Publications by authors named "Kanematsu Y"

Deuterium isotope effects on interaction energies and geometrical parameters in several HO(DO)ene and HO+(DO)yne complexes, which involve O-H(D)π interactions, have been analyzed using the MP2 level of the multi-component molecular orbital method (MC_MP2), which can incorporate the nuclear quantum effects of light nuclei, such as protons and deuterons. The MC_MP2 calculations revealed that DO replacement reduced the interaction energies of the complexes and induced changes in geometrical parameters. In addition, natural energy decomposition analysis (NEDA) revealed a strong correlation between the H/D isotope effects on the H/Dπ distances and on each energy component.

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  • The study aimed to analyze the ischemic penumbra and prognosis in patients with acute cerebral infarction using multi-delay pseudo-continuous arterial spin-labeling (pCASL) imaging data, focusing on cerebral blood flow (CBF) and delay time (DT).
  • The participant group consisted of 25 patients treated for cerebral infarction, with evaluations including CBF, DT, infarct sizes, and clinical outcomes through NIHSS scores, alongside treatment variations such as tPA and thrombectomy.
  • Results indicated a significant relationship between CBF and infarct size and NIHSS scores, with DT at the penumbra identified as the most reliable predictor of infarct enlargement, particularly in patients who did not achieve recanalization
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  • - The study investigates how charge transfer occurs during chemical reactions at metal-organic interfaces, focusing on a self-assembled monolayer (Im-SAM) on gold, using various spectroscopic techniques and theoretical calculations.
  • - Researchers aimed to see if adding atomic hydrogen to the imidazole groups in the Im-SAM would lead to the formation of stable imidazolium cations and promote electron transfer to the gold substrate.
  • - Results showed that hydrogen irradiation resulted in imidazolium cation formation and confirmed changes in work function, indicating successful electron transfer processes despite the insulating layer of alkanethiolate.
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Purpose: The preoperative assessment of carotid plaques is necessary to render revascularization safe and effective. The aim of this study is to evaluate the usefulness of chemical exchange saturation transfer (CEST)-MRI, particularly amide proton transfer (APT) imaging as a preoperative carotid plaque diagnostic tool.

Methods: We recorded the APT signal intensity on concentration maps of 34 patients scheduled for carotid endarterectomy.

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By introducing main-group elements such as boron and bismuth to π-conjugated systems, it is possible to modify the optical properties of π-conjugated materials through orbital interactions between the orbital on the elements and π/π*-orbitals, and the heavy atom effect. Moreover, bismuth, which is the heaviest stable element, induces a significant heavy atom effect, making organobismuth compounds promising for applications as phosphorescent materials. In this study, we synthesized new room-temperature phosphorescent materials by incorporating bismuth into thiophene units.

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The colorless solution of furan-2-yl bis(indolyl)methane (BIM) is newly revealed to work as a palladium (Pd) ion-selective chromogenic agent by turning orange. 5-(-Methyl--phenyl-aminomethyl)-furan-2-yl BIM could be synthesized from 5-chloromethylfurfural as a biorenewable feedstock one-pot and double functionalization, and a mixture of its solution and Pd ions showed the highest absorbance at 465 nm in UV-Vis analysis. On the other hand, other metal ions (Cu, Cr, Cr, Fe, Fe, Ni, Zn, In, Pt, or Ce) exhibited no response.

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Purpose: Non-convulsive status epilepticus (NCSE) is characterized by repetitive or continuous seizures without convulsions. Arterial spin labeling (ASL) is useful for assessing hyperperfusion due to neurovascular unit coupling in patients with NCSE; subarachnoid hemorrhage (SAH) impairs the neurovascular unit. We hypothesized that the sensitivity of ASL in detecting NCSE is low in patients with SAH during the acute phase.

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Background: A rete mirabile is a rare vascular anomaly, with posterior cerebral artery (PCA) involvement being especially rare. Its pathogenesis has been speculated as a remnant of "distal annexation" between the primitive anterior choroidal artery (AchA) and the PCA at this site, but the exact mechanisms remain unclear.

Observations: A 29-year-old man presented with subarachnoid hemorrhage.

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Article Synopsis
  • P450nor is a heme enzyme that converts nitric oxide (NO) into nitrous oxide (N2O) and has a complex catalytic cycle with three main steps.
  • Researchers used B3LYP calculations to investigate the unknown reaction pathway for NO generation from an intermediate, validating their model by examining heme distortions in P450nor versus other oxidoreductases.
  • Their findings revealed that the electrostatic environment of P450nor does not significantly impact the hydride affinity in the active site or the NO generation process, indicating that the reaction depends mainly on the reactivity of the heme cofactor.
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The gain of the microchannel plate temporally drops after an ion initiates an electron avalanche. Electron multiplication was expected to deplete the charge from the microchannel wall and produce the depleted charge (wall charge). Moreover, it was reported that the gain drop occurred not only in the activated channels, where the electrons are multiplied, but also in the surrounding channels.

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Background: We present the case of an individual with acute occlusion of the middle cerebral artery caused by atherosclerosis. The patient underwent angioplasty using a coronary perfusion balloon, which resulted in a favorable clinical outcome.

Case Description: A 66-year-old male patient presented with an acute onset of right hemiplegia and dysarthria.

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Ice is the most fundamental hydrogen-bonded system in which the hydrogen nuclear quantum effect significantly impacts the structure and relevant thermochemical and spectroscopic properties. While ice was experimentally investigated using proton nuclear magnetic resonance spectroscopy more than 40 years ago, the corresponding theoretical investigations have been rarely reported due to the difficulty in evaluating how the proton nuclear quantum effect influences the spectral characteristics of such a condensed material. In this study, we applied a combination of the ONIOM and multicomponent molecular orbital (MC_MO) methods for calculating the anisotropic and isotropic components of the nuclear magnetic shielding tensor of the hexagonal ice crystal to quantify the effects of nuclear quantum fluctuations on the spectroscopic properties of ice.

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Background: We report two cases who underwent mechanical thrombectomy using a stent retriever in advance of urgent carotid artery stenting (CAS) for carotid artery stenosis with free-floating thrombus (FFT).

Case Description: Two patients showing symptomatic carotid artery stenosis with FFT underwent urgent endovascular surgery due to progressive neurological symptoms. The first case showed an FFT with 70% internal carotid artery (ICA) stenosis.

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Background And Objectives: Intravenous indocyanine green (IV-ICG) videoangiography is commonly performed to detect blood flow in the microscopic view. However, intra-arterial ICG (IA-ICG) videoangiography provides high-contrast imaging, repeatability within a short period of time, and clear-cut separation of the arterial and venous phases compared with IV-ICG. These features are useful for detecting retrograde venous drainage (RVD) and shunt occlusion in arteriovenous fistulae (AVF) surgery.

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Background: Intravenous recombinant tissue plasminogen activator (IV rt-PA) and endovascular treatment have been performed for severe large vessel occlusion (LVO) and the results have been reported at high levels of evidence. However, acute treatment for LVO with mild symptom remains controversial. We retrospectively examined prognostic factors for LVO with mild symptoms.

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Background: Cerebral microbleeds (CMBs) due to traumatic brain injuries (TBI) have been shown to lead to cognitive decline and impairment. CMBs caused by TBI may be associated with pathophysiological mechanisms involving inflammation and the accumulation of amyloid-β (Aβ), tau, and phosphorylated tau (p-tau), contributing to cognitive abnormalities. However, their relationships remain unclear.

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Structure-function relationships in proteins have been one of the crucial scientific topics in recent research. Heme proteins have diverse and pivotal biological functions. Therefore, clarifying their structure-function correlation is significant to understand their functional mechanism and is informative for various fields of science.

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Myoepithelial carcinoma of the nasal cavity is extremely rare. We report the case of a 66-year-old man with myoepithelial carcinoma of the nasal cavity. Computed tomography (CT) and magnetic resonance imaging revealed a lobulated soft tissue mass with central necrosis and hemorrhage, as well as an invasion of the skull base and left orbit.

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Objective: An understanding of the complex morphology of an arteriovenous malformation (AVM) is important for successful resection. We have previously reported the utility of intra-arterial indocyanine green (ICG) videoangiography for this purpose, but that method cannot detect the angioarchitecture covered by brain tissue. 3-dimensional (3D) multimodal fusion imaging is reportedly useful for this same purpose, but cannot always visualize the exact angioarchitecture due to poor source images and processing techniques.

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The major cytoskeleton protein actin undergoes cyclic transitions between the monomeric G-form and the filamentous F-form, which drive organelle transport and cell motility. This mechanical work is driven by the ATPase activity at the catalytic site in the F-form. For deeper understanding of the actin cellular functions, the reaction mechanism must be elucidated.

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Heme proteins serve diverse and pivotal biological functions. Therefore, clarifying the mechanisms of these diverse functions of heme is a crucial scientific topic. Distortion of heme porphyrin is one of the key factors regulating the chemical properties of heme.

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Background: Convexity dural arteriovenous fistulae (dAVF) usually reflux into cortical veins without involving the venous sinuses. Although direct drainage ligation is curative, transarterial embolization (TAE) may be an alternative treatment.

Case Description: Between September 2018 and January 2021, we encountered four patients with convexity dAVFs.

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Revascularization for common carotid artery (CCA) occlusion might be difficult. We reported our strategy for revascularizing CCA occlusion by giant clots. A 94-year-old woman was transferred to our hospital because of right hemiparesis and aphasia.

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Background: Dural arteriovenous fistula (DAVF) can present with massive hematoma, which sometimes requires emergent removal. Therefore, a surgical strategy for single-session hematoma removal and shunt occlusion in the same surgical field is important.

Observations: A 73-year-old man was transferred to the authors' hospital with a headache.

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Background: Sufficient understanding of the angioarchitecture of an arteriovenous fistula (AVF) at the craniocervical junction (CCJ) is crucial to surgical treatment but is often difficult because of the complex vascular anatomy. Intraarterial indocyanine green (ICG) videoangiography has emerged as a more useful option for understanding the vascular anatomy than intravenous ICG videoangiography. This report describes two cases of CCJ AVFs successfully treated by surgery using intraarterial ICG videoangiography and describes the efficacy of this technique.

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