Group IVB metallocene polyesters containing camphoric acid and preliminary cancer cell activity

Polyesters were formed from the reaction of the salt of camphoric acid and Group IVB metallocene dichlorides using the interfacial polycondenzation process. The polyesters were formed in good yields with moderate chain lengths. Fourier transform infrared spectroscopy shows bands characteristic of the presence of both reactants with new bands characteristic of the formation of the M?O and M–O(CO) linkage present. The polymers largely exist in a bridging geometry of the carbonyl groups about the metal atom. Nuclear magnetic resonance shows the presence of bands derived from both reactants. Matrix-assisted laser desorption/ionization mass spectroscopy shows ion fragments to three units for the polymers with isotopic abundance characteristic of the presence of metal atoms in the ion fragment clusters. All the polymers exhibit good ability to inhibit all the tested cancer cell lines but the zironocene and hafnocene polymers exhibit especially good inhibition of the tested cancer cell lines that included two pancreatic cancer cell lines. They represent a potential new group of anticancer drugs.     

(Re)conceptualising the boundaries between home and homelessness: the unheimlich

A burgeoning cross-disciplinary literature signifies a move towards diversifying understandings of the meanings of ‘home’. Homelessness is inextricably bound up in these definitions. While earlier work has considered meanings of homelessness, attempts to advance understandings of the relationship between home and homelessness have been sporadic. This article attempts to reinvigorate discussion around the home–homelessness relationship by problematizing the binaries in current understandings and poses a different way of theorizing the interplay between the two concepts. Drawing on interviews with women accessing homelessness services in the North of England, discussion interweaves women’s meanings of home and homelessness with the Freudian notion of the ‘unheimlich’. The ‘unheimlich’ captures the uncanny process of inversion whereby the familiar domestic sphere of the house turns into a frightening place; and a typical space of homelessness—the hostel—is considered home. The article seeks to contribute more adequate theoretical tools for future research to better understand and articulate the complexities of home and homelessness.     

Stable Synthetic Bacteriochlorins for Photodynamic Therapy: Role of Dicyano Peripheral Groups,Central Metal Substitution (2H,Zn, Pd), and Cremophor EL Delivery

A series of four stable synthetic bacteriochlorins was tested in vitro in HeLa cells for their potential in photodynamic therapy (PDT). The parent bacteriochlorin (BC), dicyano derivative (NC)₂BC and corresponding zinc chelate (NC)₂BC–Zn and palladium chelate (NC)₂BC–Pd were studied. Direct dilution of a solution of bacteriochlorin in an organic solvent (N,N‐dimethylacetamide) into serum‐containing medium was compared with the dilution of bacteriochlorin in Cremophor EL (CrEL; polyoxyethylene glycerol triricinoleate) micelles into the same medium. CrEL generally reduced aggregation (as indicated by absorption and fluorescence) and increased activity up to tenfold (depending on bacteriochlorin), although it decreased cellular uptake. The order of PDT activity against HeLa human cancer cells after 24 h incubation and illumination with 10 J cm^?2 of near‐infrared (NIR) light is (NC)₂BC–Pd (LD₅₀=25 nM ) > (NC)₂BC > (NC)₂BC–Zn ≈ BC. Subcellular localization was determined to be in the endoplasmic reticulum, mitochondria and lysosomes, depending on the bacteriochlorin. (NC)₂BC–Pd showed PDT‐mediated damage to mitochondria and lysosomes, and the greatest production of hydroxyl radicals as determined using a hydroxyphenylfluorescein probe. The incorporation of cyano substituents provides an excellent motif for the enhancement of the photoactivity and photostability of bacteriochlorins as PDT photosensitizers.     

Lake extent changes in Basotu,Tanzania: a mixed-methods approach to understanding the impacts of anthropogenic influence and climate variability

Incompatible land use is a major contributor to ecosystem degradation, and is often exacerbated by climate change impacts. We investigate Lake Basotu, Tanzania as a case study where natural lake variability has been affected by agricultural land use. Comparisons between a satellite-derived history of lake surface area, local precipitation records, and corresponding anthropogenic activity show the impacts of agricultural and historical practices. We argue that insufficient consideration to the wider ecological impacts of large agricultural projects has lasting implications. This is particularly true in semi-arid environments where food production demands need to be continuously met. In the future, major conservation strategies should be investigated to maintain the environmental integrity and sustainability of freshwater resources.     

Intentional forgetting as a facilitator for recalling new product attributes.

When market changes alter what product attributes are deemed important, consumers may intentionally try to forget old product information in an attempt to remember new product information. In Experiment 1, the authors demonstrated that intentional forgetting of this nature temporarily inhibits retrieval of old product information and leads to a benefit to memory for new product information. The results show that, after a short delay, benefits continue in the absence of costs, which is supportive of a multiple-process account of intentional forgetting. Experiment 2 extends these effects using an advertising message to stimulate forgetting. Across both experiments, results also show that brand preference is based on learning of new attribute information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Note on the Statistical Dynamics of Two Mutually Phase-Locked Oscillators

This note demonstrates that the behavior of two mutually synchronized phase-locked oscillators using delay compensation is equivalent to that of a first-order loop with the loop parameters degraded by the residual uncompensated delays of the system. In particular, the probability density of phase differences between the two oscillators is derived and the numerical results are also presented. The cycle slipping rate is easily obtained from this density.     

Analysis of trace levels of sulfonamide and tetracycline antimicrobials in groundwater and surface water using solid-phase extraction and liquid chromatography/mass spectrometry

A method has been developed for the trace analysis of two classes of antimicrobials consisting of six sulfonamides (SAs) and five tetracyclines (TCs), which commonly are used for veterinary purposes and agricultural feed additives and are suspected to leach into ground and surface water. The method used solid-phase extraction and liquid chromatography/mass spectrometry (LC/MS) with positive ion electrospray. The unique combination of a metal chelation agent (Na2EDTA) with a macroporous copolymer resulted in quantitative recoveries by solid-phase extraction (mean recovery, 98 +/- 12%) at submicrogramper-liter concentrations. An ammonium formate/formic acid buffer with a methanol/water gradient was used to separate the antimicrobials and to optimize the signal intensity. Mass spectral fragmentation and ionization characteristics were determined for each class of compounds for unequivocal identification. For all SAs, a characteristic m/z 156 ion representing the sulfanilyl fragment was identified. TCs exhibited neutral losses of 17 amu resulting from the loss of ammonia and 35 amu from the subsequent loss of water. Unusual matrix effects were seen only for TCs in this first survey of groundwater and surface water samples from sites around the United States, requiring that TCs be quantitated using the method of standard additions.     

A randomized controlled trial of cognitive-behavioral therapy, light therapy, and their combination for seasonal affective disorder.

This first controlled psychotherapy trial for seasonal affective disorder (SAD) compared SAD-tailored cognitive-behavioral therapy (CBT), light therapy (LT), and their combination to a concurrent wait-list control. Adults (N = 61) with major depression, recurrent with seasonal pattern, were randomized to one of four 6-week conditions: CBT (1.5-hr twice-weekly group therapy), LT (10,000-lux for 90-min/day with administration time individually adjusted), combined CBT + LT, or a minimal contact/delayed LT control (MCDT; LT following 6 weeks of monitoring). CBT, LT, and CBT + LT significantly and comparably improved depression severity relative to MCDT in intent-to-treat and completer samples. CBT + LT (73%) had a significantly higher remission rate than MCDT (20%). Using prospectively measured summer mood status to estimate the "functional" population, CBT + LT also had a significantly larger proportion of participants with clinically significant change over treatment compared with MCDT. The LT condition outcomes virtually replicated results from prior trials. CBT, alone or combined with LT, holds promise as an efficacious SAD treatment and warrants further study. If replicated, CBT + LT's remission rate would represent a clinically meaningful improvement over the 53% observed across LT studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)