Maximum power point tracking CMOS circuit to connect a solar cell into a solid-state battery

This paper presents a Maximum Power Point Tracking (MPPT) circuit in CMOS technology for integration into an energy harvesting solution, comprising a solid-state thin-film lithium battery fabricated in the back side of a plastic solar cell. The MPPT CMOS circuit is required in the energy transfer process from the solar cell to the battery. The MPPT circuit was designed in the 0.7 µm CMOS process from on semiconductor (former AMIS, Alcatel-Mietec). The pulse width modulation (PWM) gate control of the DC-DC step-up converter is obtained only with analog circuits, which are composed by rail-to-rail operational amplifiers, analog multipliers and a ring oscillator. The ripple correlation control algorithm is used in the implementation of the analog MPPT circuit. This is a dynamically rapid method (e.g., 5 ms step response was measured) where the inevitable ripple of the inductor current of the DC-DC converter is analyzed and used to adjust the set-point of the same DC-DC converter. The full energy harvesting is also described in this paper

Identification of microplastics using Raman spectroscopy: latest developments and future prospects

Widespread microplastic pollution is raising growing concerns as to its detrimental effects upon living organisms. A realistic risk assessment must stand on representative data on the abundance, size distribution and chemical composition of microplastics. Raman microscopy is an indispensable tool for the analysis of very small microplastics (<20 μm). Still, its use is far from widespread, in part due to drawbacks such as long measurement time and proneness to spectral distortion induced by fluorescence. This review discusses each drawback followed by a showcase of interesting and easily available solutions that contribute to faster and better identification of microplastics using Raman spectroscopy. Among discussed topics are: enhanced signal quality with better detectors and spectrum processing; automated particle selection for faster Raman mapping; comprehensive reference libraries for successful spectral matching. A last section introduces non-conventional Raman techniques (non-linear Raman, hyperspectral imaging, standoff Raman) which permit more advanced applications such as real-time Raman detection and imaging of microplastics.publishe

Liposome Formulations for the Strategic Delivery of PARP1 Inhibitors: Development and Optimization

first_pagesettingsOrder Article Reprints Open AccessArticle Liposome Formulations for the Strategic Delivery of PARP1 Inhibitors: Development and Optimization by Carlota J. F. Conceição 1,2ORCID,Elin Moe 3,4,Paulo A. Ribeiro 2ORCID andMaria Raposo 2,*ORCID 1 CEFITEC, Department of Physics, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal 2 Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL), Department of Physics, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal 3 Institute of Chemical and Biological Technology (ITQB NOVA), The New University of Lisbon, 2780-157 Oeiras, Portugal 4 Department of Chemistry, UiT—The Arctic University of Norway, N-9037 Tromsø, Norway * Author to whom correspondence should be addressed. Nanomaterials 2023, 13(10), 1613; https://doi.org/10.3390/nano13101613 Received: 4 April 2023 / Revised: 7 May 2023 / Accepted: 9 May 2023 / Published: 11 May 2023 (This article belongs to the Special Issue Application of Lipid Nanoparticles in Drug and Gene Delivery) Download Browse Figures Review Reports Versions Notes Abstract The development of a lipid nano-delivery system was attempted for three specific poly (ADP-ribose) polymerase 1 (PARP1) inhibitors: Veliparib, Rucaparib, and Niraparib. Simple lipid and dual lipid formulations with 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1′-glycerol) sodium salt (DPPG) and 1,2-dipalmitoyl-sn-glycero-3-phosphocoline (DPPC) were developed and tested following the thin-film method. DPPG-encapsulating inhibitors presented the best fit in terms of encapsulation efficiency (>40%, translates into concentrations as high as 100 µM), zeta potential values (below −30 mV), and population distribution (single population profile). The particle size of the main population of interest was ~130 nm in diameter. Kinetic release studies showed that DPPG-encapsulating PARP1 inhibitors present slower drug release rates than liposome control samples, and complex drug release mechanisms were identified. DPPG + Veliparib/Niraparib presented a combination of diffusion-controlled and non-Fickian diffusion, while anomalous and super case II transport was verified for DPPG + Rucaparib. Spectroscopic analysis revealed that PARP1 inhibitors interact with the DPPG lipid membrane, promoting membrane water displacement from hydration centers. A preferential membrane interaction with lipid carbonyl groups was observed through hydrogen bonding, where the inhibitors’ protonated amine groups may be the major players in the PARP1 inhibitor encapsulation mode

Thermoelectric generator and solid-state battery for stand-alone microsystems

This paper presents a thermoelectric (TE) generator and a solid-state battery for powering microsystems. Prototypes of TE generators were fabricated and characterized. The TE generator is a planar microstructure based on thin films of n-type bismuth telluride (Bi2Te3) and p-type antimony telluride (Sb2Te3), which were deposited using co-evaporation. The measurements on selected samples of Bi2Te3 and Sb2Te3 thin films indicated a Seebeck coefficient in the range of 90–250 μV K−1 and an in-plane electrical resistivity in the range of 7–17 μÄ m. The measurements also showed TE figures-of-merit, ZT, at room temperatures (T = 300 K) of 0.97 and 0.56, for thin films of Bi2Te3 and Sb2Te3, respectively (equivalent to a power factor, PF, of 4.87 mW K−2 m−1 and 2.81 mW K−2 m−1). The solid-state battery is based on thin films of: an anode of tin dioxide (SnO2), an electrolyte of lithium phosphorus oxynitride (LixPOyNz, known as LiPON) and a cathode of lithium cobaltate (LiCoO2, known as LiCO), which were deposited using the reactive RF (radio-frequency) sputtering. The deposition and characterization results of these thin-films layers are also reported in this paper.This work was fully supported by FCT/PTDC/EEA-ENE/66855/2006 project

Micro-simulation of the impact of different speeds on safety road travel and urban travel time: case study in the city of Guimarães

In recent days, the use of micro-simulation as an additional tool for the study of the network makes this management faster and more efficient, avoiding in situ studies. However, although it is a useful tool, it is necessary that the model under study is the best represented possible in order to obtain results that best fit the reality of the road, and a poor calibration of the model can provide results that do not fit the good management of the road under study. In this sense, using micro-simulation, more precisely to the VISSIM PTV software, a road network at the microscopic level will be evaluated as well as the parameters that most influence the route of the users within that network. The parameters will be modified according to the modeler so as to obtain a model as close to reality as possible. The most appropriate criteria for the calibration and validation of the model will also be chosen. The road safety of the network will also be analyzed using the SSAM software. Here the network's points of conflict will be analyzed, characterizing them as to the type and its severity. Subsequently, a sensitivity analysis will be introduced, where some parameters will be modified individually or together, in order to assess their influence on the network, thus assessing the importance of each in the vehicles.(undefined

Analysis by vibrational spectroscopy of seaweed polysaccharides with potential use in food, pharmaceutical and cosmetic industries

Polysaccharides present in several seaweeds (Kappaphycus alvarezii, Calliblepharis jubata, and Chondrus crispus—Gigartinales, Rhodophyta; Gelidium corneum and Pterocladiella capillacea—Gelidiales, Rhodophyta; Laurencia obtusa—Ceramiales, Rhodophyta; Himanthalia elongata, Undaria pinnatifida, Saccorhiza polyschides, Sargassum vulgare, and Padina pavonica—Phaeophyceae, Ochrophyta) are analyzed by spectroscopic techniques. The nature of the polysaccharides (with extraction and without any type of extraction) present in these seaweeds was determined with FTIR-ATR and FT-Raman analysis of extracted phycocolloids and ground dry seaweed

Primary Effects on Skeletal Muscle

The present study was supported by the Portuguese Society of Diabetes. JS was supported by a PhD Grant from the Portuguese Foundation for Science and Technology, PD/BD/105890/2014.Epidemiological studies showed that chronic caffeine intake decreased the risk of type 2 diabetes. Previously, we described that chronic caffeine intake prevents and reverses insulin resistance induced by hypercaloric diets and aging, in rats. Caffeine has several cellular mechanisms of action, being the antagonism of adenosine receptors the only attained with human coffee consumption. Here, we investigated the subtypes of adenosine receptors involved on the effects of chronic caffeine intake on insulin sensitivity and the mechanisms and sex differences behind this effect. Experiments were performed in male and female Wistar rats fed either a chow or high-sucrose (HSu) diet (35% of sucrose in drinking water) during 28 days, to induce insulin resistance. In the last 15 days of diet the animals were submitted to DPCPX (A1 antagonist, 0.4 mg/kg), SCH58261 (A2A antagonist, 0.5 mg/kg), or MRS1754 (A2B antagonist, 9.5 μg/kg) administration. Insulin sensitivity, fasting glycaemia, blood pressure, catecholamines, and fat depots were assessed. Expression of A1, A2A, A2B adenosine receptors and protein involved in insulin signaling pathways were evaluated in the liver, skeletal muscle, and visceral adipose tissue. UCP1 expression was measured in adipose tissue. Paradoxically, SCH58261 and MRS1754 decreased insulin sensitivity in control animals, whereas they both improved insulin response in HSu diet animals. DPCPX did not alter significantly insulin sensitivity in control or HSu animals, but reversed the increase in total and visceral fat induced by the HSu diet. In skeletal muscle, A1, A2A, and A2B adenosine receptor expression were increased in HSu group, an effect that was restored by SCH58261 and MRS1754. In the liver, A1, A2A expression was increased in HSu group, while A2B expression was decreased, being this last effect reversed by administration of MRS1754. In adipose tissue, A1 and A2A block upregulated the expression of these receptors. A2 adenosine antagonists restored impaired insulin signaling in the skeletal muscle of HSu rats, but did not affect liver or adipose insulin signaling. Our results show that adenosine receptors exert opposite effects on insulin sensitivity, in control and insulin resistant states and strongly suggest that A2 adenosine receptors in the skeletal muscle are the majors responsible for whole-body insulin sensitivity.publishersversionpublishe

Predicting olive phenology in Portugal in a warming climate

Prediction of flowering of olive trees should account for chilling requirements, using an appropriate chilling unit for the accounting of chilling accumulation. After chilling requirements are satisfied, dormancy break takes place. Thereafter, the trees enter the forcing phase, in which the thermal time approach is used, but an appropriate base temperature must be determined. Such a model was developed, calibrated and validated for many olive cultivars (De Melo-Abreu et al., 2004). After flowering, the occurrence of developmental stages may be predicted using a thermal time approach, but for warm regions a saw-tooth model, which is a model that reduces the effect of supra-optimal temperatures, is mandatory (Garcia-Huidobro et al., :1.982). According to the simulations of the model HadCM3, developed by the Hadley Centre, global climate warming will result in average temperature anomalies in winter, in Continental Portugal, of about 2°C, in SRES scenarios 81 and 82, 3°C in scenario A2, and 4 °C in scenario A:tFI, by the end of XXI century. (Miranda et al., 2006). In this study, we discuss the prediction of flowering and subsequent phenological stages and calculate and map the times of occurrence of flowering under three warming scenarios. No flowering or abnormal flowering events are also predicted.Portuguese Foundation for Science and Technology (FCT) under Project Futurolive (PTDC/AGR-AAM/:1.04562/2008)

Study of sardine oil antioxidant properties for the development of topical therapeutic formulations

Sardine is one of the most common fish of the Portuguese coast with important nutritional features. Sardine oil is also a natural source of nutrients with proven benefits for human health, being rich in omega-3 fatty acids, particularly EPA and DHA (polyunsaturated fatty acids-PUFAs) [1]. Several studies show that there is a direct link between a diet enriched in omega-3 and the prevention of diseases such as cardiovascular disease, inflammatory conditions, mental disorders and prevention of various types of cancer [2]. The aim of this work was to characterize the antioxidant role of sardine oil for the development of topical applications. To evaluate the antioxidant effect of sardine oil on skin, human fibroblasts (BJ-5ta), human melanocytes (A375) and human keratinocytes (NCTC2544) were used. Concentrations of oil higher than 8 mg/ml affected significantly the cell viability while for lower concentrations the effect was reduced. The lowest concentrations, 0.5 and 4 mg/ml, were tested to evaluate the protective role of sardine oil in situation of induced oxidative stress. These two concentrations were able to protect cells from damage with a higher effect measured for the fibroblasts. Moreover the incubation of cells with the sardine oil was able to activate a transcription factor Nuclear factor-erythroid-2-related factor 2 (Nrf2) which plays a crucial role in the coordinated induction of genes encoding many stress-responsive and cytoprotective enzymes and related proteins [3]. These results open the opportunity to develop new therapeutic and cosmetic applications based on sardine-derived compounds. Their incorporation in topical creams may contribute to a better treatment of inflammation and in the prevention of skin aging