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Little is known about antibody responses to natural Omicron infection and the risk factors for poor responders in patients with hematological malignancies (HM). We conducted a multicenter, prospective cohort study during the latest Omicron wave in Chongqing, China, aiming to compare the antibody responses, as assessed by IgG levels of anti‐receptor binding domain of spike protein (anti‐S‐RBD), to Omicron infection in the HM cohort (HMC) with healthy control cohort (HCC), and solid cancer cohort (SCC). In addition, we intend to explore the risk factors for poor responders in the HMC. Among the 466 HM patients in this cohort, the seroconversion rate was 92.7%, no statistically difference compared with HCC (98.2%, p = 0.0513) or SCC (100%, p = 0.1363). The median anti‐S‐RBD IgG titer was 29.9 ng/mL, significantly lower than that of HCC (46.9 ng/mL, p < 0.0001) or SCC (46.2 ng/mL, p < 0.0001). Risk factors associated with nonseroconversion included no COVID‐19 vaccination history (odds ratio [OR] = 4.58, 95% confidence interval [CI]: 1.75–12.00, p = 0.002), clinical course of COVID‐19 ≤ 7 days (OR = 2.86, 95% CI: 1.31–6.25, p = 0.008) and severe B‐cell reduction (0–10/μL) (OR = 3.22, 95% CI: 1.32–7.88, p = 0.010). Risk factors associated with low anti‐S‐RBD IgG titer were clinical course of COVID‐19 ≤ 7 days (OR = 2.58, 95% CI: 1.59–4.18, p < 0.001) and severe B‐cell reduction (0–10/μL) (OR = 2.87, 95% CI: 1.57–5.24, p < 0.001). This study reveals a poor antibody responses to Omicron (BA.5.2.48) infection in HM patients and identified risk factors for poor responders. Highlights that HM patients, especially those with these risk factors, may be susceptible to SARS‐CoV‐2 reinfection, and the postinfection vaccination strategies for these patients should be tailored. Clinical trial: ChiCTR2300071830. [ABSTRACT FROM AUTHOR]

With the development of advanced nanofabrication techniques over the past decades, different nanostructure-based plasmonic fiber-optic sensors have been developed and have presented a low limit of detection for various biomolecules. However, owing to both the dependence on complex equipment and the trade-off between the fabrication cost and sensing performance, nanostructured plasmonic fiber-optic sensors are rarely used outside laboratories. To facilitate wider application of the plasmonic fiber-optic sensors, a parylene-mediated hybrid plasmonic–photonic cavity-based sensor was developed. Compared with a similar plasmonic sensor which only works in the plasmonic mode, the proposed hybrid sensor shows a higher reproducibility (CV < 2.5%) due to its resistance to fabrication variations. Meanwhile, a self-referenced detection mechanism and a novel miniaturized system were developed to adapt to the hybrid resonance sensor. The entire system only has a weight of 263 g, and a size of 12 cm × 10 cm × 8 cm, and is especially suitable for outdoor applications in a handheld manner. In experiments, a high refractive index sensitivity of 3.148 RIU−1 and real-time biomolecule monitoring at nanomolar concentrations were achieved by the proposed system, further confirming the potential of the miniaturized system as a candidate for point-of-care health diagnostics outside laboratories. [ABSTRACT FROM AUTHOR]

The trans-epithelial electrical resistance (TEER) is widely used to quantitatively evaluate cellular barrier function at the organ level in vitro. The measurement of the TEER in organ-on-chips (organ chips) plays a significant role in medical and pharmacological research. However, due to the limitation of the electrical equivalent model for organ chips, the existing TEER measurements usually neglect the changes of the TEER during cell proliferation, resulting in the low accuracy of the measurements. Here, we proposed a new whole-region model of the TEER and developed a real-time TEER measurement system that contains an organ chip with a plate electrode. A whole region circuit model considering the impedance of the non-cell covered region was also established, which enables TEER measurements to be independent of the changes in the cell covered region. The impedance of the non-cell covered region is here attributed to the resistance of the porous membrane. By combining the real-time measurement system and the whole region model, subtle changes in cellular activity during the proliferation stage were measured continuously every 6 minutes and a more sensitive TEER response was obtained. Furthermore, the TEER measurement accuracy was also verified by the real-time measurement of the TEER with stimulation using the permeability enhancer ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA). The obtained results indicated that the new proposed whole region model and the real-time measurement system have higher accuracy and greater sensitivity than the traditional model. [ABSTRACT FROM AUTHOR]

Point-of-care testing (POCT) techniques based on microfluidic devices enabled rapid and accurate tests on-site, playing an increasingly important role in public health. As the critical component of capillary-driven microfluidic devices for POCT use, the capillary microfluidic valve could schedule multi-step biochemical operations, potentially being used for broader complex POCT tasks. However, owing to the reciprocal relationship between the capillary force and aperture in single-pore microchannels, it was challenging to achieve a high gating threshold and high operable liquid volume simultaneously with existing 2D capillary trigger valves. This paper proposed a 3D capillary-driven multi-microporous membrane-based trigger valve to address the issue. Taking advantage of the high gating threshold determined by micropores and the self-driven capillary channel, a 3D trigger valve composed of a microporous membrane for valving and a wedge-shaped capillary channel for flow pumping was implemented. Utilizing the capillary pinning effect of the multi-micropore membrane, the liquid above the membrane could be triggered by putting the drainage agent into the wedge-shaped capillary channel to wet the underside of the membrane, and it could also be cut off by taking away the agent. After theoretical analysis and performance characterizations, the 3D trigger valve performed a high gating threshold (above 1000 Pa) and high trigger efficiency with an operable liquid volume above 150 μL and a trigger-to-drain time below 6 s. Furthermore, the retention and trigger states of the valve could be switched for repeatable triggering for three cycles within 5 min. Finally, the microbead-based immunoreaction and live cell staining applications verified the valve's ability to perform multi-step operations. The above results showed that the proposed 3D trigger valve could be expected to play a part in wide-ranging POCT application scenarios. [ABSTRACT FROM AUTHOR]

Tumor-derived exosomes have been recognized as potential biomarkers for cancer diagnosis because they are actively involved in cancer progression and metastasis. However, progress in practical exosome analysis is still slow due to the limitation in exosome isolation and detection. The development of microfluidic devices has provided a promising analytical platform compared with traditional methods. In this study, we develop an exosome isolation and detection method based on a microfluidic device (ExoDEP-chip), which realized microsphere mediated dielectrophoretic isolation and immunoaffinity detection. Exosomes were firstly isolated by binding to antibodies pre-immobilized on the polystyrene (PS) microsphere surface and were further detected using fluorescently labeled antibodies by fluorescence microscopy. Single microspheres were then trapped into single microwells under the DEP force in the ExoDEP-chip. A wide range from 1.4 × 103 to 1.4 × 108 exosomes per mL with a detection limit of 193 exosomes per mL was obtained. Through monitoring five proteins (CD81, CEA, EpCAM, CD147, and AFP) of exosomes from three different cell lines (A549, HEK293, and HepG2), a significant difference in marker expression levels was observed in different cell lines. Therefore, this method has good prospects in exosome-based tumor marker detection and cancer diagnosis. [ABSTRACT FROM AUTHOR]

The development of surface-enhanced Raman scattering (SERS) devices for detection of trace pesticides has attracted more and more attention. In this work, a large-area self-assembly approach assisted with reactive ion etching (RIE) is proposed for preparing SERS devices consisting of Ag-covered "hedgehog-like" nanosphere arrays (Ag/HLNAs). Such a SERS device has an enhancement factor of 2. 7 9 × 1 0 7 , a limit of detection (LOD) up to 10 − 1 2 M for Rhodamine 6G (R6G) analytes, and a relative standard deviation (RSD) smaller than 10%, demonstrating high uniformity. Besides, for pesticide detections, the device achieves an LOD of 10 − 8 M for thiram molecules. It indicates that the proposed SERS device has a promising opportunity in detecting toxic organic pesticides. [ABSTRACT FROM AUTHOR]

In this work, we develop a new method for fabricating wafer-level gold nanoparticles covered silicon nanopillars (SNPs) combined with surface chemical modification to detect trace level carbonyl compounds based on surface-enhanced Raman scattering (SERS) technique. The SNPs are fabricated with an etching process using nano masks synthesized in oxygen-plasma bombardment of photoresist, and further deposited with gold nanoparticles on the surface, thus forming a 3D 'particles on pillars' nanostructure for sensitive SERS detection. The enhancement factor (EF) of the devices for R6G detection can achieve 1.56 × 106 times compared with a flat Si substrate. We also developed an oximation click chemistry reaction procedure by chemically modifying the nanostructures with aminooxy dodecane thiol (ADT) self-assemble modification. The chip is further integrated with a polydimethylsiloxane (PDMS) microfluidic chamber, which allows fast and convenient detection of trace carbonyl compounds in liquid samples. The SERS detection capability was demonstrated by the dropwise addition of fluorescent carbonyl compounds before and after elution. Furthermore, the device was proved with high surface consistency(<70%) for repeated measurement, which has the potential for ppb(parts per billion) level concentration of carbonyl compounds detection. [ABSTRACT FROM AUTHOR]

Conventionally, Porcine teschovirus (PTV) consists of 13 genotypes (PTV 1–13, which belong to Teschovirus A); however, several novel members including PTV 14–22 have been discovered recently. PTV 21 was identified as a novel Teschovirus species named Teschovirus B. In this study, almost all 22 reported PTV genotypes except PTV 6, 7, 12 and 20 were identified in the pig populations of western Jiangxi, China, which reflects the high genotype diversity. Moreover, to the best of our knowledge, the nearly complete genome of PTV 22‐JiangX1 was first sequenced in the present study. The homology comparison of the polyprotein genes showed that PTV 22‐JiangX1 shared a relatively high nucleotide and deduced amino acid sequence identities ranging from 78.3% to 82.0% and 84.6% to 89.3%, respectively, with PTV 19 and 21. Additionally, the PTV strain of JiangX1 represents genotype 22 with the PTV 19, and 21 strains proved to be members of Teschovirus B based on the phylogenetic and evolutionary divergence analyses. Finally, we determined that the novel Teschovirus B species comprises at least three PTV genotypes. [ABSTRACT FROM AUTHOR]

Parylene-C is a popular polymer material in biomedical applications, with excellent physicochemical properties and microfabrication capability. Like many aromatic polymers, parylene-C also has autofluorescence, which was usually taken as a negative background noise in biomedical detection studies. However, the fluorescence intensity of thin-film (＜1 μm) parylene-C was relatively weak, which may be a big limitation in visualization. In this work, we reported a simple annealing method to significantly enhance the fluorescence and achieve sufficient intensity as a visual marker. We studied the behaviors and mechanisms of the enhanced parylene-C fluorescence, then verified the feasibility and reliability of parylene-C for preparing fluorescent pipettes in targeted neuronal electrophysiology, where fluorescent guidance was strongly needed. The powerful parylene-C fabrication technique enables a precisely-controlled conformal coating along with a mass production capability, which further resulted in high-quality electrophysiological recordings of both cultured hippocampal neurons and acute hippocampal brain slices. Moreover, the enhanced parylene-C fluorescence can also be applied in more general biological operations, such as designable fluorescent micro-patterns for visualization in broader biomedical fields. [ABSTRACT FROM AUTHOR]

Surface functionalization of polydimethylsiloxane (PDMS) is important in developing high-performance microfluidic devices. This work applied the thermal chemical vapor deposition (t-CVD) of Parylene-C onto PDMS to caulk the molecular network while retaining the original surface properties for the oxygen plasma bonding. The very low deposition rates (for example, a nominal rate of 0.12 Å min−1 at 135 °C) of Parylene-C at elevated substrate temperatures enabled the reactive Parylene-C monomers to penetrate into the PDMS matrix up to 4.6 ± 0.1 μm (135 °C), which was verified for the first time by a scanning electron microscope with an energy dispersive X-ray analysis (SEM-EDAX). The Parylene-C caulked in the molecular network of PDMS matrix guaranteed an excellent resistance to small molecule permeations. Meanwhile, only discrete nucleation islands were formed on the top surface rather than a continuous Parylene-C layer as observed under the AFM scan, which made the processed PDMS surface ready for device assembly. This surface functionalization method has better long-term stability than the other wet-type rivals. The barrier for oxygen plasma bonding in previously reported dry surface treatments was also avoided, thereby, facilitating the device assembly. The present work successfully developed a novel pcPDMS (Parylene-C caulked PDMS) technique, which overcame the bonding difficulty in the previous works but retained the low small molecule permeability as before. Caulking a molecular network through the t-CVD of Parylene-C also demonstrated a new strategy of functionalizing polymer surfaces and preparing new hybrid materials for wide lab-on-a-chip applications. [ABSTRACT FROM AUTHOR]

TC-1 observational results clearly indicate that the velocity of the flows in the near-Earth region is dependent on the satellite location. The flow speed decreases while satellite moves close to the Earth. The plasma flow in the region close to the Earth tends to drift into the midnight region from the dawn and dusk region while the flow in the region away from the Earth shows an opposite drift. The observational results also show that the tailward flows are mainly located in the plasma sheet boundary while the earthward flow becomes dominant in the plasma sheet. It is found that both the strong tailward and earthward flows are distributed in the region around X= -11Re, which coincides with the trigger region of the substorm onset. Hence, it may suggest that the flows are related with the trigger of the substorm onset. In addition, the BBFs coming from the mid-tail maily distributed in the region where X<-9RE and IZI<3RE that differs from the convection. [ABSTRACT FROM AUTHOR]

On July 11, 2004, a substorm process in the period of continuous tailward flow was observed by the joint exploration of the TC-1, IMAGE and ACE satellites. The substorm observed by the TC-1 in the near-Earth has three stages: the growth phase (from 11:43 to 12:19), the pre-expansion process (from 12:19 to 12:28) and the dipolarization process. The auroral brightening was at 12:26 recorded by the FUV instrument on IMAGE, and the dipolarization occurred two minutes later. During the 45 mm period of the tailward flow, the magnetotail experienced the growth phase and the pre-expansion process. When the dipolarization process began, the TC-1 entered the plasma sheet and observed a high speed earthward flow. The field-aligned tailward flow is characterized by the low temperature and high density, which is consistent with the properties of the flow from the ionosphere detected in the near-Earth magnetotail by other satellites. The tailward flow is closely related with the southward interplanetary magnetic field (IMF), and may have an important effect on the substorm. [ABSTRACT FROM AUTHOR]

The electroporation system can serve as a tool for the intracellular delivery of foreign cargos. However, this technique is presently limited by the inaccurate electric field applied to the single cells and lack of a real-time electroporation metrics subsystem. Here, we reported a microfluidic system for precise and rapid single-cell electroporation and simultaneous impedance monitoring in a constriction microchannel. When single cells (A549) were continuously passing through the constriction microchannel, a localized high electric field was applied on the cell membrane, which resulted in highly efficient (up to 96.6%) electroporation. During a single cell entering the constriction channel, an abrupt impedance drop was noticed and demonstrated to be correlated with the occurrence of electroporation. Besides, while the cell was moving in the constriction channel, the stabilized impedance showed the capability to quantify the electroporation extent. The correspondence of the impedance variation and electroporation was validated by the intracellular delivery of the fluorescence indicator (propidium iodide). Based on the obtained results, this system is capable of precise control of electroporation and real-time, label-free impedance assessment, providing a potential tool for intracellular delivery and other biomedical applications. [ABSTRACT FROM AUTHOR]

Circulating tumor cells (CTCs), a type of cancer cell that spreads from primary tumors into human peripheral blood and are considered as a new biomarker of cancer liquid biopsy. It provides the direction for understanding the biology of cancer metastasis and progression. Isolation and analysis of CTCs offer the possibility for early cancer detection and dynamic prognosis monitoring. The extremely low quantity and high heterogeneity of CTCs are the major challenges for the application of CTCs in liquid biopsy. There have been significant research endeavors to develop efficient and reliable approaches to CTC isolation and analysis in the past few decades. With the advancement of microfabrication and nanomaterials, a variety of approaches have now emerged for CTC isolation and analysis on microfluidic platforms combined with nanotechnology. These new approaches show advantages in terms of cell capture efficiency, purity, detection sensitivity and specificity. This review focuses on recent progress in the field of nanotechnology-assisted microfluidics for CTC isolation and detection. Firstly, CTC isolation approaches using nanomaterial-based microfluidic devices are summarized and discussed. The different strategies for CTC release from the devices are specifically outlined. In addition, existing nanotechnology-assisted methods for CTC downstream analysis are summarized. Some perspectives are discussed on the challenges of current methods for CTC studies and promising research directions. [ABSTRACT FROM AUTHOR]

Micropore arrays have attracted a substantial amount of attention due to their strong capability to separate specific cell types, such as rare tumor cells, from a heterogeneous sample and to perform cell assays on a single cell level. Micropore array filtration has been widely used in rare cell type separation because of its potential for a high sample throughput, which is a key parameter for practical clinical applications. However, most of the present micropore arrays suffer from a low throughput, resulting from a low porosity. Therefore, a robust microfabrication process for high-porosity micropore arrays is urgently demanded. This study investigated four microfabrication processes for micropore array preparation in parallel. The results revealed that the Parylene-C molding technique with a silicon micropillar array as the template is the optimized strategy for the robust preparation of a large-area and high-porosity micropore array, along with a high size controllability. The Parylene-C molding technique is compatible with the traditional micromechanical system (MEMS) process and ready for scale-up manufacture. The prepared Parylene-C micropore array is promising for various applications, such as rare tumor cell separation and cell assays in liquid biopsy for cancer precision medicine. [ABSTRACT FROM AUTHOR]

Parylene C is a widely used polymer material in microfabrication because of its excellent properties such as chemical inertness, biocompatibility and flexibility. It has been commonly adopted as a structural material for a variety of microfluidics and bio-MEMS (micro-electro-mechanical system) applications. However, it is still difficult to achieve a controllable Parylene C pattern, especially on film thicker than a couple of micrometers. Here, we proposed an SF6 optimized O2 plasma etching (SOOE) of Parylene C, with titanium as the etching mask. Without the SF6, noticeable nanoforest residuals were found on the O2 plasma etched Parylene C film, which was supposed to arise from the micro-masking effect of the sputtered titanium metal mask. By introducing a 5-sccm SF6 flow, the residuals were effectively removed during the O2 plasma etching. This optimized etching strategy achieved a 10 μm-thick Parylene C etching with the feature size down to 2 μm. The advanced SOOE recipes will further facilitate the controllable fabrication of Parylene C microstructures for broader applications. [ABSTRACT FROM AUTHOR]

The photocatalytic conversion of CO 2 into hydrocarbon fuel holds immense potential for achieving a carbon closed loop and carbon neutrality. Developing efficient photocatalysts plays a pivotal role in enabling the widespread application of photocatalytic CO 2 reduction on a large scale. Herein, a novel S-scheme MnWO 4 /LaTiO 2 N heterojunction composite is successfully synthesized by a hydrothermal method. This composite catalyst demonstrates excellent photocatalytic activity in the reduction of CO 2 to CO and CH 4 using water molecules as electron donors under visible light irradiation, and the optimized 30% MnWO 4 /LaTiO 2 N composite displays significantly enhanced CO and CH 4 yields of 3.94 and 0.81 μmol g -1 h -1 , respectively, and the corresponding utilized photoelectron number reaches 14.7 μmol g -1 h -1 , which is approximately 7.7 and 12.9 times that of LaTiO 2 N and MnWO 4 . The enhancement in photocatalytic activity of the composites can be ascribed to the construction of an S-scheme heterojunction, which exhibits improved charge transfer dynamics, retains the strongest redox capacity, and effectively suppresses back reactions. In situ Fourier-transform infrared imaging provides evidence, to a certain extent, for the existence of a temporal gradient order in the generation of multiple products during the photocatalytic reduction of CO 2 .