In clinical practice, a variety of diagnostic applications require the identification of target cells. Density has been used as a physical marker to distinguish cell populations since metabolic activities could alter the cell densities. Magnetic levitation offers great promise for separating cells at the single cell level within heterogeneous populations with respect to cell densities. Traditional magnetic levitation platforms need bulky and precise optical microscopes to visualize levitated cells. Moreover, the evaluation process of cell densities is cumbersome, which also requires trained personnel for operation. In this work, we introduce a device (HologLev) as a fusion of the magnetic levitation principle and lensless digital inline holographic microscopy (LDIHM). LDIHM provides ease of use by getting rid of bulky and expensive optics. By placing an imaging sensor just beneath the microcapillary channel without any lenses, recorded holograms are processed for determining cell densities through a fully automated digital image processing scheme. The device costs less than $100 and has a compact design that can fit into a pocket. We perform viability tests on the device by levitating three different cell lines (MDA-MB-231, U937, D1 ORL UVA) and comparing them against their dead correspondents. We also tested the differentiation of mouse osteoblastic (7F2) cells by monitoring characteristic variations in their density. Last, the response of MDA-MB-231 cancer cells to a chemotherapy drug was demonstrated in our platform. HologLev provides cost-effective, label-free, fully automated cell analysis in a compact design that could be highly desirable for laboratory and point-of-care testing applications.Semiconducting metal oxide-based gas sensors have inadequate selectivity as they are responsive toward a variety of gases. Here, we report the implementation of gas sensing kinetic analysis of the sensor to identify the tested volatile organic compounds (VOCs) (2-propanol, formaldehyde, methanol, and toluene) precisely. A single chemiresistive sensor was employed having tin oxide-based hollow spheres as the sensing material, which were obtained by chemical synthesis. The gas sensing measurements were conducted in a dynamic manner where the sensor displayed excellent response with high sensitivity. Eley-Rideal model was adopted to obtain the kinetic properties of the gas sensing phenomenon through theoretical fitting of response transient curves and their corresponding kinetic parameters. The calculated characteristic kinetic properties were further examined to discriminate among different VOCs. The approach of using gas sensing kinetic analysis for multiple gas discrimination is an attractive solution to mitigate the problem of cross-sensitivity for resistive gas sensors.Transition metal dichalcogenides are regarded as promising anode materials for potassium-ion batteries (PIBs) because of their high theoretical capacities. However, due to the large atomic radius of K+, the structural damage caused by the huge volume expansion upon potassiation is **** more severe than that of their lithium counterparts. In this research, a stress-dispersed structure with Co3Se4 nanocrystallites orderly anchored on graphene sheets is achieved through a two-step hydrothermal treatment to alleviate the structural deterioration. The ability to reduce the contact stress by the well-dispersed Co3Se4 nanocrystallites during K+ intercalation, together with the highly conductive graphene matrix, provides a more reliable and efficient anode architecture than its two agminated counterparts. Given these advantages, the optimized electrode delivers excellent cycling stability (301.8 mA h g-1 after 500 cycles at 1 A g-1), as well as an outstanding rate capacity (203.8 mA h g-1 at 5 A g-1). Further in situ and ex situ characterizations and density functional theory calculations elucidate the potassium storage mechanism of Co3Se4 during the conversion reaction and reveal the fast electrochemical kinetics of the rationally designed electrode. This work provides a practical approach for constructing stable metal-selenide anodes with long cycle life and high-rate performance for PIBs.Contaminant-bearing fine biochar particles (FBPs) may exert significantly different toxicity profiles from their contaminant-free counterparts. While the role of FBPs in promoting contaminant uptake has been recognized, it is unclear whether the binding of contaminants can modify the biochemical reactivity and toxicological profiles of FBPs. Here, we show that binding of benzo[a]pyrene (B(a)P, a model polycyclic aromatic hydrocarbon) at environmentally relevant exposure concentrations markedly alters the cytotoxicity of FBPs to macrophages, an important line of innate immune defense against airborne particulate matters (PMs). Specifically, B(a)P-bearing FBPs elicit more severe disruption of the phospholipid membrane, endocytosis, oxidative stress, autophagy, and compromised innate immune defense, as evidenced by blunted proinflammatory effects, compared with B(a)P-free FBPs. Notably, the altered cytotoxicity cannot be attributed to the dissolution of B(a)P from the B(a)P-bearing FBPs, but appears to be related to B(a)P adsorption-induced changes of FBPs bioreactivity toward macrophages. Our findings highlight the significance of environmental chemical transformation in altering the bioreactivity and toxicity of PMs and call for further studies on other types of carbonaceous nanoparticles and additional exposure scenarios.Advances in the field of structural DNA nanotechnology have produced a growing number of nanostructures that are now being developed for diverse applications. Often, these nanostructures contain not only nucleic acids but also a myriad of other classes of molecules and materials such as proteins, lipids, sugars, and synthetic polymers. https://www.selleckchem.com/products/Sunitinib-Malate-(Sutent).html Increasing structural and compositional complexity promises new functional capabilities, but also demands new tools for design verification. Systematically verifying the design of DNA-scaffolded nanomaterials is necessary to identify and to refine their design rules, and to enable the field to progress toward "real world" applications. In this issue of ACS Nano, Bertosin et al. used single-particle cryo-electron microscopy to characterize the structure of multilayer DNA origamis following coating with oligolysine-based polymers, a class of material which has previously been shown to stabilize DNA nanostructures in physiological environments for use in biological applications. This Perspective summarizes their findings, discusses the broader challenges of verifying the design of DNA nanotechnologies incorporating complex materials, and highlights future directions for advancing their applications.
In clinical practice, a variety of diagnostic applications require the identification of target cells. Density has been used as a physical marker to distinguish cell populations since metabolic activities could alter the cell densities. Magnetic levitation offers great promise for separating cells at the single cell level within heterogeneous populations with respect to cell densities. Traditional magnetic levitation platforms need bulky and precise optical microscopes to visualize levitated cells. Moreover, the evaluation process of cell densities is cumbersome, which also requires trained personnel for operation. In this work, we introduce a device (HologLev) as a fusion of the magnetic levitation principle and lensless digital inline holographic microscopy (LDIHM). LDIHM provides ease of use by getting rid of bulky and expensive optics. By placing an imaging sensor just beneath the microcapillary channel without any lenses, recorded holograms are processed for determining cell densities through a fully automated digital image processing scheme. The device costs less than $100 and has a compact design that can fit into a pocket. We perform viability tests on the device by levitating three different cell lines (MDA-MB-231, U937, D1 ORL UVA) and comparing them against their dead correspondents. We also tested the differentiation of mouse osteoblastic (7F2) cells by monitoring characteristic variations in their density. Last, the response of MDA-MB-231 cancer cells to a chemotherapy drug was demonstrated in our platform. HologLev provides cost-effective, label-free, fully automated cell analysis in a compact design that could be highly desirable for laboratory and point-of-care testing applications.Semiconducting metal oxide-based gas sensors have inadequate selectivity as they are responsive toward a variety of gases. Here, we report the implementation of gas sensing kinetic analysis of the sensor to identify the tested volatile organic compounds (VOCs) (2-propanol, formaldehyde, methanol, and toluene) precisely. A single chemiresistive sensor was employed having tin oxide-based hollow spheres as the sensing material, which were obtained by chemical synthesis. The gas sensing measurements were conducted in a dynamic manner where the sensor displayed excellent response with high sensitivity. Eley-Rideal model was adopted to obtain the kinetic properties of the gas sensing phenomenon through theoretical fitting of response transient curves and their corresponding kinetic parameters. The calculated characteristic kinetic properties were further examined to discriminate among different VOCs. The approach of using gas sensing kinetic analysis for multiple gas discrimination is an attractive solution to mitigate the problem of cross-sensitivity for resistive gas sensors.Transition metal dichalcogenides are regarded as promising anode materials for potassium-ion batteries (PIBs) because of their high theoretical capacities. However, due to the large atomic radius of K+, the structural damage caused by the huge volume expansion upon potassiation is much more severe than that of their lithium counterparts. In this research, a stress-dispersed structure with Co3Se4 nanocrystallites orderly anchored on graphene sheets is achieved through a two-step hydrothermal treatment to alleviate the structural deterioration. The ability to reduce the contact stress by the well-dispersed Co3Se4 nanocrystallites during K+ intercalation, together with the highly conductive graphene matrix, provides a more reliable and efficient anode architecture than its two agminated counterparts. Given these advantages, the optimized electrode delivers excellent cycling stability (301.8 mA h g-1 after 500 cycles at 1 A g-1), as well as an outstanding rate capacity (203.8 mA h g-1 at 5 A g-1). Further in situ and ex situ characterizations and density functional theory calculations elucidate the potassium storage mechanism of Co3Se4 during the conversion reaction and reveal the fast electrochemical kinetics of the rationally designed electrode. This work provides a practical approach for constructing stable metal-selenide anodes with long cycle life and high-rate performance for PIBs.Contaminant-bearing fine biochar particles (FBPs) may exert significantly different toxicity profiles from their contaminant-free counterparts. While the role of FBPs in promoting contaminant uptake has been recognized, it is unclear whether the binding of contaminants can modify the biochemical reactivity and toxicological profiles of FBPs. Here, we show that binding of benzo[a]pyrene (B(a)P, a model polycyclic aromatic hydrocarbon) at environmentally relevant exposure concentrations markedly alters the cytotoxicity of FBPs to macrophages, an important line of innate immune defense against airborne particulate matters (PMs). Specifically, B(a)P-bearing FBPs elicit more severe disruption of the phospholipid membrane, endocytosis, oxidative stress, autophagy, and compromised innate immune defense, as evidenced by blunted proinflammatory effects, compared with B(a)P-free FBPs. Notably, the altered cytotoxicity cannot be attributed to the dissolution of B(a)P from the B(a)P-bearing FBPs, but appears to be related to B(a)P adsorption-induced changes of FBPs bioreactivity toward macrophages. Our findings highlight the significance of environmental chemical transformation in altering the bioreactivity and toxicity of PMs and call for further studies on other types of carbonaceous nanoparticles and additional exposure scenarios.Advances in the field of structural DNA nanotechnology have produced a growing number of nanostructures that are now being developed for diverse applications. Often, these nanostructures contain not only nucleic acids but also a myriad of other classes of molecules and materials such as proteins, lipids, sugars, and synthetic polymers. https://www.selleckchem.com/products/Sunitinib-Malate-(Sutent).html Increasing structural and compositional complexity promises new functional capabilities, but also demands new tools for design verification. Systematically verifying the design of DNA-scaffolded nanomaterials is necessary to identify and to refine their design rules, and to enable the field to progress toward "real world" applications. In this issue of ACS Nano, Bertosin et al. used single-particle cryo-electron microscopy to characterize the structure of multilayer DNA origamis following coating with oligolysine-based polymers, a class of material which has previously been shown to stabilize DNA nanostructures in physiological environments for use in biological applications. This Perspective summarizes their findings, discusses the broader challenges of verifying the design of DNA nanotechnologies incorporating complex materials, and highlights future directions for advancing their applications.
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