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In this study, we reviewed smog chamber systems and methodologies used in secondary organic aerosol (SOA) formation studies. Many important chambers across the world have been reviewed, including 18 American, 24 European, and 8 Asian chambers. The characteristics of the chambers (location, reactor size, wall materials, and light sources), measurement systems (popular equipment and working principles), and methodologies (SOA yield calculation and wall-loss correction) are summarized. This review discussed key experimental parameters such as surface-to-volume ratio (S/V), temperature, relative humidity, light intensity, and wall effect that influence the results of the experiment, and how the methodologies have evolved for more accurate simulation of atmospheric processes. In addition, this review identifies the sources of uncertainties in finding SOA yields that are originated from experimental systems and methodologies used in previous studies. The intensity of the installed artificial lights (photolysis rate of NO2 varied from 0.1/min to 0.40/min), SOA density assumption (varied from 1 g/cm3 to 1.45 g/cm3), wall-loss management, and background contaminants were identified as important sources of uncertainty. The methodologies developed in previous studies to minimize those uncertainties are also discussed. [ABSTRACT FROM AUTHOR]

Toxic fission products, such as cesium (137Cs) and iodine (129I) are of great concern because of their long half-lives and high solubility in water. The simultaneous removal of Cs and I using a single adsorbent is an area of increasing interest. In this study, MXene/silver nanowire (AgNW) composite was synthesized through physical mixing and employed for simultaneous removal of iodide (I−) and cesium (Cs+) ions from contaminated water. The MXene/AgNW composite demonstrated excellent adsorption capacities of 84.70 and 26.22 mg/g for I− and Cs+, respectively. The experimental data supported the hypothesis of multilayer adsorption of Cs+ owing to the inter-lamellar structures and the presence of heterogeneous adsorption sites in MXene. The interaction between I− and the AgNW involved chemisorption followed by monolayer adsorption. MXene/AgNW composite material exhibited promising results in the presence of competitive ions under extreme pH conditions. Thus, synthesized composite materials holds promising potential as an adsorbent for the remediation of radioactive liquid waste. [ABSTRACT FROM AUTHOR]

In GMAW (gas metal arc welding) of Zn (zinc)-coated steel sheets, defects such as pores occur in the weld due to trapped Zn vapor. To solve this problem, we investigated the pore-free welding condition using conventional solid wire. We verified through experiments that the combination of 20% CO2-Ar shielding gas and DCEP (direct current electrode positive) polarity has a higher pore-free performance than other combinations. A higher performance of pore-free welding was obtained by reducing the CTWD (contact tip to work distance) and using ER70S-3 wire. In conclusion, the optimized welding conditions at 10 mm overlap, 80 cm/min welding speed, and 30° work angle are 160 A arc current, 20 V voltage, 15 mm CTWD, 10° push angle, DCEP polarity, 20% CO2-Ar shielding gas with 20 L/min flow rate, and ER70S-3 wire type. For flow pattern analysis, a high-speed camera with blue laser was used, and it was observed that a longer weld pool and smaller droplets could improve the efficiency of Zn vapor emission. With ER70S-3, a longer weld pool can be obtained, as it has a lower viscosity due to lower percentages of Si and Mn in its composition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pantoea sp. PL-1 inhibits biofilm in AI-2 QS strains, hindering DPD concentration. • PL-1 degrades DPD more efficiently (15 times) than Acinetobacter sp. DKY-1. • Applying PL-1 in an MBR showed 40% more biofilm reduction than DKY-1. • PL-1 alters microbial communities, potentially suppressing EPS production genes. • Hydrophilic, low molecule of PL-1′s AI-2 QQ substance needs crucial exploration. Prior investigations concerning quorum quenching (QQ), which hinders quorum sensing (QS) in microbial communication, concentrated predominantly on N -acylhomoserine lactones (AHLs), which are communicated merely by gram-negative bacteria. However, to combat biofouling more effectively, particularly biofilm-related issues, it is important to explore the inhibition of autoinducer-2 (AI-2), a universal signal (interspecies communication) employed by both gram-negative and gram-positive bacteria. This study aimed to isolate and identify novel strains capable of more effectively inhibiting AI-2 signaling for use in engineering fields. The results revealed that the newly isolated strain Pantoea sp. PL-1 demonstrated remarkable efficacy in attenuating AI-2 signals, leading to a substantial reduction in the AI-2 precursor (S)-4,5-dihydroxy-2,3-pentandione (DPD) in both its pellet (with a DPD removal efficiency of 90.8 % after 180 min, with a rate constant of k = 0.8 h−1) and supernatant form (66.9 %, k = 0.37 h−1). Interestingly, the findings indicate that strain DKY-1, a strain previously reported to exhibit AI-2 QQ activity, only reduced DPD levels in its supernatant form (extracellular activity), while both the pellet and the supernatant of strain PL-1 demonstrated AI-2 QQ activity, indicating both intracellular and extracellular QQ activity. Adding the PL-1 supernatant to co-cultures of two AI-2 QS strains, E. coli K12 and P. mirabilis , successfully reduced DPD by 40 % and 70 %, respectively, without impeding their growth. Additionally, when assessing the impact of PL-1 to minimize membrane biofouling in a membrane bioreactor, it demonstrated superior performance compared to the DKY-1 strain, with a 40 % improvement. The AI-2 QQ compound of PL-1 has been identified as highly hydrophilic and low-molecular-weight, and its exact properties have not yet been fully elucidated. Therefore, uncovering its identity may be an important goal for future research. [ABSTRACT FROM AUTHOR]

Benzylalkyldimethylammonium chloride (BAC), a quaternary ammonium compound (QAC), is utilized in industrial and biomedical applications for antimicrobial purposes. Since the coronavirus disease (COVID-19) outbreak, various types of BAC-containing household chemicals have been produced. BACs have several adverse effects; however, their biological uptake, translocation, and excretion in animal models (essential for better understanding in vivo behavior and toxicological impact) remain unclear. In this study, we performed the first biodistribution and whole-body imaging studies of BAC in male Sprague Dawley rats, using two different administration routes. Quantitative whole-body autoradiography (QWBA) data obtained for intranasal 14C-labeled BAC ([14C]C12-BAC) exposure showed substantial uptake values for the respiratory organs (e.g. 346 ng g−1 of lung at 3 h post administration) and the radiotracer was transported to other internal organs. The amount of radiotracer in the heart, adrenal gland, and pancreas were 198, 1410, and 186 ng g−1 tissue respectively at 168 h following exposure. Autoradiograms obtained after intravenous injection also showed high accumulation and slow excretion in these organs. The cumulative excretion analysis revealed that approximately 6.4% of the administered radioactivity remained in rats after a week. The results indicated that continuous inhalation exposure to BAC leads to potential toxic effects in extrapulmonary organs and the respiratory tract. Thus, the radiolabeling method utilized may help assess various synthetic QACs in living subjects. [Display omitted] • The radiolabeled benzylalkyldimethylammonium chloride (BAC) was synthesized. • Biological uptake and in vivo behavior of BAC were assessed using the radiotracer. • 14C-labeled BAC was administered in rats via the intranasal and intravenous routes. • After the inhalation exposure, BAC was translocated to extrapulmonary organs. • Significant accumulations were observed in the heart, adrenal gland, and pancreas. [ABSTRACT FROM AUTHOR]

[Display omitted] • The biodistribution of CMIT/MIT was assessed using a 14C-labeled radiotracer. • After exposure via the inhalation routes, CMIT/MIT is rapidly distributed to the lungs. • Intratracheal exposure induces greater lung damage than intranasal instillation. • The amount of CMIT/MIT in the lungs is positively associated with the toxicity. A variety of isothiazolinone-containing small molecules have been registered and used as chemical additives in many household products. However, their biodistribution and potential harmful effects on human health, especially respiratory effects, were not yet identified in sufficient detail. The purpose of this study was to investigate whether a biocide comprising a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) could reach the lungs and induce lung injury when exposure occurs by two administration routes involving the respiratory tract: intratracheal and intranasal instillation. To investigate the biodistribution of CMIT/MIT, we quantified the uptake of 14C-labeled CMIT/MIT in experimental animals for up to seven days after intratracheal and intranasal instillation. In the toxicity study, lung injury was assessed in mice using total inflammatory cell count in bronchoalveolar lavage fluid (BALF) and lung histopathology. The results of the biodistribution study indicated that CMIT/MIT were rapidly distributed throughout the respiratory tract. Using quantitative whole-body autoradiogram analysis, we confirmed that following intranasal exposure, CMIT/MIT reached the lungs via the respiratory tract (nose–trachea–lung). After 5 min post intratracheal and intranasal instillation, the amount of radiotracer ([14C]CMIT/MIT) in the lungs was 2720 ng g−1 and 752 ng g−1 tissue, respectively, and lung damage was observed. A higher amount of the radiotracer resulted in higher toxicity. Both intratracheal and intranasal instillation of CMIT/MIT increased inflammatory cell counts in the BALF and induced injuries in the alveoli. The frequency and the severity scores of injuries caused by intratracheal instillation were approximately-four to five times higher than those induced by intranasal instillation. Therefore, we concluded that CMIT/MIT could reach the lungs following nasal and intratracheal exposure and cause lung injuries, and the extent of injury was dependent on the exposure dose. [ABSTRACT FROM AUTHOR]

Nanotechnology has played a tremendous role in molecular imaging and cancer therapy. Over the last decade, scientists have worked exceptionally to translate nanomedicine into clinical practice. However, although several nanoparticle-based drugs are now clinically available, there is still a vast difference between preclinical products and clinically approved drugs. An efficient translation of preclinical results to clinical settings requires several critical studies, including a detailed, highly sensitive, pharmacokinetics and biodistribution study, and selective and efficient drug delivery to the target organ or tissue. In this context, technetium-99m (99mTc)-based radiolabeling of nanoparticles allows easy, economical, non-invasive, and whole-body in vivo tracking by the sensitive clinical imaging technique single-photon emission computed tomography (SPECT). Hence, a critical analysis of the radiolabeling strategies of potential drug delivery and therapeutic systems used to monitor results and therapeutic outcomes at the preclinical and clinical levels remains indispensable to provide maximum benefit to the patient. This review discusses up-to-date 99mTc radiolabeling strategies of a variety of important inorganic and organic nanoparticles and their application to preclinical imaging studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • New fluorescent probes (8a–d) were designed and synthesized based on a curcumin scaffold. • Probe 8b displayed an emission wavelength in the NIR region and a good binding affinity for the Aβ aggregates. • Probe 8b achieved clear visualization of Aβ plaques in 5XFAD transgenic mice. • The signal intensity of 8b in the brain of the 5XFAD mouse was much higher than that of the control group. • The biological uptake of 8b into the internal organs and brain was confirmed via ex vivo experiments. The abnormal self-assembly of amyloid-beta (Aβ) peptides into oligomers, as well as insoluble fibrils, has been identified as a key factor for monitoring the progression of Alzheimer's disease (AD). The noninvasive imaging of Aβ aggregates utilizing chemical probes can be a powerful and practical technique for accurately diagnosing and monitoring the progress of AD, as well as evaluating the effectiveness of therapeutic drug candidates in treating or managing it. Particularly, the near-infrared (NIR) fluorescence imaging of Aβ plaques is a potentially promising approach toward the efficient detection of the biomarker. In this study, we describe a new NIR fluorophore, which was based on curcumin derivatives. The fluorophore is equipped with desirable optical properties for in vivo brain imaging. The emission wavelength of the probe, 8b , is 667 nm, and its fluorescent intensity is significantly increased through binding with the Aβ aggregates. The probe allows the clear visualization of the Aβ plaques 10 min post administration, and the intensity of the fluorescent signal in the brain of a 5XFAD transgenic mouse model is more than three times higher than that of the normal control group. These results demonstrate that the designed probe can be an effective tool for visualizing Aβ plaques, as well as investigating the pathological progress of AD. [ABSTRACT FROM AUTHOR]