The IPGA1-ANGUSTIFOLIA module regulates microtubule organisation and pavement cell shape in Arabidopsis.

Plant cells continuously experience mechanical stress resulting from the cell wall that bears internal turgor pressure. Cortical microtubules align with the predicted maximal tensile stress direction to guide cellulose biosynthesis and therefore results in cell wall reinforcement. We have previously identified Increased Petal Growth Anisotropy (IPGA1) as a putative microtubule-associated protein in Arabidopsis, but the function of IPGA1 remains unclear. Here, using the Arabidopsis cotyledon pavement cell as a model, we demonstrated that IPGA1 forms protein granules and interacts with ANGUSTIFOLIA (AN) to cooperatively regulate microtubule organisation in response to stress. Application of mechanical perturbations, such as cell ablation, led to microtubule reorganisation into aligned arrays in wild-type cells. This microtubule response to stress was enhanced in the IPGA1 loss-of-function mutant. Mechanical perturbations promoted the formation of IPGA1 granules on microtubules. We further showed that IPGA1 physically interacted with AN both in vitro and on microtubules. The ipga1 mutant alleles exhibited reduced interdigitated growth of pavement cells, with smooth shape. IPGA1 and AN had a genetic interaction in regulating pavement cell shape. Furthermore, IPGA1 genetically and physically interacted with the microtubule-severing enzyme KATANIN. We propose that the IPGA1-AN module regulates microtubule organisation and pavement cell shape.

WIF1 enhanced dentinogenic differentiation in stem cells from apical papilla.

BACKGROUND: Odontogenic mesenchymal stem cells (MSCs) isolated from tooth tissues are a reliable resource that can be utilized for dental tissue regeneration. Exploration of the mechanisms underlying the regulation of their differentiation may be helpful for investigating potential clinical applications. The stem cell niche plays an important role in maintaining cell functioning. Previous studies found that Wnt inhibitory factor 1 (WIF1) is more highly expressed in apical papilla tissues than in stem cells from apical papilla (SCAPs) using microarray analysis. However, the function of WIF1 in SCAPs remains unclear. In the present study, we investigated the function of WIF1 during dentinogenic differentiation in SCAPs. METHODS: A retrovirus containing HA-WIF1 was used to overexpress WIF1 in SCAPs. Using Western blot analysis, we verified the expression of HA-WIF1. Alkaline phosphatase (ALP) activity assays, Alizarin Red staining and quantitative calcium analysis were performed to investigate the in vitro potential for dentinogenic differentiation in SCAPs. The expression of dentinogenesis-associated genes DSPP, DMP1, Runx2 and OSX were assayed using real-time RT-PCR. Transplantation experiments were used to measure dentinogenesis potential in vivo. RESULTS: The real time RT-PCR results showed that WIF1 was more highly expressed in apical papilla tissues than in SCAPs, and its expression was increased during the process of dentinogenic differentiation. Overexpression of WIF1 enhanced ALP activity and mineralization in vitro, as well as the expression of DSPP, DMP1 and OSX in SCAPs. Moreover, in vivo transplantation experiments revealed that dentinogenesis in SCAPs was enhanced by WIF1 overexpression. CONCLUSION: These results suggest that WIF1 may enhance dentinogenic differentiation potential in dental MSCs via its regulation of OSX and identified potential target genes that could be useful for improving dental tissue regeneration.

LIM homeobox 8 reduced apoptosis and promoted periodontal tissue regeneration function of dental pulp stem cells.

Stem cell-mediated tissue regeneration is a promising strategy for repairing tissue defects and functional reconstruction in periodontitis, a common disease that leads to the loss of alveolar bone and teeth. However, stem cell apoptosis, widely observed during tissue regeneration, impairs its efficiency. Therefore, the regulation of stem cell apoptosis is critical for improving regeneration efficiency. The LIM homeobox 8 gene LHX8, belongs to the LIM homeobox family, which was involved in tooth morphogenesis. Here, we found that LHX8 was significantly expressed in dental pulp. LHX8 knockdown significantly increased dental pulp mesenchymal stem cells (DPSCs) apoptosis, as confirmed by RT-PCR, western blotting, flow cytometry, and transmission electron microscopy. Additionally, LHX8 overexpression inhibited apoptosis and enhanced the osteo/odontogenic differentiation potential of hDPSCs in vitro. Furthermore, LHX8-overexpression could enhance the periodontal tissue regeneration efficiency of hDPSCs in mice with periodontitis. In conclusion, the present study indicates that LHX8 inhibits stem cell apoptosis and promotes functional tissue formation in stem cell-based tissue regeneration engineering, suggesting a new therapeutic target to increase the efficacy of periodontal tissue regeneration.

Circularly polarized coherent anti-Stokes Raman scattering microscopy.

We demonstrate circularly polarized coherent anti-Stokes Raman scattering (CP-CARS) microscopy that significantly suppresses the nonresonant background for high-contrast vibrational imaging. Circularly polarized pump and Stokes fields with opposite handedness are used to excite CARS signal. In this case, theoretically the nonresonant CARS signal and resonant CARS signal from isotropic media will completely vanish, while the resonant CARS signal from anisotropic structures can still exist. This allows CARS imaging of anisotropic samples with enhanced resonant contrast. Furthermore, we performed CP-CARS imaging on fibroin fibers from silkworm silk, and the results confirmed its effectiveness in background suppression.

Nanoscale hematoporphrin-based frameworks for photo-sono synergistic cancer therapy via utilizing Al(III) as metal nodes rather than heavy metals.

Nanoscale metal-organic frameworks composed of heavy metal ions (such as Fe3+ and Cu2+) as metal nodes have been utilized for cancer therapy, but they suffer from serious quenching in fluorescence and photo-sono sensitization due to their paramagnetism and unsaturated 3d orbitals. To solve these problems, we synthesize nanoscale hematoporphrin-based frameworks with Al3+ ions as metal nodes (AlHFs) rather than heavy metals and achieve enhanced photo-sono therapy of malignant tumors. The hydrophilic AlHFs are prepared by first assembling hematoporphrin molecules and Al(III) trimers via covalent coordination and then surface-modifying them with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-(polyethylene glycol) (DSPE-PEG) molecules. Under excitation with 660 nm light or ultrasound, AlHFs-PEG can produce 3.6-fold or 2.8-fold more 1O2 species than the as-synthesized nanoscale Fe-hematoporphrin frameworks (FeHFs) because the Al3+ ions without 3d orbitals are not beneficial for energy transfer, while Fe3+ ions with unsaturated 3d orbitals and paramagnetism can cause significant energy transfer. AlHFs-PEG exhibits high biocompatibility and can be engulfed by cells to produce intracellular 1O2 for efficient destruction of cells. With the high biosafety and the photo-sono sensitization, the growth rate of tumors in mice with the AlHFs-PEG injection is significantly inhibited upon exposure to both light and ultrasound, showing higher therapeutic efficacy than photodynamic therapy or sonodynamic therapy alone. Therefore, the present work not only presents the preparation of AlHFs-PEG for tumor photo-sono therapy but also provides some insights for developing nanoscale frameworks with light metal ions as metal nodes.

Recent Advances in Cell and Functional Biomaterial Treatment for Spinal Cord Injury.

Spinal cord injury (SCI) is a devastating central nervous system disease caused by accidental events, resulting in loss of sensory and motor function. Considering the multiple effects of primary and secondary injuries after spinal cord injury, including oxidative stress, tissue apoptosis, inflammatory response, and neuronal autophagy, it is crucial to understand the underlying pathophysiological mechanisms, local microenvironment changes, and neural tissue functional recovery for preparing novel treatment strategies. Treatment based on cell transplantation has become the forefront of spinal cord injury therapy. The transplanted cells provide physical and nutritional support for the damaged tissue. At the same time, the implantation of biomaterials with specific biological functions at the site of the SCI has also been proved to improve the local inhibitory microenvironment and promote axonal regeneration, etc. The combined transplantation of cells and functional biomaterials for SCI treatment can result in greater neuroprotective and regenerative effects by regulating cell differentiation, enhancing cell survival, and providing physical and directional support for axon regeneration and neural circuit remodeling. This article reviews the pathophysiology of the spinal cord, changes in the microenvironment after injury, and the mechanisms and strategies for spinal cord regeneration and repair. The article will focus on summarizing and discussing the latest intervention models based on cell and functional biomaterial transplantation and the latest progress in combinational therapies in SCI repair. Finally, we propose the future prospects and challenges of current treatment regimens for SCI repair, to provide references for scientists and clinicians to seek better SCI repair strategies in the future.

Development of Polymer-Ceramic-Metal Graded Acoustic Matching Layers via Cold Sintering.

A family of three phase, polymer-ceramic-metal (Poly-cer-met) electrically conducting composites was developed via cold sintering for acoustic matching application in medical ultrasound transducers. A range of acoustic impedance ( Z ) between MRayl with low attenuation (<3.5 dB/mm, measured at 10 MHz) was achieved in composites of zinc oxide, silver, and in thermoplastic polymers like Ultem polyetherimide (PEI) or polytetrafluoroethylene (PTFE) at sintering pressure less than 50 MPa and temperature of 150 °C. Densities exceeding 95% were achieved, with resistivities less than 1 Ω -cm. The acoustic velocity was homogeneous across the part (variations <5%). The acoustic velocities exceeded 2500 m/s for Z above 12 MRayl. The experimentally measured acoustic impedance of ZnO/Ag/PEI composites was observed to be in close agreement with the theoretical logarithmic model developed for different volume fractions of individual phases at the percolation limit for Ag. Thus, the acoustic properties of this family of matching layers (MLs) can be predicted to a good approximation before experimental realization. Additionally, a non-conducting low Z (5 MRayl MRayl) with acoustic velocities exceeding 2000 m/s was achieved using hydrozincite as the ceramic component. Scaling of the composites to 2'' diameter was demonstrated. A -6 dB bandwidth greater than 85% was measured for a three ML ultrasound transducer, fabricated using a single cold sintered layer ( Z = 19 MRayl) and two other commercial layers in the stack. Finally, a co-cold sintered graded prototype consisting of three tape-casted formulations corresponding to Z = 5 , 9, and 19 MRayl, while still retaining the correct distributions of the components was demonstrated.

Broad-spectrum CRISPR-mediated inhibition of SARS-CoV-2 variants and endemic coronaviruses in vitro.

A major challenge in coronavirus vaccination and treatment is to counteract rapid viral evolution and mutations. Here we demonstrate that CRISPR-Cas13d offers a broad-spectrum antiviral (BSA) to inhibit many SARS-CoV-2 variants and diverse human coronavirus strains with >99% reduction of the viral titer. We show that Cas13d-mediated coronavirus inhibition is dependent on the crRNA cellular spatial colocalization with Cas13d and target viral RNA. Cas13d can significantly enhance the therapeutic effects of diverse small molecule drugs against coronaviruses for prophylaxis or treatment purposes, and the best combination reduced viral titer by over four orders of magnitude. Using lipid nanoparticle-mediated RNA delivery, we demonstrate that the Cas13d system can effectively treat infection from multiple variants of coronavirus, including Omicron SARS-CoV-2, in human primary airway epithelium air-liquid interface (ALI) cultures. Our study establishes CRISPR-Cas13 as a BSA which is highly complementary to existing vaccination and antiviral treatment strategies.

Introducing RGD peptides on PHBV films through PEG-containing cross-linkers to improve the biocompatibility.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a biodegradable polyester, has been a good candidate of biomaterial employed in tissue engineering. However, the PHBV film is hydrophobic and has no recognition sites for cell attachment. In this study, PHBV films are activated by ammonia plasma treatment to produce amino groups on the surface, followed by sequential reactions with a heterobifunctional cross-linker containing a segment of poly(ethylene glycol) (PEG) and further with RGD-containing peptides. XPS analyses of modified surfaces after each reaction step reveal that the RGD-containing peptides have been covalently grafted onto PHBV films. The result of cell viability assay indicates that the RGD-modified PHBV films exhibit a distinctly improved cellular compatibility. Moreover, according to the results of serum adsorption tests by optical waveguide lightmode spectroscopy (OWLS) and fibrinogen adsorption tests by enzyme-linked immunosorbent assay (ELISA) on unmodified and modified PHBV surfaces, the introduced PEG chains can significantly decrease the nonspecific adsorption of proteins from serum and fibrinogen from plasma, thus decreasing the risk of thrombus formation and improving the blood compatibility of implanted materials.

[Ultrasound subgingival scaling combined with manual root planing for treatment of chronic periodontitis in elderly patients].

OBJECTIVE: To evaluate the clinical efficacy of ultrasound subgingival scaling combined with manual root planing for treatment of chronic periodontitis in elderly patients. METHODS: Forty elderly patients with chronic periodontitis were randomly divided into test group for treatment with ultrasound and Gracey subgingival curette for subgingival scaling combined with manual root planing and control group treated with ultrasound subgingival curette scaling (n=20). We compared plaque index (PLI), bleeding index (BI), probing depth (PD), and attachment loss (AL) between the two groups before and at 6 weeks and 12 weeks after the treatment. RESULTS: After periodontal treatment, PLI, BI, PD and AL all decreased significantly in both groups compared with the levels before the treatment (P < 0.05). The patients in the test group showed significantly more obvious decrease of PD and AL than those in the control group (P < 0.05), but the reduction of PLI and BI was comparable between the two groups (P>0.05). CONCLUSIONS: Ultrasound subgingival scaling combined with manual root planing produces better therapeutic effect than ultrasonic subgingival scaling alone for treatment of chronic periodontitis in elderly patients.

Susceptibility-based MR Imaging of Nitinol Stent.

Conventional MR techniques have difficulty to accurately localize the stent position and access the stent restenosis because of the effects of susceptibility and radiofrequency (RF) shielding artifacts caused by stent mesh. Previous studies have demonstrated that a susceptibility-based positive contrast MR method exhibits excellent efficacy for visualizing MR compatible metal devices by taking advantage of their high magnetic susceptibility. However, the method is not evaluated in the visualization of stents. Therefore, the purpose of this study is to prospectively assess whether the susceptibility-based positive contrast method can be used to visualize the nitinol stents, with the comparison of two typical MR positive contrast techniques, i.e., susceptibility gradient mapping using the original resolution (SUMO) and the gradient echo acquisition for super-paramagnetic particles with positive contrast (GRASP). The experiment results showed that the susceptibility-based method provided better visualization and more precise localization of the stent than SUMO and GRASP.

Investigation of zero TE MR in preoperative planning in dentistry.

Preoperative planning in dentistry relies on imaging to assess the separation between the teeth and mandibular canal. Cone beam CT(CBCT) shows inferior contrast of the mandible canal and features radiation. In this work, the use of zero TE (zTE) imaging as an alternative to CBCT imaging for preoperative planning in dentistry is investigated. Twenty-two patients (11 males, 11 females, age 26-65) were enrolled in this prospective study. The performance of zTE imaging was assessed using CBCT as a gold standard in preoperative planning for tooth extraction (qualitative classification) and implanting (quantitative dimensional measurement). Zero TE imaging showed clear delineation of teeth and mandible, and showed better depiction of the mandible canal as compared to CBCT. In assessing the spatial relationship between the third molar and the mandibular canal, identical results were obtained from two readers based on zTE and CBCT images; in spatial measurements related to the second premolar, high intraclass coefficient was obtained in all the performed measurements between zTE and CBCT (0.782 to 0.921) and between reviewers (0.812 to 0.958). The results of Bland Altman analysis also indicated low level of bias (max -1.8%) and disagreements (max -15.1% to 11.3%) between the results of zTE and CBCT. Zero TE imaging may be a potential imaging tool in preoperative planning in dentistry when CBCT is undesirable.

Direct hydrodeoxygenation of raw woody biomass into liquid alkanes.

Being the only sustainable source of organic carbon, biomass is playing an ever-increasingly important role in our energy landscape. The conversion of renewable lignocellulosic biomass into liquid fuels is particularly attractive but extremely challenging due to the inertness and complexity of lignocellulose. Here we describe the direct hydrodeoxygenation of raw woods into liquid alkanes with mass yields up to 28.1 wt% over a multifunctional Pt/NbOPO4 catalyst in cyclohexane. The superior performance of this catalyst allows simultaneous conversion of cellulose, hemicellulose and, more significantly, lignin fractions in the wood sawdust into hexane, pentane and alkylcyclohexanes, respectively. Investigation on the molecular mechanism reveals that a synergistic effect between Pt, NbOx species and acidic sites promotes this highly efficient hydrodeoxygenation of bulk lignocellulose. No chemical pretreatment of the raw woody biomass or separation is required for this one-pot process, which opens a general and energy-efficient route for converting raw lignocellulose into valuable alkanes.

Epidemiological and etiological characteristics of hand, foot, and mouth disease in Henan, China, 2008-2013.

Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by enteroviruses. HFMD outbreaks and reported cases have sharply increased in China since 2008. Epidemiological and clinical data of HFMD cases reported in Henan Province were collected from 2008 to 2013. Clinical specimens were obtained from a subset of these cases. Descriptive epidemiological methods were used to analyze the time, region and population distribution. The VP1 gene from EV71 and CA16 isolates was amplified, and the sequences were analyzed. 400,264 cases of HFMD were reported in this study, including 22,309 severe and 141 fatal cases. Incidence peaked between April and May. Laboratory confirmation was obtained for 27,692 (6.9%) cases; EV71, CA16, and other enteroviruses accounted for 59.5%, 14.1%, 26.4%, respectively. Phylogenetic analysis revealed that EV71 belonged to the C4a evolution branch of C4 sub-genotype and CA16 belonged to subtype B1a or B1b. The occurrence of HFMD in Henan was closely related to season, age and region distribution. Children under five were the most affected population. The major pathogens causing HFMD and their genotypes have not notably changed in Henan. The data strongly support the importance of EV71 vaccination in a high population density area such as Henan, China.

A metabolic profiling analysis of the acute toxicological effects of the realgar (As2S2) combined with other herbs in Niuhuang Jiedu Tablet using ¹H NMR spectroscopy.

ETHNOPHARMACOLOGICAL RELEVANCE: Niuhuang Jiedu Tablet (NJT), composed of Realgar (As2S2), Bovis Calculus Artificialis, Borneolum Synthcticum, Gypsum Fibrosum, Rhei Radix et Rhizoma (RR), Scutellariae Radix (SR), Platycodonis Radix (PR) and Glycyrrhizae Radix et Rhizoma (GR), is an effective formula of traditional Chinese medicine (TCM) used in treating acute tonsillitis, pharyngitis, periodontitis and mouth ulcer. In the formula, significant level of realgar (As2S2) as a potentially toxic element is contained. In our pervious experiments, NJT was significantly less toxic than realgar (As2S2), and the material bases of toxicity alleviation effect to realgar (As2S2) were RR, SR, PR and GR. However, the toxicity alleviation effect of each above mentioned four herbs to realgar (As2S2) and their synergistic detoxification effects to realgar (As2S2) were still obscure. MATERIALS AND METHODS: Male Wistar rats were divided into 11 groups: control, group R (treated with Realgar), group RRSPG (treated with Realgar, RR, SR, PR and GR), group RRSP (treated with Realgar, RR, SR and PR), group RRSG (treated with Realgar, RR, SR and GR), group RRPG (treated with Realgar, RR, PR and GR), group RSPG (treated with Realgar, SR, PR and GR), group RR (treated with Realgar and RR), group RS (treated with Realgar and SR), group RP (treated with Realgar and PR) and group RG (treated with Realgar and GR). Based on (1)H NMR spectra of urine and serum from rats, PCA and PLS-DA were performed to identify different metabolic profiles. Liver and kidney histopathology examinations and serum clinical chemistry analysis were also performed. RESULTS: The metabolic profiles of groups RR, RS, RP and RG were similar to those of group R, while the metabolic profiles of groups RRSPG, RRSP, RRSG, RRPG and RSPG were almost in line with those of control group. Statistics results were confirmed by the histopathological examination and biochemical assay. CONCLUSION: The present work suggested that the toxicity alleviation effects of RR, SR, PR and GR to realgar (As2S2) were not obvious when combined with realgar (As2S2) respectively, but they had synergistic detoxification effects on realgar (As2S2) mutually.

Frontiers in biomedical engineering and biotechnology.

The 2nd International Conference on Biomedical Engineering and Biotechnology (iCBEB 2013), held in Wuhan on 11­13 October 2013, is an annual conference that aims at providing an opportunity for international and national researchers and practitioners to present the most recent advances and future challenges in the fields of Biomedical Information, Biomedical Engineering and Biotechnology. The papers published by this issue are selected from this conference, which witnesses the frontier in the field of Biomedical Engineering and Biotechnology, which particularly has helped improving the level of clinical diagnosis in medical work.

(1)H NMR-based metabonomics study on the toxicity alleviation effect of other traditional Chinese medicines in Niuhuang Jiedu tablet to realgar (As2S2).

ETHNOPHARMACOLOGICAL RELEVANCE: Niuhuang Jiedu Tablet (NJT) is an effective prescription of traditional Chinese medicine (TCM) used in treating acute tonsillitis, pharyngitis, periodontitis and mouth ulcer. NJT is prepared from Xionghuang (Realgar, As2S2), Rengong Niuhuang (Bovis Calculus Artificialis), Bingpian (Borneolum Synthcticum), Shigao (Gypsum Fibrosum), Dahuang (Rhei Radix et Rhizoma), Huangqin (Scutellariae Radix), Jiegeng (Platycodonis Radix) and Gancao (Glycyrrhizae Radix et Rhizoma). In the prescription, significant level of realgar (As2S2) as a potentially toxic element is contained. AIM OF THE STUDY: In this study, (1)H NMR-based metabonomics approach has been used to investigate the toxicity of realgar (As2S2) after being counterbalanced by other TCMs in NJT. MATERIALS AND METHODS: Male Wistar rats were divided into five groups: control, group I (treated with Realgar), group II (treated with Realgar, Bovis Calculus Artificialis, Borneolum Synthcticum, Gypsum Fibrosum, Rhei Radix et Rhizoma, Scutellariae Radix, Platycodonis Radix and Glycyrrhizae Radix et Rhizoma), group III (treated with Realgar, Bovis Calculus Artificialis, Borneolum Synthcticum and Gypsum Fibrosum) and group IV (treated with Realgar, Rhei Radix et Rhizoma, Scutellariae Radix, Platycodonis Radix and Glycyrrhizae Radix et Rhizoma). Based on (1)H-NMR spectra of urine and serum from rats, PCA and PLS-DA were performed to identify different metabolic profiles. Liver and kidney histopathology examinations and serum clinical chemistry analysis were also performed. RESULTS: PLS-DA scores plots demonstrated that the cluster of group I was separated from that of control rats, while group II was located close to control rats, indicating that metabolic profiles of group II were restored toward those of control rats. The metabolic profiles of group III were similar to those of group I, while the metabolic profiles of group II were almost in line with those of group II. Statistics results were confirmed by the histopathological examination and biochemical assay. CONCLUSION: Our results indicated that it was more secure and much less toxic for counterbalanced realgar (As2S2) in NJT. The effective material bases of toxicity alleviation to realgar (As2S2) were Dahuang (Rhei Radix et Rhizoma), Huangqin (Scutellariae Radix), Jiegeng (Platycodonis Radix) and Gancao (Glycyrrhizae Radix et Rhizoma), which regulated energy metabolism, choline metabolism, amino acid metabolism and gut flora disorder affected by realgar (As2S2) exposure.

Analysis of phthalate migration from plastic containers to packaged cooking oil and mineral water.

The migration of phthalates (PAEs), a class of typical environmental estrogen contaminants in food, from food packaging to packaged food attracts more and more attention worldwide. Many factors will affect the migration processes. The purpose of this study was to evaluate PAE migration from plastic containers to cooking oil and mineral water packed in authentic commercial packaging and stored under various conditions (different storage temperatures, contact times, and storage states (static or dynamic state)) and to identify a potential relationship between the amount and type of PAEs migrated and the lipophilic character of the food matrix. The samples were analyzed by a novel method of liquid chromatography combined with solid-phase extraction by an electrospun nylon 6 nanofibers mat, with PAE detection limits of 0.001 µg/L in mineral water and 0.020 µg/L in cooking oil, respectively. The results demonstrated that the cooking oil was a more suitable medium for the migration of PAEs from packages into foodstuffs than mineral water. Scilicet, the migration potential of the PAEs into foodstuffs, depends on the lipophilic characteristics of the food matrix. The results also demonstrated that migrations were more significant at higher temperature, longer contact time, and higher dynamic frequency; thus, the migration tests should be evaluated with consideration of different storage temperatures and contact times. Mathematical models with good logarithmic relationships were established to demonstrate the relationship between the PAE migration and food/packaging contact time for different storage temperatures. These established mathematical models would be expected to become a set of practical tools for the prediction of PAE migration.

[Flushing of phenanthrene in sandy soils by triton X-100 and sodium dodecyl sulfate].

A comparison of column flushing for phenanthrene-contaminated sandy soils was made by using an anionic surfactant, sodium dodecyl sulfate (SDS), a nonionic surfactant, Triton X-100 (TX100), and their mixed surfactants (SDS-TX100). The tested concentrations of surfactants were 1000, 1750, 2500 and 3250 mg x L(-1) while the mass ratios of SDS to TX100 (S:T) in the mixed surfactants were 1:1, 1:2 and 1:4. It was shown that the elution curves (phenanthrene concentration in elutant versus porous volume number) by SDS were zigzag fluctuating rather than regular patterns while those by TX100 and SDS-TX100 were regular ones in which the phenanthrene concentrations in elutant increased, achieved maximum and then decreased with the porous volume numbers of eluting solutions. Moreover, the maximum phenanthrene concentrations increased and the total porous volume numbers decreased with surfactant concentration increasing. Given the surfactant and total porous volume number, the removal efficiencies of phenanthrene were positively related to surfactant concentrations. The removal efficiencies by TX100 and SDS-TX100 depended on concentration and ratio of surfactant and were much larger than those by SDS. Given 1000, 1750 and 2500 mg x L(-1) of the surfactant concentrations respectively, the removal efficiencies by TXl00 and SDS-TX100 were more than 95% but the total porous volume numbers by SDS-TX100 were less than those by TX100. Given 3250 mg x L(-1) of the surfactant concentration, the total removal efficiencies by five surfactants (i.e., SDS, TX100, S:T = 1:1, S:T = 1:2 and S:T = 1:4) achieved their maximum values as 70.8%, 99.9%, 99.9%, 98.7% and 99.2%, respectively, but the needed porous volume numbers by TX100 were the least among those by all surfactants. The results illustrates that the factors such as type, concentration and ratio of surfactant play important roles in surfactant-enhanced flushing remediation for soils contaminated by organics.

Fast release of lipophilic agents from circulating PEG-PDLLA micelles revealed by in vivo forster resonance energy transfer imaging.

Understanding the in vivo behavior of nanoparticles is critical for the translation of nanomedicine from laboratory research to clinical trials. In this work, in vivo Forster resonance energy transfer (FRET) imaging was employed to monitor the release of hydrophobic molecules from circulating poly(ethylene glycol)-poly( D, L-lactic acid) (PEG-PDLLA) micelles. A lipophilic FRET pair (DiIC(18) and DiOC(18)) was physically entrapped into micelle cores by mimicking the loading of hydrophobic drugs. The FRET efficiency was found significantly reduced within 15 min after intravenous injection, implying that DiIC(18) and DiOC(18) quickly escaped from the circulating micelles. FRET spectroscopy studies further demonstrated that alpha- and beta-globulins were major factors for the observed fast release, while gamma-globulins, albumin, and red blood cells played minor roles. These results provide useful information for developing blood-stable micelles to deliver hydrophobic drugs to the target site via prolonged circulation and extravasation from the vascular system.