Engineering a "turn-on" NIR fluorescent sensor-based hydroxyphenyl benzothiazole with a cinnamoyl unit for hydrazine and its environmental and in-vitro applications

Hydrazine (N2H4), a chemical compound widely used in various industrial applications, causes significant environmental and biological hazards. Therefore, it is crucial to develop methodologies for the visualization and real time tracking of N2H4. In this regard, we have constructed a novel near-infrared fluorescent probe (HBT-Cy) that can effectively detect N2H4 in various samples. HBT-Cy contains 2-(2'-hydroxyphenyl)benzothiazole (HBT), cinnamoyl (Cy), and pyridinium (Py) moieties. Importantly, HBT-Cy exhibits a rapid, selective, and highly sensitive response to N2H4. This response results in the release of HBT-Py and the generation of considerable colorimetric changes along with a significant NIR (near infrared) fluorescence signal, peaking at 685 nm. Advantages of this system include turn on NIR fluorescence with large Stokes shift, (approximately 171 nm), low limit of detection (LOD = 0.11 μM) and quantum yield (0.211). The probe with low cytotoxic behavior demonstrates strong NIR fluorescence imaging capabilities to visualize endogenous and exogenous N2H4 in live cells. This mitochondria-targetable probe shows effective subcellular localization. These results suggest that HBT-Cy is a valuable probe for tracking and investigating the behavior of N2H4 in biological systems and environmental samples.

RF Characterization of GaAs HBT under Load Mismatch with Reverse Wave Injection Technique

RF PAs need to be reliable enough to protect them from damage under load mismatch conditions. This paper investigated the characteristics of GaAs heterojunction bipolar transistors (HBTs) under load mismatch conditions using a novel reverse wave injection technique to realize large VSWR ruggedness measurement with the circle centered at 50 Ohm and optimal impedance separately to analyze the device in real applications. With a real-time waveform measurement system, the RF voltage and current waveform information can be acquired, which provide a more-accurate view of what is occurring at the current generator plane of the HBT device. Thereby, the potential failure mechanisms and load impedance can be identified to design the most-suitable PA circuits in communication systems.

Impact of genus (Geotrigona, Melipona, Scaptotrigona) in the targeted 1H-NMR organic profile, and authenticity test by interphase emulsion of honey processed in cerumen pots by stingless bees in Ecuador

The biodiversity of Ecuadorian stingless bees is almost 200 species. Traditional pot-honey harvest in Ecuador is mostly done from nests of the three genera selected here Geotrigona Moure, 1943, Melipona Illiger, 1806, and Scaptotrigona Moure, 1942. The 20 pot-honey samples collected from cerumen pots and three ethnic honeys "abeja de tierra", "bermejo", and "cushillomishki" were analyzed for qualitative and quantitative targeted 1H-NMR honey profiling, and for the Honey Authenticity Test by Interphase Emulsion (HATIE). Extensive data of targeted organic compounds (41 parameters) were identified, quantified, and described. The three honey types were compared by ANOVA. Amino acids, ethanol, hydroxymethylfurfural, aliphatic organic acids, sugars, and markers of botanical origin. The number of phases observed with the HATIE were one in Scaptotrigona and three in Geotrigona and Melipona honeys. Acetic acid (19.60 ± 1.45 g/kg) and lactic acid (24.30 ± 1.65 g/kg) were particularly high in Geotrigona honey (in contrast to 1.3 g/kg acetic acid and 1.6 g/kg lactic acid in Melipona and Scaptotrigona), and with the lowest fructose + glucose (18.39 ± 1.68) g/100g honey compared to Melipona (52.87 ± 1.75) and Scaptotrigona (52.17 ± 0.60). Three local honeys were tested using PCA (Principal Component Analysis), two were assigned with a correct declared bee origin, but "bermejo" was not a Melipona and grouped with the Scaptotrigona cluster. However after HCA (Hierarchical Cluster Analysis) the three honeys were positioned in the Melipona-Scaptotrigona cluster. This research supports targeted 1H-NMR-based profiling of pot-honey metabolomics approach for multi-parameter visualization of organic compounds, as well as descriptive and pertained multivariate statistics (HCA and PCA) to discriminate the stingless bee genus in a set of Geotrigona, Melipona and Scaptotrigona honey types. The NMR characterization of Ecuadorian honey produced by stingless bees emphasizes the need for regulatory norms. A final note on stingless bee markers in pot-honey metabolites which should be screened for those that may extract phylogenetic signals from nutritional traits of honey. Scaptotrigona vitorum honey revealed biosurfactant activity in the HATIE, originating a fingerprint Honey Biosurfactant Test (HBT) for the genus in this set of pot-honeys.

Monolithic Integration of Nano-Ridge Engineered InGaP/GaAs HBTs on 300 mm Si Substrate

Nano-ridge engineering (NRE) is a novel method to monolithically integrate III–V devices on a 300 mm Si platform. In this work, NRE is applied to InGaP/GaAs heterojunction bipolar transistors (HBTs), enabling hybrid III-V/CMOS technology for RF applications. The NRE HBT stacks were grown by metal-organic vapor-phase epitaxy on 300 mm Si (001) wafers with a double trench-patterned oxide template, in an industrial deposition chamber. Aspect ratio trapping in the narrow bottom part of a trench results in a threading dislocation density below 10⁶∙cm⁻² in the device layers in the wide upper part of that trench. NRE is used to create larger area NRs with a flat (001) surface, suitable for HBT device fabrication. Transmission electron microscopy inspection of the HBT stacks revealed restricted twin formation after the InGaP emitter layer contacts the oxide sidewall. Several structures, with varying InGaP growth conditions, were made, to further study this phenomenon. HBT devices—consisting of several nano-ridges in parallel—were processed for DC and RF characterization. A maximum DC gain of 112 was obtained and a cut-off frequency f_t of ~17 GHz was achieved. These results show the potential of NRE III–V devices for hybrid III–V/CMOS technology for emerging RF applications.

Transformation of sulfadiazine in humic acid and polystyrene microplastics solution by horseradish peroxidase coupled with 1-hydroxybenzotriazole

Enzyme catalyzed coupling with redox mediators are considered as great interesting and viable technologies to transform antibiotics. This work demonstrated the horseradish peroxidase (HRP) was effective in transforming sulfadiazine (SDZ) transformation coupled with 1-hydroxybenzotriazole (HBT) at varying conditions. The removal of SDZ was independent of Na⁺ and its ionic strength, but Ca²⁺ could enhance transformation efficiency by increasing the enzyme activity of HRP. The presence of humic acid (HA) and polystyrene (PS) microplastics showed inhibition on the transformation of SDZ, and the transformation rate constants (k) decreased with the concentration of HA and PS particles increased. These primarily attributed to covalent coupling and electrostatic interaction between SDZ and HA, SDZ and PS, respectively, which reduced the concentration of free SDZ in the reaction solution. The presence of cation recovered the inhibition of SDZ transformation by HA and PS particles, which ascribed to compete between cation and SDZ. The divalent cations (Ca²⁺) showed more substantial competitiveness than mono (Na⁺) due to more carried charge. Eight possible transformation products were identified, and potential SDZ transformation pathways were proposed, which include δ-cleavage, γ-cleavage, carbonylation, hydroxylation, SO₂ extrusion and SO₃ extrusion. In addition, HA and PS particles couldn't affect the transformation pathways of SDZ. These findings provide novel understandings of the transformation and the fate of antibiotics in the natural environment by HRP coupled with redox mediators.

Rational design of an ESIPT-based fluorescent probe for selectively monitoring glutathione in live cells and zebrafish

Glutathione (GSH), an extremely important antioxidant, is a major participant in maintaining redox homeostasis and tightly associated with various clinical diseases. Thus, accurate and rapid detection of intracellular GSH is imperative to elucidate its role in physiological and pathological processes. Herein, by modifying 2-(2'-hydroxyphenyl) benzothiazole (HBT) scaffold, we developed an excited-state intramolecular proton transfer (ESIPT)-based fluorescent probe BTFMD for tracking GSH, which exhibited good selectivity, excellent water solubility, a large Stokes shift (181 nm) and fast response rate (within 10 min). Furthermore, the probe was successfully applied for imaging of endogenous GSH in live cells and zebrafish, and probing into the role of GSH in the development of cancer and Parkinson's disease.

Emerging Transistor Technologies Capable of Terahertz Amplification: A Way to Re-Engineer Terahertz Radar Sensors

This paper reviews the state of emerging transistor technologies capable of terahertz amplification, as well as the state of transistor modeling as required in terahertz electronic circuit research. Commercial terahertz radar sensors of today are being built using bulky and expensive technologies such as Schottky diode detectors and lasers, as well as using some emerging detection methods. Meanwhile, a considerable amount of research effort has recently been invested in process development and modeling of transistor technologies capable of amplifying in the terahertz band. Indium phosphide (InP) transistors have been able to reach maximum oscillation frequency (fmax) values of over 1 THz for around a decade already, while silicon-germanium bipolar complementary metal-oxide semiconductor (BiCMOS) compatible heterojunction bipolar transistors have only recently crossed the fmax = 0.7 THz mark. While it seems that the InP technology could be the ultimate terahertz technology, according to the fmax and related metrics, the BiCMOS technology has the added advantage of lower cost and supporting a wider set of integrated component types. BiCMOS can thus be seen as an enabling factor for re-engineering of complete terahertz radar systems, for the first time fabricated as miniaturized monolithic integrated circuits. Rapid commercial deployment of monolithic terahertz radar chips, furthermore, depends on the accuracy of transistor modeling at these frequencies. Considerations such as fabrication and modeling of passives and antennas, as well as packaging of complete systems, are closely related to the two main contributions of this paper and are also reviewed here. Finally, this paper probes active terahertz circuits that have already been reported and that have the potential to be deployed in a re-engineered terahertz radar sensor system and attempts to predict future directions in re-engineering of monolithic radar sensors.

Risk-based management of drinking water safety in Australia: Implementation of health based targets to determine water treatment requirements and identification of pathogen surrogates for validation of conventional filtration

The safety of drinking water in Australia is ensured using a risk management framework embedded within the Australian Drinking Water Guidelines (ADWG). This framework includes elements for hazard identification, risk assessment, risk mitigation, verification of barrier performance and monitoring for any changes to the hazards that influence source water quality. The next revision of the ADWG will incorporate Health-Based Targets (HBTs) for achieving microbiologically safe drinking water. This incorporates Quantitative Microbial Risk Assessment and the metric of Disability Adjusted Life Year (DALY) to define safety, with a target of 1 × 10^− 6 Disability Adjusted Life Year (1 microDALY) set as the maximum tolerable disease burden from drinking water, which in the case of Cryptosporidium is < 1.3 × 10^− 5 oocysts/L. The resulting product water specification, in combination with knowledge of pathogen challenges in source waters, allows the determination of the treatment requirements to ensure public safety. The ADWG revision provides default removal values for Cryptosporidium for particular treatment processes, such as conventional coagulation and dual media filtration. However, these values are based on assumptions regarding treatment plant design, operation and water quality. To properly manage risk and demonstrate compliance with the guidelines, water utilities may need to validate treatment performance for Cryptosporidium removal. A particular limitation is the absence of Cryptosporidium surrogates for full-scale filter validation. This paper will provide an overview of risk-based management of drinking water safety in Australia, the development of health-based targets for microbial pathogens and the evaluation of Cryptosporidium surrogates for conventional coagulation and dual media filtration.

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Used pilot-scale coagulation, sedimentation, granular media filter water treatment

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Compared the removals of Cryptosporidium oocysts and surrogates

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Pilot-scale treated water quality was comparable to full-scale treatment.

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Modified microspheres most similar to oocyst filtration removal

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Clostridium spores, algae and turbidity conservative indicators of oocyst removal

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Turbidity, algae have great potential as on-line indicators for oocyst removal.

Neonatal olfactory bulbectomy enhances locomotor activity, exploratory behavior and binding of NMDA receptors in pre-pubertal rats

In this study, we investigated the effect of neonatal olfactory bulbectomy (nOBX) on behavioral paradigms related to olfaction such as exploratory behavior, locomotor activity in a novel environment and social interaction. We also studied the effect of nOBX on the activity of the N-methyl-d-aspartate (NMDA) subtype of glutamate receptors during development. The behavioral effects of nOBX (postnatal day 7, PD7) were investigated in pre- (PD30) and post-pubertal (PD60) Wistar rats. NMDA receptor activity was measured with [(125)I]MK-801 in the brain regions associated with the olfactory circuitry. A significant increase in the novelty-induced locomotion was seen in the pre-pubertal nOBX rats. Although the locomotor effect was less marked than in pre-pubertal rats, the nOBX rats tested post-pubertally failed to habituate to the novel situation as quickly as the sham- and normal- controls. Pre-pubertally, the head-dipping behavior was enhanced in nOBX rats compared with sham-operated and normal controls, while normal exploratory behavior was observed between groups in adulthood. In contrast, social interaction was increased in post-pubertal animals that underwent nOBX. Both pre- and post-pubertal nOBX rats recovered olfaction. Interestingly, pre-pubertal rats showed a significant increase in the [(125)I]MK-801 binding in the piriform cortex, dorsal hippocampus, inner and outer layers of the frontal cortex and outer layer of the cingulate cortex. At post-pubertal age, no significant differences in [(125)I]MK-801 binding were observed between groups at any of the brain regions analyzed. These results suggest that nOBX produces pre-pubertal behavioral disturbances and NMDA receptor changes that are transitory with recovery of olfaction early in adulthood.

Biomarkers for the evaluation of population health status 16 years after the intervention of arsenic-contaminated groundwater in Xinjiang, China

The arsenicosis endemic area in the region of Kuitun and Chepaizi, Dzungaria district, Xinjiang, People Republic of China was the first identified arsenic endemic area in China where arsenic concentration of up to 850 μg/L in the groundwater was reported. An intervention was put in place in 1985 by government to provide an alternative water source at a centralized community level. Sixteen years on since the intervention, we evaluated the health status of 178 villagers from endemic and 179 villagers from control sites. Biomarkers in their urine, included arsenic, porphyrins and malondialdehyde (MDA) were measured and the prevalence of skin lesions was also assessed. The average urinary arsenic (117 ± 8.3 μg/g of creatinine) from the endemic-villages was significantly higher (p<0.001) than that of the controls (73.6 ± 3.2 μg/g of creatinine) while no significant difference was found in urinary porphyrins and malondialdehyde concentrations in the overall studies subjects from these two areas. However when the urinary arsenic was higher than 150 μg/g of creatinine, MDA and porphyrins were higher in the endemic-villagers compared to the controls. Fifty-one out of 178 people from the arsenic endemic area showed skin lesions related to arsenicosis but these were absent among villagers from the control site. Of particular concern, skin lesions related to arsenicosis were observed in 4 out of 9 subjects 16 years of age or younger who were from different villages and born after the completion of water intervention. Although sporadic exposure and/or voluntary drinking contaminated water were thought to be a contributor of arsenicosis after the water intervention, the contribution from other dietary arsenic intakes remain unclear.

Removal of trace organic contaminants by an MBR comprising a mixed culture of bacteria and white-rot fungi

The degradation of 30 trace organic contaminants (TrOC) by a white-rot fungus-augmented membrane bioreactor (MBR) was investigated. The results show that white-rot fungal enzyme (laccase), coupled with a redox mediator (1-hydroxy benzotriazole, HBT), could degrade TrOC that are resistant to bacterial degradation (e.g. diclofenac, triclosan, naproxen and atrazine) but achieved low removal of compounds (e.g. ibuprofen, gemfibrozil and amitriptyline) that are well removed by conventional activated sludge treatment. Overall, the fungus-augmented MBR showed better TrOC removal compared to a system containing conventional activated sludge. The major role of biodegradation in removal by the MBR was noted. Continuous mediator dosing to MBR may potentially enhance its performance, although not as effectively as for mediator-enhanced batch laccase systems. A ToxScreen3 assay revealed no significant increase in the toxicity of the effluent during MBR treatment of the synthetic wastewater comprising TrOC, confirming that no toxic by-products were produced.