Investigating Theoretical Frameworks: Comprehending the Relationship between σ, n, and µ in MnO2 Dispersed Films.

Solid polymer electrolytes (SPEs) made from a polymer-salt matrix show great potential for use in various applications, such as batteries, fuel cells, supercapacitors, solar cells, and electrochromic devices. Research on various theoretical and experimental aspects of these SPEs is highly pursued worldwide. However, due to the lack of direct experimental techniques for the measurement of the number of charge carriers (n) and their mobility (µ), reports on their correlation with conductivity (σ) and their exact theoretical justification are rare in literature studies. This paper is an attempt toward the search for the well-established theoretical formulation for n and µ that can justify the experimental results. In a previous attempt, it could only be demonstrated that the available theoretical bases show different values, but we could not come to any concrete conclusion. This research involves the use of three theoretical models, namely, the Rice and Roth model, the Trukhan model, and the Schutt and Gerdes model. The purpose of this study is to analyze the varying conductivity levels by calculating the concentration and mobility of charge carriers. To obtain the required parameters, impedance spectroscopy data were used. The Trukhan model was used to determine the precise value of the diffusion coefficient. By utilizing the dielectric tangent loss, the concentration of charge carriers and ion mobility were calculated. The Schutt and Gerdes (S&G) model was also used; this model is based on the dielectric constant and the relaxation frequency, which were derived from the EIS data. Finally, the Rice and Roth model was also employed, which is known for the ion transport in "super" ionic conductors. This was employed on the temperature-dependent impedance data for three different compositions of the films. A correlation is established between n and µ with σ using all three models. However, the Trukhan model is the most suitable for explaining the behavior of our system.

C-Reactive Protein Level can be a Better Indicator than Erythrocyte Sedimentation Rate in Assessing the Severity of Inflammation and Guiding Glucocorticoid Therapy in Subacute Thyroiditis.

Background: Despite the widespread use of several diagnostic tests in subacute thyroiditis (SAT), their usage remains largely subjective. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are useful indicators of inflammation in patients with SAT. The purpose of this study was to compare the scope for utilising CRP and ESR objectively in deciding the requirement of glucocorticoid therapy. Methods: A total of 28 patients with SAT were included in this study. Serum CRP and ESR were measured in all the patients. The characteristics of these tests were assessed firstly by using previously accepted positivity criterion for the particular diagnostic test. The area under the receiver operating characteristics (ROC) curve was obtained to provide an index of the overall discriminative ability of both tests. Results: Fifteen out of 28 patients were found to have features of significant thyroid inflammation eventually requiring glucocorticoid based on the current recommendations. The mean CRP value was significantly higher in patients requiring glucocorticoids. The ROC curves indicated that the optimal positivity criterion was 19.3 mg/L for the CRP level and 46 mm at the 1st hour for ESR. CRP with a sensitivity of 0.67, a specificity of 0.92, a positive likelihood ratio of 8.67, and an accuracy of 0.64 appeared better than ESR, which showed a sensitivity of 0.93, a specificity of 0.53, a positive likelihood ratio of 2.02, and an accuracy of 0.60. Conclusions: The serum CRP level provided a clear advantage over ESR in the assessment of the severity of inflammation before initiation of glucocorticoid therapy in SAT. However, a well-powered study is needed to examine the clinical relevance of such a role for CRP in thyroidology.

Real-time photovoltaic parameters assessment of carbon quantum dots showing strong blue emission.

The need for replacing conventional sources of energy with renewable ones has been on a swift rise since the last couple of decades. In this context, the progress in third-generation solar cells has taken a good leap in the last couple of years with increasing prospects of high efficiency, stability, and lifetime. Quite recently, a new form of carbon has been discovered accidentally in the form of carbon quantum dots (C QD), which is being pursued actively owing to its chemical stability and luminescent properties. In the current work, we report highly luminescent C QD prepared via a simple hydrothermal route. Transmission electron microscopy revealed an average particle size of 3.4 nm. The prepared C QD were used in a co-sensitized solar cell, where an improvement in the device characteristics was observed. The enhancement in the device characteristics is supported by impedance and electron life-time analysis. Further, the time-dependent analysis of the current and voltage revealed the functioning of the solar cell in real-time condition.

Fluorescence Quenching by Förster Resonance Energy Transfer in Carbon-Cadmium Sulfide Core-Shell Quantum Dots.

Carbon quantum dots (QDs) are an active subject of research in many areas of science and engineering for various applications. The present work reports the first occurrence of a carbon-cadmium sulfide core-shell QD prepared by an extremely simplified wet chemical approach where the CdS shell plays the role of a fluorescence quencher to the carbon core. The quenching effect was confirmed by fluorescence spectroscopy (steady-state and lifetime). These QDs stand as a potential candidate for sensing and imaging applications.

Effect of cell microenvironment on the drug sensitivity of hepatocellular cancer cells.

The native hepatocellular cancer (HCC) microenvironment is characterized by more hypoxic, hypoglycemic, and acidic conditions than those used in standard cell culture. This study aimed to investigate whether HCC cells cultured in more native conditions have an altered phenotype and drug sensitivity compared to those cultured in standard conditions. Six HCC cell lines were cultured in "standard" (21% O2, 25 mM glucose) or more "native" (1% O2, 5 mM glucose, 10 mM lactate) conditions. Cells were assessed for growth rates, cell cycle distribution, relevant metabolite and protein levels, genome-wide gene expression, mitochondrial DNA sequence and sensitivity to relevant drugs. Many differences in cellular and molecular phenotypes and drug sensitivity were observed between the cells. HCC cells cultured in native conditions had slower doubling times, increased HK2 and GLUT, lower PHDA and ATP levels, and mutations in mitochondrial DNA. Thirty-one genes, including the hypoxia-associated NDRG1, were differentially expressed between the cells. HCC patients in The Cancer Genome Atlas (TCGA) with tumors with a high score based on these 31 genes had a poorer prognosis than those with a low score (p = 0.002). From 90 comparisons of drug sensitivity, increased resistance and sensitivity for cells cultured in native conditions was observed in 14 (16%) and 8 (9%) comparisons respectively. In conclusion, cells cultured in more native conditions can have a more glycolytic and aggressive phenotype and varied drug sensitivity to those cultured in standard conditions, and may provide new insights to understanding tumor biology and drug development.

An Ultra-Simple Method for Synthesis of Violet CdS Quantum Dots at Sub-Room Temperature.

The emergence of fluorescence quantum dots (QDs) has led to the development of variety of applications in science and technology. Owing to the diverse optical and electrical properties of CdS QDs we have synthesized the same using wet chemical method. The QDs have been prepared at sub-room temperature using a new solvent comprising a mixture of water and methanol. The QDs when seen under UV light radiate violet color. The band-gap of the QDs deduced from the absorption spectra was 3.08 eV while PL spectra of the QDs suggested possibility of multiple exciton generation with a close to narrow size distribution. XRD analysis confirmed cubic structure of the particles. The obtained results suggest that these QDs can play ideal role in quantum dot sensitized solar cells (QDSSC) or in light emitting diodes (LEDs).

Biogenic synthesis and thermo-magnetic study of highly porous carbon nanotubes.

Nanomaterials synthesis using natural sources is the technology to up come with advanced materials through extracts of plant, microorganisms, poultry waste etc. In this study, the authors report the synthesis of porous carbon nanotubes using high-temperature decomposition technique facilitated by cobalt salt using chicken fats, a poultry waste as a precursor. Since chicken fats contain fatty acids which can decompose into short hydrocarbon chains and cobalt can act as the catalyst. The formation of carbon nanotubes was confirmed by Raman spectra, peaks at 1580 and 1350.46 cm-1 confirmed the graphite mode G-band and structural imperfections defect mode D-band, respectively. Transmission electron microscopy showed the formation of tube-like structures. Nitrogen adsorption-desorption studies showed the high-surface area of 418.1 m2g-1 with an estimated pore diameter of 8.1 nm. Thermogravimetry analysis-derivative thermogravimetric analysis-differential thermal analysis showed the instant weight loss at 517°C attributed to the rapid combustion of nanotubes. A vibrating-sample magnetometer showed the paramagnetic nature of the so-formed carbon nanotubes formed.

Water quality assessment of the ecologically stressed Hooghly River Estuary, India: A multivariate approach.

Spatio-temporal and seasonal variation of the water quality characteristics of the Hooghly River Estuary, India were studied considering eight stations of diverse eco-hydrological characteristics. Wide variations in turbidity, total dissolved solids and fecal coliform exceeded the permissible BIS drinking water level limit. The estuary is observed to be relatively low-oxygenated, mesotropic and phosphate limiting. Spatial heterogeneity and impact of the southwest monsoon were remarkably pronounced in the distribution of the inorganic nutrients revealing the following values (expressed in µgatml-1): nitrate+nitrite (2.42-37.19), phosphate (0.41-1.52) and silicate (38.5-187.75). Water Quality Index (WQI) values confirmed the prevailing 'bad' condition, detrimental for sustenance of aquatic biota. Results of Principal Component Analysis identified the major factors liable for water quality deterioration while cluster analysis categorized the stations on the basis of similar water quality status. The authors recommend adopting preventive measures for water quality improvement linked to biodiversity conservation.

Acquired resistance to PI3K/mTOR inhibition is associated with mitochondrial DNA mutation and glycolysis.

Acquired resistance (AQR) to drug treatment occurs frequently in cancer patients and remains an impediment to successful therapy. The aim of this study was to gain insight into how AQR arises following the application of PI3K/mTOR inhibitors. H1975 lung cancer cells with EGFR T790M mutations that confer resistance to EGFR inhibitors underwent prolonged treatment with the PI3K/mTOR inhibitor, BEZ235. Monoclonal cells with stable and increased resistance to BEZ235 were obtained after 8 months treatment. These AQR clones showed class-specific resistance to PI3K/mTOR inhibitors, reduced G1 cell cycle arrest and impedance of migration following PI3K/mTOR inhibition, reduced PTEN expression and increased Akt and S6RP phosphorylation. Transcriptome analysis revealed the AQR clones had increased expression of the metabolite transporters SLC16A9 and SLC16A7, suggestive of altered cell metabolism. Subsequent experiments revealed that AQR clones possess features consistent with elevated glycolysis, including increased levels of glucose, lactate, glutamine, glucose dependence, GLUT1 expression, and rates of post-glucose extracellular acidification, and decreased levels of reactive oxygen species and rates of oxygen consumption. Combination treatment of BEZ235 with the glycolysis inhibitor 3-bromopyruvate was synergistic in AQR clones, but only additive in parental cells. DNA sequencing revealed the presence of a mitochondrial DNA (mtDNA) MT-C01 variant in AQR but not parental cells. Depletion of mitochondrial DNA in parental cells induced resistance to BEZ235 and other PI3K/mTOR inhibitors, and was accompanied by increased glycolysis. The results of this study provide the first evidence that a metabolic switch associated with mtDNA mutation can be an underlying mechanism for AQR.

Acquired resistance to combination treatment through loss of synergy with MEK and PI3K inhibitors in colorectal cancer.

Historically, understanding of acquired resistance (AQR) to combination treatment has been based on knowledge of resistance to its component agents. To test whether an altered drug interaction could be an additional factor in AQR to combination treatment, models of AQR to combination and single agent MEK and PI3K inhibitor treatment were generated. Combination indices indicated combination treatment of PI3K and MEK inhibitors remained synergistic in cells with AQR to single agent but not combination AQR cells. Differences were also observed between the models in cellular phenotypes, pathway signaling and drug cross-resistance. Genomics implicated TGFB2-EDN1 overexpression as candidate determinants in models of AQR to combination treatment. Supplementation of endothelin in parental cells converted synergism to antagonism. Silencing of TGFB2 or EDN1 in cells with AQR conferred synergy between PI3K and MEK inhibitor. These results highlight that AQR to combination treatment may develop through alternative mechanisms to those of single agent treatment, including a change in drug interaction.

The Warburg effect and drug resistance.

: The Warburg effect describes the increased utilization of glycolysis rather than oxidative phosphorylation by tumour cells for their energy requirements under physiological oxygen conditions. This effect has been the basis for much speculation on the survival advantage of tumour cells, tumourigenesis and the microenvironment of tumours. More recently, studies have begun to reveal how the Warburg effect could influence drug efficacy and how our understanding of tumour energetics could be exploited to improve drug development. In particular, evidence is emerging demonstrating how better modelling of the tumour metabolic microenvironment could lead to a better prediction of drug efficacy and the identification of new combination strategies. This review will provide details of the current understanding of the complex interplay between glucose metabolism and pharmacology and discuss opportunities for utilizing the Warburg effect in future drug development.

Human-induced ecological changes in western part of Indian Sundarban megadelta: A threat to ecosystem stability.

The study first illustrates a comprehensive account of large-scale changes in water quality characteristics and plankton community structure due to occurrence of Annual Gangasagar Festival (AGF) at Sagar Island, western part of Indian Sundarban megadelta for 3-year duration (2012-2014; n=36). About 1 million pilgrims across India converge to take their holy bath at the confluence of Hooghly estuary and Bay of Bengal during January each year. This mass scale bathing results negative impact on water quality due to high turbidity (14.02 ± 2.34 NTU) coupled with low chlorophyll a (1.02 ± 0.21 mg m(-3)) and dissolved oxygen (3.94 ± 1.1 mg l(-1)). A marked decrease in abundance (from 4140 to 2997 cells l(-1)) and diversity (H'=2.72-1.33) of phytoplankton and microzooplankton tintinnids (from 450 to 328 ind l(-1); H'=4.31-2.21) was recorded. The festival acts as multiple stressors modifying natural functions of the delta. Sound and sustainable management strategies are to be adopted to maintain the protection-usage equilibrium.

Effect of variation of average pore size and specific surface area of ZnO electrode (WE) on efficiency of dye-sensitized solar cells.

Mesoporous ZnO nanoparticles have been synthesized with tremendous increase in specific surface area of up to 578 m(2)/g which was 5.54 m(2)/g in previous reports (J. Phys. Chem. C 113:14676-14680, 2009). Different mesoporous ZnO nanoparticles with average pore sizes ranging from 7.22 to 13.43 nm and specific surface area ranging from 50.41 to 578 m(2)/g were prepared through the sol-gel method via a simple evaporation-induced self-assembly process. The hydrolysis rate of zinc acetate was varied using different concentrations of sodium hydroxide. Morphology, crystallinity, porosity, and J-V characteristics of the materials have been studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), BET nitrogen adsorption/desorption, and Keithley instruments.

Bioaccumulation of trace elements in dominant mesozooplankton group inhabiting in the coastal regions of Indian Sundarban mangrove wetland.

Mesozooplankton (Body size 20-200 µm) along with the surface water were collected from coastal regions of Sundarban, northeastern part of Bay of Bengal considering three seasons, namely premonsoon, monsoon and postmonsoon. Samples were analyzed for community structure and the dominant copepod species were further analyzed for trace metal concentration. In total, 50 copepods were identified (22 families and 43 genera). The dominant mesozooplankton species included 9 copepods and an epipelagic chaetognath, exhibited both spatial and seasonal variations. Metal concentration exhibited considerable inter-specific variations for the copepods and the mean concentrations were: Fe, 1350.2-51118.3 µg/g; Al, 647.2-73019.1 µg/g; Ni, 32.4-110.3 µg/g; Mn, 122.8-1066.5 µg/g; Pb, 0.04-97.5 µg/g; Pb, 10.6-97.5 µg/g; Cd, 4.2-21.6 µg/g; Cu, 17.4-145.1 µg/g; Zn, 225.7-1670.9 µg/g; Cr, 21.7-194.3 µg/g; Co, 1.32-111.1 µg/g. Metal concentrations showed the following order: Sagitta bedoti>Coryceas danae>Oithona sp.>Eucalanus subcrassus>Labidocera euchaeta>Paracalanus parvus>Acartiella tortaniformis>Acartia spinicauda>Pseudocalanus serricaudatus.

Commonness and rarity in the marine biosphere.

Explaining patterns of commonness and rarity is fundamental for understanding and managing biodiversity. Consequently, a key test of biodiversity theory has been how well ecological models reproduce empirical distributions of species abundances. However, ecological models with very different assumptions can predict similar species abundance distributions, whereas models with similar assumptions may generate very different predictions. This complicates inferring processes driving community structure from model fits to data. Here, we use an approximation that captures common features of "neutral" biodiversity models--which assume ecological equivalence of species--to test whether neutrality is consistent with patterns of commonness and rarity in the marine biosphere. We do this by analyzing 1,185 species abundance distributions from 14 marine ecosystems ranging from intertidal habitats to abyssal depths, and from the tropics to polar regions. Neutrality performs substantially worse than a classical nonneutral alternative: empirical data consistently show greater heterogeneity of species abundances than expected under neutrality. Poor performance of neutral theory is driven by its consistent inability to capture the dominance of the communities' most-abundant species. Previous tests showing poor performance of a neutral model for a particular system often have been followed by controversy about whether an alternative formulation of neutral theory could explain the data after all. However, our approach focuses on common features of neutral models, revealing discrepancies with a broad range of empirical abundance distributions. These findings highlight the need for biodiversity theory in which ecological differences among species, such as niche differences and demographic trade-offs, play a central role.

Seasonal variations in species composition, abundance, biomass and production rate of tintinnids (Ciliata: Protozoa) along the Hooghly (Ganges) River Estuary, India: a multivariate approach.

The study is the first documentation of seasonal variations in species composition, abundance and diversity of tintinnid (Ciliata: Protozoa), in relation to water quality parameters along the stretch of the Hooghly (Ganges) River Estuary (HRE), eastern coastal part of India. A total of 26 species (22 agglomerated and 4 non-agglomerated) belonging to 8 genera has been identified from 8 study sites where Tintinnopsis (17 species) represented the most dominant genera, contributing up to 65 % of total tintinnid community followed by Tintinnidium (2 species), Leprotintinnus (2 species) and Dadayiella, Favella, Metacylis, Eutintinnus and Helicostomella (each with solitary species). The maximum (1,666 ind. l(-1)) and minimum (62 ind. l(-1)) abundance of tintinnids was recorded during post-monsoon and monsoon, respectively. A distinct seasonal dynamics in terms of biomass (0.005-2.465 µg C l(-1)) and daily production rate (0.04-3.13 µg C l(-1) day(-1)) was also noticed, accounting highest value during pre-monsoon. Chlorophyll a and nitrate were found to be potential causative factors for the seasonal variations of tintinnids as revealed by a stepwise multiple regression model. The result of ANOVA showed a significant variation between species abundance and months (F = 2.36, P ≤ 0.05). k-dominance curves were plotted to determine the comparison of tintinnid dominance between the investigated stations. Based on a principal component analysis (PCA), three main groups were delineated with tintinnid ciliates and environmental parameters. The changes in lorica morphology in terms of temperature and salinity, recorded for three dominant species, provided information on the ecological characteristics of the species assemblage in this estuarine system.

Levels and chemical speciation of arsenic in representative biota and sediments of a tropical mangrove wetland, India.

The general concern for arsenic in the marine environment is associated with its wide distribution and potential toxicity. In the present work, concentrations and chemical speciation of arsenic were characterized in sediments and representative biota from the Indian Sundarban, the largest continuous mangrove tract formed at the mouth of the Hugli (Ganges) River estuary, northeastern part of the Bay of Bengal. Analyzed organisms included both shellfish (Macoma birmanica, Sanguinolaria acuminata and Meretrix meretrix) and finfish (Liza parsia, Liza tade, Harpodon nehereus and Eleutheronema tetradactylum). Arsenic concentrations in sediments did not exceed 4 µg g(-1) dry weight with the contribution of inorganic molecules (arsenate and arsenite) ranging from 61.7 to 81.3%. Total As (TAs) concentrations varied from less than 2 to 16 µg g(-1) in tissues of bivalves; the more elevated As accumulation was observed in gills and the mantle probably due to ion exchange properties of the mucous layer covering these organs, whereas adductor muscle and the podium showed limited values. Distribution of various arsenic compounds followed a quite similar trend in bivalve tissues; arsenobetaine (AsB) was the most dominant form followed by compounds such as dimethylarsinate (DMA), trimethyl arsine-oxide (TMAO), tetramethyl arsonium (TETRA) and arsenocholine (AsC), while inorganic arsenic (IAs) represented a minor constituent (0.2 to 6.9%). Among the fish, detritivorous/herbivorous species (L. parsia and L. tade) exhibited TAs concentrations of 10.8 and 9.71 µg g(-1) dry wt with a prevalence of AsB (52-67%) and TETRA (26-35%); higher concentrations of TAs were measured in the two carnivorous species (20.62 and 19.67 µg g(-1) dry wt, in H. nehereus and E. tetradactylum respectively) mostly as AsB (63.3-72.3%) and AsC (17.5-28.6%). The obtained results can be considered as baseline levels for arsenic in the investigated area, confirming the predominance of organoarsenicals in marine organisms compared to more toxic inorganic compounds. Considering the ecological importance of this ecosystem and the increasing anthropogenic impact, the distribution of arsenic through the food chain should be continuously monitored, using organisms of different feeding guilds as indicators.

Significant role of serum CRP in differentiating inflammatory from non-inflammatory causes of thyrotoxicosis.

BACKGROUND: C-reactive protein (CRP), which is a marker of inflammation, has not been widely studied in inflammatory thyroid disorders particularly in sub-acute thyroiditis (SAT). AIM: This study was aimed to find the significance of CRP level rise in patients with SAT and compare that to the rise in erythrocyte sedimentation rate (ESR), a gold standard laboratory parameter in establishing the diagnosis of SAT. MATERIALS AND METHODS: Serum CRP levels were measured at initial presentation in 28 subjects with SAT(12 male, 16 female, age (Mean +SD) 37.96 ±8.5 years),and 19 patients with Graves' disease (2 male, 17 female, age [Mean +SD] 36.8 ±16.5 years) as controls. Erythrocyte sedimentation rate (ESR) was measured in all 28 patients with SAT by Westergrens' method. Either Tc(99) nucleotide thyroid scan or high resolution ultrasonography (HR-USG) was performed to differentiate SAT from Graves' disease.Fine needle aspiration cytology (FNAC) of thyroid was performed selected patients. RESULTS: Serum CRP level was high in 61% of SAT patients but in none of the Graves'patients. Mean (SEM) (90%CI) serum CRP level (mg/L) was also significantly higher (P <0.0004) in the SAT group [27.55 (5.76) (15.72-39.38)], than in the Graves' group [4.09 (0.12) (3.81-4.36)]. The sensitivity of serum CRP was 73.33%, specificity 53.85%, positive predictive value (PPV) 64.71%, and negative predictive value (NPV) 63.64% as compared to the sensitivity (53.57%), specificity (15.38%), PPV (57.69 %), and NPV (13.33%) of ESR. CONCLUSION: There is significantly higher rise in serum CRP level in patients with SAT is compared to patients with Graves' disease. It correlates well with the rise in ESR. Such findings of this pilot study highlight the scope of using serum CRP as a diagnostic marker of SAT specially in situations when it may be confused with Graves' disease, another common cause of thyrotoxicosis. It is logical to carry out studies to find a particular cut-off for serum CRP which can serve as an objective parameter for grading the inflammation in patients with SAT.

Perfluorinated compounds in surficial sediments of the Ganges River and adjacent Sundarban mangrove wetland, India.

This study reports the first evidence of the quantification of two dominant perfluorinated compounds (PFCs), namely perfluorooctanesulfate (PFOS) and perfluorooctannoate (PFOA), in surface sediment samples (0-5 cm; n=13) from the Ganges (Hugli) River including Sundarban wetland, India using HPLC-MS/MS. The concentrations of PFOA exhibited a wide range of concentrations from <0.5 to 14.09 ng/g dry wt, whereas the concentration of PFOS was always below the detection limit of <0.5 ng/g dry wt. A consistent enrichment of PFOA was recorded in all the five sites of Sundarban (mean value 11.61±1.86) whereas it was of moderate concentration or below the detection level in the seven sites along with the lower stretch of the Ganges (Hugli) River estuary (mean value 5.96 ng/g dry wt±5.36). Wastewater and untreated effluents are likely the major causes of accumulation of PFCs in sediments. The present paper could be used as baseline study to assess future monitoring programs of the ecosystem.

JAK-STAT and AKT pathway-coupled genes in erythroid progenitor cells through ontogeny.

BACKGROUND: It has been reported that the phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway regulates erythropoietin (EPO)-induced survival, proliferation, and maturation of early erythroid progenitors. Erythroid cell proliferation and survival have also been related to activation of the JAK-STAT pathway. The goal of this study was to observe the function of EPO activation of JAK-STAT and PI3K/AKT pathways in the development of erythroid progenitors from hematopoietic CD34+ progenitor cells, as well as to distinguish early EPO target genes in human erythroid progenitors during ontogeny. METHODS: Hematopoietic CD34+ progenitor cells, isolated from fetal and adult hematopoietic tissues, were differentiated into erythroid progenitor cells. We have used microarray analysis to examine JAK-STAT and PI3K/AKT related genes, as well as broad gene expression modulation in these human erythroid progenitor cells. RESULTS: In microarray studies, a total of 1755 genes were expressed in fetal liver, 3844 in cord blood, 1770 in adult bone marrow, and 1325 genes in peripheral blood-derived erythroid progenitor cells. The erythroid progenitor cells shared 1011 common genes. Using the Ingenuity Pathways Analysis software, we evaluated the network pathways of genes linked to hematological system development, cellular growth and proliferation. The KITLG, EPO, GATA1, PIM1 and STAT3 genes represent the major connection points in the hematological system development linked genes. Some JAK-STAT signaling pathway-linked genes were steadily upregulated throughout ontogeny (PIM1, SOCS2, MYC, PTPN11), while others were downregulated (PTPN6, PIAS, SPRED2). In addition, some JAK-STAT pathway related genes are differentially expressed only in some stages of ontogeny (STATs, GRB2, CREBB). Beside the continuously upregulated (AKT1, PPP2CA, CHUK, NFKB1) and downregulated (FOXO1, PDPK1, PIK3CG) genes in the PI3K-AKT signaling pathway, we also observed intermittently regulated gene expression (NFKBIA, YWHAH). CONCLUSIONS: This broad overview of gene expression in erythropoiesis revealed transcription factors differentially expressed in some stages of ontogenesis. Finally, our results show that EPO-mediated proliferation and survival of erythroid progenitors occurs mainly through modulation of JAK-STAT pathway associated STATs, GRB2 and PIK3 genes, as well as AKT pathway-coupled NFKBIA and YWHAH genes.