julilili42/papers huggingface dataset:
Synthese und Kristallstruktur des Lewis‐Säure/Base‐Addukts AlCl3·C3N3Cl3
2007-02-08

Abstract Synthesis and Crystal Structure of the Lewis Acid‐Base Adduct AlCl 3 ·C 3 N 3 Cl 3 The reaction between cyanuric chloride (C 3 N 3 Cl 3 ) and the strong Lewis acid AlCl 3 yielded colorless crystals of the adduct AlCl 3 ·C 3 N 3 Cl 3 . The crystal structure was determined by single crystal X‐ray diffraction at room temperature and was solved in the space group with Z = 4, a = 7.3802(7) Å, b = 9.688(1) Å, c = 16.272(2) Å, α = 72.80(1)°, β = 89.97(1)°, γ = 87.23(1)°, and V = 1110.0(2) Å 3 . In the crystal structure, AlCl 3 is closely associated to the triazine ring with Al–N distances of 2.042(3) Å and 2.067(4) Å, respectively. The AlCl 3 ·C 3 N 3 Cl 3 units are connected with each other via intermolecular N···Cl donor–acceptor interactions, forming tape‐like arrangements in the ac‐plane, with tapes running parallel to the a ‐axis.
The impact of contact structure on infectious disease control: influenza and antiviral agents
2007-02-09

SUMMARY Planning adequate public health responses against emerging infectious diseases requires predictive tools to evaluate the impact of candidate intervention strategies. With current interest in pandemic influenza very high, modelling approaches have suggested antiviral treatment combined with targeted prophylaxis as an effective first-line intervention against an emerging influenza pandemic. To investigate how the effectiveness of such interventions depends on contact structure, we simulate the effects in networks with variable degree distributions. The infection attack rate can increase if the number of contacts per person is heterogeneous, implying the existence of high-degree individuals who are potential super-spreaders. The effectiveness of a socially targeted intervention suffers from heterogeneous contact patterns and depends on whether infection is predominantly transmitted to close or casual contacts. Our findings imply that the various contact networks' degree distributions as well as the allocation of contagiousness between close and casual contacts should be examined to identify appropriate strategies of disease control measures.
Neuroma Formation in a Rat Median Nerve Model: Influence of Distal Stump and Muscular Coating
2007-02-09

These results demonstrate an association between neuroma formation and distal stump distance. This observation may be explained by the factors originating from the distal stump that were blocked when the proximal nerve stump was completely buried in the muscle. For clinical application, the authors recommend not only burying the proximal stump in a muscle but also surgically augmenting the gap between the proximal and distal stumps.
New family with paroxysmal exercise‐induced dystonia and epilepsy
2007-02-09

Abstract To date, there are few reports of paroxysmal exercise‐induced dystonia associated with familial epilepsy. We describe a family with 4 affected members spanning 3 generations, suggestive of autosomal‐dominant inheritance, who exhibited typical exercise‐induced dystonia, different types of epilepsy (absence and primary generalized seizures), developmental delay, and migraine in variable combinations. Linkage of the disease to loci on chromosome 2 (paroxysmal nonkinesigenic dyskinesia) and chromosome 16 (paroxysmal kinesigenic choreoathetosis, infantile convulsions with choreoathetosis) was excluded, suggesting an as yet unidentified underlying genetic basis. © 2007 Movement Disorder Society
UNDERLYING GAUGE SYMMETRIES OF SECOND-CLASS CONSTRAINTS SYSTEMS
2007-02-10

Gauge-invariant systems in unconstrained configuration and phase spaces, equivalent to second-class constraints systems upon a gauge-fixing, are discussed. A mathematical pendulum on an (n-1)-dimensional sphere S n-1 as an example of a mechanical second-class constraints system and the O(n) nonlinear sigma model as an example of a field theory under second-class constraints are discussed in details and quantized using the existence of underlying dilatation gauge symmetry and by solving the constraint equations explicitly. The underlying gauge symmetries involve, in general, velocity dependent gauge transformations and new auxiliary variables in extended configuration space. Systems under second-class holonomic constraints have gauge-invariant counterparts within original configuration and phase spaces. The Dirac's supplementary conditions for wave functions of first-class constraints systems are formulated in terms of the Wigner functions which admit, as we show, a broad set of physically equivalent supplementary conditions. Their concrete form depends on the manner the Wigner functions are extrapolated from the constraint submanifolds into the whole phase space.
The XMM-Newton survey in the Marano field
2007-02-12

We report on a medium deep XMM-Newton survey of the Marano Field and optical follow-up observations. The mosaicked XMM-Newton pointings in this optical quasar survey field cover 0.6 deg2 with a total of 120 ks good observation time. We detected 328 X-ray sources in total. The turnover flux of our sample is erg cm-2 s-1 in the 0.2-10 keV band. With VLT FORS1 and FORS2 spectroscopy we classified 96 new X-ray counterparts. The central 0.28 deg2, where detailed optical follow-up observations were performed, contain 170 X-ray sources (detection likelihood ), out of which 48 had already been detected by ROSAT. In this region we recover 23 out of 29 optically selected quasars. With a total of 110 classifications in our core sample we reach a completeness of ~65%. About one-third of the XMM-Newton sources are classified as type II AGN with redshifts mostly below 1.0. Furthermore, we detect five high redshift type II AGN (). We show that the true redshift distribution of type II AGN remains uncertain, since their lack of emission lines in a wide optical wavelength range hampers their identification in the redshift range . The optical and X-ray colours of the core sample indicate that most of the still unidentified X-ray sources are likely to be type II AGN. We calculate absorbing column densities and show that the ratio of absorbed to unabsorbed objects is significantly higher for type II AGN than for type I AGN. Nevertheless, we find a few unabsorbed type II AGN. The X-ray hardness ratios of some high redshift type I AGN also give an indication of heavy absorption. However, none of these type I objects is bright enough for spectral extraction and detailed model fitting. Types I and II AGN cover the same range in intrinsic X-ray luminosity, (), although type II AGN have a lower median intrinsic X-ray luminosity (log ) compared to type I AGN (log ). Furthermore, we classified three X-ray bright optically normal galaxies (XBONGs) as counterparts. They show properties similar to type II AGN, probably harbouring an active nucleus.
Cellular and subcellular localization of Huntington aggregates in the brain of a rat transgenic for Huntington disease
2007-02-13

Abstract Huntington disease (HD) is a progressive neurodegenerative disorder characterized by emotional, cognitive, and motor dysfunctions. Aggregation of huntingtin is a hallmark of HD and, therefore, a crucial parameter for the evaluation of HD animal models. We investigated here the regional, cellular, and subcellular distribution of N‐terminal huntingtin aggregates and associated neuropathological changes in the forebrain of a rat transgenic for HD (tgHD). The tgHD rat brain showed enormously enlarged lateral ventricles and a similar atrophy of cortical and subcortical areas as known in HD patients. Huntingtin aggregates of varying size and forms were regionally identified in neuronal nuclei, cytoplasm, dendrites, dendritic spines, axons, and synaptic terminals, closely resembling the results described earlier for human HD brains and in established HD mouse models. Huntingtin aggregates in mitochondria support mitochondrial dysfunction as contributing to the disease pathogenesis. Dark cell degeneration was reminiscent of results in HD individuals and HD mouse models. Interestingly, huntingtin aggregates were especially well accumulated in two interacting limbic forebrain systems, the ventral striatopallidum and the extended amygdala, which may contribute to the early onset of emotional changes observed in the tgHD rat. In conclusion, the tgHD rat model reflects to a remarkable extent the cellular and subcellular neuropathological key features as observed in human HD and HD mouse brains and hints of changes in limbic forebrain systems, which may elucidate the emotional dysfunction in the tgHD rat and affective disturbances in HD patients. J. Comp. Neurol. 501:716–730, 2007. © 2007 Wiley‐Liss, Inc.
Interferon‐γ regulates cathepsin G activity in microglia‐derived lysosomes and controls the proteolytic processing of myelin basic protein in vitro
2007-02-14

Summary The serine protease cathepsin (Cat) G dominates the proteolytic processing of the multiple sclerosis (MS)‐associated autoantigen myelin basic protein (MBP) in lysosomes from primary human B cells and dendritic cells. This is in contrast to B‐lymphoblastoid cell lines, where the asparagine endopeptidase (AEP) is responsible for this task. We have analysed microglia‐derived lysosomal proteases for their ability to process MBP in vitro . In lysosomes derived from primary murine microglia, CatD, CatS, AEP and CatG were involved in the processing of MBP. Interestingly, when microglia were treated with interferon‐γ to mimic a T helper type 1‐biased cytokine milieu in MS, CatG was drastically down‐regulated, in contrast to CatS, CatB, CatL, CatD or AEP. This resulted in significantly increased stability of MBP and a selective lack of CatG‐derived proteolytic fragments; however, it did not affect the gross pattern of MBP processing. Inhibition of serine proteases eliminated the processing differences between lysosomal extracts from resting microglia compared to interferon‐stimulated microglia. Thus, the cytokine environment modulates lysosomal proteases in microglia by a selective down‐regulation of CatG, leading to decreased MBP‐processing by microglia‐derived lysosomal proteases in vitro.
Changes in purine specificity in tandem GAF chimeras from cyanobacterial cyaB1 adenylate cyclase and rat phosphodiesterase 2
2007-02-14

The C‐terminal catalytic domains of the 11 mammalian phosphodiesterase families (PDEs) are important drug targets. Five of the 11 PDE families contain less well‐characterized N‐terminal GAF domains. cGMP is the ligand for the GAF domains in PDEs 2, 5, 6 and 11, and cAMP is the ligand for PDE10. Structurally related tandem GAF domains signalling via cAMP are present in the cyanobacterial adenylate cyclases cyaB1 and cyaB2. Because current high‐resolution crystal structures of the tandem GAF domains of PDE2 and cyaB2 do not reveal how cNMP specificity is encoded, we generated chimeras between the tandem GAF domains of cyaB1 and PDE2. Both bind the ligand in the GAF B subdomains. Segmental replacements in the highly divergent β1–β3 region of the GAF B subdomain of cyaB1 by the corresponding PDE2 regions switched signalling from cAMP to cGMP. Using 10 chimeric constructs, we demonstrated that, for this switch in purine specificity, only 11% of the sequence of the cyanobacterial GAF B needs to be replaced by PDE2 sequences. We were unable, however, to switch the purine specificity of the PDE2 tandem GAF domain from cGMP to cAMP in reverse constructs, i.e. by replacement of PDE2 segments with those from the cyaB1 GAF tandem domain. The data provide a novel view on the structure–function relationships underlying the purine specificity of cNMP‐binding GAF domains and indicate that, as potential drug targets, they must be characterized structurally and biochemically one by one.
Surgical treatment of peripapillary choroidal neovascularisation
2007-02-14

In this small case series of PPCNV, functional improvement was achieved after surgery in the majority of patients. Surgical extraction of the CNV represents an alternative treatment option in eyes with vision-threatening extensive PPCNV. Randomised controlled studies seem to be justified to evaluate further the beneficial effect and long-term functional outcome of this therapy approach.
N-{(Z)-2-[1-(Triisopropylsilyl)-1H-indol-3-yl]-2-(triisopropylsilyloxy)vinyl}-2-(3,4,5-trimethoxyphenyl)acetamide
2007-02-14

The molecular structure of the title compound, C 39 H 62 N 2 O 5 Si 2 , obtained as an unexpected side product, was determined in the course of our studies on the synthesis of N -triisopropyl-1 H -indol-3-yl derivatives. Interestingly, although the triisopropylsilyl group was intended as a temporary protecting group, the compound comprises a remarkably stable N—Si bond. The vinyl C=C double bond possesses a Z configuration.
Transcriptional regulation of epidermal cell fate in theArabidopsisembryo
2007-02-15

How distinct cell fates are specified at correct positions within the plant embryo is unknown. In Arabidopsis, different cell fates are generated early on, starting with the two daughter cells of the zygote. To address mechanisms of position-dependent gene activation and cell fate specification,we analyzed the regulatory region of the Arabidopsis thaliana MERISTEM LAYER 1 (ATML1) gene, which is already expressed at the one-cell stage and whose expression is later restricted to the outermost, epidermal cell layer from its inception. A sensitive, multiple GFP reporter revealed a modular organization to the ATML1 promoter. Each region contributes positively to specific spatial and temporal aspects of the overall expression pattern, including position-dependent but auxin-independent regulation along the apical-basal axis of the embryo. A 101 bp fragment that conferred all aspects of ATML1 expression contained known binding sites for homeodomain transcription factors and other regulatory sequences. Our results suggest that expression patterns associated with cell fate determination in the plant embryo result from positional signals targeting different regulatory sequences in complex promoters.
Memantine Treatment of Complex Regional Pain Syndrome
2007-02-15

Based on these first results, the use of Memantine for treatment of CRPS seems promising and supports the hypothesis of a CNS contribution to the pathogenesis and maintenance of neuropathic pain syndromes.
Acute Hemodynamic Collapse After Induction of General Anesthesia for Emergent Pulmonary Embolectomy
2007-02-15

In Response: Webb and Arrowsmith (1) suggest that femoro-femoral cardiopulmonary bypass should be considered before inducing anesthesia in patients, on the basis of the possibility of acute hemodynamic deterioration after induction of anesthesia in these patients (2). Femoral cannulation can usually be performed without difficulty to prepare patients for cardiopulmonary bypass before the induction of general anesthesia (3). Indeed femoral cannulation is a possible alternative for patients undergoing surgical pulmonary embolectomy who have significant ventricular dysfunction or for those with anticipated difficult airways. Nevertheless, we (4) have previously demonstrated that up to 26% of patients undergoing pulmonary embolectomy have extrapulmonary thromboemboli, primarily within the inferior vena cava. Manipulation during femoral cannulation may dislodge these extrapulmonary thromboemboli, which may subsequently lodge in the pulmonary circulation and cause additional hemodynamic instability. The incidence of this phenomenon is unknown. We believe that the most important aspect of managing patients undergoing surgical pulmonary embolectomy is vigilant preparation for the rapid institution of cardiopulmonary bypass. Peter Rosenberger, MD Holger K. Eltschig, MD Department of Anesthesiology and Intensive Care Medicine Tübingen University Clinic Tübingen, Germany Stanton K. Shernan, MD Department of Anesthesiology, Perioperative and Pain Medicine Brigham and Women’s Hospital Harvard Medical School Boston, Massachusetts [email protected]
Evidence for Holocene environmental changes in the northern Fertile Crescent provided by pedogenic carbonate coatings
2007-02-16

Abstract Holocene environmental changes in the northern Fertile Crescent remain poorly understood because of the scarcity of local proxy records in the region. In this study we investigated pedogenic (soil-formed) carbonate coatings on stones at the Pre-Pottery Neolithic site Göbekli Tepe as an indicator of local early-mid Holocene environmental changes. The 14 C ages and stable isotopic composition of carbon and oxygen in thin (0.2–0.3 mm thick) pedogenic carbonate lamina indicate two main periods of coating formation: the early-Holocene (ca. 10000–6000 cal yr BP) and the mid-Holocene (ca. 6000–4000 cal yr BP). During the first period, there was an inverse relationship between δ 13 C and δ 18 O curves: a decrease in δ 13 C values coincide with an increase in δ 18 O values. For this period a trend towards higher temperatures is suggested. In the mid-Holocene, the mean rate of coating growth was 2–3 times higher than in the early Holocene. Both δ 13 C and δ 18 O reached their maximum values during this time and the direction of changes of the δ 13 C and δ 18 O curves became similar. The combination of data suggests that this period was the most humid in the Holocene and on average warmer than the early Holocene. At ca. 4000 cal yr BP secondary accumulation of carbonate ceased, presumably reflecting a shift to a more arid climate.
The Reovirus σ1 Aspartic Acid Sandwich
2007-02-16

Reovirus attachment protein sigma1 mediates engagement of receptors on the surface of target cells and undergoes dramatic conformational rearrangements during viral disassembly in the endocytic pathway. The sigma1 protein is a filamentous, trimeric molecule with a globular beta-barrel head domain. An unusual cluster of aspartic acid residues sandwiched between hydrophobic tyrosines is located at the sigma1 subunit interface. A 1.75-A structure of the sigma1 head domain now reveals two water molecules at the subunit interface that are held strictly in position and interact with neighboring residues. Structural and biochemical analyses of mutants affecting the aspartic acid sandwich indicate that these residues and the corresponding chelated water molecules act as a plug to block the free flow of solvent and stabilize the trimer. This arrangement of residues at the sigma1 head trimer interface illustrates a new protein design motif that may confer conformational mobility during cell entry.
Sleep problems and daytime somnolence in a German population‐based sample of snoring school‐aged children
2007-02-19

Summary Habitual snoring is associated with daytime symptoms like tiredness and behavioral problems. Its association with sleep problems is unclear. We aimed to assess associations between habitual snoring and sleep problems in primary school children. The design was a population‐based cross‐sectional study with a nested cohort study. The setting was twenty‐seven primary schools in the city of Hannover, Germany. Habitual snoring and sleep problems were assessed in primary school children using an extended version of Gozal's sleep‐disordered breathing questionnaire ( n = 1144). Approximately 1 year later, parents of children reported to snore habitually ( n = 114) and an equal number of children who snored never or occasionally were given the Sleep Disturbance Scale for Children, a validated questionnaire for the assessment of pediatric sleep problems. Snoring status was re‐assessed using the initial questionnaire and children were then classified as long‐term habitual snorers or ex‐habitual snorers. An increasing prevalence of sleep problems was found with increasing snoring frequency for sleep‐onset delay, night awakenings, and nightmares. Long‐term habitual snorers were at significantly increased risk for sleep–wake transition disorders (e.g. rhythmic movements, hypnic jerks, sleeptalking, bruxism; odds ratio, 95% confidence interval: 12.0, 3.8–37.3), sleep hyperhidrosis (3.6, 1.2–10.8), disorders of arousal/nightmares (e.g. sleepwalking, sleep terrors, nightmares; 4.6, 1.3–15.6), and excessive somnolence (i.e. difficulty waking up, morning tiredness, daytime somnolence; 6.3, 2.2–17.8). Ex‐habitual snorers were at increased risk for sleep–wake transition disorders (4.4, 1.4–14.2). Habitual snoring was associated with several sleep problems in our study. Long‐term habitual snorers were more likely to have sleep problems than children who had stopped snoring spontaneously.
Specialization on a technologically stagnant sector need not be bad for growth
2007-02-19

This paper presents a two-sector, North-South model of endogenous growth, where the investment goods sector features learning by doing. There are no technological spillovers across countries that are integrated only via goods markets. In equilibrium, South specializes on the consumption sector. Despite strict concavity of the production function for consumption goods, the endogenous decline in the relative price of investment goods maintains the incentives for capital accumulation. Hence, specialization on the stagnant consumption sector does not entail a growth penalty. The model is consistent with a number of empirical observations: (i) the relative price of investment goods has been declining in many countries; (ii) poor countries are net importers of investment equipment; (iii) per capita income convergence has stopped in the sample of open economies. Copyright 2007 , Oxford University Press.
Discovery of a flux-related change of the cyclotron line energy in Hercules X-1
2007-02-20

Aims. We present the results of ten years of repeated measurements of the Cyclotron Resonance Scattering Feature (CRSF) in the spectrum of the binary X-ray pulsar <ns0:ext-link ext-link-type="aoi">Her X-1</ns0:ext-link> and report the discovery of a positive correlation of the centroid energy of this absorption feature in pulse phase averaged spectra with source luminosity. Methods. Our results are based on a uniform analysis of observations by the <ns0:sans-serif>RXTE</ns0:sans-serif> satellite from 1996 to 2005, using sufficiently long observations of 12 individual 35-day Main-On states of the source. Results. The mean centroid energy Ec of the CRSF in pulse phase averaged spectra of <ns0:ext-link ext-link-type="aoi">Her X-1</ns0:ext-link> during this time is around 40 keV, with significant variations from one Main-On state to the next. We find that the centroid energy of the CRSF in <ns0:ext-link ext-link-type="aoi">Her X-1</ns0:ext-link> changes by ~5% in energy for a factor of 2 in luminosity. The correlation is positive, contrary to what is observed in some high luminosity transient pulsars. Conclusions. Our finding is the first significant measurement of a positive correlation between Ec and luminosity in any X-ray pulsar. We suggest that this behaviour is expected in the case of sub-Eddington accretion and present a calculation of a quantitative estimate, which is very consistent with the effect observed in <ns0:ext-link ext-link-type="aoi">Her X-1</ns0:ext-link>. We urge that <ns0:ext-link ext-link-type="aoi">Her X-1</ns0:ext-link> is regularly monitored further and that other X-ray pulsars are investigated for a similar behaviour.
Confining solution of the Dyson-Schwinger equations in Coulomb gauge
2007-02-20

The Dyson-Schwinger equations arising from minimizing the vacuum energy density in the Hamiltonian approach to Yang-Mills theory in Coulomb gauge are solved numerically. A new solution is presented which gives rise to a strictly linearly rising static quark potential and whose existence was previously observed in the infrared analysis of the Dyson-Schwinger equations. For the new solution we also present the static quark potential and calculate the running coupling constant from the ghost-gluon vertex.