Publications by authors named "Raluca Ioana Stefan-van Staden"

Heliotropium bacciferum plant is very important and has been used for medicinal values since ancient times. The present study deals with the extraction of essential oil (0.14 w/w) of this plant and its GC-MS analysis, anti-inflammatory, and anti-bacterial activities evaluation.

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A 2D platform was designed and validated for fast screening of milk for deoxynivalenol. The qualitative and quantitative assay of deoxynivalenol in the milk samples was done using a 2D stochastic sensor based on single walled carbon nanotubes modified with [N-(pyridine-4-yl-methyl)]octadec-9-enamide. The working concentration range was between 10 and 10 g mL, with a sensitivity of 5.

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The significance of HER-1 and CA 125 lies in their ability to guide cancer diagnosis, treatment, and monitoring, improving personalized care and enhancing prognostic accuracy. The utilization of HER-1 and CA 125 as screening biomarkers for the anticipation of early-stage cancer and monitoring cancer progression is expanding due to the invasive and costly nature of present techniques. In this study, a novel stochastic sensor was developed for the simultaneous determination of HER-1 and CA 125 in whole blood, saliva, and gastric tumor tissue samples using a fast, easy, inexpensive, and portable method.

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The levels of the MMPs in the biological samples of confirmed patients with gastric cancer are significantly elevated compared to those found in healthy people. Therefore, a novel 3D stochastic microsensor based on graphene oxide, modified with gold nanoparticles and (Z)-N-(pyridin-4-yl-methyl) octadec-9-enamide (namely N2-AuNP/GO), was designed for the determination of MMP-2 in biological samples, and validated for the screening tests of biological samples in order to be used for the early diagnosis of gastric cancer. The proposed sensor presents a low limit of quantification (1.

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Background: MLH1, one of the MMR proteins, is linked to DNA replication, its role being to repair the incorrect DNA sequences and to replace them with proper ones. The loss of the MLH1 gene expression is part of Lynch syndrome which can lead to a series of cancers like colorectal and endometrial ones. The aim of this paper is to correlate the levels of MLH1 in four different bio-logical fluids with clinicopathological features in colorectal cancer patients in order to predict them with high probability.

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Vitamins are essential for supporting daily physiological functions and are crucial for metabolic processes, including preventing vascular events and delaying the progression of diabetic nephropathy. The specific assessment of food and pharmaceutical compound quality requires the highly sensitive evaluation of vitamins B5, B7, and B9. Therefore, it is necessary to have a fast screening method for multivitamin tablets, pharmaceutical tablets, water, food, including raw egg yolk, and biological fluids, including urine, in order to ensure the precise identification and measurement of vitamins B5, B7, and B9.

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(1) Background: The human MutS homolog, hMSH2, is known to be involved in DNA mismatch repair and is responsible for maintaining the stability of the genome. When DNA damage occurs, MSH2 promotes cell apoptosis via the regulation of ATR/Chk2/p53 signal transduction, and MSH2 deficiency is also related to accelerated telomere shortening in humans. MSH2 missense mutations are involved in a defective DNA reparation process, and it can be implied in carcinogenesis, as it is already involved in well-known cancer-related syndromes such as Lynch syndrome.

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Two-needle 3D stochastic microsensors based on boron- and nitrogen-decorated gra-phenes, modified with N-(2-mercapto-1H-benzo[d]imidazole-5-yl), were designed and used for the molecular recognition and quantification of CA 72-4, CA 19-9, CEA and CA 125 biomarkers in biological samples such as whole blood, urine, saliva and tumoral tissue. The NBGr-2 sensor yielded lower limits of determination. For CEA, the LOD was 4.

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Two stochastic microsensors based on the immobilization of inulins: inutec and frutafit in a paste obtained from a graphene decorated with nitrogen (10.8 %), and boron (2.6 %), and paraffin oil (IR purity) were designed, characterized and validated for the molecular recognition and analysis of mismatch repair proteins like MLH1, MSH2, MSH6, PMS2, and of KRAS in biological samples such as: whole blood, urine, saliva, and tumoral tissues.

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Two miniaturized electrochemical devices were designed for the simultaneous bioanalysis of MMR (MLH1, MSH2, MSH6, PMS2), and of KRAS in whole blood, urine, saliva, and tumoral tissues. The devices comprised besides the electronic part of the potentiostat a combined 3D stochastic microsensor (combined microplatform) with the sensing part based on the modification of graphene decorated with nitrogen, sulfur and boron (NSB-EGR) modified with two types of frutafit: FTEX and FHD. For the assay of MSH2, MSH6, KRAS, and PMS2 higher sensitivities were recorded when the microdevice based on FHD was used, while for the assay of MLH1 the best sensitivity was achieved by using the microdevice based on FTEX.

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Using a detection platform based on an integrated sensor constructed by modifying TiO and reduced graphene oxide paste with calix[6]arene, a novel stochastic approach for both quantitative and qualitative analysis of nonivamide in pharmaceuticals and water samples has been developed. A wide analytical range of 1.00 × 10 to 1.

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(1) Background: Human SERPINB5, commonly known as maspin, has diverse functions as a tumor suppressor. Maspin has a novel role in cell cycle control, and common variants were discovered to be associated with gastric cancer (GC). Maspin was proven to also affect the EMT and angiogenesis of gastric cancer cells via the ITGB1/FAK pathway.

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Article Synopsis
  • Scientists created special sensors using nanographene, cyclodextrin, gold nanoparticles, and copper to help identify important proteins called HER3 and HER4 in people.
  • These sensors connect to a smartphone and can measure tiny amounts (like super small drops) of these proteins in the body.
  • The sensors are useful for checking if patients with stomach cancer have these proteins, as well as for testing healthy people too.
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A novel electrochemical platform for amaranth determination has been developed using a rapid, easy, inexpensive, and portable molecularly imprinted polymer technique. The MIP platform was fabricated by electropolymerizing melamine as monomer in the presence of amaranth as template on the surface of ZnO-MWCNT/SPCE. Then, amaranth was completely eluted, leaving imprinted cavities in the polymeric film that could effectively recognize amaranth in solution.

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Maspin is an important biomarker which was proven to be correlated to many pathological features that can help the oncologists, the surgeons and also the pathologists for choosing the personalized treatment of the patients. Maspin expression correlates with the budding of colorectal adenocarcinomas that is usually used mostly in immunohistochemistry. In this preliminary study, a small number of patients with clinical and pathological features were selected.

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Article Synopsis
  • Bacterial infections are becoming a serious issue due to rising antibiotic resistance, prompting urgent efforts to develop new treatments or enhance existing ones.
  • Graphene decorated with silver nanoparticles (Gr-Ag) shows strong potential as an antibacterial agent, exhibiting inhibitory effects against tested bacterial strains.
  • A HEPA filter modified with Gr-Ag demonstrated enhanced bactericidal properties, particularly against Gram-negative bacteria, and effectively reduced the bacteria's ability to form colonies, suggesting a significant advancement in antibacterial technology.
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Vitamins are essential for sustaining daily activities and perform crucial roles in metabolism, such as preventing vascular events and delaying the development of diabetic nephropathy. The ultrasensitive assessment of thiamine in foods is required for food quality evaluation. A mini-platform utilizing two 3D sensors based on nanographene and gold nanoparticles paste modified with protoporphyrin IX and protoporphyrin IX cobalt chloride is proposed for the detection of thiamine in blueberry syrup, multivitamin tablets, water, and a biological sample (urine).

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Since the determination of the high toxicity of bisphenol A, alternative structures for bisphenols have been synthesized, resulting in bisphenols C, E, F, S, and Z. These bisphenols have replaced bisphenol A in plastic bottles, toys, and cans used for preserving food. Later, the toxicity and negative effects of all of these bisphenols on people's health were proven.

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The study aims to provide evidence regarding the impact of the extraction of heavy metals into food products through conventional cooking and preserving of foods like seafood, tuna, and poultry. The optical emission spectrometric technique with an inductively coupled plasma source (ICP-OES) was employed to determine trace levels of heavy metals in the muscle tissue of seafood, fish meat, tuna species, poultry, and turkey that was collected raw, cooked, frozen, and preserved. Conventional cooking increased the concentration of some heavy metals (Al, Sn, Fe, Co, Ti, and Mn) by more than 100.

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A multimode sensor (a sensor responding simultaneously to more than one mode, e.g., stochastic mode, amperometric mode, voltammetric mode) based on graphite paste modified with -methylfulleropyrrolidine was proposed for the determination of butoconazole nitrate in its pharmaceutical formulation.

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Human epidermal growth factor receptor-3, human epidermal growth factor-receptor-4, and heregulin-α are some of the biomarkers related to gastric cancer currently being used for early detection, personalized treatment, and evaluation of the efficiency of the treatment. Two stochastic sensors based on graphene decorated with TiO and/or Au modified with maltodextrin were proposed for the screening of two types of whole blood and tissue samples for the simultaneous recognition and analysis of the three biomarkers. The sensitivity of the two sensors showed high values, whereas the limits of determination were of fg mL magnitude order.

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A polymer-based carbon paste electrode was constructed by electropolymerized Alizarin Red S (ARS) film on the carbon paste electrode (CPE) surface. The electrochemical properties of poly-ARS/CPE were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) was utilized for electrode characterization.

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V-set and Immunoglobulin domain containing 1 (VSIG1) is a cell-cell adhesion molecule which role in the genesis and evolution of gastric cancer (GC) is not understood. Only three Medline-indexed papers have focused on the role of VSIG1 in GC. The clinicopathological features of 94 GCs were examined in association with immunohistochemical (IHC) patterns of VSIG1, E-cadherin, and β-catenin which were assessed in the tumor core (central) vs.

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Two microsensors obtained by the physical immobilization of 5,10,15,20-tetraphenyl-21H,23H-porphine (TPP) and 5,10,15,20-tetrakis (pentafluorophenyl chloride)-21H,23H-iron (III) porphyrin (Fe(TPFPP)Cl) in carbon nanopowder decorated with gold nanoparticles (AuNp) were designed, characterized, validated and used for the molecular recognition and simultaneous ultrasensitive determination of CEA, CA15-3 and HER2 in whole blood. High sensitivities were recorded for both microsensors. Low limits of quantification were recorded for all biomarkers: CEA (12.

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Article Synopsis
  • An electrochemical cell with graphite rods and a specific electrolyte was used to synthesize graphene (EGr) by applying a 7 V bias for 3 hours.
  • After the synthesis, characterization techniques like SEM, XRD, and FTIR were employed to analyze the structure and morphology of the graphene material, which was then used to modify a glassy carbon electrode (EGr/GC).
  • The EGr/GC electrode demonstrated significantly improved electrochemical performance for detecting azithromycin (AZT), showing a higher oxidation peak at a lower potential and three times greater sensitivity compared to the bare GC electrode.
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