R1 Values Research Articles

Three new members of the hakite series, Cu6(Cu4Me2+2)Sb4Se13: hakite-(Cd), hakite-(Fe) and hakite-(Zn) from the Bytíz deposit, uranium and base-metal Příbram ore district, Czech Republic

Abstract Hakite-(Cd), hakite-(Fe) and hakite-(Zn) are new minerals belonging to the tetrahedrite group and forming, along with hakite-(Hg), the hakite series. They have been discovered in samples collected from the Bytíz deposit, in the uranium and base-metal Příbram ore district, Central Bohemia, Czech Republic. They occur as anhedral grains, up to 300 μm in size, in a calcite gangue, associated with clausthalite, cadmoselite, hakite-(Hg) [for hakite-(Cd)], berzelianite, bukovite, bytízite, crookesite, chaméanite, eskebornite, příbramite, the not yet approved giraudite-(Hg) and giraudite-(Cu), hakite-(Hg), umangite, chalcopyrite, tetrahedrite-(Zn) and a new Cu–As selenide [for hakite-(Fe) and -(Zn)]. The three new species are black, with a metallic lustre. Mohs hardness is ca. 3½–4; calculated density is 6.019 (Hak-Cd), 6.011 (Hak-Fe) and 6.081 g.cm–3 (Hak-Zn). In reflected light, they are isotropic, pale grey with bluish (Hak-Cd) or brownish (Hak-Fe and Hak-Zn) shades. Empirical formulae of hakite-(Cd), hakite-(Fe), and hakite-(Zn) are Cu9.71Ag0.24Cd1.51Hg0.43Zn0.03(Sb3.94As0.13)Σ4.07Se11.35S1.57, Cu10.11Ag0.18Fe0.81Zn0.50Hg0.26(Sb3.72As0.41)Σ4.13Se12.65S0.12, and Cu10.03Ag0.24Zn0.61Fe0.53Hg0.45(Sb3.55As0.60)Σ4.15Se12.82S0.08, respectively. These formulae correspond to the end-member formulae Cu6(Cu4Cd2)Sb4Se13 (Hak-Cd), Cu6(Cu4Fe2)Sb4Se13 (Hak-Fe), and Cu6(Cu4Zn2)Sb4Se13 (Hak-Zn). All these new members of the hakite series are cubic, I $\bar{4}$ 3m, Z = 2, with unit-cell parameters a = 10.8860(6) Å, V = 1290.0(2) Å3 (Hak-Cd); a = 10.7983(4) Å, V = 1259.12(14) Å3 (Hak-Fe); and a = 10.8116(14) Å, V = 1263.8(5) Å3 (Hak-Zn). These species are isotypic with the other members of the tetrahedrite group, and their crystal structures have been refined on the basis of single-crystal X-ray diffraction data down to R1 values of 0.0230 (Hak-Cd), 0.0254 (Hak-Fe), and 0.0302 (Hak-Zn). These structural data allow us to describe the S-to-Se partitioning in hakite-series minerals and to understand the mechanisms avoiding too short Me–Se distances in these selenides.

Optimization of Harmony Improvement in Led Lights Using The MQPSO Method

Currently, there are many types of lighting used in the lighting field, one of which is LED lighting. Harmonics is a phenomenon in the electrical system that causes quality disturbances because the current waveform or voltage of the power source is distorted and can cause disturbances in the electrical system. In this research, mathlab was used with the MQPSO method to optimize LED lamp harmonics and reduce the THD value. This method uses a series of LED lighting components to optimize harmonic values. The components that make up the LED light circuit in question are resistors, capacitors and inductors. The optimization results show the best R, L, and C values ​​in the 53rd swarm (particle), and convergence values ​​are achieved in the 17th iteration with a fitness value of 0.5 and an R1 value of 550 Ω, and R2 530 Ω, R3 220 Ω, C1 1.0409 μF, C2 1.0117 μF, C3 1.0221 μF, L1 4.9984 H. The resulting THD and C-RMS values ​​are 1.4901% and 61.674%.

Effects of Mixed Metal Exposure on MRI Metrics in Basal Ganglia.

Welding fumes contain various metals. Past studies, however, mainly focused on Manganese (Mn)-related neurotoxicity. This study investigated welding-related mixed metal exposure effects on MRI metrics in the basal ganglia (BG) and their dose-response relationship. Subjects with (N = 23) and without (N = 24) a welding exposure history were examined. Metal exposure was estimated with exposure history questionnaire and whole blood metal levels. T1 (weighted-intensity and relaxation time; estimates of brain Mn accumulation), diffusion tensor imaging [Axial (AD), mean (MD), radial diffusivity (RD), and fractional anisotropy (FA); estimates of microstructural differences] metrics in BG [caudate nucleus, putamen, and globus pallidus (GP)] and voxel-based morphometry (for volume) were examined and related with metal exposure measures. Compared to controls, welders showed higher GP R1 (1/T1; p = 0.034) but no differences in blood metal and T1-weighted (T1W) values in any ROIs (p's > 0.120). They also had higher AD and MD values in the GP (p's < 0.033) but lower FA values in the putamen (p = 0.039) with no morphologic differences. In welders, higher blood Mn and Vanadium (V) levels predicted higher BG R1 and T1W values (p's < 0.015). There also were significant overall metal mixture effects on GP T1W and R1 values. Moreover, GP AD and MD values showed non-linear associations with BG T1W values: They increased with increasing T1W values only above certain threshold of T1 values. The current findings suggest that Mn and V individually but also metal mixtures jointly predict GP T1 signals that may in turn contribute to altered DTI metrics in the BG after certain exposure threshold levels.

Elevated cerebral blood flow proxy with increased beta-amyloid burden in Alzheimer’s disease preclinical phase evaluated by dual-phase 18F-florbetaben positron emission tomography

This study investigated the earliest change of cerebral blood flow (CBF) and its relationship with β-amyloid (Aβ) burden in preclinical Alzheimer’s disease (AD) employing dual-phase 18F-florbetaben (FBB) PET. Seventy-one cognitively normal (NC) individuals were classified as Aβ negative (Aβ−NC) or positive (Aβ+NC) based on two different cutoff values: an SUVR of > 1.08 and a Centiloid scale of > 20. The PET scans were acquired in two phases: an early phase (0–10 min, eFBB) and a delayed phase (90–110 min, dFBB), which were averaged to generate single-frame images for each phase. Furthermore, an R1 parametric map was generated from the early phase data using a simplified reference tissue model. We conducted regional and voxel-based analyses to compare the eFBB, dFBB, and R1 images between the Aβ positive and negative groups. In addition, the correlations between the CBF proxy R1 and the dFBB SUVR were analyzed. The Aβ+NC group showed significantly higher dFBB SUVR in both the global cerebral cortex and target regions compared to the Aβ−NC group, while no significant differences were observed in eFBB SUVR between the two groups. Furthermore, the Aβ+NC group exhibited significantly higher R1 values, a proxy for cerebral perfusion, in both the global cerebral cortex and target regions compared to the Aβ−NC group. Significant positive correlations were observed between R1 and dFBB SUVR in both the global cerebral cortex and target regions, which remained significant after controlling for demographics and cognitive profiles, except for the medial temporal and occipital cortices. The findings reveal increased CBF in preclinical AD and a positive correlation between CBF and amyloid pathology. The positive correlation between R1 and amyloid burden may indicate a compensatory mechanism in the preclinical stage of Alzheimer’s disease, but to elucidate this hypothesis, further longitudinal observational studies are necessary.

Non-contrast magnetic resonance evaluation of active multiple sclerosis lesions: Emerging role of quantitative synthetic magnetic resonance imaging.

The current study aims to explore the utility of novel synthetic MRI-derived quantitative parameters including myelin-correlated volume (MyC) in identifying active MS lesions without injecting gadolinium contrast. 43 MS patients underwent institutional MS protocol including 3D FLAIR and post-contrast 3D T1VIBE sequence on a 1.5T MR Scanner in addition to synthetic MRI sequence. MS plaques were categorised into enhancing (C) and non-enhancing (N) lesions. They were also sub-categorised based on location into periventricular WM lesions (P), deep WM lesions (D), infratentorial lesions (I) and cortical-juxtacortical (C) lesions. ROIs were placed on Synthetic FLAIR images in MS lesions and quantitative parameters of R1, R2, PD and myelin-correlated volume (MyC) obtained. Sensitivity and specificity for various cut-off values to differentiate enhancing from non-enhancing multiple sclerosis lesions were calculated by performing ROC curve analysis and logistic regression analysis. Contrast enhancing lesions demonstrated significantly higher mean R1, R2 values and lower mean PD values in comparison to non-enhancing lesions (p < 0.05) but with limited specificity. Region-wise analysis revealed high AUC values for mean R1 and R2 at cortical-juxtacortical lesions (p < 0.001) followed by periventricular lesions (p < 0.003) for differentiating enhancing from non-enhancing lesions with no significant contribution from MyC and PD values. Synthetic MRI-derived quantitative parameters of mean R1, R2, MyC and PD hold value in differentiating contrast enhancing and non-enhancing MS lesions without administering gadolinium-based contrast agent. However, the current study did not achieve significant specificity for establishing the same.

Optimization of micelle-encapsulated extremely small sized iron oxide nanoparticles as a T1 contrast imaging agent: biodistribution and safety profile

BackgroundIron oxide nanoparticles (IONPs) have been cleared by the Food and Drug Administration (FDA) for various clinical applications, such as tumor-targeted imaging, hyperthermia therapy, drug delivery, and live-cell tracking. However, the application of IONPs as T1 contrast agents has been restricted due to their high r2 values and r2/r1 ratios, which limit their effectiveness in T1 contrast enhancement. Notably, IONPs with diameters smaller than 5 nm, referred to as extremely small-sized IONPs (ESIONs), have demonstrated potential in overcoming these limitations. To advance the clinical application of ESIONs as T1 contrast agents, we have refined a scale-up process for micelle encapsulation aimed at improving the hydrophilization of ESIONs, and have carried out comprehensive in vivo biodistribution and preclinical toxicity assessments.ResultsThe optimization of the scale-up micelle-encapsulation process, specifically employing Tween60 at a concentration of 10% v/v, resulted in ESIONs that were uniformly hydrophilized, with an average size of 9.35 nm and a high purification yield. Stability tests showed that these ESIONs maintained consistent size over extended storage periods and dispersed effectively in blood and serum-mimicking environments. Relaxivity measurements indicated an r1 value of 3.43 mM− 1s− 1 and a favorable r2/r1 ratio of 5.36, suggesting their potential as T1 contrast agents. Biodistribution studies revealed that the ESIONs had extended circulation times in the bloodstream and were primarily cleared via the hepatobiliary route, with negligible renal excretion. We monitored blood clearance and organ distribution using positron emission tomography and magnetic resonance imaging (MRI). Additionally, MRI signal variations in a dose-dependent manner highlighted different behaviors at varying ESIONs concentrations, implying that optimal dosages might be specific to the intended imaging application. Preclinical safety evaluations indicated that ESIONs were tolerable in rats at doses up to 25 mg/kg.ConclusionsThis study effectively optimized a scale-up process for the micelle encapsulation of ESIONs, leading to the production of hydrophilic ESIONs at gram-scale levels. These optimized ESIONs showcased properties conducive to T1 contrast imaging, such as elevated r1 relaxivity and a reduced r2/r1 ratio. Biodistribution study underscored their prolonged bloodstream presence and efficient clearance through the liver and bile, without significant renal involvement. The preclinical toxicity tests affirmed the safety of the ESIONs, supporting their potential use as T1 contrast agent with versatile clinical application.

Employing antagonistic C-X-C motif chemokine receptor 4 antagonistic peptide functionalized NaGdF4 nanodots for magnetic resonance imaging-guided biotherapy of breast cancer

C-X-C motif chemokine receptor 4 (CXCR4) is a promising therapeutic target of breast cancer because it is overexpressed on cell surface of all molecular subtypes of breast cancer including triplenegative breast cancer (TNBC). Herein, CXCR4 antagonistic peptide-NaGdF4 nanodot conjugates (termed as anti-CXCR4-NaGdF4 NDs) have been constructed for magnetic resonance imaging (MRI)-guided biotherapy of TNBC through conjugation of the C-X-C Motif Chemokine 12 (CXCL12)-derived cyclic peptide with tryptone coated NaGdF4 nanodots (5 ± 0.5 nm in diameter, termed as Try-NaGdF4 NDs). The as-prepared anti-CXCR4-NaGdF4 NDs exhibits high longitudinal relaxivity (r1) value (21.87 mM−1S−1), reasonable biocompatibility and good tumor accumulation ability. The features of anti-CXCR4-NaGdF4 NDs improve the tumor-MRI sensitivity and facilitate tumor biotherapy after injection in mouse-bearing MDA-MB-231 tumor model in vivo. MRI-guided biotherapy using anti-CXCR4-NaGdF4 NDs enables to suppress 46% tumor growth. In addition, about 47% injection dose of anti-CXCR4-NaGdF4 NDs is found in the mouse urine at 24 h post-injection. These findings demonstrate that anti-CXCR4-NaGdF4 NDs enable to be used as renal clearable nanomedicine for biotherapy and MRI of breast cancer.

Nanoprobes based on quantum dots and Gd(III) complexes for dual optical and magnetic resonance imaging

The combination of more than one clinical technique has been increasingly explored to improve imaging diagnosis, suppressing the limitations of individual procedures. Quantum dots (QDs) have been associated with paramagnetic complexes (GdDOTA) to develop optical-magnetic nanoprobes for imaging techniques. Herein, we report the preparation of bimodal nanoprobes by conjugating fluorescent QDs with GdDOTA complexes through dative bonds. These nanoprobes showed an enhancement in their emission intensity compared to bare QDs. Moreover, the nanosystems exhibited r1 values up to 69% higher than the clinical GdDOTA. Therefore, the bimodal systems demonstrated promising performance for both optical and magnetic resonance imaging, exhibiting potential as bimodal contrast agents.

Circadian rapid eye movement sleep expression is associated with brain microstructural integrity in older adults

Rapid eye movement sleep (REMS) is increasingly suggested as a discriminant sleep state for subtle signs of age-related neurodegeneration. While REMS expression is under strong circadian control and circadian dysregulation increases with age, the association between brain aging and circadian REMS regulation has not yet been assessed. Here, we measure the circadian amplitude of REMS through a 40-h in-lab multiple nap protocol in controlled laboratory conditions, and brain microstructural integrity with quantitative multi-parameter mapping (MPM) imaging in 86 older individuals. We show that reduced circadian REMS amplitude is related to lower magnetization transfer saturation (MTsat), longitudinal relaxation rate (R1) and effective transverse relaxation rate (R2*) values in several white matter regions mostly located around the lateral ventricles, and with lower R1 values in grey matter clusters encompassing the hippocampus, parahippocampus, thalamus and hypothalamus. Our results further highlight the importance of considering circadian regulation for understanding the association between sleep and brain structure in older individuals.

RANCANG BANGUN PENGENDALI LAMPU DENGAN KOMUNIKASI SERIAL BERBASIS MIKROKONTROLLER PIC16F877 DAN 16F876 MELALUI JARINGAN LISTRIK RUMAH

Serial data transmission can be applied by the use of the grid as a carrier is one alternative that has some advantages, such as reducing the use of cables In this design project created a special application of serial data communication via the electricity network that uses circuit PIC16F877di Microcontroller Master controller as the main controller to control ON / OFF to 5 pieces Slave controller circuit using the PIC16F876 microcontroller to control the lights as the electrical load. Research conducted using a modulation method Frequency Shift Keying (FSK) as modulator and demodulator, also using a series transformer coupling and high pass filter circuit. The main component Frequency Shift Keying (FSK) the Integrated Circuit (IC) XR2206 as a Modulator and Demodulator IC XR2211 as, as well as using a passive filter that serves to pass a predetermined frequency is 70KHz - 80KHz. The frequency value to be achieved by calculating the value of an external capacitor and resistor. The results of the calculations at the design stage modulator, with a value of C = 10nF obtained value R1 = 1428Ω, R2 = 1250Ω. Keywords: PIC16F877, PIC16F876, XR2206, XR2211

Self-Assembling Peptide-Based High-Relaxivity Targeted MRI Contrast Agents.

Concentration-dependent increases in relaxivity (r1) were found to be induced by self-assembly when Fmoc is adjacent to tryptophan in peptide-based MRI contrast agents featuring Gd-DOTA. A series of di- and tri-peptides were synthesized to test the effect of ionic strength, N-terminal substituent, peptide length, net charge, and relative location of Fmoc and tryptophan on r1 and critical aggregation concentration (CAC) at 1.0 Tesla. Compared to nominal r1 values of 3.5-7.4 mM-1 s-1 per Gd(III), r1 values increased dramatically to 13.2-16.9 mM-1 s-1 per Gd(III) upon self-assembly, with CACs between 0.22 and 2.59 mM when tested in H2O or PBS. When tested in fetal bovine serum (FBS), the compounds maintained high r1 values of 11.2-13.0 mM-1 s-1, but had dramatically lower CAC values below 25 μM. These findings guided the synthesis of two targeted, high-relaxivity MRI contrast agents that contained PSMA-binding ligand, DCL. Their r1 values in H2O or PBS increased from 5.9-7.4 mM-1 s-1 to 13.5-14.8 mM-1 s-1 with CAC values of 1.65-2.70 mM. In FBS, their r1 values were found to be 11.2-11.9 mM-1 s-1, with CAC values below 25 μM. By the conjugation of targeting agents in the last step of synthesis, a broadly applicable route to targeted, high-relaxivity MRI contrast agents is offered.

Gadolinium-doped carbon dots with long-wavelength emission for dual-modal imaging

Subject of study. This study is focused on luminescent carbon dots derived from o-phenylenediamine and gadolinium chloride or nitrate hexahydrate. Aim of study. The study aims to fabricate long-wavelength photoluminescent gadolinium-doped carbon dots that could function as contrast agents for magnetic resonance imaging. Additionally, the study investigates the impact of the precursor type used on the chemical composition and optical transitions of the resulting nanoparticles. Method. Carbon dots were synthesized using a one-step solvothermal method, and their composition and optical properties were analyzed using spectroscopy methods. Magnetic resonance imaging was conducted using a clinical magnetic resonance imaging scanner with a field strength of 1.5 T. Main results. In this study, two types of carbon dots were synthesized from o-phenylenediamine and gadolinium chloride or nitrate hexahydrate using the solvothermal method. Metal doping, at a concentration sufficient for further investigations, is achieved only when gadolinium chloride is used. Additionally, the presence of gadolinium chloride during the synthesis leads to the formation of luminescent centers within the carbon dots with emission at 600–720 nm and a photoluminescence quantum yield of 6.3%. In contrast, gadolinium nitrate increases the nitrogen content within the o-phenylenediamine-based carbon dots while inhibiting metal doping. The luminescent band with an emission maximum at 550 nm and a photoluminescence quantum yield of 7.4% originates from the o-phenylenediamine derivatives formed within such carbon dots. The study results also show that the gadolinium-doped carbon dots alter the relaxation times during magnetic resonance scanning, and the calculated relaxivity (r1 and r2) values are 6.4 and 38.6L⋅mmol−1⋅s−1, respectively. Thus, the synthesized carbon dots function as positive contrast agents during magnetic resonance scanning. Practical significance. Carbon dots with long-wavelength emission are promising nanoprobes for luminescence imaging. With gadolinium doping, these nanoparticles can also be used as contrast agents during magnetic resonance imaging. Consequently, carbon dots based on o-phenylenediamine and gadolinium chloride hexahydrate can be further utilized as dual-mode nanoprobes for bioimaging.

WITHDRAWN: Organic molecule-mediated synthesis of GdPO4:Eu3+ micro/nano-luminescent materials and MRI tracing performance evaluation

The influence of the introduction of structural modifiers citric acid and acetic acid on the morphology, luminescence properties and magnetic resonance imaging (MRI) tracer properties of GdPO4:Eu3+ micro-nanoparticles synthesized in ethanol system was investigated in the paper. In this system, GdPO4:Eu3+ micro-nanomaterials such as square flake, hexagram, waist drum morphologies can be prepared by adjusting the ratios of structural modifier, phosphoric acid and gadolinium nitrate, respectively. In addition, the synthesized products were analyzed by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), fluorescence spectroscopy (PL), and magnetic resonance imaging (MRI) detection. The products were found to exhibit good crystallinity, particularly in terms of their luminescent properties, which exhibited notable differences. Overall, the luminescent properties of GdPO4:Eu3+ synthesized by citric acid modification were significantly enhanced compared with acetate modification, with at least five times more luminescent intensity than that of acetate modification. And amazingly, the GdPO4:Eu3+ luminescence intensity is strongest when the square flake-hexagram coexisting. The tracer properties of GdPO4:Eu3+ MRI with better luminescent square flake, hexagram, and square flake-hexagram coexisting morphologies were also investigated. It was found that the square flake had better T1-longitudinal relaxation imaging with a relaxation rate r1 value of 0.79 mM−1s−1. This work is a good advancement for organic molecule-mediated modulation, synthesis of gadolinium phosphate-based rare-earth micro-nanomaterials and study of their applications in luminescence and MRI tracing.

Ligand-Induced Atomically Segregation-Tunable Alloy Nanoprobes for Enhanced Magnetic Resonance Imaging.

Bimetallic iron-noble metal alloy nanoparticles have emerged as promising contrast agents for magnetic resonance imaging (MRI) due to their biocompatibility and facile control over the element distribution. However, the inherent surface energy discrepancy between iron and noble metal often leads to Fe atom segregation within the nanoparticle, resulting in limited iron-water molecule interactions and, consequently, diminished relaxometric performance. In this study, we present the development of a class of ligand-induced atomically segregation-tunable alloy nanoprobes (STAN) composed of bimetallic iron-gold nanoparticles. By manipulating the oxidation state of Fe on the particle surface through varying molar ratios of oleic acid and oleylamine ligands, we successfully achieve surface Fe enrichment. Under the application of a 9 T MRI system, the optimized STAN formulation, characterized by a surface Fe content of 60.1 at %, exhibits an impressive r1 value of 2.28 mM-1·s-1, along with a low r2/r1 ratio of 6.2. This exceptional performance allows for the clear visualization of hepatic tumors as small as 0.7 mm in diameter in vivo, highlighting the immense potential of STAN as a next-generation contrast agent for highly sensitive MR imaging.

In vivo demonstration of globotriaosylceramide brain accumulation in Fabry Disease using MR Relaxometry

PurposeHow to measure brain globotriaosylceramide (Gb3) accumulation in Fabry Disease (FD) patients in-vivo is still an open challenge. The objective of this study is to provide a quantitative, non-invasive demonstration of this phenomenon using quantitative MRI (qMRI).MethodsIn this retrospective, monocentric cross-sectional study conducted from November 2015 to July 2018, FD patients and healthy controls (HC) underwent an MRI scan with a relaxometry protocol to compute longitudinal relaxation rate (R1) maps to evaluate gray (GM) and white matter (WM) lipid accumulation. In a subgroup of 22 FD patients, clinical (FAbry STabilization indEX -FASTEX- score) and biochemical (residual α-galactosidase activity) variables were correlated with MRI data. Quantitative maps were analyzed at both global (“bulk” analysis) and regional (“voxel-wise” analysis) levels.ResultsData were obtained from 42 FD patients (mean age = 42.4 ± 12.9, M/F = 16/26) and 49 HC (mean age = 42.3 ± 16.3, M/F = 28/21). Compared to HC, FD patients showed a widespread increase in R1 values encompassing both GM (pFWE = 0.02) and WM (pFWE = 0.02) structures. While no correlations were found between increased R1 values and FASTEX score, a significant negative correlation emerged between residual enzymatic activity levels and R1 values in GM (r = -0.57, p = 0.008) and WM (r = -0.49, p = 0.03).ConclusionsWe demonstrated the feasibility and clinical relevance of non-invasively assessing cerebral Gb3 accumulation in FD using MRI. R1 mapping might be used as an in-vivo quantitative neuroimaging biomarker in FD patients.

Folate Receptor Targeting Mn(II) Complex Encapsulated Porous Silica Nanoparticle as an MRI Contrast Agent for Early-State Detection of Cancer.

Cancer is recognized as one of the major causes of mortality, however, early-stage detection can increase the survival chance greatly. It is recognized that folate receptors are gradually overexpressed in the cellular membrane with the progress of cancer from stage 1 to stage 4. Utilizing the fact, herein, developed a porous silica nanoparticle system C1@SiO2-FA-NP; A) impregnated with thermodynamically stable Mn(II) complex (1) molecules within the core of the nanoparticle, and B) surface functionalized with folate units. It exhibited a high longitudinal relaxivity value r1 = 21.45 mM-1s-1 that substantially increased to r1 = 40.97 mM-1s-1 in the presence of 0.67mM concentration of BSA under the physiological condition. The in vitro fluorescent images after surface conjugation of C1@SiO2-FA-NP with FITC (fluorescein isothiocyanate) buttressed the inclusion of the nanoparticle exclusively within the cancerous HeLa cells than that of healthy HEK293 cells. The importance of the surface-bound folate unit in the nanoparticle is further established by comparing the fluorescent images of HeLa cells in the absence of the group. Finally, the applicability of C1@SiO2-FA-NP as the T1-weighted MRI contrast agent for early-stage cancer diagnosis is established within C57BL/6 mice after infecting the mice with HeLa cells.

Re-emergence of foot-and-mouth disease in the Republic of Korea caused by the O/ME-SA/Ind-2001e lineage.

The O/ME-SA/Ind-2001e foot-and-mouth disease virus (FMDV) lineage is a pandemic strain that has recently become dominant within East and Southeast Asia. During May 2023, this viral lineage spread to the Republic of Korea, where 11 outbreaks were detected on cattle and goat farms located in Cheongju and Jeungpyeong. Infected animals displayed typical FMD signs including vesicular lesions with drooling and anorexia. Molecular diagnostic testing and genetic analysis (VP1 sequencing) showed that the causative FMDVs belonged to the O/ME-SA/Ind-2001e lineage and shared the closest nucleotide identity (97.95-99.21%) to viruses that have been collected from Mongolia and South-East Asian countries. Phylogenetic analyses showed that these sequences were distinct to those collected from the previous Korean O/ME-SA/Ind-2001e lineage outbreaks in 2019, demonstrating that these cases are due to a new incursion of the virus into the country. Prompt implementation of emergency vaccination using antigenically matched serotype O vaccines (r1 value: 0.74-0.93), together with intensive active surveillance on farms surrounding the infected premises has successfully prevented further spread of FMD. These recent FMD outbreaks reinforce the importance of research to understand the risks associated with transboundary pathways in the region, in order to reduce the possibility of a further reintroduction of FMD into the Republic of Korea.

Benchmarking Guanidinium Organosulfonate Hydrogen-Bonded Frameworks for Structure Determination of Encapsulated Guests.

Single crystal X-ray diffraction (SCXRD) is arguably the most definitive method for molecular structure determination, but it is often challenged by compounds that are liquids or oils at room temperature or do not form crystals adequate for analysis. Our laboratory previously reported a simple, cost-effective, single-step crystallization method based on guanidinium organosulfonate (GS) hydrogen bonded frameworks for structure determination of a wide range of encapsulated guest molecules, including assignment of the absolute configuration of chiral centers. Herein, we expand on those results and report a head-to-head comparison of the GS method with adamantoid "molecular chaperones", which have been reported to be useful hosts for structure determination. Inclusion compounds limited to only two GS hosts are characterized by low R1 values and Flack parameters, infrequent disorder of the host and guest, and manageable disorder when it does exist. The structures of some target molecules that were not included or resolved using the adamantoid chaperones were successfully included and resolved by the GS hosts, and vice versa. Of the 32 guests attempted by the GS method, 31 inclusion compounds afforded successful guest structure solutions, a 97% success rate. The GS hosts and adamantoid chaperones are complementary with respect to guest inclusion, arguing that both should be employed in the arsenal of methods for structure determination. Furthermore, the low cost of organosulfonate host components promises an accessible route to molecular structure determination for a wide range of users.

Kilogram scale facile synthesis and systematic characterization of a Gd-macrochelate as T1-weighted magnetic resonance imaging contrast agent

To overcome the problems of commercial magnetic resonance imaging (MRI) contrast agents (CAs) (i.e., small molecule Gd chelates), we have proposed a new concept of Gd macrochelates based on the coordination of Gd3+ and macromolecules, e.g., poly(acrylic acid) (PAA). To further decrease the r2/r1 ratio of the reported Gd macrochelates that is an important factor for T1 imaging, in this study, a superior macromolecule hydrolyzed polymaleic anhydride (HPMA) was found to coordinate Gd3+. The synthesis conditions were optimized and the generated Gd-HPMA macrochelate was systematically characterized. The obtained Gd-HPMA29 synthesized in a 100 L of reactor has a r1 value of 16.35 mM−1 s−1 and r2/r1 ratio of 2.05 at 7.0 T, a high Gd yield of 92.7% and a high product weight (1074 g), which demonstrates the feasibility of kilogram scale facile synthesis. After optimization of excipients and sterilization at a high temperature, the obtained Gd-HPMA30 formulation has a pH value of 7.97, osmolality of 691 mOsmol/kg water, density of 1.145 g/mL, and viscosity of 2.2 cP at 20 ℃ or 1.8 cP at 37 ℃, which meet all specifications and physicochemical criteria for clinical injections indicating the immense potential for clinical applications.Graphical

Synthesis and characterization of cellulose nanocrystals/Gd2O3 nanocomposite as a dual-mode contrast agent for MRI via gamma-ray irradiation

This study developed a biocompatible nanocomposite using cellulose nanocrystals (CNCs), polyethylene glycol (PEG), and sodium hydroxide (NaOH), combined with gadolinium oxide nanoparticles (Gd2O3-NPs) through gamma radiation to decrease the size of nanoparticles and increase their uniformity. This research found that the (CNCs-PEG/NaOH)/Gd2O3 nanocomposite exhibits notable characteristics, including high saturation magnetization (1.44 emu/g), remarkable colloidal stability with a highly negative surface charge of −31.4 mV, and a small hydrodynamic size of 5.5 ± 0.7 nm. Furthermore, the MTT assay conducted on HeLa cell lines revealed the excellent biocompatibility of the (CNCs-PEG/NaOH)/Gd2O3 nanocomposite. No cytotoxic effects were observed, and the nanocomposite exhibited adequate cellular uptake. Moreover, the (CNCs-PEG/NaOH)/Gd2O3 nanocomposite displayed a remarkable enhancement effect on both T1 and T2-weighted images, with high r1 and r2 relaxivity values of 21.694 mM−1 s−1 and 43.799 mM−1 s−1, respectively, resulting in a relaxivity ratio (r2/r1) of 2.02 when compared to clinical and commercial agents. This biocompatible nanocomposite holds promise as a dual contrast agent in MRI and various other biomedical applications. It is envisaged that gamma irradiation is a good method to produce nanoparticles within the nanoscale range.