To make pollution evaluation of potentially hazardous elements in the soil more accurately, the regional geochemical baseline concentrations of eight potentially hazardous elements (Cr, Ni, Cu, Zn, ...As, Cd, Hg, and Pb) were established in Huilai County using cumulative frequency distribution curves. Then, the pollution load index and enrichment factor were applied to estimate the contamination levels, based on these geochemical baseline concentrations. The results suggested that topsoil was moderately polluted by potentially hazardous elements, while Cd pollution in the construction land and As pollution in the farmland was relatively severe. The possible sources of eight potentially hazardous elements were analyzed by correlation analysis, geostatistics and positive matrix factorization. Four sources have been determined and apportioned, namely industrial activities, natural sources, agricultural practices, and traffic emissions. Combining the health risk assessment with the source profiles, the health risks quantified from four sources were estimated under farmland, construction land, and woodland. The results showed that agricultural practices were the most main source of non-cancer and cancer risks under woodland and farmland for adults; industrial activities were the most main source of non-cancer and cancer risks under construction land for adults. Children's health risks, both carcinogenic risk and non-carcinogenic risk, were greater than adults, and the health risk trends of adults and children showed similarities. Therefore, agricultural practices under woodland and farmland should be controlled and managed as a priority, while industrial activities should be given priority to control and management under construction land.
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•Establish geochemical baseline concentrations to more accurately evaluate pollution.•Three types of land use were contaminated by potentially hazardous elements in different degrees.•Four sources of potentially hazardous elements were identified and apportioned by geostatistics and PMF.•Combine health risk assessment and positive matrix factorization to determine priority pollution source.
The contents of ten heavy metals (Cr, Hg, As, Pb, Ni, Cd, Ti, Cu, Zn and V) in 413 topsoil samples from Puning City, Guangdong Province, China were investigated. Obvious enrichment of Hg, As, Pb, Cd ...and Zn were presented, and the contents of Hg and As in 5.8% and 3.4% samples respectively were higher than the guideline values recommended by the Chinese Environmental Quality Standard for Soils. Chromium and V were presented no enrichment and no pollution. According to one-way analysis of variance, the mean contents of Hg, Pb, Cu and Zn in land for construction were significantly higher than farmland and natural vegetation, but the land use had no obvious effect on other heavy metals. Furthermore, the potential sources of ten heavy metals were identified and apportioned in combination with geostatistics, correlation analysis and positive matrix factorization model. The results were following as: a) Pb, Zn and Cu mainly origin from vehicle emission and atmosphere deposition, and the hotspots approximately distributed in the areas of intensive traffic and near main roads; b) Hg and Cd were derived to industrial activities related to pharmaceutical industries, the textile and dyeing industries and e-waste recycling industries, and high-value areas were mainly concentrated in the northeast of the urban area where the industrial parks have been distributed; c) Soil parent material (Jurassic shale) was the main source of Cr, Ni, V and Ti; d) As mainly came from agricultural inputs such as pesticides or herbicides, livestock and fertilizers. Meanwhile, the contributions of four sources were 33.08%, 24.04%, 27.11% and 15.77% of the total contribution, respectively.
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•Obvious enrichment of Hg, Cd, Pb and Zn were found in Puning soils.•Four sources of soil heavy metals were apportioned by geostatistics and PMF.•Vehicle emission and industrial activities were the main anthropogenic source.
•The advantages and classifications of S-CO2 cycles are presented.•Applications of cycles especially in nuclear and solar industries are summarized.•The theoretical and experimental analysis of ...system and component are investigated.•The comparison of working fluids and component designs are analyzed.•The challenges to improve the efficiency of S-CO2 cycle applications are concluded.
The development technology and applications of supercritical CO2 power cycle have recently been gaining a lot of attention for applications to different energy industries. The advantage of the S-CO2cycle is high-efficiency within an economic and convenient structure. The stable chemical properties make it be proper to a range of metal material applications. This study provides a detailed comprehensive study of the recent development trends of the S-CO2 power cycle and the different applications of S-CO2 power cycle in various energy industries, especially nuclear energy and solar energy. The theoretical analysis, experimental analysis and the classification of different approaches are summarized for energy sources. The comparison of working fluids, component designs are presented in the article as well. The challenges for improving the efficiency of S-CO2 power cycle applications are analyzed. The study will be a beneficial complement to understanding the recent progress.
•Current various S-CO2 Brayton cycle layouts are introduced in detail.•Several S-CO2 Brayton cycles are integrated into existing mature molten salt SPT.•Different S-CO2 Brayton cycles are compared ...for application in SPT.•Current S-CO2 cycles yield high efficiency, but small specific work and narrow temperature difference.
In the present study, several current S-CO2 Brayton cycle layouts are reviewed, and considered to be integrated into the existing mature molten salt solar power tower (SPT) systems. The SPT systems integrated with S-CO2 Brayton cycles are completely modeled by an integrative approach. The performances of these different cycles are compared comprehensively for applications in molten salt SPT systems from the aspects of the efficiency, the specific work, and the incorporation ability with the thermal energy storage indicated by the molten salt temperature difference across the solar receiver. The results indicate: (1) The intercooling cycle can generally offer the highest efficiency, followed by the partial-cooling cycle, and the recompression cycle; The precompression cycle can yield higher efficiency than the recompression cycle when the compressor inlet temperature is high; The increase in the hot salt temperature cannot always result in the efficiency improvement of the SPT systems. (2) The partial-cooling cycle can offer the largest specific work, while the recompression cycle and the split expansion cycle yield the lowest specific work. (3) The molten salt temperature differences of SPT systems with the simple recuperation cycle, the partial-cooling cycle, and the precompression cycle are slightly larger than those of SPT systems with the recompression cycle, the split expansion cycle, and the intercooling cycle. (4) As a classical approach to improve efficiency, reheating can decrease the system efficiency in the cases with high hot molten salt temperature; SPT systems without reheating can yield larger molten salt temperature difference than those with reheating. (5) Although the current S-CO2 Brayton cycle layouts can offer high efficiency, there are still several challenges for integrating them into the SPT systems: the specific work is relatively small, and the temperature difference across the solar receiver is narrow. Further work remains to build novel S-CO2 cycle layouts with high efficiency, large specific work, and wide temperature difference.
Mesoporous silica nanoparticles (MSNs), one of the important porous materials, have garnered interest owing to their highly attractive physicochemical features and advantageous morphological ...attributes. They are of particular importance for use in diverse fields including, but not limited to, adsorption, catalysis, and medicine. Despite their intrinsic stable siliceous frameworks, excellent mechanical strength, and optimal morphological attributes, pristine MSNs suffer from poor drug loading efficiency, as well as compatibility and degradability issues for therapeutic, diagnostic, and tissue engineering purposes. Collectively, the desirable and beneficial properties of MSNs have been harnessed by modifying the surface of the siliceous frameworks through incorporating supramolecular assemblies and various metal species, and through incorporating supramolecular assemblies and various metal species and their conjugates. Substantial advancements of these innovative colloidal inorganic nanocontainers drive researchers in promoting them toward innovative applications like stimuli (light/ultrasound/magnetic)‐responsive delivery‐associated therapies with exceptional performance in vivo. Here, a brief overview of the fabrication of siliceous frameworks, along with discussions on the significant advances in engineering of MSNs, is provided. The scope of the advancement in terms of structural and physicochemical attributes and their effects on biomedical applications with a particular focus on recent studies is emphasized. Finally, interesting perspectives are recapitulated, along with the scope toward clinical translation.
Mesoporous silica nanoparticles (MSNs) have garnered enormous interest owing to their highly advantageous physicochemical and morphological attributes. Collectively, progression has been made by modifying the surface of the siliceous frameworks through incorporating diverse supramolecular assemblies. An overview of the fabrication of MSNs and discussions on significant advances in engineering of MSNs, along with their scope toward clinical translation, is provided.
It is necessary to establish local geochemical baseline concentrations (GBCs) due to the lack or the inapplicability of regional background values in the study area. The establishment of GBCs of ...heavy metal (HM) in soil helps in making the accurate assessment of pollution, and then provides a basis for pollution control. Based on this, a case study was undertaken to study the GBCs of the Jiedong District, Guangdong Province, China. In this research, cumulative frequency distribution curves were utilized to determine the local GBCs in the subsoils. The determined GBCs of Cr, Hg, As, Pb, Ni, Cd, Cu, Zn, Co and V were 39.91, 0.072, 11.48, 47.62, 12.70, 0.17, 14.22, 64.54, 6.31, and 68.14 mg/kg, respectively. The average concentrations of Hg, As, Pb, Cd, Cu and Zn in the topsoils exceeded the corresponding baseline concentrations. In particular, the contents of Cd and Hg were 1.53 and 2.22 times higher than GBCs. According to this baseline criterion, enrichment factor (EF), pollution load index (PLI) and ecological risk index (RI) were applied to assessing HM pollution. EF and PLI suggested that most areas were under moderate contamination, while Hg and Cd pollution was more serious. And the RI values presented that the potential ecological risks were low in most parts of the study area. The possible origins of HMs were identified by combining positive matrix factorization with EF and geostatistics. Comprehensive analysis indicated that Hg and Cd were related to industrial activities, such as textile and garment processing, plastic and rubber production and metal manufacturing. Arsenic and part of Cu mainly came from agricultural activities, namely the use of pesticides, fertilizers and livestock manures. Lead and Zn were mainly attributed to traffic emissions. Chromium, Ni, V, Co, and part of Cu were originated from natural source controlled by parent materials. The corresponding contributions of these sources were 20.61%, 24.20%, 19.22% and 35.97%, respectively. This work provides information to prevent and control the soil HM pollution by proposing the efficient management of anthropogenic sources.
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•There were different content characteristics of heavy metals under different land use.•Ecological and human health risks from different sources were quantitatively ...calculated.•Industrial activities contributed the most to ecological risks.•Agricultural practices were the largest source of human health risks.
Heavy metals (HMs) in soil cause adverse effects on ecosystem and human health. Quantifying ecological risk and human health risk (HHR) from sources can determine priority sources and help to mitigate the risks. In this research, geostatistics and positive matrix factorization (PMF) were used to identify and quantify the sources of soil HMs; and then ecological risk and HHR from different sources under woodland, construction land and farmland were quantitatively calculated by combining the potential ecological risk index (RI) and HHR assessment models with PMF model. Taking Jiedong District as an example, four sources were quantitatively apportioned, which were agricultural practices (23.08%), industrial activities (29.10%), natural source (22.87%) and traffic emissions (24.95%). For ecological risk, industrial activities were the greatest contributor, accounting for about 49.71%, 48.11% and 47.15% under construction land, woodland and farmland, respectively. For non-carcinogenic risk, agricultural practices were the largest source under woodland and farmland, while industrial activities were the largest source under construction land. As for carcinogenic risk, no matter which kind of land use, agricultural practices were the largest source. In addition, the health risks of children, including non-carcinogenic and carcinogenic risks, were higher than those of adults, and the trends in health risks for children and adults were similar. The integrated approach was useful to evaluate ecological risk and HHR quantification from sources under different land use, thereby providing valuable suggestions for reducing pollution and protecting human health from the sources.
To evaluate the impact of the entry of biosimilars on the pricing of eight biologic products in 57 countries and regions. We utilized an interrupted time series design and IQVIA MIDAS® data to ...analyze the annual sales data of eight biologic products (adalimumab, bevacizumab, epoetin, etanercept, filgrastim, infliximab, pegfilgrastim, and trastuzumab) across 57 countries and regions from January 1, 2012, to December 31, 2019. We examined the immediate and long-term changes in biologics ex-manufacturer pricing following the entry of biosimilars to the market. Following the entry of biosimilars, the average price per dose of biologic product was immediately reduced by $438 for trastuzumab, $112 for infliximab, and $110 for bevacizumab. The persistent effect of biosimilars' market entry led to further reductions in price per dose every year: by $49 for adalimumab, $290 for filgrastim, $21 for infliximab, and $189 for trastuzumab. Similarly, we analyzed the impact of biosimilars on four biologics' prices in the US, where the prices of three biologics significantly decreased every year, with filgrastim, pegfilgrastim, and infliximab decreasing by $955, $753, and $104, respectively. The introduction of biosimilars has significantly reduced the prices of biologics both globally and in the US. These findings not only demonstrate the economic benefits of increasing biosimilar utilization, but also emphasize the importance of biosimilars in controlling healthcare costs. Policies should aim to expand the availability of biosimilars to counteract the exponential growth of medical spending caused by the use of biologics.
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