Modeling of Burial History, Source Rock Maturity, and Hydrocarbon Generation of Marine-Continental Transitional Shale of the Permian Shanxi Formation, Southeastern Ordos Basin.

The Ordos Basin is characterized by abundant natural gas resources, and the marine-continental transitional shale gas of the Permian Shanxi Formation has great exploration and development potential. However, few systematic studies have focused on the burial history, thermal maturity, and hydrocarbon generation of the shale, which limits the understanding of shale gas enrichment and resource evaluation. To reveal the shale gas resource potential, we focused on the Shanxi Formation shale in the southeastern Ordos Basin. Net erosion was estimated, and then one-dimensional (1D) and three-dimensional (3D) geological models were constructed using PetroMod to simulate the burial-thermal history and hydrocarbons generated in the Shanxi Formation shale, and finally, the gas generation intensity was evaluated. The results show that four periods of uplift and erosion events have occurred in the study area since the Mesozoic, of which the erosion in the Late Cretaceous was the most severe. The burial center gradually shifted from east to northwest in the study area, and the basin reached the maximum burial depth in the Late Cretaceous and then gradually changed to a monoclinal tilted east to west after uplift and erosion. The Shanxi Formation shale reached the hydrocarbon generation threshold at 233 Ma (Ro = 0.5%), reached the oil generation peak at 200 Ma (Ro = 1.0%), and entered the high maturity stage rapidly (Ro = 1.3%). Currently, the average maturity is approximately 2.48%, which is in the overmature stage. The center of shale maturity was in the southern part of the study area before the Late Jurassic and shifted northeast in the late Early Cretaceous. Cumulative gas generated to date is 44.0 × 1012 m3, and the center of gas generation was in the middle-eastern region of the study area before the Early-Middle Jurassic and shifted northwest in the Early Cretaceous. This study provides a theoretical basis and guidance for the exploration and development of marine-continental transitional shale in the Ordos Basin.

Effect of Wrist Dorsiflexion/Palmar Flexion on Median Nerve Deviation and Cross-Sectional Area in Patients with Carpal Tunnel Syndrome.

Objective: To evaluate the effect of wrist dorsiflexion/palmar flexion on median nerve excursion and cross-sectional area in patients with carpal tunnel syndrome. Methods: From November 2019 to December 2021, 85 patients (110 affected wrists) who presented to our department and were diagnosed with carpal tunnel syndrome were collected and classified by severity as mild to moderate. Twenty-five healthy controls were selected during the same period, with a total of 50 healthy wrists. All patients and healthy volunteers underwent high-frequency ultrasonography to measure the vertical deviation between the median nerve and the transverse carpal ligament during wrist dorsiflexion/palmar flexion and the changes in the cross-sectional area of the median nerve in the pisiform plane. All patients with carpal tunnel syndrome underwent neurophysiological testing to measure median nerve sensory conduction velocity, sensory latency time, and sensorimotor point fluctuation amplitude. Results: The mean age of the patients was 50 ± 8 years, the proportion of males was 18%, and the disease course was 2.3 ± 1.2 years. In terms of severity grading, 38 patients (34.5%) had mild carpal tunnel syndrome, 30 patients (27.3%) had moderate carpal tunnel syndrome, and 42 patients (38.2%) had severe carpal tunnel syndrome. Compared with the control group, the distance between the proximal median nerve and the transverse carpal ligament, the distance between the distal median nerve and the transverse carpal ligament, and the cross-sectional area were decreased in the carpal tunnel syndrome group compared with those during wrist dorsiflexion, and the differences were statistically significant (P < 0.05). Compared with the control group, there were significant differences in the vertical distance and cross-sectional area between the median nerve and the transverse carpal ligament at the proximal and distal ends in the mild, moderate, and severe groups (P < 0.05). The proximal vertical distance of the median nerve was positively correlated with sensory latency (P < 0.05) and negatively correlated with sensory conduction velocity (P < 0.05). The vertical distance of the distal end of the median nerve was also significantly positively correlated with sensory latency (P < 0.05) and significantly negatively correlated with sensory conduction velocity (P < 0.05). Conclusion: Wrist dorsiflexion/palmar flexion can affect median nerve deviation and cross-sectional area in patients with carpal tunnel syndrome. High-frequency ultrasound is helpful to detect such an effect and can also help determine the severity of carpal tunnel syndrome, which is worthy of clinical promotion.

[Articular external fixation for chronic dorsal instability of distal radioulnar joint].

OBJECTIVE: To discuss the clinical result of extrinsic radioulnar tether combined with anchoring nail fixation for treating chronic dorsal instability of the distal radioulnar joint (DRUJ). METHODS: Between July 2011 and December 2012, 6 patients with chronic dorsal instability of the DRUJ were treated with extrinsic radioulnar tether combined with anchoring nail fixation. There were 1 male and 5 females with the average age of 27.3 years (range, 22-35 years). All of 6 patients had a wrist trauma history. The average disease duration was 4.8 years (range, 6 months to 15 years). Radiographs were taken postoperatively to observe the anchoring nail loosening. The stress test and forearm rotation test were used to evaluate the function of DRUJ. The complications, the grip power, range of motion, and visual analogue scale (VAS) scores were recorded at last follow-up. And the joint function was evaluated by disability of arm, shoulder, and hand (DASH) score. RESULTS: Primary healing of incision was obtained in all cases, without any complications such as infection and ulnar neck fracture. All 6 patients were followed up 6-24 months (mean, 13.7 months). Stability was achieved in all patients. Radiographs showed that the joint space was widened and dislocation of the ulnar head was improved at 3 and 6 months after operation. The results of the stress test and forearm rotation test were negative. At last follow-up, the grip power, DASH score, VAS score, and range of motion of the wrist were significantly improved when compared with preoperative ones (P < 0.05). CONCLUSION: Extrinsic radioulnar tether combined with anchoring nail fixation is an easy method of surgical revision to treat chronic dorsal instability of DRUJ, which can maintain the stability and protect the blood supply of triangular fibrocartilage complex.

[APPLICATION OF BUTTERFLY SHAPED LOCKING COMPRESSION PLATE IN COMPLEX DISTAL RADIUS FRACTURES].

OBJECTIVE: To investigate the effectiveness of butterfly shaped locking compression plate for the treatment of complex distal radius fractures. METHODS: Between June 2011 and January 2013, 20 cases of complex distal radius fractures were treated with butterfly shaped locking compression plate fixation. There were 11 males and 9 females with an average age of 54 years (range, 25-75 years). Injury was caused by falling in 10 cases, by traffic accident in 7 cases, and by falling from height in 3 cases. All of fractures were closed. According to AO classification system, there were 8 cases of type C1, 8 cases of type C2, and 4 cases of type C3. Of them, 9 cases had radial styloid process fracture, 4 cases had sigmoid notch fracture, and 7 cases had both radial styloid process fracture and sigmoid notch fracture. The mean interval between injury and operation was 5.2 days (range, 3-15 days). RESULTS: All incisions healed by first intention; no complications of infection and necrosis occurred. All cases were followed up 14 months on average (range, 10-22 months). All factures healed after 9.3 weeks on average (range, 6-11 weeks). No complications such as displacement of fracture, joint surface subsidence, shortening of the radius, and carpal tunnel syndrome were found during follow-up. At last follow-up, the mean palmar tilt angle was 10.2° (range, 7-15°), and the mean ulnar deviation angle was 21.8° (range, 17-24°). The mean range of motion of the wrist was 45.3° (range, 35-68°) in dorsal extension, 53.5° (range, 40-78°) in palmar flexion, 19.8° (range, 12-27°) in radial inclination, 26.6° (range, 18-31°) in ulnar inclination, 70.2° (range, 45-90°) in pronation, and 68.4° (range, 25-88°) in supination. According to the Dienst scoring system, the results were excellent in 8 cases, good in 10 cases, and fair in 2 cases, and the excellent and good rate was 90%. CONCLUSION: Treatment of complex distal radius fractures with butterfly shaped locking compression plate can reconstruct normal anatomic structures, especially for radial styloid process and sigmoid notch fractures, and it can get good functional recovery of the wrist and the distal radioulnar joint.