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Background: Due to its effective osteogenic ability, BMP9 is a promising candidate for bone regeneration medicine. Whereas, BMP9 can also induce adipogenesis simultaneously. LCN2 is a cytokine associated with osteogenesis and adipogenesis. Reducing the adipogenic potential may be a feasible measure to enhance the osteogenic capability of BMP9. Objective: The objective of the study was to explore the role of LCN2 in regulating the BMP9-initialized osteogenic and adipogenic differentiation in mouse embryonic fibroblasts (MEFs), and clarify the possible underlying mechanism. Methods: Histochemical stain, western blot, real-time PCR, laser confocal, immunoprecipitation, cranial defect repair, and fetal limb culture assays were used to evaluate the effects of LCN2 on BMP9-induced osteogenic and adipogenic differentiation, as well as Wnt/β-catenin signaling. Results: LCN2 was down-regulated by BMP9. The BMP9-induced osteogenic markers were inhibited by LCN2 overexpression, but the adipogenic markers were increased; LCN2 knockdown exhibited opposite effects. Similar results were found in bone defect repair and fetal limb culture tests. The level of β-catenin nucleus translocation was found to be reduced by LCN2 overexpression, but increased by LCN2 knockdown. The inhibitory effect of LCN2 overexpression on the osteogenic capability of BMP9 was reversed by β-catenin overexpression; whereas, the effect of LCN2 knockdown on promoting BMP9 osteogenic potential was almost eliminated by β-catenin knockdown. LCN2 could bind with LRP6 specifically, and the inhibitory effect of LCN2 on the osteogenic potential of BMP9 could not be enhanced by LRP6 knockdown. Conclusion: LCN2 inhibits the BMP9-induced osteogenic differentiation but promotes its adipogenic potential in MEFs, which may be partially mediated by reducing Wnt/β-catenin signaling via binding with LRP6.

The direct Pd-catalyzed β-C-H arylation of aldehydes and ketones was developed by using 2-amino-N,N'-diisopropylsuccinamide as a novel transient directing group (TDG). The TDG showed good versatility in functionalizing unactivated β-C-H bonds of aldehydes and ketones. It was effective not only for aliphatic aldehydes and ketones but also for aromatic aldehydes and ketones. Besides, it was applicable to o-methylbenzaldehydes.

We introduce a method which based on Bell inequalities, to study quantum phase transitions. By using the non-linear programming, we compare two different kinds of Bell inequalities, the original Bell inequality and Clauser-Horne-Shimony-Holt (CHSH) inequality. And we find that the original Bell inequality is more accurate in detecting the Bell non-locality. By defining the maximal violation of Bell inequalities, we calculate two kinds of transitions, the one is magnetic transition in the spin- $\frac {1}{2}$ XX model and the other is topological transition in the Kitaev honeycomb model. The critical points are detected successfully. Compared with traditional methods, our method requires no prior knowledge of order parameters and it is base-free.

To explore the hot compression behavior and microstructural evolution, fine-grained Al−1.88Mg−0.18Sc− 0.084Er (wt.%) aluminum alloy wires were fabricated with Castex (continuous casting−extrusion) and ECAP-Conform, and their hot compression behavior was investigated at temperatures of 673−793 K and strain rates of 0.001−10 s−1; the microstructures were characterized by optical microscope, X-ray diffractometer, transmission electron microscope, and electron backscattered diffractometer, and the flow stresses were obtained by thermal compression simulator. Microstructural evolution and flow curves reveal that dynamic recovery is the dominant softening mechanism. Continuous dynamic recrystallization followed by dynamic grain growth takes place at a temperature of 773 K and a strain rate of 0.001 s−1; the yielding drop phenomenon was discovered. Hyperbolic sine constitutive equation incorporating dislocation variables was presented, and a power law constitutive equation was established. The stress exponent is 3.262, and the activation energy for deformation is 154.465 kJ/mol, indicating that dislocation viscous glide is the dominant deformation mechanism.

Sign prediction is a significant research content in signed social networks, so it has attracted increasing attention from the field of online social networks recently. Traditionally, the basic idea of motif-based predictive method is to calculate the motif number on the predicted edge (i.e., the single edge-dependent motif based method), and then use a machine learning predictor for sign prediction. Although this intuition-based method can achieve great performance for sign prediction, up to now its reasonability has not been proved theoretically. Furthermore, the method of counting the number of edge-dependent motif can not distinguish the distinct role of each node on the neighborhood of the predicted edge. In this study, firstly we propose a Single Motif Naive Bayes (SMNB) model for sign prediction, which can not only explain why the single edge-dependent motif based method is efficient, but also quantify the role of each neighbor node (for 3-node predictors) or neighbor edge (for 4-node predictors) which is connected by the predicted edge for the task of sign prediction. Then, we extend SMNB by merging two types of motifs, and propose a Two Motif Naive Bayes (TMNB) model. Experimental results on real-world networks indicate that the proposed algorithms outperform the state-of-the-art approaches. Finally, we explore the intrinsic relationship among different motifs according to the matrix of Maximal Information Coefficient (MIC). Our research not only extends the traditional motif theory by proving the rationality of the edge-dependent motif based method and distinguishing a node (or an edge) contribution for sign prediction, but also is helpful to further understand the evolution mechanism of signed social networks based on the correlation among different motifs.

IntroductionIrritable bowel syndrome (IBS) is a common chronic functional gastrointestinal disorder that presents with abdominal pain/discomfort and altered bowel patterns. IBS has multiple potential causes for which conventional medicines have had limited success, resulting in a significant number of patients who do not sensitively respond to pharmacotherapy for a period of 12 months and who develop a continuing symptom profile (described as refractory IBS) and seek help through (non)pharmacological treatments. The aim of this study is to investigate the efficacy and safety of acupuncture therapy for refractory IBS on the basis of conventional treatments.Methods and analysisA total of 170 eligible patients who meet the Rome IV criteria for refractory IBS will be randomly allocated to receive acupuncture or sham acupuncture. Each patient will receive 12 sessions of acupuncture over 4 weeks and a 4-week follow-up. The primary outcome will be the IBS Symptom Severity Score. Secondary outcomes will include the proportion of participants experiencing adequate relief of global IBS symptoms, the weekly frequency of defecation, the stool properties assessed by the Bristol Grading Scale, the Work and Social Adjustment Scale, the IBS-Quality of Life score, and the Self-Rating Depression Scale and Self-Rating Anxiety Scale anxiety and depression scores. Outcome measures will be collected at baseline, 2 and 4 weeks of the intervention, and 6 and 8 weeks after the intervention. Categorical variables will be compared with Fisher’s exact test or the Wilcoxon rank-sum test, and continuous variables will be compared using Student’s t-test or the Wilcoxon rank-sum test.Ethics and disseminationThe entire project has been approved by the ethics committees of Beijing University of Chinese Medicine (2020BZYLL0507) and Sichuan Province Regional Institution for Conducting Research on Traditional Chinese Medicine (2020KL-025). The outcomes of the trial will be disseminated through peer-reviewed publications.Trial registration numberNCT04276961.

Hydrogen sulfide (H2S) has been proven to be a multifunctional signaling molecule in plants. In this study, we attempted to explore the effects of H2S on the climacteric fruit tomato during postharvest storage. H2S fumigation for 1 d was found to delay the peel color transition from green to red and decreased fruit firmness induced by ethylene. Further investigation showed that H2S fumigation downregulated the activities and gene expressions of cell wall–degrading enzymes pectin lyase (PL), polygalacturonase (PG), and cellulase. Furthermore, H2S fumigation downregulated the expression of ethylene biosynthesis genes SlACS2 and SlACS3. Ethylene treatment for 1 d was found to induce the expression of SlACO1, SlACO3, and SlACO4 genes, whereas the increase was significantly inhibited by H2S combined with ethylene. Furthermore, H2S decreased the transcript accumulation of ethylene receptor genes SlETR5 and SlETR6 and ethylene transcription factors SlCRF2 and SlERF2. The correlation analysis suggested that the fruit firmness was negatively correlated with ethylene biosynthesis and signaling pathway. The current study showed that exogenous H2S could inhibit the synthesis of endogenous ethylene and regulate ethylene signal transduction, thereby delaying fruit softening and the ripening process of tomato fruit during postharvest storage.

In this work, the MoS2 fillers were prepared through chemical exfoliation method and used as fillers to fabricate epoxy (EP)/MoS2 nanocomposites. The effects of molybdenum disulfide (MoS2) intercalation conditions on the properties of EP/MoS2 nanocomposites were investigated. As the intercalation time was prolonged, the surface of MoS2 exhibited a totally crumpled structure and more functional groups formed. Because of the higher functional group concentration, the interfacial adhesion force between EP and MoS2 was enhanced. With the addition of 1.0 wt% exfoliated MoS2 fillers, the tensile strength and tensile modulus of EP were even improved ~500% and ~6800%, respectively. Therefore, this work provides a facile way to produce high-performance EP nanocomposites.

Alzheimer's disease (AD) is a fatal neurodegenerative disease for which currently no cure is available. Electroacupuncture (EA) has been widely used in China as an alternative therapeutic approach for neurological diseases. The cognitive decline in patients with AD has been reported to be closely related to the deposition of amyloid-β (Aβ) in the hippocampus of the brain, and the Morris water maze (MWM) test is a widely used method for assessing the behavior of animal models. In this study, the MWM test was performed to evaluate the effects of EA treatment on cognitive function and memory, and the micro-positron emission tomography scan was used to assess the hippocampal Aβ deposition. The results showed that the cognitive function of APP/PS1 mice was significantly improved and the rate of [18F]AV-45 uptake was reduced in the EA group, compared with the AD group. Our study suggested that EA can exert a therapeutic effect in AD by improving spatial learning and memory and inhibiting the hippocampal Aβ deposition.电针对APP/PS1转基因小鼠行为学的改善可能与减少海马Aβ沉积有关 摘要:老年痴呆症疾病(AD)是一种致命的神经退行性疾病，目前没有治愈方法。电针作为神经疾病的替代治疗手段，在我国已得到广泛应用。据报道，阿尔茨海默病患者的认知功能下降与β-淀粉样蛋白沉积于大脑海马区关系密切，Morris水迷宫(MWM)试验是一种广泛应用的动物模型行为评估方法，本研究采用Morris水迷宫试验评估电针治疗对阿尔茨海默病模型动物认知功能和记忆的影响，并用微型正电子断层扫面技术评估海马区β-淀粉样蛋白沉积，结果表明电针组与模型组相比，APP/PS1小鼠认知功能明显改善，[18F]AV-45摄取率降低，我们的研究提示电针可通过改善模型动物小鼠空间学习记忆和抑制海马区β-淀粉样蛋白沉积，对阿尔茨海默病起到一定的治疗作用。.

The Nazarov electrocyclization reaction is a convenient, widely used method for construction of cyclopentenones. In the past few decades, catalytic asymmetric versions of the reaction have been extensively studied, but the strategies used to control the position of the double bond limit the substituent pattern of the products and thus the synthetic applications of the reaction. Herein, we report highly enantioselective silicon-directed Nazarov reactions which were cooperatively catalyzed by a Lewis acid and a chiral Bronsted acid. The chiral cyclopentenones we synthesized using this method generally cannot be obtained by means of other catalytic enantioselective reactions, including previously reported methods for enantioselective Nazarov cyclization. The silicon group in the dienone substrate stabilized the β-carbocation of the intermediate, thereby determining the position of the double bond in the product. Mechanistic studies suggested that the combination of Lewis and Bronsted acids synergistically activated the dienone substrate and that the enantioselectivity of the reaction originated from a chiral Bronsted acid promoted proton transfer reaction of the enol intermediate.

We investigate how the correlated actions of quantum channels affect the robustness of entangled states. We consider the Bell-like state and random two-qubit pure states in the correlated depolarizing, bit flip, bit-phase flip, and phase flip channels. It is found that the robustness of two-qubit pure states can be noticeably enhanced due to the correlations between consecutive actions of these noisy channels, and the Bell-like state is always the most robust one. We also consider the robustness of three-qubit pure states in correlated noisy channels. For the correlated bit flip and phase flip channels, the result shows that although the most robust and most fragile states are locally unitary equivalent, they exhibit different robustness in different correlated channels, and the effect of channel correlations on them is also significantly different. However, for the correlated depolarizing and bit-phase flip channels, the robustness of two special three-qubit pure states is exactly the same. Moreover, compared with the random three-qubit pure states, they are neither the most robust states nor the most fragile states.

Neurotoxic methylmercury (MeHg) in environments poses substantial risks to human health. Saturated sediments are basic sources of MeHg in food chains; however, distribution patterns and environmental drivers of MeHg at a global scale remain largely unexplored. Here, we characterized global patterns of MeHg distribution and environmental drivers of MeHg production based on 495 sediment samples across five typical ecosystems from the literature (1995–2018) and our own field survey. Our results showed the MeHg concentration ranged from 0.009 to 55.7 μg kg−1 across the different ecosystems, and the highest MeHg concentration and Hg methylation potential were from the sediments of paddy and marine environments, respectively. Further, using combined analysis of random forest and structural equation modeling, we identified temperature and precipitation as important regulators of MeHg production after accounting for the well-known drivers including Hg availability and sediment geochemistry. More importantly, we found increased MeHg production in sediments with elevated mean annual Hg precipitation, and warmer temperature could also accelerate MeHg production by facilitating activities of microbial methylators. Together, this work advances our understanding of global MeHg distribution in sediments and environmental drivers, which are fundamental to the prediction and management of MeHg production and its potential health risk globally.

This paper provides a new idea in research field of collaborative transportation using multiple mobile manipulators, where the force constraint problem, caused by force sensors in traditional control method, between robotic arm and moving objects is transformed into position constraint problem of position sensors in flexible grasping point that placed on lifting mechanism. And the lifting mechanism is grasped flexibility by each mobile manipulator by a robotic arm with six degree of freedom. The hardware designing processes of mobile manipulator and lifting mechanism is provided in details firstly. Then the designing of software, including monitoring configuration software in upper computer (MRCC) that running on the host PC and the lower computer software that running on core control board of each mobile manipulator, is given. Finally, the application of collaborative transportation system is described, which includes two different parts: verification in debugging mode and designment of control block in automatic mode, and the automatic mode is an open interface that it makes possible for researchers to design their own collaborative control law.

The CRISPR/Cas9 system is a powerful tool which has been extensively used for genome editing in the past few years. Nuclease-dead Cas9 (CRISPR/dCas9), a Cas9 protein mutant without splicing ability, along with loss-of- function (LOF), gain-of-function (GOF), or non-coding genes scanning approaches can reveal genome-scale functional determinants. CRISPR/Cas9 has been widely adopted to decipher disease mechanisms and pinpoint drug targets in the life science field, and also provide novel insights into animal genetics and breeding. In this review, we summarize the research progress in high-throughput CRISPR/Cas9 screening for revealing the functional genes and regulatory elements in the whole genome. We also highlight the applications of CRISPR/Cas9 system in the animal cells, providing a reference for gene editing and other related research in related fields.CRISPR/Cas9系统是一种近年来被广泛应用于基因组编辑的强大工具。通过将CRISPR/Cas9系统中的Cas9蛋白突变后,使其失去剪切活性而成为dCas9 (nuclease-dead Cas9),再结合基因功能丧失(loss-of-function, LOF)、基因功能激活(gain-of-function, GOF)以及非编码功能基因鉴定技术即可实现全基因组高通量的功能基因及调控元件靶向鉴定和筛选。目前,该技术已被广泛应用于疾病免疫机理、药物靶点筛选和动物遗传育种等研究,为生命医学和基础科学带来了全新高效的技术方法和研究思路。本文综述了基于CRISPR/Cas9技术在全基因组中高通量筛选功能基因及调控元件的方法及研究进展,重点阐述了CRISPR/Cas9系统在动物细胞中筛选功能性基因的方法,以期为基因编辑及相关研究领域提供参考。.

Most real-world systems evolve over time in which entities and the interactions between entities are added and removed—new entities or relationships appear and old entities or relationships vanish. While most network evolutionary models can provide an iterative process for constructing global properties, they cannot capture the evolutionary mechanisms of real systems. Link prediction is hence proposed to predict future links which also can help us understand the evolution law of real systems. The aim of link prediction is to uncover missing links from known parts of the network or quantify the likelihood of the emergence of future links from current structures of the network. However, almost all existing studies ignored that old nodes tend to disappear and new nodes appear over time in real networks, especially in social networks. It is more challenging for link prediction since the new nodes do not have pre-existing structure information. To solve the temporal link prediction problems with new nodes, here we take into account nodal attribute similarity and the shortest path length, namely, ASSPL, to predict future links with new nodes. The results tested on scholar social network and academic funding networks show that it is highly effective and applicable for ASSPL in funding networks with time-evolving. Meanwhile, we make full use of an efficient parameter to exploit how network structure or nodal attribute has an impact on the performance of temporal link prediction. Finally, we find that nodal attributes and network structure complement each other well for predicting future links with new nodes in funding networks.

In this work, a melamine functionalized molybdenum disulfide (M-MoS2) was prepared and used as fillers to form epoxy (EP)/MoS2 nanocomposites. The effects of molybdenum disulfide (MoS2) and melamine functionalized molybdenum disulfide (M-MoS2) loading on the mechanical properties of epoxy composites were investigated and compared. With only addition of 0.8 wt% M-MoS2, the tensile strength and modulus of EP/M-MoS2 nanocomposites showed 4.5 and 4.0 times increase over the neat epoxy. Interestingly, the elongation at break value of EP was also increased with the introduction of M-MoS2 fillers. These properties could result from the good dispersion and strong interfacial adhesion of M-MoS2 fillers and the EP matrix. Therefore, this work provides a facile way to produce of high-performance EP nanocomposites.

Although the application of synthetic fertilizers remarkably improves crop yields, their excessive application can bring about serious environmental pollution. However, previous studies largely focused on life cycle assessment about environmental risk and impact through measuring environmental emissions, or fertilization scheme recommendation with single optimization goal based on field experiments. In this study, we used soil testing and formulated fertilization field data from the experimental region (Ezhou, South China) to acquire the optimal application scheme of synthetic fertilizers for paddy field crops. Based on four crops (i.e. rapeseed, early rice, middle rice and late rice) and two rotation systems (i.e. rapeseed-rice rotation and rice-rice rotation), we applied the life cycle assessment method to analyze life cycle inventories and assess environmental impacts. The fertilizer production and resource consumption were defined as the initial boundary, and the crop production and environmental emissions were defined as the terminal boundary. Four crops were assessed and compared under 1t crop grain functional unit and 1hm2 cropland area functional unit, and two rotation systems were assessed and compared under 1hm2 cropland area functional unit. The environmental impact categories assessed were energy consumption, climate change, eutrophication, environmental acidification, land use and water consumption. Based on three fertilization schemes (i.e. fertilization on benchmark value ( Scheme b ), yield balance value ( Scheme yb ) and threshold value ( Scheme t )), we subsequently simulated crop yields and environmental emissions of fertilization schemes. The results show that the estimated environmental impact category indicators assessed by life cycle per t of rapeseed were higher than rice, and that per hm2 of rapeseed-rice rotation were lower than rice-rice rotation. Eutrophication contributed the most (over 80%) to the environmental impact of producing 1t crop, followed by environmental acidification. Ammonia (NH3) emission accounted for a high contribution to eutrophication (about 30%) or environmental acidification (about 90%), and nitrate ion (NO3-) loss contributed the most to eutrophication (about 40%). The results also show that paddy field crops reached maximum yields but caused greatest environmental impact under the Scheme yb . Whereas, the Scheme t could guarantee paddy field crops to keep average yields but cause minimum environmental impact, which was the optimal fertilization scheme. Our study indicates that producing 1t rice and 1hm2 rapeseed-rice rotation had higher environmental benefit than producing 1t rapeseed and 1hm2 rice-rice rotation respectively. Eutrophication could lead to the biggest threat to ecological environment, and the key to alleviating this environmental impact was reducing NH3 volatilization and NO3- loss. Our work implies that the optimal fertilization scheme can both guarantee food sufficiency and reduce environmental pollution, which is applicable combining with soil testing and formulated fertilization technology in Ezhou.

We investigate the single qubit transformations under several typical coherence-free operations, such as, incoherent operation (IO), strictly incoherent operation (SIO), physically incoherent operation (PIO), and coherence preserving operation (CPO). Quantitative connection has been built between IO and SIO in single qubit systems. Moreover, these coherence-free operations have a clear hierarchical relationship in single qubit systems: CPO $\subset$ PIO $\subset$ SIO=IO. A new and explicit proof for the necessary and sufficient condition of single qubit transformation via IO or SIO has been provided, which indicates that SIO with only two Kraus operators are enough to realize this transformation. The transformation regions of single qubits via CPO and PIO are also given. Our method provides a geometric illustration to analyze single qubit coherence transformations by introducing the Bloch sphere depiction of the transformation regions, and tells us how to construct the corresponding coherence-free operations., 12 pages, 6 figures

Tomato grey mould disease, which is caused by Botrytis cinerea , is a serious threat to tomato postharvest handling and storage. Clonostachys rosea is an effective antagonistic fungus to B. cinerea and can prevent this disease in tomatoes. To elucidate the mechanism of C. rosea -induced resistance in tomato, fruit were subjected to four treatments: spraying with B. cinerea, spraying with C. rosea, inoculation with C. rosea after spraying with B. cinerea , and inoculation with B. cinerea after spraying with C. rosea . Compared to the control (water), increases in indole acetic acid (IAA), salicylic acid (SA) and NO levels and enhanced phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) activities were observed, whereas catalase (CAT) activity and abscisic acid (ABA) levels decreased, particularly in the B. cinerea- plus- C. rosea- and C. rosea -plus- B. cinerea- treated fruit. We identified 22 proteins differentially expressed in the treated fruit compared to the control fruit using two-dimensional electrophoresis (2-DE) and mass spectrometry. ATP synthase CF1 alpha subunit was identified as an abundant protein in fruit sprayed with C. rosea . This study advances our understanding of C. rosea biocontrol mechanisms in tomato fruit.

In this work, we demonstrate theoretically that a planar metamaterial can achieve electromagnetically induced transparency (EIT), in which insensitive to the incident angle and polarization of electromagnetic waves. We describe simple metamaterial designs that able to support exciting the high Q-value antisymmetric trapped-mode. These features enable the proposed metamaterials to achieve potential applications in filtering, data storing, switching, and sensing. Finally, we have realized analog of electromagnetically induced absorption (EIA) by its complementary of this metamaterials structure.

In the present study, a total of 1130 soil samples were collected in 2003 and 2013 in the Ningbo city district, and the content of eight typical heavy metals were measured. The degree of heavy metal pollution in the soil in the study area was evaluated using the pollution index evaluation method. The temporal and spatial variation in the pollution were analyzed by the geostatistics method, and principal component analysis (PCA) and the UNMIX model were used to analyze the heavy metal pollution sources. The results showed that:① excluding As, the mean values of the other seven heavy metals in both periods exceeded the soil background values in Zhejiang province and national background values, which indicated that heavy metal pollution is common in the soil from the study area. From 2003 to 2013, the mean content of all elements increased to some degree, indicating that the heavy metals pollution was generally aggravated in 10 a; the increase in the mean Hg content was the greatest. ② The evaluation results based on the single-factor pollution index showed that the pollution degree was high for Hg; moderate for Cd, Cu, and Pb; slight for Zn, Cr, and Ni; and unpolluted for As. The evaluation results based on Nemero's comprehensive pollution index showed that the pollution index for all samples exceeded the precaution value, and the number of soil samples that were characterized as heavily polluted with a comprehensive pollution index over 3 had increased significantly. ③ The spatial distribution of the same heavy metal in different periods presented similar characteristics. Generally speaking, the spatial distribution of Pb was similar to that of Hg, and the spatial distributions of Cr, As, Cu, Zn, and Ni were similar to each other; high value areas were mainly concentrated in the four areas of Haishu, Jiangbei, Jiangdong, and Zhenhai districts, where the polluted enterprises were densely distributed and human activities were frequent. ④ Based on PCA and the UNMIX receptor model, the source analysis results of soil heavy metals in 2013 were essentially the same, i.e., the source of heavy metal pollution in the study area included industrial sources and living sources. Industrial sources of heavy metal pollution had the highest contribution rate and derived from industrial wastewater, waste gas, and waste residue discharged by plasticizing, mining, and metallurgical enterprises; chemical and mechanical manufacturing enterprises; etc., causing the accumulation of Cr, As, Cu, Zn, and Ni in the soil. The living sources had the second highest contribution rate and originated from the pollution of particulates and dust caused by domestic waste, automobile exhaust, and road wear. Additionally, natural factors had small contribution rates, mainly due to the spread of pollutants by prevailing winds and atmospheric settlement.

The differences between the XXZ model with topological and periodical boundary conditions were compared by studying their entanglement, quantum discord, and critical temperature above which the entanglement vanishes. It shows that the different boundary conditions mainly affect bipartite quantum correlations of the boundary spins rather than that of other spin pairs. The topological boundary spins can protect entanglement and discord against strong magnetic fields while the periodical boundary spins can protect them against nonuniform magnetic fields. Compared with the periodical XXZ model, the critical temperature is significantly improved for the topological XXZ model. The topological XXZ model also allows us to improve significantly its critical temperature by increasing the strength of magnetic field, which is not feasible for the periodical XXZ model. It is therefore more promising for preparing entangled states at high temperature in the topological XXZ model.