110 research outputs found
Singularity-free Aerial Deformation by Two-dimensional Multilinked Aerial Robot with 1-DoF Vectorable Propeller
Two-dimensional multilinked structures can benefit aerial robots in both
maneuvering and manipulation because of their deformation ability. However,
certain types of singular forms must be avoided during deformation. Hence, an
additional 1 Degrees-of-Freedom (DoF) vectorable propeller is employed in this
work to overcome singular forms by properly changing the thrust direction. In
this paper, we first extend modeling and control methods from our previous
works for an under-actuated model whose thrust forces are not unidirectional.
We then propose a planning method for the vectoring angles to solve the
singularity by maximizing the controllability under arbitrary robot forms.
Finally, we demonstrate the feasibility of the proposed methods by experiments
where a quad-type model is used to perform trajectory tracking under
challenging forms, such as a line-shape form, and the deformation passing these
challenging forms
Examining the Validity of Efforts of the Muscular Dystrophy Medical Network in Nagano : A Questionnaire Study
Article信州医学雑誌 66(3): 205-212(2018)journal articl
Efficacy of vonoprazan against bleeding from endoscopic submucosal dissection-induced gastric ulcers under antithrombotic medication: A cross-design synthesis of randomized and observational studies
Vonoprazan, a potassium-competitive acid blocker, is expected to be superior to proton pump inhibitors (PPIs) in preventing post-endoscopic submucosal dissection (ESD)-induced gastric bleeding. However, the results of randomized controlled trials (RCTs) and observational studies on the efficacy of vonoprazan have been inconsistent. This study aimed to evaluate the effectiveness of vonoprazan in antithrombotic drug users, a population that has been excluded from RCTs. Treatment effects were assessed using cross-design synthesis, which can be adjusted for differences in study design and patient characteristics. We used data from an RCT in Japan (70 patients in the vonoprazan group and 69 in the PPI group) and an observational study (408 patients in the vonoprazan group and 870 in the PPI group). After matching, among the antithrombotic drug users in the observational study, post-ESD bleeding was noted in 8 out of 86 patients in the vonoprazan group and 18 out of 86 patients in the PPI group. After pooling the data from the RCT and observational study, the risk difference for antithrombotic drug users was -14.6% (95% CI: -22.0 to -7.2). CDS analysis suggested that vonoprazan is more effective than PPIs in preventing post-ESD bleeding among patients administered antithrombotic medications
Versatile Multilinked Aerial Robot with Tilting Propellers: Design, Modeling, Control and State Estimation for Autonomous Flight and Manipulation
Multilinked aerial robot is one of the state-of-the-art works in aerial
robotics, which demonstrates the deformability benefiting both maneuvering and
manipulation. However, the performance in outdoor physical world has not yet
been evaluated because of the weakness in the controllability and the lack of
the state estimation for autonomous flight. Thus we adopt tilting propellers to
enhance the controllability. The related design, modeling and control method
are developed in this work to enable the stable hovering and deformation.
Furthermore, the state estimation which involves the time synchronization
between sensors and the multilinked kinematics is also presented in this work
to enable the fully autonomous flight in the outdoor environment. Various
autonomous outdoor experiments, including the fast maneuvering for interception
with target, object grasping for delivery, and blanket manipulation for
firefighting are performed to evaluate the feasibility and versatility of the
proposed robot platform. To the best of our knowledge, this is the first study
for the multilinked aerial robot to achieve the fully autonomous flight and the
manipulation task in outdoor environment. We also applied our platform in all
challenges of the 2020 Mohammed Bin Zayed International Robotics Competition,
and ranked third place in Challenge 1 and sixth place in Challenge 3
internationally, demonstrating the reliable flight performance in the fields
The plant-derived triterpenoid, cucurbitacin B, but not cucurbitacin E, inhibits the developmental transition associated with ecdysone biosynthesis in Drosophila melanogaster
In insects, some sterols are essential not only for cell membrane homeostasis, but for biosynthesis of the steroid hormone ecdysone. Dietary sterols are required for insect development because insects cannot synthesize sterols de novo. Therefore, sterol-like compounds that can compete with essential sterols are good candidates for insect growth regulators. In this study, we investigated the effects of the plant-derived triterpenoids, cucurbitacin B and E (CucB and CucE) on the development of the fruit fly, Drosophila melanogaster. To reduce the effects of supply with an excess of sterols contained in food, we reared D. melanogaster larvae on low sterol food (LSF) with or without cucurbitacins. Most larvae raised on LSF without supplementation or with CucE died at the second or third larval instar (L2 or L3) stages, whereas CucB-administered larvae mostly died without molting. The developmental arrest caused by CucB was partially rescued by ecdysone supplementation. Furthermore, we examined the effects of CucB on larval-prepupal transition by transferring larvae from LSF supplemented with cholesterol to that with CucB just after the L2/L3 molt. L3 larvae raised on LSF with CucB failed to pupariate, with a remarkable developmental delay. Ecdysone supplementation rescued the developmental delay but did not rescue the pupariation defect. Furthermore, we cultured the steroidogenic organ, the prothoracic gland (PG) of the silkworm Bombyx mori, with or without cucurbitacin. Ecdysone production in the PG was reduced by incubation with CucB, but not with CucE. These results suggest that CucB acts not only as an antagonist of the ecdysone receptor as previously reported, but also acts as an inhibitor of ecdysone biosynthesis
Immune Reactions Against Elongation Factor 2 Kinase: Specific Pathogenesis of Gastric Ulcer from Helicobacter pylori Infection
Helicobacter pylori (H. pylori) infection is a definite causative factor for gastric ulcers (GUs). In the present study we detected a specific antigen of gastric epithelial cells (HGC-27) using cell ELISA, which was recognized by the sera of GU patients (n = 20) but not in patients with chronic gastritis (CG; n = 20) or in healthy volunteers (HC; n = 10). This antigen was over-expressed by a stressful (heat-stressed) environment, and was identified as elongation factor 2 kinase (EF-2K) by western blotting. The GU patients' lymphocytes stimulated by H. pylori specifically disrupted heat-stressed HGC-27 cells in a cytotoxic assay. In flow cytometry, the effector cells (lymphocytes) from GU patients were significantly differentiated to T helper type 1 lymphocyte (Th1) and cytotoxic T lymphocyte (CTL) as opposed to those from CG patients. The target cells (HGC-27) expressed EF-2K and MHC-class I together with costimulatory molecules from heat stress. This antigen specific immune mechanism could have a prominent role in the pathogenesis of GU
Incidence of Serious Upper Gastrointestinal Bleeding in Patients Taking Non-steroidal Anti-infl ammatory Drugs in Japan
Upper gastrointestinal bleeding is a major adverse event of non-steroidal anti-inflammatory drugs (NSAIDs), and co-administration of proton pump inhibitors and H2 receptor antagonists has been established as a means of preventing such an eff ect. However, the incidence of bleeding associated with NSAID-induced ulcers under conditions where such strong anti-acid agents are used for prevention has yet to be clarified. We aimed to determine the annual incidence of serious upper gastrointestinal
ulcer bleeding among Japanese patients in whom NSAIDs were used in our hospital. Before commencing the study, we recommended to all the physicians in our hospital the best method for caring for NSAID users, focusing on the concomitant use of proton pump inhibitors or H2 receptor antagonists. We conducted a cohort study involving 17,270 patients for whom NSAIDs had been newly prescribed.
Bleeding from gastric ulcers was observed in 8 of the 17,270 patients using NSAIDs (0.05%). The pooled incidence rate for bleeding was calculated as 2.65 (95% confidence interval, 2.56-2.74) and 1.29 (1.27-1.31) per 1,000 patient years for low-dose aspirin and non-aspirin NSAID users, respectively. None of the bleeding ulcer patients required blood transfusion or were in serious condition. In conclusion, gastric ulcer bleeding occurred in low-dose aspirin or non-aspirin NSAID users, but its incidence
was low and outcomes were not serious when adequate preventive measures were taken.</p
Endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type differ between patients with and without Helicobacter pylori infection: a retrospective observational study
Background The endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type have not been fully investigated in relation to Helicobacter pylori infection status. We compared the morphology, color, and location of these lesions between patients with and without H. pylori infection. Methods We retrospectively enrolled 165 patients (180 lesions) from 10 institutions. We divided the patients into the (i) Hp group (patients with current H. pylori infection [active gastritis, n = 13] and those with past infection [inactive gastritis, n = 76]) and (ii) uninfected group (H. pylori-uninfected patients, n = 52). We compared the clinical and endoscopic features of the two groups. We also performed an analysis between (i) lesions with atrophy of the surrounding gastric mucosa (atrophy group) and (ii) lesions without atrophy of the surrounding gastric mucosa (non-atrophy group). Results The average age was older in the Hp group than in the uninfected group (68.1 +/- 8.1 vs. 63.4 +/- 8.7 years, p < 0.01). Although the difference was not statistically significant (p = 0.09), multiple lesions were observed in 9 of 89 patients (10.1%) in the Hp group and in only 1 of 52 patients (1.9%) in the uninfected group. Meanwhile, significant differences were observed in the prevalence of lesions located in the gastric fornix or cardia (uninfected group: 67.3% vs. Hp group: 38.0%, p < 0.01), with an elevated morphology (80.0% vs. 56.0%, p < 0.01), with a subepithelial-like appearance (78.2% vs. 42.0%, p < 0.01), and with a color similar to that of the peripheral mucosa (43.6% vs. 25.0%, p = 0.02). The male-to-female ratio, lesion size, and presence or absence of vascular dilatation or black pigmentation on the surface were not different between the two groups. In the analysis comparing lesions with and without mucosal atrophy, the prevalence of multiple lesions was significantly higher (p = 0.02) in the atrophy group (5/25 patients, 20.0%) than in the non-atrophy group (7/141 patients, 5.0%). Conclusions The endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type differ between patients with and without H. pylori infection
Endoscopic resection is a suitable initial treatment strategy for oxyntic gland adenoma or gastric adenocarcinoma of the fundic gland type
The aim of this study was to reveal the histological features of oxyntic gland adenomas and gastric adenocarcinoma of the fundic-gland type (GA-FG). We retrospectively examined the histological features of 126 lesions of oxyntic gland adenoma and/or GA-FG in 116 patients. The prevalence of oxyntic gland adenomas and GA-FG was approximately equal. The majority of the lesions were resected by endoscopic mucosal resection using a diathermic snare (EMR, n=42) or endoscopic submucosal dissection (ESD, n=72). Histologically, there were no lesions with invasion at the level of the muscularis propria or deeper, and lymphovascular invasion was present in 1.6%. Of the ESD and EMR specimens, there were no lesions that were positive for vertical margins. Among the eight GA-FG patients with deep (>= 500 mu m) submucosal invasion, six were treated with endoscopic resection alone, and no recurrence was documented. No patients died of the disease during the median follow-up period of 14.5 months. In conclusion, all lesions were confined to the mucosa or submucosa and were negative for vertical margins. Lymphovascular invasion was present in only 1.6% of the patients. Thus, we believe that endoscopic resection is a suitable initial treatment method for oxyntic gland adenoma and GA-FG
Lesion size, elevated morphology, and non or closed-type atrophy are predictive factors for gastric adenocarcinoma of the fundic gland type rather than oxyntic gland adenoma
Background: An oxyntic gland neoplasm confined to the mucosal layer (T1a) is classified as an oxyntic gland adenoma, whereas that with submucosal invasion (T1b) is defined as gastric adenocarcinoma of the fundic gland type (GA-FG).
Methods: To reveal the differences in clinical features between them, we retrospectively investigated 136 patients with 150 oxyntic gland adenoma and GA-FG lesions.
Results: The univariate analysis revealed that the mean size (GA-FG vs. oxyntic gland adenoma, 7.7±5.4 vs. 5.5±3.1 mm), the prevalence of elevated morphology (79.1% vs. 51.8%), black pigmentation within the lesion (23.9% vs. 9.6%), and non or closed-type atrophy (81.2% vs. 65.1%) were different between the two groups. A multivariate logistic regression analysis revealed that ≥5 mm lesion size (odds ratio, 2.96; 95% confidence interval: 1.21–7.23), elevated morphology (odds ratio, 2.40; 95% confidence interval: 1.06–5.45), and no or closed-type atrophy (odds ratio, 2.49; 95% confidence interval: 1.07–5.80) were factors in distinguishing GA-FG from oxyntic gland adenoma. When oxyntic gland neoplasms with no or one feature were judged as oxyntic gland adenomas and those with two or three features were judged as GA-FG, the sensitivity and specificity were 85.1% and 43.4% for GA-FG, respectively.
Conclusions: We identified three possible distinctive features of GA-FG compared to oxyntic gland adenoma: lesion size ≥5 mm, elevated morphology, and no or closed-type atrophy
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