Optimization of tracheoesophageal fistula model established with Tshaped magnet system based on magnetic compression technique

BACKGROUND The magnetic compression technique has been used to establish an animal model of tracheoesophageal fistula(TEF),but the commonly shaped magnets present limitations of poor homogeneity of TEF and poor model control.We designed a Tshaped magnet system to overcome these problems and verified its effectiveness via animal experiments.AIM To investigate the effectiveness of a T-shaped magnet system for establishing a TEF model in beagle dogs.METHODS Twelve beagles were randomly assigned to groups in which magnets of the Tshaped scheme(study group,n=6)or normal magnets(control group,n=6)were implanted into the trachea and esophagus separately under gastroscopy.Operation time,operation success rate,and accidental injury were recorded.After operation,the presence and timing of cough and the time of magnet shedding were observed.Dogs in the control group were euthanized after X-ray and gastroscopy to confirm establishment of TEFs after coughing,and gross specimens of TEFs were obtained.Dogs in the study group were euthanized after X-ray and gastroscopy 2 wk after surgery,and gross specimens were obtained.Fistula size was measured in all animals,and then harvested fistula specimens were examined by hematoxylin and eosin(HE)and Masson trichrome staining.RESULTS The operation success rate was 100%for both groups.Operation time did not differ between the study group(5.25 min±1.29 min)and the control group(4.75 min±1.70 min;P=0.331).No bleeding,perforation,or unplanned magnet attraction occurred in any animal during the operation.In the early postoperative period,all dogs ate freely and were generally in good condition.Dogs in the control group had severe cough after drinking water at 6-9 d after surgery.X-ray indicated that the magnets had entered the stomach,and gastroscopy showed TEF formation.Gross specimens of TEFs from the control group showed the formation of fistulas with a diameter of 4.94 mm±1.29 mm(range,3.52-6.56 mm).HE and Masson trichrome staining showed scar tissue formation and hierarchical structural disorder at the fistulas.Dogs in the study group did not exhibit obvious coughing after surgery.X-ray examination 2 wk after surgery indicated fixed magnet positioning,and gastroscopy showed no change in magnet positioning.The magnets were removed using a snare under endoscopy,and TEF was observed.Gross specimens showed well-formed fistulas with a diameter of 6.11 mm±0.16 mm(range,5.92-6.36 mm),which exceeded that in the control group(P<0.001).Scar formation was observed on the internal surface of fistulas by HE and Masson trichrome staining,and the structure was more regular than that in the control group.CONCLUSION Use of the modified T-shaped magnet scheme is safe and feasible for establishing TEF and can achieve a more stable and uniform fistula size compared with ordinary magnets.Most importantly,this model offers better controllability,which improves the flexibility of follow-up studies.

Establishment of acquired tracheoesophageal fistula using a modified magnetic compression technique in rabbits and its postmodeling evaluation

BACKGROUND Previous studies have validated the efficacy of both magnetic compression and surgical techniques in creating rabbit tracheoesophageal fistula(TEF)models.Magnetic compression achieves a 100%success rate but requires more time,while surgery,though less frequently successful,offers rapid model establishment and technical maturity in larger animal models.AIM To determine the optimal approach for rabbit disease modeling and refine the process.METHODS TEF models were created in 12 rabbits using both the modified magnetic compression technique and surgery.Comparisons of the time to model establishment,success rate,food and water intake,weight changes,activity levels,bronchoscopy findings,white blood cell counts,and biopsies were performed.In response to the failures encountered during modified magnetic compression modeling,we increased the sample size to 15 rabbit models and assessed the repeatability and stability of the models,comparing them with the original magnetic compression technique.RESULTS The modified magnetic compression technique achieved a 66.7%success rate,whereas the success rate of the surgery technique was 33.3%.Surviving surgical rabbits might not meet subsequent experimental requirements due to TEF-related inflammation.In the modified magnetic compression group,one rabbit died,possibly due to magnet corrosion,and another died from tracheal magnet obstruction.Similar events occurred during the second round of modified magnetic compression modeling,with one rabbit possibly succumbing to aggravated lung infection.The operation time of the first round of modified magnetic compression was 3.2±0.6 min,which was significantly reduced to 2.1±0.4 min in the second round,compared to both the first round and that of the original technique.CONCLUSION The modified magnetic compression technique exhibits lower stress responses,a simple procedure,a high success rate,and lower modeling costs,making it a more appropriate choice for constructing TEF models in rabbits.

Magnetic compression anastomosis to restore biliary tract continuity after obstruction following major abdominal trauma:A case report

BACKGROUND The combination of magnetic compression anastomosis(MCA)and endoscopy has been used to treat biliary stricture after liver transplantation.However,its use for the treatment of complex biliary obstruction after major abdominal trauma has not been reported.This case report describes the successful use of MCA for the treatment of biliary obstruction resulting from major abdominal trauma.A 23-year-old man underwent major abdominal surgery(repair of liver rupture,right half colon resection,and ileostomy)following a car accident one year ago.The abdominal drainage tube,positioned at the Winslow foramen,was draining approximately 600-800 mL of bile per day.During the two endoscopic retrograde cholangiopancreatography procedures,the guide wire was unable to enter the common bile duct,which prevented placement of a biliary stent.MCA combined with endoscopy was used to successfully achieve magnetic anastomosis of the peritoneal sinus tract and duodenum,and then a choledochoduodenal stent was placed.Finally,the external biliary drainage tube was removed.The patient achieved internal biliary drainage leading to the removal of the external biliary drainage tube,which improved the quality of life.CONCLUSION Magnetic compression technique can be used for the treatment of complex biliary obstruction with minimal operative trauma.

Novel magnetic compression technique for the treatment of postoperative anastomotic stenosis in rectal cancer:A case report

BACKGROUND The treatment of postoperative anastomotic stenosis after excision of rectal cancer is challenging.Endoscopic balloon dilation and radial incision are not effective in all patients.We present a new endoscopy-assisted magnetic compression technique(MCT)for the treatment of rectal anastomotic stenosis.We successfully applied this MCT to a patient who developed an anastomotic stricture after radical resection of rectal cancer.A 50-year-old man had undergone laparoscopic radical rectal cancer surgery at a local hospital 5 months ago.A colonoscopy performed 2 months ago indicated that the rectal anastomosis was narrow due to which ileostomy closure could not be performed.The patient came to the Magnetic Surgery Clinic of the First Affiliated Hospital of Xi'an Jiaotong University after learning that we had successfully treated patients with colorectal stenosis using MCT.We performed endoscopy-assisted magnetic compression surgery for rectal stenosis.The magnets were removed 16 d later.A follow-up colonoscopy performed after 4 months showed good anastomotic patency,following which,ileostomy closure surgery was performed.CONCLUSION MCT is a simple,non-invasive technique for the treatment of anastomotic stricture after radical resection of rectal cancer.The technique can be widely used in clinical settings.

Treatment of anastomotic stricture after rectal cancer operation by magnetic compression technique:A case report

BACKGROUNDThe treatment of postoperative anastomotic stenosis(AS)after resection of colorectalcancer is challenging.Endoscopic balloon dilation is used to treat stenosisin such cases,but some patients do not show improvement even after multipleballoon dilations.Magnetic compression technique(MCT)has been used for gastrointestinalanastomosis,but its use for the treatment of postoperative AS aftercolorectal cancer surgery has rarely been reported.CASE SUMMARYWe report a 72-year-old man who underwent radical resection of colorectal cancerand ileostomy one year ago.An ileostomy closure was prepared six months ago,but colonoscopy revealed a narrowing of the rectal anastomosis.Endoscopic balloondilation was performed three times,but colonoscopy showed no significantimprovement in stenosis.The AS was successfully treated using MCT.CONCLUSIONMCT is a minimally invasive method that can be used for the treatment of postoperativeAS after colorectal cancer surgery.

Comparative study of cylindrical vs circular ring magnets for colonic anastomosis in rats

BACKGROUND Magnetic compression anastomosis(MCA)offers a simple and reliable technique for inducing anastomoses at any point along the digestive tract.Evidence regarding whether the design of the MCA device influences the anastomosis effect is lacking.AIM To investigate any difference in the side-to-side colonic anastomosis effect achieved with cylindrical vs circular ring magnets.METHODS We designed cylindrical and circular ring magnets suitable for side-to-side colonic anastomosis in rats.Thirty Sprague-Dawley rats were randomly divided into a cylindrical group,circular ring group,and cylindrical–circular ring group(n=10/group).Side-to-side colonic anastomosis was completed by transanal insertion of the magnets without incision of the colon.Operation time,perioperative complications,and magnet discharge time were recorded.Rats were euthanized 4 weeks postoperatively,and anastomotic specimens were obtained.The burst pressure and anastomotic diameter were measured sequentially,and anastomosis formation was observed by naked eye.Histological results were observed by light microscopy.RESULTS In all 30 rats,side-to-side colonic anastomosis was completed,for an operation success rate of 100%.No postoperative complications of bleeding and intestinal obstruction occurred,and the postoperative survival rate were 100%.The operation time,magnet discharge time,anastomotic bursting pressure,and anastomotic diameter did not differ significantly among the three designs(P>0.05).Healing was similar across the groups,with gross specimens showing good anastomotic healing and good mucosal continuity observed on histological analysis.CONCLUSION This study found no significant difference in the establishment of rat side-to-side colonic anastomosis with the use of cylindrical vs circular ring magnets.

Sutureless Intestinal Anastomosis with a Novel Device of Magnetic Compression Anastomosis

Objective To explore the feasibility and efficiency of a novel magnetic compression anastomats(MCAs) in intestinal anastomosis.Methods A total of 36 male mongrel canines underwent intestinal anastomosis using traditional hand-sewn(n=18) or a novel MCAs(n=18).We compared the anastomosis time,postoperative complications,bursting strength of anastomoses,gross appearance,and pathology between two groups at each time-point of follow-up.Results The mean anastomosis time with MCAs was significantly less than that with hand-sewn(8.50±1.95 vs.31.1±4.32 minutes,P<0.001).The blood stools and intussusceptions occurred in both groups during follow-up period.Only 1 mongrel canine receiving intestinal anastomosis by MCAs experienced anastomotic leakage.The average bursting pressure of anastomoses obtained from mongrel canines undergoing intestinal anastomosis by MCAs was significantly higher than that by traditional hand-sewn at 1 week's follow-up time(P<0.05).Gross appearance of the anastomoses constructed by MCAs was relatively smoother and flatter.Pathological evalution of anastomoses revealed that general inflammation was greater in hand-sewn anastomoses than magnetic anastomosis.Conclusion The magnetic compression anastomat is a safe and effective device of sutureless intestinal anastomosis in canine models.

Fedora-type magnetic compression anastomosis device for intestinal anastomosis

BACKGROUND Although previous studies have confirmed the feasibility of magnetic compression anastomosis(MCA),there is still a risk of long-term anastomotic stenosis.For traditional MCA devices,a large device is associated with great pressure,and eventually increased leakage.AIM To develop a novel MCA device to simultaneously meet the requirements of pressure and size.METHODS Traditional nummular MCA devices of all possible sizes were used to conduct ileac anastomosis in rats.The mean(±SD)circumference of the ileum was 13.34±0.12 mm.Based on short-and long-term follow-up results,we determined the appropriate pressure range and minimum size.Thereafter,we introduced a novel“fedora-type”MCA device,which entailed the use of a nummular magnet with a larger sheet metal.RESULTS With traditional MCA devices,the anastomoses experienced stenosis and even closure during the long-term follow-up when the anastomat was smaller thanΦ5 mm.However,the risk of leakage increased when it was larger thanΦ4 mm.On comparison of the different designs,it was found that the“fedora-type”MCA device should be composed of aΦ4-mm nummular magnet with aΦ6-mm sheet metal.CONCLUSION The diameter of the MCA device should be greater than 120%of the enteric diameter.The novel“fedora-type”MCA device controls the pressure and optimizes the size.

Magnetic compression anastomosis for reconstruction of digestive tract after total gastrectomy in beagle model

BACKGROUND Magnetic compression anastomosis(MCA)is a simple procedure contributing to a reliable anastomosis.However,digestive-tract reconstruction after total gastrectomy using MCA has not yet been reported.AIM To investigate the feasibility of MCA for simultaneous esophagojejunostomy and jejunojejunostomy after total gastrectomy using beagle dogs.METHODS Sixteen beagles were randomly divided into an MCA group(study group,n=8)and a manual-suture anastomosis group(control group,n=8).Two different magnetic anastomosis devices were used in the study group for esophagojejunal and jejunojejunal anastomoses.Both devices included a pair of circular daughter and parent magnets each.The time of esophagojejunostomy and jejunojejunostomy,postoperative complications,and survival rate of the two groups were compared.The dogs were sacrificed one month after the operation and their anastomotic specimens were obtained.Healing was observed by the naked eye and a light microscope.RESULTS Digestive-tract reconstruction after total gastrectomy was successfully completed in both groups(survival rate=100%).In the study group,esophagojejunal and jejunojejunal anastomoses took 6.13±0.58 and 4.06±0.42 min,respectively,significantly lower than those in the control group(15.63±1.53 min,P<0.001 and 10.31±1.07 min,P<0.001,respectively).Complications such as bleeding,anastomotic leakage,and anastomotic stenosis were not observed.In the study group,the magnets did not interfere with each other.Discharge time of the jejunojejunal magnetic anastomosis device was 10.75±1.28 d,while that of the esophagojejunal magnetic anastomosis device was 12.25±1.49 d.Residual silk was found in the control group.The study group showed a greater smoothness of the anastomosis than that of the control group.All layers of anastomosis healed well in both groups.CONCLUSION MCA is a safe and feasible procedure for digestive-tract reconstruction after total gastrectomy in this animal model.

Endoscopic magnetic compression stricturoplasty for congenital esophageal stenosis:A case report

BACKGROUND Congenital esophageal stenosis(CES)is a rare malformation of the digestive tract.Endoscopic dilation and thoracotomy have been the main treatments for CES.However,there is no well-defined management protocol.Magnetic compression stricturoplasty(MCS)has been used in refractory esophageal stricture in children after esophageal atresia.CASE SUMMARY We describe the first case of MCS for CES in one female child patient.The child(aged 3 years and 1 mo)was admitted due to frequent vomiting and choking after eating complementary food since 7 mo old.Esophagography and gastroendoscopy showed that there was stenosis in the lower esophagus,suggesting a diagnosis of CES.The patient did not receive any treatment for esophageal stricture including surgery or endoscopic dilation procedures before MCS.MCS procedure was smoothly conducted without complications.At 24 mo after MCS,durable esophageal patency without dysphagia was achieved.CONCLUSION MCS may serve as an alternative and efficient method for patients with CES.

Primary repair of esophageal atresia gross type C via thoracoscopic magnetic compression anastomosis:A case report

BACKGROUND Esophageal atresia(EA)is a life-threatening congenital malformation in newborns,and the traditional repair approaches pose technical challenges and are extremely invasive.Therefore,surgeons have been actively investigating new minimally invasive techniques to address this issue.Magnetic compression anastomosis has been reported in several studies for its potential in repairing EA.In this paper,the primary repair of EA with magnetic compression anastomosis under thoracoscopy was reported.CASE SUMMARY A full-term male weighing 3500 g was diagnosed with EA gross type C.The magnetic devices used in this procedure consisted of two magnetic rings and several catheters.Tracheoesophageal fistula ligation and two purse strings were performed.The magnetic compression anastomosis was then completed thoracoscopically.After the primary repair,no additional operation was conducted.A patent anastomosis was observed on the 15th day postoperatively,and the magnets were removed on the 23rd day.No leakage existed when the transoral feeding started.CONCLUSION Thoracoscopic magnetic compression anastomosis may be a promising minimally invasive approach for repairing EA.

Magnetic compression anastomosis for sigmoid stenosis treatment:A case report

BACKGROUND Endoscopic balloon dilation is a minimally invasive treatment for colorectal stenosis.Magnetic compression anastomosis can be applied against gastrointestinal anastomosis.When combined with endoscopy,it offers a unique approach to the recanalization of colorectal stenosis.CASE SUMMARY We have reported here the case of a 53-year-old female patient who underwent a descending colostomy due to sigmoid obstruction.Postoperative fistula restoration was not possible in her due to sigmoid stenosis.Accordingly,endoscopicassisted magnetic compression anastomosis for sigmoid stenosis was performed,and the sigmoid stenosis was recanalized 15 d after the surgery.Subsequently,a reduction colostomy was successfully performed after 10 d.CONCLUSION This case report proposes a novel minimally invasive treatment approach for colorectal stenosis.

Quasi-static magnetic compression of field-reversed configuration plasma:amended scalings and limits from two-dimensional MHD equilibrium

In this work,several key scaling laws of the quasi-static magnetic compression of field reversed configuration(FRC)plasma(Spencer et al 1983 Phys.Fluids 261564)are amended from a series of two-dimensional FRC MHD equilibriums numerically obtained using the Grad–Shafranov equation solver NIMEQ.Based on the new scaling for the elongation and the magnetic fields at the separatrix and the wall,the empirically stable limits for the compression ratio,the fusion gain,and the neutron yield are evaluated,which may serve as a more accurate estimate for the upper ceiling of performance from the magnetic compression of FRC plasma as a potential fusion energy as well as neutron source devices.

Y–Z deformable magnetic ring for the treatment of rectal stricture: A case report and review of literature

BACKGROUND Treatment of postoperative anastomotic stenosis for colorectal cancer is often challenging,especially for patients who do not respond well to endoscopy.In cases where patients have undergone an enterostomy,the stenosis can be easily resolved through magnetic compression.However,common magnetic compre-ssion techniques cannot be performed on those without enterostomy.We design-ed a novel Y–Z deformable magnetic ring(Y–Z DMR)and successfully applied it to a patient with a stenosis rectal anastomosis and without enterostomy after rectal cancer surgery.CASE SUMMARY We here report the case of a 57-year-old woman who had undergone a laparo-scopic radical rectum resection(Dixon)for rectal cancer.However,she started facing difficulty in defecation 6 months after surgery.Her colonoscopy indicated stenosis of the rectal anastomosis.Endoscopic balloon dilation was performed six times on her.However,the stenosis still showed a trend of gradual aggravation.Because the patient did not undergo an enterostomy,the conventional endoscopic magnetic compression technique could not be performed.Hence,we imple-mented a Y–Z DMR implemented through the anus under single channel.The magnetic ring fell off nine days after the operation and the rectal stenosis was relieved.The patient was followed up for six months and reported good defeca-tion.CONCLUSION The Y–Z DMR deformable magnetic ring is an excellent treatment strategy for patients with rectal stenosis and without enterostomy.

Influence of different magnetic forces on the effect of colonic anastomosis in rats

BACKGROUND Despite much work having been conducted on magnetic compression anastomo-sis(MCA)in the digestive tract,there are no reports on the influence of magnetic force on the anastomosis.AIM To investigate the effect of different magnetic force magnets on the MCA of the digestive tract.METHODS Two groups of magnets of the same sizes but different magnetic forces were designed and produced.A total of 24 Sprague-Dawley rats were randomly assigned into two groups(powerful magnet group and common magnet group),with 12 rats in each group.Two types of magnets were used to complete the colonic side-to-side anastomosis of the rats.The operation time and magnet discharge time were recorded.The anastomotic specimens were obtained 4 wk after the operation and then the burst pressure and diameter of the anastomosis were measured,and the anastomosis was observed via the naked eye and subjected to histological examination.RESULTS The magnetic forces of the powerful and common magnet groups at zero distance were 8.26 N and 4.10 N,respectively.The colonic side-to-side anastomosis was completed in all 24 rats,and the operation success rate and postoperative survival rate were 100%.No significant difference was noted in the operation time between the two groups.The magnet discharge time of the powerful magnet group was slightly longer than that of the common magnet group,but the difference was not statistically significant(P=0.513).Furthermore,there was no statistical difference in the burst pressure(P=0.266)or diameter of magnetic anastomosis(P=0.095)between the two groups.The gross specimens of the two groups showed good anastomotic healing,and histological observation indicated good mucosal continuity without differences on healing.CONCLUSION In the rat colonic side-to-side MCA model,both the powerful magnet with 8.26 N and the common magnet with 4.10 N showed no significant impact on the anastomosis establishment process or its effect.

Roux-en-Y choledochojejunostomy using novel magnetic compressive anastomats in canine model of obstructive jaundice

BACKGROUND:The traditional hand-sewn Roux-en-Y choledochojejunostomy is technically complicated,and the incidence of postoperative complications has remained high.A set of novel magnetic compressive anastomats was introduced to facilitate choledochojejunostomy and improve the prognosis of patients.METHODS:After ligating the common bile duct for 7 days,16 dogs were randomly divided into two groups (n=8 per group).Anastomats were used in the study group,and the traditional hand-sewn method was used in the control group for standard Roux-en-Y choledochojejunostomy.We compared the operation time,incidence of complications,gross appearance,and pathological disparity in stoma between the two groups in 1-month and 3-month follow-up examinations.RESULTS:The time spent on constructing the anastomosis for the study group was significantly shortened.Although no anastomotic stenosis occurred in the two groups,the narrowing rate of biliary-enteric anastomosis was much higher in the control group.There was one case of bile leakage in the control group,whereas no bile leakage occurred in the study group.A smoother surface,an improved layer apposition,and a lower local inflammatory response were identified in the anastomosis of the study group.CONCLUSION:The structures of the novel magnetic compressive anastomats are simple,and they are time-saving,safe and efficient for performing Roux-en-Y choledocho- jejunostomy procedures in a canine model of obstructive jaundice.

Fast magnetic reconstruction of the portal vein with allogeneic blood vessels in canines

BACKGROUND： The resection and reconstruction of large vessels, including the portal vein, are frequently needed in tumor resection. Warm ischemia before reconstruction might have deleterious effects on the function of some vital organs and therefore, how to reconstruct the vessels quickly after resection is extremely important. The present study was to introduce a new type of magnetic compression anastomosis （MCA） device to establish a quick non-suture anastomosis of the portal vein after resection in canines.

Regularization by Multiple Dual Frames for Compressed Sensing Magnetic Resonance Imaging With Convergence Analysis

Plug-and-play priors are popular for solving illposed imaging inverse problems. Recent efforts indicate that the convergence guarantee of the imaging algorithms using plug-andplay priors relies on the assumption of bounded denoisers. However, the bounded properties of existing plugged Gaussian denoisers have not been proven explicitly. To bridge this gap, we detail a novel provable bounded denoiser termed as BMDual,which combines a trainable denoiser using dual tight frames and the well-known block-matching and 3D filtering(BM3D)denoiser. We incorporate multiple dual frames utilized by BMDual into a novel regularization model induced by a solver. The proposed regularization model is utilized for compressed sensing magnetic resonance imaging(CSMRI). We theoretically show the bound of the BMDual denoiser, the bounded gradient of the CSMRI data-fidelity function, and further demonstrate that the proposed CSMRI algorithm converges. Experimental results also demonstrate that the proposed algorithm has a good convergence behavior, and show the effectiveness of the proposed algorithm.

Primary animal experiment to test the feasibility of a novel Y-Z magnetic hepatic portal blocking band

BACKGROUND Hepatic portal blood flow occlusion is a common technique for reducing hepatic hemorrhage during hepatectomy.We designed a novel Y-Z magnetic hepatic portal blocking band(Y-Z MHPBB)based on the principle of magnetic compression technique.AIM To introduce the Y-Z MHPBB device and verify the feasibility of this device for hepatic portal blood flow occlusion in dogs.METHODS Ten beagles were randomly divided into the experimental group and control group.The operation time,intraoperative blood loss,the number of portal blood flow occlusions,the total time spent on adjusting the blocking band,and the average time spent on adjusting the blocking band were recorded.The surgeons evaluated the feasibility and flexibility of the two portal occlusion devices.RESULTS Laparoscopic hepatectomy was successfully performed in both the experimental group and control group.There was no statistical difference between the two groups in the operation time,intraoperative blood loss,and the number of hepatic portal blood flow occlusions.With respect to the total time spent on adjusting the blocking band and the average time spent on adjusting the blocking band,the experimental group showed significantly better outcomes than the control group,with a statistical difference(P<0.05).The operators found that the Y-Z MHPBB was superior to the modified T-tube in terms of operational flexibility.CONCLUSION The Y-Z MHPBB seems to be an ingenious design,accurate blood flow occlusion effect,and good flexibility;and it can be used for hepatic portal blood flow occlusion during laparoscopic hepatectomy.

柴北缘骆驼泉剖面新生代地层磁组构特征及其构造意义

青藏高原东北部新生代构造演化对理解高原隆升和变形模式具有重要意义,而目前对于该地区挤压应力方向转变过程仍存在很大争议.本文对柴北缘逆冲带北西部骆驼泉剖面新生代地层开展系统磁组构(本文特指磁化率各项异性)研究,以揭示该地区挤压应力方向的转变特征.系统岩石磁学结果表明,骆驼泉剖面新生代样品中主要磁性矿物是顺磁性组分和赤铁矿以及少量磁铁矿.通过对磁组构特征分析及其与古水流方向对比表明,骆驼泉剖面新生代地层磁组构主要为初始变形磁组构,可用于指示沉积成岩时期的挤压应力方向.磁组构结果揭示,骆驼泉地区挤压应力方向在上干柴沟组下部沉积时期为NNE-SSW向,而上干柴沟组上部和油砂山组沉积时期转变为NE-SW向.结合柴北缘逆冲带已有磁组构结果指出,该地区早期N-S向或NNE-SSW向挤压应力可能与印度—欧亚板块早新生代以来近N-S向碰撞挤压过程有关,指示印度—欧亚碰撞的挤压应力自下干柴沟组下部沉积时期就已传播至高原东北部地区;而后期NE-SW向挤压应力方向与该地区现今GPS揭示的上地壳运动方向一致,可能与该时段高原东北部巨型走滑断裂构造体系(尤其是阿尔金断裂)有关.此外,柴北缘逆冲带新生代挤压应力方向转变在其北西部起始于上干柴沟组下部沉积时期,而南东部起始于上油砂山组下部沉积时期,与地震反射剖面揭示的断裂活动等地质证据共同揭示柴北缘逆冲带新生代的构造活动自靠近阿尔金断裂的北西部向南东部传播和扩展.综合分析青藏高原东北部地区挤压应力方向转变和其他地质证据发现,挤压应力方向转变显示出自柴北缘逆冲带北西部向东、西和南向扩展特征,与阿尔金断裂在上干柴沟组下部-上油砂山组下部沉积时期剪切应力集中于断裂本身,而上油砂山组下部沉积以来开始散布于高原东北部内部地区的两阶段走滑活动相关.