Manganese-doped carbon quantum dots for fluorometric and magnetic resonance (dual mode) bioimaging and biosensing.

Manganese-doped carbon quantum dots (MnCQDs) were prepared through one-step hydrothermal method using citric acid and manganese tetraphenyl porphyrin as carbon sources in aqueous media. The structure of MnCQDs was confirmed by TEM, XRD, and XPS. The MnCQDs display a typical excitation-dependent emission behavior and exhibit bright green luminescence (with a peak at 482 nm) under UV irradiation (365 nm) and a fluorescence quantum yield of 13%. The MnCQDs can be used as a fluorescent probe for ferric ion in aqueous solution with a 220 nM detection limit. The MTT assay demonstrated the low cytotoxicity of MnCQDs towards HeLa cells. Due to the excitation-dependent emission properties, MnCQDs can be used as a multi-color (blue, green, and red) bioimaging agent in cancer cells and in living zebrafish. The application of MnCQDs as selective biosensing probe for Fe3+ was also realized in cells and zebrafish mode. Because of the existence of paramagnetic ions, MnCQDs demonstrate an enhanced magnetic resonance (MR) signal. Thus, the MnCQDs can serve as a positive contrast agent for MR imaging. Graphical abstract Schematic presentation of the preparation of luminescent manganese-doped carbon quantum dots (MnCQDs). MnCQDs showed good magnetic resonance effect and can be used as a fluorescence probe for the detection of Fe3+ in HeLa cells and zebrafish.

Evolution and mutations of hepatitis B virus quasispecies in genotype B and C during vertical transmission.

Evolution patterns of HBV QS between genotype B and C during vertical transmission are not well understood. In this study, we enrolled 10 HBV infected mother-infant pairs (four pairs with genotype B, four pairs with genotype C, and two with co-infection) without anti-viral therapy. Serum HBV DNA of mothers and infants were sequenced, HBV QS complexity and diversity were analyzed, polymorphisms and mutation sites were recorded, and phylogenetic trees were performed. Our result showed that the QS complexities in P (amino acid), C/PreC (amino acid), and PreS1 (nucleotide) gene were significantly higher in mothers than in infants in pairs with genotype C (P < 0.05), however, full-length and other genes showed non-significant differences (P > 0.05). Unlike genotype C, QS complexity of P gene (nucleotide) was significantly higher in infants than in mothers (P < 0.05) in pairs with genotype B, similarly, QS complexities of full-length and other genes (except Pre S2) were also higher in infants than in mothers but without significant differences (P > 0.05). QS diversities of full-length and most genes in genotype B were comparable between mothers and their infants (P > 0.05), in pairs with genotype C, dS of P, X, RT genes, genetic distance of Pre S1 gene (amino acid) and dN of Pre S1 gene were significant higher in mothers than in infants (P < 0.05). Several HBV mutations correlated with immune escape, e antigen loss and drug resistance were observed in infants. The results indicated that differences of HBV QS evolution patterns between genotype B and C during vertical transmission might contribute to distinct prognosis.

In Situ Electropolymerizing Toward EP-CoP/Cu Tandem Catalyst for Enhanced Electrochemical CO2-to-Ethylene Conversion.

Electrochemical CO2 reduction has garnered significant interest in the conversion of sustainable energy to valuable fuels and chemicals. Cu-based bimetallic catalysts play a crucial role in enhancing *CO concentration on Cu sites for efficient C─C coupling reactions, particularly for C2 product generation. To enhance Cu's electronic structure and direct its selectivity toward C2 products, a novel strategy is proposed involving the in situ electropolymerization of a nano-thickness cobalt porphyrin polymeric network (EP-CoP) onto a copper electrode, resulting in the creation of a highly effective EP-CoP/Cu tandem catalyst. The even distribution of EP-CoP facilitates the initial reduction of CO2 to *CO intermediates, which then transition to Cu sites for efficient C─C coupling. DFT calculations confirm that the *CO enrichment from Co sites boosts *CO coverage on Cu sites, promoting C─C coupling for C2+ product formation. The EP-CoP/Cu gas diffusion electrode achieves an impressive current density of 726 mA cm-2 at -0.9 V versus reversible hydrogen electrode (RHE), with a 76.8% Faraday efficiency for total C2+ conversion and 43% for ethylene, demonstrating exceptional long-term stability in flow cells. These findings mark a significant step forward in developing a tandem catalyst system for the effective electrochemical production of ethylene.

Population structure and phylogeography of three closely related tree peonies.

Paeonia decomposita, Paeonia rotundiloba, and Paeonia rockii are three closely related species of Sect. Moutan is distributed in the montane area of the Eastern Hengduan Mountain region. Understanding the population history of these three tree peony species could contribute to unraveling the evolutionary patterns of undergrowth species in this hotspot area. We used one nuclear DNA marker (internal transcribed spacer region, ITS) and two chloroplast DNA markers (matK, ycf1) to reconstruct the phylogeographic pattern of the populations. In total, 228 individuals from 17 populations of the three species were analyzed in this study. Three nuclear clades (Clade I - Clade III) and four maternal clades (Clade A - Clade D) were reconstructed. Molecular dating suggested that young lineages diverged during the late Pliocene and early Pleistocene, younger than the uplift of the Hengduan Mountains but older than the last glacial maximum (LGM). Significant population and phylogeographic structures were detected at both markers. Furthermore, the populations of these tree peonies were overall at equilibrium during the climatic oscillations of the Pleistocene. The simulated palaeoranges of the three species during the LGM period mostly overlapped, which could have led to cross-breeding events. We propose an evolutionary scenario in which mountain orogenesis around the Hengduan Mountain area triggered parapatric isolation between maternal lineages of tree peonies. Subsequent climatic fluctuations drove migration and range recontact of these populations along the valleys. This detailed evolutionary history provides new insights into the phylogeographic pattern of species from mountain-valley systems.

Phylogeography of Buddleja crispa (Buddlejaceae) and its correlation with drainage system evolution in southwestern China.

PREMISE OF THE STUDY: Southwestern China is an area of active tectonism and erosion, yielding a dynamic, deeply eroded landscape that is hypothesized to have influenced the genetic structure of the resident populations of plants and animals. However, few studies have been conducted to examine the influence of changing river channels, particularly in the Yarlung Tsangpo area, on genetic distributions in plants. We here examine the population structure of Buddleja crispa, a dominant element of the dry, warm/hot river-valley communities, seeking to delimit the current population genetic structure and its relation to past changes in the courses of the major rivers in this area. • METHODS: Two chloroplast DNA fragments were used to estimate the genetic variation and phylogeographic structure of the populations, and to infer nested clades, of the species. • KEY RESULTS: We detected low intrapopulational haplotype diversity and higher overall population haplotype diversity (h(S) = 0.085, h(T) = 0.781). Molecular variance was mainly observed between groups (81.42%). Robust population genetic structure were detected by AMOVA (F(ST) = 0.967), coinciding with three nested clades (identified by NCPA) and five phylo-groups linked with paleo-drainage systems (identified by SAMOVA). No support for extensive spatial or demographical expansion was obtained. • CONCLUSIONS: A general pattern of genetic isolation by vicariance was inferred, and detected disjunct patterns strongly indicate that currently discontinuous drainage systems were historically linked. Most importantly, population subdivisions and genetic variation perfectly reflect the putative Paleo-Red-River drainage pattern, and Yarlung Tsangpo populations are closely related to Central Yunnan Plateau populations, indicating that they were previously connected by ancient river courses. Divergence times between these river systems estimated by molecular dating (in the Pleistocene) agree with previous findings.

Comparative phylogenetic analysis of complete plastid genomes of Renanthera (Orchidaceae).

Owing to its attractive flower shape and color, Renanthera (Orchidaceae), comprising about 19 species, has significant ornamental value as a houseplant, in floral design and in landscape gardens. Two species of Renanthera are categorized as endangered and critically endangered in China's Red List and international trade in these orchids is currently strictly monitored by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This paper reports on the de novo assembled and annotated plastome of four species of Renanthera; R. citrina, R. coccinea, R. imschootiana, and R. philippinensis. The length of the plastome sequences ranged from 144,673 bp (R. imschootiana) to 149,007 bp (R. coccinea) with GC content of 36.6-36.7%. The plastomes showed a typical quadripartite structure, including a large single-copy (84,241-86,404 bp), a small single-copy (11,468-12,167 bp), and a pair of inverted repeats (24,482-25,715 bp) regions. Of the 120 genes detected, 74 were protein coding, 38 were tRNA, and eight were rRNA genes. The plastome of Renanthera is rather conserved, but nucleotide variations that could distinguish them apart are noticeable-the total number of tandem repeats ranged from 62 (in R. imschootiana) to 74 (in R. citrina); while the number of long repeats ranged from 21 (in R. imschootiana and R. philippinensis) to 43 (in R. citrina). Three hypervariable regions (psbI-trnS-GCU, trnG-GCC, rpl32) were identified. Phylogenetic analyses based on the CDS using maximum likelihood (ML) and Bayesian inference (BI) revealed that Renanthera is closely related to Holcoglossum, Neofinetia, Pendulorchis, and Vanda. The relationship between the four species of Renanthera was fully resolved; a monophyletic clade was formed and R. coccinea was recorded as the first to diverge from the rest. The genetic data obtained from this study could serve as a useful resource for species identification in Renanthera as well as contribute to future research on the phylogenomics of Orchidaceae.

Organic Nanoparticles Based on D-A-D Small Molecule: Self-Assembly, Photophysical Properties, and Synergistic Photodynamic/Photothermal Effects.

Cancer is one of the major diseases threatening human health. Traditional cancer treatments have notable side-effects as they can damage the immune system. Recently, phototherapy, as a potential strategy for clinical cancer therapy, has received wide attention due to its minimal invasiveness and high efficiency. Herein, a small organic molecule (PTA) with a D-A-D structure was prepared via a Sonogashira coupling reaction between the electron-withdrawing dibromo-perylenediimide and electron-donating 4-ethynyl-N,N-diphenylaniline. The amphiphilic organic molecule was then transformed into nanoparticles (PTA-NPs) through the self-assembling method. Upon laser irradiation at 635 nm, PTA-NPs displayed a high photothermal conversion efficiency (PCE = 43%) together with efficient reactive oxygen species (ROS) generation. The fluorescence images also indicated the production of ROS in cancer cells with PTA-NPs. In addition, the biocompatibility and photocytotoxicity of PTA-NPs were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and live/dead cell co-staining test. Therefore, the as-prepared organic nanomaterials were demonstrated as promising nanomaterials for cancer phototherapy in the clinic.

The complete chloroplast genome of Ranunculus yunnanensis (Ranunculaceae).

Ranunculus yunnanensis Franch is endemic in Yunnan and Sichuan Provinces, southwestern China. Here, we report the complete chloroplast (cp) genome of R. yunnanensis. The chloroplast genome is 156,050 bp in length, with 111 encoded genes, including 78 protein-coding genes, 29 tRNA genes, and four rRNA genes. Maximum-likelihood phylogenetic reconstruction using the existing data of Ranunculus shows that R. yunnanensis is revealed at the basal position of the marsh buttercup clade. This result has improved a better understanding of the internal relationship of the Ranunculus.

The complete chloroplast genome of Beesia deltophylla (Ranunculaceae).

Beesia deltophylla is an endemic and rare species only distributed in Xizang, China. The chloroplast genome of B. deltophylla is 157,397 bp in length, with 112 encoded genes including 78 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Phylogenetic reconstruction has confirmed the placement of B. deltophylla as sister to B. calthifolia. These two species formed a clade closely to a Japan endemic species Anemonopsis macrophylla.

Triphenylamine-perylene diimide conjugate-based organic nanoparticles for photoacoustic imaging and cancer phototherapy.

Phototherapy has gained great attention in the past decade owing to the advantages of high selectivity and low toxicity. However, it's still a challenge to develop a single photosensitizer that can achieve both photothermal and photodynamic effects. Herein, we design and synthesize a new organic compound (PIT) with a typical D-A-D structure through the covalent conjugation of perylene diimides (PDI) and triphenylamine (TPA). The amphiphilic PIT could be transformed to the nanoparticles (PIT NPs) through nanoprecipitation method. PIT NPs exhibit good water dispersibility with particle size around 70 nm. Because of the efficient NIR absorption, PIT NPs display high photothermal conversion efficiency (PCE) (η = 46.1 %) and strong photoacoustic signal under irradiation of 635 nm laser. Moreover, under the same laser irradiation, significant reactive oxygen species can be induced by PIT NPs both in aqueous solution and cancer cells. The MTT assay demonstrate the good biocompatibility and outstanding photocytotoxicity of PIT NPs. Thus, the as-prepared PIT NPs could be used as excellent candidates for photoacoustic imaging and photodynamic/photothermal therapy.

Self-assembly of methylene violet-conjugated perylene diimide with photodynamic/photothermal properties for DNA photocleavage and cancer treatment.

Near-infrared (NIR) light-activated phototherapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), has gained considerable attention due to the advantages of high efficiency and minimally invasiveness. However, the development of a single component therapeutic agent with clear structure and molecular weight that achieve photodynamic/photothermal synergistic therapy is still challenging. Herein, we design and synthesize a new smart photosensitizer (PRX) by conjugation of perylene diimide (PDI) and methylene violet (RAX). The typical donor-acceptor (D-A) structure of RAX facilitates the red-shift of absorption to the near-infrared (NIR) region. The amphiphilic PRX could self-assemble into monodispersed nanoparticles (PRX NPs) with enhanced and broadened absorption. Under a single 808 nm laser irradiation, PRX NPs could generate efficient reactive oxygen species (ROS) and heat simultaneously with the photothermal conversion efficiency as high as 59%. PRX NPs displays strong interaction with DNA and can damage plasmid DNA upon light irradiation. The biocompatibility and high phototoxicity of PRX NPs against A549 cells are further confirmed through MTT assay. Therefore, the as-prepared PRX NPs could be served as a promising antitumor nanoagent through photothermal/photodynamic combination manner.

A Simple Strategy to Fabricate Phthalocyanine-Encapsulated Nanodots for Magnetic Resonance Imaging and Antitumor Phototherapy.

Photothermal agents can transfer the absorbed light to heat energy, offering a noninvasive and controllable method to kill tumor cells and tissues. Here, we develop a simple and high-output strategy to prepare photothermal nanodots (MnPc-NDs) by the self-assembly and carbonization of manganese phthalocyanine. The aggregation of phthalocyanine molecules in the nanodots induces an efficient photothermal conversion. Thanks to the high thermal stability of phthalocyanine, the macrocycle is well preserved in the core of nanodots under the controlled hydrothermal temperature. Moreover, the as-prepared MnPc-NDs disperse well in aqueous solution with an average nanoscale size around 60 nm. The intense absorption in near-infrared (NIR) region, along with efficient reactive oxygen generation, high photothermal conversion efficiency (η = 59.8%), and excellent magnetic resonance contrast performances of MnPc-NDs endow them with great potential for MRI-guided cancer phototherapy. Therefore, the contribution provides a facile way to develop theranostic MnPc-NDs for precise and efficient cancer imaging and therapy.

Facile Preparation of Phthalocyanine-Based Nanodots for Photoacoustic Imaging and Photothermal Cancer Therapy In Vivo.

The development of near-infrared (NIR)-absorbing nanoagents for personalized multifunctional phototheranostics has attracted considerable attention in the past decade. Recently, the organic nanomaterials with good biosafety are considered as promising phototheranostic agents, while their facile synthesis remains challenging. Inspired by the preparation of carbon nanodots, we fabricate the NIR-absorbing phthalocyanine-based nanodots (ZnPc-NDs) using a facile method for multifunctional phototheranostics. The significant aggregation of phthalocyanines in nanodots induces a complete fluorescence quenching, which affords a high photothermal conversion efficiency (η = 45.7%). The ZnPc-NDs disperse very well in water media with an average diameter around 80 nm. Further conjugation of biotin on the surface of ZnPc-NDs affords tumor-targeting phthalocyanine nanodots (ZnPc-BT). The ZnPc-BT are demonstrated with favorable biocompatibility, intense photoacoustic signals, high tumor accumulation, and effective tumor suppression in vivo. This Article provides a new insight for further developing nanomedicines with imaging and therapeutic functions to treat cancers precisely and effectively.

Correction to: Carbon Dots @ Platinum Porphyrin Composite as Theranostic Nanoagent for Efficient Photodynamic Cancer Therapy.

AbstractFollowing publication of the original article [1], it was flagged that Fig. 4 and Fig. 5 in the article were (incorrectly) formatted with a yellow highlighting of the background of the figures.

Ln(III) chelates-functionalized carbon quantum dots: Synthesis, optical studies and multimodal bioimaging applications.

The carbon quantum dots termined with amine groups (CQDs-NH2) were synthesized in one-pot hydrothermal method with citric acid as carbon source and branched polyethylenimine (BPEI) as passive agent, which was then covalently linked to 1, 4, 7, 10-tetraazacyclononane (DOTA) framework to yield CQDs-DOTA. The CQDs-DOTA provide excellent ligand scaffolds for the chelation of lanthanide ions, yielding the related complexes CQDs-DOTA-Ln (Ln = Eu, Tb, Yb and Gd). The successful preparation of CQDs-DOTA-Ln was validated by TEM, XRD, XPS, and FT-IR spectroscopy. The CQDs-DOTA-Ln (Ln = Eu, Tb and Yb) exhibited the characteristic emissions of related lanthanide ions, indicating the CQDs could sensitize the luminescence of lanthanide ions. Besides, the CQDs-DOTA-Gd could serve as an excellent T1-weighted MR imaging probe due to the chelation of paramagnetic Gd (III) ions and good hydrophilicity. The cytotoxicity of CQDs-DOTA-Ln was evaluated through MTT assay upon HeLa cells. The images from fluorescence microscopy further verified their applications in bioimaging in vitro. Due to the good biocompatibility, low toxicity, and high contrast efficiency, the CQDs-DOTA-Ln with Vis/NIR fluorescence and MR multi-modal imaging performance could be used as potential contrast agents for clinic applications.

Small-Molecule Porphyrin-Based Organic Nanoparticles with Remarkable Photothermal Conversion Efficiency for in Vivo Photoacoustic Imaging and Photothermal Therapy.

Near-infrared (NIR)-absorbing organic nanoparticles (ONPs) are emerging candidates for "one-for-all" theranostic nanomaterials with considerations of safety and formulation in mind. However, facile fabrication methods and improvements in the photothermal conversion efficiency (PCE) and photostability are likely needed before a clinically viable set of candidates emerges. Herein, a new organic compound, [porphyrin-diketopyrrolopyrrole (Por-DPP)] with the donor-acceptor structure was synthesized, where porphyrin was used as a donor unit while diketopyrrolopyrrole was used as an acceptor unit. Por-DPP exhibited efficient absorption extending from visible to NIR regions. After self-assembling into nanoparticles (NPs) (∼120 nm), the absorption spectrum of Por-DPP NPs broadened and red-shifted to some extent, relative to that of organic molecules. Furthermore, the architecture of NPs enhanced the acceptor-donor structure, leading to emission quenching and facilitating nonradiative thermal generation. The PCE of Por-DPP NPs was measured and calculated to be 62.5%, higher than most of ONPs. Under 808 nm laser irradiation, the Por-DPP NPs possessed a distinct photothermal therapy (PTT) effect in vitro and can damage cancer cells efficiently in vivo without significant side effects after phototherapy. Thus, the small-molecule porphyrin-based ONPs with high PCE demonstrated promising application in photoacoustic imaging-guided PTT.

Carbon Dots @ Platinum Porphyrin Composite as Theranostic Nanoagent for Efficient Photodynamic Cancer Therapy.

Photosensitizers are light-sensitive molecules that are highly hydrophobic, which poses a challenge to their use for photodynamic therapy. Hence, considerable efforts have been made to develop carriers for the delivery of PSs. Herein, we synthesized a new theranostic nanoagent (CQDs@PtPor) through the electrostatic interaction between the tetraplatinated porphyrin complex (PtPor) and the negatively charged CQDs. The size and morphology of as-prepared CQDs and CQDs@PtPor were characterized by a series of methods, such as XRD, TEM, XPS, and FTIR spectroscopy. The CQDs@PtPor composite integrates the optical properties of CQDs and the anticancer function of porphyrin into a single unit. The spectral results suggested the effective resonance energy transfer from CQDs to PtPor in the CQDs@PtPor composite. Impressively, the CQDs@PtPor composite showed the stronger PDT effect than that of organic molecular PtPor, suggesting that CQDs@PtPor is advantageous over the conventional formulation, attributable to the enhanced efficiency of 1O2 production of PtPor by CQDs. Thus, this CQDs-based drug nanocarrier exhibited enhanced tumor-inhibition efficacy as well as low side effects in vitro, showing significant application potential in the cancer therapy.

Molecular differentiation and species composition of genus Culicoides biting midges (Diptera: Ceratopogonidae) in different habitats in southern China.

Culicoides biting midges (Diptera:Ceratopogonidae) cause a significant biting nuisance to humans, livestock, which are the biological vectors of a range of risky pathogens. Accurate illustration of vector play a key role in arthropod borne diseases surveillance. However, few studies have focused on the Culicoides, which caused bluetongue disease in 29 provinces of China since 1979. In this study, we assessed cytochrome oxidase subunit I (COI) mtDNA molecular marker for identification of ten major vector species and analyzed the Culicoides species community and diversity in different habitats. A total of 20,795 Culicoides samples collected from 11 sample sites were identified as 23 species belonging to 7 subgenera. Sequences of COI gene worked well as barcodes for identifying all the determined specimen in this study and were comparable with the existing sequence data from GenBank. We first reported COI barcode sequences of C. morisitai, C. insignipennis and C. homotomus. Morphological identification of Culicoides spp. samples within southern China appears relatively robust and some unidentified species were required further study. Our study shows that the COI sequence data can be used as a tool to identify species of Culicoides in Jiangxi Province. In our sampled area, the most abundant species was C. arakawae (61.89%), followed by C. oxystoma (13.77%), C. punctatus (10.10%), C. nipponensis (8.82%), C. homotomus (3.19%) and C.morisitai (1.17%) in this study. C. punctatus was the dominant species of Park habitat (62.22%), C. arakawae was the predominant species of Chicken habitat (96.66%), Vegetable plot habitat (92.0%), and Peasant household habitat (83.21%), respectively. C. oxystoma was the abundant species of Residential area habitat (40.11%), Hospital habitat (56.65%), and Pig & Cow habitat (48.77%), respectively. Results also show that the potential Bluetongue virus vectors belong to the Obsoletus and Pulicaris groups, are also included and relatively abundant, notably: Culicoides punctatus. These findings expand the current knowledge of Culicoides population composition in the southern part of China.