Dilepton Polarization as a Signature of Plasma Anisotropy.

We propose the angular distribution of lepton pairs produced in ultrarelativistic heavy-ion collisions as a probe of thermalization of the quark-gluon plasma. We focus on dileptons with invariant masses large enough that they are produced through quark-antiquark annihilation in the early stages of the collision. The angular distribution of the lepton in the rest frame of the pair then reflects the angular distribution of quark momenta. At early times, the transverse pressure of the quark-gluon plasma is larger than its longitudinal pressure as a result of the fast longitudinal expansion, which results in an oblate lepton distribution. By contrast, direct (Drell-Yan) production by quarks and antiquarks from incoming nuclei, whose momenta are essentially longitudinal, results in a prolate distribution. As the invariant mass increases, Drell-Yan gradually becomes the dominant source of dilepton production, and the lepton distribution evolves from oblate to prolate. The invariant mass at which the transition occurs is highly sensitive to the equilibration time of the quark-gluon plasma or, equivalently, the shear viscosity over entropy ratio η/s in the early stages of the collision.

Equilibration of the Quark-Gluon Plasma at Finite Net-Baryon Density in QCD Kinetic Theory.

We explore the out-of-equilibrium dynamics of the quark-gluon plasma at zero and finite net-baryon density based on an effective kinetic theory of quantum chromodynamics (QCD). By investigating the isotropization of the longitudinal pressure, we determine the relevant time and temperature scales for the onset of viscous hydrodynamics and quantify the dependence on the chemical composition of the quark-gluon plasma. By extrapolating our results to realistic coupling strength, we discuss phenomenological consequences regarding the role of the preequilibrium phase at different collision energies.

[CLASSIFICATION OF ADULT CUBOID FRACTURE AND EFFECTIVENESS ANALYSIS].

OBJECTIVE: To study the classification criteria of adult cuboid fracture and its guidance feasibility and effect of treatment. METHODS: A retrospective analysis was made on the clinical data of 415 adult patients (416 feet) with cuboid fractures who had complete CT data treated between May 2009 and April 2014. There were 337 males and 78 females, aged 19 to 64 years (mean, 38.8 years). The left foot, right foot, and bilateral feet were involved in 220 cases, 194 cases, and 1 case respectively. The causes of injury were sprain in 106 cases, traffic accident in 65 cases, falling from height in 129 cases, and heavy crushing in 115 cases. The interval of injury and hospitalization was 2 hours to 3 days (mean, 8.5 hours). Based on CT findings, the classification criteria of cuboid fracture was proposed and methods of treatment was statistically analyzed. The external fixation surgery was performed in patients of type I (285 feet), type IIa (18 feet), and type III (5 feet); open reduction and internal fixation were performed in patients of type IIb (41 feet) and type III (67 feet), and bone grafting was used to repair defects in 58 feet (type III). RESULTS: All patients were followed up 1 year to 5 years and 11 months (mean, 2 years and 3 months). Primary healing of incision was obtained. In patients with type I fracture, fracture healed in 165 feet at 4-6 weeks (mean, 5.5 weeks), fracture did not heal in the other 120 feet; the American Orthopaedic Foot and Ankle Society (AOFAS) score was 95-100(mean, 96.7) at last follow-up. In patients with type II fracture, fracture healed in all feet at 6-8 weeks (mean, 6.5 weeks); the AOFAS score was 92-100(mean, 95.5) at last follow-up. In patients with type III fracture, malunion was observed at 6-8 weeks in 5 feet undergoing external fixation, and in 9 feet undergoing open reduction and internal fixation with foot lateral column shortening, forefoot abduction deformity, osteoarthritis, lateral foot pain; fracture healed at 8-12 weeks in 58 feet undergoing open reduction and internal fixation, without osteoarthritis, cuboid bone shortening, and pain at cuboid bone; and AOFAS score was 75-97(mean,93.5) at last follow-up. CONCLUSIONS: The classification criteria of cuboid fracture proposed based on CT examination is feasible and has guiding significance to the choice of treatment method.

Free dermatoplasty combined with vacuum sealing drainage for the treatment of large-area soft tissue defects accompanied by bone exposure in the lower leg.

The aim of this study was to investigate the clinical efficacy of free dermatoplasty combined with vacuum sealing drainage (VSD) for the treatment of large-area soft tissue defects accompanied by bone exposure in the lower leg (crus). Free dermatoplasty combined with VSD was used to treat 36 patients with large-area soft tissue defects accompanied by bone exposure in the lower leg. The areas of the soft tissue defects ranged from 25×12 to 35×30 cm and the areas of exposed bone ranged from 6×4 to 10×6 cm. When evaluated by the open fracture Gustilo classification, 14 cases were of Gustilo type IIIA and 22 cases were of type IIIB. During surgery, adjacent available muscle flaps were transferred to cover the outer areas of the exposed bone and reduce the bone exposure range. Following VSD treatment, granulation tissues grew well and free dermatoplasty combined with VSD was used to treat and repair the wound surfaces. The patients were followed up for 1-5 years (mean duration, 2.5 years). All 36 cases with skin flap grafts survived, the free skin graft texture on the wound surface was good, the recovery of lower limb function was satisfactory and the success rate was 80.56%. Free dermatoplasty combined with VSD used for the treatment of large-area soft tissue defects accompanied by bone exposure in the lower leg may eliminate the need for amputation and complex surgery, and is a simple, fast and effective treatment method.

[Treatment of fresh closed fracture-dislocation of midtarsal joint].

OBJECTIVE: To investigate the treatment method and effectiveness of fresh closed fracture-dislocation of the midtarsal joint. METHODS: Between April 2004 and April 2011, 73 patients (75 feet) with fresh closed fracture-dislocation of the midtarsal joint were treated with closed reduction combined with open reduction and internal fixation. There were 56 males (58 feet) and 17 females (17 feet), aged from 19 to 62 years (mean, 35.8 years). Injuries were caused by falling from height in 35 cases, by sprain in 4 cases, by machine twist in 5 cases, by heavy pound in 9 cases, and by traffic accident in 20 cases. The time from injury to admission ranged from 1 hour and 30 minutes to 48 hours (mean, 4.5 hours). According to Main's classification standard, 6 feet were rated as vertical compression injury, 33 feet as medial displacement injury, 17 feet as lateral displacement injury, 9 feet as flexion injury, and 10 feet as crush injury. Concomitant injuries included midfoot fracture-dislocation (34 feet), scaphoid fracture (6 feet), cuboid bone fracture (18 feet), calcaneal fracture (8 feet), talus fracture (7 feet), tibiotalar joint dislocation (2 feet), subtalar joint dislocation (2 feet), medial malleolus fracture (1 foot), and acute compartment syndrome (3 feet). RESULTS: Healing of incision by first intention was achieved in 65 cases (67 feet), by second intention in 8 cases (8 feet). Sixty-two cases (62 feet) were followed up from 11 months to 7 years and 11 months (mean, 3 years and 6 months). After operation, feet pain occurred in 26 cases, and stiffness or discomfort of the affected foot in 36 feet when walking. The X-ray examination showed good reduction of fracture-dislocation of the midtarsal joint and concomitant injuries with no re-dislocation or bone nonunion in 59 feet; 3 feet had flatfoot secondary to navicular necrosis, and underwent arthrodesis. The American Orthopaedic Foot and Ankle Society (AOFAS) score was 77-90 (mean, 88.6) at last follow-up. CONCLUSION: According to the preoperative evaluation of the damage, using the manual reduction combined with internal fixation (mini-plate or hollow screw with Kirschner wire) methods can obtain good effectiveness in the treatment of fracture-dislocation of the midtarsal joint.

Basal and Src kinase-mediated activation of the EphA2 promoter requires a cAMP-responsive element but is CREB-independent.

We have previously identified the EphA2 receptor tyrosine kinase as a potentially important injury-responsive gene and a transcriptional target of Src kinase activity in renal ischemia-reperfusion injury (IRI). In the present study, we confirmed, using EphA2 gene trap mice that the endogenous EphA2 promoter is strongly activated following renal IRI. We also examined in more detail the mechanisms responsible for Src kinase-induced activation of the -2 kb human EphA2 promoter and found that the minimal Src-responsive elements were contained in the -145 to +137 region of the human EphA2 gene. This region contains a canonical cAMP-responsive element (CRE) that we found to be critical for both basal and Src kinase-induced transcriptional activity. However, despite activation of the prototypical CRE-binding factor CREB by the Src kinase Fyn, siRNA-mediated knockdown of CREB had no significant impact on either basal or Fyn-induced EphA2 promoter activity. Similarly, activation of CREB by the adenylate cyclase agonist forskolin failed to induce EphA2 promoter activation. Thus, Src kinase-induced activation of the EphA2 promoter is CRE-dependent but CREB-independent.

[Analysis of diagnosis and treatment of talus lateral process fracture].

OBJECTIVE: To analyse and summarize the diagnosis, treatment, and clinical effects of talus lateral process fracture. METHODS: Between February 2001 and March 2009, 21 male patients with an average age of 33.6 years (range, 18-46 years) with talus lateral process fractures were treated. Fracture was caused by falling from height in 18 cases, by tumbling in 2 cases, and by sprain in 1 case. According to Hawkins classification, there were 4 cases of type I, 15 cases of type II, and 2 cases of type III, all being closed fractures. The disease course was from 2 hours to 26 days. In 17 patients whose fracture fragments were more than 1 cm x 1 cm x 1 cm or whose fracture fragments shifting was more than 1 mm, open reduction and internal fixation with AO hollow titanium nails were performed in 14 patients, open reduction and internal fixation with door-shape self-made nail in 1 patient, and open reduction and internal fixation with absorbable screws in 2 patients. In 4 patients whose fracture fragments were less than 0.6 cm x 0.5 cm x 0.5 cm or whose fracture fragments shifting was less than 1 mm, fragments removal was performed in 2 patients, Kirschner pins in 1 patient, and plaster conservative therapy in 1 patient. In patients with ligaments injury, the ligaments was reconstructed during the operation. RESULTS: All the incisions achieved primary healing. Twenty-one patients were followed up 9.5 months to 8 years. No ankle pain occurred and the range of joint motion was normal after operation. The X-ray films showed that all cases achieved fracture union. And the healing time was from 8 weeks to 14 weeks (10 weeks on average). According to American Orthopaedic Foot & Ankle Society (AOFAS) for foot, the results were excellent in 17 cases, good in 3 cases, and moderate in 1 case; the excellent and good rate was 95.24%. CONCLUSION: The size and displacement of fracture fragment should be considered first in the treatment of lateral process fracture of talus; in patients who are complicated by lateral malleolus ligament injury, the ligament should be reconstructed to avoid the chronic non-stability of lateral ankle.

[Flexor digitorum (hallucis) longus muscle tendon transfer in the repair of old rupture of the Achilles tendon].

OBJECTIVE: To explore the operative technique of repair and its curative effect of old rupture of the Achilles tendon with flexor digitorum (hallucis)longus tendon transfer. METHODS: From Nov 2001 to May 2005, 13 patients who had old rupture of the Achilles tendon were treated with this operative technique. Five of them were treated with flexor digitorum longus tendon transfer and 8 with flexor hallucis longus tendon. All patients had the history of closed injury of Achilles tendon(9 male and 4 female, 8 left feet and 5 right feet). The age ranged from 32 to 69 years(mean 41 years). OPERATIVE TECHNIQUE: flexor digitorum (hallucis)longus tendon was cut down alternatively. The distal end of flexor digitorum longus tendon should be sutured to flexor hallucis longus tendon if the flexor digitorum longus tendon was cut. The distal end of flexor hallucis longus tendon should be sutured to flexor digitorum longus tendon if the flexor hallucis longus tendon was cut. The proximal end of tendon to be cut down was sew up a suture line and pulled out from the incision to reveal the Achilles tendon. A transverse hole was drilled through the anterior aspect of the insertion of the tendon of the calcareous, and then drilled upward perpendicularly. The two holes were cross-connected by towel clamp. The flexor digitorum (hallucis)longus tendon to be transferred was pulled through the first hole from wall outward and upward, and then pulled through superior extremity of the second hole. The end of tendon was sutured firmly with the Achilles tendon. RESULTS: All patients have no infection or re-rupture during follow-up (average 24 months;range 11 to 54 months). There was no subsequent hammer-toe deformity. Dorsiflexion at least to neutral and normal plantar flexion were obtained in all patients. According to Arner-Lindholm standard,the final results were excellent in 9 patients(6 cases were used flexor hallucis langus tendon, and 3 cases were used flexor digitorum longus tendon),good in 3 patients(2 cases were used flexor hallucis longus tendon and 1 case was used flexor digitorum longus tendon) and poor in 1 patient used with flexor digitorum longus tendon. CONCLUSION: The repair of old rupture of the Achilles tendon with flexor digitorum (hallucis) longus tendon transfer is an ideal and effective method. Furthermore, the use of flexor hallucis longus muscle tendon tends to be more reasonable.

[The effect of micro-trauma technic with small incision on treating hallux valgus].

OBJECTIVE: To explore an effective micro-trauma technic with small incision for hallux valgus. METHODS: From August 2002 to June 2004, 136 cases (263 feet) with hallux valgus were treated with micro-trauma technic with small incision and postoperative external elastic fixation. Of all the cases, 7 were males and 129 were females. Their ages ranged from 19 to 84 years. According to Coughlin classification, there were 24 gentle cases, 63 medium cases, and 49 severe cases. All the feet were with some degree of pain and flatfoot. Symptom, sign and the results of X-ray were evaluated. RESULTS: Wound healed at stage I. All cases were followed up for 8 to 26 months, 19 months on average. Hallux valgus of the 263 feet were completely healed, feet pain disappeared, and no nonunion or osteonecrosis was observed. X-ray examination indicated that 105 feet's hallux valgus angle was less than 12 degrees, inter metatarsal angle less than 9 degrees, and remedy subluxation of the tibial sesamoid less than 50%. Evaluation on the result indicated that there were 84 cases of excellent result, 48 cases of good result, 3 cases of fair result, and 1 case of poor result. The rate of excellent and good was 97%. CONCLUSION: With less injury, less pain, complete restoration, and fewer possibility of relapse, micro-trauma technic with small incision is effective in treating hallux valgus.