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An innovative and rapid method for permanent hydrophilic modification of polydimethylsiloxane (PDMS) chip surfaces
Polydimethylsiloxane (PDMS), a fundamental material in the fabrication of microfluidic devices, suffers from nonspecific adsorption of biological samples due to its hydrophobic nature. Herein, by employing a radiation-induced grafting strategy to introduce hydrophilic functional groups onto the PDMS surface, a significant improvement in hydrophilicity is achieved, leading to a notable reduction in the contact angle by up to ∼90° and improvement of antifouling performance against biological samples. Effects between monomer concentration, grafting efficiency, and mechanical integrity are balanced to optimize the grafting process, achieving promised hydrophilicity enhancement while the mechanical properties are not degraded. The content of carboxyl groups exposed on the surface of grafted PDMS was computationally analyzed using MD simulations, which revealed the key role of carboxyl groups in the wettability of the PDMS surface. Our study extensively showcases the effective grafting of acrylic acid onto PDMS, which is characterized by diverse grafting rates. Remarkably, the hydrophilic modification is stable over time compared to conventional plasma treatment, offering a more reliable and enduring strategy, and making it a valuable enhancement for PDMS chips with extensive applications.
Platelet indicators do not influence the impact of ABO blood groups on lung adenocarcinoma susceptibility
Catalytic asymmetric C–N cross-coupling towards boron-stereogenic 3-amino-BODIPYs
All-optical vector magnetometry based on fine and hyperfine interactions in spin-32 centers in silicon carbide
The possibility of using axial spin centers with S=3/2 in silicon carbide for all-optical measurement of the projection Bz of the external magnetic field onto the c-axis of the SiC crystal, as well as the polar and azimuthal angles of the magnetic field relative to the direction of the c-axis, at room and significantly higher temperatures is shown. Spin centers in SiC, where optically induced spin alignment occurs, have a unique system of spin levels in a magnetic field, caused by the interaction of the fine structure and hyperfine interaction with the 29Si nuclei. There is a wide range of level anticrossings (LACs) resulting in an extremely strong change in the photoluminescence intensity at LAC. The dependence of the LAC spectrum on the orientation of the external magnetic field is also observed. The proposed magnetometer is based on the compensation of the external magnetic field at the position of the optical excitation spot of the confocal microscope. The sensitivity to a constant magnetic field for the z-component of the magnetic field (Bz) is better than 0.1μT/Hz in the confocal volume at room temperature. The sensitivity of polar and azimuthal angle determination depends on the sensitivity of the perpendicular component of the magnetic field, which is better than ∼0.01mT/Hz in the range from −0.4 to 0.4 mT.
The pathomechanism of bone marrow edema in the femoral head necrosis with pericollapse stage
Siah2 antagonism of Pard3/JamC modulates Ntn1-Dcc signaling to regulate cerebellar granule neuron germinal zone exit
A radial micro-vibration system for reducing friction of passive interventional guidewire
Endovascular guidewire interventional surgery is an effective treatment for vascular diseases. However, due to factors, such as blood viscosity and complex vascular morphology, the guidewire is interfered by strong varying resistance when moving in the lesion’s vasculature. This greatly affects the efficiency and safety of the clinical operation. Here, we develop a novel system that applies ultrasonic micro-amplitude vibration to the conventional passive guidewire for studying a drag reduction effect under multiple factors. The system is mainly composed of a sandwich-type ultrasonic transducer and a step-type horn for concentrating the unidirectional energy for micro-vibration. Subsequently, comparative experiments are designed to verify the effectiveness of this system for drag reduction. Through the multifactorial interactions, we study the friction reduction law of the microvibration-assisted method on the guidewire and the optimal drag reduction parameter combinations. The results show that the drag reduction effect varies with the amplitude–frequency response curve. An ultrasound vibration amplitude and a simulated vessel bending angle were the most significant factors. Only vibration frequency and amplitude interacted with a simulated vessel shape. Finally, using the resonance frequency and the maximum vibration amplitude to drive the guidewire vibration, the maximum friction reduction rate can be obtained, up to 85.2%. This system is expected to have important applications in clinical vascular interventional procedures.
Subject-specific biomechanics influences tendon strains in patients with Achilles tendinopathy
Safety and immunogenicity of an optimized self-replicating RNA platform for low dose or single dose vaccine applications: a randomized, open label Phase I study in healthy volunteers
Electrical properties of ScN thin films controlled by defect engineering using oxygen ion implantation
Defects tend to modify significantly the properties of semiconductors, such as transport properties, by increasing the scattering of electrons and phonons, or optical properties, by modifying the band structure and the Fermi level. The high interest of ScN thin films for thermoelectric applications results from the incorporation of oxygen, which is well known to be the source for their degenerate n-type state and their significant power factor. Indeed, oxygen acts as a donor defect when substituted to nitrogen. In this study, oxygen ion implantation was performed at a high damage level as a way to modify electrical properties through defect engineering. Hence, we measured the changes in electrical properties induced by oxygen implantation at room temperature. Two types of defects have been identified as being responsible for the change in resistivity, carrier concentration, mobility, and Seebeck coefficient. At first, the point-like defects, recombining from 440 K and onward, introduce localized states near the Fermi level, inducing a change in the conduction mode from a metallic-like to a hopping mechanism. The relationship between Mott's temperature and defect concentration has been clearly demonstrated through in situ resistivity measurements in the 80–750 K temperature range. Furthermore, these measurements highlight that oxygen induced defects result not only from ballistic effects, but also from chemical effects that are involved. Second, the complex-like defects introduce deep acceptor levels into the bandgap and act as scattering centers that modify the Debye temperature as well as the electron–phonon interactions. These complexes, likely between scandium vacancies and oxygen atoms (VSc-yO, y ≤ 4), are primarily responsible for the increase of the Seebeck coefficient and the reduced mobility. The concentration of such defects can qualitatively be assessed as their formation introduces an additional term, independent of temperature, in the variation of resistivity, mobility, and also the Seebeck coefficient. The recovery of the complex-like defects takes place at a minimum temperature of 750 K. Results show that the effectiveness of oxygen in creating defects exceeds that of noble gases in terms of concentration, demonstrating the promise of this approach to control the electrical properties of ScN.
The effect of NLRP3 inflammasome on cardiovascular prognosis in patients with acute coronary syndrome
Author Correction: Back flux during anaerobic oxidation of butane support archaea-mediated alkanogenesis
Photoluminescence dynamics and ligand exchange in PbS/CdS core/shell nanocrystal films
Photoluminescence studies in PbS/CdS core/shell nanocrystal thin films reveal that the length of organic ligands at the nanocrystal surface controls the photoluminescence rise time and the short-lived decay component. The long-lived photoluminescence does not depend on the ligand length but strongly depends on the detection wavelength and temperature. We conclude that the observed complex photoluminescence dynamics are governed by a combination of energy transfer and exciton recombination and propose a method to separate these processes.
Repeated 5-aminolevulinic acid mediated sonodynamic therapy using magnetic resonance guided focused ultrasound in rat brain tumour models
AbstractSonodynamic therapy is an emerging therapeutic approach against brain tumours. However, the treatment scheme and ultrasound parameters have yet to be explored for clinical translation. Our study aimed to optimize ultrasound parameters for sonodynamic therapy (SDT) with 5-ALA as a sonosensitizing agent and to evaluate its therapeutic outcome on the rodent 9L gliosarcoma and the human U87 glioblastoma models. We stereotactically implanted brain tumour cells in rats and monitored tumour volume via MRI. SDT was conducted weekly using a 60 mg/kg dose of 5-ALA, injected intravenously 6 h before sonication. We used a driving frequency of 580 kHz with 0.75 MPa and evaluated the effect of different burst lengths to optimize ultrasound parameters. We also tested SDT against advanced-stage brain tumours to verify its efficacy further. Our results showed that a longer burst length could improve therapeutic outcomes. Tumour growth inhibition was established only in the first three weeks with 10 ms and 50 ms burst length sonication, but 86 ms burst length greatly improved the survival outcome. Therefore, the therapeutic efficacy is proportionate to the burst length and, thus, the total delivered energy. Repeated SDT using multiple targets to cover the entire tumour volume with optimal ultrasound parameters can achieve significant anti-tumour effects in both 9L and U87 models. Lastly, our results on late-stage tumour treatments showed that SDT can still provide prolonged survival. These promising findings demonstrate that repeated SDT using transcranial-focused ultrasound together with 5-ALA can optimize anti-tumour effects and even lead to complete clearance of the tumours. This weekly treatment with pulsed ultrasound sonication strategy is practical for future clinical translation.
Roof renewal disparities widen the equity gap in residential wildfire protection
Abstract Wildfires are having disproportionate impacts on U.S. households. Notably, in California, over half of wildfire-destroyed homes (54%) are in low-income areas. We investigate the relationship between social vulnerability and wildfire community preparedness using building permits from 16 counties in California with 2.9 million buildings (2013–2021) and the U.S. government’s designation of disadvantaged communities (DACs), which classifies a census tract as a DAC if it meets a threshold for certain burdens, such as climate, environmental, and socio-economic. Homes located in DACs are 29% more likely to be destroyed by wildfires within 30 years, partly driven by a gap in roof renewals, one of several important home hardening actions. Homes in DACs have 28% fewer roof renewals than non-DACs and post-wildfire, non-DAC homes have more than twice the increase in renewals (+17%) compared to DAC homes (+7%). Our research offers policy insights for narrowing this equity gap in renewals for wildfire-prone areas. We recommend increasing financial support for roof renewals and targeted awareness campaigns for existing programs which are not sufficiently emphasized in wildfire strategies, particularly in DACs.
Study of the recrystallization behaviors induced by annealing and irradiation on amorphous SiC
Silicon carbide and its derivatives are promising materials with potential applications in various types of nuclear reactors. To better understand their characteristics, this paper investigates the recrystallization behavior of amorphous SiC prepared through pre-irradiation using 800 keV Kr2+. Following different annealing processes, Raman spectra revealed that recrystallization happened beyond 873 K, and nearly complete recrystallization of the amorphous layer occurs at 1423 K. Afterward, in situ annealing and He+ irradiation experiments were conducted. The results indicate that the recrystallization progress is a layer-by-layer epitaxial regrowth on the amorphous–crystal interface under 873 K annealing, and the epitaxial recrystallization would slow down mainly due to the accumulation of defects and Kr atoms. However, under 30 keV He+ irradiation at 873 K, the interface continues to move. Moreover, when the irradiation dose rises, nanocrystals and helium bubbles appear simultaneously, growing in both size and density. The different recrystallization behaviors caused by irradiation and non-irradiation conditions could be explained by radiation-enhanced atomic diffusion, and helium bubbles are likely to be the by-products of nanocrystal formation. A possible explanation is proposed. This study provides insights into the practical application of amorphous silicon carbide in reactors and other irradiation environments.
E3 ligase RNF128 restricts A. alternata-induced ILC2 activation and type 2 immune response in the murine lung
DNA methylation modulates nucleosome retention in sperm and H3K4 methylation deposition in early mouse embryos
Abstract In the germ line and during early embryogenesis, DNA methylation (DNAme) undergoes global erasure and re-establishment to support germ cell and embryonic development. While DNAme acquisition during male germ cell development is essential for setting genomic DNA methylation imprints, other intergenerational roles for paternal DNAme in defining embryonic chromatin are unknown. Through conditional gene deletion of the de novo DNA methyltransferases Dnmt3a and/or Dnmt3b , we observe that DNMT3A primarily safeguards against DNA hypomethylation in undifferentiated spermatogonia, while DNMT3B catalyzes de novo DNAme during spermatogonial differentiation. Failing de novo DNAme in Dnmt3a / Dnmt3b double deficient spermatogonia is associated with increased nucleosome occupancy in mature sperm, preferentially at sites with higher CpG content, supporting the model that DNAme modulates nucleosome retention in sperm. To assess the impact of altered sperm chromatin in formatting embryonic chromatin, we measure H3K4me3 occupancy at paternal and maternal alleles in 2-cell embryos using a transposon-based tagging approach. Our data show that reduced DNAme in sperm renders paternal alleles permissive for H3K4me3 establishment in early embryos, independently of possible paternal inheritance of sperm born H3K4me3. Together, this study provides evidence that paternally inherited DNAme directs chromatin formation during early embryonic development.
Temperature dependent thermoelectric transport in PEDOT–PSS conducting polymer: The effect of additives
We report on both the electrical and thermoelectric transport properties as a function of temperature in poly(3,4-ethylene dioxythiophene) (PEDOT)–poly(styrene sulfonate) conducting polymers for a wide range of dimethyl sulfoxide (DMSO) additives. Whereas an insulating-like electrical behavior is found over the whole temperature range, a metallic-like thermopower is mainly observed. We show that the resistivity appears to be governed by a three-dimensional variable range hopping mechanism due to disordered regions with a decreasing localization temperature T0 and an increasing scaling factor ρ0 as a function of the DMSO ratio. The correlation between T0 and ρ0 demonstrates that they are both controlled by the localization length ξ0, which is strongly enhanced by the DMSO in agreement with the morphological evolution of the PEDOT chains with the additive. On the other hand, the high-T positive metallic-like thermopower seems rather unaffected by the additive in contrast to its low-T counterpart, which appears negative below a characteristic temperature Tswitch. By showing that the latter is closely related to the localization temperature, we propose to ascribe this sign switch to the thermoelectric contribution originating from disordered regions, which competes with the metallic ones due to ordered domains. While still controlled by the localization temperature, this negative contribution appears to be consistent with a phonon-drag component with a scaling behavior as T0T−3. These analyses allow us to discuss the overall temperature dependent thermoelectric properties in a consistent way by considering a heterogeneous structure with both ordered and disordered domains. By relating explicitly the electrical resistivity to the thermopower, our results do not only reconcile these transport coefficients, but they also provide a unified picture of the properties of the conducting polymers.