AIM:To introduce and evaluate the clinical efficacy of a new technique,the use of viscoelastic substances(VS)to close leaking sclerotomy in 23G microincision vitrectomy,and to observe its effect on the visual acuity a...AIM:To introduce and evaluate the clinical efficacy of a new technique,the use of viscoelastic substances(VS)to close leaking sclerotomy in 23G microincision vitrectomy,and to observe its effect on the visual acuity and intraocular pressure(IOP)of patients.METHODS:Patients who underwent 23G vitrectomy in Ningbo Eye Hospital before the use of VS technique(June 2019 to September 2020)and after the use of VS technique(October 2020 to December 2021)were selected as the subjects of this study.The above cases underwent operation by the same surgeon and were retrospectively analyzed.VS technique was used as the alternative to suturing,in which a small amount of VS was injected at the leaking sclerotomy and then gently massaged to confirm leaking sclerotomy closure.RESULTS:A total of 174 eyes were covered in the study,including 84 eyes in the control group(before the use of VS technique)and 90 eyes in the VS technique group.The number of eyes that needed to be sutured decreased considerably from 42.9%in the control group to 3.3%in the VS technique group,and the proportion of subconjunctival hemorrhage at 1-2d after surgery decreased remarkably from 35.7%in the control group to 2.2%in the VS technique group.No substantial differences in the incidence of mean IOP and low IOP were found between 1-2 and 3-20d after surgery in the VS technique group.No major complications associated with VS technique were identified during the study.CONCLUSION:In 23G microincision vitrectomy,VS technique is a safe,simple,and effective method to close leaking sclerotomy.展开更多
Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explo...Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explosion accident occurring in China in 2013 by modeling analysis,field surveys,and numerical simulations.The total amount of the spilled oil was up to2044.4 m3 due to improper disposal.The long residence time of the oil remaining in a confined space permitted the formation of explosive mixtures and caused the vapor cloud explosion.A numerical model was developed to estimate the consequence of the explosion based on volatilization testing results.The results show that the death-leading zone and the glass-breaking zone could be 18 m and 92 m,respectively,which are consistent with the field investigation.The severity of the explosion is related to the amount of the oil spill,properties of oil,and volatilization time.It is recommended that a comprehensive risk assessment be conducted to analyze the possible consequences upon oil spilling into a confined space.Prompt collection and ventilation measures should be taken immediately after the spill occurs to reduce the time for oil volatilization and prevent the mixture from reaching its explosive limit.展开更多
Based on the non-linear air leakage seepage equation for an anisotropic porous medium, on the seepage diffusion equation of multicomponent gas and on the seepage synthetic heat transfer equation of a porous medium, th...Based on the non-linear air leakage seepage equation for an anisotropic porous medium, on the seepage diffusion equation of multicomponent gas and on the seepage synthetic heat transfer equation of a porous medium, the numerical model for field flow problems of irregular patterns of a goaf with multiple points of leaking air is established and simultaneously solved by the upwind mode finite element method (G3 computer program). According to the complexity of irregular patterns of a goaf with multiple points of leaking air, the flow pattern in a large area of such a goaf and the variation in gases of methane, oxygen and CO and in temperature are theoretically described. In the calculation, the goaf is regarded as a caving anisotropic medium and the coupling effect of methane effusion on spontaneous combustion is considered. The simulation results agree well with practical experience. In addition, the spontaneous combustion process is also simulated, indicating that 1) the spontaneous combustion often takes place near the area where fresh air leaks in and 2) the fire sources can be classified into static and dynamic zones. Therefore, in practical fire preventing and extinguishing, we should clearly distinguish the upstream air leaking points from the downstream ones in order to take proper measures for leakage stopping.展开更多
Dear Editor,In a recent interventional case report,Allon et al )hydrated corneal stroma with cefuroxime to seal a small traumatic leaky corneal perforation that was unresponsive to prior soft bandage contact lens app...Dear Editor,In a recent interventional case report,Allon et al )hydrated corneal stroma with cefuroxime to seal a small traumatic leaky corneal perforation that was unresponsive to prior soft bandage contact lens application for 6d.展开更多
In order to develop the technology of the controlled recircuIation of airflow in the world, some formulas about the airflow recirculation system in the working face with leaking airflow are deduced,which reduces the e...In order to develop the technology of the controlled recircuIation of airflow in the world, some formulas about the airflow recirculation system in the working face with leaking airflow are deduced,which reduces the error between calculating and real values. on the base of the application of the formulas mentioned above, the problem about lack of airflow in the working face 2712 was solved successfully in Xiandewang Coal Mine.展开更多
This paper deals with the temperature and displacement fields of the top mid block of south transition at Long Spruce Generating Station, in the North of Manitoba, Canada. According to the experimental results of Man...This paper deals with the temperature and displacement fields of the top mid block of south transition at Long Spruce Generating Station, in the North of Manitoba, Canada. According to the experimental results of Manitoba Hydro in the past two years, the top mid block is assumed to be a rectangular one that has two supposed temperature distributions at its boundary sides. Then, the temperature fields for the top mid block are obtained from the analytical solutions by separation of variables. By using the analytical solution of temperature field, the displacement behavior of the top block in various temperature fields is discussed in details. The numerical results are given to show the causes of the leakage between the top mid block and the dam. Finally, the repair methods for leakage are discussed for practical leaking repair and its engineering applications.展开更多
Gardening style in south of the Yangtze River was reviewed, and aesthetic features of local gardens were summarized as full of humanistic connotations, modeling after the nature, graceful and free from vulgarity, refi...Gardening style in south of the Yangtze River was reviewed, and aesthetic features of local gardens were summarized as full of humanistic connotations, modeling after the nature, graceful and free from vulgarity, refined and refreshing, implying profound significance in detailed designs, integrated virtual and real scenery. On this basis, form and meaning of leaking windows in the gardens were analyzed, and artistic means of designing leaking windows were summarized from the perspectives of leaking through scenery and borrowed scenery, virtual and real scenery, in-motion and in-position scenery.展开更多
Objectives:Anastomotic leakage(AL)stands out as a prevalent and severe complication following gastric cancer surgery.It frequently precipitates additional serious complications,significantly influencing the overall su...Objectives:Anastomotic leakage(AL)stands out as a prevalent and severe complication following gastric cancer surgery.It frequently precipitates additional serious complications,significantly influencing the overall survival time of patients.This study aims to enhance the risk-assessment strategy for AL following gastrectomy for gastric cancer.Methods:This study included a derivation cohort and validation cohort.The derivation cohort included patients who underwent radical gastrectomy at Sir Run Run Shaw Hospital,Zhejiang University School of Medicine,from January 1,2015 to December 31,2020.An evidence-based predictor questionnaire was crafted through extensive literature review and panel discussions.Based on the questionnaire,inpatient data were collected to form a model-derivation cohort.This cohort underwent both univariate and multivariate analyses to identify factors associated with AL events,and a logistic regression model with stepwise regression was developed.A 5-fold cross-validation ensured model reliability.The validation cohort included patients from August 1,2021 to December 31,2021 at the same hospital.Using the same imputation method,we organized the validation-queue data.We then employed the risk-prediction model constructed in the earlier phase of the study to predict the risk of AL in the subjects included in the validation queue.We compared the predictions with the actual occurrence,and evaluated the external validation performance of the model using model-evaluation indicators such as the area under the receiver operating characteristic curve(AUROC),Brier score,and calibration curve.Results:The derivation cohort included 1377 patients,and the validation cohort included 131 patients.The independent predictors of AL after radical gastrectomy included age65 y,preoperative albumin<35 g/L,resection extent,operative time240 min,and intraoperative blood loss90 mL.The predictive model exhibited a solid AUROC of 0.750(95%CI:0.694e0.806;p<0.001)with a Brier score of 0.049.The 5-fold cross-validation confirmed these findings with a calibrated C-index of 0.749 and an average Brier score of 0.052.External validation showed an AUROC of 0.723(95%CI:0.564e0.882;p?0.006)and a Brier score of 0.055,confirming reliability in different clinical settings.Conclusions:We successfully developed a risk-prediction model for AL following radical gastrectomy.This tool will aid healthcare professionals in anticipating AL,potentially reducing unnecessary interventions.展开更多
Objective:A vesicourethral anastomotic leak(VUAL)is a known complication following robotic-assisted radical prostatectomy.The natural history of a VUAL has been well described and is frequently managed with prolonged ...Objective:A vesicourethral anastomotic leak(VUAL)is a known complication following robotic-assisted radical prostatectomy.The natural history of a VUAL has been well described and is frequently managed with prolonged catheterization.With increasing emphasis on patient reported outcomes,catheter duration and VUAL are associated with significant short-term quality of life impairment.We aimed to present a case series of our robotic early post-prostatectomy anastomotic repair technique,defined as revision within 6 weeks from index surgery.Methods:A single institution prospective database identified eleven patients with a VUAL from July 2016 to October 2022 who underwent robotic early post-prostatectomy anastomotic repair by a single surgeon.Patients were diagnosed with a VUAL on pre-operative CT urogram or CT/fluoroscopic cystogram.The primary outcome was resolution of the anastomotic leak,defined as no contrast extravasation on post-operative cystography.Secondary outcomes included post-repair catheter duration and continence on the last follow-up defined as pad(s)per day.Results:The mean time to intervention after robotic-assisted radical prostatectomy was 21 days.Eight of the eleven(72.7%)patients had no evidence of extravasation on postrepair cystogram.The range from intervention to first cystogram was 7e20 days.The median catheter duration for those with successful intervention was 10 days.The median catheter duration for those with the leak on initial post-operative cystogram was 20 days.At a mean follow-up time of 25 months,eight(72.7%)patients reported using no pads per day,and three(27.3%)patients reported one pad per day.Conclusion:Management of a VUAL has traditionally relied on prolonged catheter drainage and the tincture of time.As the role of robotic reconstruction has been shown to be a viable modality for management of bladder neck contracture,it is important to reconsider prior dogmas of urologic care.Our case series suggests that an early repair is safe and has a high success rate.Early robotic intervention gives providers an additional tool in aiding patient recovery.展开更多
BACKGROUND Pancreatic ductal leaks complicated by endoscopic ultrasonography-guided tissue sampling(EUS-TS)can manifest as acute pancreatitis.CASE SUMMARY A 63-year-old man presented with persistent abdominal pain and...BACKGROUND Pancreatic ductal leaks complicated by endoscopic ultrasonography-guided tissue sampling(EUS-TS)can manifest as acute pancreatitis.CASE SUMMARY A 63-year-old man presented with persistent abdominal pain and weight loss.Diagnosis:Laboratory findings revealed elevated carbohydrate antigen 19-9(5920 U/mL)and carcinoembryonic antigen(23.7 ng/mL)levels.Magnetic resonance imaging of the pancreas revealed an approximately 3 cm ill-defined space-occupying lesion in the inferior aspect of the head,with severe encasement of the superior mesenteric artery.Pancreatic ductal adenocarcinoma was confirmed after pathological examination of specimens obtained by EUS-TS using the fanning method.Interventions and outcomes:The following day,the patient experienced severe abdominal pain with high amylase(265 U/L)and lipase(1173 U/L)levels.Computed tomography of the abdomen revealed edematous wall thickening of the second portion of the duodenum with adjacent fluid collections and a suspicious leak from either the distal common bile duct or the main pancreatic duct in the head.Endoscopic retrograde cholangiopancreatography revealed dye leakage in the head of the main pancreatic duct.Therefore,a 5F 7 cm linear plastic stent was deployed into the pancreatic duct to divert the pancreatic juice.The patient’s abdominal pain improved immediately after pancreatic stent insertion,and amylase and lipase levels normalized within a week.Neoadjuvant chemotherapy was then initiated.CONCLUSION Using the fanning method in EUS-TS can inadvertently cause damage to the pancreatic duct and may lead to clinically significant pancreatitis.Placing a pancreatic stent may immediately resolve acute pancreatitis and shorten the waiting time for curative therapy.When using the fanning method during EUSTS,ductal structures should be excluded to prevent pancreatic ductal leakage.展开更多
BACKGROUND Resection of hepatic metastasis from neuroendocrine tumors(NETs)improves quality of life and prolongs 5-year survival.Ablation can be utilized with surgery to achieve complete resection.Although several stu...BACKGROUND Resection of hepatic metastasis from neuroendocrine tumors(NETs)improves quality of life and prolongs 5-year survival.Ablation can be utilized with surgery to achieve complete resection.Although several studies report long-term out-comes for patients undergoing ablation,none have explored perioperative effects of ablation in patients with metastatic NETs.AIM To determine if intra-operative ablation during hepatectomy increases risk of ad-verse outcomes such as surgical site infections(SSIs),bleeding,and bile leak.METHODS A retrospective analysis of the hepatectomy National Surgical Quality Impro-vement Program database from 2015-2019 was performed to determine the odds of SSIs,bile leaks,or bleeding in patients undergoing intraoperative ablation when compared to hepatectomy alone.RESULTS Of the 966 patients included in the study,298(30.9%)underwent ablation during hepatectomy.There were 78(11.7%)patients with SSIs in the hepatectomy alone group and 39(13.1%)patients with a SSIs in the hepatectomy with ablation group.Bile leak occurred in 41(6.2%)and 14(4.8%)patients in the two groups,respec-tively;bleeding occurred in 117(17.5%)and 33(11.1%),respectively.After con-trolling for confounding variables,ablation did not increase risk of SSI(P=0.63),bile leak(P=0.34)or bleeding(P=0.07)when compared to patients undergoing resection alone on multivariate analysis.CONCLUSION Intraoperative ablation with hepatic resection for NETs is safe in the perioperative period without significant increased risk of infection,bleeding,or bile leak.Surgeons should utilize this modality when appropriate to a-chieve optimal disease control and outcomes.展开更多
BACKGROUND Bile leakage is a common and serious complication of open hepatectomy for the treatment of biliary tract cancer.AIM To evaluate the incidence,risk factors,and management of bile leakage after open hepatecto...BACKGROUND Bile leakage is a common and serious complication of open hepatectomy for the treatment of biliary tract cancer.AIM To evaluate the incidence,risk factors,and management of bile leakage after open hepatectomy in patients with biliary tract cancer.METHODS We retrospectively analyzed 120 patients who underwent open hepatectomy for biliary tract cancer from February 2018 to February 2023.Bile leak was defined as bile drainage from the surgical site or drain or the presence of a biloma on imaging.The incidence,severity,timing,location,and treatment of the bile leaks were recorded.The risk factors for bile leakage were analyzed using univariate and multivariate logistic regression analyses.RESULTS The incidence of bile leak was 16.7%(20/120),and most cases were grade A(75%,15/20)according to the International Study Group of Liver Surgery classification.The median time of onset was 5 d(range,1-14 d),and the median duration was 7 d(range,2-28 d).The most common location of bile leakage was the cut surface of the liver(70%,14/20),followed by the anastomosis site(25%,5/20)and the cystic duct stump(5%,1/20).Most bile leaks were treated conservatively with drainage,antibiotics,and nutritional support(85%,17/20),whereas some required endoscopic retrograde cholangiopancreatography with stenting(10%,2/20)or percutaneous transhepatic cholangiography with drainage(5%,1/20).Risk factors for bile leakage include male sex,hepatocellular carcinoma,major hepatectomy,blood loss,and blood transfusion.CONCLUSION Bile leakage is a frequent complication of open hepatectomy for biliary tract cancer.However,most cases are mild and can be conservatively managed.Male sex,hepatocellular carcinoma,major hepatectomy,blood loss,and blood transfusion were associated with an increased risk of bile leak.展开更多
BACKGROUND Surgical resection is the cornerstone treatment for colorectal cancer.Rapid rehabilitation care predicated on evidence-based medical theory aims to improve postoperative nursing care,subsequently reducing t...BACKGROUND Surgical resection is the cornerstone treatment for colorectal cancer.Rapid rehabilitation care predicated on evidence-based medical theory aims to improve postoperative nursing care,subsequently reducing the physical and mental traumatic stress response and helping patients who undergo surgery recover rapidly.AIM To assess the effect of rapid rehabilitation care on clinical outcomes,including overall postoperative complications,anastomotic leaks,wound infections,and intestinal obstruction in patients with colorectal cancer.METHODS We searched the PubMed,Web of Science,Embase,Elsevier Science Direct,and Springer Link databases from January 1,2010,to January 1,2024,to screen eligible studies on rapid rehabilitation care among patients who underwent colorectal cancer surgery.Patients were screened based on the inclusion and exclusion criteria.RevMan 5.4 software was used for statistical analysis of the data.RESULTS Twelve studies were enrolled,which included 2420 patients.The results showed that rapid rehabilitation care decreased the incidence of overall postoperative complications(OR:0.44,95%CI:0.26–0.74,P=0.002),anastomotic leaks(OR:0.68,95%CI:0.41–1.12,P=0.13),wound infections(OR:0.45,95%CI:0.29–0.72,P=0.0007),and intestinal obstruction(OR:0.54,95%CI:0.34–0.86,P=0.01)compared to conventional care.Further trials and studies are needed to confirm these results.CONCLUSION Rapid rehabilitation care decreased the occurrence of postoperative complications,anastomotic leaks,wound infections,and intestinal obstruction compared to conventional care in patients who underwent colorectal surgery.Therefore,promoting the application of rapid rehabilitation care in clinical practice cannot be overemphasized.展开更多
BACKGROUND The neutrophil-to-lymphocyte ratio(NLR),a composite inflammatory biomarker,is associated with the prognosis in patients with colorectal tumors.However,whether the NLR can be used as a predictor of symptomat...BACKGROUND The neutrophil-to-lymphocyte ratio(NLR),a composite inflammatory biomarker,is associated with the prognosis in patients with colorectal tumors.However,whether the NLR can be used as a predictor of symptomatic postoperative ana-stomotic leakage(AL)in elderly patients with colon cancer is unclear.AIM To assess the role of the NLR in predicting the occurrence of symptomatic AL after surgery in elderly patients with colon cancer.METHODS Data from elderly colon cancer patients who underwent elective radical colectomy with anastomosis at three centers between 2018 and 2022 were retrospectively analyzed.Receiver operating characteristic curve analysis was performed to determine the best predictive cutoff value for the NLR.Twenty-two covariates were matched using a 1:1 propensity score matching method,and univariate and multivariate logistic regression analyses were used to determine risk factors for the development of postoperative AL.RESULTS Of the 577 patients included,36(6.2%)had symptomatic AL.The optimal cutoff value of the NLR for predicting AL was 2.66.After propensity score matching,the incidence of AL was significantly greater in the≥2.66 NLR subgroup than in the<2.66 NLR subgroup(11.5%vs 2.5%;P=0.012).Univariate logistic regression analysis revealed statistically significant correlations between blood transfusion intraoperatively and within 2 d postoper-atively,preoperative albumin concentration,preoperative prognostic nutritional index,and preoperative NLR and AL occurrence(P<0.05);multivariate logistic regression analysis revealed that an NLR≥2.66[odds ratio(OR)=5.51;95%confidence interval(CI):1.50-20.26;P=0.010]and blood transfusion intraoperatively and within 2 d postoperatively(OR=2.52;95%CI:0.88-7.25;P=0.049)were risk factors for the occurrence of symptomatic AL.CONCLUSION A preoperative NLR≥2.66 and blood transfusion intraoperatively and within 2 d postoperatively are associated with a higher incidence of postoperative symptomatic AL in elderly patients with colon cancer.The preoperative NLR has predictive value for postoperative symptomatic AL after elective surgery in elderly patients with colon cancer.展开更多
Laparoscopic colectomy with ileorectal anastomosis may be beneficial for patients with slow transit constipation who do not respond to conservative treatment,particularly if the superior rectal artery(SRA)is preserved...Laparoscopic colectomy with ileorectal anastomosis may be beneficial for patients with slow transit constipation who do not respond to conservative treatment,particularly if the superior rectal artery(SRA)is preserved.Several important concerns have been addressed in this commentary.It is important to first go over the definition of surgical procedure as it is used in this text.Second,the current study lacked a control group that had SRA preservation.Thirdly,it would be best to use a prospective,randomized controlled study.Lastly,a description of the mesenteric defect’s state following a laparoscopic colectomy is necessary.展开更多
Purpose: This article investigates the critical importance of integrating surgeons’ direct input into the development of innovative technologies that address gaps in surgical care, including those aimed at reducing a...Purpose: This article investigates the critical importance of integrating surgeons’ direct input into the development of innovative technologies that address gaps in surgical care, including those aimed at reducing anastomotic leaks (AL), a major complication in gastrointestinal surgery. While traditional quantitative research methods are prevalent, they often overlook the invaluable insights of the surgeons who manage these complications firsthand. Subjects and Methods: This study employs a qualitative approach, utilizing semi-structured interviews with 40 surgeons from various specialties, including general, bariatric, colorectal, trauma, hepato-biliary, and thoracic surgery. The interviews were designed to probe the needs of surgeons, challenges currently faced, and gaps in clinical practice, research, and technology for detection and/or management of AL. The data were analyzed using thematic analysis, which revealed significant gaps in current technologies for early detection and prevention of leaks. Results: Surgeons expressed strong interest in FluidAI’s Stream™ Platform, a non-invasive medical device designed to monitor postoperative drainage fluid in real-time, providing continuous data on AL risk. The ability of this platform to offer early prediction through pH and electrical conductivity analysis was particularly appealing to participants, who emphasized the importance of timely interventions in improving patient outcomes. The study’s findings highlight not only the clinical challenges but also the emotional toll that AL takes on surgeons, underlining the need for innovations that are both data-driven and humanistic. Conclusion: By centering surgeons’ perspectives, this research advocates for a human-centered approach to technological advancement, ensuring that new tools are both clinically effective and aligned with the real-world needs of surgical practitioners.展开更多
BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an imp...BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation.Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features.Despite the advances in experimental protocols and techniques,designing a high-quality study is still challenging for the investigators as there is a plethora of different models used.AIM To review current state of the art for experimental protocols in high-risk anastomosis in rats.METHODS This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.To identify eligible studies,a comprehensive literature search was performed in the electronic databases PubMed(MEDLINE)and Scopus,covering the period from conception until 18 October 2023.RESULTS From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis.Methods of assessing anastomotic healing were extracted and were individually appraised.CONCLUSION Anastomotic healing studies have evolved over the last decades,but the findings are yet to be translated into human studies.There is a need for high-quality,well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.展开更多
A widely used aortic valve bioprosthesis is susceptible to regurgitation between the sewing ring and the frame of the valve due to its relatively thin fabric coverage. In some cases this leak has been shown to resolve...A widely used aortic valve bioprosthesis is susceptible to regurgitation between the sewing ring and the frame of the valve due to its relatively thin fabric coverage. In some cases this leak has been shown to resolve with administration of protamine, however, tension on this area from annular sutures placed in an asymmetric bicuspid valve annulus may exacerbate the defect.展开更多
Molten salt is often used for heat transfer and thermal energy storage in concentrated solar power.Molten salt leakage and migration is a significant issue in its application.Molten salt migration and solidification i...Molten salt is often used for heat transfer and thermal energy storage in concentrated solar power.Molten salt leakage and migration is a significant issue in its application.Molten salt migration and solidification in thermal porous foundation materials through cracks are experimentally investigated.The impact of factors,including crack length and width,operation temperature,and leakage mass of molten salt,are studied through an experimental device modeling the leakage of the actual molten salt storage tank.Experimental results show that the crack width and length slightly affect the migration depth,but directly affect the shape of the agglomeration of solidified salt and porous foundation material.The most important factor affecting the migration depth of molten salt leaking through cracks is the tank operating temperature.The molten salt migration depth when the operating temperature is 500℃ is 95.8% higher than that with an operating temperature of 300℃.As the leakage molten salt mass reached 400 g,the average migration width increased by 23.6%,but the migration depth only increased by 5.2%.It is found that the foundation material temperatures after leakage accidents increase with an increase in the mass of leaked molten salt.展开更多
The Zengmu Basin located in the shallow water area of the southern South China Sea,is rich in oil and gas resources,within which faults and mud-diapir are developed,but it is unknown whether oil and gas migrate to the...The Zengmu Basin located in the shallow water area of the southern South China Sea,is rich in oil and gas resources,within which faults and mud-diapir are developed,but it is unknown whether oil and gas migrate to the seafloor surface.The newly collected multibeam data across the Zengmu Basin reveal a large number of depressions,with depths of 2-4 m,widths of several tens of meters,large distribution range of 1.8-8 km along survey line,up to~50 km,and their backscatter intensity(-26 dB)is much greater than that of the surrounding area(-38 dB).Combined with the developed mud-diapir and fracture structures,and abundant oil and gas resources within this basin,these depressions are presumed to be pockmarks.Furthermore,more than 110 mono-sized small circular pockmarks,with a depth of less than 1 m and a width of 5 m,are observed in an area of less than 0.03 km2,which are not obliterated by sediment infilling with high sedimentation rate,implying an existence of unit-pockmarks that are or recently were active.In addition,seismic profiles across the Zengmu Basin show characterization of upward migration of hydrocarbons,expressed as mud-diapir structures,bright spots in the shallow formation with characteristics of“low frequency increase and high frequency attenuation”.The subbottom profiles show the mud-diapir structures,as well as the gas-bearing blank zones beneath the seafloor.These features suggest large gas leaking and occurrence of large amounts of carbonate nodules on the seafloor.This indicates the complex and variable substrate type in the Zengmu Basin,while the area was once thought to be mainly silty sand and find sand.This is the first report on the discovery of pockmarks in the Zengmu Basin;it will provide basic information for submarine stability and marine engineering in China’s maritime boundaries.展开更多
基金Supported by General Class A of the Zhejiang Medical and Health Science and Technique Plan Project in 2020(No.2020ky288)Zhejiang Provincial Science and Technique Program of Traditional Chinese Medicine(No.2021ZB268)+2 种基金Health Science and Technique Program of Zhejiang Province(No.2021PY073)Yinzhou District Agriculture and Social Development Field Science and Technique Project(No.2021AS0058No.2020AS0080)。
文摘AIM:To introduce and evaluate the clinical efficacy of a new technique,the use of viscoelastic substances(VS)to close leaking sclerotomy in 23G microincision vitrectomy,and to observe its effect on the visual acuity and intraocular pressure(IOP)of patients.METHODS:Patients who underwent 23G vitrectomy in Ningbo Eye Hospital before the use of VS technique(June 2019 to September 2020)and after the use of VS technique(October 2020 to December 2021)were selected as the subjects of this study.The above cases underwent operation by the same surgeon and were retrospectively analyzed.VS technique was used as the alternative to suturing,in which a small amount of VS was injected at the leaking sclerotomy and then gently massaged to confirm leaking sclerotomy closure.RESULTS:A total of 174 eyes were covered in the study,including 84 eyes in the control group(before the use of VS technique)and 90 eyes in the VS technique group.The number of eyes that needed to be sutured decreased considerably from 42.9%in the control group to 3.3%in the VS technique group,and the proportion of subconjunctival hemorrhage at 1-2d after surgery decreased remarkably from 35.7%in the control group to 2.2%in the VS technique group.No substantial differences in the incidence of mean IOP and low IOP were found between 1-2 and 3-20d after surgery in the VS technique group.No major complications associated with VS technique were identified during the study.CONCLUSION:In 23G microincision vitrectomy,VS technique is a safe,simple,and effective method to close leaking sclerotomy.
基金supported by China Scholarship Council(201809110035)the State Key Research and Development Plan Project of China(2016YFC0801500).
文摘Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explosion accident occurring in China in 2013 by modeling analysis,field surveys,and numerical simulations.The total amount of the spilled oil was up to2044.4 m3 due to improper disposal.The long residence time of the oil remaining in a confined space permitted the formation of explosive mixtures and caused the vapor cloud explosion.A numerical model was developed to estimate the consequence of the explosion based on volatilization testing results.The results show that the death-leading zone and the glass-breaking zone could be 18 m and 92 m,respectively,which are consistent with the field investigation.The severity of the explosion is related to the amount of the oil spill,properties of oil,and volatilization time.It is recommended that a comprehensive risk assessment be conducted to analyze the possible consequences upon oil spilling into a confined space.Prompt collection and ventilation measures should be taken immediately after the spill occurs to reduce the time for oil volatilization and prevent the mixture from reaching its explosive limit.
基金supported by the National Natural Science Foundation of China (No.50574038)the Scientific Research Foundation of Liaoning Technical University (No.2004-241).
文摘Based on the non-linear air leakage seepage equation for an anisotropic porous medium, on the seepage diffusion equation of multicomponent gas and on the seepage synthetic heat transfer equation of a porous medium, the numerical model for field flow problems of irregular patterns of a goaf with multiple points of leaking air is established and simultaneously solved by the upwind mode finite element method (G3 computer program). According to the complexity of irregular patterns of a goaf with multiple points of leaking air, the flow pattern in a large area of such a goaf and the variation in gases of methane, oxygen and CO and in temperature are theoretically described. In the calculation, the goaf is regarded as a caving anisotropic medium and the coupling effect of methane effusion on spontaneous combustion is considered. The simulation results agree well with practical experience. In addition, the spontaneous combustion process is also simulated, indicating that 1) the spontaneous combustion often takes place near the area where fresh air leaks in and 2) the fire sources can be classified into static and dynamic zones. Therefore, in practical fire preventing and extinguishing, we should clearly distinguish the upstream air leaking points from the downstream ones in order to take proper measures for leakage stopping.
文摘Dear Editor,In a recent interventional case report,Allon et al )hydrated corneal stroma with cefuroxime to seal a small traumatic leaky corneal perforation that was unresponsive to prior soft bandage contact lens application for 6d.
文摘In order to develop the technology of the controlled recircuIation of airflow in the world, some formulas about the airflow recirculation system in the working face with leaking airflow are deduced,which reduces the error between calculating and real values. on the base of the application of the formulas mentioned above, the problem about lack of airflow in the working face 2712 was solved successfully in Xiandewang Coal Mine.
文摘This paper deals with the temperature and displacement fields of the top mid block of south transition at Long Spruce Generating Station, in the North of Manitoba, Canada. According to the experimental results of Manitoba Hydro in the past two years, the top mid block is assumed to be a rectangular one that has two supposed temperature distributions at its boundary sides. Then, the temperature fields for the top mid block are obtained from the analytical solutions by separation of variables. By using the analytical solution of temperature field, the displacement behavior of the top block in various temperature fields is discussed in details. The numerical results are given to show the causes of the leakage between the top mid block and the dam. Finally, the repair methods for leakage are discussed for practical leaking repair and its engineering applications.
文摘Gardening style in south of the Yangtze River was reviewed, and aesthetic features of local gardens were summarized as full of humanistic connotations, modeling after the nature, graceful and free from vulgarity, refined and refreshing, implying profound significance in detailed designs, integrated virtual and real scenery. On this basis, form and meaning of leaking windows in the gardens were analyzed, and artistic means of designing leaking windows were summarized from the perspectives of leaking through scenery and borrowed scenery, virtual and real scenery, in-motion and in-position scenery.
基金This workwas supported by the Medical and Health Science and Technology Project of Zhejiang Province(No.2021KY180).
文摘Objectives:Anastomotic leakage(AL)stands out as a prevalent and severe complication following gastric cancer surgery.It frequently precipitates additional serious complications,significantly influencing the overall survival time of patients.This study aims to enhance the risk-assessment strategy for AL following gastrectomy for gastric cancer.Methods:This study included a derivation cohort and validation cohort.The derivation cohort included patients who underwent radical gastrectomy at Sir Run Run Shaw Hospital,Zhejiang University School of Medicine,from January 1,2015 to December 31,2020.An evidence-based predictor questionnaire was crafted through extensive literature review and panel discussions.Based on the questionnaire,inpatient data were collected to form a model-derivation cohort.This cohort underwent both univariate and multivariate analyses to identify factors associated with AL events,and a logistic regression model with stepwise regression was developed.A 5-fold cross-validation ensured model reliability.The validation cohort included patients from August 1,2021 to December 31,2021 at the same hospital.Using the same imputation method,we organized the validation-queue data.We then employed the risk-prediction model constructed in the earlier phase of the study to predict the risk of AL in the subjects included in the validation queue.We compared the predictions with the actual occurrence,and evaluated the external validation performance of the model using model-evaluation indicators such as the area under the receiver operating characteristic curve(AUROC),Brier score,and calibration curve.Results:The derivation cohort included 1377 patients,and the validation cohort included 131 patients.The independent predictors of AL after radical gastrectomy included age65 y,preoperative albumin<35 g/L,resection extent,operative time240 min,and intraoperative blood loss90 mL.The predictive model exhibited a solid AUROC of 0.750(95%CI:0.694e0.806;p<0.001)with a Brier score of 0.049.The 5-fold cross-validation confirmed these findings with a calibrated C-index of 0.749 and an average Brier score of 0.052.External validation showed an AUROC of 0.723(95%CI:0.564e0.882;p?0.006)and a Brier score of 0.055,confirming reliability in different clinical settings.Conclusions:We successfully developed a risk-prediction model for AL following radical gastrectomy.This tool will aid healthcare professionals in anticipating AL,potentially reducing unnecessary interventions.
文摘Objective:A vesicourethral anastomotic leak(VUAL)is a known complication following robotic-assisted radical prostatectomy.The natural history of a VUAL has been well described and is frequently managed with prolonged catheterization.With increasing emphasis on patient reported outcomes,catheter duration and VUAL are associated with significant short-term quality of life impairment.We aimed to present a case series of our robotic early post-prostatectomy anastomotic repair technique,defined as revision within 6 weeks from index surgery.Methods:A single institution prospective database identified eleven patients with a VUAL from July 2016 to October 2022 who underwent robotic early post-prostatectomy anastomotic repair by a single surgeon.Patients were diagnosed with a VUAL on pre-operative CT urogram or CT/fluoroscopic cystogram.The primary outcome was resolution of the anastomotic leak,defined as no contrast extravasation on post-operative cystography.Secondary outcomes included post-repair catheter duration and continence on the last follow-up defined as pad(s)per day.Results:The mean time to intervention after robotic-assisted radical prostatectomy was 21 days.Eight of the eleven(72.7%)patients had no evidence of extravasation on postrepair cystogram.The range from intervention to first cystogram was 7e20 days.The median catheter duration for those with successful intervention was 10 days.The median catheter duration for those with the leak on initial post-operative cystogram was 20 days.At a mean follow-up time of 25 months,eight(72.7%)patients reported using no pads per day,and three(27.3%)patients reported one pad per day.Conclusion:Management of a VUAL has traditionally relied on prolonged catheter drainage and the tincture of time.As the role of robotic reconstruction has been shown to be a viable modality for management of bladder neck contracture,it is important to reconsider prior dogmas of urologic care.Our case series suggests that an early repair is safe and has a high success rate.Early robotic intervention gives providers an additional tool in aiding patient recovery.
文摘BACKGROUND Pancreatic ductal leaks complicated by endoscopic ultrasonography-guided tissue sampling(EUS-TS)can manifest as acute pancreatitis.CASE SUMMARY A 63-year-old man presented with persistent abdominal pain and weight loss.Diagnosis:Laboratory findings revealed elevated carbohydrate antigen 19-9(5920 U/mL)and carcinoembryonic antigen(23.7 ng/mL)levels.Magnetic resonance imaging of the pancreas revealed an approximately 3 cm ill-defined space-occupying lesion in the inferior aspect of the head,with severe encasement of the superior mesenteric artery.Pancreatic ductal adenocarcinoma was confirmed after pathological examination of specimens obtained by EUS-TS using the fanning method.Interventions and outcomes:The following day,the patient experienced severe abdominal pain with high amylase(265 U/L)and lipase(1173 U/L)levels.Computed tomography of the abdomen revealed edematous wall thickening of the second portion of the duodenum with adjacent fluid collections and a suspicious leak from either the distal common bile duct or the main pancreatic duct in the head.Endoscopic retrograde cholangiopancreatography revealed dye leakage in the head of the main pancreatic duct.Therefore,a 5F 7 cm linear plastic stent was deployed into the pancreatic duct to divert the pancreatic juice.The patient’s abdominal pain improved immediately after pancreatic stent insertion,and amylase and lipase levels normalized within a week.Neoadjuvant chemotherapy was then initiated.CONCLUSION Using the fanning method in EUS-TS can inadvertently cause damage to the pancreatic duct and may lead to clinically significant pancreatitis.Placing a pancreatic stent may immediately resolve acute pancreatitis and shorten the waiting time for curative therapy.When using the fanning method during EUSTS,ductal structures should be excluded to prevent pancreatic ductal leakage.
文摘BACKGROUND Resection of hepatic metastasis from neuroendocrine tumors(NETs)improves quality of life and prolongs 5-year survival.Ablation can be utilized with surgery to achieve complete resection.Although several studies report long-term out-comes for patients undergoing ablation,none have explored perioperative effects of ablation in patients with metastatic NETs.AIM To determine if intra-operative ablation during hepatectomy increases risk of ad-verse outcomes such as surgical site infections(SSIs),bleeding,and bile leak.METHODS A retrospective analysis of the hepatectomy National Surgical Quality Impro-vement Program database from 2015-2019 was performed to determine the odds of SSIs,bile leaks,or bleeding in patients undergoing intraoperative ablation when compared to hepatectomy alone.RESULTS Of the 966 patients included in the study,298(30.9%)underwent ablation during hepatectomy.There were 78(11.7%)patients with SSIs in the hepatectomy alone group and 39(13.1%)patients with a SSIs in the hepatectomy with ablation group.Bile leak occurred in 41(6.2%)and 14(4.8%)patients in the two groups,respec-tively;bleeding occurred in 117(17.5%)and 33(11.1%),respectively.After con-trolling for confounding variables,ablation did not increase risk of SSI(P=0.63),bile leak(P=0.34)or bleeding(P=0.07)when compared to patients undergoing resection alone on multivariate analysis.CONCLUSION Intraoperative ablation with hepatic resection for NETs is safe in the perioperative period without significant increased risk of infection,bleeding,or bile leak.Surgeons should utilize this modality when appropriate to a-chieve optimal disease control and outcomes.
文摘BACKGROUND Bile leakage is a common and serious complication of open hepatectomy for the treatment of biliary tract cancer.AIM To evaluate the incidence,risk factors,and management of bile leakage after open hepatectomy in patients with biliary tract cancer.METHODS We retrospectively analyzed 120 patients who underwent open hepatectomy for biliary tract cancer from February 2018 to February 2023.Bile leak was defined as bile drainage from the surgical site or drain or the presence of a biloma on imaging.The incidence,severity,timing,location,and treatment of the bile leaks were recorded.The risk factors for bile leakage were analyzed using univariate and multivariate logistic regression analyses.RESULTS The incidence of bile leak was 16.7%(20/120),and most cases were grade A(75%,15/20)according to the International Study Group of Liver Surgery classification.The median time of onset was 5 d(range,1-14 d),and the median duration was 7 d(range,2-28 d).The most common location of bile leakage was the cut surface of the liver(70%,14/20),followed by the anastomosis site(25%,5/20)and the cystic duct stump(5%,1/20).Most bile leaks were treated conservatively with drainage,antibiotics,and nutritional support(85%,17/20),whereas some required endoscopic retrograde cholangiopancreatography with stenting(10%,2/20)or percutaneous transhepatic cholangiography with drainage(5%,1/20).Risk factors for bile leakage include male sex,hepatocellular carcinoma,major hepatectomy,blood loss,and blood transfusion.CONCLUSION Bile leakage is a frequent complication of open hepatectomy for biliary tract cancer.However,most cases are mild and can be conservatively managed.Male sex,hepatocellular carcinoma,major hepatectomy,blood loss,and blood transfusion were associated with an increased risk of bile leak.
基金Supported by the Fourth Batch of Self-funded Projects of the Baise Scientific Research and Technology Development Plan in 2022,No.20223734the 2023 National Key Research and Development Program:Research on Susceptibility Mechanisms and Screening Key Technologies for Major Viral Diseases,No.2023YFC2605400.
文摘BACKGROUND Surgical resection is the cornerstone treatment for colorectal cancer.Rapid rehabilitation care predicated on evidence-based medical theory aims to improve postoperative nursing care,subsequently reducing the physical and mental traumatic stress response and helping patients who undergo surgery recover rapidly.AIM To assess the effect of rapid rehabilitation care on clinical outcomes,including overall postoperative complications,anastomotic leaks,wound infections,and intestinal obstruction in patients with colorectal cancer.METHODS We searched the PubMed,Web of Science,Embase,Elsevier Science Direct,and Springer Link databases from January 1,2010,to January 1,2024,to screen eligible studies on rapid rehabilitation care among patients who underwent colorectal cancer surgery.Patients were screened based on the inclusion and exclusion criteria.RevMan 5.4 software was used for statistical analysis of the data.RESULTS Twelve studies were enrolled,which included 2420 patients.The results showed that rapid rehabilitation care decreased the incidence of overall postoperative complications(OR:0.44,95%CI:0.26–0.74,P=0.002),anastomotic leaks(OR:0.68,95%CI:0.41–1.12,P=0.13),wound infections(OR:0.45,95%CI:0.29–0.72,P=0.0007),and intestinal obstruction(OR:0.54,95%CI:0.34–0.86,P=0.01)compared to conventional care.Further trials and studies are needed to confirm these results.CONCLUSION Rapid rehabilitation care decreased the occurrence of postoperative complications,anastomotic leaks,wound infections,and intestinal obstruction compared to conventional care in patients who underwent colorectal surgery.Therefore,promoting the application of rapid rehabilitation care in clinical practice cannot be overemphasized.
基金Supported by the Natural Science Foundation of Gansu Province,China,No.21JR1RA075 and No.22JR5RA895and Lanzhou Science and Technology Program,China,No.2021-1-109.
文摘BACKGROUND The neutrophil-to-lymphocyte ratio(NLR),a composite inflammatory biomarker,is associated with the prognosis in patients with colorectal tumors.However,whether the NLR can be used as a predictor of symptomatic postoperative ana-stomotic leakage(AL)in elderly patients with colon cancer is unclear.AIM To assess the role of the NLR in predicting the occurrence of symptomatic AL after surgery in elderly patients with colon cancer.METHODS Data from elderly colon cancer patients who underwent elective radical colectomy with anastomosis at three centers between 2018 and 2022 were retrospectively analyzed.Receiver operating characteristic curve analysis was performed to determine the best predictive cutoff value for the NLR.Twenty-two covariates were matched using a 1:1 propensity score matching method,and univariate and multivariate logistic regression analyses were used to determine risk factors for the development of postoperative AL.RESULTS Of the 577 patients included,36(6.2%)had symptomatic AL.The optimal cutoff value of the NLR for predicting AL was 2.66.After propensity score matching,the incidence of AL was significantly greater in the≥2.66 NLR subgroup than in the<2.66 NLR subgroup(11.5%vs 2.5%;P=0.012).Univariate logistic regression analysis revealed statistically significant correlations between blood transfusion intraoperatively and within 2 d postoper-atively,preoperative albumin concentration,preoperative prognostic nutritional index,and preoperative NLR and AL occurrence(P<0.05);multivariate logistic regression analysis revealed that an NLR≥2.66[odds ratio(OR)=5.51;95%confidence interval(CI):1.50-20.26;P=0.010]and blood transfusion intraoperatively and within 2 d postoperatively(OR=2.52;95%CI:0.88-7.25;P=0.049)were risk factors for the occurrence of symptomatic AL.CONCLUSION A preoperative NLR≥2.66 and blood transfusion intraoperatively and within 2 d postoperatively are associated with a higher incidence of postoperative symptomatic AL in elderly patients with colon cancer.The preoperative NLR has predictive value for postoperative symptomatic AL after elective surgery in elderly patients with colon cancer.
文摘Laparoscopic colectomy with ileorectal anastomosis may be beneficial for patients with slow transit constipation who do not respond to conservative treatment,particularly if the superior rectal artery(SRA)is preserved.Several important concerns have been addressed in this commentary.It is important to first go over the definition of surgical procedure as it is used in this text.Second,the current study lacked a control group that had SRA preservation.Thirdly,it would be best to use a prospective,randomized controlled study.Lastly,a description of the mesenteric defect’s state following a laparoscopic colectomy is necessary.
文摘Purpose: This article investigates the critical importance of integrating surgeons’ direct input into the development of innovative technologies that address gaps in surgical care, including those aimed at reducing anastomotic leaks (AL), a major complication in gastrointestinal surgery. While traditional quantitative research methods are prevalent, they often overlook the invaluable insights of the surgeons who manage these complications firsthand. Subjects and Methods: This study employs a qualitative approach, utilizing semi-structured interviews with 40 surgeons from various specialties, including general, bariatric, colorectal, trauma, hepato-biliary, and thoracic surgery. The interviews were designed to probe the needs of surgeons, challenges currently faced, and gaps in clinical practice, research, and technology for detection and/or management of AL. The data were analyzed using thematic analysis, which revealed significant gaps in current technologies for early detection and prevention of leaks. Results: Surgeons expressed strong interest in FluidAI’s Stream™ Platform, a non-invasive medical device designed to monitor postoperative drainage fluid in real-time, providing continuous data on AL risk. The ability of this platform to offer early prediction through pH and electrical conductivity analysis was particularly appealing to participants, who emphasized the importance of timely interventions in improving patient outcomes. The study’s findings highlight not only the clinical challenges but also the emotional toll that AL takes on surgeons, underlining the need for innovations that are both data-driven and humanistic. Conclusion: By centering surgeons’ perspectives, this research advocates for a human-centered approach to technological advancement, ensuring that new tools are both clinically effective and aligned with the real-world needs of surgical practitioners.
文摘BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation.Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features.Despite the advances in experimental protocols and techniques,designing a high-quality study is still challenging for the investigators as there is a plethora of different models used.AIM To review current state of the art for experimental protocols in high-risk anastomosis in rats.METHODS This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.To identify eligible studies,a comprehensive literature search was performed in the electronic databases PubMed(MEDLINE)and Scopus,covering the period from conception until 18 October 2023.RESULTS From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis.Methods of assessing anastomotic healing were extracted and were individually appraised.CONCLUSION Anastomotic healing studies have evolved over the last decades,but the findings are yet to be translated into human studies.There is a need for high-quality,well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.
文摘A widely used aortic valve bioprosthesis is susceptible to regurgitation between the sewing ring and the frame of the valve due to its relatively thin fabric coverage. In some cases this leak has been shown to resolve with administration of protamine, however, tension on this area from annular sutures placed in an asymmetric bicuspid valve annulus may exacerbate the defect.
基金Project supported by the National Natural Science Foundation of China(No.52036008)。
文摘Molten salt is often used for heat transfer and thermal energy storage in concentrated solar power.Molten salt leakage and migration is a significant issue in its application.Molten salt migration and solidification in thermal porous foundation materials through cracks are experimentally investigated.The impact of factors,including crack length and width,operation temperature,and leakage mass of molten salt,are studied through an experimental device modeling the leakage of the actual molten salt storage tank.Experimental results show that the crack width and length slightly affect the migration depth,but directly affect the shape of the agglomeration of solidified salt and porous foundation material.The most important factor affecting the migration depth of molten salt leaking through cracks is the tank operating temperature.The molten salt migration depth when the operating temperature is 500℃ is 95.8% higher than that with an operating temperature of 300℃.As the leakage molten salt mass reached 400 g,the average migration width increased by 23.6%,but the migration depth only increased by 5.2%.It is found that the foundation material temperatures after leakage accidents increase with an increase in the mass of leaked molten salt.
基金Supported by the Special Support Program for Cultivating High-level Talents in Guangdong Province(No.2019BT02H594)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0104)+3 种基金the National Natural Science Foundation of China(Nos.41876052,42076218,U1901217,91855101,41773039)the Guangdong Basic and Applied Basic Research Foundation(Nos.2022A1515011836,2021A1515110851)the Science and Technology Planning Project of Guangzhou(No.202201010230)the Special Research Assistant Program of Chinese Academy of Sciences to Junhui YU。
文摘The Zengmu Basin located in the shallow water area of the southern South China Sea,is rich in oil and gas resources,within which faults and mud-diapir are developed,but it is unknown whether oil and gas migrate to the seafloor surface.The newly collected multibeam data across the Zengmu Basin reveal a large number of depressions,with depths of 2-4 m,widths of several tens of meters,large distribution range of 1.8-8 km along survey line,up to~50 km,and their backscatter intensity(-26 dB)is much greater than that of the surrounding area(-38 dB).Combined with the developed mud-diapir and fracture structures,and abundant oil and gas resources within this basin,these depressions are presumed to be pockmarks.Furthermore,more than 110 mono-sized small circular pockmarks,with a depth of less than 1 m and a width of 5 m,are observed in an area of less than 0.03 km2,which are not obliterated by sediment infilling with high sedimentation rate,implying an existence of unit-pockmarks that are or recently were active.In addition,seismic profiles across the Zengmu Basin show characterization of upward migration of hydrocarbons,expressed as mud-diapir structures,bright spots in the shallow formation with characteristics of“low frequency increase and high frequency attenuation”.The subbottom profiles show the mud-diapir structures,as well as the gas-bearing blank zones beneath the seafloor.These features suggest large gas leaking and occurrence of large amounts of carbonate nodules on the seafloor.This indicates the complex and variable substrate type in the Zengmu Basin,while the area was once thought to be mainly silty sand and find sand.This is the first report on the discovery of pockmarks in the Zengmu Basin;it will provide basic information for submarine stability and marine engineering in China’s maritime boundaries.