ABSTRACT
Electrospinning has gained much attention in recent years due to its ability to easily produce high-quality polymeric nanofibers. However, electrospinning suffers from limited production capacity and a method to readily scale up this process is needed. One obvious approach includes the use of multiple electrospinning needles operating in parallel. Nonetheless, such an implementation has remained elusive, partly due to the uneven electric field distribution resulting from the Coulombic repulsion between the charged jets and needles. In this work, the uniformization of the electric field was performed for a linear array of twenty electrospinning needles using lateral charged plates as auxiliary electrodes. The effect of the auxiliary electrodes was characterized by investigating the semi-vertical angle of the spun jets, the deposition area and diameter of the fibers, as well as the thickness of the produced membranes. Finite element simulation was also used to analyze the impact of the auxiliary electrodes on the electric field intensity below each needle. Implementing parallel lateral plates as auxiliary electrodes was shown to help achieve uniformization of the electric field, the semi-vertical angle of the spun jet, and the deposition area of the fibers for the multi-needle electrospinning process. The high-quality morphology of the polymer nanofibers obtained by this improved process was confirmed by scanning electron microscopy (SEM). These findings help resolve one of the primary challenges that have plagued the large-scale industrial adoption of this exciting polymer processing technique.
ABSTRACT
Vaccines against COVID-19 (and its emerging variants) are an essential global intervention to control the current pandemic situation. Anaphylactic reactions have been reported after SARS-CoV2 RNA vaccines. Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction. This risk is estimated at 1/1,000,000 in the context of vaccine safety surveillance programs. The COVID-19 vaccination is rolling-out vastly in different courtiers and surveillance programs are key to monitor severe adverse reactions, such as anaphylaxis. Anaphylaxis due to vaccine is extremely rare and specific cases should receive individualized investigation and care. The here presented recommendations and follow-up from the French allergy community and the Montpellier WHO Collaborating Center in order to support the vaccination program and intends to support to healthcare professionals in their daily basis.
ABSTRACT
Levofloxacin, a quinolone used in the treatment of an upper respiratory tract infection is involved in skin reactions. Patch tests are helpful for the aetiological diagnosis. Unfortunately, they are known for their lack of sensibility. A weak transcutaneous penetration due to the physicochemical characteristics of tested drugs is a well-known cause of false negative results but these characteristics are usually unknown. The aim of the present study was to evaluate physicochemical parameters by potentiometric method in order to optimize the transcutaneous penetration of a preparation for patch test. This method is applicable to a medium such as the preparation for patch test. In order to value the stability of the preparation, qualitative and quantitative analysis of the level of levofloxacin was effectuated. In our study, spectrophotometric and potentiometric data at T0 and six months later with the preparation showed the stability of the preparation. The proportions of non-ionized (45%) and ionized levofloxacin (55%) were not modified. Further experiments are needed to choose the minimal efficient dose of the suspected molecule able to detect a positive reaction in cases of allergic reaction. In addition, this method could be useful in qualitative and quantitative control of preparations made at hospital.
