Emission measurements were obtained for a variety of military vehicles at Hill Air Force Base (Ogden, UT) in November 2000 as part of a Strategic Environmental Research and Development Program. ...Aircraft ground support equipment vehicles using gasoline, diesel, and JP8 fuels were tested using chassis dynamometers under predetermined load. The exhaust from the tested vehicle was passed to a dilution tunnel where it was diluted 30−40 times and collected using Micro-Orifice Uniform Deposit Impactor (MOUDI) fitted with aluminum substrates, an XAD-coated annular denuder, and a filter followed by a solid adsorbent. All MOUDI substrates were analyzed for mass and for organic and elemental (EC) carbon by the thermal/optical reflectance method and for polycyclic aromatic hydrocarbons (PAHs) by GC/MS. Black carbon was measured with a photoacoustic instrument. The denuder and filter/solid adsorbent samples were analyzed for semivolatile PAH. Overall, there is more mass and higher EC contribution when the vehicle is run under higher load in comparison with the low load. However, older vehicles generally show more mass and EC emissions than newer vehicles, and there is a shift toward smaller particle sizes for the low load, which is most pronounced for newer vehicles. The particle-associated semivolatile PAHs and nonvolatile four- through six-ring PAHs are present predominantly on the submicron particles collected on MOUDI stages 0.1−0.18, 0.18−0.32, and 0.32−0.56 μm. For the low-load runs, the distribution of PAHs seems to be shifted toward smaller size particles. The gas-particle phase distribution of semivolatile PAHs depends also on the engine loading. For idle, not only are the more volatile two- and three-ring PAHs, from naphthalene to dimethylphenanthrenes, retained on the denuder portion, but also less volatile four-ring PAHs, such as fluoranthene and pyrene, are retained by the denuder at the 80−90% range, which implies that they are present predominantly in the gas phase. In contrast, for engines under high loads, a much larger portion of three- and four-ring PAHs are partitioned to the particle phase.
Polydiacetylenic nanofibers (PDA-Nfs) obtained by photopolymerization of surfactant 1 were optimized for intracellular delivery of small interfering RNAs (siRNAs). PDA-Nfs/siRNA complexes efficiently ...silenced the oncogene Lim-1 in the renal cancer cells 786-O in vitro. Intraperitoneal injection of PDA-Nfs/siLim1 downregulated Lim-1 in subcutaneous tumor xenografts obtained with 786-O cells in nude mice. Thus, PDA-Nfs represent an innovative system for in vivo delivery of siRNAs.
We present new photometric and spectroscopic observations of an unusual luminous blue variable (LBV) in NGC 3432, covering three major outbursts in 2008 October, 2009 April and 2009 November. ...Previously, this star experienced an outburst also in 2000 (known as SN 2000ch). During outbursts the star reached an absolute magnitude between −12.1 and −12.8. Its spectrum showed H, He i and Fe ii lines with P-Cygni profiles during and soon after the eruptive phases, while only intermediate-width lines in pure emission (including He iiλ4686) were visible during quiescence. The fast-evolving light curve soon after the outbursts, the quasi-modulated light curve, the peak magnitude and the overall spectral properties are consistent with multiple episodes of variability of an extremely active LBV. However, the widths of the spectral lines indicate unusually high wind velocities (1500–2800 km s−1), similar to those observed in Wolf–Rayet stars. Although modulated light curves are typical of LBVs during the S-Dor variability phase, the luminous maxima and the high frequency of outbursts are unexpected in S-Dor variables. Such extreme variability may be associated with repeated ejection episodes during a giant eruption of an LBV. Alternatively, it may be indicative of a high level of instability shortly preceding the core-collapse or due to interaction with a massive, binary companion. In this context, the variable in NGC 3432 shares some similarities with the famous stellar system HD 5980 in the Small Magellanic Cloud, which includes an erupting LBV and an early Wolf–Rayet star.
The unique properties and atomic thickness of two-dimensional (2D) materials enable smaller and better nanoelectromechanical sensors with novel functionalities. During the last decade, many studies ...have successfully shown the feasibility of using suspended membranes of 2D materials in pressure sensors, microphones, accelerometers, and mass and gas sensors. In this review, we explain the different sensing concepts and give an overview of the relevant material properties, fabrication routes, and device operation principles. Finally, we discuss sensor readout and integration methods and provide comparisons against the state of the art to show both the challenges and promises of 2D material-based nanoelectromechanical sensing.
A precise measurement of the differential cross sections dσ/dΩ and the linearly polarized photon beam asymmetry Σ_{3} for Compton scattering on the proton below pion threshold has been performed with ...a tagged photon beam and almost 4π detector at the Mainz Microtron. The incident photons were produced by the recently upgraded Glasgow-Mainz photon tagging facility and impinged on a cryogenic liquid hydrogen target, with the scattered photons detected in the Crystal Ball/TAPS setup. Using the highest statistics Compton scattering data ever measured on the proton along with two effective field theories (both covariant baryon and heavy-baryon) and one fixed-t dispersion relation model, constraining the fits with the Baldin sum rule, we have obtained the proton electric and magnetic polarizabilities with unprecedented precision: α_{E1}=10.99±0.16±0.47±0.17±0.34, β_{M1}=3.14±0.21±0.24±0.20±0.35; in units of 10^{-4} fm^{3} where the errors are statistical, systematic, spin polarizability dependent, and model dependent.
Protein glycosylation events that happen early in the secretory pathway are often dysregulated during tumorigenesis. These events can be probed, in principle, by monosaccharides with bioorthogonal ...tags that would ideally be specific for distinct glycan subtypes. However, metabolic interconversion into other monosaccharides drastically reduces such specificity in the living cell. Here, we use a structure-based design process to develop the monosaccharide probe NE-(S)-azidopropionylgalactosamine (GalNAzMe) that is specific for cancer-relevant Ser/Thr(O)–linked N-acetylgalactosamine (GalNAc) glycosylation. By virtue of a branched N-acylamide side chain, GalNAzMe is not interconverted by epimerization to the corresponding N-acetylglucosamine analog by the epimerase N-acetylgalactosamine–4-epimerase (GALE) like conventional GalNAc–based probes. GalNAzMe enters O-GalNAc glycosylation but does not enter other major cell surface glycan types including Asn(N)-linked glycans. We transfect cells with the engineered pyrophosphorylase mut-AGX1 to biosynthesize the nucleotidesugar donor uridine diphosphate (UDP)-GalNAzMe from a sugar-1-phosphate precursor. Tagged with a bioorthogonal azide group, GalNAzMe serves as an O-glycan–specific reporter in superresolution microscopy, chemical glycoproteomics, a genome-wide CRISPR-knockout (CRISPR-KO) screen, and imaging of intestinal organoids. Additional ectopic expression of an engineered glycosyltransferase, “bump-and-hole” (BH)–GalNAc-T2, boosts labeling in a programmable fashion by increasing incorporation of GalNAzMe into the cell surface glycoproteome. Alleviating the need for GALE-KO cells in metabolic labeling experiments, GalNAzMe is a precision tool that allows a detailed view into the biology of a major type of cancer-relevant protein glycosylation.
The increasing demand of renewable energy sources led researchers to investigate new materials and blends for energy generation and harvesting. In this context, the utilization of conjugated polymers ...has led to the development of optoelectronic devices that exhibit excellent response characteristics while remaining cost-effective and flexible. Moreover, blends can be produced in solution, using natural biopolymers aiming to produce electrodes for capacitors. For instance, the pseudocapacitive behavior of polyaniline (PANI) enables its application in high-power density supercapacitors. In this paper, PANI and Lignin blends were prepared and applied as an electrode in supercapacitors. Lignin, a naturally occurring biopolymer found in plants and commonly produced as a residue in the paper industry, was utilized in this study. The Lignin content was changed from 25 up to 75% (wt: wt) in relation to PANI. AFM images revealed that the PANI: Lignin blend exhibits a surface morphology with distinct pores, a feature that can impact positively the performance of electrodes. The device prepared with 25% Lignin (wt: wt) demonstrated the best performance, with a capacitance of 518 F g
−1
(at 1 A g
−1
) and a retention capacity of 71% after 1000 cycles. Moreover, the incorporation of Lignin influenced the mechanical properties of PANI, due to a strong interaction between these two polymers. Therefore, PANI: Lignin blends emerge as low-cost and an eco-friendly alternatives for energy storage while facilitating the reuse of waste materials from the paper industry.
Over approximately the past decade, a subfield of plasma science has arisen that is redefining frontiers in the physics of low temperature plasma and its applications. Concerned with the confinement ...of weakly ionized, nonequilibrium plasma to cavities having mesoscopic dimensions, the emerging area of microcavity plasmas has advanced rapidly in surpassing several milestones, primarily with respect to electron density and cavity geometries, and is establishing new avenues of research. To date, peak electron densities above 10 17 cm -3 , cavity dimensions as small as 3 μm , microchannel aspect ratios (length: width) of 10 3 :1 , plasma packets propagating at velocities up to 20 km s -1 , and coupling between e - -h + and e - -ion plasmas have all been observed, but every indication is that these results are only a foretaste of the future. This review describes several recent device geometries and provides a synopsis of the physics. Promising applications of this technology in chemical processing, lighting, water disinfection, and medicine are also discussed briefly.
The time to neutrophil engraftment for adult patients after myeloablative double unit umbilical cord blood (UCB) transplantation is 23 days when the two units are given i.v. We hypothesized that the ...intra-BM injection (IBMI) of one of the two UCB units would reduce systemic loss of hematopoietic progenitors and shorten time to neutrophil recovery after myeloablation. Ten patients with a median age of 35 years were transplanted. The unit to be given by IBMI was randomly assigned; the other unit was given i.v. The median infused graft total nucleated cell dose was 3.7 x 10(7)/kg with no difference between i.v. and IBMI units. All patients tolerated the procedure well, and there was no severe adverse event related to IBMI. The median time to neutrophil engraftment and plt recovery >50 000/microl was 21 and 69 days, respectively. In all, 9 of 10 patients engrafted, 5 with the i.v. unit and 4 with the IBMI unit; 7 of 8 evaluable patients developed acute GVHD and 5 of 10 patients died from treatment-related causes. Survival was 47% at 1 year. Despite safety of administration, IBMI of one of two UCB units did not shorten the time to neutrophil engraftment and offers no advantage over conventional double unit transplantation.
Manganese‐catalyzed C−H bond activation chemistry is emerging as a powerful and complementary method for molecular functionalization. A highly reactive seven‐membered MnI intermediate is detected and ...characterized that is effective for H‐transfer or reductive elimination to deliver alkenylated or pyridinium products, respectively. The two pathways are determined at MnI by judicious choice of an electron‐deficient 2‐pyrone substrate containing a 2‐pyridyl directing group, which undergoes regioselective C−H bond activation, serving as a valuable system for probing the mechanistic features of Mn C−H bond activation chemistry.
Look left, look right: A highly reactive seven‐membered manganese(I) intermediate has been detected and characterized that is effective for H‐transfer or reductive elimination to deliver alkenylated or pyridinium products, respectively. The two pathways are determined at MnI by judicious choice of an electron‐deficient 2‐pyrone substrate containing a 2‐pyridyl directing group, which undergoes regioselective C−H activation.
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