Paramagnetic Gd Research Articles

Impact of structural, electrical and magnetic features due to paramagnetic gd3+ ion doping on thea-site of lafeo3 solid solution

Impact of structural, electrical and magnetic features due to paramagnetic gd3+ ion doping on thea-site of lafeo3 solid solution

Fast proton transport enables the magnetic relaxation response of graphene quantum dots for monitoring the oxidative environment in vivo.

A magnetic relaxation switch (MRS) that targets small molecules such as H2O2 is difficult to realize because of the small size of the targets, which cannot gather enough MRS probes to form aggregates and generate a difference in magnetic relaxation times. Therefore, the development of small molecule-targeted MRS is strongly dependent on changes in the interfacial structure of the probe, which modulates the proton transport behavior near the probe. Herein, functionalized graphene quantum dots (GQDs) consisting of GQDs with disulfide bonds, polyethylene glycol (PEG), and paramagnetic Gd3+ were used as the MRS probe to sense H2O2. The structure of GQDs changed after reacting with H2O2. The PEG assembled a tube for transmitting changes in GQDs via proton transport and thus enabled the magnetic relaxation response of the probe towards H2O2. Pentaethylene glycol was experimentally and theoretically proven to have the strongest ability to transport protons. Such a probe can be applied in the differentiation of healthy and senescent cells/tissues using in vitro fluorescent imaging and in vivo magnetic resonance imaging. This work provides a reliable solution for building a proton transport route, which not only enables the response of the MRS probe towards the targets but also demonstrates the design of carbon nanostructures with proton transport behaviors.

Silica-based monoliths functionalized with DTPA for the removal of transition and lanthanide ions from aqueous solutions.

Transition and rare earth metals serve as indispensable raw materials across a broad spectrum of technological applications. However, their utilization is frequently linked to substantial waste production. Consequently, the recycling and recovery of these metals from end-of-life products or metal-contaminated aqueous environments hold significant importance within the framework of a circular economy. In our investigation, we employed synthetic mesoporous silica monoliths, synthesized via the sol-gel method and functionalized with chelating groups, for the efficient recovery of metal ions from aqueous matrices. The monoliths were characterized using a multi-technique approach and were tested in the recovery of paramagnetic Gd3+, Cu2+ and Co2+ ions from aqueous solutions, using 1H-NMR relaxometry to evaluate their uptake performance in real time and under simple conditions. Detailed information on the kinetics of the capture process was also highlighted. Finally, the possibility to regenerate the solid sorbents was evaluated.

Changes in the kinetic characteristics of free charge carriers in a narrow-gap semiconductor Pb<sub>1 – <i>x</i></sub>Gd<sub><i>x</i></sub>Te under the influence of electron paramagnetic resonance processes of Gd<sup>3+</sup> ions

In crystals of the narrow-gap semiconductor Pb1 – xGdxTe (x = 1.5 · 10–4) at temperatures T = 5–100 K, the method of electron paramagnetic resonance (EPR) revealed unusual dependences of the line shape of the EPR spectra of paramagnetic Gd3+ centers on temperature and the microwave power level in the spectrometer cavity. Based on the results of the analysis of the shape parameters of resonance lines recorded in the X-band, it was concluded that the most probable cause of changes in the observed EPR spectra is the effect of resonance transitions between the spin levels of Gd3+ centers on the kinetic characteristics of free charge carriers bound by exchange interactions with Gd3+ ions.

Detection of Paramagnetic Spins with an Ultrathin van der Waals Quantum Sensor.

Detecting magnetic noise from small quantities of paramagnetic spins is a powerful capability for chemical, biochemical, and medical analysis. Quantum sensors based on optically addressable spin defects in bulk semiconductors are typically employed for such purposes, but the 3D crystal structure of the sensor inhibits sensitivity by limiting the proximity of the defects to the target spins. Here we demonstrate the detection of paramagnetic spins using spin defects hosted in hexagonal boron nitride (hBN), a van der Waals material that can be exfoliated into the 2D regime. We first create negatively charged boron vacancy (VB-) defects in a powder of ultrathin hBN nanoflakes (<10 atomic monolayers thick on average) and measure the longitudinal spin relaxation time (T1) of this system. We then decorate the dry hBN nanopowder with paramagnetic Gd3+ ions and observe a clear T1 quenching under ambient conditions, consistent with the added magnetic noise. Finally, we demonstrate the possibility of performing spin measurements, including T1 relaxometry using solution-suspended hBN nanopowder. Our results highlight the potential and versatility of the hBN quantum sensor for a range of sensing applications and make steps toward the realization of a truly 2D, ultrasensitive quantum sensor.

Redox ferrocenylseleno compounds modulate longitudinal and transverse relaxation times of FNPs-Gd MRI contrast agents for multimodal imaging and photo-Fenton therapy.

Developing a feasible way to feature longitudinal (T1) and transverse (T2) relaxation performance of contrast agents for magnetic resonance imaging (MRI) is important in cancer diagnosis and therapy. Improved accessibility to water molecule is essential for accelerating the relaxation rate of water protons around the contrast agents. Ferrocenyl compounds have reversible redox property for modulating the hydrophobicity/hydrophilicity of assemblies. Thus, they could be the candidates that can change water accessibility to the contrast agent surface. Herein, we incorporated ferrocenylseleno compound (FcSe) with Gd3+-based paramagnetic UCNPs, to obtain FNPs-Gd nanocomposites using T1-T2 MR/UCL trimodal imaging and simultaneous photo-Fenton therapy. When the surface of NaGdF4:Yb,Tm UNCPs was ligated by FcSe, the hydrogen bonding between hydrophilic selenium and surrounding water molecules accelerated their proton exchange to initially endow FNPs-Gd with high r1 relaxivity. Then, hydrogen nuclei from FcSe disrupted the homogeneity of the magnetic field around the water molecules. This facilitated T2 relaxation and resulted in enhanced r2 relaxivity. Notably, upon the near-infrared light-promoted Fenton-like reaction in the tumor microenvironment, hydrophobic ferrocene(II) of FcSe was oxidized into hydrophilic ferrocenium(III), which further increased the relaxation rate of water protons to obtain r1=1.90±0.12 mM-1 s-1 and r2=12.80±0.60 mM-1 s-1. With an ideal relaxivity ratio (r2/r1) of 6.74, FNPs-Gd exhibited high contrast potential of T1-T2 dual-mode MRI in vitro and in vivo. This work confirms that ferrocene and selenium are effective boosters that enhance the T1-T2 relaxivities of MRI contrast agents, which could provide a new strategy for multimodal imaging-guided photo-Fenton therapy of tumors. STATEMENT OF SIGNIFICANCE: T1-T2 dual-mode MRI nanoplatform with tumor-microenvironment-responsive features has been an attractive prospect. Herein, we designed redox ferrocenylseleno compound (FcSe) modified paramagnetic Gd3+-based UCNPs, to modulate T1-T2 relaxation time for multimodal imaging and H2O2-responsive photo-Fenton therapy. Selenium-hydrogen bond of FcSe with surrounding water molecules facilitated water accessibility for fast T1 relaxation. Hydrogen nucleus in FcSe perturbed the phase coherence of water molecules in an inhomogeneous magnetic field and thus accelerated T2 relaxation. In tumor microenvironment, FcSe was oxidized into hydrophilic ferrocenium via NIR light-promoted Fenton-like reaction which further increased both T1 and T2 relaxation rates; Meanwhile, the released toxic •OH performed on-demand cancer therapy. This work confirms that FcSe is an effective redox mediate for multimodal imaging-guided cancer therapy.

Novel Nanogels Loaded with Mn(II) Chelates as Effective and Biologically Stable MRI Probes.

Here it is described nanogels (NG) based on a chitosan matrix, which are covalently stabilized by a bisamide derivative of Mn-t-CDTA (t-CDTA = trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid). the Mn(II) complex acts both as a contrast medium and as a cross-linking agent. These nanogels are proposed as an alternative to the less stable paramagnetic nanogels obtained by electrostatic interactions between the polymeric matrix and paramagnetic Gd(III) chelates. The present novel nanogels show: i) relaxivity values seven times higher than that of typical monohydrated Mn(II) chelates at the clinical fields, thanks to the combination of a restricted mobility of the complex with a fast exchange of the metal-bound water molecule; ii) high stability of the formulation over time at pH 5 and under physiological conditions, thus excluding metal leaking or particles aggregation; iii) good extravasation and accumulation, with a maximum contrast achieved at 24h post-injection in mice bearing subcutaneous breast cancer tumor; iv) high T1 contrast (1 T) in the tumor 24h post-injection. These improved properties pave the way for the use of these paramagnetic nanogels as promising magnetic resonance imaging (MRI) probes for in vitro and in vivo preclinical applications.

How to Develop Bioresponsive MRI Probes Based on Paramagnetic Gd(III) for in vivo Applications

AbstractAmong the many biological imaging techniques, magnetic resonance imaging (MRI) has been widely adopted for biomedical and clinical diagnostic applications, because of its ability to image deep tissues with high spatiotemporal resolution. Bioresponsive contrast agents are the key to expanding the diagnostic potential of MRI by providing anatomical information and discerning biochemical activity. Recent developments in the field of responsive and gadolinium‐based agents have resulted in novel complexes that can sense their chemical microenvironments and thus study various functional processes in the tissue. Herein, we discuss the design and use of Gd(III)‐based and bioresponsive MRI contrast agents for specific biological markers such as Ca(II) and Zn(II) cations and zwitterionic amino acid neurotransmitters. Combining their basic physicochemical characteristics with aspects that should be considered for their use in vivo would achieve the desired sensing features and enable their applications in functional molecular imaging to visualize essential biological processes.

Dynamics of the Ligand Excited States Relaxation in Novel β-Diketonates of Non-Luminescent Trivalent Metal Ions.

Complexes emitting in the blue spectral region are attractive materials for developing white-colored light sources. Here, we report the luminescence properties of novel coordination compounds based on the trivalent group 3, 13 metals, and the 1-phenyl-3-methyl-4-cyclohexylcarbonyl-pyrazol-5-onate (QCH) ligand. [M(QCH)3] (M = Al, Ga, and In), [M(QCH)3(H2O)] (M = Sc, Gd, and Lu), [Lu(QCH)3(DMSO)], and [La(QCH)3(H2O)(EtOH)] complexes were synthesized and structurally characterized by a single-crystal X-ray diffraction study. It has been found that the luminescence quantum yields of the ligand increase by one order of magnitude upon metal coordination. A significant correspondence between the energies of the ligand's excited states and the luminescence quantum yields to the metal ion's atomic numbers was found using molecular spectroscopy techniques. The replacement of the central ion with the heavier one leads to a monotonic increase in singlet state energy, while the energy of the triplet state is similar for all the complexes. Time-resolved measurements allowed us to estimate the intersystem crossing (ISC) rate constants. It was shown that replacing the Al3+ ion with the heavier diamagnetic Ga3+ and In3+ ions decreased the ISC rate, while the replacement with the paramagnetic Gd3+ ion increased the ISC rate, which resulted in a remarkably bright and room-temperature phosphorescence of [Gd(QCH)3(H2O)].

Cu-In-S/ZnS:Gd3+ quantum dots with isolated fluorescent and paramagnetic modules for dual-modality imaging in vivo

Gd3+-doped quantum dots (QDs) have been widely used as small-sized bifunctional contrast agents for fluorescence/magnetic resonance (FL/MR) dual-modality imaging. However, Gd3+ doping will always compromise the FL of host QDs. Therefore, balancing the Gd3+ doping and the optical properties of QDs is crucial for constructing high-performance bifunctional nanoprobes. Additionally, most paramagnetic QDs are synthesized in the organic phase and need to be transferred to the aqueous phase for bioimaging. Herein, ingeniously designed shell-doped Cu-In-S/ZnS:Gd3+ QDs have been prepared in the aqueous phase. It has been demonstrated that isolating paramagnetic Gd3+ from fluorescent Cu-In-S core via doping Gd3+ into ZnS shell not only avoided the decrease of FL quantum yield (QY), but also ensured the water accessibility of paramagnetic Gd3+ ions, by which the FL QY and r1 relaxivity of Cu-In-S/ZnS:Gd3+ QDs achieved as much as 15.6% and 15.33 mM-1·s-1, respectively. These high-performance QDs with excellent stability, low biotoxicity, and good tumor permeability were successfully applied for in vivo tumor FL/MR dual-modality imaging, and have shown significant potential in the precision detection and diagnosis of diseases.

Gd-Encapsulated Carbon Nanotubes as Dual-Modal Probes for Magnetic Resonance and Second Near-Infrared Emission

We report a second near-infrared (NIR-II) fluorescence and magnetic resonance (MR) dual-modal probe composed of fluorescent carbon nanotubes (CNTs) encapsulated with paramagnetic Gd compounds. The Gd-filled CNTs are synthesized via a vapor-phase technique using gadolinium halides as precursors, and the CNTs exhibit the strong photoluminescence even after Gd filling. We have investigated NIR-II fluorescence and MR imaging in vivo as well as in vitro, demonstrating that the Gd-filled CNTs can be used for dual-modal imaging of tissues and vessels in living mice, creating avenues for disease diagnosis and prognosis.

High Relaxivity with No Coordinated Waters: A Seemingly Paradoxical Behavior of [Gd(DOTP)]5- Embedded in Nanogels.

Nanogels (NGs) obtained by electrostatic interactions between chitosan and hyaluronic acid and comprising paramagnetic Gd chelates are gaining increasing attention for their potential application in magnetic resonance bioimaging. Herein, the macrocyclic complexes [Gd(DOTP)]5−, lacking metal-bound water molecules (q = 0), were confined or used as a cross-linker in this type of NG. Unlike the typical behavior of Gd complexes with q = 0, a remarkable relaxivity value of 78.0 mM–1 s–1 was measured at 20 MHz and 298 K, nearly 20 times greater than that found for the free complex. A careful analysis of the relaxation data emphasizes the fundamental role of second sphere water molecules with strong and long-lived hydrogen bonding interactions with the complex. Finally, PEGylated derivatives of nanoparticles were used for the first in vivo magnetic resonance imaging study of this type of NG, revealing a fast renal excretion of paramagnetic complexes after their release from the NGs.

Yb/Er/Ho-engineered rare earth fluoride nanoparticles to unlock multimodal in vivo medical imaging.

Fluorescence imaging with advanced multi-channel observation, high sensitivity, and high spatio-temporal resolution holds great promise for biomedical applications. However, the different absorption and scattering spectra of complex tissue structures present significant challenges for real-time investigations of live biological and physiological processes. Herein, we present Yb/Er/Ho-engineered rare earth fluoride nanoparticles with integrated multimodal imaging functions that can provide synergistic effects over any modality alone. The engineered nanoparticles can realize efficient and accurate diagnoses in clinical research. Employing Yb3+ sensitizers and both Er3+ and Ho3+ emitters, NaGdF4:15%Yb,15%Er,x%Ho nanoparticles absorb an excitation wavelength of 980 nm and emit luminescence centered at 1525 nm and 1155 nm in the second near-infrared (NIR-II) window. In addition, upconversion emission in the visible region is also observed for multiplex signals. T1- and T2-weighted magnetic resonance (MR) imaging is achieved owing to the presence of paramagnetic Gd3+ and Ho3+ species. The high X-ray attenuation ability of the elemental constituents permits the use of the prepared nanoparticles as high-contrast X-ray computed tomography (CT) imaging agents. Taken together, this study shows the construction of an alternative multimodal nanoprobe with synergistic T1- and T2-MR/CT/downconversion luminescence (DCL) imaging abilities, which can provide an alternative approach for in vivo disease diagnosis and supervision.

The impact of highly paramagnetic Gd3+ cations on structural, spectral, magnetic and dielectric properties of spinel nickel ferrite nanoparticles

In this work, fabrication of Gd3+ substituted nickel spinel ferrite (NiGdxFe2-xO4) nanoparticles was carried out via co-precipitation route. X-ray powder diffraction (XRD) confirmed the spinel cubic structure of NiGdxFe2-xO4 nanoparticles. XRD data also facilitated to determine the divalent and trivalent metal cations distribution at both A and B sites of the ferrite lattice. Site radii, hopping and bond lengths were also calculated from XRD data. The spectral studies elucidated the formation of cubic spinel ferrite structure as well as stretching vibrations of M–O (metal–oxygen) bond at A and B sites of ferrites, represented by two major bands υ1 and υ2 respectively. FESEM analysis confirmed the irregular morphology of NiGdxFe2-xO4 nanoparticles. EDX spectrographs estimated the elemental compositions. The dielectric attributes were explained on the basis of the Debye-relaxation theory and Koop’s phenomenological model. At higher applied frequencies (AC) no prominent dielectric loss was observed. Magnetic parameter variations can be attributed to the substitution of the rare earth cations having larger ionic radii as compared to the radii of Fe3+ ions. Moreover, spin canting, magneto-crystalline anisotropy and exchange energy of electrons also helped in magnetic evaluation. Due to small coercivity values NiGdxFe2-xO4 nanoparticles can be employed significantly in high-frequency data storage devices.

Graphene Nanoflake Antibody Conjugates for Multimodal Imaging of Tumors

Graphene‐based materials are promising scaffolds for use in the design of tailored‐made nanomedicines. Herein, the synthesis and characterization of a series of multifunctional carboxylated graphene nanoflakes (GNFs) conjugated to monoclonal antibodies (mAbs) for tumor‐specific binding and modulation of pharmacokinetics is presented. GNF–mAb constructs are coupled to a fluorophore (4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene [BODIPY]) for applications in optical imaging, a paramagnetic Gd3+ complex, [GdDOTAGA(H2O)]−, and the hexadentate chelate desferrioxamine B (DFO) for radiolabeling with 89Zr4+ (t1/2 = 78.41 h) ions and applications in dual‐modality positron emission tomography/magnetic resonance imaging (PET/MRI). Experimental properties of [89Zr]GdDOTAGA–ZrDFO–GNF–trastuzumab are tested in extensive chemical, spectroscopic, radiochemical, and cellular assays in vitro, and assessment of the pharmacokinetics by PET imaging in mice bearing a human ovarian cancer model illustrates the potential of using GNF–mAbs to develop multifunctional PET/MRI probes.

Modified amino-dextrans as carriers of Gd-chelates for retrograde transport and visualization of peripheral nerves by magnetic resonance imaging (MRI)

Amino-dextrans (AD) conjugated with gadolinium (Gd3+) were developed as neuro-specific contrast agents (CA) for the visualization of the sciatic nerve in rats by magnetic resonance imaging (MRI). AD with 3, 10, and 70 kDa molecular weights were assessed as carrier molecules known to be transported with various speed by axonal microtubules. Detailed spectroscopic characterizations, analyses by Fast Protein Liquid Chromatography (FPLC), Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE), and inductively coupled plasma-mass spectrometry (ICP-MS), were carried out. For MRI, the paramagnetic Gd3+ ion was coupled as a T1 signal enhancer. The well-established linear chelator, diethylenetriaminepentaacetic acid (DTPA), was used and subsequently replaced by the more stable cyclic chelator 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). In addition, a fluorescently labeled AD-DTPA-Gd was prepared to demonstrate an active transport to the spinal cord by histochemistry. After successful synthesis and characterization, molecular migration of the AD-DTPA-Gd in the sciatic nerve of healthy Sprague Dawley rats was monitored by MRI for up to seven days. Enhancement of nerve structures was evaluated by MRI and correlated with ICP-MS analyses. To investigate the distribution of CA along the neuraxis, all animals were sacrificed after the final MRI monitoring. Nerves, spinal ganglions, and corresponding spinal cord sections were harvested, to determine the localization and concentration of the paramagnetic element. This is the first report that demonstrates the active uptake and transport of AD-Gd conjugates within the sciatic nerve. This new concept may serve as a potential diagnostic tool for the direct visualization and monitoring of the continuity of injured nerves.

Magnetic domains orientation in (Fe3O4/γ-Fe2O3) nanoparticles coated by Gadolinium-diethylenetriaminepentaacetic acid (Gd3+-DTPA)

In this work, the magnetic domains (MDs) orientation was evaluated from magnetite/maghemite nanoparticles (Fe3O4/γ-Fe2O3) NPs coated with Gadolinium (Gd3+) chelated with diethylenetriamine pentaacetate acid (Gd–DTPA). The (Fe3O4/γ–Fe2O3) superparamagnetic cores were configured by adding a DTPA organic layer and paramagnetic Gd as (Fe3O4/γ–Fe2O3)@Gd–DTPA NPs. The cores were obtained by coprecipitation and coated with additional modifications to the synthesis with Gd–DTPA. Analysis of properties showed that particles 9–12 nm, with Gd–DTPA layer thickness ∼10 nm increased their magnetisation from 62.72 to 75.82 emu/g. The result showed that the structure, particle size, composition, thickness and interface defects, as well as the anisotropy, play an important role in MDs orientation of (Fe3O4/γ–Fe2O3)@Gd–DTPA NPs. Magnetic force microscopy (MFM) analysis showed an MDs uniaxial orientation of 90° at magnetisation and disorder at zero conditions and demagnetisation. The MDs interactions showed uniaxial anisotropy defined in the direction of the magnetic field. These addressable and rotational features could be considered for potential applications to induce hydrogen proton alignment in water by longitudinal spin-lattice relaxation T 1 and transversal spin-spin relaxation T 2 as a dual contrast agent and as a theranostic trigger.

T2- and T1 relaxivities and magnetic hyperthermia of iron-oxide nanoparticles combined with paramagnetic Gd complexes

The present paper reports the synthesis of iron-oxide nanoparticles (diameter 12.8±2.2 nm) coated with silica shell doped with paramagnetic Gd(III)-based complexes. The resulting nanoparticles with a silica shell thickness of about 45 nm have an average diameter of 113.1±14.3 nm and feature high transverse and longitudinal relaxivities (356 and 25 mM−1 s−1, respectively) at 1.5 T and 25 °C on a medical whole body NMR scanner. It has been also revealed using magnetic heating measurements that the prepared core-shell nanoparticles possess a high specific adsorption rate of around 236 W/g in aqueous media. The surface of the composite nanoparticles was decorated by amino-groups for a greater cellular uptake behaviour. The cell viability measurements reveal the concentration-dependent cytotoxicity of the nanoparticles, which agrees well with the high content of Gd(III) complexes in the nanomaterial. The obtained results show that the core-shell design of nanoparticles with superparamagnetic and paramagnetic parts can be promising for high transverse (and longitudinal) relaxivity as well as magnetic hyperthermia.

Hyperpolarized 89Y-EDTMP complex as a chemical shift-based NMR sensor for pH at the physiological range

Yttrium (III) complexes are interesting due to the similarity of their chemistry with gadolinium complexes that are used as contrast agents in nuclear magnetic resonance (NMR) spectroscopy or imaging (MRI). While most of the paramagnetic Gd3+-based MRI contrast agents are T1 or T2 relaxation-based sensors such as Gd3+-complexes for zinc or pH detection, a number of diamagnetic Y3+-complexes rely on changes in the chemical shift for potential quantitative MRI in biological milieu. 89Y, however, is a challenging nucleus to work with in conventional NMR or MRI due to its inherently low sensitivity and relatively long T1 relaxation time. This insensitivity problem in 89Y-based complexes can be circumvented with the use of dissolution dynamic nuclear polarization (DNP) which allows for several thousand-fold enhancement of the NMR or MRI signal relative to thermal equilibrium signal. Herein, we report on the feasibility of using hyperpolarized 89Y-complexes with phosphonated open-chain ligands, 89Y-EDTMP and 89Y-DTPMP, as potential chemical shift-based pH NMR sensors. Our DNP-NMR data show that hyperpolarized 89Y-DTPMP has an apparent pKa ~ 7.01 with a 4 ppm-wide chemical shift dispersion with the signal disappearing at pH below 6.2. On the other hand, pH titration data on hyperpolarized 89Y-EDTMP show that it has an apparent pKa of pH 6.7 and a 16-ppm wide chemical shift dispersion at pH 5–9 range. In comparison, the previously reported hyperpolarized pH NMR sensor 89Y-DOTP has a pKa of 7.64 and ~ 10-ppm wide chemical shift dispersion at pH 4–9 range. Overall, our data suggest that hyperpolarized 89Y-EDTMP is better than hyperpolarized 89Y-DOTP in terms of pH sensing capability at the physiological range.

Monte Carlo modeling of bulk Gd

To understand the interplay between lattice structure and spin degrees of freedom, a bulk-Gd lattice as a hexagonal close-packed structure was generated and populated with paramagnetic Gd3+ ions with random projections (MSGd(i), i = 1, 245, or 443). Isotropic interactions of every site with their 12 nearest neighbors were taken into account. On the basis of the Monte Carlo Metropolis algorithm, the variation with temperature and magnetic field strength was obtained for the following physical quantities: magnetization M(T,H), the product of the magnetic susceptibility and temperature χmol∗T, magnetic specific heat C(T,H), entropy variation ΔS(T,ΔH), and statistics of spin projections MSGd(i,T). We also show the resulting interatomic exchange JGd−Gd, the reorientation of the spin temperature, the behavior of the Curie temperature versus a magnetic field, and magnetocaloric properties of bulk Gd.