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131.
132.
Toshihiko Ogura 《Biochemical and biophysical research communications》2010,391(1):198-202
Analytical tools of nanometre-scale resolution are indispensable in the fields of biology, physics and chemistry. One suitable tool, the soft X-ray microscope, provides high spatial resolution of visible light for wet specimens. For biological specimens, X-rays of water-window wavelength between carbon (284 eV; 4.3 nm) and oxygen (540 eV; 2.3 nm) absorption edges provide high-contrast imaging of biological samples in water. Among types of X-ray microscope, the transmission X-ray microscope using a synchrotron radiation source with diffractive zone plates offers the highest spatial resolution, approaching 15-10 nm. However, even higher resolution is required to measure proteins and protein complexes in biological specimens; therefore, a new type of X-ray microscope with higher resolution that uses a simple light source is desirable. Here we report a novel scanning-electron generation X-ray microscope (SGXM) that demonstrates direct imaging of unstained wet biological specimens. We deposited wet yeasts in the space between two silicon nitride (Si3N4) films. A scanning electron beam of accelerating voltage 5 keV and current 1.6 nA irradiates the titanium (Ti)-coated Si3N4 film, and the soft X-ray signal from it is detected by an X-ray photodiode (PD) placed below the sample. The SGXM can theoretically achieve better than 5 nm resolution. Our method can be utilized easily for various wet biological samples of bacteria, viruses, and protein complexes. 相似文献
133.
Following our established theoretical model to deal with the second-harmonic generation (SHG) excited by a linearly polarized
focused beam in type I collagen, in this paper, we further quantitatively characterize the differences between SHG emissions
in type I collagen excited by collimated and focused beams. The effects of the linear polarization angle (α) and the fibril polarity characterized by the hyperpolarizability ratio ρ on SHG emission has been compared under collimated and focused beam excitation, respectively. In particular, SHG emission
components along the i axis ( I2w,i )\left( {I_{2\omega {,}i} } \right) (i = x,y,z), the induced SHG emission deviation angle γ
ij
, and the detected SHG signals (I
2ω,ij
) in the ij plane by rotating the applied polarizer angle φ
ij
have been investigated (i = x, x, y; j = y, z, z). Results show that under our simulation model, SHG emission in the xy plane, such as I
2ω,x
,I
2ω,y
,γ
xy
and I
2ω,xy
varying as polarization angle (α) under collimated and focused light, presents no significant difference. The reverse of the fibril polarity has induced great
impact on I
2ω,x
,γ
xy
and I
2ω,xy
in both collimated and focused light. I
2ω,x
and γ
xy
show similarity, but I
2ω,xy
at α = 30° demonstrates a slight difference in focused light to that in collimated light. Under focused light, the reverse of
fibril polarity causes obvious changes of the collected SHG intensity I
2ω,xz
and I
2ω,yz
at a special polarization angle α = 60° and γ
xz
, γ
yz
along α. 相似文献
134.
Di Pietro C Piro S Tabbì G Ragusa M Di Pietro V Zimmitti V Cuda F Anello M Consoli U Salinaro ET Caruso M Vancheri C Crimi N Sabini MG Cirrone GA Raffaele L Privitera G Pulvirenti A Giugno R Ferro A Cuttone G Lo Nigro S Purrello R Purrello F Purrello M 《Apoptosis : an international journal on programmed cell death》2006,11(1):57-66
135.
136.
Suitable instrumentation for laser-accelerated proton (ion) beams is critical for development of integrated, laser-driven ion accelerator systems. Instrumentation aimed at beam diagnostics and control must be applied to the driving laser pulse, the laser–plasma that forms at the target and the emergent proton (ion) bunch in a correlated way to develop these novel accelerators. This report is a brief overview of established diagnostic techniques and new developments based on material presented at the first workshop on ‘Instrumentation for Diagnostics and Control of Laser-accelerated Proton (Ion) Beams’ in Abingdon, UK. It includes radiochromic film (RCF), image plates (IP), micro-channel plates (MCP), Thomson spectrometers, prompt inline scintillators, time and space-resolved interferometry (TASRI) and nuclear activation schemes. Repetition-rated instrumentati on requirements for target metrology are also addressed. 相似文献
137.
138.
Experiments were conducted to measure optical backscatter and beam transmission of suspensions of 180, 150 and 90 μm sand,
and 40 μm clay, in a recirculation tank designed to house an optical backscatterance sensor (O.B.S.) and a beam transmissometer.
Particle size was determined using gravimetric techniques and Coulter counter. By contriving known sediment distributions
from the fractionated sediment samples, it was found that both the O.B.S. and beam transmissometer responded approximately
linearly to narrow band and broad band particle suspensions. The beam transmissometer showed greater sensitivity to the fine-grain
fraction of a poly-disperse suspension than the O.B.S. 相似文献
139.
Rushil Patel John Roberson Devina Prakash Rina Meyer Laura Hogan Christeen Azmy Valmore Suprenant Samuel Ryu Alexander Stessin 《Reports of Practical Oncology and Radiotherapy》2021,26(1):143
Primary hepatic rhabdomyosarcoma is rare, making decisions regarding locoregional management with resection and/or conventional radiation difficult. We present a novel treatment approach for a pediatric patient diagnosed with rhabdomyosarcoma diffusely involving the liver. This patient underwent treatment with yttrium-90 (Y-90) microspheres followed by external beam radiation therapy (EBRT ) to residual disease, interdigitated with systemic chemotherapy. Initial post-radiation imaging showed significant response to treatment, and she experienced minimal acute toxicities and no long-term toxicities. She developed recurrent PET-avid disease 23 months after Y-90 treatment, necessitating further local and continued systemic therapies. We report on the tumor control following Y-90 and EBRT treatment. 相似文献
140.
Tomoko Abe 《Journal of phycology》2012,48(3):706-709
In the marine crop Pyropia yezoensis (Ueda) M. S. Hwang et H. G. Choi, it is known that conchospores from heterozygous conchocelis develop into sectored gametophytic blades (chimeras), but archeospores asexually released from haploid blades do not usually grow into chimeric blades. In this study, chimeras with mosaic pattern consisting of the green and wildtype colors were developed from archeospores that were released from a blade piece containing a cell cluster of green color induced by heavy‐ion beam irradiation. To make clear whether these archeospores were produced from the green‐colored cells or the wildtype‐colored cells, cell clusters of the green mutant, wildtype, and mosaic pattern were cut out from the grown chimera, and archeospores were released from each of the three blade pieces. Archeospores from the green‐mutant blade piece and from the wildtype blade piece developed into only green‐mutant blades and wildtype blades, respectively. In contrast, archeospores from the blade piece with mosaic pattern developed into green‐mutant blades, wildtype blades, and chimeric blades with mosaic pattern of the two colors, although the frequency of the chimeras was low. Because each gametophytic cell possesses a single plastid, it is difficult to explain the occurrence of the new chimeras as a mutation of the plastid DNA. Thus, the new chimeras are considered to be due to transposable elements in Pyropia. 相似文献