Hasil untuk "Environmental sciences"

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S2 Open Access 2005
A Toxicologic Review of Quantum Dots: Toxicity Depends on Physicochemical and Environmental Factors

Ron C. Hardman

As a growing applied science, nanotechnology has considerable global socioeconomic value, and the benefits afforded by nanoscale materials and processes are expected to have significant impacts on almost all industries and all areas of society. A diverse array of engineered nanoscale products and processes have emerged [e.g., carbon nanotubes, fullerene derivatives, and quantum dots (QDs)], with widespread applications in fields such as medicine, plastics, energy, electronics, and aerospace. With the nanotechnology economy estimated to be valued at $1 trillion by 2012, the prevalence of these materials in society will be increasing, as will the likelihood of exposures. Importantly, the vastness and novelty of the nanotechnology frontier leave many areas unexplored, or underexplored, such as the potential adverse human health effects resulting from exposure to novel nanomaterials. It is within this context that the need for understanding the potentially harmful side effects of these materials becomes clear. The reviewed literature suggests several key points: Not all QDs are alike; engineered QDs cannot be considered a uniform group of substances. QD absorption, distribution, metabolism, excretion, and toxicity depend on multiple factors derived from both inherent physicochemical properties and environmental conditions; QD size, charge, concentration, outer coating bioactivity (capping material and functional groups), and oxidative, photolytic, and mechanical stability have each been implicated as determining factors in QD toxicity. Although they offer potentially invaluable societal benefits such as drug targeting and in vivo biomedical imaging, QDs may also pose risks to human health and the environment under certain conditions.

2149 sitasi en Chemistry, Medicine
DOAJ Open Access 2026
Synergistic effect of cerium oxide nanoparticles and vermicompost on hemp productivity under lead contaminated soils

Xia Cheng, Yan Luo, Minghua Dong et al.

Industrial hemp has an excellent tolerance for lead (Pb) and accumulation capacity. Further improving the Pb tolerance in industrial hemp is of great interest for its future application in phytoremediation. Present study was performed to evaluate the various Pb contaminated soils (normal soil; Pb spiked soil using Pb(NO3)2 and Pb polluted mine soil) with the Pb level 1300 mg kg−1 and various treatments of the vermicompost (VC) and cerium oxide nanoparticles (CeO2 NPs), (T0 = no VC and CeO2-NPs; T1 = CeO₂ NPs (30 mg L−1); T2 = VC (5 % w/w of soil); and T3 = T1 + T2 on the Pb accumulation and hemp productivity. The findings indicated that Pb stress (artificially spiked and natural contamination) led to significant reduction in the growth, biomass, and physiological traits of hemp. The Pb polluted mine soil exhibits more harmful impacts in comparison to artificially Pb spiked soil. The sole application of CeO2-NPs leads to less pronounced enhancements in growth and development parameters at rapid growth and harvesting stage in comparison with soil applied VC treatment under the treated and untreated Pb-stressed plants. Combined application of CeO2-NPs and VC effectively reduced the malondialdehyde contents (41.34 %), increased the soluble protein (62.35 %) and soluble sugar (29.97 %) as compared to control group. Moreover, the co-active effect of VC and CeO2-NPs also had the prospects of reducing Pb accumulation in difference tissues by enhancing physiological resiliency in hemp. Particularly, combined use of VC and CeO2-NPs counteracted the adverse effect of Pb stress by boosting growth, biomass, enzymatic antioxidants, and osmoprotectants through limiting the Pb accumulation. Use of organic amendments (VC) and metallic oxide NPs (CeO2-NPs) holds promising tool for mitigating the Pb stress, offering a practical and viable approach for hemp production.

S2 Open Access 2016
From science to action: Principles for undertaking environmental research that enables knowledge exchange and evidence-based decision-making.

C. Cvitanovic, J. McDonald, A. Hobday et al.

Effective conservation requires knowledge exchange among scientists and decision-makers to enable learning and support evidence-based decision-making. Efforts to improve knowledge exchange have been hindered by a paucity of empirically-grounded guidance to help scientists and practitioners design and implement research programs that actively facilitate knowledge exchange. To address this, we evaluated the Ningaloo Research Program (NRP), which was designed to generate new scientific knowledge to support evidence-based decisions about the management of the Ningaloo Marine Park in north-western Australia. Specifically, we evaluated (1) outcomes of the NRP, including the extent to which new knowledge informed management decisions; (2) the barriers that prevented knowledge exchange among scientists and managers; (3) the key requirements for improving knowledge exchange processes in the future; and (4) the core capacities that are required to support knowledge exchange processes. While the NRP generated expansive and multidisciplinary science outputs directly relevant to the management of the Ningaloo Marine Park, decision-makers are largely unaware of this knowledge and little has been integrated into decision-making processes. A range of barriers prevented efficient and effective knowledge exchange among scientists and decision-makers including cultural differences among the groups, institutional barriers within decision-making agencies, scientific outputs that were not translated for decision-makers and poor alignment between research design and actual knowledge needs. We identify a set of principles to be implemented routinely as part of any applied research program, including; (i) stakeholder mapping prior to the commencement of research programs to identify all stakeholders, (ii) research questions to be co-developed with stakeholders, (iii) implementation of participatory research approaches, (iv) use of a knowledge broker, and (v) tailored knowledge management systems. Finally, we articulate the individual, institutional and financial capacities that must be developed to underpin successful knowledge exchange strategies.

324 sitasi en Medicine, Engineering
DOAJ Open Access 2025
Synergistic heterojunction effects in Ag3PO4/SnO2 nanocomposites: a photocatalytic study on isoproturon degradation

Rishi Ram, Bhawna, Sanjeev Kumar et al.

IntroductionPesticides such as isoproturon are widely employed and represent a considerable environmental concern. The development of sustainable and efficient degrading techniques is crucial. Photocatalytic degradation employing semiconductor materials is a compelling solution. This study examines the synergistic advantages of heterojunction formation by synthesizing, characterizing, and improving the photocatalytic efficacy of Ag3PO4/SnO2 nanocomposites for the degradation of isoproturon.MethodsThe Ag3PO4/SnO2 nanocomposite was characterised using powder X-ray diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Ultraviolet-Diffuse Reflectance Spectroscopy (UV-DRS) and X-ray Photoelectron Spectroscopy (XPS). The effective synthesis of the Ag3PO4/SnO2 heterojunction was confirmed by characterization data from various techniques (PXRD, FTIR, SEM, UV-DRS, XPS).Results and DiscussionElemental mapping confirmed uniform distribution of O, P, Ag, and Sn. High-resolution mass spectrometry (HRMS) was employed to analyse degradation products. The Ag3PO4/SnO2 nanocomposite exhibited improved photocatalytic degradation of isoproturon compared to its precursors. In contrast to 25% for pure SnO2 and 41% for Ag3PO4, over 97% degradation was achieved using Ag3PO4/SnO2 nanocomposite within 120 min of light irradiation under identical conditions. The synergistic effects of heterojunction formation significantly enhanced isoproturon degradation using the Ag3PO4/SnO2 nanocomposite. The heterojunction reduces electron-hole recombination rate and enhances photogenerated charge carriers for degradation via effective charge separation. The improved photocatalytic activity is ascribed to the increased surface area of the nanocomposite. The analysis of HRMS data revealed the degradation products. The findings demonstrate the efficacy of Ag3PO4/SnO2 nanocomposites as photocatalysts for environmental remediation, namely in the breakdown of pesticides.

DOAJ Open Access 2025
Hormonal Regulation of Avocado (Persea americana) Across Altitudinal Gradients

Walid El Kayal, Maya Salameh, Diana Nacouzi

ABSTRACT Avocado (Persea americana) stands out as one of the most significant crops globally. Due to its abundance in essential nutrients and phytochemicals, its consumption and commercialization have notably surged in recent years. The interplay between genotype and environment profoundly influences fruit maturity dates and physicochemical attributes. This study aimed to assess the transcript levels of genes involved in hormone regulation and biosynthesis in avocado fruits, correlating their expression with the crop's physiological characteristics across varying altitudes during maturity and ripening stages. The study focused on five prevalent avocado varieties: Fuerte, Hass, Pinkerton, Lambhass, and Reed. Sixteen genes participating in diverse metabolic pathways and five hormones: Abscisic acid, Jasmonic acid, Salicylic acid, Gibberellic acid, and Zeatin were quantified over the harvesting season across seven locations in Lebanon. Results revealed a notable correlation between the expression of certain genes and hormone levels in the tested varieties, contingent upon both variety and location. Phytohormone quantification exhibited significant variations across locations compared to varieties. Additionally, physicochemical characteristics were evaluated, with principal component analysis demonstrating a positive correlation between some quantified phytohormones and maturity indices among varieties and locations. This study significantly advances our understanding of the intricate relationship among phytohormones, altitudes, fruit maturity, and ripening processes across five of the most common avocado varieties.

Environmental sciences, Botany
DOAJ Open Access 2025
Genome-wide identification of potassium transporters and channels in Malus domestica genome

Muhammad Waqas, Habibullah Nadeem, Ayshah Aysh Alrashidi et al.

Abstract Potassium (K+) is an essential nutrient for plants. It contributes to most physiological and biochemical pathways for plant metabolism, growth, and development. It is the most available plant nutrient, comprising 10–15% of plant weight. Plants have a sophisticated system of K+ transporters and channels for distribution in plant body. Apple is one of the most consumed fruits in the world. Its fruit quality and yield are positively affected by K+. However, limited information is available about K+ transport systems in Apple. In this study, 47 candidate genes (26 K+ transporters and 21 K+ channels) have been identified in Apple (Malus domestica) genome. The phylogenetic comparisons with other plants (Glycine max, Arabidopsis thaliana, and Oryza sativa) indicated that the K+ transport system is much conserved among different plants. The analysis of Gene structure showed the presence of specific introns and exon patterns for these gene families. Transcriptomic data analysis and RT-qPCR demonstrated significant variations in the transcript abundance of these genes in response to abiotic stresses. The current project represents the first report about the K+ transport system in Apple. Therefore, it may act as a starting point for further functional characterizations.

Medicine, Science
CrossRef Open Access 2024
Improving the Health and Environmental Health Literacy of Professionals: Evaluating the Effect of a Virtual Intervention on Phthalate Environmental Health Literacy

Kathryn S. Tomsho, Marlee R. Quinn, Zifan Wang et al.

The American College of Obstetricians and Gynecologists provided updated guidance in 2021, recommending that reproductive health professionals should include discussion of environmental exposures with their patients. However, environmental health is seldom included in medical training, with endocrine-disrupting chemicals, such as phthalates—linked to adverse pregnancy outcomes—being among the least discussed. We developed a one-hour virtual educational intervention to train reproductive health professionals on the routes of phthalate exposure, potential associated health impacts, and suggestions on how to discuss exposure reduction with patients. The intervention was designed to include perspectives from patients, scientists, and clinicians. Using a pre/post/post design, we evaluated the impact of the intervention on reproductive health professionals’ phthalate-related reproductive health literacy via a validated environmental health literacy (EHL) scale, their confidence in discussing phthalates, and the frequency of discussions about phthalates with patients. All materials, including the study questionnaires and intervention materials, were administered virtually to reproductive health professionals (n = 203) currently seeing patients working in the United States. After completing the intervention, reproductive health professionals’ average EHL increased (pre-course: 22.3, post-course: 23.7, 2 months post-course: 24.0), as did their confidence in discussing phthalates with their patients (pre-course: 1% (2/203) reported being quite confident, post-course: 64% (131/203) reported being quite confident, and 2 months post course: 86% (174/203) reported being quite confident). Additionally, the reported frequency of discussions about phthalates with patients rose substantially (pre-course: 0% (0/203) reported usually discussing phthalates with patients, and 2 months post-course: 86% (175/203) reported usually discussing phthalates with patients): In line with the recommendations of the American College of Obstetricians and Gynecologists, this online phthalate educational intervention tool increased EHL among reproductive health professionals and shifted clinical care to include discussion about phthalates, a reproductive toxicant.

DOAJ Open Access 2024
Local and Nonlocal Biophysical Effects of Historical Land Use and Land Cover Changes in CMIP6 Models and the Intermodel Uncertainty

Xing Luo, Jun Ge, Yipeng Cao et al.

Abstract Land use and land cover changes (LULCCs) can influence surface temperature through local and nonlocal biophysical processes, which remain inadequately addressed. In this study, we separate the local and nonlocal effects of historical (1850–2014) LULCCs based on model outputs from the Coupled Model Intercomparison Project Phase 6. We also attempt to explore the sources of intermodel differences in the effects of LULCCs. The multimodel mean shows a cooling effect of −0.05°C (with an intermodel range of −0.24–0.06°C) at the global scale due to cropland and pastureland expansion, consisting of dominant nonlocal cooling of −0.06°C (with an intermodel range of −0.26–0.06°C) and slight local warming of 0.01°C (with an intermodel range of −0.01–0.05°C). The modeling results show some clear consistency in the effects of LULCCs despite considerable intermodel uncertainties. The local effects cause warming at low latitudes and cooling in boreal regions via changes in upward shortwave radiation and sensible and latent heat fluxes. The nonlocal effects mainly cause cooling via decreases in downward longwave radiation and increases in upward shortwave radiation. Intermodel differences in the total effects are dominated by those in the nonlocal effects, which are further attributed to divergent changes in downward longwave radiation and sensible heat flux across the models. This study highlights the importance of the nonlocal effects of LULCCs in terms of strength and intermodel uncertainty, with implications for designing land‐based solutions aimed at climate change mitigation.

Environmental sciences, Ecology
DOAJ Open Access 2024
Assessment of musical interventions and its effect on blood pressure among United States populations: a systematic review and meta-analysis

Shreya Meda, Joyce Gyamfi, Kahini Patel et al.

BackgroundHypertension (HTN) currently affects over 120 million Americans, in the United States (US). Thus, the implementation of evidence-based interventions (EBI) for blood pressure (BP) reduction is pivotal in minimizing this burden. We sought to evaluate evidence from published literature on the effectiveness of musical interventions for BP reduction within the US.MethodsA systematic review of studies that utilize music interventions to manage BP was conducted in October of 2022. An extensive search of several databases utilizing MeSH terms and relevant keywords was conducted for articles published through October 2022. An updated search was conducted in October 2023 to identify additional studies.Results2,381 studies were screened for title/abstract relevancy. 1,885 studies were deemed irrelevant, and 495 studies were examined for full-text review; of which 384 were excluded due to being non-US-based. Overall, 25 studies were found where BP was the primary outcome and discussed musical interventions within the US. Of the 25 studies, 72% reported a significant decrease in BP after the administration of a musical intervention and only 28% reported the race and ethnicity of participants.ConclusionThere are limited studies that examine the effect of music interventions on BP reduction in the US, as a primary outcome. However, based on the evidence, musical interventions are effective for BP reduction. Moreover, the studies that were conducted in the US include a low percentage of high-risk racial and ethnic minority populations. Future EBI should target this underserved/high-burden group to improve disparity gaps within BP reduction via non-pharmacological means. Systematic Review RegistrationOpen Science Framework, doi: 10.17605/OSF.IO/4G3EB.

Diseases of the circulatory (Cardiovascular) system
DOAJ Open Access 2024
System Usability Scale Validation from The Expert Perspective

Fiandhika Muhammad Fajar, Kelana Bayu

The System Usability Scale (SUS) is a well-known method for quickly evaluating usability. Although SUS corresponds more strongly with user preference, quantitative data like SUS score is challenging to express in absolute terms. Therefore, the research aims to explore the validity of SUS evaluation results of an e-budgeting system from the expert perspective. With a comparative study approach, the research compared each of the 10 SUS indicators’ scores with the result of the qualitative usability evaluation. Data were obtained from three usability experts, who conducted Nielsen’s heuristic evaluation, the SUS measurement, and interviews. The research obtained two main findings. Firstly, no entirely valid scores of SUS indicators were found from three usability evaluations of the three usability experts. Secondly, only the score of ease of use shows significant relevance to the heuristic evaluation and interview result. Those findings may provide new insights when evaluating usability.

Environmental sciences
DOAJ Open Access 2024
A Benzimidazole-Based N-Heterocyclic Carbene Derivative Exhibits Potent Antiproliferative and Apoptotic Effects against Colorectal Cancer

Sarah Al-Nasser, Maha Hamadien Abdulla, Noura Alhassan et al.

<i>Background and Objectives</i>: Colorectal cancer (CRC) remains a major global health issue. Although chemotherapy is the first-line treatment, its effectiveness is limited due to drug resistance developed in CRC. To overcome resistance and improve the prognosis of CRC patients, investigating new therapeutic approaches is necessary. <i>Materials and Methods</i>: Using human colorectal adenocarcinoma (HT29) and metastatic CRC (SW620) cell lines, the potential anticancer properties of a newly synthesized compound 1-(Isobutyl)-3-(4-methylbenzyl) benzimidazolium chloride (IMBZC) were evaluated by performing MTT cytotoxicity, cell migration, and colony formation assays, as well as by monitoring apoptosis-related protein and gene expression using Western blot and reverse transcription–quantitative polymerase chain reaction technologies. <i>Results:</i> Tested at various concentrations, the half-maximal inhibitory concentrations (IC<sub>50</sub>) of IMBZC on HT29 and SW620 cell growth were determined to be 22.13 µM (6.97 μg/mL) and 15.53 µM (4.89 μg/mL), respectively. IMBZC did not alter the cell growth of normal HEK293 cell lines. In addition, IMBZC inhibited cell migration and significantly decreased colony formation, suggesting its promising role in suppressing cancer metastasis. Mechanistic analyses revealed that IMBZC treatment increased the expression of pro-apoptotic proteins p53 and Bax, while decreasing the expression of anti-apoptotic proteins Bcl-2 and Bcl-xL, thus indicating the induction of apoptosis in IMBZC-treated CRC cells, compared to untreated cells. Additionally, the addition of IMBZC to conventional chemotherapeutic drugs (i.e., 5-fluorouracil, irinotecan, and oxaliplatin) resulted in an increase in the cytotoxic potential of the drugs. <i>Conclusions</i>: This study suggests that IMBZC has substantial anticancer effects against CRC cells through its ability to induce apoptosis, inhibit cancer cell migration and colony formation, and enhance the cytotoxic effects of conventional chemotherapeutic drugs. These findings indicate that IMBZC could be a promising chemotherapeutic drug for the treatment of CRC. Further research should be conducted using in vivo models to confirm the anti-CRC activities of IMBZC.

Medicine (General)
DOAJ Open Access 2024
A downward-counterfactual analysis of flash floods in Germany

P. Voit, M. Heistermann

<p>Counterfactuals are scenarios that describe alternative ways of how an event, in this case an extreme rainfall event, could have unfolded. In this study, we present the results of a counterfactual search for flash flood events in Germany. We used a radar-based precipitation dataset from Germany's national meteorological service (Deutscher Wetterdienst) to identify the 10 most extreme precipitation events in Germany from 2001 to 2022 and then assumed that any of these top 10 events could have happened anywhere in Germany. In other words, the events were shifted around all over Germany. For all resulting positions of the precipitation fields, we simulated the corresponding peak discharge for any affected catchment smaller than 750 km<span class="inline-formula"><sup>2</sup></span>. From all the realizations of this simulation experiment, the maximum peak discharge was identified for each catchment.</p> <p>In a case study, we first focused on the devastating flood event in July 2021 in western Germany. We found that a moderate shifting of the event in space could change the event peak flow at the Altenahr gauge by a factor of 2. Compared to the peak flow of 1004 m<span class="inline-formula"><sup>3</sup></span> s<span class="inline-formula"><sup>−1</sup></span> caused by the event in its original position, the worst-case counterfactual of that event led to a peak flow of 1311 m<span class="inline-formula"><sup>3</sup></span> s<span class="inline-formula"><sup>−1</sup></span>. Shifting another event that had occurred just 1 month earlier in eastern Germany over the Ahr River valley even effectuated a simulated peak flow of 1651 m<span class="inline-formula"><sup>3</sup></span> s<span class="inline-formula"><sup>−1</sup></span>.</p> <p>For all analysed subbasins in Germany, we found that, on average, the highest counterfactual peak exceeded the maximum original peak (between 2001 and 2022) by a factor of 5.3. For 98 % of the basins, the factor was higher than 2.</p> <p>We discuss various limitations of our analysis, which are important to be aware of, namely, the quantification and selection of candidate rainfall events, the hydrological model, and the design of the counterfactual search experiment. Still, we think that these results might help to expand the view of what could happen in the case that certain extreme events occurred elsewhere and thereby reduce the element of surprise in disaster risk management.</p>

Environmental technology. Sanitary engineering, Geography. Anthropology. Recreation

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