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Manoharan H, Selvarajan S, Aluvalu R, Abdelhaq M, Alsaqour R, Uddin M. Diagnostic structure of visual robotic inundated systems with fuzzy clustering membership correlation. PeerJ Comput Sci 2023; 9:e1709. [PMID: 38192458 PMCID: PMC10773856 DOI: 10.7717/peerj-cs.1709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 10/29/2023] [Indexed: 01/10/2024]
Abstract
The process of using robotic technology to examine underwater systems is still a difficult undertaking because the majority of automated activities lack network connectivity. Therefore, the suggested approach finds the main hole in undersea systems and fills it using robotic automation. In the predicted model, an analytical framework is created to operate the robot within predetermined areas while maximizing communication ranges. Additionally, a clustering algorithm with a fuzzy membership function is implemented, allowing the robots to advance in accordance with predefined clusters and arrive at their starting place within a predetermined amount of time. A cluster node is connected in each clustered region and provides the central control center with the necessary data. The weights are evenly distributed, and the designed robotic system is installed to prevent an uncontrolled operational state. Five different scenarios are used to test and validate the created model, and in each case, the proposed method is found to be superior to the current methodology in terms of range, energy, density, time periods, and total metrics of operation.
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Affiliation(s)
- Hariprasath Manoharan
- Department of Electronics and Communication Engineering, Panimalar Engineering College, Poonamallee, Chennai, Tamil Nadu, India
| | | | - Rajanikanth Aluvalu
- Department of IT, Chaitanya Bharathi Institute of Technology, Hyderabad, India
| | - Maha Abdelhaq
- Department of Information Technology, College of Computer and Information Sciences, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Raed Alsaqour
- Department of Information Technology, College of Computing and Informatics, Saudi Electronic University, Riyadh, Saudi Arabia
| | - Mueen Uddin
- College of Computing and IT, University of Doha for Science and Technology, Qatar
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Koyama Y, Fukuzawa M, Aikawa H, Nemoto D, Muramatsu T, Matsumoto T, Uchida K, Madarame A, Morise T, Yamaguchi H, Kono S, Nagata N, Sugimoto M, Kawai T, Saito Y, Itoi T. Underwater endoscopic submucosal dissection for colorectal tumors decreases the incidence of post-electrocoagulation syndrome. J Gastroenterol Hepatol 2023; 38:1566-1575. [PMID: 37321649 DOI: 10.1111/jgh.16259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/18/2023] [Accepted: 05/28/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND AIMS Underwater endoscopic submucosal dissection (U-ESD) is a recently developed procedure that has the potential to prevent post-ESD coagulation syndrome (PECS) owing to its heat-sink effect. We aimed to clarify whether U-ESD decreases the incidence of PECS compared with conventional ESD (C-ESD). METHODS A total of 205 patients who underwent colorectal ESD (C-ESD: 125; U-ESD: 80) were analyzed. Propensity score matching analysis was performed to adjust for patient backgrounds. Ten C-ESD and two U-ESD patients with muscle damage or perforation during ESD were excluded when comparing PECS. The primary outcome was to compare the incidence of PECS between the U-ESD and C-ESD groups (54 matched pairs). Secondary outcomes were to compare procedural outcomes between the C-ESD and U-ESD groups (62 matched pairs). RESULTS Among the 78 patients who underwent U-ESD, PECS occurred in only one patient (1.3%). Adjusted comparisons between the U-ESD and C-ESD groups demonstrated a significantly lower incidence of PECS in the U-ESD group (0% vs 11.1%; P = 0.027). Median dissection speed was significantly faster in the U-ESD than in the C-ESD group (10.9 mm2 /min vs 6.9 mm2 /min; P < 0.001). En bloc and complete resection rates were 100% in the U-ESD group. Although perforation and delayed bleeding occurred in one patient each (1.6%) as adverse events in the U-ESD group, there were no differences compared with the C-ESD group. CONCLUSIONS Our study demonstrates that U-ESD effectively decreases the incidence of PECS and is a faster and safer method for colorectal ESD.
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Affiliation(s)
- Yohei Koyama
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
- Department of Gastroenterology and Hepatology, Niizashiki Central General Hospital, Saitama, Japan
| | - Masakatsu Fukuzawa
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
| | - Hiroyuki Aikawa
- Department of Gastroenterology and Hepatology, Niizashiki Central General Hospital, Saitama, Japan
| | - Daiki Nemoto
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
- Department of Gastroenterology and Hepatology, Niizashiki Central General Hospital, Saitama, Japan
| | - Takahiro Muramatsu
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
| | - Taisuke Matsumoto
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
| | - Kumiko Uchida
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
| | - Akira Madarame
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
| | - Takashi Morise
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
| | - Hayato Yamaguchi
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
| | - Shin Kono
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
| | - Naoyoshi Nagata
- Department of Gastroenterological Endoscopy, Tokyo Medical University Hospital, Tokyo, Japan
| | - Mitsushige Sugimoto
- Department of Gastroenterological Endoscopy, Tokyo Medical University Hospital, Tokyo, Japan
| | - Takashi Kawai
- Department of Gastroenterological Endoscopy, Tokyo Medical University Hospital, Tokyo, Japan
| | - Yutaka Saito
- Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan
| | - Takao Itoi
- Department of Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan
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Möller F, Jacobi E, Hoffmann U, Vogt T. Physiological and cognitive responses to hyperoxic exercise in full water submersion. Eur J Sport Sci 2023:1-11. [PMID: 37009949 DOI: 10.1080/17461391.2023.2193942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
Abstract
AbstractThe positive effects of combined hyperoxia and physical exercise on physiological parameters and cognitive functioning are established for normobaric laboratory contexts. Still, increased practicability exists in hyperbaric settings like underwater activities and SCUBA diving, where environmental and sport-specific factors might moderate effects. Improved cognition, reduced ventilation (VE), and lower blood lactate concentrations [Lac-] are highly relevant, especially during high-stress and rescue scenarios. Fifteen participants performed 3 × 8 min of continuous underwater fin-swimming at 25% (low), 45% (moderate), and 75% (vigorous) heart rate reserve (HRR) in each test. Three separate test days differed solely by the inspiratory oxygen partial pressure (PIO2: 29kPa, 56kPa, and 140kPa). VE was measured continuously, whereas breathing gas analysis, blood sampling, and Eriksen Flanker tasks for inhibitory control (100 stimuli) were performed post-exercise. Two-way ANOVAs with repeated measures on the factors PIO2 and exercise intensity investigated physiological outcome variables and reactions times (RT) and accuracy (ACC) of inhibitory control. VE was significantly reduced for 140kPa during moderate and vigorous and for 56kPa during vigorous compared to 29kPa. 56kPa and 140kPa showed no differences. [Lac-], post-exercise VCO2, and velocity were unaffected by PIO2. Faster RTs but lower ACC of inhibitory control were observed following exercise at 75% HRR compared to rest, 25%, and 45% HRR, while PIO2 produced no effects. Underwater performance in hyperoxia presents reduced VE, possible by dampened chemoreceptor sensitivity, and effects on cognition that differ from laboratory results and emphasize the moderating role of sport-specific factors.
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Affiliation(s)
- Fabian Möller
- Department of Exercise Physiology, German Sport University Cologne, Cologne, Germany
- Institute of Professional Sport Education and Sport Qualifications, German Sport University Cologne, Cologne, Germany
| | - Elena Jacobi
- Department of Exercise Physiology, German Sport University Cologne, Cologne, Germany
| | - Uwe Hoffmann
- Department of Exercise Physiology, German Sport University Cologne, Cologne, Germany
| | - Tobias Vogt
- Institute of Professional Sport Education and Sport Qualifications, German Sport University Cologne, Cologne, Germany
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Barković I, Jurilj Z, Marinelli F, Maričić V, Pavlović M, Turk Wensveen T, Peršić V. Arterial blood gases' analysis in elite breath-hold divers at extreme depths. Eur J Appl Physiol 2023; 123:857-865. [PMID: 36512132 DOI: 10.1007/s00421-022-05110-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE To showcase results of arterial blood gases' analysis in elite breath-hold divers sampled at depths where their total lung capacities are below their residual lung volume on surface. METHODS Three male elite breath-hold divers performed body plethysmographies to determine their lung volumes. Two dives were performed, one on normal inhalation to 60 m of depth and the second on complete exhalation to 10 m of depth. Blood samples were taken on five occasions; before the first dive, at 60 and 10 m of depth and immediately after resurfacing after both dives. RESULTS Arterial blood gases' analysis at 60 m of depth showed an increase in partial pressures of oxygen and carbon dioxide, a consequent decrease in pH and an increase in concentration of HCO3-. After resurfacing, in two divers, values mostly returned to normal; hypoxemia was observed in one diver. At 10 m of depth, all values showed similar variation, and hypoxemia was observed in the same diver but at depth. Upon resurfacing, all values returned to normal. CONCLUSION This is the first study performed at depths where the total lung capacities of participants are below their residual lung volumes at the surface. Partial pressure of carbon dioxide increases at depth to higher than normal values causing pH to decrease thus exceeding the buffering potential of the blood. In addition, previous assumptions that maximum depth in breath-hold divers is where total lung capacity is reduced to their residual volume proved wrong as our group of divers had no symptoms after resurfacing.
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Affiliation(s)
- Igor Barković
- Faculty of Medicine, Center for Research and Education in Underwater, Hyperbaric and Maritime Medicine, University of Rijeka, Rijeka, Croatia.
- Department for Underwater and Hyperbaric Medicine, University Hospital Rijeka, Rijeka, Croatia.
- Department of Pulmonology, Clinic for Internal Medicine, University Hospital Rijeka, Rijeka, Croatia.
| | - Zdravko Jurilj
- Faculty of Medicine, Center for Research and Education in Underwater, Hyperbaric and Maritime Medicine, University of Rijeka, Rijeka, Croatia
- Department for Underwater and Hyperbaric Medicine, University Hospital Rijeka, Rijeka, Croatia
- Department of Anesthesiology and Intensive Care Unit, University Hospital Rijeka, Rijeka, Croatia
| | - Frano Marinelli
- Faculty of Medicine, Center for Research and Education in Underwater, Hyperbaric and Maritime Medicine, University of Rijeka, Rijeka, Croatia
- Department for Underwater and Hyperbaric Medicine, University Hospital Rijeka, Rijeka, Croatia
- Department of Pulmonology, Clinic for Internal Medicine, University Hospital Rijeka, Rijeka, Croatia
| | - Vitomir Maričić
- AIDA - International Association for the Development of Apnea, Rijeka, Croatia
| | - Marijana Pavlović
- Department of Pulmonology, Clinic for Internal Medicine, University Hospital Rijeka, Rijeka, Croatia
| | - Tamara Turk Wensveen
- Specialized Hospital for Medical Rehabilitation of Cardiac, Pulmonary and Rheumatic Diseases, Thalassotherapia Opatija, Opatija, Croatia
| | - Viktor Peršić
- Specialized Hospital for Medical Rehabilitation of Cardiac, Pulmonary and Rheumatic Diseases, Thalassotherapia Opatija, Opatija, Croatia
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Shi Z, Rao L, Wang P, Zhang L. Influences of different carbon substrates on the morphologies of carbon/g-C 3N 4 photocatalytic composites and the purification capacities of different composites in the weak UV underwater environment. Chemosphere 2022; 308:136257. [PMID: 36057358 DOI: 10.1016/j.chemosphere.2022.136257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 08/11/2022] [Accepted: 08/26/2022] [Indexed: 06/15/2023]
Abstract
In order to explore the influence of various carbon introduction on the morphology and photodegradation performance of C/g-C3N4 composites, three kinds of different carbon materials: carbon nanotubes (CNT), graphene (GN) and carbon fibers (CF) were introduced to modify g-C3N4, and the morphologies, light absorption capacities and the underwater purifications of the composite photocatalysts were investigated. Results showed that the composites synthesized with different carbon substrates shows great differences in growth morphology. In addition, the introduction of various carbon sources also has a great impact on the physical and chemical properties of the composites. Compared with GN/g-C3N4 and CF/g-C3N4, CNT/g-C3N4 shows strong light absorption ability, especially in long-wavelength region (570-660 nm). To further study the difference of degradation ability of the composites in the underwater environment, the purification performance of modified g-C3N4 at different water depths were carried out. The results show that under 40 cm of water, where the light intensity and ultra violet spectral are seriously attenuated, the purification efficiency of CNT/g-C3N4 at 40 cm is 3.35 times than that of g-C3N4. This work provides insight in the design of highly efficient metal-free photocatalysts for the environmental remediation.
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Affiliation(s)
- Zhenyu Shi
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Lei Rao
- College of Mechanics and Materials, Hohai University, Nanjing, 210098, China.
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
| | - Lixin Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
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Shi Z, Rao L, Wang P, Zhang L. The photocatalytic activity and purification performance of g-C 3N 4/carbon nanotubes composite photocatalyst in underwater environment. Environ Sci Pollut Res Int 2022; 29:83981-83992. [PMID: 35776310 DOI: 10.1007/s11356-022-21535-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Graphite carbon nitride (g-C3N4) is a promising photocatalyst for its high catalytic activity, low-cost and high-biosafety characteristics. Due to the complexity of underwater photochemical reaction conditions and the disadvantages of g-C3N4 itself such as low specific surface area, easy recombination of photogenerated electron-hole pairs and insufficient light absorption capacity, the application of g-C3N4 in the field of water purification is limited. For improving underwater photocatalytic performance of g-C3N4, a g-C3N4/carbon nanotubes (CNT-CN) composite photocatalyst with high specific surface area and enhanced light absorption capacity were prepared by in situ solvothermal method. Its photodegradation efficiency at different underwater transmission light was further studied. The results show that CNT has good compatibility with g-C3N4. g-C3N4 can grow in situ on the surface of CNT and form a stable composite structure. Moreover, its degradation efficiency under long-wavelength irradiation is improved significantly. The degradation rate of CNT-CN at 550-700 nm was about 3 times than that of g-C3N4. Furthermore, CNT-CN can maintain higher photocatalytic activity under water. At 40 cm depth where light intensity and ultraviolet spectra were attenuated 63.8% and 80.1%, respectively, the degradation rate of CNT-CN3 can still reach 3.49 times than that of g-C3N4. Based on this study, the introduction of CNT effectively promotes the electron-hole separation efficiency of g-C3N4, widens its spectral response range, and thus improves its underwater degradation efficiency.
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Affiliation(s)
- Zhenyu Shi
- Key Laboratory of Integrated Regulation and Resource Development On Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Lei Rao
- College of Mechanics and Materials, Hohai University, Nanjing, 210098, China.
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resource Development On Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Lixin Zhang
- Key Laboratory of Integrated Regulation and Resource Development On Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
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Myung YS, Kwon H, Han J, Lim J, Choi SY, Baeg MK, Han SW. Underwater versus conventional cold snare polypectomy of colorectal polyps 4-9 mm in diameter: a prospective randomized controlled trial. Surg Endosc 2022; 36:6527-6534. [PMID: 35024932 DOI: 10.1007/s00464-022-09013-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/03/2022] [Indexed: 10/19/2022]
Abstract
BACKGROUND AND AIMS Cold snare polypectomy (CSP) has been reported as safe and effective method for the removal of small colorectal polyps. However, some studies showed low R0 resection rate. Underwater endoscopic mucosal resection is an effective technique to increase the proportions of complete resection. Therefore, the aim was to compare the rate of R0 resection of colorectal polyps 4-9 mm in diameter between conventional CSP (C-CSP) and underwater CSP (U-CSP). METHODS This study was a prospective randomized controlled trial. A total of 198 polyps (4-9 mm) in 110 patients were enrolled between December 2019 and June 2020. The polyps were randomized to be treated with either C-CSP (100 polyps) or U-CSP (98 polyps). RESULTS The R0 resection rate was significantly higher in U-CSP group than in C-CSP groups (84.7% vs. 59.0%; p < 0.001). The polyp retrieval rate of C-CSP and U-CSP was 94.5% and 100% (p = 0.030). The rate of polyp fragmentation of C-CSP and U-CSP group was 5.3% and 0% (p = 0.027). The resection time and retrieval time were longer in C-CSP than U-CSP (45.0 ± 37.7 s vs. 34.1 ± 21.2 s, p = 0.032 and 51.9 ± 67.7 s vs. 12.7 ± 12.4 s, p < 0.001). No clinically significant bleeding or perforation occurred in either group. CONCLUSIONS The results of this study were excellent with U-CSP of 4-9 mm colorectal polyps in terms of R0 resection, polyp retrieval and fragmentation rate, and procedure/retrieval time. Therefore, U-CSP is a safe and effective technique for removing colorectal polyps 4-9 mm in diameter. KCT (0004530).
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Affiliation(s)
- Yu Sik Myung
- Gastroenterology, Department of Internal Medicine, International St. Mary's Hospital, Catholic Kwandong University of Medicine, 100Gil 25 Simgok-ro, Seo-gu, Inchon, 22711, Korea.
| | - Hyuki Kwon
- Gastroenterology, Department of Internal Medicine, International St. Mary's Hospital, Catholic Kwandong University of Medicine, 100Gil 25 Simgok-ro, Seo-gu, Inchon, 22711, Korea
| | - Jaeho Han
- Gastroenterology, Department of Internal Medicine, International St. Mary's Hospital, Catholic Kwandong University of Medicine, 100Gil 25 Simgok-ro, Seo-gu, Inchon, 22711, Korea
| | - Jongreul Lim
- Gastroenterology, Department of Internal Medicine, International St. Mary's Hospital, Catholic Kwandong University of Medicine, 100Gil 25 Simgok-ro, Seo-gu, Inchon, 22711, Korea
| | - Soo Yong Choi
- Gastroenterology, Department of Internal Medicine, International St. Mary's Hospital, Catholic Kwandong University of Medicine, 100Gil 25 Simgok-ro, Seo-gu, Inchon, 22711, Korea
| | - Myong Ki Baeg
- Gastroenterology, Department of Internal Medicine, International St. Mary's Hospital, Catholic Kwandong University of Medicine, 100Gil 25 Simgok-ro, Seo-gu, Inchon, 22711, Korea
| | - Sok Won Han
- Gastroenterology, Department of Internal Medicine, International St. Mary's Hospital, Catholic Kwandong University of Medicine, 100Gil 25 Simgok-ro, Seo-gu, Inchon, 22711, Korea
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Nagl S, Ebigbo A, Goelder SK, Roemmele C, Neuhaus L, Weber T, Braun G, Probst A, Schnoy E, Kafel AJ, Muzalyova A, Messmann H. Underwater vs Conventional Endoscopic Mucosal Resection of Large Sessile or Flat Colorectal Polyps: A Prospective Randomized Controlled Trial. Gastroenterology 2021; 161:1460-1474.e1. [PMID: 34371000 DOI: 10.1053/j.gastro.2021.07.044] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 07/26/2021] [Accepted: 07/29/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Conventional endoscopic mucosal resection (CEMR) with submucosal injection is the current standard for the resection of large, nonmalignant colorectal polyps. We investigated whether underwater endoscopic mucosal resection (UEMR) is superior to CEMR for large (20-40mm) sessile or flat colorectal polyps. METHODS In this prospective randomized controlled study, patients with sessile or flat colorectal polyps between 20 and 40 mm in size were randomly assigned to UEMR or CEMR. The primary outcome was the recurrence rate after 6 months. Secondary outcomes included en bloc and R0 resection rates, number of resected pieces, procedure time, and adverse events. RESULTS En bloc resection rates were 33.3% in the UEMR group and 18.4% in the CEMR group (P = .045); R0 resection rates were 32.1% and 15.8% for UEMR vs CEMR, respectively (P = .025). UEMR was performed with significantly fewer pieces compared to CEMR (2 pieces: 45.5% UEMR vs 17.7% CEMR; P = .001). The overall recurrence rate did not differ between both groups (P = .253); however, subgroup analysis showed a significant difference in favor of UEMR for lesions of >30 mm to ≤40 mm in size (P = .031). The resection time was significantly shorter in the UEMR group (8 vs 14 minutes; P < .001). Adverse events did not differ between both groups (P = .611). CONCLUSIONS UEMR is superior to CEMR regarding en bloc resection, R0 resection, and procedure time for large colorectal lesions and shows significantly lower recurrence rates for lesions >30 mm to ≤40 mm in size. UEMR should be considered for the endoscopic resection of large colorectal polyps.
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Affiliation(s)
- Sandra Nagl
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany.
| | - Alanna Ebigbo
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | - Stefan Karl Goelder
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | - Christoph Roemmele
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | - Lukas Neuhaus
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | - Tobias Weber
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | - Georg Braun
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | - Andreas Probst
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | - Elisabeth Schnoy
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | | | - Anna Muzalyova
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
| | - Helmut Messmann
- Department of Gastroenterology, University Hospital Augsburg, Augsburg, Germany
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Abstract
BACKGROUND Underwater polypectomy without the need for submucosal injection has been reported. A heat-sink effect by immersing the polyp in water was proposed but no such experiment has been performed to support the claim. We compared the temperature rise on the serosal side during polypectomy between air- and water-filled colon. METHOD Freshly harvested porcine colons were placed in a metal tray with cautery electrode pad attached to its bottom. An upper endoscope was used with a cap and a rubber band mounted to the distal end. A mucosal site was randomly selected and identified on its serosal surface with a marker while suction was applied. Suction was applied again and a ligation band was applied to create a polyp. A cautery snare grasped the artificial polyp just below the band. An assistant placed the tip of a thermometer at the marked site on the serosal surface to record the baseline temperature before cautery and the highest temperature during polypectomy. Seven polypectomies in air and underwater were performed. RESULTS Mean (standard deviation) baseline temperature were 23.3 (0.6) °C and 23.4 (0.6) °C in the air and water groups, respectively. The maximum rise in temperature during polypectomy was 6.1 (4.5) °C and 1.4 (1.0) °C in the air and water groups, respectively (P = 0.004). CONCLUSIONS The maximum temperature rise during polypectomy was significantly less when polypectomy was performed underwater, supporting the hypothesis that a heat-sink effect does exist during underwater polypectomy.
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Affiliation(s)
- Chih-Wei Tseng
- Division of Gastroenterology, Department of Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, 2 Minsheng Road, Dalin, Chiayi, 62247, Taiwan.,School of Medicine, Buddhist Tzu Chi University, Hualien, Taiwan
| | - Yu-Hsi Hsieh
- Division of Gastroenterology, Department of Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, 2 Minsheng Road, Dalin, Chiayi, 62247, Taiwan. .,School of Medicine, Buddhist Tzu Chi University, Hualien, Taiwan.
| | - Chung-Chih Lin
- Department of Mechanical and Computer-Aided Engineering, National Formosa University, Yilan, Taiwan
| | - Malcolm Koo
- Graduate Institute of Long-Term Care, Tzu Chi University of Science and Technology, Hualien, Taiwan.,Dalla Lana School of Public Health, University of Toronto, Ontario, ON, Canada
| | - Felix W Leung
- Sepulveda Ambulatory Care Center, Veterans Affairs Greater Los Angeles Healthcare System, North Hill, CA, USA.,David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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Iwami K, Watanabe T, Yokota M, Hara M, Osuka K, Miyachi S. Feasibility of underwater microvascular decompression for hemifacial spasm: a technical note. Acta Neurochir (Wien) 2021; 163:2435-2444. [PMID: 34218323 DOI: 10.1007/s00701-021-04899-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 06/07/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND We present a case series of underwater microvascular decompression (MVD) for hemifacial spasm (HFS) and an evaluation of its feasibility and safety. METHODS This retrospective study was conducted at a single institution and included 20 patients with HFS who underwent underwater MVD between September 2019 and January 2021. Surgery was performed in 3 steps, as follows: exoscopic wound opening (soft tissue, bone, dura, and arachnoid around the cerebellomedullary cistern), underwater endoscopic surgery (decompression of the facial nerve), and exoscopic wound closure. In underwater endoscopic surgery, the surgical field was continuously irrigated with artificial cerebrospinal fluid. Abnormal muscle response and brainstem auditory evoked potentials (BAEPs) were monitored. RESULTS Neurovascular conflicts were clearly observed in all patients without fogging and soiling of the endoscope lens. HFS was completely relieved in 19 patients (95%). An amplitude reduction of wave V of BAEPs of more than 50% was not observed in any of the cases. In 5 cases (25%), the latency of wave V of BAEPs was prolonged for more than 1.0 ms; these changes completely or near completely returned to baseline values at dural closure in all 5 cases. A postoperative complication of transient facial palsy was observed in 1 patient (5%) during postoperative days 10-30. There were no other complications. CONCLUSIONS Our findings suggest that underwater MVD is a safe and feasible option for the treatment of HFS. However, it did not show advantages over conventional endoscopic MVD when the protective effect on the eighth cranial nerve was evaluated.
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Affiliation(s)
- Kenichiro Iwami
- Department of Neurosurgery, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi Prefecture, 480-1195, Japan.
| | - Tadashi Watanabe
- Department of Neurosurgery, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi Prefecture, 480-1195, Japan
| | - Mao Yokota
- Department of Neurosurgery, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi Prefecture, 480-1195, Japan
| | - Masato Hara
- Department of Neurosurgery, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi Prefecture, 480-1195, Japan
| | - Koji Osuka
- Department of Neurosurgery, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi Prefecture, 480-1195, Japan
| | - Shigeru Miyachi
- Department of Neurosurgery, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi Prefecture, 480-1195, Japan
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Tziatzios G, Gkolfakis P, Triantafyllou K, Fuccio L, Facciorusso A, Papanikolaou IS, Antonelli G, Nagl S, Ebigbo A, Probst A, Hassan C, Messmann H. Higher rate of en bloc resection with underwater than conventional endoscopic mucosal resection: A meta-analysis. Dig Liver Dis 2021; 53:958-64. [PMID: 34059445 DOI: 10.1016/j.dld.2021.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Previous meta-analysis including nonrandomized studies showed marginal benefit of underwater endoscopic mucosal resection(U-EMR) compared to conventional EMR(C-EMR) in terms of polypectomy outcomes. We evaluated U-EMR compared to C-EMR in the treatment of colorectal polyps with respect to effectiveness and safety by analyzing only randomized controlled trials(RCTs). MATERIAL AND METHODS PubMed and Cochrane Library databases were searched for RCTs published until 11/2020, evaluating U-EMR vs. C-EMR regarding en bloc resection, post-endoscopic resection adenoma recurrence, complete resection, adverse events rates and difference in resection time. Abstracts from Digestive Disease Week, United European Gastroenterology Week and ESGE Days meetings were also searched. Effect size on outcomes is presented as risk ratio(RR; 95% confidence interval[CI]) or mean difference(MD; 95%CI). The I2 test was used for quantifying heterogeneity, while Grading of Recommendations Assessment, Development and Evaluation(GRADE) was used to assess strength of evidence. RESULTS Six RCTs analyzing outcomes from 1157 colorectal polypectomies(U-EMR589;C-EMR,568) were included. U-EMR associated with significant higher rate of en bloc resection compared to C-EMR [RR(95%CI):1.26(1.01-1.58); Chi² for heterogeneity=30.43, P<0.0001; I²=84%, GRADE: Very low]. This effect was more prominent regarding resection of polyps sized ≥20 mm compared to polyps <20 mm [RR(95%CI):1.64(1.22-2.20) vs. 1.10(0.98-1.23)]. Post-resection recurrence [RR(95%CI):0.52(0.28-0.94);GRADE:Low] was lower significantly in U-EMR group. In contrast, no significant difference was detected between U-EMR and C-EMR regarding complete resection [RR(95%CI): 1.06(0.91-1.24) GRADE:Very low] and adverse events occurrence[RR(95%CI):1.00 (0.72-1.39); GRADE:Low]. CONCLUSION Meta-analysis of RCTs supports that U-EMR resection achieves higher rate of en bloc resection compared to conventional EMR. This effect is driven when resecting large(≥20 mm) polyps.
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12
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Mucciarone DA, DeJong HB, Dunbar RB, Takeshita Y, Albright R, Mertz K. Autonomous submersible multiport water sampler. HardwareX 2021; 9:e00197. [PMID: 35492048 PMCID: PMC9041238 DOI: 10.1016/j.ohx.2021.e00197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/22/2021] [Accepted: 04/05/2021] [Indexed: 05/22/2023]
Abstract
Oceanography and limnology projects often require the collection of water samples for chemical analysis. Manual water sample collection is labor-intensive and often difficult, especially in remote locations or during nighttime hours. Here we describe a compact and inexpensive autonomous submersible multiport water sampler (AutoSampler) that is largely fabricated with off-the-shelf parts making it easier to build and maintain. The system can collect up to 12 discrete samples at user controllable times or intervals and is operated using open source Arduino hardware and software that can be user modified to meet deployment requirements. While the underwater pressure housing presented here is custom built from readily available materials, there are many commercially available pressure case options that can be used as a substitute. The electronic mounting plates and battery pack are designed so that they can easily be adapted to fit into other pressure case housings. Samples can be collected into bags or syringes and sample volume is set by adjusting how long the peristaltic pump is actuated. This AutoSampler allows research that would otherwise be too labor-intensive or logistically difficult to conduct, especially in remote locations.
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Affiliation(s)
- David A. Mucciarone
- Stanford University, Earth System Science, Stanford, CA 94305, United States
- Corresponding author.
| | - Hans B. DeJong
- Stanford University, Earth System Science, Stanford, CA 94305, United States
| | - Robert B. Dunbar
- Stanford University, Earth System Science, Stanford, CA 94305, United States
| | - Yui Takeshita
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, United States
| | - Rebecca Albright
- California Academy of Sciences, San Francisco, CA 94118, United States
| | - Keaton Mertz
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, United States
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Codd-Downey R, Jenkin M, Dey BB, Zacher J, Blainey E, Andrews P. Monitoring Re-Growth of Invasive Plants Using an Autonomous Surface Vessel. Front Robot AI 2021; 7:583416. [PMID: 33553245 PMCID: PMC7862761 DOI: 10.3389/frobt.2020.583416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/21/2020] [Indexed: 11/13/2022] Open
Abstract
Invasive aquatic plant species, and in particular Eurasian Water-Milfoil (EWM), pose a major threat to domestic flora and fauna and can in turn negatively impact local economies. Numerous strategies have been developed to harvest and remove these plant species from the environment. However it is still an open question as to which method is best suited to removing a particular invasive species and the impact of different lake conditions on the choice. One problem common to all harvesting methods is the need to assess the location and degree of infestation on an ongoing manner. This is a difficult and error prone problem given that the plants grow underwater and significant infestation at depth may not be visible at the surface. Here we detail efforts to monitor EWM infestation and evaluate harvesting methods using an autonomous surface vessel (ASV). This novel ASV is based around a mono-hull design with two outriggers. Powered by a differential pair of underwater thrusters, the ASV is outfitted with RTK GPS for position estimation and a set of submerged environmental sensors that are used to capture imagery and depth information including the presence of material suspended in the water column. The ASV is capable of both autonomous and tele-operation.
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Affiliation(s)
- Robert Codd-Downey
- Department of Electrical Engineering and Computer Science, York University, Toronto, ON, Canada
| | - Michael Jenkin
- Department of Electrical Engineering and Computer Science, York University, Toronto, ON, Canada
| | - Bir Bikram Dey
- Department of Electrical Engineering and Computer Science, York University, Toronto, ON, Canada
| | - James Zacher
- Judy Dan Research and Treatment Centre, Toronto, ON, Canada
| | - Eva Blainey
- Department of Electrical Engineering and Computer Science, York University, Toronto, ON, Canada
| | - Peter Andrews
- Farlain Lake Community Association, Tiny, ON, Canada
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Gurera D, Bhushan B. Movement of air bubbles under various liquids using bioinspired conical surfaces. J Colloid Interface Sci 2021; 582:41-50. [PMID: 32818715 DOI: 10.1016/j.jcis.2020.08.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 01/29/2023]
Abstract
Gas bubbles are of interest in various applications. The study of their movement is of importance. Gas bubbles are typically formed under liquids. Movement of liquid droplets on bioinspired conical surfaces is known to be facilitated by the Laplace pressure gradient. These conical surfaces, with various wettabilities and shapes, can also be used to move gas bubbles. In this study, effect of various liquids on movement of air bubble under liquid was studied. It was found that liquids with high surface tension and high density are more efficient in moving air bubbles. High surface tension and higher density increases the Laplace pressure gradient force and the buoyancy force, respectively, which drive under liquid air bubbles.
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Affiliation(s)
- Dev Gurera
- Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue, Columbus, OH 43210-1142, United States
| | - Bharat Bhushan
- Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue, Columbus, OH 43210-1142, United States.
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Mucciarone DA, DeJong HB, Dunbar RB. Autonomous underwater pumping system. HardwareX 2020; 8:e00154. [PMID: 35498232 PMCID: PMC9041212 DOI: 10.1016/j.ohx.2020.e00154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/14/2020] [Accepted: 10/22/2020] [Indexed: 05/30/2023]
Abstract
We present an inexpensive autonomous underwater pumping system that is lightweight, compact, independent, and versatile, making it easy to deploy in a multitude of settings. This system can be used to pump water into discrete and flow-through sensor systems. With the exception of the custom built pressure case housing, this system can be fabricated with off-the-shelf parts, making it easier to maintain. This system uses open source Arduino software code for easier customization and operations. The electronics and battery pack used to power this system can be adapted to fit into commercially available pressure case housings.
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Maida M, Sferrazza S, Murino A, Lisotti A, Lazaridis N, Vitello A, Fusaroli P, de Pretis G, Sinagra E. Effectiveness and safety of underwater techniques in gastrointestinal endoscopy: a comprehensive review of the literature. Surg Endosc. 2021;35:37-51. [PMID: 32856154 DOI: 10.1007/s00464-020-07907-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/17/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Conventional endoscopic resection techniques such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD), represent the standard of care for treatment of superficial gastrointestinal lesions. In 2012 a novel technique called underwater endoscopic mucosal resection (U-EMR) was described by Binmoeller and colleagues. This substantial variation from the standard procedure was afterwards applied at endoscopic submucosal dissection (U-ESD) and recently proposed also for peroral endoscopic myotomy (U-POEM) and endoscopic full-thickness resection (U-EFTR). METHODS This paper aims to perform a comprehensive review of the current literature related to supporting the underwater resection techniques with the aim to evaluate their safety and efficacy. RESULTS Based on the current literature U-EMR appears to be feasible and safe. Comparison studies showed that U-EMR is associated with higher "en-bloc" and R0 resection rates for colonic lesions, but lower "en-bloc" and R0 resection rates for duodenal non-ampullary lesions, compared to standard EMR. In contrast to U-EMR, little evidence supporting U-ESD are currently available. A single comparison study on gastric lesions showed that U-ESD had shorter procedural times and allowed a similar "en-bloc" resection rates compared to standard ESD. No comparison studies between U-ESD and ESD are available for colonic lesions. Finally, only some anecdotal experiences have been reported for U-POEM or U-EFTR, and the feasibility and effectiveness of these techniques need to be further investigated. CONCLUSIONS Further prospective studies are necessary to better explore the advantages of underwater techniques compared to the respective standards of care, especially in the setting of U-ESD where consistent data are lacking and where standardization of the technique is needed.
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Muhayat N, Matien YA, Sukanto H, Saputro YCN, Triyono. Fatigue life of underwater wet welded low carbon steel SS400. Heliyon 2020; 6:e03366. [PMID: 32072056 DOI: 10.1016/j.heliyon.2020.e03366] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/13/2020] [Accepted: 02/03/2020] [Indexed: 11/23/2022] Open
Abstract
Underwater welding is widely used for maintenance and repairs of underwater structures such as undersea pipes, offshore structures and nuclear power plants. In practice, underwater welding has the disadvantage related to high cooling rate and unstable welding arc due to the water hydrostatic pressure. This affects the microstructure and mechanical properties of underwater welded joints. Many of previous research works on underwater welding have been carried out only on a laboratory scale in shallow water depth, whereas underwater welding was used to weld in the depth of the water with a metre scale. Undersea structures experience fatigue load due to the fluctuation force of water flow. Therefore, this study aims to determine the effect of water depth on the fatigue life of underwater welded joints. Low carbon steel SS400 specimens were welded underwater with depths of 2.5 m, 5 m and 10 m. The air welded joint was also evaluated for comparison purposes. Fatigue life was evaluated according to the ASTM E466 standard by using a rotary bending machine. Furthermore, tensile test, micro hardness measurement and microstructure evaluation were also conducted for gathering supporting data. The fatigue and tensile strength of the air welded joints were higher than those of the underwater welded joints. The porosities caused by the dissolved hydrogen gas, carbon (monoxide and dioxide) gases and water vapor in weld metal of the underwater welded joints decreased the fatigue and tensile strength. An interesting phenomenon on the underwater welded joints was that the deeper the water level, the higher became the fatigue, tensile strength as well as hardness. Based on the microstructure analysis, the number of acicular ferrite structures in weld metal increased as the water level depth increased.
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18
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Eleftherakis D, Vicen-Bueno R. Sensors to Increase the Security of Underwater Communication Cables: A Review of Underwater Monitoring Sensors. Sensors (Basel) 2020; 20:s20030737. [PMID: 32013207 PMCID: PMC7038480 DOI: 10.3390/s20030737] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/20/2020] [Accepted: 01/27/2020] [Indexed: 11/25/2022]
Abstract
Underwater communication cables transport large amounts of sensitive information between countries. This fact converts these cables into a critical infrastructure that must be protected. Monitoring the underwater cable environment is rare and any intervention is usually driven by cable faults. In the last few years, several reports raised issues about possible future malicious attacks on such cables. The main objective of this operational research and analysis (ORA) paper is to present an overview of different commercial and already available marine sensor technologies (acoustic, optic, magnetic and oceanographic) that could be used for autonomous monitoring of the underwater cable environment. These sensors could be mounted on different autonomous platforms, such as unmanned surface vehicles (USVs) or autonomous underwater vehicles (AUVs). This paper analyses a multi-threat sabotage scenario where surveying a transatlantic cable of 13,000 km, (reaching water depths up to 4000 m) is necessary. The potential underwater threats identified for such a scenario are: divers, anchors, fishing trawls, submarines, remotely operated vehicles (ROVs) and AUVs. The paper discusses the capabilities of the identified sensors to detect such identified threats for the scenario under study. It also presents ideas on the construction of periodic and permanent surveillance networks. Research study and results are focused on providing useful information to decision-makers in charge of designing surveillance capabilities to secure underwater communication cables.
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Bosco G, Paganini M, Rizzato A, Martani L, Garetto G, Lion J, Camporesi EM, Moon RE. Arterial blood gases in divers at surface after prolonged breath-hold. Eur J Appl Physiol 2020; 120:505-512. [PMID: 31912227 DOI: 10.1007/s00421-019-04296-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 12/29/2019] [Indexed: 11/25/2022]
Abstract
PURPOSE Adaptations during voluntary breath-hold diving have been increasingly investigated since these athletes are exposed to critical hypoxia during the ascent. However, only a limited amount of literature explored the pathophysiological mechanisms underlying this phenomenon. This is the first study to measure arterial blood gases immediately before the end of a breath-hold in real conditions. METHODS Six well-trained breath-hold divers were enrolled for the experiment held at the "Y-40 THE DEEP JOY" pool (Montegrotto Terme, Padova, Italy). Before the experiment, an arterial cannula was inserted in the radial artery of the non-dominant limb. All divers performed: a breath-hold while moving at the surface using a sea-bob; a sled-assisted breath-hold dive to 42 m; and a breath-hold dive to 42 m with fins. Arterial blood samples were obtained in four conditions: one at rest before submersion and one at the end of each breath-hold. RESULTS No diving-related complications were observed. The arterial partial pressure of oxygen (96.2 ± 7.0 mmHg at rest, mean ± SD) decreased, particularly after the sled-assisted dive (39.8 ± 8.7 mmHg), and especially after the dive with fins (31.6 ± 17.0 mmHg). The arterial partial pressure of CO2 varied somewhat but after each study was close to normal (38.2 ± 3.0 mmHg at rest; 31.4 ± 3.7 mmHg after the sled-assisted dive; 36.1 ± 5.3 after the dive with fins). CONCLUSION We confirmed that the arterial partial pressure of oxygen reaches hazardously low values at the end of breath-hold, especially after the dive performed with voluntary effort. Critical hypoxia can occur in breath-hold divers even without symptoms.
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Affiliation(s)
- Gerardo Bosco
- Master in Diving and Hyperbaric Medicine, Department of Biomedical Sciences, University of Padova, Via Marzolo, 3, 35131, Padova, Italy
| | - Matteo Paganini
- Master in Diving and Hyperbaric Medicine, Department of Biomedical Sciences, University of Padova, Via Marzolo, 3, 35131, Padova, Italy.
| | - Alex Rizzato
- Master in Diving and Hyperbaric Medicine, Department of Biomedical Sciences, University of Padova, Via Marzolo, 3, 35131, Padova, Italy
| | - Luca Martani
- Master in Diving and Hyperbaric Medicine, Department of Biomedical Sciences, University of Padova, Via Marzolo, 3, 35131, Padova, Italy
| | | | - Jacopo Lion
- Master in Diving and Hyperbaric Medicine, Department of Biomedical Sciences, University of Padova, Via Marzolo, 3, 35131, Padova, Italy
| | | | - Richard E Moon
- Department of Anesthesiology, Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC, USA
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Yamasaki Y, Harada K, Oka S, Takashima S, Inokuchi T, Sugihara Y, Takahara M, Hiraoka S, Okada H. Feasibility of Underwater Clip Closure for Large Mucosal Defects after Colorectal Endoscopic Submucosal Dissection. Digestion 2019; 99:327-332. [PMID: 30212809 DOI: 10.1159/000492815] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/07/2018] [Indexed: 02/04/2023]
Abstract
BACKGROUND/AIMS Clip closure of mucosal defects after colorectal endoscopic submucosal dissection (C-ESD) may decrease the incidence of delayed adverse events. The size of the defect to be closed by conventional clip is limited, however, and we sometimes encounter incomplete closure when the defect is located at the flexure. As, theoretically, underwater clip closure (UCC) could achieve complete closure despite these difficult cases, we investigated its feasibility. METHODS We retrospectively analyzed 21 patients who underwent UCC after C-ESD. The main outcome was the UCC success rate, defined as complete closure of the defect. Other outcomes were procedure time, number of clips, and the delayed adverse event rate. RESULTS The median resected specimen size was 31 mm (range 18-47 mm). The UCC success rate was 100%. The median procedure time was only 11 min (range 6-21 min). The median number of clips was 9 (range 5-16). No delayed adverse event occurred. CONCLUSION It is feasible to use UCC to close large mucosal defects, although further studies are warranted to assess its efficacy.
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Affiliation(s)
- Yasushi Yamasaki
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan,
| | - Keita Harada
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
| | - Shohei Oka
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
| | - Shiho Takashima
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
| | - Toshihiro Inokuchi
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
| | - Yuusaku Sugihara
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
| | - Masahiro Takahara
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
| | - Sakiko Hiraoka
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
| | - Hiroyuki Okada
- Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
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Yen AW, Amato A, Cadoni S, Friedland S, Hsieh YH, Leung JW, Liggi M, Sul J, Leung FW. Underwater polypectomy without submucosal injection for colorectal lesions ≤ 20 mm in size-a multicenter retrospective observational study. Surg Endosc 2019; 33:2267-2273. [PMID: 30334167 PMCID: PMC6470040 DOI: 10.1007/s00464-018-6517-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 10/11/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Underwater polypectomy (UWP) of large (≥ 20 mm) colorectal lesions is well described, but reports of UWP for lesions ≤ 20 mm in size, which account for > 95% of polyps encountered in routine clinical practice, are limited. We assessed the feasibility of UWP in routine practice across various sites for colorectal lesions ≤ 20 mm in size. METHODS A multicenter retrospective study was performed on pooled data from nine colonoscopists at 3 U.S., 1 Taiwanese and 2 Italian sites. Outcomes related to UWP on lesions ≤ 20 mm in size were analyzed. RESULTS In 117 patients, UWP netted 169 lesions. Polypectomy by hot (HSP, 54%) or cold (CSP, 41%) snare, and cold forceps (CFP, 5%) were performed successfully without endoscopic evidence of residual neoplasia or immediate clinically significant adverse events. The majority (74.6%) were tubular adenomas; 60.9% were from the proximal colon. Histopathologic margins were positive in 4 and unavailable in 26 CSP and 24 HSP specimens. The remainder had negative resection margins on pathologic reports. CONCLUSION UWP for colorectal lesions ≤ 20 mm in routine practice across multiple sites confirms the feasibility and acceptability of this technique. Improvement of resection outcomes by UWP in routine practice deserves further evaluation in a randomized controlled trial.
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Affiliation(s)
- A W Yen
- Division of Gastroenterology, Sacramento VA Medical Center, VANCHCS, 10535 Hospital Way, 111/G, Mather, CA, 95655, USA.
- University of California Davis School of Medicine, Sacramento, CA, USA.
| | - A Amato
- Division of Gastroenterology, Valduce Hospital, Como, Italy
| | - S Cadoni
- Digestive Endoscopy Unit, S. Barbara Hospital, 09016, Iglesias, CI, Italy
| | - S Friedland
- Division of Gastroenterology, Palo Alto VAMC, Palo Alto, CA, USA
- Stanford University, Palo Alto, CA, USA
| | - Y H Hsieh
- Division of Gastroenterology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan, Republic of China
- Tzu Chi University, Hualien, Taiwan, Republic of China
| | - J W Leung
- Division of Gastroenterology, Sacramento VA Medical Center, VANCHCS, 10535 Hospital Way, 111/G, Mather, CA, 95655, USA
- University of California Davis School of Medicine, Sacramento, CA, USA
| | - M Liggi
- Digestive Endoscopy Unit, S. Barbara Hospital, 09016, Iglesias, CI, Italy
| | - J Sul
- Division of Gastroenterology, West Los Angeles VAMC, VAGLAHS, Los Angeles, CA, USA
- David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - F W Leung
- David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Division of Gastroenterology, VAGLAHS, Sepulveda ACC, North Hill, CA, USA
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Siau K, Ishaq S, Cadoni S, Kuwai T, Yusuf A, Suzuki N. Feasibility and outcomes of underwater endoscopic mucosal resection for ≥ 10 mm colorectal polyps. Surg Endosc 2017; 32:2656-2663. [PMID: 29101560 DOI: 10.1007/s00464-017-5960-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/23/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Underwater endoscopic mucosal resection (UEMR) is an emerging strategy for the management of colorectal polyps. We aimed to evaluate the efficacy and safety of UEMR for clinically significant (≥ 10 mm) colorectal polyps. METHODS We performed a prospective dual-centre study of polyps ≥ 10 mm undergoing UEMR between June 2014 and March 2017. Outcomes measured comprised: (1) completeness of resection at index UEMR, (2) intraprocedural and 30-day complications, (3) rates and predictors of submucosal lift, en bloc resection, polyp/adenoma recurrence and (4) pain score. Endoscopy records were correlated with histology. RESULTS 85 patients underwent UEMR of 97 polyps. Resection was endoscopically complete at index UEMR in 97.9%. The median pain score was 0 (no pain). Submucosal lift was required in 29.9% and correlated with polyp size ≥ 30 mm (p = 0.03) and clip placement (p = 0.004). En bloc resection was achieved in 45.4%, and inversely correlated with polyp size ≥ 20 mm (p < 0.001). 30-day complications (4.1%) were minor and consisted of intraprocedural bleeding (n = 2) and delayed bleeding (n = 2). 60.8% attended endoscopy post-UEMR after a median interval of 6 months, with 20.3% polyp and 13.6% adenoma recurrence. Polyp recurrence was associated with piecemeal resection (p = 0.04), recurrent polyp (p = 0.02), female sex (p = 0.01) and poor access (p = 0.005). Predictors for adenoma recurrence included female gender (p = 0.01) and difficult access (p < 0.001). Recurrence rates did not differ with polyp size, site, morphology, dysplasia status, submucosal injection, patient age, or study centre. CONCLUSIONS UEMR is an effective, safe and well tolerated option for significant colorectal polyps. Piecemeal resection, recurrent polyp, female gender, and difficult access are predictors of post-UEMR polyp recurrence.
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Affiliation(s)
- Keith Siau
- Joint Advisory Group on Gastrointestinal Endoscopy, Royal College of Physicians, London, UK
- Department of Gastroenterology, Dudley Group Hospitals NHS Foundation Trust, Dudley, UK
| | - Sauid Ishaq
- Department of Gastroenterology, Dudley Group Hospitals NHS Foundation Trust, Dudley, UK.
- Department of Medicine, Birmingham City University, Birmingham, B5 5JU, UK.
| | - Sergio Cadoni
- Digestive Endoscopy Unit, CTO Hospital, Iglesias, Italy
| | - Toshio Kuwai
- Department of Gastroenterology, National Hospital Organization, Kure Medical Centre and Chugoku Cancer Centre, Kure, Japan
| | | | - Noriko Suzuki
- Wolfson Unit for Endoscopy, St Mark's Hospital, London, UK
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Schenck RJ, Jahann DA, Patrie JT, Stelow EB, Cox DG, Uppal DS, Sauer BG, Shami VM, Strand DS, Wang AY. Underwater endoscopic mucosal resection is associated with fewer recurrences and earlier curative resections compared to conventional endoscopic mucosal resection for large colorectal polyps. Surg Endosc. 2017;31:4174-4183. [PMID: 28342125 DOI: 10.1007/s00464-017-5474-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 02/15/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Studies comparing the efficacy and safety of conventional saline-assisted piecemeal endoscopic mucosal resection (EMR) to underwater EMR (UEMR) without submucosal lifting of colorectal polyps are lacking. The objective of this study was to compare the efficacy and safety of EMR to UEMR of large colorectal polyps. METHODS Two hundred eighty-nine colorectal polyps were removed by a single endoscopist from 7/2007 to 2/2015 using EMR or UEMR. 135 polyps (EMR: 62, UEMR: 73) that measured ≥15 mm and had not undergone prior attempted polypectomy were evaluated for rates of complete macroscopic resection and adverse events. 101 of these polyps (EMR: 46, UEMR: 55) had at least 1 follow-up colonoscopy and were studied for rates of recurrence and the number of procedures required to achieve curative resection. RESULTS The rate of complete macroscopic resection was higher following UEMR compared to EMR (98.6 vs. 87.1%, p = 0.012). UEMR had a lower recurrence rate at the first follow-up colonoscopy compared to EMR (7.3 vs. 28.3%, OR 5.0 for post-EMR recurrence, 95% CI: [1.5, 16.5], p = 0.008). UEMR required fewer procedures to reach curative resection than EMR (mean of 1.0 vs. 1.3, p = 0.002). There was no significant difference in rates of adverse events. CONCLUSIONS UEMR appears superior to EMR for the removal of large colorectal polyps in terms of rates of complete macroscopic resection and recurrent (or residual) abnormal tissue. Compared to conventional EMR, UEMR may offer increased procedural effectiveness without compromising safety in the removal of large colorectal polyps without prior attempted resection.
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Chen L, Liu Q, Li Y, Lu R, Wu S, Li X, Hou T. Leakage diffusion of underwater crude oil in wind fields. Springerplus 2016; 5:1875. [PMID: 27833834 PMCID: PMC5081989 DOI: 10.1186/s40064-016-3457-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 10/04/2016] [Indexed: 11/10/2022]
Abstract
Leakage of underwater crude oil pipes causes severe pollution to soil and water, and results in great economic loss. To predict the diffusion area of spilled oil before it reaches the water's surface and to reduce the time required for emergency response, numerical simulations were conducted on underwater spilled oil diffusion of bare crude oil pipes using FLUENT software. The influences of water-surface wind speed, leakage hole diameter, water velocity, and initial leakage velocity on oil diffusion were analyzed. The results revealed the following: (1) with wind blowing on the surface of the water, the vertical displacement of spilled oil jet-flow was affected by the combined action of water flow and wind, making it difficult for a high-speed jet-flow to form. A horizontal oil flow mostly moved in the direction of the bottom water, and frontier oil droplets dispersed quickly; (2) during the diffusion of spilled oil in water, the maximum horizontal displacement mostly increased linearly, while the maximum vertical displacement initially increased quickly and then slowed; (3) the greater the initial velocity and leakage hole diameter, the higher the oil jet-flow and the wider the diffusion area; the higher the water flow rate and water-surface wind speed, the smaller the vertical displacement of spilled oil. The existence of water-surface wind had no obvious influence on the horizontal displacement of underwater spilled oil.
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Affiliation(s)
- Liqiong Chen
- School of Petroleum Engineering, Southwest Petroleum University, Chengdu, Sichuan China
| | - Qi Liu
- School of Petroleum Engineering, Southwest Petroleum University, Chengdu, Sichuan China
| | - Yunyun Li
- China Petroleum Engineering Huabei Company, Renqiu, Hebei China
| | - Rui Lu
- National Computer Network Emergency Response Technical Team/Coordination Center of China, Beijing, China
| | - Shijuan Wu
- Guangxi Oil Production Plant, Southwest Oil and Gas Company, Sinopec, Deyang, Sichuan China
| | - Xin Li
- China Petroleum and Natural Gas Co., Ltd. Da Gang Oil Field Branch, Tianjin, China
| | - Tao Hou
- China Petroleum and Natural Gas Co., Ltd. Da Gang Oil Field Branch, Tianjin, China
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Jones B, Cooper CE. Underwater Near-Infrared Spectroscopy: Muscle Oxygen Changes in the Upper and Lower Extremities in Club Level Swimmers and Triathletes. Adv Exp Med Biol 2016; 876:35-40. [PMID: 26782192 DOI: 10.1007/978-1-4939-3023-4_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
To date, measurements of oxygen status during swim exercise have focused upon systemic aerobic capacity. The development of a portable, waterproof NIRS device makes possible a local measurement of muscle hemodynamics and oxygenation that could provide a novel insight into the physiological changes that occur during swim exercise. The purpose of this study was to observe changes in muscle oxygenation in the vastus lateralis (VL) and latissimus dorsi (LD) of club level swimmers and triathletes. Ten subjects, five club level swimmers and five club level triathletes (three men and seven women) were used for assessment. Swim group; mean±SD=age 21.2±1.6 years; height 170.6±7.5 cm; weight 62.8±6.9 kg; vastus lateralis skin fold 13.8±5.6 mm; latissimus dorsi skin fold 12.6±3.7. Triathlete group; mean±SD=age 44.0±10.5 years; height 171.6±7.0 cm; weight 68.6±12.7 kg; vastus lateralis skin fold 11.8±3.5 mm; latissimus dorsi skin fold 11.2±3.1. All subjects completed a maximal 200 m freestyle swim, with the PortaMon, a portable NIR device, attached to the subject's dominant side musculature. ΔTSI% between the vastus lateralis and latissimus dorsi were analysed using either paired (2-tailed) t-tests or Wilcoxon signed rank test. The level of significance for analysis was set at p<0.05. No significant difference (p=0.686) was found in ΔTSI (%) between the VL and LD in club level swimmers. A significant difference (p=0.043) was found in ΔTSI (%) between the VL and LD in club level triathletes. Club level swimmers completed the 200 m freestyle swim significantly faster (p=0.04) than club level triathletes. Club level swimmers use both the upper and lower muscles to a similar extent during a maximal 200 m swim. Club level triathletes predominately use the upper body for propulsion during the same exercise. The data produced by NIRS in this study are the first of their kind and provide insight into muscle oxygenation changes during swim exercise which can indicate the contribution of one muscle compared to another. This also enables a greater understanding of the differences in swimming techniques seen between different cohorts of swimmers and potentially within individual swimmers.
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26
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Gaspar JP, Stelow EB, Wang AY. Approach to the endoscopic resection of duodenal lesions. World J Gastroenterol 2016; 22:600-17. [PMID: 26811610 PMCID: PMC4716062 DOI: 10.3748/wjg.v22.i2.600] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 10/14/2015] [Accepted: 11/09/2015] [Indexed: 02/06/2023] Open
Abstract
Duodenal polyps or lesions are uncommonly found on upper endoscopy. Duodenal lesions can be categorized as subepithelial or mucosally-based, and the type of lesion often dictates the work-up and possible therapeutic options. Subepithelial lesions that can arise in the duodenum include lipomas, gastrointestinal stromal tumors, and carcinoids. Endoscopic ultrasonography with fine needle aspiration is useful in the characterization and diagnosis of subepithelial lesions. Duodenal gastrointestinal stromal tumors and large or multifocal carcinoids are best managed by surgical resection. Brunner's gland tumors, solitary Peutz-Jeghers polyps, and non-ampullary and ampullary adenomas are mucosally-based duodenal lesions, which can require removal and are typically amenable to endoscopic resection. Several anatomic characteristics of the duodenum make endoscopic resection of duodenal lesions challenging. However, advanced endoscopic techniques exist that enable the resection of large mucosally-based duodenal lesions. Endoscopic papillectomy is not without risk, but this procedure can effectively resect ampullary adenomas and allows patients to avoid surgery, which typically involves pancreaticoduodenectomy. Endoscopic mucosal resection and its variations (such as cap-assisted, cap-band-assisted, and underwater techniques) enable the safe and effective resection of most duodenal adenomas. Endoscopic submucosal dissection is possible but very difficult to safely perform in the duodenum.
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27
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Sugimoto S, Mizukami T. Diagnostic and therapeutic applications of water-immersion colonoscopy. World J Gastroenterol 2015; 21:6451-6459. [PMID: 26074684 PMCID: PMC4458756 DOI: 10.3748/wjg.v21.i21.6451] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/15/2015] [Accepted: 04/28/2015] [Indexed: 02/06/2023] Open
Abstract
Colonoscopy techniques combining or replacing air insufflation with water infusion are becoming increasingly popular. They were originally designed to reduce colonic spasms, facilitate cecal intubation, and lower patient discomfort and the need for sedation. These maneuvers straighten the rectosigmoid colon and enable the colonoscope to be inserted deeply without causing looping of the colon. Water-immersion colonoscopy minimizes colonic distension and improves visibility by introducing a small amount of water. In addition, since pain during colonoscopy indicates risk of bowel perforation and sedation masks this important warning, this method has the potential to be the favored insertion technique because it promotes patient safety without sedation. Recently, this water-immersion method has not only been used for colonoscope insertion, but has also been applied to therapy for sigmoid volvulus, removal of lesions, lower gastrointestinal bleeding, and therapeutic diagnosis of abnormal bowel morphology and irritable bowel syndrome. Although a larger sample size and prospective head-to-head-designed studies will be needed, this review focuses on the usefulness of water-immersion colonoscopy for diagnostic and therapeutic applications.
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McLaughlin KE, Kunc HP. Changes in the acoustic environment alter the foraging and sheltering behaviour of the cichlid Amititlania nigrofasciata. Behav Processes 2015; 116:75-9. [PMID: 25937344 DOI: 10.1016/j.beproc.2015.04.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 04/17/2015] [Accepted: 04/25/2015] [Indexed: 11/19/2022]
Abstract
Anthropogenic noise can affect behaviour across a wide range of species in both terrestrial and aquatic environments. However, behaviours might not be affected in isolation. Therefore, a more holistic approach investigating how environmental stressors, such as noise pollution, affect different behaviours in concert is necessary. Using tank-based noise exposure experiments, we tested how changes in the acoustic environment affect the behaviour of the cichlid Amatitlania nigrofasciata. We found that exposure to anthropogenic noise affected a couple of behaviours: an increase in sheltering was accompanied by a decrease in foraging. Our results highlight the multiple negative effects of an environmental stressor on an individual's behaviour.
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Affiliation(s)
- Kirsty Elizabeth McLaughlin
- Queen's University Belfast, Institute for Global Food Security, School of Biological Sciences, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK.
| | - Hansjoerg P Kunc
- Queen's University Belfast, Institute for Global Food Security, School of Biological Sciences, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK.
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Abstract
Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwater breathing apparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body. One of the common consequences of hyperbaric gas is the narcotic effect of inert gas. Nitrogen (a major component of air) under pressure can impede mental function and physical performance at depths of as little as 10 m underwater. With increased depth, symptoms can worsen to include confusion, disturbed coordination, lack of concentration, hallucinations and unconsciousness. Narcosis has been shown to contribute directly to up to 6% of deaths in divers and is likely to be indirectly associated with other diving incidents at depth. This article explores inert gas narcosis, the effect on divers' movement and function underwater and the proposed physiological mechanisms. Also discussed are some of the factors that affect the susceptibility of divers to the condition. In conclusion, understanding the cause of this potentially debilitating problem is important to ensure that safe diving practices continue.
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Affiliation(s)
- James E Clark
- Centre of Human & Aerospace Physiological Sciences and British Heart Foundation Excellence Centre, Cardiovascular Division, St Thomas' Hospital, King's College London, London, SE1 7EH UK
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Veiga S, Mallo J, Navandar A, Navarro E. Effects of different swimming race constraints on turning movements. Hum Mov Sci 2014; 36:217-26. [PMID: 24875044 DOI: 10.1016/j.humov.2014.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 03/11/2014] [Accepted: 04/07/2014] [Indexed: 11/21/2022]
Abstract
The aim of this study was to investigate the effects of different swimming race constraints on the evolution of turn parameters. One hundred and fifty-eight national and regional level 200-m (meters) male swimming performances were video-analyzed using the individualized-distance model in the Open Comunidad de Madrid tournament. Turn (p<.001, ES=0.36) and underwater distances (p<.001, ES=0.38) as well as turn velocity (p<.001, ES=0.69) significantly dropped throughout the race, although stroke velocity and underwater velocity were maintained in the last lap of the race (p>.05). Higher expertise swimmers obtained faster average velocities and longer distances in all the turn phases (p<.001, ES=0.59), except the approach distance. In addition, national level swimmers showed the ability to maintain most of the turn parameters throughout the race, which assisted them in improving average velocity at the end of races. Therefore, the variations in the turning movements of a swimming race were expertise-related and focused on optimizing average velocity. Turning skills should be included in the swimming race action plan.
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