On-chip light-scattering enhancement enables high performance single-particle tracking under conventional bright-field microscope

Scattering-based single-particle tracking (S-SPT) has opened new avenues for highly sensitive label-free detection and characterization of nanoscopic objects, making it particularly attractive for various analytical applications. However, a long-standing issue hindering its widespread applicability is its high technical demands on optical systems. The most promising solution entails implementing on-chip light-scattering enhancement, but the existing field-enhancement technology fails as their highly localized field is insufficient to cover the three-dimensional trajectory of particles within the interrogation time. Here, we present a straightforward and robust on-chip microlens-based strategy for light-scattering enhancement, providing an enhancement range ten times greater than that of near-field optical techniques. These properties are attributed to the increased long-range optical fields and complex composite interactions between two closely spaced structures. Thanks to this strategy, we demonstrate that high-performance S-SPT can be achieved, for the first time, under a conventional bright-field microscope with illumination powers over 1,000 times lower than typically required. This significantly reduces the technical demands of S-SPT, representing a significant step forward in facilitating its practical application in biophotonics, biosensors, diagnostics, and other fields.Comment: 29 pages,4 figure

Ionic liquid-mediated regeneration of cellulose dramatically improves decrystallization, TEMPO-mediated oxidation and alkyl/alkenyl succinylation

This work demonstrated a successful strategy that simple ionic liquids (ILs) mediated pretreatment could effectively reduce crystallinity of cellulose from 71 % to 46 % (by C2MIM.Cl) and 53 % (by C4MIM.Cl). The IL-mediated regeneration of cellulose greatly promoted its reactivity for TEMPO-catalyzed oxidation, which the resulting COO− density (mmol/g) increased from 2.00 for non-IL-treated cellulose to 3.23 (by C2MIM.Cl) and 3.42 (C4MIM.Cl); and degree of oxidation enhanced from 35 % to 59 % and 62 %, respectively. More significantly, the yield of oxidized cellulose increased from 4 % to 45–46 %, by 11-fold. IL-regenerated cellulose can also be directly subjected to alkyl/alkenyl succinylation without TEMPO-mediated oxidation, producing nanoparticles with properties similar to oxidized celluloses (55-74 nm in size, −70–79 mV zeta-potential and 0.23–0.26 PDI); but in a much higher overall yield (87–95 %) than IL-regeneration-coupling-TEMPO-oxidation (34–45 %). Alkyl/alkenyl succinylated TEMPO-oxidized cellulose showed 2–2.5 times higher ABTS* scavenging ability than non-oxidized cellulose; however, alkyl/alkenyl succinylation also resulted in a significant decline in Fe2+ chelating property

Impact of microRNA polymorphisms on high-dose methotrexate-related hematological toxicities in pediatric acute lymphoblastic leukemia

ObjectivesIt is well known that transporter and enzyme genes could be regulated by microRNA (miRNA) at the post-transcriptional level, and single-nucleotide polymorphisms (SNPs) in miRNA, which are involved in the miRNA production and structure, may impact the miRNA expression level and then influence drug transport and metabolism. In this study, we aim to evaluate the association between miRNA polymorphisms and high-dose methotrexate (HD-MTX) hematological toxicities in Chinese pediatric patients with acute lymphoblastic leukemia (ALL).MethodA total of 181 children with ALL were administered with 654 evaluable cycles of HD-MTX. Their hematological toxicities were evaluated according to the National Cancer Institute Common Terminology Criteria for Adverse Events v5. The association between 15 candidate SNPs of miRNA and hematological toxicities (leukopenia, anemia, and thrombocytopenia) was analyzed using Fisher's exact test. Further multiple backward logistic regression analysis was used to explore the independent risk factors for grade 3/4 hematological toxicities.ResultRs2114358 G>A in pre-hsa-miR-1206 was related to HD-MTX-related grade 3/4 leukopenia after multiple logistic regression [GA + AA vs. GG: odds ratio (OR): 2.308, 95% CI: 1.219–4.372, P = 0.010], and rs56103835 T > C in pre-hsa-mir-323b was associated with HD-MTX-related grade 3/4 anemia (TT + TC vs. CC: OR: 0.360, 95% CI: 0.239–0.541, P = 0.000); none of the SNPs were significantly associated with grade 3/4 thrombocytopenia. Bioinformatics tools predicted that rs2114358 G>A and rs56103835 T>C would impact the secondary structure of pre-miR-1206 and pre-miR-323b, respectively, and then probably influence the expression level of mature miRNAs and their target genes.ConclusionRs2114358 G>A and rs56103835 T>C polymorphism may potentially influence HD-MTX-related hematological toxicities, which may serve as candidate clinical biomarkers to predict grade 3/4 hematological toxicities in pediatric patients with ALL

Mechanical-force-induced non-local collective ferroelastic switching in epitaxial lead-titanate thin films.

Ferroelastic switching in ferroelectric/multiferroic oxides plays a crucial role in determining their dielectric, piezoelectric, and magnetoelectric properties. In thin films of these materials, however, substrate clamping is generally thought to limit the electric-field- or mechanical-force-driven responses to the local scale. Here, we report mechanical-force-induced large-area, non-local, collective ferroelastic domain switching in PbTiO3 epitaxial thin films by tuning the misfit-strain to be near a phase boundary wherein c/a and a1/a2 nanodomains coexist. Phenomenological models suggest that the collective, c-a-c-a ferroelastic switching arises from the small potential barrier between the degenerate domain structures, and the large anisotropy of a and c domains, which collectively generates much larger response and large-area domain propagation. Large-area, non-local response under small stimuli, unlike traditional local response to external field, provides an opportunity of unique response to local stimuli, which has potential for use in high-sensitivity pressure sensors and switches

Hydrodynamic Characteristics of a Pilot-Scale Dual Fluidized Bed with Continuous Feeding and Discharging of Solids: Experiment and 3D Simulation

The hydrodynamic properties of a dual fluidized bed (DFB) with continuous feeding and discharging of solids were investigated on a pilot-scale plant in cold mode and simulated coupled with the structure-based drag model. We present a deep analysis that focuses directly on the problem of predicting the fluid dynamics behavior of this type of system for which empirical data is limited or unavailable. The fluidization of a DFB shows complex hydrodynamic characteristics because of the intricate interactions between different compartments experimentally. We prove that the simulation based on the structure-based drag model involving different fluidized structures is able to give an accurate prediction of pilot-scale DFB fluidization and capture the correct flow behaviors under different conditions. This work is expected to give thorough analysis and further exploration of the overall fluidization dynamics for DFB optimization and scale-up

Spatio-temporal distribution pattern and the correlation with key environmental factors of Eurasian otter (Lutra lutra) in Northeast China

Long-term baselines of species distribution are valuable for understanding factors that influence species distribution and conservation management. We revised and supplemented the historical distribution records of the Eurasian otter using interviews and questionnaires. The species distribution model was used to reconstruct the distribution pattern of Eurasian otter in Northeast China across the last 70 years, and the correlation between the change in distribution pattern and environmental factors was calculated. Our results show that the distribution of otters in Northeast China has decreased by 46 % and the occurrence point record has decreased by 60 % over the past 70 years. We found that the spatial distribution pattern of suitable habitats for otters is positively correlated with precipitation in the driest season and percentage of forest land, and negatively correlated with density of residential spots and percentage of cultivated land. In terms of temporal changes in distribution, the distribution of suitable habitats for otters may shrink in time affected by density of residential spots and percentage of cultivated land. Over the past 70 years, otter distribution has declined mainly in low-elevation plains. Controlling human disturbances, especially at the border between mountains and plains, could be key to the recovery of populations of otters. Planning for the protection of freshwater ecosystems in the Greater Khingan Mountains should be prioritized