Experimental study on influence of particle shape on shockwave from collapse of cavitation bubble.

The bubble dynamics under the influence of particles is an unavoidable issue in many cavitation applications, with a fundamental aspect being the shockwave affected by particles during bubble collapse. In our experiments, the method of spark-induced bubbles was used, while a high-speed camera and a piezoresistive pressure sensor were utilized to investigate how particle shape affects the evolution of shockwaves. Through the high-speed photography, we found that the presence of the particle altered the consistency of the liquid medium around the bubble, which result in the emitting of water hammer shockwave and implosion shockwave respectively during the collapse of the bubble. This stratification effect was closely related to the bubble-particle relative distance φ and particle shape δ. Specifically, when the bubble-particle relative distance φ < 1.34 e-0.10δ, particles disrupted the medium consistency around the bubbles and led to a nonspherical collapse and the consequent stratification of the shockwave. By measuring the stratified shockwave intensity affected by different particle shapes, we found that the stratified shockwave intensity experienced varying degrees of attenuation. Furthermore, as the particle shape δ increased, the attenuation of the particle on shockwave intensity gradually reduced. These new findings hold significant theoretical implications for elucidating cavitation erosion mechanisms in liquid-solid two-phase flows and applications and prevention strategies in liquid-solid two-phase cavitation fields.

Acquired Concurrent EGFR T790M and Driver Gene Resistance From EGFR-TKIs Hampered Osimertinib Efficacy in Advanced Lung Adenocarcinoma: Case Reports.

The acquired resistance of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is inevitable and heterogeneous. The strategies to overcome acquired resistance are significant. For patients with secondary T790M-positive after early generation EGFR-TKIs, osimertinib is the standard second-line therapy. In patients resistant to prior early generation EGFR-TKIs, the acquired T790M mutation overlaps with other driver gene resistance, such as HER2-and MET amplification, accounting for 4-8%. The efficacy of osimertinib is unclear in patients with concurrent multiple driver gene resistance. We here report a patient who acquired EGFR T790M, STRN-ALK fusion, and EGFR amplification after gefitinib progression and subsequent MET amplification acquired from osimertinib. The other patient acquired EGFR T790M and MET amplification post-dacomitinib and acquired CCDC6-RET fusion after osimertinib treatment. Besides, subsequent new bypass activations were the possible resistance mechanisms to second-line osimertinib. Both patients had progression-free survival (PFS) less than 4 months and limited benefits from osimertinib second-line therapy. The T790M accompanying driver gene resistance will be a new subtype after EGFR-TKIs progression, needing effective treatment options.

Comparative pharmacokinetics of intravenous and intramuscular cefquinome sulfate administration in ducklings and goslings.

OBJECTIVE: To compare the pharmacokinetics of cefquinome sulfate in ducklings and goslings after IV or IM administration of a single dose. ANIMALS: 216 healthy Muscovy ducklings (Cairina moschata) and 216 healthy Sichuan white goslings (Anser cygnoides). PROCEDURES: Ducklings and goslings were each randomly assigned to 3 groups (n = 72/group) that received a single dose (2 mg/kg) of injectable cefquinome sulfate administered IV or IM or of injectable cefquinome sulfate suspension administered IM. Blood samples were collected at various points after drug administration (n = 6 birds/time point). Plasma cefquinome concentrations were measured by high-performance liquid chromatography with UV detection, and pharmacokinetic parameters were calculated with a 2-compartment model method. RESULTS: After IV injection, mean distribution half-life of cefquinome was longer in goslings (0.446 hours) than in ducklings (0.019 hours), whereas volume of distribution at steady state was greater (0.432 vs 0.042 L/kg) and elimination half-life was slower (1.737 vs 0.972 hours). After IM administration of injectable cefquinome sulfate, bioavailability of the drug was higher in goslings (113.9%) than in ducklings (67.5%). After IM administration of injectable cefquinome sulfate suspension, bioavailability was also higher in goslings (123.1%) than in ducklings (96.8%), whereas elimination half-life was slower (6.917 vs 1.895 hours, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: In goslings, IV administration of cefquinome resulted in slower distribution and metabolism of the drug than in ducklings and IM administration resulted in higher bioavailability. The delayed-release effect of the injectable cefquinome sulfate suspension when administered IM was observed only in goslings.