RESUMO
Continuous monitoring of ammonia (NH3) in humid environments poses a notable challenge for gas sensing applications because of its effect on sensor sensitivity. The present work investigates the detection of NH3 in a natural humid environment utilizing ReS2/Ti3C2Tx heterostructures as a sensing platform. ReS2 nanosheets were vertically grown on the surface of Ti3C2Tx sheets through a hydrothermal synthetic approach, resulting in the formation of ReS2/Ti3C2Tx heterostructures. The structural, morphological, and optical properties of ReS2/Ti3C2Tx were investigated using various state-of-the-art techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, zeta potential, Brunauer-Emmett-Teller technique, and Raman spectroscopy. The heterostructures exhibited 1.3- and 8-fold increases in specific surface area compared with ReS2 and Ti3C2Tx, respectively, potentially enhancing the active gas adsorption sites. The electrical investigations of the ReS2/Ti3C2Tx-based sensor demonstrated enhanced selectivity and superior sensing response ranging from 7.8 to 12.4% toward 10 ppm of NH3 within a relative humidity range of 15-85% at room temperature. These findings highlight the synergistic effect of ReS2 and Ti3C2Tx, offering valuable insights for NH3 sensing in environments with high humidity, and are explained in the gas sensing mechanism.
RESUMO
The urgent need to address the current climate crisis has led to concerted efforts to develop low-cost and sustainable methods to remove carbon dioxide from the atmosphere. Carbon capture and storage (CCS) and negative emissions technologies (NET's) offer the most promising paths forward to offsetting global emissions. In this study, we explore the potential of kraft lignin, a readily available biomaterial, as a low-cost alternative for the development of a CO2 sorbent. The approach leverages the known ability of amines to reacting with carbon dioxide and forming a stable compound. Commercially available kraft lignin was modified with diethylenetriamine (DETA), triethylenetetramine (TETA), and tetraethylenepentamine (TEPA) using a one-pot synthesis approach via the Mannich reaction. The sorbent was evaluated for porosity, accessible amine density, and nitrogen content. The CO2 capture experiments revealed that the resulting sorbent can capture 0.80 (±0.03) mmol of CO2 per gram of sorbent.
RESUMO
Modern manufacturing of textiles, pharmaceuticals, food, cosmetics, plastics, paper, etc. involves the utilization of anionic and cationic dyes that lead to significant water contamination. Recent research has explored the use of nanomaterials toward developing nanoadsorbents for water decontamination caused by industrial pollution. Here, we report on a novel platform for anionic dye remediation, consisting of a polyethylenimine-functionalized lignin nanosphere (PEI-LNS). The designed nanomaterial shows significant ability to adsorb an anionic dye selected as a proof-of-concept-Sulforhodamine B, from aqueous solutions. The PEI lignin nanoadsorbents (PEI-LNS) showed a better ability to adsorb Sulforhodamine B sodium salt (SBSS) when compared to the raw lignin nanosphere adsorbent (LNS), especially in acidic conditions. The nanomaterial was characterized through transmission electron microscopy, scanning electron microscopy, Brunauer-Emmett-Teller surface area analysis, elemental analysis, zeta potential, thermogravimetric analysis, Fourier transform infrared spectroscopy, and nuclear magnetic resonance. The impacts of ionic strength, contact time, pH, and adsorbent concentration have been evaluated. The ability of PEI-LNS to adsorb SBSS was found to be consistent with Langmuir isotherms and pseudo-second-order kinetic models. The PEI-LNS could be recycled three times, reaching a good (85%) adsorbing capacity even in the third cycle. The study demonstrates that PEI-LNS has a strong affinity as a novel adsorbent for anionic dyes and could be employed in environmental cleanups pertaining to such contaminations.
RESUMO
In this work, we report the first single-step, size-controlled synthesis of Cu3VSe4 cuboidal nanocrystals, with the longest dimension ranging from 9 to 36 nm, and their use in replacing the platinum counter electrode in dye-sensitized solar cells. Cu3VSe4, a ternary semiconductor from the class of sulvanites, is theoretically predicted to have good hole mobility, making it a promising candidate for charge transport in solar photovoltaic devices. The identity and crystalline purity of the Cu3VSe4 nanocrystals were validated by X-ray powder diffraction (XRD) and Raman spectroscopy. The particle size was determined from the XRD data using the Williamson-Hall equation and was found in agreement with the transmission electron microscopy imaging. Based on the electrochemical activity of the Cu3VSe4 nanocrystals, studied by cyclic voltammetry, the nanomaterials were further employed for fabricating counter electrodes (CEs) in Pt-free dye-sensitized solar cells. The counter electrodes were prepared from Cu3VSe4 nanocrystals as thin films, and the charge transfer kinetics were studied by electrochemical impedance spectroscopy. The work demonstrates that Cu3VSe4 counter electrodes successfully replace platinum in DSSCs. CEs fabricated with the Cu3VSe4 nanocrystals having an average particle size of 31.6 nm outperformed Pt, leading to DSSCs with the highest power conversion efficiency (5.93%) when compared with those fabricated with the Pt CE (5.85%).
RESUMO
BACKGROUND: In patients with secondary tricuspid regurgitation (STR), right atrial remodeling (RAR) is a proven marker of disease progression. However, the prognostic value of RAR, assessed by indexed right atrial volume (RAVi) and reservoir strain (RAS), remains to be clarified. Accordingly, the aim of our study is to investigate the association with outcome of RAR in patients with STR. METHODS: We enrolled 397 patients (44% men, 72.7 ± 13 years old) with mild to severe STR. Complete two-dimensional and speckle-tracking echocardiography analysis of right atrial and right ventricular (RV) size and function were obtained in all patients. The primary end point was the composite of death from any cause and heart failure hospitalization. RESULTS: After a median follow-up of 15 months (interquartile range, 6-23), the end point was reached by 158 patients (39%). Patients with RAS <13% and RAVi >48 mL/m2 had significantly lower survival rates compared to patients with RAS ≥13% and RAVi ≤48 mL/m2 (log-rank P < .001). On multivariable analysis, RAS <13% (hazard ratio, 2.11; 95% CI, 1.43-3.11; P < .001) and RAVi > 48 mL/m2 (hazard ratio, 1.49; 95% CI, 1.01-2.18; P = .04) remained associated with the combined end point, even after adjusting for RV free-wall longitudinal strain, significant chronic kidney disease, and New York Heart Association class. Secondary tricuspid regurgitation excess mortality increased exponentially with values of 18.2% and 51.3 mL/m2 for RAS and RAVi, respectively. In nested models, the addition of RAS and RAVi provided incremental prognostic value over clinical, conventional echocardiographic parameters of RV size and function and RV free-wall longitudinal strain. CONCLUSIONS: In patients with STR, RAR was independently associated with mortality and heart failure hospitalization. Assessment of RAR could improve risk stratification of patients with STR, potentially identifying those who may benefit from optimization of medical therapy and a closer follow-up.
Assuntos
Remodelamento Atrial , Ecocardiografia , Átrios do Coração , Insuficiência da Valva Tricúspide , Humanos , Masculino , Feminino , Insuficiência da Valva Tricúspide/fisiopatologia , Insuficiência da Valva Tricúspide/complicações , Idoso , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/fisiopatologia , Remodelamento Atrial/fisiologia , Ecocardiografia/métodos , Prognóstico , Seguimentos , Taxa de Sobrevida , Pessoa de Meia-Idade , Progressão da DoençaRESUMO
Melanoma, the tumor arising from the malignant transformation of pigment-producing cells-the melanocytes-represents one of the most severe cancer types. Despite their rarity compared to cutaneous melanoma, the extracutaneous subtypes such as uveal melanoma (UM), acral lentiginous melanoma (ALM), and mucosal melanoma (MM) stand out due to their increased aggressiveness and mortality rate, demanding continuous research to elucidate their specific pathological features and develop efficient therapies. Driven by the emerging progresses made in the preclinical modeling of melanoma, the current paper covers the most relevant in vitro, in vivo, and in ovo systems, providing a deeper understanding of these rare melanoma subtypes. However, the preclinical models for UM, ALM, and MM that were developed so far remain scarce, and none of them is able to completely simulate the complexity that is characteristic to these melanomas; thus, a continuous expansion of the existing library of experimental models is pivotal for driving advancements in this research field. An overview of the applicability of precision medicine in the management of rare melanoma subtypes is also provided.
RESUMO
Background: Endoscopic retrograde cholangiopancreatography (ERCP) represents a major pivotal point in gastrointestinal endoscopy. Little is known about acute kidney injury (AKI) post-ERCP. This study analyses the incidence, risk factors, and prognosis of post-ERCP AKI. Methods: A total of 396 patients were prospectively studied. AKI was defined by an increase in serum creatinine (SCr) ≥ 0.3 mg/dL or by an increase in SCr ≥ 50% in the first 48 h post-ERCP. Logistic regression analysis was used to identify the predictors of AKI and in-hospital mortality. A two-tailed p value < 0.05 was considered significant. Results: One hundred and three patients (26%) developed post-ERCP AKI. Estimated glomerular filtration rate (adjusted odds ratio (aOR) = 0.95, 95% confidence interval (CI): 0.94−0.96, p < 0.001), nonrenal Charlson Comorbidity Index (Aor = 1.19, 95% CI: 1.05−1.35, p = 0.006), choledocholithiasis (aOR = 4.05, 95% CI: 1.98−8.29, p < 0.001), and bilirubin (aOR = 1.1, 95% CI: 1.05−1.15, p < 0.001) were associated with post-ERCP AKI. Post-ERCP AKI was associated with longer hospital stay (p < 0.001) and with increased in-hospital mortality (7.76% versus 0.36%, p < 0.001). Moderate-to-severe (stage 2 and 3) AKI was independently associated with in-hospital mortality (aOR = 6.43, 95% CI: 1.48−27.88, p < 0.013). Conclusions: Post-ERCP AKI represented an important complication associated with longer hospital stay. Moderate-to-severe post-ERCP AKI was an independent risk factor for in-hospital mortality.
RESUMO
Chronic venous disease (CVD) is a common pathology that significantly affects the quality of life (QoL) of patients. Methods: QoL was assessed in 317 patients diagnosed with CVD who underwent surgeries, including cryostripping (n = 113), high ligation and stripping (HL&S, n = 96), and phlebectomies (n = 108). CVD symptoms and QoL were assessed before surgery and 2 weeks after surgery using the following questionnaires: CIVIQ-20, VAS, Eq-5D, PHQ-9 and GAD-9. Results. The results reveal a significant correlation (p < 0.05) between CEAP score and QoL questionnaires performed preoperatively and postoperatively in all three surgical technique groups, with a statistical improvement postoperatively. Phlebectomy had the best postoperative QoL score (r = 0.495) compared to the other two types of procedures. Conclusions: Analyzing patients' subjective perception following conventional surgery for CVD treatment, an improved QoL is observed both in functional and psychosocial aspects, even early postoperatively. Classical surgical procedures remain an effective and feasible option in CVD treatment.
RESUMO
Niobium sulvanites Cu3NbX4 (X = S, Se) have been theoretically predicted as promising candidates for solar photovoltaics and photocatalytic water splitting. This report outlines the first synthesis of Cu3NbS4 and Cu3NbSe4 in a nanocrystalline form. The crystal structures were investigated by X-ray diffraction, identity was confirmed by Raman spectroscopy, and the optoelectronic properties and morphology of Cu3NbS4 and Cu3NbSe4 nanocrystals were examined by UV-vis spectroscopy and transmission electron microscopy, respectively. To gain insight into the Cu3NbX4 formation, a mechanistic study was conducted for Cu3NbSe4 monitoring the nanoparticles' formation as a function of reaction time. Methylene blue photodegradation tests were conducted to evaluate the photoactivity of Cu3NbS4 and Cu3NbSe4. The degradation rates, 2.81 × 10-2 min-1 and 1.22 × 10-2 min-1 proved the photocatalysts' potential of nanoscale Cu3NbX4.
RESUMO
Herein, we report the in situ photocatalytic deposition of cesium lead bromide (CsPbBr3) perovskite quantum dots on mesoporous TiO2-coated fluorine-doped tin oxide (FTO/TiO2) electrodes. The mesoporous TiO2 layer is used as a photocatalyst to promote the following: (1) the Pb deposition from a Pb2+ aqueous solution and (2) the in situ Pb conversion into CsPbBr3 perovskite in the presence of a CsBr methanolic solution without any organic capping agent. Both steps are carried out under ultraviolet light irradiation under ambient conditions without any post-treatment. The obtained FTO/TiO2/CsPbBr3 film was characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction, photoluminescence spectroscopy, scanning electron microscopy, and transmission electron microscopy. The FTO/TiO2/CsPbBr3 heterojunction exhibited enhanced visible-light photodegradation activity demonstrated for the oxidation of curcumin organic dye as a model system. The novel and simple approach to fabricating a supported photocatalyst represents a scalable general method to use semiconductors as a platform to incorporate different perovskites, either all-inorganic or hybrid, for optoelectronic applications. The perovskite deposition method mediated by the UV light at room temperature could be further applied to flexible and wearable solar power electronics.
RESUMO
Background and Objectives: Neonatal mortality is a global public health issue, disproportionately affecting low- and middle-income nations. Although Romania is a high-income nation, according to the European Union's most recent demographic data, it had the second-highest infant death rate in 2019. Although significant progress has been made in the last three decades in lowering newborn mortality, more initiatives to accelerate progress are required to meet the 2030 Sustainable Development Goals (SDG) objective. Therefore, we aimed to develop an observational study to determine the influence of maternal factors on in-hospital neonatal intensive care unit admission and mortality in premature infants born in western Romania. While newborn mortality has decreased globally, the pace of decline is far less than what is desired. Materials and Methods: A retrospective study comprising 328 premature patients and 422 full-term newborns, was developed at a tertiary obstetrics and gynecology clinic in western Romania, comprising the period of the last 24 months before the COVID-19 pandemic and the first 24 months of the pandemic. Results: The following variables were identified as statistically significant risk factors for neonatal intensive care unit admission: age > 35 years, OR = 1.59; twin births, OR = 1.14; low gestational age, OR = 1.66; preeclampsia, OR = 2.33; and peripartum infection, OR = 2.25. The same risk factors, with the exception of twin births, were significantly associated with in-hospital neonatal mortality. Except for a longer duration of maternal hospitalization and neonatal therapy with surfactant, steroids, and antibiotics, the COVID-19 pandemic did not cause significant differences in the evolution and outcomes of preterm newborns. Conclusions: The major maternal risk factors for NICU admission were advanced age, twin pregnancy, low gestational age, preeclampsia, and peripartum infection. Additionally, these characteristics contributed to a high likelihood of death, despite adequate access to medical care and advanced life support for the neonates. Understanding the causes of morbidity and death in neonates admitted to the neonatal intensive care unit enables better prioritization and planning of health services, resource reallocation, and care quality improvement.
Assuntos
COVID-19 , Pré-Eclâmpsia , Complicações na Gravidez , Adulto , Feminino , Mortalidade Hospitalar , Hospitalização , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Pandemias , Gravidez , Estudos Retrospectivos , Romênia/epidemiologiaRESUMO
Background and Objectives: Throughout the COVID-19 pandemic, health systems worldwide adapted to support COVID-19 patients while continuing to provide assistance to patients with other potentially fatal illnesses. While patients with cancer may be at an elevated risk of severe COVID-19-related complications, their oncologic therapies generally cannot be postponed indefinitely without a negative effect on outcomes. Taking this into account, a thorough examination of the therapy management of various cancers is necessary, such as cervical cancer. Therefore, we aimed to develop a retrospective cohort study to measure the impact of the COVID-19 pandemic on the delivery of cancer care services for women diagnosed with cervical cancer staged IB2-IVA, necessitating chemo- and radiotherapy in Romania, as well as determine the difference in cervical cancer staging between the pandemic and pre-pandemic period. Materials and Methods: Using a multicentric hospital database, we designed a retrospective study to compare the last 24 months of the pre-pandemic period to the first 24 months of the SARS-CoV-2 pandemic to evaluate the variation in the proportion of women diagnosed with cervical cancer and the percentage of inoperable cases requiring chemotherapy and radiotherapy, as well as to detail their clinical presentation and other findings. Results: We observed that the likelihood of cervical cancer patients requiring radiation therapy at a later stage than before the pandemic increased by about 20% during the COVID-19 pandemic. Patients at an advanced FIGO stage of cervical cancer had a 3.39 higher likelihood of disease progression after radiotherapy (CI [2.06−4.21], p-value < 0.001), followed by tumor size at diagnosis with a hazard ratio (HR) of 3.12 (CI [2.24−4.00], p-value < 0.001). The factors related to the COVID-19 pandemic, postponed treatment and missed appointments, were also identified as significant risk factors for cervical cancer progression (HR = 2.51 and HR = 2.24, respectively). Conclusions We predict that there will be a considerable rise in cervical cancer cases over the next several years based on existing data and that expanding screening and treatment capacity will attenuate this with a minimal increase in morbidity and fatality.
RESUMO
Being one of the most common malignancies in young women, cervical cancer is frequently successfully screened around the world. Early detection enables for an important number of curative options that allow for more than 90% of patients to survive more than three years without cancer relapse. Unfortunately, the COVID-19 pandemic put tremendous pressure on healthcare systems and access to cancer care, determining us to develop a study on the influence the pandemic had on surgical care of cervical cancer, and to assess changes in its management and outcomes. A retrospective study design allowed us to compare cervical cancer trends of the last 48 months of the pre-pandemic period with the first 24 months during the COVID-19 pandemic, using the database from the Timis County Emergency Clinical Hospital. New cases of cervical cancer presented to our clinic in more advanced stages (34.6% cases of FIGO stage III during the pandemic vs. 22.4% before the pandemic, p-value = 0.047). These patients faced significantly more changes in treatment plans, postponed surgeries, and postponed radio-chemotherapy treatment. From the full cohort of cervical cancer patients, 160 were early stages eligible for curative intervention who completed a three-year follow-up period. The disease-free survival and overall survival were not influenced by the surgical treatment of choice, or by the SARS-CoV-2 infection (log-rank p-value = 0.449, respectively log-rank p-value = 0.608). The individual risk factors identified for the three-year mortality risk were independent of the SARS-CoV-2 infection and treatment changes during the COVID-19 pandemic. We observed significantly fewer cases of cervical cancer diagnosed per year during the first 24 months of the COVID-19 pandemic, blaming the changes in healthcare system regulations that failed to offer the same conditions as before the pandemic. Even though we did not observe significant changes in disease-free survival of early-stage cervical cancers, we expect the excess of cases diagnosed in later stages to have lower survival rates, imposing the healthcare systems to consider different strategies for these patients while the pandemic is still ongoing.
RESUMO
Despite the significant evolution in recent years in the medical field, many fetal conditions that can be detected in the early stages, remain a social and economic burden due to a lack of diagnostic and treatment programs. The main objective of the present study was to realize a screening program related to the early detection of Down syndrome, by analyzing biochemical and imaging markers, in women from the rural areas of Southwest Romania. Accordingly, data from 269 pregnant women were taken into evaluation for maternal age, maternal weight, smoking and diabetic statuses, along with ultrasound measurements that were performed to establish fetal nuchal translucency (FNT) and biochemical analysis of free ß-human chorionic gonadotropin (ß-hCG) and pregnancy-associated plasma protein (PAPP-A). Patients at high risk for trisomy 21 (≥1:250) were counseled and the optimal protocol was established for each case. Of the 269 patients studied, 5.6% were included in the risk group based on ß-hCG-associated MoM (multiple median approaches) analysis, sonographic measurements and maternal age correlation. Specifically, 60% of patients at risk presented a ß-hCG MoM value >1.5 and 20% of patients at risk presented a value ≤0.5 for PAPP-A MoM, and the average maternal age was 33. Measurement of FNT and serum markers, together with associated MoM intervals, was not sufficient to establish the diagnosis of trisomy 21 and to make a risk group inclusion. In summary, the association between sonographic measurements and serum marker values, together with maternal age, are predetermined and indispensable conditions for the most accurate classification in a high-risk group.
RESUMO
Two-dimensional CuFeSe2 nanosheets have been successfully obtained via solution-phase synthesis using a sacrificial template method. The high purity was confirmed by X-ray diffraction and the two-dimensional morphology was validated by transmission electron microscopy. The intense absorption in the 400-1400 nm region has been the basis for the CuFeSe2 nanosheets' photothermal capabilities testing. The colloidal CuFeSe2 (CFS) nanosheets capped with S2- short ligands (CFS-S) exhibit excellent biocompatibility in cell culture studies and strong photothermal effects upon 808 nm laser irradiation. The nanosheets were further loaded with the cancer drug doxorubicin and exposed to laser irradiation, which accelerated the release of doxorubicin, achieving synergy in the therapeutic effect.
RESUMO
The class of ternary copper chalcogenides Cu3MX4 (M = V, Nb, Ta; X = S, Se, Te), also known as the sulvanite family, has attracted attention in the past decade as featuring promising materials for optoelectronic devices, including solar photovoltaics. Experimental and theoretical studies of these semiconductors have provided much insight into their properties, both in bulk and at the nanoscale. The recent realization of sulvanites at the nanoscale opens new avenues for the compounds toward printable electronics. This review is aimed at the consideration of synthesis methods, relevant properties and the recent developments of the most important sulvanites.
RESUMO
Two-dimensional (2D) ternary materials recently generated interest in optoelectronics and energy-related applications, alongside their binary counterparts. To date, only a few naturally occurring layered 2D ternary materials have been explored. The plethora of benefits owed to reduced dimensionality prompted exploration of expanding non-layered ternary chalcogenides into the 2D realm. This work presents a templating method that uses 2D transition metal dichalcogenides as initiators to be converted into the corresponding ternary chalcogenide upon addition of copper, via a solution-phase synthesis, conducted in high boiling point solvents. The process starts with preparation of VSe2 nanosheets, which are next converted into Cu3VSe4 sulvanite nanosheets (NSs) which retain the 2D geometry while presenting an X-ray diffraction pattern identical with the one for the bulk Cu3VSe4. Both the scanning electron microscopy and transmission microscopy electron microscopy show the presence of quasi-2D morphology. Recent studies of the sulfur-containing sulvanite Cu3VS4 highlight the presence of an intermediate bandgap, associated with enhanced photovoltaic (PV) performance. The Cu3VSe4 nanosheets reported herein exhibit multiple UV-Vis absorption peaks, related to the intermediate bandgaps similar to Cu3VS4 and Cu3VSe4 nanocrystals. To test the potential of Cu3VSe4 NSs as an absorber for solar photovoltaic devices, Cu3VSe4 NSs thin-films deposited on FTO were subjected to photoelectrochemical testing, showing p-type behavior and stable photocurrents of up to ~ 0.036 mA/cm2. The photocurrent shows a ninefold increase in comparison to reported performance of Cu3VSe4 nanocrystals. This proves that quasi-2D sulvanite nanosheets are amenable to thin-film deposition and could show superior PV performance in comparison to nanocrystal thin-films. The obtained electrical impedance spectroscopy signal of the Cu3VSe4 NSs-FTO based electrochemical cell fits an equivalent circuit with the circuit elements of solution resistance (Rs), charge-transfer resistance (Rct), double-layer capacitance (Cdl), and Warburg impedance (W). The estimated charge transfer resistance value of 300 Ω cm2 obtained from the Nyquist plot provides an insight into the rate of charge transfer on the electrode/electrolyte interface.
RESUMO
The ternary chalcogenide Cu3VSe4 (CVSe) with sulvanite structure has been theoretically predicted to be a promising candidate for photovoltaic applications due to its suitable bandgap for solar absorption and the relatively earth-abundant elements in its composition. To realize the absorber layer via an inexpensive route, printed thin-films could be fabricated from dispersions of nano-sized Cu3VSe4 precursors. Herein, cubic Cu3VSe4 nanocrystals were successfully synthesized via a hot-injection method. Similar with reported Cu3VS4 nanocrystals, Cu3VSe4 nanocrystals with cubic structure exhibit three absorption bands in the UV-Visible range indicative of a potential intermediate bandgap existence. A thin film fabricated by depositing the nanoparticles Cu3VSe4 on FTO coated glass substrate, exhibited a p-type behavior and a photocurrent of ~ 4 µA/cm2 when measured in an electrochemical cell setting. This first demonstration of photocurrent exhibited by a CVSe nanocrystals thin film signifies a promising potential in photovoltaic applications.
Assuntos
Nanopartículas/química , Compostos de Selênio/química , Compostos de Selênio/síntese química , Técnicas Eletroquímicas , Nanopartículas/ultraestrutura , Tamanho da Partícula , Processos Fotoquímicos , SemicondutoresRESUMO
Females require at a certain period of life the administration or supplementation of specific hormones (estrogen, progesterone), for various needs, such as: prevention of unwanted pregnancies, decreased menstrual bleeding, dysmenorrhea and pelvic pain in endometriosis, alleviation of symptoms associated with menopause, regulation of certain skin processes related to acne or aging and others. Also, hormones could act as oncogenes being known eloquent examples of estrogens labeled both as promoters of cell specific alteration or as mutagenic agents. The use of hormones and exposure to solar radiation is expected to cause a number of adverse changes to the body, especially due to their association with malignant processes. The current study was purported as a basis for understanding certain processes that occur with the administration of hormones and exposure to ultraviolet B (UVB) radiation. The animal model was made on healthy adult female BALB∕c mice, which were separated into groups and treated with Ethinylestradiol (EES), Levonorgestrel (LNG) and their combination in the presence of UVB radiation. Changes in skin physiological parameters were analyzed by non-invasive methods, biochemical parameters related to changes in blood circulating system were evaluated by standard methods and histopathological analysis was conducted to point out the changes at the level of the internal body. Measurement of skin parameters such as erythema, melanin, skin hydration, has highlighted some changes in hormone-treated and exposed to UVB radiation groups which were significant only in the case of erythema. Biochemical parameters showed variations in terms of liver enzymes in groups treated with active substances. Histologically, aspects of internal organs revealed significant changes in the group treated with EES and LNG and exposed to UVB radiation.
Assuntos
Fenômenos Fisiológicos da Pele , Raios Ultravioleta , Animais , Estrogênios , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Pele , Raios Ultravioleta/efeitos adversosRESUMO
The ex situ decontamination of uranium polluted soils was performed by alkaline washing using mechanical agitation and ultrasound field. Two types of polluted soils were considered in terms of texture and organic content. The tests were performed using experimental design: a 23 factorial plan for mechanical washing and Taguchi L18 orthogonal matrix for ultrasound (US)-assisted decontamination. The factors considered in mechanical washing were temperature, duration, and pH. For ultrasound decontamination, the US frequency was added. The optimum was estimated based on statistical analysis and validated by confirmation experiments. The study revealed that in ultrasound field, the decontamination degree is increased with over 25% compared with mechanical stirring, while the duration of the process is drastically reduced (from 120 to 25 min). The most important factor leading to the increase of decontamination is the ultrasound frequency. To refine the result, artificial neural network modeling and subsequent optimization by genetic algorithms were also carried out for the decontamination in ultrasound field, and new optimum operating conditions were identified and validated. The best operating conditions identified were temperature around 50 °C, pH = 8, and ultrasound frequency of 24 kHz. In these conditions, the decontamination degree reached 85% for Soil 1 (characterized by low clay and organic content) and 69% for Soil 2 (with high clay and organic content).