Browsing by Issue Date, starting with "2023-11-10"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- Integrated process of immediate one-step lime precipitation, atmospheric carbonation, constructed wetlands, or adsorption for industrial wastewater treatment: A reviewPublication . Simão Madeira, Luís Miguel; Carvalho, Fátima; Almeida, Adelaide; Ribau Teixeira, MargaridaThe transition from the linear economy paradigm to the circular economy in industrial wastewater treatment systems is on the global agenda. The search for new simple, eco-innovative, and low-cost processes for treating industrial wastewater, which can also be used by small and medium-sized industries, has been a constant challenge especially when environmental sustainability is considered. So, a new integrated industrial wastewater treatment system has been developed that includes the immediate one-step lime precipitation process (IOSLM) and atmospheric carbonation (AC), followed by constructed wetlands (CWs) or adsorption. The current review provides an overview of industrial wastewater treatment strategies for high- and low-biodegradable wastewater. A background on functionality, applicability, advantages and disadvantages, operating variables, removal mechanisms, main challenges, and recent advances are carried out for each process that makes up the IOSLM+AC+CW/adsorption integrated system. The prospects of the IOSLM+AC+CW/adsorption integrated system are also discussed. Not neglecting the improvements that still need to be made in the integrated treatment system as well as its application to various types of industrial wastewater, this review highlights that this treatment system is promising in industrial wastewater treatment and consequent by-product recovery. The IOSLM+AC integrated system showed that it can remove high amounts of organic matter, total suspended solids, oils and fats, phosphorus, and ammonium nitrogen from industrial effluents. On the other hand, constructed wetlands/adsorption can be alternatives for refining effluents still containing organic matter and nitrogen that were not possible to remove in the previous steps.
- Biosensors based on stanniocalcin-1 protein antibodies thin films for prostate cancer diagnosisPublication . Ferreira, Renato; Ribeiro, Paulo A.; Canário, Adelino V. M.; Raposo, MariaProstate cancer is one of the most prevalent tumors in men, accounting for about 7.3% of cancer deaths. Although there are several strategies for diagnosing prostate cancer, these are only accurate when the tumor is already at a very advanced stage, so early diagnosis is essential. Stanniocalcin 1 (STC1) is a secreted glycoprotein, which has been suggested as a tumor marker as its increased expression is associated with the development and/or progression of different types of malignant tumors. In this work, an electronic tongue (ET) prototype, based on a set of four sensors prepared from thin films that included STC1 antibodies for detecting prostate cancer, was developed. In the preparation of the thin films, polyelectrolytes of polyallylamine hydrochloride, polystyrene sulfonate of sodium and polyethyleneimine, and the biomolecules chitosan, protein A, and STC1 antibody were used. These films were deposited on quartz lamellae and on solid supports using layer-on-layer and self-assembly techniques. The deposition of the films was analyzed by ultraviolet-visible spectroscopy, and the detection of STC1 in aqueous solutions of PBS was analyzed by impedance spectroscopy. The impedance data were statistically analyzed using principal component analysis. The ETs formed by the four sensors and the three best sensors could detect the antigen at concentrations in the range from 5 × 10−11 to 5 × 10−4 M. They showed a linear dependence with the logarithm of the antigen concentration and a sensitivity of 5371 ± 820 and 4863 ± 634 per decade of concentration, respectively. Finally, the results allow us to conclude that this prototype can advance to the calibration phase with patient samples.
- Modulation of a RBP as potential therapeutic strategy for SCA2Publication . Couto, Filipa Lopes; Nóbrega, ClévioSpinocerebellar ataxia type 2 (SCA2) is one of the nine polyglutamine disease (polyQ), characterized by an abnormally long expansion of the adenine-cytosine-guanine (CAG) trinucleotide within each respective disease-associated gene. PolyQ diseases are dominantly inherited neurodegenerative disorders in which, affected people experience a myriad of highly debilitating motor symptoms. SCA2 arises from a mutation within the coding region of the ATXN2 gene, which is translated into ataxin-2 protein bearing an abnormally long polyQ tract. This mutant protein is prone to aggregate and known to gain toxic function, which is in the basis for disrupting several molecular pathways, which ultimately lead to neuronal death, within specific brain region, including the pons and the cerebellum. Among other, these disrupted pathways might include aberrant RNA metabolism or even loss of cellular proteostasis. Unfortunately, there are no therapeutic options capable of preventing such pathways to became dysregulated, which mean that people affected by SCA2 have no therapies able to cure nor delay the disease progression, ultimately suffering a premature death. To understand whether reestablishing cellular proteostasis could, in fact mitigate SCA2-associated pathology we sought to evaluate the impact of expressing HSPA8, a crucial chaperone involved in the mechanism of proteome homeostasis. In this work we used both in vitro and in vivo approaches to assess whether HSPA8 expression was able prevent SCA2 pathology. We observed that in in vitro models of SCA2 and in an in vivo lentiviral model of this disease, HSPA8 expression was able to both prevent the number of ataxin-2 aggregates and at the same time preserve the neuronal tissue. This work suggests that the expression of HSPA8, a chaperone involved in the mechanism of cellular proteostasis, was able to mitigate SCA2-associated disease hallmarks. Therefore, HPSPA8 could represent a novel therapeutic target for SCA2.
- Extracellular electrical transducers for recording signals of cells in culturePublication . Inácio, Pedro Miguel Cavaco Carrilho Dos Santos; Félix, Rute Castelo; Gomes, Henrique LeonelThe development of instruments and methods for basic neuroscience and cell biology studies has played a significant role in advancing our understanding about fundamental biological process. Most of this knowledge has been gathered through using invasive methods such as the patch clamp method, to study the electrical response of neuronal cells. Recent advancements in microelectronics have revolutionized these studies by enabling non-invasive extracellular electrode recordings using extracellular electrodes know as Microelectrode array (MEAS) technology. This breakthrough has sparked significant interest in the scientific community, as it opens a wider range of applications, including, fundamental studies in neurosciences, drug screening, environmental monitoring, and toxin detection. Microelectrode array (MEA) technology has evolved into a mature technology, and it is widely considered as the gold standard for electrophysiological studies. Nevertheless, MEAs have been primarily optimized to measure excitable cells. Excitable cell is a term used to refer to cells with biological mechanisms that enable them to generate action potentials (APs). Two examples of excitable cells are neurons and cardiac cells. Somatic cells, such as cancer cells, fibroblasts, secretory cells, and epithelial cells, are considered non-electrogenic cell types. Non-electrogenic cells lack the biological mechanisms to generate a response to an electrical stimulus. However, non-excitable cells have other signaling mechanisms that allow them to generate electrical fluctuations. A well-known example are chemical waves which propagate across the cell tissue. Communication process trough chemical waves requires synchronization among a population of cells. Calcium waves are examples of this signaling mechanism. Chemical waves can be detected and recorded using optical fluorescence techniques. However, the optical detection has a few major handicaps. Optical methods require the incubation using fluorescence molecules with a lifetime limited to a few hours. Furthermore, the require microscopes equipped with lasers as well as fast optical detection systems. Additionally, cells are subjected to light pulse, that may interfere with normal cell behavior. Therefore, there is a strong need for an electrical-based technique that detects voltage oscillations generated by chemical waves in real time. This thesis is positioned in this context and aims to fabricate and test devices to record extracellular signals generated by non-excitable cells. The work builds on the group's previous experience, which was crucial in developing the technique for measuring ultra-weak signals with amplitudes as small as a few micro-volts in the millihertz frequency. It is essential to emphasize that the work developed in this thesis is based on the group's previous experience, whose contribution was fundamental for the development of the technique for measuring ultra-weak signals with amplitudes of just a few micro-volts. The group has already demonstrated electrophysiological based devices with an unrivalled detection limit of 20 nanovolts. However, there are still some challenges to be addressed. A critical objective is to minimize the intrinsic noise of the devices using innovative materials, such as conductive polymers and nano−fibrous bacterial cellulose substrates. This improvement will bring the detection limit of the device to low voltages and allow access to faint signals as well as to increase the signal-to-noise ratio (SNR). Other important goal is to establish a clear relation between the electrode geometry and the properties of the native signals generated by the population of cells.