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N-glycosylation is a highly heterogeneous post-translational modification that modulates protein function. Defects in N-glycosylation are directly linked to various human diseases. Despite the importance of quantifying N-glycans with high precision, existing glycoinformatics tools are limited. Here, we developed nQuant, a glycoinformatics tool that enables label-free and isotopic labeling quantification of N-glycomics data obtained via LC-MS/MS, ensuring a low false quantitation rate. Using the label-free quantification module, we profiled the N-glycans released from purified glycoproteins and HEK293 cells as well as the dynamic changes of N-glycosylation during mouse corpus callosum development. Through the isotopic labeling quantification module, we revealed the dynamic changes of N-glycans in acute promyelocytic leukemia cells after all-trans retinoic acid treatment. Taken together, we demonstrate that nQuant enables fast and precise quantitative N-glycomics.

Spinal cord injury (SCI) often results in irreversible loss of sensory and motor functions, and most SCIs are incurable with current medical practice. One of the hardest challenges in treating SCI is the development of a dysfunctional pathological microenvironment, which mainly comprises excessive inflammation, deposition of inhibitory molecules, neurotrophic factor deprivation, glial scar formation, and imbalance of vascular function. To overcome this challenge, implantation of functional biomaterials at the injury site has been regarded as a potential treatment for modulating the dysfunctional microenvironment to support axon regeneration, remyelination at injury site, and functional recovery after SCI. This review summarizes characteristics of dysfunctional pathological microenvironment and recent advances in biomaterials as well as the technologies used to modulate inflammatory microenvironment, regulate inhibitory microenvironment, and reshape revascularization microenvironment. Moreover, technological limitations, challenges, and future prospects of functional biomaterials to promote efficient repair of SCI are also discussed. This review will aid further understanding and development of functional biomaterials to regulate pathological SCI microenvironment.

Astrocytes constitute a major part of the central nervous system and the delineation of their activity patterns is conducive to a better understanding of brain network dynamics. This study aimed to develop a magnetic resonance imaging (MRI)-based method in order to monitor the brain-wide or region-specific astrocytes in live animals. Adeno-associated virus (AAVs) vectors carrying the human glial fibrillary acidic protein (GFAP) promoter driving the EGFP-AQP1 (Aquaporin-1, an MRI reporter) fusion gene were employed. The following steps were included: constructing recombinant AAV vectors for astrocyte-specific expression, detecting MRI reporters in cell culture, brain regions, or whole brain following cell transduction, stereotactic injection, or tail vein injection. The astrocytes were detected by both fluorescent imaging and Diffusion-weighted MRI. The novel AAV mutation (Site-directed mutagenesis of surface-exposed tyrosine (Y) residues on the AAV5 capsid) significantly increased fluorescence intensity (p< 0.01) compared with the AAV5 wild type. Transduction of the rAAV2/5 carrying AQP1 induced the titer-dependent changes in MRI contrast in cell cultures (p< 0.05) and caudate-putamen (CPu) in the brain (p< 0.05). Furthermore, the MRI revealed a good brain-wide alignment between AQP1 levels and ADC signals, which increased over time in most of the transduced brain regions. In addition, the rAAV2/PHP.eB serotype efficiently introduced AOP1 expression in the whole brain via tail vein injection. This study provides an MRI-based approach to detect dynamic changes in astrocytes in live animals. The novel in vivo tool could help us to understand the complexity of neuronal and glial networks in different pathophysiological conditions.

The unidirectional rolled Mg–Zn–Gd sheet usually exhibited non-basal texture with two peaks whose tilting angle were about 42° from normal direction to transverse direction (TD), which would cause the mechanical anisotropy. In this study, multi-cross rolling followed by annealing was used to tailor the texture and mechanical anisotropy for Mg–Zn–Gd alloy. With increasing annealing temperature, the rolled basal texture with two peaks gradually transformed into the circle texture with multi-peaks. In order to figure out different texture components evolution during annealing, the basal texture, R-texture and T-texture component were defined and studied. The results showed that the change of R-texture and T-texture component was asynchronous with increasing annealing temperature from 250 to 400 °C. The tilting angle of R-texture component increased slightly, while the tilting angle of T-texture component increased obviously, and this phenomenon was attributed to the preferential nucleation at grain nucleation stage rather than preferential grain growth. The yield strength along TD was more sensitive to annealing temperature compared with that along rolling direction (RD), resulting in different descending slopes and yield strength anisotropy with increasing annealing temperature. Annealing at 300 °C was the best annealing temperature due to low yield strength anisotropy, moderate strength and good elongation among these annealing temperatures. The Schmid factor for basal slip indicated that the activity of basal slip along RD increased slightly, while that along TD increased obviously with increasing annealing temperature from 250 to 400 °C, which should be caused by the asynchronous change of R-texture component and T-texture component, consequently resulting in the transformation from isotropic yield strength to anisotropic yield strength.

The microstructure and texture transformation of 3%Y2O3p/ZGK200 composites after wedge-shaped rolling were investigated. The 3%Y2O3p/ZGK200 composites could be wedge-shaped rolled for 50 % reduction without obvious edge cracks. Basal slip, prismatic slip and pyramidal slip detected by in-grain misorientation axes (IGMA) combined with Schmid factor (SF) analysis were abundantly activated during the whole rolling process. Different from the activation of all kinds of dislocation slips, many {10 1‾2} extension twins and few {101‾1}-{101‾2} secondary twins were activated with a reduction of 10 %. With increasing reduction from 30 % to 50 %, {101‾1}-{101‾2} secondary twins and {101‾1} compression twins started to play more important roles. Finally, the rolled deformed grains were elongated along rolling direction (RD) with abundant twins. During the whole rolling process, few recrystallized grains were found in the composites due to the effect of Gd addition. The {101‾2} extension twins whose c-axis oriented along normal direction (ND) should be attributed to the formation of basal texture, which was kept unchanged during the whole rolling process.

The Huo–Xue–Hua–Yu decoction (HXHYD) prescription, which possesses good clinical properties for healing fractures, is made up of 12 types of traditional Chinese medicines (TCMs). According to the drug efficacy of TCM, HXHYD consists of four drug-group prescriptions. This study focused on the type of active mechanism in these drug groups and the type of interaction between them in HXHYD. Surface-enhanced Raman scattering (SERS) spectroscopy was employed to study the effect of the incorporation of calcium hydroxyapatite (CHA), protein and lipid groups on the repair of complete tibial fractures in rats treated with HXHYD and its drug-group prescriptions and without treatment to reveal the efficacy rule of the drug groups in the prescription. The rats were divided into seven groups, each of which was subdivided into three subgroups (evaluated on days 15, 21 and 30 after surgery). The six treatment groups were treated HXHYD, four drug-group prescriptions and Gu–Zhe–Cuo–Shang capsule therapy (treated control). SERS readings were taken at the fractured sites. The results showed that the medical ingredients in HXHYD were not the simple addition of four drug-group prescriptions and the efficacy of HXHYD was stronger than every other drug group prescription because it contained the highest content of CHA and highest carbonate-to-phosphate and phosphate-to-phenylalanine ratios among the treatment groups at all time points in comparison with the fractured control group (no treatment). Thus, the SERS technique has great potential to provide a novel method for effectively and accurately studying the efficacy rule of drug groups in one prescription with the aim to optimize prescriptions.

Combining analyses of spatial and temporal characteristics of the ionosphere is of great significance for scientific research and engineering applications. Tensor decomposition is performed to explore the temporal–longitudinal–latitudinal characteristics in the ionosphere. Three-dimensional tensors are established based on the time series of ionospheric vertical total electron content maps obtained from the Centre for Orbit Determination in Europe. To obtain large-scale characteristics of the ionosphere, rank-1 decomposition is used to obtain $$U^{(1)}$$ U(1) , $$U^{(2)}$$ U(2) , and $$U^{(3)}$$ U(3) , which are the resulting vectors for the time, longitude, and latitude modes, respectively. Our initial finding is that the correspondence between the frequency spectrum of $$U^{(1)}$$ U(1) and solar variation indicates that rank-1 decomposition primarily describes large-scale temporal variations in the global ionosphere caused by the Sun. Furthermore, the time lags between the maxima of the ionospheric $$U^{(2)}$$ U(2) and solar irradiation range from 1 to 3.7 h without seasonal dependence. The differences in time lags may indicate different interactions between processes in the magnetosphere–ionosphere–thermosphere system. Based on the dataset displayed in the geomagnetic coordinates, the position of the barycenter of $$U^{(3)}$$ U(3) provides evidence for north–south asymmetry (NSA) in the large-scale ionospheric variations. The daily variation in such asymmetry indicates the influences of solar ionization. The diurnal geomagnetic coordinate variations in $$U^{(3)}$$ U(3) show that the large-scale EIA (equatorial ionization anomaly) variations during the day and night have similar characteristics. Considering the influences of geomagnetic disturbance on ionospheric behavior, we select the geomagnetic quiet GIMs to construct the ionospheric tensor. The results indicate that the geomagnetic disturbances have little effect on large-scale ionospheric characteristics.

Spatiotemporal geomagnetic variation is a significant research topic of geomagnetism and space physics. Generated by convection and flows within the fluid outer core, latitude dependence and asymmetry, as the inherent spatiotemporal properties of geomagnetic field, have been extensively studied. We apply and modify an extension of existing method, Hidden Markov Model (HMM), which is an efficient tool for modeling the statistical properties of time series. Based on ground magnetic measurement data set in mainland China, first, we find the parameters of HMM can be used as the geomagnetic statistical signature to represent the spatiotemporal geomagnetic variations for each site. The results also support the existence of the geomagnetic latitude dependence more apparently. Furthermore, we provide solid empirical evidence for geomagnetic asymmetry relying on such ground magnetic measurement data set. The parameters of HMM can be used as the geomagnetic variations' statistical signatureThe results support the existence of the geomagnetic latitude dependence more apparentlyWe provide empirical evidence for geomagnetic asymmetry using ground magnetic measurement data

The low‐latitude longitudinally periodic density structure with three or four peaks at a fixed local time is well known. Both harmonic analysis of observations and numerical simulations have been extensively performed to ascribe the periodic structures to different atmospheric tides. But to date, no research has been done to explain how the two structures transform between seasons. Besides, other different wave structures have also been reported. To clarify these uncertainties, the COSMIC electron density data during 2006–2019 are used to further examine the spatiotemporal variations of the longitudinal structure. The results show that a wavenumber‐4 structure is clearly distinguishable during equinoxes and the four peaks are basically the same size, but in two solstices, a wavenumber‐3 structure is finally observed and the three peaks vary greatly in size. The wavenumber‐4 is well established before noon while the stable wavenumber‐3 form cannot be reached until after noon. Due to the blurred boundary caused by plasma transportation, the density distribution can be characterized by other wave structures before reaching its stable form during solstices. Subdividing the data, we find that from vernal (autumn) equinox to June (December) solstice, the peak in American sector gradually merges with its west (east) side peak into a super‐large one, its east (west) side peak weakens into a small one, and the peak in Southeast Asian sector gradually shrinks (expands). We speculate that the transition from wavenumber‐4 to wavenumber‐3 is due to the modulation of transequatorial winds and magnetic declination. Four peaks of roughly equal size are clearly distinguishable during equinoxes while three peaks varying greatly in size are formed during solsticesWN4 structure is well established before noon during equinoxes, but WN3 reaches its stable waveform after noon during solsticesTransition from WN4 to WN3 is due to the modulation of transequatorial winds and magnetic declination Four peaks of roughly equal size are clearly distinguishable during equinoxes while three peaks varying greatly in size are formed during solstices WN4 structure is well established before noon during equinoxes, but WN3 reaches its stable waveform after noon during solstices Transition from WN4 to WN3 is due to the modulation of transequatorial winds and magnetic declination