関: SAXS

WordNet

slight or limited; especially in degree or intensity or scope; "a series of death struggles with small time in between"
a garment size for a small person
the slender part of the back
limited or below average in number or quantity or magnitude or extent; "a little dining room"; "a little house"; "a small car"; "a little (or small) group" (同)little
have fine or very small constituent particles; "a small misty rain"
on a small scale; "think small"
emit as rays; "That tower rays a laser beam for miles across the sky"
(mathematics) a straight line extending from a point
a branch of an umbel or an umbelliform inflorescence
any of the stiff bony spines in the fin of a fish
cartilaginous fishes having horizontally flattened bodies and enlarged winglike pectoral fins with gills on the underside; most swim by moving the pectoral fins
move or proceed at an angle; "he angled his way into the room"
the space between two lines or planes that intersect; the inclination of one line to another; measured in degrees or radians
fish with a hook
a light shower that falls in some locations and not others nearby (同)sprinkle, sprinkling
a small number (of something) dispersed haphazardly; "the first scatterings of green"; "a sprinkling of grey at his temples" (同)sprinkling
the physical process in which particles are deflected haphazardly as a result of collisions
the 24th letter of the Roman alphabet (同)x, ex

PrepTutorEJDIC

(大きさが)『小さい』,小形の;(量が)『少ない』,わずかな / 『取るに足りない』,ささいな(trivial) / 《名詞の前にのみ用いて》(仕事・活動などが)『小規模の』,ささやかな / 心が狭い,利己的な / (音・声が)弱い,小さい / (文字が)小型の,小文字の / 《the~》小さいもの;(…の)細い部分《+『of』+『名』》 / 《複数形で》《英》(衣類・ハンカチなどの)小物,小間物 / 小さく,細かく / (声などが)低く,弱く / 小規模に,こぢんまりと
『光線』;熱線;放射線 / 《a ~》(希望などの)一筋(ひとすじ),ごく少量《+『of』+『名』》 / 放射状に突き出たもの;(ヒトデなどの)腕
(魚の)エイ
『かど』,すみ(corner) / 『角』,角度 / 《話》(ものを見る)角度,観点(point of view) / …'を'ある角度に動かす(向ける,曲げる) / …'を'ある角度から見る
(楽しみとして)魚釣りをする;(魚を)釣る《+『for』+『名』》
〈U〉〈C〉まき散らすこと,散布 / (また scatter)〈C〉《単数形で》分散した少数(少量)(の…)《+『of』+『名』》
Christ / Christian

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/10/26 15:00:12」(JST)

wiki en

Concepts common to small-angle X-ray scattering and small-angle neutron scattering are described in the overarching lemma small-angle scattering.

Small-angle X-ray scattering (SAXS) is a small-angle scattering (SAS) technique where the elastic scattering of X-rays (wavelength 0.1 ... 0.2 nm) by a sample which has inhomogeneities in the nm-range, is recorded at very low angles (typically 0.1 - 10°). This angular range contains information about the shape and size of macromolecules, characteristic distances of partially ordered materials, pore sizes, and other data. SAXS is capable of delivering structural information of macromolecules between 5 and 25 nm, of repeat distances in partially ordered systems of up to 150 nm.^[1] USAXS (ultra-small angle X-ray scattering) can resolve even larger dimensions.

SAXS and USAXS belong to a family of X-ray scattering techniques that are used in the characterization of materials. In the case of biological macromolecules such as proteins, the advantage of SAXS over crystallography is that a crystalline sample is not needed. Nuclear magnetic resonance spectroscopy methods encounter problems with macromolecules of higher molecular mass (> 30-40 kDa). However, owing to the random orientation of dissolved or partially ordered molecules, the spatial averaging leads to a loss of information in SAXS compared to crystallography.

Applications

SAXS is used for the determination of the microscale or nanoscale structure of particle systems in terms of such parameters as averaged particle sizes, shapes, distribution, and surface-to-volume ratio. The materials can be solid or liquid and they can contain solid, liquid or gaseous domains (so-called particles) of the same or another material in any combination. Not only particles, but also the structure of ordered systems like lamellae, and fractal-like materials can be studied. The method is accurate, non-destructive and usually requires only a minimum of sample preparation. Applications are very broad and include colloids of all types, metals, cement, oil, polymers, plastics, proteins, foods and pharmaceuticals can be found in research as well as in quality control. The X-ray source can be a laboratory source or synchrotron light which provides a higher X-ray flux.

SAXS instruments

In a SAXS instrument a monochromatic beam of X-rays is brought to a sample from which some of the X-rays scatter, while most simply go through the sample without interacting with it. The scattered X-rays form a scattering pattern which is then detected at a detector which is typically a 2-dimensional flat X-ray detector situated behind the sample perpendicular to the direction of the primary beam that initially hit the sample. The scattering pattern contains the information on the structure of the sample. The major problem that must be overcome in SAXS instrumentation is the separation of the weak scattered intensity from the strong main beam. The smaller the desired angle, the more difficult this becomes. The problem is comparable to one encountered when trying to observe a weakly radiant object close to the sun, like the sun's corona. Only if the moon blocks out the main light source does the corona become visible. Likewise, in SAXS the non-scattered beam that merely travels through the sample must be blocked, without blocking the closely adjacent scattered radiation. Most available X-ray sources produce divergent beams and this compounds the problem. In principle the problem could be overcome by focusing the beam, but this is not easy when dealing with X-rays and was previously not done except on synchrotrons where large bent mirrors can be used. This is why most laboratory small angle devices rely on collimation instead. Laboratory SAXS instruments can be divided into two main groups: point-collimation and line-collimation instruments:

Point-collimation instruments have pinholes that shape the X-ray beam to a small circular or elliptical spot that illuminates the sample. Thus the scattering is centro-symmetrically distributed around the primary X-ray beam and the scattering pattern in the detection plane consists of circles around the primary beam. Owing to the small illuminated sample volume and the wastefulness of the collimation process — only those photons are allowed to pass that happen to fly in the right direction — the scattered intensity is small and therefore the measurement time is in the order of hours or days in case of very weak scatterers. If focusing optics like bent mirrors or bent monochromator crystals or collimating and monochromating optics like multilayers are used, measurement time can be greatly reduced. Point-collimation allows the orientation of non-isotropic systems (fibres, sheared liquids) to be determined.
Line-collimation instruments confine the beam only in one dimension so that the beam profile is a long but narrow line. The illuminated sample volume is much larger compared to point-collimation and the scattered intensity at the same flux density is proportionally larger. Thus measuring times with line-collimation SAXS instruments are much shorter compared to point-collimation and are in the range of minutes. A disadvantage is that the recorded pattern is essentially an integrated superposition (a self-convolution) of many pinhole adjacent pinhole patterns. The resulting smearing can be easily removed using model-free algorithms or deconvolution methods based on Fourier transformation, but only if the system is isotropic. Line collimation is of great benefit for any isotropic nanostructured materials, e.g. proteins, surfactants, particle dispersion and emulsions.

References

^ Glatter O, Kratky O, ed. (1982). Small Angle X-ray Scattering. Academic Press. ISBN 0-12-286280-5. http://physchem.kfunigraz.ac.at/sm/Software.htm.

External links

SAXS at a Synchrotron
A movie explaining the workings of a pinhole collimated SAXS apparatus
A movie explaining the workings of a slit collimated SAXS apparatus
A movie demonstrating small-angle scattering using laserlight on a hair
Small-angle scattering special interest group at the Advanced Photon Source, Argonne National Laboratory, USA

List of SAXS beamlines

SAXS/D, SSRL Beamline 4-2, SLAC USA
SAXS/WAXS/GISAXS Beamline, Advanced Light Source 7.3.3, LBNL USA
SAXS endstation at the SIBYLS Beamline, Advanced Light Source 12.3.1 USA
SAXS1 and SAXS2 beamlines at Brazilian Synchrotron Light Laboratory Brazil
ID02 SAXS/WAXS/USAXS beamline Grenoble, France
SWING Beamline at Synchrotron SOLEIL Saint-Aubin, France
Anomalous small-angle x-ray scattering (ASAXS) Hamburg, Germany
BW4 Beamline at DESY (DORIS) Hamburg, Germany
X33 Beamline at DESY (DORIS) Hamburg, Germany
P12 Beamline at DESY (PETRA III) Hamburg, Germany
BL9 beamline of DELTA, Technical University of Dortmund Germany
SAXS Beamline at Elettra Trieste, Italy
cSAXS beamline, Swiss Light Source Villigen, Switzerland
I22 beamline at Diamond Light Source, Harwell Science & Innovation Campus England, UK
APS USAXS instrument, Advanced Photon Source, Argonne National Laboratory USA
BNL SAXS/WAXS X9 beamline, National Synchrotron Light Source, Brookhaven National Laboratory USA
D1 beamline (GISAXS/GIWAXS/SAXS), CHESS Cornell University USA
G1 beamline (SAXS/BioSAXS/GISAXS), CHESS Cornell University USA
SaxsWaxs, BM26B Dutch-Belgian beamline at ESRF Grenoble, France
3C, 4C, and 9A beamlines at PAL (SAXS I, SAXS II, and U-SAXS), POSTECH, Pohang, South Korea

SAXS Instrument Manufacturers

Anton Paar GmbH, Austria
Bruker AXS, Germany
Hecus X-Ray Systems Graz, Austria
PANalytical. The Netherlands
Rigaku Corporation, Japan
Xenocs, France

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English Journal

Lubrication synergy: Mixture of hyaluronan and dipalmitoylphosphatidylcholine (DPPC) vesicles.

Raj A1, Wang M2, Zander T3, Wieland DC4, Liu X5, An J6, Garamus VM7, Willumeit-Römer R8, Fielden M9, Claesson PM10, Dėdinaitė A11.
Journal of colloid and interface science.J Colloid Interface Sci.2017 Feb 15;488:225-233. doi: 10.1016/j.jcis.2016.10.091. Epub 2016 Nov 1.
Phospholipids and hyaluronan have been implied to fulfil important roles in synovial joint lubrication. Since both components are present in synovial fluid, self-assembly structures formed by them should also be present. We demonstrate by small angle X-ray scattering that hyaluronan associates with
PMID 27835815

Miscanthus Giganteus: A commercially viable sustainable source of cellulose nanocrystals.

Cudjoe E1, Hunsen M2, Xue Z1, Way AE1, Barrios E1, Olson RA1, Hore MJ1, Rowan SJ3.
Carbohydrate polymers.Carbohydr Polym.2017 Jan 2;155:230-241. doi: 10.1016/j.carbpol.2016.08.049. Epub 2016 Aug 20.
With a goal of identifying a new scalable source for cellulose nanocrystals (CNCs), we successfully isolated CNCs from a sustainable, non-invasive grass, Miscanthus x. Giganteus (MxG). Subjecting MxG stalks to base hydrolysis, bleaching and acid hydrolysis allowed access to cellulose nanocrystals (M
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Integration of lysozyme into chitosan nanoparticles for improving antibacterial activity.

Wu T1, Wu C2, Fu S1, Wang L1, Yuan C3, Chen S1, Hu Y4.
Carbohydrate polymers.Carbohydr Polym.2017 Jan 2;155:192-200. doi: 10.1016/j.carbpol.2016.08.076. Epub 2016 Aug 25.
Lysozyme was integrated into chitosan nanoparticles (CS-NPs) to improve the antibacterial activity. CS-NPs and chitosan-lysozyme nanoparticles (CS-Lys-NPs) were prepared according to the ionic gelation technique and then characterized by average size, zeta potential, polydispersity index (PDI), atom
PMID 27702504

Japanese Journal

Kinetics of low pH-induced lamellar to bicontinuous cubic phase transition in dioleoylphosphatidylserine/monoolein

Alam Mahay Md.,Oka Toshihiko,Ohta Noboru,Yamazaki Masahito
Journal of Chemical Physics 134(14), 145102, 2011-04-12
… To reveal their kinetic pathway and mechanism, we investigated the low pH-induced L(α) to Q(II) (D) phase transitions in 20%-dioleoylphosphatidylserine (DOPS)/80%-monoolein (MO) using time-resolved small-angle x-ray scattering and a rapid mixing method. …
NAID 120003021844

Near-surface relaxation structure of annealed block copolymer film on Si substrates examined by grazing-incidence small-angle scattering utilizing soft X-rays

Okuda Hiroshi,Takeshita Kohki,Ochiai Shojiro,Sakurai Shin-ichi,Kitajima Yoshinori
Journal of Applied Crystallography 44(2), 380-384, 2011-04
… Two-dimensional grazing-incidence small-angle X-ray scattering (GISAXS) measurements of SEBS8 block copolymer films deposited on Si(001) substrates have been performed to demonstrate depth-sensitive GISAXS utilizing soft X-rays of 1.77 keV. …
NAID 80021714663