the x ray fluorescence microscopy revolution

... to the average co-ordinates (the blue colour denotes the side chains of Arg2, Tyr4, Ile5, His6 and the yellow the side chains of Val3 and Pro7) (a) with the the X- ray structure of AII in the ... inside the folded conformation of the molecule, and Arg2 is exposed to the solvent, as illustrated in Fig 5B,a The stabilization of the folded conformation can be explained by the stacking of the ... all the backbone NH, with the exception of the Arg2, are above the dashed line, indicating that these peptide protons are somewhat exposed The Arg2 backbone NH is most probably implicated in the...

Ngày tải lên: 20/02/2014, 23:20

... Trung 11 X- Ray Fluorescence TS : Nguyễn Ngọc Trung 12 X- Ray Fluorescence VD : máy phân giải bước sóng đa kênh : TS : Nguyễn Ngọc Trung 13 X- Ray Fluorescence TS : Nguyễn Ngọc Trung 14 X- Ray Fluorescence ... Ngọc Trung X- Ray Fluorescence Sự khác trình tạo điện tử Auger huỳnh quang tia X (Chúng khác lượng ) TS : Nguyễn Ngọc Trung X- Ray Fluorescence 3.Thiết bị phân tích tia X • Muốn phân tích XRF ta đo ... X- Ray Fluorescence 1.Giới Thiệu XRF • XRF (huỳnh quang tia X) kỹ thuật quang phổ sử dụng chủ yếu với mẫu rắn,trong phát x tia X thứ cấp sinh kích thích điện tử mẫu nguồn phát tia X • Dựa...

Ngày tải lên: 28/06/2014, 11:20

... diameter vertical X- ray beam path through the center of the sample and reference sensors of the DSC cell Thermal isolation was maintained by using beryllium metal foil to seal the X- ray optical path ... carbon dioxide, and other volatiles evolved, which indicates thermal degradation Thermal degradation after the melt was also indicated by exothermic behavior observed from the DSC experiments ... between the first and second scan may have contributed to the small shift in the onset temperature The endotherm was not observed during the third scan, because the sample melted at 210 °C during the...

Ngày tải lên: 14/02/2014, 03:20

... it takes the position of the adenine ring in the ATP-binding site, as shown in Fig The oxygen atoms of the pantoate are spatially coincident with the nitrogen atoms of the adenine ring The O1, ... The backbone carbonyl oxygen of Phe56 is also hydrogenbonded to the O4 atom of pantoate via one of the water molecules in the same network The phenolic oxygen of Tyr71 is hydrogen-bonded to the ... in the presence of ATP, the His34 backbone HN chemical shift reverted back to the resonance position observed for the free form of the protein The observed changes in resonance positions in the...

Ngày tải lên: 16/02/2014, 09:20

... model and the experimental data: N X IðSj Þ À Iexp ðSj Þ2 v2 ¼ ð8Þ N À j¼1 rðSj Þ where for each momentum transfer value, Sj, I(Sj) is the theoretical scattering, Iexp(Sj) is the experimentally ... estimation of the maximal dimension The forward scattering is proportional to the product of the molecular mass and concentration of the scattering particle For a mixture of particles, the total ... us Neither of these parameters are within the range of our experimental observations, and therefore the predominant species in solution are the monomer and dimer Additional evidence that the crystallographic...

Ngày tải lên: 22/02/2014, 07:20

... enhances the rate due to the release of the sixth axial ligand from the heme-iron which allows for the peroxide anion to bind At pH 4.5 the FEBS Journal 272 (2005) 2441–2455 ª 2005 FEBS At pH 7.0 the ... groups of C15 and C18 form thioether linkages with the two vinyl groups of the heme The N-terminal a-helix (helix 1) is distorted so the thioether bond from C15 to the heme can form (Fig 1) Such ... are extremely sensitive to the chemical nature of the axial ligands to the hemeiron [41] Upon replacing the native Met ligand with either an exogenous or protein-based ligand a change in the distribution...

Ngày tải lên: 07/03/2014, 17:20

... sample of 10% of the X- ray data was excluded from the refinement and was taken as the test data set, and the agreement between the calculated and observed structure factors of the test data set ... concentration exceeded M These results reflect the tightness of the heme attaching to the polypeptide of cyt b5 For the Phe35fiTyr mutant the heme pocket traps the heme even more strongly than the wild-type ... of these ligands remains attached to the heme in the unfolded stateÕ [49,50] Here, we provide the detailed CD spectra evidencing the existence of the intermediate and a reasonable explanation The...

Ngày tải lên: 08/03/2014, 10:20

... hydrogen-bonded to the carbonyl oxygen of Arg106 (b) The N-terminal nitrogens of these three residues are hydrogen-bonded to the carbonyl oxygen of Asn107 (c) The C-terminal carbonyl oxygens of these residues ... are grouped in a superfamily of metzincin which exhibits some typical structural features, such as the Met-turn and active-site consensus HExxHxxGxxH sequence [15–17] Some organisms and mammalian ... bond to the carbonyl oxygen of Arg106, as the side-chain carboxylic group of Asp (pKa ¼ 3.65) is deprotonated in our assay system (pH 8.0) On the other hand, the small Ala residue does not experience...

Ngày tải lên: 08/03/2014, 23:20

... shown in the following, the interpretation of the EXAFS of the mutant enzymes is conrmed by a comparative analysis of the zinc K-edge spectra (XANES spectra, see Fig 2) of the wild-type and the mutants ... Thus, already the visual inspection of the EXAFS data suggests that the number of sulfur atoms ligated to the zinc of MtaA increases upon formation of the MtaAcoenzyme M complex explainable by ... detector saturation The spot size of the X- ray beam on the sample was 4.75 ã 1.13 mm2; not more than four scans of 1-h duration were taken on the same spot of the sample Comparison of the rst and fourth...

Ngày tải lên: 17/03/2014, 23:20

... lactose, is the natural substrate of the system Thus, GGal taken up by the Mgl transporter will induce expression of the lac operon, and so promote further uptake and utilization of the compound ... (2R)-glyceryl-b-D-galactopyranoside S Sooriyaarachchi et al Fig Extension of the GGal site Stereoview of the residues lining the water-filled tunnel that extends from the glyceryl moiety to the surface of GBP are shown Thr110 ... with O2¢ These interactions increase the number of hydrogen bonds between the protein and ligand by five compared with the monosaccharides The glyceryl moiety of GBP lies near the hinge of the protein,...

Ngày tải lên: 23/03/2014, 04:21

... the proteins are dissociating from the DNA Therefore, cross-linking of Pol b and the XRCC1–DNA ligase IIIa heterodimer correlates well with the kinetics of repair We next immunodepleted the XRCC1–DNA ... immunodepletion of PNK did not affect the amounts of XRCC1 and Pol b in the extract (Fig 5B) Using the same extract, we found efficient cross-linking of XRCC1 to the 3¢-OH gapped substrate (Fig 5C) ... single-nucleotide gap in the absence of XRCC1–DNA ligase IIIa (Fig 3C), suggesting that Pol b probably binds first, processes the gapped DNA to the ligatable stage by filling the gap, and then recruits XRCC1–DNA...

Ngày tải lên: 23/03/2014, 11:20

... and the UFD of uba2 interact at the a1 region (b) The region below the a1 helix consists mainly of the N-terminal extension of a1 and loops between the b2 and b3 strands and the b6 strand and the ... shown together with the published structure of the E2–E3–substrate complex in Fig 7B In the modelled E1–E2–SUMO complex (Fig 7B, bottom), the E1 enzyme Aos1-uba2 forms the core structure The E2 ... of a long extended stretch between the fourth b-strand and the second a-helix [27] Chemical shift perturbation experiments have shown that the a3 helix of ubc9 displays affinity to the Cys domain...

Ngày tải lên: 30/03/2014, 04:20

... Anốt nóng lên x tia X Do tia X thờng có hai loại x x đặc trng x kìm hm - Bức x x đặc trng: Là nhng x tia X có lợng đặc trng cho nguyên tố chế tạo đích - Bức x kìm hm : x ba loại tơng ... tia X vật thể Chùm tia sau suy giảm tác động vào film tạo nên ảnh ảnh X- Quang ảnh x p chồng nghĩa kết chồng lên hình ảnh đối tợng nằm đờng tia X Trớc hết ta tìm hiểu x tia X B1 Bức x tia X Tia ... loại X - Quang Thiết bị chụp X- Quang đợc phân loại theo nhiều cách khác nh: - Phân loại theo chức - Phân loại theo công suất - Phân loại theo công nghệ - Phân loại theo khả động - Phân loại theo...

Ngày tải lên: 14/05/2014, 09:09

... never exposed to the sky The official goal of the experiment: the detection of X- ray fluorescence from the lunar soil as a means to identify the composition of the soil In other words, X rays and ... a beam of X rays; the amount of attenuation depends on the atomic number of the material, its density, its thickness, and the energy of the X ray itself The detection of an X ray is therefore ... with the X- rays used in dentists’ and doctors’ offices There, the X rays have interacted with light-sensitive grains on photographic film.10 The absorption of the X rays by the grains causes the...

Ngày tải lên: 11/06/2014, 10:39

... each fixed structure type X (X = C, I, D), the size n of clusters follows a lognormal distribution fX (n) = exp − sX /2 2π X sX exp − log n − log X 2s2 X , (4) M Ladisa et al with mode X and ... profile, the NSR increases from 2% to 5% (see Figure and text for details) where SX denotes the size of the largest cluster of type X, xX is the number fraction of each structure type ( X xX = 1), ... Parameter X sX n0 X X X wX 4000 3000 2000 1000 0.2 0.3 0.4 0.5 0.6 ϑ (rad) 0.7 0.8 0.9 (7) Figure 1: Synthetic XRD intensity profiles as a function of the scattering angle From the upper to the lower...

Ngày tải lên: 22/06/2014, 20:20

... If drx = the wood density measured by x ray: apparent density of the cell wall = drx / cell wall proportion = drx · S/s = drx · R · T / [X · (T + R) – X2 ] = drx · R · T / [X · (T + R – X) ] 2.3.2 ... = (R – x) · (T – x) Figure Rectangular (left) and hexagonal (right) cell and lumen models Let X = · x = width of the double cell wall: s = R · T – [(R – X) · (T – X) ], s = X · (T + R) – X2 , s ... again, if drx = the wood density measured by x ray: apparent density of the cell wall = drx / cell wall proportion = drx · S/s = drx · H2 / (H2 – H’2) The use of rectangular and hexagonal models...

Ngày tải lên: 08/08/2014, 01:22

... the derivative of the spline function Theoretically, the maximum represents an inflexion point in the intra-ring wood density profile and could be determined mathematically Another study [18] also ... 18] to define the earlywood latewood transition These methods are commonly known as maximum derivative methods where the transition point is generally defined as the maximum of the derivative ... were extracted with cyclohexane/ethanol (2:1) solution for 24 hours and then with hot water for another 24 hours to remove extraneous compounds After the extraction, the strips were air dried...

Ngày tải lên: 08/08/2014, 14:20

... automatically The neck axis was positioned in the middle of the femoral neck, bisecting the centre of the neck The femoral axis was determined as a line parallel to the femoral shaft passing through the ... the patient's hips at 15° internal rotation From the digitized x- rays the minimal joint space width (JSW) was assessed at the medial, axial, superior and lateral points of the joint or any other ... in the model: the BMC of the medial part of the femoral head, the BMC of the inferior part of the femoral head and the BMC of the femoral neck (Model 2) After cross-validation the model's performance...

Ngày tải lên: 09/08/2014, 14:22

... with high density and excellent stability Although the sizes of these nanoparticles are smaller than the currently achieved resolution of X- ray microscopy, the aggregation of the nanoparticles after ... modulating the size and the number of formed vesicles Further studies on the details of the dynamics of these processes with respect to the size of the clusters are underway Figure 13 emphasizes another ... water was exposed for to the x- rays emitted by the 01A beamline of the National Synchrotron Radiation Research Center (NSRRC), Hisnchu, Taiwan The photon energies of this beamline are in the 8-15...

Ngày tải lên: 11/08/2014, 00:23

... [13] The principle of this imaging method is based on the autofluorescence of endogenous or exogenous fluorophores inside the tissues after excitation by an external laser light source The laser ... of the airway wall are obtained by placing the tip of the miniprobe onto the airway wall surface Another advantage of FCFM and its miniprobe is the ability to reach and therefore visualize the ... 10% spray in the nose and throat Instillation of Lignocaine 1% solution in separate lung segments was applied to further dampen the cough reflex The oxygen saturation and heart rate of the participant...

Ngày tải lên: 12/08/2014, 13:22