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1.
Anal Chem ; 96(17): 6634-6642, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38622069

RESUMEN

The ability to deploy decentralized laboratories with autonomous and reliable disease diagnosis holds the potential to deliver accessible healthcare services for public safety. While microfluidic technologies provide precise manipulation of small fluid volumes with improved assay performance, their limited automation and versatility confine them to laboratories. Herein, we report the utility of multicolor assay-on-a-chip processed by robotic operation (MACpro), to address this unmet need. The MACpro platform comprises a robot-microfluidic interface and an eye-in-hand module that provides flexible yet stable actions to execute tasks in a programmable manner, such as the precise manipulation of the microfluidic chip along with different paths. Notably, MACpro shows improved detection performance by integrating the microbead-based antibody immobilization with enhanced target recognition and multicolor sensing via Cu2+-catalyzed plasmonic etching of gold nanorods for rapid and sensitive analyte quantification. Using interferon-gamma as an example, we demonstrate that MACpro completes a sample-to-answer immunoassay within 30 min and achieves a 10-fold broader dynamic range and a 10-fold lower detection limit compared to standard enzyme-linked immunosorbent assays (0.66 vs 5.2 pg/mL). MACpro extends the applications beyond traditional laboratories and presents an automated solution to expand diagnostic capacity in diverse settings.


Asunto(s)
Dispositivos Laboratorio en un Chip , Robótica , Humanos , Inmunoensayo/métodos , Interferón gamma/análisis , Técnicas Analíticas Microfluídicas/instrumentación , Oro/química
2.
Chem Rev ; 122(9): 8126-8180, 2022 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-35234463

RESUMEN

Microorganisms have gained defense systems during the lengthy process of evolution over millions of years. Such defense systems can protect them from being attacked by invading species (e.g., CRISPR-Cas for establishing adaptive immune systems and nanopore-forming toxins as virulence factors) or enable them to adapt to different conditions (e.g., gas vesicles for achieving buoyancy control). These microorganism defense systems (MDS) have inspired the development of biosensors that have received much attention in a wide range of fields including life science research, food safety, and medical diagnosis. This Review comprehensively analyzes biosensing platforms originating from MDS for sensing and imaging biological analytes. We first describe a basic overview of MDS and MDS-inspired biosensing platforms (e.g., CRISPR-Cas systems, nanopore-forming proteins, and gas vesicles), followed by a critical discussion of their functions and properties. We then discuss several transduction mechanisms (optical, acoustic, magnetic, and electrical) involved in MDS-inspired biosensing. We further detail the applications of the MDS-inspired biosensors to detect a variety of analytes (nucleic acids, peptides, proteins, pathogens, cells, small molecules, and metal ions). In the end, we propose the key challenges and future perspectives in seeking new and improved MDS tools that can potentially lead to breakthrough discoveries in developing a new generation of biosensors with a combination of low cost; high sensitivity, accuracy, and precision; and fast detection. Overall, this Review gives a historical review of MDS, elucidates the principles of emulating MDS to develop biosensors, and analyzes the recent advancements, current challenges, and future trends in this field. It provides a unique critical analysis of emulating MDS to develop robust biosensors and discusses the design of such biosensors using elements found in MDS, showing that emulating MDS is a promising approach to conceptually advancing the design of biosensors.


Asunto(s)
Técnicas Biosensibles , Nanoporos , Ácidos Nucleicos , Sistemas CRISPR-Cas , Proteínas
3.
Soft Matter ; 19(7): 1293-1299, 2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36524440

RESUMEN

Precise manipulation of liquid metal (LM) droplets possesses the potential to enable a wide range of applications in reconfigurable electronics, robotics, and microelectromechanical systems. Although a variety of methods have been explored to actuate LM droplets on a 2D plane, versatile 3D manipulation remains a challenge due to the difficulty in overcoming their heavy weight. Here, foam-core liquid metal (FCLM) droplets that can maintain the surface properties of LM while significantly reducing the density are developed, enabling 3D manipulation in an electrolyte. The FCLM droplet is fabricated by coating LM on the surface of a copper-grafted foam sphere. The actuation of the FCLM droplet is realized by electrically inducing Marangoni flow on the LM surface. Two motion modes of the FCLM droplet are observed and studied and the actuation performance is characterized. Multiple FCLM droplets can be readily controlled to form 3D structures, demonstrating their potential to be further developed to form collaborative robots for enabling wider applications.

4.
Anal Chem ; 94(21): 7475-7482, 2022 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-35578791

RESUMEN

Current methods for fabricating microparticles offer limited control over size and shape. Here, we demonstrate a droplet microfluidic method to form polyhedral microparticles with controlled concavity. By manipulating Laplace pressure, buoyancy, and particle rheology, we generate microparticles with diverse shapes and curvatures. Additionally, we demonstrate the particles provide increased capture efficiency when used for particle-templated emulsification. Our approach enables microparticles with enhanced chemical and biological functionality.


Asunto(s)
Técnicas Analíticas Microfluídicas , Técnicas Analíticas Microfluídicas/métodos , Microfluídica , Tamaño de la Partícula , Reología
5.
Appl Microbiol Biotechnol ; 105(2): 587-597, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33394159

RESUMEN

Light management strategy can be used to improve algal biomass and nutrient production. However, the response of algal metabolism to different light qualities, especially their interaction with other environmental factors, is not well understood. This study focuses on the interactive effects of light quality and culturing temperature on algal protein content and carbohydrate content of C. reinhardtii. Three LED light sources (blue light, red-orange light, and white-yellow light) were applied to grow algae in batch cultures with a light intensity of 105 µmol/m2s under the temperatures of 24 °C to 32 °C. The protein and carbohydrate content were measured in both the late exponential growth phase and the late stationary growth phase. The results revealed that there was an interactive effect of light quality and culturing temperature on the protein and carbohydrate content. The combined conditions of blue light and a temperature of 24 °C or 28 °C, which induced a larger algal cell size with a prolonged cell cycle and a low division rate, resulted in the highest protein content; the protein mass fraction and concentration were 32% and 52% higher than that under white-yellow light at 32 °C. The combined conditions of red-orange light and a temperature of 24 °C, which promoted both the cell division and size growth, enhanced the carbohydrate content; the carbohydrate mass fraction and concentration were 161% and 155% higher than that under white-yellow light at 24 °C. When there was temperature stress (32 °C) or nutrient stress, the effect of light quality reduced, and the difference of protein and carbohydrate content among the three light qualities decreased. KEY POINTS: • Studied light quality-temperature interactive effect on protein, carbohydrate synthesis. • Protein content was high under low cell division rate. • Carbohydrate content was high under high cell division and cell size growth rate.


Asunto(s)
Metabolismo de los Hidratos de Carbono , Carbohidratos , Biomasa , Tamaño de la Célula , Temperatura
6.
Pharmacology ; 105(9-10): 505-513, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32784309

RESUMEN

OBJECTIVE: This research was aimed to explore protective effects of allicin on rat model of myocardial infarction via JNK signaling pathway. METHODS: Rat myocardial ischemia model was established with subcutaneous injection of isoproterenol (ISO). Seventy-five rats were randomly divided into 5 groups (n = 15): sham group, ISO group, low-dose group (1.2 mg/kg/days for 7 days), medium-dose group (1.8 mg/kg/days for 7 days), and high-dose group (3.6 mg/kg/days for 7 days). Routine HE staining and Masson staining were performed to observe myocardial histopathology. The expression of oxidative stress-related indicators, heart tissue apoptosis-related proteins, and JNK and p-JNK proteins were measured for different groups. RESULTS: Compared with the sham group, the T wave value of the ISO group was significantly increased (p < 0.01). When allicin was administered, the T wave values at different time points in all groups were all decreased. Compared with the sham group, the ratio of eNOS, Bcl-2/Bax was significantly decreased, and p-eNOS, iNOS, caspase-3, caspase-9, and Cyt-c were significantly elevated in the ISO group (p < 0.05). After allicin was administered, significant changes in these proteins were observed in the medium- and high-dose groups. There was no significant change in the expression of JNK protein in the ISO group compared with the sham group; however, the expression of eNOS and p-JNK protein were significantly upregulated (p < 0.01) and the expression of p-eNOS and iNOS were significantly downregulated (p < 0.01). When allicin was administered, expression of p-JNK protein was significantly downregulated. CONCLUSION: Allicin can reduce oxidative stress damage and cardiomyocyte apoptosis in rat model of myocardial infarction and can significantly regulate JNK signaling pathway.


Asunto(s)
Antioxidantes/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/metabolismo , Ácidos Sulfínicos/farmacología , Animales , Antioxidantes/uso terapéutico , Apoptosis/efectos de los fármacos , Modelos Animales de Enfermedad , Disulfuros , Isoproterenol/toxicidad , Proteínas Quinasas JNK Activadas por Mitógenos/efectos de los fármacos , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Masculino , Infarto del Miocardio/inducido químicamente , Miocardio/metabolismo , Miocardio/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Óxido Nítrico Sintasa de Tipo II/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo III/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo III/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Ácidos Sulfínicos/uso terapéutico
7.
Soft Matter ; 14(35): 7113-7118, 2018 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-30182111

RESUMEN

The locomotion of liquid metal droplets enables enormous potential for realizing various applications in microelectromechanical systems (MEMSs), biomimetics, and microfluidics. However, current techniques for actuating liquid metal droplets are either associated with intense electrochemical reactions or require modification of their physical properties by coating/mixing them with other materials. These methods either generate gas bubbles or compromise the stability and liquidity of the liquid metal. Here, we introduce an innovative method for controlling the locomotion of liquid metal droplets using Lorentz force induced by magnetic fields. Remarkably, utilizing a magnetic field to induce actuation avoids the generation of gas bubbles in comparison to the method of forming a surface tension gradient on the liquid metal using electrochemistry. In addition, the use of Lorentz force avoids the need of mixing liquid metals with ferromagnetic materials, which may compromise the liquidity of liquid metals. Most importantly, we discover that the existence of a slip layer for liquid metal droplets distinguishes their actuation behaviors from solid metallic spheres. We investigate the parameters affecting the actuation behavior of liquid metal droplets and explore the science behind its operation. We further conducted a series of proof-of-concept experiments to verify the controllability of our method for actuating liquid metal droplets. As such, we believe that the presented technique represents a significant advance in comparison to reported actuation methods for liquid metals, and possesses the potential to be readily adapted by other systems to advance the fields of MEMS actuation and soft robotics.

8.
Anal Bioanal Chem ; 410(3): 791-800, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29214530

RESUMEN

Recent breakthroughs in organ-on-a-chip and related technologies have highlighted the extraordinary potential for microfluidics to not only make lasting impacts in the understanding of biological systems but also to create new and important in vitro culture platforms. Adipose tissue (fat), in particular, is one that should be amenable to microfluidic mimics of its microenvironment. While the tissue was traditionally considered important only for energy storage, it is now understood to be an integral part of the endocrine system that secretes hormones and responds to various stimuli. As such, adipocyte function is central to the understanding of pathological conditions such as obesity, diabetes, and metabolic syndrome. Despite the importance of the tissue, only recently have significant strides been made in studying dynamic function of adipocytes or adipose tissues on microfluidic devices. In this critical review, we highlight new developments in the special class of microfluidic systems aimed at culture and interrogation of adipose tissue, a sub-field of microfluidics that we contend is only in its infancy. We close by reflecting on these studies as we forecast a promising future, where microfluidic technologies should be capable of mimicking the adipose tissue microenvironment and provide novel insights into its physiological roles in the normal and diseased states. Graphical abstract This critical review focuses on recent developments and challenges in applying microfluidic systems to the culture and analysis of adipocytes and adipose tissue.


Asunto(s)
Adipocitos/metabolismo , Tejido Adiposo/metabolismo , Técnicas Analíticas Microfluídicas/métodos , Adipocitos/citología , Adipoquinas/metabolismo , Tejido Adiposo/citología , Animales , Técnicas de Cultivo de Célula/instrumentación , Técnicas de Cultivo de Célula/métodos , Diseño de Equipo , Ácidos Grasos/metabolismo , Glucosa/metabolismo , Hormonas/metabolismo , Humanos , Insulina/metabolismo , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas de Cultivo de Tejidos/instrumentación , Técnicas de Cultivo de Tejidos/métodos
9.
Anal Chem ; 89(11): 6153-6159, 2017 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-28467848

RESUMEN

Fluorescence is widely used for small-volume analysis and is a primary tool for on-chip detection in microfluidic devices, yet additional expertise, more elaborate optics, and phase-locked detectors are needed for ultrasensitive measurements. Recently, we designed a microfluidic analog to an optical beam chopper (µChopper) that alternated formation of picoliter volume sample and reference droplets. Without complex optics, the device negated large signal drifts (1/f noise), allowing absorbance detection in a mere 27 µm optical path. Here, we extend the µChopper concept to fluorescence detection with standard wide-field microscope optics. Precision of droplet control in the µChopper was improved by automation with pneumatic valves, allowing fluorescence measurements to be strictly phase locked at 0.04 Hz bandwidth to droplets generated at 3.50 Hz. A detection limit of 12 pM fluorescein was achieved when sampling 20 droplets, and as few as 310 zeptomoles (3.1 × 10-19 mol) were detectable in single droplets (8.8 nL). When applied to free fatty acid (FFA) uptake in 3T3-L1 adipocytes, this µChopper permitted single-cell FFA uptake rates to be quantified at 3.5 ± 0.2 × 10-15 mol cell-1 for the first time. Additionally, homogeneous immunoassays in droplets exhibited insulin detection limits of 9.3 nM or 190 amol (1.9 × 10-16 mol). The combination of this novel, automated µChopper with lock-in detection provides a high-performance platform for detecting small differences with standard fluorescence optics, particularly in situations where sample volume is limited. The technique should be simple to implement into a variety of other droplet fluidics devices.


Asunto(s)
Automatización , Ácidos Grasos/análisis , Fluorescencia , Técnicas Analíticas Microfluídicas , Imagen Óptica , Células 3T3-L1 , Adipocitos/química , Adipocitos/metabolismo , Animales , Ácidos Grasos/metabolismo , Ratones , Tamaño de la Partícula , Propiedades de Superficie
10.
Bioorg Med Chem ; 24(13): 2999-3005, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-27209170

RESUMEN

Triterpene sapogenins are a group of biologically active compounds with antibacterial activity. However, the limited solubility and poor bioavailability of triterpene sapogenins restrict their therapeutic application. Polyarginine peptides are small cationic peptides with high affinities for multiple negatively charged cell membranes and possess moderate antibacterial activities. In this study, we designed and synthesized a series of sapogenin-polyarginine conjugates in which the triterpene sapogenin moiety was covalently appended to the positively charged polyarginine via click chemistry. A clear synergistic effect was found, and the conjugates exhibited potent and selective antibacterial activity against Gram-positive strains. Among them, BAc-R3 was the most promising compound, which was also proven to be nontoxic toward mammalian cells as well as stable in plasma. The mechanism of BAc-R3 primarily involves an interaction with the bacterial membrane, similar to that of antimicrobial peptides (AMPs). This scaffold design opens an avenue for the further development of novel antibiotics comprised of the combination of a peptide and a natural product.


Asunto(s)
Antibacterianos/farmacología , Bacterias Grampositivas/efectos de los fármacos , Animales , Antibacterianos/química , Humanos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Transmisión , Estructura Molecular , Péptidos/química , Péptidos/farmacología , Plasma/química , Sapogeninas/química , Sapogeninas/farmacología , Triterpenos/química , Triterpenos/farmacología
11.
Int J Mol Sci ; 15(10): 18281-309, 2014 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-25310652

RESUMEN

As an ideal method to manipulate biological particles, the dielectrophoresis (DEP) technique has been widely used in clinical diagnosis, disease treatment, drug development, immunoassays, cell sorting, etc. This review summarizes the research in the field of bioparticle manipulation based on DEP techniques. Firstly, the basic principle of DEP and its classical theories are introduced in brief; Secondly, a detailed introduction on the DEP technique used for bioparticle manipulation is presented, in which the applications are classified into five fields: capturing bioparticles to specific regions, focusing bioparticles in the sample, characterizing biomolecular interaction and detecting microorganism, pairing cells for electrofusion and separating different kinds of bioparticles; Thirdly, the effect of DEP on bioparticle viability is analyzed; Finally, the DEP techniques are summarized and future trends in bioparticle manipulation are suggested.


Asunto(s)
Separación Celular/métodos , Electroforesis/métodos , Micromanipulación/métodos , Animales , Bacterias/aislamiento & purificación , Separación Celular/instrumentación , Electroforesis/instrumentación , Diseño de Equipo , Humanos , Dispositivos Laboratorio en un Chip , Procedimientos Analíticos en Microchip/métodos , Micromanipulación/instrumentación
12.
bioRxiv ; 2024 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-37609281

RESUMEN

Single cell sequencing is useful for resolving complex systems into their composite cell types and computationally mining them for unique features that are masked in pooled sequencing. However, while commercial instruments have made single cell analysis widespread for mammalian cells, analogous tools for microbes are limited. Here, we present EASi-seq (Easily Accessible Single microbe sequencing). By adapting the single cell workflow of the commercial Mission Bio Tapestri instrument, this method allows for efficient sequencing of individual microbes' genomes. EASi-seq allows thousands of microbes to be sequenced per run and, as we show, can generate detailed atlases of human and environmental microbiomes. The ability to capture large shotgun genome datasets from thousands of single microbes provides new opportunities in discovering and analyzing species subpopulations. To facilitate this, we develop a companion bioinformatic pipeline that clusters microbes by similarity, improving whole genome assembly, strain identification, taxonomic classification, and gene annotation. In addition, we demonstrate integration of metagenomic contigs with the EASi-seq datasets to reduce capture bias and increase coverage. Overall, EASi-seq enables high quality single cell genomic data for microbiome samples using an accessible workflow that can be run on a commercially available platform.

13.
Adv Mater ; : e2404705, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38884448

RESUMEN

High humidity in extremely cold weather can undermine the insulation capability of the clothing, imposing serious life risks. Current clothing insulation technologies have inherent deficiencies in terms of insulation efficiency and humidity adaptability. Here, we report humidity-stimulated self-heating clothing using aluminum core-liquid metal shell microparticles (Al@LM-MPs) as the filler. Al@LM-MPs exhibit a distinctive capability to react to water molecules in the air to generate heat, exhibiting remarkable sensitivity across a broad temperature range. This ability leads to the creation of intelligent clothing capable of autonomously responding to extreme cold and wet weather conditions, providing both enduring heat retention and insulation capabilities. This article is protected by copyright. All rights reserved.

14.
Nat Commun ; 15(1): 454, 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38212623

RESUMEN

Emerging evidence indicates that the activation of ferroptosis by glutathione peroxidase 4 (GPX4) inhibitors may be a prominent therapeutic strategy for tumor suppression. However, the wide application of GPX4 inhibitors in tumor therapy is hampered due to poor tumor delivery efficacy and the nonspecific activation of ferroptosis. Taking advantage of in vivo self-assembly, we develop a peptide-ferriporphyrin conjugate with tumor microenvironment specific activation to improve tumor penetration, endocytosis and GPX4 inhibition, ultimately enhancing its anticancer activity via ferroptosis. Briefly, a GPX4 inhibitory peptide is conjugated with an assembled peptide linker decorated with a pH-sensitive moiety and ferriporphyrin to produce the peptide-ferriporphyrin conjugate (Gi-F-CAA). Under the acidic microenvironment of the tumor, the Gi-F-CAA self-assembles into large nanoparticles (Gi-F) due to enhanced hydrophobic interaction after hydrolysis of CAA, improving tumor endocytosis efficiency. Importantly, Gi-F exhibits substantial inhibition of GPX4 activity by assembly enhanced binding (AEB) effect, augmenting the oxidative stress of ferriporphyrin-based Fenton reaction, ultimately enabling antitumor properties in multiple tumor models. Our findings suggest that this peptide-ferriporphyrin conjugate design with AEB effect can improve the therapeutic effect via induction of ferroptosis, providing an alternative strategy for overcoming chemoresistance.


Asunto(s)
Ferroptosis , Neoplasias , Humanos , Endocitosis , Hemina , Hidrólisis , Péptidos/farmacología , Línea Celular Tumoral , Neoplasias/tratamiento farmacológico , Microambiente Tumoral
15.
Natl Sci Rev ; 11(4): nwae028, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38425424

RESUMEN

Mitochondriopathy inspired adenosine triphosphate (ATP) depletions have been recognized as a powerful way for controlling tumor growth. Nevertheless, selective sequestration or exhaustion of ATP under complex biological environments remains a prodigious challenge. Harnessing the advantages of in vivo self-assembled nanomaterials, we designed an Intracellular ATP Sequestration (IAS) system to specifically construct nanofibrous nanostructures on the surface of tumor nuclei with exposed ATP binding sites, leading to highly efficient suppression of bladder cancer by induction of mitochondriopathy-like damages. Briefly, the reported transformable nucleopeptide (NLS-FF-T) self-assembled into nuclear-targeted nanoparticles with ATP binding sites encapsulated inside under aqueous conditions. By interaction with KPNA2, the NLS-FF-T transformed into a nanofibrous-based ATP trapper on the surface of tumor nuclei, which prevented the production of intracellular energy. As a result, multiple bladder tumor cell lines (T24, EJ and RT-112) revealed that the half-maximal inhibitory concentration (IC50) of NLS-FF-T was reduced by approximately 4-fold when compared to NLS-T. Following intravenous administration, NLS-FF-T was found to be dose-dependently accumulated at the tumor site of T24 xenograft mice. More significantly, this IAS system exhibited an extremely antitumor efficacy according to the deterioration of T24 tumors and simultaneously prolonged the overall survival of T24 orthotopic xenograft mice. Together, our findings clearly demonstrated the therapeutic advantages of intracellular ATP sequestration-induced mitochondriopathy-like damages, which provides a potential treatment strategy for malignancies.

16.
Nat Microbiol ; 9(2): 524-536, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38297167

RESUMEN

Ammonia-oxidizing microorganisms (AOM) contribute to one of the largest nitrogen fluxes in the global nitrogen budget. Four distinct lineages of AOM: ammonia-oxidizing archaea (AOA), beta- and gamma-proteobacterial ammonia-oxidizing bacteria (ß-AOB and γ-AOB) and complete ammonia oxidizers (comammox), are thought to compete for ammonia as their primary nitrogen substrate. In addition, many AOM species can utilize urea as an alternative energy and nitrogen source through hydrolysis to ammonia. How the coordination of ammonia and urea metabolism in AOM influences their ecology remains poorly understood. Here we use stable isotope tracing, kinetics and transcriptomics experiments to show that representatives of the AOM lineages employ distinct regulatory strategies for ammonia or urea utilization, thereby minimizing direct substrate competition. The tested AOA and comammox species preferentially used ammonia over urea, while ß-AOB favoured urea utilization, repressed ammonia transport in the presence of urea and showed higher affinity for urea than for ammonia. Characterized γ-AOB co-utilized both substrates. These results reveal contrasting niche adaptation and coexistence patterns among the major AOM lineages.


Asunto(s)
Archaea , Bacterias , Archaea/metabolismo , Bacterias/metabolismo , Amoníaco/metabolismo , Nitrógeno/metabolismo , Oxidación-Reducción , Nitrificación , Filogenia , Microbiología del Suelo , Urea/metabolismo
17.
Anal Chem ; 85(21): 10556-64, 2013 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-24070333

RESUMEN

Currently, one of the most prominent methods used to impart biocompatibility to aqueous-in-oil droplets is to synthesize a triblock copolymer surfactant composed of perfluoropolyether and polyether blocks. The resulting surfactants (EA surfactant, KryJeffa, etc.) allow generation of highly biocompatible droplet surfaces while maintaining the heat stability of the starting material. However, production of these surfactants requires expertise in synthetic organic chemistry, creating a barrier to widespread adoption in the field. Herein, we describe a simple alternative to synthetic modification of surfactants to impart biocompatibility. We have observed that aqueous-in-oil droplet surfaces can be made biocompatible and heat stable by merely exploiting binding interactions between polyetherdiamine additives in the aqueous phase and carboxylated perfluorocarbon surfactants in the oil phase. Droplets formed under these conditions are shown to possess biocompatible surfaces capable of supporting picoliter-scale protein assays, droplet polymerase chain reaction (PCR), and droplet DNA amplification with isothermal recombinase polymerase amplification (RPA). Droplets formed with polyetherdiamine aqueous additives are stable enough to withstand temperature cycling during PCR (30-40 cycles at 60-94 °C) while maintaining biocompatibility, and the reaction efficiency of RPA is shown to be similar to that with a covalently modified surfactant (KryJeffa). The binding interaction was confirmed with various methods, including FT-IR spectroscopy, NMR spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and fluorescence microscopy. Overall, our results suggest that, by simply introducing a commercially-available, polyetherdiamine additive (Jeffamine ED-900) to the aqueous phase, researchers can avoid synthetic methods in generating biocompatible droplet surfaces capable of supporting DNA and protein analysis at the subnanoliter scale.


Asunto(s)
Aminas/química , Materiales Biocompatibles , Fluorocarburos/química , Aceites , Tensoactivos/química , Agua , Cromatografía Liquida , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Reacción en Cadena de la Polimerasa , Espectroscopía Infrarroja por Transformada de Fourier
18.
J Biotechnol ; 375: 28-39, 2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37640267

RESUMEN

Effective strategies to optimize algal growth and lipid productivity are critical for the sustainable production of biomass for various applications. Light management has emerged as a promising approach, but the intricate relationship between light intensity, spectral quality, and algal responses remains poorly understood. This study investigated the effects of different light qualities (blue, red-orange, and white-yellow) and intensities (45-305 µmol/m2·s) on Chlamydomonas reinhardtii. Red-orange light exhibited the highest promotion of biomass growth and lipid productivity, with specific growth rates of 1.968 (d-1) and biomass productivity of 0.284 (g/L/d) at 155 µmol/m2·s and 205 µmol/m2·s, respectively. Within the intensity range of 205 µmol/m2·s to 305 µmol/m2·s, lipid mass fractions ranged from 10.5% w/w to 11.0% w/w, accompanied by lipid concentrations ranging from 68.6 mg/L to 74.9 mg/L. Red-orange light positively influenced carbohydrate accumulation, while blue light promoted protein synthesis. These findings highlight the importance of optimizing light quality and intensity to enhance algal biomass productivity and manipulate biochemical composition. Understanding the complex relationship between light parameters and algal physiology will contribute to sustainable algal cultivation practices and the use of microalgae as a valuable bioresource.


Asunto(s)
Chlamydomonas reinhardtii , Cinética , Luz , Biomasa , Lípidos
19.
Artículo en Inglés | MEDLINE | ID: mdl-38127607

RESUMEN

Generating consecutive descriptions for videos, that is, video captioning, requires taking full advantage of visual representation along with the generation process. Existing video captioning methods focus on an exploration of spatial-temporal representations and their relationships to produce inferences. However, such methods only exploit the superficial association contained in a video itself without considering the intrinsic visual commonsense knowledge that exists in a video dataset, which may hinder their capabilities of knowledge cognitive to reason accurate descriptions. To address this problem, we propose a simple, yet effective method, called visual commonsense-aware representation network (VCRN), for video captioning. Specifically, we construct a Video Dictionary, a plug-and-play component, obtained by clustering all video features from the total dataset into multiple clustered centers without additional annotation. Each center implicitly represents a visual commonsense concept in a video domain, which is utilized in our proposed visual concept selection (VCS) component to obtain a video-related concept feature. Next, a concept-integrated generation (CIG) component is proposed to enhance caption generation. Extensive experiments on three public video captioning benchmarks: MSVD, MSR-VTT, and VATEX, demonstrate that our method achieves state-of-the-art performance, indicating the effectiveness of our method. In addition, our method is integrated into the existing method of video question answering (VideoQA) and improves this performance, which further demonstrates the generalization capability of our method. The source code has been released at https://github.com/zchoi/VCRN.

20.
Front Plant Sci ; 14: 1178245, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37235032

RESUMEN

Introduction: Begonia L., one of the 10 largest plant genera, contains over 2,100 species, most of which have a very limited distribution range. Understanding the spatial genetic structure and distribution dynamics of a widespread species in this genus will contribute to clarifying the mechanism responsible for Begonia speciation. Methods: In this study, we used three chloroplast DNA markers (ndhF-rpl32, atpI-atpH, and ndhA intron), coupled with species distribution modeling (SDM), to investigate the population genetic structure and distribution dynamics of Begonia grandis Dryand., the species of Begonia with the widest distribution in China. Results: Thirty-five haplotypes from 44 populations clustered into two groups, and haplotype divergence began in the Pleistocene (1.75 Mya). High genetic diversity (H d = 0.894, H T = 0.910), strong genetic differentiation (F ST = 0.835), and significant phylogeographical structure (G ST/N ST = 0.848/0.917, P < 0.05) were observed. The distribution range of B. grandis migrated northwards after the last glacial maximum, but its core distribution area remained stable. Discussion: Combined, the observed spatial genetic patterns and SDM results identified the Yunnan-Guizhou Plateau, the Three Gorges region, and the Daba Mountains as potential refugia of B. grandis. BEAST-derived chronogram and haplotype network analysis do not support the Flora Reipublicae Popularis Sinicae and Flora of China for subspecies classification based on morphological characteristics. Our results support the hypothesis that population-level allopatric differentiation may be an important speciation process for the Begonia genus and a key contributor to its rich diversity.

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