julilili42/papers huggingface dataset:
Correlations between sex rate estimates and fitness across predominantly parthenogenetic flatworm populations
2007-11-07

Abstract One explanation for the success of sexual reproduction is that sex increases the efficacy of natural selection. Recombination and segregation lead to fitness variance among offspring which then offers a wider target for natural selection. Consequently, adaptation to changing environments is accelerated and population mean fitness will increase. We investigated whether low levels of sex are associated with increased fitness variance and mean in parthenogenetic biotypes of the planarian flatworm Schmidtea polychroa . Parthenogenetic S. polychroa are triploid and reproduce clonally with occasional sexual reproduction. By‐products and measures of occasional sex are the local presence of tetraploids and elevated levels of genotypic diversity. We correlated the proportion of tetraploids and genotypic diversity with fitness attributes of six genetically differentiated locations within one meta‐population. Results indicate strong, positive correlations with variance and with mean offspring number produced during a 5‐week period. The ecological and evolutionary implications for the maintenance of parthenogenetic S. polychroa are discussed.
Human epithelial cells establish direct antifungal defense through TLR4-mediated signaling
2007-11-08

Mammalian TLRs are central mediators of the innate immune system that instruct cells of the innate and adaptive response to clear microbial infections. Here, we demonstrate that human epithelial TLR4 directly protected the oral mucosa from fungal infection via a process mediated by polymorphonuclear leukocytes (PMNs). In an in vitro epithelial model of oral candidiasis, the fungal pathogen Candida albicans induced a chemoattractive and proinflammatory cytokine response but failed to directly modulate the expression of genes encoding TLRs. However, the addition of PMNs to the C. albicans-infected model strongly upregulated cytoplasmic and cell-surface epithelial TLR4 expression, which correlated directly with protection against fungal invasion and cell injury. C. albicans invasion and cell injury was restored by the addition of TLR4-specific neutralizing antibodies and knockdown of TLR4 using RNA interference, even in the presence of PMNs, demonstrating the direct role of epithelial TLR4 in the protective process. Furthermore, treatment with neutralizing antibodies specific for TNF-alpha resulted in strongly reduced TLR4 expression accompanied by augmented epithelial cell damage and fungal invasion. To our knowledge, this is the first description of such a PMN-dependent, TLR4-mediated protective mechanism at epithelial surfaces, which may provide significant insights into how microbial infections are managed and controlled in the oral mucosa.
Safety, penetration and efficacy of topically applied bevacizumab: evaluation of eyedrops in corneal neovascularization after chemical burn
2007-11-08

Abstract. Purpose: That vascular endothelial growth factor (VEGF) plays a major role in inflammatory angiogenesis has been well established. This pilot study was designed to evaluate experimental treatment with bevacizumab eyedrops in corneal neovascularization induced by alkali burn. The feasibility of topical administration, corneal cell viability and corneal penetration were investigated in an animal model. Methods: Eighteen chinchilla bastard rabbit corneas injured with 1 m NaOH were divided into three groups: untreated, early and late treatment groups. Eyedrops of bevacizumab solution (25 mg/ml) were administered five times daily. Clinical examination under stereoscopic microscope was performed to evaluate corneal opacity, neovascularization, vessel size and oedema. Histopathology was analysed for vessel density and apoptotic reaction. Additionally, intracameral bevacizumab concentration was measured with enzyme‐linked immunosorbent assay (ELISA) after repeated topical applications. Results: A fast increase in aqueous bevacizumab concentration was achieved when the solution was instilled every minute onto a healthy eye surface. As well as clear anti‐angiogenic effects, anti‐fibrotic effects were also seen after corneal burn, maintaining corneal transparency. Early treatment of actively growing vessels showed a significantly better outcome, although apoptosis of pre‐existing vessels could also be induced by the late treatment. No specific toxicity was seen regarding epithelium, keratocytes or endothelium. Conclusions: The data from this pilot study suggest that bevacizumab eyedrops can sufficiently penetrate the corneal stroma and anterior chamber. When administered soon after alkali burn, bevacizumab seems to significantly reduce corneal damage. Combinations of established treatment regimens with topical bevacizumab might be considered in severe injuries with otherwise devastating prognoses.
The onset and origin of differentiated Rhine Graben volcanism based on U-Pb ages and oxygen isotopic composition of zircon
2007-11-08

Ion microprobe U-Pb zircon ages for late (phase II) syenite dikes of the Katzenbuckel (SW Germany) average 69.6 ± 1.9 Ma (mean square of weighted deviates MSWD =0.36; number of spot analyses n =9; 2σ error) and represent a minimum age for the emplacement of earlier, volumetrically dominant phonolites and nepheline syenites (phase I). This age is ~ 13 and 6 Ma older than previously published K-Ar whole-rock and bulk biotite ages for phase I rocks, respectively. Because of close chemical affinities in magma composition and the small volume of the Katzenbuckel subvolcanic intrusion, zircon crystallization in phase II syenite dikes presumably only shortly postdates phase I magmatism. Trachytes from the Northern Upper Rhine Graben (Sprendlinger Horst, Wetterau) yielded similar U-Pb zircon ages of 68.1 ± 1.4 Ma (MSWD =2.2) and 70.3 ± 1.6 Ma (MSWD =0.4), respectively. Zircon oxygen isotopic ratios of Katzenbuckel indicate primitive mantle-like compositions, whereas Sprendlinger Horst and Wetterau trachytes zircons show minor crustal contamination. The investigated differentiates rank among the oldest known post-Permian igneous rocks in the Northern foreland of the Alpine collisional belt, and are contemporaneous with recently dated lamprophyres in the Northern Rhine Graben area. This suggests that a short (<1–2 Ma) but regionally widespread magmatic pulse occurred along the E and NE flanks of the nascent Rhine Graben rift as early as Late Maastrichtian.
Prototropic rearrangements in cycloheptatrienyl PCP pincer iridium complexes
2007-11-09

When the cycloheptatriene iridium(iii) pincer complex (PCP)Ir(CO)(H)(Cl) (3) (PCP = 2,7-(CH(2)P(t)Bu(2))(2)C(7)H(5)) is treated with the bases NaH, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and lithium 2,2,6,6-tetramethylpiperidide (LiTMP) under various conditions different products are obtained. At elevated temperatures and with DBU or LiTMP as a base the trans dihydride (PCP')Ir(CO)(H)(2) (PCP' = 2-(CHP(t)Bu(2))-7-(CH(2)P(t)Bu(2))C(7)H(4)) (5) is formed where the pi-system extends into one of the phosphine bridges. This compound loses H(2) to give the square-planar iridium(I) carbonyl complex (PCP'IrCO). The dihydride 5 can also rearrange to the new isomeric iridium(I) carbonyl 6 (PCP''IrCO, PCP'' = 2,7-(CH(2)P(t)Bu(2))(2)C(7)H(5)). Thus the two hydrides have moved into the ligand backbone creating a methylene group in the 3-position of the cycloheptatriene ring. Alternatively, 6 is formed by a rearrangement from 6a which differs from 6 by having the methylene group in the 4-position of the cycloheptatriene ring. The iridium(I) carbonyl 6a in turn is made from 3 by treatment with DBU at room temperature. Interestingly, when compound is heated to reflux in THF the hydrogen bound at the metal carbon is shifted to a carbon atom in the cycloheptatriene ring generating a ring methylene group (3a). From this complex HCl is eliminated upon chromatography forming 6 as the final product. Quantum chemical calculations at various levels of theory illustrate the relative energetic stabilities of all iridium complexes.
The Search for Objective Criteria at the Limit of Viability
2007-11-09

&lt;i&gt;Background:&lt;/i&gt; Defining the limit of viability among very preterm infants remains a difficult issue. A recent study suggested severity of intrauterine growth retardation as a decisive criterion, reporting very poor survival for infants born at ≤28 weeks with birth weight &lt;2nd centile. &lt;i&gt;Objective:&lt;/i&gt; To check whether the above criterion can be confirmed in a similar analysis of German data. &lt;i&gt;Methods:&lt;/i&gt; Analyses were based on German population-based data from Lower Saxony, including preterm neonates (22–28 weeks) without severe congenital malformations (n = 3,453), born 1991–1999. For the definition of growth retardation postnatal (&lt;3rd, &lt;10th centile) and antenatal (&lt;3rd centile) reference values were used. &lt;i&gt;Results:&lt;/i&gt; Depending on the definition used, proportions of growth retarded infants varied considerably (4–16%). Survival rates increased from 0 to 64%, arguing against considering infants &lt;28 weeks’ GA as a homogenous group with regard to their odds for survival. &lt;i&gt;Conclusion:&lt;/i&gt; There is an association between severity of growth retardation and VLBW mortality in general, but overinterpreting results from single studies may lead to dangerous conclusions. Data from preterm infants should be stratified by week of gestation.
Amino-closo-dodecaborate—a new ligand in coordination chemistry
2007-11-12

The synthesis and characterization of three ruthenium complexes [Bu(3)MeN][Ru(PPh(3))(2)(NH(2)-B(12)H(11))Cl], [Bu(4)N][Ru(dppb)(NH(2)-B(12)H(11))Cl] and [RuCO(PPh(3))(2)(NH(2)-B(12)H(11))] with amino-closo-dodecaborate as the coordinating ligand are described.
Linear‐scaling Cholesky decomposition
2007-11-12

Abstract We present linear‐scaling routines for the calculation of the Cholesky decomposition of a symmetric positive‐definite matrix and its inverse. As an example, we consider the inversion of the overlap matrix of DNA and amylose fragments as well as of linear alkanes, where the largest system corresponds to a 21,442 × 21,442 matrix. The efficiency and the scaling behavior are discussed and compared to standard LAPACK routines. Our Cholesky routines are publicly available on the web. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Curcumin downregulates the inflammatory cytokines CXCL1 and -2 in breast cancer cells via NFκB
2007-11-13

The dietary antioxidant Curcumin has been proposed for cancer chemoprevention since it induces apoptosis and inhibits the formation of breast cancer metastases. Curcumin acts through the inhibition of phosphorylation of the inhibitor of kappa B (IkappaB), which in turn reduces the nuclear translocation of nuclear factor kappa B (NFkappaB), an inflammation- and cell survival-related transcription factor. However, it is not clear whether the strong antimetastatic effect can exclusively be explained by inhibition of NFkappaB. Here, we addressed the effects of Curcumin (IC(50) = 17 muM) in MDA-MB-231 breast cancer cells using microarray gene expression analyses. Among the 62 genes whose expression was significantly altered, we found the two inflammatory cytokines CXCL1 and -2 (Groalpha and -beta) that were downregulated. Further validation of the microarray results by quantitative real-time reverse transcription-polymerase chain reaction, western blots and enzyme-linked immunosorbent assay revealed that Curcumin impairs transcription of CXCL1 and -2 >24 h and reduces the corresponding proteins. Using small interfering RNA techniques, we elucidated the underlying molecular mechanism revealing that reduction of CXCL1 and -2 messenger RNA levels is NFkappaB dependent and requires intact IkappaBalpha expression. Moreover, CXCL1 and -2 silencing leads to downregulation of several metastasis-promoting genes among which we found the cytokine receptor CXCR4. We therefore suggest that the decrease of CXCL1 and -2 mediated by Curcumin is involved in the inhibition of metastasis.
Late Pleistocene human remains from Wezmeh Cave, western Iran
2007-11-13

Abstract Paleontological analysis of remains from Wezmeh Cave in western Iran have yielded a Holocene Chalcolithic archeological assemblage, a rich Late Pleistocene carnivore faunal assemblage, and an isolated unerupted human maxillary premolar (P 3 or possibly P 4 ). Species representation and U‐series dating of faunal teeth place the carnivore assemblage during oxygen isotope stages (OIS) 3 and 2, and noninvasive gamma spectrometry dating of the human premolar places it at least as old as early OIS 2. The human premolar crown morphology is not diagnostic of late archaic versus early modern human affinities, but its buccolingual diameter places it at the upper limits of Late Pleistocene human P 3 and P 4 dimensions and separate from a terminal Pleistocene regional sample. Wezmeh Cave therefore provides additional Paleolithic human remains from the Zagros Mountains and further documents Late Pleistocene human association with otherwise carnivore‐dominated cave assemblages. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Management of late recurrence of a low-grade endometrial stromal sarcoma (LGESS): treatment with letrozole.
2007-11-13

Low grade endometrial stromal sarcoma (LGESS) is a rare disease. LGESS usually expresses steroidal receptors and is regarded to be hormone-sensitive. Due to the rarity of the tumor, only few case series have been published so far. Here, we report the case of a 36-year-old woman who underwent an abdominal hysterectomy with bilateral salpingo-oophorectomy and adjuvant radiotherapy for a G1 LGESS in 1991. Twelve years later she presented to us with pelvic and peritoneal masses. The patient was treated with letrozole achieving a partial response which is lasting 39 months. Treatment is ongoing. Aromatase inhibitors represent an interesting treatment option for LGESS.
A new fixation aid for the radiotherapy of eye tumors
2007-11-14

A modified swim goggle holding a light spot as an optical guide for actively aligning the eye in a reproducible orientation has been constructed to perform radiotherapy of ocular tumors. This device is compatible with computed tomography (CT) and magnetic resonance imaging systems. Image fusion of these data sets yielded clinically acceptable results. The reproducibility of the eye's positioning is tested by repeated CT. The eye's alignment during radiotherapy is monitored by an infrared TV camera with individual markings of the eye's position on the TV‐monitor screen. From 2003–2006, 50 patients were treated with this fixation aid by radiosurgery with good patient compliance.
2-(6-Amino-7H-purin-7-yl)-1-phenylethanone
2007-11-14

In the title compound, C13H11N5O, the exocyclic amino group of one purine molecule forms two intermolecular N—H⋯N hydrogen bonds to different ring N atoms of another molecule. The purine system is orientated almost perpendicular [77.96 (6)°] to the phenylethanone substituent. The preparation of the title compound occurred via a regioselective synthesis using the methyl(aqua)cobaloxime complex CH3Co(DH)2OH2 as a temporary auxiliary, and its X-ray crystal structure confirmed the regioselective N-alkylation of this molecule.
Wide-Range Multiwavelength Observations of Northern TeV Blazars With MAGIC / HESS, Suzaku And KVA
2007-11-14

We have conducted multiwavelength observations of several northern TeV blazars employing the ground-based {gamma}-ray observatories MAGIC and HESS, the optical KVA telescope, and the Suzaku X-ray satellite. The data taken in 2006 establish measurements of the contemporaneous spectral energy distributions of the rapidly variable blazar emission over a wide range of frequencies. Results allow us to test leptonic and hadronic emission and particle acceleration models which predict different correlations between the optical, X-ray, and very high energy {gamma}-ray emissions. In this presentation, we report on the highlights of the results of these observations.
Involvement of decreased Galectin‐3 expression in the pathogenesis and progression of prostate cancer
2007-11-15

Abstract BACKGROUND Altered expression or loss of function of Galectin‐3 (Gal‐3) was suggested to be involved in the pathogenesis and progression of various human cancer entities. The aim of the present study is to determine the expression of Gal‐3 in prostate tissue emerging from a benign to a malignant, in the beginning hormone‐sensitive and finally hormone‐refractory status to further elucidate the role of this carbohydrate‐binding protein for the pathogenesis and/or progression of malignant prostatic disease. MATERIALS AND METHODS Five hundred and eighty three tissue samples from malignant, tumor adjacent benign, and histologically benign intra‐prostatic areas, retrieved out of 25 whole mounted prostate cancer (CaP) specimens and additional 95 samples of hormone‐refractory CaP, were processed to tissue microarrays. Immunohistochemical Gal‐3 expression was correlated with clinicopathological parameters among the different tissue entities. RESULTS Gal‐3 expression was significantly decreased in the hormone‐sensitive CaP specimens when compared with the respective benign tissue either localized far distant from the malignant lesion ( P &lt; 0.0001, Wilcoxon test) or directly neighboring the primary tumor ( P &lt; 0.0001). The staining reaction in the benign tissue areas directly neighboring the primary cancerous lesions differed significantly from the benign glands localized distant from the primary tumors ( P &lt; 0.001). A statistically highly significant, almost complete loss of Gal‐3 was observed in the hormone‐refractory when compared with the hormone‐sensitive tumors ( P &lt; 0.0001; mean staining score: 27.7% vs. 8.5%). CONCLUSIONS The present investigation clearly indicates decreased expression of Gal‐3 to be substantially involved in the pathogenesis and further progression of CaP from benign prostate glands to a finally hormone‐refractory malignant disease. Prostate 68: 72–77, 2008. © 2007 Wiley‐Liss, Inc.
Interferon-γ and tumor necrosis factor-α sensitize primarily resistant human endometrial stromal cells to Fas-mediated apoptosis
2007-11-15

The subtle interaction between the implanting embryo and the maternal endometrium plays a pivotal role during the process of implantation. Human endometrial stromal cells (ESCs) express Fas and the implanting trophoblast cells secrete Fas ligand (FASLG, FasL), suggesting a possible role for Fas-mediated signaling during early implantation. Here we show that ESCs are primarily resistant to Fas-mediated apoptosis independently of their state of hormonal differentiation. Pre-treatment of ESCs with interferon (IFN)-γ and tumor necrosis factor (TNF)-α sensitizes them to become apoptotic upon stimulation of Fas by an agonistic anti-Fas antibody. Incubation of ESCs with the early embryonic signal human chorionic gonadotropin (hCG, CGB) does not influence their reaction to Fas stimulation. The sensitizing effect of IFN-γ and TNF-α was accompanied by a significant upregulation of Fas and FLICE-inhibitory protein (FLIP, CFLAR) expression in ESCs. Additionally, we observed an activation of caspase 3, caspase 8 and caspase 9 upon apoptotic Fas triggering. In summary, we demonstrate that IFN-γ and TNF-α sensitize primarily apoptosis-resistant ESCs to Fas-mediated cell death. This might be due to an upregulation of Fas expression, and apoptosis seems to be mediated by active caspase 3, caspase 8 and caspase 9. The observed pro-apoptotic effect of IFN-γ and TNF-α on ESCs could play an important role in the modulation of early implantation.
Perception and Understanding of Others' Actions and Brain Connectivity
2007-11-15

Abstract Perception and understanding of dispositions and intentions of others through their actions are of immense importance for adaptive daily-life behavior and social communication. Here we ask whether, and, if so, how this ability is impaired in adolescents who were born premature and suffer early periventricular damage, periventricular leukomalacia (PVL) that affects brain connectivity. The visual event arrangement (EA) task was administered to PVL patients and two control groups, premature-born and term-born adolescents without brain abnormalities on a magnetic resonance imaging scan. Performance on the EA task was significantly lower in PVL patients as compared with controls. No difference was found between premature-born participants without lesions and term-born controls. Performance on the EA task was inversely related to the volumetric extent of lesions in the parieto-occipital regions of both hemispheres and, in particular, to the right temporal periventricular lesions. Whereas our earlier work reveals that compromised visual processing of biological motion, impairments in visual navigation, and other visual-perceptual disabilities in PVL patients are associated with parieto-occipital lesions, difficulties in the visual EA task solely are specifically linked to the right temporal periventricular lesions. For the first time, we show that the severity of the right temporal PVL can serve as a predictor of the ability for perception and understanding of others' actions. We assume that impairments in this ability in PVL patients are caused by disrupted brain connectivity to the right temporal cortex, a key node of the social brain.
Comment on “Dynamics of nuclear fluid. VIII. Time-dependent Hartree-Fock approximation from a classical point of view”
2007-11-15

The phase-space paths introduced by Cheuk-Yin Wong in Phys. Rev.C25, 1460 (1982) and discussed recently in the literature can be used for calculation of evolution of the Wigner function to first order in the time increments only. The first-order solutions are helpful to determine the phase-space Green function in the framework of the phase-space path integral method.
Optical properties of pentacene and perfluoropentacene thin films
2007-11-16

The optical properties of pentacene (PEN) and perfluoropentacene (PFP) thin films on various SiO2 substrates were studied using variable angle spectroscopic ellipsometry. Structural characterization was performed using x-ray reflectivity and atomic force microscopy. A uniaxial model with the optic axis normal to the sample surface was used to analyze the ellipsometry data. A strong optical anisotropy was observed, and enabled the direction of the transition dipole of the absorption bands to be determined. Furthermore, comparison of the optical constants of PEN and PFP thin films with the absorption spectra of the monomers in solution shows significant changes due to the crystalline environment. Relative to the monomer spectrum, the highest occupied molecular orbital to lowest unoccupied molecular orbital transition observed in PEN (PFP) thin film is reduced by 210meV (280meV). A second absorption band in the PFP thin film shows a slight blueshift (40meV) compared to the spectrum of the monomer with its transition dipole perpendicular to that of the first absorption band.