947 research outputs found
Macrophage migration inhibition-activity after implantation of methylcholanthrene-induced sarcoma, Ehrlich ascites cancer or mouse ascites hepatoma-134 cancer cells in mice
Cells from methylcholanthrene-induced tumor (MC-tumor), Ehrlich ascites cancer or mouse ascites hepatoma (MH-134) were subcutaneously implanted in dorsal area of mice to examine the specific cell mediated immunity following implantation. The migration index (MI) of lymphocytes was determined at various time periods after cell transplantation. The MI-activity increased under all three implantations, reached maximum at a certain period, decreased gradually and disappeared. The maximum MI-activity coincided with the proliferation period of the implanted tumor cells. This peak occurred on the tenth postimplantation day with MC-tumors, on the fifth day with Ehrlich ascites cancer and on the sixth day with MH-134 cancer. In lymphoid tissues of animals with MC-tumor and Ehrlich ascites cancer, strong MI-activity appeared early in the regional axillary lymph nodes, while weak activity was observed consistently in the distant mesenterial lymph nodes. The MI-activity of the splenic lymphoid cells resembled the axillary lymph nodes cell activity. The MI-activity of venous blood lymphoid cells was parallel to the average value of lymphoid cells of the spleen and axillary and mesenterial lymph nodes.</p
Properties of Reaction Intermediates from Unzipping Nanotubes via the Diketone Formation: A Computational Study
We investigated properties of an armchair nanotube attached by specific numbers of diketone groups along the tube axis using density functional theory (DFT) calculations. The results from DFT calculations show that multiple diketone attachments into an armchair nanotube cleave the CC bonds along the tube axis, forming a large hole. Then, the six-membered rings surrounding the hole are planarized, and zigzag edges appear. Due to these geometrical changes, the functionalized armchair nanotubes exhibit properties similar to those in corresponding graphene ribbons with zigzag edges. For example, diketone-attached nanotubes have a spin-polarized ground state with frontier orbitals whose amplitudes are localized at diketone O atoms. As a consequence of the existence of the localized orbitals, unpaired electrons appear only on the diketone O atoms in an armchair nanotube
Reactive Oxygen Species and Sperm Cells
Many cases of male factor infertility are idiopathic, but 30–40% of cases may have excessive levels of reactive oxygen species (ROS) in their semen. The origins of endogenous ROS are leukocytes and immature spermatozoa, and external causes are various. On the contrary, seminal plasma contains various antioxidants. Low levels of ROS are essential for the fertilization process, but excessive levels of ROS lead to oxidative stress and can have harmful effects such as lipid peroxidation of a membrane, sperm deoxyribonucleic acid fragmentation, and apoptosis on the fertile capacity. In order to evaluate oxidative stress appropriately, ROS is measured by the chemiluminescence method with neat semen and quantification of 8-OH-2′-deoxyguanosine and malondialdehyde in seminal plasma. Antioxidant potential is often measured using total antioxidant capacity (TAC) assay. The oxidation-reduction potential measured by a MiOXSYS analyzer is a novel, easier, quicker, and less expensive technology to measure oxidative stress. In order to minimize oxidative stress and improve clinical outcomes, sperm-sorting methods, lifestyle modifications, shortening the ejaculatory abstinence, and treatments such as oral antioxidants, varicocelectomy, and testicular sperm extraction are taken into account. As a future prospect, proteomics, metabolomics, and genomics are still developing areas that have the potential to discover new findings and highly sensitive biomarkers
Automated Sperm Assessment Framework and Neural Network Specialized for Sperm Video Recognition
Infertility is a global health problem, and an increasing number of couples
are seeking medical assistance to achieve reproduction, at least half of which
are caused by men. The success rate of assisted reproductive technologies
depends on sperm assessment, in which experts determine whether sperm can be
used for reproduction based on morphology and motility of sperm. Previous sperm
assessment studies with deep learning have used datasets comprising images that
include only sperm heads, which cannot consider motility and other morphologies
of sperm. Furthermore, the labels of the dataset are one-hot, which provides
insufficient support for experts, because assessment results are inconsistent
between experts, and they have no absolute answer. Therefore, we constructed
the video dataset for sperm assessment whose videos include sperm head as well
as neck and tail, and its labels were annotated with soft-label. Furthermore,
we proposed the sperm assessment framework and the neural network, RoSTFine,
for sperm video recognition. Experimental results showed that RoSTFine could
improve the sperm assessment performances compared to existing video
recognition models and focus strongly on important sperm parts (i.e., head and
neck).Comment: Accepted at Winter Conference on Applications of Computer Vision
(WACV) 202
Rearrangement of Variable Region T Cell Receptor y Genes in Acute Lymphoblastic Leukemia Vy Gene Usage Differs in Mature and Immature T Cells
Using probes recognizing variable regions (V gamma) and joining regions (J gamma) of the T cell receptor (TCR) gamma gene, we have analyzed the usage of V gamma genes in 24 patients with T cell acute lymphoblastic leukemia (ALL) and 36 patients with B-precursor ALL. In CD3- T-ALL derived from immature T cells, V gamma genes more proximal to J gamma were frequently rearranged; V gamma 8, V gamma 9, V gamma 10, and V gamma 11 were used in 19 of 24 rearrangements. In contrast, CD3+ T-ALL derived from a more mature stage of T cell ontogeny, showed a high frequency of rearrangements involving V gamma genes distal to J gamma; V gamma 2, V gamma 3, V gamma 4, and V gamma 5 were used in 17 of 25 rearrangements. In B-precursor ALL, no notable bias of V gamma gene usage was observed. This probably reflects the possibility that TCR genes may not rearrange according to a T cell hierarchy when under control of a B cell gene program. Furthermore, deletions of those V gamma genes located 3' to rearranged V gamma genes were observed in all patients analyzed. This supports the theory that loop deletion is a major mechanism for TCR-gamma gene rearrangement
Fabrication of high strength PVA/SWCNT composite fibers by gel spinning
High-strength composite fibers were prepared from polyvinyl alcohol (PVA) (Degree of polymerization: 1500) reinforced by single-walled carbon nanotubes (SWCNTs) containing few defects. The SWCNTs were dispersed in a 10 wt.% PVA/dimethylsulfoxide solution using a mechanical homogenizer that reduced the size of SWCNT aggregations to smaller bundles. The macroscopically homogeneous dispersion was extruded into cold methanol to form fibers by gel spinning followed by a hot-drawing. The tensile strength of the well-oriented composite fibers with 0.3 wt.% SWCNTs was 2.2 GPa which is extremely high value among PVA composite fibers ever reported using a commercial grade PVA. The strength of neat PVA fibers prepared by the same procedure was 1.7 GPa. Structural analysis showed that the PVA component in the composite fibers possessed almost the same structure as that of neat PVA fibers. Hence a small amount of SWCNTs straightforward enhanced by 0.5 GPa the tensile strength of PVA fibers. The results of mechanical properties and Raman spectra for the SWCNT composites suggest the relatively good interfacial adhesion of the nanotubes and PVA that improves the load transfer from the polymer matrix to the reinforcing phase.ArticleCARBON. 48(7):1977-1984 (2010)journal articl
プレターゲティング法による薬物輸送を指向した新規融合抗体の創出
学位の種別:課程博士University of Tokyo(東京大学
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