Preparation and Applications of Polydimethylsiloxane-Based Fluorescent Materials.

In the past few years, fluorescent materials have received significant attention due to their fascinating luminescent properties and wide-ranging applications. Polydimethylsiloxane (PDMS) has also attracted the interest of many researchers due to its remarkable performances. The combination of fluorescence and PDMS will undoubtedly produce abundant advanced multifunctional materials. Although numerous achievements have been made in this field, there is still no review to summarize the relevant research. This review summarizes the state-of-the-art achievements made in PDMS-based fluorescent materials (PFMs). First, the preparation of PFM is overviewed following a classification according to the fluorescent sources, including organic fluorescent molecules, perovskite, photoluminescent nanomaterials, and metal complexes. Their applications in sensors, fluorescent probes, multifunctional coatings, and anticounterfeiting are then introduced. Finally, the challenges and development trends in the field of PFMs are presented.

[Progress in stimuli-responsive molecularly imprinted polymers for enrichment analysis of trace components in traditional Chinese medicine].

Molecularly imprinted polymers demonstrate outstanding performance in the research on trace ingredients because of their high selectivity. Stimuli-responsive molecularly imprinted polymers(STR-MIPs) with the introduction of different responsive groups on the basis of traditionally imprinted materials can undergo reversible transformations when exposed to external stimuli such as temperature, magnetism, pH or light. Such responsiveness, combined with the specific recognition, endows STR-MIPs with excellent perfor-mance in trace component studies. Traditional Chinese medicine(TCM) contains complex components with trace content, and thus STR-MIPs have broad application prospects in the enrichment analysis of trace components in TCM. This paper elaborates on the application of STR-MIPs in the enrichment analysis of trace components in TCM from the perspectives of different stimuli, summarized relevant research achievements in the recent five years to broaden the application fields of molecular imprinting, and proposed a few opi-nions about their future development.

Optically active porous hybrid particles constructed by alkynylated cellulose nanocrystals, helical substituted polyacetylene, and inorganic silica for enantio-differentiating towards naproxen.

This article reports on a novel type of ternary chiral porous hybrid particles (TCPHPs) constructed by alkynylated cellulose nanocrystals (A-CNCs), helical substituted polyacetylene, and inorganic silica. The resulting TCPHPs combine the respective advantages of the three components. A-CNCs serve as stabilizer, co-monomer, and chiral source simultaneously and transfer their chirality to the resulting helical substituted polyacetylenes in the course of copolymerization with achiral acetylenic monomer following "sergeants and soldiers rule". Helical substituted polyacetylenes form chiral helical structures and thus endow TCPHPs with the anticipated optical activity. Inorganic silica constitutes the rigid framework and is covalently bonded with the organic components through hydrolysis of Si-O-Et groups. Phase separation between the organic and inorganic components renders TCPHPs with abundant pores. Scanning electron microscope (SEM) images confirm the formation of spherical particles with porous structures. Circular dichroism spectra demonstrate the optical activity of the chiral hybrid particles. The as-prepared TCPHPs exhibit capacity for enantio-differentiating performance towards chiral naproxen.

Preparation and Chiral Applications of Optically Active Polyamides.

Chirality is omnipresent in nature and plays vital roles in living organism, and has become a hot research topic across multidisciplinary fields including chemistry, biology, physics, and material science. Meanwhile, polyamides constitute an important class of polymers and have received significant attention owing to their outstanding properties and wide-ranging applications in many areas. Judiciously introducing chirality into polyamides will undoubtedly obtain attractive chiral polymers, namely, optically active polyamides. This review describes the preparation methods of chiral polyamides, including solution polycondensation, interfacial polycondensation, ring-open polymerization, and others; the newly emerging categories of chiral polyamides, i.e., helical polyamides, chiral polyamide-imides, are also presented. The applications of optically active polyamides in chiral research fields including asymmetric catalysis, membrane separation, and enantioselective crystallization are also summarized. In addition, current challenges in chiral polyamides are further presented and future perspectives in the field are proposed.

The Gut Bacterial Community Composition of Wild Cervus albirostris (White-Lipped Deer) Detected by the 16S Ribosomal RNA Gene Sequencing.

Cervus albirostris (white-lipped deer) is an endemic species in China. As the name implies, C. albirostris has a characteristic pure white marking around their mouth and on the underside of the throat. The animal is a typical alpine species normally living at the height of 3500-4300 m. In this study, by pyrosequencing the 16S rRNA gene sequences, we for the first time analyzed the gut bacterial community composition in eight feces samples of wild C. albirostris. From a total of 243,634 high-quality sequences, we identified 186 genera, included in 17 prokaryotic phyla in the feces. The relative proportions of Firmicutes and Bacteroidetes were highly consistent in each individual sample. The most frequently detected genus was Ruminococcaceae UCG-005, ranging from 6.70 to 21.00%, displaying positively connections with the Rikenellaceae RC9 gut group. The bacterial communities associated with C. albirostris provide the basic knowledge for further microbiological studies and facilitates the conservation efforts of this vulnerable deer species.

Recent Advances in Quaternary Ammonium Monomers for Dental Applications.

Resin-based dental materials have been one of the ideal choices among various materials in the treatment of dental caries. However, resin-based dental materials still have some drawbacks, such as the lack of inherent antibacterial activity. Extensive research has been conducted on the use of novel quaternary ammonium monomers (QAMs) to impart antibacterial activity to dental materials. This review provides a comprehensive overview of the recent advances in quaternary ammonium monomers (QAMs) for dental applications. The current progress and limitations of QAMs are discussed based on the evolution of their structures. The functional diversification and enhancement of QAMs are presented. QAMs have the potential to provide long-term antibacterial activity in dental resin composites, thereby prolonging their service life. However, there is a need to balance antibacterial performance with other material properties and the potential impact on the oral microbiome and general health. Finally, the necessity for further scientific progress in the development of novel quaternary ammonium monomers and the optimization of dental resin formulations is emphasized.

Legumain protease-sheddable PEGylated, tuftsin-modified nanoparticles for selective targeting to tumour-associated macrophages.

Tumour-associated macrophages (TAMs) represent an attractive cell target for anticancer therapy. However, selective and efficient targeting of TAMs remains difficult. Here, we constructed a novel dually functionalised nanoparticle platform (s-Tpep-NPs) by surface co-modification of nanoparticles (NPs) with tuftsin (Tpep) and legumain protease-sheddable polyethylene glycol 5k (PEG5k) to achieve selective targeted delivery to TAMs. The fluorescence resonance energy transfer experiment and in vitro cellular uptake assay confirmed that s-Tpep-NPs can responsively shed PEG5k and transform into active Tpep-NPs upon the cleavage of legumain that is overexpressed on TAM surfaces, which then promotes TAM phagocytosis through Fc receptor-mediated pathways. Owing to the shielding effect by legumain-sheddable PEG5k, s-Tpep-NPs can effectively decrease the Tpep-induced non-specific accumulation in mononuclear phagocyte system (MPS) organs during systemic circulation. Moreover, s-Tpep-NPs can significantly enhance the tumoural accumulation and improve the specificity and efficiency of targeting to TAMs, as compared with both controls of Tpep-NPs and non-sheddable ns-Tpep-NPs. Overall, this study provides a robust nanoplatform with a novel avenue for improved selectivity of targeted delivery to TAMs.

A Classification-Guided Segmentation Algorithm Based on Deep Learning for Epithelium Segmentation in Histopathological Images of Radicular Cysts.

In histopathological analysis of radicular cysts (RCs), lesions in epithelium can provide pathologists with rich information on pathologic degree, which is helpful to determine the type of periapical lesions and make precise treatment planning. Automatic segmentation and localization of epithelium from whole slide images (WSIs) can assist pathologists to complete pathological diagnosis more quickly. However, the class imbalance problem caused by the small proportion of fragmented epithelium in RCs imposes challenge on the typical automatic one-stage segmentation method. In this paper, we proposed a classification-guided segmentation algorithm (CGSA) for accurate segmentation. Our method was a two-stage model, including a classification network for region of interest (ROI) location and a segmentation network guided by classification. The classification stage eliminated most irrelevant areas and alleviated the class imbalance problem faced by the segmentation model. The results of 5-fold cross validation demonstrated that CGSA outperformed the one-stage segmentation method which was lacking in prior epithelium localization information. The epithelium segmentation achieved an overall Dice's coefficient of 0.722, and intersection over union (IoU) of 0.593, which improved by 5.5% and 5.9% respectively compared with the one-stage segmentation method using UNet.Clinical Relevance- This work presents a framework for automatic epithelium segmentation in histopathological images of RCs. It can be applied to make up for the shortcomings of manual annotation which is labor-intensive, time-consuming and objective.

Treating metastatic triple negative breast cancer with CD44/neuropilin dual molecular targets of multifunctional nanoparticles.

Metastasis of cancer makes up the vast majority of cancer-related deaths, and it usually initiates from tumor cells invasiveness and develops through tumor neovasculature. In this work, we have fabricated a CD44/neuropilin dual receptor-targeting nanoparticulate system (tLyP-1-HT NPs) with endogenous or FDA approved components for treating metastatic triple negative breast cancer (TNBC). The enhanced specific targeting of tLyP-1-HT NPs to both metastatic tumor cells and metastasis-supporting tumor neovasculature was contributed by means of CD44/neuropilin dual receptor-mediated interaction. The NPs not only effectively suppress the invasive capability of tumor cells themselves, but also significantly restrain the metastasis incidence via extravasation as well as the eventual colonization in lungs. In all the three types of TNBC-bearing mice models, orthotopic, post-metastasis and metastasis prevention models, the docetaxel-loaded tLyP-1-HT NPs exhibited markedly enhanced anti-tumor and anti-metastasis efficacy. The inhibitory rates of tLyP-1-HT NPs against orthotopic tumor growth and lung metastasis achieved 79.6% and 100%, respectively. The metastasis inhibition rate and life extension rate of the tLyP-1-HT NPs against post-pulmonary metastasis mice reached 85.1% and up to 62.5%, respectively. All the results demonstrated the designed dual receptor-targeting multifunctional NPs hold great potential in treating metastatic TNBC and lung metastasis.

In vitro and in vivo studies of different liposomes containing topotecan.

Liposome as a carrier of topotecan (TPT), a promising anticancer drug, has been reported in attempt to improve the stability and antitumor activity of TPT. However, the biodistribution pattern of TPT liposome in vivo and PEG-modified liposome containing TPT have not been studied systemically. In this paper, the in vitro stability and in vivo biodistribution behavior of several liposomes containing TPT with different lipid compositions and PEG-modification were studied. Compared with the 'fluid' liposome (S-Lip) composed of soybean phosphatidylcholine (SPC), the 'solid' liposome (H-Lip) composed of hydrogenated soybean phosphatidylcholine HSPC decreased the leaking efficiency of TPT from liposome and enhanced the stability of liposome in fetal bovine serum (FBS) or human blood plasma (HBP). The results of biodistribution studies in S180 tumor-bearing mice showed that liposomal encapsulation increased the concentrations of total TPT and the ratio of lactone form in plasma. Compared with free TPT, S-Lip and H-Lip resulted in 5- and 19-fold increase in the area under the curve (AUC(0-->infinity)), respectively. PEG-modified H-Lip (H-PEG) showed 3.7-fold increase in AUC(0-->infinity) compared with H-Lip, but there was no significant increase in t(1/2) and AUC(0-->infinity) for PEG-modified S-Lip (S-PEG) compared with S-Lip. Moreover, the liposomal encapsulation changed the biodistribution behavior, and H-Lip and H-PEG dramatically increased the accumulation of TPT in tumor, and the relative tumor uptake ratios were 3.4 and 4.3 compared with free drug, respectively. There was also a marked increase in the distribution of TPT in lung when the drug was encapsulated into H-Lip and H-PEG. Moreover, H-PEG decreased the accumulation of TPT in bone marrow compared with unmodified H-Lip. All these results indicated that the membrane fluidity of liposome has an important effect on in vitro stability and in vivo biodistribution pattern of liposomes containing TPT, and PEG-modified 'solid' liposome may be an efficient carrier of TPT.

Computed tomographic morphometric analysis of the pediatric occipital condyle for occipital condyle screw placement.

STUDY DESIGN: This study is a computed tomographic (CT)-based morphometric analysis of the pediatric occipital condyles as related to occipital condyle screw placement. OBJECTIVE: To quantify reference data concerning the dimensions of the immature occipital condyles to guide the placement of occipital condyle screw. SUMMARY OF BACKGROUND DATA: To the best of our knowledge, no published study has provided insight into the anatomy of occipital condyle of the pediatric population with different age groups. METHODS: Sixty-nine pediatric patients were divided into 4 age groups, and their occipital condyles were studied on CT scans. Condylar length, width, height, sagittal angle, and sagittal angle lengths were measured on Philips Brilliance 16 CT. RESULTS: The mean pediatric coronal height, sagittal length, and axial width noted statistically significant age-related differences were 9.0 mm, 21.3 mm, and 9.8 mm, respectively. The mean sagittal angle for all patients was 27.2 ± 5.1° (range, 15.1-41.0°). In 82.6% (114/138) of the occipital condyles, the anatomy could accept the occipital condyle screw (width ≥8 mm and height ≥6.5 mm). CONCLUSION: Our investigation provides insight into the anatomy of occipital condyle of the pediatric population with different age groups. As the pediatric occipital condyles have sufficient occipital bone for appropriate fixation or fusion, the occipital condyle screws fixation is a feasible technique for children. Even so, given the evolution of this technique being still in its infancy and the complexity inherent to the craniovertebral junction, a careful radiological analysis of occipital condyle must be required in preoperative planning and feasibility determination. LEVEL OF EVIDENCE: N/A.

[Growth activity of osteoblast on a novel strontium incorporated calcium sulfate].

OBJECTIVE: To investigate the growth activity of osteoblast on a novel strontium incorporated calcium sulfate and make comparison with normal calcium sulfate material. METHODS: Osteoblast was inoculated on samples and cell proliferation was measured on the 1st, 3rd, 5th days, and the activities of ALP and osteocalcin were observed on the 5th day. And microcosmic morphology of osteoblast was observed by scanning electron microscopy(SEM). RESULTS: Osteoblast grows robustly on tested material. Cell quantity on the surface of novel material was obviously higher than normal calcium sulfate material (P < 0.05). The activity of ALP and osteocalcin on novel material was 57.8% and 40.2% higher than on normal calcium sulfate material respectively (P < 0.05). On strontium incorporated surface, osteoblast spread well. Cells were polygonal with abundant cytoplasm and the morphology was active. CONCLUSION: Strontium incorporated calcium sulfate can sustain robust growth activity of osteoblast, which is promising to be used for bone substitute materials.