Advancing Chemical Separations: Unraveling the Structure and Dynamics of Phase Splitting in Liquid-Liquid Extraction.

Liquid-liquid extraction (LLE), the go-to process for a variety of chemical separations, is limited by spontaneous organic phase splitting upon sufficient solute loading, called third phase formation. In this study we explore the applicability of critical phenomena theory to gain insight into this deleterious phase behavior with the goal of improving separations efficiency and minimizing waste. A series of samples representative of rare earth purification were constructed to include each of one light and one heavy lanthanide (cerium and lutetium) paired with one of two common malonamide extractants (DMDOHEMA and DMDBTDMA). The resulting postextraction organic phases are chemically complex and often form rich hierarchical structures whose statics and dynamics near the critical point were probed herein with small-angle X-ray scattering and high-speed X-ray photon correlation spectroscopy. Despite their different extraction behaviors, all samples show remarkably similar critical behavior with exponents well described by classical critical point theory consistent with the 3D Ising model, where the critical behavior is characterized by fluctuations with a single diverging length scale. This unexpected result indicates a significant reduction in relevant chemical parameters at the critical point, indicating that the underlying behavior of phase transitions in LLE rely on far fewer variables than are generally assumed. The obtained scalar order parameter is attributed to the extractant fraction of the extractant/diluent mixture, revealing that other solution components and their respective concentrations simply shift the critical temperature but do not affect the nature of the critical fluctuations. These findings point to an opportunity to drastically simplify studies of liquid-liquid phase separation and phase diagram development in general while providing insights into LLE process improvement.

Opioid Prescribing Patterns and Patient Satisfaction with Care.

We sought to examine the relationship between opioid prescribing patterns and patient reported satisfaction with care. Opioid prescribing was characterized in terms of morphine equivalent daily dosing (MEDD), total morphine equivalent dosing (TMED), and total number of opioid prescriptions. A total of 1,666 opioid prescriptions were written for a TMED of 379,660 and a median MEDD of 204 (interquartile range [IQR] 195-269) from 2017-2019. Two hundred and forty-four patient satisfaction surveys were obtained for review and comparison. During the study period, 2,358 cases were performed, and no statistically significant differences were found with respect to case distribution among orthopaedic surgeons at our institution. High patient satisfaction, defined as achieving a 100 on a 0-to-100 scale, was found to have no association with MEDD (odds ratio = 0.968; 95% confidence interval [CI], 0.925-1.014), TMED (odds ratio = 1.00; 95% CI, 1.00-1.01), or total number of opioid prescriptions (odds ratio = 1.003; 95% CI, 0.905-1.112). (Journal of Surgical Orthopaedic Advances 30(2):085-089, 2021).

Nanoscale Critical Phenomena in a Complex Fluid Studied by X-Ray Photon Correlation Spectroscopy.

The advent of high-speed x-ray photon correlation spectroscopy now allows the study of critical phenomena in fluids to much smaller length scales and over a wider range of temperatures than is possible with dynamic light scattering. We present an x-ray photon correlation spectroscopy study of critical fluctuation dynamics in a complex fluid typical of those used in liquid-liquid extraction (LLE) of ions, dodecane-DMDBTDMA with extracted aqueous Ce(NO_{3})_{3}. We observe good agreement with both static and dynamic scaling without the need for significant noncritical background corrections. Critical exponents agree with 3D Ising values, and the fluctuation dynamics are described by simple exponential relaxation. The form of the dynamic master curve deviates somewhat from the Kawasaki result, with a more abrupt transition between the critical and noncritical asymptotic behavior. The concepts of critical phenomena thus provide a quantitative framework for understanding the structure and dynamics of LLE systems and a path forward to new LLE processes.

Screw versus helical proximal femoral nail in the treatment of unstable trochanteric fractures in the elderly.

PURPOSE: Comparison of clinical, radiological and functional outcomes of screw proximal femoral nail (PFN) and helical PFN in management of unstable trochanteric fractures. METHODS: This prospective randomised comparative study included 60 patients with closed unstable intertrochanteric fractures (AO classification-A2.2-A2.3 & A3.1-A3.3). Patients were randomised to 2 treatment groups using simple random sampling method utilizing computer based randomisation. Screw PFN and helical PFN were used for internal fixation with 30 patients in each group. RESULTS: Both groups were similar in respect of age, gender, fracture classification, quality of fracture reduction, duration of hospitalization, post-operative complications, residual/late deformity as well as functional assessment. However, mean duration of surgery was significantly lower (23.1%) in helical PFN group as compared to screw PFN group (43.32 ±â€¯8.20 min vs. 35.20 ±â€¯6.03 min, p < 0.001). Furthermore, mean blood loss was not significant in either of the study groups but it was significantly lesser (30.1%) in helical PFN group as compared to screw PFN group (77.80 ±â€¯17.39 ml vs. 59.80 ±â€¯14.96 ml, p < 0.001). Also, mean number of images taken was significantly lower (58.7%) in helical PFN group as compared to screw PFN group (29.52 ±â€¯4.85 no vs. 18.60 ±â€¯3.12 no, t = 9.47; p < 0.001). CONCLUSION: Both screw PFN and helical PFN are equally effective implants in internal fixation of unstable trochanteric fractures with no statistically significant difference (p > 0.05) in any of the outcome measures. However, helical PFN group fared marginally better in terms of operative time, blood loss and imaging required.

[Investigative findings on the reconstruction with tissue materials after partial laryngectomy]. / Wlasne doswiadczenia w zastosowaniu materialów tkankowych do rekonstrukcji krtani po laryngektomiach czesciowych.

Between 1987 and 1999--1289 patients were treated by surgery in the Department of Otolaryngology and Laryngologic Oncology PAM in Szczecin due to the cancer of the larynx. In this group total, eventual subtotal excision of the larynx was carried out in 801 cases. In 154 cases the phonation way was restored. In this study the remaining group of 502 patients was analysed, which underwent partial aiming at restoration of all basic functions of the larynx. In the mentioned group partial vertical laryngectomy was done in 176 cases, and partial horizontal laryngectomy in 326 cases. Larynx reconstruction with the use of tissue materials was carried out in 59 cases after vertical and in 88 cases after horizontal laryngectomy. Shortcomings and advantages of the method of various tissue application were discussed (cartilage of epiglottis, vasculary based pedicle flap of thyroid gland, submaxillary salivary gland, strap muscles among others were used).

[Thyroid gland function after therapy of the laryngeal cancer: prospective examinations]. / Funkcja hormonalna tarczycy po leczeniu raka krtani--badania prospektywne.

The paper presents the results of the study concerning thyroid gland function of the patients suffering from larynx cancer treated with: a) surgery only (n = 31), b) surgery with further radiotherapy with radical doses 5400-7000 cGy (n = 44), c) radiotherapy along with radical doses 6400-7000 cGy (n = 7). 82 patients (M-73, F-9) were examined. Average age was 58 (min. 30, max. 80). Thyroid gland function was evaluated by measurement of: a) hTSH, fT3, fT4, b) serum lipids concentration. The examinations mentioned above were performed before as well as after the treatment at: a) 1, b) 1-6, c) 6-12, d) 12-24, e) longer than 24 months after completion of treatment. The longest period of observation involved 8 years. Our results show that hypothyroidism (mostly subclinical) occurs seldom (6% of all the cases) in the early phase (up to 1 month) after surgical treatment. After radiotherapy only--no subclinical hypothyroidism was observed. The combined treatment seems to be the most frequent cause of subclinical hypothyroidism. Its frequency increases (up to 27%) with the length of time since the conclusion of treatment. We also tried to explain the pathogenesis of subclinical hypothyroidism on the basis of histopathologic examination of thyroid tissue (n = 13) derived from the patients after various ways of treatment. The studies were compared to the results of histological examinations of the thyroid sections obtained during autopsy (n = 20) from the control group (not suffered from thyroid diseases).

[Results of surgical treatment in advanced (T3, T4) cancer of the larynx]. / Wyniki leczenia chirurgicznego zaawansowanych przypadków (T3, T4) raka krtani.

In ENT Clinic of Medical Academy in Szczecin 962 patients with advanced cancer of the larynx was surgically treated between 1976 to 1995 year. In this group local statement of T3 was observed in 510 cases (53%) and T4 in 452(47%). In the analysis group total laryngectomy was performed in 506 (62.3%) cases, subtotal laryngectomy with phonatory way reconstruction was performed in 234 (24.4%) cases, partial laryngectomy with airway reconstruction in 223 cases (in this number horizontal partial laryngectomy in 207 cases and vertical partial laryngectomy in 15 cases. Efficacy of surgical treatment in 5-years of survival was estimate. In whole material it was 505/962 (52.4%) of cases. Cause of failure, possibility and efficacy its treatment is described.

[Vascular pedicle flap of the thyroid or submandibular gland in the reconstruction following partial laryngectomy]. / Naczyniowo uszypulowany przeszczep tarczycy i slinianki podzuchwowej jako material rekonstrukcyjny w czesciowych laryngektomiach.

The paper presents the merits and drawbacks of vascular pedicled flaps of thyroid and submandibular glands in the reconstructive surgery following partial laryngectomy (combined with the resection of tongue base if necessary), as well as the results of clinical, radiological, radionucleoloid++ and histological investigation carried out in 81 cases with various extend of neoplasm (T1-T4). The average observation period was 8.2 (min. 1, max. 14) years. The discussed flaps were satisfactorily elastic and rigid, allowed formation in monobloc even complex structures (for instance vocal cord, arytenoid eminence, lateral wall of the larynx) with the high healing rate (1 total and 2 partial losses only), with an insignificant degree of atrophy in the larynx and a considerably greater one in the tongue base (despite a very difficient cover with mucosa), as well as a small local recidive range (3/81 cases all coming from the tissue out of the flap). With the above data, the discussed flaps seem to be superior in many respects to the materials conventionally used in the reconstruction of the larynx. A subclinical form of hypothyreosis (reduced level of T3, T4 and TSH) was stated in 1 case only, whereas xerostomy was not observed in any. The detailed oncological and functional results obtained in the whole group of patients will be published in another paper.

[The choice of transplantation in reconstructive surgery of the larynx after partial laryngectomy]. / W sprawie wyboru przeszczepu w chirurgii rekonstrukcyjnej krtani po laryngektomii czesciowej.

Hitherto applied methods of larynx reconstruction after laryngectomies of various extension or extended by the tongue base were discussed. Disadvantages of hitherto applied transplants were pointed out. The possibility of application of vascular pedicle transport of thyroid gland or submandibular gland for larynx reconstruction was presented.