Correction to a novel framework for rapid diagnosis of COVID-19 on computed tomography scans

Pattern Analysis and Applications - A correction to this paper has been published: https://doi.org/10.1007/s10044-021-00969-x     

Mechanobiology of platelets: techniques to study the role of fluid flow and platelet retraction forces at the micro- and nano-scale

Coagulation involves a complex set of events that are important in maintaining hemostasis. Biochemical interactions are classically known to regulate the hemostatic process, but recent evidence has revealed that mechanical interactions between platelets and their surroundings can also play a substantial role. Investigations into platelet mechanobiology have been challenging however, due to the small dimensions of platelets and their glycoprotein receptors. Platelet researchers have recently turned to microfabricated devices to control these physical, nanometer-scale interactions with a higher degree of precision. These approaches have enabled exciting, new insights into the molecular and biomechanical factors that affect platelets in clot formation. In this review, we highlight the new tools used to understand platelet mechanobiology and the roles of adhesion, shear flow, and retraction forces in clot formation.     

New approach to bone tissue engineering: simultaneous application of hydroxyapatite and bioactive glass coated on a poly(L-lactic acid) scaffold

A combination of bioceramics and polymeric nanofibers holds promising potential for bone tissue engineering applications. In the present study, hydroxyapatite (HA), bioactive glass (BG), and tricalcium phosphate (TCP) particles were coated on the surface of electrospun poly(L-lactic acid) (PLLA) nanofibers, and the capacity of the PLLA, BG-PLLA, HA-PLLA, HA-BG-PLLA, and TCP-PLLA scaffolds for bone regeneration was investigated in rat critical-size defects using digital mammography, multislice spiral-computed tomography (MSCT) imaging, and histological analysis. Electrospun scaffolds exhibited a nanofibrous structure with a homogeneous distribution of bioceramics along the surface of PLLA nanofibers. A total of 8 weeks after implantation, no sign of complication or inflammation was observed at the site of the calvarial bone defect. On the basis of imaging analysis, a higher level of bone reconstruction was observed in the animals receiving HA-, BG-, and TCP-coated scaffolds compared to an untreated control group. In addition, simultaneous coating of HA and BG induced the highest regeneration among all groups. Histological staining confirmed these findings and also showed an efficient osseointegration in HA-BG-coated nanofibers. On the whole, it was demonstrated that nanofibrous structures could serve as an appropriate support to guide the healing process, and coating their surface with bioceramics enhanced bone reconstruction. These bioceramic-coated scaffolds can be used as new bone-graft substitutes capable of efficiently inducing osteoconduction and osseointegration in orthopedic fractures and defects.     

A novel fault ride-through technique for grid-connected Photo Voltaic energy systems

In this article, a novel fault ride-through technique has been implanted with a double control loop method. This method is implemented with voltage-source converters, where the active and reactive power could be easily done with the voltage control loop and inherent current control loop. The proposed system has been implemented to grid-connected photovoltaic systems, and the results have been explored and compared with the existing techniques. An additional control strategy is implemented successfully for satisfactory performance of the system during low irradiance periods, and the system is made capable to provide Q-support to the grid according to the system operators request with the help of Q-set point.     

Liposomal diltiazem HCl as ocular drug delivery system for glaucoma

In this study, unilamellar liposomal vesicles of diltiazem HCl (DH) were prepared using either reversed phase evaporation (REV) or proliposome methods. Soya phosphatidylcholine (SPC) was used for preparing the liposomes, and the vesicles were rigidified using cholesterol (Chol) or cetyl alcohol (CA) in different molarities. The major differences in both the entrapment efficiency percent (EE%) and drug release were evaluated as a function of the method of preparation, Chol or CA contents, and charging lipids. Moreover, the morphology of the vesicles was confirmed by transmission electron microscopy. The effects of Chol or CA incorporation into the liposomes were discussed based on thermal analysis. The in vivo evaluation of liposomal DH was assessed using intra-ocular pressure (IOP), reducing effects in rabbit eyes. Liposomes prepared via REV exhibited higher EE% and lower release rates when compared with those prepared from proliposomes. The incorporation of either Chol or CA in the liposomes enhanced the EE% and decreased the release rates; however, Chol yielded higher results than CA. In addition, both dicetyl phosphate (DCP; negative charge inducer) and stearyl amine (SA, positive charge inducer) decreased the EE% and increased the DH release rate. The in vivo antiglaucoma effects of the liposomes were calculated according to the area above the IOP/Time curve, the maximum response and the time for the maximum response and were compared with effects of the DH solution. The results were in the following order: DH solution?相似文献   

Evaluation of the physical and antimicrobial properties of silver doped hydroxyapatite depending on the preparation method

In the present study, the effect of the preparation method on the physical and antibacterial properties of silver doped hydroxyapatite (HAp/Ag) samples was investigated. HAp/Ag with 0.1–5 % of silver was prepared using two different modified wet chemical precipitation methods. A comparison of thermal stability and thermodynamical properties indicated that the thermal stability and sintering temperature of HAp/Ag were higher than those of pure hydroxyapatite if Ca(NO₃)₂·4H₂O, AgNO₃, NH₄OH and (NH₄)₂HPO₄ were used as raw materials. Phase composition and silver release were determined by XRD and ICP-MS. The study showed that, after 50 h in simulated body fluid 0.8–1.8 % of silver of the total silver amount was released from compact HAp/Ag scaffolds, and release kinetics strongly depended on the HAp/Ag preparation method. In vitro antibacterial activity of samples from each method against the bacterial strains Staphylococcus epidermidis and Pseudomonas aeruginosa was approved. Results showed that, in the case of using Ca(OH)₂, H₃PO₄ and AgNO₃ as raw materials for HAp/Ag synthesis, higher antibacterial activity towards both bacterial strains could be obtained.