Sensing mechanism of an Au-TiO2-Ag nanograting based on Fano resonance effects

In recent years, with the development of nano-photonics, Fano resonance has gained increasing attention. Due to its high sensitivity, real-time detection, and label-free properties, the Fano resonance sensor has been widely applied in the fields of biochemistry and environmental detection. To improve the sensing characteristics of Fano resonance, an A u-T i O 2-A g grating structure is proposed in this paper, and the sensing performance is enhanced by a bi-metallic grating and deposited T i O 2. The characteristics of both sensing and field distribution of the model are accordingly analyzed using the finite-difference time-domain method. By varying the structural parameters such as grating period, grating height, silver film thickness, and T i O 2 layer thickness, the tuning of sensing characteristics can be realized, and afterwards, the sensing performance is improved; consequently, the Fano resonance reflection spectrum with high sensitivity and a high figure of merit (FOM) value is obtained. When the grating period P = 200 nm, grating height T1 = 90 nm, silver film thickness T2 = 20 nm, T i O 2 layer thickness T3 = 20 nm, and S i O 2 layer thickness T4 = 600 nm, such a structure indicates favorable sensing performance, and sensor detection accuracy can reach 10-3; maximum sensitivity is 1400 nm/RIU, and maximum FOM can reach 4212R I U -1. The results demonstrate that the designed Fano resonance sensing model has good potential for application.

Estimation of the value of curative therapies in oncology: a willingness-to-pay study in China

The objective of this study was to estimate the willingness to pay (WTP) per quality-adjusted life year (QALY) among people with malignancies in China. The WTP for a QALY was estimated using a contingent valuation survey. Health utility was measured in EuroQol-5 dimensions (EQ-5D). The questionnaires were completed in face-to-face interviews. Respondents consisted of patients with malignant tumors and their family members and came from three tertiary hospitals in different cities with high, medium, and low gross domestic product (GDP) levels. In this study, we offered lump-sum payments and 10 year installment plans to respondents. Finally, we conducted sensitivity analysis and stepwise regression analyses to identify factors that affected the WTP/QALY ratios. A total of 1264 people participated in this survey, and 1013 people gave WTP responses for further analysis. The mean and median WTP/QALY values based on the lump-sum payments were 366,879 RMB (53,171USD, 5.1 times the GDP per capita) and 99,906 RMB (14,479USD, 1.39 times the GDP per capita) for the overall sample; 339,330 RMB (49,178USD, 4.71 times the GDP per capita) and 83,875 RMB (12,156USD, 1.16 times the GDP per capita) for the patient group; and 407,396 RMB (59,043USD, 5.66 times the GDP per capita) and 149,436 RMB (21,657USD, 2.08 times the GDP per capita) for the family group. Considering the skewedness of the data distribution, we suggest setting the cost-utility threshold with reference to the median. When the payment plan changed to 10-year installments, the median increased to 134,734RMB (19,527USD), 112,390 RMB (16,288USD) and 173,838 RMB (25,194USD) for the above groups, respectively. EQ-5D-5L health utility, annual household income per capita, patients with other chronic diseases, occupation, regular physical examinations (patients) and age (family members) were significantly related to WTP/QALY. This study provides empirical evidence of the monetary value of a QALY from a sample of the Chinese population with malignancies. In addition, the ratio of the WTP/QALY to GDP per capita was related to the disease and hypothetical scenario, and a higher ratio of GDP per capita for malignant tumor therapies should be considered.

ELAPOR1 suppresses tumor progression in colorectal cancer and indicates favorable prognosis

BACKGROUND

The role of ELAPOR1 has been evaluated in several cancers but has not been elucidated in colorectal cancer (CRC).

OBJECTIVE

To investigate the role of ELAPOR1 in CRC.

METHODS

In the present study, the correlation between ELAPOR1 and survival of CRC patients in TCGA-COAD-READ datasets was predicted, and the difference in ELAPOR1 expression between tumor and normal tissues was analyzed. ELAPOR1 expression in CRC tissues was measured by immunohistochemistry. Then, ELAPOR1 and ELAPOR1-shRNA plasmids were constructed and transfected into SW620 and RKO cells. The effects were assessed by CCK-8, colony formation, transwell, and wound healing assays. Transcriptome sequencing and bioinformatics analysis were performed on the genes before and after ELAPOR1 overexpression in SW620 cells; the differentially expressed genes were substantiated by real-time quantitative reverse transcription PCR.

RESULTS

High level of ELAPOR1 is associated with favorable disease-free survival and overall survival. Compared to normal mucosa, ELAPOR1 is lower in CRC. Moreover, ELAPOR1 overexpression significantly inhibits cell proliferation and invasion in vitro in SW260 and RKO cells. Conversely, ELAPOR1-shRNA promotes CRC cell proliferation and invasion. Among the 355 differentially expressed mRNAs identified, 234 were upregulated and 121 were downregulated. Bioinformatics indicated that these genes are involved in receptor binding, plasma membrane, negative regulation of cell proliferation, as well as common cancer signaling pathways.

CONCLUSIONS

ELAPOR1 plays an inhibitory role in CRC and may be used as a prognostic indicator and a potential target for treatment.

Intra-arterial Thrombolysis for Acute Retinal Ischemia: A Retrospective, Observational, Cohort Study

BACKGROUND

To determine whether intra-arterial thrombolysis (IAT) within 16 hours after the onset of symptoms is feasible and associated with better visual outcomes in patients with acute retinal ischemia (ARI).

METHODS

The retrospective cohort study was performed from January 2014 to December 2021 in the Xuanwu Hospital of Capital Medical University. Patients with ARI who initially presented visual acuity of 20/100 or worse were screened in the study. Visual end points were evaluated at one week and at final visit after treatment. Serious adverse events were recorded during operation and within 1 week after IAT treatment.

RESULTS

The amount of clinically significant visual improvement (≥0.3 logarithm of the minimum angle of resolution) in the IAT group was significantly higher than that in the conservative treatment group at one week after the treatment (47.8% vs 16.7%; P = 0.014) and at final visit (52.2% vs 20%; P = 0.014). After controlling confounding factors, ARI treatment was the only factor significantly associated with the amount of clinically significant visual improvement (OR, 4.364; 95 CI, 1.298-14.667; P = 0.017). A patient (4.3%) experienced retinal hemorrhage without symptom within 1 week after IAT treatment. No patients experienced new symptomatic cerebral infarction, intracranial hemorrhage, TIA, artery dissection, vascular perforation, and distal embolization during operation and within 1 week after IAT treatment.

CONCLUSIONS

IAT may be associated with better visual improvement within 16 hours after the onset of symptoms. Besides, IAT is feasible and associated with a low risk of periprocedural complications for ARI. This study will aid in feasibility testing and sample size calculations in advance of future, fully-powered efficacy studies for ARI.

Inhibition of SIZ1-mediated SUMOylation of HOOKLESS1 promotes light-induced apical hook opening in Arabidopsis

The apical hook protects cotyledons and the shoot apical meristem from mechanical injuries during seedling emergence from the soil. HOOKLESS1 (HLS1) is a central regulator of apical hook development, as a terminal signal onto which several pathways converge. However, how plants regulate the rapid opening of the apical hook in response to light by modulating HLS1 function remains unclear. In this study, we demonstrate that the small ubiquitin-like modifier (SUMO) E3 ligase SAP AND MIZ1 DOMAIN-CONTAINING LIGASE1 (SIZ1) interacts with HLS1 and mediates its SUMOylation in Arabidopsis thaliana. Mutating SUMO attachment sites of HLS1 results in impaired function of HLS1, indicating that HLS1 SUMOylation is essential for its function. SUMOylated HLS1 was more likely to assemble into oligomers, which are the active form of HLS1. During the dark-to-light transition, light induces rapid apical hook opening, concomitantly with a drop in SIZ1 transcript levels, resulting in lower HLS1 SUMOylation. Furthermore, ELONGATED HYPOCOTYL5 (HY5) directly binds to the SIZ1 promoter and suppresses its transcription. HY5-initiated rapid apical hook opening partially depended on HY5 inhibition of SIZ1 expression. Taken together, our study identifies a function for SIZ1 in apical hook development, providing a dynamic regulatory mechanism linking the post-translational modification of HLS1 during apical hook formation and light-induced apical hook opening.

Light-Elicited and Oxygen-Saved Iridium Nanocapsule for Oxidative Damage Intensified Oncotherapy

Regulating redox homeostasis in tumor cells and exploiting oxidative stress to damage tumors is an efficacious strategy for cancer therapy. However, the strengths of organic nanomaterials within this strategy are often ignored. In this work, a light-triggered reactive oxygen species (ROS) damaging nanoamplifier (IrP-T) was developed for enhanced photodynamic therapy (PDT). The IrP-T was fabricated with an amphiphilic iridium complex and a MTH1 inhibitor (TH287). Under green light stimulation, IrP-T catalyzed the oxygen in cells to generate ROS for realizing oxidative damage; meanwhile, TH287 increased the accumulation of 8-oxo-dGTP, further strengthening oxidative stress and inducing cell death. IrP-T could maximize the use of a small amount of oxygen, thus further boosting the efficacy of PDT in hypoxic tumors. The construction of nanocapsules provided a valuable therapeutic strategy for oxidative damage and synergizing PDT.

DriverGenePathway: Identifying driver genes and driver pathways in cancer based on MutSigCV and statistical methods

Although computational methods for driver gene identification have progressed rapidly, it is far from the goal of obtaining widely recognized driver genes for all cancer types. The driver gene lists predicted by these methods often lack consistency and stability across different studies or datasets. In addition to analytical performance, some tools may require further improvement regarding operability and system compatibility. Here, we developed a user-friendly R package (DriverGenePathway) integrating MutSigCV and statistical methods to identify cancer driver genes and pathways. The theoretical basis of the MutSigCV program is elaborated and integrated into DriverGenePathway, such as mutation categories discovery based on information entropy. Five methods of hypothesis testing, including the beta-binomial test, Fisher combined p-value test, likelihood ratio test, convolution test, and projection test, are used to identify the minimal core driver genes. Moreover, de novo methods, which can effectively overcome mutational heterogeneity, are introduced to identify driver pathways. Herein, we describe the computational structure and statistical fundamentals of the DriverGenePathway pipeline and demonstrate its performance using eight types of cancer from TCGA. DriverGenePathway correctly confirms many expected driver genes with high overlap with the Cancer Gene Census list and driver pathways associated with cancer development. The DriverGenePathway R package is freely available on GitHub: https://github.com/bioinformatics-xu/DriverGenePathway.

Hydrophilic magnetic host-guest Ti-phenolic networks: a promising material for the highly sensitive enrichment of glycopeptides and phosphopeptides

Protein glycosylation and phosphorylation are the two most important post-translational modifications, which play a vital role in physiological and pathological processes. Before the comprehensive characterization of glycoproteome/phosphoproteome through the mass spectrometry (MS) technique, it is necessary to perform a highly specific enrichment procedure because glycoproteins/phosphoproteins inherently occur in low abundances. Herein, we have reported a novel magnetic β-cyclodextrin-based host-guest Ti-phenolic network material, focusing on the simultaneous enrichment of glycopeptides/phosphopeptides via hydrophilic interaction chromatography and immobilized metal ion chromatography. Ti ions and glutathione-derived adamantine were introduced by metal-phenolic interactions and host-guest interactions. The material possesses biocompatibility, good hydrophilicity, strong magnetic response, metal chelation effect, and demonstrates an excellent enrichment ability towards glycopeptides/phosphopeptides. Combined with MS detection, high sensitivity (0.035/0.01 fmol for IgG/β-casein) and good reusability (6 times) were achieved. In addition, its outstanding specificity was validated in quantities as low as 500 : 1 : 1 for BSA : IgG : β-casein (m/m/m). Benefiting from these merits, the adsorbent material was successfully used for the simultaneous enrichment of phosphopeptides/glycopeptides from human serum and HeLa cell lysate and can be expected to exhibit great applicability for precious and small amounts of biosamples in the study of glycoproteomics/phosphoproteomics.

Database of human well-being and eco-sustainability under planetary pressures of the Belt and Road 1990-2018

The Belt and Road (B&R) Initiative is considered as closely aligned with the UN's Sustainable Development Goals by 2030 and could have a huge global impact. Its sustainable development issues have attracted worldwide attention. However, both the existing research and data accumulation on this aspect are seriously insufficient. Starting from the logic of the ultimate goal of sustainable development (namely within the ecological limitations, maximizing human well-being with minimum ecological consumption and minimizing the planetary pressures with maximum resource utilization efficiency), we have constructed a comprehensive evaluation method on sustainable development, namely the Consumption-Pressure-Output-Efficiency method in our previous study. Based on it, we provide a database with five datasets, which includes four core datasets (ecological consumption, planetary pressures, human well-being outputs and ecological well-being output efficiency) and a related dataset (biocapacity, ecological surplus/deficit, population), covering 61 B&R countries, B&R regional average and global average from 1990 to 2018. It can be used for further comprehensive research on sustainable development under planetary pressures and others of B&R.

Two-Way Reversible Shape Memory Behavior of Chitosan/Glycerol Film Triggered by Water

Reversible shape memory polymers (SRMPs) have been identified as having great potential for biomedical applications due to their ability to switch between different shapes responding to stimuli. In this paper, a chitosan/glycerol (CS/GL) film with a reversible shape memory behavior was prepared, and the reversible shape memory effect (SME) and its mechanism were systematically investigated. The film with 40% glycerin/chitosan mass ratio demonstrated the best performance, with 95.7% shape recovery ratio to temporary shape one and 89.4% shape recovery ratio to temporary shape two. Moreover, it shows the capability to undergo four consecutive shape memory cycles. In addition, a new curvature measurement method was used to accurately calculate the shape recovery ratio. The suction and discharge of free water change the binding form of the hydrogen bonds inside the material, which makes a great reversible shape memory impact on the composite film. The incorporation of glycerol can enhance the precision and repeatability of the reversible shape memory effect and shortens the time used during this process. This paper gives a hypothetical premise to the preparation of two-way reversible shape memory polymers.

Tunable Nonlinear Optical Response of ITO Films with Au@Ag Bimetallic Nanoparticles

The nonlinear optical (NLO) response of indium tin oxide films covered with Au@Ag colloid layer was characterized by a femtosecond single-beam open aperture (OA) Z-scan technique in this study. As the Au@Ag thickness increased, the transition from saturated absorption (SA) to reverse saturated absorption (RSA) was found in these ITO matrix composites. The nonlinear absorption coefficient for these composite materials can be regulated from -6.85 × 10^-7 m/W to 26.06 × 10^-7 m/W. In addition, this work also characterized the structure, morphology, and other optical properties of the specimen, and the finite-difference time-domain (FDTD) results were consistent with the experimental results. The NLO response of the ITO/Au@Ag composites can be attributed to the phase properties, synergistic competition effect, strong interaction based on the epsilon-near-zero (ENZ) mode, and localized surface plasmon resonance (LSPR) between the indium tin oxide films and Au@Ag.

Circ_0020256 induces fibroblast activation to drive cholangiocarcinoma development via recruitment of EIF4A3 protein to stabilize KLF4 mRNA

Cancer-associated fibroblasts (CAFs) are a kind of stromal cells in the cholangiocarcinoma (CCA) microenvironment, playing crucial roles in cancer development. However, the potential mechanisms of the interaction between CCA cells and CAFs remain obscure. This work investigated the role of circ_0020256 in CAFs activation. We proved circ_0020256 was up-regulated in CCA. High circ_0020256 expression facilitated TGF-β1 secretion from CCA cells, which activated CAFs via the phosphorylation of Smad2/3. Mechanistically, circ_0020256 recruited EIF4A3 protein to stabilize KLF4 mRNA and upregulate its expression, then KLF4 bound to TGF-β1 promoter and induced its transcription in CCA cells. KLF4 overexpression abrogated the inhibition of circ_0020256 silencing in TGF-β1/Smad2/3-induced CAFs activation. Furthermore, CCA cell growth, migration, and epithelial-mesenchymal transition were favored by CAFs-secreted IL-6 via autophagy inhibition. We also found circ_0020256 accelerated CCA tumor growth in vivo. In conclusion, circ_0020256 promoted fibroblast activation to facilitate CCA progression via EIF4A3/KLF4 pathway, providing a potential intervention for CCA progression.

Docking guided phase display to develop fusion protein with novel scFv and alkaline phosphatase for one-step ELISA salbutamol detection

Introduction

Salbutamol (SAL) is a β2 adrenergic receptor agonist which has potential hazardous effects for human health. It is very important to establish a sensitive and convenient method to monitor SAL.

Methods

Here we introduce a method to combine the information from docking and site specific phage display, with the aim to obtain scFv with high affinity to SAL. First, single chain variable fragment (scFv) antibodies against SAL were generated through phage display. By using molecular docking approach, the complex structure of SAL with antibody was predicted and indicated that H3 and L3 contribute to the binding. Then new libraries were created by randomization specific residues located on H3 and L3 according to the docking results.

Results and discussion

Anti-SAL scFv antibodies with high efficiency were finally identified. In addition, the selected scFv was fused with alkaline phosphatase and expressed in E coli to develop a rapid and low-cost one step ELISA to detect SAL.

Simultaneous amplification of DNA in a multiplex circular array shaped continuous flow PCR microfluidic chip for on-site detection of bacterial

Based on time to place conversion, continuous flow polymerase chain reaction (CF-PCR) can realize a rapid amplification of DNA by running the PCR reagent in a serpentine microchannel but a larger space is required for each sample, which greatly reduces the efficiency of the CF-PCR. Herein, we propose a multiplex circular array shaped CF-PCR microfluidic chip for on-site detection of bacteria. There were 12 serpentine microchannels which were distributed on the disc in an annular form, and each microchannel consisted of an inlet for sample injection, and an outlet for the detection of the PCR products based on fluorescence. Samples could be simultaneously driven into each inlet by a one-to-twelve diverter through a syringe. Moreover, the method of adding fluorescent dyes at the end of the microchannel can solve the inhibition effect of excessive fluorescent dyes on the PCR reaction. The process finished with simultaneous amplification of 12 different target genes from Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Escherichia coli, and on-site detection of their corresponding positives within 23 min. The fastest detectable PCR reaction time was 5.38 ± 0.2 min at a flow rate of 1 mL h^-1. For E. coli, the minimum detectable concentration was 2.5 × 10^-3 ng μL^-1 in this microfluidic system. Such a system can increase the throughput of CF-PCR for point-of-care testing of pathogens.

Corrigendum: Loss of hepatic Surf4 depletes lipid droplets in the adrenal cortex but does not impair adrenal hormone production

[This corrects the article DOI: 10.3389/fcvm.2021.764024.].

Construction of an La-BiVO4/O-Doped g-C3N4 Heterojunction Photocatalyst Embedded in Electrospinning Nanofibers

BiVO₄ has been widely used in the field of photocatalysis due to its nontoxic and moderate band gap. However, single BiVO₄ has the disadvantages of a high recombination rate of photogenerated carriers and weak response to visible light, inhibiting its photocatalytic applications. To explore viable solutions, a hybrid material composed of lanthanum-doped bismuth vanadate (La-BiVO₄) and oxygen-doped porous graphite carbon nitride (O-doped g-C₃N₄), i.e., La-BiVO₄/O-doped g-C₃N₄ powder, was prepared by a facile hydrothermal reaction and low-temperature calcination. Then, the powder was loaded on polyacrylonitrile nanofibers (NFs) through the electrospinning fiber technique. Various surface science characterizations, including transmission electron microscopy and nitrogen absorption and desorption analysis, confirmed the successful synthesis of a mesoporous heterojunction material. The La³⁺-doping as well as the porous morphologies and larger specific surface area of the O-doped g-C₃N₄ ultimately improve the photocatalytic abilities via a proposed Z-scheme heterojunction mechanism. The roles of La³⁺-doping and morphology modification in promoting the separation of the photogenerated carriers and broadening the optical absorption range were experimentally discussed. The RhB degradation experiment indicated that the La-BiVO₄/O-doped g-C₃N₄ powder has excellent photocatalytic activity, which is about 2.85 and 2 times higher than that of the pure BiVO₄ and O-doped g-C₃N₄, respectively. Meanwhile, the La-BiVO₄/O-doped g-C₃N₄ NF shows good stability and recoverability after a 10-cycle testing. Such a hybrid photocatalyst with a proposed Z-scheme heterojunction mechanism and good plasticity might pave a feasible way to fabricate a new library of photocatalysts.

Oligomeric Proanthocyanidins: An Updated Review of Their Natural Sources, Synthesis, and Potentials

Oligomeric Proanthocyanidins (OPCs), as a class of compounds widely found in plants, are particularly abundant in grapes and blueberries. It is a polymer comprising many different monomers, such as catechins and epicatechins. The monomers are usually linked to each other by two types of links, A-linkages (C-O-C) and B-linkages (C-C), to form the polymers. Numerous studies have shown that compared to high polymeric procyanidins, OPCs exhibit antioxidant properties due to the presence of multiple hydroxyl groups. This review describes the molecular structure and natural source of OPCs, their general synthesis pathway in plants, their antioxidant capacity, and potential applications, especially the anti-inflammatory, anti-aging, cardiovascular disease prevention, and antineoplastic functions. Currently, OPCs have attracted much attention, being non-toxic and natural antioxidants of plant origin that scavenge free radicals from the human body. This review would provide some references for further research on the biological functions of OPCs and their application in various fields.

Structural and Scintillation Properties of Ce3+:Gd3Al3Ga2O12 Translucent Ceramics Prepared by One-Step Sintering

Cerium-doped gadolinium aluminum gallium garnet (Ce³⁺:Gd₃Al₃Ga₂O₁₂, Ce³⁺:GAGG) ceramic is a promising scintillation material. In this study, Ce³⁺:Gd₃Al₃Ga₂O₁₂ scintillation ceramics were prepared by the one-step sintering of commercially available Gd₂O₃, Al₂O₃, Ga₂O₃, and CeO₂ powders in a flowing oxygen atmosphere at 1600 °C by solid-phase reaction sintering. For all the Ce³⁺:Gd₃Al₃Ga₂O₁₂ ceramic samples doped with different amounts of Ce³⁺ doping, dense ceramics were obtained. The structure, photoluminescence, and scintillation properties of the Ce³⁺:Gd₃Al₃Ga₂O₁₂ ceramics have been investigated. The average grain size of samples sintered at 1600 °C is about 2 μm. The X-ray excitation luminescence peak is around 560 nm, which is consistent with that of Ce³⁺:Gd₃Al₃Ga₂O₁₂ single crystals, matching well with the computed tomography X-ray detector's response sensitivity. The light yield is higher compared to the standard reference sample-lutetium yttrium orthosilicate single crystal.

Solid-state self-catalyzed growth of N-doped carbon tentacles on an M(Fe, Co)Se surface for rechargeable Zn-air batteries

A scalable and facile solid-catalyzed growth approach is reported to integrate N-doped carbon tentacles with metal selenide nanoparticles, showing great potential for mass production of non-precious metal catalysts for rechargeable Zn-air batteries.

Superhydrophobic and easy-to-clean full-packing nanopatterned microlens array with high-quality imaging

The high-quality imaging and easy cleaning property of microlens array (MLA) are two very important factors for its outdoor work. Herein, a superhydrophobic and easy-to-clean full-packing nanopatterned MLA with high-quality imaging is prepared by thermal reflow together with sputter deposition. Scanning electronic microscopy (SEM) images demonstrate that the sputter deposition method can improve 84% packing density of MLA prepared by thermal reflow to 100% and add nanopattern on the surface of microlens. The prepared full-packing nanopatterned MLA (npMLA) possess clear imaging with a significant increase of signal-to-noise ratio and higher transparency compared with the MLA prepared by thermal reflow. Besides for excellent optical properties, the full-packing surface displays a superhydrophobic property with a contact angle of 151.3°. Further, the full-packing contaminated by chalk dust become easier to be cleaned by nitrogen blowing and deionized water. As a result, the prepared full-packing is considered to be potential for various applications in the outdoor.

Modeling and in-depth analysis of the mid-spatial-frequency error influenced by actual contact pressure distribution in sub-aperture polishing

In ultra-precision optical processing, the sub-aperture polishing is prone to produce a mid-spatial-frequency (MSF) error. However, the generation mechanism of the MSF error is still not fully clarified, which seriously affects the further improvement of optical component performance. In this paper, it is proved that the actual contact pressure distribution between the workpiece and tool is a crucial source which affects the MSF error characteristics. A rotational periodic convolution (RPC) model is proposed to reveal the quantitative relationship among the contact pressure distribution, speed ratio (spin velocity/feed speed) and MSF error distribution. In-depth analyses show that the MSF error is linearly related to the symmetry level of contact pressure distribution and inversely proportional to the speed ratio, where the symmetry level is effectively evaluated by the proposed method based on Zernike polynomials. In the experiments, according to the actual contact pressure distribution obtained from the pressure-sensitive paper, the error rate of modeling results under different processing conditions is around 15%, which proves the validity of the proposed model. The influence of contact pressure distribution on the MSF error is further clarified through the establishment of RPC model, which can further promote the development of sub-aperture polishing.

Lower fluidic resistance of double-layer droplet continuous flow PCR microfluidic chip for rapid detection of bacteria

BACKGROUND

Rapid diagnosis of harmful microorganisms demonstrated its great importance for social health. Continuous flow PCR (CF-PCR) can realize rapid amplification of target genes by placing the microfluidic chip on heaters with different temperature. However, bubbles and evaporation always arise from heating, which makes the amplification not stable. Water-in-oil droplets running in CF-PCR microfluidic chip with uniform height takes long time because of the high resistance induced by long meandering microchannel. To overcome those drawbacks, we proposed a double-layer droplet CF-PCR microfluidic chip to reduce the fluidic resistance, and meanwhile nanoliter droplets were generated to minimize the bubbles and evaporation.

RESULTS

Experiments showed that (1) fluidic resistance could be reduced with the increase of the height of the serpentine microchannel if the height of the T-junction part was certain. (2) Running speed, the size and the number of generated droplets were positively correlated with the cross-sectional area of the T-junction and water pressure. (3) Droplet fusion happened at higher water pressure if other experimental conditions were the same. (4) 0.032 nL droplet was created if the cross-sectional area of T-junction and water pressure were 1600 μm² (40 × 40 μm) and 7 kPa, respectively. Finally, we successfully amplified the target genes of Porphyromonas gingivalis within 11'16″ and observed the fluorescence from droplets.

SIGNIFICANCE AND NOVELTY

Such a microfluidic chip can effectively reduce the high resistance induced by long meandering microchannel, and greatly save time required for droplets CF-PCR. It offers a new way for the rapid detection of bacterial.

Characterization of a Riboflavin-Producing Mutant of Bacillus subtilis Isolated by Droplet-Based Microfluidics Screening

Bacillus subtilis is one of the commonly used industrial strains for riboflavin production. High-throughput screening is useful in biotechnology, but there are still an insufficient number of articles focusing on improving the riboflavin production of B. subtilis by this powerful tool. With droplet-based microfluidics technology, single cells can be encapsulated in droplets. The screening can be carried out by detecting the fluorescence intensity of secreted riboflavin. Thus, an efficient and high-throughput screening method suitable for riboflavin production strain improvement could be established. In this study, droplet-based microfluidics screening was applied, and a more competitive riboflavin producer U3 was selected from the random mutation library of strain S1. The riboflavin production and biomass of U3 were higher than that of S1 in flask fermentation. In addition, the results of fed-batch fermentation showed that the riboflavin production of U3 was 24.3 g/L, an 18% increase compared with the parent strain S1 (20.6 g/L), and the yield (g riboflavin/100 g glucose) increased by 19%, from 7.3 (S1) to 8.7 (U3). Two mutations of U3 (sinR^G89R and icd^D28E) were identified through whole genome sequencing and comparison. Then they were introduced into BS168DR (parent of S1) for further analysis, which also caused riboflavin production to increase. This paper provides protocols for screening riboflavin-producing B. subtilis with droplet-based microfluidics technology and reveals mutations in riboflavin overproduction strains.

Textile waste water treatment: analysis of mapping knowledge domains

Textile waste water contains dyes and chemicals that produce harmful vapors and exhaust gases, which is hazardous to the environment and public health. Therefore, it must be carefully treated before discharged. To understand the research evolution in the research area of textile waste water treatment, based on bibliometrics, an in-depth analysis of the publications and hotspots in this area was presented in this paper. For the analysis, totally 6774 papers related to the research area that are published between the year 1964 and 2023 were collected from the Web of Science Core Collection. Using CiteSpace and VOSviewer as bibliometric analysis tools, the collaboration of countries, regions, and organizations was investigated. Besides, an analysis for citation and co-citation of journals, authors, references, and co-occurrence of keywords was performed. The evolution of research hotspots in the three major research directions related to degradation, oxidation, and adsorption is also analyzed in this paper. The analysis results show that researches related to oxidation and adsorption are active in recent years, while nanocomposite adsorbents and graphene oxide are the current research hotspots.