation and cleavage of freely programmable DNA building blocks. Going across hierarchical levels, we demonstrate transient side-chain functionalized nucleic acid polymers, and further introduce the concept of transient cooperative multivalency as a key to bridge length scales to pioneer fuel-driven encapsulation, self-assembly of colloids, and non-equilibrium transient narcissistic colloidal self-sorting on a systems level. The fully programmable and functionalizable DNA components pave the way to design chemically fueled 4D (3 space, 1 time) molecular multicomponent systems and autonomous materials.


Assuntos
Trifosfato de Adenosina/química , Bioengenharia/métodos , DNA/química , Nanotecnologia/métodos , Coloides , DNA Ligases/química , Desoxirribonucleases de Sítio Específico do Tipo II/química , Conformação de Ácido Nucleico , Polimerização , Polímeros/química
4.
Environ Sci Pollut Res Int ; 27(28): 35065-35077, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32583117

RESUMO

Understanding the behavior and fate of clay colloids in water-saturated porous media is critical to assess its environmental impact and potential risk since clay is commonly a carrier of many contaminants. Column experiments with four-packing configurations were designed to understand the coupled effects of column structural heterogeneity and the flow velocity on the transport and fate of kaolinite colloids in the saturated porous media. The results showed that the structural heterogeneity could have facilitated the transport of kaolinite colloids in saturated porous media. For the columns with strong heterogeneity, the preferential flow paths led to an early breakthrough of kaolinite. Only few kaolinite colloids were released with slow flow rate; however, the released peak concentration and release percentage of kaolinite colloids had further increased with the high flow velocity. In the layered column, there was significant kaolinite's retention at the interface where water passed from fine to coarse quartz sand. All results indicated that both flow rates and media characteristics played an important role in controlling kaolinite's fate and transport in porous media. A thorough understanding of these processes had an important significance for pollution control in subsurface natural environment where heterogeneous soil and variation in flow pattern are usually common.


Assuntos
Coloides , Caulim , Argila , Porosidade , Quartzo , Dióxido de Silício
5.
Environ Sci Pollut Res Int ; 27(25): 31872-31883, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32504431

RESUMO

Natural colloids (NCs) are ubiquities in aquatic environments, which play an important role in the fate and transport of metal elements. Combined with a multi-method analytical approach, this study investigates the spectral characteristics and the contamination of metals of NCs from the five tributaries of Poyang Lake and the lakes in Nanchang City. Results showed that NCs in river samples were characteristic by the smaller molecular weight, lower chromophoric dissolved organic matter (CDOM) concentration, higher aromaticity, and higher CDOM contribution to the organic carbon than those in lake samples. Based on the parallel factor analysis model, three fluorophores were identified, including two humic-like components (C1 and C2) and a protein-like component (C3). NCs in river and lake waters were dominant by the humic-like substance (C1) and the protein-like substance (C3), respectively, with the relatively high fluorescence intensity for all the fluorophores in lake samples. Furthermore, NCs from the river samples were primarily terrestrial NCs with a high degree of humification. The average detection frequency of metal elements was nearly 50% for both river and lake samples, whereas the concentrations of the metal elements were higher in lake samples. Principal component analysis (PCA) results showed that the contamination of the detected metals could divide into three categories, with relatively high concentrations of Ba, Pb, Zn, Al, Sr, and Fe in lake samples. Moreover, PCA results showed that NCs in lakes with higher values of the absorbance and fluorescence parameters were associated with the higher concentration of metal elements, revealing that the spectral characteristic could be the proxy indicator of the contamination of metal elements of NCs.


Assuntos
Lagos , Rios , China , Coloides , Análise Fatorial , Metais , Espectrometria de Fluorescência
6.
Nat Commun ; 11(1): 2670, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32471993

RESUMO

The assembly of active and self-propelled particles is an emerging strategy to create dynamic materials otherwise impossible. However, control of the complex particle interactions remains challenging. Here, we show that various dynamic interactions of active patchy particles can be orchestrated by tuning the particle size, shape, composition, etc. This capability is manifested in establishing dynamic colloidal bonds that are highly selective and directional, which greatly expands the spectrum of colloidal structures and dynamics by assembly. For example, we demonstrate the formation of colloidal molecules with tunable bond angles and orientations. They exhibit controllable propulsion, steering, reconfiguration as well as other dynamic behaviors that collectively reflect the bond properties. The working principle is further extended to the co-assembly of synthetic particles with biological entities including living cells, giving rise to hybrid colloidal molecules of various types, for example, a colloidal carrousel structure. Our strategy should enable active systems to perform sophisticated tasks in future such as selective cell treatment.


Assuntos
Coloides/química , Condutividade Elétrica , Interações de Partículas Elementares , Escherichia coli/química , Ciência dos Materiais/métodos , Estrutura Molecular , Nanoestruturas/química , Tamanho da Partícula , Leveduras/química
7.
Food Chem ; 328: 127082, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32464554

RESUMO

Acorn flour was used as a gluten-free ingredient to produce acorn muffins. Interaction effects between xanthan (X), carboxymethyl cellulose (CMC) and κ-carrageenan (κ-C) (0-0.3%) on the height and textural parameters of the formulated acorn flour muffins were investigated using a mixture design approach. Each studied parameter was optimized individually. Then, an optimal formulation giving a product with characteristics as close as possible to those of a wheat flour muffin sample was determined. Results revealed that addition of each hydrocolloid separately, or their ternary combination improved the muffin height. Optimal height value was predicted to reach 3.96 cm when using 26.8% X, 50.5% CMC and 22.7% κ-C. As regard to textural parameters (firmness, cohesiveness, springiness and adhesiveness), presence of the three hydrocolloids had an antagonistic effect. The best hydrocolloids mixture giving optimal height (3.92 cm), firmness (3.19 N) and adhesiveness (0.66 N) was that containing 20.5% X and 79.5% CMC.


Assuntos
Farinha/análise , Quercus/química , Carragenina/química , Coloides , Dieta Livre de Glúten , Humanos , Polissacarídeos Bacterianos/química
8.
Food Chem ; 326: 127009, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32438230

RESUMO

A rapid Surface Enhanced Raman Spectroscopy (SERS) method to detect SO2 in wine is presented, exploiting the preferential binding of silver nanoparticles (AgNPs) with sulfur-containing species. This interaction promotes the agglomeration of the AgNPs and inducing the formation of SERS "hot spots" responsible for SO2 signals enhancement. For increasing SO2 concentrations from 0 to100 mg/l in wine simulant, SERS intensity showed an increasing trend, following a Langmuir absorption function (R2 = 0.94). Due to the wine matrix variability, a standard additions method was then employed for quantitative analysis in red and white wines. This method does not require the SO2 separation but only a matrix pre-cleaning by solid phase extraction. The limit of detection (LOD) was defined for each wine tested, ranging from 0.6 mg/l to 9.6 mg/l. The results obtained were validated by comparison with the International Organization of Vine and Wine method (OIV-MA-AS323-04A).


Assuntos
Dióxido de Enxofre/análise , Vinho/análise , Coloides/química , Limite de Detecção , Nanopartículas Metálicas/química , Prata/química , Extração em Fase Sólida , Análise Espectral Raman
9.
Nat Commun ; 11(1): 2495, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427872

RESUMO

Colloidal crystal engineering with nucleic acid-modified nanoparticles is a powerful way for preparing 3D superlattices, which may be useful in many areas, including catalysis, sensing, and photonics. To date, the building blocks studied have been primarily based upon metals, metal oxides, chalcogenide semiconductors, and proteins. Here, we show that metal-organic framework nanoparticles (MOF NPs) densely functionalized with oligonucleotides can be programmed to crystallize into a diverse set of superlattices with well-defined crystal symmetries and compositions. Electron microscopy and small-angle X-ray scattering characterization confirm the formation of single-component MOF superlattices, binary MOF-Au single crystals, and two-dimensional MOF nanorod assemblies. Importantly, DNA-modified porphyrinic MOF nanorods (PCN-222) were assembled into 2D superlattices and found to be catalytically active for the photooxidation of 2-chloroethyl ethyl sulfide (CEES, a chemical warfare simulant of mustard gas). Taken together, these new materials and methods provide access to colloidal crystals that incorporate particles with the well-established designer properties of MOFs and, therefore, increase the scope of possibilities for colloidal crystal engineering with DNA.


Assuntos
Coloides/química , DNA/química , Estruturas Metalorgânicas/química , Nanopartículas/química , Cristalização , DNA/genética , Engenharia/métodos , Microscopia Eletrônica de Transmissão e Varredura/métodos , Nanopartículas/ultraestrutura , Nanotubos/química , Nanotubos/ultraestrutura , Tamanho da Partícula , Espalhamento a Baixo Ângulo , Prata/química , Difração de Raios X
10.
Chemosphere ; 255: 126912, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32408126

RESUMO

Nanoplastics (NPTs) are defined as colloids that originated from the unintentional degradation of plastic debris. To understand the possible risks caused by NPTs, it is crucial to determine how they are transported and where they may finally accumulate. Unfortunately, although most sources of plastic are land-based, risk assessments concerning NPTs in the terrestrial environmental system (soils, aquifers, freshwater sediments, etc.) have been largely lacking compared to studies concerning NPTs in the marine system. Furthermore, an important limitation of environmental fate studies is that the NPT models used are questionable in terms of their environmental representativeness. This study describes the fate of different NPT models in a porous media under unfavorable (repulsive) conditions, according to their physical and chemical properties: average hydrodynamic diameters (200-460 nm), composition (polystyrene with additives or primary polystyrene) and shape (spherical or polymorphic). NPTs that more closely mimic environmental NPTs present an inhomogeneous shape (i.e., deviating from a sphere) and are more deposited in a sand column by an order of magnitude. This deposition was attributed in part to physical retention, as confirmed by the straining that occurred for the larger size fractions. Additionally, different Derjaguin-Landau-Verwey-Overbeek (DLVO) models -the extended DLVO (XDLVO) and a DLVO modified by surface element integration (SEI) method-suggest that the environmentally relevant NPT models may alter its orientation to diminish repulsion from the sand surface and may find enough kinetic energy to deposit in the primary energetic minimum. These results point to the importance of choosing environmentally relevant NPT models.


Assuntos
Microplásticos/química , Modelos Químicos , Coloides , Água Subterrânea , Hidrodinâmica , Modelos Teóricos , Porosidade , Areia
11.
Zhonghua Shao Shang Za Zhi ; 36(5): 370-377, 2020 May 20.
Artigo em Chinês | MEDLINE | ID: mdl-32456374

RESUMO

Objective: To explore the influence of inhalation injury on fluid resuscitation of massive burn patients during shock stage. Methods: A total of 74 massive burn patients (65 males and 9 females, aged 21 to 65 years) admitted to the Second Affiliated Hospital of Air Force Medical University (n=57) and Yan'an University Affiliated Hospital (n=17) from May 2009 to December 2019 were enrolled in this retrospective cohort study. Patients were divided into inhalation injury group (n=56) and non-inhalation injury group (n=18) based on clinical symptoms, vital signs, and results of bronchofibroscopy. Then 26 patients in inhalation injury group and 13 patients in non-inhalation injury group were 1∶2 matched by case-control matching based on the difference of total burn surface area. The total fluid replacement coefficient, crystalloid replacement coefficient, colloid replacement coefficient, glucose input volume, ratio of crystalloid to colloid, urine volume, and cumulative ratio of input to output volume during the first 24 h post injury, the second 24 h post injury, and the third 24 h post injury, heart rate, respiratory rate, mean arterial pressure (MAP), and hematocrit (HCT) at post injury hour (PIH) 24, 48, and 72 were recorded and compared between the two groups. Data were statistically analyzed with analysis of variance for repeated measurement and Bonferroni correction, t test, Fisher's exact probability test, and Mann-Whitney U test. Results: (1) After matching, during the first to third 24 h post injury, the total fluid replacement coefficient and glucose input volume of patients in inhalation injury group were significantly higher than those in non-inhalation injury group (F=4.202, 10.671, P<0.05 or P<0.01). During the first, second, and third 24 h post injury, the total fluid replacement coefficient, crystalloid replacement coefficient, colloid replacement coefficient, and ratio of crystalloid to colloid were similar between the patients in two groups(t=-1.336, -1.452, -1.998; -0.148, 0.141, 0.561; 0.916, -0.046, -0.509; -1.024, 0.208, 0.081, P>0.05). During the first, second, and third 24 h post injury, the glucose input volume of patients in inhalation injury group were respectively (2 996±1 176), (2 659±1 030), and (2 680±1 509) mL, which were significantly higher than (2 125±898), (1 790±828), and (1 632±932) mL in non-inhalation injury group (t=-2.334, -2.639, -2.297, P<0.05). (2) After matching, in overall comparison between groups, during the first to third 24 h post injury, the urinary output volumes and cumulative ratios of input to output volume of patients in inhalation injury group were significantly lower or higher than those in non-inhalation injury group, respectively (F=12.158, 9.111, P<0.01). At PIH 24, 48, and 72, heart rate of patients in inhalation injury group were significantly higher than those in non-inhalation injury group (F=4.675, P<0.05). There were no statistically significant differences in heart rate, respiratory rate, MAP, and HCT between patients in the two groups at PIH 24 and 48 (t=-0.039, -1.688, 1.399, 1.299, -1.741, 0.754, -0.677, 0.037, P>0.05). During the first and second 24 h post injury, the urine volume and cumulative ratio of input to output volume of patients in inhalation injury group were respectively significantly lower and higher than those in non-inhalation injury group (t(urine volume)=2.421, 2.876, t(cumulative ratio of input to output volume)=-2.687、-2.943, P<0.05 or P<0.01). At PIH 72, the heart rate and HCT of patients in inhalation injury group ( (114±13) times/min, 0.42±0.06) were significantly higher than those in non-inhalation injury group ( (98±18) times/min, 0.38±0.06, t=-3.182, -2.123, P<0.05 or P<0.01), there were no statistically significant differences in respiratory rate and MAP between the patients in two groups (t=0.359, 1.722, P>0.05). During the third 24 h post injury, there were no statistically significant differences in urine volume and cumulative ratio of input to output volume between the patients in two groups (t=1.664, -1.895, P>0.05). Conclusions: The presence of inhalation injury can lead to increased fluid requirement in massive burn patients during shock stage. An appropriate increase of fluid volume in the fluid resuscitation of burn patients combined with inhalation injury would be beneficial for maintaining ideal urine output.


Assuntos
Queimaduras por Inalação/terapia , Queimaduras , Hidratação/métodos , Ressuscitação/métodos , Choque , Adulto , Idoso , Queimaduras por Inalação/complicações , Coloides , Feminino , Humanos , Exposição por Inalação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
12.
Ecotoxicol Environ Saf ; 199: 110754, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32446105

RESUMO

Antibiotics, a highly prevalent class of environmental organic pollutants, are becoming a matter of global concern. Clay minerals that are ubiquitous in subsurface environments may play an important role in the fate and transport of antibiotics. Taking ciprofloxacin (CIP) as a model antibiotic, this work explored the role of clay colloids (kaolinite and montmorillonite) on the adsorption and transport of CIP under different chemical solution conditions. The adsorption isotherms showed that montmorillonite colloids had a larger CIP sorption capacity than kaolinite colloids. The results of transport experiments indicated that montmorillonite colloids could promote CIP transport in saturated sand columns, but the addition of kaolinite colloids affected CIP mobility to a much smaller extent. The much stronger transport-enhancement effect of montmorillonite colloids was due to CIP adsorbed strongly to the colloids and desorption hysteresis of colloid-adsorbed CIP, likely stemming from the intercalation of this antibiotic in the interlayer of montmorillonite. Interestingly, transport of clay colloids increased with the increasing pH from 5.0 to 9.0; however, CIP transport decreased with the increasing pH in the presence of clay colloids. The observations were likely attributable to pH-dependent ciprofloxacin adsorption/desorption to clay minerals. Increasing the concentrations of NaCl and CaCl2 generally decreased the contaminant-mobilizing ability of montmorillonite colloids, mainly by increasing the aggregation of colloids and thus, decreasing the transport of colloid-adsorbed CIP. Moreover, under the test conditions (1 mM NaCl and pH 7.0), the presence of CIP inhibited the transport of clay colloids due to the increase in aggregate size of clay colloids with the addition of CIP. Overall, these findings suggest that clay colloids with high adsorption abilities for antibiotics in the subsurface environment may act as a carrier for certain antibiotic compounds.


Assuntos
Antibacterianos/análise , Ciprofloxacino/análise , Argila/química , Poluentes Ambientais/análise , Quartzo/química , Areia/química , Adsorção , Bentonita/química , Coloides , Caulim/química , Tamanho da Partícula , Porosidade , Soluções , Propriedades de Superfície
13.
Water Res ; 181: 115923, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32422451

RESUMO

Natural organic matter (NOM) can influence the toxicity and speciation of chromium (Cr) in subsurface through redox reactions and complexation. Under anoxic conditions, NOM can be reduced by microorganisms or geochemical reductants, and the reduced NOM (NOMred) represents a large reservoir of organic matter observed in anoxic sediments and water. While the current body of work has established the kinetic of Cr(VI) reduction by oxidized NOM (NOMox) under oxic conditions, much less is known about the rates and mechanisms of Cr(VI) reduction triggered by NOMred under anoxic conditions and the colloidal properties of the reaction products. This study provided new information regarding the NOMred-mediated Cr(VI) reduction and colloidal stability of reduced Cr(III) particles over a wide range of environmentally relevant anoxic conditions. We show that under dark anoxic conditions reduced humic acid (HAred) moieties (e.g., quinone) can quickly reduce Cr(VI) to Cr(III), and the reduced Cr(III) can subsequently complex with carboxyl groups of HA leading to the formation of stable HA-Cr(III) colloids. Rates of Cr(VI) reduction by HAred are 3-4 orders of magnitude higher than those by oxidized HA (HAox) due primarily to the higher reducing capacity of HAred. The stable HA-Cr(III) colloids are formed across a range of HA concentrations (8-150 mg C/L) and pH conditions (6-10) with hydrodynamic diameter in the range of 210-240 nm. Aberration-corrected scanning transmission electron microscopy (Cs-STEM) and X-ray photoelectron spectroscopy (XPS) confirmed that the particles are composed of HA-Cr(III). The high colloidal stability of HA-Cr(III) particles could be attributed to the enhanced electrosteric stabilization effect from free and adsorbed HA, which decreased particle aggregation. However, the presence of divalent cations (Ca2+ and Mg2+) promoted particle aggregation at pH 6. These new findings are valuable for our fundamental understanding of the fate and transport of Cr in organic-rich anoxic environments, which also have substantial implications for the development and optimization of subsurface Cr sequestration technology.


Assuntos
Cromo , Substâncias Húmicas , Coloides , Oxirredução
14.
Environ Sci Process Impacts ; 22(5): 1190-1200, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32250376

RESUMO

Surface adsorption of two commonly detected emerging contaminants, amlodipine (AMP) and carbamazepine (CBZ), onto model colloidal microplastics, natural organic matter (NOM), and fullerene nanomaterials have been investigated. It is found that AMP accumulation at these colloidal-aqueous interfaces is markedly higher than that of CBZ. Measurements of surface excess and particle zeta potential, along with pH-dependent adsorption studies, reveal a distinct influence of colloidal functional group on the adsorption properties of these pharmaceuticals. AMP shows a clear preference for a surface containing carboxylic group compared to an amine modified surface. CBZ, in contrast, exhibit a pH-dependent surface proclivity for both of these microparticles. The type of interactions and molecular differences with respect to structural rigidity and charge properties explain these observed behaviors. In this work, we also demonstrate a facile approach in fabricating uniform microspheres coated with NOM and C60 nanoclusters. Subsequent binding studies on these surfaces show considerable adsorption on the NOM surface but a minimal uptake of CBZ by C60. Adsorption induced colloidal aggregation was not observed. These findings map out the extent of contaminant removal by colloids of different surface properties available in the aquatic environment. The methodology developed for the adsorption study also opens up the possibility for further investigations into colloidal-contaminant interactions.


Assuntos
Fulerenos , Microplásticos , Adsorção , Coloides , Poluentes Ambientais , Modelos Teóricos , Plásticos , Propriedades de Superfície
15.
Medicine (Baltimore) ; 99(17): e19953, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32332678

RESUMO

Intra-operative fluid therapy (IFT) is the cornerstone of peri-operative management as it may significantly influence the treatment outcome. Therefore, we sought to evaluate nationwide clinical practice regarding IFT in Poland.A cross-sectional, multicenter, point-prevalence study was performed on April 5, 2018, in 31 hospitals in Poland. Five hundred eighty-seven adult patients undergoing non-cardiac surgery were investigated. The volume and type of fluids transfused with respect to the patient and procedure risk were assessed.The study group consisted of 587 subjects, aged 58 (interquartile range [IQR] 40-67) years, including 142 (24%) American Society of Anesthesiology Physical Status (ASA-PS) class III+ patients. The median total fluid dose was 8.6 mL kg h (IQR 6-12.5), predominantly including balanced crystalloids (7.0 mL kg h, IQR 4.9-10.6). The dose of 0.9% saline was low (1.6 mL kg h, IQR 0.8-3.7). Synthetic colloids were used in 66 (11%) subjects. The IFT was dependent on the risk involved, while the transfused volumes were lower in ASA-PS III+ patients, as well as in high-risk procedures (P < .05).The practice of IFT is liberal but is adjusted to the preoperative risk. The consumption of synthetic colloids and 0.9% saline is low.


Assuntos
Hidratação/normas , Cuidados Intraoperatórios/normas , Adulto , Idoso , Coloides/uso terapêutico , Estudos Transversais , Soluções Cristaloides/uso terapêutico , Feminino , Hidratação/métodos , Hidratação/estatística & dados numéricos , Humanos , Cuidados Intraoperatórios/métodos , Cuidados Intraoperatórios/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Polônia , Prevalência
16.
Environ Sci Pollut Res Int ; 27(17): 21692-21701, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32279272

RESUMO

The co-transport of pollutants with colloidal particles to lower depths of groundwater and porous environments has been demonstrated in many studies in recent three decades. Despite the numerous researches, all experimental and numerical studies of pollutant transfer in the presence of colloidal particles have been carried out in one dimension, which causes significant errors in this phenomenon. In this study, the two-dimensional transfer experiment of chromium in the presence of bentonite colloidal particles is done in saturated porous media. In order to conduct the experiment in two-dimensional conditions, the sampling was done in central and lateral of the last experiment column section. The results have been demonstrated that the transmission along the longitudinal direction is higher than lateral in the three tests of the transfer of chromium, bentonite, and chromium in the presence of bentonite colloidal particles at the beginning of the experiment, and due to completed mixing in the section, it reached to a constant value as lateral samples. While the presence of bentonite colloidal particles facilitates the transfer of chromium in both longitudinal and lateral directions, increasing the bentonite colloidal particle concentration causes more getting stuck of colloid particles between the sand grains and reduction of the chromium transfer in both longitudinal and lateral directions. So, it can be concluded that transfer in the lateral direction is lower in bentonite colloidal particles compared with chromium, and the reason is the bentonite colloidal particles getting stuck between sand grains, which is exacerbated by increasing the concentration of the bentonite. Also, due to the chromium co-transport with colloid particles in the fraction of chromium total transport, increasing the bentonite concentration causes decreasing the chromium lateral transfer.


Assuntos
Bentonita , Água Subterrânea , Cromo , Coloides , Porosidade
20.
Nat Biomed Eng ; 4(5): 518-530, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32313101

RESUMO

The detection and quantification of low-abundance molecular biomarkers in biological samples is challenging. Here, we show that a plasmonic nanoscale construct serving as an 'add-on' label for a broad range of bioassays improves their signal-to-noise ratio and dynamic range without altering their workflow and readout devices. The plasmonic construct consists of a bovine serum albumin scaffold with approximately 210 IRDye 800CW fluorophores (with a fluorescence intensity approximately 6,700-fold that of a single 800CW fluorophore), a polymer-coated gold nanorod acting as a plasmonic antenna and biotin as a high-affinity biorecognition element. Its emission wavelength can be tuned over the visible and near-infrared spectral regions by modifying its size, shape and composition. It improves the limit of detection in fluorescence-linked immunosorbent assays by up to 4,750-fold and is compatible with multiplexed bead-based immunoassays, immunomicroarrays, flow cytometry and immunocytochemistry methods, and it shortens overall assay times (to 20 min) and lowers sample volumes, as shown for the detection of a pro-inflammatory cytokine in mouse interstitial fluid and of urinary biomarkers in patient samples.


Assuntos
Bioensaio/métodos , Corantes Fluorescentes/química , Nanopartículas/química , Animais , Células da Medula Óssea/citologia , Linhagem Celular Tumoral , Coloides/química , Células Dendríticas/citologia , Feminino , Citometria de Fluxo , Fluorescência , Humanos , Imunoensaio , Lipopolissacarídeos/farmacologia , Camundongos Endogâmicos C57BL , Microesferas , Proteômica , Padrões de Referência
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