Two-dimensional MOF-based materials:Preparations and applications as electrodes in Li-ion batteries

Two-dimensional(2D)metal-organic frameworks(MOFs)are rapidly emerging as a unique class of mushrooming family of 2D materials offering distinctive features,such as hierarchical porosity,extensive surface area,easily available active sites,and versatile,adaptable structures.These promising characteristics have positioned them as highly appealing alternatives for a wide range of applications in energy storage technologies,including lithium batteries.Nevertheless,the poor conductivity and limited stability of 2D MOFs have limited their real applications in electrochemical energy storage.These limitations have therefore warranted ongoing research to enhance the performance of 2D MOFs.Given the significance of 2D MOF-based materials as an emerging class of advanced materials,a multitude of strategy has been devised to address these challenges such as synthesizing 2D conductive MOFs and derivatives along with 2D MOF hybridization.One promising approach involves the use of 2D MOF derivatives,including transition metal oxides,which due to their abundant unsatu rated active metal sites and shorter diffusion paths,offer superior electrochemical performance.Additionally,by combining pristine 2D MOFs with other materials,hybrid 2D MOF materials can be created.These hybrids,with their enhanced stability and conductivity,can be directly utilized as active materials in lithium batteries.In the present review,we categorize 2D MOF-based materials into three distinct groups:pristine 2D MOFs,2D MOFderived materials,and 2D MOF hybrid materials.The synthesis methods for each group,along with their specific applications as electrode materials in lithium-ion batteries,are discussed in detail.This comprehensive review provides insights into the potential of 2D MOFs while highlighting the opportunities and challenges that are present in this evolving field.

Floristic composition and edaphic relationships in ferruginous campo rupestre reference ecosystems

Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the planet.Some environments with high economic relevance,such as the ferruginous campo rupestre(rupestrian grassland known as Canga in Brazil),are even more susceptible to severe impacts due to their extreme habitat conditions and low resilience.The determination of reference ecosystems based on the intrinsic characteristics of the ecosystem is essential for conservation as well as to the implementation of ecological restoration.We proposed the reference ecosystem of the three main types of habitats of the ferruginous campo rupestre based on their floristic composition.We described the floristic composition of each habitat and evaluated the physicochemical properties of the soils and the relationship between plants and soils.All three habitats showed high diversity of plant species and many endemic species,such as Chamaecrista choriophylla,Cuphea pseudovaccinium,Lychnophora pinaster,and Vellozia subalata.The distribution of vegetation was strongly related with the edaphic characteristics,with a set of species more adapted to high concentration of base saturation,fine sand,organic carbon,and iron,while another set of species succeeded in more acidic soils with higher S and silt concentration.We provide support for the contention that the ferruginous campo rupestre is a mosaic of different habitats shaped by intrinsic local conditions.Failure to recognize the floristic composition of each particular habitat can lead to inappropriate restoration,increased habitat homogenization and increased loss of biodiversity and ecosystem services.This study also advances the knowledge base for building the reference ecosystem for the different types of ferruginous campo rupestre habitats,as well as a key database for highlighting those species contribute most to community assembly in this diverse and threatened tropical mountain ecosystem.

No generality in biodiversity-productivity relationships along elevation in temperate and subtropical forest landscapes

An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.

Relationship of Trace Elements Concentration and Growth Rate in Alsidium triquetrum (Rhodophyta)

Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesium, and especially iron, seems to be common in Chlorophyta;while Rhodophyta and Heterokontophyta show higher affinity to manganese. The red agarophyte Alsidium triquetrum was used to analyze the relationship between metal concentration, environmental conditions and growth rate. Specimens grown in situ showed a large variability of Fe, Mn, Mg, and Al, in thallus tissue concentrations. Further, a compelling relationship between the growth rate and the thallus concentration of Mg and Mn, Zn, and Al was detecte. Manganese, unlike the other trace elements analyzed showed a positive linear relationship between growth rate and tissue content during the period of greatest vegetative growth.

Post-operative imaging in liver transplantation: State-of-the-art and future perspectives

Orthotopic liver transplantation(OLT)represents a major treatment for end-stage chronic liver disease,as well as selected cases of hepatocellular carcinoma and acute liver failure.The ever-increasing development of imaging modalities significantly contributed,over the last decades,to the management of recipients both in the pre-operative and post-operative period,thus impacting on graft and patients survival.When properly used,imaging modalities such as ultrasound,multidetector computed tomography,magnetic resonance imaging(MRI)and procedures of direct cholangiography are capable to provide rapid and reliable recognition and treatment of vascular and biliary complications occurring after OLT.Less defined is the role for imaging in assessing primary graft dysfunction(including rejection)or chronic allograft disease after OLT,e.g.,hepatitis C virus(HCV)recurrence.This paper:(1)describes specific characteristic of the above imaging modalities and the rationale for their use in clinical practice;(2)illustrates main imaging findings related to post-OLTcomplications in adult patients;and(3)reviews future perspectives emerging in the surveillance of recipients with HCV recurrence,with special emphasis on MRI.

Relationship between angiotensin-(1-7) and angiotensin Ⅱ correlates with hemodynamic changes in human liver cirrhosis

AIM： To measure circulating angiotensins at different stages of human cirrhosis and to further evaluate a possible relationship between renin angiotensin system （RAS） components and hemodynamic changes. METHODS： Patients were allocated into 4 groups： mild-to-moderate liver disease （MLD）, advanced liver disease （ALD）, patients undergoing liver transplantation, and healthy controls. Blood was collected to determine plasma renin activity （PRA）, angiotensin （Ang） Ⅰ, Ang Ⅱ, and Ang-（1-7） levels using radioimmunoassays. During liver transplantation, hemodynamic parameters were determined and blood was simultaneously obtained from the portal vein and radial artery in order to measure RAS components. RESULTS： PRA and angiotensins were elevated in ALD when compared to MLD and controls （P 〈 0.05）. In contrast, Ang Ⅱ was significantly reduced in MLD. Ang-（1-7）/Ang Ⅱ ratios were increased in MLD when compared to controls and ALD. During transplantation, Ang Ⅱ levels were lower and Ang-（1-7）/Ang Ⅱ ratios were higher in the splanchnic circulation than in the peripheral circulation （0.52 ± 0.08 vs 0.38 ±0.04, P 〈 0.02）, whereas the peripheral circulating Ang Ⅱ/Ang Ⅰ ratio was elevated in comparison to splanchnic levels （0.18 ±0.02 vs 0.13 ±0.02, P 〈 0.04）. Ang-（1-7）/ Ang Ⅱ ratios positively correlated with cardiac output （r = 0.66） and negatively correlated with systemic vascular resistance （r = -0.70）. CONCLUSION： Our findings suggest that the relationship between Ang-（1-7） and Ang Ⅱ may play a role in the hemodynamic changes of human cirrhosis.

Perspectives on new biomarkers in gastric cancer: Diagnostic and prognostic applications

Gastric cancer is considered one of the most deadly tumors worldwide. Even with the decline in its incidence, the mortality rate of this disease has remained high, mainly due to its late diagnosis and to the lack of precise prognostic markers. The main purpose of this review is to present genetic, epigenetic and proteomic molecular markers that may be used in a diagnostic and prognostic manner and to discuss the pros and cons of each type of marker for improving clinical practice. In this sense, we observed that the use of genetic markers, especially mutations and polymorphisms, should be carefully considered, as they are strongly affected by ethnicity. Proteomic-based markers show promise, but the higher costs of the associated techniques con-tinue to make this approach expensive for routine use. Alternatively, epigenetic markers appear to be very promising, as they can be detected in bodily fluids as well as tissues. However, such markers must be used carefully because epigenetic changes may occur due to environmental factors and aging. Despite the advances in technology and its access, to date, there are few defined biomarkers of prognostic and diagnostic use for gastric tumors. Therefore, the use of a panel of several approaches(genetic, epigenetic and proteomic) should be considered the best alternative for clinical practice.

Gene expression analysis of primary normal human hepatocytes infected with human hepatitis B virus

AIM： To find the relationship between hepatitis B virus （HBV） and hepatocytes during the initial state of infection by cDNA microarray. METHODS： Primary normal human hepatocytes （PNHHs） were isolated and infected with HBV. From the PNHHs, RNA was isolated and inverted into complement DNA （cDNA） with Cy3- or Cy5- labeled dUTP for microarray analysis. The labeled cDNA was hybridized with microarray chip, including 4224 cDNAs. From the image of the microarray, expression profiles were produced and some of them were confirmed by RT-PCR, immunoblot analysis, and NF-κB luciferase reporter assay. RESULTS： From the cDNA microarray, we obtained 98 differentially regulated genes. Of the 98 genes, 53 were up regulated and 45 down regulated. Interestingly, in the up regulated genes, we found the TNF signaling pathway-related genes： LT-α, TRAF2, and NIK. By using RT-PCR, we confirmed the up-regulation of these genes in HepG2, HuhT, and Chang liver cells, which were transfected with pHBV1.2x, a plasmid encoding all HBV messages. Moreover, these three genes participated in HBV- mediated NF-κB activation. CONCLUSION： During the initial state of HBV infection, hepatocytes facilitate the activation of NF-κB through up regulation of LT-α, TRAF2, and NIK.

Presence of c.3956del C mutation in familial adenomatous polyposis patients from Brazil

AIM: To characterize APC gene mutations and correlate them with patient phenotypes in individuals diagnosed with familial adenomatous polyposis(FAP) in northern Brazil. METHODS: A total of 15 individuals diagnosed with FAP from 5 different families from the north of Brazil were analyzed in this study. In addition to patients with histopathological diagnosis of FAP,family members who had not developed the disease were also tested in order to identify mutations and for possible genetic counseling. All analyzed patients or their guardians signed a consent form approved by the Research Ethics Committee of the Jo?o de Barros Barreto University Hospital(Belem,Brazil). DNA extracted from the peripheral blood of a member of each of the affected families was subjected to direct sequencing. The proband of each family was sequenced to identify germline mutations using the Ion Torrent platform. To validate the detected mutations,Sanger sequencing was also performed. The samples from all patients were also tested for the identification of mutations by real-time quantitative polymerase chain reaction using the amplification refractory mutation system. RESULTS: Through interviews with relatives and a search of medical records,it was possible to construct genograms for three of the five families included in the study. All 15 patients from the five families with FAP exhibited mutations in the APC gene,and all mutations were detected in exon 15 of the APC gene. In addition to the patients with a histological diagnosis of FAP,family members without disease symptoms showed the mutation in the APC gene. In the present study,we detected two of the three most frequent germline mutations in the literature: the mutation at codon 1309 and the mutation at codon 1061. The presence of c.3956 del C mutation was found in all families from this study,and suggests that this mutation was introduced in the population of the State of Pará through ancestor immigration(i.e.,a de novo mutation that arose in one member belonging to this state from Brazil). CONCLUSION: Regardless of its origin,the c.3956 del C mutation is a strong candidate biomarker of this hereditary cancer syndrome in families of northern Brazil.

Influence of Surgical Technique on Overall Survival, Disease Free Interval and New Lesion Development Interval in Dogs with Mammary Tumors

The best surgical technique for the treatment of mammary tumors in female dogs has been exhaustively debated among the scientific community. Despite biological knowledge of these tumors, some authors have suggested aggressive procedures, without any clinical advantage. The aim of this study was to evaluate the influence of surgical procedure on the overall survival, disease-free interval and new lesion development interval in dogs with mammary tumors treated according to established prognostic factors. This prospective study included 143 intact female dogs that underwent surgery for mammary neoplasms and were followed up for about 738.5 days. Each animal represented a repetition. Each surgical technique represented a group: lumpectomy (P1), mammectomy (P2), regional mastectomy without cranial abdominal gland involvement (P3), regional mastectomy with cranial abdominal gland involvement (P4), and radical mastectomy (P5). Considering only the first surgical event, 84.6% of animals had more than one mammary tumor, and tumors were identified in two mammary chains in 52.5%. There was no difference in ipsilateral and contralateral tumor development when surgical techniques were compared. Only 33 dogs developed new lesions in remaining mammary tissue, without correlation with primary lesion. Surgical technique had no effect on the overall survival, disease-free interval and new lesion development interval in patients on this study, which respected oncological surgery principles and established prognostic factors for mammary gland tumors in dogs.

Proof of concept study to identify candidate biomarkers of fibrosis using high throughput peptide aptamer microarray and validate by enzyme linked immunosorbant assay

Background: Nine proteins were identified as putative profibrotic biomarkers in systemic sclerosis (SSc) and an unrelated fibrotic disease in a previously published proteomic study. As the majority of these proteins were orphans of commercially available antibodies, the nine proteins were investigated to determine whether binding peptide aptamers of the Stefin A quadruple mutant-Tracy variant (referred to as “affimers”) could be validated by enzyme linked immunosorbant assay (ELISA) to allow the quantification of these candidate biomarkers in the sera of SSc patients. Materials and Methods: Candidate biomarker peptides were analysed by high throughput affimer microarray to identify binding affimers. Two candidate biomarkers were prioritised, and binding affimers were expressed from genetically modified BL21 competent E. coli strains and purified. These affimers were used in indirect ELISA, and then sandwich ELISA formats against the candidate biomarker recombinant proteins osteonectin and pigment epi-thetlium-derived factor (PEDF). Results: 39 affimers were identified as binders for eight of the nine candidate biomarker peptides were by affimer microarray;six for osteonectin and eleven for PEDF. Two of the six and all eleven were able to recognize physiological concentrations (5 and 1 μg·ml﹣1) of osteonectin and PEDF, respectively by indirect ELISA. In sandwich ELISA format: two affimers were able to detect recombinant PEDF;however, the two affimers identified in indirect ELISA were unable to recognise recombinant osteonectin, and were thus hypothesised to bind to osteonectin at the same binding site. Discussion: SSc is currently an orphan of fully validated biomarkers, which is required for the development of stratified medicine in this field. This approach has laid the groundwork for an affimer based on multiplexed assay, to validate biomarkers in the sera of SSc patients in the future.

Is there a window of opportunity for the therapeutic use of vitamin D in multiple sclerosis?

Multiple sclerosis is an autoimmune treatable but not curable disease.There are a multiplicity of medications for multiple sclerosis therapy,including a class entitled disease-modifying drugs that are mainly indicated to reduce the number and severity of disease relapses.Not all patients respond well to these therapies,and minor to severe adverse effects have been reported.Vitamin D,called sunshine vitamin,is being studied as a possible light at the end of the tunnel.In this review,we recapitulated the similar immunopathogenesis of multiple sclerosis and experimental autoimmune encephalomyelitis,the immunomodulatory and neuroprotective potential of vitamin D and the state-of-art concerning its supplementation to multiple sclerosis patients.Finally,based on our and other groups’experimental findings,we analyzed the need to consider the relevance of the route and the different time-point administration aspects for a more rational indication of this vitamin to multiple sclerosis patients.

Advances in cellular technology in the hematology field: What have we learned so far?

Despite the advances in the hematology field, blood transfusion-related iatrogenesis is still a major issue to be considered during such procedures due to blood antigenic incompatibility. This places pluripotent stem cells as a possible ally in the production of more suitable blood products. The present review article aims to provide a comprehensive summary of the state-of-theart concerning the differentiation of both embryonic stem cells and induced pluripotent stem cells to hematopoietic cell lines. Here, we review the most recently published protocols to achieve the production of blood cells for future application in hemotherapy, cancer therapy and basic research.

POSVP21, a major secretory androgen-dependent protein from sand rat seminal vesicles, identified as a transgelin

The seminal vesicles of adult sand rat contain a major secretory protein band （MW 21 kDa） designated as Psammomys obesus seminal vesicles protein of 21 kDa （POSVP21）. This protein is abundant in secretions, regulated by androgens and also present in the vaginal plug. POSVP21 accounts for over 22.3% of soluble proteins from homogenate during the breeding season, 13.3% during the middle season and 5.3% during the hormonal regression season. It is absent during the non-breeding season. POSVP21 is localized in the cytoplasm of epithelial cells and in secretory products in the lumen. It presents an immunological homology with two epididymal proteins with the same molecular weight and a high degree of homology with transgelin from rat （Rattus norvegicus）.

Diversity in global gene expression and morphology across a watercress (Nasturtium officinale R. Br.) germplasm collection: first steps to breeding

Watercress(Nasturtium officinale R.Br.)is a nutrient intense,leafy crop that is consumed raw or in soups across the globe,but for which,currently no genomic resources or breeding programme exists.Promising morphological,biochemical and functional genomic variation was identified for the first time in a newly established watercress germplasm collection,consisting of 48 watercress accessions sourced from contrasting global locations.Stem length,stem diameter and anti-oxidant(AO)potential varied across the accessions.This variation was used to identify three extreme contrasting accessions for further analysis.Variation in global gene expression was investigated using an Affymetrix Arabidopsis ATH1 microarray gene chip,using the commercial control(C),an accession selected for dwarf phenotype with a high AO potential(dwarfAO,called‘Boldrewood’)and one with high AO potential alone.A set of transcripts significantly differentially expressed between these three accessions,were identified,including transcripts involved in the regulation of growth and development and those involved in secondary metabolism.In particular,when differential gene expression was compared between C and dwarfAO,the dwarfAO was characterised by increased expression of genes encoding glucosinolates,which are known precursors of phenethyl isothiocyanate,linked to the anti-carcinogenic effects well-documented in watercress.This study provides the first analysis of natural variation across the watercress genome and has identified important underpinning information for future breeding for enhanced anti-carcinogenic properties and morphology traits in this nutrient-intense crop.

Biomass and Community Structure of Epilithic Biofilm on the Yellow and East Coasts of Korea

Spatial biomass variation and community structure of epilithic biofilms were examined using cell counts, chlorophyll a extraction, and remote-sensing techniques. Samples were collected at two levels of wave exposure along the Yellow and East Coasts of Korea in December 2010. Cyanobacteria were dominant, occupying about 88% of biofilm, irrespective of wave exposure levels. The cyanobacteria species, Aphanotece spp. was abundant in the Yellow Coast location and Lyngbya spp. was abundant in the East coast location. The representative diatoms were Navicula spp. and Achnanthes spp. on the rocky shores of all study sites. Average Normalized Difference Vegetation Index (NDVI) was significantly greater in the Yellow Coast (mean 0.46) than that in the East Coast (mean 0.21);a similar pattern was observed in Vegetation Index (VI). Chlorophyll a content was three times greater on the Yellow Coast (20.50 μg/cm2) than that on the East Coast (8.21 μg/cm2), and it was greater at the Gosapo and Bangpo shore sites than that at the Gyeokpo site, on the Yellow Coast. However, chlorophyll a contents were not different between 23.33 and 17.66 μg/cm2 at exposed- and sheltered-shores of Yellow Coast, and were 9.62 μg/cm2 and 6.80 μg/cm2 on the East Coast. Vegetation indices were positively correlated with chlorophyll a contents. In conclusion, biofilm of Korean upper rocky shore was mainly composed of cyanobacteria and biofilm biomass that differed between the Yellow and East Coast.

Value of predictive bioinformatics in inherited metabolic diseases

Typically,inherited metabolic diseases arise from point mutations in genes encoding metabolic enzymes. Although some of these mutations directly affect amino acid residues in the active sites of these enzymes,the majority do not. It is now well accepted that the majority of these disease-associated mutations exert their effects through alteration of protein stability,which causes a reduction in enzymatic activity. This finding suggests a way to predict the severity of newly discovered mutations. In silico prediction of the effects of amino acid sequence alterations on protein stability often correlates with disease severity. However,no stability prediction tool is perfect and,in general,better results are obtained if the predictions from a variety of tools are combined and then interpreted. In addition to predicted alterations to stability,the degree of conservation of a particular residue can also be a factor which needs to be taken into account: alterations to highly conserved residues are more likely to be associated with severe forms of the disease. The approach has been successfully applied in a variety of inherited metabolic diseases,but further improvements are necessary to enable robust translation into clinically useful tools.

Evaluating soil nutrients of Dacrydium pectinatum in China using machine learning techniques

Background: The accurate estimation of soil nutrient content is particularly important in view of its impact on plant growth and forest regeneration. In order to investigate soil nutrient content and quality for the natural regeneration of Dacrydium pectinatum communities in China, designing advanced and accurate estimation methods is necessary.Methods: This study uses machine learning techniques created a series of comprehensive and novel models from which to evaluate soil nutrient content. Soil nutrient evaluation methods were built by using six support vector machines and four artificial neural networks.Results: The generalized regression neural network model was the best artificial neural network evaluation model with the smallest root mean square error(5.1), mean error(-0.85), and mean square prediction error(29). The accuracy rate of the combined k-nearest neighbors(k-NN) local support vector machines model(i.e. k-nearest neighbors-support vector machine(KNNSVM)) for soil nutrient evaluation was high, comparing to the other five partial support vector machines models investigated. The area under curve value of generalized regression neural network(0.6572) was the highest, and the cross-validation result showed that the generalized regression neural network reached 92.5%.Conclusions: Both the KNNSVM and generalized regression neural network models can be effectively used to evaluate soil nutrient content and quality grades in conjunction with appropriate model variables. Developing a new feasible evaluation method to assess soil nutrient quality for Dacrydium pectinatum, results from this study can be used as a reference for the adaptive management of rare and endangered tree species. This study, however, found some uncertainties in data acquisition and model simulations, which will be investigated in upcoming studies.

Low genetic diversity in the endangered marine alga Silvetia siliquosa(Ochrophyta:Fucaceae)and the implication to conservation

Although signifi cant research eff orts have been targeted toward conservation and management of endangered terrestrial fl ora and fauna,attempts have been limited to conserve threatened seaweeds.Silvetia siliquosa is an ecologically and commercially vital brown alga that is uniquely distributed in the Yellow-Bohai Sea and along the southwest coast of Korea.A massive decline in its distribution range and biomass from the mid-1990s onward indicates that this species has become endangered.In the present study,we used nuclear internal transcribed spacer and concatenated mitochondrial cytochrome oxidase I subunit+intergenic spacer to estimate the genetic diversity,population connectivity,and degree of genetic diff erentiation of S.siliquosa in China and Korea.The molecular results exhibited strikingly low levels of haplotype/ribotype and nucleotide diversity in S.siliquosa populations,with only three mitochondrial haplotypes and nuclear ribotypes detected in 136 and 143 specimens,respectively.The analysis of molecular variance revealed 85%-95%of genetic variance among populations.Population diff erentiation coeffi cient(F_(ST))and gene fl ow(N_(m))suggested that two populations(JIN and GWA)along the southern coast of Korea are highly divergent from the others,with weak genetic exchange.No signifi cant genetic diff erentiation was observed among populations either in China or along the geographically proximate west coast of Korea.Thus,four independent management units were designated for sustainable management:the LII and RUS populations in China,the YEO and CHA populations along the west coast of Korea,and each of the GWA and JIN populations along the south coast of Korea.We suggest that artifi cial cultivation and transplantation of S.siliquosa are the eff ective approaches for restoration and conservation.

External versus Internal Loads of Nutrients of an Urban Eutrophic Tropical Reservoir （Southeastern Brazil）

This study aimed to evaluate the external and internal fluxes of nutrients of an urban eutrophic reservoir （lbirit6 reservoir, SE-Brazil）. External loads were estimated in the tributaries （Pintados and Ibirit6 creeks） through nutrient concentrations and discharge measurements. Using Fick＇s law, internal loads were estimated in the reservoir from fluxes across sediment-water interface from nutrient concentration gradients between the pore water and the water. The Ibirit6 creek （urban sewage recipient） contributes with 72%-47% of ammonium （NH4^＋） and 100%-8% of SRP （soluble reactive phosphorus） of the total quantity entering the reservoir, whereas the Pintados creek （oil refinery effluent recipient） contributions are 20%-19% and 44%-100%, respectively. Despite the high external loads （130 and 2.2 ton-yr^-1 of NH4＋ and SRP, respectively）, internal loads （average flux of 120 and 2 mg·cm^-2yr^-1, respectively） correspond to 25% of the total external loads which may sustain a high productivity in the reservoir for a long time even if the external loads are controlled. The stocks of ammonium and SRP of the interstitial water （100 cm of sediment） would be released to the water in six years and five months, respectively, The release time would be extremely larger （〉 3,000 years） considering the stocks of total N and bioavailable P.