The fragmentation equation with size diffusion: Well posedness and long-term behaviour

The dynamics of the fragmentation equation with size diffusion is investigated when the size ranges in $(0,\infty)$ . The associated linear operator involves three terms and can be seen as a nonlocal perturbation of a Schrödinger operator. A Miyadera perturbation argument is used to prove that it is the generator of a positive, analytic semigroup on a weighted $L_1$ -space. Moreover, if the overall fragmentation rate does not vanish at infinity, then there is a unique stationary solution with given mass. Assuming further that the overall fragmentation rate diverges to infinity for large sizes implies the immediate compactness of the semigroup and that it eventually stabilizes at an exponential rate to a one-dimensional projection carrying the information of the mass of the initial value.

Towards a Standard Method for Estimating Fragmentation Rates in Emulsification Experiments

The fragmentation rate function connects the fundamental drop breakup process with the resulting drop size distribution and is central to understanding or modeling emulsification processes. There is a large interest in being able to reliably measure it from an emulsification experiment, both for generating data for validating theoretical fragmentation rate function suggestions and as a tool for studying emulsification processes. Consequently, several methods have been suggested for measuring fragmentation rates based on emulsion experiments. Typically, each study suggests a new method that is rarely used again. The lack of an agreement on a standard method has become a substantial challenge. This contribution critically and systematically analyses four influential suggestions of how to measure fragmentation rate in terms of validity, reliability, and sensitivity to method assumptions. The back-calculation method is identified as the most promising—high reliability and low sensitivity to assumption—whereas performing a non-linear regression on a parameterized model (as commonly suggested) is unsuitable due to its high sensitivity. The simplistic zero-order method is identified as an interesting supplemental tool that could be used for qualitative comparisons but not for quantification.

Effect of Performance of Soil Cultivator with Different Surface Textures of Shovel Wing

Cultivating the soil is a necessary measure to ensure the growth of potatoes, and it has a significant impact on potato yield. In this study, a soil cultivator with a textured shovel wing was designed to address the problem that soil cultivators have poor working performance. Based on a combination of discrete element simulation and a digital soil trench verification test, the effects of the structure parameters of the surface textures on the traction resistance and soil fragmentation rate of the soil cultivator with a textured shovel wing were studied. These parameters were optimized to provide a basis for the design of the soil cultivator. The main research results of this paper are as follows. (1) The factors influencing the traction resistance of the soil cultivator were as follows: blade penetration angle > convex hull distance > convex hull diameter. The convex hull diameter was the main factor affecting the soil fragmentation rate. The traction resistance of the soil cultivator with a textured wing was reduced by 9.49%, and the soil fragmentation rate was increased by 10.67%, showing that the quality of soil cultivation was significantly improved. (2) The best parameters for the texture structure of the shovel wing were a blade penetration angle of 26°, a convex hull diameter of 34.4 mm, and a convex hull distance of 28.5 mm. (3) The relative errors between the simulation and the soil trench test for the traction resistance and the soil fragmentation rate were 2.60% and 13.97%, respectively. This study can provide technical support for the design of soil cultivators and is of great significance in improving the quality of soil cultivators.

Impact of Paternal Genome with a High DNA Fragmentation Index (>60%) on Early Embryonic Development

: Objectives: The objective of this study is to propose thresholds of the sperm DNA fragmentation rate (IFA≤30% IFA31%-60% IFA>60%), in order to assess the clinical effects of the paternal genome on intra cytoplasmic sperm injection parameters, in particular the effect of the latter on early embryonic development. Materials and Methods: The procedure is a retrospective study, which involved 101 patients enrolled in an ICSI program with their partners. The index of spermatic DNA fragmentation rate was measured using the Sperm Chromatin Dispersion assay. Results: There is a negative correlation between high levels of the spermatic DNA fragmentation index and spermiological characteristics: Concentration P=0.002 and mobility P=0.0001. For ICSI results, there are different observations on the existence of a correlation between the spermatic DNA fragmentation index and fertility rate. On the other hand, the rate of sperm DNA fragmentation does not seem to influence early embryonic development, and even couples whose partners have a high fragmentation index manage to obtain the best quality embryos (P=0.002). We observe a decrease in the rate of implantation with an increase in the rate of alteration of the sperm genome, but this remains insignificant P > 0.05. Conclusion: ICSI remains the only alternative for men with a high rate of sperm DNA fragmentation. Moreover, the operator seems to influence the results more than is suggested. This does not exclude the paternal effect which may influence the quality of the concepltus later on. Keywords: DNA Fragmentation Index, ICSI, Fertilization Rate, Embryos Quality.

P–019 Sperm parameter and ICSI / IVF outcomes after sperm selection using microfluidic sperm separator and density gradient centrifugation with swim-up in split semen sample

Study question To analyze whether microfluidic sperm selection (MSS) by ZyMōt™ improves sperm DNA fragmentation rate and embryonic development compared to density gradient centrifugation with swim-up (DGCS). Summary answer MSS by ZyMōt™ selects sperm for clinical use with less DNA damage significantly compared to DGCS. What is known already Conventional sperm preparation methods, such as density gradient centrifugation and the swim-up method utilize centrifugation during processing, may damage the sperm. MSS may allow for improved selection of normal sperm compared with conventional sperm preparation as it yields sperm with a lower DNA fragmentation rate. However, there are few clinical studies by sibling oocytes study compared to DGCS. Study design, size, duration This prospective study was performed between March 2020 and May 2020 at a reproductive center. All patients involved gave written consent, and institutional review board approval was granted. A total of 575 metaphase II oocytes were collected from 49 cycles. Wife’s age was 34.7 ± 3.9 years old. Raw sperm concentration and motile sperm concentration was 63.1 ± 78.7M/mL, and 41.6 ± 67.7M/mL, respectively. Participants/materials, setting, methods Patients who performed ART for the first or second time were divided into two groups according to MSS and DGCS. Sperm DNA fragmentation rate (SDFR) and motile sperm concentration were compered between MSS and DGCS. SDFR was measured by sperm chromatin structure assay (SCSA) using a flow cytometer. Sibling oocytes were randomized into MSS-IVF, DGCS-IVF, MSS-ICSI, and DGCS-ICSI. Rate of two pronuclear (2PN) oocytes, blastocysts development, and good-quality blastocysts were compared between each group. Main results and the role of chance SDFR was 13.5 ± 11.8% for raw semen. SDFR was significantly lower after MSS (3.6 ± 4.1%) than that for raw semen and after DGCS (17.4 ± 14.8%) (P < 0.01). Motile sperm concentration after MSS (19.0 ± 28.3M/mL) was significantly higher after than after DGCS (15.4 ± 15.3M/mL) (P < 0.01). The number of IVF performed was 145 for MSS and 132 for DGCS. IVF results (MSS vs DGCS) were 2PN rate (73.1% vs 72.0%), blastocysts development rate (65.3% vs 55.4%), and good quality blastocysts rate (43.2% vs 34.9%). The number of ICSI performed was 149 for MSS and 149 for DGCS. ICSI results (MSS vs DGCS) were 2PN rate (77.9% vs 79.2%), blastocysts development rate (68.8% vs 65.8%), and good quality blastocysts rate (35.8% vs 30.6%). No significant difference was observed between MSS and DGCS for each parameter both IVF and ICSI. Limitations, reasons for caution The participants were limited to those who collected semen of 2mL or more and motile sperm concentration of above 1M/mL, because semen sample needed to be divided to MSS and DGCS. Wider implications of the findings: This is the first study to conducted in sibling oosytes study with MSS and DGCS, in both IVF and ICSI. MSS is effective in collecting sperm with less DNA damage compared to DGCS. Motile sperm concentration after using MSS is sufficient to perform IVF as well as DGCS. Trial registration number Not applicable

Efficacy and safety of peroral cholangioscopy with intraductal lithotripsy for difficult biliary stones: a systematic review and meta-analysis

Background Peroral cholangioscopy with intraductal lithotripsy facilitates optically guided stone fragmentation of difficult biliary stones refractory to conventional endoscopic therapy. The aim of this study was to evaluate the efficacy and safety of peroral cholangioscopy with intraductal lithotripsy for difficult biliary stones. Methods Searches of PubMed, EMBASE, Web of Science, and Cochrane databases were performed in accordance with PRISMA and MOOSE guidelines. Measured outcomes included overall fragmentation success, single-session fragmentation and duct clearance, and rate of adverse events. Sensitivity and subgroup analyses were performed based upon cholangioscopy technique and type of lithotripsy (laser versus electrohydraulic). Heterogeneity was assessed with I 2 statistics. Publication bias was ascertained by funnel plot and Egger regression testing. Results 35 studies were included with 1762 participants (43.4 % men; mean age 61.5 [standard deviation (SD) 11.0]). Prior cholecystectomy had been performed in 37 % of patients, with a mean number of 1.6 (SD 0.5) ERCPs performed prior to lithotripsy. Mean stone size was 1.8 (SD 0.3) cm. Peroral cholangioscopy with intraductal lithotripsy achieved an overall stone fragmentation success of 91.2 % (95 %CI 88.1 % – 93.6 %; I 2 = 63.2 %) with an average of 1.3 [SD 0.6] lithotripsy sessions performed. Complete single-session fragmentation success was 76.9 % (95 %CI 71.6 % – 81.4 %; I 2 = 74.3 %). The adverse events rate was 8.9 % (95 %CI 6.5 % – 12.2 %; I 2 = 60.6 %). Mean procedure time for peroral cholangioscopy was 67.1 (SD 21.4) minutes. There was no difference in overall fragmentation rate or adverse events; however, laser lithotripsy was associated with a higher single-session fragmentation rate and shorter procedure time compared with electrohydraulic lithotripsy. Conclusions Peroral cholangioscopy with intraductal lithotripsy appears to be a relatively safe and effective modality for difficult biliary stones.