Publications by authors named "Koji Kimura"

To tackle disorder in crystals and short- and intermediate-range order in amorphous materials, such as glass, we developed a carry-in diffractometer to utilise X-ray fluorescence holography (XFH) and anomalous X-ray scattering (AXS), facilitating element-specific analyses with atomic resolution using the wavelength tunability of a synchrotron X-ray source. Our diffractometer unifies XFH and AXS configurations to determine the crystal orientation via diffractometry. In particular, XFH was realised even for a crystal with blurred emission lines by a standing wave in a hologram, and high-throughput AXS with sufficient count statistics and energy resolution was achieved using three multi-array detectors with crystal analysers.

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In mammals, various molecules are involved in biochemical interaction between conceptus and endometrium for pregnancy recognition and establishment. In ruminants, interferon tau (IFNT) is the pregnancy recognition factor; however, IFNT alone does not explain corpus luteum maintenance. Although data on factors expressed during implantation has been accumulated, we hypothesized that the conceptus produces additional, uncharacterized molecules during the period of conceptus attachment.

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The local structure of a two-dimensional layered material, BiRhSe, in which superconducting (SC) and charge-density wave (CDW) states coexist, was investigated using Bi Lα and Lγ X-ray fluorescence holography (XFH). The crystal of BiRhSe adopts a monoclinic lattice with a space group of 2/ (No. 12) at room temperature; however, the structure below the CDW transition (∼240 K) is still unclear because of the difficulty in analyzing single-crystal X-ray diffraction.

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Embryo survival and pre-implantation development depend on uterine luminal fluid, which is believed to play a role in early embryonic death and infertility in cows. Extracellular vesicles (EVs) in the uterine luminal fluid contain microRNAs (miRNAs), crucial mediators of intercellular communication. miRNAs regulate conceptus-maternal interactions and participate in embryonic development by suppressing gene expression.

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The objective of this study is to evaluate the effect of hydrogen gas on the biological functions of human adipose-derived stem cells (hADSC) in cryopreservation. hADSC were cryopreserved by a commercial cell preservation solution in the presence of hydrogen gas. After cryopreservation at -80 °C, the viability, initial attachment morphology, and biological parameters of cells cryopreserved were evaluated to compare with those of cells cryopreserved in the absence of hydrogen gas.

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Cryptochrome (Cry) in some species could act as a quantum senser to detect the inclination angle of geomagnetic field, the function of which attributes the magnetic sensitivity of spins of unpaired electrons in radical pair (RP) in CRY generated by blue light irradiation. However, the effect of blue light on the structure and molecular behavior of Cry has not been well investigated. We conducted the size exclusion chromatography (SEC) and small-angle X-ray scattering (SAXS) analyses to inspect the molecular structure and behavior of cryptochrome 4a (ErCry4a) from European robin, a representative magnetosensory animal.

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Article Synopsis
  • Adalimumab (ADM) is a treatment for inflammatory bowel disease (IBD), but some patients stop responding to it, making it important to find ways to improve its effectiveness.
  • The study used a statistical method to predict how much ADM would be in patients' blood and its therapeutic effects during the initial treatment phase, comparing these predictions to real outcomes.
  • Results showed that the predictions were accurate in most cases, suggesting this new approach could help doctors tailor ADM treatment for IBD patients more effectively.
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A intermediate multidomain state and large crystallographic tilting of 1.78° for the (hh0) planes of a (001)-oriented single-domain Mn-doped BiFeO (BFMO) thin film were found when an electric field was applied along the [110] direction. The anomalous crystallographic tilting was caused by ferroelastic domain switching of the 109° domain switching.

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The local structure of the two-dimensional van der Waals material, FeGeTe, which exhibits unique structural/magnetic phase transitions, was investigated by Te K-edge extended X-ray absorption fine structure (EXAFS) and Te Kα X-ray fluorescence holography (XFH) over a wide temperature range. The formation of a trimer of Te atoms at low temperatures has been fully explored using these methods. An increase in the Te-Fe distance at approximately 150 K was suggested by EXAFS and presumably indicates the formation of a Te trimer.

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FeGeTe is a two-dimensional van der Waals material that exhibits ferromagnetic order with a high Curie temperature () of around room temperature. In addition to , two magnetic transitions occur with decreasing temperature, and a charge-ordered state is observed at low temperatures. We employed Ge Kα X-ray fluorescence holography (XFH) for FeGeTe to directly investigate the local structure in the charge-ordered state, i.

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Insulin-like growth factor-1 (IGF-1) plays a crucial role in follicular growth and stimulates steroid hormone production in bovine follicles. Steroid hormones are synthesized through the actions of steroidogenic enzymes, specifically STAR, CYP11A1, HSD3B, and CYP19A1 in both theca cells (TCs) and granulosa cells (GCs), under the influence of gonadotropins. Particularly, estradiol 17β (E2) assumes a central role in follicular development and selection by activating estrogen receptors β (ESR2) in GCs.

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Inelastic x-ray scattering (IXS) measurements were performed for observing the excitation of bulk plasmons in metallic liquid silicon (Si). The peak due to plasmon excitation was observed within the energy loss around 17 eV. Combined with IXS data of crystalline Si measured at several elevated temperatures, it was found that temperature dependence of the excitation energy in the crystalline solid state is explained by the electron gas including the band gap effect, whereas in the metallic liquid state near the melting point, it exhibits a departure from the electron gas; the plasmon energy takes a lower value than that of the electron gas.

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In Brief: Interferon tau (IFNT) stimulates lysosomal activation via the Janus-activated kinase in peripheral blood leukocytes during pregnancy recognition. IFNT-mediated lysosomal activation could serve as a novel marker for early pregnancy in cattle.

Abstract: IFNT is important in establishing pregnancy in ruminants.

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Point defect chemistry strongly affects the fundamental properties of materials and has a decisive impact on device performance. The Group-V dopant is prominent acceptor species with high hole concentration in CdTe; however, its local atomic structure is still not clear owing to difficulties in definitive measurements and discrepancies between experimental observations and theoretical models. Herein, we report on direct observation of the local structure for the As dopant in CdTe single crystals by the X-ray fluorescence holography (XFH) technique, which is a powerful tool to visualize three-dimensional atomic configurations around a specific element.

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Superovulation (SOV) treatment of cows results in unovulated follicles and inconsistent quality of the recovered embryos. It has been demonstrated that luteinizing hormone (LH) secretion is suppressed during SOV treatment of cows, which may cause insufficient follicle development and variation in the development of recovered embryos and unovulated follicles. Pulsatile gonadotropin-releasing hormone/LH secretion is controlled by the activity of kisspeptin, neurokinin B and dynorphin (KNDy) neurons in the arcuate nucleus in many mammals.

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Prostaglandin E2 (PGE2) is considered as a luteoprotective factor, influencing the corpus luteum during the early pregnant period in the bovine species. Cyclic AMP (cAMP) is activated in response to PGE2 and plays a role in many physiological processes. The maternal recognition signal, interferon τ (IFNT), induces PGE2 secretion from the endometrial epithelial cells, the function of which in stroma cells has not been completely understood.

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X-ray fluorescence holography (XFH) is a powerful atomic resolution technique capable of directly imaging the local atomic structure around atoms of a target element within a material. Although it is theoretically possible to use XFH to study the local structures of metal clusters in large protein crystals, the experiment has proven difficult to perform, especially on radiation-sensitive proteins. Here, the development of serial X-ray fluorescence holography to allow the direct recording of hologram patterns before the onset of radiation damage is reported.

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To investigate possible causes of reproductive failure, we conducted global endometrial gene expression analyses in fertile and subfertile cows. Ingenuity pathway analysis showed that RICTOR and SIRT3 are significant upstream regulators for highly expressed genes in fertile cows, and are predicted to be activated upstream regulators of normal mitochondrial respiration. Canonical pathway analysis revealed that these highly expressed genes are involved in the activation of mitochondrial oxidative phosphorylation.

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Doping a typical topological insulator, BiSe, with Ag impurity causes a semiconductor-metal (S-M) transition at 35 K. To deepen the understanding of this phenomenon, structural and transport properties of Ag-doped BiSe were studied. Single-crystal X-ray diffraction (SC-XRD) showed no structural transitions but slight shrinkage of the lattice, indicating no structural origin of the transition.

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In Brief: Spontaneous contraction of oviductal smooth muscle is essential for gamete transport to the fertilization site in mammals. This study sheds light on the mechanism of elevated contraction amplitude in the bovine oviductal isthmus just before ovulation.

Abstract: Rhythmic contraction of the oviducts is essential for transporting gametes and embryos at peri-ovulation; however, its regulatory mechanism during the estrous cycle is unclear.

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The oviductal epithelium consists of ciliated and non-ciliated cells, and their numbers vary depending on the segment of the oviduct and stage of the estrous cycle. Compared with the ampulla, fewer cyclic changes in the number of the two types of cells occur in the isthmus. Recently, we have reported that the epithelium in the ampullary oviduct is composed of many types of cells during different translational/transcriptional states, and their numbers change during the estrous cycle.

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X-ray fluorescence holography (XFH) is a relatively new technique capable of providing unique three-dimensional structural information around specific atoms that act as a light source in crystalline samples. So far, XFH has typically been applied to inorganic materials such as dopants in metals and semiconductors. Here, we investigate the possibility of using XFH to visualize the metal active site in sperm whale myoglobin (Mb), a monomeric oxygen storage heme protein.

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Early embryo and sperm transport through the oviductal isthmus depends on the contraction and relaxation of the smooth muscle layers. Dysfunction of the oviduct transport is considered to be one of the causes of infertility. For human infertility, Chinese medicine is used in East Asia.

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In ruminants, uterine glands play key roles in the establishment of pregnancy by secreting various factors into the uterine lumen. Although a three-dimensional (3D) culture system has been used for investigating cellular functions in vitro, the detailed functions of uterine gland have not been fully elucidated. In this study, we examined the benefits of 3D culture system to examine the innate functions of bovine uterine glands.

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Article Synopsis
  • The study aims to identify reliable predictors that can indicate how well patients with inflammatory bowel disease (IBD) will respond to anti-TNFα therapy, which includes medications like infliximab and adalimumab.
  • Researchers analyzed data from 26 IBD patients, using a pharmacokinetic and pharmacodynamic model to measure the relationship between inflammation suppression and treatment response.
  • The results showed a significant correlation between the ratio of Kanti-TNFα0/Kelse and improvement in disease activity, suggesting that this ratio can help tailor more effective treatments and avoid unnecessary use of anti-TNFα drugs.
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