Abstract Background To discuss the risk factors affecting the recurrence of pheochromocytoma after surgery. Methods We retrospectively reviewed patients who were hospitalized and underwent surgery for PCC between January 2012 and December 2020 at Chinese PLA General Hospital. Inclusion criteria were pathological diagnosis of PCC and availability of follow up. Results In total, 451 patients met the inclusion criteria. The average age was 45.89 years, and the median tumor diameter was 5.75 cm. The mean recurrence time was 34.24 months. Of the 451 patients receiving surgery, there were 35 recurrent cases (7.85%). The univariate test showed that age, hypertension, history of PCC recurrence, Ki-67 index ≥ 5, bilateral tumor, duration of phenazopyridine administration, DBP at admission, open operation, intraoperative HR minimum, intraoperative times of HR over 120, times of instability, and intraoperative bleeding were associated with recurrence after radical surgery. Multivariate COX regression analysis of age (HR(hazard ratio) 0.95), hypertension (HR 7.14), history of PCC recurrence (HR 69.35), family history of hypertension (HR 16.30), bilateral tumor (HR 7.38), tumor size (HR 1.05), times of instability (HR 114.91) and length of instability in minutes (HR 1.12) were the independent influences on recurrence after pheochromocytoma resection. Conclusions Age, hypertension, history of PCC recurrence, family history of hypertension, bilateral tumor, tumor size, intraoperative times of instability, and intraoperative instability minutes were independent influences on recurrence after pheochromocytoma resection.
Finding the parameter values of differential equation models from data is an important part of the modelling process. Large models and sparse data often make the parameters very difficult to find. Over the years there have been a number of methods proposed to solve this problem, some with good results but there is still plenty of room for improvement. In this work, we combine ideas from sequential Monte Carlo methods and genetic algorithms to create a new method to fit model parameters. One strength of our method is that it can perform well even when the order of magnitude of the parameters is unknown. We test our method in different models with real and simulated data and it is able to retrieve good parameter values.
Nowadays, microfluidics is attracting more and more attentions in the biological society and has provided powerful solutions for various applications. This paper reported a microfluidic strategy for aqueous sample sterilization. A well-designed small microchannel with a high hydrodynamic resistance was used to function as an in-chip pressure regulator. The pressure in the upstream microchannel was thereby elevated which made it possible to maintain a boiling-free high temperature environment for aqueous sample sterilization. A 120 °C temperature along with a pressure of 400 kPa was successfully achieved inside the chip to sterilize aqueous samples with E. coli and Staphylococcus aureus inside. This technique will find wide applications in portable cell culturing, microsurgery in wild fields, and other related micro total analysis systems.
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