BACKGROUND Pedicled abdominal flaps are a widely used surgical technique for forearm reconstruction in patients with soft tissue defects.However,some drawbacks include restricted flap size,partial flap loss,and donor-...BACKGROUND Pedicled abdominal flaps are a widely used surgical technique for forearm reconstruction in patients with soft tissue defects.However,some drawbacks include restricted flap size,partial flap loss,and donor-site morbidity.To address these concerns,we present a case of a pedicled abdominal flap using the deep inferior epigastric artery perforators(DIEP)for forearm reconstruction in a patient with a large soft tissue defect.CASE SUMMARY A 46-year-old male patient was admitted to our hospital with forearm injury caused by a pressing machine.A 15 cm×10 cm soft tissue defect with complete rupture of the ulnar side structures of the forearm was found.One week after orthopedic management of the neurovascular injury and fractures using the first stage of Masquelet technique,the patient was referred to the plastic and recon-structive surgery department for wound coverage.Surgical debridement and negative-pressure wound therapy revealed a 20 cm×15 cm soft tissue defect.A pedicle abdominal flap with the DIEP was used to cover the defect.Three weeks later,the flap was detached from the abdomen,and the abdominal defect was directly closed.Subsequently,the second stage of Masquelet technique was performed at the fracture site at week 10.Finally,all donor and recipient sites healed without complications,such as flap dehiscence,infection,hematoma,or necrosis.Fracture site osteosynthesis was achieved without complications.CONCLUSION Pedicled abdominal flap using the DIEP provides a reliable option for forearm reconstruction in patients with large soft tissue defects.展开更多
Resume of the study & Background: Radial forearm free flap with all its present day modifications is the workhorse of soft tissue reconstruction. Although there are several advantages, it requires sacrifice of a m...Resume of the study & Background: Radial forearm free flap with all its present day modifications is the workhorse of soft tissue reconstruction. Although there are several advantages, it requires sacrifice of a major artery of forearm. Several modifications are described in harvesting a forearm flap. In order to achieve a reliable, safe flap harvest & design one must have a very clear understanding of radial artery perforators, relative to its distribution, territory & flow. The purpose of this study is to determine the location, size & vascular territory of the radial artery cutaneous perforators & to demonstrate application of shape modification of radial forearm free flap based on its distal & proximal perforators in various head & neck defects. Materials & Methods: Anatomical Study: 12 fresh human cadavers & 24 cadaveric forearms were dissected to determine the number, location, size & vascular territory of radial artery perforator. The cutaneous territory of distally dominant perforators was analyzed using methylene blue injections & three-dimensional computed tomographic angiogram to determine the vascular network. Clinical Study: 15 patients with various head neck defects following oncological resections were reconstructed with shape modified adipo-fascio cutaneous free forearm flap. All these patients were prospectively followed for donor site healing, motor & sensory nerve deficit, function & quality of life questioner for donor site assessment. Results: 12 fresh human cadavers & 24 cadaveric forearms were dissected, and a total of 222 perforators were dissected for an average of 18.5 perforators per forearm. 118 were smaller than 0.5 mm in diameter (53.15%) & were not clinically significant. 104 perforators were greater than 0.5 mm in diameter (46.84%) & were clinically significant. 127 perforators (57.20%) were radially distributed & 95 perforators (42.79%) had ulnar distribution. 90 perforators (40.54%) were identified on distal side (Radial styloid) & 132 perforators (59.45%) were identified on proximal side (Lateral epicondyle). Mean number of perforators, on radial side was 10.6 & 7.9 on ulnar side;comparison of both using student t paired test gives a P value of 0.006, which is significant. Comparison of mean number of perforators on the distal side was 7.5 & proximal side was 11.0;Student Paired t test gives a P value of 0.003, which was statistically significant. Comparison of mean diameter of perforators on Distal side (1.11) & Proximal side (0.86), side using Student Paired t test gives a P value of 0.01 which was statistically significant. A chi square test was done to compare mean diameter of perforators on distal side, which was more than 1 mm (80%) & less than 1 mm (20%) & on proximal side more than 1 mm (35.6%) & less than 1 mm (64.4%). Chi square value of 42.406 was obtained, degree of freedom value was 1 & P value of Conclusion: Increase in knowledge of vascular territory of radial artery perforators with regards to numbers, size, location, & cutaneous territory can lead to expanded use of radial forearm flap based on either distal or proximal perforator alone. Shape modified technique for harvesting radial forearm flap allows primary closure of donor site. Donor site is better healed and shows a predicted pattern, which is functionally and aesthetically good.展开更多
Colonoscopy represents a safe procedure that is widely used in medical practice either to diagnose or treat various gastrointestinal diseases.During the last few years,the incidence rate of perforations in colonoscopi...Colonoscopy represents a safe procedure that is widely used in medical practice either to diagnose or treat various gastrointestinal diseases.During the last few years,the incidence rate of perforations in colonoscopic procedures has increased,especially in therapeutic colonoscopies.The recent advancements in endoscopic techniques and gastrointestinal tumoral resection procedures such as endoscopic mucosal resection,endoscopic full-thickness resection,and endoscopic submucosal dissection(ESD)could be a risk factor for this increased risk.The incidence rate of mortality of serious colonoscopic perforations is 7.1%.The management plan for these perforations starts with conservative treatment in mild cases,endoscopic closure,and surgical management in severe cases.Recently,endoluminal vacuum therapy was found to be effective in the management of colorectal perforations and this has been reported in multiple case reports.This editorial provides an overview of the current guidelines for the management of iatrogenic colorectal perforations.These insights are from the perspectives of endoscopists and gastroenterologists.We also present a management algorithm based on the guidelines of the European Society of Gastrointestinal Endoscopy,the American Gastroenterological Association,and the World Society of Emergency Surgery.We also discussed in brief the use of endoluminal vacuum therapy in colorectal perforations.展开更多
An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on t...An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on the formation of perforation by AWJ is unclear yet.In this study,we investigate AWJ impacts on three types of granite samples with different mineral fractions using a polarizing microscope and scanning electron microscope(SEM).The results show that when the grain size is doubled,the perforation depth increases by 16.22%under the same type of structure and properties.In general,fractures are more likely to be created at the position of rough surfaces caused by abrasive impact,and the form of fractures is determined by the mineral type.In addition,microstructure analysis shows that transgranular fractures typically pass through large feldspar particles and quartz removal occurs along mineral boundaries.The longitudinal extension of perforation depends mainly on the strong kinetic energy of the jet,while the lateral extension is controlled by the backflow.The results contribute to a better understanding of the process involved in the breaking of hard rock by abrasive jets during deep geothermal drilling.展开更多
A theoretical analysis on the perforation of Weldox 460E steel plates struck by flat-nosed projectiles is presented using a previously developed model within a unified framework.This model contains a dimensionless emp...A theoretical analysis on the perforation of Weldox 460E steel plates struck by flat-nosed projectiles is presented using a previously developed model within a unified framework.This model contains a dimensionless empirical equation to describe the variation of energy absorbed through global deformation as a function of impact velocity.The study further investigates the energy absorption mechanisms of Weldox 460E steel plates,with particular focus on the“plateau”phenomenon,i.e.,limited increase in ballistic limit with increasing plate thickness.This phenomenon is explained and compared with results from previously studied 2024-T351 aluminium plates.The model predictions agree well with experimental data for Weldox 460E steel plates impacted by flat-nosed projectiles,including:relationship between global deformation and impact velocity,ballistic limit,residual velocity,and critical conditions for the transition of failure modes.Moreover,the model effectively predicts the“plateau”phenomenon observed in intermediate plate thickness range.It is also found that the indentation absorption energy contributes a significantly larger fraction of the total absorption energy in Weldox 460E steel plates perforated by flat-nosed projectiles than in 2024-T351 aluminium plates,due to the differences in material properties.展开更多
BACKGROUND Motorcycle accidents often result in abdominal trauma in patients seeking emergency care.Injuries to the hollow viscera,including the duodenum,jejunum,urinary bladder,and colorectum,are relatively common.In...BACKGROUND Motorcycle accidents often result in abdominal trauma in patients seeking emergency care.Injuries to the hollow viscera,including the duodenum,jejunum,urinary bladder,and colorectum,are relatively common.In contrast,owing to the protective function of the anterior rib cage,gastric rupture is exceptionally rare,with an incidence of<1.7%.Gastric rupture typically occurs in the anterior wall and rarely presents as multiple ruptures.This report describes an unusual case of multiple gastric ruptures resulting from blunt trauma.CASE SUMMARY A 21-year-old man,who was involved in a motorcycle collision at 70 km/hour after consuming a large meal,presented with hypotension.Physical examination revealed abdominal tenderness.Laboratory test results indicated elevated amylase,lipase,and liver enzyme levels.Computed tomography showed pneumoperitoneum,hemoperitoneum,and gastric wall discontinuation,suggesting gastric perforation alongside pancreatic,splenic,and hepatic injuries.Angiographic embolization was performed because of active contrast leakage in the left gastric and right gastroepiploic arteries.Emergency laparotomy revealed substantial blood loss,hematoma,and gastric contents scattered throughout the abdominal cavity.Two 10 cm gastric perforations in the anterior and posterior walls were identified,as well as severe liver damage,splenic injury,and pancreatic contusion.Surgical interventions included primary closure of the gastric wall,splenectomy,and partial hepatectomy.After temporary abdominal closure,the patient underwent a second surgery without further bleeding.The gastric repair site was resected and reinforced for optimal tissue healing.CONCLUSION Gastric rupture following blunt trauma is fatal.However,patients without severe complications can recover through surgical interventions and postoperative care.展开更多
BACKGROUND Pediatric perforated appendicitis(PPA)is a severe acute condition requiring surgical intervention and postoperative antibiotic therapy.Antibiotic selection differs significantly among pediatric centers,and ...BACKGROUND Pediatric perforated appendicitis(PPA)is a severe acute condition requiring surgical intervention and postoperative antibiotic therapy.Antibiotic selection differs significantly among pediatric centers,and an ideal postoperative antiinfective approach for PPA management has yet to be established.AIM To examine the spectrum of pathogenic bacteria in pediatric PPA and to summarize the postoperative experience with carbapenem(CBP)and cephalosporin(CPS)antibiotics.METHODS We retrospectively analyzed medical records of 65 children(43 boys,22 girls;mean age 6.92±3.41 years)with PPA who underwent surgery at our hospital between December 2019 and August 2022.Data were collected in September 2023.Based on postoperative antibiotic selection,patients were divided into CBP(32 cases)and CPS(33 cases)groups.Chi-square and T-tests compared recovery outcomes,while univariate and multivariate regression models identified independent factors affecting postoperative recovery.RESULTS There were no significant differences between the two groups in gender,age,weight,height,body mass index,baseline ear temperature,or heart rate(P>0.05).Escherichia coli(40.00%)and Pseudomonas aeruginosa(24.62%)were the most common pathogens in PPA.Postoperative analysis showed significantly shorter C-reactive protein(CRP)recovery times in the CPS group than in the CBP group[(6.18±1.84)vs(8.12±3.48)days,P=0.009].Univariate logistic regression indicated CPS selection(OR=0.32,95%CI:0.10-0.97,P=0.044)was significantly associated with a higher CRP recovery rate within 7 days.Multivariate analysis confirmed CPS selection(OR=3.49,95%CI:1.19-10.24,P=0.023)as an independent factor affecting CRP recovery within 7 days postoperatively.CONCLUSION The choice of CBP or CPS independently affects CRP recovery within 7 days.CBP offers no advantage over CPS in treating PPA,with CPS also demonstrating favorable clinical outcomes.展开更多
BACKGROUND Post-polypectomy syndrome(PPS)is a rare but relevant complication of endo-scopic colorectal polyp removal.Although its course is usually benign,it may conceal more severe conditions.This case report present...BACKGROUND Post-polypectomy syndrome(PPS)is a rare but relevant complication of endo-scopic colorectal polyp removal.Although its course is usually benign,it may conceal more severe conditions.This case report presents several complications resulting from a colorectal polypectomy.CASE SUMMARY We report the case of a 67-year-old man who presented with asthenia and abdo-minal discomfort after a scheduled polypectomy.The patient was initially diagnosed with PPS and managed conservatively.However,progressive clinical deterioration led to hospital admission.Imaging revealed a right-sided intra-abdominal abscess secondary to colonic perforation.The initial polyp was iden-tified as a subepithelial lipoma.The patient underwent successful percutaneous drainage,antibiotic therapy,and recovered without the need for surgical inter-vention.CONCLUSION This case highlights the importance of accurate endoscopic diagnosis and te-chnique selection.PPS should not preclude the consideration of concurrent comp-lications.Early identification and a tailored therapeutic approach can prevent Core Tip:Although therapeutic colonoscopy is generally safe,it may be associated with significant complications.This case illustrates how post-polypectomy syndrome can mask a colonic perforation with subsequent abscess formation.It em-phasizes the importance of an accurate initial endoscopic assessment,the use of advanced resection and closure techniques,and close clinical follow-up.Recognizing this spectrum of complications and intervening early can help prevent major surgical procedures and improve patient outcomes.展开更多
BACKGROUND Single-balloon enteroscopy(SBE)is an established procedure for evaluating small bowel lesions.While its efficacy is well recognized,the incidence of major complications and their associated risk factors in ...BACKGROUND Single-balloon enteroscopy(SBE)is an established procedure for evaluating small bowel lesions.While its efficacy is well recognized,the incidence of major complications and their associated risk factors in a large population remain unclear.AIM To investigate the complications and risk factors associated with diagnostic SBE.METHODS This multicenter retrospective study included consecutive patients who underwent diagnostic SBE at three tertiary care hospitals between January 2016 and September 2024.Data on baseline characteristics,procedural parameters,indications,findings,and major complications were collected and analyzed.RESULTS A total of 2865 SBE procedures were performed in 1840 patients.The mean age was 51±18 years,and 64.5%were male.The most common indication was obscure gastrointestinal bleeding(57.1%),followed by abdominal pain(30.5%).The major complication rate was 0.4%(7/1840),all of which involved acute intestinal perforation identified during the procedure.Among the perforation cases,6 occurred in patients undergoing SBE for abdominal pain and 1 for obscure gastrointestinal bleeding.The perforation sites included the ileum(6/7)and duodenum(1/7).All cases were successfully managed surgically.Previous abdominal surgery and the use of abdominal compression were significantly associated with an increased risk of perforation(P value<0.001 for both).In subgroup analysis,perforation rates were 2.1%(6/288)in patients with prior abdominal surgery and 1.6%(7/428)with abdominal compression.CONCLUSION Acute intestinal perforation is a rare but serious complication.Prior abdominal surgery and abdominal compression are important risk factors,and careful patient selection is recommended to minimize complications.展开更多
This pictorial review discusses the imaging approach to evaluate for proper placement or complications of pediatric gastrostomy tube(G-tube)placement and long-term use.G-tubes are crucial for long-term nutritional sup...This pictorial review discusses the imaging approach to evaluate for proper placement or complications of pediatric gastrostomy tube(G-tube)placement and long-term use.G-tubes are crucial for long-term nutritional support in patients facing challenges with oral intake.The article depicts the role of imaging such as contrast radiography,fluoroscopy,ultrasound,and computed tomography scans for confirming G-tube position and evaluating complications,in addition to basic anatomical considerations and placement techniques.Complications discussed include malposition,intraperitoneal placement,buried bumper syndrome,and tube malfunction.Specific imaging techniques and checklists are provided to guide clinicians in assessing G-tube placement accurately.The latter half of the review is a comprehensive exploration of pearls and pitfalls of imaging when employed to detect complications to avoid false positives and negatives.展开更多
BACKGROUND Intestinal obstruction(IO)in pregnancy,though rare(1:1500-1:66000),carries high maternal(6%-10%)and fetal mortality(26%).Adhesions from prior surgery are the leading cause.Diagnosis is often delayed due to ...BACKGROUND Intestinal obstruction(IO)in pregnancy,though rare(1:1500-1:66000),carries high maternal(6%-10%)and fetal mortality(26%).Adhesions from prior surgery are the leading cause.Diagnosis is often delayed due to symptom overlap with nor-mal pregnancy,increasing risks of perforation and sepsis.CASE SUMMARY A 25-year-old gravida 2 para 1 woman at 28 weeks of gestation presented with 1-week constipation,feculent vomiting,and abdominal distension.She had a history of exploratory laparotomy in 2015 for blunt abdominal trauma.The diagnosis of IO in pregnancy was confirmed via abdominopelvic ultrasound and clinical findings.Interventions included conservative measures(nasogastric tube decompression,enemas)followed by emergency laparotomy with bowel resec-tion/anastomosis.Despite surgical management,the patient succumbed to septic shock.CONCLUSION High clinical suspicion,expedited cross-sectional imaging(computed tomogra-phy/Magnetic resonance imaging),and emergent surgery are critical to reduce mortality.展开更多
Background: Numerous reconstruction methods have been developed for myelomeningocele defects;however,no published reports have been published on the preferred reconstruction method in Malaysia.This study reviewed reco...Background: Numerous reconstruction methods have been developed for myelomeningocele defects;however,no published reports have been published on the preferred reconstruction method in Malaysia.This study reviewed reconstruction techniques and outcomes in patients with myelomeningocele at our center.Methods: A retrospective study was conducted on reconstruction methods and outcomes in patients with myelomeningocele referred to the Plastic and Reconstructive Unit,Hospital Universiti Sains Malaysia(HUSM),Kelantan,for wound coverage from to 1997–2023.Data on patient demographics,defect size,reconstruction methods,operation duration,flap-related complications,and secondary repairs were collected and analyzed.Results: Thirteen patients were identified in this retrospective study,comprising 5 female patients,7 male patients,and 1 ambiguous gender patient.Wound closures were performed using primary closure method,local flaps,or regional flap closure.Nine(69.2%) of the thirteen patients underwent soft tissue reconstruction using the local flap,three(23.1%) underwent primary closure,and only one(7.7%) patient underwent wound closure with a regional flap.Flap-related complications were observed in four of the thirteen patients,including wound breakdown in two cases and partial flap necrosis in two cases.Of these four patients,secondary repair was required in three: split-thickness skin grafting was performed in two,and primary closure in one.The remaining patient was managed conservatively with dressings.Patients were followed up for a mean duration of56.6(±62.4) months,and complete healing was achieved in all cases.Conclusion: Myelomeningocele repair remains challenging,and a multidisciplinary approach is recommended.We demonstrated various local and regional flap closure methods with good outcomes.Reconstruction techniques should be tailored for individual cases based to the surgeon expertise.展开更多
Natural gas hydrate widely exists in the South China Sea as clean energy.A three-phase transition layer widely exists in low permeability Class I hydrates in the Shenhu offshore area.Therefore,taking into account the ...Natural gas hydrate widely exists in the South China Sea as clean energy.A three-phase transition layer widely exists in low permeability Class I hydrates in the Shenhu offshore area.Therefore,taking into account the low-permeability characteristics with an average permeability of 5.5 mD and moderate heterogeneity,a 3-D geological model of heterogeneous Class I hydrate reservoirs with three-phase transition layers is established by Kriging interpolation and stochastic modeling method,and a numerical simulation model is used to describe the depressurization production performance of the reservoir.With the development of depressurization,a specific range of complete decomposition zones appear both in the hydrate and transition layers.The entire decomposition zone of the whole reservoir tends to outward and upward diffusion.There is apparent methane escape in the three-phase transition layer.Due to the improvement of local permeability caused by the phase transition of hydrate dissociation,some methane accumulation occurs at the bottom of the hydrate layer,forming a local methane enrichment zone.The methane migration trends in reservoirs are mainly characterized by movement toward production wells and hydrate layers under the influence of gravity.However,due to the permeability limitation of hydrate reservoirs,many fluids have not been effectively produced and remain in the reservoir.Therefore,to improve the effective pressure drop of the reservoir,the perforation method and pressure reduction method were optimized by analyzing the influencing factors based on the gas production rate.The comparative study demonstrates that perforating through the free gas layer combined with one-time depressurization can enhance the effective depressurization and improve production performance.The gas production rate from perforating through the free gas layer can be twice as high as that from perforating through the transition layer.This study can provide theoretical support for the utilization of marine energy.展开更多
It has been experimentally observed that,in the perforation of metal plates by a flat-nosed projectile,there exists a plateau phenomenon where the ballistic limit increases slightly with increasing plate thickness,whi...It has been experimentally observed that,in the perforation of metal plates by a flat-nosed projectile,there exists a plateau phenomenon where the ballistic limit increases slightly with increasing plate thickness,which is related to a change in the mode of failure.No theoretical model has so far explained this phenomenon satisfactorily.This paper presents a combined numerical and theoretical study on the perforation of 2024-T351 aluminum plates struck by flat-nosed projectiles.First,numerical simulations are performed to investigate the failure mechanisms/deformation modes of the aluminum plates.Then,a theoretical model is proposed based on the numerical results and the experimental observations within a unified framework.The model takes into account the main energy absorbing mechanisms and the corresponding energies absorbed are determined analytically.In particular,a dimensionless equation is suggested to describe the relationship between global deformations and impact velocity.It transpires that the model predictions are in good agreement with the test data and the numerical results for the perforation of 2024-T351 aluminum plates struck by rigid flat-nosed projectiles in terms of residual velocity,ballistic limit,relationship between global deformations and impact velocity,and transition of failure modes.It also transpires that the present model can predict the“plateau”phenomenon,which shows a slight increase in ballistic limit as plate thickness increases.Furthermore,the energy absorption mechanisms are discussed on the basis of the theoretical analysis.展开更多
Background: The lumbar artery perforator(LAP) flap is an important autologous option in breast reconstruction.As the lumbar perforator flap is relatively new in this field,several questions remain regarding preoperati...Background: The lumbar artery perforator(LAP) flap is an important autologous option in breast reconstruction.As the lumbar perforator flap is relatively new in this field,several questions remain regarding preoperative preparation,especially concerning computed tomography(CT) and magnetic resonance imaging of the donor site.The objective of this study was to aid the surgical approach to the LAP flap in female patients by precisely determining the characteristics of the lumbar perforators.Methods: We retrospectively reviewed the computed tomographic angiography images of 20 patients who underwent evaluation of the perforator positions from the four lumbar arteries.Four characteristics were studied:length,diameter,path of the lumbar pedicle,and thickness of the tissues available for transfer.Results: We analyzed 20 CT images,identifying 149 perforating vessels of the lumbar artery.The most suitable perforator for flap harvesting was the L4 perforator,which exhibited a larger diameter,a greater number of perforasomes,and a higher percentage of the cutaneous-septal tract.Conclusion: The LAP flap is a viable option for breast reconstruction and as a free flap in women.The L4 perforator artery is the most suitable for harvesting,owing to its superior perfusion capacity,diameter,and course;however,an interposition graft may be required to lengthen the vascular pedicle.展开更多
BACKGROUND Peptic ulcer disease(PUD)during pregnancy is extremely rare.Perforated peptic ulcer(PPU)during pregnancy has high maternal and fetal mortality.Symptoms attributed to pregnancy and other diagnoses make the d...BACKGROUND Peptic ulcer disease(PUD)during pregnancy is extremely rare.Perforated peptic ulcer(PPU)during pregnancy has high maternal and fetal mortality.Symptoms attributed to pregnancy and other diagnoses make the diagnosis of preoperative PPU during pregnancy and puerperium challenging.AIM To identify predictive factors for early diagnosis and treatment,and the association between the diagnosis and maternal/neonatal outcomes.METHODS We searched PubMed,PubMed Central,and Google Scholar.Articles were analyzed following preferred reporting items for systematic reviews and metaanalysis.The search items included:‘ulcer’,‘PUD’,‘pregnancy’,‘puerperium’,‘postpartum’,‘gravid’,‘labor’,‘perforated ulcer’,‘stomach ulcer’,‘duodenal ulcer’,‘peptic ulcer’.Additional studies were extracted by reviewing reference lists of retrieved studies.We included all available full-text cases and case series.Demographic,clinical,obstetric,diagnostic and treatment parameters,and outcomes were collected.RESULTS Forty-three cases were collected.The mean maternal age was 30.9 years;36.6%were multiparous,and 63.4%were nulliparous or primiparous,with multiparas being older than primiparas.Peptic ulcer perforated in 44.2%of postpartum and 55.8%of antepartum patients.Antepartum PPU incidence increased with advancing gestation 2.3%in the first,7%in the second,and 46.5%in the third trimester.The most common clinical findings were abdominal tenderness(72.1%),rigidity(34.9%),and distension(48.8%).Duodenal ulcer predominated(76.7%).In 79.5%,the time from delivery to surgery or vice versa was>24 hours.The maternal mortality during the third trimester and postpartum was 10%and 31.6%,respectively.The trimester of presentation did not influence maternal mortality.The fetal mortality was 34.8%,with all deaths in gestational weeks 24-32.CONCLUSION Almost all patients with PPU in pregnancy or puerperium presented during the third trimester or the first 8 days postpartum.Early intervention reduced fetal mortality but without influence on maternal mortality.Maternal mortality did not depend on the use of X-ray imaging,perforation location,delivery type,trimester of presentation,and maternal age.Explorative laparoscopy was never performed during pregnancy,only postpartum.展开更多
Corrosion failure of N80-Q tubing occurred in a gas well.The causes of corrosion failure were investigated through macroscopic morphology,corrosion product analysis,and microbial analysis.The results show that the cor...Corrosion failure of N80-Q tubing occurred in a gas well.The causes of corrosion failure were investigated through macroscopic morphology,corrosion product analysis,and microbial analysis.The results show that the corrosion patterns of N80-Q tubing were diverse.The failure resulted from the combined action of microbial corrosion,CO_(2)/Cl^(-) corrosion,and erosion corrosion.展开更多
BACKGROUND Acute abdominal pain is one of the most common gastrointestinal symptoms.The etiology of acute abdomen can be challenging for gastroenterologists to establish.Cecal foreign body is a rare cause of cecal per...BACKGROUND Acute abdominal pain is one of the most common gastrointestinal symptoms.The etiology of acute abdomen can be challenging for gastroenterologists to establish.Cecal foreign body is a rare cause of cecal perforation.CASE SUMMARY We report a 35-year-old male from China who initially exhibited symptoms suggestive of acute appendicitis.However,during a minimally invasive colonoscopy procedure,the authors found that a wooden toothpick caused the perforation.The patient presented to our emergency department with a 2 days history of right lower abdominal pain and low grade fever.The patient was in good health and had eaten fish 2 days earlier.Physical examination revealed mild pain with positive rebound tenderness in the right lower abdomen.However,computed tomography of the abdomen confirmed a strip of high-density shadows protruding beyond the intestinal cavity outline,with a small amount of peritoneal seepage in the ileocecal area.Combined with the medical history,the possibility of foreign body perforation by a fishbone and peripheral peritonitis were considered.However,the high-density shadow was identified as a wooden toothpick,which was removed via a minimally invasive procedure using a foreign body forceps under colonoscopy.The patient's condition improved significantly within 5 days after treatment.CONCLUSION We emphasize the importance of a detailed patient history,accurate diagnosis and proper treatment in patients with acute abdomen.展开更多
Currently,unconventional reservoirs are characterized by low single well-controlled reserves,high initial production but fast production decline.This paper sorts out the problems of energy dispersion and limited lengt...Currently,unconventional reservoirs are characterized by low single well-controlled reserves,high initial production but fast production decline.This paper sorts out the problems of energy dispersion and limited length and height of main hydraulic fractures induced in staged multi-cluster fracturing,and proposes an innovative concept of“energy-focused fracturing development”.The technical connotation,theoretical model,and core techniques of energy-focused fracturing development are systematically examined,and the implementation path of this technology is determined.The energy-focused fracturing development technology incorporates the techniques such as geology-engineering integrated design,perforation optimization design,fracturing process design,and drainage engineering control.It transforms the numerous,short and dense hydraulic fractures to limited,long and sparse fractures.It focuses on fracturing energy,and aims to improve the fracture length,height and lateral width,and the proppant long-distance transportation capacity,thus enhancing the single well-controlled reserves and development effect.The energy-focused fracturing development technology has been successfully applied in the carbonate reservoirs in buried hill,shallow coalbed methane reservoirs,and coal-rock gas reservoirs in China,demonstrating the technology's promising application.It is concluded that the energy-focused fracturing development technology can significantly increase the single well production and estimated ultimate recovery(EUR),and will be helpful for efficiently developing low-permeability,unconventional and low-grade resources in China.展开更多
In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool...In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool boiling heat transfer potentially induced by combining perforated copper particles on a heated surface with a sodium dodecyl sulfate(SDS)surfactant in saturated deionized water.Experiments were conducted at standard atmospheric pressure,with heat flux ranging from 20 to 100 kW/m2.The heating surface,positioned below the layer of freely moving copper beads,allowed the particle layer to shift due to liquid convection and steam nucleation.The study reports on the influence of copper bead diameter(2,3,4,and 5 mm),particle quantity,arrangement,and SDS concentration(20,200,and 500 ppm).It is shown that the combination of 5 mm particles and a 500 ppm SDS concentration can yield a remarkable 139%improvement in heat transfer efficiency.As demonstrated by direct flow visualization,bubble formation occurs primarily in the gaps between the particles and the heated surface,with the presence of SDS reducing bubble size and accelerating bubble detachment.展开更多
基金Supported by The Bio&Medical Technology Development Program of the National Research Foundation(NRF)funded by the Korean government(MSIT),No.RS-2023-00220408.
文摘BACKGROUND Pedicled abdominal flaps are a widely used surgical technique for forearm reconstruction in patients with soft tissue defects.However,some drawbacks include restricted flap size,partial flap loss,and donor-site morbidity.To address these concerns,we present a case of a pedicled abdominal flap using the deep inferior epigastric artery perforators(DIEP)for forearm reconstruction in a patient with a large soft tissue defect.CASE SUMMARY A 46-year-old male patient was admitted to our hospital with forearm injury caused by a pressing machine.A 15 cm×10 cm soft tissue defect with complete rupture of the ulnar side structures of the forearm was found.One week after orthopedic management of the neurovascular injury and fractures using the first stage of Masquelet technique,the patient was referred to the plastic and recon-structive surgery department for wound coverage.Surgical debridement and negative-pressure wound therapy revealed a 20 cm×15 cm soft tissue defect.A pedicle abdominal flap with the DIEP was used to cover the defect.Three weeks later,the flap was detached from the abdomen,and the abdominal defect was directly closed.Subsequently,the second stage of Masquelet technique was performed at the fracture site at week 10.Finally,all donor and recipient sites healed without complications,such as flap dehiscence,infection,hematoma,or necrosis.Fracture site osteosynthesis was achieved without complications.CONCLUSION Pedicled abdominal flap using the DIEP provides a reliable option for forearm reconstruction in patients with large soft tissue defects.
文摘Resume of the study & Background: Radial forearm free flap with all its present day modifications is the workhorse of soft tissue reconstruction. Although there are several advantages, it requires sacrifice of a major artery of forearm. Several modifications are described in harvesting a forearm flap. In order to achieve a reliable, safe flap harvest & design one must have a very clear understanding of radial artery perforators, relative to its distribution, territory & flow. The purpose of this study is to determine the location, size & vascular territory of the radial artery cutaneous perforators & to demonstrate application of shape modification of radial forearm free flap based on its distal & proximal perforators in various head & neck defects. Materials & Methods: Anatomical Study: 12 fresh human cadavers & 24 cadaveric forearms were dissected to determine the number, location, size & vascular territory of radial artery perforator. The cutaneous territory of distally dominant perforators was analyzed using methylene blue injections & three-dimensional computed tomographic angiogram to determine the vascular network. Clinical Study: 15 patients with various head neck defects following oncological resections were reconstructed with shape modified adipo-fascio cutaneous free forearm flap. All these patients were prospectively followed for donor site healing, motor & sensory nerve deficit, function & quality of life questioner for donor site assessment. Results: 12 fresh human cadavers & 24 cadaveric forearms were dissected, and a total of 222 perforators were dissected for an average of 18.5 perforators per forearm. 118 were smaller than 0.5 mm in diameter (53.15%) & were not clinically significant. 104 perforators were greater than 0.5 mm in diameter (46.84%) & were clinically significant. 127 perforators (57.20%) were radially distributed & 95 perforators (42.79%) had ulnar distribution. 90 perforators (40.54%) were identified on distal side (Radial styloid) & 132 perforators (59.45%) were identified on proximal side (Lateral epicondyle). Mean number of perforators, on radial side was 10.6 & 7.9 on ulnar side;comparison of both using student t paired test gives a P value of 0.006, which is significant. Comparison of mean number of perforators on the distal side was 7.5 & proximal side was 11.0;Student Paired t test gives a P value of 0.003, which was statistically significant. Comparison of mean diameter of perforators on Distal side (1.11) & Proximal side (0.86), side using Student Paired t test gives a P value of 0.01 which was statistically significant. A chi square test was done to compare mean diameter of perforators on distal side, which was more than 1 mm (80%) & less than 1 mm (20%) & on proximal side more than 1 mm (35.6%) & less than 1 mm (64.4%). Chi square value of 42.406 was obtained, degree of freedom value was 1 & P value of Conclusion: Increase in knowledge of vascular territory of radial artery perforators with regards to numbers, size, location, & cutaneous territory can lead to expanded use of radial forearm flap based on either distal or proximal perforator alone. Shape modified technique for harvesting radial forearm flap allows primary closure of donor site. Donor site is better healed and shows a predicted pattern, which is functionally and aesthetically good.
文摘Colonoscopy represents a safe procedure that is widely used in medical practice either to diagnose or treat various gastrointestinal diseases.During the last few years,the incidence rate of perforations in colonoscopic procedures has increased,especially in therapeutic colonoscopies.The recent advancements in endoscopic techniques and gastrointestinal tumoral resection procedures such as endoscopic mucosal resection,endoscopic full-thickness resection,and endoscopic submucosal dissection(ESD)could be a risk factor for this increased risk.The incidence rate of mortality of serious colonoscopic perforations is 7.1%.The management plan for these perforations starts with conservative treatment in mild cases,endoscopic closure,and surgical management in severe cases.Recently,endoluminal vacuum therapy was found to be effective in the management of colorectal perforations and this has been reported in multiple case reports.This editorial provides an overview of the current guidelines for the management of iatrogenic colorectal perforations.These insights are from the perspectives of endoscopists and gastroenterologists.We also present a management algorithm based on the guidelines of the European Society of Gastrointestinal Endoscopy,the American Gastroenterological Association,and the World Society of Emergency Surgery.We also discussed in brief the use of endoluminal vacuum therapy in colorectal perforations.
基金supported by the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233326)the Chongqing Science Fund for Distinguished Young Scholars(Grant No.CSTB2022NSCQJQX0028)the National Natural Science Foundation of China(Grant Nos.U23A20597,52274112).
文摘An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on the formation of perforation by AWJ is unclear yet.In this study,we investigate AWJ impacts on three types of granite samples with different mineral fractions using a polarizing microscope and scanning electron microscope(SEM).The results show that when the grain size is doubled,the perforation depth increases by 16.22%under the same type of structure and properties.In general,fractures are more likely to be created at the position of rough surfaces caused by abrasive impact,and the form of fractures is determined by the mineral type.In addition,microstructure analysis shows that transgranular fractures typically pass through large feldspar particles and quartz removal occurs along mineral boundaries.The longitudinal extension of perforation depends mainly on the strong kinetic energy of the jet,while the lateral extension is controlled by the backflow.The results contribute to a better understanding of the process involved in the breaking of hard rock by abrasive jets during deep geothermal drilling.
文摘A theoretical analysis on the perforation of Weldox 460E steel plates struck by flat-nosed projectiles is presented using a previously developed model within a unified framework.This model contains a dimensionless empirical equation to describe the variation of energy absorbed through global deformation as a function of impact velocity.The study further investigates the energy absorption mechanisms of Weldox 460E steel plates,with particular focus on the“plateau”phenomenon,i.e.,limited increase in ballistic limit with increasing plate thickness.This phenomenon is explained and compared with results from previously studied 2024-T351 aluminium plates.The model predictions agree well with experimental data for Weldox 460E steel plates impacted by flat-nosed projectiles,including:relationship between global deformation and impact velocity,ballistic limit,residual velocity,and critical conditions for the transition of failure modes.Moreover,the model effectively predicts the“plateau”phenomenon observed in intermediate plate thickness range.It is also found that the indentation absorption energy contributes a significantly larger fraction of the total absorption energy in Weldox 460E steel plates perforated by flat-nosed projectiles than in 2024-T351 aluminium plates,due to the differences in material properties.
文摘BACKGROUND Motorcycle accidents often result in abdominal trauma in patients seeking emergency care.Injuries to the hollow viscera,including the duodenum,jejunum,urinary bladder,and colorectum,are relatively common.In contrast,owing to the protective function of the anterior rib cage,gastric rupture is exceptionally rare,with an incidence of<1.7%.Gastric rupture typically occurs in the anterior wall and rarely presents as multiple ruptures.This report describes an unusual case of multiple gastric ruptures resulting from blunt trauma.CASE SUMMARY A 21-year-old man,who was involved in a motorcycle collision at 70 km/hour after consuming a large meal,presented with hypotension.Physical examination revealed abdominal tenderness.Laboratory test results indicated elevated amylase,lipase,and liver enzyme levels.Computed tomography showed pneumoperitoneum,hemoperitoneum,and gastric wall discontinuation,suggesting gastric perforation alongside pancreatic,splenic,and hepatic injuries.Angiographic embolization was performed because of active contrast leakage in the left gastric and right gastroepiploic arteries.Emergency laparotomy revealed substantial blood loss,hematoma,and gastric contents scattered throughout the abdominal cavity.Two 10 cm gastric perforations in the anterior and posterior walls were identified,as well as severe liver damage,splenic injury,and pancreatic contusion.Surgical interventions included primary closure of the gastric wall,splenectomy,and partial hepatectomy.After temporary abdominal closure,the patient underwent a second surgery without further bleeding.The gastric repair site was resected and reinforced for optimal tissue healing.CONCLUSION Gastric rupture following blunt trauma is fatal.However,patients without severe complications can recover through surgical interventions and postoperative care.
基金Supported by Jiaxing Science and Technology Plan Project,No.2024AD30035.
文摘BACKGROUND Pediatric perforated appendicitis(PPA)is a severe acute condition requiring surgical intervention and postoperative antibiotic therapy.Antibiotic selection differs significantly among pediatric centers,and an ideal postoperative antiinfective approach for PPA management has yet to be established.AIM To examine the spectrum of pathogenic bacteria in pediatric PPA and to summarize the postoperative experience with carbapenem(CBP)and cephalosporin(CPS)antibiotics.METHODS We retrospectively analyzed medical records of 65 children(43 boys,22 girls;mean age 6.92±3.41 years)with PPA who underwent surgery at our hospital between December 2019 and August 2022.Data were collected in September 2023.Based on postoperative antibiotic selection,patients were divided into CBP(32 cases)and CPS(33 cases)groups.Chi-square and T-tests compared recovery outcomes,while univariate and multivariate regression models identified independent factors affecting postoperative recovery.RESULTS There were no significant differences between the two groups in gender,age,weight,height,body mass index,baseline ear temperature,or heart rate(P>0.05).Escherichia coli(40.00%)and Pseudomonas aeruginosa(24.62%)were the most common pathogens in PPA.Postoperative analysis showed significantly shorter C-reactive protein(CRP)recovery times in the CPS group than in the CBP group[(6.18±1.84)vs(8.12±3.48)days,P=0.009].Univariate logistic regression indicated CPS selection(OR=0.32,95%CI:0.10-0.97,P=0.044)was significantly associated with a higher CRP recovery rate within 7 days.Multivariate analysis confirmed CPS selection(OR=3.49,95%CI:1.19-10.24,P=0.023)as an independent factor affecting CRP recovery within 7 days postoperatively.CONCLUSION The choice of CBP or CPS independently affects CRP recovery within 7 days.CBP offers no advantage over CPS in treating PPA,with CPS also demonstrating favorable clinical outcomes.
文摘BACKGROUND Post-polypectomy syndrome(PPS)is a rare but relevant complication of endo-scopic colorectal polyp removal.Although its course is usually benign,it may conceal more severe conditions.This case report presents several complications resulting from a colorectal polypectomy.CASE SUMMARY We report the case of a 67-year-old man who presented with asthenia and abdo-minal discomfort after a scheduled polypectomy.The patient was initially diagnosed with PPS and managed conservatively.However,progressive clinical deterioration led to hospital admission.Imaging revealed a right-sided intra-abdominal abscess secondary to colonic perforation.The initial polyp was iden-tified as a subepithelial lipoma.The patient underwent successful percutaneous drainage,antibiotic therapy,and recovered without the need for surgical inter-vention.CONCLUSION This case highlights the importance of accurate endoscopic diagnosis and te-chnique selection.PPS should not preclude the consideration of concurrent comp-lications.Early identification and a tailored therapeutic approach can prevent Core Tip:Although therapeutic colonoscopy is generally safe,it may be associated with significant complications.This case illustrates how post-polypectomy syndrome can mask a colonic perforation with subsequent abscess formation.It em-phasizes the importance of an accurate initial endoscopic assessment,the use of advanced resection and closure techniques,and close clinical follow-up.Recognizing this spectrum of complications and intervening early can help prevent major surgical procedures and improve patient outcomes.
文摘BACKGROUND Single-balloon enteroscopy(SBE)is an established procedure for evaluating small bowel lesions.While its efficacy is well recognized,the incidence of major complications and their associated risk factors in a large population remain unclear.AIM To investigate the complications and risk factors associated with diagnostic SBE.METHODS This multicenter retrospective study included consecutive patients who underwent diagnostic SBE at three tertiary care hospitals between January 2016 and September 2024.Data on baseline characteristics,procedural parameters,indications,findings,and major complications were collected and analyzed.RESULTS A total of 2865 SBE procedures were performed in 1840 patients.The mean age was 51±18 years,and 64.5%were male.The most common indication was obscure gastrointestinal bleeding(57.1%),followed by abdominal pain(30.5%).The major complication rate was 0.4%(7/1840),all of which involved acute intestinal perforation identified during the procedure.Among the perforation cases,6 occurred in patients undergoing SBE for abdominal pain and 1 for obscure gastrointestinal bleeding.The perforation sites included the ileum(6/7)and duodenum(1/7).All cases were successfully managed surgically.Previous abdominal surgery and the use of abdominal compression were significantly associated with an increased risk of perforation(P value<0.001 for both).In subgroup analysis,perforation rates were 2.1%(6/288)in patients with prior abdominal surgery and 1.6%(7/428)with abdominal compression.CONCLUSION Acute intestinal perforation is a rare but serious complication.Prior abdominal surgery and abdominal compression are important risk factors,and careful patient selection is recommended to minimize complications.
文摘This pictorial review discusses the imaging approach to evaluate for proper placement or complications of pediatric gastrostomy tube(G-tube)placement and long-term use.G-tubes are crucial for long-term nutritional support in patients facing challenges with oral intake.The article depicts the role of imaging such as contrast radiography,fluoroscopy,ultrasound,and computed tomography scans for confirming G-tube position and evaluating complications,in addition to basic anatomical considerations and placement techniques.Complications discussed include malposition,intraperitoneal placement,buried bumper syndrome,and tube malfunction.Specific imaging techniques and checklists are provided to guide clinicians in assessing G-tube placement accurately.The latter half of the review is a comprehensive exploration of pearls and pitfalls of imaging when employed to detect complications to avoid false positives and negatives.
文摘BACKGROUND Intestinal obstruction(IO)in pregnancy,though rare(1:1500-1:66000),carries high maternal(6%-10%)and fetal mortality(26%).Adhesions from prior surgery are the leading cause.Diagnosis is often delayed due to symptom overlap with nor-mal pregnancy,increasing risks of perforation and sepsis.CASE SUMMARY A 25-year-old gravida 2 para 1 woman at 28 weeks of gestation presented with 1-week constipation,feculent vomiting,and abdominal distension.She had a history of exploratory laparotomy in 2015 for blunt abdominal trauma.The diagnosis of IO in pregnancy was confirmed via abdominopelvic ultrasound and clinical findings.Interventions included conservative measures(nasogastric tube decompression,enemas)followed by emergency laparotomy with bowel resec-tion/anastomosis.Despite surgical management,the patient succumbed to septic shock.CONCLUSION High clinical suspicion,expedited cross-sectional imaging(computed tomogra-phy/Magnetic resonance imaging),and emergent surgery are critical to reduce mortality.
文摘Background: Numerous reconstruction methods have been developed for myelomeningocele defects;however,no published reports have been published on the preferred reconstruction method in Malaysia.This study reviewed reconstruction techniques and outcomes in patients with myelomeningocele at our center.Methods: A retrospective study was conducted on reconstruction methods and outcomes in patients with myelomeningocele referred to the Plastic and Reconstructive Unit,Hospital Universiti Sains Malaysia(HUSM),Kelantan,for wound coverage from to 1997–2023.Data on patient demographics,defect size,reconstruction methods,operation duration,flap-related complications,and secondary repairs were collected and analyzed.Results: Thirteen patients were identified in this retrospective study,comprising 5 female patients,7 male patients,and 1 ambiguous gender patient.Wound closures were performed using primary closure method,local flaps,or regional flap closure.Nine(69.2%) of the thirteen patients underwent soft tissue reconstruction using the local flap,three(23.1%) underwent primary closure,and only one(7.7%) patient underwent wound closure with a regional flap.Flap-related complications were observed in four of the thirteen patients,including wound breakdown in two cases and partial flap necrosis in two cases.Of these four patients,secondary repair was required in three: split-thickness skin grafting was performed in two,and primary closure in one.The remaining patient was managed conservatively with dressings.Patients were followed up for a mean duration of56.6(±62.4) months,and complete healing was achieved in all cases.Conclusion: Myelomeningocele repair remains challenging,and a multidisciplinary approach is recommended.We demonstrated various local and regional flap closure methods with good outcomes.Reconstruction techniques should be tailored for individual cases based to the surgeon expertise.
基金supported by the Sinopec Technology Research and Development Project(No.30000000-22-ZC0607-0235,No.33550000-22-ZC0607-0009)the National Natural Science Foundation of China(No.52334002).
文摘Natural gas hydrate widely exists in the South China Sea as clean energy.A three-phase transition layer widely exists in low permeability Class I hydrates in the Shenhu offshore area.Therefore,taking into account the low-permeability characteristics with an average permeability of 5.5 mD and moderate heterogeneity,a 3-D geological model of heterogeneous Class I hydrate reservoirs with three-phase transition layers is established by Kriging interpolation and stochastic modeling method,and a numerical simulation model is used to describe the depressurization production performance of the reservoir.With the development of depressurization,a specific range of complete decomposition zones appear both in the hydrate and transition layers.The entire decomposition zone of the whole reservoir tends to outward and upward diffusion.There is apparent methane escape in the three-phase transition layer.Due to the improvement of local permeability caused by the phase transition of hydrate dissociation,some methane accumulation occurs at the bottom of the hydrate layer,forming a local methane enrichment zone.The methane migration trends in reservoirs are mainly characterized by movement toward production wells and hydrate layers under the influence of gravity.However,due to the permeability limitation of hydrate reservoirs,many fluids have not been effectively produced and remain in the reservoir.Therefore,to improve the effective pressure drop of the reservoir,the perforation method and pressure reduction method were optimized by analyzing the influencing factors based on the gas production rate.The comparative study demonstrates that perforating through the free gas layer combined with one-time depressurization can enhance the effective depressurization and improve production performance.The gas production rate from perforating through the free gas layer can be twice as high as that from perforating through the transition layer.This study can provide theoretical support for the utilization of marine energy.
文摘It has been experimentally observed that,in the perforation of metal plates by a flat-nosed projectile,there exists a plateau phenomenon where the ballistic limit increases slightly with increasing plate thickness,which is related to a change in the mode of failure.No theoretical model has so far explained this phenomenon satisfactorily.This paper presents a combined numerical and theoretical study on the perforation of 2024-T351 aluminum plates struck by flat-nosed projectiles.First,numerical simulations are performed to investigate the failure mechanisms/deformation modes of the aluminum plates.Then,a theoretical model is proposed based on the numerical results and the experimental observations within a unified framework.The model takes into account the main energy absorbing mechanisms and the corresponding energies absorbed are determined analytically.In particular,a dimensionless equation is suggested to describe the relationship between global deformations and impact velocity.It transpires that the model predictions are in good agreement with the test data and the numerical results for the perforation of 2024-T351 aluminum plates struck by rigid flat-nosed projectiles in terms of residual velocity,ballistic limit,relationship between global deformations and impact velocity,and transition of failure modes.It also transpires that the present model can predict the“plateau”phenomenon,which shows a slight increase in ballistic limit as plate thickness increases.Furthermore,the energy absorption mechanisms are discussed on the basis of the theoretical analysis.
文摘Background: The lumbar artery perforator(LAP) flap is an important autologous option in breast reconstruction.As the lumbar perforator flap is relatively new in this field,several questions remain regarding preoperative preparation,especially concerning computed tomography(CT) and magnetic resonance imaging of the donor site.The objective of this study was to aid the surgical approach to the LAP flap in female patients by precisely determining the characteristics of the lumbar perforators.Methods: We retrospectively reviewed the computed tomographic angiography images of 20 patients who underwent evaluation of the perforator positions from the four lumbar arteries.Four characteristics were studied:length,diameter,path of the lumbar pedicle,and thickness of the tissues available for transfer.Results: We analyzed 20 CT images,identifying 149 perforating vessels of the lumbar artery.The most suitable perforator for flap harvesting was the L4 perforator,which exhibited a larger diameter,a greater number of perforasomes,and a higher percentage of the cutaneous-septal tract.Conclusion: The LAP flap is a viable option for breast reconstruction and as a free flap in women.The L4 perforator artery is the most suitable for harvesting,owing to its superior perfusion capacity,diameter,and course;however,an interposition graft may be required to lengthen the vascular pedicle.
文摘BACKGROUND Peptic ulcer disease(PUD)during pregnancy is extremely rare.Perforated peptic ulcer(PPU)during pregnancy has high maternal and fetal mortality.Symptoms attributed to pregnancy and other diagnoses make the diagnosis of preoperative PPU during pregnancy and puerperium challenging.AIM To identify predictive factors for early diagnosis and treatment,and the association between the diagnosis and maternal/neonatal outcomes.METHODS We searched PubMed,PubMed Central,and Google Scholar.Articles were analyzed following preferred reporting items for systematic reviews and metaanalysis.The search items included:‘ulcer’,‘PUD’,‘pregnancy’,‘puerperium’,‘postpartum’,‘gravid’,‘labor’,‘perforated ulcer’,‘stomach ulcer’,‘duodenal ulcer’,‘peptic ulcer’.Additional studies were extracted by reviewing reference lists of retrieved studies.We included all available full-text cases and case series.Demographic,clinical,obstetric,diagnostic and treatment parameters,and outcomes were collected.RESULTS Forty-three cases were collected.The mean maternal age was 30.9 years;36.6%were multiparous,and 63.4%were nulliparous or primiparous,with multiparas being older than primiparas.Peptic ulcer perforated in 44.2%of postpartum and 55.8%of antepartum patients.Antepartum PPU incidence increased with advancing gestation 2.3%in the first,7%in the second,and 46.5%in the third trimester.The most common clinical findings were abdominal tenderness(72.1%),rigidity(34.9%),and distension(48.8%).Duodenal ulcer predominated(76.7%).In 79.5%,the time from delivery to surgery or vice versa was>24 hours.The maternal mortality during the third trimester and postpartum was 10%and 31.6%,respectively.The trimester of presentation did not influence maternal mortality.The fetal mortality was 34.8%,with all deaths in gestational weeks 24-32.CONCLUSION Almost all patients with PPU in pregnancy or puerperium presented during the third trimester or the first 8 days postpartum.Early intervention reduced fetal mortality but without influence on maternal mortality.Maternal mortality did not depend on the use of X-ray imaging,perforation location,delivery type,trimester of presentation,and maternal age.Explorative laparoscopy was never performed during pregnancy,only postpartum.
文摘Corrosion failure of N80-Q tubing occurred in a gas well.The causes of corrosion failure were investigated through macroscopic morphology,corrosion product analysis,and microbial analysis.The results show that the corrosion patterns of N80-Q tubing were diverse.The failure resulted from the combined action of microbial corrosion,CO_(2)/Cl^(-) corrosion,and erosion corrosion.
文摘BACKGROUND Acute abdominal pain is one of the most common gastrointestinal symptoms.The etiology of acute abdomen can be challenging for gastroenterologists to establish.Cecal foreign body is a rare cause of cecal perforation.CASE SUMMARY We report a 35-year-old male from China who initially exhibited symptoms suggestive of acute appendicitis.However,during a minimally invasive colonoscopy procedure,the authors found that a wooden toothpick caused the perforation.The patient presented to our emergency department with a 2 days history of right lower abdominal pain and low grade fever.The patient was in good health and had eaten fish 2 days earlier.Physical examination revealed mild pain with positive rebound tenderness in the right lower abdomen.However,computed tomography of the abdomen confirmed a strip of high-density shadows protruding beyond the intestinal cavity outline,with a small amount of peritoneal seepage in the ileocecal area.Combined with the medical history,the possibility of foreign body perforation by a fishbone and peripheral peritonitis were considered.However,the high-density shadow was identified as a wooden toothpick,which was removed via a minimally invasive procedure using a foreign body forceps under colonoscopy.The patient's condition improved significantly within 5 days after treatment.CONCLUSION We emphasize the importance of a detailed patient history,accurate diagnosis and proper treatment in patients with acute abdomen.
基金Supported by the PetroChina Scentific and Technological Projects(2023ZZ082023ZZ28)。
文摘Currently,unconventional reservoirs are characterized by low single well-controlled reserves,high initial production but fast production decline.This paper sorts out the problems of energy dispersion and limited length and height of main hydraulic fractures induced in staged multi-cluster fracturing,and proposes an innovative concept of“energy-focused fracturing development”.The technical connotation,theoretical model,and core techniques of energy-focused fracturing development are systematically examined,and the implementation path of this technology is determined.The energy-focused fracturing development technology incorporates the techniques such as geology-engineering integrated design,perforation optimization design,fracturing process design,and drainage engineering control.It transforms the numerous,short and dense hydraulic fractures to limited,long and sparse fractures.It focuses on fracturing energy,and aims to improve the fracture length,height and lateral width,and the proppant long-distance transportation capacity,thus enhancing the single well-controlled reserves and development effect.The energy-focused fracturing development technology has been successfully applied in the carbonate reservoirs in buried hill,shallow coalbed methane reservoirs,and coal-rock gas reservoirs in China,demonstrating the technology's promising application.It is concluded that the energy-focused fracturing development technology can significantly increase the single well production and estimated ultimate recovery(EUR),and will be helpful for efficiently developing low-permeability,unconventional and low-grade resources in China.
基金supported by the National Natural Science Foundation of China(Project No.52166004)the National Key Research and Development Program of China(Project No.2022YFC3902000)+2 种基金the Major Science and Technology Special Project of Yunnan Province(Project Nos.202202AG050007202202AG050002)the Research on the Development of Complete Sets of Technology for Extraction of Aromatic Substances from Tobacco Waste and Its Application,Applied Research-Pyrolysis Process Technology Research(2023QT01).
文摘In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool boiling heat transfer potentially induced by combining perforated copper particles on a heated surface with a sodium dodecyl sulfate(SDS)surfactant in saturated deionized water.Experiments were conducted at standard atmospheric pressure,with heat flux ranging from 20 to 100 kW/m2.The heating surface,positioned below the layer of freely moving copper beads,allowed the particle layer to shift due to liquid convection and steam nucleation.The study reports on the influence of copper bead diameter(2,3,4,and 5 mm),particle quantity,arrangement,and SDS concentration(20,200,and 500 ppm).It is shown that the combination of 5 mm particles and a 500 ppm SDS concentration can yield a remarkable 139%improvement in heat transfer efficiency.As demonstrated by direct flow visualization,bubble formation occurs primarily in the gaps between the particles and the heated surface,with the presence of SDS reducing bubble size and accelerating bubble detachment.
