Breaking through the Size Control Dilemma of Silver Chalcogenide Quantum Dots via Trialkylphosphine-Induced Ripening: Leading to Ag2Te Emitting from 950 to 2100 nm.

Ag2Te is one of the most promising semiconductors with a narrow band gap and low toxicity; however, it remains a challenge to tune the emission of Ag2Te quantum dots (QDs) precisely and continuously in a wide range. Herein, Ag2Te QDs emitting from 950 to 2100 nm have been synthesized via trialkylphosphine-controlled growth. Trialkylphosphine has been found to induce the dissolution of small-sized Ag2Te QDs due to its stronger ability to coordinate to the Ag ion than that of 1-octanethiol, predicated by the density functional theory. By controlling this dissolution effect, the monomer supply kinetics can be regulated, achieving precise size control of Ag2Te QDs. This synthetic strategy results in state-of-the-art silver-based QDs with emission tunability. Only by taking advantage of such an ultrawide emission has the sizing curve of Ag2Te been obtained. Moreover, the absolute photoluminescence quantum yield of Ag2Te QDs can reach 12.0% due to their well-passivated Ag-enriched surface with a density of 5.0 ligands/nm2, facilitating noninvasive in vivo fluorescence imaging. The high brightness in the long-wavelength near-infrared (NIR) region makes the cerebral vasculature and the tiny vessel with a width of only 60 µm clearly discriminable. This work reveals a nonclassical growth mechanism of Ag2Te QDs, providing new insight into precisely controlling the size and corresponding photoluminescence properties of semiconductor nanocrystals. The ultrasmall, low-toxicity, emission-tunable, and bright NIR-II Ag2Te QDs synthesized in this work offer a tremendous promise for multicolor and deep-tissue in vivo fluorescence imaging.

External quality assessment scheme for sperm DNA fragmentation: a pilot study in China.

BACKGROUND: The aim of this article is to establish an external quality assessment (EQA) scheme for sperm Deoxyribonucleic acid (DNA) fragmentation (SDF) detection, and to assess the feasibility of the scheme. In addition, this article provides some case analysis of abnormal results in order to really help improve the performance of the laboratory. RESULTS: In 2021 and 2022, 10 and 28 laboratories in China volunteered to participate in the EQA program respectively. Two samples were selected for EQA each year, a large spread of results was obtained for the four samples, and the highest values were 13.7, 4.2, 8.0 and 4.0 times the lowest respectively. The coefficients of variation (CVs) were very high for the four samples, at 46.6%, 30.1%, 26.7% and 30.3%, respectively. The CVs of the samples with high SDF values were lower than those of the samples with low SDF values. There was no significant difference between the results of sperm chromatin structure assay (SCSA) and sperm chromatin dispersion (SCD). For the 10 laboratories that participated in EQA in 2021 and 2022, the CVs of low SDF value samples and high SDF value samples decreased from 46.6% and 30.1% in 2021 to 32.5% and 22.7% in 2022, respectively. CONCLUSION: This is the first study to evaluate the EQA program on SDF, which involved a number of laboratories and was demonstrated to be feasible. It is recommended that all laboratories participate in the EQA of SDF to ensure the accuracy of the results.

RéSUMé: CONTEXTES: L'objectif de cet article est d'établir un système externe d'évaluation de la qualité (EEQ) pour la détection de la fragmentation de l'ADN des spermatozoïdes (SDF) et d'évaluer la faisabilité de ce système. En outre, cet article fournit une analyse de cas de résultats anormaux afin d'aider réellement à améliorer les performances du laboratoire. RéSULTATS: En 2021 et 2022, respectivement 10 et 28 laboratoires en Chine se sont portés volontaires pour participer au programme EEQ. Deux échantillons ont été sélectionnés chaque année pour l'EEQ ; un large éventail de résultats a été obtenu pour les quatre échantillons, et les valeurs les plus élevées étaient respectivement de 13,7, 4,2, 8,0 et 4,0 fois les plus faibles. Les coefficients de variation (CV) étaient très élevés pour les quatre échantillons, soit respectivement 46,6 %, 30,1 %, 26,7 % et 30,3 %. Les CV des échantillons avec des valeurs de SDF élevées étaient inférieurs à ceux des échantillons avec de faibles valeurs de SDF. Il n'y avait pas de différence significative entre les résultats du test de structure de la chromatine des spermatozoïdes (SCSA) et ceux de la dispersion de la chromatine des spermatozoïdes (SCD). Pour les 10 laboratoires qui ont participé à l'EEQ en 2021 et 2022, les CV des échantillons à faible valeur de SDF et ceux des échantillons à valeur élevée de SDF ont diminué, passant respectivement de 46,6 % et 30,1 % en 2021 à 32,5 % et 22,7 % en 2022. CONCLUSIONS: Il s'agit de la première étude à évaluer le programme externe d'évaluation de la qualité (EEQ) de l'analyse de la SDF, qui a impliqué un certain nombre de laboratoires, et qui s'est avéré réalisable. Il est recommandé que tous les laboratoires participent à l'EEQ de la SDF afin d'en assurer l'exactitude des résultats.

Exosome plays an important role in the development of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most malignant cancers around the world. However, the early biomarkers for its detection and treatment are limited currently. Exosomes, classified as intercellular messenger shuttling their cargoes between cells, regulate cell differentiation and tissue development. They contain messenger RNA (mRNA), microRNA (miRNA), long non-coding RNA (lncRNA), circular RNA (circRNA), proteins, lipids and transcription factors. Therefore, exosomes play a crucial role in the development of HCC. In this review, we highlight the exosomal cargoes which could serve as biomarkers for the prediction and diagnosis of HCC. Exosomes are involved in metastases of HCC and they show great potential in immunotherapy and drug resistance mechanism. In summary, exosome suggests new clues in clinical application of HCC.

Gd-DTPA-coupled Ag2Se quantum dots for dual-modality magnetic resonance imaging and fluorescence imaging in the second near-infrared window.

Near-infrared (NIR) fluorescent quantum dots (QDs) are ideal platforms to fabricate multifunctional contrast agents for multimodal imaging. Herein, second near-infrared window fluorescent (NIR-II) Ag2Se QDs were coupled with gadopentetate dimeglumine injection (Gd-DTPA) for dual-modality T1-weighted magnetic resonance (MR) imaging and fluorescence imaging. In vitro experiments suggested that the prepared Ag2Se-Gd QDs exhibit low cytotoxicity, remarkable T1-weighted MR imaging, and fluorescence imaging contrast properties. In vivo experiment results showed that Ag2Se-Gd QDs were the preferred contrast agents for dual-modality T1-weighted MR imaging and fluorescence imaging with high spatial resolution. Moreover, excellent temporal resolution and high tissue penetration depth were also achieved by fluorescence imaging. These results indicate the potential of Ag2Se-Gd QDs as multifunctional contrast agents for multimodal imaging in clinical diagnosis and research.