According to the experimental data of the orifice discharge coefficient for the flow through a vertical sharp-edged orifice obtained in the previous study of this work,a theoretical criterion for flow mechanisms of sm...According to the experimental data of the orifice discharge coefficient for the flow through a vertical sharp-edged orifice obtained in the previous study of this work,a theoretical criterion for flow mechanisms of small orifice（viz.thick-walled orifice and nozzle） and large orifice（viz.thin-walled orifice） was proposed based on the ratio of orifice diameter to plate thickness.It can help explain the dissipation of the mechanical energy loss in the flow process for the two flow mechanisms under different operating regimes.The main parameters such as orifice diameter,plate thickness and liquid head were correlated,and a semi-empirical model for orifice coefficient and an empirical model with high precision at the stable region were developed.展开更多
Experiments are performed in choked circular hot and cold nitrogen jets issuing from a 2.44 cm diameter sharp-edged orifice at a fully expanded jet Mach number of 1.85 in an effort to investigate the character of scre...Experiments are performed in choked circular hot and cold nitrogen jets issuing from a 2.44 cm diameter sharp-edged orifice at a fully expanded jet Mach number of 1.85 in an effort to investigate the character of screech phenomenon. The stagnation temperature of the cold and the hot jets are 299 K and 319 K respectively. The axial distribution of the centerline Mach number was obtained with a pitot tube, while the screech data (frequency and amplitude) at different axial and radial stations were measured with the aid of microphones. The fundamental screech frequency of the hot jet is slightly increased relative to that of the cold jet. It is concluded that temperature effects on the screech amplitude are manifested with regard to the fundamental and the subharmonic even at relatively small temperature range considered.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
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
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 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
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
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
Over the last 20 years, laparoscopic colorectal surgery has shown equal efficacy for benign and malignant colorectal diseases when compared to open surgery. However, a laparoscopic approach reduces postoperative morbi...Over the last 20 years, laparoscopic colorectal surgery has shown equal efficacy for benign and malignant colorectal diseases when compared to open surgery. However, a laparoscopic approach reduces postoperative morbidity and shortens hospital stay. In the quest to optimize outcomes after laparoscopic colorectal surgery, reduction of access trauma could be a way to improve recovery. To date, one method to reduce access trauma is natural orifice specimen extraction(NOSE). NOSE aims to reduce access trauma in laparoscopic colorectal surgery. The specimen is delivered via a natural orifice and the anastomosis is created intracorporeally. Different methods are used to extract the specimen and to create a bowel anastomosis. Currently, specimens are delivered transcolonically, transrectally, transanally, or transvaginally. Each of these NOSEprocedures raises specific issues with regard to operative technique and application. The presumed benefits of NOSE-procedures are less pain, lower analgesia requirements, faster recovery, shorter hospital stay, better cosmetic results, and lower incisional hernia rates. Avoidance of extraction site laparotomy is the most important characteristic of NOSE. Concerns associated with the NOSE-technique include bacterial contamination of the peritoneal cavity, inflammatory response, and postoperative outcomes, including postoperative pain and the functional and oncologic outcomes. These issues need to be studied in prospective randomized controlled trials. The aim of this systematic review is to describe the role of NOSE in minimally invasive colorectal surgery.展开更多
AIM:To introduce transvaginal or transanal specimen extraction in laparoscopic total mesorectal excision surgery to avoid an abdominal incision. METHODS:Between January 2009 and December 2011,21 patients with rectal c...AIM:To introduce transvaginal or transanal specimen extraction in laparoscopic total mesorectal excision surgery to avoid an abdominal incision. METHODS:Between January 2009 and December 2011,21 patients with rectal cancer underwent laparoscopic radical resection and the specimen was retrieved by two different ways:transvaginal or transanal rectal removal.Transvaginal specimen extraction approach was strictly limited to elderly post-menopausal women who need hysterectomy.Patients aged between 30 and 80 years,with a body mass index of less than 30 kg/m2, underwent elective surgery.The surgical technique and the outcomes related to the specimen extraction,such as duration of surgery,length of hospital stay,and the complications were retrospectively reviewed. RESULTS:Laparoscopic resection using a natural orifice removal approach was successful in all of the 21 patients.Median operating time was 185 min(range,122-260 min)and the estimated blood loss was 48 mL. The mean length of hospital stay was 7.5 d(range,2-11 d).One patient developed postoperative ileus and had an extended hospital stay.The patient complained of minimal pain.There were no postoperative complications or surgery-associated death.The mean size of the lesion was 2.8 cm(range,1.8-6.0 cm),and the mean number of lymph nodes harvested was 18.7(range, 8-27).At a mean follow-up of 20.6 mo(range,10-37 mo),there were no functional disorders associated with the transvaginal and transanal specimen extraction. CONCLUSION:Transvaginal or transanal extraction in L-TME is a safe and effective procedure.Natural orifice specimen extraction can avoid the abdominal wall incision and its potential complications.展开更多
BACKGROUND This case-control study compared the short-term clinical efficacy of natural orifice specimen extraction surgery(NOSES) using a prolapsing technique and the conventional laparoscopic-assisted approach for l...BACKGROUND This case-control study compared the short-term clinical efficacy of natural orifice specimen extraction surgery(NOSES) using a prolapsing technique and the conventional laparoscopic-assisted approach for low rectal cancer.AIM To further explore the application value of the transanal placement of the anvil and to evaluate the short-term efficacy of NOSES for resecting specimens of low rectal cancer, as well as to provide a theoretical basis for its extensive clinical application.METHODS From June 2015 to June 2018, 108 consecutive laparoscopic-assisted low rectal cancer resections were performed at our center. Among them, 26 specimens were resected transanally using a prolapsing technique(NOSES), and 82 specimens were resected through a conventional abdominal wall small incision(LAP). A propensity score matching method was used to select 26 pairs of matched patients, and their perioperative data were analyzed.RESULTS The baseline data were comparable between the two matched groups. All 52 patients underwent the surgery successfully. The operative time, blood loss,number of harvested lymph nodes, postoperative complication rate,circumferential margin involvement, postoperative follow-up data, and postoperative anal function were not statistically significant. The NOSES group had shorter time to gastrointestinal function recovery(2.6 ± 1.0 d vs 3.4 ± 0.9 d, P= 0.006), shorter postoperative hospital stay(7.1 ± 1.7 d vs 8.3 ± 1.1 d, P = 0.003),lower pain score(day 1: 2.7 ± 1.8 vs 4.6 ± 1.9, day 3: 2.0 ± 1.1 vs 4.1 ± 1.2, day 5: 1.7± 0.9 vs 3.3 ± 1.0, P < 0.001), a lower rate of additional analgesic use(11.5% vs61.5%, P = 0.001), and a higher satisfaction rate in terms of the aesthetic appearance of the abdominal wall after surgery(100% vs 23.1%, P < 0.001).CONCLUSION NOSES for low rectal cancer can achieve satisfactory short-term efficacy and has advantages in reducing postoperative pain, shortening the length of postoperative hospital stay, and improving patients' satisfaction in terms of a more aesthetic appearance of the abdominal wall.展开更多
Natural orifice translumenal surgery(NOTES) has garnished significant attention from surgeons and gastroenterologists,due to the fusion of flexible endoscopy and operative technique.Preliminary efforts suggest that NO...Natural orifice translumenal surgery(NOTES) has garnished significant attention from surgeons and gastroenterologists,due to the fusion of flexible endoscopy and operative technique.Preliminary efforts suggest that NOTES holds potential for a less invasive approach with certain surgical conditions.Many of the hurdles encountered during the shift from open to laparoscopic surgery are now being revisited in the development of NOTES.Physician directed efforts,coupled with industry support,have brought about several NOTES specific devices and platforms to help address limitations with current instrumentation.This review addresses current flexible platforms and their attributes,advantages,disadvantages and limitations.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
Clinical natural orifice surgery has been applied to abdominal surgery in recent years,mostly using transvaginal and transgastric access.Rectal and transcolonic natural orifice transluminal endoscopic surgery(NOTES) w...Clinical natural orifice surgery has been applied to abdominal surgery in recent years,mostly using transvaginal and transgastric access.Rectal and transcolonic natural orifice transluminal endoscopic surgery(NOTES) were tested in animal and cadaver models by a few research groups.Despite the potential advantages of transcolonic NOTES for colorectal diseases,it has not yet been clinically applied.The first successful series of human applications of transcolonic NOTES in the literature from the NOTES Research Group in Brazil provide new possibilities in the field in new transrectal procedures for rectal cancer and benign disease.Successful first human reports on Transcolonic NOTES potentially brings new frontiers and applications for minimally invasive surgery.The treatment of colorectal diseases through flexible Perirectal NOTES Access is a promising new approach alongside existing laparoscopic and open surgery to improve patient care.展开更多
The orifice plate energy dissipater is an economic and highly efficient dissipater. However, there is a risk of cavitaion around the orifice plate flow： In order to provide references for engineering practice, we exa...The orifice plate energy dissipater is an economic and highly efficient dissipater. However, there is a risk of cavitaion around the orifice plate flow： In order to provide references for engineering practice, we examined the cavitation mechanism around the orifice plate and its influencing factors by utilizing mathematical analysis methods to analyze the flow conditions around the orifice plate in view of gas bubble dynamics. Through the research presented in this paper, the following can be observed： The critical radius and the critical pressure of the gas nucleus in orifice plate flow increase with its initial state parameter r0 ; the development speed of bubbles stabilizes at a certain value after experiencing a peak value and a small valley value; and the orifice plate cavitation is closely related to the distribution of the gas nucleus in flow. For computing the orifice plate cavitation number, we ought to take into account the effects of pressure fluctuation. The development time of the gas nucleus from the initial radius to the critical radius is about 107-10-5 s; therefore, the gas nucleus has sufficient time to develop into bubbles in the negative half-cycle of flow fluctuation. The orifice critical cavitation number is closely related to the orifice plate size, and especially closely related with the ratio of the orifice plate radius to the tunnel radius. The approximate formula for the critical cavitation number of the square orifice plate that only considers the main influencing factor was obtained by model experiments.展开更多
Natural orifice translumenal endoscopic surgery(NOTES) training is unique in that it crosses specialty lines and most practitioners do not possess both the knowledge and skill to perform the procedures in their curren...Natural orifice translumenal endoscopic surgery(NOTES) training is unique in that it crosses specialty lines and most practitioners do not possess both the knowledge and skill to perform the procedures in their current form.The learning process becomes even more complex because the field is in constant evolution with advances in technology and technique being introduced almost daily! The challenges of learning NOTES illustrates a larger problem in all procedurally based medical specialties today-the pace of change has become so rapid that a practicing physician's technical skills become out of date within five to ten years of completing residency or fellowship training.As a result,practicing physicians must develop a strategy to rapidly learn about a new technique or technology and introduce it safely into their practice while satisfying the concerns of their hospital's credentialing committee.This chapter will explore the options for learning new procedures and discuss the rapidly expanding armamentarium of education institutes and the developing technology to measure procedural competence.展开更多
The advent of minimally invasive surgery and the advances in endoluminal flexible endoscopy have converged to generate a new concept in digestive surgery,whose acronym natural orifice transluminal endoscopic surgery(N...The advent of minimally invasive surgery and the advances in endoluminal flexible endoscopy have converged to generate a new concept in digestive surgery,whose acronym natural orifice transluminal endoscopic surgery(NOTES),has become a familiar term in the surgical community.NOTES has been performed through the mouth,the bladder,the rectum and the vagina.Of these four approaches,the vagina has gained most popularity for several reasons.It is not only readily accessible and easy to decontaminate but it also provides safe entry and simple closure.The transvaginal approach has been described in the experimental and the clinical setting as an option for cholecystectomy,nephrectomy,splenectomy,segmental gastrectomy,retroperitoneal exploration and bariatric surgery.However,larger series are needed to delineate the exact risks of this approach,and to transcend cultural barriers that impede its wider introduction.Prospective randomized trials will shed light on the definitive role of the vaginal approach in minimal invasive surgery of the future.展开更多
基金supported by the National Natural Science Foundation of China(20806090)
文摘According to the experimental data of the orifice discharge coefficient for the flow through a vertical sharp-edged orifice obtained in the previous study of this work,a theoretical criterion for flow mechanisms of small orifice（viz.thick-walled orifice and nozzle） and large orifice（viz.thin-walled orifice） was proposed based on the ratio of orifice diameter to plate thickness.It can help explain the dissipation of the mechanical energy loss in the flow process for the two flow mechanisms under different operating regimes.The main parameters such as orifice diameter,plate thickness and liquid head were correlated,and a semi-empirical model for orifice coefficient and an empirical model with high precision at the stable region were developed.
文摘Experiments are performed in choked circular hot and cold nitrogen jets issuing from a 2.44 cm diameter sharp-edged orifice at a fully expanded jet Mach number of 1.85 in an effort to investigate the character of screech phenomenon. The stagnation temperature of the cold and the hot jets are 299 K and 319 K respectively. The axial distribution of the centerline Mach number was obtained with a pitot tube, while the screech data (frequency and amplitude) at different axial and radial stations were measured with the aid of microphones. The fundamental screech frequency of the hot jet is slightly increased relative to that of the cold jet. It is concluded that temperature effects on the screech amplitude are manifested with regard to the fundamental and the subharmonic even at relatively small temperature range considered.
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.
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 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.
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.
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.
文摘Over the last 20 years, laparoscopic colorectal surgery has shown equal efficacy for benign and malignant colorectal diseases when compared to open surgery. However, a laparoscopic approach reduces postoperative morbidity and shortens hospital stay. In the quest to optimize outcomes after laparoscopic colorectal surgery, reduction of access trauma could be a way to improve recovery. To date, one method to reduce access trauma is natural orifice specimen extraction(NOSE). NOSE aims to reduce access trauma in laparoscopic colorectal surgery. The specimen is delivered via a natural orifice and the anastomosis is created intracorporeally. Different methods are used to extract the specimen and to create a bowel anastomosis. Currently, specimens are delivered transcolonically, transrectally, transanally, or transvaginally. Each of these NOSEprocedures raises specific issues with regard to operative technique and application. The presumed benefits of NOSE-procedures are less pain, lower analgesia requirements, faster recovery, shorter hospital stay, better cosmetic results, and lower incisional hernia rates. Avoidance of extraction site laparotomy is the most important characteristic of NOSE. Concerns associated with the NOSE-technique include bacterial contamination of the peritoneal cavity, inflammatory response, and postoperative outcomes, including postoperative pain and the functional and oncologic outcomes. These issues need to be studied in prospective randomized controlled trials. The aim of this systematic review is to describe the role of NOSE in minimally invasive colorectal surgery.
基金Supported by Jilin University,China,No.3R211P163428
文摘AIM:To introduce transvaginal or transanal specimen extraction in laparoscopic total mesorectal excision surgery to avoid an abdominal incision. METHODS:Between January 2009 and December 2011,21 patients with rectal cancer underwent laparoscopic radical resection and the specimen was retrieved by two different ways:transvaginal or transanal rectal removal.Transvaginal specimen extraction approach was strictly limited to elderly post-menopausal women who need hysterectomy.Patients aged between 30 and 80 years,with a body mass index of less than 30 kg/m2, underwent elective surgery.The surgical technique and the outcomes related to the specimen extraction,such as duration of surgery,length of hospital stay,and the complications were retrospectively reviewed. RESULTS:Laparoscopic resection using a natural orifice removal approach was successful in all of the 21 patients.Median operating time was 185 min(range,122-260 min)and the estimated blood loss was 48 mL. The mean length of hospital stay was 7.5 d(range,2-11 d).One patient developed postoperative ileus and had an extended hospital stay.The patient complained of minimal pain.There were no postoperative complications or surgery-associated death.The mean size of the lesion was 2.8 cm(range,1.8-6.0 cm),and the mean number of lymph nodes harvested was 18.7(range, 8-27).At a mean follow-up of 20.6 mo(range,10-37 mo),there were no functional disorders associated with the transvaginal and transanal specimen extraction. CONCLUSION:Transvaginal or transanal extraction in L-TME is a safe and effective procedure.Natural orifice specimen extraction can avoid the abdominal wall incision and its potential complications.
基金Supported by National Natural Science Foundation of China,No.81500430 and No.U1304802(to Lin XH)Basic and Frontier Technology Research Program of Henan Province,No.162300410101(to Hu JH)+1 种基金Wu Jieping Medical Foundation of Clinical Research Special Fund,No.320.2710.1836(to Hu JH)The Henan Science and Technology Planning Project,No.182102310544(to Lin XH)
文摘BACKGROUND This case-control study compared the short-term clinical efficacy of natural orifice specimen extraction surgery(NOSES) using a prolapsing technique and the conventional laparoscopic-assisted approach for low rectal cancer.AIM To further explore the application value of the transanal placement of the anvil and to evaluate the short-term efficacy of NOSES for resecting specimens of low rectal cancer, as well as to provide a theoretical basis for its extensive clinical application.METHODS From June 2015 to June 2018, 108 consecutive laparoscopic-assisted low rectal cancer resections were performed at our center. Among them, 26 specimens were resected transanally using a prolapsing technique(NOSES), and 82 specimens were resected through a conventional abdominal wall small incision(LAP). A propensity score matching method was used to select 26 pairs of matched patients, and their perioperative data were analyzed.RESULTS The baseline data were comparable between the two matched groups. All 52 patients underwent the surgery successfully. The operative time, blood loss,number of harvested lymph nodes, postoperative complication rate,circumferential margin involvement, postoperative follow-up data, and postoperative anal function were not statistically significant. The NOSES group had shorter time to gastrointestinal function recovery(2.6 ± 1.0 d vs 3.4 ± 0.9 d, P= 0.006), shorter postoperative hospital stay(7.1 ± 1.7 d vs 8.3 ± 1.1 d, P = 0.003),lower pain score(day 1: 2.7 ± 1.8 vs 4.6 ± 1.9, day 3: 2.0 ± 1.1 vs 4.1 ± 1.2, day 5: 1.7± 0.9 vs 3.3 ± 1.0, P < 0.001), a lower rate of additional analgesic use(11.5% vs61.5%, P = 0.001), and a higher satisfaction rate in terms of the aesthetic appearance of the abdominal wall after surgery(100% vs 23.1%, P < 0.001).CONCLUSION NOSES for low rectal cancer can achieve satisfactory short-term efficacy and has advantages in reducing postoperative pain, shortening the length of postoperative hospital stay, and improving patients' satisfaction in terms of a more aesthetic appearance of the abdominal wall.
文摘Natural orifice translumenal surgery(NOTES) has garnished significant attention from surgeons and gastroenterologists,due to the fusion of flexible endoscopy and operative technique.Preliminary efforts suggest that NOTES holds potential for a less invasive approach with certain surgical conditions.Many of the hurdles encountered during the shift from open to laparoscopic surgery are now being revisited in the development of NOTES.Physician directed efforts,coupled with industry support,have brought about several NOTES specific devices and platforms to help address limitations with current instrumentation.This review addresses current flexible platforms and their attributes,advantages,disadvantages and limitations.
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Clinical natural orifice surgery has been applied to abdominal surgery in recent years,mostly using transvaginal and transgastric access.Rectal and transcolonic natural orifice transluminal endoscopic surgery(NOTES) were tested in animal and cadaver models by a few research groups.Despite the potential advantages of transcolonic NOTES for colorectal diseases,it has not yet been clinically applied.The first successful series of human applications of transcolonic NOTES in the literature from the NOTES Research Group in Brazil provide new possibilities in the field in new transrectal procedures for rectal cancer and benign disease.Successful first human reports on Transcolonic NOTES potentially brings new frontiers and applications for minimally invasive surgery.The treatment of colorectal diseases through flexible Perirectal NOTES Access is a promising new approach alongside existing laparoscopic and open surgery to improve patient care.
基金supported by the National Natural Science Foundation of China (Grant No.50879021)
文摘The orifice plate energy dissipater is an economic and highly efficient dissipater. However, there is a risk of cavitaion around the orifice plate flow： In order to provide references for engineering practice, we examined the cavitation mechanism around the orifice plate and its influencing factors by utilizing mathematical analysis methods to analyze the flow conditions around the orifice plate in view of gas bubble dynamics. Through the research presented in this paper, the following can be observed： The critical radius and the critical pressure of the gas nucleus in orifice plate flow increase with its initial state parameter r0 ; the development speed of bubbles stabilizes at a certain value after experiencing a peak value and a small valley value; and the orifice plate cavitation is closely related to the distribution of the gas nucleus in flow. For computing the orifice plate cavitation number, we ought to take into account the effects of pressure fluctuation. The development time of the gas nucleus from the initial radius to the critical radius is about 107-10-5 s; therefore, the gas nucleus has sufficient time to develop into bubbles in the negative half-cycle of flow fluctuation. The orifice critical cavitation number is closely related to the orifice plate size, and especially closely related with the ratio of the orifice plate radius to the tunnel radius. The approximate formula for the critical cavitation number of the square orifice plate that only considers the main influencing factor was obtained by model experiments.
文摘Natural orifice translumenal endoscopic surgery(NOTES) training is unique in that it crosses specialty lines and most practitioners do not possess both the knowledge and skill to perform the procedures in their current form.The learning process becomes even more complex because the field is in constant evolution with advances in technology and technique being introduced almost daily! The challenges of learning NOTES illustrates a larger problem in all procedurally based medical specialties today-the pace of change has become so rapid that a practicing physician's technical skills become out of date within five to ten years of completing residency or fellowship training.As a result,practicing physicians must develop a strategy to rapidly learn about a new technique or technology and introduce it safely into their practice while satisfying the concerns of their hospital's credentialing committee.This chapter will explore the options for learning new procedures and discuss the rapidly expanding armamentarium of education institutes and the developing technology to measure procedural competence.
文摘The advent of minimally invasive surgery and the advances in endoluminal flexible endoscopy have converged to generate a new concept in digestive surgery,whose acronym natural orifice transluminal endoscopic surgery(NOTES),has become a familiar term in the surgical community.NOTES has been performed through the mouth,the bladder,the rectum and the vagina.Of these four approaches,the vagina has gained most popularity for several reasons.It is not only readily accessible and easy to decontaminate but it also provides safe entry and simple closure.The transvaginal approach has been described in the experimental and the clinical setting as an option for cholecystectomy,nephrectomy,splenectomy,segmental gastrectomy,retroperitoneal exploration and bariatric surgery.However,larger series are needed to delineate the exact risks of this approach,and to transcend cultural barriers that impede its wider introduction.Prospective randomized trials will shed light on the definitive role of the vaginal approach in minimal invasive surgery of the future.
