Distribution In Different Organs Research Articles

Citrus yellow vein clearing virus infection triggers phloem remobilization of iron- and zinc-nicotianamine in citrus.

Citrus yellow vein clearing virus (CYVCV) is a worldwide and highly destructive disease of citrus, but the mechanisms involved in CYVCV-inhibited plant growth are not well understood. This study examined nutrient levels and their cellular distribution in different organs of healthy and CYVCV-affected citrus (Citrus reticulata 'Kanpei') plants. We found that CYVCV-infected plants exhibit characteristic symptoms, including a significant reduction in iron (Fe) and other elemental nutrients in the shoots. Our data suggest that CYVCV-induced chlorosis in citrus leaf veins is primarily due to iron deficiency, leading to reduced chlorophyll synthesis. Further analysis revealed a marked decrease in iron concentration within the pith and xylem of citrus petioles post-CYVCV infection, contrasting with increased Fe and zinc (Zn) concentrations in the phloem. Moreover, a substantial accumulation of starch granules was observed in the pith, xylem, and phloem vessels of infected plants, with vessel blockage due to starch accumulation reaching up to 81%, thus significantly obstructing Fe transport in the xylem. Additionally, our study detected an upregulation of genes associated with nicotinamide metabolism and Fe and Zn transport following CYVCV infection, leading to increased levels of nicotinamide metabolites. This suggests that CYVCV-infected citrus plants may induce nicotinamide synthesis in response to Fe deficiency stress, facilitating the transport of Fe and Zn in the phloem as nicotinamide-bound complexes. Overall, our findings provide insight into the mechanisms of long-distance Fe and Zn transport in citrus plants in response to CYVCV infection and highlight the role of nutritional management in mitigating the adverse effects of CYVCV, offering potential strategies for cultivating CYVCV-resistant citrus varieties.

Toxicokinetics, in vivo metabolic profiling and tissue distribution of chlorfenapyr in mice.

Chlorfenapyr is a novel broad-spectrum insecticide derived from natural pyrrole derivatives produced by Streptomyces spp. It acts as a pro-insecticide and is metabolically converted to the active metabolite, tralopyril. Chlorfenapyr poisoning is known for its delayed neurological symptoms and high mortality. Unfortunately, information on the toxicokinetics, metabolism and tissue distribution of chlorfenapyr and tralopyril is still lacking. In this study, the metabolic profile, toxicokinetics and tissue distribution of chlorfenapyr and tralopyril after oral administration at a toxic dose in mice were investigated. Twenty metabolites were identified in plasma, urine and feces, which were mainly formed by dealkylation, oxidative dechlorination and reductive dechlorination. Toxicokinetic results showed that chlorfenapyr was rapidly converted to tralopyril after administration, and the in vivo half-life (t1/2), area under the curve (AUC) and peak concentration (Cmax) values of tralopyril were significantly higher than those of chlorfenapyr (P < 0.05). Tissue distribution experiments confirmed that the metabolite tralopyril had a longer half-life, a lower clearance and a wide distribution in different organs and tissues compared to chlorfenapyr. It was also able to cross the blood-brain barrier, suggesting a potential association with brain lesions. In addition, a sensitive and rapid LC-MS/MS analytical method was established for the detection of chlorfenapyr and tralopyril. In conclusion, this study provided valuable metabolic, toxicokinetic and tissue distribution information, contributing to future risk assessment and forensic identification in cases of chlorfenapyr poisoning. We recommend considering the assessment of tralopyril levels, which may be of greater therapeutic importance in the management of chlorfenapyr poisoning.

BnaC4.BOR2 mediates boron uptake and translocation in Brassica napus under boron deficiency.

Boron (B) is an essential microelement in plant growth and development. However, the molecular mechanisms underlying B uptake and translocation in Brassica napus are poorly understood. Herein, we identified a low-B (LB)-inducible gene, namely BnaC4.BOR2, with high transcriptional activity in root tips, stele cells, leaves, and floral organs. The green fluorescence protein labelled BnaC4.BOR2 protein was localised to the plasma membrane to demonstrate the B efflux activity in yeast and Arabidopsis. BnaC4.BOR2 knockout considerably reduced B concentration in the root and xylem sap, and altered B distribution in different organs at low B supply, exacerbating B sensitivity at the vegetative and reproductive stages. Additionally, the grafting experiment showed that BnaC4.BOR2 expression in the roots contributed more to B deficiency adaptability than that in the shoots. The pot experiments with LB-soil revealed B concentration in leaves and siliques of BnaC4.BOR2 mutants were markedly reduced, showing an obvious B-deficient phenotype of 'flowering without seed setting' and a considerable reduction in seed yield in B-deficient soil. Altogether, the findings of this study highlight the crucial role of BnaC4.BOR2 in B uptake and translocation during B. napus growth and seed yield under LB conditions.

Seasonal variations in C/N/P/K stoichiometric characteristics in different plant organs in the various forest types of Sygera Mountain.

We explored the resource acquisition and growth strategies of plants adapting to different environments, focusing on the typical forest types of Sygera Mountain: Pinus armandii, Picea likiangensis var. Linzhiensis, Abies georgei var. Smithii, and Juniperus saltuaria. Then, we analyzed the nutrient content and stoichiometric ratios of C, N, P, and K in different plant organs (leaves, branches, trunks, and roots) to examine the stoichiometric characteristics and nutrient balance mechanisms in these forests. Results show that within the same forest type, different plant organs exhibit high C and low N, P, and K levels. N content in all organs followed the order leaves > branches > roots > trunks. During the growth phase, the concentrations of P and K in PLL and AGS follow the order branches > leaves > roots > trunks. In the dormant phase, the distribution in different organs had the order leaves > branches > roots > trunks. C content remained relatively stable over time. In the same organ across different forest types, increase in nitrogen content in plant leaves is an active adaptation of JS plants, indicating that JS has a conservative growth strategy and can adapt to environmental stress. Owing to the influence of seasons, the evolution process of N and P content fluctuates, allocating nutrients to supporting and transporting organs for resource optimization and allocation. The N and P content were lower in the growth phase than in the dormant phase. Seasonal variations in the C/N, C/P, and C/K ratios in different forests were inversely correlated with changes in N, P, and K content in plant organs, supporting the "growth rate hypothesis." Stoichiometric analysis suggests that different limiting elements exist in organs across various forest types. Principal component analysis indicates that the seasonal patterns of stoichiometric ratios in the organs of different forest types show species-specific characteristics, reflecting the evolutionary nutrient utilization strategies of plant genera. In summary, plant growth in different Sygera Mountain forest types is limited by N and P, with a high tendency toward nitrogen limitation. The nutrient utilization and distribution differences among various organs during different growth stages are primarily influenced by the limited availability of environmental nutrients and inherent physiological characteristics of the plants.

Regulation of magnesium and calcium homeostasis in citrus seedlings under varying magnesium supply

Magnesium (Mg) and calcium (Ca) are two essential macronutrients in plants; however, the characteristics of Mg and Ca concentrations in organ, subcellular and chemical forms and their relationships in citrus plants, especially under varying Mg supply, are not well understood. In this study, Citrus sinensis seedlings (cv. Xuegan) were cultivated in conditions of Mg deficiency (0 mmol Mg2+ L−1) and Mg sufficiency (2 mmol Mg2+ L−1) to investigate the responses of Mg and Ca homeostasis in different organs and fractions. Compared with Mg sufficiency, Mg deficiency significantly decreased root and shoot growth, with the shoot biomass reduction of branch organs was greater than that of parent organs. In addition to increasing the Ca concentration in the parent stem and lateral root organs, Mg deficiency significantly decreased the concentrations and accumulations of Mg and Ca in citrus seedlings, further altering their distribution in different organs. More than 50% of Ca and Mg were sequestrated in the cell wall and soluble fractions, respectively, with Mg concentration decreasing by 15.4% in roots and 46.9% in leaves under Mg deficiency, while Ca concentration decreased by 27.6% in roots and increased by 23.6% in parent leaves. Approximately 90% of Mg exists in inorganic, water-soluble, and pectate and protein-bound forms, and nearly 90% of Ca exists in water-soluble, pectate and protein-bound, phosphate and oxalate acid forms. Except for the decreased inorganic Mg in roots and water-soluble Mg and Ca in leaves, Mg deficiency increased the proportions of Mg and Ca in all chemical forms. However, Mg deficiency generally increased the Ca/Mg ratio in various organs, subcellular and chemical forms, with negative relationships between Mg concentration and Ca/Mg ratio, and the variations of Mg and Ca were highly separated between Mg supply and organs. In conclusion, our results provide insights into the effects of Mg supply on Mg and Ca homeostasis in citrus plants.

Effector and cytolytic function of natural killer cells in anticancer immunity.

Adaptive immune cells play an important role in mounting antigen-specific antitumor immunity. The contribution of innate immune cells such as monocytes, macrophages, natural killer (NK) cells, dendritic cells, and gamma-delta T cells is well studied in cancer immunology. NK cells are innate lymphoid cells that show effector and regulatory function in a contact-dependent and contact-independent manner. The cytotoxic function of NK cells plays an important role in killing the infected and transformed host cells and controlling infection and tumor growth. However, several studies have also ascribed the role of NK cells in inducing pathophysiology in autoimmune diseases, promoting immune tolerance in the uterus, and antitumor function in the tumor microenvironment. We discuss the fundamentals of NK cell biology, its distribution in different organs, cellular and molecular interactions, and its cytotoxic and noncytotoxic functions in cancer biology. We also highlight the use of NK cell-based adoptive cellular therapy in cancer.

Response to Hypersalinity of Four Halophytes Growing in Hydroponic Floating Systems: Prospects in the Phytomanagement of High Saline Wastewaters and Extreme Environments.

Hypersaline environments occur naturally worldwide in arid and semiarid regions or in artificial areas where the discharge of highly saline wastewaters, such as produced water (PW) from oil and gas industrial setups, has concentrated salt (NaCl). Halophytes can tolerate high NaCl concentrations by adopting ion extrusion and inclusion mechanisms at cell, tissue, and organ levels; however, there is still much that is not clear in the response of these plants to salinity and completely unknown issues in hypersaline conditions. Mechanisms of tolerance to saline and hypersaline conditions of four different halophytes (Suaeda fruticosa (L.) Forssk, Halocnemum strobilaceum (Pall.) M. Bieb., Juncus maritimus Lam. and Phragmites australis (Cav.) Trin. ex Steudel) were assessed by analysing growth, chlorophyll fluorescence and photosynthetic pigment parameters, nutrients, and sodium (Na) uptake and distribution in different organs. Plants were exposed to high saline (257 mM or 15 g L-1 NaCl) and extremely high or hypersaline (514, 856, and 1712 mM or 30, 50, and 100 g L-1 NaCl) salt concentrations in a hydroponic floating culture system for 28 days. The two dicotyledonous S. fruticosa and H. strobilaceum resulted in greater tolerance to hypersaline concentrations than the two monocotyledonous species J. maritimus and P. australis. Plant biomass and major cation (K, Ca, and Mg) distributions among above- and below-ground organs evidenced the osmoprotectant roles of K in the leaves of S. fruticosa, and of Ca and Mg in the leaves and stem of H. strobilaceum. In J. maritimus and P. australis the rhizome modulated the reduced uptake and translocation of nutrients and Na to shoot with increasing salinity levels. S. fruticosa and H. strobilaceum absorbed and accumulated elevated Na amounts in the aerial parts at all the NaCl doses tested, with high bioaccumulation (from 0.5 to 8.3) and translocation (1.7-16.2) factors. In the two monocotyledons, Na increased in the root and rhizome with the increasing concentration of external NaCl, dramatically reducing the growth in J. maritimus at both 50 and 100 g L-1 NaCl and compromising the survival of P. australis at 30 g L-1 NaCl and over after two weeks of treatment.

Enrichment of Heavy Metals by Different Varieties of Rice

Pot experiment was carried out to compare the difference of Cr accumulation and distribution in different organs of 3 rice cultivars under different treatment of Cr. The results showed that the average values of Cr concentration in root, stem, leaf, chaff and grain of all cultivars were 7.63~141.09, 2.29~8.58, 14.01~39.93, 3.65~5.21 and 0.46~0.92 mg•kg-1, respectivly. Compared with the control, the accumulation and translocation of Cr in rice was significantly affected by the stress of exogenous Cr. At control treament, most of Cr was distributed in leafs, but the proportion of Cr in roots was significantly increased under the stress of exogenous Cr. At the same Cr application rate level, the distribution of Cr in II You-838 and Yixiangyou-10 followed the pattern: root &gt; leaf &gt; chaff &gt; stem &gt; grain, while it showed root &gt; leaf &gt; stem &gt; chaff &gt; grain in Jinfuyou-270. The distribution of Cr in different parts of rice was very uneven for three rice cultivars. With increasing Cr treatment levels, the proportion of Cr in roots was increasing, while a decrease was observed in aerial parts, and their bioconcentration factors (BCF) and translocation factors (TF) of Cr also declined. The transport ability of Cr from root to leaf was stronger, but weak ability in translocating Cr from root to stem, chaff and grain. There were different in Cr accumulation and distribution in organs of 3 rice cultivars. The falling sequence of accumulation and translocation ability of Cr in rice was Jinfuyou-270 &gt; Yixiangyou-10 &gt; II You-838. The Cr concentration in the grain of Jinfuyou-270 was 0.70~0.92 mg•kg-1, which was quite close to the national food heavy metal limits hygienic standard.

Effects of Exogenous ALA on Leaf Photosynthesis, Photosynthate Transport, and Sugar Accumulation in Prunus persica L.

Peaches/nectarines (Prunus persica L.) are widely cultivated worldwide. As with other species, the sugar content is the most important trait for fruit quality, especially for precocious cultivars. Most fruits need to improve their sugar content in order to be more profitable under fierce market competition. 5-Aminolevulinic acid (ALA), a naturally occurring δ-amino acid, has been shown to improve leaf photosynthesis and fruit quality, especially sugar content. However, the mechanisms are not clear. The objective of this study is to determine the effects of exogenous ALA on leaf photosynthesis, assimilate transport, and sugar accumulation during fruit development. We used the field-cultivated precocious nectarine ‘Zhongyoutao 4’ and potted cultivated peach ‘Zhongai 33’ as materials, whereas in the second experiment, we used 14C radiolabeling to trace 14C fixation in leaves, transport in branches, and distribution in different organs. The results showed that ALA significantly enhanced the photosynthetic gas exchange capacity, and the effects were maintained for at least one month. The results of the 14C radiolabel experiment showed that ALA enhanced 14C fixation in leaves, promoted the transport to fruits, and reduced the allocation rate of young leaves. This suggests that ALA enlarges “source” volume and strengthens “sink” competition; therefore, assimilate translocation to fruits is promoted. It was observed that sucrose contributed the main saccharide for peach fruit quality at maturity, which might not be converted from glucose or fructose but from starch degradation. ALA improved starch accumulation in the young fruits as well as degradation during maturity. The RT-qPCR showed that the expression of most genes involved in sugar metabolism did not correlate or even negatively correlate with fruit sucrose content. However, the expressions of SWEET1/6/7/8/15/16/17 were highly correlated with the sucrose content, and exogenous ALA treatment up-regulated the gene expression at fruit maturity, suggesting they might play an important role in fruit sugar accumulation. These results provide important theoretical support for ALA application in fruit quality improvement, as well as a regulatory mechanism study on sugar accumulation in fruits.

Widely targeted metabolomic deciphers the vertical spatial distribution of flavor substances in Houttuynia cordata Thunb

The volatile components in Houttuynia cordata Thunb. have a distinctive odor, which is the source of their unique flavor as food. Although volatile compounds are widely present in Houttuynia cordata Thunb., little is known about their accumulation in vertical distribution in different organs. In this study, gas chromatography-mass spectrometry (GC-MS) and chemometrics were used to determine volatile substance’s types and relative contents, especially 2-undecanone in different parts of Houttuynia cordata Thunb. The results showed that 933 species and 16 classes of volatile compounds were identified in the leaves, aerial stems, subterranean stems, and roots. Among them, the accumulation of 2-undecanone, d-limonene, and α-pinene were significantly higher in subterranean stems than in other organs. The related KEGG pathway-limonene and pinene degradation, was identified. The study's results can provide a reference for the industrial extraction and utilization of volatile compounds from different parts of Houttuynia cordata Thunb.

The bianchetto truffle (Tuber borchii) a lead-resistant ectomycorrhizal fungus increases Quercus cerris phytoremediation potential.

Tuber borchii is a European edible truffle which forms ectomycorrhizas with several soft- and hardwood plants. In this article, the effects of high level of Pb on the in vitro growth of five T. borchii strains and the molecular mechanisms involved in Pb tolerance were studied. Moreover, the effects of the Pb treatment on T. borchii ectomycorrhizas and on the growth, element uptake and distribution in different organs of Quercus cerris seedlings were investigated. The results showed an extraordinary tolerance of T. borchii mycelium to Pb: all the tested strains were able to grow at Pb concentration over 4000 mg L-1 . The mechanisms of tolerance seem related to Pb sequestration in the vacuole and its immobilization as crystal of Pb oxalate outside the hyphae rather than detoxification processes, considering the low expression of glutaredoxin and thioredoxin genes. T. borchii-Q. cerris mycorrhizas tolerate a soil concentration of Pb from 1869 to 4030 mg kg-1 although, at these Pb concentrations, T. borchii showed a reduced ability to colonize roots. T. borchii mycorrhization increased the uptake of Pb by Q. cerris. Mycorrhization and Pb treatment also significantly influenced the uptake and translocation in the plant of other elements.

Spatial metabolomics shows contrasting phosphonolipid distributions in tissues of marine bivalves

Lipids are an integral part of cellular membranes that allow cells to alter stiffness, permeability, and curvature. Among the diversity of lipids, phosphonolipids uniquely contain a phosphonate bond between carbon and phosphorous. Despite this distinctive biochemical characteristic, few studies have explored the biological role of phosphonolipids, although a protective function has been inferred based on chemical and biological stability. We analyzed two species of marine mollusks, the blue mussel Mytilus edulis and pacific oyster Crassostrea gigas, and determined the diversity of phosphonolipids and their distribution in different organs. High-resolution spatial metabolomics revealed that the lipidome varies significantly between tissues within one organ. Despite their chemical similarity, we observed a high heterogeneity of phosphonolipid distributions that originated from minor structural differences. Some phosphonolipids are ubiquitously distributed, while others are present almost exclusively in the layer of ciliated epithelial cells. This distinct localization of certain phosphonolipids in tissues exposed to the environment could support the hypothesis of a protective function in mollusks. This study highlights that the tissue specific distribution of an individual metabolite can be a valuable tool for inferring its function and guiding functional analyses.

Technical note: A wearable radiation measurement system for collection of patient-specific time-activity data in radiopharmaceutical therapy: system design and Monte Carlo simulation results.

Purpose: A high level of personalization in Molecular Radiotherapy (MRT) could bring advantages in terms of treatment effectiveness and toxicity reduction. Individual organ‐level dosimetry is crucial to describe the radiopharmaceutical biodistribution expressed by the patient, to estimate absorbed doses to normal organs and target tissue(s). This paper presents a proof‐of‐concept Monte Carlo simulation study of “WIDMApp” (Wearable Individual Dose Monitoring Apparatus), a multi‐channel radiation detector and data processing system for in vivo patient measurement and collection of radiopharmaceutical biokinetic data (i.e., time‐activity data). Potentially, such a system can increase the amount of such data that can be collected while reducing the need to derive it via nuclear medicine imaging. Methods: a male anthropomorphic MIRD phantom was used to simulate photons (i.e., gamma‐rays) propagation in a patient undergoing a 131I thyroid treatment. The administered activity was set to the amount usually administered for the treatment of differentiated carcinoma while its initial distribution in different organs was assigned following the ICRP indications for the 131I biokinetics. Using this information, the simulation computes the Time‐dependent Counts Curves (TCCs) that would have been measured by seven WIDMApp‐like sensors placed and oriented to face each one of five emitting organs plus two thyroid lobes. A deconvolution algorithm was then applied on this simulated data set to reconstruct the Time‐Activity Curve (TAC) of each organ. Deviations of the reconstructed TACs parameters from values used to generate them were studied as a function of the deconvolution algorithm initialization parameters and assuming non‐Poisson fluctuation of the TCCs data points. Results: This study demonstrates that it is possible, at least in the simple simulated scenario, to reconstruct the organ cumulated activity by measuring the time dependence of counts recorded by several detectors placed at selected positions on the patient's body. The ability to perform in vivo sampling more frequently than conventional biokinetic studies increases the number of time points and therefore the accuracy in TAC estimates. In this study, an accuracy on cumulated activity of 5% is obtained even with a 20% error on the TCC data points and a 50% error on the initial guess on the parameters of the deconvolution algorithm. Conclusions: the WIDMApp approach could provide an effective tool to characterize more accurately the radiopharmaceutical biokinetics in MRT patients, reducing the need of resources of nuclear medicine departments, such as technologist and scanner time, to perform individualized biokinetics studies. The relatively simple hardware for the approach proposed would allow its application to large numbers of patients. The results obtained justify development of an actual prototype system to characterize this technique under realistic conditions.

Magnesium absorption, translocation, subcellular distribution and chemical forms in citrus seedlings.

Magnesium (Mg) is an essential macronutrient for plant growth and development; however, the adaptive mechanisms of Mg deficiency to underlying changes in Mg translocation, subcellular distribution and chemical forms in citrus plants are unknown. In this study, we conducted a sand culture experiment with 0 (Mg-deficiency) or 2 (Mg-sufficiency) mmoll-1Mg2+ treatments to investigate the responses underlying Mg adaptability, as well as the resulting growth and Mg transport features in citrus seedlings [Citrus sinensis (L.) Osbeck cv. 'Xuegan']. We found that Mg-deficiency significantly depressed biomass by 39% in the whole plant and by 66% in branch organs compared with Mg-sufficient conditions, which further resulted in a subsequent decrease in Mg concentration and accumulation with changes in its distribution in different organs and a reduction in root growth. Under Mg-sufficiency, >50% of Mg was sequestered in the soluble fraction and this was reduced by 30% under Mg-deficiency. Furthermore, >70% of Mg existed as inorganic (42%) and water-soluble (31%) forms with high mobility across treatments and organs. Under Mg-deficiency, the proportion of water-soluble Mg was reduced in leaf and increased in root, whereas the proportion of inorganic Mg increased in main stem leaves and decreased in branch leaves and root. However, under Mg-deficiency, the proportion of Mg forms with low mobility, including pectates and proteins, phosphates, oxalates and residues, was increased in leaf and root organs, with the exception of pectate and protein Mg, which was decreased in root. The Mg transfer factor showed that Mg-deficiency improved Mg transport from parent to branch organs, which was related to Mg subcellular distribution and chemical forms. Taken together, our study establishes a defined process to clarify the mechanisms of Mg absorption and translocation and reveals a possible strategy to effectively improve Mg mobility and availability in citrus plants.

The impact of environmental and occupational exposures of manganese on pulmonary, hepatic, and renal functions.

Manganese (Mn) is an essential trace element for humans, but long-term environmental or occupational exposures can lead to numerous health problems. Although many studies have identified an association between Mn exposures and neurological abnormalities, emerging data suggest that occupationally and environmentally relevant levels of Mn may also be linked to multiple organ dysfunction in the general population. In this regard, many experimental and clinical studies provide support for a causal link between Mn exposure and structural and functional changes that are responsible for organ dysfunction in major organs like lung, liver, and kidney. The underlying mechanisms suggested to Mn toxicity include altered activities of the components of intracellular signaling cascades, oxidative stress, apoptosis, affected cell cycle regulation, autophagy, angiogenesis, and an inflammatory response. We further discussed the sources and possible mechanisms of Mn absorption and distribution in different organs. Finally, treatment strategies available for treating Mn toxicity as well as directions for future studies were discussed.

One-pot synthesis of Eu-MOFs for bioimaging and drug delivery

Objective The use of metal-organic framework (MOF) platforms has been a topic of growing interest in the fields of drug delivery and bioimaging. This study was designed to develop and evaluate a novel MOF-based drug and radiation delivery nanosystem. Methods Eu-MOFs were characterized in vitro via X-ray diffraction, scanning electronic microscopy, and FT-IR spectrometry. Nanocarrier uptake and associated cell viability were assessed using a CCK-8 assay and using a high content screening system. Biodistribution studies were conducted with a Luminal II IVIS imaging system to assess nanocarrier distribution in different organs. As such, paclitaxel was selected as a model drug in the present study to evaluate Eu-MOF drug loading and release characteristics in vitro via HPLC. Results A straightforward one-step approach was used to successfully fabricate sea urchin-shaped Eu-MOFs that were self-assembled from Eu3+ and 1,3,5-pyromellitic acid. These MOFs exhibited robust red fluorescence owing to the antenna effect. Owing to their fluorescent properties, these Eu-MOFs were able to facilitate in vivo imaging with a high quantum yield and low background signal. Importantly, our Eu-MOFs exhibited good biocompatibility, low cytotoxicity, and high imaging efficiency. As they exhibited slow-release kinetics and targeted biodistribution profiles, these Eu-MOFs additionally hold great promise as potential anti-cancer agents in clinical settings. Conclusion Herein, we designed a novel Eu-MOF active targeted drug delivery nanocarrier platform and found that it represents a promising therapeutic tool for cancer treatment.

Effects of drought stress on the stoichiometric characteristics in different organs of three shrub species

In order to explore how water stress affects the stoichiometric characteristics in leaves, stems, very fine roots (0-1 mm), fine roots (1-2 mm) and thick roots (>2 mm) of three shrub species, we studied the effects of three water treatments [(75±5)%, (55±5)% and (35±5)% of field water capacity (FC)] on the stoichiometric characteristics of different organs of Syringa oblata, Rosa xanthina and Forsythia suspensa in a pot experiment. The results showed that there were significant differences in nitrogen (N) and phosphorus (P) contents, C:N, C:P and N:P of the same organ among the three species. With the intensification of drought stress, there was no significant change of C content in all organs of the three species. The N content increased in leaves, but decreased gradually in stems. The N content in very fine roots and fine roots increased first and then decreased. The P content decreased in leaves and stems, while increased first and then decreased in very fine roots and fine roots. Under drought stress, leaf C:N decreased, C:P and N:P of leaf and stem increased. There was the strongest effect of drought stress on the C:N of very fine roots and C:P and N:P of leaves. There was the least effect of drought stress on C:N, N:P of thick roots and C:P of very fine roots. There was no significant correlation between the contents of C, N in soil and the contents of C, N and P in shrub organs, but soil P content was significantly correlated with the contents of C, N and P in leaves and roots. It was concluded that the relative P limitation in soil was the most important factor affecting the stoichiometric characteristics of shrub organs. Drought had different effects on the stoichiometry of different organs in different shrub species. The stoichio-metry of leaves and very fine roots was more sensitive to drought stress than that of other organs. Drought might affect the stoichiometric characteristics especially related to P in different organs of shrubs, mainly by affecting plant absorption of soil P and its distribution in different organs.

Distinct Proteins in Protein Corona of Nanoparticles Represent a Promising Venue for Endogenous Targeting - Part II: In vitro and in vivo Kinetics Study.

IntroductionNanoparticles (NPs), upon introduction to the biological systems, become wrapped by serum and cellular proteins constituting the protein corona (PC). This PC contributes largely to the NPs’ interaction with the biological systems and their subsequent functions. On the one hand, PC can decrease the efficiency of targeting by directing the NPs to the reticuloendothelial system (RES) or by masking the active targeting moieties and decreasing their ability to bind to their target receptors. On the other hand, some components of PC have offered hopes for achieving endogenous targeting.MethodsIn this study, we aimed at the investigation of the role of the PC in determining the behavior of cRGDyk peptide-unconjugated and -conjugated NPs (uNPs and cNPs) exhibiting different physicochemical properties and their interaction with melanoma on in vitro and in vivo levels. Mathematical modeling has been utilized to understand the kinetics of the interaction of NPs with the tumor cells and different organs, respectively.ResultsEndocytosis and exocytosis were reported to occur simultaneously for the utilized NPs. The balance was largely dependent on the NPs’ physicochemical properties and the role of the PC. In addition, distinct proteins present in the PC (illustrated in the results of the PC analysis in part I) have also determined the patterns of the NPs’ distribution in different organs and tissues of the vascular system, the RES system and the target tumot tissue. Vitronectin (VN) was found to mediate higher accumulation in integrin receptor-expressing melanoma cells, while complement 3 protein (C3) and clusterin (CLU), as an opsonin and dysopsonin, respectively, regulated the balance between the RES uptake and blood circulation.DiscussionPC, if properly modulated by tuning NPs’ physicochemical properties, can serve as a potential venue for optimum utilization of NPs in cancer therapy.

Planting models and mulching material strategies to reduce bundle sheath cell leakage and improve photosynthetic capacity and maize production in semi-arid climate.

Better understanding of soil water storage and photosynthetic regulation of maize production will be useful to develop a water-saving strategy in rain-fed conditions. Therefore, maize crop was grown under the different cultivation practices for analyzed light and CO2-response curves under various mulching strategies during 2017-2018years. Six different treatments were used such as the following: PP, ridges and furrows zone covered with plastic film mulching; PS, ridges covered with plastic film and furrows zone with stalk mulching; PN, ridges covered with plastic film and furrows zone without mulching; TP, conventional flat planting with plastic film mulching; TS, conventional flat planting with stalk mulching; and TN, conventional flat planting without mulching. The PP treatment had considerable effects on rainwater collection, improved SWS, and maize productivity than that of TP treatment. Significantly increase of SWS was observed under the PP treatment as a result photosynthetic capacity (An) improved under light and CO2-response curves, apparent quantum efficiency (α), respiration rate, total chlorophyll ab content, and 13C-photosynthates distribution in different organs. Under the PP and TP treatments, the maize might keep a great photosynthetic capacity at the post-flowering stage through improving An, LAI, soluble protein, Rubisco contents, and grain yield. The CO2 and light-response curves were significantly enhanced at the PP treatment due to higher 13C carbon isotope (Δ‰) and Ci/Ca as a result lower bundle sheath to leakiness of CO2 (ɸ) compared with the rest of all treatments. The results suggested that PP cultivation practice was the best water-saving strategy because it reduced bundle sheath leakiness to CO2 (ɸ); as a result there's a significant improvement in soil water storage, LAI, 13C-photosynthates distribution, photosynthetic capacity parameters, and maize production.

Spatiotemporal Distribution of Agrin after Intrathecal Injection and Its Protective Role in Cerebral Ischemia/Reperfusion Injury.

Intrathecal injection, drugs transporting along perivascular spaces, represents an important route for maintaining blood–brain barrier (BBB) integrity after cerebral ischemia/reperfusion (I/R) injury. However, after being directly injected into cerebrospinal fluid (CSF), the temporal and spatial changes in the distribution of therapeutic protein drugs have remained unknown. Here, with positron emission tomography (PET) imaging, the uptake of 89Zr‐agrin is noninvasively and dynamically monitored. These data demonstrate the time–activity curve of drugs in the brain subregions and their spatial distribution in different organs after intrathecal administration. Furthermore, agrin treatment effectively inhibits BBB disruption by reducing the loss of tight‐junctional proteins. Importantly, the infarct volume is reduced; the number of apoptotic neurons is decreased; and neurological function is improved in mouse I/R injury models. Thus, intrathecal injection of agrin provides the basis for a new strategy to research and develop protein drugs for reducing the aggravation of I/R injury.