3DP process for fine mesh structure printing

Three dimensional printing (3DP) is a unique technique for creating complex shapes. However, printing feature sizes at less than 500 μm with high integrity and intricate structures have not been possible. In this study, TiNiHf shape memory alloy (SMA) powder was printed into 3D mesh structures of 300 μm wire width. Effects of printing layer thickness and binder saturation level on the integrity and dimensional accuracy of the 3D mesh structures were evaluated. 35 μm printing layer thickness and 170% binder saturation level offer the highest mesh structure integrity. Also, 35 μm printing layer thickness results in the smallest dimensional deviation from the designed 200 μm mesh width with the smallest standard deviation. Overall, 35 μm printing layer thickness and 170% binder saturation level are the most preferred printing condition for the designed 3D mesh structure.     

从大都市到多中心都市

巨型城市区域：一个新现象 多中心巨型城市区域（MCR：mega-cityregion）作为一个全新的现象,正在当今世界上高度城市化的地区出现。它的出现经历了一个从中心大城市到邻近小城市的漫长扩散过程。这些小城市或新或旧。虽然戈特曼（Jean Gottmann）早在1961年就已在其关于都市带的先驱研究中最早界定美国高度城市化的东北海岸为巨型城市区域．     

Adverse events with silicone hydrogel continuous wear.

High Dk silicone hydrogel lenses have overcome many of the hypoxic problems associated with traditional extended wear and the popularity of continuous wear (up to 30 nights) with these lens types is increasing. Results from clinical trials indicate that the typical physiological changes associated with edema from conventional extended wear of low Dk/t lenses do not occur with continuous wear of silicone hydrogel lenses. These changes include neovascularization, striae, microcysts and an increase in bulbar and limbal hyperemia. It is perhaps not surprising though that a number of adverse events do still occur with silicone hydrogel lenses when they are worn on a continuous wear basis. These include inflammatory conditions such as contact lens-induced peripheral ulcers (CLPU), contact lens-induced acute red eye (CLARE), infiltrative keratitis (IK) and contact lens papillary conjunctivitis (CLPC). Other events such as superior epithelial arcuate lesions (SEAL) and localised CLPC may be due to mechanical influences. While these conditions are not sight threatening, they may be painful and are certainly inconvenient to both the patient and the practitioner. It is therefore very important that the signs and symptoms associated with these events be recognised in order that they may be accurately identified and appropriately managed. The purpose of this review article is to describe the pathophysiology, etiology, and clinical presentation of these adverse events when observed with continuous wear contact lenses and to discuss their associated risk factors and incidence. Clear management and treatment strategies are also presented and a number of approaches to minimize adverse events with continuous wear of silicone hydrogel contact lenses are suggested.     

The effects of irradiation on quality of injected fresh pork loins

A comparison of irradiation effects on injected and uninjected fresh pork loin quality was conducted. Sixty pork loins from pigs of similar genetics were obtained from a pork harvesting facility immediately prior to processing. Thirty loins were injected with a brine composed of 2.17% salt/3.04% phosphate/20.8% lactate brine while thirty were not injected. Injected loins were pumped to 13% added weight. Ten loins of each group of thirty were not irradiated while an additional 10 loins were irradiated at 2.2 kGy and the final ten loins were irradiated at 4.4 kGy. Lipid oxidation, color, purge, volatiles, and tenderness were measured on sections of the treated loins after 0, 7, 21, and 35 days of refrigerated storage. Lipid oxidation was minimal for the 0 and the 2.2 kGy-treated loins, but was significantly greater (P<0.05) at day 35 for the loins treated with 4.4 kGy. Warner-Bratzler shear (WBS) force measurements were significantly lower (P<0.05) for the injected loins, but irradiation did not have an effect on shear force. Purge was significantly lower for the uninjected loins irradiated at 2.2 kGy than for those irradiated at 0 and 4.4 kGy. The injection treatment did not alter the effects of irradiation on the quality characteristics measured.     

Seeing a phrase “time and again” matters: The role of phrasal frequency in the processing of multiword sequences.

Are speakers sensitive to the frequency with which phrases occur in language? The authors report an eye-tracking study that investigates this by examining the processing of multiword sequences that differ in phrasal frequency by native and proficient nonnative English speakers. Participants read sentences containing 3-word binomial phrases (bride and groom) and their reversed forms (groom and bride), which are identical in syntax and meaning but that differ in phrasal frequency. Mixed-effects modeling revealed that native speakers and nonnative speakers, across a range of proficiencies, are sensitive to the frequency with which phrases occur in English. Results also indicate that native speakers and higher proficiency nonnatives are sensitive to whether a phrase occurs in a particular configuration (binomial vs. reversed) in English, highlighting the contribution of entrenchment of a particular phrase in memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Evaluation of a radioiodine plume increasing in concentration at the Savannah River Site

Field and laboratory studies were carried out to understand the cause for steady increases in (129)I concentrations emanating from radiological basins located on the Savannah River Site, South Carolina. The basins were closed in 1988 by adding limestone and slag and then capping with a low permeability engineered cover. Groundwater (129)I concentrations in a well near the basins in 1993 were 200 pCi L(-1) and are presently between 400 and 1000 pCi L(-1). Iodine speciation in the plume contained wide ranges of iodide, iodate, and organo-iodine concentrations. First-order calculations based on a basin sediment desorption study indicate that the modest increase of 0.7 pH units detected in the study site groundwater over the last 17 years since closure of the basins may be sufficient to produce the observed increased groundwater (129)I concentrations near the basins. Groundwater monitoring of the plume at the basins has shown that the migration of many of the high risk radionuclides originally present at this complex site has been attenuated. However, (129)I continues to leave the source at a rate that may have been exacerbated by the initial remediation efforts. This study underscores the importance of identifying the appropriate in situ stabilization technologies for all source contaminants, especially if their geochemical behaviors differ.     

Ecosystem,Location, and Climate Effects on Foliar Secondary Metabolites of Lodgepole Pine Populations from Central British Columbia

Lodgepole pines, Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson, are encountering increased abiotic stress and pest activity due to recent increases in temperature and changes in precipitation throughout their range. This tree species counters these threats by producing secondary metabolites, including phenolics and terpenoids. We examined foliar levels of lignin, soluble phenolics, monoterpenoids, sesquiterpenoids, and diterpenoids in 12 stands in British Columbia, Canada. We used these data to assess associations among foliar secondary metabolite levels and ecosystem, geographic, and climatic variables. Regressions were also performed to observe which combinations of variables best explained secondary metabolite variance. Stands of P. c. latifolia in the Coastal Western Hemlock and Interior Cedar/Hemlock biogeoclimatic zones had consistently greater foliar levels of almost all measured secondary metabolites than did other stands. Lignin was present in greater amounts in Boreal White/Black Spruce ecosystem (i.e., northern) stands than in southern stands, suggesting a role for this metabolite in pine survival in the boreal forest. Attempts to develop regression models with geographic and climatic variables to explain foliar secondary metabolite levels resulted in multiple models with similar predictive capability. Since foliar secondary metabolite levels appeared to vary most between stand ecosystem types and not as much due to geographic and climatic variables, metabolic profiles appeared best matched to the stress levels within local environments. It is unknown if differences in secondary metabolite levels are the result of genetic adaptation or phenotypic plasticity, but results from this and other studies suggest that both are important. These results are interpreted in light of ongoing efforts to assist in the migration of certain populations of P. c. latifolia northward in an effort to counter predicted effects of climate change.     

Comparison of N-Heterocyclic Aromatics Dibenzo[c,g]Carbazole and Dibenz[a,j]Acridine : Metabolism,DNA Binding and Mutation

N-Heterocyclic aromatics, such as carbazole and acridine derivatives, are environmental carcinogenic pollutants. Examples of these compounds are 7H-dibenzo[c,g]carbazole (DBC) and dibenz[a,j]acridine (DBA). The ionization potential (IP) for DBC is lower than for DBA. DBC is metabolized in lung and liver by way of phenols or directly through radical cations. DBC-induced liver and lung tumors have mutations in the 61^st codon of ras. DBA is metabolized in skin by way of a diol-epoxide of DBA. DBA-induced skin tumors have mutations in 12^th, 13^th and 61^st codons of ras. In summary, the metabolic activation of DBC proceeds through different adduction pattern pathways than does DBA and leads to different ras mutational spectra.