The swelling and shrinking and flocculation and deflocculation of clays is of fundamental importance in the transport of solutes through a porous medium because these processes affect the permeability of the medium. Since organic solutes frequently occur in toxic wastes, we conducted an investigation of the effect of eight soluble organic compounds, representing different kinds of structures and functional groups, on the swelling and flocculation of sodium saturated Upton montmorillonite. These compounds were ethanol, 1,4‐dioxane, phenol, urea, benzamide, ethylamine hydrochloride, acetic acid, and sodium acetate. In general, we found that increases in the concentration of the compounds that ionize in water decreased swelling and increased flocculation to a greater extent than those that remained un‐ionized, i.e., electrically neutral. However, 1,4‐dioxane was exceptional in that, despite its electrical neutrality, it reduced swelling and increased flocculation significantly. Possible reasons for the effects of the different compounds on swelling and flocculation were advanced.
Purpose To investigate the long-term (> 7 years) clinical outcomes of percutaneous endoscopic lumbar discectomy for lumbar degenerative disease to address postoperative problems including postoperative dysesthesia (POD), residual back pain and segmental instability. Methods Inclusion and exclusion criteria were established. All patients who met the above criteria were treated by PELD using the transforaminal approach. Limited discectomy was performed to preserve the disc material in the intervertebral space as much as possible. The Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score for back pain (VAS-B) and leg pain (VAS-L) and Modified MacNab’s criterion were used for clinical evaluation. Radiographic parameters including height of intervertebral disc and segmental instability were also evaluated. Results Forty-two patients (24 men and 18 women) who met our inclusion and exclusion criteria were included in our study. The average follow-up period was 95.71±5.63 months (ranging from 87 to 105 months). There were no neurological complications associated with the operation. POD was found in 14.29% of patients, while only 2 patients (4.76%) complained of mild dysesthesia at final follow-up. Two patients (4.76%) required revision surgery during the follow-up period. The final follow-up ODI, JOA score, VAS-B and VAS-L were significantly better than preoperative values. The average disc-height ratio was 84.52±5.66% of the preoperative disc height. No instability at the operation level was noted at final follow-up. Conclusion Our study showed that PELD using the transforaminal approach can provide favorable results after a long-term follow-up period. POD is a common complication at initial prognosis. Limited discectomy can preserve the disc height well and minimize the risk of residual back pain.
To investigate the prognostic values of clinical factors 72 h within traumatic cervical spinal cord injury (TCSCI). Data were extracted from the medical materials of 57 TCSCI cases. AIS was used as the outcome measure and divided into dichotomous variables by two methods, i.e. “complete(AIS = A)/incomplete(AIS ≠ A) SCI” and “motor complete(AIS = A or B)/incomplete(AIS ≠ A and B) SCI”. Relationships between evaluated factors and outcomes were investigated by univariate and multivariate methods. MRI Cord transection (MCT) cases, most significantly related to complete SCIs by univariate analysis (P = 0.006), all showed complete SCIs when discharged, which makes it unsuitable for logistic regression. With MCT cases removed, univariate analysis was conducted again, then logistic regression. At last, only C5 spine injury (P = 0.024, OR = 0.241) was related to complete SCI. Cases with compression flexion injury mechanism (CFIM), most significantly related to motor complete SCIs by univariate analysis (P = 0.001), was also unsuitable for logistic regression for the same reason. At last, C3 spine injury (P = 0.033, OR = 0.068) and high energy injury (P = 0.033, OR = 14.763) were related to motor complete SCIs with CFIM cases removed. The results show that MCT and C5 spine injury are good predictors for complete/incomplete SCIs. CFIM, C3 spine injury and high energy injury are good predictors for motor complete/incomplete SCIs.
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