bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of 1‐Methyl‐6,10‐diphenylheptalene Derivatives
Authors: Jin Xudong , Linden Anthony , Hansen Hans‐Jürgen
Published: April 2010

The reduction of heptalene diester 1 with diisobutylaluminium hydride (DIBAH) in THF gave a mixture of heptalene‐1,2‐dimethanol 2a and its double‐bond‐shift (DBS) isomer 2b (Scheme 3). Both products can be isolated by column chromatography on silica gel. The subsequent chlorination of 2a or 2b with PCl5 in CH2Cl2 led to a mixture of 1,2‐bis(chloromethyl)heptalene 3a and its DBS isomer 3b. After a prolonged chromatographic separation, both products 3a and 3b were obtained in pure form. They crystallized smoothly from hexane/Et2O 7 : 1 at low temperature, and their structures were determined by X‐ray crystal‐structure analysis (Figs. 1 and 2). The nucleophilic exchange of the Cl substituents of 3a or 3b by diphenylphosphino groups was easily achieved with excess of (diphenylphospino)lithium (=lithium diphenylphosphanide) in THF at 0° (Scheme 4). However, the purification of 4a/4b was very difficult since these bis‐phosphines decomposed on column chromatography on silica gel and were converted mostly by oxidation by air to bis(phosphine oxides) 5a and 5b. Both 5a and 5b were also obtained in pure form by reaction of 3a or 3b with (diphenylphosphinyl)lithium (=lithium oxidodiphenylphospanide) in THF, followed by column chromatography on silica gel with Et2O. Carboxaldehydes 7a and 7b were synthesized by a disproportionation reaction of the dimethanol mixture 2a/2b with catalytic amounts of TsOH. The subsequent decarbonylation of both carboxaldehydes with tris(triphenylphosphine)rhodium(1+) chloride yielded heptalene 8 in a quantitative yield. The reaction of a thermal‐equilibrium mixture 3a/3b with the borane adduct of (diphenylphosphino)lithium in THF at 0° gave 6a and 6b in yields of 5 and 15%, respectively (Scheme 4). However, heating 6a or 6b in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in toluene, generated both bis‐phosphine 4a and its DBS isomer 4b which could not be separated. The attempt at a conversion of 3a or 3b into bis‐phosphines 4a or 4b by treatment with t‐BuLi and Ph2PCl also failed completely. Thus, we returned to investigate the antipodes of the dimethanols 2a, 2b, and of 8 that can be separated on an HPLC Chiralcel‐OD column. The CD spectra of optically pure (M)‐ and (P)‐configurated heptalenes 2a, 2b, and 8 were measured (Figs. 4, 5, and 9).
Oligonucleotide Analogues with Integrated Bases and Backbones. Part 23
Authors: Bogliotti Nicolas , Bernet Bruno , Vasella Andrea
Published: April 2010

The sulfone 2, and the sulfoxides (S)‐3 and (R)‐3 were obtained by oxidation of the thiomethylene‐linked A*[s]U dinucleoside 1. Conformational analysis and association studies of 2, (S)‐3, and (R)‐3 reveal a strong influence of the configuration on the conformation of the linking unit and on the self‐association of the dinucleosides.
Oligonucleotide Analogues with Integrated Bases and Backbones. Part 24
Authors: Chiesa Katja , Shvoryna Alyena , Bernet Bruno , Vasella Andrea
Published: April 2010

Inspection of Maruzen models and force‐field calculations suggest that oligonucleotide analogues integrating backbone and bases (ONIBs) with an aminomethylene linker form similar cyclic duplexes as the analogous oxymethylene linked dinucleosides. The self‐complementary adenosine‐ and uridine‐derived aminomethylene‐linked A*[n]U dinucleosides 15–17 were prepared by an aza‐Wittig reaction of the aldehyde 10 with an iminophosphorane derived from azide 6. The sequence‐isomeric U*[n]A dinucleosides 18–20 were similarly prepared from aldehyde 3 and azide 12. The N‐ethylamine 5, the acetamides 7 and 14, and the amine 13 were prepared as references for the conformational analysis of the dinucleosides. In contradistinction to the results of calculations, the N‐ethylamine 5 exists as intramolecularly H‐bonded hydroxyimino tautomer. The association in CDCl3 of these dinucleosides was studied by 1H‐NMR and CD spectroscopy. The A*[n]U dinucleosides 16 and 17 associate more strongly than the sequence isomers 19 and 20; the cyclic duplexes of 16 form preferentially Watson–Crick‐type base pairs, while 17, 19, and 20 show both Watson–Crick‐ and Hoogsteen‐type base pairing. The cyclic duplexes of the aminomethylene‐linked dinucleosides prefer a gg‐orientation of the linker. No evidence was found for an intramolecular H‐bond of the aminomethylene group. The CD spectra of 16 and 17 show a strong, those of 19 a weak, and those of 20 almost no temperature dependence.
Stereochemical Models for Discussing Additions to α,β‐Unsaturated Aldehydes Organocatalyzed by Diarylprolinol or Imidazolidinone Derivatives – Is There an ‘(E)/(Z)‐Dilemma’?
Authors: Seebach Dieter , Gilmour Ryan , Grošelj Uroš , Deniau Gildas , Sparr Christof , Ebert Marc‐Olivier , Beck Albert K. , McCusker Lynne B. , Šišak Dubravka , Uchimaru Tadafumi
Published: April 2010

The structures of iminium salts formed from diarylprolinol or imidazolidinone derivatives and α,β‐unsaturated aldehydes have been studied by X‐ray powder diffraction (Fig. 1), single‐crystal X‐ray analyses (Table 1), NMR spectroscopy (Tables 2 and 3, Figs. 2–7), and DFT calculations (Helv. Chim. Acta 2009, 92, 1, 1225, 2010, 93, 1; Angew. Chem., Int. Ed. 2009, 48, 3065). Almost all iminium salts of this type exist in solution as diastereoisomeric mixtures with (E)‐ and (Z)‐configured +NC bond geometries. In this study, (E)/(Z) ratios ranging from 88 : 12 up to 98 : 2 (Tables 2 and 3) and (E)/(Z) interconversions (Figs. 2–7) were observed. Furthermore, the relative rates, at which the (E)‐ and (Z)‐isomers are formed from ammonium salts and α,β‐unsaturated aldehydes, were found to differ from the (E)/(Z) equilibrium ratio in at least two cases (Figs. 4 and 5, a, and Fig. 6, a); more (Z)‐isomer is formed kinetically than corresponding to its equilibrium fraction. Given that the enantiomeric product ratios observed in reactions mediated by organocatalysts of this type are often ≥99 : 1, the (E)‐iminium‐ion intermediates are proposed to react with nucleophiles faster than the (Z)‐isomers (Scheme 5 and Fig. 8). Possible reasons for the higher reactivity of (E)‐iminium ions (Figs. 8 and 9) and for the kinetic preference of (Z)‐iminium‐ion formation are discussed (Scheme 4). The results of related density functional theory (DFT) calculations are also reported (Figs. 10–13 and Table 4).
Combined action of the dinuclear platinum compound BBR3610 with the PI3‐K inhibitor PX‐866 in glioblastoma
Authors: Gwak Ho‐Shin , Shingu Takashi , Chumbalkar Vaibhav , Hwang Yeo‐Hyeon , DeJournett Robert , Latha Khatri , Koul Dimpy , Alfred Yung W. K. , Powis Garth , Farrell Nicholas P. , Bögler Oliver
Published: April 2010

Polynuclear platinum compounds are more effective at killing glioblastoma cells than cisplatin, work by a different mechanism, and typically do not induce high levels of apoptosis at early time points after exposure. Here, we tested the hypothesis that combining BBR3610, the most potent polynuclear platinum, with a phosphoinositide‐3‐kinase (PI3K) inhibitor would promote apoptosis and enhance the impact on glioblastoma cells. The PI3K pathway is commonly activated in glioblastoma and promotes tumor cell survival, suggesting that its inhibition would make cells more sensitive to cytotoxic agents. We chose PX‐866 as a PI3K inhibitor as it is a clinically promising agent being evaluated for brain tumor therapy. Combining BBR3610 and PX‐866 resulted in synergistic killing of cultured glioma cells and an extension of survival in an orthotopic xenograft animal model. Both agents alone induced autophagy, and this appeared to be saturated, because when they were combined no additional autophagy was observed. However, the combination of PX‐866 and BBR3610 did induce statistically significant increases in the level of apoptosis, associated with a reduction in pAkt and pBad, as well as inhibition of transwell migration. We conclude that combining polynuclear platinums with PI3K inhibitors has translational potential and alters the cellular response to include early apoptosis.
Personal history of breast cancer as a significant risk factor for endometrial serous carcinoma in women aged 55 years old or younger
Authors: Liang Sharon X. , Pearl Micheal , Liang Shu , Xiang Li , Jia Lin , Yang Binlie , Fadare Oluwole , Schwartz Peter E. , Chambers Setsuko K. , Kong Beihua , Zheng Wenxin
Published: April 2010

A comparative study between endometrial serous carcinoma (ESC) and endometrial endometrioid carcinoma (EEC) was performed to determine whether a personal history of breast cancer is a risk factor for ESC in women aged ≤55 yr. Study subjects consisted of 348 women who were diagnosed with ESC and 830 comparison subjects who had EEC. Variables studied included age at diagnosis, a history of breast cancer, tamoxifen therapy, hormonal replacement therapy and smoking history. Overall, 19.4% of women with ESC had a history of breast cancer, which was significantly higher than that of 3% in comparison subjects. Among the study subjects, the incidence of a prior breast cancer was significantly higher in patients who were 55 yr of age or younger (41.5%) than those who were older than 55 yr (16%). The statistical significance of both of the aforementioned comparisons was independent of tamoxifen usage on multivariate analyses. The mean time interval between prior breast cancer and endometrial cancer was 92.5 mo (range 7–240 mo) in the study group and 79 mo (range 7–192 mo) in the comparison group. For the whole cohort and individual subgroups (ESC, EEC, ≤55 yr and >55 yr), a personal history of breast cancer did not adversely affect the patient outcomes, which was largely dependent on standard clinicopathologic parameters such as International Federation of Gynecology and Obstetrics stage, as has previously been demonstrated. These findings suggest that a personal history of breast cancer may be a significant risk factor for the development of ESC in women aged ≤55 yr. Further studies are needed to clarify the relationship between these two cancers in this age group and whether this increased risk is reflective of a genetic predisposition.
Ethnicity in trauma and psychiatric disorders: findings from the collaborative longitudinal study of personality disorders
Authors: Pérez Benítez Carlos I. , Yen Shirley , Shea M. Tracie , Edelen Maria O. , Markowitz John C. , McGlashan Thomas H. , Ansell Emily B. , Grilo Carlos M. , Skodol Andrew E. , Gunderson John G. , Morey Leslie C.
Published: April 2010

The study's aims are to explore ethnic differences in rates of adverse childhood experiences and lifetime traumatic events and in rates of psychiatric disorders for patients exposed to similar traumas. Rates of these events and rates of major depressive disorder, posttraumatic stress, substance use, and borderline personality disorders were compared among 506 non‐Hispanic Whites (N‐HW), 108 Latina(o)s, and 94 African Americans (AA) participating in the Collaborative Longitudinal Personality Disorder Study. We found that Whites reported higher rates of neglect than African Americans and Latina(o)s, higher rates of verbal/emotional abuse than African Americans, and higher rates of accidents and injuries/feared serious injury than Latina(o)s. African Americans had higher rates of seeing someone injured/killed than Whites. No significant interaction was observed between adverse events and ethnicity for mental disorders. © 2010 Wiley Periodicals, Inc. J Clin Psychol: 66:1–16, 2010.
Many new down‐ and up‐regulatory signaling pathways, from known cancer progression suppressors to matrix metalloproteinases, differ widely in cells of various cancers
Authors: DeLassus Gregory S. , Cho Hyojin , Hoang Stanley , Eliceiri George L.
Published: April 2010

Previously we detected new signaling pathways, some downregulatory and others upregulatory, from seven known suppressors of cancer progression to the expression of eight cancer‐promoting matrix metalloproteinases (MMPs) in breast cancer cells. The goals of the present study were to test whether the preceding observations occur only in breast cancer cells and, if not, whether the same downregulatory and upregulatory signaling pathways are active in cells of other human cancers, focusing on activator protein‐2α, E‐cadherin, fibulin1D, interleukin 4, p16INK4α, p53, PTEN, and RKIP, and on MMP1, MMP2, MMP7, MMP13, MMP14, MMP16, MMP19, and MMP25. To this end, in the present study we tested the effects of raising the cellular levels of wild‐type copies of these known suppressors of cancer progression on the expression of these MMPs. This study yielded several unexpected results. We have detected 53 new signaling pathways in cells of prostate, brain, lung, ovarian and breast human cancers, with an abundance of signaling pathways as high as ∼40% of the cancer progression regulator/MMP pairs tested in cells of prostate and breast cancers. Cells of various cancers differed widely and sequence‐specifically in the identity of their signaling pathways, so that almost 90% of the pathways were different in cells from one cancer to another. In each of 18 out of 51 signaling pathways, a known suppressor of cancer progression stimulated, rather than inhibited, the expression of a cancer‐promoting MMP. Ten signaling pathways were upregulatory in cells of some cancers and downregulatory in cells of other cancers. J. Cell. Physiol. 224: 549–558, 2010. © 2010 Wiley‐Liss, Inc.
Novel 2‐hydrazino‐pyrimidin‐4(3H)‐one derivatives as potential dihydrofolate reductase inhibitors
Authors: Degani Mariam S. , Bag Seema , Bairwa Ranjeet , Tawari Nilesh R. , Queener Sherry F.
Published: April 2010

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Novel substituted 2‐hydrazino‐pyrimidin‐4(3H)‐one derivatives were synthesized and examined for their antifolate activity against DHFR from Pneumocystis carinii (pc), Toxoplasma gondii (tg), Mycobacterium avium (ma), and rat liver (rl). A novel, simple, and feasible methodology was developed for the synthesis of the titled compounds. Amongst these, compound 8 6‐phenyl‐2‐(2‐(1‐(thiophen‐2‐yl) ethylidene)hydrazinyl) pyrimidin‐4(3H)‐one exhibited 17.74 μM activity against pcDHFR. J. Heterocyclic Chem., (2010).
A comparative study of incisor procumbency and mandibular morphology in vampire bats
Authors: Davis Jillian S. , Nicolay Christopher W. , Williams Susan H.
Published: April 2010

The three species of vampire bats (Phyllostomidae: Desmodontinae), Desmodus rotundus, Diaemus youngi, and Diphylla ecaudata, are the only mammals that obtain all nutrition from vertebrate blood (sanguinivory). Because of the unique challenges of this dietary niche, vampire bats possess a suite of behavioral, physiological, and morphological specializations. Morphological specializations include a dentition characterized by small, bladelike, non‐occlusive cheek teeth, large canines, and extremely large, procumbent, sickle‐shaped upper central incisors. The tips of these incisors rest in cuplike pits in the mandible behind the lower incisors (mandibular pits). Here, we use microCT scanning and high‐resolution radiography to describe the morphology of the mandible and anterior dentition in vampire bats, focusing on the relationship between symphyseal fusion, mandibular pit size, incisor size, and procumbency. In Desmodus and Diaemus, highly procumbent upper incisors are associated with relatively small mandibular pits, an unfused mandibular symphysis with substantial bony interdigitations linking the dentaries, and a diastema between the lower central incisors that helps to facilitate the lapping of blood from a wound. In Diphylla, less procumbent upper incisors are associated with relatively large mandibular pits, a completely fused mandibular symphysis, and a continuous lower toothrow lacking a central diastema. We hypothesize that symphyseal morphology and the presence or absence of the diastema are associated with the angle of upper incisor procumbency and mandibular pit development, and that spatial constraints influence the morphology of the symphysis. Finally, this morphological variation suggests that Diphylla utilizes a different feeding strategy as compared to Desmodus and Diaemus, possibly resulting from the functional demands of specialization on avian, rather than mammalian, blood. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.
Shape of articular surface of crocodilian (Archosauria) elbow joints and its relevance to sauropsids
Authors: Fujiwara Shin‐ichi , Taru Hajime , Suzuki Daisuke
Published: April 2010

The determination of area and shape of articular surfaces on the limb bones of extinct archosaurs is difficult because of postmortem decomposition of the fibrous tissue and articular cartilages that provide the complex three‐dimensional joint surfaces in vivo. This study aims at describing the shape of the articular cartilages in the elbow joints of six crocodilian specimens; comparing its structure with that of four birds, three testudines, and five squamates; and comparing the shapes of the surfaces of the calcified and the articular cartilages in the elbow joints of an Alligator specimen. The shapes of the articular cartilages of crocodilian elbow joint are shown to resemble those of birds. The humerus possesses an olecranon fossa positioned approximately at the midportion of the distal epiphysis and bordering the margin of the extensor side of the articular surface. The ulna possesses a prominent intercotylar process at approximately the middle of its articular surface, and splits the surface into the radial and ulnar cotylae. This divides the articular cartilage into an articular surface on the flexor portion, and the olecranon on the extensor portion. The intercotylar process fits into the olecranon fossa to restrict elbow joint extension. Dinosaurs and pterosaurs, phylogenetically bracketed by Crocodylia and Aves (birds), may have possessed a similar olecranon fossa and intercotylar process on their articular cartilages. Although these shapes are rarely recognizable on the bones, their impressions on the surfaces of the calcified cartilages provide an important indication of the extensor margin of the articular surfaces. This, in turn, helps to determine the maximum angle of extension of the elbow joint in archosaurs. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.
Composition and stability of soil aggregates in Fluvisols under forest, meadows, and 100 years of conventional tillage
Authors: Gajić Boško , Đurović Nevenka , Dugalić Goran
Published: April 2010

Conversion of meadow and forest ecosystems to agricultural land generally leads to changes in soil structure. This comparative study presents the composition and stability of structural aggregates in humus horizons (0–30 cm) of noncarbonate silty‐clay Fluvisols in the Kolubara River Valley, W Serbia. Aggregates collected from under a native forest were compared to aggregates from meadows and arable fields which underwent crop rotation for > 100 y. The results show that size distribution and stability of structural aggregates in the humus horizons of arable soil are significantly impaired due to long‐term anthropogenization. In the humus horizons, the content of the agronomically most valuable aggregates (0.25–10 mm) decreased by a factor of ≈ 2, from 68%–74% to 37%–39%, while the percentage of cloddy aggregates (>10 mm) increased by a factor of ≈ 2, from 23%–31% to 48%–62%, compared to forest aggregates. The long‐term‐arable soil had significantly (p < 0.05) lower aggregate stability, determined by wet sieving, than meadow and forest soils. The lowest aggregate stability was found in aggregates > 3 mm. Their content is ≈ 2.5–3 times lower in arable soil (13%–16%) than in forest soil (32%–42%) at a depth of 0–20 cm. The largest mean weight diameters of dry aggregates (dMWD) with a range between 12.6 and 14.7 mm were found in arable soil, vs. 9.5–9.9 mm in meadow and 6.5–8.3 mm in forest. The arable soil had significantly lower mean weight diameters of wet‐stable aggregates (wMWD) and a lower structure coefficient (Ks) than forest and meadow soils. The dispersion ratio (DR) of arable soil was significantly higher than that of forest and meadow soils. Forest and meadow showed a significantly higher soil organic‐matter content (SOM) by 74% and 39%, respectively, compared with arable soil, while meadow uses decreased the SOM content by 57% compared with forest at a depth of 0–10 cm. In conclusion, the results showed that long‐term conventional tillage of soils from natural forest and meadow in the lowland ecosystems of W Serbia degraded soil aggregate–size distribution and stability and reduced SOM content, probably resulting in lower productivity and reduced crop yields.
Modeling carbon dynamics in subsoils using simple models
Authors: Helfrich Mirjam , Flessa Heiner , Ludwig Bernard
Published: April 2010

Soil C dynamics below the plow layer have been little studied, despite a suspected large C‐stabilization potential of subsurface horizons. The objective of this study was to test two simple models (model A: single compartment for C3‐ and for C4‐derived C; model B: division of C3‐ and C4‐derived C into active and passive compartments) in their ability to simulate the C dynamics in subsoil horizons of a Haplic Phaeozem after conversion from C3 (rye) to C4 cropping (maize). The models were calibrated on an unfertilized maize soil and then validated on a maize soil with NPK fertilization. Both models simulated well C3‐C and C4‐C dynamics in the investigated soil depths (20–40 cm and 40–60 cm). In all cases, the model efficiency EF was > 0, which indicated that the simulated values described the trend in the measured data better than the mean of the observations. However, we observed some inconsistency in the obtained parameter set (e.g., a higher proportion of passive C for C4‐derived than for C3‐derived C or a very low decomposition rate constant for passive C4‐C in 40–60 cm), which we assume to result from data restrictions on the investigated soils. More detailed data on SOC pools and turnover rates in subsoils which are generally not yet available for most experimental plots is vitally needed—especially for applying more sophisticated C‐dynamics models.
Effects of a biomimetic iron‐porphyrin on soil respiration and maize root morphology as by a microcosm experiment
Authors: Gelsomino Antonio , Tortorella Demetrio , Cianci Vincenzo , Petrovičová Beatrix , Sorgonà Agostino , Piccolo Alessandro , Rosa Abenavoli Maria
Published: April 2010

A synthetic, water‐soluble iron‐porphyrin [meso‐tetra(2,6‐dichloro‐3‐sulfonatophenyl) porphyrinate of Fe(III) chloride] has recently been proposed as a biomimetic catalyst in the process of oxidative polymerization of terrestrial humic acids, to increase their conformational stability and thus contribute to a reduction of soil CO2 release into the atmosphere. This study was aimed at investigating changes in selected soil chemical properties, CO2 efflux, and maize root morpho‐topology after the addition of iron‐porphyrin as a microcosm‐style experiment, located in a greenhouse. The addition of mature compost was also included as an experimental factor in order to reveal synergistic effects in regard to freshly added organic materials. Iron‐porphyrin determined a negligible effect on soil organic budget in both unplanted and planted microcosms. Conversely, the biomimetic catalyst was found to have significant and contrasting effects on soil respiration, apparently reflecting different iron porphyrin–plant–compost interactions. Consequently, iron‐porphyrin significantly reduced CO2 efflux from the bare (unplanted) soil, which was, conversely, stimulated in maize‐planted microcosms. Additionally, combined iron‐porphyrin and compost addition synergistically acted in increasing soil respiration in planted microcosms. Moreover, root biomass was increased with the addition of iron‐porphyrin, and a further effect on maize root morphology was noted when used in combination with compost; notably the length of coarse and fine roots increased. We hypothesized that the efficacy of iron‐porphyrin in reducing CO2 efflux from soil may be mediated by morphological changes in the plant‐root system.
Comparison of critical limits for crop plant growth based on different indicators for the state of soil compaction
Authors: Kaufmann Manfred , Tobias Silvia , Schulin Rainer
Published: April 2010

Soil compaction affects physical soil condition, in particular aeration, soil strength, and water availability and has adverse effects on plant growth. Bulk density is the most frequently used indicator to describe the state of compaction of a soil. However, this parameter lacks a direct functional relationship with plant growth. Various indicators have been proposed to simultaneously characterize the state of compaction of agricultural soil and its suitability for plant growth. This paper examines and compares the critical limits for crop plant growth based on three of these indicators: packing density, least limiting water range, and S parameter (the latter is the slope of the soil water‐retention curve in the inflexion point). In a first step, we reviewed the literature for published optimum and limiting values of bulk density and found that these values were highly dependent on clay and silt content. Converting them into corresponding values of packing density (composite index of bulk density and clay content), a value of 1.70 was found to effectively distinguish between optimum and limiting soil conditions for plant growth. In a second step, the packing density of 59 soil horizons sampled in N Switzerland was compared with the least limiting water range and the S parameter of these soil horizons (both determined by means of pedotransfer functions taken from the literature). A linear relationship between the three parameters was found, which allowed for a comparison of the published critical limits for plant growth based on these parameters. The critical limits of the three indicators, which had been postulated independently of each other in the literature, were found to agree well with each other. This means that all of them could equally be used to describe the compaction state of a soil and its physical suitability for plant growth. However, the proposed critical limits of packing density, least limiting water range, and S parameter still need further validation by field studies relating plant growth to soil compaction.
Accumulation of cadmium, fluorine, magnesium, and zinc in soil after application of phosphate fertilizer for 31 years in a grazing trial
Authors: McGrath Dave , Tunney Hubert
Published: April 2010

Phosphate fertilizers are recognized as a potential source of elements that could contribute to soil pollution. The objective of this study was to determine the extent to which use of phosphate fertilizer in the past had resulted in an increase in heavy‐metal content in Irish soils. Samples were taken from a long‐term replicated (six replicates of 0.18 ha each) plot experiment with grazing cattle. Phosphate as superphosphate had been applied at two rates, 0 and 930 kg ha–1 total P, over a 31 y period. Phosphorus, pH, soil organic matter, Cd, F, Mg, and Zn were measured in 0–10 and 10–20 cm soil layers in addition to extractable P and Mg (Morgan's solution) and Zn (0.5M EDTA). Increases in the phosphate‐enriched soil were significant at p < 0.05 except for F at both soil layers and for Cd at the 10–20 cm layer (p < 0.1) Recoveries for P, Cd, and F were in fair agreement with application. High recoveries of total Mg and Zn were encountered which could not readily be explained. These increases were paralleled by increases in extractable‐soil‐test values for these elements. Accumulation in soil of P over the period was such as to now necessitate little application of this element to soil for the near future. At the same time, increase in soil Cd was small, little more than 0.05 mg kg–1 in soil, although it amounted to a sizable proportion of Cd in the soil. Similarly, increases in other elements, although real, would not lead to major concerns at the present time.
Effect of air‐drying on phosphorus fractions in clay soil
Authors: Soinne Helena , Räty Mari , Hartikainen Helinä
Published: April 2010

Despite the publication of a number of papers dealing with the effect of drying on the soil labile P pool, less attention has been paid to the possible drying‐evoked changes in the more stable P pools. We applied Hedley's sequential fractionation procedure that aims at quantifying soil P reserves according to their decreasing plant availability to examine the effects of drying on soil P fractions in clayey soil samples of different cultivation history. To further investigate the contribution of organic matter disruption to the solubility of soil P, the P extracted in each fractionation step was divided into two size classes by filtering the suspension through a 0.2 μm membrane filter. There were no air‐drying‐induced changes in the total amount of P extracted in each fractionation step. However, air‐drying changed the distribution of water‐extractable P in size fractions; increase in the small‐sized P took place at the expense of large‐sized P. Air‐drying increased also small‐sized molybdate‐unreactive P (MUP) in the NaOH fraction giving evidence that drying‐induced alterations take place also in less labile P forms. The results revealed that air‐drying alters the extractability and distribution of P in various pools rather than the total amount of extracted P and that a large proportion of H2O‐ and NaOH‐extractable large‐sized MUP may remain undetected if only filtered samples are analyzed.
Molecularly imprinted hydrogel displaying reduced non‐specific binding and improved protein recognition
Authors: Tov Ortal Yom , Luvitch Shlomit , Bianco‐Peled Havazelet
Published: April 2010

A novel approach for enhancing protein recognition in molecularly imprinted hydrogel (MIH) is presented. This approach was developed based on the hypothesis that the number of specific binding sites created in the previously described MIH is very small, thus attempts to enhance the capacity result in most cases in additional non‐specific binding and loss of selectivity. Thus, blocking the non‐specific binding sites could lead to higher capacities and better selectivity. To test this hypothesis, MIH interpenetrating networks designed to block non‐specific binding sites were synthesized using two separate stages of polymerization. Re‐binding of the template protein (lysozyme) and a competitor protein (cytochrome C) was measured, and the results were compared with the similar experiment performed using a control non‐imprinted hydrogel and a “conventional” MIH. The imprinting efficacy of the MIH interpenetrating network was found to be much higher than that of the controls. Furthermore, competitive adsorption assays have demonstrated the superiority of the new formulation.
Attributes affecting the level of tourist satisfaction with and loyalty towards theatrical performance in China: Evidence from a qualitative study
Authors: Song Hanqun , Cheung Catherine
Published: April 2010

This study seeks to explore attributes affecting the level of tourist satisfaction with and loyalty towards theatrical performance in China. Based on four focus group discussions with 31 participants, the study identifies 34 attributes that affect the level of tourist satisfaction with theatrical performance, and groups them into five categories: stage, performance, venue, service and tourist‐related attributes. The findings on tourist loyalty reveal that 21 of the 31 respondents would not watch the same theatrical performance alone in the future; however, they would recommend it to others. The study concludes with a discussion of the rich and insightful findings and their implications for tourism industry practitioners. Copyright © 2010 John Wiley & Sons, Ltd.
The (193–209) 17‐residues peptide of bovine β‐casein is transported through Caco‐2 monolayer
Authors: Regazzo Daniela , Mollé Daniel , Gabai Gianfranco , Tomé Daniel , Dupont Didier , Leonil Joëlle , Boutrou Rachel
Published: April 2010

Although the bioavailability of large peptides with biological activity is of great interest, the intestinal transport has been described for peptides up to only nine residues. β‐casein (β‐CN, 193–209) is a long and hydrophobic peptide composed of 17 amino acid residues (molecular mass 1881 Da) with immunomodulatory activity. The present work examined the transport of the β‐CN (193–209) peptide across Caco‐2 cell monolayer. In addition, we evaluated the possible routes of the β‐CN (193–209) peptide transport, using selective inhibitors of the different routes for peptide transfer through the intestinal barrier. The results showed that the β‐CN (193–209) peptide resisted the action of brush‐border membrane peptidases, and that it was transported through the Caco‐2 cell monolayer. The main route involved in transepithelial transport of the β‐CN (193–209) peptide was transcytosis via internalized vesicles, although the paracellular transport via tight‐junctions could not be excluded. Our results demonstrated the transport of an intact long‐chain bioactive peptide in an in vitro model of intestinal epithelium, as an important step to prove the evidence for bioavailability of this peptide.
Changes in arterial blood pressure after single oral administration of milk‐casein‐derived peptides in spontaneously hypertensive rats
Authors: Miguel Marta , Gómez‐Ruiz José Ángel , Recio Isidra , Aleixandre Amaya
Published: April 2010

In this study we evaluated the short‐term oral antihypertensive effect of several peptide sequences isolated from casein fractions, previously characterized as in vitro angiotensin‐converting enzyme‐inhibitors, in spontaneously hypertensive rats (SHR). Systolic blood pressure (SBP) and the diastolic blood pressure (DBP) of the rats were measured by the tail cuff method before administration and also 2, 4, 6, 8 and 24 h post‐administration. The sequences LVYPFTGPIPN, HLPLP, IAK, YAKPVA and WQVLPNAVPAK showed a clear decrease in SBP and DBP in SHR. HPHPHLSF caused a significant decrease of the DBP in the SHR, but this sequence did not modify the SBP of these animals in a significant manner. KKYNVPQL did not modify SBP in the SHR, and caused a slight, but significant and maintained, decrease in DBP in these animals. SBP and DBP returned to baseline values 24 h post‐administration of all peptides. In conclusion, these peptides are bioactive ingredients with potential benefit in the prevention and treatment of hypertension or other associated disorders.
Inhibitory effects of 5‐hydroxy polymethoxyflavones on colon cancer cells
Authors: Qiu Peiju , Dong Ping , Guan Huashi , Li Shiming , Ho Chi‐Tang , Pan Min‐Hsiung , McClements David Julian , Xiao Hang
Published: April 2010

Hydroxylated polymethoxyflavones (PMFs) are a class of novel flavonoid compounds mainly found in citrus plants. We studied the effects of three major 5‐hydroxy PMFs, namely: 5‐hydroxy‐6,7,8,3′,4′‐pentamethoxyflavone, 5‐hydroxy‐3,6,7,8,3′,4′‐hexamethoxyflavone, and 5‐hydroxy‐6,7,8,4′‐tetramethoxyflavone, on human colon cancer HCT116 and HT29 cells. Their effects were compared with those produced by their permethoxylated counterparts, namely: nobiletin, 3,5,6,7,8,3′,4′‐heptamethoxylflavone, and tangeretin. 5‐Hydroxy PMFs showed much stronger inhibitory effects on the growth of the colon cancer cells in comparison with their permethoxylated counterparts, suggesting the pivotal role of hydroxyl group at 5‐position in the enhanced inhibitory activity by 5‐hydroxy PMFs. Flow cytometry analysis demonstrated that three 5‐hydroxy PMFs produced different effects on the cell cycle and apoptosis, which may suggest that three 5‐hydroxy PMFs act through different mechanisms. For example, 5‐hydroxy‐6,7,8,3′,4′‐pentamethoxyflavone caused cell cycle arrest at G2/M phase in HT29 cells, while 5‐hydroxy‐3,6,7,8,3′,4′‐hexamethoxyflavone led to significant G0/G1 phase arrest. In contrast, 5‐hydroxy‐6,7,8,4′‐tetramethoxyflavone increased sub‐G0/G1 cell population, which has been confirmed to be due to enhanced apoptosis. Our results further demonstrated that the inhibitory effects of 5‐hydroxy PMFs were associated with their ability in modulating key signaling proteins related to cell proliferation and apoptosis, such as p21Cip1/Waf1, CDK‐2, CDK‐4, phosphor‐Rb, Mcl‐1, caspases 3 and 8, and poly ADP ribose polymerase (PARP).
Buffer layers and transparent conducting oxides for chalcopyrite Cu(In,Ga)(S,Se)2based thin film photovoltaics: present status and current developments
Authors: Naghavi N. , Abou‐Ras D. , Allsop N. , Barreau N. , Bücheler S. , Ennaoui A. , Fischer C.‐H. , Guillen C. , Hariskos D. , Herrero J. , Klenk R. , Kushiya K. , Lincot D. , Menner R. , Nakada T. , Platzer‐Björkman C. , Spiering S. , Tiwari A.N. , Törndahl T.
Published: April 2010

The aim of the present contribution is to give a review on the recent work concerning Cd‐free buffer and window layers in chalcopyrite solar cells using various deposition techniques as well as on their adaptation to chalcopyrite‐type absorbers such as Cu(In,Ga)Se2, CuInS2, or Cu(In,Ga)(S,Se)2. The corresponding solar‐cell performances, the expected technological problems, and current attempts for their commercialization will be discussed. The most important deposition techniques developed in this paper are chemical bath deposition, atomic layer deposition, ILGAR deposition, evaporation, and spray deposition. These deposition methods were employed essentially for buffers based on the following three materials: In2S3, ZnS, Zn1 − xMgxO. Copyright © 2010 John Wiley & Sons, Ltd.
Microcrystalline silicon solar cells: effect of substrate temperature on cracks and their role in post‐oxidation
Authors: Python M. , Dominé D. , Söderström T. , Meillaud F. , Ballif C.
Published: April 2010

Microcrystalline silicon (µc‐Si:H) cells can reach efficiencies up to typically 10% and are usually incorporated in tandem micromorph devices. When cells are grown on rough substrates, “cracks” can appear in the µc‐Si:H layers. Previous works have demonstrated that these cracks have mainly detrimental effects on the fill factor and open‐circuit voltage, and act as bad diodes with a high reverse saturation current. In this paper, we clarify the nature of the cracks, their role in post‐oxidation processes, and indicate how their density can be reduced. Regular secondary ion mass spectrometry (SIMS) and local nano‐SIMS measurements show that these cracks are prone to local post‐oxidation and lead to apparent high oxygen content in the layer. Usually the number of cracks can be decreased with an appropriate modification of the substrate surface morphology, but then, the required light scattering effect is reduced due to a lower roughness. This study presents an alternative/complementary way to decrease the crack density by increasing the substrate temperature during deposition. These results, also obtained when performing numerical simulation of the growth process, are attributed to the enhanced surface diffusion of the adatoms at higher deposition temperature. We evaluate the cracks density by introducing a fast method to count cracks with good statistics over approximately 4000 µm of sample cross‐section. This method is proven to be useful to quickly visualize the impact of substrate morphology on the density of cracks in microcrystalline and in micromorph devices, which is an important issue in the manufacturing process of modules. Copyright © 2010 John Wiley & Sons, Ltd.
Four‐junction solar cells using lattice‐matched II–VI and III–V semiconductors
Authors: Wu S.‐N. , Ding D. , Johnson S. R. , Yu S.‐Q. , Zhang Y.‐H.
Published: April 2010

Four‐junction solar cells are designed using lattice‐matched II–VI (ZnCdSeTe) and III–V (AlGaAsSb) semiconductors grown on GaSb substrates. These materials have a zinc blende crystal structure, similar thermal expansion coefficients, and bandgaps that cover the entire solar spectrum. Numerical simulations of the energy conversion efficiencies of various designs for both the AM0 and AM1.5D spectra are performed using published material parameters. These results indicate that the achievable 1 sun AM0 efficiency is 43% for an optimal design and 40% for a more practical design; for comparison the ideal limit provided by Henry's model is 49%. While for the AM1.5D spectrum an optimal design can reach 46% under 1 sun and 55% under 1000 suns while a more practical design can reach 44 and 54%, respectively; for comparison Henry's model gives 51 and 62%, respectively. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of precursor layer ablation on laser doping of silicon
Authors: Köhler J. R. , Eisele S.
Published: April 2010

This paper presents a numerical model, which quantitatively demonstrates that ablation and partial recondensation of the dopant precursor layer are some of the dominating physical processes in laser doping (LD) of crystalline silicon. Our pulsed LD process uses a line focused laser beam, enabling the creation of solar cell emitters without the generation of dislocations, if the width w of the short axis of the line focus is w < 10 μm. The concentration profiles of the dopant atoms strongly depend on the pulse energy density Ep, the pulse to pulse separation Δx and the number of laser scans Ns. By comparing measured with modeled concentration profiles, we are able to evaluate the ablation width as well as the amount of the ablated precursor layer. In case of a sputtered phosphorus precursor layer, the ablation width wa is wa = 6 μm, whereas the width of the molten silicon layer wm is wm = 5 μm. The model also explains the dependence of experimental dopant concentration profiles on the number of subsequent laser scans Ns and pulse to pulse separation Δx. Copyright © 2010 John Wiley & Sons, Ltd.
Parallel‐connected monolithic dye‐sensitised solar modules
Authors: Pettersson Henrik , Gruszecki Tadeusz , Schnetz Christine , Streit Micha , Xu Yunhua , Sun Licheng , Gorlov Mikhail , Kloo Lars , Boschloo Gerrit , Häggman Leif , Hagfeldt Anders
Published: April 2010

Light‐soaking and high‐temperature storage testing of monolithic dye‐sensitised solar modules with total area module efficiencies above 5% have been performed. Our experiences from the development of a four‐layer monolithic dye‐sensitised solar test cell for comparative testing of material components for dye‐sensitised solar cells have directed our module development to a novel device design consisting of parallel‐connection of individual monolithic cells. The results from the accelerated testing of the modules (total area of 17.0 cm2) with four parallel‐connected cells (active area of 3.38 cm2/cell) are equivalent to those obtained for the monolithic single test cells when using identical device components. The successful transfer from cell to module stability is an important milestone in our ambition to develop a low‐cost Photovoltaic (PV) technology. Moreover, our results indicate that intensified research and development to define the procedures for relevant accelerated testing of dye‐sensitised solar modules is urgently required. Copyright © 2010 John Wiley & Sons, Ltd.
Lambertian matched absorption enhancement in PECVD poly‐Si thin film on aluminum induced textured glass superstrates for solar cell applications
Authors: Jin Guangyao , Widenborg Per I. , Campbell Patrick , Varlamov Sergey
Published: April 2010

This paper examines the effectiveness of a range of aluminum induced textured (AIT) glass topographies at enhancing light absorption in silicon thin film diode structures deposited on the textured glass side, operating in the superstrate configuration. The aluminum layer used to produce the AIT can be deposited either by thermal evaporation or magnetron sputtering. Varying AIT process parameters produces a wide range of feature roughness and uniformity, providing scope to optimize texture effectiveness and process repeatability. We report strong correlation between the degree of absorption enhancement from these textures and both dark field microscope images of the AIT glass and reduction of the interference envelope in spectral reflectance of the deposited silicon films. Our findings corroborate earlier modeling work based on ray tracing, which predicted that the best enhancement occurs when the feature size is close to the film thickness. In this paper we investigate AIT samples in the 1 – 3 µm film thickness range, some of which trap light in silicon as strongly as at the Lambertian limit. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐state conformational equilibrium in the Par‐4 leucine zipper domain
Authors: Schwalbe Martin , Dutta Kaushik , Libich David S. , Venugopal Hariprasad , Claridge Jolyon K. , Gell David A. , Mackay Joel P. , Edwards Patrick J. B. , Pascal Steven M.
Published: April 2010

Prostate apoptosis response factor‐4 (Par‐4) is a pro‐apoptotic and tumor‐suppressive protein. A highly conserved heptad repeat sequence at the Par‐4 C‐terminus suggests the presence of a leucine zipper (LZ). This C‐terminal region is essential for Par‐4 self‐association and interaction with various effector proteins. We have used nuclear magnetic resonance (NMR) spectroscopy to fully assign the chemical shift resonances of a peptide comprising the LZ domain of Par‐4 at neutral pH. Further, we have investigated the properties of the Par‐4 LZ domain and two point mutants under a variety of conditions using NMR, circular dichroism (CD), light scattering, and bioinformatics. Results indicate an environment‐dependent conformational equilibrium between a partially ordered monomer (POM) and a predominantly coiled coil dimer (CCD). The combination of techniques used allows the time scales of the equilibrium to be probed and also helps to identify features of the amino acid sequence that may influence the equilibrium. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Structure and interactions of the C‐terminal metal binding domain of Archaeoglobus fulgidus CopA
Authors: Agarwal Sorabh , Hong Deli , Desai Nirav K. , Sazinsky Matthew H. , Argüello José M. , Rosenzweig Amy C.
Published: April 2010

The Cu+‐ATPase CopA from Archaeoglobus fulgidus belongs to the P1B family of the P‐type ATPases. These integral membrane proteins couple the energy of ATP hydrolysis to heavy metal ion translocation across membranes. A defining feature of P1B‐1‐type ATPases is the presence of soluble metal binding domains at the N‐terminus (N‐MBDs). The N‐MBDs exhibit a conserved ferredoxin‐like fold, similar to that of soluble copper chaperones, and bind metal ions via a conserved CXXC motif. The N‐MBDs enable Cu+ regulation of turnover rates apparently through Cu‐sensitive interactions with catalytic domains. A. fulgidus CopA is unusual in that it contains both an N‐terminal MBD and a C‐terminal MBD (C‐MBD). The functional role of the unique C‐MBD has not been established. Here, we report the crystal structure of the apo, oxidized C‐MBD to 2.0 Å resolution. In the structure, two C‐MBD monomers form a domain‐swapped dimer, which has not been observed previously for similar domains. In addition, the interaction of the C‐MBD with the other cytoplasmic domains of CopA, the ATP binding domain (ATPBD) and actuator domain (A‐domain), has been investigated. Interestingly, the C‐MBD interacts specifically with both of these domains, independent of the presence of Cu+ or nucleotides. These data reinforce the uniqueness of the C‐MBD and suggest a distinct structural role for the C‐MBD in CopA transport. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Growth of pattern‐free InN micropyramids by metalorganic chemical vapor deposition
Authors: Jamil Muhammad , Xu Tianming , Zaidi Tahir , Melton Andrew , Jampana Balakrishnam , Tan Chee‐Loon , Ooi Boon S. , Ferguson Ian T.
Published: April 2010

We report on the growth of unidirectional InN micropyramids by using a simple pattern‐free epitaxial technique. These pyramids were grown on a GaN layer deposited on sapphire via metalorganic chemical vapor deposition (MOCVD). The XRD full width at half maximum (FWHM) was observed to be as low as 0.16° for the InN (0002)ωrocking curve which indicates very good crystal quality of these InN pyramids. The Photoluminescence (PL) emission of InN micropyramids is ∼0.78 eV. The dependency on growth conditions of pyramid density, facet stabilization, and pyramid structural quality have been evaluated and discussed.