Low Concentration Region Research Articles

A Pair of Indicators for Characterizing Cerebral Microbleeds Based on Raman Spectrum and Two-Photon Imaging.

Cerebral microbleeds (CMBs) lead to cognitive decline, linked to the axonal structure composed of phospholipid bilayers. Current methods are difficult to obtain in situ changes of biochemical component concentration during CMB. In this study,by Raman spectrum and two-photon imaging, we achieve in situ changes in the information of biochemical components concentration during CMB. The overall concentration of phospholipids in the damaged tissue significantly decreases after CMB, forming a large region of low concentration, but the relative concentration of phosphatidylinositol (PI) increases, reflecting the inhibition role of the phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) pathway. Accordingly, two-photon images of neurons show a clear decrease in the number of axons, indicating a close correlation between phospholipid hydrolysis and axon damage, as well as cognitive impairment. Therefore, the decrease in phospholipid concentration and theincrease in the PI concentration might serve as a pair of indicators for characterizing CMB and its relationship with cognitive decline.

Plasmon scattering at a junction in double-layer two-dimensional electron gas plasmonic waveguide

Abstract The scattering of plasmons at a junction within a double-layer two-dimensional electron gas plasmonic waveguide is studied via a full electromagnetic method. The dispersion relation is derived by utilizing the transfer matrix method and can be extended to the situation of an arbitrary number of layers. By numerically solving the dispersion equations, both the acoustic and optical plasmon modes are identified in this double layer system, and the unstable plasmon modes arising from plasmon coupling in different layers are discussed elaborately. Subsequently, the total fields are expanded with eigenmodes and matched at the interface to analyze the scattering characteristics at the junction. The results indicate that the total power of the plasmon mode is amplified when the electron fluid flows from a high concentration region to a low concentration region, and the amplification is more evident at a higher drift velocity. Additionally, we address the scattering of unstable plasmons caused by the two-stream instability and find that the transmitted plasmons are excited intensively at the incidence of the growing plasmon, leading to the plasmon amplification. The detailed examination of plasmon scattering at junction is the prerequisite for studying more complex structures of terahertz plasmonic devices and comprehending the corresponding amplification mechanism.

Numerical investigation and passive control of dust pollution on a minivan

A dynamic model using a discrete phase approach was developed to study dust pollution on a minivan's side and rear surfaces. Numerical simulations, validated by road tests, analyzed dust concentration and distribution. A significant factor in sidewall dust pollution is the pressure difference inside and outside the wheel cavity, particularly behind the wheel cavity, which affects about 40% of the sidewall. Large trailing vortices at the rear create a low-pressure zone, leading to rear dust pollution characterized by low concentration, large area, and dispersed regions. Aerodynamic devices were proposed to mitigate pollution. Simulations showed that side attachments, such as wheel deflectors, wheel cavity baffle, and mudguards, reduce aerodynamic drag and sidewall dust pollution, with wheel cavity baffles reducing the affected area by about 48.98%. Rear attachments, like diffusers and roof deflector, minimize rear dust pollution, with roof deflector reducing the area by approximately 87.24%. These findings highlight the effectiveness of aerodynamic modifications in controlling dust pollution on a minivan.

A novel synthesis route with large-scale sublattice asymmetry in boron doped graphene on Ni(111)

One of the promising ways to functionalize graphene is incorporation of heteroatoms in carbon sp2 lattice, as it is proven to be an efficient and versatile method for controllably tuning chemistry of graphene. We present unique, contamination-free method for selectively doping graphene with B dopants, which are incorporated in layer from a reservoir created in the bulk of Ni(111) single crystal, during standard CVD growth process, leading to clean, versatile and efficient method for creating B-doped graphene. We combine experimental (STM, XPS) and theoretical (DFT, simulated STM) studies to understand structural and chemical properties of substitutional B dopants. Along with previously reported substitutional B in fcc sites, we have observed, for the first time, two more defects, namely substitutional B in top sites and interstitial B in octahedral subsurface sites. Extensive STM investigations confirm presence of low and high concentration regions of B dopants in as-prepared B-doped graphene, indicating non-uniform boron incorporation. Among two substitutional sites, no preference is observed in low-concentration B-doped regions, whereas in high B concentration regions, one of the sublattices is preferred for incorporation, along with alignment of defects. This generates an asymmetric sublattice doping in as-grown B-doped graphene, which is theoretically predicted to result in notable band gap.

Performance enhancement of nanotube junctionless FETs with low doping concentration rings

To reduce the static power consumption of the NT JLFET and the effect of SCEs on the NT JLFET, A nanotube junctionless field effect transistor with cyclic low doping concentration regions (C NT JLFET) is proposed. Based on Sentaurus TCAD numerical simulations, the electrical properties of the C NT JLFET and the NT JLFET were comparatively investigated, and the effects of the length (L CD) and radius (R CD) of cyclic low doping concentration regions on the electrical properties of the C NT JLFETs were studied. The C NT JLFET reduces the gate-induced drain leakage (GIDL) due to lateral band-to-band-tunneling (L-BTBT) as compared to the NT JLFET. As the L CD or R CD increases, the off-state current decreases. In addition, the C NT JLFET suffers from fewer short channel effects (SCEs), such as threshold voltage roll-off, drain-induced barrier lowering and subthreshold swing deterioration, compared to the NT JLFET. The inhibition of L-BTBT and attenuation of SCEs by cyclic low doping concentration regions remains when the channel length of the C NT JLFET is shortened to 10 nm. The C NT JLFET are suitable for low power applications as they exhibit reduced L-BTBT and suffer from fewer SCEs.

Physico-chemical features of acid decomposition and production of extraction phosphoric acid based on moroccan phosphorites

The results of research on the establishment of physicochemical features of acid processing of North African (Moroccan) phosphorites, as well as their influence on the technological process and technical and economic indicators of extraction phosphate acid (EPA) production are presented. Significant differences have been established in the nature of the acid decomposition process, syngony and the size of the formed calcium sulfate crystals for different grades of phosphorites, which is due to a significant influence on the decomposition process not only of the technological mode of the process, but to a large extent differences in the mineralogical composition of phosphate ores. Thus, the increased content of carbonate apatites in phosphorites of the K-9 and K-10 grades led to a higher reactivity in the region of low concentrations. At the same time, the high reactivity of carbonateapatites leads to a number of negative processes, in particular, abundant foaming and passivation of grains of phosphate raw materials with fine-crystalline calcium sulfate precipitate, formed due to the rapid supersaturation of the system, which in turn leads to a sharp decrease in the degree of decomposition. A significant difference in the nature of calcium sulfate crystallization for the conditions for obtaining EPA from the known data was established, which made it possible to conclude that the rate and nature of the process of calcium sulfate recrystallization in the CaO-P2O5- H2O system is determined not only by temperature, sulfate regime and P2O5 content in the liquid phase, but also by the nature and composition of phosphate raw materials. Based on experimental data, conclusions were drawn about a decrease in power during the transition from apatite to phosphorites from 21.89 to 24.23% (depending on the brand of Moroccan phosphorite), a significant increase in the load on filters and a decrease of 1.5–2 times in the amount of fluorine compounds released into the gas phase during decomposition.

Electrokinetic ion transport of viscoelastic fluids in a pH-regulated nanochannel

The objects of nanofluidics-based biological detection are usually viscoelastic fluids, and the rheological properties of viscoelastic fluids can have complex effects on electroosmotic flow and electrokinetic ion transport in nanochannels. However, researchers have mainly focused on Newtonian fluids. In this study, numerical simulations were performed on the electrokinetic ion transport of viscoelastic fluids in a pH-regulated nanochannel. The Oldroyd-B model is used to describe the behavior of the polyacrylamide (PAM) solution, and the Poisson-Nernst-Planck model is used to describe the potential and ion concentration in the electrolyte solution. Compared with the Newtonian fluid, at pH = 8, the PAM solution of cp = 500 ppm has a larger region of low ion concentration in front of the nanochannel entrance and has a larger region of high ion concentration behind the nanochannel exit. When the pH is increased to 8, the surface charge density |σw| increases sharply, which is about 5 times of that at pH = 6. At pH = 8, cKCl = 20 mM, and cp = 500 ppm, two distinct vortices appear behind the nanochannel exit, and rotate in opposite directions.

Low-temperature iodinated plasmonically tuned Ag@AgI core-shell nanostructured thin films for highly specific ascorbic acid SERS detection at ultra-low concentrations

A simple low temperature iodination route was developed to controllably iodinate silver nanoislands film (Ag) into silver@silver iodide core-shell nanoparticles film (Ag@AgI) as a chemically stable, near infrared active surface enhanced Raman scattering (SERS) substrate. The localised surface plasmon resonance (LSPR) of the core-shell film exhibits a huge red-shift of 100 nm. The formation of Ag core and a complete ultra-thin AgI shell layer on top of the core is confirmed by transmission electron microscope. Selected area electron diffraction reveals the amorphous nature of AgI shell layer. These results are further substantiated by Raman and x-ray diffraction measurements. The enhancement factor of Ag@AgI film estimated with methylene blue is 5 × 106, an order of magnitude higher compared to that of Ag film. It demonstrated excellent chemical stability and unwavering SERS performance for two months since fabrication. The Ag@AgI film fielded as a label-free SERS substrate exhibited a lowest limit-of-detection of 1 × 10−12 M for ascorbic acid and a linear detection range of 1 × 10−6 to 1 × 10−12 M. The ascorbic acid selective signal enhancement of Ag@AgI film at low concentration region offers a practical sample dilution strategy to suppress interference from non-target molecules in biofluids.

Study on motion behaviour of coal water slurry particles under vibration conditions

This study uses computational fluid dynamics (CFD) to simulate the motion behavior of coal-water slurry (CWS) particles under vibration conditions. Results show that without vibration, the coal particles settle to the bottom of the container due to gravity, forming distinct regions of low, transition, and high concentration. Under low vibration intensity, the slight energy activates particle motion and promotes settlement. Under high vibration intensity, violent reciprocating motion causes severe shaking and uncertainty, resulting in non-uniform particle distribution and back mixing. Particle velocity distribution is significantly influenced by vibration, with higher frequencies and amplitudes resulting in greater velocities. Additionally, particle pseudo-temperature is higher in the near-wall area due to collisions with particles and wall surfaces. Low frequency and amplitude promote particle settlement, increasing compactness in the bottom area and reducing concentration in the top area. The findings provide valuable insights into CWS behavior under vibration conditions, which can be used to optimize the design and operation of CWS handling and transportation systems.

Water detection in organic solvents using a copolymer membrane immobilised with a fluorescent intramolecular charge transfer-type dye: effects of intramolecular hydrogen bonds.

Numerous fluorescent dye-based optical sensors have been developed to detect water in organic solvents. However, only a few such sensors can detect water in polar solvents such as methanol or dimethyl sulfoxide, and their detection range is generally narrow. Therefore, in this study, a copolymer membrane incorporated with a pyridinium betaine dye (denoted PB1), which exhibited intramolecular charge transfer (ICT) characteristics, was developed to realise simple water detection in organic solvents. The pyridinium betaine structure, comprising intramolecular hydrogen bonds between the oxygen in the maleimide moiety and the hydrogen in the pyridinium, was vital for achieving efficient fluorescence emission. The membrane was prepared by copolymerising PB1 with the N,N-dimethyl acrylamide/acrylamide monomer on a glass plate, and the fluorescence in water-mixed organic solvents was investigated (λabs = 490 nm, λfl = 630 nm). The fluorescence intensity of the dye-immobilised membrane decreased with increasing water content of the organic solvents. The detection ranges in tetrahydrofuran, ethanol, methanol, and dimethyl sulfoxide were approximately <40, <40, <40, and <60 vol% water, respectively. In contrast, membranes based on a quaternary pyridinium dye (without intramolecular hydrogen bonds) did not detect water in methanol and dimethyl sulfoxide, although it was more sensitive than PB1 in the narrow region of low water concentration in THF. Theoretical calculations corroborated the importance of the pyridinium betaine structure in detecting water in organic solvents, with the increase in polarity and the formation of intermolecular hydrogen bonds between PB1 and water found to induce molecular rotation and fluorescence quenching.

Transport of pollutants in groundwater of domestic waste landfills in karst regions and its engineering control technologies

Domestic waste produces leachate with a high concentration of pollutants in the landfill process due to biochemical degradation stages like compaction and fermentation. A large number of cases show that anti-seepage membranes widely used in refuse landfills tend to rupture under long-term tension and corrosion, causing leachate to enter the groundwater system and pollute the environment. To reveal the phenomenon of groundwater contamination in refuse landfills, typical domestic waste landfills in karst regions were examined, on the basis of a summary of hydrogeological conditions and hydrochemical characteristics, a three-dimensional groundwater flow model and solute transport model were constructed to analyze the pattern of pollutant diffusion, and its controlling factors, under the current conditions and massive rupture of anti-seepage membrane. The results show that with a minor rupture of the anti-seepage membrane, the area of the low pollution region increases first and then decreases while that of the slight pollution region continuously increases; When a massive rupture of the anti-seepage membrane appears, the ranges of heavy pollution region and total pollution regions continue to grow; Pollutant migrates along the same direction as the groundwater flow and diffuse from high concentration region to low concentration regions under the differential concentration effect. Based on the temporal-spatial distribution characteristics of groundwater pollutants, two engineering control schemes, namely, curtain grouting blocking and group well pumping, were established. A comparison of the two control schemes shows that group well pumping stably maintains water quality safety over the long term, pollutants overflow from both sides of the curtain after they have accumulated to a certain point of concentration, causing damage to the groundwater environment in the conservation area.

Gas sensing with 7-decade dynamic range by laser vector spectroscopy combining absorption and dispersion

Laser absorption spectroscopy (LAS) has been widely used for unambiguous detection and accurate quantification of gas species in a diverse range of fields. However, up-to-date LAS-based gas sensors still face challenges in applications where gas concentrations change in a wide range, since it is extremely difficult to balance spectral analysis strategies for different optical thicknesses. Here we present laser vector spectroscopy that combines absorption spectroscopy with dispersion spectroscopy, simultaneously taking advantage of the former’s high sensitivity in the low-concentration region and the latter’s high linearity in the high-concentration region. In the proof-of-concept demonstration of acetylene measurement, it achieves a linear dynamic range of 6×107 (R2&gt;0.9999), which surpasses all other state-of-the-art LAS techniques by more than an order of magnitude, with the capability of highly accurate quantification retained. The proposed laser spectroscopic method paves a novel way of developing large-dynamic-range gas sensors for environmental, medical, and industrial applications.

Alignment interaction and band formation in assemblies of autochemorepulsive walkers.

Chemotaxis refers to the motion of an organism induced by chemical stimuli and is a motility mode shared by many living species that has been developed by evolution to optimize certain biological processes such as foraging or immune response. In particular, autochemotaxis refers to chemotaxis mediated by a cue produced by the chemotactic particle itself. Here, we investigate the collective behavior of autochemotactic particles that are repelled by the cue and therefore migrate preferentially towards low-concentration regions. To this end, we introduce a lattice model inspired by the true self-avoiding walk which reduces to the Keller-Segel model in the continuous limit, for which we describe the rich phase behavior. We first rationalize the chemically mediated alignment interaction between walkers in the limit of stationary concentration fields, and then describe the various large-scale structures that can spontaneously form and the conditions for them to emerge, among which we find stable bands traveling at constant speed in the direction transverse to the band.

Creation of Polymer Hydrogelator/Poly(Vinyl Alcohol) Composite Molecular Hydrogel Materials.

Polymer hydrogels, including molecular hydrogels, are expected to become materials for healthcare and medical applications, but there is a need to create new functional molecular gels that can meet the required performance. In this paper, for creating new molecular hydrogel materials, the gel formation behavior and its rheological properties for the molecular gels composed of a polymer hydrogelator, poly(3-sodium sulfo-p-phenylene-terephthalamide) polymer (NaPPDT), and water-soluble polymer with the polar group, poly(vinyl alcohol) (PVA) in various concentrations were examined. Molecular hydrogel composites formed from simple mixtures of NaPPDT aqueous solutions (0.1 wt.%~1.0 wt.%) and PVA aqueous solutions exhibited thixotropic behavior in the relatively low concentration region (0.1 wt.%~1.0 wt.%) and spinnable gel formation in the dense concentration region (4.0 wt.%~8.0 wt.%) with 1.0 wt.% NaPPDT aq., showing a characteristic concentration dependence of mechanical behavior. In contrast, each single-component aqueous solution showed no such gel formation in the concentration range in the present experiments. No gel formation behavior was also observed when mixed with common anionic polymers other than NaPPDT. This improvement in gel-forming ability due to mixing may be due to the increased density of the gel's network structure composed of hydrogelator and PVA and rigidity owing to NaPPDT.

Peculiarities of the effect of different types of SOR nanoimpurities on the value of ionic component of the electrical conductivity of the homeotropically aligned nematic liquid crystal 6 СВ

In this paper, the effects of SOR5, SOR10, and SOR15 nanoimpurities on the value of the ionic conductivity of the homeotropically aligned nematic liquid crystal 6CB are reported. Electrical measurements are carried out within a wide frequency range (from 6 Hz to 106 Hz) at room temperature (293 K). The largest changes in the electrical conductivity occur in the low-frequency range (less than 103 Hz) and depend on the type of nanoimpurity and on its concentration. Despite the similarity in the chemical composition of SOR5, SOR10, and SOR15, the measured dependences of the electrical conductivity of the studied samples on the concentration of nanoimpurities are substantially different. In the case of the SOR10 impurity, the ionic component of the electrical conductivity depends on the concentration of SOR10 according to a power law with an exponent approximately equal to 0.5, which is typical for the bimolecular recombination of charge carriers (i.e., the behavior of a weak electrolyte). Liquid crystal samples containing SOR5 and SOR15 nanoimpurities behave in a similar way in a low concentration region (between 0.01 and 0.05 mass %). Interestingly, further increase in the concentration of nanodopants (&gt;0.05 mass %) results in a dramatically different behavior. The electrical conductivity of liquid crystals doped with SOR5 undergoes a sharp increase whereas the electrical conductivity of samples containing SOR15 decreases.

Reproduction of bacterial chemotaxis by a non-living self-propelled object

Taxic behavior as a response to an external stimulus is a fundamental function of living organisms. Some bacteria successfully implement chemotaxis without directly controlling the direction of movement. They periodically alternate between run and tumble, i.e., straight movement and change in direction, respectively. They tune their running period depending on the concentration gradient of attractants around them. Consequently, they respond to a gentle concentration gradient stochastically, which is called “bacterial chemotaxis.” In this study, such a stochastic response was reproduced by a non-living self-propelled object. We used a phenanthroline disk floating on an aqueous solution of Fe^{2+}. The disk spontaneously alternated between rapid motion and rest, similar to the run-and-tumble motion of bacteria. The movement direction of the disk was isotropic independent of the concentration gradient. However, the existing probability of the self-propelled object was higher at the low-concentration region, where the run length was longer. To explain the mechanism underlying this phenomenon, we proposed a simple mathematical model that considers random walkers whose run length depends on the local concentration and direction of movement against the gradient. Our model adopts deterministic functions to reproduce the both effects, which is instead of stochastic tuning the period of operation used in the previous reports. This allows us to analyze the proposed model mathematically, which indicated that our model reproduces both positive and negative chemotaxis depending on the competition between the local concentration effect and it’s gradient effect. Owing to the newly introduced directional bias, the experimental observations were reproduced numerically and analytically. The results indicate that the directional bias response to the concentration gradient is an essential parameter for determining bacterial chemotaxis. This rule might be universal for the stochastic response of self-propelled particles in living and non-living systems.

Specific Ion Effect on the “Water Bridge” Interaction at an Interface: A New Understanding into the Extraction and Separation Selectivity Based upon Competitive Diffusion and Adsorption

Understanding the essence of a specific ion effect on the intermolecular interaction at the near-interface boundary layer during solvent extraction is crucial for developing new approaches to achieve enhanced extraction and separation of various valuable metals from complex aqueous solutions. The present work aims to detect the microscopic effect from competitive diffusion and adsorption of various salt cations in the near-interface boundary layer on their interaction with amphiphilic model molecules, 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (P507), at the air–water interface by using the Langmuir–Blodgett (LB) monolayer technique. It was found that the interaction between cations and P507 molecules through a long-range hydrogen bond “water bridge” confined in the near-interface boundary layer plays a crucial role in determining the difference in the diffusion mass transfer rate of ions with different hydration abilities. Conventional understanding about competitive extraction of various metal cations controlled mainly by their thermodynamic difference in the interaction intensity with the P–O and P═O groups in P507 molecules cannot explain such a kind of specific ion effect on the mass transfer kinetics via ion hydration. Molecular dynamics simulation revealed that the hydration ability of ions is the key factor determining the mass transfer rate and interaction intensity. In the low salt concentration region, the interaction intensity of salt cations with the P–O and P═O groups in P507 molecules is one of the determinants of the competitive adsorption behavior at the interface. However, in a higher salt concentration region, the specific ion salting-out effect via ion hydration becomes significant, causing a decrease in hydration of the target salt cation; therefore, it dominated the diffusion mass transfer rate of ions. This work provides a new insight to understand the kinetic role of competitive diffusion and adsorption of ions in the near-interface boundary layer and their effect on extraction and separation selectivity. It lays the foundation for achieving controllable separation of target metal ions by adjusting the coexisting ion species and their concentrations.

Numerical simulation of single bubble growth and heat transfer of R32+R1234yf binary mixtures during saturated pool boiling

As a promising alternative refrigerant for meeting carbon reduction targets, R32+R1234yf binary mixtures combine the thermal performance of R32 with the environmental performance of R1234yf. Since the degree of heat dissipation during the boiling process is closely related to bubble behavior, the bubble growth and heat transfer characteristics of R32+R1234yf mixtures must be understood in depth. Accordingly, this study proposed a numerical model for single bubble growth during nucleate pool boiling of mixtures. Numerical simulations of single bubble growth in R32, R1234yf, and four binary mixtures thereof were conducted. Owing to the preferential evaporation of the more volatile component, a low concentration region of R32 appeared in the liquid near the heating surface, while the concentration of R32 in the vapor was generally higher than that in the liquid. The evaporation heat flux at the bubble interface in the mixtures was significantly lower than in pure R32, indicating that the existence of mass transfer resistance considerably reduced the heat transfer capacity of mixtures. In contrast to a pure fluid, the microlayer evaporation in a mixture might terminate owing to an increase in the local bubble point temperature, and two modes of microlayer evaporation—called “bubble-point-controlled mode” and “thickness-controlled mode”—were identified accordingly. The total heat transferred during bubble growth first decreased and then increased with an increase in the bulk concentration of R32; a minimum value was observed at an R32 mol fraction of approximately 0.4. This result is consistent with the observed variation in the difference between the vapor and liquid phase concentrations. Overall, this study provides a detailed description of the mass and heat transfer characteristics during single bubble growth in binary mixtures, contributing to a deeper understanding of the associated boiling heat transfer mechanisms.

Ferromagnetism by p−d exchange spin-orbit coupling in n -type ferromagnetic semiconductors

The exchange interaction between carrier and localized spin in magnets generates intrinsic spin-orbit coupling induced by the magnetism. Recent studies for the exchange spin-orbit coupling (ESOC) in ferromagnets and antiferromagnets suggest the ESOC and the transport phenomena for spintronics. However, the study on the effects of ESOC on the magnetic phase transition has been still lacking especially for ferromagnets even though the ESOC should be one of the fundamental interactions to stabilize the magnetic phase. In this paper, we study the role of the ferromagnetic properties of the ESOC induced by the $p\text{\ensuremath{-}}d$ exchange interaction of the valence band in $n$-type ferromagnetic semiconductors. Based on the mean-field and $\mathbit{k}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbit{p}$ methods, our theory explains the spin polarization of localized and carrier spin, and the Curie temperature ${T}_{c}$ for the iron concentration, electron density, and host semiconductor dependence. The theoretical ${T}_{c}$ fits experimental values well in low iron concentration and intermediate electron density regions, and the $p\text{\ensuremath{-}}d$ exchange interaction is essential for ${T}_{c}$. Furthermore, the ${T}_{c}$ is higher for narrower gap host semiconductors to provide insights into higher ${T}_{c}$. The theoretical framework of this paper is not limited to the specific materials and will find potential materials for spintronics and the fundamental aspects.

1α,25(OH)2D3 regulates pro-angiogenic factors in endothelial cells transformed by Kaposi's sarcoma-associated herpesvirus G protein coupled receptor

When tumoral cell expansion exceeds the vascular supply, regions of hypoxia or low oxygen concentration are generated promoting the formation of new vessels through cell proliferation and migration. Viral G protein-coupled receptor (vGPCR) is associated to Kaposi's sarcoma pathology and induces a paracrine transformation when is stably expressed in murine endothelial cells activating hypoxia-induced transcription factors. Previously, we reported the antiproliferative actions of 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) in endothelial cells transformed by the vGPCR (SVEC-vGPCR). Herein, we further investigated if pro-angiogenic factors as AP-1, HIF-1α and VEGF are modulated by 1α,25(OH)2D3. We found by qRT-PCR analysis that the mRNA level of JunB, a negative regulator of cell proliferation, was similarly increased at all-time points tested after 1α,25(OH)2D3 treatment in SVEC-vGPCR cells. Also, mRNA levels of the pro-angiogenic factor c-Fos, which induces tumor invasion, were only decreased during one short period treatment. In addition, Hif-1α mRNA and protein levels were significantly reduced after 1α,25(OH)2D3 treatment in a VDR dependent fashion. However, mRNA levels of the angiogenic activator Vegf, promoted in turn by Hif-1α expression, were surprisingly high depending on VDR expression as well. Moreover, Egr-1, which has been reported to induce VEGF expression independently of HIF-1α, diminished its expression with 1α,25(OH)2D3 treatment, fact that was related to the decline of p-ERK1/2. Altogether, these results suggest a negative modulation of some pro-angiogenic factors like AP-1 and HIF-1α, as part of the antiproliferative mechanism of 1α,25(OH)2D3 in SVEC-vGPCR endothelial cells.