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81.
Cassandra E. Callmann Matthew K. Vasher Anindita Das Caroline D. Kusmierz Chad A. Mirkin 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(24):2300097
The biological properties of spherical nucleic acids (SNAs) are largely independent of nanoparticle core identity but significantly affected by oligonucleotide surface density. Additionally, the payload-to-carrier (i.e., DNA-to-nanoparticle) mass ratio of SNAs is inversely proportional to core size. While SNAs with many core types and sizes have been developed, all in vivo analyses of SNA behavior have been limited to cores >10 nm in diameter. However, “ultrasmall” nanoparticle constructs (<10 nm diameter) can exhibit increased payload-to-carrier ratios, reduced liver accumulation, renal clearance, and enhanced tumor infiltration. Therefore, we hypothesized that SNAs with ultrasmall cores exhibit SNA-like properties, but with in vivo behavior akin to traditional ultrasmall nanoparticles. To investigate, we compared the behavior of SNAs with 1.4-nm Au102 nanocluster cores (AuNC-SNAs) and SNAs with 10-nm gold nanoparticle cores (AuNP-SNAs). Significantly, AuNC-SNAs possess SNA-like properties (e.g., high cellular uptake, low cytotoxicity) but show distinct in vivo behavior. When intravenously injected in mice, AuNC-SNAs display prolonged blood circulation, lower liver accumulation, and higher tumor accumulation than AuNP-SNAs. Thus, SNA-like properties persist at the sub-10-nm length scale and oligonucleotide arrangement and surface density are responsible for the biological properties of SNAs. This work has implications for the design of new nanocarriers for therapeutic applications. 相似文献
82.
Multifrequency Measurements of the Effects of Soil Moisture, Soil Texture, And Surface Roughness 总被引:2,自引:0,他引:2
Wang James R. O'Neill Peggy E. Jackson Thomas J. Engman Edwin T. 《Geoscience and Remote Sensing, IEEE Transactions on》1983,(1):44-51
An experiment on remote sensing of soil moisture content was conducted over bare fields with microwave radiometers at the frequencies of 1.4, 5, and 10.7 GHz, during July-September of 1981. Three bare fields with different surface roughnesses and soil textures were prepared for the experiment. Ground-truth acquisition of soil temperatures and moisture contents for 5 layers down to the depths of 15 cm was made concurrently with radiometric measurements. The experimental results show that the effect of surface roughness is to increase the soil's brightness temperature and to reduce the slope of regression between brightness temperature and moisture content. The slopes of regression for soils with different textures are found to be comparable and the effect of soil texture is reflected in the difference of regression line intercepts at brightness-temperature axis. The result is consistent with laboratory measurement of soil's dielectric permittivity. Measurements on wet smooth bare fields give lower brightness temperatures at 5 than at 1.4 GHz. This phenomenon is not expected from current radiative transfer theory, using laboratory measurements of the relationship between dielectric permittivity and moisture content for different soil-water mixtures at frequencies of <5 GHz. 相似文献
83.
The potential large-scale production of fullerene C60 and its widespread use in consumer products may translate into occupational and public exposure and in long-term environmental exposure. To assess the risk and fate of C60 in the environment, it is important to understand its solvate formation in common industrial solvents as the solvates may affect various properties of C60 including reactivity and toxicity, particularly when solvates occur in C60 clusters. In this study, the solubility measurements in mixed solvent system can provide useful information about solvate formation. The solubility of C60 was measured in pure toluene, tetrahydrofuran, ethanol, and acetonitrile to be 3000, 11, 1.4, and 0.04 mg/L, respectively. Additionally, the solubility of C60 was measured in mixtures of toluene-acetonitrile, toluene-ethanol, toluene-tetrahydrofuran, and acetonitrile-tetrahydrofuran. The solubility data were modeled with some accuracy using Wohl's equation. The estimated crystal energy term for C60 in tetrahydrofuran was different than that in the other solvents, indicating that the C60 solid phase in equilibrium with tetrahydrofuran solution may be a solvated crystal. 相似文献
84.
Many procedures have been described to correct velopharyngeal incompetence. Significant complications can occur, and the results may not be satisfactory. If the short soft palate has satisfactory muscle function and if it could be moved toward the posterior pharyngeal wall by distraction osteogenesis of the hard palate, an entirely new concept of treatment for velopharyngeal incompetence would be available. The object of the present study was to explore the possibility of osteogenesis occurring in the hard palate in dogs after gradual distraction (callus distraction). Six adult, mix-bred dogs were anesthetized, and the palatal mucosa was elevated. A midpalatal transverse osteotomy and two lateral osteotomies were performed. Tantalum bone markers for cephalometric analysis were placed, and an individually fabricated, orthodontic-like distraction device with an expansion screw in the sagittal direction was inserted. The device was stabilized on the premolars and fixed to the palatal bone with titanium miniscrews. Gradual distraction began after a latency period of 10 to 18 days. The rate of the distraction varied from 0.25 to 0.75 mm per day. The device was left in place for 6 to 8 weeks after expansion to allow for bony consolidation. Assessment was by direct examination, cephalograms, computed tomography, and histology with bone labeling. Impressions of the jaws were taken preoperatively and after device removal to examine plaster cast changes in the dental occlusion. Cephalometric and computed tomographic scan analysis demonstrated a distraction of up to 8 mm. All gaps were filled with de novo osteogenesis. Comparison of the plaster casts revealed no change in the occlusion. At 1 month after distraction, the computed tomographic scan showed the first signs of ossification of the experimental gap from the anterior and posterior bone ends. After 4.5 months ossification was almost complete with a small translucent zone in the middle of the experimental gap. After 7 months ossification was complete. 相似文献
85.
Jackson I Schijns H Schmitt DR Mu J Delmenico A 《The Review of scientific instruments》2011,82(6):064501
Novel laboratory equipment has been modified to allow both torsional and flexural oscillation measurements at sub-microstrain amplitudes, thereby providing seismic-frequency constraints on both the shear and compressional wave properties of cylindrical rock specimens within the linear regime. The new flexural mode capability has been tested on experimental assemblies containing fused silica control specimens. Close consistency between the experimental data and the results of numerical modelling with both finite-difference and finite-element methods demonstrates the viability of the new technique. The capability to perform such measurements under conditions of independently controlled confining and pore-fluid pressure, with emerging strategies for distinguishing between local (squirt) and global (specimen-wide) fluid flow, will have particular application to the study of frequency-dependent seismic properties expected of cracked and fluid-saturated rocks of the Earth's upper crust. 相似文献
86.
Marine biogeochemical cycling of mercury 总被引:2,自引:0,他引:2
87.
88.
Venkatesh Balan Chad A. Rogers Shishir P. S. Chundawat Leonardo da Costa Sousa Patricia J. Slininger Rajesh Gupta Bruce E. Dale 《Journal of the American Oil Chemists' Society》2009,86(2):157-165
We have come up with a novel, integrated approach for making biodiesel by in-house producion of ethanol after fermentation
of hexane extracted edible oil cake fiber. In addition, we have demonstrated how ethanol could be manufactured from commonly
available oil cakes (such as canola, sunflower, sesame, soy, peanut) and dried distiller’s grains with solubles (DDGS). The
edible oil cakes and DDGS were hexane extracted, ammonia fiber expansion pretreated, enzymatically hydrolysed and fermented
to produce ethanol. From all the oil cakes tested in this work, DDGS and peanut oil cake showed the most promising results
giving more than 180 g of glucose/kg of oil cake. These two feedstock’s were hydrolyzed at 15% solids loading and fermented
by a native strain of Pichia stipitis. Most sugars were consumed during the first 24 h, with no pronounced inhibition of P. stipitis by the degradation products in the hydrolysate. Xylose consumption was more effective for peanut cake hydrolyzate compared
to DDGS. 相似文献
89.
Magrans-Courtney T Wilborn C Rasmussen C Ferreira M Greenwood L Campbell B Kerksick CM Nassar E Li R Iosia M Cooke M Dugan K Willoughby D Soliah L Kreider RB 《Journal of the International Society of Sports Nutrition》2011,8(1):8-17
Background
The purpose of this study was to determine whether sedentary obese women with knee OA initiating an exercise and weight loss program may experience more beneficial changes in body composition, functional capacity, and/or markers of health following a higher protein diet compared to a higher carbohydrate diet with or without GCM supplementation.Methods
Thirty sedentary women (54 ± 9 yrs, 163 ± 6 cm, 88.6 ± 13 kg, 46.1 ± 3% fat, 33.3 ± 5 kg/m2) with clinically diagnosed knee OA participated in a 14-week exercise and weight loss program. Participants followed an isoenergenic low fat higher carbohydrate (HC) or higher protein (HP) diet while participating in a supervised 30-minute circuit resistance-training program three times per week for 14-weeks. In a randomized and double blind manner, participants ingested supplements containing 1,500 mg/d of glucosamine (as d-glucosamine HCL), 1,200 mg/d of chondroitin sulfate (from chondroitin sulfate sodium), and 900 mg/d of methylsulfonylmethane or a placebo. At 0, 10, and 14-weeks, participants completed a battery of assessments. Data were analyzed by MANOVA with repeated measures.Results
Participants in both groups experienced significant reductions in body mass (-2.4 ± 3%), fat mass (-6.0 ± 6%), and body fat (-3.5 ± 4%) with no significant changes in fat free mass or resting energy expenditure. Perception of knee pain (-49 ± 39%) and knee stiffness (-42 ± 37%) was decreased while maximal strength (12%), muscular endurance (20%), balance indices (7% to 20%), lipid levels (-8% to -12%), homeostasis model assessment for estimating insulin resistance (-17%), leptin (-30%), and measures of physical functioning (59%), vitality (120%), and social function (66%) were improved in both groups with no differences among groups. Functional aerobic capacity was increased to a greater degree for those in the HP and GCM groups while there were some trends suggesting that supplementation affected perceptions of knee pain (p < 0.08).Conclusions
Circuit style resistance-training and weight loss improved functional capacity in women with knee OA. The type of diet and dietary supplementation of GCM provided marginal additive benefits.Trial Registration
ClinicalTrials.gov: NCT01271218 相似文献90.
David L. Compton Michael A. Jackson 《Journal of the American Oil Chemists' Society》2011,88(11):1799-1805
Two mesoporous silicas functionalized with propylsulfonic (SBA-15-PSA) and arenesulfonic (SBA-15-ASA) acid groups, and a highly
acidic, functionalized styrene divinylbenzene copolymer ion exchange resin (Amberlyst-15) were examined for their ability
to catalyze the ethanolic esterification of the ω-sulfhydryl fatty acid, 11-mercaptoundecanoic acid (MUA), without catalyzing
unwanted side reactions at the sulfhydryl group. All three solid acid catalysts catalyzed the MUA esterification in excess
ethanol. The activation energy for the catalytic esterifications were determined from 50 to 75 °C, resulting in apparent E
a of 54, 71, and 59 kJ/mol for SBA-15-PSA, SBA-15-ASA, and Amberlyst-15, respectively. GC–MS analysis determined that all three
catalysts produced near quantitative conversion of MUA to its ethyl ester with very little reactivity towards the sulfhydryl
group. This was a marked improvement over the esterifications catalyzed by sulfuric and p-toluenesulfonic acids which produced thioethers and disulfide side products. The MUA ethyl ester synthesis was demonstrated
on a gram scale at 70 °C catalyzed by Amberlyst-15, and the desired product was isolated in 80% yield at >95% purity with
a minimum of purification. 相似文献