Modeling the air pollutant concentration near a cement plant co-processing wastes.

In this study, for the first time, we conducted full life-cycle studies on pollutants in a cement plant co-processing hazardous waste (HW) via the combined use of thermodynamic equilibrium calculations and the American Meteorological Society/Environmental Protection Regulatory Model. Results showed that the potential toxic elements (PTEs) can be classified into three categories: (1) non-volatized elements, Co; (2) semi-volatized elements, Cr and Ni; and (3) volatized elements, Cd, Pb and As. Besides, the spatial distributions of pollutants were strongly influenced by the prevalent wind direction and the size of the particulate matter they were absorbed on. The highest concentrations of most pollutants tended to be centralized at a distance in the range of 400 to 800 m away from the cement plant. Finally, validated results indicated that there is good agreement between the simulated and observed concentrations in this study. These findings can facilitate and assist local government authorities and policy makers with the management of urban air quality.

Effectiveness of Common Fabrics to Block Aqueous Aerosols of Virus-like Nanoparticles.

Layered systems of commonly available fabric materials can be used by the public and healthcare providers in face masks to reduce the risk of inhaling viruses with protection that is about equivalent to or better than the filtration and adsorption offered by 5-layer N95 respirators. Over 70 different common fabric combinations and masks were evaluated under steady-state, forced convection air flux with pulsed aerosols that simulate forceful respiration. The aerosols contain fluorescent virus-like nanoparticles to track transmission through materials that greatly assist the accuracy of detection, thus avoiding artifacts including pore flooding and the loss of aerosol due to evaporation and droplet breakup. Effective materials comprise both absorbent, hydrophilic layers and barrier, hydrophobic layers. Although the hydrophobic layers can adhere virus-like nanoparticles, they may also repel droplets from adjacent absorbent layers and prevent wicking transport across the fabric system. Effective designs are noted with absorbent layers comprising terry cloth towel, quilting cotton, and flannel. Effective designs are noted with barrier layers comprising nonwoven polypropylene, polyester, and polyaramid.

Whole slide imaging of circulating tumor cells captured on a capillary microchannel device.

Liquid biopsy with circulating tumor cells (CTCs) can aid in cancer detection at early stages and determine whether a certain treatment is effective or not. However, existing CTC techniques focus on one or two aspects of CTC management including sampling, enrichment, enumeration, and treatment selection. This paper reports an integrated capillary microchannel device that allows efficient capturing of CTCs with a wide microchannel, rapid enumeration of captured CTCs with whole slide cell imaging, and in situ drug testing with captured CTCs. Blood is drawn into the microchannel whose height is appropriate to the diameter of cancer cells, while its width is a thousand times larger than the diameter of cancer cells. The inner bottom surface of the microchannel is modified with long chain polymers that have cell adhesive ends to efficiently capture CTCs from blood. With this design, cells including CTCs are forced to move through the polymer coated microchannel, and the chance of cell adhesive ends interacting with specific antigens overexpressed on surfaces of cancer cells is significantly enhanced without a channel blockage issue. Captured CTCs are enumerated with a whole slide imaging platform via dual LED autofocusing technology then exposed to anti-cancer drugs, followed by live/dead assay and fluorescence imaging. Given its straightforward, easy and powerless operation, this device with whole slide imaging will be useful for cancer diagnosis, prognosis and point-of-care treatments.

Tumor targeted, stealthy and degradable bismuth nanoparticles for enhanced X-ray radiation therapy of breast cancer.

Nanoparticles of heavy elements can be used as radiosensitizers to enhance X-ray radiation therapy, but a major roadblock in translating nanoparticle radiosensitizers into clinical practice of cancer treatment is related to the non-degradable nature of the nanoparticles, which can cause accumulation inside body and long-term toxicity. This paper reports the use of a folate-inserted, red blood cell membrane-modified bismuth (i.e., F-RBC bismuth) nanoparticles in X-ray radiation therapy for breast cancer, where cell membrane coating provides long blood circulation time, folate acts as tumor targeting agent, X-ray and bismuth nanoparticles interaction generates more free radicals for cancer cells damage, and physiological condition helps dissolve bismuth nanoparticles after treatment. Significant tumor inhibition and improved survival ratio in mice was confirmed when F-RBC bismuth nanoparticles were used to sensitize X-ray radiation. In vivo bio-distribution and histological analysis indicated F-RBC bismuth nanoparticles were excreted from animal body after 15 days and no evident damage or inflammatory was observed in major organs. Cell membrane modification and dissolution of bismuth nanoparticles in body allow the fine tune of the circulation, radiation enhancement and body clearance in such a way that treatment effect can be maximized and long term toxicity can be minimized.

Formation of active inclusion bodies induced by hydrophobic self-assembling peptide GFIL8.

BACKGROUND: In the last few decades, several groups have observed that proteins expressed as inclusion bodies (IBs) in bacteria could still be biologically active when terminally fused to an appropriate aggregation-prone partner such as pyruvate oxidase from Paenibacillus polymyxa (PoxB). More recently, we have demonstrated that three amphipathic self-assembling peptides, an alpha helical peptide 18A, a beta-strand peptide ELK16, and a surfactant-like peptide L6KD, have properties that induce target proteins into active IBs. We have developed an efficient protein expression and purification approach for these active IBs by introducing a self-cleavable intein molecule. RESULTS: In this study, the self-assembling peptide GFIL8 (GFILGFIL) with only hydrophobic residues was analyzed, and this peptide effectively induced the formation of cytoplasmic IBs in Escherichia coli when terminally attached to lipase A and amadoriase II. The protein aggregates in cells were confirmed by transmission electron microscopy analysis and retained ~50% of their specific activities relative to the native counterparts. We constructed an expression and separation coupled tag (ESCT) by incorporating an intein molecule, the Mxe GyrA intein. Soluble target proteins were successfully released from active IBs upon cleavage of the intein between the GFIL8 tag and the target protein, which was mediated by dithiothreitol. A variant of GFIL8, GFIL16 (GFILGFILGFILGFIL), improved the ESCT scheme by efficiently eliminating interference from the soluble intein-GFIL8 molecule. The yields of target proteins at the laboratory scale were 3.0-7.5 µg/mg wet cell pellet, which is comparable to the yields from similar ESCT constructs using 18A, ELK16, or the elastin-like peptide tag scheme. CONCLUSIONS: The all-hydrophobic self-assembling peptide GFIL8 induced the formation of active IBs in E. coli when terminally attached to target proteins. GFIL8 and its variant GFIL16 can act as a "pull-down" tag to produce purified soluble proteins with reasonable quantity and purity from active aggregates. Owing to the structural simplicity, strong hydrophobicity, and high aggregating efficiency, these peptides can be further explored for enzyme production and immobilization.