Biosafety of human environments can be supported by effective use of renewable biomass.

Preventing pathogenic viral and bacterial transmission in the human environment is critical, especially in potential outbreaks that may be caused by the release of ancient bacteria currently trapped in the permafrost. Existing commercial disinfectants present issues such as a high carbon footprint. This study proposes a sustainable alternative, a bioliquid derived from biomass prepared by hydrothermal liquefaction. Results indicate a high inactivation rate of pathogenic virus and bacteria by the as-prepared bioliquid, such as up to 99.99% for H1N1, H5N1, H7N9 influenza A virus, and Bacillus subtilis var. niger spores and 99.49% for Bacillus anthracis Inactivation of Escherichia coli and Staphylococcus epidermidis confirmed that low-molecular-weight and low-polarity compounds in bioliquid are potential antibacterial components. High temperatures promoted the production of antibacterial substances via depolymerization and dehydration reactions. Moreover, bioliquid was innoxious as confirmed by the rabbit skin test, and the cost per kilogram of the bioliquid was $0.04427, which is notably lower than that of commercial disinfectants. This study demonstrates the potential of biomass to support our biosafety with greater environmental sustainability.

Analysis of Fluid Replacement in Two Fluidic Chambers for Oblique-Incidence Reflectivity Difference (OI-RD) Biosensor.

Optical biosensors have a significant impact on various aspects of our lives. In many applications of optical biosensors, fluidic chambers play a crucial role in facilitating controlled fluid delivery. It is essential to achieve complete liquid replacement in order to obtain accurate and reliable results. However, the configurations of fluidic chambers vary across different optical biosensors, resulting in diverse fluidic volumes and flow rates, and there are no standardized guidelines for liquid replacement. In this paper, we utilize COMSOL Multiphysics, a finite element analysis software, to investigate the optimal fluid volume required for two types of fluidic chambers in the context of the oblique-incidence reflectivity difference (OI-RD) biosensor. We found that the depth of the fluidic chamber is the most crucial factor influencing the required liquid volume, with the volume being a quadratic function of the depth. Additionally, the required fluid volume is also influenced by the positions on the substrate surface bearing samples, while the flow rate has no impact on the fluid volume.

Matched Kinetics Process Over Fe2O3-Co/NiO Heterostructure Enables Highly Efficient Nitrate Electroreduction to Ammonia.

Tandem nitrate electroreduction reaction (NO3 -RR) is a promising method for green ammonia (NH3) synthesis. However, the mismatched kinetics processes between NO3 --to-NO2 - and NO2 --to-NH3 results in poor selectivity for NH3 and excess NO2 - evolution in electrolyte solution. Herein, a Ni2+ substitution strategy for developing oxide heterostructure in Co/Fe layered double oxides (LDOs) was designed and employed as tandem electrocataltysts for NO3 -RR. (Co0.83Ni0.16)2Fe exhibited a high NH3 yield rate of 50.4 mg ⋅ cm-2 ⋅ h-1 with a Faradaic efficiency of 97.8 % at -0.42 V vs. reversible hydrogen electrode (RHE) in a pulsed electrolysis test. By combining with in situ/operando characterization technologies and theoretical calculations, we observed the strong selectivity of NH3 evolution over (Co0.83Ni0.16)2Fe, with Ni playing a dual role in NO3 -RR by i) modifying the electronic behavior of Co, and ii) serving as complementary site for active hydrogen (*H) supply. Therefore, the adsorption capacity of *NO2 and its subsequent hydrogenation on the Co sites became more thermodynamically feasible. This study shows that Ni substitution promotes the kinetics of the NO3 -RR and provides insights into the design of tandem electrocatalysts for NH3 evolution.

[Mechanism of heat-clearing prescriptions in alleviating type 2 diabetes mellitus:a review].

Type 2 diabetes mellitus(T2DM), a common chronic metabolic disease, is often accompanied by internal heat syndrome. Heat-clearing prescriptions are widely used to treat different heat syndromes of T2DM from the aspects of clearing stagnant heat, excess heat, damp heat, phlegm heat, and heat toxin, demonstrating remarkable effects. The mechanism of blood sugar-lowering agents has always been a hotspot of research. Recently, the basic studies of heat-clearing prescriptions from different perspectives have been increasing year by year. To clarify the mechanisms of heat-clearing prescriptions and find specific mechanisms, we systematically reviewed the basic studies of heat-clearing prescriptions commonly used for the treatment of T2DM in the past decade, intending to provide a reference for related research.

Lysocardiolipin acyltransferase regulates NSCLC cell proliferation and migration by modulating mitochondrial dynamics.

Lysocardiolipin acyltransferase (LYCAT), a cardiolipin (CL)-remodeling enzyme, is crucial for maintaining normal mitochondrial function and vascular development. Despite the well-characterized role for LYCAT in the regulation of mitochondrial dynamics, its involvement in lung cancer, if any, remains incompletely understood. In this study, in silico analysis of TCGA lung cancer data sets revealed a significant increase in LYCAT expression, which was later corroborated in human lung cancer tissues and immortalized lung cancer cell lines via indirect immunofluorescence and immunoblotting, respectively. Stable knockdown of LYCAT in NSCLC cell lines not only reduced CL and increased monolyso-CL levels but also reduced in vivo tumor growth, as determined by xenograft studies in athymic nude mice. Furthermore, blocking LYCAT activity using a LYCAT mimetic peptide attenuated cell migration, suggesting a novel role for LYCAT activity in promoting NSCLC. Mechanistically, the pro-proliferative effects of LYCAT were mediated by an increase in mitochondrial fusion and a G1/S cell cycle transition, both of which are linked to increased cell proliferation. Taken together, these results demonstrate a novel role for LYCAT in promoting NSCLC and suggest that targeting LYCAT expression or activity in NSCLC may provide new avenues for the therapeutic treatment of lung cancer.

TAT delivery of a PTEN peptide inhibitor has direct cardioprotective effects and improves outcomes in rodent models of cardiac arrest.

We have recently shown that pharmacologic inhibition of PTEN significantly increases cardiac arrest survival in a mouse model, however, this protection required pretreatment 30 min before the arrest. To improve the onset of PTEN inhibition during cardiac arrest treatment, we have designed a TAT fused cell-permeable peptide (TAT-PTEN9c) based on the C-terminal PDZ binding motif of PTEN for rapid tissue delivery and protection. Western blot analysis demonstrated that TAT-PTEN9c peptide significantly enhanced Akt activation in mouse cardiomyocytes in a concentration- and time-dependent manner. Mice were subjected to 8 min asystolic arrest followed by CPR, and 30 mice with successful CPR were then randomly assigned to receive either saline or TAT-PTEN9c treatment. Survival was significantly increased in TAT-PTEN9c-treated mice compared with that of saline control at 4 h after CPR. The treated mice had increased Akt phosphorylation at 30 min resuscitation with significantly decreased sorbitol content in heart or brain tissues and reduced release of taurine and glutamate in blood, suggesting improved glucose metabolism. In an isolated rat heart Langendorff model, direct effects of TAT-PTEN9c on cardiac function were measured for 20 min following 20 min global ischemia. Rate pressure product was reduced by >20% for both TAT vehicle and nontreatment groups following arrest. Cardiac contractile function was completely recovered with TAT-PTEN9c treatment given at the start of reperfusion. We conclude that TAT-PTEN9c enhances Akt activation and decreases glucose shunting to the polyol pathway in critical organs, thereby preventing osmotic injury and early cardiovascular collapse and death.NEW & NOTEWORTHY We have designed a cell-permeable peptide, TAT-PTEN9c, to improve cardiac arrest survival. It blocked endogenous PTEN binding to its adaptor and enhanced Akt signaling in mouse cardiomyocytes. It improved mouse survival after cardiac arrest, which is related to improved glucose metabolism and reduced glucose shunting to sorbitol in critical organs.

Tolerance and detoxification mechanisms to cadmium stress by hyperaccumulator Erigeron annuus include molecule synthesis in root exudate.

Cadmium (Cd) is one of the most toxic environmental pollutants affecting the growth and reproduction of various plants. Analysis of the biological adaptation and tolerance mechanisms of the hyperaccumulator Erigeron annuus to Cd stress may help identify new plant species for phytoremediation and in optimizing the process. This study is to the first to analyze the molecular composition and diversity of dissolved organic matter (DOM) secreted by roots using FT-ICR MS, and multiple physiological and biochemical indexes of E. annuus seedlings grown in solutions containing 0-200 Cd µmol L-1. The results showed that E. annuus had strong photosynthetic adaptation and protection ability under Cd stress. Cd was immobilized or compartmentalized by cell walls and vacuoles in the plant, thus alleviating Cd stress. Activation of anti-oxidation defense mechanisms also played an important role in alleviating or eliminating Cd toxicity in E. annuus. High Cd stress promoted production of a higher proportion of new molecules in DOM secreted by E. annuus roots compared to low Cd stress. DOM secreted by roots contributed to plant resistance to Cd-induced stress via producing more carbohydrates, aromatic structures and tannins. Results indicate the mechanisms underpinning the potential use of E. annuus as a phytoremediator in environments with moderate Cd pollution.

Influence of process parameters on hydrothermal modification of soybean residue: Insight into the nutrient, solid biofuel, and thermal properties of hydrochars.

Soybean (SB) solid residue after oil extraction was investigated in a hydrothermal modification process to provide an eco-friendly solution to SB solid waste disposal for an actual environmental management effort. SB hydrochars (HCs) were derived either by conventional heating hydrothermal treatment (HTT) under intense conditions (200, 250, and 300 °C for 2 h) or by microwave-assisted hydrothermal treatment (MHTT) under mild conditions (160, 190, and 220 °C for 1 h). Physicochemical properties of SB HCs and the transformation of nitrogen (N) and phosphorus (P) functionalities during HTT and MHTT were characterized using several tools. Ultimate and XPS analyses elucidated N transformation, e.g., 5.51 wt % N of raw SB residue decreased to 3.48 and 3.51 wt % after HTT and MHTT, respectively. The P bioavailability of raw SB (3.46 mg/g) was improved after HTT (26.7 mg/g) and MHTT (10.9 mg/g), depicting the practical application of HCs for soil amendment. Atomic H/C and O/C ratios of SB HCs decreased as treatment temperature increased. HCs showed credible higher heating value (HHV; 22.3-25.5 MJ/kg for HTT and 20.5-22.1 MJ/kg for MHTT), higher than various low-rank coals. Besides, energy densification and fuel ratio improved in intense conditions. The thermogravimetric analysis showed HCs possessed better thermal stability. The improved performance of SB HCs indicated that HTT and MHTT provided a green environmental route of SB waste management, valorization, and utilization.

Extraneous Fe Increased the Carbon Retention of Sludge-Based Biochar.

Pyrolysis is a promising technology for the disposal of sewage sludge. In this study, FeCl3 was selected as an additive for sludge pyrolysis. The results indicated that the FeCl3-addition strategy not only enhanced carbon retention but also enhanced the nitrogen retention of sludge-based biochar. The best enhancement effect both occurred at 500°C, and the enhanced amount reached 29.7 mg C/g sludge and 1.33 mg N/g sludge, respectively. This enhancement may be attributed to the physical isolation provided by newly formed metallic complexes or oxides. Besides, the added FeCl3 improved the polarity and aromaticity of modified biochar by retaining more oxygen-containing functional groups, and could also catalyze the decomposition of tar, resulting in the release of more small molecular substances. The quantitative estimation of carbon and nitrogen retention in provinces of China found that the enhancement in coastal provinces was significantly preceded that of inland provinces.

Urgently reveal longly hidden toxicant in a familiar fabrication process of biomass-derived environment carbon material.

Biomass-derived N-doped carbon (BNC) is an important environmental material and widely used in the fields of water purification and soil remediation. However, the toxicant in the commonly used synthesis process of BNC materials have been largely ignored. Herein, we firstly report the presence of a highly toxic by-product (KCN) in the activation process of BNC materials consequential of the carbothermal reduction reaction. Because this carbothermal reduction reaction also regulates the N-doping and pore development of BNC materials, the KCN content directly relates with the properties of BNC material properties. Accordingly, a high KCN content (∽ 611 mg) can occur in the production process of per g BNC material with high specific surface area (∽ 3600 m2/g). Because the application performance of BNC material is determined by the surface area and available N doping, therefore, production of a BNC material with high performance entails high risk. Undoubtedly, this study proves a completely new risk recognition on a familiar synthesis process of biomass-based material. And, strict protective device should be taken in fabrication process of biomass-derived carbon material.

Porcine deltacoronavirus enters cells via two pathways: A protease-mediated one at the cell surface and another facilitated by cathepsins in the endosome.

Porcine deltacoronavirus (PDCoV) is a pathogen belonging to the genus Deltacoronavirus that in 2014 caused outbreaks of piglet diarrhea in the United States. To identify suitable therapeutic targets, a more comprehensive understanding of the viral entry pathway is required, particularly of the role of proteases. Here, we identified the proteases that activate the viral spike (S) glycoprotein to initiate cell entry and also pinpointed the host-cellular pathways that PDCoV uses for entry. Our results revealed that cathepsin L (CTSL) and cathepsin B (CTSB) in lysosomes and extracellular trypsin in cell cultures independently activate the S protein for membrane fusion. Pretreating the cells with the lysosomal acidification inhibitor bafilomycin-A1 (Baf-A1) completely inhibited PDCoV entry, and siRNA-mediated ablation of CTSL or CTSB expression significantly reduced viral infection, indicating that PDCoV uses an endosomal pathway for entry. Of note, trypsin treatment of cell cultures also activated PDCoV entry, even when the endosomal pathway was inhibited. This observation indicated that trypsin-induced S protein cleavage and activation in cell cultures enables viral entry directly from the cell surface. Our results provide critical insights into the PDCoV infection mechanism, uncovering two distinct viral entry pathways: one through cathepsin L and cathepsin B in the endosome and another via a protease at the cell surface. Because PDCoV infection sites represent a proteases-rich environment, these findings suggest that endosome inhibitor treatment alone is insufficient to block PDCoV entry into intestinal epithelial cells in vivo Therefore, approaches that inhibit viral entry from the cell membrane should also be considered.

Degradation of group V secretory phospholipase A2 in lung endothelium is mediated by autophagy.

Group V secretory phospholipase A2 (gVPLA2) is a potent inflammatory mediator in mammalian tissues that hydrolyzes phospholipids and initiates eicosanoid biosynthesis. Previous work has demonstrated that multiple inflammatory stimuli induce its expression and secretion in several cell types, including the lung endothelium. However, little is known about the mechanism(s) by which gVPLA2 inflammatory signaling is subsequently downregulated. Therefore, in this study we characterized potential clearance mechanisms for gVPLA2 in lung endothelial cells (EC). We observed that exogenous gVPLA2 is taken up rapidly by nutrient-starved human pulmonary artery EC (HPAEC) in vitro, and its cellular expression subsequently is reduced over several hours. In parallel experiments performed in pulmonary vascular EC isolated from mice genetically deficient in gVPLA2, the degradation of exogenously applied gVPLA2 occurs in a qualitatively similar fashion. This degradation is significantly attenuated in EC treated with ammonium chloride or chloroquine, which are lysosomal inhibitors that block autophagic flux. In contrast, the proteasomal inhibitor MG132 fails to prevent the clearance of gVPLA2. Both immunofluorescence microscopy and proximity ligation assay demonstrate the co-localization of LC3 and gVPLA2 during this process, indicating the association of gVPLA2 with autophagosomes. Nutrient starvation, a known inducer of autophagy, is sufficient to stimulate gVPLA2 degradation. These results suggest that a lysosome-mediated autophagy pathway contributes to gVPLA2 clearance from lung EC. These novel observations advance our understanding of the mechanism by which this key inflammatory enzyme is downregulated in the lung vasculature.

Bioactive scaffolds based on collagen filaments with tunable physico-chemical and biological features.

Native tissues such as nerve bundles, blood vessels and tendons have extracellular matrices with a characteristic linear orientation, which cannot be fully achieved with the current technology for the development of regenerative biomaterials. In this study, bioactive and oriented collagen filaments have been fabricated using a combination of wet-spinning and carbodiimide-based crosslinking. The wet-spinning techniques, including extrusion and collection rates, and their influences on collagen filaments were studied and optimized. The diameter of the attained collagen filaments can be adjusted ranging from 30 µm to 650 µm. Further characterizations, such as circular dichroism, scanning electron microscopy, small-angle X-ray scattering and Fourier transform infrared spectra analysis, showed that the native structure of the collagen was greatly preserved after the filament preparation process. The measurements of weight swelling ratio and degradation rate indicate that the crosslinking method can efficiently regulate the physico-chemical properties of collagen filaments, including water absorption and degradation behaviors. In particular, the mechanical strength of collagen filaments can be greatly improved via crosslinking. In addition, cells can adhere and spread on collagen filaments in well-aligned patterns, showing appropriate biological features. It can be concluded that the bioactive collagen filaments with tunable properties are preferable for developing tissue engineering scaffolds with characteristic orientation features. With further study of the interactions between collagen filaments and cells, this work may shed light on the development of collagen based biomaterials that would be beneficial in the field of tissue engineering.

Hydrochar-Facilitated Anaerobic Digestion: Evidence for Direct Interspecies Electron Transfer Mediated through Surface Oxygen-Containing Functional Groups.

Acceleration of the anaerobic digestion (AD) process is crucial to achieving energy-efficient recycling of organic wastes. Hydrochar is produced by hydrothermal liquefaction of biomass, yet its application in the AD process is rarely reported. The present study showed that sewage sludge-derived hydrochar (SH) enhanced the methane production rate of glucose by 37%. SH increased the methane production rate from acetate but did not affect acidification and the methane production rate from H2/CO2. SH enhanced hydrogenotrophic methanogenesis, which could be due to direct interspecies electron transfer (DIET) by converting H+, e-, and CO2 to methane. Trichococcus and Methanosaeta were dominant in the AD process with SH. Label-free proteomic analysis showed Methanosaeta was involved in DIET as reflected by the up-regulation of proteins involved in hydrogenotrophic methanogenesis. Hydrochars derived from corn straw (CH), Enteromorpha algae (EH), and poplar wood (PH), as well as activated carbon (AC), were also tested in the AD process. SH, CH, and EH obviously increased the methane production rates, which were 39%, 15%, and 20% higher than the control experiment, respectively. It was neither electrical conductivity nor the total redox property of hydrochars and AC but the abundances of surface oxygen-containing functional groups that correlated to the methane production rates.

Interferon gamma inhibits transmissible gastroenteritis virus infection mediated by an IRF1 signaling pathway.

Interferon gamma (IFN-γ) is best known for its ability to regulate host immune responses; however, its direct antiviral activity is less well studied. Transmissible gastroenteritis virus (TGEV) is an economically important swine enteric coronavirus and causes acute diarrhea in piglets. At present, little is known about the function of IFN-γ in the control of TGEV infection. In this study, we demonstrated that IFN-γ inhibited TGEV infection directly in ST cells and intestine epithelial IPEC-J2 cells and that the anti-TGEV activity of IFN-γ was independent of IFN-α/ß. Moreover, IFN-γ suppressed TGEV infection in ST cells more efficiently than did IFN-α, and the combination of IFN-γ and IFN-α displayed a synergistic effect against TGEV. Mechanistically, using overexpression and functional knockdown experiments, we demonstrated that porcine interferon regulatory factor 1 (poIRF1) elicited by IFN-γ primarily mediated IFN-γ signaling cascades and the inhibition of TGEV infection by IFN-γ. Importantly, we found that TGEV elevated the expression of poIRF1 and IFN-γ in infected small intestines and peripheral blood mononuclear cells. Thus, IFN-γ plays a crucial role in curtailing enteric coronavirus infection and may serve as an effective prophylactic and/or therapeutic agent against TGEV infection.

Inherent Metals of a Phytoremediation Plant Influence Its Recyclability by Hydrothermal Liquefaction.

Plants used for phytoremediation of contaminated soil are often enriched in certain metals present in the soil. However, the role of the inherent metal content of the plants on their recycling by hydrothermal liquefaction (HTL) has not been considered in previous studies. The present study showed that Rhus chinensis plants grown in highly Pb-polluted soil can release inherent metals (such as Pb, K, Ca, Na, and Mg) into the HTL solution, further enhancing the production of formic and acetic acids and decreasing the yield of levulinic acid. Theoretical calculations using HTL reactions of model compounds showed that a low Pb content could enhance production of levulinic and formic acids via catalysis of the rehydration reaction for 5-(hydroxymethyl)furfural, while a high Pb content promoted the decomposition of levulinic acid to acetic acid. Fourier transform ion cyclotron resonance mass spectrometry analysis confirmed that Pb2+ preferentially promoted the depolymerization of macromolecular compounds with the lignin structure. In general, the inherent metals occurring in the phytoremediation plant influenced the production of organic acids during HTL recycling. Undoubtedly, the combination of phytoextraction and HTL reaction can present a practical pathway toward a sustainable soil remediation technology.

Detection and complete genome characteristics of Posavirus 1 from pigs in China.

Porcine stool-associated RNA virus 1 (Posavirus 1) is a novel member of picornaviruses and first identified from fecal samples of 30-day-old pigs with diarrhea in USA in 2011. To evaluate the existence of Posavirus 1 in swine herds, 118 clinical samples from diarrheal pigs and 31 fecal swabs from healthy pigs were collected and detected by reverse transcription-polymerase chain reaction (RT-PCR) using Posavirus 1-specific primers. Only five fecal samples from diarrheal pigs on two swine farms were positive for Posavirus 1. The complete genome sequences [excluding poly (A) tail] of two representative isolates SDQD-25 and HBTS-11 are determined and consist of 9840 and 9819 nucleotides in length, and encode one putative polyprotein of 3070 and 2952 amino acids, respectively. They share 90.3% homology with each other and 81.3-95.4% homologies with American Posavirus 1 isolates or strains at the nucleotide sequence level. The phylogenetic analysis based on the entire genomes of reference picornavirus strains or isolates showed SDQD-25, HBTS-11 cluster together with American Posavirus 1 isolates or strains, yet are clearly distant from the other picornaviruses. The complete genome sequences of Chinese Posavirus 1 isolates will enrich the information of Posavirus 1 sequence database and further expedite posavirus research on the genetic diversity, epidemiology, and evolution in China.

Influences of Temperature and Metal on Subcritical Hydrothermal Liquefaction of Hyperaccumulator: Implications for the Recycling of Hazardous Hyperaccumulators.

Waste Sedum plumbizincicola, a zinc (Zn) hyperaccumulator during phytoremediation, was recycled via a subcritical hydrothermal liquefaction (HTL) reaction into multiple streams of products, including hydrochar, bio-oil, and carboxylic acids. Results show approximately 90% of Zn was released from the S. plumbizincicola biomass during HTL at an optimized temperature of 220 °C, and the release risk was mitigated via HTL reaction for hydrochar production. The low-Zn hydrochar (∼200 mg/kg compared to original plant of 1558 mg/kg) was further upgraded into porous carbon (PC) with high porosity (930 m2/g) and excellent capability of carbon dioxide (CO2) capture (3 mmol/g). The porosity, micropore structure, and graphitization degree of PCs were manipulated by the thermal recalcitrance of hydrochar. More importantly, results showed that the released Zn2+ could effectively promote the production of acetic acid via the oxidation of furfural (FF) and 5-(hydroxymethyl)-furfural (HMF). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with negative electrospray ionization analysis confirmed the deoxygenation and depolymerization reactions and the production of long chain fatty acids during HTL reaction of S. plumbizincicola. This work provides a new path for the recycling of waste hyperaccumulator biomass into value-added products.

Production Temperature Effects on the Structure of Hydrochar-Derived Dissolved Organic Matter and Associated Toxicity.

Hydrochar is a carbonaceous material derived from hydrothermal liquefaction, and it carries good potential as a new material for environmental applications. However, little is known about the dissolved organic matter (DOM) associated with hydrochar and the consequences of its release. The relationship between the production temperature and the characteristics of DOM released from hydrochar as well as the associated biotoxicity was investigated using a suite of advanced molecular and spectroscopic tools. With the increase in production temperature, the resulted hydrochar-based DOM contained a higher content of phenols and organic acids but less sugars and furans. Meanwhile, the molecular structure of DOM shifted to lower molecular weight with higher organic contents containing <6 O atoms per compound, aromatics, and N-containing substances. While low-temperature hydrochar-derived DOM showed minimal biotoxicity, increase in production temperature to 330 °C led to a great rise in toxicity. This might be attributed to the increased contents of phenols, organic acids, and organics containing <6 O atoms and 1 N atom per compound. These results suggest that hydrochar-derived DOM have more negative impacts on the environment than the organics associated with biochar production. Such understanding highlights the importance of controlling the hydrochar production process.

Fast Focal Point Correction in Prism-Coupled Total Internal Reflection Scanning Imager Using an Electronically Tunable Lens.

Total internal reflection (TIR) is useful for interrogating physical and chemical processes that occur at the interface between two transparent media. Yet prism-coupled TIR imaging microscopes suffer from limited sensing areas due to the fact that the interface (the object plane) is not perpendicular to the optical axis of the microscope. In this paper, we show that an electrically tunable lens can be used to rapidly and reproducibly correct the focal length of an oblique-incidence scanning microscope (OI-RD) in a prism-coupled TIR geometry. We demonstrate the performance of such a correction by acquiring an image of a protein microarray over a scan area of 4 cm² with an effective resolution of less than 20 microns. The electronic focal length tuning eliminates the mechanical movement of the illumination lens in the scanning microscope and in turn the noise and background drift associated with the motion.