Rapid crystallization of L-arginine acetate on engineered surfaces using metal-assisted and microwave-accelerated evaporative crystallization()

We report the application of our newly described crystallization technique, which employs silver island films (SIFs) and microwave heating, to rapid crystallization of L-arginine acetate (LAA). Using our technique, LAA crystals (~ 1.2 mm in length) were grown from a 20 μl solution in 1 min on surface functionalized SIFs. In control experiments (glass slides and at room temperature) the growth of LAA crystals (0.1-0.3 mm) took ~ 55 min.     

Intermolecular Gold(I)‐Catalyzed Alkyne Carboalkoxylation Reactions for the Multicomponent Assembly of β‐Alkoxy Ketones

A new gold(I)‐catalyzed multicomponent synthesis of β‐alkoxy ketones from aldehydes, alcohols, and alkynes is described. This atom economical synthesis was achieved through the use of the gold complex (SPhos)AuNTf₂ as a catalyst, and allows for the preparation of a diverse array of β‐alkoxy ketone products. Mechanistic studies illustrate that these reactions proceed via gold(I)‐catalyzed hydrolysis of the alkyne to an aryl ketone, which then undergoes an aldol reaction with an oxocarbenium ion generated in situ from the aldehyde and alcohol components.     

Evaluation of vapor intrusion using controlled building pressure

The use of measured volatile organic chemical (VOC) concentrations in indoor air to evaluate vapor intrusion is complicated by (i) indoor sources of the same VOCs and (ii) temporal variability in vapor intrusion. This study evaluated the efficacy of utilizing induced negative and positive building pressure conditions during a vapor intrusion investigation program to provide an improved understanding of the potential for vapor intrusion. Pressure control was achieved in five of six buildings where the investigation program was tested. For these five buildings, the induced pressure differences were sufficient to control the flow of soil gas through the building foundation. A comparison of VOC concentrations in indoor air measured during the negative and positive pressure test conditions was sufficient to determine whether vapor intrusion was the primary source of VOCs in indoor air at these buildings. The study results indicate that sampling under controlled building pressure can help minimize ambiguity caused by both indoor sources of VOCs and temporal variability in vapor intrusion.     

Where Were We?

This essay examines the twentieth-century water infrastructure of Phoenix, Arizona. An extensive network of canals transformed the desert into farmland, then farmland into suburban sprawl. This infrastructure can be studied as a vital force, one whose arrival so contradicted preexisting geology and ecology that it produced unexpected effects and admitted uninvited visitors. Historical documentation of the canals' transition from agricultural to suburban infrastructure reveals complex human-nature interactions mediated by engineered waters. This brief account argues for the potential of infrastructural history as a form of vibrant postnatural history, one which challenges the notion of genius loci on sites where terrestrial definitions of region have been ruptured.     

Cisplatin-loaded porous Si microparticles capped by electroless deposition of platinum

The loading and release of the anti-cancer drug platinum cis-dichlorodiamine (cisplatin) from mesoporous silicon (pSi) microparticles is studied. The pSi microparticles are modified with 1-dodecene or with 1,12-undecylenic acid by hydrosilylation, and each modified pSi material acts as a reducing agent, forming a deposit of Pt on its surface that nucleates further deposition, capping the mesoporous structure and trapping free (unreduced) cisplatin within. Slow oxidation and hydrolytic dissolution of the Si/SiO(2) matrix in buffer solution or in culture medium leads to the release of drugs from the microparticles. The drug-loaded particles show significantly greater toxicity toward human ovarian cancer cells (in vitro), relative to an equivalent quantity of free cisplatin. This result is consistent with the mechanism of drug release, which generates locally high concentrations of the drug in the vicinity of the degrading particles. Control assays with pSi particles loaded in a similar manner with the therapeutically inactive trans isomer of the platinum drug, and with pSi particles containing no drug, result in low cellular toxicity. A hydrophobic pro-drug, cis,trans,cis-[Pt(NH(3))(2)(O(2)C(CH(2))(8)CH(3))(2)Cl(2)], is loaded into the pSi films from chloroform without concomitant reduction of the pSi carrier.     

Evidence that gendered wording in job advertisements exists and sustains gender inequality.

Social dominance theory (Sidanius & Pratto, 1999) contends that institutional-level mechanisms exist that reinforce and perpetuate existing group-based inequalities, but very few such mechanisms have been empirically demonstrated. We propose that gendered wording (i.e., masculine- and feminine-themed words, such as those associated with gender stereotypes) may be a heretofore unacknowledged, institutional-level mechanism of inequality maintenance. Employing both archival and experimental analyses, the present research demonstrates that gendered wording commonly employed in job recruitment materials can maintain gender inequality in traditionally male-dominated occupations. Studies 1 and 2 demonstrated the existence of subtle but systematic wording differences within a randomly sampled set of job advertisements. Results indicated that job advertisements for male-dominated areas employed greater masculine wording (i.e., words associated with male stereotypes, such as leader, competitive, dominant) than advertisements within female-dominated areas. No difference in the presence of feminine wording (i.e., words associated with female stereotypes, such as support, understand, interpersonal) emerged across male- and female-dominated areas. Next, the consequences of highly masculine wording were tested across 3 experimental studies. When job advertisements were constructed to include more masculine than feminine wording, participants perceived more men within these occupations (Study 3), and importantly, women found these jobs less appealing (Studies 4 and 5). Results confirmed that perceptions of belongingness (but not perceived skills) mediated the effect of gendered wording on job appeal (Study 5). The function of gendered wording in maintaining traditional gender divisions, implications for gender parity, and theoretical models of inequality are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Spatial analysis of diffusion tensor tractography statistics along the inferior fronto-occipital fasciculus with application in progressive supranuclear palsy

Background

The purpose of the study was to develop a method for analysis of diffusion parameters along white matter (WM) tracts, using spatial normalization based on anatomical landmarks, and to introduce the apparent area coefficient (AAC). The method’s applicability was tested in the inferior fronto-occipital fasciculus (IFO) in patients with progressive supranuclear palsy (PSP) and healthy controls (HCs).

Methods

A framework for analysis of diffusion parameters was developed. Spatial normalization of the tracts was performed using anatomical landmarks, to avoid deformations caused by cerebral atrophy. Initially, 38 HCs were used to optimize a threshold for the minimal size of regions that differ between groups. The fractional anisotropy, mean diffusivity, AAC, and the hemispheric asymmetry index (AI), were compared between 11 PSP patients and 15 HCs.

Results

The method was feasible for analysis of PSP patients and HCs. The AI showed that the observed hemispheric asymmetry of AAC was significantly larger in PSP patients compared with HCs in small regions of the IFO.

Conclusions

The method was successfully employed for analysis of diffusion parameters along the IFO in a patient group. This method can be potentially useful in studies of WM diseases, with or without cerebral atrophy.     

Attention bias in nicotine withdrawal and under stress.

Drug motivation models postulate that attention biasing toward smoking-related cues is a cognitive mechanism supporting continued or renewed drug use, and they predict that drug use history, deprivation, and distress should modulate the extent of this bias. The present study used the modified Stroop paradigm to extend past research regarding attention biasing toward smoking and unpleasant, pleasant, and neutral words among adult nonsmokers and daily smokers. Both nonsmokers and smokers showed differential attention toward unpleasant and pleasant cues, particularly pleasant cues, but did not show a unique bias toward smoking-related stimuli. Results suggested that, among smokers, nicotine deprivation and exogenous stress (threat of electric shock) have a nonadditive effect on attention toward pleasant cues but no effect on attention to smoking cues specifically. Similarly, instructing smokers that they would have an opportunity to smoke did not significantly increase the bias of nicotine-deprived smokers' attention toward smoking-related cues, relative to arousing unpleasant and pleasant cues. Overall, results suggest that smokers' attention may be biased toward both smoking-related and other salient cues when deprived of nicotine and anticipating an opportunity to smoke. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of message framing and ethnic targeting on mammography use among low-income women.

The authors examined the effects that differently framed and targeted health messages have on persuading low-income women to obtain screening mammograms. The authors recruited 752 women over 40 years of age from community health clinics and public housing developments and assigned the women randomly to view videos that were either gain or loss framed and either targeted specifically to their ethnic groups or multicultural. Loss-framed, multicultural messages were most persuasive. The advantage of loss-framed, multicultural messages was especially apparent for Anglo women and Latinas but not for African American women. These effects were stronger after 6 months than after 12 months. (PsycINFO Database Record (c) 2010 APA, all rights reserved)