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Objective: Cerebral vasospasm is an unelucidated complication of subarachnoid hemorrhage. Various treatments exist against cerebral vasospasms however, consensus on the optimal treatment is lacking. We use clazosentan, which is used to prevent cerebral vasospasm, with multidrug combinations. In this study, we aimed to clarify the initial results of using clazosentan in multidrug combinations in the real world. Methods: We retrospectively investigated 54 patients who were treated for subarachnoid hemorrhage and received clazosentan. We compared the results of these patients on the basis of two groups: those with good outcomes (modified Rankin scale score: 0–3) and poor outcomes (4–6) at discharge. Results: Among the patients, poor outcome was observed in 19 patients (35.2 %). Angiographic vasospasms occurred in 10 patients (good outcome [n = 6] vs. poor outcome [n = 4]; p = 0.73), and symptomatic vasospasms occurred in 4 patients (n = 2 vs. n = 2, p = 0.61). The incidence of pleural effusion (28.6 % vs. 73.7 %, p

Abstract Background Recently, discussions have increasingly focused on “withdrawal from dialysis” among patients undergoing dialysis who experience severe brain dysfunction as post-stroke sequelae. In this context, the lack of understanding regarding functional prognosis after spontaneous intracerebral hemorrhage in patients undergoing hemodialysis becomes a particularly important issue. Therefore, we aimed to evaluate the functional prognosis of intracerebral hemorrhage in patients undergoing hemodialysis when life-saving was prioritized and dialysis was not withdrawn. Furthermore, we sought to identify factors influencing life and functional prognosis. Methods We retrospectively analyzed data of 100 consecutive hemodialysis patients who experienced spontaneous intracerebral hemorrhage between 2012 and 2021. The in-hospital mortality rates and modified Rankin Scale (mRS) and Functional Independence Measure (FIM) scores at discharge and 90 days after onset were examined. Results The mean age of the patients was 65.7 years, with 29% of them undergoing life-saving brain surgery. The mRS score at discharge was 0, 1, 2, 3, 4, 5, and 6 (indicating death) in 0, 1, 13, 9, 26, 20, and 31 cases, respectively. Among the 69 surviving patients, the median FIM score at discharge was 37 (19–81), with 14 patients having an FIM score of 18 (i.e., complete dependence). Patients who underwent life-saving brain surgery showed a higher median mRS score [5, interquartile range (IQR) 5–6] and a lower FIM score (18, IQR 18–22) at discharge compared with those who did not undergo the surgery. Patients discharged with mRS and FIM scores of 5 and 18, respectively, had the same functional status at 90 days. The Functional Outcome in Patients With Primary Intracerebral Hemorrhage (FUNC) score and intraventricular extension at admission were predictive of a mRS score ≥ 5 (area under the receiver operating characteristic curve = 0.92, p

Abstract Recent studies have indicated the involvement of neutrophil-mediated inflammatory responses in the process leading to intracranial aneurysm (IA) rupture. Receptors mediating neutrophil recruitment could thus be therapeutic targets of unruptured IAs. In this study, complement C5a receptor 1 (C5AR1) was picked up as a candidate that may cause neutrophil-dependent inflammation in IA lesions from comprehensive gene expression profile data acquired from rat and human samples. The induction of C5AR1 in IA lesions was confirmed by immunohistochemistry; the up-regulations of C5AR1/C5ar1 stemmed from infiltrated neutrophils, which physiologically express C5AR1/C5ar1, and adventitial fibroblasts that induce C5AR1/C5ar1 in human/rat IA lesions. In in vitro experiments using NIH/3T3, a mouse fibroblast-like cell line, induction of C5ar1 was demonstrated by starvation or pharmacological inhibition of mTOR signaling by Torin1. Immunohistochemistry and an experiment in a cell-free system using recombinant C5 protein and recombinant Plasmin indicated that the ligand of C5AR1, C5a, could be produced through the enzymatic digestion by Plasmin in IA lesions. In conclusion, we have identified a potential contribution of the C5a–C5AR1 axis to neutrophil infiltration as well as inflammatory responses in inflammatory cells and fibroblasts of IA lesions. This cascade may become a therapeutic target to prevent the rupture of IAs.

BACKGROUND: Cerebral vasospasm (CVS) is one of the most critical factors associated with clinical outcomes of patients with subarachnoid hemorrhage (SAH). Clazosentan has been investigated worldwide as a prophylactic agent to prevent CVS. We evaluated a new CVS management protocol which included clazosentan. METHODS: Consecutive 138 patients with SAH, hospitalized in our institution between January 2017 and December 2022, were included in this study. Baseline characteristics, clinical findings, and operative records were analyzed retrospectively. From May 2022, 10 mg/h clazosentan was co-administered with fasudil to all patients according to the indication in the Japanese label. Patients admitted before this date received the conventional combined protocol using the fasudil hydrochloride, nicardipine, and ozagrel. RESULTS: Eighteen (13.0%) patients received the new protocol during the CVS period (defined as day 1 up to day 14 after SAH onset). There were 54 (39.1%) elderly patients aged 75 years or older. Seventy-two (52.2%) patients underwent neurosurgical clipping, whereas 55 (39.9%) patients received endovascular coiling. Among the patients with new protocol, only one patient (5.6%) had symptomatic CVS, compared with 18 patients (15.0%) in those with conventional protocol. More patients who received the new protocol had fluid retention compared with control group (38.9% [7/18] vs. 8.3% [10/120]). Other results did not differ between the two groups. CONCLUSIONS: Clinical outcomes of the new protocol were comparable to those of conventional protocol. Clazosentan may simplify anti-vasospasm treatment. Fluid retention was a specific side-effect of clazosentan, which requires attention especially in the first half of the CVS period.

The number of elderly patients with chronic subdural hematomas (CSDH) is increasing worldwide; however, there is limited data regarding the clinical outcomes in this population. Our therapeutic method using burr hole evacuation for CSDH is based on the hematoma characteristics, using simple drainage for single-layer lesions and drainage with irrigation for multiple-layer lesions. This study aimed to compare the postoperative outcomes of elderly and younger patients, identify the predictors of outcomes in elderly patients, and verify the validity of our therapeutic methods. In total, we included 214 patients who underwent burr hole evacuation between April 2018 and March 2022. Baseline characteristics, hematoma characteristics, recurrence, and clinical outcomes were compared between the elderly and younger patients. Overall, 96 elderly patients (44.9%) were included in the study, and more elderly patients underwent antithrombotic therapy than younger patients (33.3% vs. 19.5%, p = 0.027). Moreover, elderly patients had significantly fewer favorable outcomes than younger patients (70.8% vs. 91.5%; p < 0.001); however, this was not significant after adjusting for the baseline modified Rankin Scale (mRS). Similarly, elderly patients had higher recurrence rates than younger patients (10.4% vs. 2.5%; p = 0.021). However, the baseline mRS score was the only predictor of unfavorable outcomes. In conclusion, although the clinical outcomes of elderly patients were comparable to those of younger patients, the higher rate of preoperative antithrombotic therapy in elderly patients may result in a higher rate of recurrence requiring a long-term follow-up.

Abstract Background Cerebral amyloid angiopathy is a common cause of subcortical hemorrhage in older adults. Although open hematoma removal may be performed for severe subcortical hemorrhage, its safety in patients with cerebral amyloid angiopathy has not been established, and postoperative rebleeding may occur. Therefore, this study aimed to investigate factors associated with postoperative rebleeding. Methods Out of 145 consecutive patients who had undergone craniotomy for surgical removal of subcortical intracerebral hemorrhage between April 2010 and August 2019 at a single institution in Japan, we examined 109 patients with subcortical hemorrhage who met the inclusion criteria. After excluding 30 patients whose tissue samples were unsuitable for the study, the final study cohort comprised 79 patients. Results Of the 79 patients, 50 (63%) were diagnosed with cerebral amyloid angiopathy (cerebral amyloid angiopathy group) and 29 (37%) were not diagnosed with noncerebral amyloid angiopathy (noncerebral amyloid angiopathy group). Postoperative rebleeding occurred in 12 patients (24%) in the cerebral amyloid angiopathy group and in 2 patients (7%) in the noncerebral amyloid angiopathy group. Preoperative prothrombin time–international normalized ratio and intraoperative bleeding volume were significantly associated with postoperative rebleeding in the cerebral amyloid angiopathy group (odds ratio = 42.4, 95% confidence interval = 1.14–1578; p = 0.042 and odds ratio = 1.005, 95% confidence interval = 1.001–1.008; p = 0.007, respectively). Conclusions Patients with cerebral amyloid angiopathy-related cerebral hemorrhage who are receiving antithrombotic therapy, particularly warfarin therapy, are at a high risk of postoperative rebleeding. Trial registration Registry and Registration Number of the study: 19–220, 2019/12/23, retrospectively registered.

Abstract Polymers are often combined with magnetostrictive materials to enhance their toughness. This study reports a cellulose nanofibril (CNF)-based composite paper containing dispersed CoFe2O4 particles (CNF–CoFe2O4). Besides imparting magnetization and magnetostriction, the incorporation of CoFe2O4 particles decreased the ultimate tensile strength and increased the fracture elongation of the CNF–CoFe2O4 composite paper. CNF was responsible for the tensile properties of CNF–CoFe2O4 composite paper. Consequently, the magnetic and magnetostrictive properties and tensile properties of CNF–CoFe2O4 composite paper can be controlled by changing the mixture ratio of CNF and CoFe2O4 particles.

Abstract Subarachnoid hemorrhage being the rupture of intracranial aneurysm (IA) as a major cause has quite poor prognosis, despite the modern technical advances. Thereby, the mechanisms underlying the rupture of lesions should be clarified. Recently, we and others have clarified the formation of vasa vasorum in IA lesions presumably for inflammatory cells to infiltrate in lesions as the potential histopathological alternation leading to rupture. In the present study, we clarified the origin of vasa vasorum as arteries located at the brain surface using 3D-immunohistochemistry with tissue transparency. Using Hypoxyprobe, we then found the presence of hypoxic microenvironment mainly at the adventitia of intracranial arteries where IA is formed. In addition, the production of vascular endothelial growth factor (VEGF) from cultured macrophages in such a hypoxic condition was identified. Furthermore, we found the accumulation of VEGF both in rupture-prone IA lesions induced in a rat model and human unruptured IA lesions. Finally, the VEGF-dependent induction of neovessels from arteries on brain surface was confirmed. The findings from the present study have revealed the potential role of hypoxic microenvironment and hypoxia-induced VEGF production as a machinery triggering rupture of IAs via providing root for inflammatory cells in lesions to exacerbate inflammation.

In this article, the stress/stress sensing capability of FeSiB thin films is demonstrated and discussed. The sensing relies on the change in permeability by the application of stress, compressive and tensile, and the application of DC magnetic field. This susceptibility/permeability was tested by the exciting field (AC) being in the same direction with the applied stress. The susceptibility was shown to exhibit a maximal value at a given applied stress, the critical stress. Moreover, this maximal amplitude and position was changing with the application of an external DC magnetic field. For the DC field applied in the direction of the exciting field (AC) and longitudinal to the stress, the critical stress was shifted toward negative values and for the DC field applied perpendicularly, the critical stress was shifted toward larger positive values. This was experimentally demonstrated, and a model was constructed for a better understanding.

As sensor materials for structural health monitoring (SHM, a nondestructive test for the continuous evaluation of the conditions of individual structural components and entire assemblies), magnetostrictive materials, piezoelectric materials, and optical fibers have attracted significant interest. In this study, the mode I interlaminar fracture load and crack self-detection potential of glass fiber-reinforced polymer (GFRP)–embedded magnetostrictive Fe–Co fibers were investigated via double cantilever beam testing. The results indicated that by controlling the amount of Fe–Co fibers introduced into GFRP, the number of Fe–Co fibers could be reduced without compromising the performance of GFRP. Furthermore, the magnetic flux density increased significantly with crack propagation, indicating that the magnetic flux density change could determine crack propagation.

Wide-bandgap gallium nitride (GaN)-based semiconductors offer significant advantages over traditional Si-based semiconductors in terms of high-power and high-frequency operations. As it has superior properties, such as high operating temperatures, high-frequency operation, high breakdown electric field, and enhanced radiation resistance, GaN is applied in various fields, such as power electronic devices, renewable energy systems, light-emitting diodes, and radio frequency (RF) electronic devices. For example, GaN-based high-electron-mobility transistors (HEMTs) are used widely in various applications, such as 5G cellular networks, satellite communication, and radar systems. When a current flows through the transistor channels during operation, the self-heating effect (SHE) deriving from joule heat generation causes a significant increase in the temperature. Increases in the channel temperature reduce the carrier mobility and cause a shift in the threshold voltage, resulting in significant performance degradation. Moreover, temperature increases cause substantial lifetime reductions. Accordingly, GaN-based HEMTs are operated at a low power, although they have demonstrated high RF output power potential. The SHE is expected to be even more important in future advanced technology designs, such as gate-all-around field-effect transistor (GAAFET) and three-dimensional (3D) IC architectures. Materials with high thermal conductivities, such as silicon carbide (SiC) and diamond, are good candidates as substrates for heat dissipation in GaN-based semiconductors. However, the thermal boundary resistance (TBR) of the GaN/substrate interface is a bottleneck for heat dissipation. This bottleneck should be reduced optimally to enable full employment of the high thermal conductivity of the substrates. Here, we comprehensively review the experimental and simulation studies that report TBRs in GaN-on-SiC and GaN-on-diamond devices. The effects of the growth methods, growth conditions, integration methods, and interlayer structures on the TBR are summarized. This study provides guidelines for decreasing the TBR for thermal management in the design and implementation of GaN-based semiconductor devices.

Intracranial chondrosarcomas located in the region of the posterior clinoid process have not been focused on. Here, we report the case of a 29-year-old woman with a skull base tumor in that region. Seven years after the diagnosis, the tumor had grown and showed calcification and tumor stain; chondrosarcoma, posterior clinoid meningioma, and chordoma were suspected. The patient underwent subtotal tumor resection, and the histopathological study revealed that the tumor was a low-grade chondrosarcoma. Chondrosarcomas can be located in the region of the posterior clinoid process, and not only chordomas but also posterior clinoid meningiomas should be considered as a differential diagnosis of tumors located in that region, especially when the tumor has calcification or receives a vascular supply.

The Internet of Things (IoT) requires power supplies without recharging. We conceived the idea of generating electricity from the impact of magnetostrictive materials against a propeller. This study evaluated the energy harvesting performance and energy storage capabilities of Fe–Co alloy and Ni clad (Fe–Co/Ni) films that directly strike propellers rotated by the wind in a duct airflow. The 0.08- and 0.2-mm-thick Fe–Co/Ni films generated powers of 28.1 and 89.4 µW, respectively. Moreover, the 0.08-mm-thick Fe–Co/No film generated power lower than that generated by the 0.2-mm-thick Fe–Co/Ni film. However, at a wind speed of 1.5 m/s, the 0.08-mm-thick Fe–Co/Ni film generated power, whereas the 0.2-mm-thick Fe–Co/Ni film stopped the rotation of propellers and did not generate any power. Furthermore, the Fe–Co/Ni film was successfully charged in a capacitor, and the stored voltages were 108.3 mV for the 0.08-mm-thick Fe–Co/Ni films for 30 min and 337.3 mV for the 0.2-mm-thick Fe–Co/Ni films for 1 h. It is also worth noting that no damage occurred to the surfaces of the Fe–Co/Ni films.

Endovascular embolization is generally thought to be safe and effective for the cavernous sinus dural arteriovenous fistula (CS DAVF); however, some complications have been reported. We report an extremely rare brainstem hemorrhage associated with transvenous embolization (TVE) of CS DAVF. A 66-year-old man presented with right-sided conjunctival chemosis and exophthalmos. His brain magnetic resonance image showed right CS DAVF. Thus, emergent TVE was performed. Although his symptoms improved after the first TVE, magnetic resonance image showed brainstem edema, and venous congestion was suspected because of incomplete TVE. Second TVE was performed. Thereafter, computed tomography showed brainstem hemorrhage, resulting in the occurrence of right abducent nerve palsy, right-sided facial palsy, and ataxia. The patient's condition gradually improved, and a year has passed without recurrence. Incomplete TVE of CS DAVF can result in life-threatening complications, such as cerebral hemorrhage. To avoid these complications, the anatomical structure of the cavernous sinus should be understood accurately, and important drainage veins should be determined.

Little is known about how the strength of biodegradable polymers changes during decomposition. This study investigated the changes in the tensile properties of polybutylene succinate (PBS) and basalt-fiber (BF)-reinforced PBS (PBS-BF) composite sheets during degradation in bacterial solutions. Seven days after the start of the experiment, the elongation at break of the PBS specimens decreased significantly, and the PBS-BF composite specimens were characterized by barely any change in ultimate tensile strength (UTS) after immersion in the bacteria-free medium for 7 and 56 days. Meanwhile, when immersed in the bacterial solution, the UTS of the PBS-BF composite specimens showed a tendency to decrease after 7 days. After 56 days, the UTS decreased to about half of its value immediately after fabrication. The degradation of the material was attributed to infiltration of the bacterial solution into structurally weak areas, causing decomposition throughout the material.

Cerebral amyloid angiopathy (CAA) is a disease in which amyloid β (Aβ) is deposited on the walls of blood vessels in the brain, making those walls brittle and causing cerebral hemorrhage. However, the mechanism underlying its onset is not well understood. The aggregation and accumulation of Aβ cause the occlusion and fragility of blood vessels due to endothelial cell damage, breakdown of the blood-brain barrier, and replacement with elements constituting the blood vessel wall. In this study, we observed the effect of Aβ on human primary brain microvascular endothelial cells (hBMECs) in real-time using quantum dot nanoprobes to elucidate the mechanism of vascular weakening by Aβ. It was observed that Aβ began to aggregate around hBMECs after the start of incubation and that the cells were covered with aggregates. Aβ aggregates firmly anchored the cells on the plate surface, and eventually suppressed cell motility and caused cell death. Furthermore, Aβ aggregation induced the organization of abnormal actin, resulting in a significant increase in intracellular actin dots over 10 μm2. These results suggest that the mechanism by which Aβ forms a fragile vessel wall is as follows: Aβ aggregation around vascular endothelial cells anchors them to the substrate, induces abnormal actin organization, and leads to cell death.

Abstract Automation and labor saving in agriculture have been required recently. However, mechanization and robots for growing fruits have not been advanced. This study proposes a method of detecting fruits and automated harvesting using a robot arm. A highly fast and accurate method with a Single Shot MultiBox Detector is used herein to detect the position of fruit, and a stereo camera is used to detect the three-dimensional position. After calculating the angles of the joints at the detected position by inverse kinematics, the robot arm is moved to the target fruit’s position. The robot then harvests the fruit by twisting the hand axis. The experimental results showed that more than 90% of the fruits were detected. Moreover, the robot could harvest a fruit in 16 s.

We characterize fine particulate matter (PM2.5) emitted from Indonesian peatland fires using ground-based source-dominated samplings of PM2.5 near peatland fire sources at two Regencies in Riau, Sumatra, Indonesia (number of samples = 13). Organic carbon (OC), elemental carbon, water-soluble OC (WSOC), the carbon content of humic-like substances (HULIS-C), and biomass burning tracers are determined. The carbon mass ratios of WSOC to OC (0.085 ± 0.015) and HULIS-C to WSOC (0.55 ± 0.085) are fairly constant and independent of the peatland fire sampling sites. By comparing diagnostic ratios using OC, WSOC, and HULIS-C at the peatland fire source and the receptor site (Malaysia) during peatland fire-induced haze periods, secondary WSOC and HULIS-C formation during transport from the source to the receptor site is highly possible. Interestingly, the mass ratio of syringic acid to levoglucosan (0.045 ± 0.0075) is fairly constant at Indonesian peatland fire sources. Because syringic acid is less stable than levoglucosan, this ratio is an aging indicator for Indonesian peatland fires at receptor sites. By comparing the mass fraction of each organic compound in the present study and previous studies, it is evident that the source profile for the coburning of peat with surface vegetation is significantly different compared with the burning of peat alone. Further knowledge of peat burning emissions is needed, particularly with respect to burning conditions, peat composition, and the effects of vegetative burning on peatland. Improved knowledge of these factors would lead to more reliable speciated emission inventories of Indonesian peatland fires, advancing chemical transport and radiative forcing modeling, as well as health risk assessment.

Bone metastasis is relatively common in patients with lung cancers. Although there are some reports of osteolytic skull base metastasis in lung cancer, osteoblastic skull base metastasis is quite rare. A 56-year-old male presented with lung adenocarcinoma who developed vision loss due to papilledema in both eyes with intracranial hypertension. Magnetic resonance imaging revealed no obvious lesions in the intracranial space. Bone scintigraphy, magnetic resonance venography, and computed tomography showed left internal jugular vein stenosis with osteoblastic metastasis protruding into the left jugular foramen. Ventriculoperitoneal shunt surgery improved papilledema and ameliorated vision loss. This case is a reminder that a patient with lung cancer can demonstrate osteoblastic skull base metastasis, and ventriculoperitoneal shunt surgery is an effective and palliative method for such patients.

Background and Objectives: Nutritional management in patients with subarachnoid hemorrhage (SAH) during the acute phase is important; however, there is no proper evidence or recommendations on the appropriate nutrients for early enteral nutrition. This study compared the influence the two different tube-feeding liquid diets for early enteral nutrition might have on the prognosis of patients with SAH. Materials and Methods: In a seven-year period, this single-center retrospective study included 245 patients with aneurysmal SAH who underwent craniotomy and aneurysm neck clipping and received enteral nutrition. The patients were divided into two groups according to the nutrient received: (1) high-protein whey peptide oligomeric formula diet (oligomeric group, 109 patients); and (2) high eicosapentaenoic acid-containing polymeric formula diet (polymeric group, 136 patients). The modified Rankin Scale (mRS) score at discharge was evaluated as the primary outcome. The presence or absence of diarrhea (watery stool and mushy stool) during the period from initiation of enteral nutrition to discharge from the stroke unit was also evaluated. Results: There were no significant differences in patient characteristics between groups. The time until initiation of enteral feeding in the oligomeric and polymeric groups was 2.8 ± 2.3 and 2.9 ± 2.2 days, respectively. The proportion of patients with mRS scores of 0–1 was significantly higher in the oligomeric group (25.7%) than in the polymeric group (14.7%) (p = 0.036), while the incidence of watery stool was significantly lower in the oligomeric group (15.8% to 34.3% in the polymeric group) (p = 0.003). Multivariate analyses confirmed that the oligomeric diet and the presence or absence of diarrhea significantly affected the mRS scores. Conclusions: The adoption of early enteral nutrition with high-protein whey peptide digestive nutrients might be associated with superior mRS scores at discharge and decreased diarrhea in patients with SA, indicating that the choice of nutrients might affect the outcome and prognosis.

In addition to its use in the conventional textile industry, Bombyx Mori silk has attracted significant attention in the materials science and biomedical engineering disciplines. Recently, the possibility of drawing silk fibers with superior toughness has gained particular research interest. Cellulose nanofiber (CNF) is widely studied as a reinforcement material owing to its excellent mechanical properties combined with relatively low density and promising biocompatibility. This paper reports silkworm silk fibers dispersed with CNF that present outstanding tensile properties compared with conventional silk fibers. The silkworm diet was modified by including CNFs, and tensile tests were carried out for the drawn silk fibers. Tensile testing of the drawn silk showed improved Young's modulus and tensile strength when the diet included CNFs at 5 wt% concentration. Fourier transform infrared spectroscopy and atomic force microscopy studies were also conducted to determine the reason for the observed improvement in properties. Morphological studies revealed that the individual fibrils or fibril bundles are aligned in the longitudinal direction of the silk fibers and are uniformly dispersed. Moreover, finite element analysis was performed to estimate the volume fraction of CNF in the silkworm silk fiber. This work opens the door for development of renewable and sustainable bio-composites.

Moyamoya disease is a chronic cerebrovascular disease characterized by spontaneous and progressive stenosis or occlusion of the internal carotid artery and its branches. Revascularization procedures have been shown to improve cerebral hemodynamics and decrease the risk of strokes, but several postoperative complications are known to occur.A 14-year-old girl with moyamoya disease with a history of left-sided revascularization surgery underwent right-sided revascularization. On postoperative day 4, she experienced a transient neurological event (left hemiparesis). Magnetic resonance imaging revealed large cortical and subcortical hyperintense lesions in the middle cerebral artery territory on diffusion-weighted imaging and apparent diffusion coefficient imaging. Subsequently, the radiographic findings improved within several days with resolution of the symptoms.This case is a reminder that hemodynamic complications can develop subacutely in patients who have undergone successful revascularization for moyamoya disease. The radiological features and mechanisms of this rare condition associated with revascularization surgery for moyamoya disease are discussed. Keywords: Moyamoya disease, Atypical, Revascularization surgery

Background: We evaluated the possibility that 3.0 T MRA was sufficient for unique imaging modality before aneurysmal clipping in patients with contraindication to contrast media. Method: 13 cases (16 aneurysms) were retrospectively evaluated. Ruptured aneurysms were 3 cases (3 aneurysms). 10 cases (12 aneurysms) were operated on after preoperative evaluation using only 3.0 T MRA because of contraindication to contrast media, whereas both 3D-DSA/CTA and 3.0 T MRA were performed in 3 cases (4 aneurysms) before the operation because of each clinical reasons. In these 13 cases, we compared aneurysmal findings between intraoperative views and images of 3D-time of flight MRA with volume rendering at 3.0 T. Results: Compared to operative views, the shape of aneurysm including bleb in MRA tended not to be slightly sharp, but the size of neck and dome of aneurysms did not show significant differences. These discrepancies did not affect the intraoperative procedures. Regarding perforators, posterior communicating artery and anterior choroidal artery were confirmed in the operation as same view with MRA findings. It was difficult to distinguish double anterior communicating artery aneurysm by 3.0 T MRA. In thrombosed case, it was necessary to examine raw data of MRA as pretreatment planning tool in order to evaluate the extent of thrombus in aneurysmal neck. Reviewing the cases operated using only 3.0 T MRA retrospectively, there was no case that showed treatment planning by 3.0 T MRA was insufficient. Conclusions: This paper may suggest that treatment planning of aneurysmal clipping on the basis of 3.0 T MRA is feasible and an effective option for patients with contraindication to contrast media. Keywords: Aneurysm, Clipping, MRA, CTA, DSA, Contrast media

It is difficult to distinguish a stump of occluded intracranial arteries from saccular aneurysms on computed tomography (CT) and angiography images. To our knowledge, a middle cerebral artery (MCA) vascular stump which mimicking an aneurysm is extremely rare. Although several cases of MCA vascular stump have been reported, they are usually asymptomatic or involve cases of ischemic stroke. Herein, we report a unique case of an occluded middle cerebral artery stump, which was considered as the source of a subarachnoid hemorrhage on preoperative CT angiogram images.

Fe–Co alloys are attracting attention as magnetostrictive materials for energy harvesting and sensor applications. This work investigated the magnetostriction characteristics and crystal structure of additive-manufactured Fe–Co alloys using directed energy deposition. The additive-manufactured Fe–Co parts tended to exhibit better magnetostrictive performance than the hot-rolled Fe–Co alloy. The anisotropy energy ΔK1 for the Fe–Co bulk, prepared under a power of 300 W (referred to as bulk−300 W), was larger than for the rolled sample. For the bulk−300 W sample in a particular plane, the piezomagnetic constant d was large, irrespective of the direction of the magnetic field. Elongated voids that formed during additive manufacturing changed the magnetostrictive behavior in a direction perpendicular to these voids. Magnetic property measurements showed that the coercivity decreased. Since sensors should be highly responsive, Fe–Co three-dimensional parts produced via additive manufacturing can be applied as force sensors.

Cellulose acetate (CA) is widely used as an alternative to conventional plastics because of the minor environmental impact of its decomposition cycle. This study synthesized five-layer environmentally friendly composites from CA bioplastic and basalt fibers (BFs) to produce a high-strength marine-biodegradable polymer. Maleic anhydride-grafted polypropylene (PP-g-MAH) was mixed with CA as a surface-active agent (SAA) to understand the effect of surface treatment on the mechanical properties of the composite. Tensile tests and scanning electron microscopy were conducted to observe the fracture surfaces. The ultimate tensile strength (UTS) of the BF/CA composite increased by approximately a factor of 4 after adding 11 vol.% unidirectional BF. When the SAA was added, the UTS of the composite with 11 vol.% BF was multiplied by a factor of about 7, which indicates that the surface treatment has a significant positive effect on the mechanical properties. However, the improvement is not apparent when the added BFs are in a plain weave with a vertical orientation. A photodecomposition experiment was then conducted by adding TiO2. Observing the UTS changes of the CA and BF/CA composites, the effect of the photocatalyst on the decomposition of the materials was explored.

A class of lightweight FeCo/AlSi magnetostrictive composites was prepared in this study to explore the feasibility for 1-3 metal-matrix magnetostrictive materials for serving as sensors, actuators and energy harvesters. The FeCo fibers were inset into the AlSi metal liquid and then the composites were solidified at a protective atmosphere. The microstructural observations for these FeCo/AlSi composites illustrate the presence of the element diffusion and the disappearance of the cold-rolled preferred orientation. The refined microstructure was obtained during solidification and then further improved the magnetostrictive properties of the FeCo/AlSi composites. A zigzag interface with well transfer in stress and strain between the FeCo fiber and AlSi matrix existed through both physical and chemical bonding. There are two different experimental groups in this work. One group is aimed to evaluate the effect of the diameter of the FeCo/AlSi composite on the output voltage under compression. Another group with different numbers of the FeCo fibers is employed for analyzing the effect of the volume fraction of the FeCo fiber on the output performance. The results exhibit that a smaller diameter for the lightweight 1-3 FeCo/AlSi composite contributes to exciting a greater output voltage. Furthermore, the output voltage is proportional to the number of the FeCo fiber. An optimal resistive load of 500 Ω for this harvesting setup is obtained. Theoretical analysis through a magneto-mechanical coupling model for the FeCo/AlSi composites was conducted for accurately predicting the practical output performance. Keywords: Metal-matrix composite, Iron cobalt, Inverse magnetostrictive effect, Lightweight devices

It is well known that the curing residual stress induced during a fabrication process has a great influence on the performance of piezoelectric composite devices. The purpose of this work was to evaluate the residual thermal stress of lead zirconate titanate piezoelectric fiber aluminum (Al) matrix (piezoelectric fiber/Al) composites generated during fabrication numerically and experimentally and to understand the effect of the residual thermal stress on the electromechanical response. The three-dimensional finite element method was employed, and the residual stress generated during the solidification process of the Al matrix was calculated. The output voltage was also calculated in the analysis when putting stresses on the composite materials in the length direction of the piezoelectric fiber. It was shown that the cooling from higher temperatures increases the electromechanical conversion capability. Furthermore, we also performed the simulation, and we recorded the output voltage under concentrated load to investigate its application as a load position detection sensor, and we also discussed the influence of the position by changing the modeling with a different fiber position in the Al. The residual stress of hot press molded piezoelectric fiber/Al composite was then measured, and the comparison was made with the calculated values. The simulation results revealed that our model predictions reproduced and explained the experimental observations of curing residual stress. After this study, similar models of composite materials can be analyzed by this simulation, and the result can be used to design piezoelectric composite materials.

The purpose of this paper is to investigate the through-thickness stresses of woven glass fiber reinforced polymer (GFRP) composite laminates under combined tensile and shear loading. Tensile tests were carried out with cross specimens at room temperature under various stacking angles, and the through-thickness strength properties of the woven GFRP laminates were evaluated. The failure characteristics of the woven GFRP laminates were also studied by optical microscopy observations. A three-dimensional finite element analysis (FEA) was carried out to calculate the stress distributions in the cross specimens, and the failure conditions of the specimens were examined. The numerically determined interlaminar tensile and shear stresses at failure location were consistent with Hoffman and Mohr-Coulomb failure criteria when the stacking angle was relatively small. This work is the first attempt to quantify the relation between interlaminar tensile and shear strengths of GFRP composite laminates under tensile and shear loading simultaneously using a combined numerical and experimental approach. A method based on finite element stress analysis was developed for estimating the through-thickness strength of the composite laminates using the experimentally determined fracture load and location. The results suggest that the through-thickness strength under combined tensile and shear loading can be determined effectively by this approach for relatively small stacking angles.

Cellulose nanofiber (CNF) has been accepted as a valid nanofiller that can improve the mechanical properties of composite materials by mechanical and chemical methods. The purpose of this work is to numerically and experimentally evaluate the mechanical behavior of CNF-reinforced polymer composites under tensile loading. Finite element analysis (FEA) was conducted using a model for the representative volume element of CNF/epoxy composites to determine the effective Young’s modulus and the stress state within the composites. The possible random orientation of the CNFs was considered in the finite element model. Tensile tests were also conducted on the CNF/epoxy composites to identify the effect of CNFs on their tensile behavior. The numerical findings were then correlated with the test results. The present randomly oriented CNF/epoxy composite model provides a means for exploring the property interactions across different length scales.

Epoxy resins are a widely used common polymer due to their excellent mechanical properties. On the other hand, cellulose nanofiber (CNF) is one of the new generation of fibers, and recent test results show that CNF reinforced polymers have high mechanical properties. It has also been reported that an extremely low CNF addition increases the mechanical properties of the matrix resin. In this study, we prepared extremely-low CNF (~1 wt.%) reinforced epoxy resin matrix (epoxy-CNF) composites, and tried to understand the strengthening mechanism of the epoxy-CNF composite through the three-point flexural test, finite element analysis (FEA), and discussion based on organic chemistry. The flexural modulus and strength were significantly increased by the extremely low CNF addition (less than 0.2 wt.%), although the theories for short-fiber-reinforced composites cannot explain the strengthening mechanism of the epoxy-CNF composite. Hence, we propose the possibility that CNF behaves as an auxiliary agent to enhance the structure of the epoxy molecule, and not as a reinforcing fiber in the epoxy resin matrix.

TiB-reinforced Ti-3Al-2.5V matrix composites, in which TiB whiskers are oriented parallel to the direction of heat extrusion, were fabricated via mechanical alloying and hot isostatic pressing (HIP). To investigate the near-threshold fatigue crack propagation in TiB-reinforced Ti-3Al-2.5V matrix composites, stress intensity factor K-decreasing tests were conducted for disk-shaped compact specimens having two different orientations of TiB whiskers at force ratios from 0.1 to 0.8 under ambient conditions. The crack growth rates, da/dN, for the composites incorporating TiB whiskers oriented perpendicular to the direction of crack growth were constantly lower than those obtained in the case where the orientation was parallel at the same stress intensity range ΔK, while the threshold stress intensity range, ΔKth, was higher. This effect can be explained by the increase in the degree of roughness-induced crack closure resulting from the perpendicular TiB, because fatigue cracks preferentially propagated across the boundaries between the matrix and the TiB in certain regions. In contrast, the effective threshold stress intensity range, ΔKeff,th, for composites was unaffected by the TiB orientation at low force ratios.

Carbon fiber reinforced plastic (CFRP) is an excellent choice in the areas where weight reduction is important and multi-functionalization of CFRP, especially by adding sensor capabilities, is a promising approach to realize lightweight battery-free devices in structural health monitoring (SHM). In this study, we fabricated hybrid CFRP with Fe-Co fibers and evaluated the inverse magnetostrictive response characteristics. It was shown that the measured magnetic flux density of the CFRP fluctuates in response to cyclic bending load. It was also revealed that our Fe-Co fiber inserted CFRP has damage self-sensing ability. In addition, it seems that the optimization of design and more experimental and numerical investigation improves the capability of the hybrid CFRP with Fe-Co fiber as sensor composite materials.

We fabricated fully dense titanium boride (TiB) whisker-reinforced Ti-6Al-4V alloy matrix (Ti6Al4V-TiB) composites, with a homogeneous dispersion, a TiB orientation perpendicular to the loading direction (; two-dimensional random direction) and an intimate Ti/TiB interface without an intermediate interfacial layer in the Ti-6Al-4V alloy matrix, by spark plasma sintering. Microstructural analysis allows us to present the tensile properties of the Ti6Al4V-TiB composites with the theories for discontinuous fiber-reinforced composites. The Ti6Al4V-TiB 10 vol.% composite yielded a Young’s modulus of 130 GPa, an ultimate tensile strength (UTS) of 1193 MPa and an elongation of 2.8%. The obtained experimental Young’s modulus and UTS of the Ti6Al4V-TiB composites were consistent with the theoretical values estimated by the Halpin-Tsai and Shear-lag models. The good agreement between our experimental results and these models indicates that the TiB whiskers behave as discontinuous fibers in the Ti-6Al-4V alloy matrix.

Wearable energy harvesting devices attract attention as the devices provide electrical power without inhibiting user mobility and independence. While the piezoelectric materials integrated shoes have been considered as wearable energy harvesting devices for a long time, they can lose their energy harvesting performance after being used several times due to their brittleness. In this study, we focused on Fe−Co magnetostrictive materials and fabricated Fe−Co magnetostrictive fiber integrated shoes. We revealed that Fe−Co magnetostrictive fiber integrated shoes are capable of generating 1.2 µJ from 1000 steps of usual walking by the Villari (inverse magnetostrictive) effect. It seems that the output energy is dependent on user habit on ambulation, not on their weight. From both a mechanical and functional point of view, Fe−Co magnetostrictive fiber integrated shoes demonstrated stable energy harvesting performance after being used many times. It is likely that Fe−Co magnetostrictive fiber integrated shoes are available as sustainable and wearable energy harvesting devices.

Anterior inferior cerebellar artery (AICA)–posterior inferior cerebellar artery (PICA) is a well-known variant in cerebral arteries. However, aneurysms located on the variant are rare and a giant one has not been reported. We report a case of a partially thrombosed giant aneurysm arising from an AICA–PICA variant. The patient was a 42-year-old man who presented with right hearing loss and facial numbness associated with left hemidysesthesia. Magnetic resonance imaging revealed an approximately 3.0-cm mass lesion at the right cerebello-pontine angle (CPA). Angiography showed a partially thrombosed aneurysm arising from the right AICA–PICA. The aneurysm was treated with endovascular trapping and surgical thrombectomy. Although cerebral aneurysm is known to occur at this site, this case provides awareness, that manifestations of aneurysms in the CPA include progressive multiple cranial nerve palsies and sensory disturbance caused by brainstem compression.

We report a case of small internal carotid–posterior communication artery (IC–PC) aneurysm that was completely thrombosed after initial bleeding, but subsequently became symptomatic, causing a mass effect. A 54-year-old woman initially presented with grade-five subarachnoid hemorrhage from a small right IC–PC aneurysm. The aneurysm was treated conservatively and completely thrombosed within 35 days. The patient slowly recovered and remained well until 4 years later, when she developed right oculomotor nerve palsy. Imaging revealed relapse of the aneurysm, and repair led to symptom resolution. This case offers a reminder that totally thrombosed aneurysms carry a risk of regrowth if left untreated.

Background: Cupping therapy is an alternative treatment that uses a small glass cup to suck the skin with a needle and has been used to manage skin problems and pain. However, serious complications have been reported. Herein, we describe a case of intracranial mycotic aneurysm rupture after cupping therapy. Case Description: A 25-year-old male patient presented with a headache and fever after cupping therapy for atopic dermatitis. He was diagnosed with infective endocarditis, and antibiotic therapy was initiated. After that, he suddenly lost consciousness, and head imaging revealed a cerebral hemorrhage due to a ruptured intracranial mycotic aneurysm. He underwent craniotomy, which was successful, and he was transferred to a rehabilitation center with a modified Rankin scale score of 2 at three months post-stroke. Conclusion: This case serves as a reminder of life-threatening infectious complication risks after cupping therapy. A patient who has a compromised skin barrier may experience serious adverse effects, especially when cupping is performed without implementing suitable infection prevention measures. [ABSTRACT FROM AUTHOR]

Background: Surgery is effective for extracranial internal carotid artery (EICA) aneurysms. However, the risk of cranial nerve injury associated with surgical repair, such as graft-assisted resection and extracranial-intracranial bypass techniques, is relatively high. Here, we report two cases of surgical treatment for EICA aneurysms and describe the surgical techniques and strategies to avoid cranial nerve injury. Methods: Two patients presented to our facility with an increasing cervical pulsatile mass and no neurological symptoms. Angiography showed a large aneurysm in the cervical internal carotid artery. Surgical treatment was performed to prevent rupture of the aneurysm. In both patients, the aneurysm was strongly attached to the vagus nerve. The aneurysm and vagus nerve were carefully dissected using a low-power bipolar (20 Malis; 3 watts), leaving connective tissue on the vagus nerve side. Results: The aneurysm was detached from the vagus nerve without injury. Based on intraoperative findings, one patient underwent clipping, and the other underwent aneurysmectomy and primary closure for aneurysm obliteration and angioplasty. Both patients were discharged without any cranial nerve dysfunction. Conclusion: The selection of a strategy based on intraoperative findings and low-power bipolar cutting is important for the treatment of extracranial carotid artery aneurysms to preserve cranial nerves. [ABSTRACT FROM AUTHOR]