Outcomes of Excimer Laser Ablation Combined with Drug-coated Balloon in Atherosclerotic Lesions of the Popliteal Artery.

BACKGROUND: The treatment of atherosclerotic lesions in the popliteal artery is challenging. This study aims to investigate the efficacy and safety of excimer laser ablation (ELA) combined with drug-coated balloon (DCB) for these lesions. METHODS: From June 2019 to December 2021, data of patients who underwent ELA combined with DCB in the popliteal artery were retrospectively reviewed. Demographics, lesion characteristics, periprocedural complications, and follow-up information were analyzed. The primary endpoint was primary patency. Secondary endpoints included major amputation-free survival rate, technical success, bailout stenting, clinically-driven target lesion reintervention, improvement of ankle-brachial index (ABI), and Rutherford class. RESULTS: A total of 61 patients were enrolled. The mean age was 73.4 ± 11.7 years. 20 (32.8%) patients had stenotic lesions, while 41 (67.2%) patients had chronic total occlusions. The mean length of these lesions was 7.3 ± 2.8 cm. Procedure technical success rate was 95.1%. Bailout stent was performed in 3 (4.9%) patients. Intraprocedural distal embolization occurred in 3 (4.9%) patients, while flow limiting dissections occurred in 3 (4.9%) patients. The mean ABI was significantly improved from 0.45 ± 0.13 at baseline to 0.90 ± 0.12 after ELA, 0.88 ± 0.11 at 6 months and 0.85 ± 0.12 at 12 months during the follow-up period. The median follow-up time was 28.2 ± 6.1 months. Reintervention was performed in 5 (8.2%) patients. The 2-year primary patency was 83.5%. CONCLUSIONS: ELA combined with DCB is a safe and effective strategy in the treatment of popliteal artery atherosclerotic lesions with low rates of bail-out stenting and high primary patency.

Results of Excimer Laser Ablation Combined with Drug-Coated Balloon for Atherosclerotic Obliterans of Lower Extremity and Risk Factors for Loss of Primary Patency.

BACKGROUND: The results of excimer laser ablation (ELA) combining with drug-coated balloon (DCB) in the treatment for atherosclerotic obliterans (ASO) remains unclear. METHODS: Retrospectively enrolled patients who underwent ELA combined with DCB in 2 centers. The primary endpoint was primary patency, and secondary endpoints included technical success, procedure-related complications, major amputation, clinically driven target lesions reintervention (CD-TLR), measurements of ankle-brachial index (ABI), and quality of life (QoL). RESULTS: 102 patients were enrolled. The primary patency was 86.7% (95% confidence interval [CI]: 72.9%-89.0%) at 12 months and 82.6% (95% CI: 78.2%-92.1%) at 24 months. The freedom from reintervention was 87.8% (95% CI: 79.5%-92.9%) at 12 months and 86.6% (95% CI: 78.1%-92.0%) at 24 months. The ABI measurement and QoL were significantly improved at each follow-up point. Sixteen (15.7%) patients lost the primary patency. Patients losing the primary patency demonstrated higher Rutherford class (P = 0.004), worse runoff (P < 0.001), higher Peripheral Arterial Calcium Scoring System (PACSS) (P < 0.001), and smaller ratio of tube diameter to reference vessel diameter (TD/RVD) (P < 0.001) compared with patients without losing it. The run-off ≥7 (adjusted odds ratio [aOR]: 34.3; 95% CI: 2.9-398.3; P = 0.005) and TD/RVD <4.9 (aOR: 24.7; 95% CI: 1.7-359.5; P = 0.019) were independent risk factors for loss of primary patency. CONCLUSIONS: ELA combined with DCB seemed an effective and safe treatment for ASO of lower extremity, and it could not only reduce the implantation of stent but significantly improve QoL. The run-off ≥7 and TD/RVD <4.9 were independent risk factors for loss of primary patency.

Anemia as a risk factor for restenosis in femoropopliteal arterial disease after drug-coated balloon angioplasty.

OBJECTIVE: This study aimed to investigate the relationship between anemia and restenosis in patients with femoropopliteal arterial disease following drug-coated balloon (DCB) angioplasty. METHODS: 194 patients treated with DCB for femoropopliteal lesions were retrospectively analyzed for up to 12 months of follow-up between January 2017 and September 2020. Baseline clinical and procedural characteristics were compared between the anemia and non-anemia patients, and predictors of restenosis were identified using logistic regression. RESULTS: 32.5% of the patients undergoing DCB angioplasty had anemia. Patients with anemia were significantly older, with higher rates of hypertension, coronary artery disease, chronic renal insufficiency, and diabetes, and with lower rates of smoking and male gender. In the multivariate analysis, anemia was independently and significantly associated with a higher risk of restenosis (OR, 3.872; 95% CI, 1.556-9.638; P = 0.004). CONCLUSION: Anemia is independently associated with restenosis in patients treated with DCB for femoropopliteal arterial disease. Patients with lower baseline hemoglobin might have more chances to develop restenosis at follow-up.

Mandibular muscle troponin of the Florida carpenter ant Camponotus floridanus: extending our insights into invertebrate Ca2+ regulation.

Ants use their mandibles for a variety of functions and behaviors. We investigated mandibular muscle structure and function from major workers of the Florida carpenter ant Camponotus floridanus: force-pCa relation and velocity of unloaded shortening of single, permeabilized fibres, primary sequences of troponin subunits (TnC, TnI and TnT) from a mandibular muscle cDNA library, and muscle fibre ultrastructure. From the mechanical measurements, we found Ca2+-sensitivity of isometric force was markedly shifted rightward compared with vertebrate striated muscle. From the troponin sequence results, we identified features that could explain the rightward shift of Ca2+-activation: the N-helix of TnC is effectively absent and three of the four EF-hands of TnC (sites I, II and III) do not adhere to canonical sequence rules for divalent cation binding; two alternatively spliced isoforms of TnI were identified with the alternatively spliced exon occurring in the region of the IT-arm α-helical coiled-coil, and the N-terminal extension of TnI may be involved in modulation of regulation, as in mammalian cardiac muscle; and TnT has a Glu-rich C-terminus. In addition, a structural homology model was built of C. floridanus troponin on the thin filament. From analysis of electron micrographs, we found thick filaments are almost as long as the 6.8 µm sarcomeres, have diameter of ~ 16 nm, and typical center-to-center spacing of ~ 46 nm. These results have implications for the mechanisms by which mandibular muscle fibres perform such a variety of functions, and how the structure of the troponin complex aids in these tasks.

The role of Misshapen NCK-related kinase (MINK), a novel Ste20 family kinase, in the IRES-mediated protein translation of human enterovirus 71.

Human Enterovirus 71 (EV71) commonly causes Hand, Foot and Mouth Disease in young children, and occasional occurrences of neurological complications can be fatal. In this study, a high-throughput cell-based screening on the serine/threonine kinase siRNA library was performed to identify potential antiviral agents against EV71 replication. Among the hits, Misshapen/NIKs-related kinase (MINK) was selected for detailed analysis due to its strong inhibitory profile and novelty. In the investigation of the stage at which MINK is involved in EV71 replication, virus RNA transfection in MINK siRNA-treated cells continued to cause virus inhibition despite bypassing the normal entry pathway, suggesting its involvement at the post-entry stage. We have also shown that viral RNA and protein expression level was significantly reduced upon MINK silencing, suggesting its involvement in viral protein synthesis which feeds into viral RNA replication process. Through proteomic analysis and infection inhibition assay, we found that the activation of MINK was triggered by early replication events, instead of the binding and entry of the virus. Proteomic analysis on the activation profile of p38 Mitogen-activated Protein Kinase (MAPK) indicated that the phosphorylation of p38 MAPK was stimulated by EV71 infection upon MINK activation. Luciferase reporter assay further revealed that the translation efficiency of the EV71 internal ribosomal entry site (IRES) was reduced after blocking the MINK/p38 MAPK pathway. Further investigation on the effect of MINK silencing on heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) localisation demonstrated that cytoplasmic relocalisation of hnRNP A1 upon EV71 infection may be facilitated via the MINK/p38 MAPK pathway which then positively regulates the translation of viral RNA transcripts. These novel findings hence suggest that MINK plays a functional role in the IRES-mediated translation of EV71 viral RNA and may provide a potential target for the development of specific antiviral strategies against EV71 infection.

[Study on Microbial Diversity of Peri-implantitis Subgingival by High-throughput Sequencing].

OBJECTIVE: To study microbial diversity of peri-implantitis subgingival with high-throughput sequencing, and investigate microbiological etiology of peri-implantitis. METHODS: Subgingival plaques were sampled from the patients with peri-implantitis (D group) and non-peri-implantitis subjects (N group). The microbiological diversity of the subgingival plaques was detected by sequencing V4 region of 16S rRNA with Illumina Miseq platform. The diversity of the community structure was analyzed using Mothur software. RESULTS: A total of 156 507 gene sequences were detected in nine samples and 4 402 operational taxonomic units (OTUs) were found. Selenomonas, Pseudomonas, and Fusobacterium were dominant bacteria in D group, while Fusobacterium, Veillonella and Streptococcus were dominant bacteria in N group. Differences between peri-implantitis and non-peri-implantitis bacterial communities were observed at all phylogenetic levels by LEfSe, which was also found in PcoA test. CONCLUSION: The occurrence of peri-implantitis is not only related to periodontitis pathogenic microbe, but also related with the changes of oral microbial community structure. Treponema, Herbaspirillum, Butyricimonas and Phaeobacte may be closely related to the occurrence and development of peri-implantitis.

Preparation and characterization of molecularly imprinted poly(hydroxyethyl methacrylate) microspheres for sustained release of gatifloxacin.

Molecularly imprinted poly(hydroxyethyl methacrylate) microspheres (PHEMA MIPMs) were prepared via precipitation polymerization in this article, using gatifloxacin (GFLX), hydroxyethyl methacrylate (HEMA), and ethylene glycol dimethacrylate (EGDMA) as template molecule, functional monomer and cross-linker, respectively. The effects of reaction medium, initial total monomers, cross-linker and molecular imprinting on the polymerization were investigated systematically. The interaction between GFLX and HEMA in pre-solution was studied by UV-Visible spectrophotometer, both size and morphology of products were characterized by a scanning electron microscope. When the total initial monomer concentration was 1 vol%, EGDMA content was 70 mol%, a group of uniform PHEMA MIPMs were prepared at different GFLX/MAA molar ratios, with diameter range from 2.06 ± 0.07 to 2.82 ± 0.20 µm. The results of drug loading and in vitro release experiments demonstrated that PHEMA MIPMs could achieve a higher GFLX loading content and a more acceptable sustained release than non-imprinted ones.

The emerging nexus of active DNA demethylation and mitochondrial oxidative metabolism in post-mitotic neurons.

The variable patterns of DNA methylation in mammals have been linked to a number of physiological processes, including normal embryonic development and disease pathogenesis. Active removal of DNA methylation, which potentially regulates neuronal gene expression both globally and gene specifically, has been recently implicated in neuronal plasticity, learning and memory processes. Model pathways of active DNA demethylation involve ten-eleven translocation (TET) methylcytosine dioxygenases that are dependent on oxidative metabolites. In addition, reactive oxygen species (ROS) and oxidizing agents generate oxidative modifications of DNA bases that can be removed by base excision repair proteins. These potentially link the two processes of active DNA demethylation and mitochondrial oxidative metabolism in post-mitotic neurons. We review the current biochemical understanding of the DNA demethylation process and discuss its potential interaction with oxidative metabolism. We then summarise the emerging roles of both processes and their interaction in neural plasticity and memory formation and the pathophysiology of neurodegeneration. Finally, possible therapeutic approaches for neurodegenerative diseases are proposed, including reprogramming therapy by global DNA demethylation and mitohormesis therapy for locus-specific DNA demethylation in post-mitotic neurons.

Lignin hydrogel sensor with anti-dehydration, anti-freezing, and reproducible adhesion prepared based on the room-temperature induction of zinc chloride-lignin redox system.

In recent years, flexible sensors constructed mainly from hydrogels have received increasing attention. However, conventional hydrogels need to be prepared by high-temperature or radiation-induced polymerization reactions, which limits their practical applications due to their suboptimal electrical conductivity and weak mechanical properties. In this paper, using sodium lignosulfonate as the raw material, a dynamic catechol-quinone redox system formed by lignin­zinc ions was constructed to initiate rapid free radical polymerization of acrylamide (AM) monomer at room temperature. In addition, Deep eutectic solvent (DES) can form a strong hydrogen bonding network within the molecules and between the molecules of the hydrogel, resulting in a hydrogel with good tensile properties (hydrogel elongation at break of 727.19 %, breaking strength of 84.09 kPa), and provides the hydrogel with high electrical conductivity, anti-dehydration, anti-freezing, and anti-bacterial properties. Meanwhile, the addition of lignin also improved the adhesion and UV resistance of the hydrogel. This hydrogel assembled into a flexible sensor can sense various small and large amplitude movements such as nodding, smiling, frowning, etc., and has a wide range of applications in flexible sensors.

Aspirin/amoxicillin loaded chitosan microparticles and polydopamine modified titanium implants to combat infections and promote osteogenesis.

It is known that titanium (Ti) implant surfaces exhibit poor antibacterial properties and osteogenesis. In this study, chitosan particles loaded with aspirin, amoxicillin or aspirin + amoxicillin were synthesized and coated onto implant surfaces. In addition to analysing the surface characteristics of the modified Ti surfaces, the effects of the modified Ti surfaces on the adhesion and viability of rat bone marrow-derived stem cells (rBMSCs) were evaluated. The metabolic activities of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) biofilms on the modified Ti surfaces were also measured in vitro. Moreover, S. aureus was tested for its antibacterial effect by coating it in vivo. Using water as the droplet medium, the contact angles of the modified Ti surfaces increased from 44.12 ± 1.75° to 58.37 ± 4.15°. In comparison to those of the other groups tested, significant increases in rBMSC adhesion and proliferation were observed in the presence of aspirin + amoxicillin-loaded microspheres, whereas a significant reduction in the metabolic level of biofilms was observed in the presence of aspirin + amoxicillin-loaded microspheres both in vitro and in vivo. Aspirin and amoxicillin could be used in combination to coat implant surfaces to mitigate bacterial activities and promote osteogenesis.

A novel multi-unit tablet for treating circadian rhythm diseases.

This study aimed to develop and evaluate a novel multi-unit tablet that combined a pellet with a sustained-release coating and a tablet with a pulsatile coating for the treatment of circadian rhythm diseases. The model drug, isosorbide-5-mononitrate, was sprayed on microcrystalline cellulose (MCC)-based pellets and coated with Eudragit(®) NE30D, which served as a sustained-release layer. The coated pellets were compressed with cushion agents (a mixture of MCC PH-200/ MCC KG-802/PC-10 at a ratio of 40:40:20) at a ratio of 4:6 using a single-punch tablet machine. An isolation layer of OpadryII, swellable layer of HPMC E5, and rupturable layer of Surelease(®) were applied using a conventional pan-coating process. Central-composite design-response surface methodology was used to investigate the influence of these coatings on the square of the difference between release times over a 4 h time period. Drug release studies were carried out on formulated pellets and tablets to investigate the release behaviors, and scanning electron microscopy (SEM) was used to monitor the pellets and tablets and their cross-sectional morphology. The experimental results indicated that this system had a pulsatile dissolution profile that included a lag period of 4 h and a sustained-release time of 4 h. Compared to currently marketed preparations, this tablet may provide better treatment options for circadian rhythm diseases.

Removal of nanoplastics from aqueous solution by aggregation using reusable magnetic biochar modified with cetyltrimethylammonium bromide.

Nanoplastics (NPs) pollution has become an emerging threat to the aquatic environment and its organisms. The removal of NPs from contaminated water is a global challenge. In this study, an efficient and reusable composite was prepared from cetyltrimethylammonium bromide (CTAB) modified magnetic biochar. The performances of CTAB modified magnetic biochar (CMB) to remove polystyrene (PS) and carboxylate-modified polystyrene (CPS) nanoparticles from water were systematically evaluated. The results showed that the PS and CPS removal performance of magnetic biochar was improved by CTAB modification. These increases were assigned to the increase in the surface hydrophobicity of CMB. Due to the strong electrostatic repulsion between the nanoparticles, PS and CPS maintained high stability in alkaline conditions, resulting in a significant decrease in removal efficiency. The removal efficiency was decreased to 67.4% for PS and to 40.7% for CPS at pH 11. The inhibition effects of NaCl on the PS and CPS removal efficiencies were decreased gradually with the increase of NaCl concentration. Among the anions studied, H2PO4- had the biggest impact on the removal performance of CMB. Besides, CMB could be used to remove PS and CPS in real surface water, and the removal efficiencies of PS and CPS were 95.3% and 97.8%, respectively. Particularly, the removal efficiencies of PS and CPS were 90.2% for PS and 94.8% for CPS when CMB was recycled five times. According to the characterization results of XRD, TGA, SEM, FTIR and XPS, PS and CPS nanoparticles were removed by CMB from water mainly through aggregation instead of adsorption. The efficient removal of PS and CPS by CMB via aggregation process offers new insight into the removal of NPs from aquatic environment.

Identification of specific and shared epitopes at the extreme N-terminal VP1 of Coxsackievirus A4, A2 and A5 by monoclonal antibodies.

Hand, foot and mouth disease (HFMD) is caused by a variety of serotypes in species A of the Enterovirus genus, including recently re-emerged Coxsackievirus A2 (CV-A2), CV-A4 and CV-A5. For development of diagnostic reagents, for surveillance, and the development of multivalent vaccines against HFMD, the antigenicity of HFMD-associated enteroviruses warrants investigation. The purified virions of CV-A4 were inoculated into Balb/c mice and hybridomas were obtained secreting monoclonal antibodies (mAbs) directed against CV-A4 and cross-reacting with other closely related species A enteroviruses. The mAbs were characterized by ELISA, Western blotting and in vitro neutralizing assays. The majority of mAbs was non-neutralizing, with only 2% of the mAbs neutralizing CV-A4 specifically. Most of mAbs bound to linear VP1 epitopes of CV-A4. Interestingly, four types of mAbs were obtained which bound specifically to CV-A4 or were broadly to CV-A4/-A2, CV-A4/-A5 and CV-A4/-A2/-A5, respectively. Mapping with overlapping or single-amino-acid mutant peptides revealed that the four types of mAbs all bound to the first 15 amino acids at the N-terminus of the VP1. This region of picornaviruses is functionally important as it is involved in uncoating and releasing of viral RNA into the cytosol. The binding footprints of four type mAbs are composed of conserved and variable residues and are different from each other. The newly discovered broadly cross-reactive mAbs reflect the high homology of CV-A4/ CV-A2/CV-A5. The results also demonstrate that it is possible and beneficial to develop the diagnostic reagents to detect rapidly the main pathogens of enteroviruses associated with HFMD cause by CV-A4/CV-A2/CV-A5.

[Ultrastructural observation on nymphal Armillifer sp. by scanning electron microscopy and phylogenetic analysis based on 18S rRNA].

OBJECTIVE: To observe the ultrastructure of nymphal Armillifer sp. isolated from Macaca fascicularis by using scanning electron microscope (SEM), and analyze the phylogenetic relationships based on 18S rRNA gene sequences. METHODS: The parasite samples stored in 70% alcohol were fixed by glutaraldehyde and osmium peroxide. Ultrastructural characters of those samples were observed under SEM. Amplification and sequencing of the 18S rRNA gene were performed following the extraction of total genome DNA. Sequence analysis was performed based on multiple alignment using ClustalX1.83, while phylogenetic analysis was made by Neighbor-Joining method using MEGA4.0. RESULTS: The nymphs were in cylindrical shape, the body slightly claviform tapering to posterior end. Abdominal annuli were gradually widened from anterior to posterior parts, the 12th-13th abdominal annuli of which were similar in width. The annuli ranged closer in the front half body, whereas in the latter part there were certain gaps between them. The circular-shaped mouth located in the middle of head ventrally. Folds were seen in inner margin of the mouth with a pair of curved hooks on both sides above it which practically disposed in a straight line. Two pairs of large sensory papillae were observed symmetrically over the last thoracic annulus of cephalothoraxs lying below the outer hook, and the first abdominal annulus was near the median ventral line. The number of abdominal annuli was 29, not including 2 incomplete terminal annuli. Rounded sensory papillae were fully distributed on the body surface, except the dorsal side of head and the ventral part of the terminal annulus. Agglomerate-like anus opening was observed at the end of ventral abdominal annuli and distinctly sub-terminal. These morphological features demonstrated that the nymphs were highly similar with that of Armillifer moniliformis Diesing, 1835. A fragment of 18SrRNA gene (1 836 bp) sequences was obtained by PCR combined with sequencing, and was registered to the GeneBank database with an accession number HM048870. The phylogenetic tree indicated that A. moniliformis, A.agkistrodon and A.armillatus were at the same clade with a bootstrap value at 95%, and A. moniliformis and A. agkistrodon were solo at a clade with a bootstrap value of 75%. CONCLUSION: The nymphs isolated from Macaca fascicularis are identified as A. moniliformis temporarily.

Efficacy of Coxsackievirus A2 vaccine candidates correlating to humoral immunity in mice challenged with a mouse-adapted strain.

BACKGROUND: In recent years, Coxsackievirus A2 (CV-A2) has become one of the main serotypes of enterovirus species A associated with hand, foot and mouth disease (HFMD) in China. It has also caused HFMD epidemics in many countries all over the world. Currently, there are no effective, preventive vaccines against it. METHODS: A CV-A2 strain was isolated in RD cells and then adapted to grow in Vero cells. This is in compliance with guidelines for cell substrates allowed for human vaccines by the Chinese regulatory authority. Groups of newborn Kunming mice were inoculated on day 3 and day 9 using two formulations of candidate vaccines, empty particles and full particles. They were then challenged on day 14 at a lethal dose with a mouse-adapted strain. RESULTS: The mice in the control group all died within 14 days post-challenge whereas most of the mice in the candidate vaccine groups survived. It was found that the titers of neutralizing antibodies was dose-dependent in sera of immunized mice. The results also showed that the vaccine candidates stimulated a strong humoral immune response and protected the mice from disease and death. The virus loads in tissues or organs were significantly reduced and pathological changes were either weak or not observed in the immunized groups compared with those in Al(OH)3 control group. Preliminary mapping of the nucleotide and amino acid residues potentially related to cell tropism of the vaccine strain and virulence of the challenge strain was performed. CONCLUSION: The results showed that the RD cell-isolated and Vero cell-adapted CV-A2 strain is a promising vaccine candidate. This active immunization-challenge mouse model mimics the vaccination and then exposure to wildtype viruses, compared with passive immunization-challenge model, and is invaluable for efficacy evaluation in studies on multivalent vaccines containing CV-A2 against HFMD.

A novel and green cellulose-based Schiff base-Cu (II) complex and its excellent antibacterial activity.

Cellulose-based materials are widely used in the biomedical field. However, the lack of antibacterial activities of cellulose fibers inevitably causes bacterial infection damages. In this study, Schiff base was first introduced to endow the cellulose fibers good antibacterial property and copper ions were complexed with Schiff base to form a complex. The prepared complex greatly enhanced the antibacterial properties of the cellulose fibers. FT-IR, XRD, UV-vis and SEM-EDS results proved the successful synthesis of Schiff base and its copper (II) complex. The antibacterial tests indicated that the width of the inhibition zone of the as-prepared cellulose-based Schiff base-Cu (II) complex against E. coli and S. aureus increased by 472 % and 823 %, respectively, in comparison to the Schiff base ligand. This significant increase could be attributed to the incorporation of the copper ions (II). This Schiff base-Cu (II) complex containing cellulose-based antibacterial materials are expected to be widely used for biomedical application.

Tumor cell targeting using folate-conjugated fluorescent quantum dots and receptor-mediated endocytosis.

BACKGROUND: Luminescent nanobioprobes with cell-targeting specificity are likely to find important applications in bioanalysis, biomedicine, and clinical diagnosis. Quantum dots (QDs) are unique and promising materials for such a purpose because of their fluorescence and large surface area for attaching cell-targeting molecules. METHODS: We produced water-dispersible QDs by coating hydrophobic QDs with small amphiphilic polyethylene glycol (PEG) molecules via hydrophobic interactions. We covalently coupled folate (FA) onto the water-dispersible PEG-coated QDs (PEG-QDs) to produce FA-coupled PEG-QDs (FA-PEG-QDs). RESULTS: These FA-PEG-QD nanoparticles functioned as fluorescent nanobioprobes that specifically recognized folate receptors (FRs) overexpressed in human nasopharyngeal cells (KB cells) but not in an FR-deficient lung carcinoma cell line (A549 cells). Using confocal fluorescence microscopy, we demonstrated uptake of FA-PEG-QDs by KB cells but no uptake of folate-free PEG-QDs. The specificity of this receptor-mediated internalization was confirmed by comparing the uptake by KB vs A549 cells. CONCLUSIONS: Our results suggest that such cell-targeting fluorescent nanobioprobes are potentially very powerful tools for recognizing target cells and delivering and tracking drugs and other therapeutic materials.

Selective molecularly imprinted stationary phases for bisphenol A analysis prepared by modified precipitation polymerization.

Bisphenol A (BPA)-imprinted polymeric microspheres were synthesized by modified precipitation polymerization (MPP) method. Influences of cross-linker, monomer, porogen volume, and agitation on polymerization were investigated. Proper amount of cross-linker ethyleneglycol-dimethacrylate (EGDMA) was critical to achieve narrowly dispersed microspheres. For template BPA, monomer 4-vinylpyridine (4-VP) was better than MAA to get the best imprinted effects. The optimum template/monomer ratio was 1:6. Increasing porogen volume increased size dispersity and decreased binding characters. Agitation increased coagulation and resulted in irregular particles. Microspheres with the best binding characters were used as selective stationary phase of chromatographic column to detect BPA in milk, pig urine, and chicken meat. Under optimal chromatographic conditions, the calibration graph was linear with R2 = 0.9994 in the range of 3-50 micromol/L. The LOD and LOQ were 1 and 3 micromol/L, respectively. When large amounts (20 mL or 20 g) of samples were analyzed, the recoveries ranged from 70.2 to 87.3% with RSD less than 4.85% in all samples spiked with 0.05-0.2 micromol/L BPA. The intra-day and inter-day RSD were less than 1.83 and 3.96%, respectively. Microspheres prepared by MPP are successfully used in molecularly imprinted polymer (MIP)-based analytical column to detect trace BPA in different biologic samples with acceptable accuracy and repeatability.

[A microplate fluorimetric assay for sacchariase activity measurement].

With the fluorescent compound conjugates substrates, soil xylanase and cellulose in a free-air carbon dioxide enrichment (FACE) experiment were measured on the base of 96 microplate and fluorescence detection, aiming at testing its feasibility in sacchariase activity measurement. The results show that sacchariase activity can be tested and the data exhibit better repeatability(coefficient of variability <= 4.879%). Compared with spectrophotometric assay, this method allows a large number of soil samples and/or enzymes to be analyzed in a short time accurately and conveniently. Soil xylanase activity tends to be greater at elevated CO2 which significantly increases in jointing, heading and ripening stages of wheat and in heading and ripening stages of rice (P < 0.05), and the crop metabolizes rapidly under FACE condition and soil microorganisms are affected, which causes elevation of xylanase acitivy. Compared with ambient CO2, soil cellulose activity decreased slightly under elevated CO2 but there was no significant difference between treatments, indicating the cellulose activity was not influenced intensively in a short time.

[Distribution Characteristics and Ecological Risk Assessment of Organochlorine Pesticides in Sediments of Zhanjiang Bay].

Sixteen surface sediment samples were collected from the estuary of the Suixi river to the mouth of Zhanjiang Bay and then analyzed for organochlorine pesticides (OCPs) by GC-MS to investigate their distribution and ecological risk. The results showed that the concentrations of OCPs in the sediments ranged from nd to 189.52 ng·g-1 (mean 32.17 ng·g-1), including HCHs (mean 5.81 ng·g-1) and DDTs (mean 26.90 ng·g-1). The distribution characteristics showed that the highest OCPs concentrations were found in the estuary and the main shipping lane areas, and the concentration in the nearshore area was higher than that offshore. Source analysis indicated that the HCHs mainly originated from agricultural applications, while no industrial input was observed. Some "hot-spots" areas occurred in harbors and shipping channels, likely as a result of the presence of paint flakes. Additionally, the concentrations of DDTs were found to be higher than the limits of Chinese Marine sediment quality criteria, and p,p'-DDT was the main type of DDT, presenting inevitable adverse biological effects and high ecological risk. Compared with other bays in China, the concentrations of OCPs in this study were in the upper-median pollution level, especially in harbors and boat maintenance facility areas. High OCPs inputs may occur, and thereby represent a certain ecological risk in Zhanjiang Bay.