ABSTRACT
Photoelectrochemical (PEC) water splitting is gaining recognition as an effective method for producing green hydrogen. However, the absence of in situ, continuous decoding hydrogen generation tools hampers a detailed understanding of the physics and chemistry involved in hydrogen generation within PEC systems. In this article, we present a quantitative, spatiotemporally resolved optical sensor employing a fiber Bragg grating (FBG) to probe hydrogen formation and temperature characteristics in the PEC system. Demonstrating this principle, we observed hydrogen formation and temperature changes in a novel cappuccino cell using a BiVO4/TiO2 photoanode and a Cu2O/CuO/TiO2 photocathode. Our findings demonstrate that FBG sensors can probe dynamic hydrogen formation at 0.5 s temporal resolution; these sensors are capable of detecting hydrogen concentrations as low as 0.6 mM. We conducted in situ and continuous monitoring of hydrogen and temperature to ascertain various parameters: the rate of hydrogen production at the photocathode surface, the time to reach hydrogen saturation, the distribution of hydrogen and temperature, and the rate of hydrogen transfer in the electrolyte under both external bias and unbiased voltage conditions. These results contribute valuable insights into the design and optimization of PEC water-splitting devices, advancing the in situ comprehensive monitoring of PEC water-splitting processes.
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BACKGROUND: Acute liver injury (ALI) is a serious syndrome with a high mortality rate due to viral infection, toxic exposure, and autoimmunity, and its severity can range from mildly elevated liver enzymes to severe liver failure. Activation of the nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome is closely associated with the development of ALI, and the search for an inhibitor targeting this pathway may be a novel therapeutic option. Anoectochilus roxburghii polysaccharide (ARP) is a biologically active ingredient extracted from Anoectochilus roxburghii with immunomodulatory, antioxidant, and anti-inflammatory bioactivities and pharmacological effects. In this study, we focused on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced acute liver injury by ARP through inhibition of NLRP3 inflammasome. METHODS: An inflammasome activation model was established in bone marrow-derived macrophages (BMDMs) to investigate the effects of ARP on caspase-1 cleavage, IL-1ß secretion, and ASC oligomerization in inflammasomes under different agonists. We used the D-GalN/LPS-induced acute liver injury model in mice, intraperitoneally injected ARP or MCC950, and collected liver tissues, serum, and intraperitoneal lavage fluid for pathological and biochemical indexes. RESULTS: ARP effectively inhibited the activation of the NLRP3 inflammasome and had an inhibitory effect on non-classical NLRP3, AIM2, and NLRC4 inflammasomes. It also effectively inhibited the oligomerization of apoptosis-associated speck-like protein (ASC) from a variety of inflammatory vesicles. Meanwhile, ARP has good therapeutic effects on acute liver injury induced by D-GaIN/LPS. CONCLUSION: The inhibitory effect of ARP on a wide range of inflammasomes, as well as its excellent protection against acute liver injury, suggests that ARP may be a candidate for acute liver injury.
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The interfacial correlation factor f(m,x), where m refers to the interaction among ice, water and the substrate and x refers to the ratio of the critical nucleation size to the surface topography characteristic size of the substrate, plays a crucial role in the classical theory of heterogeneous ice nucleation as it significantly impacts the energy of nucleation. Generally, a smaller value of f(m,x) indicates a higher propensity for ice nucleation. The degree of structural compatibility between ice and the substrate greatly influences f(m,x), particularly on specific substrates. Several approaches have been proposed to calculate the lattice matching based on this idea, which allows whether a surface is favorable for nucleation to be determined. However, none of these methods adequately correlates the mismatch index with ice growth phenomena. In this paper, we embarked on a new attempt to calculate the mismatch index by combining the lattice parameter and Miller index (LPMI). Droplet freezing experiments have been carried out on α-Al2O3 and silicon surfaces with different Miller indices to verify the rationality of the LPMI method. Furthermore, we validated the LPMI method extensively against other works and further demonstrated its readiness, accuracy and universality for freezing problems. The results consistently show that δd = 2|di - ds|/(di + ds) with interplanar spacing more accurately predicts heterogeneous ice nucleation rates across a wide range of substrates than δ1 = (ai - as)/ai with the lattice parameter of ice and the substrate and is more generally applicable than δ2D = (di - di)/di with the distances between two adjacent and congener atoms on the same plane. We believe that the proposed approach will aid in the selection of substrates for promoting or inhibiting heterogeneous nucleation on a specific substrate.
ABSTRACT
Riparian zones, regarded as hotspots for greenhouse gas (GHG) emissions, where the variation in temperature sensitivity (Q10) of GHG emissions is crucial for assessing GHG budgets under global warming. However, the seasonal Q10 of GHG emissions from high-elevation riparian zones and underlying microbial mechanisms are poorly documented. This study focuses on seasonal Q10 patterns of GHG emissions from riparian zones along the Lhasa River on the Tibetan Plateau. CO2 and CH4 emissions from riparian soils were more sensitive to temperature in spring than in summer. The opposite trend was observed for Q10 of N2O emissions. Soil organic carbon (SOC) had relatively large direct effects on the Q10-CO2 value in summer, whereas soil nitrate nitrogen (SNO3--N) was the determinant of Q10-CO2 value in spring. mcrA:pmoA and soil microbial biomass C (SMBC) had strong direct effects on the Q10 of CH4 emissions in summer; the Q10-CH4 value in spring was significantly affected by the mcrA abundance. SMBC and the nirK + nirS abundance were key factors affecting the Q10-N2O value. Q10-CO2 and Q10-CH4 values exhibited strong seasonalities in the lower reaches of riparian soils, mainly due to the seasonalities of SNO3--N and mcrA:pmoA, respectively. The Q10-N2O value in the middle and upper reaches of riparian soils presented seasonality, which was largely due to the seasonalities of soil ammonia nitrogen and microbial biomass carbon. During thawing, plant productivity increased, substrate carbon was sufficient, microbial biomass increased, and inorganic nitorgen and denitrifier abundance decreased, causing 29.67% and 37.47% decreases in the Q10-CO2 and Q10-CH4 values, respectively, and a 70.85% increase in the Q10-N2O value, indicating that the potential release of N2O from riparian zones along the plateau river was more susceptible to seasonal variations. Our findings are conducive to accurately evaluating the potential contribution of GHG emissions from high-elevation riparian zones to global warming.
Subject(s)
Air Pollutants , Environmental Monitoring , Greenhouse Gases , Methane , Seasons , Temperature , Greenhouse Gases/analysis , Environmental Monitoring/methods , Methane/analysis , Air Pollutants/analysis , Soil/chemistry , Carbon Dioxide/analysis , Tibet , Rivers/chemistry , Global Warming , Nitrous Oxide/analysisABSTRACT
A growing demand for sustainable, alternative protein sources that are nutrient-dense, such as microorganisms, and insects, has gradually evolved. When paired with effective processing techniques, yeast cells contain substantial substances that could supply the population's needs for food, medicine, and fuel. This review article explores the potential of yeast proteins as a sustainable and viable alternative to animal and plant-based protein sources. It highlights the various yeast protein extraction methods including both mechanical and non-mechanical methods. The application of nanoparticles is one example of the fast-evolving technology used to damage microbial cells. SiO2 or Al2O3 nanoparticles break yeast cell walls and disrupt membranes, releasing intracellular bioactive compounds. Succinylation of yeast protein during extraction can increase yeast protein extraction rate, lower RNA concentration, raise yeast protein solubility, increase amino acid content, and improve yeast protein emulsification and foaming capabilities. Combining physical and enzymatic extraction methods generates the most representative pool of mannose proteins from yeast cell walls. Ethanol or isoelectric precipitation purifies mannose proteins. Mannoproteins can be used as foamy replacement for animal-derived components like egg whites due to their emulsification, stability, and foaming capabilities. Yeast bioactive peptide was separated by ultrafiltration after enzymatic hydrolysis of yeast protein and has shown hypoglycemic, hypotensive, and oxidative action in vitro studies. Additionally, the review delves into the physicochemical properties and stability of yeast-derived peptides as well as their applications in the food industry. The article infers that yeast proteins are among the promising sources of sustainable protein, with a wide range of potential applications in the food industry.
Subject(s)
Mannose , Saccharomyces cerevisiae , Animals , Silicon Dioxide , Food Industry , Fungal Proteins , Plant Proteins/chemistry , PeptidesABSTRACT
Yarrowia lipolytica is widely used in biotechnology to produce recombinant proteins, food ingredients and diverse natural products. However, unstable expression of plasmids, difficult and time-consuming integration of single and low-copy-number plasmids hampers the construction of efficient production pathways and application to industrial production. Here, by exploiting sequence diversity in the long terminal repeats (LTRs) of retrotransposons and ribosomal DNA (rDNA) sequences, a set of vectors and methods that can recycle multiple and high-copy-number plasmids was developed that can achieve stable integration of long-pathway genes in Y. lipolytica. By combining these sequences, amino acids and antibiotic tags with the Cre-LoxP system, a series of multi-copy site integration recyclable vectors were constructed and assessed using the green fluorescent protein (HrGFP) reporter system. Furthermore, by combining the consensus sequence with the vector backbone of a rapidly degrading selective marker and a weak promoter, multiple integrated high-copy-number vectors were obtained and high levels of stable HrGFP expression were achieved. To validate the universality of the tools, simple integration of essential biosynthesis modules was explored, and 7.3 g/L of L-ergothioneine and 8.3 g/L of (2S)-naringenin were achieved in a 5 L fermenter, the highest titres reported to date for Y. lipolytica. These novel multi-copy genome integration strategies provide convenient and effective tools for further metabolic engineering of Y. lipolytica.
Subject(s)
Yarrowia , Yarrowia/genetics , Yarrowia/metabolism , Plasmids/genetics , Metabolic Engineering , Biotechnology , Recombinant Proteins/geneticsABSTRACT
Droplet directional transport is one of the central topics in microfluidics and lab-on-a-chip applications. Selective transport of diverse droplets, particularly in another liquid phase environment with controlled directions, is still challenging. In this work, we propose an electric-field gradient-driven droplet directional transport platform facilitated by a robust lubricant surface. On the platform, we clearly demonstrated a liquid-inherent critical frequency-dominated selective transport of diverse droplets and a driving mechanism transition from electrowetting to liquid dielectrophoresis. Enlightened by the Kelvin-Helmholtz theory, we first realize the directional droplet transport in another liquid phase whenever a permittivity difference exists. Co-transport of multiple droplets and various combinations of droplet types, as well as multifunctional droplet transport modes, are realized based on the presented powerful electric-field gradient-driven platform, overcoming the limitations of the surrounding environment, liquid conductivity, and intrinsic solid-liquid wetting property existing in traditional droplet transport strategies. This work may inspire new applications in liquid separation, multiphase microfluidic manipulation, chemical reagent selection, and so on.
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Self-assembling peptides are valuable building blocks to fabricate supramolecular biomaterials, which have broad applications from biomedicine to biotechnology. However, limited choices to induce different globular proteins into hydrogels hinder these designs. Here, an easy-to-implement and tunable self-assembling strategy, which employs Ure2 amyloidogenic peptide, are described to induce any target proteins to assemble into supramolecular hydrogels alone or in combination with notable compositional control. Furthermore, the collective effect of nanoscale interactions among amyloid nanofibrils and partially disordered elastomeric polypeptides are investigated. This led to many useful macroscopic material properties simultaneously emerging from one pure protein material, i.e. strong adhesion to any substrates under wet conditions, rapidly self--assembling into robust and porous hydrogels, adaptation to remodeling processes, strongly promoting cell adhesion, proliferation and differentiation. Moreover, he demonstrated this supramolecular material's robust performance in vitro and vivo for tissue engineering, cosmetic and hemostasis applications and exhibited superior performance compared to corresponding commercial counterparts. To the best of his knowledge, few pure protein-based materials could meet such seemingly mutually exclusive properties simultaneously. Such versatility renders this novel supramolecular nanomaterial as next-generation functional protein-based materials, and he demonstrated the sequence level modulation of structural order and disorder as an untapped principle to design new proteins.
Subject(s)
Amyloidogenic Proteins , Insect Proteins , Nanostructures , Peptides/chemistry , Nanostructures/chemistry , Amyloid/chemistry , Biocompatible Materials/chemistry , Hydrogels/chemistryABSTRACT
Reversed-electrowetting based droplet electricity generator (REWOD-DEG) shows merits in high power densities, tunable output formats, and wide adaptability to diverse mechanical energies. However, the surface charge trapping and dielectric failure, which are also common challenges for electrowetting system, hinders the development of reliable REWOD-DEGs for long-term running. We innovatively introduce a slippery lubricant-infused porous surface (SLIPS) into REWOD-DEG. Benefits from the significant inhibitory effect for surface charge trapping and ambient contamination, self-healing characteristic given by SLIPS, and robust reversed-electrowetting based energy harvesting were achieved. The SLIPS enhanced REWOD-DEG experienced 100 days of intermittent energy harvesting without deterioration. In addition, the device shows robust performances when exposed to a variety of extreme working conditions, like low temperature, pH, humidity, fouling, and even scratching. This work may address the core application challenges of REWOD based devices, and inspire the development of other robust droplet-based electricity generators.
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BACKGROUND: Children with acute lymphoblastic leukaemia (ALL) experience multiple symptoms that occur in complicated patterns and negatively affect patient outcomes. To date, no systematic review has been performed on the prevalence of symptoms in children with ALL. OBJECTIVE: The study aimed to report and analyse the prevalence of symptoms in children with ALL during treatment. METHODS: A systematic search was conducted in eight databases (PubMed, Ovid Embase, Web of Science, CINAHL, PsycINFO, China WanFang Database, China Science and Technology Journal Database, and China National Knowledge Infrastructure) for studies published between January 1, 2000, and August 12, 2023. The methodological quality of the included studies was evaluated and a meta-analysis was performed to pool the prevalence of symptoms. RESULTS: In total, 17 studies were included, from which 34 symptoms were identified. The symptom prevalence ranged between 1.5 and 91.0% and the most frequent symptoms observed were fatigue, lack of energy, dry mouth, lack of appetite, sweating, and feeling irritable, which occurred in at least 60% of the patients. CONCLUSIONS: Symptoms remain highly prevalent in paediatric patients with ALL, which provides support for the need for symptom assessment in the clinical setting. Specific intervention is urgently needed to mitigate the symptoms in children with ALL and help them cope with the symptom burden.
Subject(s)
Emotions , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Humans , Child , Prevalence , China/epidemiology , Fatigue/epidemiology , Fatigue/etiology , Fatigue/therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/complications , Precursor Cell Lymphoblastic Leukemia-Lymphoma/epidemiologyABSTRACT
Grasslands represent the largest ecosystem in China, accurate and efficient extraction of its integrated vegetation cover (IVC) plays a crucial role in supporting policy decisions. This study presented a method for grassland monitoring via IVC derived from high-resolution satellite data. Taking the multispectral data of Gaofen-1 (GF-1) and Gaofen-6 (GF-6) with 16 m resolution as the main data source, vegetation cover of six representative regions was assessed based on mixed-pixel decomposition model. Using grassland vegetation cover and ratio of grassland area, the IVC in each site was calculated and verified against ground-measured sample data. The results showed that the IVC of grassland was closely related to vegetation habitat driven by regional hydrothermal regime. Yichang grassland, dominated with warm-temperate shrub tussock type, had the highest IVC (80.06 %) due to its favorable hydrothermal conditions. For the main grassland types in Hulunbuir and Gansu Province (temperate meadow steppe and temperate typical steppe), the IVC was 79.38 % and 58.46 %, respectively. In both Xilin-Gol and Nagqu, vegetation cover decreased gradually from east to west, and the IVC was merely 42.83 % and 42.61 %, respectively. Both regions are endowed with less hydrothermal resources to different degrees. Alxa, with a predominately temperate desert landscape, had the lowest IVC of 15.58 % where precipitation is extremely scarce. Based on the grass species of measured samples, the dominant species and biodiversity of different grassland types in Gansu Province and Hulunbuir Municipality of Inner Mongolia Autonomous Region were analyzed. The results showed that the meadow grassland has the richest biodiversity. The temperate mountain meadows in Gansu Province have a high species diversity, with a total of 90 grass species, and the lowland meadows in Hulunbuir have a total of 49 grass species. This study utilizes high-resolution data to conduct large-scale vegetation monitoring, which is a viable alternative for efficient assessment of steppe ecology.
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The waste-to-energy and manganese industries face significant ecological challenges due to two major risk sources: municipal solid waste incineration (MSWI) fly ash and electrolytic manganese residue (EMR), especially, the MSWI fly is classified as hazardous waste. High temperature melting is a promising method for harmless disposal of solid wastes. However, it has yet to be industrialized due to the high costs and energy consumption. This study proposes using EMR as an additive to co-melt with MSWI fly ash, aiming to develop a method that minimizes energy consumption while producing high value-added products. To this end, the phase evolution and phase-change cooling characteristics during the co-melting process of MSWI fly ash and EMR were experimentally investigated. XRD and SEM analyses revealed that pure vitreous slag can be obtained when mixtures are heated to 1500 °C for 120 min with ≥40 wt% EMR addition under natural air-cooling conditions. Additionally, to produce vitreous slag by air-cooling and increase MSWI fly ash treatment capacity, the molten mixture with 30 wt% EMR addition was adopted in the directional solidification experiments to establish a predictive model relating the average cooling rate to the glass content. The findings ultimately contribute to the advancement of melting-based industrial applications.
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PURPOSE: To investigate the level of fear of cancer recurrence (FCR) in spouses of patients with lymphoma and its relationship with patients' FCR, as well as the correlations between FCR, sense of spousal support (SSS), anxiety, and depression in the couples. METHODS: A cross-sectional study of 233 couples where one partner had lymphoma was conducted from May 2021 to February 2022. Participants provided demographic information and completed the Spouse Support Inventory and Hospital Anxiety and Depression Scale. The Fear of Progression Questionnaire (for patients) and Fear of Progression Questionnaire for Partners (for spouses) were used to measure FCR. Descriptive analyses, t-tests, variance analysis, Spearman's correlation analysis, and multiple linear regression analysis was performed. RESULTS: The prevalence of FCR, anxiety, and depression in patients was 37.7%, 68.7%, and 83.3%, respectively. The prevalence of FCR, anxiety, and depression in spouses was 56.2%, 78.1%, and 81.1%, respectively. Spouses' FCR scores were higher than those of patients, whereas patients' SSS and anxiety scores were higher than those of their spouses. Multiple linear regression analysis showed that patients' anxiety and SSS, as well as spouses' FCR were significantly associated with patients' FCR. Variables significantly associated with higher FCR among spouses were anxiety, per capita monthly household income, and patients' FCR. CONCLUSIONS: Patients with lymphoma and their spouses have a certain degree of FCR, anxiety, and depression. FCR levels in spouses are higher than in patients. IMPLICATIONS FOR CANCER SURVIVORS: Psychological support interventions for couples may be effective in reducing FCR and facilitating family adaptation to cancer.
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The assessment of land cover and changes will help to understand the temporal and spatial pattern of land cover in the world and the Belt and Road (B&R) region, and provide reference information for global sustainable development and the Belt and Road construction. In this paper, the 1 km global land cover classification maps of 2016 and 2020 with a high accuracy of 88% are mapped using the Moderate Resolution Imaging Spectroradiometer (MODIS) time series surface reflectance products. Based on the maps, the land cover status of the world and the Belt and Road region, the land cover change from 2016 to 2020, and the mutual transformation characteristics between various types, are analyzed. The research results indicate that from 2016 to 2020, the global change rates of cropland, forest, grassland, and impervious surface are 0.25%, 0.22%, 0.08% and 3.41%, respectively. In the Belt and Road region, the change rates of cropland, forest, grassland, and impervious surface are 0.42%, 0.60%, -0.55% and 2.98% respectively. The assessment results will help to clarify the spatial pattern of land cover change in the five years from 2016 to 2020, so as to provide valuable scientific information for the global realization of sustainable development goals and the construction of the B&R.
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BACKGROUND: Escherichia coli can cause severe infections. The latter can lead to disseminated intravascular coagulation (DIC). The importance of an early diagnosis of DIC is illustrated through this case report. AIM: Review the utility and shortcomings of representative clinical indicators of E coli infection and DIC. CASE REPORT: A 48-year-old man presented with diarrhea, nausea, and vomiting with fever of 2-day duration, during which consciousness was lost for 12 hour. Hematology was undertaken. The coagulation profile, liver function, and kidney function were determined, and blood cultures undertaken. The final diagnosis was acute gastroenteritis complicated by DIC. Meropenem (1.0 g, q8h, i.v.) was started, along with active replacement of fluids. Anticoagulant therapy (low-molecular-weight heparin 0.4 mL, q.d.s.) was given. Plasma supplementation of coagulation factors and albumin was applied. On day-5 of therapy, hematology showed the platelet count, D-dimer level, and prothrombin time to be improved significantly. Low-molecular-weight heparin treatment was stopped and antibiotic treatment was continued for 1 week. The patient made a full recovery. CONCLUSIONS: In severe infection, timely assessment of the platelet count, procalcitonin level, coagulation function, as well as rational use of antibiotics, can improve the prognosis of patients.
Subject(s)
Disseminated Intravascular Coagulation , Male , Humans , Middle Aged , Disseminated Intravascular Coagulation/diagnosis , Disseminated Intravascular Coagulation/etiology , Escherichia coli , Anticoagulants/therapeutic use , Blood Coagulation Tests , Heparin, Low-Molecular-WeightABSTRACT
PURPOSE: This study aimed to explore the positive experiences of dyadic coping between patients with acute leukemia and their spouses in China, and to highlight the target factors that could promote coping and adaptation. METHODS: A qualitative descriptive study was employed. This study was conducted at a tertiary hospital in China from September 2021 to February 2022. A purposive sampling method was used to select participants, and 17 patients diagnosed with acute leukemia and their spouses were interviewed. Qualitative data were analyzed using the content analysis method. This study followed the COREQ checklist. RESULTS: This study's data were categorized into five themes and twelve subthemes: (1) adapting to a new role-couples used role adjustments to adapt; (2) commitment to companionship-patients benefit from spousal commitment in word or in deed; (3) active communication-allows couples to get to know each other better; (4) white lies-shield partner from negative information; (5) seeking external support-outside of couple cohesion. In sum, positive dyadic coping experiences between couples follow the marital commitment of "never forsake." CONCLUSIONS: This study contributes new knowledge to the understanding of the dyadic coping experiences of patients with acute leukemia and their spouses within the Chinese social-cultural context and contributes to cross-cultural comparisons. The results can be used to design and implement couple-based intervention programs to support couples by enhancing their mutual support to cope with and adjust to acute leukemia effectively.
Subject(s)
Leukemia , Spouses , Humans , Adaptation, Psychological , Interpersonal Relations , Stress, Psychological , Leukemia/therapyABSTRACT
Lipids are a large group of essential nutrients in daily diets that provide energy and maintain various physiological functions. As the global population is rapidly expanding, there is an urgent need to enhance the production and quality of food lipids. The development of modern biotechnology allows the manipulation of oil production in plants and microorganisms and the improvement of the nutritional value of food lipids. Various metabolic engineering strategies have been exploited to increase oil production and produce value-added oils in traditional oil crops and other novel lipid sources (e.g., plant vegetative tissues, microalgae, and oleaginous microorganisms). Furthermore, natural lipid structures can be modified by lipases to prepare functional lipids, e.g., diacylglycerols, medium-long-medium-type structured triacylglycerols, human milk-fat substitutes, and structuralphospholipids, for specific nutritional demands. In this review, we focus on the recent advances in metabolic engineering of lipid production in plants and microorganisms, and the preparation of functional lipids via biocatalysis.
Subject(s)
Biotechnology , Oils , Humans , Triglycerides/chemistry , Lipase/chemistry , Lipase/metabolismABSTRACT
As the gold standard for nucleic acid detection, full-process polymerase chain reaction (PCR) analysis often falls into the dilemma of complex workflow, time-consuming, and high equipment costs. Therefore, we designed and optimized a DNA quantification microfluidic system by strategically integrating sample pretreatment and a smartphone-readable gradient plasmonic photothermal (GPPT) continuous-flow PCR (CF-PCR). Through preloading and sequential injection of immiscible extraction reagents, combined with magnetic bead (MB) manipulation, the microfluidic chip successfully purified and concentrated 100 µL of HBV-DNA spiked plasma into a 20-µL purified sample within 14 minutes. With a digital PCR platform, the optimized experiments showed that the DNA extraction efficiency can reach 69% at an immiscible reagent configuration ratio of 10 : 10 : 1 : 12 : 2 (sample : lysis/binding buffer : MB : silicone oil : eluent) and a flow rate of 25 µL min-1. For the first time, we used gold nanorod (AuNR)-doped PDMS to prepare a CF-PCR submodule for the amplification of a 40 µL PCR mixture. Due to the plasmonic photothermal effect of AuNRs and the gradient intensity of an expanded laser spot, the PCR thermal gradient was formed on a coin-sized area. The compact annular thermal-microfluidic layout, optimized DNA dye concentration, and chip transmittance synergistically enable a rarely reported smartphone-based fluorescence CF-PCR, greatly simplifying thermal control and detection setup. Prototype construction and validation experiments show that the microsystem can complete the sample-to-answer quantification of HBV-DNA with a dynamic linear range from 1.2 × 101 to 1.2 × 106 copies per µL in â¼37 minutes. This novel microfluidic solution effectively bridges the technical gap between the CF-PCR, sample pretreatment and result characterization, making the workflow standardized and rapid and requiring <15% of the commercial instrument cost. The simplicity, rapidity and low cost of this work make it promising for applications in decentralized laboratories and low-resource settings.
Subject(s)
Microfluidic Analytical Techniques , Microfluidics , DNA, Viral/genetics , Smartphone , Silicone Oils , Polymerase Chain Reaction , Indicators and ReagentsABSTRACT
We report a tomographic absorption spectroscopy (TAS) study of water vapor transport in a laminar jet issuing into the ambient. The jet was generated using compressed dry air that was straightened by a honeycomb and a smooth contraction nozzle. A TAS scheme using the water vapor in the ambient as absorbing species and the absorption line near 1368.598 nm was proposed to study the H2O transport in the laminar jet with an inverse concentration gradient. One-dimensional tomography was conducted at various heights above the nozzle, and the results were validated by the predictions from computational fluid dynamics (CFD) simulations. Particularly, the variations in the concentration gradient in the shear layer at different heights were captured. The 2D distribution of water concentration in the dry laminar jet was obtained experimentally. The present study shows that TAS has great potential in the research of mass transfer and scalar field of gaseous flows.