Rotor-Stator Emulsification in the Turbulent Inertial Regime: Experiments toward a Robust Correlation for the Droplet Size.

The Sauter mean diameter, d32, is a representative parameter in emulsions that indicates the average size of the oil droplets once the emulsion becomes stable. Several mathematical and physical approaches have been employed in the literature to seek expressions for d32 under different conditions. The present work sheds light on this rich literature and emphasizes that the characterization of emulsions is still a fertile field for investigation. In this paper, a new Π-theorem-based model to predict the normalized Sauter mean diameter for the specific case of rotor-stator emulsification is sought by applying a multiple regression analysis on experimental data of oil-in-water (O-W) emulsions produced using three different oils: paraffin, soybean oil, and isopropyl myristate, at different oil-to-water (O/W) ratios and rotor speeds. The proposed model quantifies the roles of the viscous, inertial, and interfacial tension forces, besides the O/W ratio, in the emulsification process within the turbulent inertial subrange. The developed empirical correlation is then contrasted with relevant literature models for reliability assessment; predictions of the present explicit model are proven to be more accurate for the fluid properties and the experimental conditions under study.

Modified Tracheal Traction Exercise Reduces the Incidence of Dysphagia in Patients with Multilevel Anterior Cervical Discectomy and Fusion.

OBJECTIVES: Dysphagia, an impairment in swallowing, is a frequent and debilitating complication for patients undergoing anterior cervical discectomy and fusion (ACDF), a common surgical treatment for degenerative cervical myelopathy (DCM). This retrospective study aimed to assess the efficacy of modified tracheal traction exercise (MTTE) in alleviating postoperative dysphagia and improving clinical outcomes for these patients. METHODS: A cohort of 143 patients underwent multilevel fusions, equally distributed between MTTE (n = 75) and traditional tracheal traction exercise (TTTE) (n = 68) groups. Demographic parity was observed in gender distribution, age averages (MTTE: 51.43 ± 11.25 years; TTTE: 52.35 ± 10.43 years), body mass index (BMI), comorbidities, fusion segments, and preoperative hospitalization days. Surgical duration differences were assessed. Clinical outcomes, dysphagia incidence, blood loss, postoperative complications, Cervical Japanese Orthopedic Association (c-JOA) scores, and functional outcome swallowing scale evaluations were conducted. Univariate and multivariate logistic regression analyses were used to explore factors influencing dysphagia. RESULTS: Modified tracheal traction exercise demonstrated advantages with a significantly lower dysphagia incidence (25.33% vs. 44.12%, p = 0.018), reduced blood loss (102.03 ± 17.04 vs. 113.46 ± 14.92, p < 0.001), shorter surgical durations (159.04 ± 9.82 vs. 164.41 ± 12.22 min, p = 0.004), and fewer postoperative complications (choking cough, cerebrospinal fluid leakage, and hoarseness). Postoperative c-JOA scores at 2 and 6 weeks favored MTTE, but no significant differences were observed at 12 and 24 weeks. Functional outcome swallowing scale evaluations favored MTTE with significantly higher percentages of "normal" and lower incidences of "mild" and "moderate dysphagia" at various postoperative intervals compared to TTTE. Factors significantly associated with dysphagia included MTTE, age, and BMI according to logistic regression analyses. CONCLUSION: Modified tracheal traction exercise demonstrates superior short-term outcomes in multilevel ACDF, showcasing reduced dysphagia incidence, blood loss, and specific postoperative complications. Notably, factors contributing to dysphagia, including operation technique and patient-related variables, emphasize the significance of MTTE and patient characteristics in optimizing postoperative outcomes in multilevel ACDF procedures.

Biomechanical evaluation of tendon connection with novel suture techniques.

PURPOSE: Achilles tendon rupture is a severe injury with poor curative effect due to its anatomical characteristic and mechanical peculiarity. Internal fixation of limited loop (IFLL) with steel-wire has been applied on patients with tendon rupture to fix the broken ends before physical rehabilitation. The purpose of this study is to investigate the biomechanical property and radiological characteristic of such suture technique for the repairment of tendon rupture. METHODS: Tendons of pigs' hint feet were separated for the biomechanical study. Suture surgery was performed according to the protocol of IFLL. Biomechanical Testing Machine was adopted to conduct the biomechanical tensile load examination. The maximal load, elastic modulus and tendon stiffness of the stitched tendons with or without reinforcement were examined. RESULTS: The maximum tensile load of the stitched tendons using IFLL reached 1/4 of the uninjured tendon's maximum tensile load, indicating that such suture technique is capable of providing enough tension for the ruptured tendon. Surprisingly, tendons fixed with titanium wire showed the highest load tension, which was comparable to the undamaged tendon. Therefore, we found the biomechanical basis of using IFLL in effectively connecting the rupture ends of tendons. CONCLUSIONS: In conclusion, we provide biomechanical evidence for the use of IFLL in treatment of Achilles tendon rupture, by providing enough strength for the ankle function. Such suture technique could help the patients with better rehabilitation and reduced in-hospital stay after Achilles tendon injury.

[Application of Dynesys system combined with posterior lumbar interbody fusion in treating multiple lumbar degenerative disease].

OBJECTIVE: To explore the clinical effects of Dynesys system combined with posterior lumbar interbody fusion (PLIF) in treating multiple lumbar degenerative disease. METHODS: The clinical data of 46 patients with multiple lumbar degenerative diseases treated by Dynesys system combined with PLIF from September 2010 to May 2013 were retrospectively analyzed. There were 17 males and 29 females, aged from 38 to 68 years old with an average of (56.38±11.63) years. Operation section was in L2-L5 of 16 patients (6 with fusion of L4,5 and 10 with fusion of L4,5,L5S1) and in L3-S1 of 30 patients (11 with fusion of L5S1 and 19 with fusion of L4,5,L5S1). Patients were followed up for three times: postoperative 3 months, 1 year and final follow-up. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to assess clinical symptoms preoperatively and postoperatively. All patients underwent flexion/extension radiographs examinations before surgery and at final follow-up. Range of motion (ROM) and disc height index (DHI) were recorded. RESULTS: All patients were followed up from 16 to 48 months with the mean of (23.23±7.34) months. At third follow-up after operation, ODI and VAS of lumbago and leg pain were significant improved than that of preoperative (P<0.01). DHI of fusion segment was significantly increased than that of preoperative (P<0.05). There was no significant difference in adjacent non-fusion segment between preoperative and postoperative (P>0.05). Postoperative ROM of fusion and non-fusion segments were obviously decreased than that of preoperative. There was no significant difference in ROM of upper adjacent non-fusion segment between 3 months and 1 year after operation (P>0.05), but at final follow-up, the ROM was increased (P<0.05). CONCLUSION: The preliminary clinical results of the Dynesys system combined with PLIF in the treatment of multiple lumbar degenerative diseases are satisfactory. It can be determined in fusion or non-fusion according to the individual needs and can reserve the some intervertebral motion, prevent the early degeneration of adjacent segments. However, its long-term clinical efficacy should be verified with long time.

Application of internal fixation of steel-wire limited loop in early Achilles tendon rupture.

OBJECTIVE: To explore the clinical effect and safety of internal fixation of steel-wire limited loop in early Achilles tendon rupture. METHODS: Seventy-six patients respectively with early transected and avulsed types of Achilles tendon rupture were selected and treated with internal fixation of steel-wire limited loop. The patients began to take exercise for their lower limbs through continous passive motion as early as possible after surgical repair, and the loops were removed after 3-5 months. Six months later, the condition of complications including Achilles tendon re-rupture, wound fistula, wound infection and skin necrosis, cutaneous sensation in sural nerve dominance region, time back to preinjury work or learning as well as time to physical activities were observed. One year later, the therapeutic effect was evaluated, and the maximum circumferences of bilateral legs and ruptured plane circumferences of Achilles tendon were measured. RESULTS: The wound of all patients healed well, no complications like Achilles tendon re-rupture, wound fistula, wound infection and skin necrosis occured, and the cutaneous sensation in sural nerve dominance region was normal. The mean time back to preinjury work or learning as well as to pysical activities of all patients were respectively 10 and 22 weeks. Seventy out of 76 patients (92.1%) achieved an excellent effect, and 6 (7.9%) good effect. The excellent and good rate came up to 100%. The maximum circumference in the affected leg decreased to 2 mm averagely compared with the offside, while the ruptured plane circumferences of Achilles tendon in the affected side increased to 2.2 mm compared with the offside. CONCLUSIONS: For early Achilles tendon rupture, internal fixation of steel-wire limited loop can recover the ankle function better, return to the preinjury state in the shortest time, and has few complications.