Solar System Exploration Sciences by EQUULEUS on SLS EM-1 and Science Instruments Development Status

EQUULEUS is a spacecraft to explore the cislunar region including the Earth-Moon Lagrange point L2 (EML2) and will be launched by NASA’s SLS EM-1 rocket. Although the size of EQUULEUS is only 6U, the spacecraft carries three different science instruments. By using these instruments, the spacecraft will demonstrate three missions for solar system exploration science during and after the flight to EML2; imaging of the plasmasphere around the earth, observation of space dust flux in the cislunar region, and observation of lunar impact flashes at the far side of the moon. The developments and verifications of the flight models of these science instruments were completed by the end of 2018, and we started flight model integration and testing. This paper introduces the details of the scientific objectives, design results and development statuses of the instruments. In addition, results of the integration and pre-flight tests are also described

Arterial spin labeling灌流画像で得られる血管内高信号は内頚動脈の閉塞部位を予測する

Introduction Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Methods Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Results Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1–C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3–C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1–C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. Conclusion High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site

Optimal design of a coproduction system of electricity and hydrogen to manage imbalances resulting from forecast errors in photovoltaic outputs

Renewable power sources are increasing mainly because of economic institutions such as renewable portfolio standard or feed-in tariff program. In Japan, the feed-in tariff program triggered explosive growth of photovoltaic systems because of its high tariff level. Although mass introduction of photovoltaic systems certainly contributes to reduce CO2 emissions, it causes instability issues in power systems. One of the most serious issues is management of imbalances resulting from forecast errors in photovoltaic outputs. On the other hand, power-to-gas technologies are attracting our attention, since these technologies could convert surplus of renewable energy to other energy carriers. In particular, hydrogen is efficiently produced from electricity using electrolysis. We could use hydrogen to manage the imbalances by the system, in which uncertain parts of photovoltaic outputs are used to produce hydrogen. In this paper, we propose a coproduction system of electricity and hydrogen to reduce the imbalances. For this purpose, a novel mathematical model is developed, in which we determine the structure of the coproduction system with a mixed integer linear programming method. Evaluated results indicated that the coproduction system is economical under appropriate capacity of the electrolyzer

Analysis on waste-heat transportation systems with different heat-energy carriers

The transport of what would otherwise be waste-heat (at temperatures between 30°C and 300°C) through pipelines using as an energy carrier either methanol or hydrogen gas has been studied. By using numerical models, the relative costs of new kinds of waste-heat transportation systems are evaluated and compared with those using vapor or hot water, which have been the major energy-carriers in pipeline transmission systems until now. Also, environmental regulations and a carbon tax are investigated as incentives for introducing these systems.

Essential updates 2021/2022: Update in surgical strategy for perihilar cholangiocarcinoma

Abstract Resection is the only potential curative treatment for perihilar cholangiocarcinoma (PHC); however, complete resection is often technically challenging due to the anatomical location. Various innovative approaches and procedures were invented to circumvent this limitation but the rates of postoperative morbidity (20%–78%) and mortality (2%–15%) are still high. In patients diagnosed with resectable PHC, deliberate and coordinated preoperative workup and optimization of the patient and future liver remnant are crucial. Biliary drainage is recommended to relieve obstructive jaundice and optimize the clinical condition before liver resection. Biliary drainage for PHC can be performed either by endoscopic biliary drainage or percutaneous transhepatic biliary drainage. To date there is no consensus about which method is preferred. The volumetric assessment of the future remnant liver volume and optimization mainly using portal vein embolization is the gold standard in the management of the risk to develop post hepatectomy liver failure. The improvement of systemic chemotherapy has contributed to prolong the survival not only in patients with unresectable PHC but also in patients undergoing curative surgery. In this article, we review the literature and discuss the current surgical treatment of PHC