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1Latest Papers from Table of Contents or Articles in PressM. F. Berger ; M. S. Lawrence ; F. Demichelis ; Y. Drier ; K. Cibulskis ; A. Y. Sivachenko ; A. Sboner ; R. Esgueva ; D. Pflueger ; C. Sougnez ; R. Onofrio ; S. L. Carter ; K. Park ; L. Habegger ; L. Ambrogio ; T. Fennell ; M. Parkin ; G. Saksena ; D. Voet ; A. H. Ramos ; T. J. Pugh ; J. Wilkinson ; S. Fisher ; W. Winckler ; S. Mahan ; K. Ardlie ; J. Baldwin ; J. W. Simons ; N. Kitabayashi ; T. Y. MacDonald ; P. W. Kantoff ; L. Chin ; S. B. Gabriel ; M. B. Gerstein ; T. R. Golub ; M. Meyerson ; A. Tewari ; E. S. Lander ; G. Getz ; M. A. Rubin ; L. A. Garraway
Nature Publishing Group (NPG)
Published 2011Staff ViewPublication Date: 2011-02-11Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Carrier Proteins/genetics ; Case-Control Studies ; Cell Adhesion Molecules/genetics ; Chromatin/genetics/metabolism ; Chromosome Aberrations ; Chromosome Breakpoints ; Epigenesis, Genetic/genetics ; Gene Expression Regulation, Neoplastic ; Genome, Human/*genetics ; Humans ; Male ; PTEN Phosphohydrolase/genetics/metabolism ; Prostatic Neoplasms/*genetics ; Recombination, Genetic/genetics ; Signal Transduction/genetics ; Transcription, GeneticPublished by: -
2Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] In their report on tumour chromosomes, Makino et al.1 included tables giving the chromosome complements of single tumours. The chromosome complements of three female gastric carcinomata of the effusion type were recorded in this way. Calculations on the heterogeneity of the complements of each ...Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesStaff View
ISSN: 1432-0924Source: Springer Online Journal Archives 1860-2000Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsNotes: Abstract The paper describes a special finite element for three-dimensional, large displacement analysis of contact problems with slip and friction. This element may be used to model contact between several finite element bodies or contact between a finite element body and a flexible or rigid geometrical surface fixed in space or moving with time. The contact formulation is based on the concept of a spring-supported, moving disk that transfers normal contact forces and Coulomb friction forces. The contact surface has a finite, prescribed boundary. The contact element has been incorporated into the general-purpose, nonlinear, finite element program FENRIS. Three examples of its application are described in the paper.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 1617-4623Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary Drosophila males were exposed to a sublethal concentration of cyanide gas prior to the injection of formaldehyde solutions. Compared to the controls which only received formaldehyde the frequency of sex-linked lethals was increased after the cyanide pretreatment in altogether six independent experiments. These results are taken as further proof that formaldehyde exerts at least part of its mutagenic effects via the formation of peroxides. It is suggested that an excessive amount of hydrogen peroxide, due to inhibition of the cytochrome and catalase enzyme systems, favours the formation of a mutagenic, organic peroxide, presumably dihydroxydimethyl peroxide. The fact that formaldehyde exerts an inhibiting effect on catalase in its own right might be of importance for the interpretation of its mutagenic action. It was also observed that after cyanide pretreatment, the mutagenic effectiveness of a mixture of formaldehyde and hydrogen peroxide was lower than that of formaldehyde alone. These findings can be interpreted by assuming that high concentrations of dihydroxydimethyl peroxide or of a combination of cyanide and this peroxide, eliminate selectively germ cells with induced mutations. It is possible that the same explanation applies to the low mutagenic effectiveness of a mixture of formaldehyde and hydrogen peroxide compared with that of formaldehyde alone when both are preceded by cyanide.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesZdzienicka, M. Z. ; Arwert, F. ; Neuteboom, I. ; Rooimans, M. ; Simons, J. W. I. M.
Springer
Published 1990Staff ViewISSN: 1572-9931Source: Springer Online Journal Archives 1860-2000Topics: BiologyMedicineNotes: Abstract It has been shown by genetic complementation analysis that a mitomycin C-sensitive mutant (V-H4) of Chinese hamster V79 cells is the first rodent equivalent of Fanconi anemia (FA) group A. The V-H4 mutant shows many typical characteristics of cells derived from FA patients. V-H4 cells exhibit increased sensitivity towards cross-linking agents as MMC (∼30-fold), cis-DDP (∼10-fold), DEB (∼10-fold), and PUVA (∼1.6-fold), but an only slightly increased sensitivity to monofunctional alkylating agents (EMS and MMS) and actinomycin D. V-H4 cells are also moderately sensitive to adriamycin (1.6-fold), and not sensitive to H2O2. The levels of chromosomal aberrations induced by MMC and cis-DDP treatment are higher (4- to 6-fold) in V-H4 cells than in the wild-type V79 cells. Genetic complementation analysis with other Chinese hamster mutants hypersensitive to MMC (irs1, irs1SF, UV20 and UV41) indicates clearly that V-H4 belongs to a different, new complementation group. This unique mutant is very stable and can serve as a vehicle to isolate the complementing FA-A gene from normal human DNA.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1572-9931Source: Springer Online Journal Archives 1860-2000Topics: BiologyMedicineNotes: Abstract Clonal variation has been studied in CHO cells. The variant phenotype was an altered morphology of clones in agar: the parental CHO cells give rise to solid clumps of cells (wild-type colonies); occasionally, dispersed colonies arise, and the cells display an invasive growth in agar (INGA-type colonies). The frequency of this altered phenotype can be enhanced by treatment with a variety of mutagens (EMS, ENU, 4NQO, N-Ac-AAF, ultraviolet light, and X-irradiation). Enhancement was not due to a selective killing of wild-type cells or to a side-effect of cytotoxicity, which suggests that DNA damage is the cause of the altered phenotype. The INGA-trait breeds true, but most of the isolated clones have an inherent instability.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 1572-9931Source: Springer Online Journal Archives 1860-2000Topics: BiologyMedicineNotes: Abstract When mammalian cells are cultured at low concentrations of toxic drugs, they often become phenotypically resistant. We studied whether this phenotypic resistance is due to selection of preexisting variants. The drugs 8-azaguaine (AG) and 6-thioguanine (TG) were used and, as a parameter for resistance, the incorporation of hypoxanthine was determined. Preexisting variation among clones in the uptake of hypoxanthine was found, and this variation has a hereditary component. This transmission of aberrant incorporation of hypoxanthine does not appear a stable trait, and the aberrant cell lines returned gradually to the original steady state. There are indications that within a cell population cells with altered levels of incorporation of hypoxanthine arise continuously and at a high frequency. Treatment with marginally toxic concentrations of AG or TG indicates that, at least for AG, survival is not related to the preexisting variation in hypoxanthine uptake. The observed phenomena could be of importance for the selection of drugs to be used in cancer chemotherapy.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesVolman, D. H. ; Simons, J. W. ; Seed, J. R. ; Sterling, C.
Hoboken, NJ : Wiley-Blackwell
Published 1960Staff ViewISSN: 0022-3832Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyPhysicsNotes: Water vapor sorption isotherms of a commercial dextrin prepared by dry acid treatment, amylose recrystallized from n-butanol, and amylopectin precipitated from methanol were determined at various temperatures in the range of 10-40°C. The differential thermodynamic functions for water vapor sorption on the various materials were calculated, and B.E.T. constants were determined. A striking characteristic of the thermodynamic functions is the strong similarity for amylopectin and amylose. A model for the sorption is proposed. X-ray patterns for the starch samples equilibrated with water vapor at various relative pressures of water vapor were determined. The major changes are explicable on the basis of intramicellar swelling. As the relative pressures increase, the crystalline patterns gradually fade and disappear. However, some new spacings appear with increased sorption in amylose and amylopectin. These spacings are explained on the basis of the formation of transitory lattices during the swelling of the starch crystallites.Additional Material: 7 Ill.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesScott, R. L. ; Richardson, A. E. ; Simons, J. W. ; Hase, W. L.
New York, NY : Wiley-Blackwell
Published 1975Staff ViewISSN: 0538-8066Keywords: Chemistry ; Physical ChemistrySource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: The decomposition rate of chemically activated ethyltrimethylgermane from the reaction 1CH2 + (CH3)4Ge, where 1CH2 was produced from diazomethane photolysis at 3660 Å, is 8.6 × 105 sec-1. This result combined with RRKM theory and critical energy estimates yields an Arrhenius A factor of log[A (sec-1)/methyl] = 14.7 ± 0.8 for methyl rupture from germanium.Log A values for methyl rupture from carbon, silicon, and germanium linearly correlate with the vibrational-rotational entropies of the corresponding tetramethyls. Extrapolation predicts log[A (sec-1)/methyl] = 14.4 and 14.3 for methyl rupture from tin and lead, respectively.Additional Material: 2 Ill.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 0538-8066Keywords: Chemistry ; Physical ChemistrySource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: Chemically activated ethane, with an excitation energy of 114.9 ± 2 kcal/mole, was formed by reaction with methane of excited singlet methylene radicals produced by the 4358 Å photolysis of diazomethane. A decomposition rate constant of (4.6 ± 1.2) × 109 sec-1 was measured for the chemically activated ethane. This result agrees, via RRKM theory, with most other chemically activated ethane data, and the result predicts, via RRKM and absolute rate theory for E0 = 85.8 kcal/mole, E* = 114.9 kcal/mole, and kE = 4.6 × 101 sec-1, a thermal A-factor at 600°K of 1016.6±0.2 sec-1, in approximate agreement with the more recent experimental values. Combining 2 kcal/mole uncertainties in E0 and E* with the uncertainty in our rate constant yields an A-factor range of 1016.6±0.7 sec-1. It is emphasized that this large uncertainty in the A-factor results from an improbable combination of uncertainty limits for the various parameters. These decomposition results predict, via absolute rate theory (with E0(recombination) = 0) and statistical thermodynamic equilibrium constants, methyl radical recombination rates at 25°C of between 4.4 × 108 to 3.1 × 109 l.-mole-1-sec-1, which are 60 to 8 times lower, respectively, than the apparently quite reliable experimental value. A value of E0(recombination) greater than zero offers no improvement, and a value less than zero would be quite unusual. Activated complexes consistent with the experimental recombination rate and E0(recombination) = 0 greatly overestimate the experimental chemical activation and high pressure thermal decomposition rate data. Absolute rate theory as it is applied here in a straightforward way has failed in this case, or a significant amount of internally consistent data are in serious error. Some corrections to our previous calculations for higher alkanes are discussed in Appendix II.Additional Material: 3 Ill.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesSimons, J. W. ; Hase, W. L. ; Phillips, R. J. ; Porter, E. J. ; Growcock, F. B.
New York, NY : Wiley-Blackwell
Published 1975Staff ViewISSN: 0538-8066Keywords: Chemistry ; Physical ChemistrySource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: The specific decomposition rates of chemically activated methylcyclobutane produced from CH2(1A1) reaction with cyclobutane have been determined. CH2(1A1)was produced from ketene photolyses at 3340 and 3130 Å and from diazomethane photolyses at 4358 and 3660 Å. Comparisons of the excitation energies of the methylcyclobutane, determined by RRKM theory calculations, and the experimental results for the ketene systems, with thermochemically predicted maximum excitation energies, favor an Arrhenius A factor in the range of 5 × 1015 to 1 × 1016 sec-1 for methylcyclobutane. This result is consistent with (1) the comparison of RRKM theory calculations and the experimental unimolecular falloff for methylcyclobutane, (2) the comparison of experimental A factors for cyclobutane and other alkylcyclobutane decompositions, and (3) two out of three reported experimental A factors for methylcyclobutane. An analysis of these and previous results leads to a value of the CH2(1A1) ↔ CH2(3B1) energy splitting of 9±3 kcal/mole.Additional Material: 3 Ill.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 0538-8066Keywords: Chemistry ; Physical ChemistrySource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: A study of the structural isomerization rate of chemically activated 1,1-dimethylcyclopropane from singlet methylene addition to the double bond of isobutene is reported. Singlet methylenes were produced from the 4358- and 3660-Å photolysis of diazomethane in the presence of added oxygen. Theoretical rates calculated via RRKM theory are in excellent agreement with experiment for calculations utilizing activated complex structures and critical energies consistent with known thermal Arrhenius parameters, and excitation energies consistent with previous determinations of ΔHf00(CH2) + E*(CH2) = 116.1 and 112.6 kcal/mole for diazomethane photolyses at 3660 and 4358 Å, respectively.Additional Material: 5 Ill.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 0538-8066Keywords: Chemistry ; Physical ChemistrySource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: An experimental study of the decomposition kinetics of chemically activated 2-methyl-l-butene and 3-methyl-l-butene produced from photolysis of diazomethane-isobutene-neopentane-oxygen mixtures is reported. The experimental rate constants for 3-methyl-l-butene decomposition were 1.74 ± 0.44 × 108 sec-1 and 1.01 ± 0.25 × 108 sec-1 at 3660 and 4358 Å, respectively. 2-Methyl-l-butene experimental decomposition rate constants were found to be 5.94 ± 0.59 × 107 sec-1 at 3660 Å and 3.42 ± 0.34 × 107 sec-1 at 4358 Å. Activated complex structures giving Arrhenius A-factors calculated from absolute rate theory of 1016.6 ± 0.5 sec-1 for 3-methyl-l-butene and 1016.2 ± 0.4 sec-1 for 2-methyl-l-butene, both calculated at 1000°K, were required to fit RRKM theory calculated rate constants to the experimental rate constants at reasonable E0 and E* values. Corrected calculations (adjusted E0 values) on previous results for 2-pentene decomposition gave an Arrhenius A-factor of 1016.45 ± 0.35 sec-1 at 1000°K. The predicted A-factors for these three alkene decompositions giving resonance-stabilized methylully radicals are in good internal agreement. The fact that these A-factors are only slightly less than those for related alkane decompositions indicates that methylallylic resonance in the decomposition products leads to only a small amount of tightening in the corresponding activated complexes. This tightening is a significantly smaller factor than the large reduction in the critical energy due to resonance stabilization.Additional Material: 1 Ill.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 0538-8066Keywords: Chemistry ; Physical ChemistrySource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: The total decomposition rates of the chemically activated alkanes n-butane, n-pentane, isopentane, and neohexane were measured using an internal comparison technique. Chemical activation was by the C—H insertion reaction of excited singlet-state methylene radicals. A total of ten rate constants ranging from 4.6 × 105 to 2.3 × 107 sec-1 were measured for these alkanes at different excitation energies. These rates correlate via RRKM theory calculations with thermal A-factors in the range of 1016.1 to 1017.1 sec-1 for free rotoractivated complex models and in the range of 1016.4 to 1017.8 sec-1 for vibrator-activated complex models. It was found that high critical energies for decomposition, “tight” radical models, and activated complex models with free internal rotations were required to correlate the decomposition rates of these alkanes with estimated alkyl radical recombination rates. The correlation is just barely possible even for these favorable extremes, indicating that there may be a basic discrepancy between the recombination rate and decomposition rate data for alkanes.Additional Material: 7 Ill.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 0538-8066Keywords: Chemistry ; Physical ChemistrySource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: The decomposition kinetics of chemically activated methyl-d1-methylsilane-d2 (DMS-d3*) and ethylsilane-d3 (ES-d3*) from the Si-D and C-H insertion reactions of CH2 (1A1) with methylsilane-d3 have been studied. The total rate constants for decomposition of chemically activated DMS-d3 and ES-d3 have been measured. The individual rate constants for molecular elimination of CH3D, CH2D2, and D2 from DMS-d3* and for molecular elimination of CH3CH2D and D2 from ES-d3* have been measured. All of the above rate constants exhibit the expected kinetic isotope effect when compared to those found previously in the undeuterated system. RRKM theory calculations of the rate constants for the expected C-Si and Si-D bond rupture processes, based on energetics and activated comple× models deduced previously for the undeuterated system, were carried out. In the case of DMS-d3* the RRKM theory calculations of rate constants for the bond rupture processes combined with experimental rate constants for the molecular elimination processes gave a total rate constant for decomposition in agreement with the measured value. The results of a high-pressure study of the CH3D/CH2D2 ratio from chemically activated DMS-d3 decomposition were consistent with complete randomization of internal energy up to a pressure of 4 atmospheres (lifetime of ∼1.7 × 10×11 sec). This is not an unexpected result in light of earlier work.Additional Material: 6 Ill.Type of Medium: Electronic ResourceURL: