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NLP7 (NIN-LIKE-PROTEIN 7) is the major transcriptional factor responsible for the primary nitrate response (PNR), but the role of its homolog, NLP6, in nitrogen signaling and the interplay between NLP6 and NLP7 remain to be elucidated. In this study, we show that, like NLP7, nuclear localization of NLP6 via a nuclear retention mechanism is nitrate dependent, but nucleocytosolic shuttling of both NLP6 and NLP7 is independent of each other. Compared with single mutants, the nlp6nlp7 double mutant displays a synergistic growth retardation phenotype in response to nitrate. The transcriptome analysis of the PNR showed that NLP6 and NLP7 govern ∼50% of nitrate-induced genes, with cluster analysis highlighting 2 distinct patterns. In the A1 cluster, NLP7 plays the major role, whereas in the A2 cluster, NLP6 and NLP7 are partially functionally redundant. Interestingly, comparing the growth phenotype and PNR under high- and low-nitrate conditions demonstrated that NLP6 and NLP7 exert a more dominant role in the response to high nitrate. Apart from nitrate signaling, NLP6 and NLP7 also participated in high ammonium conditions. Growth phenotypes and transcriptome data revealed that NLP6 and NLP7 are completely functionally redundant and may act as repressors in response to ammonium. Other NLP family members also participated in the PNR, with NLP2 and NLP7 acting as broader regulators and NLP4, -5, -6, and -8 regulating PNR in a gene-dependent manner. Thus, our findings indicate that multiple modes of interplay exist between NLP6 and NLP7 that differ depending on nitrogen sources and gene clusters.

Surface engineering of triboelectric nanogenerator for room temperature self-powered formaldehyde (FA) sensor is demonstrated. Such device delivers not only high power density but also remarkable selectivity and ultra-fast response time to FA gas.

Micromixing devices often utilize complex architectures to mix miscible liquid streams and can be complex and expensive to fabricate. Here, we developed, built, experimentally tested, and computationally analyzed a serpentine micromixer that can be fabricated using simple tools and supplies available in non-microdevice dedicated laboratories. Fluorescence imaging was used to quantify its mixing effectiveness experimentally. A Computational Fluid Dynamics (CFD) software package (COMSOL) was used to model the micromixing process. The predictions were in excellent agreement with the experimental data. The serpentine micromixer can achieve significant levels of mixing efficiency. CFD predictions for a straight microfluidic channel of the same length as the serpentine favorably compared with previous theoretical predictions, indicating that the serpentine's mixing efficiency was vastly superior. Finally, CFD predictions were conducted for different and possibly improved designs of the basic serpentine. In all cases, the mixing efficiency was primarily associated with the number of 90o elbows in the device rather than the straight sections' length, with the first serpentine bend playing a significant role. Future design improvements should focus on incorporating as many elbows as possible in the device to maximize mixing efficiency and reduce the device size.

Stretchable electronics have received great attention in recent years because they are able to accommodate large mechanical deformation without damage to their electronic properties. These features are highly desirable for novel applications, including wearable devices, health-monitoring electronics, electronic skin, and artificial neural devices. A key factor in the area of stretchable electronics is the development of intrinsically stretchable polymer semiconductors. This review will survey different approaches that can significantly enhance the stretchability of polymer semiconductors without sacrificing their charge-transport properties. To develop stretchable polymer semiconductors, two approaches have been reported: (1) the engineering of the chemical structures of conjugated polymers; and (2) the physical blending of conjugated polymers in an elastomeric matrix. In addition to these two approaches, the influence of the fabrication process (e.g., solution shearing, nanoconfinement, and electrospinning) on the mechanical and electrical properties of polymer semiconductor films is also reviewed. In the final part, we will introduce novel applications of stretchable polymer semiconductors (e.g., electronic skin, artificial neural electronics, and self-healing polymer semiconductors) and the challenges facing these emerging technologies. This review provides a comprehensive introduction to the development of intrinsically stretchable polymer semiconductors covering molecular design, solution processes, and novel applications.

The discrete steps of transcriptional rewiring have been proposed to occur neutrally to ensure steady gene expression under stabilizing selection over long time-scales, especially when a regulon is being transferred from one transcription factor (TF) to another. Cooperative DNA binding between redundant regulatory components at the intermediate transition stage is believed to mediate this process, enabling a conflict-free switch between two TFs without a disruptive change in gene expression. Here, we have performed an evolutionary repair experiment on the Lachancea kluyveri yeast sef1Δ mutant by means of a suppressor development strategy. Complete loss of SEF1 forced cells to activate a rewiring process to compensate for the pleiotropic defects arising from misexpression of multiple TCA cycle genes. Using different selective conditions, we identified one generalist and one specialist suppressive loss-of-function mutation of IRA1 and AZF1, respectively. Our subsequent analyses show that Azf1 is a weak transcriptional activator regulated by the Ras1-PKA pathway. Azf1 loss-of-function triggers extensive gene expression changes responsible for both the compensatory and trade-off phenotypes. Our results indicate that the pleiotropic effects of dual perturbation of transcriptional networks are a potential mechanism for rapid adaptive compensation, facilitating the process of incipient transcriptional rewiring, and formation of complex traits.

Trichloroethylene (TCE) was once a widely applied industrial solvent, but is now an infamous contaminant in groundwater. Although anaerobic reductive dechlorination is considered a greener remediation approach, the accumulation of toxic intermediates, such as vinyl chloride (VC), and a longer remediation period are highly concerning. Biostimulation and bioaugmentation have been developed to solve these problems. The former method may not be effective, and the latter may introduce foreign genes. Here, we propose a new approach by applying environmental stresses to reshape the indigenous microbiome. In this study, by using the Taguchi method, the effects of heating, pH, salinity, and desiccation were systematically examined. The optimum conditions were defined as 50 °C, pH 9, 3.50% salinity (w/v), and 21% volumetric water content (θ

A huge challenge for developing self-healing materials is achieving a good compromisation between mechanical properties and self-healing efficiency. For this purpose, a facile route by introducing ...

The two liquid-water states, which lead to some anomalies when temperature crosses over 50 ± 10 °C at the atmospheric pressure, have been continuously catching popular attention. In this study, using the excited-state proton transfer (ESPT) catalyzed by water molecules as a prototypical reaction, we demonstrate that the kinetics of ESPT indeed is influenced by the two liquid-water states. In the water-catalyzed ESPT of 3-cyano-7-azaindole (3CAI), a repetitive and comprehensive temperature-dependent study of ESPT in H2O from 0 to 90 °C shows anomalous behavior. The plot of the logarithm of ESPT rate constant as a function of inverse of absolute temperature deviates from a straight line. The convex-Arrhenius behavior manifests the activation free energy for water-assisted ESPT being dependent on temperature and hence the liquid water structure. To simplify the discussion, the plot is well fitted by using two straight lines that are crossed over in the vicinity of 40 °C. The free energy difference between water-solvated 3CAI and the 1:1 H2O:3CAI complex is deduced to be 2.29 ± 0.04 and 1.96 ± 0.04 kcal·mol-1 in the regions of 0-40 and 40-90 °C water, respectively, which also results in different frequency factors, i.e., the proton transfer/tunneling rates of (5.83 ± 0.36) × 1010 and (3.48 ± 0.27) × 1010 s-1, respectively. In a qualitative manner, the results are then rationalized by the different types of H-bonding configuration as proposed for two liquid-water phases, rendering experimental evidence to support the different water phases in ambient temperatures at 1 bar.

The need is critical and urgent for a real-time, highly specific, and sensitive acute kidney injury biomarker. This study sought to establish a sensitive and specific Miox-NanoLuc transgenic mouse for early detection of drug-induced nephrotoxicity. We generated Miox-NanoLuc transgenic mice with kidney-specific NanoLuc overexpression. Our data showed that Miox-NanoLuc-produced luminescence was kidney-specific and had good stability at room temperature, 4 °C, − 20 °C, and repeated freeze–thaw cycles. Serum levels of BUN and creatinine were significantly increased at day 2 or 3 in cisplatin-treated mice and at day 5 in aristolochic acid (AAI)-treated mice. Particularly, the serum and urine Miox-NanoLuc luminescence levels were significantly increased at day 1 in cisplatin-treated mice and at day 3 in AAI-treated mice. Renal pathological analysis showed that the kidney sections of cisplatin-treated mice at day 5 and AAI-treated mice at day 13 showed cytolysis and marked vacuolization of tubular cells. In conclusion, we developed a new platform to early quantify drug-induced nephrotoxicity before serum BUN and creatinine levels increased and pathological tubular cell injury occurred. This model may serve as an early detection for drug- and food-induced nephrotoxicity and as an animal model to investigate tubular cell injury.

An easy and novel synthetic concept for building intrinsically stretchable and elastic semiconducting polymers is designed in this study, in which a conjugated rod–coil block copolymer with a rigid...

Microfluidic devices are constructed from polydimethylsiloxane (PDMS) due to their biocompatibility, fabrication ease, well-established protocols, and simplicity. PDMS-based microfluidic devices are constructed by (i) applying liquid PDMS to a negative mold (usually a silicon or 3D-printed mold) and (ii) curing the PDMS with heat exposure over a set time period. Unreacted resin monomers in 3D-printed molds prevent PDMS from fully curing, resulting in improper channel formation in PDMS and reducing the PDMS device’s efficacy. An in-house protocol that uses SU-8 as a “non-stick” coating on 3D-printed molds facilitates the successful casting of PDMS. Contact angle, surface profile, optical profile, and force testing prove that PDMS cast from SU-8-treated molds resembles pristine PDMS, unlike PDMS cast from untreated molds. Further, this method is generalized to commercial 3D prints using different 3D printing resins. To demonstrate this technique’s viability in microfluidic devices, a microfluidic tree using PDMS from treated 3D prints shows vibrant colors and clear lines. This is absent from an untreated PDMS.

We herein aim to probe the emission quenched by O2 on silica gel. Our special focus is on the O2 quenching of the fluorescence of a series of organic D–π–A phosphonium compounds 1–3. The results show that the O2 quenching rate constants for the fluorescence of 1–3 are on the order of 1010 M−1 s−1, which are nearly on the same order as those measured for 1–3 and common organic compounds in solution. In yet another approach, the study of O2 quenching of phosphorescence in the solid phase indicates that the O2 quenching rate constant for the triplet state, i.e., , is smaller than by two orders of magnitude. Detailed investigation indicates that this distinction stems from the intrinsic O2 quenching rate constants for the singlet and triplet states subsequent to the formation of collisional complexes. In the absence of the solvent cage effect, is greatly influenced by the formation energy of the O2–dye CT complex, whereas in the solid phase is a nearly diffusion-controlled rate. Due to the larger distinction between and in the solid phase, O2 quenching of fluorescence is efficient for dyes in the solid phase. This leads to a feasible application of sensing O2 with regular fluorescent dyes adsorbed on porous solid substrates.

An NP-μFEC is a reusable, novel microfluidic electrochemical cell with multiple non-planar interdigitated microelectrode arrays, minimal sample volume, and enhanced electric field penetration for highly sensitive electrochemical analysis. (i) The NP-μFEC features spatial 3-electrode architecture, and a small sample volume (∼4 μL). (ii) Here, [Fe(CN)

In this work we report the use of a gas sensor that can be used in inline configuration for applications like organ-on-a-chip. The key element of the device is a microfluidic channel with a thickness of 140 μm and width of 500 μm. This microfluidic channel is sandwiched between a top and bottom substrate, each substrate containing microelectrodes making this a non-planar interdigitated microelectrode (NP-IμE) configuration. Room temperature ionic liquids (RTILs) are used as electrolyte in the microfluidic channel. Due to the dimensions of the microfluidic channel only low volume of RTILs are required as electrolyte. RTILs can be tuned to selectively capture specific gases. This in addition to other favourable properties such as wide electrochemical window, thermal stability and negligible vapor pressure makes it a good candidate as the selective electrolyte in electrochemical gas sensor. The use of NP-IμE makes the electric field penetrate through the channel. This allows us to register the perturbations in signal caused by absorption of CO2 from the entire cross-section of the channel, thereby increasing the sensitivity of the device (as compared to a planar architecture). 1-ethyl-3-methylimidazolium 2-cyanopyrolide ([EMIM][2-CNpyr]) was used as the RTIL, as it has been shown to be a good sorbent of CO2 with high capacity at low partial pressures due to its chemical affinity. The RTILs exposed to different concentrations of CO2 was injected into the microfluidic channel. Cyclic Voltammetry (CV), Differential pulse voltammetry (DPV) and Electrochemical impedance spectroscopy (EIS) experiments were done using our microfluidic device. During the CV and DPV experiments, RTIL exposed to CO2 shows a reduction peak (of CO2). This along with the changes in EIS spectrum (Nyquist plot) can be used to detect the presence of CO2. We used CO2 as a test gas to analyse the sensitivity of our microfluidic device combined with RTIL. In future we will be using this same setup to sense biomarker gases and other toxic gases by changing the RTIL and tuning its affinity towards the target analytes.

The ESSENCE platform is an electrochemical sensor system that utilizes non-planar porous microelectrode microfluidic chips with a fully programmable fluidic/sample system to be a “portable, automatic, rapid, sensitive, and selective” for different emerging contaminants and liquid biopsy. The system is designed with non-planar porous microelectrode interfaces, containing different functional capturing probes for specific sensing tasks. From our previous report, this 3D non-planar structure has advantages such as increased flow’s convective fluxes and disrupts diffusive processes like the electric double layer (EDL). The porous electrode structure utilized the packing material’s higher Zeta potential than the bare glass surface, resulting in the EDL length will be significantly smaller than the clear channel. Due to a smaller EDL length, the relaxation frequency will increase, which shifts the EIS signal to a higher frequency range (1kHz to 100MHz) and results in a fast response with a higher signal-to-noise ratio in Electrochemical Impedance Spectroscopy (EIS) measurements. From the perspective of electric field penetration, the top-down electric direction covers all the packing sensing areas, providing a generally higher electronic signal response than the traditional planar electrode system, leading to a higher signal-to-noise ratio. A second feature from the perspective of microfluidics is the significant fluidic shear force generated due to flow through the porous electrode surface. This higher shear force on the surface can unbind most false-positive signals generated by non-specific binding, such as physical adhesive or biofouling. These unique benefits provide physical enhancements of sensitivity and selectivity without manipulating the chemical material in the system. Earlier we showed that our detection of the biomolecules like DNA (fM sensitivity, which can distinguish against a mismatched DNA), proteins (breast cancer biomarker p53, fM sensitivity, which can distinguish it against another breast cancer biomarker HER2), PFOS (Perfluorooctanesulfonate, 0.5 ng) under the traditional desktop Electrochemical Impedance Spectroscopy (EIS) analyzer in the total process of hourly. In this talk, we have further developed our previous ESSENCE platform to a modular, automatic, and portable, one-stop instrument for clinicians to screen for infectious diseases, liquid biopsy, and toxin detection to detect emerging pathogens while significantly reducing false positives and false negatives, but also decreasing our detecting process to 15 mins in much more hazard background conditions to meet the criteria of POC. Second, A small (15 cm x 17cm) USB programable fluidic/oscilloscope base with a 15 minutes total detecting protocol is applied to our ESSENCE system for a fast Point-of-care (POC) diagnostic. This portable ESSENCE platform can respond to the measurable EIS signals from the oscilloscope with 25 ul samples size (DNA and HER2 proteins in undiluted artificial Urine) with a fully automatic process at the uM to pM regions in 15 minutes. Each ESSENCE chip is also significantly cheaper than the ELISA; the chip costs about $20 (for an academic lab) and can be reused. Figure 1

The D-π-A type phosphonium salts in which electron acceptor (A=-+ PR3 ) and donor (D=-NPh2 ) groups are linked by polarizable π-conjugated spacers show intense fluorescence that is classically ascribed to excited-state intramolecular charge transfer (ICT). Unexpectedly, salts with π=-(C6 H4 )n - and -(C10 H6 C6 H4 )- exhibit an unusual dual emission (F1 and F2 bands) in weakly polar or nonpolar solvents. Time-resolved fluorescence studies show a successive temporal evolution from the F1 to F2 emission, which can be rationalized by an ICT-driven counterion migration. Upon optically induced ICT, the counterions move from -+ PR3 to -NPh2 and back in the ground state, thus achieving an ion-transfer cycle. Increasing the solvent polarity makes the solvent stabilization dominant, and virtually stops the ion migration. Providing that either D or A has ionic character (by static ion-pair stabilization), the ICT-induced counterion migration should not be uncommon in weakly polar to nonpolar media, thereby providing a facile avenue for mimicking a photoinduced molecular machine-like motion.

Rapid and sensitive detection and quantification of trace and ultra-trace analytes is critical to environmental remediation, analytical chemistry and defense from chemical and biological contaminants. Though affinity based electrochemical sensors have gained immense popularity, they frequently do not meet the requirements of desired sensitivity and detection limits. Here, we demonstrate a complementary luminescence mode that can significantly enhance sensitivity of impedance or voltammetric electrochemical sensors. Our methodology involves using a redox probe, whose luminescence properties change upon changing the oxidation state. By tailoring the system such that these luminescence changes can be correlated with the capture of target analytes, we are able to significantly lower the detection limit and improve the efficiency of detection compared to the electrochemical modes alone. Our proof-of-concept demonstration, using a model system designed for Ca2+ capture, illustrated that the luminescent mode allowed us to lower the limits of detection by three-orders of magnitude compared to the impedance or voltammetric modes alone without requiring any modification of electrode design or cell configuration. Further, the linear ranges of detection are 10−8 to 10−3 M in the voltammetry mode, 10−8 to 10−5 M in the impedance mode and 2.5 × 10−11 to 10−7 M in the luminescent mode, providing a large range of operational flexibility.

BackgroundMDR Elizabethkingia anophelis strains are implicated in an increasing number of healthcare-associated infections worldwide, including a recent cluster of E. anophelis infections in the Midwestern USA associated with significant morbidity and mortality. However, there is minimal information on the antimicrobial susceptibilities of E. anophelis strains or their antimicrobial resistance to carbapenems and fluoroquinolones.ObjectivesOur aim was to examine the susceptibilities and genetic profiles of clinical isolates of E. anophelis from our hospital, characterize their carbapenemase genes and production of MBLs, and determine the mechanism of fluoroquinolone resistance.MethodsA total of 115 non-duplicated isolates of E. anophelis were examined. MICs of antimicrobial agents were determined using the Sensititre 96-well broth microdilution panel method. QRDR mutations and MBL genes were identified using PCR. MBL production was screened for using a combined disc test.ResultsAll E. anophelis isolates harboured the blaGOB and blaB genes with resistance to carbapenems. Antibiotic susceptibility testing indicated different resistance patterns to ciprofloxacin and levofloxacin in most isolates. Sequencing analysis confirmed that a concurrent GyrA amino acid substitution (Ser83Ile or Ser83Arg) in the hotspots of respective QRDRs was primarily responsible for high-level ciprofloxacin/levofloxacin resistance. Only one isolate had no mutation but a high fluoroquinolone MIC.ConclusionsOur study identified a strong correlation between antibiotic susceptibility profiles and mechanisms of fluoroquinolone resistance among carbapenem-resistant E. anophelis isolates, providing an important foundation for continued surveillance and epidemiological analyses of emerging E. anophelis opportunistic infections. Minocycline or ciprofloxacin has the potential for treatment of severe E. anophelis infections.

BackgroundCiliates are an ancient and diverse eukaryotic group found in various environments. A unique feature of ciliates is their nuclear dimorphism, by which two types of nuclei, the diploid germline micronucleus (MIC) and polyploidy somatic macronucleus (MAC), are present in the same cytoplasm and serve different functions. During each sexual cycle, ciliates develop a new macronucleus in which newly fused genomes are extensively rearranged to generate functional minichromosomes. Interestingly, each ciliate species seems to have its way of processing genomes, providing a diversity of resources for studying genome plasticity and its regulation. Here, we sequenced and analyzed the macronuclear genome of different strains ofParamecium bursaria, a highly divergent species of the genusParameciumwhich can stably establish endosymbioses with green algae.ResultsWe assembled a high-quality macronuclear genome ofP.bursariaand further refined genome annotation by comparing population genomic data. We identified several species-specific expansions in protein families and gene lineages that are potentially associated with endosymbiosis. Moreover, we observed an intensive chromosome breakage pattern that occurred during or shortly after sexual reproduction and contributed to highly variable gene dosage throughout the genome. However, patterns of copy number variation were highly correlated among genetically divergent strains, suggesting that copy number is adjusted by some regulatory mechanisms or natural selection. Further analysis showed that genes with low copy number variation among populations tended to function in basic cellular pathways, whereas highly variable genes were enriched in environmental response pathways.ConclusionsWe report programmed DNA rearrangements in theP.bursariamacronuclear genome that allow cells to adjust gene copy number globally according to individual gene functions. Our results suggest that large-scale gene copy number variation may represent an ancient mechanism for cells to adapt to different environments.

We herein aim to probe the emission quenched by O2 on silica gel. Our special focus is on the O2 quenching of the fluorescence of a series of organic D-π-A phosphonium compounds 1-3. The results show that the O2 quenching rate constants for the fluorescence of 1-3 are on the order of 1010 M-1 s-1, which are nearly on the same order as those measured for 1-3 and common organic compounds in solution. In yet another approach, the study of O2 quenching of phosphorescence in the solid phase indicates that the O2 quenching rate constant for the triplet state, i.e., , is smaller than by two orders of magnitude. Detailed investigation indicates that this distinction stems from the intrinsic O2 quenching rate constants for the singlet and triplet states subsequent to the formation of collisional complexes. In the absence of the solvent cage effect, is greatly influenced by the formation energy of the O2-dye CT complex, whereas in the solid phase is a nearly diffusion-controlled rate. Due to the larger distinction between and in the solid phase, O2 quenching of fluorescence is efficient for dyes in the solid phase. This leads to a feasible application of sensing O2 with regular fluorescent dyes adsorbed on porous solid substrates.

Ocean-bottom seismometers (OBSs) were deployed at a shallow water depth (

Additional file 1: Figure S1. De novo assembly of the P. bursaria MAC genome. Figure S2. P. bursaria introns have very conserved 5′ and 3′ splice sites. Figure S3. PFG Southern blot analysis of the genomic DNA of different P. bursaria strains. Figure S4. The extensive chromosome breakage pattern in the MAC. Figure S5. A model showing how highly variable breaking sites lead to non-uniform gene dosage. Figure S6. Contig copy number is uniform in T. thermophila. Different P. bursaria strains show similar patterns of copy number distribution. Figure S7. Conserved GA-rich motifs are found near chromosome breakage sites. Figure S8. DK1 and DK2 strains are the real F1 progeny of Dd1 and KM2.