Double-nylon purse-string suture in closing postoperative wounds following endoscopic resection of large(≥3 cm)gastric submucosal tumors

BACKGROUND Endoscopic full-thickness resection(EFTR)of gastric submucosal tumors(SMTs)is safe and effective;however,postoperative wound management is equally important.Literature on suturing following EFTR for large(≥3 cm)SMTs is scarce and limited.AIM To evaluate the efficacy and clinical value of double-nylon purse-string suture in closing postoperative wounds following EFTR of large(≥3 cm)SMTs.METHODS We retrospectively analyzed the data of 85 patients with gastric SMTs in the fundus of the stomach or in the lesser curvature of the gastric body whose wounds were treated with double-nylon purse-string sutures after successful tumor resection at the Endoscopy Center of Renmin Hospital of Wuhan University.The operative,postoperative,and follow-up conditions of the patients were evaluated.RESULTS All tumors were completely resected using EFTR.36(42.35%)patients had tumors located in the fundus of the stomach,and 49(57.65%)had tumors located in the body of the stomach.All patients underwent suturing with double-nylon sutures after EFTR without laparoscopic assistance or further surgical treatment.Postoperative fever and stomach pain were reported in 13(15.29%)and 14(16.47%)patients,respectively.No serious adverse events occurred during the intraoperative or postoperative periods.A postoperative review of all patients revealed no residual or recurrent lesions.CONCLUSION Double-nylon purse-string sutures can be used to successfully close wounds that cannot be completely closed with a single nylon suture,especially for large(≥3 cm)EFTR wounds in SMTs.

Early Triassic Volcanic Rocks in the Western Yarlung Zangbo Suture Zone:Implications for the Opening of the Neo-Tethys Ocean

In this study,zircon U-Pb dating of volcanic rocks from the Zhongba ophiolite of the Yarlung Zangbo Suture Zone(YZSZ)in southern Xizang(Tibet)yielded an age of 247±3 Ma.According to whole rock geochemical and Sr-NdPb isotopic data,the Early Triassic samples could be divided into two groups:Group 1 with P-MORB affinity,showing initial^(87)Sr/^(86)Sr ratios of 0.70253–0.70602,ε_(Nd)(t)values of 4.2–5.3,(^(206)Pb/^(204)Pb)_(t)ratios of 16.353–18.222,(^(207)Pb/^(204)Pb)_(t)ratios of 15.454–15.564,and(^(208)Pb/^(204)Pb)_(t)ratios of 35.665–38.136;Group 2 with OIB affinity,showing initial^(87)Sr/^(86)Sr ratios of 0.70249–0.70513,ε_(Nd)(t)values of 4.4–4.9,(^(206)Pb/^(204)Pb)_(t)ratios of 17.140–18.328,(^(207)Pb/^(204)Pb)_(t)ratios of 15.491–15.575,and(^(208)Pb/^(204)Pb)_(t)ratios of 36.051–38.247.Group 2 rocks formed by partial melting of the mantle source enriched by a former plume,and assimilated continental crustal material during melt ascension.The formation of Group 1 rocks corresponds to the mixing of OIB melts,with the same components as Group 2 and N-MORBs.The Zhongba Early Triassic rocks belong to the continental margin type ophiolite and formed in the continental–oceanic transition zone during the initial opening of the Neo-Tethys in southern Xizang(Tibet).

Thirty-gauge needle-guided purse-string suture pupilloplasty:a new technique

AIM:To observe the clinical outcomes of 30-gauge(G)needle-guided 10-0 prolene suture purse-string pupilloplasty for atonic pupil management.METHODS:Eight patients with atonic pupils who underwent suture purse-string pupilloplasty were retrospectively analyzed.Preoperative data and at least 6mo of postoperative data were collected from all the patients.RESULTS:The corrected distance visual acuity(CDVA)before and after surgery was 0.58±0.22 and 0.20±0.10 logMAR,respectively(P=0.002).The pre-and postoperative pupil size was 7.38±0.88 and 3.09±0.71 mm(P=0.000),respectively.The corneal endothelial cell count was 2841±176/mm^(2) before and 2692±143/mm^(2) after surgery(P=0.000).No intraoperative or postoperative complications were reported.During the follow-up period of at least 6mo,all treated pupils were centered and generally or nearly round.Furthermore,the patients did not exhibit photophobia,glare,or diplopia.CONCLUSION:This technique is a simple and effective method for pupil reduction.

Transcriptomic and cellular decoding of scaffolds-induced suture mesenchyme regeneration

Precise orchestration of cell fate determination underlies the success of scaffold-based skeletal regeneration.Despite extensive studies on mineralized parenchymal tissue rebuilding,regenerating and maintaining undifferentiated mesenchyme within calvarial bone remain very challenging with limited advances yet.Current knowledge has evidenced the indispensability of rebuilding suture mesenchymal stem cell niches to avoid severe brain or even systematic damage.But to date,the absence of promising therapeutic biomaterials/scaffolds remains.The reason lies in the shortage of fundamental knowledge and methodological evidence to understand the cellular fate regulations of scaffolds.To address these issues,in this study,we systematically investigated the cellular fate determinations and transcriptomic mechanisms by distinct types of commonly used calvarial scaffolds.Our data elucidated the natural processes without scaffold transplantation and demonstrated how different scaffolds altered in vivo cellular responses.A feasible scaffold,polylactic acid electrospinning membrane(PLA),was next identified to precisely control mesenchymal ingrowth and self-renewal to rebuild non-osteogenic suture-like tissue at the defect center,meanwhile supporting proper osteointegration with defect bony edges.Especially,transcriptome analysis and cellular mechanisms underlying the well-orchestrated cell fate determination of PLA were deciphered.This study for the first time cellularly decoded the fate regulations of scaffolds in suture-bony composite defect healing,offering clinicians potential choices for regenerating such complicated injuries.

Single self-leading suture technique for iridodialysis repairment

Dear Editor,We described an innovative“single self-leading suture technique”for repairing iridodialysis.Instead of moving the needle forth and back,our method is easier to manipulate in the narrow surgical space between the cornea and lens,which will decrease the unnecessary complications related to iatrogenic injury.We provide an economical friendly and less time-taking method,which improves the suture accuracy.

Intermittent sliding-lock-knot suture for limbal conjunctival autograft fixation in pterygium surgery:a technique note

AIM:To report a technique used with intermittent slidinglock-knot(ISLK)fixation for limbal conjunctival autografts in pterygium surgery and compared with those of routine intermittent(RI)fixation.METHODS:Consecutive patients with primary pterygium who had undergone pterygium excision combined with limbal conjunctival autograft transplantation between March 2021 and March 2022 at our institute were retrospectively analyzed.Primary outcome measures were mean duration of surgery and suture removal,degree of conjunctival hyperemia on postoperative day 1,pain score at suture removal,postoperative symptoms at 6mo,including conjunctival hyperemia,foreign body sensation,and graft stability.RESULTS:Ninety-eight patients underwent monocular surgery and were divided into ISLK(51 eyes)and RI(47 eyes)groups according to the type of conjunctiva autograft fixation method planned.There was no significant difference in mean duration of surgery between the two groups(18.59±2.39min vs 18.15±2.20min,P=0.417);however,compared to the RI group,shorter suture removal times were observed in the ISLK group[0.58min(0.42-0.87)vs 3.00min(2.21-4.15),P<0.001].The degree of conjunctival hyperemia on postoperative day 1 was milder in the ISLK group(P<0.001).Pain scores at suture removal were lower in the ISLK group than in RI group[1(0-3)vs 2(1-4),P<0.001].Postoperative symptoms at 6mo were comparable between the groups(P=0.487),with no recurrence.CONCLUSION:ISLK is an innovative method for limbal conjunctival autograft fixation after pterygium excision.Compared to RI fixation,ISLK facilitates suture removal and reduces discomfort,with comparable surgery duration and less conjunctival hyperemia.

Outcomes of a non-randomised audit of single pigtail suture stents in urolithiasis management of Asian patients in Singapore

Objective:Double-J(DJ)ureteric stents are commonly placed perioperatively for semirigid or flexible ureteroscopic renal surgery.It is believed that lesser stent material within the bladder mitigates stent-related symptoms.This study aimed to evaluate the J-Fil ureteral stent,a single pigtail suture stent compared with conventional DJ stent in relation to stent symptoms in an Asian population undergoing ureterorenal intervention.Methods:Based on internal audit committee recommendation approval,the records of 50 patients retrieved,available data of 41 patients who were prospectively enrolled into two groups(Group 1[J-Fil stent group],n=21 and Group 2[DJ stent group],n=20)between August 2020 to January 2021,were analysed.Parameters compared were nature of procedure,stone location and size,ease of deployment or removal,and complications.A modified universal stent symptom questionnaire was used to assess morbidity of stent symptoms within 48 h of insertion and at removal.Results:Both groups had similar median age,distribution in male to female ratio,and stone size.The overall median universal stent symptom questionnaire score at insertion was similar for bladder pain,flank or loin pain,and quality of life between Group 1 and 2;however,at removal Group 1 fared significantly better than Group 2,especially for flank or loin pain and pain at voiding.Both groups had similar ease in insertion with no hospital readmissions.Conclusion:Our audit favoured the single pigtail suture stent in Asian ureters in mitigating stent-related issues.It showed a good safety profile with easy deployment and removal.It promises a new standard in stenting.

Arthroscopic M-shaped suture fixation for tibia avulsion fracture of posterior cruciate ligament:A modified technique and case series

BACKGROUND Tibial avulsion fractures of the posterior cruciate ligament(PCL)are challenging to treat and compromise knee stability and function.Traditional open surgery often requires extensive soft tissue dissection,which may increase the risk of morbidity.In response to these concerns,arthroscopic techniques have been evolving.The aim of this study was to introduce a modified arthroscopic tech-nique utilizing an M-shaped suture fixation method for the treatment of tibial avulsion fractures of the PCL and to evaluate its outcomes through a case series.AIM To evaluate the effects of arthroscopic M-shaped suture fixation on treating tibia avulsion fractures of the PCL.METHODS We developed a modified arthroscopic M-shaped suture fixation technique for tibia avulsion fractures of the PCL.This case series included 18 patients who underwent the procedure between January 2021 and December 2022.The patients were assessed for range of motion(ROM),Lysholm score and International knee documentation committee(IKDC)score.Postoperative complications were also recorded.RESULTS The patients were followed for a mean of 13.83±2.33 months.All patients showed radiographic union.At the final follow-up,all patients had full ROM and a negative posterior drawer test.The mean Lysholm score significantly improved from 45.28±8.92 preoperatively to 91.83±4.18 at the final follow-up(P<0.001),and the mean IKDC score improved from 41.98±6.06 preoperatively to 90.89±5.32 at the final follow-up(P<0.001).CONCLUSION The modified arthroscopic M-shaped suture fixation technique is a reliable and effective treatment for tibia avulsion fractures of the PCL,with excellent fracture healing and functional recovery.

关节镜辅助下Suture-button弹性固定治疗高位踝关节扭伤

背景:高位踝关节扭伤容易漏诊导致踝关节功能障碍,关节镜检查可发现隐匿性高位踝关节扭伤,采用Suture-button弹性固定能恢复远端胫腓联合的生物力学稳定性。目的:探讨踝关节镜辅助下采用Suture-button弹性固定治疗高位踝关节扭伤的临床疗效。方法:回顾性分析2019年8月至2021年8月武汉市第四医院足踝外科在踝关节镜辅助下进行Suture-button弹性固定治疗的40例高位踝关节扭伤患者的病历资料。所有患者均采用Suture-button弹性固定,记录患者术前及术后末次随访美国矫形外科足踝协会踝-后足功能评分、目测类比疼痛评分、踝关节活动度,将患者术前影像学数据与术中关节镜下分离程度进行相关性分析,按照Meislin标准进行疗效评估并记录术后并发症发生情况。结果与结论:①40例患者术后获16-48个月随访;②术后末次随访美国矫形外科足踝协会踝-后足功能评分为(88.95±6.64)分,目测类比评分为(1.78±1.23)分,踝背伸活动度为(33.50±5.79)°,踝跖屈活动度为(34.50±5.97)°,与术前相比差异均有显著性意义(P<0.05);③影像学分离指标与关节镜下分离程度存在低度正相关(r=0.612,P<0.01);④采用Meislin标准对疗效进行评估,优良率为95%(38/40);术后踝关节疼痛减轻,踝关节自主活动明显改善;⑤随访期间所有患者均未出现神经损伤及切口感染情况;1例患者因术后存在皮肤刺激、下蹲卡顿感取出内固定;⑥提示采取关节镜辅助Suture-button弹性固定治疗高位踝关节扭伤的临床疗效确切,能够更有效地恢复患肢足踝功能,恢复并维持关节稳定性且无需二次取出,值得临床应用。

Suture Button装置修复下胫腓联合损伤的初步报告

[目的]探讨Suture Button装置治疗下胫腓联合损伤后的手术方法及临床效果。[方法]对截止于2007年9月利用Suture Button装置固定的下胫腓联合急、慢性损伤的13例病人进行连续随访观察,通过术后X线片数字化测量和标准的踝足功能评分,评估其疗效并探讨临床应用前景。[结果]除1例病人因术后短期再次创伤意外,行2次手术更换为传统螺钉内固定外,其余病人均在术后6周开始部分负重功能锻炼,术后第3个月功能平均评分达到满意,术后第6、12个月功能平均评分达到优良,X线片未发现内固定失效。[结论]Suture Button装置治疗下胫腓联合损伤具有技术简单、手术时间短、内固定器物理特性符合人体正常解剖生理、固定强度足够、无需2次手术取出等多项优势,可能成为下胫腓联合损伤新的治疗标准。

关节镜下Suture-Bridge线桥技术止点足印重建前交叉韧带撕脱骨折

目的 ：探讨关节镜下复位、Suture-Bridge线桥技术止点足印重建前交叉韧带撕脱骨折的手术方法及临床疗效。方法：2010年3月至2012年9月,对6例膝关节前交叉韧带（ACL）胫骨端止点撕脱骨折患者,在关节镜下行撕脱骨块解剖复位、Suture-Bridge线桥技术ACL止点胫骨端足印重建术。ACL止点撕脱骨折Meyers-Mc KeeverZaricznyj分型：Ⅲ型2例,Ⅳ型4例;其中男2例,女4例;年龄14～52岁,青少年2例,分别为男14岁和女15岁）。术前患膝前抽屉试验及Lachman试验均呈阳性。结果：所有患者获随访,时间均超过2年。术后患膝前抽屉试验及Pivotshift均阴性,无伸膝受限。术后影像学复查示ACL止点撕脱骨折均愈合,骨折复位良好,ACL走行正常。术后3个月及1、2年的Lysholm及IKDC评分均较术前改善。结论 ：关节镜下复位、Suture-Bridge线桥技术止点足印重建前交叉韧带撕脱骨折的手术方式安全有效,实现ACL胫骨止点解剖重建,尤其适用于撕脱骨块碎裂严重或胫骨骨骺未闭合的青少年患者。

Suture-anchor锚钉在Weber C型踝关节骨折合并下胫腓联合损伤中的应用

目的 研究Suture-anchor锚钉修复下胫腓前韧带在Weber C型踝关节骨折合并下胫腓联合损伤中的临床应用效果。方法 回顾性分析延安大学附属医院2017年3月至2021年3月间收治的84例Weber C型踝关节骨折合并下胫腓联合损伤患者的临床资料,根据患者下胫腓前韧带修复方法将其分为锚钉组(Suture-anchor锚钉修复,n=39)与螺钉组(皮质骨螺钉内固定,n=45),比较两组患者围术期相关指标、复位质量以及术后6个月美国足踝外科协会(AOFAS)踝足评分系统和踝关节Baird-Jackson功能得分情况。结果 锚钉组患者的手术耗时和术中透视次数分别为(103.69±17.79) min、(14.49±3.36)次,明显短(少)于螺钉组的(126.41±20.15) min和(18.41±4.15)次,差异均具有统计学意义(P<0.05);锚钉组患者的下胫腓联合前间距(ITFACS)为(1.86±0.26) mm,明显短于螺钉组的(2.79±0.32) mm,差异有统计学意义(P<0.05),但两组患者的下胫腓联合后间距(ITFPCS)比较差异无统计学意义(P>0.05);锚钉组患者的骨折愈合时间及术后恢复正常工作时间分别为(3.26±0.43)个月和(3.43±0.63)个月,明显短于螺钉组的(3.61±0.39)个月和(3.79±0.71)个月,差异均有统计学意义(P<0.05);术后6个月,两组患者的Baird-Jackson功能评分系统得分及AOFAS踝足功能量表得分比较差异均无统计学意义(P>0.05);锚钉组患者术后并发症发生率为2.56%,略低于螺钉组的17.78%,但差异无统计学意义(P>0.05)。结论 与皮质骨螺钉内固定比较,带线骨锚钉内固定在治疗Weber C型踝关节骨折合并下胫腓联合损伤中更具优势,其可有效增加下胫腓联合前切迹的解剖复位率,且安全性高。

Suture Endobutton与跖肌腱重建Lisfranc韧带的生物力学对比研究

目的通过Suture Endobutton与跖肌腱重建Lisfranc韧带的生物力学对比研究,评价两种方法对恢复Lisfranc关节稳定性的作用,为临床治疗Lisfranc损伤提供理论依据。方法选取10例成人新鲜尸体小腿标本,依次制备Lisfranc韧带完整模型、损伤模型及损伤后的Suture Endobutton或跖肌腱重建模型,并分别给予轴向或外展载荷,记录内侧楔骨（C1）～第2跖骨（M2）基底的平均位移变化。结果轴向载荷和外展载荷下,完整模型C1～M2的平均位移变化分别为（0.70±0.05）mm、（1.21±0.10）mm,损伤模型为（1.59±0.07）mm、（3.73±0.11）mm,Suture Endobutton重建模型为（0.84±0.04）mm、（1.29±0.06）mm,跖肌腱重建模型为（1.01±0.05）mm、（1.34±0.05）mm。轴向或外展载荷下,完整模型和重建模型C1～M2间位移变化明显小于损伤模型,差异具有统计学意义（P〈0.05）;重建模型的位移变化略大于完整模型,但差异无统计学意义（P〉0.05）;Suture Endobutton与跖肌腱重建模型之间位移变化相似,差异无明显统计学意义（P〉0.05）;任一模型外展载荷时的C1～M2位移变化大于轴向载荷。结论 （1）在恢复Lisfranc关节稳定性上,Suture Endobutton与跖肌腱的重建方法提供的生物力学强度相似;（2）相对于轴向载荷的位移变化,外展载荷的实验结果差异更加明显,推荐使用外展载荷进行Lisfranc关节相关力学试验。

V-Locsutures与普通可吸收线在后腹腔镜肾部分切除术中应用比较

目的:比较V-Loc sutures与普通可吸收线在后腹腔镜肾癌部分切除术中的应用价值。方法:2012年5月-2013年6月,本手术组共收治了25例确诊的病理分期为T1N0M0的肾癌患者,其中12例术中肾脏创面缝合均采用V-Loc sutures,其中男9例,女3例,年龄28-68岁,平均48.2岁;肿瘤大小为0.9-4.7cm,平均2.8cm;另13例术中采用普通可吸收线缝合创面,其中男8例,女5例,年龄34-74岁,平均45.5岁;肿瘤大小为1.2-4.5cm,平均2.6cm;比较两组患者手术中的手术时间、术中出血量、肾动脉阻断时间、创面缝合时间、各组手术前后测血肌酐、胱抑素C变化,术后并发症。结果:25例手术均在后腹腔镜下顺利完成。V-Loc sutures组和普通可吸收线组手术时间、术中出血、肾动脉阻断时间、肾创面缝合时间均有差异(P<0.05);V-Loc sutures组手术前后血肌酐、胱抑素C无明显差异(P>0.05),普通可吸收线组手术前后血肌酐、胱抑素C有差异(P<0.05);V-Loc sutures组出现1例血尿,普通可吸收线组出现1例漏尿。结论:V-Loc sutures较普通可吸收线可缩短手术时间及肾创面缝合时间,减少术中出血,更好的保护小肾癌患者的肾功能。

使用Suture-anchor治疗Ⅲ度肩锁关节脱位

[目的]评估使用Suture-anchor治疗肩锁关节脱位的效果。[方法]肩锁关节脱位17例,其中男11例,女6例,均为Tossi III型。年龄17～53岁,平均29．3岁。随访时间6—24个月,平均13．5个月。采用主观评价和Constant评分评价术后肩关节功能,术后X光片评价治疗结果。[结果]术后X-光片显示复位固定良好;肩关节功能评分为93．4分,主观评分为1．7分。[结论]Suture-anchor治疗肩锁关节脱位,创伤小,复位固定确实,术后功能恢复好。

SHRIMP Zircon U-Pb Dating of Gabbro and Granite from the Huashan Ophiolite,Qinling Orogenic Belt,China: Neoproterozoic Suture on the Northern Margin of the Yangtze Craton

The recently identified Huashan ophiolitic mélange was considered as the eastern part of the Mianlüe suture in the Qinling orogenic belt. SHRIMP zircon U-Pb geochronology on gabbro from the Huashan ophiolite and granite intruding basic volcanic rocks indicates crystallization ages of 947±14 Ma and 876±17 Ma respectively. These ages do not support a recently proposed Hercynian Huashan Ocean, but rather favor that a Neoproterozoic suture assemblage （ophiolite） is incorporated into the younger （Phanerozoic） Qinling orogenic belt.

How many sutures in the southern Central Asian Orogenic Belt:Insights from East Xinjiang-West Gansu(NW China)?

How ophiolitic mèlanges can be defined as sutures is controversial with regard to accretionary orogenesis and continental growth.The Chinese Altay,East junggar,Tianshan,and Beishan belts of the southern Central Asian Orogenic Belt（CAOB） in Northwest China,offer a special natural laboratory to resolve this puzzle.In the Chinese Altay,the Erqis unit consists of ophiolitic melanges and coherent assemblages,forming a Paleozoic accretionary complex.At least two ophiolitic melanges（Armantai,and Kelameili） in East Junggar,characterized by imbricated ophiolitic melanges,Nb-enriched basalts,adakitic rocks and volcanic rocks,belong to a Devonian-Carboniferous intra-oceanic island arc with some Paleozoic ophiolites,superimposed by Permian arc volcanism.In the Tianshan,ophiolitic melanges like Kanggurtag,North Tianshan,and South Tianshan occur as part of some Paleozoic accretionary complexes related to amalgamation of arc terranes.In the Beishan there are also several ophiolitic melanges,including the Hongshishan,Xingxingxia-Shibangjing,Hongliuhe-Xichangjing,and Liuyuan ophiolitic units.Most ophiolitic melanges in the study area are characterized by ultramafic,mafic and other components,which are juxtaposed,or even emplaced as lenses and knockers in a matrix of some coherent units.The tectonic settings of various components are different,and some adjacent units in the same melange show contrasting different tectonic settings.The formation ages of these various components are in a wide spectrum,varying from Neoproterozoic to Permian.Therefore we cannot assume that these ophiolitic melanges always form in linear sutures as a result of the closure of specific oceans.Often the ophiolitic components formed either as the substrate of intra-oceanic arcs,or were accreted as lenses or knockers in subduction-accretion complexes.Using published age and paleogeographic constraints,we propose the presence of （1） a major early Paleozoic tectonic boundary that separates the Chinese Altay-East Junggar multiple subduction systems of the southern Siberian active margin from those of the northern Tarim;and （2） a major Permian suture zone that separates the Tianshan-Beishan from the northern active margin of the Tarim Craton.These new observations and interpretations have broad implications for the architecture and crustal growth of central Asia and other ancient orogens as well.

Middle Jurassic-early Cretaceous radiolarian assemblages of the western Yarlung Zangbo Suture Zone: Implications for the evolution of the Neo-Tethys

Cherts in the Zhongba melange of the western Yarlung Zangbo Suture Zone(YZSZ) contain well preserved radiolarian assemblages. These radiolarian assemblages indicate that the Zhongba melange has middle Jurassic-early Cretaceous remnant, are coeval with those from the central and eastern parts of the YZSZ. Cherts from the Najiu area yield Aalenian to Aptian radiolarians, while cherts interbedded with siliceous mudstones from the Bielongjiala area yield Aptian radiolarians, indicating that terrigenousderived sediments were deposited during early Aptian. The above observations indicate that the entire YZSZ have a similar geochronological framework and thus they underwent similar geological evolution:(1) during the Jurassic, the Neo-Tethys was a wide ocean with pelagic sediments distal from continents;(2) during the Cretaceous(around 130-120 Ma), the Neo-Tethys started to subduct along the southern margin of the Lhasa block, and terrigenous-derived siliceous mudstone began deposition.

Diamonds and Other Exotic Minerals Recovered from Peridotites of the Dangqiong Ophiolite, Western Yarlung-Zangbo Suture Zone, Tibet

Various combinations of diamond, moissanite, zircon, quartz, corundum, rutile, titanite, almandine garnet, kyanite, and andalusite have been recovered from the Dangqiong peridotites. More than 80 grains of diamond have been recovered, most of which are pale yellow to reddish-orange to colorless. The grains are all 100-200 μm in size and mostly anhedral, but with a range of morphologies including elongated, octahedral and subhedral varieties. Their identification was confirmed by a characteristic shift in the Raman spectra between 1325 cm^-1 and 1333 cm^-1, mostly at 1331.51 cm^-1 or 1326.96 cm^-1. Integration of the mineralogical, petrological and geochemical data for the Dongqiong peridotites suggests a multi-stage formation for this body and similar ophiolites in the Yarlung-Zangbo suture zone. Chromian spinel grains and perhaps small bodies of chromitite crystallized at various depths in the upper mantle, and encapsulated the UHP, highly reduced and crustal minerals. Some oceanic crustal slabs containing the chromian spinel and their inclusion were later trapped in suprasubduction zones（SSZ）, where they were modified by island arc tholeiitic and boninitic magmas, thus changing the chromian spinel compositions and depositing chromitite ores in melt channels.

Ophiolites from the Mianlüe Suture in the Southern Qinling and Their Relationship with the Eastern Paleotethys Evolution

The Mianlue suture extends from Derni-Nanping-Pipasi-Kangxian to the Lueyang-Mianxian area, then traverses the Bashan arcuate structure eastward to the Huashan region, and finally to the Qingshuihe area of the southern Dabie Mountains. From east to west, with a length of over 1500 km, the ophiolitic melange associations are distributed discontinuously along the suture. The rock assemblages include ophiolite, island-arc and oceanic island rock series, indicating that there existed a suture zone and a vanished paleo-ocean basin. The Mianliie paleo-ocean basin experienced its main expansion and formation process during the Carboniferous-Permian and closed totally in the Triassic. It belongs to the northern branch of the eastern paleotethys, separated from the northern margin of the Yangtze block under the paleotethys mantle dynamic system.