Covalent intermediate trapped in 2-keto-3-deoxy-6- phosphogluconate (KDPG) aldolase structure at 1.95-Å resolution

2-Keto-3-deoxy-6-phosphogluconate (KDPG) aldolase catalyzes the reversible cleavage of KDPG to pyruvate and glyceraldehyde-3-phosphate. The enzyme is a class I aldolase whose reaction mechanism involves formation of Schiff base intermediates between Lys-133 and a keto substrate. A covalent adduct was trapped by flash freezing KDPG aldolase crystals soaked with 10 mM pyruvate in acidic conditions at pH 4.6. Structure determination to 1.95-Å resolution showed that pyruvate had undergone nucleophilic attack with Lys-133, forming a protonated carbinolamine intermediate, a functional Schiff base precursor, which was stabilized by hydrogen bonding with active site residues. Carbinolamine interaction with Glu-45 indicates general base catalysis of several rate steps. Stereospecific addition is ensured by aromatic interaction of Phe-135 with the pyruvate methyl group. In the native structure, Lys-133 donates all of its hydrogen bonds, indicating the presence of an ɛ-ammonium salt group. Nucleophilic activation is postulated to occur by proton transfer in the monoprotonated zwitterionic pair (Glu-45/Lys-133). Formation of the zwitterionic pair requires prior side chain rearrangement by protonated Lys-133 to displace a water molecule, hydrogen bonded to the zwitterionic residues.

Induction of cytochrome P4501A1 by 2,3,7,8-tetrachlorodibenzo-p-dioxin or indolo(3,2-b)carbazole is associated with oxidative DNA damage.

Induction of cytochrome P4501A1 (CYP1A1) in the hepatoma Hepa1c1c7 cell line results in an elevation in the excretion rate of 8-oxoguanine (oxo8Gua), a biomarker of oxidative DNA damage and the major repair product of 8-oxo-2'-deoxyguanosine (oxo8dG) residues in DNA. Treatment of this cell line with 2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD), a nonmetabolized environmental contaminant, and indolo(3,2-b)carbazole (ICZ), a metabolite of a natural pesticide found in cruciferous vegetables, is shown to both induce CYP1A1 activity and elevate the excretion rate of oxo8Gua; 7,8-benzoflavone (7,8-BF or alpha-naphthoflavone), an inhibitor of CYP1A1 activity and an antagonist of the aryl hydrocarbon (Ah) receptor, reduced the excretion rate of oxo8Gua. The essential role of Ah-receptor, which mediates the induction of CYP1A1, is shown by the inability of TCDD to induce CYP1A1 and to increase excretion of oxo8Gua in Ah receptor-defective c4 mutant cells. While there was a significant 7.0-fold increase over 2 days in the excretion rate of oxo8Gua into the growth medium of TCDD-treated Hepa1c1c7 cells compared to control, no significant increase was detected in the steady-state level of oxo8dG in the DNA presumably due to efficient DNA repair. Thus, the induction of CYP1A1 appears to lead to a leak of oxygen radicals and consequent oxidative DNA damage that could lead to mutation and cancer.

X-ray absorption study of the ferromagnetic Cu moment at the YBa_(2)Cu_(3)O_(7)/La_(2/3)Ca_(1/3)MnO_(3) interface and variation of its exchange interaction with the Mn moment

With x-ray absorption spectroscopy and polarized neutron reflectometry we studied how the magnetic proximity effect at the interface between the cuprate high-TC superconductor YBa_(2)Cu_(3)O_(7) (YBCO) and the ferromagnet La_(2/3)Ca_(1/3)MnO_(3) (LCMO) is related to the electronic and magnetic properties of the LCMO layers. In particular, we explored how the magnitude of the ferromagnetic Cu moment on the YBCO side depends on the strength of the antiferromagnetic (AF) exchange coupling with the Mn moment on the LCMO side. We found that the Cu moment remains sizable if the AF coupling with the Mn moments is strongly reduced or even entirely suppressed. The ferromagnetic order of the Cu moments thus seems to be intrinsic to the interfacial CuO_(2) planes and related to a weakly ferromagnetic intraplanar exchange interaction. The latter is discussed in terms of the partial occupation of the Cu 3d_(3z^(2)−r^(2)) orbitals, which occurs in the context of the so-called orbital reconstruction of the interfacial Cu ions.

Cas pràctic 2. Psicologia Evolutiva de 3 a 6 anys

a) Detectar aspectes o variables personals i contextuals que afecten el desenvolupament integral del xiquet/a. b) Conèixer l’impacte que determinades situacions personals o ambientals produeixen en els diferents àmbits del desenvolupament. c) Analitzar les relacions que hi ha entre els diferents agents i com afecten el desenvolupament del xiquet/a. d) Debatre propostes i actuacions per a minimitzar o potenciar l’impacte de determinats agents en el desenvolupament del xiquet/a.

Cas pràctic 7. Psicologia Evolutiva de 3 a 6 anys

a) Detectar aspectes o variables personals i contextuals que afecten el desenvolupament integral del xiquet/a. b) Conèixer l’impacte que determinades situacions personals o ambientals produeixen en els diferents àmbits del desenvolupament. c) Analitzar les relacions que hi ha entre els diferents agents i com afecten el desenvolupament del xiquet/a. d) Debatre propostes i actuacions per a minimitzar o potenciar l’impacte de determinats agents en el desenvolupament del xiquet/a.

Annex 7.1.a. Pràctica 3. Desenvolupament psicomotor de 3 a 6 anys

El document és l'anex 7.1.a. de la práctica 3. Desenvolupament psicomotor de 3 a 6 anys.

Tab. 2,3,4 Specific resistivity of calculated models for the soundings in Lapland

Geoelectrical soundings were carried out in 29 different places in order to find permafrost and to measure its thickness. In most places above timber Iine a permafrost thickness of 10-50 m was recorded. Permafrost was found at sites with thin snow cover during winter. Here, deflation phenomena on the summits of fjells indicate the occurence of permafrost, Vegetation type might be a good indicator of permafrost, too. It seems obvious that permafrost exists extensively on fjell summits of northern Finland.

Health assessment document for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds.

"Draft, do not quote or cite."

Philippic orations 1, 2, 3, 5, 7. Edited by John R. King. 2d ed., rev. by A.C. Clark.

Mode of access: Internet.

左海文集 10巻. 絳跗草堂詩集 6巻. 左海乙集駢體文 2巻. 五經異義疏證 3巻. 左海經辨 2巻. 尚書大傳 5巻. 洪範五行傳 3巻. 東越儒林後傳 1巻. 東越文苑後傳 1巻. 東觀存稿 1巻. 齋詩翼氏學疏證 2巻. 禮堂經說 2巻

Mode of access: Internet.