With the advent of endoscopic retrograde cholangiopancreatography(ERCP)in the early 1970s,anatomic anomalies of the Vaterian system were described endoscopically[1].Although the occurrence is rare,the common bile duct...With the advent of endoscopic retrograde cholangiopancreatography(ERCP)in the early 1970s,anatomic anomalies of the Vaterian system were described endoscopically[1].Although the occurrence is rare,the common bile duct(CBD)and the pancreatic duct may fail to coalesce during embryologic development.This leads to double major papilla because both ducts open into the duodenum separately[1].In this way the cranial duct communicates with the CBD,while the caudal orifice communicates with the pancreatic duct[2].展开更多
The flow characteristics and cavitation effects of water passing throughsmall sharp-edged cylindrical orifices and valves of different shapes in water hydraulics areinvestigated. The test results using orifices with d...The flow characteristics and cavitation effects of water passing throughsmall sharp-edged cylindrical orifices and valves of different shapes in water hydraulics areinvestigated. The test results using orifices with different aspect ratios and different diametersshow that the flow coefficients in the case of non-cavitating flow are larger than that of flow inthe case of cavitation occurrence. The flow coefficients of flow with cavitation initially decreaseas Reynolds number increases and ultimately tend to be of constant values close to contractioncoefficient. Large aspect ratio has an effect of suppressing cavitation. The experimental resultsabout disc valves illustrate that the valves with sharp edge at large opening are less affected bycavitation than that at small opening. Throttle with triangle notch has better anti-cavitationability than that with square notch. The flowrate of the throttle with square notch is significantlyaffected by the flow direction or the flow passage shape.展开更多
In order to improve the baking temperature uniformity of the large ladle in steelmaking plants, the flame combustion characteristics of nozzles with different inner structures were numerically simulated with the finit...In order to improve the baking temperature uniformity of the large ladle in steelmaking plants, the flame combustion characteristics of nozzles with different inner structures were numerically simulated with the finite volume method code Fluent. The flow field and premixed combustion reaction inside and outside the nozzle with multiple gas orifices were exhibited. Meanwhile, the influences of the gas injecting angle and the number of gas orifices on temperature, velocity, and pressure fields were studied. The results show that the flame length and width at the rear of flame temperature field reach the maximum values in the nozzle with the gas injecting angle of 20° and 4 gas orifices for the control of premixed combustion inside the nozzle, which could provide better temperature uniformity in ladles. The length of the 1273 K isothermal surface is 4.89 m, and the cross-section area at 4 m away from the outlet of the nozzle is 0.13 m2. The pressure losses of different types of nozzles range from 112.2 to 169.4 Pa and decrease with the decrement in gas injecting angle and the number of gas orifices. The ladle bottom preheating temperature is increased by 320-360 K for the optimized nozzle. The inner surface temperature differences between wall and bottom of the ladle are less than 10%. There is good baking temperature uniformity after the application of optimum structurally designed nozzles.展开更多
Foam trays with porous submerged orifices endow bubbles uniformly distributed,which are considered attractive column internals to enhance the gas-liquid mass transfer process.However,its irregular orifice and complex ...Foam trays with porous submerged orifices endow bubbles uniformly distributed,which are considered attractive column internals to enhance the gas-liquid mass transfer process.However,its irregular orifice and complex gas-liquid flow make it lack pore-scale investigations concerning the transfer mechanism of dynamic bubbling.In this work,the actual porous structure of the foam tray is obtained based on micro computed tomography technology.The shape,dynamic,and mass transfer of rising bubbles at porous orifices are investigated using the volume of fluid and continue surface force model.The results demonstrate that the liquid encroaching on the gas channels causes the increasing orifices velocity,which makes the trailing bubble easily detach from the midst of the leading bubble and causes pairing coalescence.Additionally,we found that the central breakup regimes significantly improve the gas-liquid interface area and mass transfer efficiency.This discovery exemplifies the mechanism of mass transfer intensification for foam trays and serves to promote its further development.展开更多
BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are ne...BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are necessary.However,due to differences in race and sex,people’s body shapes vary.According to European guidelines,the patch should measure 10 cm×15 cm.If any part of the MPO is dissected,injury to the nerves,vascular network,or organs may occur during surgery,thereby leading to inguinal discomfort,pain,and seroma formation after surgery.Therefore,accurate localization and measurement of the boundary of the MPO are crucial for selecting the optimal patch for inguinal hernia repair.AIM To compare the size of the MPO measured on three-dimensional multislice spiral computed tomography(CT)with that measured via laparoscopy and explore the relevant factors influencing the size of the MPO.METHODS Clinical data from 74 patients who underwent laparoscopic tension-free inguinal hernia repair at the General Surgery Department of the First Affiliated Hospital of Anhui University of Science and Technology between September 2022 and July 2024 were collected and analyzed retrospectively.Transabdominal preperitoneal was performed.Sixty-four males and 10 females,with an average age of 58.30±12.32 years,were included.The clinical data of the patients were collected.The boundary of the MPO was measured on three-dimensional CT images before surgery and then again during transabdominal preperitoneal.All the preoperative and intraoperative data were analyzed via paired t-tests.A t-test was used for comparisons of age,body mass index,and sex between the groups.In the comparative analysis,a P value less than 0.05 indicated a significant difference.RESULTS The boundaries of the MPO on 3-dimensional CT images measured 7.05±0.47 cm and 6.27±0.61 cm,and the area of the MPO was 19.54±3.33 cm^(2).The boundaries of the MPO during surgery were 7.18±0.51 cm and 6.17±0.40 cm.The errors were not statistically significant.However,the intraoperative BD(the width of the MPO,P=0.024,P<0.05)and preoperative AC(the length of the MPO,P=0.045,P<0.05)significantly differed according to sex.The AC and BD measurements before and during surgery were not significantly different according to age,body mass index,hernia side or hernia type(P>0.05).CONCLUSION The application of this technology can aid in determining the most appropriate dissection range and patch size.展开更多
Zhang et al highlighted the importance of three-dimensional computed tomography reconstruction and myopectineal orifice measurement in laparo-scopic inguinal hernia repair.Their findings indicated that preoperative th...Zhang et al highlighted the importance of three-dimensional computed tomography reconstruction and myopectineal orifice measurement in laparo-scopic inguinal hernia repair.Their findings indicated that preoperative three-dimensional computed tomography provides precise anatomical mapping,allowing surgeons to optimize mesh selection and reduce recurrence rates.Recent studies have corroborated these results,demonstrating that a personalized mesh size based on myopectineal orifice dimensions leads to superior patient outcomes.This article discusses the clinical significance of these advancements in hernia surgery,and emphasises their impact on improving precision,reducing complic-ations,and optimizing surgical planning.展开更多
Gas rapid unloading(GRU)is an innovative technology for ore comminution.Increasing the production of fine powder in each ore grinding cycle is vital for scaling up the GRU method to industrial applications.This study ...Gas rapid unloading(GRU)is an innovative technology for ore comminution.Increasing the production of fine powder in each ore grinding cycle is vital for scaling up the GRU method to industrial applications.This study utilizes laboratory experiments to demon-strate that moderately reducing the orifice size significantly enhances pulverization and increases fine particle yield.Numerical simulations suggest that smaller orifices improve pulverization by increasing jet speed,reducing pressure drop,and creating a larger pressure difference inside and outside the unloading orifice.The orifice size should be optimized based on feed size to ensure efficient ore discharge.Reducing the unloading orifice size improves GRU grinding efficiency and energy use,offering guidance for the design of ore discharge ports in future industrial-scale equipment.展开更多
BACKGROUND Low-grade appendiceal mucinous neoplasms(LAMNs)are a class of histolo-gically well-differentiated adenomas that can proliferate outside the appendix in the form of malignant tumours,resulting in the accumul...BACKGROUND Low-grade appendiceal mucinous neoplasms(LAMNs)are a class of histolo-gically well-differentiated adenomas that can proliferate outside the appendix in the form of malignant tumours,resulting in the accumulation of external appen-diceal mucus.They may present as an extra-appendiceal mass-like bulge,mucus or polypoid tissue at the appendiceal orifice,or even with abdominal dissem-ination.The surgical approach is usually appendectomy,ileocecal resection or right hemicolectomy.It is essential to raise awareness of LAMNs and choose an appropriate treatment.CASE SUMMARY A 68-year-old man underwent a routine physical examination at our hospital on May 17,2022.The patient had no symptoms of abdominal pain,bloating,or weight loss,and his tumour marker levels were normal.The faecal occult blood test was negative,and no abnormalities were identified on physical examination.Colonoscopy revealed a submucosal protrusion at the appendiceal orifice.During endoscopic ultrasound,uneven echoes were observed in the appendix cavity.A contrast-enhanced computed tomography scan of the abdomen revealed a nodular thickening at the base of the appendix,with a diameter of approximately 1 cm.When all the examination results were considered,we suspected the lesion to be an appendiceal mucinous tumour.Laparoscopic surgery was performed using the double purse-string suture method.Postoperative pathology suggested a low-grade mucinous cystadenoma of the appendix with no involvement of the margins.A repeat colonoscopy 18 months after surgery revealed no significant abnormality at the appendiceal orifice.A contrast-enhanced computed tomography scan of the abdomen suggested only postoperative changes.CONCLUSION This study describes a case of LAMN that was treated by resecting the mass at the appendiceal orifice via the double purse-string suture technique and provides new insights on the diagnosis and treatment of LAMNs.展开更多
BACKGROUND Secure transluminal closure remains a fundamental barrier to endoscopic surgery.It has been reported that through-the-scope clips were used to secure the incision of the gallbladder during natural orifice t...BACKGROUND Secure transluminal closure remains a fundamental barrier to endoscopic surgery.It has been reported that through-the-scope clips were used to secure the incision of the gallbladder during natural orifice transluminal endoscopic cholecystolithotomy and were left in the body post-operation.The over-the-scope clip(OTSC)is favored for its rapid deployment and strong anchoring capabilities.Nevertheless,OTSCs are difficult to remove once implanted.The Senscure Biotechnology in China has developed a detachable over-the-scope clip(D-OTSC)for this purpose.Here,we utilized the D-OTSC to successfully close a full-thickness sigmoid defect exceeding 1 cm in diameter.Subsequently,the clip was completely removed postoperatively,yielding favorable clinical outcomes.CASE SUMMARY We present the case of a 51-year-old female patient who underwent natural orifice transluminal endoscopic cholecystolithotomy.The sigmoid incision was closed using a D-OTSC.Postoperative recovery was uneventful,with no abdominal infection or bleeding.The D-OTSC was subsequently removed via enteroscopy in the outpatient department one month later.CONCLUSION The utilization of D-OTSC presents a viable option for closing colonic mucosal incisions ranging from 1 cm to 2 cm.展开更多
The design of fuel nozzle orifices at micrometer scales is crucial for generating desired fuel spray patterns, and consequently optimizing fuel combustion and emission in internal combustion engines. Although there ha...The design of fuel nozzle orifices at micrometer scales is crucial for generating desired fuel spray patterns, and consequently optimizing fuel combustion and emission in internal combustion engines. Although there have been several recent advancements in the characterization of orifice internal geometries, quantitative studies on the orifice internal wall surface characteristics are still challeges due to the lack of effective measuring methods. A new method for quantifying the internal wall surface characteristics of fuel nozzle micro-orifices is presented in this study to achieve a better understanding and prediction of spray characteristics: Firstly, by using the synchrotron X-ray micro CT technology, a three-dimensional digital model of the fuel nozzle tip was constructed. Secondly, a data post-processing technique was then applied to unfold the orifice internal wall surface to a flat base plane. Finally, the conventional surface characteristic quantification techniques can be used to evaluate the wall surface characteristics. Two diesel nozzles with identical orifice geometry design but different hydraulic grinding time were measured using this method. One nozzle was hydro-ground for 2 s while the other was not. The internal wall surfaces of the two orifices were successfully unfolded to base planes and their surface characteristics were respectively analyzed. The surface fluctuation data were perfectly reproduced by a Gaussian distribution function. The standard deviations of the distribution demonstrate the fluctuation range and the distribution of the entire surface fluctuation profiles. As an effective parameter to evaluate the hydraulic grinding process and the spray behaviors, the standard deviation was considered feasible for the analysis of the orifice internal wall surface characteristics.展开更多
The present work deals with the computation of the gas-solid two-phase flow pressure drop across thin and thick orifices for a vertically downward flow configuration at the higher limits of a dilute phase flow situati...The present work deals with the computation of the gas-solid two-phase flow pressure drop across thin and thick orifices for a vertically downward flow configuration at the higher limits of a dilute phase flow situation(0.01≤αs,in≤0.10).The Eulerian-Eulerian(two-fluid)model has been used in conjunction with the kinetic theory of granular flow with a four-way coupling approach.The validation of the solution process has been performed by comparing the computational result with the existing experimental data.It is observed that the two-phase flow pressure drop across the orifice increases with an increase in the thickness of the orifice,and the effect is more prominent at higher solid loading.The pressure drop is found to increase with an increase in the solid volume fraction.An increase in the Reynolds number or the area ratio increases the pressure drop.An increase in the size of the particles reduces the pressure drop across the orifice at both small and relatively large solid volume fractions.Finally,a two-phase multiplier has been proposed in terms of the relevant parameters,which can be useful to evaluate the gas-solid two-phase flow pressure drop across the orifice and can subsequently help to improve the system performance.展开更多
A steady,axisymmetric vortex at an entrance of horizontal orifice,with an air- core,was formed within a special apparatus.The tangential,radial and axial velocities and their fluctuation strengths were measured in det...A steady,axisymmetric vortex at an entrance of horizontal orifice,with an air- core,was formed within a special apparatus.The tangential,radial and axial velocities and their fluctuation strengths were measured in detail.The results were given in terms of formulas or curves.It shows a clear picture of vortex flow-field.展开更多
BACKGROUND The management of polyps involving the appendiceal orifice(AO)presents notable challenges.Endoscopic resection is frequently hindered by operational complexities,a heightened risk of incomplete removal,and ...BACKGROUND The management of polyps involving the appendiceal orifice(AO)presents notable challenges.Endoscopic resection is frequently hindered by operational complexities,a heightened risk of incomplete removal,and an elevated risk of procedural complications,including appendicitis.Conversely,surgical resection may entail unnecessary excision of intestinal segments,leading to potential morbidity.CASE SUMMARY Here,we reported two patients who presented with polyps deeply situated within the AO,with indistinct boundaries making it challenging to ensure completeness using traditional endoscopic resection.To overcome these challenges,we em-ployed combined endo-laparoscopic surgery(CELS),achieving curative resection without postoperative complications.CONCLUSION The application of CELS in managing polyps involving the AO is emerging as a safe and effective treatment modality.展开更多
BACKGROUND Natural orifice specimen extraction surgery(NOSES)has emerged as a promising alternative compared to conventional laparoscopic-assisted total gastrectomy(LATG)for treating gastric cancer(GC).However,evidenc...BACKGROUND Natural orifice specimen extraction surgery(NOSES)has emerged as a promising alternative compared to conventional laparoscopic-assisted total gastrectomy(LATG)for treating gastric cancer(GC).However,evidence regarding the efficacy and safety of NOSES for GC surgery is limited.This study aimed to compare the safety and feasibility,in addition to postoperative complications of NOSES and LATG.METHODS Dual circular staplers were used in Roux-en-Y digestive tract reconstruction for transvaginal specimen extraction LATG,and its outcomes were compared with LATG in a cohort of 51 GC patients with tumor size≤5 cm.The study was conducted from May 2018 to September 2020,and patients were categorized into the NOSES group(n=22)and LATG group(n=29).Perioperative parameters were compared and analyzed,including patient and tumor characteristics,postoperative outcomes,and anastomosis-related complications,postoperative hospital stay,the length of abdominal incision,difference in tumor type,postoperative complications,and postoperative survival.RESULTS Postoperative exhaust time,operation duration,mean postoperative hospital stay,length of abdominal incision,number of specific staplers used,and Brief Illness Perception Questionnaire score were significant in both groups(P<0.01).In the NOSES group,the postoperative time to first flatus,mean postoperative hospital stay,and length of abdominal incision were significantly shorter than those in the LATG group.Patients in the NOSES group had faster postoperative recovery,and achieved abdominal minimally invasive incision that met aesthetic requirements.There were no significant differences in gender,age,tumor type,postoperative complications,and postoperative survival between the two groups.CONCLUSION The application of dual circular staplers in Roux-en-Y digestive tract reconstruction combined with NOSES gastrectomy is safe and convenient.This approach offers better short-term outcomes compared to LATG,while long-term survival rates are comparable to those of conventional laparoscopic surgery.展开更多
BACKGROUND At present,laparoscopic cholecystectomy(LC)is the main surgical treatment for gallstones.But,after gallbladder removal,there are many complications.Therefore,it is hoped to remove stones while preserving th...BACKGROUND At present,laparoscopic cholecystectomy(LC)is the main surgical treatment for gallstones.But,after gallbladder removal,there are many complications.Therefore,it is hoped to remove stones while preserving the function of the gallbladder,and with the development of endoscopic technology,natural orifice transluminal endoscopic surgery came into being.AIM To compare the quality of life,perioperative indicators,adverse events after LC and transgastric natural orifice transluminal endoscopic gallbladder-preserving surgery(EGPS)in patients with gallstones.METHODS Patients who were admitted to The First Affiliated Hospital of Xinjiang Medical University from 2020 to 2022 were retrospectively collected.We adopted propen-sity score matching(1:1)to compare EGPS and LC patients.RESULTS A total of 662 cases were collected,of which 589 cases underwent LC,and 73 cases underwent EGPS.Propensity score matching was performed,and 40 patients were included in each of the groups.In the EGPS group,except the gastr-ointestinal defecation(P=0.603),the total score,physical well-being,mental well-being,and gastrointestinal digestion were statistically significant compared with the preoperative score after surgery(P<0.05).In the LC group,except the mental well-being,the total score,physical well-being,gastrointestinal digestion,the gastrointestinal defecation was statistically significant compared with the preoperative score after surgery(P<0.05).When comparing between groups,gastrointestinal defecation had significantly difference(P=0.002)between the two groups,there was no statistically significant difference in the total postoperative score and the other three subscales.In the surgery duration,hospital stay and cost,LC group were lower than EGPS group.The recurrence factors of gallstones after EGPS were analyzed:and recurrence was not correlated with gender,age,body mass index,number of stones,and preoperative score.CONCLUSION Whether EGPS or LC,it can improve the patient’s symptoms,and the EGPS has less impact on the patient’s defecation.It needed to,prospective,multicenter,long-term follow-up,large-sample related studies to prove.展开更多
Booming low-power electric propulsion systems require 1–2 A hollow cathodes.Such cathodes are expected to go through more frequent ignitions in the low orbit,but the impact of cyclic ignitions on such 1–2 A barium t...Booming low-power electric propulsion systems require 1–2 A hollow cathodes.Such cathodes are expected to go through more frequent ignitions in the low orbit,but the impact of cyclic ignitions on such 1–2 A barium tungsten hollow cathodes with a heater was not clear.In this study,a 12,638-cyclic ignition test and a 6,000-hour-long life test on two identical cathodes were carried out.The discharge voltage of the cathode and the erosion of the orifice after cyclic ignition were all larger than that of the cathode after stable operation.This indicated that the impact of cycle ignition on the discharge performance of a low current BaO-W cathode with a heater was higher than that of stable operation.The results of the ion energy distribution function measured during the ignition period indicated that the main reason for the orifice expansion was ion bombardment.Therefore,it was necessary to pay attention to the number of ignitions for the lifetime of this kind of cathode.展开更多
BACKGROUND Guidewire slippage into the peritoneal cavity during clinical operations is extremely rare.Therefore,this paper aims to report a successful case of guidewire removal using transgastric natural orifice trans...BACKGROUND Guidewire slippage into the peritoneal cavity during clinical operations is extremely rare.Therefore,this paper aims to report a successful case of guidewire removal using transgastric natural orifice transluminal endoscopic surgery(NOTES).The goal is to enhance physicians'understanding of the management plan for this unique scenario and provide a valuable reference for clinical practice.CASE SUMMARY A 64-year-old man presented with abdominal distension and was diagnosed with cirrhosis combined with massive ascites.To proceed with treatment,the patient underwent ultrasound-guided peritoneal puncture and underwent catheterization and drainage.Unfortunately,a 0.035-inch guidewire slipped into the abdominal cavity during the procedure.Following a comprehensive evaluation and consultation by a multidisciplinary team,the guidewire was successfully removed using NOTES.CONCLUSION This case highlights the potential consideration of transgastric NOTES removal when encountering a foreign body,such as a guidewire,within the abdominal cavity.展开更多
Objective: To explore the value of hand-sewn anastomosis in totally laparoscopic radical resection of colorectal cancr with transanal specimen extraction. Methods: A retrospective descriptive study was conducted. Clin...Objective: To explore the value of hand-sewn anastomosis in totally laparoscopic radical resection of colorectal cancr with transanal specimen extraction. Methods: A retrospective descriptive study was conducted. Clinical data of 54 patients with colorectal cancer who underwent totally laparoscopic transrectal specimen extraction surgery between January 2019 and December 2023 at the Department of Gastrointestinal Surgery, Bayannur City Hospital, were collected. All patients underwent digestive tract reconstruction using hand-sewn end-to-end colonic or rectal anastomosis. Intraoperative and postoperative general conditions, pathological results, complications, and follow-up data were analyzed. Results: Among the 54 cases, 37 were male, and 17 were female. The cases included 26 sigmoid colon cancers, 27 high rectal cancers, and 1 descending colon cancer. All patients underwent totally laparoscopic radical resection of colorectal cancer with transrectal specimen extraction. The average surgical duration was 187.87 ± 61.36 minutes, with 16 (14-19) minutes required for hand-sewn anastomosis. Intraoperative blood loss was 16 (10-200) mL, with no conversions to open surgery or blood transfusions. Postoperative outcomes included first flatus time of 1 (1-3) day, liquid diet resumption on 2 (2-3) days, postoperative Visual Analog Scale (VAS) pain score of 2 (2-3), and hospital stay duration of 8 (7-9) days. The total hospitalization cost was 41,011 (25,655-148,589) Chinese yuan, with an average cost of 42,558.81 ± 8,599.30 Chinese yuan after excluding three cases with complications. Pathological examination revealed all cases to be adenocarcinomas: 20 well-differentiated, 32 moderately differentiated, and 2 poorly differentiated. All resection margins were negative. An average of 16.85 ± 7.97 lymph nodes were dissected. Pathological staging included 18 stage I, 17 stage II, and 19 stage III cases. Postoperative complications included 2 cases of anastomotic leakage (3.7%), 1 case of anastomotic stricture (1.8%), and 1 case of pulmonary infection (1.8%). No unplanned readmissions or postoperative deaths occurred during the 30-day follow-up period. Conclusion: Hand-sewn anastomosis in totally laparoscopic radical resection of colorectal cancer with transanal specimen extraction is safe and feasible.展开更多
文摘With the advent of endoscopic retrograde cholangiopancreatography(ERCP)in the early 1970s,anatomic anomalies of the Vaterian system were described endoscopically[1].Although the occurrence is rare,the common bile duct(CBD)and the pancreatic duct may fail to coalesce during embryologic development.This leads to double major papilla because both ducts open into the duodenum separately[1].In this way the cranial duct communicates with the CBD,while the caudal orifice communicates with the pancreatic duct[2].
基金This project is supported by National Natural Science Foundation of China(No.59975031).
文摘The flow characteristics and cavitation effects of water passing throughsmall sharp-edged cylindrical orifices and valves of different shapes in water hydraulics areinvestigated. The test results using orifices with different aspect ratios and different diametersshow that the flow coefficients in the case of non-cavitating flow are larger than that of flow inthe case of cavitation occurrence. The flow coefficients of flow with cavitation initially decreaseas Reynolds number increases and ultimately tend to be of constant values close to contractioncoefficient. Large aspect ratio has an effect of suppressing cavitation. The experimental resultsabout disc valves illustrate that the valves with sharp edge at large opening are less affected bycavitation than that at small opening. Throttle with triangle notch has better anti-cavitationability than that with square notch. The flowrate of the throttle with square notch is significantlyaffected by the flow direction or the flow passage shape.
文摘In order to improve the baking temperature uniformity of the large ladle in steelmaking plants, the flame combustion characteristics of nozzles with different inner structures were numerically simulated with the finite volume method code Fluent. The flow field and premixed combustion reaction inside and outside the nozzle with multiple gas orifices were exhibited. Meanwhile, the influences of the gas injecting angle and the number of gas orifices on temperature, velocity, and pressure fields were studied. The results show that the flame length and width at the rear of flame temperature field reach the maximum values in the nozzle with the gas injecting angle of 20° and 4 gas orifices for the control of premixed combustion inside the nozzle, which could provide better temperature uniformity in ladles. The length of the 1273 K isothermal surface is 4.89 m, and the cross-section area at 4 m away from the outlet of the nozzle is 0.13 m2. The pressure losses of different types of nozzles range from 112.2 to 169.4 Pa and decrease with the decrement in gas injecting angle and the number of gas orifices. The ladle bottom preheating temperature is increased by 320-360 K for the optimized nozzle. The inner surface temperature differences between wall and bottom of the ladle are less than 10%. There is good baking temperature uniformity after the application of optimum structurally designed nozzles.
基金grateful for the financial support from the National Natural Science Foundation of China(Grant No.22178249).
文摘Foam trays with porous submerged orifices endow bubbles uniformly distributed,which are considered attractive column internals to enhance the gas-liquid mass transfer process.However,its irregular orifice and complex gas-liquid flow make it lack pore-scale investigations concerning the transfer mechanism of dynamic bubbling.In this work,the actual porous structure of the foam tray is obtained based on micro computed tomography technology.The shape,dynamic,and mass transfer of rising bubbles at porous orifices are investigated using the volume of fluid and continue surface force model.The results demonstrate that the liquid encroaching on the gas channels causes the increasing orifices velocity,which makes the trailing bubble easily detach from the midst of the leading bubble and causes pairing coalescence.Additionally,we found that the central breakup regimes significantly improve the gas-liquid interface area and mass transfer efficiency.This discovery exemplifies the mechanism of mass transfer intensification for foam trays and serves to promote its further development.
基金Supported by the 2022 Provincial Quality Engineering Project for Higher Education Institutions,No.2022sx031the 2023 Provincial Quality Engineering Project for Higher Education Institutions,No.2023jyxm1071.
文摘BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are necessary.However,due to differences in race and sex,people’s body shapes vary.According to European guidelines,the patch should measure 10 cm×15 cm.If any part of the MPO is dissected,injury to the nerves,vascular network,or organs may occur during surgery,thereby leading to inguinal discomfort,pain,and seroma formation after surgery.Therefore,accurate localization and measurement of the boundary of the MPO are crucial for selecting the optimal patch for inguinal hernia repair.AIM To compare the size of the MPO measured on three-dimensional multislice spiral computed tomography(CT)with that measured via laparoscopy and explore the relevant factors influencing the size of the MPO.METHODS Clinical data from 74 patients who underwent laparoscopic tension-free inguinal hernia repair at the General Surgery Department of the First Affiliated Hospital of Anhui University of Science and Technology between September 2022 and July 2024 were collected and analyzed retrospectively.Transabdominal preperitoneal was performed.Sixty-four males and 10 females,with an average age of 58.30±12.32 years,were included.The clinical data of the patients were collected.The boundary of the MPO was measured on three-dimensional CT images before surgery and then again during transabdominal preperitoneal.All the preoperative and intraoperative data were analyzed via paired t-tests.A t-test was used for comparisons of age,body mass index,and sex between the groups.In the comparative analysis,a P value less than 0.05 indicated a significant difference.RESULTS The boundaries of the MPO on 3-dimensional CT images measured 7.05±0.47 cm and 6.27±0.61 cm,and the area of the MPO was 19.54±3.33 cm^(2).The boundaries of the MPO during surgery were 7.18±0.51 cm and 6.17±0.40 cm.The errors were not statistically significant.However,the intraoperative BD(the width of the MPO,P=0.024,P<0.05)and preoperative AC(the length of the MPO,P=0.045,P<0.05)significantly differed according to sex.The AC and BD measurements before and during surgery were not significantly different according to age,body mass index,hernia side or hernia type(P>0.05).CONCLUSION The application of this technology can aid in determining the most appropriate dissection range and patch size.
文摘Zhang et al highlighted the importance of three-dimensional computed tomography reconstruction and myopectineal orifice measurement in laparo-scopic inguinal hernia repair.Their findings indicated that preoperative three-dimensional computed tomography provides precise anatomical mapping,allowing surgeons to optimize mesh selection and reduce recurrence rates.Recent studies have corroborated these results,demonstrating that a personalized mesh size based on myopectineal orifice dimensions leads to superior patient outcomes.This article discusses the clinical significance of these advancements in hernia surgery,and emphasises their impact on improving precision,reducing complic-ations,and optimizing surgical planning.
基金financially supported by the National Natural Science Foundation of China(No.51934001)。
文摘Gas rapid unloading(GRU)is an innovative technology for ore comminution.Increasing the production of fine powder in each ore grinding cycle is vital for scaling up the GRU method to industrial applications.This study utilizes laboratory experiments to demon-strate that moderately reducing the orifice size significantly enhances pulverization and increases fine particle yield.Numerical simulations suggest that smaller orifices improve pulverization by increasing jet speed,reducing pressure drop,and creating a larger pressure difference inside and outside the unloading orifice.The orifice size should be optimized based on feed size to ensure efficient ore discharge.Reducing the unloading orifice size improves GRU grinding efficiency and energy use,offering guidance for the design of ore discharge ports in future industrial-scale equipment.
基金Supported by Jinhua City Science and Technology Plan Projects“Improve the Polarization of Cancer-related Fatigue:Clinical Efficacy Study”,No.2018-4-049.
文摘BACKGROUND Low-grade appendiceal mucinous neoplasms(LAMNs)are a class of histolo-gically well-differentiated adenomas that can proliferate outside the appendix in the form of malignant tumours,resulting in the accumulation of external appen-diceal mucus.They may present as an extra-appendiceal mass-like bulge,mucus or polypoid tissue at the appendiceal orifice,or even with abdominal dissem-ination.The surgical approach is usually appendectomy,ileocecal resection or right hemicolectomy.It is essential to raise awareness of LAMNs and choose an appropriate treatment.CASE SUMMARY A 68-year-old man underwent a routine physical examination at our hospital on May 17,2022.The patient had no symptoms of abdominal pain,bloating,or weight loss,and his tumour marker levels were normal.The faecal occult blood test was negative,and no abnormalities were identified on physical examination.Colonoscopy revealed a submucosal protrusion at the appendiceal orifice.During endoscopic ultrasound,uneven echoes were observed in the appendix cavity.A contrast-enhanced computed tomography scan of the abdomen revealed a nodular thickening at the base of the appendix,with a diameter of approximately 1 cm.When all the examination results were considered,we suspected the lesion to be an appendiceal mucinous tumour.Laparoscopic surgery was performed using the double purse-string suture method.Postoperative pathology suggested a low-grade mucinous cystadenoma of the appendix with no involvement of the margins.A repeat colonoscopy 18 months after surgery revealed no significant abnormality at the appendiceal orifice.A contrast-enhanced computed tomography scan of the abdomen suggested only postoperative changes.CONCLUSION This study describes a case of LAMN that was treated by resecting the mass at the appendiceal orifice via the double purse-string suture technique and provides new insights on the diagnosis and treatment of LAMNs.
基金Supported by Natural Science Foundation of Fujian Province,China,No.2021J01545.
文摘BACKGROUND Secure transluminal closure remains a fundamental barrier to endoscopic surgery.It has been reported that through-the-scope clips were used to secure the incision of the gallbladder during natural orifice transluminal endoscopic cholecystolithotomy and were left in the body post-operation.The over-the-scope clip(OTSC)is favored for its rapid deployment and strong anchoring capabilities.Nevertheless,OTSCs are difficult to remove once implanted.The Senscure Biotechnology in China has developed a detachable over-the-scope clip(D-OTSC)for this purpose.Here,we utilized the D-OTSC to successfully close a full-thickness sigmoid defect exceeding 1 cm in diameter.Subsequently,the clip was completely removed postoperatively,yielding favorable clinical outcomes.CASE SUMMARY We present the case of a 51-year-old female patient who underwent natural orifice transluminal endoscopic cholecystolithotomy.The sigmoid incision was closed using a D-OTSC.Postoperative recovery was uneventful,with no abdominal infection or bleeding.The D-OTSC was subsequently removed via enteroscopy in the outpatient department one month later.CONCLUSION The utilization of D-OTSC presents a viable option for closing colonic mucosal incisions ranging from 1 cm to 2 cm.
基金supported by the National Natural Science Foundation of China(Grant Nos.91441125,51106113,51006075)the Key Project of the Shanghai Synchrotron Radiation Facility(Grant No.2016-SSRF-ZD-004512)Tongji University Outstanding Young Talents Project(Grant No.2015KJ037)
文摘The design of fuel nozzle orifices at micrometer scales is crucial for generating desired fuel spray patterns, and consequently optimizing fuel combustion and emission in internal combustion engines. Although there have been several recent advancements in the characterization of orifice internal geometries, quantitative studies on the orifice internal wall surface characteristics are still challeges due to the lack of effective measuring methods. A new method for quantifying the internal wall surface characteristics of fuel nozzle micro-orifices is presented in this study to achieve a better understanding and prediction of spray characteristics: Firstly, by using the synchrotron X-ray micro CT technology, a three-dimensional digital model of the fuel nozzle tip was constructed. Secondly, a data post-processing technique was then applied to unfold the orifice internal wall surface to a flat base plane. Finally, the conventional surface characteristic quantification techniques can be used to evaluate the wall surface characteristics. Two diesel nozzles with identical orifice geometry design but different hydraulic grinding time were measured using this method. One nozzle was hydro-ground for 2 s while the other was not. The internal wall surfaces of the two orifices were successfully unfolded to base planes and their surface characteristics were respectively analyzed. The surface fluctuation data were perfectly reproduced by a Gaussian distribution function. The standard deviations of the distribution demonstrate the fluctuation range and the distribution of the entire surface fluctuation profiles. As an effective parameter to evaluate the hydraulic grinding process and the spray behaviors, the standard deviation was considered feasible for the analysis of the orifice internal wall surface characteristics.
文摘The present work deals with the computation of the gas-solid two-phase flow pressure drop across thin and thick orifices for a vertically downward flow configuration at the higher limits of a dilute phase flow situation(0.01≤αs,in≤0.10).The Eulerian-Eulerian(two-fluid)model has been used in conjunction with the kinetic theory of granular flow with a four-way coupling approach.The validation of the solution process has been performed by comparing the computational result with the existing experimental data.It is observed that the two-phase flow pressure drop across the orifice increases with an increase in the thickness of the orifice,and the effect is more prominent at higher solid loading.The pressure drop is found to increase with an increase in the solid volume fraction.An increase in the Reynolds number or the area ratio increases the pressure drop.An increase in the size of the particles reduces the pressure drop across the orifice at both small and relatively large solid volume fractions.Finally,a two-phase multiplier has been proposed in terms of the relevant parameters,which can be useful to evaluate the gas-solid two-phase flow pressure drop across the orifice and can subsequently help to improve the system performance.
文摘A steady,axisymmetric vortex at an entrance of horizontal orifice,with an air- core,was formed within a special apparatus.The tangential,radial and axial velocities and their fluctuation strengths were measured in detail.The results were given in terms of formulas or curves.It shows a clear picture of vortex flow-field.
基金Supported by the National High-Level Hospital Clinical Research Funding,No.2022-PUMCH-B-024 and No.2022-PUMCH-A-020Undergraduate Teaching Reform and Innovation Project,No.2022zlgc0108.
文摘BACKGROUND The management of polyps involving the appendiceal orifice(AO)presents notable challenges.Endoscopic resection is frequently hindered by operational complexities,a heightened risk of incomplete removal,and an elevated risk of procedural complications,including appendicitis.Conversely,surgical resection may entail unnecessary excision of intestinal segments,leading to potential morbidity.CASE SUMMARY Here,we reported two patients who presented with polyps deeply situated within the AO,with indistinct boundaries making it challenging to ensure completeness using traditional endoscopic resection.To overcome these challenges,we em-ployed combined endo-laparoscopic surgery(CELS),achieving curative resection without postoperative complications.CONCLUSION The application of CELS in managing polyps involving the AO is emerging as a safe and effective treatment modality.
文摘BACKGROUND Natural orifice specimen extraction surgery(NOSES)has emerged as a promising alternative compared to conventional laparoscopic-assisted total gastrectomy(LATG)for treating gastric cancer(GC).However,evidence regarding the efficacy and safety of NOSES for GC surgery is limited.This study aimed to compare the safety and feasibility,in addition to postoperative complications of NOSES and LATG.METHODS Dual circular staplers were used in Roux-en-Y digestive tract reconstruction for transvaginal specimen extraction LATG,and its outcomes were compared with LATG in a cohort of 51 GC patients with tumor size≤5 cm.The study was conducted from May 2018 to September 2020,and patients were categorized into the NOSES group(n=22)and LATG group(n=29).Perioperative parameters were compared and analyzed,including patient and tumor characteristics,postoperative outcomes,and anastomosis-related complications,postoperative hospital stay,the length of abdominal incision,difference in tumor type,postoperative complications,and postoperative survival.RESULTS Postoperative exhaust time,operation duration,mean postoperative hospital stay,length of abdominal incision,number of specific staplers used,and Brief Illness Perception Questionnaire score were significant in both groups(P<0.01).In the NOSES group,the postoperative time to first flatus,mean postoperative hospital stay,and length of abdominal incision were significantly shorter than those in the LATG group.Patients in the NOSES group had faster postoperative recovery,and achieved abdominal minimally invasive incision that met aesthetic requirements.There were no significant differences in gender,age,tumor type,postoperative complications,and postoperative survival between the two groups.CONCLUSION The application of dual circular staplers in Roux-en-Y digestive tract reconstruction combined with NOSES gastrectomy is safe and convenient.This approach offers better short-term outcomes compared to LATG,while long-term survival rates are comparable to those of conventional laparoscopic surgery.
基金The study was reviewed and approved by The First Affiliated Hospital of Xinjiang Medical University Institutional Review Board(No.K202311-33).
文摘BACKGROUND At present,laparoscopic cholecystectomy(LC)is the main surgical treatment for gallstones.But,after gallbladder removal,there are many complications.Therefore,it is hoped to remove stones while preserving the function of the gallbladder,and with the development of endoscopic technology,natural orifice transluminal endoscopic surgery came into being.AIM To compare the quality of life,perioperative indicators,adverse events after LC and transgastric natural orifice transluminal endoscopic gallbladder-preserving surgery(EGPS)in patients with gallstones.METHODS Patients who were admitted to The First Affiliated Hospital of Xinjiang Medical University from 2020 to 2022 were retrospectively collected.We adopted propen-sity score matching(1:1)to compare EGPS and LC patients.RESULTS A total of 662 cases were collected,of which 589 cases underwent LC,and 73 cases underwent EGPS.Propensity score matching was performed,and 40 patients were included in each of the groups.In the EGPS group,except the gastr-ointestinal defecation(P=0.603),the total score,physical well-being,mental well-being,and gastrointestinal digestion were statistically significant compared with the preoperative score after surgery(P<0.05).In the LC group,except the mental well-being,the total score,physical well-being,gastrointestinal digestion,the gastrointestinal defecation was statistically significant compared with the preoperative score after surgery(P<0.05).When comparing between groups,gastrointestinal defecation had significantly difference(P=0.002)between the two groups,there was no statistically significant difference in the total postoperative score and the other three subscales.In the surgery duration,hospital stay and cost,LC group were lower than EGPS group.The recurrence factors of gallstones after EGPS were analyzed:and recurrence was not correlated with gender,age,body mass index,number of stones,and preoperative score.CONCLUSION Whether EGPS or LC,it can improve the patient’s symptoms,and the EGPS has less impact on the patient’s defecation.It needed to,prospective,multicenter,long-term follow-up,large-sample related studies to prove.
基金supported by the Key Projects of Schoolenterprise Joint Fund(No.U22B20120)the National Science Fund for Distinguished Young Scholars(No.52107141)。
文摘Booming low-power electric propulsion systems require 1–2 A hollow cathodes.Such cathodes are expected to go through more frequent ignitions in the low orbit,but the impact of cyclic ignitions on such 1–2 A barium tungsten hollow cathodes with a heater was not clear.In this study,a 12,638-cyclic ignition test and a 6,000-hour-long life test on two identical cathodes were carried out.The discharge voltage of the cathode and the erosion of the orifice after cyclic ignition were all larger than that of the cathode after stable operation.This indicated that the impact of cycle ignition on the discharge performance of a low current BaO-W cathode with a heater was higher than that of stable operation.The results of the ion energy distribution function measured during the ignition period indicated that the main reason for the orifice expansion was ion bombardment.Therefore,it was necessary to pay attention to the number of ignitions for the lifetime of this kind of cathode.
基金Supported by the Specific Research Fund of The Innovation Platform for Academicians of Hainan Province,No.YSPTZX202313Hainan Province Clinical Medical Center,No.2021818+1 种基金Hainan Provincial Health Industry Research Project,No.22A200078and Hainan Provincial Postgraduate Innovation Research Project,No.Qhyb2022-133.
文摘BACKGROUND Guidewire slippage into the peritoneal cavity during clinical operations is extremely rare.Therefore,this paper aims to report a successful case of guidewire removal using transgastric natural orifice transluminal endoscopic surgery(NOTES).The goal is to enhance physicians'understanding of the management plan for this unique scenario and provide a valuable reference for clinical practice.CASE SUMMARY A 64-year-old man presented with abdominal distension and was diagnosed with cirrhosis combined with massive ascites.To proceed with treatment,the patient underwent ultrasound-guided peritoneal puncture and underwent catheterization and drainage.Unfortunately,a 0.035-inch guidewire slipped into the abdominal cavity during the procedure.Following a comprehensive evaluation and consultation by a multidisciplinary team,the guidewire was successfully removed using NOTES.CONCLUSION This case highlights the potential consideration of transgastric NOTES removal when encountering a foreign body,such as a guidewire,within the abdominal cavity.
基金Medical and Health Science and Technology Plan of Inner Mongolia Autonomous Region(No.202202405)Clinical Key Specialty Construction Project of Inner Mongolia Autonomous Region(2023)+1 种基金Bayannur City Science and Technology Innovation Driving Project(No.K202029,SFK2020LH05)Internal Research Project of Bayannur City Hospital(No.2019022)。
文摘Objective: To explore the value of hand-sewn anastomosis in totally laparoscopic radical resection of colorectal cancr with transanal specimen extraction. Methods: A retrospective descriptive study was conducted. Clinical data of 54 patients with colorectal cancer who underwent totally laparoscopic transrectal specimen extraction surgery between January 2019 and December 2023 at the Department of Gastrointestinal Surgery, Bayannur City Hospital, were collected. All patients underwent digestive tract reconstruction using hand-sewn end-to-end colonic or rectal anastomosis. Intraoperative and postoperative general conditions, pathological results, complications, and follow-up data were analyzed. Results: Among the 54 cases, 37 were male, and 17 were female. The cases included 26 sigmoid colon cancers, 27 high rectal cancers, and 1 descending colon cancer. All patients underwent totally laparoscopic radical resection of colorectal cancer with transrectal specimen extraction. The average surgical duration was 187.87 ± 61.36 minutes, with 16 (14-19) minutes required for hand-sewn anastomosis. Intraoperative blood loss was 16 (10-200) mL, with no conversions to open surgery or blood transfusions. Postoperative outcomes included first flatus time of 1 (1-3) day, liquid diet resumption on 2 (2-3) days, postoperative Visual Analog Scale (VAS) pain score of 2 (2-3), and hospital stay duration of 8 (7-9) days. The total hospitalization cost was 41,011 (25,655-148,589) Chinese yuan, with an average cost of 42,558.81 ± 8,599.30 Chinese yuan after excluding three cases with complications. Pathological examination revealed all cases to be adenocarcinomas: 20 well-differentiated, 32 moderately differentiated, and 2 poorly differentiated. All resection margins were negative. An average of 16.85 ± 7.97 lymph nodes were dissected. Pathological staging included 18 stage I, 17 stage II, and 19 stage III cases. Postoperative complications included 2 cases of anastomotic leakage (3.7%), 1 case of anastomotic stricture (1.8%), and 1 case of pulmonary infection (1.8%). No unplanned readmissions or postoperative deaths occurred during the 30-day follow-up period. Conclusion: Hand-sewn anastomosis in totally laparoscopic radical resection of colorectal cancer with transanal specimen extraction is safe and feasible.
