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•Novel α-mangostin loaded crosslinked fibroin nanopaticles using EDC/PEI are developed.•Compared to non-crosslinked particles, high drug entrapment and loading are achieved.•Particle ...charge, crystallinity, solubility, dissolution are controlled favorably.•All particles are stable for 6 months and decrease the drug hematotoxicity by 10-fold.•The particles increase drug anticancer efficacy in Caco-2 and MCF-7 cells.
Silk fibroin has been utilized extensively for biomedical purposes, especially the drug delivery systems. This study introduced and characterized three novel α-mangostin loaded crosslinked fibroin nanoparticles (FNPs), using EDC or PEI as a crosslinker, for cancer treatment. All three formulas were spherical particles with a mean size of approximately 300 nm. By varying the type and/or amount of the crosslinkers, particle surface charge was controllable from −15 to +30 mV. Crosslinked FNPs exhibited higher drug entrapment efficiency (70%) and drug loading (7%) than non-crosslinked FNP. FT-IR, XRD, and DSC analytical methods confirmed that α-mangostin was entrapped in FNPs in molecular dispersion form. Compared to the free α-mangostin, the crosslinked FNPs increased the drug’s solubility up to threefold. They also showed sustained release characteristics of more than 3 days, and reduced free α-mangostin hematotoxicity by 90%. The α-mangostin loaded FNPs were physicochemically stable for up to 24 h when dispersed in intravenous diluent and for at least 6 months when preserved as lyophilized powder at 4 °C. In terms of anticancer efficacy, on both Caco-2 colorectal and MCF-7 breast adenocarcinoma cell lines, all formulas maintain α-mangostin’s apoptotic effect while exhibit greater cytotoxicity than the free drug. In conclusion, α-mangostin loaded crosslinked FNPs show high potential for cancer chemotherapy.
Formulations for inhalation in the treatment of tuberculosis.
Dinh-Duy Pham, Elias Fattal, Nicolas Tsapis.
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•Tuberculosis remains an important health problem worldwide.•Direct drug ...delivery to the lungs seems promising. Various drug delivery systems (liposomes, microparticles etc.) have been developed but are yet to be tested in the clinics.•Inhalable dry powders should be considered in combination with conventional therapy to try to decrease the dosing frequency and the duration of TB therapy.
Tuberculosis (TB) remains a major global health problem as it is the second leading cause of death from an infectious disease worldwide, after the human immunodeficiency virus (HIV). Conventional treatments fail either because of poor patient compliance to the drug regimen or due to the emergence of multidrug-resistant tuberculosis. The aim of this review is to give an update on the information available on tuberculosis, its pathogenesis and current antitubercular chemotherapies. Direct lung delivery of anti-TB drugs using pulmonary delivery systems is then reviewed since it appears as an interesting strategy to improve first and second line drugs. A particular focus is place on research performed on inhalable dry powder formulations of antitubercular drugs to target alveolar macrophages where the bacteria develop. Numerous studies show that anti-TB drugs can be incorporated into liposomes, microparticles or nanoparticles which can be delivered as dry powders to the deep lungs for instantaneous, targeted and/or controlled release. Treatments of infected animals show a significant reduction of the number of viable bacteria as well as a decrease in tissue damage. These new formulations appear as interesting alternatives to deliver directly drugs to the lungs and favor efficient TB treatment.
A rapidly developing market for portable electronic devices and hybrid electrical vehicles requires an urgent supply of mature energy‐storage systems. As a result, lithium‐ion batteries and ...electrochemical capacitors have lately attracted broad attention. Nevertheless, it is well known that both devices have their own drawbacks. With the fast development of nanoscience and nanotechnology, various structures and materials have been proposed to overcome the deficiencies of both devices to improve their electrochemical performance further. In this Review, electrochemical storage mechanisms based on carbon materials for both lithium‐ion batteries and electrochemical capacitors are introduced. Non‐faradic processes (electric double‐layer capacitance) and faradic reactions (pseudocapacitance and intercalation) are generally explained. Electrochemical performance based on different types of electrolytes is briefly reviewed. Furthermore, impedance behavior based on Nyquist plots is discussed. We demonstrate the influence of cell conductivity, electrode/electrolyte interface, and ion diffusion on impedance performance. We illustrate that relaxation time, which is closely related to ion diffusion, can be extracted from Nyquist plots and compared between lithium‐ion batteries and electrochemical capacitors. Finally, recent progress in the design of anodes for lithium‐ion batteries, electrochemical capacitors, and their hybrid devices based on carbonaceous materials are reviewed. Challenges and future perspectives are further discussed.
Mad LIBs: Electrochemical storage mechanisms based on carbon materials for both lithium‐ion batteries (LIBs) and electrochemical capacitors (ECs) are introduced. Non‐faradic processes, faradic reactions, electrochemical performance, impedance behavior, cell conductivity, electrode/electrolyte interface, and ion diffusion are explained. Finally, recent progress in the design of anodes for LIBs, ECs, and their hybrids are reviewed.
In this study, top-down synthesis of sulfur-doped graphene nanosheets (SDGNs) by simple electrochemical exfoliation was explored as a means of producing metal-free electrocatalysts for oxygen ...reduction and oxygen evolution reactions (ORR and OER, respectively). In a typical procedure, graphite foils were used to obtain bulk quantities of SDGN catalysts in the presence of thiosulfate as a sulfur source. Highly stable colloidal dispersions of SDGNs were obtained by applying a voltage of 15 V at an optimized Na2S2O3:H2SO4 molar ratio of 5 : 1 (denoted SDGN(5)). Physicochemical characterizations by Raman spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy confirmed the existence of sulfur and its electronic/structural properties in graphene nanosheets. In alkaline media, SDGN(5)-modified electrodes were comparable or superior to pristine graphene and a benchmark commercial platinum-based electrodes in terms of stability, methanol tolerance, n values, and onset potential for ORR and OER. The specific capacitance (149.9 F g−1) of SDGN(5) supported its excellent ORR/OER performance and enhanced surface area.
This article proposes neural network (NN) based observer schemes and a sensorless robust optimal control scheme for partially unknown permanent magnet synchronous motors with disturbances and ...saturating voltages. First, an NN-observer scheme is designed to estimate back-electromotive force (EMF), for which the mathematical model in rotary or stationary reference frames is relaxed. The NN weight tuning law is designed via Lyapunov theory to guarantee that EMF is ultimately uniformly bounded. Second, to compensate the inexact extraction of the estimated back-EMF at any speed conditions, disturbances, and NN approximation errors, another NN-observer scheme is designed to estimate the tracking errors of rotor position and speed, for which low-pass filters and/or phase-locked loops are not needed. Third, a sensorless saturated robust optimal control scheme dealing with general disturbances and saturating voltages is designed. The scheme includes the augmented feedforward controller to transform the speed and current tracking problem into an optimal control problem. Finally, the feedback control law and worst disturbance law are obtained without estimating unknown internal dynamics. The effectiveness of the proposed schemes is tested through simulations and comparative experiments on a load drive application with a DSP board TMS320F28379D.
Methylammonium lead triiodide (MAPbI3) perovskite solar cells have gained significant attention with an impressive certified power conversion efficiency of 22.1%. Suppression of recombination at the ...interface and grain boundaries is critical to achieve high performance perovskite solar cells (PSCs). Here, we report a simple method to improve the performance of PSCs by incorporating a lead chloride (PbCl2) material into the MAPbI3 perovskite precursor through a Lewis acid-base adduct. The optimal concentration of PbCl2 that helps increase the grain size of MAPbI3 with introduction of the ideal amount secondary phases (lead iodide and methylammonium lead tri-chloride) is 2.5% (molar ratio, relative to lead iodide). Examination by steady-state photoluminescence and time-resolved photoluminescence has shown that devices based on MAPbI3-2.5% of PbCl2 facilitated longer charge carrier lifetime and electron-hole collection efficiency which is ascribed to reduced defects and concurrent improved material crystallinity. Electrochemical impedance spectra (EIS) of the corresponding PSCs have revealed that, compared to the pristine MAPbI3 perovskite film, the 2.5% PbCl2-additive increased the recombination resistance of the PSCs by 2.4-fold. Meanwhile, measurement of the surface potential of the perovskite films has indicated that the PbCl2-additive modifies the electronic properties of the film, shifting the fermi-level of the MAPbI3 film by 90 meV, leading to a more favourable energetic band matching for charge transfer. As a result, the performance of PSCs is enhanced from an average efficiency of 16.5% to an average efficiency of 18.1% with maximum efficiency reaching 19% due to the significantly improved fill-factor (from 0.69 to 0.76), while the hysteresis effect is also suppressed with the PbCl2-additive.
To report clinical findings and light microscopic results of 71 opacified hydrophilic acrylic intraocular lenses (IOLs).
Vivantes Klinikum Neukoelln, Ophthalmology Department, Berlin, Germany.
...Retrospective case series.
Sixty-three patients (71 eyes) were referred to the clinic because of vision-impairing IOL opacification between December 2012 and September 2016 after routine cataract surgery elsewhere. The explanted IOLs were analyzed with light microscopy at the John A. Moran Eye Center (University of Utah, Salt Lake City, Utah, USA). Medical records were reviewed for visual acuity, comorbidities, and complications. Clinical follow up was 6 months.
Seventy-one opacified 1-piece or 3-piece hydrophilic acrylic IOLs (Lentis) of different designs from 2009 to 2012 (LS-502-1, LS-402-1Y, LS 312-1Y, LS-313-1Y, L-402, L-312) were found. Morphological findings were surface, subsurface, or deep calcifications of the IOL material. Explantation was performed 4 years ± 1.2 (SD) after initial phacoemulsification. The mean patient age was 78.6 ± 8.2 years. Ocular and systemic comorbidities were found without statistical correlation: the most frequent were diabetes, uveitis, and glaucoma. The preoperative mean corrected distance visual acuity changed from 0.63 ± 0.47 logarithm of the minimum angle of resolution (logMAR) to 0.20 ± 0.28 logMAR postoperatively (P < .001).
Different designs of IOLs by the same manufacturer, implanted between 2009 and 2012, developed late calcification with significant visual loss after routine cataract surgery. No medical, surgical, or ophthalmologic trigger could be determined. A manufacture issue might be the reason for the opacification.
A hole transport layer (HTL) plays the role of extracting hole carriers while improving interfacial contacts of perovskite/carbon in planar heterojunction perovskite solar cells using carbon based ...electrodes (C-PSCs). For the future application of C-PSCs, the HTL also needs to have good stability and easy processability while maintaining high device efficiency. Herein, we compare the behaviour of the most widely used HTL based on spiro-OMeTAD to the much less studied HTL based on CuSCN in planar C-PSCs. The results show that 14.7% power conversion efficiency (PCE) is obtained for CuSCN based C-PSCs with good reproducibility and negligible hysteresis behaviour. In contrast, the C-PSCs using spiro-OMeTAD show a much lower PCE (12.4%) and significant hysteresis phenomenon. We conduct systematic characterisation of the electronic and energetic properties of the C-PSCs to understand this phenomenon. We find that a more favourable energy level alignment of CuSCN with the perovskite than spiro-OMeTAD leads to a reduced charge injection barrier, which favours a more efficient hole extraction capability, inhibited carrier recombination and reduced ionic capacitance. This in turn leads to better PCE and lower hysteresis for the C-PSCs. Moreover, the CuSCN based C-PSCs also demonstrate better stability against moisture with a high PCE retention ratio of 93% under a humid environment (55-70%) for 80 days without encapsulation.
Carbon electrode-based planar PSCs demonstrated higher device performance and reduced hysteresis using a CuSCN based HTL owing to its favourable energy level alignment with the perovskite compared to conventional spiro-OMeTAD based HTL.
Flash flood is one of the most common natural hazards affecting many mountainous areas. Previous studies explored flash flood susceptibility models; however, there is still a lack of case studies in ...the transport sector. This paper aimed to develop advanced hybrid machine learning (ML) algorithms for flash flood susceptibility modeling and mapping using data from the road network National Highway 6 in Hoa Binh province, Vietnam. A single ML model of reduced error pruning trees (REPT) and four hybrid ML models of Decorate-REPT, AdaBoostM1-REPT, Bagging-REPT, and MultiBoostAB-REPT were applied to develop flash flood susceptibility maps. Field surveys were conducted about the flash flood locations on the 115-km route length of the National Highway 6 in 2017, 2018, and 2019 flood events. This study used 88 flash flood locations and 14 flood conditioning factors to construct and validate the proposed models. Statistical metrics, including sensitivity, specificity, accuracy, root mean square error, and area under the receiver operating characteristic curve, were applied to evaluate the models’ performance and accuracy. The DCREPT model showed the best performance (AUC = 0.988) among the training models and had the highest prediction accuracy (AUC = 0.991) among the testing models. We found that 12,572 ha (Decorate-REPT), 9564 ha (AdaBoostM1-REPT), 11,954 ha (Bagging-REPT), 14,432 ha (MultiBoostAB-REPT), and 17,660 ha (REPT) of the 3-km buffer area of the highway are in the high- and very high-flash-flood-susceptibility areas. The proposed methodology could be potentially generalized to other transportation routes in mountainous areas to generate flash flood susceptibility prediction maps.
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