mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Nursing students’ knowledge, willingness, and attitudes toward the first aid behavior as bystanders in traffic accident trauma: A cross-sectional survey

Objectives: The purpose of the study was to investigate the nursing students’ levels of the knowledge, willingness, and attitudes toward first aid behavior as bystanders in road traffic accident and the related factors. Methods: A total of 475 nursing students were recruited by convenience choosing in Tianjin University of Traditional Chinese Medicine. The nursing students’ self-efficacy, core self-evaluation, knowledge, willingness and attitudes toward first aid behavior as bystanders in traffic accidents were investigated with a self-designed questionnaire. Results: The scores of knowledge, willingness, and attitudes toward first aid behavior in traffic accident trauma were 7.51 ± 1.93, 15.54 ± 5.03, and 7.73 ± 1.56, respectively. Students who once gained training of first aid showed lower levels of attitude toward first aid behavior than those untrained (t=-2.345, P = 0.019). It was found that self-efficacy was correlated to the knowledge (r = 0.150, P < 0.001), willingness (r = 0.182, P < 0.004) and attitudes toward behavior of the first aid (r = 0.371, P < 0.001) among nursing students. Core self-evaluation was correlated to knowledge (r = 0.193, P < 0.001) and attitudes toward behavior of the first aid (r = 0.199, P < 0.001). Conclusions: The first aid knowledge among nursing students was not satisfactory. The study suggested that an unsustainable short first-aid training program may bring negative effects. Countermeasures should be taken to ensure both quality and continuity of first aid training. Meanwhile, more attention should be paid to improving the self-efficacy and core self-evaluation of the nursing students.
Rapid identification of Dendrobium officinale using Loop-Mediated Isothermal Amplification (LAMP)method

Dendrobium officinale is not only an ornamental plant,but also a valuable medicinal herb that is widely used in traditional Chinese medicine.However,distinguishing D.officinale from other Dendrobium species is usually a difficult task.In this study,we developed a rapid identification protocol for D.officinale using the loop-mediated isothermal amplification (LAMP) method.A set of primers were specifically designed to detect a modified internal transcribed spacer region of D.officinale at 65 °C within 40 min after adding SYBR® Green I,which was used for the detection of D.officinale.Unlike commonly used adulterants,reaction mixtures containing D.officinale DNA changed from orange to green,and this color change was easily observed with the naked eye.Thus,this methodology can be used to accurately differentiate D.officinale from other Dendrobium species,is quick as all D.officinale samples were amplified within 40 min,and specific as samples of the adulterants were not amplified.The specificity of this LAMP-based method was confirmed by testing 17 samples of D.officinale and 32 adulterant samples from other Dendrobium species.This LAMP-based rapid identification method does not require expensive equipment or specialized techniques and can be used in field surveys for accurate and fast on-site identification.
Broussonin E suppresses LPS-induced inflammatory response in macrophages via inhibiting MAPK pathway and enhancing JAK2-STAT3 pathway

Macrophages play an important role in inflammation,and excessive and chronic activation of macrophages leads to systemic inflammatory diseases,such as atherosclerosis and rheumatoid arthritis.In this paper,we explored the anti-inflammatory effect of broussonin E,a novel phenolic compound isolated from the barks of Broussonetia kanzinoki,and its underlying molecular mechanisms.We discovered that Broussonin E could suppress the LPS-induced pro-inflammatory production in RAW264.7 cells,involving TNF-α,IL-1β,IL-6,COX-2 and iNOS.And broussonin E enhanced the expressions of anti-inflammatory mediators such as IL-10,CD206 and arginase-1 (Arg-1) in LPS-stimulated RAW264.7 cells.Further,we demonstrated that broussonin E inhibited the LPS-stimulated phosphorylation of ERK and p38 MAPK.Moreover,we found that broussonin E could activate janus kinase (JAK) 2,signal transducer and activator of transcription (STAT) 3.Downregulated pro-inflammatory cytokines and upregulated anti-inflammatory factors by broussonin E were abolished by using the inhibitor of JAK2-STAT3 pathway,WP1066.Taken together,our results showed that broussonin E could suppress inflammation by modulating macrophages activation state via inhibiting the ERK and p38 MAPK and enhancing JAK2-STAT3 signaling pathway,and can be further developed as a promising drug for the treatment of inflammation- related diseases such as atherosclerosis.
Do subtropical grasslands recover spontaneously after afforestation?

Aims South American Pampa grasslands are habitats of great conservation interest, with a distinct and rich flora, but have been intensely converted to other land uses, including tree plantations. While necessity for restoration grows, no information on restoration potential of grasslands after afforestation exists. Here, we aim at analyzing composition and structure of grassland vegetation with a history of eucalyptus plantations in order to assess recovery potential of these areas. We hypothesized that areas with history of eucalyptus would differ from reference grasslands with no history of land-use change in terms of floristic and functional composition and would present lower species richness. Methods Our study region comprised four sites in the southeastern part of the Pampa biome, in the coastal plain in the extreme south of Brazil, always with sites with long (50 years) history of eucalyptus plantation and reference grassland. We sampled vegetation at posteucalyptus sites (with and without resprouting) 10 years after clearclutting and in natural grasslands. We analyzed data by analysis of variance and ordination techniques, considering compositional parameters and life forms, and indicator species analysis. Important Findings Species richness and vegetation cover were higher in reference grassland than in resprout areas but did not differ from post-eucalyptus areas. Exotic species cover was significantly higher in areas with afforestation history. In terms of total composition, natural grasslands differed significantly from areas with past plantation use. Indicator species analyses revealed considerable differences between grassland types. In conclusion, vegetation development led to grassland communities that are still quite distinct from reference sites. Likely, the specificity of grassland management has a high importance in defining vegetation trajectories in time and importance for grassland recovery, and restoration needs to be addressed in more studies.
Tree phenology along a successional gradient of tropical Atlantic Forest

Aims Changes in habitat characteristics and species composition in successional gradients could determine temporal variation in phenology of second-growth forests. We evaluated phenological patterns in tree species occurring in successional forests in southern Brazil, aiming to assess community changes along succession. We tested for general patterns and phenophase seasonality of trees of forests in successional stages and for differences in occurrence, concentration, frequency and duration of phenophases. Methods Vegetative (flushing and leaf-fall) and reproductive (flowering and fruiting) phenophases of 149 individuals of 29 tree species were monitored monthly, for 2 years, in a successional gradient: early- (~10 years), mid- (~30 years) and late-successional (>80 years) forests in southern Brazil. Important Findings Forests in the successional gradient exhibited shared frequency and duration of phenological phases, probably due to climatic or historical constraints in phenology. However, we found differences in the rate of occurrence and concentration of phenological phases, suggesting that habitat changes caused by succession and species turnover are additional factors affecting phenological patterns in tropical forests.
Can an injection model replenish filaments in a weak magnetic environment?

We observed an Hsurge that occurred in NOAA Active Region 12401 on 2015 August 17, and we discuss its trigger mechanism, and kinematic and thermal properties. It is suggested that this surge was caused by a chromospheric reconnection which ejected cool and dense material with transverse velocity of about 21-28 kms-1 and initial Doppler velocity of 12 kms-1. This surge is similar to the injection of newly formed filament materials from their footpoints, except that the surge here occurred in a relatively weak magnetic environment of ~100G. Thus, we discuss the possibility of filament material replenishment via the erupting mass in such a weak magnetic field, which is often associated with quiescent filaments. It is found that the local plasma can be heated up to about 1.3 times the original temperature, which results in an acceleration of about -0.017 kms~(-2). It can lift the dense material up to 10Mm and higher with an inclination angle smaller than 50◦, namely the typical height of active region filaments, but it can hardly inject the material up to those filaments higher than 25Mm, like some quiescent filaments. Thus, we think that the injection model does not work well in describing the formation of quiescent filaments.
An adaptive loop gain selection for CLEAN deconvolution algorithm

Radio interferometry significantly improves the resolution of observed images, and the final result also relies heavily on data recovery. The Cotton-Schwab CLEAN (CS-Clean) deconvolution approach is a widely used reconstruction algorithm in the field of radio synthesis imaging. However, parameter tuning for this algorithm has always been a difficult task. Here, its performance is improved by considering some internal characteristics of the data. From a mathematical point of view, a peak signal-to-noise-based (PSNRbased) method was introduced to optimize the step length of the steepest descent method in the recovery process.We also found that the loop gain curve in the new algorithmis a good indicator of parameter tuning. Tests show that the new algorithm can effectively solve the problem of oscillation for a large fixed loop gain and provides a more robust recovery.
IU Cancri: a solar-type contact binary with mass transfer

We present new CCD photometry of the solar-type contact binary IU Cnc, which was observed from November 2017 to March 2018 with three small telescopes in China. BV light curves imply that IU Cnc is a W-type contact binary with total eclipses. The photometric solution indicates that the mass ratio and fill-out factor are q = 4.104 ± 0.004 and f = 30.2% ± 0.3%, respectively. From all available light minimum times, the orbital period may increase at a rate of dP/dt = +6.93(4)×10~(-7) d yr~(-1), which may result from mass transfer from the secondary component to the primary one. With mass transferring, IU Cnc may evolve from a contact configuration into a semi-detached configuration.
A method for aligning the plastic scintillator detector on DAMPE

The Plastic Scintillator Detector (PSD) onboard the DArk Matter Particle Explorer (DAMPE) is designed to measure cosmic ray charge (Z) and to act as a veto detector for gamma ray identification. To fully exploit the charge identification potential of PSD and to enhance its capability to identify gamma ray events, we develop an alignment method for the PSD. The path length of a given track in the volume of a PSD bar is derived taking into account the shift and rotation alignment corrections. By examining energy spectra of corner-passing events and fully contained events, position shifts and rotations of all PSD bars are obtained, and are found to be on average about 1mm and 0.0015 radian respectively. To validate the alignment method, we introduce artificial shifts and rotations of PSD bars into the detector simulation. These shift and rotation parameters can be recovered successfully by the alignment procedure. As a result of the PSD alignment procedure, the charge resolution of the PSD is improved from 4% to 8%, depending on the nuclei.
免疫性血小板减少症合并马尔尼菲蓝状菌病一例

马尔尼菲蓝状菌是一种双相型条件致病菌,是HIV感染者常见的条件致病菌之一,亦可发现于HIV阴性但免疫功能受损的人群中。该菌感染常见的临床表现包括发热、贫血、咳嗽、体重减轻、肝脾及淋巴结肿大和特征性皮损,以消化道症状为主要表现者较少。本文报道1例免疫性血小板减少症合并马尔尼菲蓝状菌病,最终死于消化道出血的患者。
Strongly screening β~– decay antineutrino energy loss in presupernova

In this study, we investigate the ion-ball screening model (model (I)), focused on the screening electrostatic potential per electron under the Wigner-Seitz approximation and the Q-value correction. By considering the changes of the Coulomb free energy and the effects of strong electron screening (SES) on the Q-value and the Coulomb chemical potential, we discuss the linear-response screening model (model (II)). We also analyze the influence of the SES on the β~– decay antineutrino energy loss rate by considering the corrections of the Q-value, the electron chemical potential, and electron energy, as well as the shell and pair effects. The antineutrino energy loss rate is found to increase by two orders of magnitude (e.g., the SES enhancement factor reaches 651.9 for model (II)) due to the SES effect.
Rapid and Sparse Labeling of Neurons Based on the Mutant Virus-Like Particle of Semliki Forest Virus

Sparse labeling of neurons contributes to uncovering their morphology, and rapid expression of a fluorescent protein reduces the experiment range. To achieve the goal of rapid and sparse labeling of neurons in vivo, we established a rapid method for depicting the fine structure of neurons at 24 h post-infection based on a mutant viruslike particle of Semliki Forest virus. Approximately 0.014 fluorescent focus-forming units of the mutant virus-like particle transferred enhanced green fluorescent protein into neurons in vivo, and its affinity for neurons in vivo was stronger than for neurons in vitro and BHK21 (baby hamster kidney) cells. Collectively, the mutant virus-like particle provides a robust and convenient way to reveal the fine structure of neurons and is expected to be a helper virus for combining with other tools to determine their connectivity. Our work adds a new tool to the approaches for rapid and sparse labeling of neurons in vivo.
Creep Behavior and Life Assessment of a Novel Heat-Resistant Austenite Steel and Its Weldment

In the present study, creep activation energy for rupture was obtained as 221–348 kJ/mol for 22Cr15Ni3.5CuNbN due to the precipitation-hardening mechanism. The extrapolation strength of creep rupture time of 10~5 h at 923 K for 22Cr15Ni3.5CuNbN is more valid (83.71 MPa) predicted by the Manson–Haferd method, which is superior to other commercial heat-resistant steels. The tensile creep tests ranging from 180 to 240 MPa at 923 K were conducted to investigate creep deformation behavior of welded joint between a novel heat-resistant austenite steel 22Cr15Ni3.5CuNbN and ERNiCrCoMo-1 weld metal. Apparent stress exponent value of 6.54 was obtained, which indicated that the ratecontrolled creep occurred in weldment during creep. A damage tolerance factor of 6.4 in the weldment illustrates that the microstructural degradation is the dominant creep damaging mechanism in the alloy. Meanwhile, the welded joints perform two types of deformation behavior with the variation in applied stress, which resulted from the different parts that govern the creep processing. Also, the morphology evolution of the fracture surfaces confirms the effects of stress level and stress state.
Numerical Investigation on Residual Stresses of the Safe-End/Nozzle Dissimilar Metal Welded Joint in CAP1400 Nuclear Power Plants

The residual stress evolution in a safe-end/nozzle dissimilar metal welded joint of CAP1400 nuclear power plants was investigated in the manufacturing process by finite element simulation. A finite element model, including cladding, buttering, post-weld heat treatment (PWHT) and dissimilar metal multi-pass welding, is developed based on SYSWELD software to investigate the evolution of residual stress in the aforementioned manufacturing process. The results reveal a large tensile axial residual stress, which exists at the weld zone on the inner surface, leads to a high sensitivity to stress corrosion cracking (SCC). PWHT process before dissimilar metal multi-pass welding process has a great influence on the magnitude and distribution of final axial residual stress. The risk of SCC on the inner surface of the pipe will increase if PWHT process is not taken into account. Therefore, such crucial thermal manufacturing process such as cladding, buttering and post-weld heat treatment, besides the multi-pass welding process, should be considered in the numerical model in order to accurately predict the distribution and the magnitude of the residual stress.
Atomic-layer-deposited (ALD) Al_2O_3 passivation dependent interface chemistry, band alignment and electrical properties of HfYO/Si gate stacks

In this work, the effects of atomic-layer-deposited (ALD) Al_2O_3 passivation layers with different thicknesses on the interface chemistry and electrical properties of sputtering-derived HfYO gate dielectrics on Si substrates have been investigated. The results of electrical measurements and X-ray photoelectron sepectroscopy (XPS) showed that 1-nm-thick Al_2O_3 passivation layer is optimized to obtain excellent electrical and interfacial properties for HfYO/Si gate stack. Then, the metal-oxide-semiconductor capacitors with HfYO/1-nm Al_2O_3/Si/Al gate stack were fabricated and annealed at different temperatures in forming gas (95% N_2+5% H_2). Capacitance-voltage (C-V) and current density-voltage (J-V) characteristics showed that the 250 ◦C-annealed HYO high-k gate dielectric thin film demonstrated the lowest border trapped oxide charge density (-3.3×10~(10) cm–2), smallest gate-leakage current (2.45×10~(-6) A/cm~2 at 2 V) compared with other samples. Moreover, the annealing temperature dependent leakage current conduction mechanism for Al/HfYO/Al_2O_3/Si/Al MOS capacitor has been investigated systematically. Detailed electrical measurements reveal that Poole-Frenkle emission is the main dominant emission in the region of low and medium electric fields while direct tunneling is dominant conduction mechanism at high electric fields.
Formation of coherent, core-shelled nano-particles in dilute Al-Sc-Zr alloys from the first-principles

We present a systematic first-principles based study on the formation of coherent L1_2-phase nanoparticles in dilute Al-Sc-Zr alloys. Bulk structures and properties, solute substitution, interface formation energies, and interfacial coherent strains are all calculated. Nucleation modeling and relevant energetic calculations are performed on various possible structures of L1_2-phase nano-precipitates, i.e. individual L1_2-Al_3Sc and L1_2-Al_3Zr, homogeneous L1_2-Al_3(Sc_xZr_(1-x)) and the core-shelled L1_2-Al_3Sc(Al_3Zr) and L1_2-Al_3Zr(Al_3Sc). The following insights are obtained. Matrix-dissolved Sc or Zr strongly prefers to substitute the X sublattice sites in L1_2-Al_3X (X = Zr or Sc), while the inter-substitution between L1_2- Al_3Sc and Al_3Zr is only weakly feasible. The cube-on-cube orientation with the (100)/(100) contacting facets is the most energy favored for the Al/Al_3Sc(L1_2), Al/Al_3Zr(L1_2) and Al_3Sc (L1_2)/Al_3Zr(L1_2) interfaces. All these interfaces are highly coherent, with fairly low formation energy. And particularly, the Al_3Sc(L1_2)/Al_3Zr(L1_2) interface has essentially zero formation energy. Ternary L1_2-Al_3(Sc_xZr_(1-x)) precipitates tend to form a Al_3Sc-based core and Al_3Zr-based shell structure, with a relatively sharp inner interface of Al_3Sc(L1_2)/Al_3Zr(L1_2). This core-shelled structure becomes energetically more favorable for the particle size R > 1–2 nm. The potential influence of the Sc/Zr ratio and temperature on the relative stabilities of L1_2-phases in Al is also evaluated and discussed.
简易法经脐单孔腹腔镜治疗剖宫产瘢痕部位妊娠5例报道

目的:探讨经脐单孔腹腔镜治疗剖宫产瘢痕部位妊娠(CSP)的临床效果。方法:对5例单孔腹腔镜手术治疗CSP的手术时间、术中出血、术后并发症、术后住院时间、术后月经恢复情况等进行分析。结果:5例患者术中平均出血29. 00 ±19. 49 ml,手术平均用时175. 60 ±58. 35分钟,术后住院天数5. 00 ± 1. 87天,术后血β-人绒毛膜促性腺激素(β-hCG)降至正常时间为34. 40 ±9. 97天,月经恢复正常时间33. 00 ±8. 09天,术中1例发生膀胱不完全破裂,术后1例出现上呼吸道感染,未发生其他术中术后并发症。术后1例月经量减少,余月经量均正常。结论:对于部分Ⅱ型和Ⅲ型CSP,单孔腹腔镜手术可以去除病灶,同时行子宫下段修复,且微创、安全。
Synthesis of Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ) and its catalytic performance on dry methane reforming

In this study, Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ) (LSCM) catalysts were synthesized via the citric acid-nitrate process (CNP) and chemical co-precipitation. The catalytic performance of Cu/Ni-LSCM catalysts on dry methane reforming was evaluated in a fixed-bed reactor at 550/650 °C and atmosphere pressure. Cu/Ni loading was investigated as an influencing factor, which led to 5 cases of samples according to the different Cu/Ni mass ratios. The catalysts were characterized by X-ray diffraction (XRD), field emissionscanning electron microscope (FE-SEM), Brunauer-Emmett-Teller (BET) measurement, X-ray photoelectron spectroscopy (XPS), hydrogen-based temperature-programmed reduction (H_2-TPR) and thermos gravimetric analyzer (TGA). The results show that the methane conversion increases, the resistance against metal sintering increases and the carbon deposition drops after the copper is introduced. This optimum performance can be obtained under Case 3 (Cu:Ni:LSCM = 1:3:6 in mass ratio).
Controlled fabrication of Pr(OH)_3 nanowires for enhanced photocatalytic activities

In this report, praseodymium hydroxide Pr(OH)_3 nanowires with different aspect ratios (length to diameter ratios) were synthesized by a facile hydrothermal approach. The variations in alkali concentration during synthesis are found to form different aspect ratios of nanowires. The X-ray diffraction and Raman spectroscopy analysis demonstrate the absence of any impurity phases in as-prepared materials. Subsequently, photocatalytic activities of as-prepared nanowires were evaluated by the degradation of methyl orange (MO). Our findings reveal that the nanowires with larger aspect ratios have higher photocatalytic efficiency than the smaller aspect ratio samples. X-ray photospectroscopy investigations reveal that the samples with higher aspect ratio are found to exhibit more oxygen vacancies as compared to lower aspect ratio samples. The enhanced photocatalytic activities can be attributed to the presence of higher percentage of active crystal facet (100), higher concentration of defects densities and narrower band gap. Thus, Pr(OH)_3 nanowires can be considered as a potential candidate for the application of wastewater treatment and related technologies.
睾丸支持细胞免疫豁免研究进展及其应用

由于独特的免疫豁免能力和有效的固有免疫调控作用,哺乳动物的睾丸拥有特殊的免疫环境。睾丸免疫豁免功能使具有免疫原性的生殖细胞免受免疫系统攻击,而局部固有免疫则在抵御病原微生物感染中发挥作用。睾丸免疫稳态遭到破坏可引起睾丸炎症,甚至男性不育。拥有复杂三维结构的睾丸支持(Sertoli)细胞是睾丸的重要组成细胞,除参与组建精原细胞生长微环境,还通过分泌多种细胞因子和免疫抑制因子调节免疫反应以维持免疫稳态。Sertoli细胞的免疫豁免特性为细胞、组织和器官的替代治疗提供了新思路。文章综述了Sertoli细胞免疫豁免机制的研究进展及其应用。
Birt-Hogg-Dube综合征一例报告

BHD综合征伴发肾肿瘤并无明确的标准治疗方案,当最大的肿瘤>3 cm时应进行外科干预。BHD伴肾肿瘤的特点具有双侧多灶性,可能需多次手术,因此建议采用肾部分切除术,并且术中应仔细探查有无影像学未发现的肿瘤,建议加用术中超声以免遗漏。目前,对于BHD伴发肾肿瘤的患者,除不适合手术或孤立肾等特殊情况外并不建议行射频消融治疗。
天然气中高含H2S的成因及其预测

充足的烃类、发育的硫酸盐（石膏）和储层经历过较高的温度是形成高含H，S天然气所必须的3个基本条件，也是硫酸盐热化学还原作用（TSR）发生的物质基础和热动力保证。TSR是一个十分复杂的有机物-无机物相互作用的地质-地球化学过程，并非具备了这3个条件就会发生TSR或形成高含H2S天然气。目前关于TSR的一些理论问题尚未完全达成共识，对其发生反应的温度条件、反应体系方程、烃类的消耗、同位素分馏、反应产物及其转化等科学问题存在较多争论。本文认为川东北和渤海湾盆地晋县凹陷高含H2S的天然气属TSR成因，并对TSR中的科学问题进行了探讨，为建立H2S的预测模型提供了参考。
开拓、创新，再创辉煌——浅议揭解青藏高原之秘

1999年以来中国地质调查局在青藏高原空白区开展了1：25万区域地质调查，这不仅是中国地质调查史中的重要举措，而且在平均海拔高达4500m以上的“第三极”进行多学科、多工种的地质调查，在世界上也是绝无仅有的。7年来地质调查取得的大量实际资料，无疑为进一步阐明青藏高原若干重大地质问题、学科创新、满足国家需求等方面都奠定了基础和提供了重要依据。青藏高原由于在全球所处的特殊地位，其形成和演化涉及到地球科学、生态科学、环境科学乃至生命科学等，因而一直是各国科学家关注和竞争研究的热点地区。从广度上我们尚需从全球角度来认识青藏高原，从深度上我们尚需从地球各圈层的相互关系来探讨青藏高原的形成、演化及其效应等问题。
DNA微阵列在猪遗传育种中的应用

DNA微阵列是高通量、微型化、自动化研究生物大分子功能的高新技术，目前已经广泛应用于动植物生物学过程的基因表达研究中。猪既是重要的经济动物，又是常用的实验动物，应用DNA微阵列对其重要经济性状主效基因的寻找和各种疾病遗传机制的探索已经成为今后该领域的一个十分重要的发展方向。
TORC2：糖尿病治疗的新靶点

胰高血糖素等通过激活受体，使胞内cAMP浓度升高，激活异生或糖原分解与糖相关的基因．从而使血糖浓度升高。此过程由转录因子cAMP应答元件结合蛋白（CREB），在其他蛋白质尤其是TORC2辅助下完成的。TORC2磷酸化时处于细胞质，脱去磷酸而进入细胞核才能发挥与CREB的共激活效应。因此，抑制TORC2的脱磷酸或进入细胞核，可以实现减少肝脏中的糖生成，从而可望在糖尿病治疗中发挥作用。