Publications by authors named "R Zhang"

21,927 Publications

Effect of osteoporosis on adjacent segmental degeneration following posterior lumbar interbody fusion under whole body vibration.

World Neurosurg 2021 Jun 12. Epub 2021 Jun 12.

School of Chinese medicine, Jinan university, Guangzhou, China. Electronic address:

Background: Adjacent segmental degeneration (ASD) is one of the common complications following posterior lumbar interbody fusion (PLIF). Both whole body vibration (WBV) and osteoporosis are important factors associated with the biomechanics of the lumbar spine. However, up to now, no literature has been published to investigate the effect of osteoporosis on ASD following PLIF under WBV.

Methods: In the current study, based on one normal model, one PLIF model and one PLIF with osteoporosis model of L1-S1 segment were developed. A 5 Hz, 40N sinusoidal vertical load was imposed on the superior surface of L1 of each model to simulate WBV, and dynamic responses and maximal values of intradiscal pressure, shear stress on annulus fibrosus, total deformation, and disc bulge were evaluated in L1-L2, L2-L3, L3-L4, and L5-S1 segments.

Results: At L1-L2, L2-L3, and L3-L4 levels, the differences of dynamic responses and maximal values in intradiscal pressure, shear stress, total deformation, and disc bulge between the PLIF and PLIF with osteoporosis models were slight. However, at L5-S1 level the dynamic response curves and maximal values of intradiscal pressure, shear stress, and disc bulge in PLIF with osteoporosis model were significantly lower than those in PLIF model.

Conclusions: Osteoporosis can mitigate the development of ASD in the lower adjacent segment, but has no obvious influence on the upper adjacent segments during WBV.
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http://dx.doi.org/10.1016/j.wneu.2021.06.031DOI Listing
June 2021

Human spatial navigation: Neural representations of spatial scales and reference frames obtained from an ALE meta-analysis.

Neuroimage 2021 Jun 12:118264. Epub 2021 Jun 12.

Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education; School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, Guangdong, 510631, China. Electronic address:

Humans use different spatial reference frames (allocentric or egocentric) to navigate successfully toward their destination in different spatial scale spaces (environmental or vista). However, it remains unclear how the brain represents different spatial scales and different spatial reference frames. Thus, we conducted an activation likelihood estimation (ALE) meta-analysis of 47 fMRI articles involving human spatial navigation. We found that both the environmental and vista spaces activated the parahippocampal place area (PPA), retrosplenial complex (RSC), and occipital place area in the right hemisphere. The environmental space showed stronger activation than the vista space in the occipital and frontal regions. No brain region exhibited stronger activation for the vista than the environmental space. The allocentric and egocentric reference frames activated the bilateral PPA and right RSC. The allocentric frame showed more stronger activations than the egocentric frame in the right culmen, left middle frontal gyrus, and precuneus. No brain region displayed stronger activation for the egocentric than the allocentric navigation. Our findings suggest that navigation in different spatial scale spaces can evoke specific and common brain regions, and that the brain regions representing spatial reference frames are not absolutely separated.
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http://dx.doi.org/10.1016/j.neuroimage.2021.118264DOI Listing
June 2021

Plastid phylogenomic analyses of Fagales reveal signatures of conflict and ancient chloroplast capture.

Mol Phylogenet Evol 2021 Jun 12:107232. Epub 2021 Jun 12.

Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China; CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China. Electronic address:

Plastid phylogenomic analyses have shed light on many recalcitrant relationships across the angiosperm Tree of Life and continue to play an important role in plant phylogenetics alongside nuclear data sets given the utility of plastomes for revealing ancient and recent introgression. Here we conduct a plastid phylogenomic study of Fagales, aimed at exploring contentious relationships (e.g., the placement of Myricaceae and some intergeneric relationships in Betulaceae, Juglandaceae, and Fagaceae) and dissecting conflicting phylogenetic signals across the plastome. Combining 102 newly sequenced samples with publically available plastomes, we analyzed a dataset including 256 species and 32 of the 34 total genera of Fagales, representing the largest plastome-based study of the order to date. We find strong support for a sister relationship between Myricaceae and Juglandaceae, as well as strongly supported conflicting signal for alternative generic relationships in Betulaceae and Juglandaceae. These conflicts highlight the sensitivity of plastid phylogenomic analyses to genic composition, perhaps due to the prevalence of uninformative loci and heterogeneity in signal across different regions of the plastome. Phylogenetic relationships were geographically structure in subfamily Quercoideae, with Quercus being non-monophyletic and its sections forming clades with co-distributed Old World or New World genera of Quercoideae. Compared against studies based on nuclear genes, these results suggest extensive introgression and chloroplast capture in the early diversification of Quercus and Quercoideae. This study provides a critical plastome perspective on Fagales phylogeny, setting the stage for future studies employing more extensive data from the nuclear genome.
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http://dx.doi.org/10.1016/j.ympev.2021.107232DOI Listing
June 2021

Comparability of thyroid-stimulating hormone immunoassays using fresh frozen human sera and external quality assessment data.

PLoS One 2021 15;16(6):e0253324. Epub 2021 Jun 15.

Department of Clinical Laboratory, Beijing Chaoyang Hospital, Beijing Center for Clinical Laboratories, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China.

Background: This study aimed to assess the comparability among assays using freshly frozen human sera and external quality assessment (EQA) data in China.

Methods: Twenty-nine serum samples and two commercial EQA materials, obtained from the National Center for Clinical Laboratories (NCCL), were analyzed in triplicate using eight routine TSH assays. The commutability of commercial EQA materials (NCCL materials) was evaluated in accordance with the CLSI EP30-A and IFCC bias analysis. Median values obtained for the NCCL EQA materials were used to determine the systematic and commutability-related biases among immunoassays through back-calculation. The comparability of TSH measurements from a panel of clinical samples and NCCL EQA data was determined on the basis of Passing-Bablok regression. Furthermore, human serum pools were used to perform commutable EQA.

Results: NCCL EQA materials displayed commutability among three or five of seven assay combinations according CLSI or IFCC approach, respectively. The mean of systematic bias ranged from -13.78% to 9.85% for the eight routine TSH assays. After correcting for systematic bias, averaged commutability-related biases ranged between -42.26% and 12.19%. After correction for systematic and commutability -related biases, the slopes indicating interassay relatedness ranged from 0.801 to 1.299 using individual human sera, from 0.735 to 1.254 using NCCL EQA data, and from 0.729 to 1.115 using pooled human serum EQA(the commutable EQA).

Conclusions: The harmonization of TSH measurement is challenging; hence, systematic and commutability-related biases should be determined and corrected for accurate comparisons among assays when using human individual serum and the commercial EQA materials.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0253324PLOS
June 2021

MDSCs interactions with other immune cells and their role in maternal-fetal tolerance.

Int Rev Immunol 2021 Jun 15:1-18. Epub 2021 Jun 15.

Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China.

MDSCs (myeloid-derived suppressor cells) are a population of immature and heterogeneous bone marrow cells with immunosuppressive functions, and they are mainly divided into two subgroups: granulocytic MDSCs (G-MDSCs) and monocytic MDSCs (M-MDSCs). Immunosuppression is the main and most important function of MDSCs, and they mainly exert an inhibitory effect through endoplasmic reticulum stress and some enzymes related to inhibitors, as well as some cytokines and other factors. In addition, MDSCs also interact with other immune cells, especially NK cells, DCs and Tregs, to participate in immune regulation. A large number of MDSCs are found during normal pregnancy. Combined with their immunosuppressive effects, these results suggest that MDSCs are likely to be closely related to maternal-fetal immune tolerance. This review mainly shows the interaction of MDSCs with other immune cells and the important role of MDSCs in maternal-fetal tolerance. The current research shows that MDSCs are mainly mediated by STAT3, HLA-G, CXCR2, Arg-1 and HIF1-α in immune regulation during pregnancy. Interpreting maternal-fetal tolerance from the perspective of MDSCs provides a special perspective for research on immune regulation and maternal-fetal tolerance of MDSCs to obtain a more comprehensive understanding of immune regulation and immune tolerance.
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http://dx.doi.org/10.1080/08830185.2021.1938566DOI Listing
June 2021