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Analytical Chemistry Apr 2023Fine particulates (FPs) are a major class of airborne pollutants. In mammals, FPs may reach the alveoli through the respiratory system, cross the air-blood barrier,...
Fine particulates (FPs) are a major class of airborne pollutants. In mammals, FPs may reach the alveoli through the respiratory system, cross the air-blood barrier, spread into other organs, and induce hazardous effects. Although birds have much higher respiratory risks to FPs than mammals, the biological fate of inhaled FPs in birds has rarely been explored. Herein, we attempted to disclose the key properties that dictate the lung penetration of nanoparticles (NPs) by visualizing a library of 27 fluorescent nanoparticles (FNPs) in chicken embryos. The FNP library was prepared by combinational chemistry to tune their compositions, morphologies, sizes, and surface charges. These NPs were injected into the lungs of chicken embryos for dynamic imaging of their distributions by IVIS Spectrum. FNPs with diameters <16 nm could cross the air-blood barrier in 20 min, spread into the blood, and accumulate in the yolk sac. In contrast, large FNPs (>30 nm) were mainly retained in the lungs and rarely detected in other tissues/organs. In addition to size, surface charge was the secondary determinant for NPs to cross the air-blood barrier. Compared to cationic and anionic particles, neutrally charged FNPs showed the fastest lung penetration. A predictive model was therefore developed to rank the lung penetration capability of FNPs by analysis. The predictions could be well validated in chicks by oropharyngeal exposure to six FNPs. Overall, our study discovered the key properties of NPs that are responsible for their lung penetration and established a predictive model that will greatly facilitate respiratory risk assessments of nanoproducts.
Topics: Chick Embryo; Animals; Chickens; Blood-Air Barrier; Nanoparticles; Lung; Coloring Agents; Particle Size; Mammals
PubMed: 37005435
DOI: 10.1021/acs.analchem.3c00034 -
Analytica Chimica Acta May 2023Single-atom catalyst (SAC), one of the most attractive catalysts in the field of energy conversion and storage, was proven as efficient accelerator for luminol-dissolved...
Single-atom catalyst (SAC), one of the most attractive catalysts in the field of energy conversion and storage, was proven as efficient accelerator for luminol-dissolved oxygen electrochemiluminescence (ECL) via the catalysis of oxygen reduction reaction (ORR). In this work, we synthesized heteroatom doping SACs of Fe-N/P-C for the catalysis of cathodic luminol ECL. The doping of P could lower the reaction energy barrier of the OH* reduction, and promote catalytic efficiency toward ORR. The formation of reactive oxygen species (ROS) during ORR triggered cathodic luminol ECL. Greatly enhanced ECL emission catalyzed by SACs proved that Fe-N/P-C exhibited higher catalytic activity to ORR compared with Fe-N-C. Since the system was highly dependent on oxygen, an ultra-sensitive detection of a typical antioxidant, ascorbic acid, was achieved with detection limit of 0.03 nM. This study provides possibility to greatly enhance the performance of ECL platform through rational tailoring of SACs via heteroatom doping.
PubMed: 37005019
DOI: 10.1016/j.aca.2023.341091 -
Frontiers in Veterinary Science 2023This report describes a new, simple and rapid surgical technique for the removal of anal sac in small dogs and cats. The anal sacs were simply everted using mosquito...
This report describes a new, simple and rapid surgical technique for the removal of anal sac in small dogs and cats. The anal sacs were simply everted using mosquito hemostatic forceps and excised with the aid of an electrocautery surgical unit. On the evaluation of postoperative complications, only one dog of 28 animals experienced short-term minor complications of mild fecal incontinence and scooting. Thus, we suggest that this new surgical technique is easy, inexpensive and time-saving and some of the complications with previously reported methods used for small dog breeds and cats may be avoided by using this technique.
PubMed: 36968460
DOI: 10.3389/fvets.2023.1105826 -
Medical Image Analysis May 2023Deep convolutional neural networks have been highly effective in segmentation tasks. However, segmentation becomes more difficult when training images include many...
Deep convolutional neural networks have been highly effective in segmentation tasks. However, segmentation becomes more difficult when training images include many complex instances to segment, such as the task of nuclei segmentation in histopathology images. Weakly supervised learning can reduce the need for large-scale, high-quality ground truth annotations by involving non-expert annotators or algorithms to generate supervision information for segmentation. However, there is still a significant performance gap between weakly supervised learning and fully supervised learning approaches. In this work, we propose a weakly-supervised nuclei segmentation method in a two-stage training manner that only requires annotation of the nuclear centroids. First, we generate boundary and superpixel-based masks as pseudo ground truth labels to train our SAC-Net, which is a segmentation network enhanced by a constraint network and an attention network to effectively address the problems caused by noisy labels. Then, we refine the pseudo labels at the pixel level based on Confident Learning to train the network again. Our method shows highly competitive performance of cell nuclei segmentation in histopathology images on three public datasets. Code will be available at: https://github.com/RuoyuGuo/MaskGA_Net.
Topics: Humans; Algorithms; Cell Nucleus; Neural Networks, Computer; Image Processing, Computer-Assisted
PubMed: 36878159
DOI: 10.1016/j.media.2023.102790 -
Veterinary and Comparative Oncology Jun 2023Apocrine gland anal sac adenocarcinoma (AGASACA) is a highly relevant disease in dogs, with a high rate of lymph node (LN) metastasis during the course of disease. A...
Apocrine gland anal sac adenocarcinoma (AGASACA) is a highly relevant disease in dogs, with a high rate of lymph node (LN) metastasis during the course of disease. A recent study showed that risk for death and disease progression was significantly associated with primary tumour size less than 2 and 1.3 cm, respectively. The objective of this study was to report the proportion of dogs that have primary tumours less than 2 cm in diameter, that are diagnosed with LN metastasis at presentation. This was a single site retrospective study of dogs that underwent treatment for AGASACA. Dogs were included if physical examination primary tumour measurements were available, abdominal staging was performed, and confirmation of abnormal lymph nodes by cytology or histology was done. Over a 5-year period, 116 dogs were included for review with 53 (46%) having metastatic LN at presentation. The metastatic rate for dogs with primary tumours <2 cm was 20% (9 of 46 dogs) compared to 63% (44 of 70 dogs) in dogs with primary tumours ≥2 cm. The association between tumour size group (<2 vs. ≥2 cm) and the presence of metastasis at presentation was significant (P < .0001) with an OR of 7.0 (95% CI: 2.9-15.7). Primary tumour size was significantly associated with LN metastasis at presentation but the proportion of dogs that presented with LN metastasis in the <2 cm group was relatively high. This data suggests that dogs with small tumours may still have aggressive tumour biology.
Topics: Dogs; Animals; Lymphatic Metastasis; Apocrine Glands; Anal Sacs; Adenocarcinoma; Retrospective Studies; Anal Gland Neoplasms; Dog Diseases; Lymph Nodes
PubMed: 36861227
DOI: 10.1111/vco.12890 -
Fish Physiology and Biochemistry Apr 2023In this study, the effects of temperature on hatching, yolk-sac absorption, larval metamorphosis, post-metamorphic growth, developmental morphology, and muscle...
Exposure to different temperature regimes at early life stages affects hatching, developmental morphology, larval growth, and muscle cellularity in rainbow trout, Oncorhynchus mykiss.
In this study, the effects of temperature on hatching, yolk-sac absorption, larval metamorphosis, post-metamorphic growth, developmental morphology, and muscle cellularity were assessed in rainbow trout, during its early development (until 52 days post-hatching, dph). From the eyed-ova stage, embryos were exposed to either low (8 ± 1 °C, LT-8) or high (16 ± 1 °C, HT-16) temperatures until hatching. Following hatching, half of the sac-fry from LT-8 group were shifted to higher temperature (16 ± 1 °C, LHT-16), and half from HT-16 group were shifted to medium temperature (13 ± 1 °C, HMT-13), for larval rearing. Incubating the eyed-ova at 16 °C preceded the hatching by 6 days, synchronized hatching duration, and minimized hatchlings' size-variation. However, it yielded smaller and morphologically less developed individuals compared to those incubated continuously at 8 ± 1 °C. Post-hatch shifting of sac-fry to high and medium temperatures, respectively, from the initial low and high regimes differentially affected the length and weight of fish. The effect on length was immediate and temporary, but on weight, it appeared to be permanent. Red muscle hypertrophy was observed to be high in HT-16 and HMT-13 individuals (high-temperature incubated groups). White muscle hypertrophy was high in HT-16 and LHT-16 individuals (high post-hatch rearing temperature groups). The effect of early-life temperature regimes on developmental morphology was found to be strong at 22 dph (82.5%) and comparatively weak at 52 dph (65%). The post-hatch rearing temperature caused an immediate but temporary effect on fin development, mainly pectoral, caudal, and anal fin (seen only at 22 dph, not at 52 dph). Contrarily, incubation temperature affected fin position, in a delayed but persistent manner (subtle at 22 dph, but stronger at 52 dph). Overall, this study provides new insights on temperature-dependent changes in developmental morphology, muscle cellularity, and larval growth in rainbow trout and shows that incubation temperature affects ontogeny profoundly than post-hatch thermal regimes.
Topics: Animals; Larva; Temperature; Oncorhynchus mykiss; Muscles; Hypertrophy
PubMed: 36826625
DOI: 10.1007/s10695-023-01175-8 -
Analytical Chemistry Mar 2023In this work, three-dimensional (3D) Ag aerogel-supported Hg single-atom catalysts (SACs) were explored as an efficient surface-enhanced Raman scattering (SERS)...
In this work, three-dimensional (3D) Ag aerogel-supported Hg single-atom catalysts (SACs) were explored as an efficient surface-enhanced Raman scattering (SERS) substrate to monitor the enhanced oxidase-like reaction. The influence of the concentrations of Hg to prepare 3D Hg/Ag aerogel networks on their SERS properties to monitor the oxidase-like reaction has been investigated, and a specific enhancement with an optimized addition of Hg has been achieved. The formation of Ag-supported Hg SACs with the optimized Hg addition was identified from a high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) image and X-ray photoelectron spectroscopy (XPS) measurement at an atomic level. This is the first discovery of Hg SACs for enzyme-like reaction applications inferred by SERS techniques. And density functional theory (DFT) was used to further reveal the oxidase-like catalytic mechanism of Hg/Ag SACs. This study provides a mild synthetic strategy to fabricate Ag aerogel-supported Hg single atoms to display promising prospects in various catalytic fields.
Topics: Metal Nanoparticles; Silver; Oxidoreductases; Mercury; Catalysis
PubMed: 36802569
DOI: 10.1021/acs.analchem.2c04548 -
Analytical Methods : Advancing Methods... Jan 2023There are at least 500 naturally occurring amino acids, of which only 20 standard proteinogenic amino acids are used universally across all organisms in the synthesis of...
There are at least 500 naturally occurring amino acids, of which only 20 standard proteinogenic amino acids are used universally across all organisms in the synthesis of peptides and proteins. Non-standard amino acids can be incorporated into proteins or are intermediates and products of metabolic pathways. While the analysis of standard amino acids is well-defined, the analysis of non-standard amino acids can be challenging due to the wide range of physicochemical properties, and the lack of both reference standards and information in curated databases to aid compound identification. It has been shown that the use of an AccQ·Tag™ derivatization kit along with LC-MS/MS is an attractive option for the analysis of free standard amino acids in complex samples because it is fast, sensitive, reproducible, and selective. It has been demonstrated that the most abundant quantitative transition for MS/MS analysis of 6-aminoquinolyl--hydroxysuccinimidyl carbamate (AQC) derivatized amino acids corresponds to the fragmentation of the molecule at the 6-aminoquinoline carbonyl group producing a common / 171 fragment ion and occurs at similar mass spectrometry collision energy and cone voltages. In this study, the unique properties of AQC derivatized amino acids producing high intensity common fragment ions, along with chromatographic separation of amino acids under generic chromatography conditions, were used to develop a novel screening method for the detection of trace levels of non-standard amino acids in complex matrices. Structural elucidation was carried out by comparing the MS/MS fragment ion mass spectra generated with predicted fragmentation spectra to enable a putative identification, which was confirmed using an appropriate analytical standard. This workflow was applied to screen human plasma samples for bioactive thiol-group modified cysteine amino acids and -allylmercaptocysteine (SAMC), -allylcysteine sulfoxide (SACS or alliin) and -propenylcysteine (S1PC) are reported for the first time to be present in human plasma samples after the administration of garlic supplements.
Topics: Humans; Amino Acids; Chromatography, Liquid; Tandem Mass Spectrometry; Indicators and Reagents; Chromatography, High Pressure Liquid
PubMed: 36602091
DOI: 10.1039/d2ay01588a -
Cancers Dec 2022Canine apocrine gland anal sac adenocarcinoma (AGASACA) is an aggressive canine tumor originating from the anal sac glands. Surgical resection, with or without adjuvant...
Canine apocrine gland anal sac adenocarcinoma (AGASACA) is an aggressive canine tumor originating from the anal sac glands. Surgical resection, with or without adjuvant chemotherapy, represents the standard of care for this tumor, but the outcome is generally poor, particularly for tumors diagnosed at an advanced stage. For this reason, novel treatment options are warranted, and a few recent reports have suggested the activation of the immune checkpoint axis in canine AGASACA. In our study, we developed canine-specific monoclonal antibodies targeting PD-1 and PD-L1. A total of 41 AGASACAs with complete clinical and follow-up information were then analyzed by immunohistochemistry for the expression of the two checkpoint molecules (PD-L1 and PD-1) and the presence of tumor-infiltrating lymphocytes (CD3 and CD20), which were evaluated within the tumor bulk (intratumor) and in the surrounding stroma (peritumor). Seventeen AGASACAs (42%) expressed PD-L1 in a range between 5% and 95%. The intratumor lymphocytes were predominantly CD3+ T-cells and were positively correlated with the number of PD-1+ intratumor lymphocytes ( = 0.36; 0.02). The peritumor lymphocytes were a mixture of CD3+ and CD20+ cells with variable PD-1 expression (range 0-50%). PD-L1 expression negatively affected survival only in the subgroup of dogs treated with surgery alone ( 14; 576 vs. 235 days). The presence of a heterogeneous lymphocytic infiltrate and the expression of PD-1 and PD-L1 molecules support the relevance of the immune microenvironment in canine AGASACAs and the potential value of immune checkpoints as promising therapeutic targets.
PubMed: 36551672
DOI: 10.3390/cancers14246188 -
Analytical Chemistry Dec 2022Fe and Co single-atom catalysts (SACs) have been widely explored in many fields, while Zn SACs are still in their infancy stage. Herein, we unexpectedly found that...
Fe and Co single-atom catalysts (SACs) have been widely explored in many fields, while Zn SACs are still in their infancy stage. Herein, we unexpectedly found that atomically dispersed Zn on N-doped carbon material (Zn-N-C) exhibited high catalytic activity on luminol-HO chemiluminescence (CL) reaction. The Zn-N-C SACs were readily prepared through simple pyrolyzation of the cheap precursors (dopamine and ZnCl). The mechanism of Zn SAC-catalyzed CL reaction of luminol-HO was investigated in detail. The activity of Zn SACs originated from the Zn-N sites in the Zn-N-C structure. The monoatomic dispersion makes Zn catalytic performance change from no activity to high activity in luminol-HO CL reaction. This study demonstrated the particularity of the monatomic metal catalyst over the conventional metal ion. This work provides the unprecedented perspective for design of new metal SACs in CL reaction.
Topics: Luminol; Hydrogen Peroxide; Carbon; Luminescence; Metals; Zinc
PubMed: 36473046
DOI: 10.1021/acs.analchem.2c03902