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1.
World Neurosurg ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38734163

RESUMO

OBJECTIVE: Hemifacial spasm (HFS) results from vascular compression at the root exit of the facial nerve. Although the underlying etiology has yet to be identified, it has been suggested that congenital vascular anomalies are involved. We have hypothesized common trunk anomaly of the anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) which may play a role in HFS. However, no previous studies have directly compared the incidence of this anomaly between HFS patients and normal subjects. The present study was designed to address this gap in the literature. METHODS: This case-control study compared magnetic resonance angiography data from 65 HFS patients and 65 normal subjects. Dominant AICA/PICA is defined as the absence of PICA/AICA, with the remaining AICA/PICA supplying both vascular territories. The term "common trunk" encompasses both dominant AICA and dominant PICA. The frequency of common trunk and dominant AICA/PICA was compared between the 2 groups. RESULTS: There were no significant differences in the incidence of a common trunk (68.5% and 64.6%), dominant AICA (30.8% and 32.3%) and dominant PICA (37.7% and 32.3%) between the 2 groups. Additionally, no differences were found in the frequency of atherosclerosis risk factors. CONCLUSIONS: There was no apparent association between common trunk anomaly and HFS. It is suspected that some vascular anomalies other than a common trunk are involved in HFS.

2.
NMC Case Rep J ; 11: 109-112, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38756141

RESUMO

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a peripheral neuropathy caused by immune-mediated demyelination, causing tremors in 3.9%-58% of affected patients. This neuropathic tremor may persist after treatment and is known to be refractory to conventional medication. We present two cases of neuropathic tremor due to CIDP in which deep brain stimulation (DBS) over a long-term period led to marked improvement. Case 1: A 66-year-old woman presented with severe 2-3-Hz resting, postural, and kinetic tremors of both hands. The tremor was refractory to medication but improved well after bilateral VIM-DBS. However, 2 months after the procedure, the tremor worsened and was accompanied by sensory disturbance in the extremities. A diagnosis of CIDP was made, and treatment with corticosteroids and intravenous immunoglobulin achieved remission 6 months later. Although there was residual tremor after CIDP remission, it has been well controlled by DBS for the last 10 years. Case 2: A 56-year-old man presented with a 6-year history of CIDP after developing sensory dullness and tremors in the extremities. The CIDP had gone into remission 1 year previously and the sensory deficits had improved, but the tremors had gradually worsened: severe 8-12-Hz postural, kinetic, and resting tremors were present in both upper extremities. Right VIM-DBS was performed and the tremors on the left side showed marked improvement. Over the next 8 years, the tremors were well controlled and there were no relapses of CIDP. DBS may achieve long-term improvement of neuropathic tremor caused by CIDP if the CIDP is in remission.

3.
Nanoscale ; 16(15): 7467-7479, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38511345

RESUMO

A high-temperature pyrolysis-controlled coordination reconstruction resulted in a single-Ni-atom structure with a Ni-Nx-C structural unit (x = N atom coordinated to Ni). Pyrolysis of Ni-phen@ZIF-8-RF at 700 °C resulted in NiNP-NC-700 with predominantly Ni nanoparticles. Upon elevating the pyrolysis temperature from 700 to 900 °C, a coordination reconstruction offers Ni-Nx atomic sites in NiSA-NC-900. A combined investigation with X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, and soft X-ray L3-edge spectroscopy suggests the stabilization of low-valent Niδ+ (0 < δ < 2) in the Ni-N-C structural units. The oxygen evolution reaction (OER) is a key process during water splitting in fuel cells. However, OER is a thermodynamically uphill reaction with multi-step proton-coupled electron transfer and sluggish kinetics, due to which there is a need for a catalyst that can lower the OER overpotentials. The adsorption energy of a multi-step reaction on a single metal atom with coordination unsaturation tunes the adsorption of each oxygenated intermediate. The promising OER activity of the NiSA-NC-900/NF anode on nickel foam was followed by the overall water splitting (OWS) using using NiSA-NC-900/NF as anode and Pt coil as the cathodic counterpart, wherein a cell potential of 1.75 V at 10 mA cm-2 was achieved. The cell potential recorded with Pt(-)/(+)NiSA-NC-900/NF was much lower than that obtained for other cells, i.e., Pt(-)/NF and NF(-)/(+)NF, which enhances the potentials of low-valent NiSAs for insightful understanding of the OER. At a constant applied potential of 1.61 V (vs. RHE) for 12 h, an small increase in current for initial 0.6 h followed by a constant current depicts the fair stability of catalyst for 12 h. Our results offer an insightful angle into the OER with a coordinatively reconstructed single-Ni-atom structure at lower valency (<+2).

4.
Cureus ; 16(2): e53695, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38455770

RESUMO

A 51-year-old man with a history of cisplatin treatment for a right testicular tumor underwent microvascular decompression for hemifacial spasm. At an early stage in the surgical procedure, the intraoperative auditory brainstem response (ABR) was diminished despite a relatively minimally invasive approach, resulting in irreversible hearing loss. Cisplatin is known to cause dose-dependent hearing impairment primarily affecting the cochlea, but it can also induce neurotoxicity. In the present case, prior cisplatin administration may have caused fragility of the cochlear nerve as well. Patients with a history of ototoxic and neurotoxic drugs such as cisplatin require more careful manipulation and thorough intraoperative auditory monitoring during neurosurgical procedures that may affect hearing, such as those for hemifacial spasms.

5.
No Shinkei Geka ; 52(1): 112-118, 2024 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-38246677

RESUMO

Cisternography using heavy T2-weighted images from 3-Tesla magnetic resonance imaging(MRI)and three-dimensional time-of-flight MR angiography(3D TOF MRA)is useful for identifying conflicting vessels in primary hemifacial spasm(HFS). Cisternography provides high-signal images of the cerebrospinal fluid and low-signal images of the cranial nerves and cerebral blood vessels, whereas 3D TOF MRA provides high-signal images with only vascular information. The combination of these two methods increases the identification rate of conflicting vessels. The neurovascular conflict(NVC)site in HFS is where the facial nerve exits the brainstem. However, on MRI, the true NVC site is often more proximal than the facial nerve attachment to the brainstem. On preoperative MRI, it is important to not miss the blood vessels surrounding the proximal portion of the facial nerve. If multiple compression vessels or deep vessels are located in the supraolivary fossette, they may be missed. Coronal section imaging and multiplanar reconstruction(MPR)minimize the chances of missing a compression vessel. Preoperative MRI and CT can also provide various other information, such as volume of the cerebellum, presence of emissary veins, shape of the petrosal bone, and size of the flocculus.


Assuntos
Espasmo Hemifacial , Humanos , Espasmo Hemifacial/diagnóstico por imagem , Espasmo Hemifacial/cirurgia , Nervo Facial/diagnóstico por imagem , Angiografia por Ressonância Magnética , Tronco Encefálico , Cerebelo
6.
Acta Neurochir (Wien) ; 165(10): 3011-3017, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37656306

RESUMO

PURPOSE: Endoscopy is known to be a useful adjunct for microvascular decompression (MVD) surgery, assisting observation in blind spots such as Meckel's cave in cases of trigeminal neuralgia (TN) and the root exit zone (REZ) in hemifacial spasm (HFS). However, few reports have discussed the usefulness of endoscopy in relation to individual patient characteristics or preoperative magnetic resonance imaging (MRI). METHODS: We retrospectively reviewed the medical records of 109 patients (98 with HFS and 11 with TN, 85 women, median age 55 years) who had undergone endoscopically assisted MVD at our institution between 2017 and 2021. The usefulness of endoscopy in individual cases was scored by three neurosurgeons using a grading scale: 2, essential and indispensable; 1, useful and helpful; 0, not necessary. The mean value of the assigned scores was taken as an indicator of "usefulness," and endoscopy was considered to have been "useful" in cases with a score of > 1.0. RESULTS: Endoscopic assistance was judged to have been useful in 69% of the patients. The proportion of patients evaluated as useful was significantly lower for TN (18.2%) than for HFS (74.5%). Patients with superior cerebellar artery compression had significantly lower scores than patients with other vessels. Endoscopy was considered useful in a significantly higher proportion of patients with anatomically complicated offending vessels (bifurcation or strong meandering) in the REZ detected by preoperative MRI (P < 0.005). CONCLUSION: Endoscopy for MVD is useful for patients with HFS, especially when preoperative MRI shows bifurcation or strongly meandering vessels in the REZ.


Assuntos
Espasmo Hemifacial , Cirurgia de Descompressão Microvascular , Neuralgia do Trigêmeo , Humanos , Feminino , Pessoa de Meia-Idade , Cirurgia de Descompressão Microvascular/efeitos adversos , Estudos Retrospectivos , Espasmo Hemifacial/diagnóstico por imagem , Espasmo Hemifacial/cirurgia , Espasmo Hemifacial/etiologia , Endoscopia/efeitos adversos , Imageamento por Ressonância Magnética/métodos , Neuralgia do Trigêmeo/diagnóstico por imagem , Neuralgia do Trigêmeo/cirurgia , Neuralgia do Trigêmeo/etiologia , Resultado do Tratamento
7.
RSC Adv ; 13(19): 12926-12940, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37114017

RESUMO

Environmental pollution is one of the biggest concerns in the world today, and solar energy-driven photocatalysis is a promising method for decomposing pollutants in aqueous systems. In this study, the photocatalytic efficiency and catalytic mechanism of WO3-loaded TiO2 nanocomposites of various structures were analyzed. The nanocomposites were synthesized via sol-gel reactions using mixtures of precursors at various ratios (5%, 8%, and 10 wt% WO3 in the nanocomposites) and via core-shell approaches (TiO2@WO3 and WO3@TiO2 in a 9 : 1 ratio of TiO2 : WO3). After calcination at 450 °C, the nanocomposites were characterized and used as photocatalysts. The kinetics of photocatalysis with these nanocomposites for the degradation of methylene blue (MB+) and methyl orange (MO-) under UV light (365 nm) were analyzed as pseudo-first-order reactions. The decomposition rate of MB+ was much higher than that of MO-, and the adsorption behavior of the dyes in the dark suggested that the negatively charged surface of WO3 played an important role in adsorbing the cationic dye. Scavengers were used to quench the active species (superoxide, hole, and hydroxyl radicals), and the results indicated that hydroxyl radicals were the most active species; however, the active species were generated more evenly on the mixed surfaces of WO3 and TiO2 than on the core-shell structures. This finding shows that the photoreaction mechanisms could be controlled through adjustments to the nanocomposite structure. These results can guide the design and preparation of photocatalysts with improved and controlled activities for environmental remediation.

8.
Int J Mol Sci ; 24(7)2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37047016

RESUMO

For effective supercapacitors, we developed a process involving chemical bath deposition, followed by electrochemical deposition and calcination, to produce WO3/SnO2 nanocomposite electrodes. In aqueous solutions, the hexagonal WO3 microspheres were first chemically deposited on a carbon cloth, and then tin oxides were uniformly electrodeposited. The synthesized WO3/SnO2 nanocomposite was characterized by XRD, XPS, SEM, and EDX techniques. Electrochemical properties of the WO3/SnO2 nanocomposite were analyzed by cyclic voltammetry, galvanostatic charge-discharge tests, and electrochemical impedance spectroscopy in an aqueous solution of Na2SO4 with/without the redox-active electrolyte K3Fe(CN)6. K3Fe(CN)6 exhibited a synergetic effect on the electrochemical performance of the WO3/SnO2 nanocomposite electrode, with a specific capacitance of 640 F/g at a scan rate of 5 mV/s, while that without K3Fe(CN)6 was 530 F/g. The WO3/SnO2 nanocomposite catalyzed the redox reactions of [Fe(CN)6]3/[Fe(CN)6]4- ions, and the [Fe(CN)6]3-/[Fe(CN)6]4- ions also promoted redox reactions of the WO3/SnO2 nanocomposite. A symmetrical configuration of the nanocomposite electrodes provided good cycling stability (coulombic efficiency of 99.6% over 2000 cycles) and satisfied both energy density (60 Whkg-1) and power density (540 Wkg-1) requirements. Thus, the WO3/SnO2 nanocomposite prepared by this simple process is a promising component for a hybrid pseudocapacitor system with a redox-flow battery mechanism.


Assuntos
Líquidos Corporais , Nanocompostos , Eletrólitos , Eletrodos , Oxirredução
9.
Neurosurgery ; 93(3): 662-669, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36975375

RESUMO

BACKGROUND: Hearing impairment is an important complication of microvascular decompression (MVD). In patients after MVD, we have occasionally noted slight to moderate hearing deterioration at low frequencies that is difficult to detect using pure tone average. OBJECTIVE: To assess the incidence and features of low-frequency hearing impairment (LF-HI) after MVD and evaluate its associated factors. METHODS: This single-center, retrospective observational study assessed the audiometric outcome of 270 patients who underwent MVD between January 2015 and December 2020. Preoperative and postoperative hearing levels were compared for each frequency. LF-HI was defined as a hearing deterioration of ≥15 dB at 125, 250, or 500 Hz. The incidence, symptoms, and associated factors of LF-HI were analyzed. RESULTS: Statistical analysis of the patients overall demonstrated slight but significant decreases in the hearing level after MVD at lower frequencies on both the operative and contralateral sides. Eighty-one patients (30.0%) had LF-HI: 49 on the operative side, 24 on the contralateral side, and 8 on both sides, while pure tone average was worsened in 5 patients (1.8%). Subjective symptoms, including hearing deterioration, ear fullness, tinnitus, and dizziness, developed in 10.4% of the patients with LF-HI but improved subsequently within several weeks. "Older age" and "operative side" were associated with LF-HI. CONCLUSION: Decreases in lower-frequency hearing levels in both the ipsilateral and contralateral (nonoperative) ears were observed after trigeminal neuralgia and hemifacial spasm surgery. LF-HI does not cause permanent symptoms but may be a noteworthy phenomenon, possibly involved in the contralateral hearing loss encountered occasionally after other types of posterior cranial fossa surgery.


Assuntos
Perda Auditiva , Espasmo Hemifacial , Cirurgia de Descompressão Microvascular , Humanos , Cirurgia de Descompressão Microvascular/efeitos adversos , Perda Auditiva/epidemiologia , Perda Auditiva/etiologia , Audição , Espasmo Hemifacial/cirurgia , Audiometria , Estudos Retrospectivos
10.
NMC Case Rep J ; 9: 383-388, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36474503

RESUMO

We report an 18-year-old female patient who developed left temporal headache and fever one month after administration of isotretinoin for acne. Imaging studies demonstrated osteolytic change in the left frontal bone, and the lesion showed gadolinium contrast enhancement. Biopsy confirmed the diagnosis of osteomyelitis, and the symptoms improved after 8 months of medication with antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs). However, the pain recurred when isotretinoin was resumed. Isotretinoin sometimes causes excessive inflammation, which may have been the reason for the osteomyelitis in this case. Although osteomyelitis is usually caused by bacterial infection, a non-bacterial mechanism should also be suspected if the condition is resistant to antibiotics.

11.
ACS Appl Mater Interfaces ; 14(30): 35027-35039, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-35875888

RESUMO

Graphene oxide (GO), single-walled carbon nanohorn (CNHox), and nitrogen-doped CNH (N-CNH) were functionalized with fluorinated poly(ethylene glycol) (F-PEG) and/or with a fluorinated dendrimer (F-DEN) to prepare a series of assembled nanocomposites (GO/F-PEG, CNHox/F-PEG, N-CNH/F-PEG, N-CNH/F-DEN, and N-CNH/F-DEN/F-PEG) that provide effective multisite O2 reservoirs. In all cases, the O2 uptake increased with time and saturated after 10-20 min. When graphitic carbons (GO and CNHox) were coated with F-PEG, the O2 uptake doubled. The O2 loading was slightly higher in N-CNH compared to CNHox. Notably, coating N-CNH with F-DEN or F-PEG, or with both F-DEN and F-PEG, was more effective. The best performance was obtained with the N-CNH/F-DEN/F-PEG nanocomposite. The O2 uptake kinetics and mechanisms were analyzed in terms of the Langmuir adsorption equation based on a multibinding site assumption. This allowed the precise determination of multiple oxygen binding sites, including on the graphitic structure and in the dendrimer, F-DEN, and F-PEG. After an initial rapid, relatively limited release, the amount of O2 trapped in the nanomaterials remained high (>95%). This amount was marginally lower for the functionalized composites, but the oxygen stored was reserved for longer times. Finally, it is shown that these systems can generate singlet oxygen after irradiation by a light-emitting diode, and this production correlates with the amount of O2 loaded. Thus, it was anticipated that the present nanocomposites hierarchically assembled from components with different characters and complementary affinities for oxygen can be useful as O2 reservoirs for singlet oxygen generation to kill bacteria and viruses and to perform photodynamic therapy.

12.
ACS Omega ; 7(20): 17161-17174, 2022 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35647438

RESUMO

Complex oxides and hydroxides of Ni, Co, and Mn from a precursor mixture were electrochemically deposited on both a cathode and an anode. On the Ni foam cathode, the complex metal hydroxides precipitated as nanolayers at -0.9 V. Simultaneously, the metal ions were oxidized and deposited as blocks on the Ni foam anode. While the concentrations of Ni(NO3)2 and Mn(NO3)2 were constant (80 mM for Ni2+ and 40 mM for Mn2+, respectively), the concentration of Co(NO3)2 was varied from 20 to 120 mM, which affected the morphology and electrochemical properties of the electrode: a Co:Ni:Mn molar ratio resulted in the highest specific capacitance (at a scan rate of 5 mV s-1, 1800 F g-1 for the cathode material and 720 F g-1 for the anode material). This cathode material was assembled into symmetric supercapacitors, which demonstrated an excellent energy density of 39 Wh kg-1 at a power density of 1300 W kg-1 and a high capacitance retention of 90% after 3000 charge/discharge cycles. This high electrochemical performance was attributed to the optimized ratio of metal oxides, and this simple preparation strategy can be applied to other nanocomposites of complex metal oxides/hydroxides with desired characteristics for various applications.

13.
World Neurosurg ; 165: e317-e324, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35717018

RESUMO

BACKGROUND: Even in the era of advanced medical treatment, brain abscess still has a high mortality rate. At our institution, brain abscess has been treated mainly using stereotactic or echo-guided aspiration followed by relatively long-term antibiotic treatment, achieving favorable outcomes. To evaluate the efficacy of our strategy involving less-invasive aspiration surgery and long-term selective antibiotic administration for brain abscess, a single-institution series of cases was investigated. METHODS: We retrospectively reviewed and analyzed the medical records of 25 cases of brain abscess treated at Saitama Medical University Hospital between 2008 and 2021. The patients comprised 16 men and 9 women aged between 39 and 85 years (median 62 years). Neurosurgical intervention was performed for 23 (92.0%) of the patients and the remaining 2 received antibiotics alone. RESULTS: Among the neurosurgery patients, 22 (95.7%) underwent echo-guided or stereotactic aspiration, and only 1 underwent craniotomy. Anaerobic bacteria were detected in 11 patients. In the surgical and conservative groups, the median duration of antibiotic treatment was 16 weeks and 23 weeks, respectively. Since 2014 when metronidazole first became available, it has replaced meropenem to cover anaerobic bacteria. The overall mortality rate was 4.0% and a favorable outcome (Glasgow Outcome Scale 4 or 5) was achieved in 76% of the patients. There was no surgical mortality or morbidity. CONCLUSIONS: Most patients underwent aspiration surgery and achieved favorable outcomes. Along with antibiotic treatment for a sufficiently long period to cover anaerobes, this approach can be expected to yield good results.


Assuntos
Abscesso Encefálico , Transtornos Respiratórios , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Abscesso Encefálico/diagnóstico por imagem , Abscesso Encefálico/tratamento farmacológico , Abscesso Encefálico/cirurgia , Feminino , Humanos , Masculino , Meropeném , Metronidazol/uso terapêutico , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
14.
No Shinkei Geka ; 50(2): 467-479, 2022 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-35400663

RESUMO

This article describes the anatomical approach and operative points of microvascular decompression for hemifacial spasm based on the author's personal experience with 1,000 cases. As vascular compression of the facial nerve is often quite caudal, it is necessary to ensure that the compressing arteries in this area are moved. Neither the vessels nor the prosthesis used to move them should not touch the root exit zone of the nerve(vascular transposition nerve isolation technique). It should also be emphasized that every effort should be made to avoid complications such as hearing impairment and postoperative subcutaneous spinal fluid accumulation.


Assuntos
Espasmo Hemifacial , Cirurgia de Descompressão Microvascular , Artérias/cirurgia , Descompressão Cirúrgica/efeitos adversos , Descompressão Cirúrgica/métodos , Nervo Facial/cirurgia , Espasmo Hemifacial/etiologia , Espasmo Hemifacial/cirurgia , Humanos , Cirurgia de Descompressão Microvascular/métodos
15.
ACS Omega ; 6(37): 23750-23763, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34568655

RESUMO

We developed a two-step chemical bath deposition method followed by calcination for the production of ZnO/Co3O4 nanocomposites. In aqueous reactions, ZnO nanotubes were first densely grown on Ni foam, and then flat nanosheets of Co3O4 developed and formed a porous film. The aspect ratio and conductivity of the Co3O4 nanosheets were improved by the existence of the ZnO nanotubes, while the bath deposition from a mixture of Zn/Co precursors (one-step method) resulted in a wrinkled plate of Zn/Co oxides. As a supercapacitor electrode, the ZnO/Co3O4 nanosheets formed by the two-step method exhibited a high capacitance, and after being calcined at 450 °C, these nanosheets attained the highest specific capacitance (940 F g-1) at a scan rate of 5 mV s-1 in the cyclic voltammetry analysis. This value was significantly higher than those of single-component electrodes, Co3O4 (785 F g-1) and ZnO (200 F g-1); therefore, the presence of a synergistic effect was suggested. From the charge/discharge curves, the specific capacitance of ZnO/Co3O4 calcined at 450 °C was calculated to be 740 F g-1 at a current density of 0.75 A g-1, and 85.7% of the initial capacitance was retained after 1000 cycles. A symmetrical configuration exhibited a good cycling stability (Coulombic efficiency of 99.6% over 1000 cycles) and satisfied both the energy density (36.6 Wh kg-1) and the power density (356 W kg-1). Thus, the ZnO/Co3O4 nanocomposite prepared by this simple two-step chemical bath deposition and subsequent calcination at 450 °C is a promising material for pseudocapacitors. Furthermore, this approach can be applied to other metal oxide nanocomposites with intricate structures to extend the design possibility of active materials for electrochemical devices.

16.
Phys Chem Chem Phys ; 23(30): 16366-16375, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34318807

RESUMO

A plasmon-enhanced photocatalytic system was designed with Ag-Pt-AgCl nanocomposites. Branched nanowires of Ag (AgBNWs) were first synthesized on indium-doped tin oxide-coated glass by electrodeposition. Then, the AgBNWs were dipped into an aqueous solution of Na2[PtCl6] at different concentrations from 1 to 5 mM to deposit Pt nanoparticles (PtNPs) on the AgBNWs via galvanic displacement. During the PtNP deposition, eluted Ag+ ions reacted with Cl- ions to precipitate AgCl on the AgBNWs. The obtained AgBNW/PtNP/AgCl nanocomposites exhibited plasmonic absorption at approximately 465 nm. The nanocomposites were then examined as photoelectrodes for hydrogen evolution. The hybridization of the PtNPs on the AgBNWs significantly decreased the overpotential for water splitting in the dark, and the large number of PtNPs resulted in a higher efficiency compared to a conventional catalyst. Under blue-light irradiation (479 nm, 100 mW cm-2), the overpotential decreased by -110 mV, and the current density increased by 27.8 mA cm-2. Under red-light irradiation (631 nm, 100 mW cm-2), the shift in onset potential was small, which could be attributed to the mismatching of the plasmonic absorption band with the excitation wavelength. The nanocomposite without AgCl (AgBNW/PtNP) was less effective at lowering the overpotential but more effective at improving the onset potential than AgBNW/PtNP/AgCl. These electrochemical behaviors were explained by the synergistic effect of the plasmon-induced photocurrent and charge transfer between Ag, Pt, and AgCl. The nanocomposite retained its photocatalytic activity after 400 cycles; therefore, the AgBNW/PtNP/AgCl nanocomposite could be useful for hydrogen evolution devices.

17.
Brain Tumor Pathol ; 38(3): 243-249, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33913040

RESUMO

Astroblastoma is an extremely rare brain tumor that has recently attracted attention owing to its association with MN1 gene alteration. However, its long-term clinical course remains unclear. We report a late recurrence of MN1-altered astroblastoma with unique pathological findings. A 24-year-old woman presented with seizures due to a left frontal lobe tumor. Gross total resection (GTR) was achieved, and the diagnosis was MN1-altered astroblastoma, which presented cell wrapping, i.e., presence of tumor cells enveloping one another. She received local radiotherapy (50 Gy). However, the tumor recurred after 12 years, and its size increased rapidly. The second surgery achieved GTR and confirmed increasing anaplasia. The patient was tumor-free for 1 year without any neurological deficits. This case implies the importance of long-term follow-up of MN1-altered astroblastoma. The pathological significance of cell wrapping in this case is unclear, but it may be associated with MN1-altered astroblastoma and should be noted in future cases.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Neuroepiteliomatosas/genética , Neoplasias Neuroepiteliomatosas/patologia , Transativadores/genética , Proteínas Supressoras de Tumor/genética , Adulto , Medicamentos Biossimilares , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/terapia , Feminino , Humanos , Mutação , Recidiva Local de Neoplasia , Neoplasias Neuroepiteliomatosas/diagnóstico por imagem , Neoplasias Neuroepiteliomatosas/terapia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Adulto Jovem
18.
Carbohydr Polym ; 256: 117536, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33483052

RESUMO

Self-standing films of cellulose nanofibril derivatives were prepared via oxidation by the 2,2,6,6-tetramethyl-1-piperidinyloxy radical and amidation with octadecylamine (ODA). The transparency and rigidity of the films decreased and their flexibility increased as the amide/carboxyl ratio increased. The introduction of the ODA also resulted in rising contact angles of water (from 43.5° to 117°) and oleic acid (from 22.5° to 57.1°). Furthermore, the films exhibited unique oil repellency: a drop of hexadecane slipped without tailing on the surface modified by ODA. This phenomenon was observed after moderate modification (water contact angle: 95-114°) and was absent for the films with the lowest and highest extents of modification. Then, the antifingerprint property of the films was examined by means of the powder test, and a reduction in fingerprints on the films was demonstrated. These results suggest the usefulness of developing transparent, self-standing oil-repellent films without perfluorinated compounds for antifingerprint and other antifouling applications.


Assuntos
Celulose Oxidada/química , Óxidos N-Cíclicos/química , Radicais Livres/química , Nanofibras/química , Ácido Oleico/química , Piperidinas/química , Alcanos/química , Módulo de Elasticidade , Flúor/química , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura , Oxirredução , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Resistência à Tração , Termogravimetria , Água , Difração de Raios X
19.
NMC Case Rep J ; 5(4): 95-97, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30327750

RESUMO

The surgical removal of giant solid hemangioblastoma involves a high risk of perioperative bleeding and requires attentive hemostasis. Here, we present a case of a giant solid hemangioblastoma accompanied with hemophilia which was previously undiagnosed. A 35-year-old man without any past medical history was admitted with diplopia and ocular motility disorder. computed tomography (CT) and magnetic resonance imaging (MRI) revealed obstructive hydrocephalus and a solid giant tumor of more than 4.0 cm in diameter in the right cerebellopontine angle (CPA). Hemangioblastoma was suspected on cerebral angiography. After ventriculoperitoneal shunt for obstructive hydrocephalus, oozing from the skin incision continued for several days. Hemophilia type A was diagnosed based on the result of laboratory blood coagulability examination. Supplemental administration of factor VIII and coil embolization of the feeding arteries of the lesion on the CPA were performed, and the tumor was subtotally resected without hemorrhagic complications. The histopathological diagnosis was hemangioblastoma. We report this case to emphasize the importance not to overlook previously undiagnosed coagulopathy before surgical excision of hemangioblastoma. And, with appropriate perioperative management for coagulopathy, surgical treatment involving a high risk of perioperative bleeding can be safely undertaken.

20.
J Oleo Sci ; 67(6): 689-696, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29863089

RESUMO

This review discusses wet processes to synthesize metallic nanoparticles with many surface projections. Such projections can be formed by the aggregation of seed nanoparticles or by anisotropic crystal growth from specific facets on a base nanoparticle. The aggregation process can be controlled by protecting agents, which also play a key role in determining the morphology of the projections and the size of the nanoparticles. The reducing agents used for this purpose are mostly moderate and therefore allow seed aggregation before crystal growth. Some reducing agents act catalytically on specific crystal facets to promote anisotropic crystal growth. Branched nanostructures with high symmetry can be prepared from monocrystalline nanoparticles by site-selective growth and etching. The optical and plasmonic properties of the nanoparticles thus obtained can be used for various applications in surface-enhanced spectroscopy and in plasmon photocatalysts.


Assuntos
Nanopartículas Metálicas/química , Análise Espectral , Ressonância de Plasmônio de Superfície , Anisotropia , Catálise , Cristalização , Nanoestruturas , Tamanho da Partícula , Transição de Fase , Soluções
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