Practical gram-scale synthesis of bicyclol metabolites M2 and M3.

Bicyclol, an innovative hepatoprotective drug, was approved by the Chinese National Medical Products Administration (NMPA) in 2001 to treat Hepatitis B and drug-induced liver injury. Two active metabolites of bicyclol have been identified as M2 and M3. To evaluate the impact on drug safety and efficacy of possible drug-drug interactions (DDIs) associated with these metabolites, a sufficient quantity of these metabolites is required. Herein, we report a concise novel route for the synthesis of M2 and M3 using the Suzuki-Miyaura coupling as the key step. Furthermore, we complete the gram-scale syntheses of M2 and M3.

Paravertebral Muscle Morphology in L4-L5 Disc Herniation: Insights from the Michigan State University Classification.

BACKGROUND Lumbar disc herniation (LDH) at L4-L5 impacts paravertebral muscle morphology. Intervertebral disc degeneration is linked to paravertebral muscle changes, affecting LDH treatment outcomes. This study explored L4-L5 LDH paravertebral muscle alterations, specifically in the erector spinae, multifidus, and psoas major, using Michigan State University's classification to guide LDH treatment. MATERIAL AND METHODS The study enrolled 160 patients, including 39 normal patients and 121 L4-L5 LDH patients. Patients with LDH were grouped according to MSU classification and compared to the normal group according to demographics and imaging changes. RESULTS In patients with L4-L5 herniation in Zone B, the FI of the ES muscle at L3-L4 level, L4-L5 level, and L5-S1 level was higher than that of normal people (P=0.018, P=0.043, P=0.010, respectively), and there was no difference between FI of MF and normal people. The Zone B patients also had a smaller CSA of the ES muscle at L4-L5 level than that in the normal group (P=0.049). Patients in the Zone C group were older than those in the normal group (P=0.014). The CSA of the PM of patients with Grade 3 herniation differed from that of the normal group at the L4-L5 and L5-S1 level. They were higher than in normal people at L4-L5 level (P=0.011) and lower at L5-S1 level (P=0.028). CONCLUSIONS In patients with L4-L5 herniation in Zone B, the FI of ES at L3-S1 level was higher than in normal people, and the CSA at L4-L5 level was smaller than in normal people. In patients with Grade3 herniation, PM CSA was larger at L4-L5 level and smaller at L5-S1 level than in normal people.

Regulation and decarbonization: how can environmental regulations more effectively facilitate industrial low-carbon transitions?

Environmental policies play an important role in the process of industrial low-carbon transition in developing countries. From the perspective of the impact condition and mechanisms, we discuss how to improve their effectiveness to give full play to the positive impact of environmental regulations. Based on provincial industrial data from 2003 to 2019 in China, this study uses a threshold regression model and endogenous regression to reveal the impact condition and mechanisms of environmental regulations on industrial low-carbon transition. The results suggest that (1) technological innovation capability and cost-bearing capacity are the key conditions for environmental regulations to exert a positive impact on low-carbon transition. (2) Environmental regulations have a positive impact on low-carbon transition through technological innovation (technology), resource reallocation (capital), and skill premium (labor). Research on the implementation conditions and mechanisms of environmental regulations will help policy-makers formulate appropriate and reasonable environmental regulations and eliminate the obstacles between environmental regulations and low-carbon transition, while an assessment of China's environmental policies will provide a reference for environmental governance in other developing countries.

Critically short telomeres derepress retrotransposons to promote genome instability in embryonic stem cells.

Telomeres, at the ends of chromosomes, protect chromosomes from fusion and preserve genomic stability. However, the molecular mechanisms underlying telomere attrition-induced genome instability remain to be understood. We systematically analyzed the expression of retrotransposons and performed genomic sequencing of different cell and tissue types with telomeres of varying lengths due to telomerase deficiency. We found that critically short telomeres altered retrotransposon activity to promote genomic instability in mouse embryonic stem cells, as evidenced by elevated numbers of single nucleotide variants, indels and copy number variations (CNVs). Transpositions of retrotransposons such as LINE1 resulting from the short telomeres can also be found in these genomes with elevated number of mutations and CNVs. Retrotransposon activation is linked to increased chromatin accessibility, and reduced heterochromatin abundance correlates with short telomeres. Re-elongation of telomeres upon recovery of telomerase partly represses retrotransposons and heterochromatin accumulation. Together, our findings suggest a potential mechanism by which telomeres maintain genomic stability by suppressing chromatin accessibility and retrotransposon activity.

CircRRAS2 promotes myogenic differentiation of bovine MuSCs and is a novel regulatory molecule of muscle development.

The proliferation and myogenic differentiation of muscle stem cells (MuSCs) are important factors affecting muscle development and beef quality. There is increasing evidence that circRNAs can regulate myogenesis. We found a novel circRNA, named circRRAS2 that is significantly upregulated in the differentiation phase of bovine MuSCs. Here, we aimed to determine its roles in the proliferation and myogenic differentiation of these cells. The results showed that circRRAS2 was expressed in several bovine tissues. CircRRAS2 inhibited MuSCs proliferation and promoted myoblast differentiation. In addition, chromatin isolation by using RNA purification and mass spectrometry in differentiated muscle cells identified 52 RNA-binding proteins that could potentially bind to circRRAS2, in order to regulate their differentiation. The results suggest that circRRAS2 could be a specific regulator of myogenesis in bovine muscle.HighlightsCircRRAS2 expression is higher in DM cells than in GM cells.CircRRAS2 could significantly inhibit the proliferation and apoptosis of bovine MuSCs.CircRRAS2 promotes the differentiation of bovine MuSCs into myotubes.CircRRAS2 may exert regulatory effects through multiple RNA binding proteins.

HDAC11 Regulates the Proliferation of Bovine Muscle Stem Cells through the Notch Signaling Pathway and Inhibits Muscle Regeneration.

Myogenesis is an essential process that can affect the yield and quality of beef. Transcriptional studies have shown that histone deacetylase 11 (HDAC11) was differentially expressed in muscle tissues of 6 and 18 month old Longlin cattle, but its role in the regulation of myogenesis remains unclear. This study aimed to determine the role of HDAC11 in the proliferation and differentiation of bovine muscle stem cells (MuSCs). HDAC11 promoted MuSC proliferation by activating Notch signaling and inhibited myoblast differentiation by reducing MyoD1 transcription. In addition, overexpression of HDAC11 inhibited the repair regeneration process of muscle in mice. HDAC11 was found to be a novel key target for the control of myogenesis, and this is a theoretical basis for the development of HDAC11-specific modulators as a new strategy to regulate myogenesis.

Research on Flashover Prediction Method of Large-Space Timber Structures in a Fire.

Due to the flammability of materials and the vastness of space, flashover fires of large-space timber structures pose a huge threat to lives as well as the structures themselves. Therefore, it is necessary to study the critical conditions, control factors and prediction methods of flashover fires. To address this issue, hundreds of design conditions were simulated by Fire Dynamics Simulator (FDS) with variations in space size, the heat release rate (HRR) of fire source and fire growth type. A temperature-time model of the maximum temperature of the smoke layer near the ceiling (Tmax) was established, and the critical condition that uses this model to predict the occurrence of flashover was determined. Furthermore, a mathematical formula was established that can accurately predict the flashover induction time when the Tmax exceeds 400 °C. This research can provide a reference for the performance-based fire safety design of large-space timber structures.

Changes in soil water holding capacity and water availability following vegetation restoration on the Chinese Loess Plateau.

Changes in land use type can lead to variations in soil water characteristics. The objective of this study was to identify the responses of soil water holding capacity (SWHC) and soil water availability (SWA) to land use type (grassland, shrubland and forestland). The soil water characteristic curve describes the relationship between gravimetric water content and soil suction. We measured the soil water characteristic parameters representing SWHC and SWA, which we derived from soil water characteristic curves, in the 0-50 cm soil layer at sites representing three land use types in the Ziwuling forest region, located in the central part of the Loess Plateau, China. Our results showed that the SWHC was higher at the woodland site than the grassland and shrubland, and there was no significant difference between the latter two sites, the trend of SWA was similar to the SWHC. From grassland to woodland, the soil physical properties in the 0-50 cm soil layer partially improved, BD was significantly higher at the grassland site than at the shrubland and woodland sites, the clay and silt contents decreased significantly from grassland to shrubland to woodland and sand content showed the opposite pattern, the soil porosity was higher in the shrubland and woodland than that in the grassland, the soil physical properties across the 0-50 cm soil layer improved. Soil texture, porosity and bulk density were the key factors affecting SWHC and SWA. The results of this study provide insight into the effects of vegetation restoration on local hydrological resources and can inform soil water management and land use planning on the Chinese Loess Plateau.

Presenilin 1 mutation likely contributes to U1 small nuclear RNA dysregulation and Alzheimer's disease-like symptoms.

Previous studies showed that U1 small nuclear RNA (snRNA) was selectively enriched in the brain of individuals with familial Alzheimer's disease (AD), resulting in widespread changes in RNA splicing. Our study further reported that presenilin-1 (PSEN1) induced an increase in U1 snRNA expression, accompanied by changed amyloid precursor protein expression, ß-amyloid level, and cell death in SH-SY5Y cells. However, the effect of U1 snRNA overexpression on learning and memory is still unclear. In the present study, we found that neuronal U1 snRNA overexpression could generate U1 snRNA aggregates in the nuclear, accompanied by the widespread alteration of RNA splicing, resulting in the impairments of synaptic plasticity and spatial memory. In addition, more U1 snRNAs is bound to the intron binding sites accompanied by an increased intracellular U1 snRNA level. This suggests that U1 snRNA overexpression regulates RNA splicing and gene expression in neurons by manipulating the recruitment of the U1 snRNA to the nascent transcripts. Using in situ hybridization staining of human central nervous system-type neurons, we identified nuclear aggregates of U1 snRNA in neurons by upregulating the U1 snRNA level. Quantitative polymerase chain reaction analysis showed U1 snRNA accumulation in the insoluble fraction of neurons with PSEN1 mutation neurons rather than other types of U snRNAs. These results show an independent function of U1 snRNA in regulating RNA splicing, suggesting that aberrant RNA processing may mediate neurodegeneration induced by PSEN1 mutation.

Assessment of the efficacy of acupuncture and chiropractic on treating Cervical spondylosis radiculopathy: A systematic review and meta-analysis.

BACKGROUND: Cervical spondylosis radiculopathy (CSR) is often described as neck pain accompanied with radiating pain and neurologic symptoms, such as numbness, muscle weakness, and diminished reflexes, in 1 or both upper extremities. As people's lifestyle changes and the population ages, the incidence of CSR continues to increase. Many clinical trials have proven that acupuncture and chiropractic has a significant effect in the treatment of CSR. In this systematic review, we aim to evaluate the effectiveness and safety of acupuncture and chiropractic for CSR. METHODS: We will search PubMed, Cochrane Library, AMED, EMbase, WorldSciNet; Nature, Science online and China Journal Full-text Database, China Biomedical Literature CD-ROM Database, and related randomized controlled trials included in the ChinaResources Database. The time is limited from the construction of the library to February, 2019. We will use the criteria provided by Cochrane 5.1.0 for quality assessment and risk assessment of the included studies, and use the Revman 5.3 and Stata13.0 software for meta-analysis of the effectiveness, recurrence rate, and symptom scores of CSR. TRIAL REGISTRATION NUMBER: CRD42019119941.

Preparation and Properties of Rubber Blends for High-Damping-Isolation Bearings.

To improve the energy dissipation capacity of rubber isolation bearings, it is important to find a new rubber material with good applicability and high damping properties. Two types of blends were prepared using nitrile rubber (NBR), brominated butyl rubber (BIIR) and ethylene-vinyl acetate copolymer (EVA): NBR/BIIR and NBR/BIIR/EVA. The vulcanization, mechanical and damping properties of the blends were analyzed. The results show that both blends exhibit excellent vulcanization plateaus and mechanical properties. For NBR/BIIR, as the BIIR content increases, the complementary effects of NBR and BIIR afforded by blending are enhanced. Two damping peaks appeared in the tanδ-T curve and shifted toward lower and higher temperatures, respectively, which clearly widened the effective damping temperature range. However, the damping value in the valley of the tanδ-T curve was as low as 0.39. For NBR/BIIR/EVA, the addition of EVA greatly increased damping in the valley of the tanδ-T curve to approximately 0.54. EVA was observed to be the optimal polymer for improving the compatibility of the NBR/BIIR blend. Moreover, hot air thermal aging tests showed that both blends demonstrated good stability.

Zscan4c activates endogenous retrovirus MERVL and cleavage embryo genes.

Endogenous retroviruses (ERVs) contribute to ∼10 percent of the mouse genome. They are often silenced in differentiated somatic cells but differentially expressed at various embryonic developmental stages. A minority of mouse embryonic stem cells (ESCs), like 2-cell cleavage embryos, highly express ERV MERVL. However, the role of ERVs and mechanism of their activation in these cells are still poorly understood. In this study, we investigated the regulation and function of the stage-specific expressed ERVs, with a particular focus on the totipotency marker MT2/MERVL. We show that the transcription factor Zscan4c functions as an activator of MT2/MERVL and 2-cell/4-cell embryo genes. Zinc finger domains of Zscan4c play an important role in this process. In addition, Zscan4c interacts with MT2 and regulates MT2-nearby 2-cell/4-cell genes through promoting enhancer activity of MT2. Furthermore, MT2 activation is accompanied by enhanced H3K4me1, H3K27ac, and H3K14ac deposition on MT2. Zscan4c also interacts with GBAF chromatin remodelling complex through SCAN domain to further activate MT2 enhancer activity. Taken together, we delineate a previously unrecognized regulatory axis that Zscan4c interacts with and activates MT2/MERVL loci and their nearby genes through epigenetic regulation.

Histone demethylase Kdm2a regulates germ cell genes and endogenous retroviruses in embryonic stem cells.

Aim: To investigate the function of Kdm2a in embryonic stem cells (ESCs). Materials & methods: Expression profile analysis after Kdm2a knockout. Analysis of Kdm2a, H3K4me3 and H3K27me3 ChIP-seq data in ESCs. qPCR analysis and ChIP-qPCR analysis of epigenetic changes after Kdm2a loss. Results:Kdm2a was dispensable for pluripotency maintenance in ESCs. Kdm2a genomic binding profile was positively correlated with that of H3K4me3, Zfx and Tet1. Kdm2a directly regulated germ cell genes in primordial germ cell-like cells. Kdm2a loss led to the reduced expression of endogenous retrovirus IAPEy and resulted in the gain of H3K36me2 and loss of H3K4me3 on IAPEy. Conclusion: Kdm2a regulates germ cell genes and endogenous retroviruses in ESCs possibly through demethylating H3K36me2 and influencing H3K4me3 deposition.

Effects of grassland afforestation on structure and function of soil bacterial and fungal communities.

Grassland afforestation strongly influences the structure and function of soil microorganisms. Yet the mechanisms of how afforestation could simultaneously alter both the soil fungal and bacterial communities and its implications for ecosystem management are poorly understood, especially in nitrogen-limited ecosystems. Using high-throughput sequencing of 16S rRNA and ITS rRNA genes, the present study investigated the changes in soil properties and soil microorganisms after afforestation of natural grasslands with Chinese pine (Pinus tabuliformis) on the Loess Plateau in China. Results showed that soil bacterial diversity had no significant differences among the grassland (GL), forest-grassland transition zone (TZ), and forestland (FL), while soil fungal diversity in the GL was significantly higher than that in the FL and TZ (P < 0.05). The proportion of shared OTUs in the soil bacterial community was higher than that in the soil fungal community among the three land use types. The dominant bacterial phylum shifted from Proteobacteria to Actinobacteria, while the dominant fungal phylum shifted from Ascomycota to Basidiomycota after the GL conversion to the FL. The functional groups of ECM fungi increased significantly while biotrophic fungi decreased significantly after grassland afforestation. Both the soil bacterial and fungal communities in the TZ showed great similarity with those in the FL. In addition, among all examined soil properties, soil nitrogen (N) showed a more significant effect on the soil microbial communities. The reduction of soil N after grassland afforestation resulted in both the structure and function changes in soil microbial communities. Our results demonstrated simultaneously differential changes in the composition and diversity of both soil bacterial and fungal communities after afforestation from grasslands to planted forests.

Transcriptome-wide identification and competitive disruption of sacum-binding partners in human colorectal cancer.

Human sacum is regulatory adaptor protein involved in cellular signaling network of colorectal cancer. Molecular evidences suggest that the protein is integrated into oncogenic signaling network by binding to SH3-containing proteins through its proline-rich motifs. In this study, we have performed a transcriptome-wide analysis and identification of sacum-binding partners in the genome profile of human colorectal cancer. The sacum-binding potency of SH3-containing proteins found in colorectal cancer was investigated by using bioinformatics modeling and intermolecular binding analysis. With the protocol we were able to predict those high-affinity domain binders of the proline-rich peptides of human sacum in a high-throughput manner, and to analyze sequence-specific interaction in the domain-peptide recognition at molecular level. Consequently, a number of putative domain binders with both high affinity and specificity were identified, from which the Src SH3 domain was selected as a case study and tested for its binding activity towards the sacum peptides. We also designed two peptide variants that may have potent capability to competitively disrupt sacum interaction with its partners.

Transcriptome-wide identification and competitive disruption of sacum-binding partners in human colorectal cancer.

Human sacum is regulatory adaptor protein involved in cellular signaling network of colorectal cancer. Molecular evidence suggests that the protein is integrated into oncogenic signaling network by binding to SH3-containing proteins through its proline-rich motifs. In this study, we have performed a transcriptome-wide analysis and identification of sacum-binding partners in the genome profile of human colorectal cancer. The sacum-binding potency of SH3-containing proteins found in colorectal cancer was investigated by using bioinformatics modeling and intermolecular binding analysis. With the protocol we were able to predict those high-affinity domain binders of the proline-rich peptides of human sacum in a high-throughput manner, and to analyze sequence-specific interaction in the domain-peptide recognition at molecular level. Consequently, a number of putative domain binders with both high affinity and specificity were identified, from which the Src SH3 domain was selected as a case study and tested for its binding activity towards the sacum peptides. We also designed two peptide variants that may have potent capability to competitively disrupt sacum interaction with its partners.

Systematic Identification and Competitive Disruption of Securin-Binding Partners in the Gene Diversity Space of Human Colorectal Cancer.

Human securin is regulatory protein involved in control of the metaphase-anaphase transition and anaphase onset of colorectal cancer. Molecular evidences suggest that the protein is integrated into oncogenic signaling network by binding to SH3-containing proteins through its proline-rich peptides. In this study, we have performed a genome-wide analysis and identification of securin-binding partners in the gene diversity space of human colorectal cancer. The securin-binding potency of SH3-containing proteins found in colorectal cancer was investigated by using bioinformatics modeling and intermolecular assay. With the protocol we were able to predict those high-affinity domain binders of the proline-rich peptides of human securin in a high-throughput manner, and to analyze sequence-specific interaction in the domain-peptide recognition at molecular level. Consequently, a number of putative domain binders with both high affinity and specificity were identified, from which the Src SH3 domain was selected as a case study and tested for its binding activity towards the securin peptides using fluorescence-based analysis. We also designed two peptide mutants that may have potent capability to competitively disrupt securin interaction with its partners. This article is protected by copyright. All rights reserved.

The association between phospholipase C epsilon gene (PLCE1) polymorphisms and colorectal cancer risk in a Chinese Han population: a case-control study.

BACKGROUND: Heritable factors contribute to the development of colorectal cancer (CRC). We investigated the association between single nucleotide polymorphisms in phospholipase C epsilon 1 (PLCE1) and CRC susceptibility. METHODS: We selected eight tag single nucleotide polymorphisms (tSNPs) and investigated whether they were associated with CRC in Chinese Han population. In this study, we used Sequenom MassARRAY technology and genotyped 276 CRC cases and 385 controls. The effects of the polymorphisms on the risk of CRC were expressed as odds ratios (ORs) with 95% confidence intervals (95% CIs), evaluated by different genetic models using unconditional logistic regression analysis adjusted for age and gender. We also analyzed the risk of the eight PLCE1 tSNPs in different histology of CRC. RESULTS: Based on x(2) tests, rs753724 (OR = 1.49, 95% CI: 1.10-2.03, P = 0.010) and rs10882424 (OR = 1.32, 95% CI: 1.02-1.70, P = 0.037) in PLCE1 were associated with CRC. In genetic model analyses, we found that rs753724 in PLCE1 may increase CRC risk (OR = 1.48, 95% CI: 1.09-2.03, P = 0.013) in the log-additive model, and rs11187842 in PLCE1 may increase CRC risk (OR = 3.09, 95% CI: 1.17-8.14, P = 0.018) in the recessive model. Rs753724 TT (OR = 4.31, P = 0.010), rs11187842 TT (OR = 5.78, P = 0.003), and rs10882424 GG (OR = 2.64, P = 0.022) in PLCE1 may increase rectal cancer in a recessive model. CONCLUSIONS: Our results suggest that PLCE1 may be associated with CRC in Han Chinese population.

[Vibrational spectra of Hetian nephrite from Xinjiang].

In previous studies, EMPA, PIXE and others were employed to study the chemical compositions of nephrite separately without a systematical measurement. In the present study, XRF, XRD, IR and LR were used together to examine chemical and spectra characteristics of white, green and black nephrite from Hetian, Xinjiang. XRD results indicate that all nephrite samples consist of tremolite. Then IR spectra of nephrite samples suggest that the M-OH stretching vibration bands show that the M1 and M3 sites are not only occupied by Mg2+ and Fe2+, but also by Fe3+, which is consistent with the chemical compositions of these samples. This information might be useful to understanding the variety of nephrite. Their Raman spectra are almost the same, while some differences exist because of different content of FeO/Fe2O3.

[Study on crystal chemistry and spectra of feldspar from Zhoukoudian granodiorite].

The chemical composition and spectra characteristic of feldspar from Zhoukoudian granodiorite were systematically analyzed. Based on the field work, some feldspar samples were selected for crystal chemistry and structure analysis through EMPA, IR, LRM and XRD. The compositions of the feldspar range between Ab (85.21) Or (0.18) An (9.11) and Ab (90.06) Or (3.00) An (13.27) by electronic microscope probe analysis. According to the XRD peak and its diffraction intensity, the mineral species was found the unit cell parameters were calculated. The absorption bands and peaks of infrared and Raman spectra were also assigned and the results show that the characteristics of its infrared and Raman spectra are in accordance with the ideal atlas of albite. The infrared spectra show that all the analyzed feldspar grains contain structural hydrogen, which occur as OH-. On the basis of the above analyses, the crystal chemistry and structure characteristics of feldspar were summarized.