117 research outputs found
A Heterothermic Kinetic Model of Hydrogen Absorption in Metals with Subsurface Transport
A versatile numerical model for hydrogen absorption into metals was developed. Our model addresses the kinetics of surface adsorption, subsurface transport (which plays an important role for metals with active surfaces), and bulk diffusion processes. This model can allow researchers to perform simulations for various conditions, such as different material species, dimensions, structures, and operating conditions. Furthermore, our calculation scheme reflects the relationship between the temperature changes in metals caused by the heat of adsorption and absorption and the temperature-dependent kinetic parameters for simulation precision purposes. We demonstrated the numerical fitting of the experimental data for various Pd temperatures and sizes, with a single set of kinetic parameters, to determine the unknown kinetic constants. Using the developed model and determined kinetic constants, the transitions of the rate-determining steps on the conditions of metal-hydrogen systems are systematically analyzed. Conventionally, the temperature change of metals during hydrogen adsorption and absorption has not been a favorable phenomenon because it can cause errors when numerically estimating the hydrogen absorption rates. However, by our calculation scheme, the experimental data obtained under temperature changing conditions can be positively used for parameter fitting to efficiently and accurately determine the kinetic constants of the absorption process, even from a small number of experimental runs. In addition, we defined an effectiveness factor as the ratio between the actual absorption rate and the virtually calculated non-bulk-diffusion-controlled rate, to evaluate the quantitative influence of each individual transport process on the overall absorption process. Our model and calculation scheme may be a useful tool for designing high-performance hydrogen storage systems
Experimental investigation of magnetic arc blow in plasma arc cutting
Oxygen plasma arc cutting is widely employed in various industrial fields. In the case of cutting magnetized plates, the magnetic field is concentrated around the cutting front as cutting progresses, and the electromagnetic force induced by the leakage of magnetic field deflects the plasma jet. The deflected plasma jet leads to poor cutting quality and sometime causes damage to the electrode and nozzle because of double arc abnormal discharge. This phenomenon is called magnetic arc blow, and it is a critical issue when applying plasma cutting on magnetized plates. In this study, magnetic arc blow behavior is investigated, and a method to prevent it is devised. We examined the relationship between operating conditions and the double arc using external magnetic fields on a plasma jet. We found criteria regarding operation conditions that induce arc blow. In addition, we succeeded in suppressing the double arc caused by the leakage external magnetic field by using a magnetic shield cap composed of ferromagnetic material around the nozzle
In-Orbit Demonstration of Propellant-Less Formation Flight with Momentum Exchange of Jointed Multiple CubeSats in the MAGNARO Mission
Recently, small satellites such as CubeSats have been applied to a variety of missions such as scientific observations and remote sensing. One of attractive applications that can be relatively easily achieved by small satellites are multi-satellite missions such as formation flight and constellation. As a new method to realize these multi-satellite missions, we propose a method to separate jointed multiple satellite magnetically to generate ΔV without thrusters. To demonstrate the proposed method, we are developing a 3U sized CubeSat called MAGNARO (MAGnetically separating NAnosatellite with Rotation for Orbit control)
トウイン ニオケル セツジョ フノウ キョクショ シンコウ ショクドウガン ノ チリョウ セイセキ
【背景】遠隔転移のない切除不能局所進行食道癌に対する標準治療は根治的化学放射線療法(CRT)だが,近年Docetaxel/5-FU/ Cisplatin 療法をはじめとした導入化学療法(ICT)からの外科的切除の有用性が報告されている.今回,当院での切除不能局所進行食道癌に対する治療成績について検証した.【対象と方法】2016年から2019年の期間で,当院で治療した切除不能局所進行食道癌9例(リンパ節T4bも含む)を対象とした.【結果】男性:6例,女性:3例.年齢:中央値 64(41-78)歳.腫瘍主占居部位:Ut/Mt/Lt=1/7/1.浸潤臓器:気管/左主気管支/大動脈=2/4/3,cN0/1/2=1/3/5,初回治療: ICT/CRT=7/2であった.初回治療別に検証すると,奏効率:ICT/CRT=5(71.4%)/0(0%)であり,ICTにて奏効が得られた5例は根治切除可能と判断し,4例(80%)でR0切除が得られた.術後合併症は,縫合不全0例,肺炎1例(20%),反回神経麻痺2例(40%)であった.術後在院日数中央値は16日(13-21)であった.R0切除4例は全例1年以上の生存が得られているが,2例で再発(リンパ節再発1例,肺・リンパ節再発1例)を認めた.R1切除例はCRTを追加し,術後2年無再発生存中である.根治切除を施行していない4例の初回治療からの1年生存率は25%と予後不良であった.【結語】切除不能局所進行食道癌であってもICTを組み入れることでconversion surgeryが安全に施行され,高いR0切除率が得られ,予後の延長に寄与する可能性がある.Background:Recently, the usefulness of surgical resection after induction chemotherapy (ICT) including Docetaxel / 5-FU / Cisplatin therapy for locally advanced esophageal cancer has been reported. Methods:Nine patients with locally advanced unresectable esophageal cancer who underwent multidisciplinary treatment in our hospital from 2016 to 2019 were eligible for this study. Results:The patients’ characteristics included a median age of 64 years; the male/female ratio of 6/3; Tumor main occupancy site Ut / Mt / Lt = 1/7/1; Invading adjacent organs: trachea / left main bronchus / aorta; 2/4/3, Lymph node metastasis (0/1/2); 1/3/5, and initial treatment ICT / CRT; 7/2. Response rate of ICT were 71.4% (5 cases) and that of CRT were 0%. Four patients (80%) of 5 patients who responded to ICT were underwent R0 resection. Postoperative complications were anastomotic leakage in 0 cases, pneumonia in 1 case (20%), and recurrent nerve paralysis in 2 cases (40%). The median length of hospital stay after surgery was 16 days. All 4 cases of R0 resection had survived for 1 year or more. The 1-year survival rate from the initial treatment of 4 patients who did not undergo radical resection was 25%. Conclusion:Conversion surgery after ICT for locally advanced unresectable esophageal cancer may contribute to a high R0 resection rate and better clinical outcomes
The unique electrical properties in an extracellular fluid of the mammalian cochlea; their functional roles, homeostatic processes, and pathological significance
トウイン ニオケル キョウクウ キョウカ ショクドウ セツジョ ノ ドウニュウ ト タンキ チリョウ セイセキ ノ ケントウ
【背景】食道癌に対する胸腔鏡手術は本邦で広く行われており、施設ごとに手術手技の定型化がなされている.胸腔鏡下手術の利点として拡大視効果や緻密な手術操作が可能となることが挙げられるが、当院でも2016年より腹臥位胸腔鏡下食道手術を導入し、出血の少ない安全かつ確実な郭清を目指し、定型化に向けてその手技を刷新している.【対象と方法】】2016年4月から2019年4月までに当院で施行した胸腔鏡下食道切除38例につき、その短期成績を検討した.【結果】男:女=32:6、年齢中央値 66歳(41-76)、cStage I / II / III / IVa: 17 / 6 / 13 / 2であった.胸腔内出血量中央値は10ml(0-53)、胸部操作時間中央値は192分(97-478)、胸腔内郭清リンパ節個数中央値は17個(1-42)であった.術後合併症は、縫合不全3例(7.9%)、反回神経麻痺7例(18.4%)、肺炎12例(31.6%)であった.術後在院日数中央値は19日(11-38)であった.導入期からの前半19例では反回神経麻痺を6例(31.6%)に認めたが、後半19例では1例(5.2%)であった(p=0.036).【結語】当院における胸腔鏡下食道切除術は安全に導入、施行可能であった.手術手技が定型化されることで反回神経麻痺を少なくする郭清が可能になると考えられた.Background: Thoracoscopic esophagectomy (TE) is increasingly being used worldwide in patients with esophageal cancer. In this study, we investigated the clinical short-term outcomes of TE performed in patients placed in the prone position. Method: We investigated the surgical and clinical outcomes in 38 patients with esophageal cancer who underwent TE at our hospital between April 2016 and April 2019. Results: Of the 39 patients investigated, 32 were men. Median patient age was 66 (range 41–76) years, the median intraoperative blood loss was 10 (0–53) mL, and the median operation time for thoracoscopy was 192 (97–478) min. The mean operation time for thoracoscopy in the latter group was significantly shorter than that in the former group (188 min vs. 232 min, p=0.013). The following postoperative complications were observed: 7 (18.4%) cases of recurrent nerve palsy, 3 (7.9%) cases of anastomotic leakage, 12 (31.6%) cases of pneumonia, and 0 (0%) cases of chylothorax. The incidence of recurrent nerve palsy was lower in the latter group than in the former group (5.2% vs. 31.6%, p=0.036). Conclusions: TE in the prone position is safe and feasible. As experience performing the procedure increases, the performance of the procedure stabilizes
DOCK2 is involved in the host genetics and biology of severe COVID-19
「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target
The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force
「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection
カンサイボウガン ト カンベツ ガ コンナンデアッタ カンケッカンキン シボウシュ ノ 1レイ
肝原発の血管筋脂肪腫(angiomyolipoma; AML)は、肝細胞癌と鑑別が困難な場合がある。今回、単発の肝腫瘍に対して肝細胞癌を否定できず切除を行ったが、病理組織学的検査でAMLと診断した一例を経験したので報告する。症例は50歳代の女性。検診にて外側区域の肝腫瘍を指摘され、加療目的に紹介となった。造影CT検査では肝外側区域、門脈臍部に接して2cm大の腫瘍性病変を認め、動脈相で濃染し平衡相でwashoutしていた。腹部MRI検査では同部位にT2強調像で高信号、T1 out of phaseにて若干の信号低下を認めた。Gadolinium-ethoxybenzyl-diethylene-triaminepentaacetic-acid(Gd-EOB-DTPA; EOB) MRIでは動脈相で濃染、門脈相から平衡相にかけてwashoutし、肝細胞相では低信号であった。画像所見から肝細胞癌を疑い、腹腔鏡下肝左葉切除術を施行した。病理組織学的には好酸性紡錘形細胞や淡明~淡好酸性細胞の上皮様配列がみられ、内部に脂肪組織が島状に介在し、また、平滑筋性の厚い壁を持った血管構造も一部存在しており、肝血管筋脂肪腫と診断した。一般に脂肪成分の少ないAMLは、肝細胞癌との鑑別が困難である。最近では、肝静脈への流出血管の有無が鑑別診断に有用であるとの報告が見られるため、これらを注意深く観察すべきと考えられた。Hepatic angiomyolipoma (AML) may be difficult to distinguish from hepatocellular carcinoma. Here we report a resected case of a hepatic AML mimicking hepatocellular carcinoma. The patient was a woman in her 50s referred for further evaluation of a tumor in the left lateral segment of the liver. Contrast-enhanced computed tomography showed a two cm-sized tumor attached with the umbilical portion in the left lateral segment of the liver, which was enhanced in the arterial phase and washed out in the portal venous phase. Abdominal MRI showed a high-intensity tumor on T2-weighted image and a slight decrease of signal intensity on T1 out of phase. The tumor on Gd-EOB-DTPA enhanced MRI displayed high intensity in the arterial phase and washout in the portal venous phase, and low signal intensity in hepatobiliary phase. Based on these imaging findings, we suspected hepatocellular carcinoma and a laparoscopic left lobectomy was performed. Histopathological examination showed spindle and perivascular epithelioid cells and a few fat cells, and immunohistochemical analysis revealed positive staining of HMB-45 and αSMA. The tumor was diagnosed as a hepatic AML. Hepatic AML with a small fatty component is generally difficult to distinguish from hepatocellular carcinoma. More recently, the presence of outflow blood vessels to the hepatic vein has been reported to be useful in the differential diagnosis for AML. These imaging findings should be carefully observed
ノウホウナイ シュッケツ ニ トモナイ シンゴウ キョウド ノ コトナッタ タボウセイ ノウホウ オ テイシタ スイショウエキセイ ノウホウ センシュ ノ 1レイ
症例は33歳,女性.経時的に増大する膵体部嚢胞性病変を認めた.MRIではT1強調画像で低信号を呈する部位とT1強調画像で淡い高信号を呈する,信号強度の異なる大小不同の多房性嚢胞性病変を認め,MRCPおよび超音波内視鏡検査で主膵管拡張および腫瘍と主膵管との交通が疑われた.以上よりmixed typeの膵漿液性嚢胞腺腫を疑ったが粘液性嚢胞腺腫や膵管内乳頭粘液性腫瘍を否定できず,腹腔鏡下脾温存膵体尾部切除術を施行した.病理組織学的検査所見では卵巣様間質は認めず,主膵管交通も認めず,mixed typeの膵漿液性嚢胞腺腫と診断した.膵漿液性嚢胞腺腫は漿液性嚢胞液を有するが,異なった信号強度を呈する多房性嚢胞を有するものはまれである.今回われわれは,信号強度の異なった多房性嚢胞を呈した膵漿液性嚢胞腺腫の1例を経験したので報告する.A 33-year-old woman presented at our hospital with cystic tumor increased over time at pancreatic body. Magnetic resonance image revealed multilocular cysts with different signal intensities, which were mixed to low and slightly high intensities in T1 weighted image. Moreover, the connection of the cyst and main pancreatic duct was suspected by magnetic resonance cholangiopancreatography and endoscopic ultrasonography. We diagnosed as mixed-type serous cystadenoma, yet we could not contradict mucinous cystadenoma and intraductal papillary mucinous neoplasm. Therefore, we performed laparoscopic spleen preserved distal pancreatectomy. Histopathological findings revealed mixed-type serous cystadenoma, and the connection of the cyst and main pancreatic duct was not seen. Serous cystadenoma usually has serous discharge in the cyst and shows uniform signal intensity in the image findings. However, serous cystadenoma with different signal intensities in the multilocular cysts is relatively rare. We described a case of serous cystadenoma of the pancreas with different signal intensities in the multilocular cysts that was treated by laparoscopic surgery
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