Magnetic Tunability via Control of Crystallinity and Size in Polycrystalline Iron Oxide Nanoparticles.

Iron oxide nanoparticles (IONPs) are widely used for biomedical applications due to their unique magnetic properties and biocompatibility. However, the controlled synthesis of IONPs with tunable particle sizes and crystallite/grain sizes to achieve desired magnetic functionalities across single-domain and multi-domain size ranges remains an important challenge. Here, a facile synthetic method is used to produce iron oxide nanospheres (IONSs) with controllable size and crystallinity for magnetic tunability. First, highly crystalline Fe3O4 IONSs (crystallite sizes above 24 nm) having an average diameter of 50 to 400 nm are synthesized with enhanced ferrimagnetic properties. The magnetic properties of these highly crystalline IONSs are comparable to those of their nanocube counterparts, which typically possess superior magnetic properties. Second, the crystallite size can be widely tuned from 37 to 10 nm while maintaining the overall particle diameter, thereby allowing precise manipulation from the ferrimagnetic to the superparamagnetic state. In addition, demonstrations of reaction scale-up and the proposed growth mechanism of the IONSs are presented. This study highlights the pivotal role of crystal size in controlling the magnetic properties of IONSs and offers a viable means to produce IONSs with magnetic properties desirable for wider applications in sensors, electronics, energy, environmental remediation, and biomedicine.

Allosteric effects of EF-G domain I mutations inducing ribosome frameshifting revealed by multiplexed force spectroscopy.

Ribosome translocation catalyzed by elongation factor G (EF-G) is a critical step in protein synthesis where the ribosome typically moves along the mRNA by three nucleotides at each step. To investigate the mechanism of EF-G catalysis, it is essential to precisely resolve the ribosome motion at both ends of the mRNA, which, to our best knowledge, is only achieved with the magnetic-based force spectroscopy developed by our groups. Here, we introduce a novel multiplexed force spectroscopy technique that, for the first time, offers single-nucleotide resolution for multiple samples. This technique combines multiple acoustic force generators with the smallest atomic magnetometer designed for biological research. Utilizing this technique, we demonstrate that mutating EF-G at the GTP binding pocket results in the ribosome moving only two nucleotides on both ends of the mRNA, thereby compromising ribosome translocation. This finding suggests a direct link between GTP hydrolysis and ribosome translocation. Our results not only provide mechanistic insights into the role of GTP binding pocket but also illuminate how allosteric mutations can manipulate translocation. We anticipate broader applications of our technique in the ribosome field, leveraging its high efficiency and single-nucleotide resolution.

Combined dynamic transcriptome and flavonoid metabolome reveal the role of Mo nanoparticles in the nodulation process in soybean.

Symbiotic nitrogen fixation can reduce the impact of agriculture on the environment by reducing fertilizer input. The rapid development of nanomaterials in agriculture provides a new prospect for us to improve the biological nitrogen fixation ability of leguminous crops. Molybdenum is an important component of nitrogenase, and the potential application of MoO3NPs in agriculture is largely unexplored. In this study, on the basis of verifying that MoO3NPs can improve the nitrogen fixation ability of soybean, the effects of MoO3NPs on the symbiotic nitrogen fixation process of soybean were investigated by using dynamic transcriptome and targeted metabolome techniques. Here we showed that compared with conventional molybdenum fertilizer, minute concentrations of MoO3NPs (0.01-0.1 mg kg-1) could promote soybean growth and nitrogen fixation efficiency. The nodules number, fresh nodule weight and nitrogenase activity of 0.1 mg kg-1 were increased by 17 %, 14 % and 27 %, and plant nitrogen accumulation increased by 17 %. Compared with conventional molybdenum fertilizer, MoO3NPs had a greater effect on apigenin, kaempferol and other flavonoid, and the expression of nodulation related genes such as ENOD93, F3'H. Based on WGCNA analysis, we identified a core gene GmCHS9 that was positively responsive to molybdenum and was highly expressed during MoO3NPs induced nodulation. MoO3NPs could improve the nitrogen fixation ability of soybean by promoting the secretion of flavonoids and the expression of key genes. This study provided a new perspective for the nano-strengthening strategy of nodules development and flavonoid biosynthesis by molybdenum.

DNA methylation induces subtle mechanical alteration but significant chiral selectivity.

DNA methylation is a major epigenetic modification that is closely related to human health. Many experimental techniques as well as theoretical methods have been used to detect the modified nucleotides and identify their effects on molecular binding. It remains challenging to resolve the effect of few methylations of nucleic acids. Using super-resolution force spectroscopy, we firstly revealed that single cytosine methylation increases the mechanical stability of the DNA duplex by 1.9 ± 0.3 pN. Methylation also induces significant chiral selectivity towards drug molecules such as d,l-tetrahydropalmatine. Our results precisely quantify the mechanical effect of methylation and suggest that drug design should take methylation into consideration for enhanced selectivity.

Revealing the Mechanistic Basis of Regulation of Phosphorus Uptake in Soybean (Glycine max) Roots by Molybdenum: An Integrated Omics Approach.

While molybdenum (Mo) application can improve phosphorus (P) availability to plants by changing P speciation in the rhizosphere, the mechanistic basis of this process remains unclear. This work investigated the impact of various combinations of Mo and P treatments on root morphology, P and Mo uptake, and root transcriptome and metabolome. Mo application significantly increased soybean biomass and the number of lateral roots at both low (5 µmol) or normal (500 µmol) P levels and significantly improved P concentration and accumulation in Normal P treatment. Compared with the Normal P treatment, Low P significantly increased the number of roots, root surface area, and root acid phosphatase secretion. A total of 6811 Mo-responsive differentially expressed genes and 135 differential metabolites were identified at two P levels. At Low P, transcriptional changes significantly increased root synthesis and secretion of succinic acid, methylmalonic acid, and other organic acids as well as acid phosphatase, thereby increasing the conversion of soil aluminum-bound P and organic P into available P. At Normal P, Mo application increased P uptake mainly by increasing the number of lateral roots. Thus, Mo helps crops adapt to different P levels by regulating root anatomy and transcriptional and metabolic profiles of their roots.

Force-Induced Visualization of Nucleic Acid Functions with Single-Nucleotide Resolution.

Nucleic acids are major targets for molecular sensing because of their wide involvement in biological functions. Determining their presence, movement, and binding specificity is thus well pursued. However, many current techniques are usually sophisticated, expensive, and often lack single-nucleotide resolution. In this paper, we report the force-induced visualization method that relies on the novel concept of mechanical force to determine the functional positions of nucleic acids with single-nucleotide resolution. The use of an adjustable mechanical force overcomes the variation of analyte concentration and differences in buffer conditions that are common in biological settings. Two examples are described to validate the method: one is probing the mRNA movement during ribosomal translocation, and the other is revealing the interacting sites and strengths of DNA-binding drugs based on the force amplitude. The flexibility of the method, simplicity of the associated device, and capability of multiplexed detection will potentially enable a broad range of biomedical applications.

Infantile Cranial Fasciitis: A Clinicopathologic Evaluation.

OBJECTIVE: To investigate the clinicopathologic features, immunophenotype, molecular genetic changes, and differential diagnosis of cranial fasciitis (CF). METHODS: The clinical manifestations, imaging, surgical technique, pathologic characteristics, special staining, and immunophenotype, as well as break-apart fluorescence in situ hybridization assay for USP6 of 19 CF cases were analyzed, retrospectively. RESULTS: The patients were 11 boys and 8 girls, aged 5 to 144 months, with a median age of 29 months. There were 5 cases (26.31%) in the temporal bone, 4 cases (21.05%) in the parietal bone, 3 cases (15.78%) in the occipital bone, 3 cases (15.78%) in the frontotemporal bone, 2 cases (10.52%) in the frontal bone, 1 case (5.26%) in the mastoid of middle ear, and 1 case (5.26%) in the external auditory canal. The main clinical manifestations were painless, with the presentation of masses that grew rapidly and frequently eroded the skull. There was no recurrence and no metastasis after the operation. Histologically, the lesion consists of spindle fibroblasts/myofibroblasts arranged in bundles, braided or atypical spokes. Mitotic figures could be seen, but not atypical forms. Immunohistochemical studies showed diffuse strong positive SMA and Vimentin in all CFs. These cells were negative for Calponin, Desmin, ß-catenin, S-100, and CD34. The ki-67 proliferation index was 5% to 10%. Ocin blue-PH2.5 staining showed blue-stained mucinous features in the stroma. The positive rate of USP6 gene rearrangement detected by fluorescence in situ hybridization assay was about 10.52%, and the positive rate was not related to age. All patients were observed for 2 to 124 months and showed no signs of recurrence or metastasis. CONCLUSIONS: In summary, CF was a benign pseudosarcomatous fasciitis that occurs in the skull of infants. Preoperative diagnosis and differential diagnosis were difficult. Computed tomography typing might be beneficial for imaging diagnosis, and pathologic examination might be the most reliable way to diagnose CF.

Clinicopathological Analysis of Sturge-Weber Syndrome with Focal Cortical Dysplasia FCD IIIc.

Objective: To investigate the clinicopathological features of children with Sturge-Weber syndrome and to analyze the correlation between the distribution area of leptomeningeal angiomatosis, the degree of cerebral cortical calcification, and the degree of cerebral atrophy associated with epileptic seizures. Methods: 10 children were diagnosed with SWS with FCD IIIc by histopathology and immunohistochemistry. Spearman correlation analysis was used to calculate the association of SWS with FCD IIIc and seizures in children. Results: The leptomeningeal angiomatosis area was markedly positively correlated with the degree of brain atrophy in 10 children with SWS (r = 0.783, p = 0.007). The distribution of leptomeningeal hemangiomatosis, the degree of cortical calcification, and brain atrophy were not significantly correlated with epilepsy. Conclusion: SWS may be accompanied by FCD IIIc. The more extensive the cerebral lobes of leptomeningeal angiomatosis in SWS, the more pronounced the brain atrophy.

Abnormal Degree Centrality in Children with Low-Function Autism Spectrum Disorders: A Sleeping-State Functional Magnetic Resonance Imaging Study.

Purpose: This study used the graph-theory approach, degree centrality (DC) to analyze whole-brain functional networks at the voxel level in children with ASD, and investigated whether DC changes were correlated with any clinical variables in ASD children. Methods: The current study included 86 children with ASD and 54 matched healthy subjects Aged 2-5.5 years. Next, chloral hydrate induced sleeping-state functional magnetic resonance imaging (ss-fMRI) datasets were acquired from these ASD and healthy subjects. For a given voxel, the DC was calculated by calculating the number of functional connections with significantly positive correlations at the individual level. Group differences were tested using two-sample t-tests (p < 0.01, AlphaSim corrected). Finally, relationships between abnormal DCs and clinical variables were investigated via Pearson's correlation analysis. Results: Children with ASD exhibited low DC values in the right middle frontal gyrus (MFG) (p < 0.01, AlphaSim corrected). Furthermore, significantly negative correlations were established between the decreased average DC values within the right MFG in ASD children and the total ABC scores, as well as with two ABC subscales measuring highly relevant impairments in ASD (ie, stereotypes and object-use behaviors and difficulties in language). Conclusion: Taken together, the results of our ss-fMRI study suggest that abnormal DC may represent an important contribution to elucidation of the neuropathophysiological mechanisms of preschoolers with ASD.

Functional Connectivity Underlying Symptoms in Preschool Boys With Autism: A Resting-State Functional Magnetic Resonance Imaging Study.

Background: Single-sex children have been regarded as one of the best subjects to understand the abnormal development patterns of autism spectrum disorders (ASDs). However, the functional connectivity (FC) behind their symptoms is still unknown. Methods: Based on FC analysis, the acquired resting-state functional magnetic resonance imaging (rs-fMRI) data sets, including 86 boys with ASD and 54 normal controls (NC), were used to detect the neural synchronous activity between brain regions. Pearson correlation analysis was used to evaluate the relationship between the abnormal FC value and clinical features. Results: Individuals with ASD showed enhanced FC between the right calcarine and the right lingual gyrus (LG). The right medial orbital frontal cortex also showed increased FC with bilateral inferior temporal gyrus (ITG) [two-tailed, voxel-level p < 0.001, gaussian random field (GRF) correction, cluster-level p < 0.05]. We did not find a correlation between the abnormal FC value and clinical scales. Conclusion: Our study reveals a possible relationship between atypical visual attention and poor learning ability in subjects with ASD, and delayed social language development may be a secondary symptom to ASD.

Effects of the SNAP25 on Integration Ability of Brain Functions in Children With ADHD.

OBJECTIVE: The present study aimed to examine the effects of SNAP25 on the integration ability of intrinsic brain functions in children with ADHD, and whether the integration ability was associated with working memory (WM). METHODS: A sliding time window method was used to calculate the spatial and temporal concordance among five rs-fMRI regional indices in 55 children with ADHD and 20 healthy controls. RESULTS: The SNAP25 exhibited significant interaction effects with ADHD diagnosis on the voxel-wise concordance in the right posterior central gyrus, fusiform gyrus and lingual gyrus. Specifically, for children with ADHD, G-carriers showed increased voxel-wise concordance in comparison to TT homozygotes in the right precentral gyrus, superior frontal gyrus, postcentral gyrus, and middle frontal gyrus. The voxel-wise concordance was also found to be related to WM. CONCLUSION: Our findings provided a new insight into the neural mechanisms of the brain function of ADHD children.

Cadmium-induced changes in composition and co-metabolism of glycerolipids species in wheat root: Glycerolipidomic and transcriptomic approach.

Lipids are the structural constituents of cell membranes and play crucial roles in plant adaptation to abiotic stresses. The aim of this study was to use glycerolipidomic and transcriptomic to analyze the changes in lipids metabolism induced by cadmium (Cd) exposure in wheat. The results indicated that Cd stress did not decrease the concentrations of monogalactosyldiacyglycerol (MGDG), phosphatidylcholine (PC), lysophosphatidylcholine (LPC) and phosphatidic acid at 6 h, but decreased digalactosyldoacylglycerol (DGDG), MGDG, PC, phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylserine (PS) and LPC concentrations in wheat root at 24 h. Although the concentrations of highly abundant glycerolipids PC and PE were decreased, the ratios of PC/PE increased thus contributing to wheat adaptation to Cd stress. Cd did not reduce the extent of total lipid unsaturation due to the unchanged concentrations of high abundance species of C36:4, C34:2, C34:3 and C36:6 at 6 h, indicative of their roles in resisting Cd stress. The correlation analysis revealed the glycerolipids species experiencing co-metabolism under Cd stress, which is driven by the activated expression of genes related to glycerolipid metabolism, desaturation and oxylipin synthesis. This study gives insights into the changes of glycerolipids induced by Cd and the roles in wheat adaptation to Cd stress.

A 4-day-old newborn with an isolated sternal cleft: A rare case and literature review.

An isolated sternal cleft is an orphan congenital defect of the sternum that presents from birth to adulthood. We report the case of a 4-day-old newborn with an isolated congenital cleft sternum. We also reviewed the related literature and operative options.

Twice exploration of tRNA +1 frameshifting in an elongation cycle of protein synthesis.

Inducing tRNA +1 frameshifting to read a quadruplet codon has the potential to incorporate a non-natural amino acid into the polypeptide chain. While this strategy is being considered for genome expansion in biotechnology and bioengineering endeavors, a major limitation is a lack of understanding of where the shift occurs in an elongation cycle of protein synthesis. Here, we use the high-efficiency +1-frameshifting SufB2 tRNA, containing an extra nucleotide in the anticodon loop, to address this question. Physical and kinetic measurements of the ribosome reading frame of SufB2 identify twice exploration of +1 frameshifting in one elongation cycle, with the major fraction making the shift during translocation from the aminoacyl-tRNA binding (A) site to the peptidyl-tRNA binding (P) site and the remaining fraction making the shift within the P site upon occupancy of the A site in the +1-frame. We demonstrate that the twice exploration of +1 frameshifting occurs during active protein synthesis and that each exploration is consistent with ribosomal conformational dynamics that permits changes of the reading frame. This work indicates that the ribosome itself is a determinant of changes of the reading frame and reveals a mechanistic parallel of +1 frameshifting with -1 frameshifting.

Ionomics analysis provides new insights into the co-enrichment of cadmium and zinc in wheat grains.

Cadmium (Cd) is present in many soils and, when enter a food chain, represents a major health threat to humans. The existent large variation in grain Cd content amongst wheat genotypes opens prospects for genetic improvement for reduced Cd uptake in this species. However, selecting low-Cd-accumulating varieties comes with a possible caveat of affecting uptake other essential nutrients. In this work, we screened 134 wheat varieties in 3 various field studies and selected 15 high- and 15 low-Cd accumulating varieties in grains for ionomics analysis. Our results showed that high-Cd accumulating varieties also possessed an ability to accumulate mineral elements of calcium, magnesium, manganese, iron and zinc, while varieties with low Cd content were deficient in many essential nutrients and, especially, zinc (Zn). The above data was confirmed in an independent trail involving another 97 wheat varieties. Thus, selecting plants for high Zn accumulation (as a part of biofortification programs) resulted in an inadvertent increase in accumulation of the toxic Cd in wheat. Vice versa, selecting low Cd-accumulating varieties comes with a danger of reducing their Zn content, with major consequences to food quality and human health. We suggest that the above conundrum can be resolved by understanding the structure-function relations of various transporters isoforms involved in Zn and Cd transport and issue-specific mode of their operation, via cell-based phenotyping followed by molecular breeding.

Association of Reduced Tract Integrity with Social Communication Deficits in Preschool Autism Children: A Tract-Based Spatial Statistics Study.

PURPOSE: To analyze the changes in white matter tracts in preschool children with autism spectrum disorder (ASD), and the correlation between these changes and social communication deficits. METHODS: Diffuse tensor imaging was used to assess white matter integrity using tract-based spatial statistics in a sample of 50 right-handed children with ASD aged 2-6 years vis a reference sample of 46 typically developing children aged 2-6 years. We then correlated these significant different fiber tracts between groups with communication and social interaction scores using the Autism Diagnostic Interview-Revised Assessment (ADI-R) Scale. RESULTS: We observed decreased fractional anisotropy (FA) in tracts including the left superior longitudinal fasciculus (SLF), the splenium of the corpus callosum (splCC), the left corticospinal tracts, and the left inferior longitudinal fasciculus (ILF) in children with ASD. Specifically, there was reduced white matter integrity of these tracts in the left cerebral hemisphere. In addition, we found that the decreased FA of left SLF and ILF was negatively associated with the ADI-R scores in children with ASD. CONCLUSION: The structural integrity of some white matter tracts in the five-level anatomical model for the social communication was reduced. The reduced integrity white matter that we observed primarily in the left cerebral hemisphere may be a neural substrate of social communication deficits in preschool children with ASD, and we speculate that the reduction is associated with the severity of social interaction. The reduced FA of the splCC might be a substantial biomarker for children with ASD.

Alterations of Regional Homogeneity in Preschool Boys With Autism Spectrum Disorders.

OBJECTIVES: The study was aimed at investigating the alterations of local spontaneous brain activity in preschool boys with autism spectrum disorders (ASD). METHODS: Based on regional homogeneity (ReHo), the acquired resting state functional magnetic resonance imaging (fMRI) data sets, which included 86 boys with ASD and 54 typically developing (TD) boys, were used to detect regional brain activity. Pearson correlation analysis was used to study the relationship between abnormal ReHo value and the Childhood Autism Rating Scale (CARS), Autism Behavior Checklist (ABC), developmental quotient, and age. RESULTS: In the ASD group, we found increased ReHo in the right calcarine as well as decreased ReHo in the opercular part of the left inferior frontal gyrus, the left middle temporal gyrus, the left angular gyrus, and the right medial orbital frontal cortex (p < 0.05, false discovery rate correction). We did not find a correlation between the results of brain regions and the CARS, ABC, and age. CONCLUSIONS: Our study found spontaneous activity changes in multiple brain regions, especially the visual and language-related areas of ASD, that may help to further understand the clinical characteristics of boys with ASD.

High-Resolution DNA Dual-Rulers Reveal a New Intermediate State in Ribosomal Frameshifting.

Ribosomal frameshifting is an important pathway used by many viruses for protein synthesis that involves mRNA translocation of various numbers of nucleotides. Resolving the mRNA positions with subnucleotide precision will provide critical mechanistic information that is difficult to obtain with current techniques. We report a method of high-resolution DNA rulers with subnucleotide precision and the discovery of new frameshifting intermediate states on mRNA containing a GA7 G motif. Two intermediate states were observed with the aid of fusidic acid, one at the "0" reading frame and the other near the "-1" reading frame, in contrast to the "-2" and "-1" frameshifting products found in the absence of the antibiotic. We termed the new near-"-1" intermediate the Post(-1*) state because it was shifted by approximately half a nucleotide compared to the normal "-1" reading frame at the 5'-end. This indicates a ribosome conformation that is different from the conventional model of three reading frames. Our work reveals uniquely precise mRNA motions and subtle conformational changes that will complement structural and fluorescence studies.

Fe3O4 Nanoparticles: Structures, Synthesis, Magnetic Properties, Surface Functionalization, and Emerging Applications.

Magnetite (Fe3O4) nanoparticles (NPs) are attractive nanomaterials in the field of material science, chemistry, and physics because of their valuable properties, such as soft ferromagnetism, half-metallicity, and biocompatibility. Various structures of Fe3O4 NPs with different sizes, geometries, and nanoarchitectures have been synthesized, and the related properties have been studied with targets in multiple fields of applications, including biomedical devices, electronic devices, environmental solutions, and energy applications. Tailoring the sizes, geometries, magnetic properties, and functionalities is an important task that determines the performance of Fe3O4 NPs in many applications. Therefore, this review focuses on the crucial aspects of Fe3O4 NPs, including structures, synthesis, magnetic properties, and strategies for functionalization, which jointly determine the application performance of various Fe3O4 NP-based systems. We first summarize the recent advances in the synthesis of magnetite NPs with different sizes, morphologies, and magnetic properties. We also highlight the importance of synthetic factors in controlling the structures and properties of NPs, such as the uniformity of sizes, morphology, surfaces, and magnetic properties. Moreover, emerging applications using Fe3O4 NPs and their functionalized nanostructures are also highlighted with a focus on applications in biomedical technologies, biosensing, environmental remedies for water treatment, and energy storage and conversion devices.

Abnormal white matter within brain structural networks is associated with high-impulse behaviour in codeine-containing cough syrup dependent users.

Codeine-containing cough syrup (CCS) is considered as one of the most popular drug of dependence among adolescents because of its inexpensiveness and easy availability. However, its relationship with neurobiological effects remains sparsely explored. Herein, we examined how high-impulse behaviours relate to changes in the brain structural networks. Forty codeine-containing cough syrup dependent (CCSD) users and age-, gender-, and number of cigarettes smoked per day -matched forty healthy control (HC) subjects underwent structural brain imaging via MRI. High-impulse behaviour was assessed using the 30-item self-rated Barratt Impulsiveness Scale (BIS-11), and structural networks were constructed using diffusion tensor imaging and AAL-90 template. Between-group topological metrics were compared using nonparametric permutations. Benjamin-Hochberg false discovery rate correction was used to correct for multiple comparisons (P < 0.05). The relationships between abnormal network metrics and clinical characteristics of CCS dependent (BIS-11 total score, CCS- dependent duration and mean dose) were examined by Spearman's correlation. Structural networks of the CCSD group demonstrated lower small-world properties than those of the HC group. Abnormal changes in nodal properties among CCSD users were located mainly in the frontal gyrus, inferior parietal lobe and olfactory cortex. NBS analysis further indicated disrupted structural connections between the frontal gyrus and multiple brain regions. There were significant correlations between abnormal nodal properties of the frontal gyrus and clinical characteristics (BIS-11 total score, CCS dependent duration and mean dose) in the CCSD group. These findings suggest that the high-impulse behavioural expression in CCS addiction is associated with widespread brain regions, particularly within those in the frontal cortex. Aberrant brain regions and disrupted connectivity of structural network may be the bases of neuropathology for underlying symptoms of high-impulse behaviours in CCSD users, which may provide a novel sight to better treat and prevent codeine dependency in adolescents.