Promotional Campaigns in the Era of Social Platforms

The rise of social media has facilitated the diffusion of information to more easily reach millions of users. While some users connect with friends and organically share information and opinions on social media, others have exploited these platforms to gain influence and profit through promotional campaigns and advertising. The existence of promotional campaigns contributes to the spread of misleading information, spam, and fake news. Thus, these campaigns affect the trustworthiness and reliability of social media and render it as a crowd advertising platform. This dissertation studies the existence of promotional campaigns in social media and explores different ways users and bots (i.e. automated accounts) engage in such campaigns. In this dissertation, we design a suite of detection, ranking, and mining techniques. We study user-generated reviews in online e-commerce sites, such as Google Play, to extract campaigns. We identify cooperating sets of bots and classify their interactions in social networks such as Twitter, and rank the bots based on the degree of their malevolence. Our study shows that modern online social interactions are largely modulated by promotional campaigns such as political campaigns, advertisement campaigns, and incentive-driven campaigns. We measure how these campaigns can potentially impact information consumption of millions of social media users

A classifier to detect informational vs. non-informational heart attack tweets

Social media sites are considered one of the most important sources of data in many fields, such as health, education, and politics. While surveys provide explicit answers to specific questions, posts in social media have the same answers implicitly occurring in the text. This research aims to develop a method for extracting implicit answers from large tweet collections, and to demonstrate this method for an important concern: the problem of heart attacks. The approach is to collect tweets containing “heart attack” and then select from those the ones with useful information. Informational tweets are those which express real heart attack issues, e.g., “Yesterday morning, my grandfather had a heart attack while he was walking around the garden.” On the other hand, there are non-informational tweets such as “Dropped my iPhone for the first time and almost had a heart attack.” The starting point was to manually classify around 7000 tweets as either informational (11%) or non-informational (89%), thus yielding a labeled dataset to use in devising a machine learning classifier that can be applied to our large collection of over 20 million tweets. Tweets were cleaned and converted to a vector representation, suitable to be fed into different machine-learning algorithms: Deep neural networks, support vector machine (SVM), J48 decision tree and naïve Bayes. Our experimentation aimed to find the best algorithm to use to build a high-quality classifier. This involved splitting the labeled dataset, with 2/3 used to train the classifier and 1/3 used for evaluation besides cross-validation methods. The deep neural network (DNN) classifier obtained the highest accuracy (95.2%). In addition, it obtained the highest F1-scores with (73.6%) and (97.4%) for informational and non-informational classes, respectively

Hypoxia-induced shift in the phenotype of proteasome from 26S toward immunoproteasome triggers loss of immunoprivilege of mesenchymal stem cells

Allogeneic mesenchymal stem cells (MSCs) are immunoprivileged and are being investigated in phase I and phase II clinical trials to treat different degenerative and autoimmune diseases. In spite of encouraging outcome of initial trials, the long-term poor survival of transplanted cells in the host tissue has declined the overall enthusiasm. Recent analyses of allogeneic MSCs based studies confirm that after transplantation in the hypoxic or ischemic microenvironment of diseased tissues, MSCs become immunogenic and are rejected by recipient immune system. The immunoprivilege of MSCs is preserved by absence or negligible expression of cell surface antigen, human leukocyte antigen (HLA)-DRα. We found that in normoxic MSCs, 26S proteasome degrades HLA-DRα and maintains immunoprivilege of MSCs. The exposure to hypoxia leads to inactivation of 26S proteasome and formation of immunoproteasome in MSCs, which is associated with upregulation and activation of HLA-DRα, and as a result, MSCs become immunogenic. Furthermore, inhibition of immunoproteasome formation in hypoxic MSCs preserves the immunoprivilege. Therefore, hypoxia-induced shift in the phenotype of proteasome from 26S toward immunoproteasome triggers loss of immunoprivilege of allogeneic MSCs. The outcome of the current study may provide molecular targets to plan interventions to preserve immunoprivilege of allogeneic MSCs in the hypoxic or ischemic environment

Influence of carbon nanotubes on printing quality and mechanical properties of 3D printed cementitious materials

This paper presents the impact of incorporating carbon nanotubes (CNTs) into the 3D printing of cementitious materials, along with the effective dispersion of CNTs. Compared to the control mix, adding CNTs with superplasticizer significantly enhanced the printing quality by reducing the error in height of two-layers from 38% to 30% and an 81% enhancement in the buildability. Moreover, rheology properties revealed shear-thinning behaviour with lower viscosity, resulting in improved flowability. The progressive increase in CNT concentrations up to 0.2% yielded a noteworthy improvement in the mechanical properties. At 28 days, the incorporation of 0.2% CNTs resulted in a significant increase in the flexural strength, compressive strength, and Young's modulus by 99%, 72%, and 43%, respectively, compared to the mix containing silica fume. Microstructural investigation of the CNT-cement matrix revealed nanoscale crack bridges formed by CNTs, reinforcing the cementitious material and improving its mechanical properties.</p

Thermal decomposition and gasification of biomass pyrolysis gases using a hot bed of waste derived pyrolysis char

Chars produced from the pyrolysis of different waste materials have been investigated in terms of their use as a catalyst for the catalytic cracking of biomass pyrolysis gases during the two-stage pyrolysis-gasification of biomass. The chars were produced from the pyrolysis of waste tyres, refused derived fuel and biomass in the form of date stones. The results showed that the hydrocarbon tar yields decreased significantly with all the char materials used in comparison to the non-char catalytic experiments. For example, at a cracking temperature of 800 °C, the total product hydrocarbon tar yield decreased by 70% with tyre char, 50% with RDF char and 9% with biomass date stones char compared to that without char. There was a consequent increase in total gas yield. Analysis of the tar composition showed that the content of phenolic compounds decreased and polycyclic aromatic hydrocarbons increased in the product tar at higher char temperatures

In search of conditions for Gd-TiO2 activation by light irradiation in photodynamic treatment of pancreatic cancer cells

With difficulty in early diagnosis, inaccessibility for the surgical approach, and high resistance to radio and chemotherapies, the resulting low treatment success rates are calling for new approaches in treating pancreatic cancer [1]. Photodynamic therapy (PDT), with the use of light or X-rays, is a method that has the potential to help overcome the problems that existing approaches meet [2,3]. Through activation of photo-sensitive particles with irradiation, PDT helps the production of reactive oxygen species, consequently stimulating cell death. We have synthesized and characterized Gadolinium-doped titanium dioxide nanoparticles (Gd-TiO2 NPs) and tested them as photosensitizers on two pancreatic cancer cell lines, MIA PaCa-2 and PANC-1. Different concentrations of NP treatment, irradiation powers, and times of irradiation were trialed as parameters of activation. Cell viability was measured 48h after treatments, and although some results implied a slight decrease in the viability of treated cells, we have met difficulties in obtaining consistency in results. Statistical significance in the decrease of the viability of treated cells in most cases was not attained, suggesting that higher concentrations or irradiation power and longer illumination time might be needed to achieve a positive PDT effect with this NP system.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad

SR FTIR spectroscopy investigation of Pd@S-CD nanocomposite system effects on biomolecules in cervical carcinoma cells

Nanocomposite system formulated from surface-modified S-doped carbon dot (S-CD) nanoparticle with a potential metallodrug, palladium(II) complex, dichloro(1,2-diaminocyclohexane)palladium(II), [Pd(dach)Cl2] (Pd@S-CD), was investigated as a model system for the treatment of cervical carcinoma (HeLa) cells. To examine the intracellular biochemical effects induced by the Pd@S-CD, we used Synchrotron Radiation-based Fourier-transform infrared spectroscopy (SR FTIR). SR FTIR spectroscopy was employed to investigate the alterations in cellular components’ biochemical composition and secondary structure upon exposure to Pd@S-CD. Spectral analysis, complemented by statistical techniques, revealed changes in biomolecules, lipids, proteins, nucleic acids, and carbohydrates caused by the treatment with Pd@CDs. These results and the increased cytotoxicity of the system demonstrate its high anti-cervical cancer therapeutic potential.ICCBIKG 2023 : 2nd International Conference on Chemo and Bioinformatics, September 28-29, 2023; Kragujeva

Carbon quantum dots/silver based metal organic framework composites in light enhanced wound healing

In recent years researchers have developed new strategies to enhance the effectiveness of wound healing by combining nanoparticles and infra red (IR) light. For example, some studies have shown that nanoparticles can be used to enhance the absorption of near-infrared laser (NIR) light by tissues, leading to increased healing rates [1]. The influence of NIR light on proliferation, collagen production, and wound healing was tested on: keratocytes (HaCaT) and fibroblasts (MRC-5) cells that are used as model systems of human skin equivalents that comprise an epidermal and a dermal compartment of skin. Also, these cells were treated with carbon quantum dots/silver-based metal-organic framework composites (Ag-MoFs-NCDs and Ag-MoFs-SCDs), which previously showed high antibacterial activity [2], without and with laser light. Firstly, we have found the most convenient and effective CW laser intensity (16 mW/cm2) and illumination time (3 minutes), which is not too high and short enough to influence human cells' proliferation and metabolism positively. Additional chemical treatment with Ag-MoFs-NCDs and Ag-MoFs-SCDs results in a further increase in human cell viability. Our measurements showed that the proliferation index in laser-illuminated cells and cells treated with Ag-MoFs-SCDs was at the level of the untreated control. Furthermore, Ag-MoFs-SCDs treatment and laser illumination induced a mild, insignificant increase in cellular proliferation. On the other hand, Ag-MoFs-NCDs treatment led to a more pronounced, albeit not significant increase, in cellular proliferation, while Ag-MoFs-NCDs treatment combined with laser illumination significantly increased proliferation. Also, we have detected a mild change in collagen level estimated by hydroxyproline assay, which may indicate a positive outcome of combined laser illumination and treatment, taking into account that after 48 hours, a change in cell's response to the treatment could be noticed. Finally, based on migration assay, we observe a complete wound closure after 48 hours in fibroblast cells treated with Ag-MoFs-NCDs and near-infrared laser light, Fig. 1.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad

Air-steam gasification of sewage sludge in a bubbling bed reactor: Effect of alumina as a primary catalyst

Numerous references can be found in scientific literature regarding biomass gasification. However, there are few works related to sludge gasification. A study of sewage sludge gasification process in a bubbling fluidised bed gasifier on a laboratory scale is here reported. The aim was to find the optimum conditions for reducing the production of tars and gain more information on the influx of different operating variables in the products resulting from the gasification of this waste. The variables studied were the equivalence ratio (ER), the steam-biomass ratio (SB) and temperature. Specifically, the ER was varied from 0.2 to 0.4, the SB from 0 to 1 and the temperature from 750 °C (1023 K) to 850 °C (1123 K). Although it was observed that tar production could be considerably reduced (up to 72%) by optimising the gasification conditions, the effect of using alumina (aluminium oxide, of proven efficacy in destroying the tar produced in biomass gasification) as primary catalyst in air and air-steam mixture tests was also verified. The results show that by adding small quantities of alumina to the bed (10% by weight of fed sludge) considerable reductions in tar production can be obtained (up to 42%) improving, at the same time, the lower heating value (LHV) of the gas and carbon conversion

Anti-cancer and imaging potential of fluorescent black carrot Carbon Dot nanoparticles

Carbon Dots (CDs) are biocompatible, fluorescent, water-soluble, and stable nanoparticles with a high potential to be used for vast biomedical applications [1,2]. We explore the application of CDs produced from natural sources, black carrots, as anti-cancer and imaging agents. These nanoparticles suppress cell growth of three different cancer cell lines, cervical (HeLa), pancreatic (PANC-1), and melanoma (A375) cell lines in vitro. However, the cytotoxic effect against A375 cells stands out, with only 20% of viable cells left after treatment (Fig.1(a)), antimetastatic potential, and a selectivity index higher than two, which indicates that the efficacy against melanoma cells is significantly greater than the toxicity against non-malignant cells (MRC-5). Furthermore, after the cellular uptake, green fluorescence was visible in the cytosol of A375 cells (Fig. 1 (b)). On the other hand, the DAPI stain for DNA was visible as a blue light in the cell nucleus. Moreover, cells with a higher intensity of green fluorescence in the nucleus, Fig. 1 (c) indicated with arrows, were the cells with condensed chromatin in the mitotic phase of the cell cycle (Fig. 1 (d) and (e)), which indicates that CDs interact with chromatin and that they could be used as a marker of cells mitosis and proliferation. In summary, we have demonstrated the great anti-cancer potential of black carrot CDs, for image-guided anti-cancer therapy of melanoma that can be used to recognize cell proliferation.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad