Target Elements Research Articles

Membrane-Targeted Quantum Dot-Based BACE1 Activity Sensors for In Vitro and In Cellulo Assays.

The need for the development of specific and robust methodologies to elucidate the intricate pathological mechanisms of neurodegenerative diseases and discover effective treatments for prevention and remediation is evident. Alzheimer's disease, in particular, has become more prevalent as the global population has aged. β-Secretase, the β-site amyloid precursor protein cleaving enzyme (BACE1), is the protease that produces the β-amyloid peptide, which is considered one of the driving factors of Alzheimer's disease and an important target for treatment development. However, an understanding of its activity, modulation, and regulation is far from complete. This is in large part due to the complex nature of following its activity. Beyond the common requirements for all biosensors (ease of preparation and use), BACE1 probes also demand both stability at acidic pH and membrane localization. To overcome these hurdles, we exploit the modular self-assembly provided by fluorescent quantum dot (QD) sensors. As compared to other fluorophores, QDs provide enhanced fluorescence brightness and photostability, and their large surface area enables functionalization with peptide substrates together with targeting elements that localize the sensor to the areas of maximal BACE1 activity, all achieved through His-tag self-assembly. In vitro, the sensor demonstrated stability under acidic conditions, and using high-throughput plate reader assays, we determined BACE1 activity in-line with literature values and enabled the obtainment of the inhibitor constant of verubecestat, a small molecule inhibitor. The sensor was also transitioned to cellular experiments, where it demonstrated sensitivity to BACE1 activity and its modulation upon inhibitor treatment in a neuroblastoma cell line.

Supply security beyond mines and scrap recycling: valorization potential of metallurgical residues.

In the context of the European Critical Raw Materials Act, this work attempts to demonstrate the potential of residual material flows from non-ferrous metallurgy and their possible contribution to the supply security of metals by locally available new secondary resources, assuming technically and economically viable processing. Based on the aluminium, zinc, copper and lead industries, the resulting waste streams are discussed and, in particular, the complex process consisting of physical, chemical and metallurgical steps is described. Their diversity, be it slags, dusts or even sludges, has a wide variety of morphologies and compositions due to the process of generation. In the past, many concepts for reprocessing were investigated, but the goal was usually only the recovery of one target element or to avoid landfilling by using it, for example, as a building material, whereby the metals contained are completely lost. If the target is the extraction of valuables, the required interdisciplinary process development must be based on an in-depth characterization to understand the behaviour of metals and trace elements in possible extraction steps and also to develop suitable strategies for influencing the behaviour of target elements with the aim of extraction. This starts with an in-depth comprehension of the formation process, which is the subject of this article and has a direct influence on the composition and morphology of the materials, thus forming the basis for understanding the behaviour in potential recycling processes. Furthermore, typical compositions of the residual material streams, sources and, if available, quantities are shown and, in summary, an attempt is made to evaluate the materials in a SWOT analysis and to address the challenges in developing extraction steps for processing. While mine tailings are mostly found outside of Europe, the potential of the residual materials from metallurgy is local due to the processing of the concentrates in Europe. This leads to several potential advantages in a possible reprocessing, such as no or shorter transport routes, which is linked to lower quantity of emissions, defined volume and known composition, no geopolitical risk, conservation of primary resources, and increasing Europe's sustainability through a more comprehensive use of the raw materials.This article is part of the discussion meeting issue 'Sustainable metals: science and systems'.

Shallow-Depth Quantum Circuit for Unstructured Database Search

Grover’s search algorithm (GSA) offers quadratic speedup in searching unstructured databases but suffers from exponential circuit depth complexity. Here, we present two quantum circuits called HX and Ry layers for the searching problem. Remarkably, both circuits maintain a fixed circuit depth of two and one, respectively, irrespective of the number of qubits used. When the target element’s position index is known, we prove that either circuit, combined with a single multi-controlled X gate, effectively amplifies the target element’s probability to over 0.99 for any qubit number greater than seven. To search unknown databases, we use the depth-1 Ry layer as the ansatz in the Variational Quantum Search (VQS), whose efficacy is validated through numerical experiments on databases with up to 26 qubits. The VQS with the Ry layer exhibits an exponential advantage, in circuit depth, over the GSA for databases of up to 26 qubits.

Ultra-high precision nano additive manufacturing of metal oxide semiconductors via multi-photon lithography

As a basic component of the versatile semiconductor devices, metal oxides play a critical role in modern electronic information industry. However, ultra-high precision nanopatterning of metal oxides often involves multi-step lithography and transfer process, which is time-consuming and costly. Here, we report a strategy, using metal-organic compounds as solid precursor photoresist for multi-photon lithography and post-sintering, to realize ultra-high precision additive manufacturing of metal oxides. As a result, we gain metal oxides including ZnO, CuO and ZrO2 with a critical dimension of 35 nm, which sets a benchmark for additive manufacturing of metal oxides. Besides, atomic doping can be easily accomplished by including the target element in precursor photoresist, and heterogeneous structures can also be created by multiple multi-photon lithography, allowing this strategy to accommodate the requirements of various semiconductor devices. For instance, we fabricate an ZnO photodetector by the proposed strategy.

Impact of urban disturbance on soil insect communities in a Brazilian Atlantic Forest biological station

Urbanization constitutes a major threat to biodiversity. Understanding its effects on insect communities is relevant because they are key elements of trophic interactions, and indicators and targets of conservation. Herein, we investigated the influence of meteorological and habitat factors on the soil entomofauna in three areas with distinct levels of urbanization at the Parque Estadual da Pedra Branca, Brazil. We investigated whether community structure differs among areas with different levels of urbanization, and how changes in the environment affect soil insect community composition and distribution. We systematically monitored communities for 12 months in three areas along a gradient of anthropogenic disturbance, representing preserved secondary forest, disturbed forest and peridomicile areas. The results revealed that the degree of urbanization affects insect communities, with a strong effect of habitat factors, such as canopy cover, presence of flooded areas, quantity of fallen trunks and mean temperature. Insect abundance did not show significant differences among areas, while biomass was higher in disturbed forest than in preserved forest and peridomicile areas. Additionally, insect richness and diversity were higher in preserved and disturbed forests than in peridomicile areas, with no significant difference between preserved and disturbed forests. Our results can be used to enhance the understanding of the effects of urbanization on taxonomically and functionally diverse groups of insects, and to advise residents and urban planners about the consequences of urbanization on biodiversity and ecosystem services in urban-sylvatic interface areas.

Evaluation of Risk Factors Associated with Selected Elements in Veterinary Active Pharmaceutical Ingredients Using ICP-MS.

One of the major concerns for animal health is the pollution of food and medicines given to animals by non-essential and toxic elements, which also poses a risk to human health via the food chain. The essential (Ca, Cr, Mn, Fe, Co, and Ni) and non-essential elements (Li, Ti, V, Ga, Ag, Cd, In, Ba, Bi, Th, and U) were monitored using inductively coupled plasma mass spectrometry (ICP-MS) in veterinary active pharmaceutical ingredients (V APIs). Samples were divided into four groups including antibiotic (14 samples), anthelmintic (7 samples), anticoccidial (5 samples), and externally used (5 samples). The results of the antibiotic group had the highest concentrations of most elements. The concentrations of the targeted elements were below the permissible limits as recommended by the United States Pharmacopeia (USP). The target hazard quotient (THQ) and the total target hazard quotient (TTHQ) were applied to evaluate the animal health risk associated with the exposure of the target elements in V API samples; the results showed that elements do not pose any risk to animals in all samples as indicated by THQ values less than 1. Validation parameters performed in this study showed good accuracy and validity of the ICP-MS analysis method, with good linearity (R2 ˃ 0.990), and the relative standard deviations (%RSD) were < 4% for all target elements. Analysis of variance (ANOVA-one way) was used to compare the means of veterinary drug groups for all targeted elements. The results showed that all elements have p-values < 0.05 except 52Cr and 54Fe.

TE-LSTM: A Prediction Model for Temperature Based on Multivariate Time Series Data

In the era of big data, prediction has become a fundamental capability. Current prediction methods primarily focus on sequence elements; however, in multivariate time series forecasting, time is a critical factor that must not be overlooked. While some methods consider time, they often neglect the temporal distance between sequence elements and the predicted target time, a relationship essential for identifying patterns such as periodicity, trends, and other temporal dynamics. Moreover, the extraction of temporal features is often inadequate, and discussions on how to comprehensively leverage temporal data are limited. As a result, model performance can suffer, particularly in prediction tasks with specific time requirements. To address these challenges, we propose a new model, TE-LSTM, based on LSTM, which employs a temporal encoding method to fully extract temporal features. A temporal weighting strategy is also used to optimize the integration of temporal information, capturing the temporal relationship of each element relative to the target element, and integrating it into the LSTM. Additionally, this study examines the impact of different time granularities on the model. Using the Beijing International Airport station as the study area, we applied our method to temperature prediction. Compared to the baseline model, our model showed an improvement of 0.7552% without time granularity, 1.2047% with a time granularity of 3, and 0.0953% when addressing prediction tasks with specific time requirements. The final results demonstrate the superiority of the proposed method and highlight its effectiveness in overcoming the limitations of existing approaches.

Evaluation of the Bioavailability of Iodine and Arsenic in Raw and Cooked Saccharina japonica Based on Simulated Digestion/Caco-2 Cell Model.

Kelp is a traditional healthy food due to its high nutritional content; however, its relatively high contents of iodine and arsenic have raised concerns about its edible safety. This study explored the effects of different cooking treatments on the contents of iodine and arsenic in kelp, evaluated the bioaccessibility and bioavailability of iodine and arsenic in kelp using in vitro digestion, and compared the differences in the transport characteristics of iodine in kelp and KIO3 using a Caco-2 monolayer cell transport model. The results show that the content of target elements that reached systemic circulation could be reduced by cooking and gastrointestinal digestion. The highest reductions in iodine and arsenic were 94.4% and 74.7%, respectively, which were achieved by boiling for 10 min. The bioaccessibility and bioavailability of iodine and arsenic were significantly improved by a cooking treatment. However, the contents of iodine and arsenic decreased significantly, with the bioaccessibility of iodine reducing from 3188.2 μg/L to 317.0 μg/L and that of arsenic reducing from 32.5 μg/L to 18.1 μg/L in the gastric phase after boiling. The findings also show that the efficiency of iodine transport in kelp and KIO3 was positively correlated with the transport time and negatively correlated with the concentration of iodine. With the increase in the iodine concentration, the rate of iodine transport in kelp decreased from 63.93% to 3.14%, but that of KIO3 was stable at around 35%, which indicates that the absorption efficiency of iodine from kelp was limited, even when too much kelp was ingested. In conclusion, the edible safety of kelp is significantly improved after cooking. The risk of excessive iodine and arsenic intake caused by consuming kelp is extremely low, and as an effective iodine supplement source, kelp has higher edible safety compared with KIO3. This study clarifies the safety of algae based on iodine and arsenic contents and also provides a basis for the formulation of food safety standards.

Assessment of Nicotine delivery capabilities and evaluation of human health risk of metals associated with selected tobacco products

The use of smokeless tobacco has increased, particularly among Ghana's youth, due in part to perceived medicinal benefits and the belief that it is less harmful and non-addictive. In response to this trend, we systematically classified 51 different tobacco products based on their potential toxicity as determined by potentially toxic elements, addiction potential, and nicotine delivery capability. Moisture, pH, and percentage-free base nicotine were measured using certified methods. X-ray fluorescence techniques were used to determine tobacco products' concentrations of target elements (Ca, Cu, Fe, K, Mn, Rb, Sr, Mo, V, S, U, Zr, Tl, and Zn). Locally produced snuff products had the highest nicotine delivery capacity, with a pH of 9.73 and 96.98% freebase nicotine. Dried tobacco leaves followed closely, with a mean pH of 7.39 and percentage free base nicotine of 25.93%, whereas cigarette products had the lowest nicotine delivery capability (mean pH: 5.49; percentage free base nicotine: 0.33%). In the snuff category, menthol-flavored products delivered more nicotine (pH of 9.96; percentage free base nicotine of 98.8%) than moringa-flavored alternatives (pH of 9.77; percentage free base nicotine of 98%). Users of the smuggled cigarette product C6 were found to be susceptible to increased non-carcinogenic health effects, as indicated by a hazard index (HI) value of 1108.35, while C4, with the highest pH of 5.58 and a corresponding %A (addiction potential) of 0.70, demonstrated the greatest addiction potential among the examined cigarette products. Our findings indicate that locally produced snuff and dried tobacco leaves have potentially high addictive properties, emphasizing the risk of tobacco dependence. Furthermore, these products may have non-carcinogenic health effects, as indicated by elevated hazard quotients and hazard indices. These findings provide important insights into the various characteristics of tobacco products in Ghana, which may aid in developing targeted public health interventions.

Targeting specific brain districts for advanced nanotherapies: A review from the perspective of precision nanomedicine.

Numerous studies are focused on nanoparticle penetration into the brain functionalizing them with ligands useful to cross the blood-brain barrier. However, cell targeting is also crucial, given that cerebral pathologies frequently affect specific brain cells or areas. Functionalize nanoparticles with the most appropriate targeting elements, tailor their physical parameters, and consider the brain's complex anatomy are essential aspects for precise therapy and diagnosis. In this review, we addressed the state of the art on targeted nanoparticles for drug delivery in diseased brain regions, outlining progress, limitations, and ongoing challenges. We also provide a summary and overview of general design principles that can be applied to nanotherapies, considering the areas and cell types affected by the most common brain disorders. We then emphasize lingering uncertainties that hinder the translational possibilities of nanotherapies for clinical use. Finally, we offer suggestions for continuing preclinical investigations to enhance the overall effectiveness of precision nanomedicine in addressing neurological conditions. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Regulation of angiogenesis by signal sequence-derived peptides.

The neuropilin-like, Discoidin, CUB and LCCL domain containing 2 (DCBLD2) is a transmembrane protein with an unusually long signal sequence (SS) composed of N-terminal (N) and C-terminal (C) subdomains, separated by a transition (tra) subdomain. DCBLD2 interacts with VEGFR-2 and regulates VEGF-induced endothelial cell signaling, proliferation and migration, as well as angiogenesis. The exact mechanisms by which DCBLD2 interacts with VEGFR2 to modulate VEGF signaling remain unclear. Searching for VEGFR2 interacting DCBLD2 domains, we generated various constructs containing different DCBLD2 domain combinations and conducted co-immunoprecipitation and signaling studies in HEK 293T and endothelial cells. Several peptides were synthesized based on the identified domain, and their effect on VEGF signaling was assessed in vitro in cell culture and in vivo using matrigel plug and corneal micropocket assays. The effect of the lead peptide was further evaluated using a murine hindlimb ischemia model. DCBLD2 SS interacted with VEGFR2 and promoted VEGF signaling. SS was not cleaved in the mature DCBLD2 and its hydrophobic transmembrane 'traC' segment, but not the 'N' subdomain, was involved in DCBLD2-VEGFR2 interaction. The smallest unit in DCBLD2 SS that interacts with VEGFR2 was the L5VL5 sequence. Even after the central valine was removed, the L10 sequence mimicked the DCBLD2 SS traC's effect on VEGF-signaling, while shorter or longer poly-leucine sequences were less effective. Finally, a synthetic traC peptide enhanced VEGF signaling in vitro, promoted VEGF-induced angiogenesis in vivo, and improved blood flow recovery following hindlimb ischemia. DCBLD2 SS along with its derivative peptides can promote VEGFR2 signaling and angiogenesis. Synthetic peptides based on DCBLD2 SS hold promise as therapeutic agents for regulating angiogenesis. Importantly these findings refine the traditional view of signal sequences as mere targeting elements, revealing a role in cellular signaling. This opens new avenues for research and therapeutic strategies.

Historical co-enrichment, source attribution, and risk assessment of critical nutrients and heavy metal/metalloids in lake sediments: insights from Chaohu Lake, China.

In Chinese freshwater lakes, eutrophication often coincides with heavy metal/metalloids (HM/Ms) pollution, yet the coevolution of critical nutrients (P, S, Se) and HM/Ms (Cd, Hg, etc.) remains understudied. To address this gap, we conducted a sedimentary chemistry analysis on a 30cm-deep core, dating back approximately 200years, retrieved from Chaohu Lake, China. The age-depth model revealed a gradual increase in deposition rates over time. Notably, the concentrations and enrichment factors (EFs) of most target elements surged in the uppermost ~ 15cm layer, covering the period from 1953 to 2013, while both the concentrations and EFs in deeper layers remained relatively stable, except for Hg. This trend indicates a significant co-enrichment and near-synchronous increase in the levels and EFs of both nutrients and HM/Ms in the upper sediment layers since the mid-twentieth century. Anthropogenic factors were identified as the primary drivers of the enrichment of P, Se, Cd, Hg, Zn, and Te in the upper core, with their contributions also showing a coupled evolutionary trend over time. Conversely, geological activities governed the enrichment of elements in the lower half of the core. The gradual accumulation of anthropogenic Hg between the - 30 to - 15cm layers might be attributed to global Hg deposition resulting from the industrial revolution. The ecological risk index (RI) associated with HM/Ms loading has escalated rapidly over the past 50years, with Cd and Hg posing the greatest threats. Furthermore, the PMF model was applied to specifically quantify source contributions of these elements in the core, with anthropogenic and geogenic factors accounting for ~ 60 and ~ 40%, respectively. A good correlation (r2 = 0.87, p < 0.01) between the PMF and Ti-normalized method was observed, indicating their feasibility and cross-validation in source apportionment. Finally, we highlighted environment impact and health implications of the co-enrichment of nutrients and HM/Ms. This knowledge is crucial for developing strategies to protect freshwater ecosystems from the combined impacts of eutrophication and HM/Ms pollution, thereby promoting water environment and human health.

Multi-targets detection via combination of multi-stimulus-response engineered bacteria and hydrogel-based separation platform

Establishing a method similar to ICP-MS that can quantitatively analyze multiple heavy metals simultaneously, conveniently, and in situ is highly anticipated. In this study, we integrated the sensing elements of multiple targets and different fluorescence reporting elements to construct an engineered Escherichia coli. When these targets are present, the engineered bacteria can emit a fluorescent signal at the corresponding wavelength. To avoid the inability to accurately distinguish and quantify the content of each target due to the overlap of fluorescence signals when multiple targets coexist, a hydrogel-based separation platform similar to a separation column was constructed. The hydrogel platform can change the detection limit (LOD) and sensitivity by adjusting the adsorption strength towards different targets, so as to realize the differentiation and recognition of their respective detection signals. The LODs of this new detection method for Cd(II), Hg(II), As(III), and Pb(II) are 1.249, 0.380, 3.917, and 0.755 μg/L, respectively. In addition, this biosensor system was applied to detect coexisting Cd(II), Hg(II), As(III), and Pb(II) in actual samples with a recovery rate of 85.61–110.30 %, which is consistent with the classical ICP-MS detection results, confirming the accuracy and reliability of the method for detecting multiple heavy metal coexisting samples.

Valorization of lithium containing slags from pyrometallurgical recycling route of spent lithium-ion batteries: The enrichment of γ-LiAlO2 phase from thermodynamic controlled and modified slags

Pyro-metallurgical processing technology is widely used in the spent lithium-ion batteries recycling to recover valuable metals such as cobalt, nickel and copper, while lithium primarily remains in the slag. The effective valorization of slag, especially lithium recovery, constitutes a significant issue in contemporary pyrometallurgical processes due to the paucity of studies. This paper proposes a novel perspective by defining slag as an aggregate of engineered artificial minerals. Thus, not only the parameters of the beneficiation process can be studied to optimize the separation efficiency during treatment, but also the slag can be re-designed to optimize the carrier minerals of target elements and gangue mineral composition in the initial step with thermodynamic tools. In this paper, the engineering of artificial minerals (EnAM) method was applied to the slag design of the Li2O-CaO-Al2O3-SiO2-MnO system, and an initial attempt was made to apply EnAM method to the flotation study. A flotation study on enrichment effect of the target phase γ-LiAlO2 from thermodynamic controlled slags is conducted.

The effect of biosecurity heat treatment on soils: implications for soil analytical methods and mineral exploration

Soils are widely used as geochemical sample media. A recent advancement in soil analytical methods for exploration developed in Australia, the UltraFine+ ® method, concentrates the clay-sized fraction of &lt;2 µm and then analyses this fraction for over 50 elemental concentrations, pH, electrical conductivity and spectral mineralogy/properties (i.e., visible –near- to shortwave and mid- infrared reflectance spectroscopy). This new approach was initially limited to Australian soils due to strict biosecurity legislation. However, since 2022 samples can be shipped to Australia and heat-treated to 160 °C to be released from quarantine-approved premises prior to analysis. A study was undertaken to determine the influence of the temperature heat treatment on the spectral and geochemical properties of soils. One hundred and three soils were collected from multiple regions of Australia to provide a background set of samples to test the effect of heat treatment on the analytical response using the clay-sized fraction analytical method. These soils comprised multiple clay types and are representative of general soil types and target commodities in mineral exploration settings. Results show that heat treatment did not significantly impact elemental abundance of common pathfinder and target elements in minerals exploration with strong correlation and linear trends between the treatments. Spectral parameters measured in the visible to mid infrared range were also unaffected by heating. Some observed elemental changes were related to inconsistent extraction of resistate elements (Hf, Nb, Zr). Counter to other studies, a pH decrease was observed in heat-treated samples. The study concludes that biosecurity release heat treatment at 160 °C does not hinder analysis of the ultrafine fraction soils with a concentrated aqua regia assay and spectral mineralogy measurements.

Recycling of Waste Secondary Battery Materials to Recovery of Lithium Carbonate By Using Eco-Friendly Pyro-Metallurgical Electrolysis Process

Recently, many types of vehicles that has been used fossil fuels energy are being replaced with EVs (Electric Vehicles) uses electrical energy. Since secondary batteries that use as the main power device of electric vehicles have a constant lifespan of 7 to 8 years, accordingly, many operating countries are constructing various plans and policies to handle with this issue. Various valuable rare metals such as nickel, cobalt, lithium, and manganese that all has limited resource, are contained in the wasted cathode material, and it could be used as a useful high-quality source if those materials can be recovered in recycle process. Thus, in this study, recover existing resources from waste cathode materials through the eco-friendly Molten Carbonate Electrolysis (MCE) process was performed. Through the process, the lithium, the main recovery target element could be recovered in the form of a compound as lithium carbonate while valuable metals such as nickel and manganese were separated and precipitated. Even though this process does not require any of acidic or organic solvent, it showed high recovery results with more environmentally friendly than the commercial hydrometallurgical recovery method while the sequence was also relatively simple. Various analysis was performed in Xray diffraction, X-ray fluorescence and FE-SEM to confirming characteristics status in recovered lithium carbonate and other precipitated powder, and thermodynamical calculation was accompanied by HSC chemistry to estimate the proper process conditions and electrode materials. In addition, through electrochemical analysis such as chronoamperometry (CA) and cyclic-voltammetry (CV), the correlation between electrode reaction tendency and lithium compound recovery rate was identified.

Quantitative Analysis of Pb in Soil Using Laser-Induced Breakdown Spectroscopy Based on Signal Enhancement of Conductive Materials.

Studying efficient and accurate soil heavy-metal detection technology is of great significance to establishing a modern system for monitoring soil pollution, early warning and risk assessment, which contributes to the continuous improvement of soil quality and the assurance of food safety. Laser-induced breakdown spectroscopy (LIBS) is considered to be an emerging and effective tool for heavy-metal detection, compared with traditional detection technologies. Limited by the soil matrix effect, the LIBS signal of target elements for soil heavy-metal detection is prone to interference, thereby compromising the accuracy of quantitative detection. Thus, a series of signal-enhancement methods are investigated. This study aims to explore the effect of conductive materials of NaCl and graphite on the quantitative detection of lead (Pb) in soil using LIBS, seeking to find a reliable signal-enhancement method of LIBS for the determination of soil heavy-metal elements. The impact of the addition amount of NaCl and graphite on spectral intensity and parameters, including the signal-to-background ratio (SBR), signal-to-noise ratio (SNR), and relative standard deviation (RSD), were investigated, and the mechanism of signal enhancement by NaCl and graphite based on the analysis of the three-dimensional profile data of ablation craters and plasma parameters (plasmatemperature and electron density) were explored. Univariate and multivariate quantitative analysis models including partial least-squares regression (PLSR), least-squares support vector machine (LS-SVM), and extreme learning machine (ELM) were developed for the quantitative detection of Pb in soil with the optimal amount of NaCl and graphite, and the performance of the models was further compared. The PLSR model with the optimal amount of graphite obtained the best prediction performance, with an Rp that reached 0.994. In addition, among the three spectral lines of Pb, the univariate model of Pb I 405.78 nm showed the best prediction performance, with an Rp of 0.984 and the lowest LOD of 26.142 mg/kg. The overall results indicated that the LIBS signal-enhancement method based on conductive materials combined with appropriate chemometric methods could be a potential tool for the accurate quantitative detection of Pb in soil and could provide a reference for environmental monitoring.

Quantitative inversion of soil trace elements from spectroscopic effects across multiple crop growth periods

Human health is directly impacted by trace components found in soil, for which hyperspectral remote sensing technology offers a novel way to rapidly assess dynamic soil environmental quality. In most studies, the premise of quantitative inversion on soil elements is that the known target elements will cause growth stress. However, such stress is unusual in non-polluted areas. Consequently, broad-area soil trace element monitoring in non-contaminated areas remains challenging. Spectral inversion of plant material has a longer time window and is more sensitive to elemental changes than soil spectral inversion (bare soil period). In this work, we conducted a wheat pot experiment with concentration gradients of four trace elements (Fe, B, Mo, and Zn), analyzed leaf (jointing stage) and spike (maturity period) samples using spectral measurements and chemical tests, and filtered the characteristic positions and inverse modeling using the spectra of the element-accumulating preference organs in plant canopies. The canopy aggregation sites differed for each element, and both simple linear regression (SLR) and multiple linear regression (MLR) models based on the spectra of canopy aggregation sites achieved high accuracy. The results of this study enable the construction of an inverse model of plant spectra-plant element content-elements in soil, which can serve as a reference for soil monitoring and assessment in typical crop cover areas.

Effect of iodine species on biofortification of iodine in cabbage plants cultivated in hydroponic cultures

Iodine is an essential trace element in the human diet because it is involved in the synthesis of thyroid hormones. Iodine deficiency affects over 2.2 billion people worldwide, making it a significant challenge to find plant-based sources of iodine that meet the recommended daily intake of this trace element. In this study, cabbage plants were cultivated in a hydroponic system containing iodine at concentrations ranging from 0.01 to 1.0 mg/L in the form of potassium iodide or potassium iodate. During the experiments, plant physiological parameters, biomass production, and concentration changes of iodine and selected microelements in different plant parts were investigated. In addition, the oxidation state of the accumulated iodine in root samples was determined. Results showed that iodine addition had no effect on photosynthetic efficiency and chlorophyll content. Iodide treatment did not considerably stimulate biomass production but iodate treatment increased it at concentrations less than 0.5 mg/L. Increasing iodine concentrations in the nutrient solutions increased iodine content in all plant parts; however, the iodide treatment was 2–7 times more efficient than the iodate treatment. It was concluded, that iodide addition was more favourable on the target element accumulation, however, it should be highlighted that application of this chemical form in nutrient solution decreased the concetrations of selected micoelement concentration comparing with the control plants. It was established that iodate was reduced to iodide during its uptake in cabbage roots, which means that independently from the oxidation number of iodine (+ 5, − 1) applied in the nutrient solutions, the reduced form of target element was transported to the aerial and edible tissues.

Short transmembrane domains target type II proteins to the Golgi apparatus and type I proteins to the endoplasmic reticulum.

Transmembrane domains (TMDs) contain information targeting membrane proteins to various compartments of the secretory pathway. In previous studies, short or hydrophilic TMDs have been shown to target membrane proteins either to the endoplasmic reticulum (ER) or to the Golgi apparatus. However, the basis for differential sorting to the ER and to the Golgi apparatus remained unclear. To clarify this point, we quantitatively analyzed the intracellular targeting of a collection of proteins exhibiting a single TMD. Our results reveal that membrane topology is a major targeting element in the early secretory pathway: type I proteins with a short TMD are targeted to the ER, and type II proteins to the Golgi apparatus. A combination of three features accounts for the sorting of simple membrane proteins in the secretory pathway: membrane topology, length and hydrophilicity of the TMD, and size of the cytosolic domain. By clarifying the rules governing sorting to the ER and to the Golgi apparatus, our study could revive the search for sorting mechanisms in the early secretory pathway.