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  • Joaquim C G Esteves da Silva
Joaquim C G Esteves da Silva

Joaquim C G Esteves da Silva
University of Porto | UP · Departamento de Geociências, Ambiente e Ordenamento do Território

PhD

About

446
Publications
95,270
Reads
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8,313
Citations
Citations since 2017
119 Research Items
4324 Citations
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201720182019202020212022202302004006008001,000
201720182019202020212022202302004006008001,000
201720182019202020212022202302004006008001,000
Additional affiliations
May 1998 - September 2015
University of Porto
Position
  • Professor (Associate)

Publications

Publications (446)
Article
Full-text available
1) Background: Superficial, including cutaneous and mucocutaneous infections are a current public health problem with universal distribution. One of the main concerns, in the present/future, is fungal/bacterial infections by resistant microorganisms. This study aimed to verify if decoctions of coptidis (Coptis chinensis, Ranunculaceae family), neem...
Article
Carbon dots (CDs) are carbon-based nanoparticles with very attractive luminescence features, which simplicity and flexibility of their fabrication can lead to an endless number of CDs with distinct properties and applications. High fluorescence quantum yields (QYFL) are generally a necessary feature for various applications of CDs. One commonly emp...
Article
Full-text available
Carbon dots (CDs) have attracted considerable interest from the scientific community due to their exceptional properties, such as high photoluminescence, broadband absorption, low toxicity, water solubility and (photo)chemical stability. As a result, they have been applied in several fields, such as sensing, bioimaging, artificial lighting and cata...
Article
Full-text available
Surface water is used for a variety of purposes, including agriculture, drinking water, and other services. Therefore, its quality is crucial for irrigation, human welfare, and health. Thus, the main objective is to improve surface water quality assessment and geochemical analysis to evaluate anthropogenic activities’ impact on surface water qualit...
Article
Full-text available
Many of the chemotherapeutic drugs for the treatment of cancer are molecules identified and isolated from plants or their synthetic derivatives. This work aimed to identify the bioactive compounds using LC-MS and GC-MS and to evaluate the anticancer activity of the methanolic extracts of roots, stems, leaves, and flowers from Cladanthus mixtus. The...
Article
Full-text available
Marine Coelenterazine is one of the most well-known chemi-/bioluminescent systems, and in which reaction the chemi-/bioluminophore (Coelenteramide) is generated and chemiexcited to singlet excited states (leading to light emission). Recent studies have shown that the bromination of compounds associated with the marine Coelenterazine system can prov...
Article
Full-text available
The present study aimed to validate a control method on the gas chromatography system (GC) based on the experimental design strategy, to examine the changes and correlation between the fermentation process and the quality of alcoholic and non-alcoholic beer product, especially the formation of diacetyl. On the other hand, spectrophotometric methods...
Article
Full-text available
Brown carbon is a type of strong light-absorbing carbonaceous aerosol associated with radiative forcing. Nevertheless, the difficulty in correlating the chemical composition of brown carbon with its light absorption properties impairs the proper elucidation of its role in radiative forcing. Here, we have used a time-dependent density functional the...
Article
Full-text available
Cancer is a very challenging disease to treat, both in terms of therapeutic efficiency and harmful side effects, which continues to motivate the pursuit for novel molecules with potential anticancer activity. Herein, we have designed, synthesized, and evaluated the cytotoxicity of different brominated coelenteramines, which are metabolic products a...
Article
Full-text available
Doping ZnO with appropriate foreign metal and/or non-metal ions is one of the most promising ways to improve both the extension of ZnO photosensitization to the visible region and the separation of charge carriers. Herein, Mn-doped ZnO nanoparticles were synthesized using a precipitation method. The effect of the Mn amount on the physico-chemical p...
Article
Full-text available
In the present work, the adsorption behavior of Eriochrome Black T (EBT) on waste hemp activat-ed carbon (WHAC) was examined. The surface of the WHAC was modified by H3PO4 acid treat-ment. The surface and structural characterization of the adsorbents was carried out using Fourier transform infrared spectroscopy (FTIR), and scanning electron microsc...
Article
Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated (OPAHs) and nitrated (NPAHs) derivatives are main chromophores of the carbonaceous aerosol brown carbon (BrC), which is linked with radiative forcing. Here, we investigated the atmospheric absorption spectra of 64 PAHs, OPAHs, and NPAHs directly over the Chinese megacity of Xi’an, by empl...
Article
Full-text available
Er 3+ /Yb 3+ doped/co-doped NaGdF4 upconversion phosphor nanoparticles were synthesized via the thermal decomposition route of synthesis. The α-phase crystal structure and nanostructure of these particles were confirmed using XRD and FE-SEM analysis. In the power dependent upconversion analysis, different emission bands at 520 nm, 540 nm, and 655 n...
Article
Full-text available
The present work was designed to investigate the effects of different extraction processes, namely ultrasonic-assisted, supercritical fluid, microwave-assisted and Soxhlet applied to carob pods. The total phenolic quantification and the antioxidant activity were assessed by the means of rapid in vitro spectrophotometric assays; the phenolic profile...
Article
Chemiluminescence is a remarkable process in which light is emitted due to a chemical reaction, without the need for photoexcitation. Among some of the most well-known chemiluminescent systems is that of marine Coelenterazine. Herein, we report the synthesis of a novel halogenated Coelenterazine analog, as well as the characterization of its potent...
Article
Full-text available
Chemi- and bioluminescence are remarkable light-emitting phenomena, in which thermal energy is converted into excitation energy due to a (bio)chemical reaction. Among a wide variety of chemi-/bioluminescent systems, one of the most well-known and studied systems is that of marine imidazopyrazinones, such as Coelenterazine and Cypridina luciferin. D...
Article
Full-text available
Cancer is still a challenging disease to treat, both in terms of harmful side effects and therapeutic efficiency of the available treatments. Herein, to develop new therapeutic molecules, we have investigated the anticancer activity of halogenated derivatives of different components of the bioluminescent system of marine Coelenterazine: Coelenteraz...
Article
The accounting and reporting of greenhouse gas emissions associated with wine production have been increasingly pursued by the wine sector, due to increasing interest regarding environmental issues and sustainable development by consumers and organizations. Herein, this report aims to review and evaluate the existent literature regarding the calcul...
Article
Full-text available
UV-based advanced oxidation processes (AOPs) (UV/H2O2 and UV/S2O82-) with a tita- nium(IV)-doped carbon dot, TiP-CD, as a catalyst were developed for the decomposition of Rema- zol Brilliant Blue R (Reactive Blue 19), an anthraquinone textile dye (at T = 25 °C and pH = 7). The Ti-CD, with marked catalytic UV properties, was successfully synthesized...
Article
Full-text available
The intramolecular chemiexcitation of high-energy peroxide intermediates, such as dioxetanones, is an essential step in different chemi- and bioluminescent reactions. Here, we employed the Time-Dependent Density Functional Theory (TD-DFT) methodology to evaluate if and how external stimuli tune the intramolecular chemiexcitation of model dioxetanon...
Article
Coelenterazine and other imidazopyrazinones are important bioluminescent substrates widespread in marine species and can be found in eight phyla of luminescent organisms. Light emission from these systems is caused by the formation and subsequent thermolysis of a dioxetanone intermediate, whose decomposition allows for efficient chemiexcitation to...
Article
Full-text available
Thymus capitatus is a Mediterranean endemic plant commonly known as “Zaïtra” in northern Morocco. As T. capitatus is widely used in traditional medicine and food, this present work aims to investigate the chemical compositions and biological activities of the T. capitatus leaves essential oil (TcLEO), acetonic (TcLAE), and methanolic extract (TcLME...
Article
In this work, the stability of antioxidant compounds in malting barley seeds before and after the production of the final products is reported. In this reflection, the findings revealed that the process of fermentation had a significant impact on antioxidant activity. In vitro, antioxidant capacities were evaluated using DPPH free radical scavengin...
Article
Full-text available
Carbon dots (CDs) are carbon-based nanomaterials with remarkable properties that can be produced from a wide variety of synthesis routes. Given that “standard” bottom-up procedures are typically associated with low synthesis yields, different authors have been trying to devise alternative high-yield fabrication strategies. However, there is a doubt...
Article
Full-text available
Superoxide anion is a reactive oxygen species (ROS) of biological interest. More specifically, it plays a role in intra- and intercellular signaling, besides being associated with conditions such as inflammation and cancer. Given this, efforts have been made by the research community to devise new sensing strategies for this ROS species. Among them...
Article
Full-text available
A catalytic ozonation advanced oxidation process (AOP) having as catalyst a copper(II) doped carbon dot, Cu-CD (using L-cysteine and polyethylene glycol (PEG) as precursors and passivation agents), was developed for textile wastewater treatment (T=25 ºC and pH=7). Four dyes were analyzed, Methyl Orange (MO), Orange II sodium salt (O-II), Reactive B...
Article
Pharmaceuticals are becoming quite relevant water contaminants, with photocatalysts (such as TiO2) being a promising approach to remove these compounds from water. However, TiO2 has poor sunlight-harvesting capacity, low photonic efficiency, and poor adsorption towards organic pollutants. One of the emerging strategies to enhance the photocatalytic...
Article
Full-text available
Activated carbon modified by phosphoric acid noted CAa was successfully used as a new low-cost adsorbent for removing Cu 2+ , Ni 2+ and Cr 6+ metal ions from artificially contaminated aqueous solutions. Experiments were performed in batches for adsorp-tion kinetics and isotherms. Scanning electron microscope (SEM) observations as well as a nitrogen...
Article
Full-text available
Matricaria chamomilla L. is a famous medicinal plant distributed worldwide. It is widely used in traditional medicine to treat all kinds of diseases, including infections, neuropsychiatric, respiratory, gastrointestinal, and liver disorders. It is also used as a sedative, antispasmodic, antiseptic , and antiemetic. In this review, reports on M. cha...
Article
The thermolysis of dioxetanones is a key process in the intramolecular chemiexcitation step of several chemi- and bioluminescent reactions. This step is generally explained with mechanisms based on either electron transfer (ET), such as the Chemically Initiated Electron-Exchange Luminescence (CIEEL) mechanism, or charge transfer (CT), such as the C...
Article
Full-text available
The chemical characterization of the Ghis-Nekor groundwater has become a concern of many researchers in Morocco. It is a crucial indicator for the environment situation and the socioeconomic development of this Moroccan region. Indeed, it helps decisionmakers carry out conscious and sustainable management. For this reason, 20 samples of the Ghis-Ne...
Article
Full-text available
In this investigation, a hybrid-biocomposite “ZnO-Bentonite/Chitosan” was synthesized using inexpensive and environmentally friendly materials (Bentonitechitosan) and (ZnO). It was used as a photocatalyst for water remediation. The structural, optical, thermal, and morphological proper- ties of the synthesized hybrid-biocomposite were investigated...
Conference Paper
Full-text available
The valorization of biomasses as a source of second generation biofuels is one of the future projects. The valorization, of seeds and shells of cistus ladaniferus as a source of biofuel by the thermal way, pyrolysis in fixed bed under the optimal conditions of temperature and heating speed present very encouraging results. The characterization of t...
Article
Full-text available
The valorization of biomasses as a source of second generation biofuels is one of the future projects. The valorization, of seeds and shells of cistus ladaniferus as a source of biofuel by the thermal way, pyrolysis in fixed bed under the optimal conditions of temperature and heating speed present very encouraging results. The characterization of t...
Article
Full-text available
Photodynamic therapy (PDT) is an anticancer therapeutic modality with remarkable ad- vantages over more conventional approaches. However, PDT is greatly limited by its dependence on external light sources. Given this, PDT would benefit from new systems capable of a light-free and intracellular photodynamic effect. Herein, we evaluated the heavy-ato...
Article
Dioxetanone is one of the prototypical cyclic peroxide intermediates in several chemiluminescent and bioluminescent systems, in which thermolysis reactions allow for efficient singlet chemiexcitation. While the chemiexcitation mechanism of dioxetanone...
Article
Full-text available
Water quality management will be a priority issue in the near future. Indeed, due to scarcity and/or contamination of the water, regulatory frameworks will be increasingly strict to reduce environmental impacts of wastewater and to allow water to be reused. Moreover, drinking water quality standards must be improved in order to account for the emer...
Article
Full-text available
Carbon dots (CDs) are fluorescence carbon-based nanomaterials that possess several properties such as photoluminescence, biocompatibility and good water solubility. They can be fabricated from a large variety of precursors; however, most available organic molecules are still expensive and their use or synthesis can lead to significant challenges to...
Article
Carbon dots (CDs) are carbon-based nanomaterials with advantageous luminescent properties, making them promising alternatives to other molecular and nanosized fluorophores. However, the development of CDs is impaired by the low synthesis yield of standard fabrication strategies, making high-yield strategies essential. To help future studies to focu...
Article
Full-text available
Phenol red (X-PR) and malachite green carbinol (MGC) are two textile finishing dyes, which are present in aquatic environments through industrial effluents. Due to the toxic nature of both dyes, they are harmful to human health. In the present study, two materials, barley seeds and the biochar of barley (Hordeum vulgare L.), were used to remove the...
Article
Full-text available
In this work, TiO2-based nanomaterials have been successfully synthesized by doping TiO2 with Co, Mn, and Ni and by co-doping it with (P,Mo) or (P,W). The structural, optical, and morphological properties of the synthesized nanomaterials have been investigated using various techniques such as XRD, FTIR spectroscopy, UV-vis diffuse reflectance spect...
Article
Full-text available
The present study aimed to investigate the chemical composition, bioactive compounds, and antioxidant activity of two wild edible mushrooms, the honey fungus (Armillaria mellea) and the parasol mushroom (Macrolepiota procera), collected from Northern Morocco (MA) and Portugal (PT). Those species were chosen due to their edibility, nutraceutical, an...
Article
Lactarius sanguifluus is part of the diverse mycological heritage in the Koudiat Taifour forest (a site of biological and ecological interest in the northern region of Morocco), although this fungus is in danger of extinction in this forest. The main objective of the research reported here was to perform an advanced chemical analysis of a methanoli...
Article
In-vitro imaging by swept-source optical coherence tomography (OCT) represents a class of advanced tomography that provides comprehensive and accurate clinical diagnostics. Here colloidal NaGdF4:Er³⁺/Yb³⁺ particles having an average size of 32 nm were successfully synthesized by a facial thermal decomposition method and then used as a contrast agen...
Article
In this study, Co–TiO2 nanoparticles were successfully synthesized using sol-gel and precipitation methods. The effect of Co amount on the physicochemical properties of these nanomaterials was investigated using various techniques. The obtained results showed that the structural and optical properties of the synthesized Co–TiO2 nanomaterials depend...
Article
Full-text available
The valorization of biomasses as a source of second generation biofuels is one of the future projects. The valorization, of seeds and shells of cistus ladaniferus as a source of biofuel by the thermal way, pyrolysis in fixed bed under the optimal conditions of temperature and heating speed present very encouraging results. The characterization of t...
Article
In the present contribution is shown the application of the recently developed functional alignment of pure vectors (FAPV) as a proper algorithm to align second-order chromatographic data with severe retention time shifts in peak position and shape. FAPV decomposed a three-way chromatographic data array in their three modes (sample, spectral and el...
Article
The human normal breast cell line MCF-10A is being widely used as a model in toxicity studies due to its structural similarity to the normal human mammary epithelium. Over the years, application of carbon dots (C-dots) in biomedicine has been increasing due to their photoluminescence properties, biocompatibility, biosafety and possible applications...
Article
High performance liquid chromatography coupled with ultra-violet, diode array detection (HPLC-UV-DAD), was used to study the degradation reactions of ultraviolet (UV) filter hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]- benzoate (DHHB). Degradation by-products were detected and identified by means of liquid chromatography coupled with diode array de...
Book
Full-text available
Em 20 de Setembro de 1519 deu-se início a uma viagem marítima com destino às Molucas (atual Indonésia) planeada e comandada pelo português Fernão de Magalhães, mas patrocinada pelo Rei de Espanha. O que começaria por ser uma viagem que tinha como objetivo acabar com o monopólio Português do fornecimento das especiarias à Europa, com particular dest...
Article
Full-text available
The west coast of Tangier, in northern Morocco, has been affected by industrial wastewater discharge that reaches the ocean through the Boukhalef river. Therefore, the Jbila and Sidikacem beaches near to the Boukhalef river mouth have been classified as polluted for many years. With the aim of determining the COVID-19 pandemic consequences on the T...
Poster
Full-text available
Asteroid Day 30/July/2020
Article
Swept-source optical coherence tomography (SSOCT) is a non-contact, non-invasive bioimaging tool that usesvarious probes to get high contrast images. Rare-earth based upconversion particles (UCPs) providea uniqueplatform to enhance the capabilities of bioimaging techniques. The UCPs can act as contrast enhancers for SSOCT with additional optical fu...
Article
In this investigation, hybrid-biocomposites “ZnO-Chitosan” were synthesized using a chitosan biomaterial and various amounts of ZnO particles (7 and 93 weight percent). The chitosan was obtained from the exoskeletons of shrimp shells, which were collected from the fishmongers in Meknes city (Morocco). Several techniques including X-ray diffraction,...
Article
Full-text available
Carbon dots (CDs) are carbon-based nanoparticles with very attractive luminescence features. Furthermore, their synthesis by bottom-up strategies is quite flexible, as tuning the reaction precursors and synthesis procedures can lead to an endless number of CDs with distinct properties and applications. However, this complex variability has made the...
Article
Full-text available
Spent co�ee grounds (SCGs) are known for containing many organic compounds of interest, including carbohydrates, lipids, phenolic compounds and proteins. Therefore, we investigated them as a potential source to obtain carbon dots (CDs) via a nanotechnology approach. Herein, a comparison was performed between CDs produced by SCGs and classic precurs...
Article
This paper proposes for the first time: (a) a qualitative analytical method based on portable and benchtop backscattering Raman spectrometers coupled to hierarchical cluster analysis (HCA) and multivariate curve resolution – alternating least-squares (MCR-ALS) to identify two polymorphs of antimalarial quinine sulfate in commercial pharmaceutical t...
Article
Full-text available
While TiO2 nanoparticles have shown potential as photocatalysts in the degradation of organic contaminants, their inability to absorb efficiently visible light has limited their industrial application. One strategy for solving this problem is monodoping TiO2 photocatalysts with transition metals, which has worked in the degradation of several pollu...
Conference Paper
Full-text available
This study was carried out in the area of the two biggest industrial zones in northern Morocco: Tangier Free Zone and Gzenaya Zone, where short-term pollution posed the problem of low quality bathing water at Jbila and Sidikacem beaches owing to the fecal contamination caused by drainage wastewaters from Free Zone and Gzenaya Zone. Our goal was to...
Article
Full-text available
This work aims to apply photonic-crystal-based nanocoatings with unusual aesthetical orientation to wood application. Structural colors are currently a formula to achieve those colorful coatings including nonfading properties. They can be produced from self-assembled colloidal spheres into photonic crystals, which possess particular optical propert...
Book
Full-text available
Leonardo da Vinci parece ter nascido em 15 de Abril de 1452 numa aldeia da província de Florença (Itália), chamada de Anchiano, pertencente à comuna de Vinci. Sessenta e sete anos depois, em 2 de Maio de 1519, Leonardo terá morrido na cidade francesa de Amboise, onde terá vivido os seus últimos anos. Assim, iniciaram-se no ano de 2019 as comemoraçõ...
Article
Full-text available
The efficiency and associated environmental impacts of different N-doping strategies of carbon dots (CDs) were evaluated. More specifically, N-doped CDs were prepared from citric acid via two main synthesis routes: Microwave-assisted hydrothermal treatment with addition of N-containing small organic molecules (urea and ethylenediamine (EDA)); and m...
Article
Carbon dots (CDs) are carbon-based nanoparticles with remarkable luminescent properties, which have made them exciting and suitable alternatives to more traditional fluorophores and even to more recent luminescent nanomaterials (such as metal-based quantum dots). However, despite this high interest on CDs, there has been no focus on their sustainab...
Article
The effects of essential oils (EOs) and their eight major components extracted from five aromatic and medicinal plant (AMP) species on the development of Fusarium oxysporum f. sp. albedinis, the phytopathogenic fungus responsible for fusarium wilt (referred to as Bayoud in Morocco) on date palm in Moroccan oases (Errachidia region), were studied. T...