Measurements and modelling of the residual mass upon impact of supercooled liquid drops

The mass of liquid remaining on a substrate following a drop impact is a crucial quantity for modelling of numerous phenomena, e.g. spray cooling, spray coating or aircraft icing. In the present study, a method to measure this residual mass after impact of liquid drops is introduced. This method is also applicable to supercooled drops, which may freeze upon impact on cold surfaces. Using the data obtained from extensive measurements in which the size, impact speed and temperature of the drops was varied, a modelling of the residual mass is formulated, following closely the theory of Riboux and Gordillo (Phys Rev Lett 113(2):024507, 2014. 10.1103/PhysRevLett.113.024507). A key adaptation of this model accounts for the deformation of drops immediately prior to impact. This modified theoretical model results in very good agreement with experiments, allowing prediction of residual mass for a given impact situation. Graphical abstract

Dissolution behaviour and imageability of ternary borate glasses for use in geniculate artery embolization

Sixteen borate glass compositions comprising K2O and SrO were screened, using a design of mixtures approach, to model compositional effects on dissolution, CT imageability, and MRI relaxivity (R2). Based on the characteristics of each network, together with dose determination and toxicological risk, the composition identified as BKSA16 was selected as a preferred composition for pre-clinical evaluations related to geniculate artery embolization (GAE). Accordingly, BKSA16 particles were subjected to a flame spheroidization process and recharacterized, including the evaluation of residual mass at 72 h in physiologically representative media along with clinical determinations of suspension time (ease of use). For both the irregular particles and microspheres residual mass was present at 72 h in physiologically representative media. Additionally, both the microspheres and irregular particles achieved suspension times deemed to be acceptable for clinical use. The collective data confirms that BKSA16 microspheres have a range of beneficial features (specifically both degradable and imageable) suited to GAE.

CFD-DEM Simulation of Backflow Blockage of Deep-Sea Multistage Pump

The multistage centrifugal pump is the critical component of mineral resources lifting in deep-sea mining. The reflux of nodules in the lifting pipe caused by the emergency pump stop can easily cause the pump to clog. In this paper, coupled Computational Fluid Dynamics and Discrete Element Method (CFD-DEM co-simulations) are used to clarify the solid-liquid two-phase flow in two-stage centrifugal pumps under different particle sizes (10–20, 20–30, 30–40, 40–50 mm) with constant particle concentration. The movement and accumulation behaviour of particles in different flow fields (pipeline to pump, the first to the second pump stage) is investigated. Meanwhile, the effect of particle size and particle reflux velocity on the blockage of the flow channel in the pump was investigated. Particle accumulation in the pump was observed to determine the key factors affecting the pump’s reflux capacity. The residual mass of particles in the pump at different particle sizes was counted. Simultaneously, the percentage of residual mass of 10–20 mm particles in the pump was compared between the experiment and the simulation with an acceptable tolerance of within 10%. In addition, pressure changes in the blockage-prone section were also investigated. A comparison between experiments and simulations verifies the consistency of the trend on the pump inlet pressure when clogged with 50 mm particles. It was found that larger particles in the range of 10–30 mm can better ensure the pump’s reflux performance.

In-Depth Study of the Microcrystalline Cellulose Amino-Functionalization Efficiency

Microcrystalline cellulose (MCC) has unique properties and its use as reinforcement for polymer composites has been increasing. However, the intrinsic incompatibility with most polymers requires surface modification to improve chemical compatibility prior to its incorporation into a polymer. In this paper, an in-depth study of silanization of MCC using 3-aminopropyltriethoxysilane (APTES), at different concentration, was done. The grafting amount of APTES onto MCC was determined by different methods: from residual mass and from nitrogen content. Solid-state 13C and 29Si nuclear magnetic resonance (NMR), field emission scanning electron microscopy with energy dispersive X-ray (SEM-EDX), spectroscopy plasma optical emission spectrometry (ICP), and a deep study of structural properties by X-ray diffraction were carried out. A better correlation for grafting amount of APTES onto MCC was observed for nitrogen content method than residual mass according the Pearson’s correlation. 13C NMR revealed all the carbon structures from cellulose and from APTES molecules and 29Si NMR revealed D, T and Q Si structures. The silane treatment did not alter the shape of MCC and all treated samples showed Si characteristic peak at ~ 1.75 kEv. From ICP was observed higher Si content before MCC addition than after, evidencing, once again, APTES grafting. The exposure to APTES in acidic medium caused several effects on the MCC, splitting larger Iβ crystallites in half and along the more reactive hydrophilic sides. The diameter of the smaller IVI crystallites was largely reduced by the treatment, especially when the silane concentration was 1:5 (m/v), above which the diameter increases again.

A Case of Giant Prolactinoma Characterized by a Nasopharyngeal Extension and Diagnosed by Nasal Cavity Biopsy

Introduction: Giant prolactinomas represent 2-3% of all prolactinomas and less than 0.5% of all pituitary lesions. Uncommon extensions of giant pituitary adenomas to areas such as nasopharynx or paranasal sinuses are even rarer. There are about 50 cases described in the literature. Here, we report a giant prolactinoma case diagnosed by biopsy from the nasal cavity. Case: A 40-year-old male patient applied to the emergency room after falling on ice. Cranial CT revealed a giant sellar mass destroying the clivus and the sphenoid bone corpus. The patient has had frontotemporal headache for 5 years, and also loss of libido and erectile dysfunction. He had right superolateral visual field defect and right-sided ptosis. Pituitary MRI showed a T2-hyperintense sellar mass measuring 58x58x70 mm, with extension to the nasopharyngeal wall, right cavernous sinus, right petrous apex and ethmoid spaces at the base of the skull. A punch biopsy was taken from the vascular mass located in the right nasal cavity, in between the middle concha and the septum. Pathological examination revealed a neoplasm that showed strong diffuse immunostaining with PRL and CK8, and focal staining with GH. Ki-68 proliferation index was 2%. Serum PRL level was 11881 ng/mL, FSH: 1.5 mIU/mL, LH: 1.3 mIU/mL, testosterone: 35.7 ng/dL, GH: 0.5 ng/mL, IGF-1: 520 ng/mL, ACTH: 73 pg/mL, cortisol: 12 mcg/dL, TSH: 0.04 uIU/mL, fT4: 14.2 pmol/L, fT3: 4.9 pmol/L and electrolytes were normal. Five days later, a right pterygonal craniotomy was performed. The mass showed the same immunostaining characteristics as the earlier biopsy specimen, and also included fibrin, monotonous cells with ischemic necrosis and distorted architecture of the reticulin pattern. According to the post-operative MRI, the right cavernous and clival part of the mass was reduced in size. Cabergoline (0.5 mg/w), levothyroxine (100 mcg/d) and testosterone propionate (250 mg/m) were started. The patient received conventional radiotherapy in a total dose of 1250 Gy, because of the residual mass. Sixth months after radiotherapy, the nasopharyngeal part of the tumor was not visualized. Cabergoline was up-titrated to a maximum dose of 3 mg/w. Prolactin levels decreased to 136 and 22 ng/mL at the third and sixth months of the treatment, respectively. Superolateral right-sided visual field defect persisted. Five years after surgery, secondary hypocortisolism has emerged, and 5 mg/day prednisolone was added to the therapy. Eight years after diagnosis, MRI revealed significant reduction in the size of the heterogeneous residual mass lesion. Discussion: Giant macroadenomas extending to nasopharynx are mostly prolactinomas, but other functional or non-functional pituitary adenomas may also have the same presentation. These lesions tend to be surgically hard to excise due to uncommon localizations, as in our case, and radiotherapy may be needed to control the residual mass.

Clinical outcome of robot-assisted residual mass resection in metastatic nonseminomatous germ cell tumor

Purpose To evaluate the outcome of robot-assisted residual mass resection (RA-RMR) in nonseminomatous germ cell tumor (NSGCT) patients with residual tumor following chemotherapy. Patients and methods Retrospective medical chart analysis of all patients with NSGCT undergoing RA-RMR at two tertiary referral centers between January 2007 and April 2019. Patients were considered for RA-RMR in case of a residual tumor between 10 and 50 mm at cross-sectional computed tomography (CT) imaging located ventrally or laterally from the aorta or vena cava, with normalized tumor markers following completion of chemotherapy, and no history of retroperitoneal surgery. Results A total of 45 patients were included in the analysis. The Royal Marsden stage before chemotherapy was IIA in 13 (28.9%), IIB in 16 (35.6%), IIC in 3 (6.7%) and IV in 13 patients (28.9%). The median residual tumor size was 1.9 cm (interquartile range [IQR] 1.4–2.8; range 1.0–5.0). Five procedures (11.1%) were converted to an open procedure due to a vascular injury (n = 2), technical difficulty (n = 2) or tumor debris leakage (n = 1). A postoperative adverse event occurred in two patients (4.4%). Histopathology showed teratoma, necrosis and viable cancer in 29 (64.4%), 14 (31.1%), and two patients (4.4%), respectively. After a median follow-up of 41 months (IQR 22–70), one patient (2.2%) relapsed in the retroperitoneum. The one- and 2-year recurrence-free survival rate was 98%. Conclusion RA-RMR is an appropriate treatment option in selected patients, potentially providing excellent cure rates with minimal morbidity. Long-term outcome data are needed to further support this strategy and determine inclusion and exclusion criteria.