Applied anatomy of the genital branch of the genitofemoral nerve in open inguinal herniorrhaphy.

OBJECTIVE: To record the anatomical variations and clinical importance of the genital branch of the genitofemoral nerve in the inguinal canal. DESIGN: Neuropathology study. SETTING: General hospital, Taiwan. SUBJECTS: 58 cadavers. INTERVENTIONS: 116 dissections findings of the genitofemoral nerve in the inguinal canal. MAIN OUTCOME MEASURES: Anatomical variations. RESULTS: All the genital branches passed through the ventral aspect of the internal ring. Almost all these branches entered the ring and continued within the spermatic cord between the fibres of the cremaster and the internal spermatic fascia. In 59% the nerve was related to the inferior fibres and in 38% it was in relation to the lateral or medial fibres. In only 3% did the genital branch run outside the spermatic cord. CONCLUSION: To avoid damage to the genital branch of the genitofemoral nerve, suturing should be done over the dorsal aspect of the internal ring. The cremaster should be incised longitudinal rather than transversely and the genital branch of the genitofemoral nerve should be identified before repair of the posterior wall.     

Selective restoration of motor function in the ulnar nerve by transfer of the anterior interosseous nerve. An anatomical feasibility study

BACKGROUND: Proximal ulnar-nerve lesions have an unfavorable prognosis. The goal of the present study was to evaluate the feasibility of selective restoration of motor function of the ulnar nerve by the transfer of the anterior interosseous nerve or one of its branches to the motor branch of the ulnar nerve. METHODS: Ten cadaveric arms were used in the present study. The ulnar nerve and its motor and sensory branches as well as the anterior interosseous nerve and its branches were dissected. The widths of the motor branch of the ulnar nerve and the anterior interosseous nerve and its motor branches as well as the relevant distances from the points of divergence were measured. The axons were counted, and the distances from the end of the main anterior interosseous nerve, its motor branches, and the motor branch of the ulnar nerve to the level of the dorsal sensory branch of the ulnar nerve were measured. RESULTS: Our results indicate that the length, width, and number of axons of the branch of the anterior interosseous nerve to the pronator quadratus make it suitable for transfer to the motor branch of the ulnar nerve. The use of the main anterior interosseous nerve or its motor branches to the flexor pollicis longus and the flexor digitorum profundus is less feasible because of the need to graft a long segment and the longer distance from the level of transfer to the motor end points. CONCLUSIONS: The findings of the present study confirm the feasibility of motor-nerve transfer for reconstruction after an injury of the ulnar nerve. Nerve-grafting would be needed for injuries distal to the level of the dorsal sensory branch of the ulnar nerve.     

大鼠肱肌肌支的脊髓神经根定位

目的 比较逆行示踪法及肌电图检测法在定位肱肌肌支及肱肌脊髓神经根起源中的价值,并探讨将肌电图检测法运用于定位人类肌皮神经肱肌肌支脊髓神经根起源的可能性.方法 在大鼠臂丛神经根切断-保留模型中运用神经元逆行示踪法定位肱肌肌支及肱肌的脊髓神经根起源;通过分析刺激大鼠各臂丛神经根时肱肌记录到的CMAP指标定位肱肌肌支及肱肌的脊髓神经根起源.结果 大鼠桡神经肱肌肌支的运动纤维主要来源于C7神经根,大鼠肌皮神经肱肌肌支的运动纤维主要来源于C5、6神经根;在定位大鼠肱肌的脊髓神经根起源时,肌电图法与逆行示踪法的检测结果基本一致.结论 通过分析逆行示踪和肌电图检测的结果,能够精确定位大鼠特定神经、肌肉的脊髓神经根来源;在临床研究中,肌电图检测法可以用于定位人类肌皮神经肱肌肌支的脊髓神经根起源.     

Intercostal nerve transfer classification

We report a new classification of intercostal nerve transfer. The specific application in brachial plexus reconstruction is described. This method was applied in intercostal nerve transfer to the musculocutaneous nerve in 15 patients. In type 1, "MOTOR to MIXED" transfer one harvest only the intercostal main motor branch which is connected at the trunk of the musculocutaneous nerve, without fascicular specificity. In type 2, "MIXED to MIXED" transfer, based on neural cartography, the main motor branch and its sensitive accessory anterior branches are connected to the musculocutaneous nerve trunk, in attempt to connect the motor fascicules together at the center and also the sensory fascicules together, at the circumference. In type 3, "MOTOR to MOTOR" transfer, the intercostal main motor branch is connected to the musculocutaneous motor branch directly destined to the biceps brachialis. The aim of this work is to evaluate the results between different series.     

The superficial branch of the radial nerve: An anatomic study with surgical implications

Twenty fresh cadaver extremities were dissected to delineate and quantify the course of the superficial branch of the radial nerve. This branch bifurcated from the radial nerve at the level of the lateral humeral epicondyle in eight specimens, and in all specimens the bifurcation was no more than 2.1 cm from the lateral epicondyle. It continued distally, deep to the brachioradialis and became subcutaneous a mean of 9.0 cm proximal to the radial styloid, traversing between the tendons of the brachioradialis and extensor carpi radialis longus. The superficial branch of the radial nerve branched a mean of 5.1 cm proximal to the radial styloid. Distally, at the level of the extensor retinaculum, the closest branches to the center of the first dorsal compartment and to Lister's tubercle were mean distances of 0.4 and 1.6 cm, respectively. In the hand, the superficial branch of the radial nerve most commonly supplied branches to the thumb, the index finger, and the dorsoradial aspect of the long finger. Knowledge of the course of the superficial branch of the radial nerve will help prevent injury during operative procedures on the radial side of the hand, wrist, and forearm and will aid in its localization in treatment of traumatic injuries or performance of nerve blocks in its distribution.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

肘部和前臂段桡神经解剖特征及损伤修复

目的 观察肘部和前臂段桡神经的解剖学特征及损伤修复的方法.方法 36侧成人上肢标本,于肘外侧做"S"形切口,从肱肌和肱桡肌间隙内解剖出桡神经肘段,沿桡神经干向远端追踪,找出桡神经深支出旋后肌的各个分支,测量深支各肌支的发出点、入肌点距肱骨髁上水平的距离和长度.逆行分离各分支,观察各分支的神经纤维在桡神经干内的分布定位特征.对12例肘部桡神经损伤的患者,采用桡神经定位缝合和不定位缝合的方法进行修复.结果 12例获得平均2.4年的随访.根据桡神经深支支配的运动区肌腱肌力恢复情况,神经定位缝合6例,术后有效率为83.3%.非定位缝合6例,有效率为50.0%.桡神经定位缝合组的有效率明显高于不定位缝合组.结论 前臂背侧距肱骨外上髁10～15cm范围内的锐器伤,伸拇困难者应考虑有骨间背神经肌支的损伤.运动支的神经纤维在桡神经干的内侧,对肘部桡神经断裂伤修复时重点应缝合内侧部分.显微定位缝合技术修复肘部和前臂段桡神经损伤是有效的方法.     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.     

Quantitation of and landmarks for the muscular branches of the ulnar nerve to the forearm for application in peripheral nerve neurotization procedures

OBJECT: In neurotization procedures, donor nerves--either whole or in part-with relatively pure motor function can be carefully chosen to provide the optimal nearby motor input with as little donor site morbidity as possible. In this context, the ulnar nerve branches to the forearm muscles are relatively dispensable; however, quantitation of and landmarks for these branches are lacking in the literature. METHODS: The ulnar branches to the flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP) muscles in 20 upper extremities obtained in adult cadaveric specimens were dissected and quantified. In the forearm, a mean of four nerve branches led to the FCU and FDP muscles. A mean of 3.4 branches led to the FCU muscle; of these, one to three were medial branches and zero to two were lateral. Medial branches to the FCU muscle originated a mean of 2.7 cm inferior to the medial epicondyle. Lateral branches to the FCU muscle originated at a mean of 3.3 cm inferior to the medial epicondyle. The mean length of the medial branches was 3.2 cm, whereas the mean length of the lateral branches was 3.3 cm. All nerves had a single trunk for the FDP muscle, and in all specimens this branch was located deep to the main ulnar nerve trunk, originating from the ulnar nerve a mean of 2.7 cm inferior to the medial epicondyle. These branches had a mean length of 5.6 cm. The mean diameter of all medial and lateral branches to the FCU muscle was 1 mm, and the mean diameter of the branch to the FDP muscle was 2.1 mm. All branches to both the FCU and FDP muscles arose from the ulnar nerve, over its first approximately 5 cm from the level of the medial epicondyle. Additionally, all branches could be easily lengthened by gentle proximal dissection from the main ulnar nerve. CONCLUSIONS: Ulnar branches to the forearm can be easily localized and used for neurotization procedures. The branch to the FDP muscle had the greatest diameter and longest length, easily reaching the median nerve and posterior interosseous nerve via a transinterosseous membrane tunneling procedure. Furthermore, this branch could be teased away from the main ulnar nerve trunk and made to reach the distal branches of the musculocutaneous nerve in the arm.     

The sensory branch distribution of the suprascapular nerve: an anatomic study

The suprascapular nerve is responsible for most of the sensory innervation to the shoulder joint and is potentially at risk during surgery. In this study, 31 shoulders in 22 cadavers were dissected to investigate the sensory innervation of the shoulder joint by the suprascapular nerve, with special reference to its sensory branches. In 27 shoulders (87.1%), a small sensory branch was observed that splits off from the main stem of the suprascapular nerve proximal (48.2%), inferior (40.7%), or distal (11.1%) to the transverse scapular ligament. This percentage is considerably higher than has been previously found. In 74.2% of the shoulders, an acromial branch was also found, originating just proximal to the scapular neck, running to the infraspinatus tendon. These cadaveric results indicate that sensory branches to the shoulder joint are more common and numerous than previously described and therefore should be considered in shoulder surgery and nerve blocks to this area.