Workability and Strength of Ceramsite Self-Compacting Concrete with Steel Slag Sand

This study focuses on the workability and compressive strength of ceramsite self-compacting concrete with fine aggregate partially substituted by steel slag sand(CSLSCC)to prevent the pollution of steel slag in the environment.The SF,J-ring,visual stability index,and sieve analysis tests are primarily employed in this research to investigate the workability of freshly mixed self-compacting concrete containing steel slag at various steel slag sand replacement rates.The experiment results indicate that CSLSCC with the 20%volume percentage of steel slag(VPS)performs better workability,higher strength,and higher specific strength.The 7-day compressive strength of CSLSCC with the 0.4 of the water-binder ratio(W/B),decreases with the increase of steel slag content,while the 28-day compressive strength increases significantly.The ceramsite self-compacting concrete with good comprehensive performance can be obtained when the substitution rate of steel slag sand for fine aggregate is less than 20%(volume percentage).

Practical Progress of SBAR Communication Model-Related Teaching in Clinical Teaching

This paper elaborates the core and essence of situation,background,assessment,recommendation(SBAR)communication model,clarify the application status of SBAR communication model in the clinical teaching of nursing students,and describe its effectiveness and limitations,so as to provide reference for improving clinical nursing teaching ability.

The Latest Research Progress in the Application of MEWS Scoring System in Clinical Nursing

This paper summarizes the background of the formation of the Modified Early Warning System(MEWS)evaluation system,its current status of clinical teaching applications in different fields of hospitals,and its significance on the medical and nursing career,aiming to provide specific theoretical basis for medical staff and lay a foundation for continuing to carry out related work on MEWS.

碳化钨粉末注射成形一步热脱脂的脱脂动力学

采用热重分析法测定了在氮气气氛中5℃/min、10℃/min、15℃/min和20℃/min不同升温速率下的石蜡、保形聚合物(PP与HDPE的混合物)、石蜡/保形聚合物和碳化钨(WC-10%Ni)粉末注射成形专用料的热解过程,采用Kissinger法和Flynn-Wall-OZAWA法对4种专用料的热分解动力学进行分析,并用Coats-Redfern研究反应级数。结果表明,用Kissinger法分析不能很好地反映混合物的复杂的热解过程,不能支持碳化钨粉末注射成形一步热脱脂的工艺制定。用Flynn-Wall-OZAWA法分析,石蜡的热分解活化能在59~72 k J/mol,保形聚合物的热分解活化能在143~252 k J/mol,石蜡/保形聚合物的热分解活化能在60~240 k J/mol和WC-10%Ni的专用料的热分解活化能在93~220 k J/mol。用CoatsRedfern法分析,石蜡与保形聚合物的热解可用一级反应来描述,而石蜡/保形聚合物与WC-10%Ni的专用料的热解则适用3个连续一级反应来描述。

单活性中心氧化还原体系引发N-异丙基丙烯酰胺在凹凸棒土表面的高效接枝聚合

利用γ-氨丙基三乙氧基硅烷(APTES)修饰凹凸棒土(ATP),然后分别与硝酸铈铵(CAN)和过硫酸铵(APS)构建单活性和双活性中心氧化还原引发体系,引发N-异丙基丙烯酰胺(NIPAM)接枝聚合制备杂化粒子。通过红外光谱、X射线光电子能谱、热失重分析和透射电镜等方法对杂化粒子进行了表征,比较了2种引发体系下的接枝效率,并详细研究了单活性中心引发体系下氧化剂和氢离子浓度及聚合温度对接枝率的影响。结果表明,单活性中心引发体系较适宜的聚合温度为30℃,氧化剂浓度为4 mmol/L,氢离子浓度为1.5 mol/L,聚合过程中的接枝效率远高于双活性中心引发体系,此条件下制得的杂化粒子的接枝率为33.3%,且具有明显的温度响应性。

光引发点击化学接枝聚合制备多壁碳纳米管接枝聚(N-异丙基丙烯酰胺)及对聚偏氟乙烯超滤膜性能的影响

以紫外光引发的巯基-炔基绿色点击化学反应接枝聚合制备多壁碳纳米管接枝聚(N-异丙基丙烯酰胺)(MWCNTs-g-PNIPAM),通过改变接枝时间得到了不同接枝率的MWCNTs-g-PNIPAM,并通过非溶剂致相分离法(NIPS)制备了聚偏氟乙烯(PVDF)/MWCNTs-g-PNIPAM复合超滤膜。通过差示扫描量热分析和红外光谱、水接触角和水通量、场发射电子显微镜和机械拉伸试验研究了MWCNTs对PVDF超滤膜的结晶度和β相结晶含量、亲水性能、表面和断面形貌、拉伸强度和断裂伸长率的影响。结果表明,无金属催化剂的光引发点击化学在接枝时间为3 h时,PNIPAM的最大接枝率为9.76%,改善了碳纳米管与PVDF的界面结合力,使碳纳米管能够满足亲水性的同时还能在PVDF基体中良好分散。其中,β相结晶含量由纯PVDF膜的68.64%提升至95.32%,结晶度由46.30%提升至57.95%,拉伸强度与断裂伸长率分别由5.37 MPa和53.2%提升至7.85 MPa和54.32%,水接触角由95°降至69.75°,水通量由3.18 LMH提升至21.68 LMH。

The Arabidopsis PRCl-like ring-finger proteins are necessary for repression of embryonic traits during vegetative growth

Polycomb group genes play crucial roles in the maintenance of the transcriptionally silenced state of genes for proper cell differentiation in animals and plants. While components of the polycomb repressive complex2 （PRC2） are evolutionarily conserved and their functions are extensively studied in plants, PRCI differs considerably between animals and plants, and its functions in plants are as yet not well described. Previous studies have identified the Arabidopsis AtRINGla and AtRINGlb as homologues of the animal PRC1 subunit RING1. Here, we show that the Atringla Atringlb double mutant exhibits derepression of embryonic traits during vegetative growth. Accordingly, several key regulatory genes involved in embryogenesis and stem cell activity are ectopically expressed in the mutant. Furthermore, we show that the mutant phenotypes and increased expression of regulatory genes are enhanced by the PRC2 mutant c/f. Finally, we show that three homologues of the animal PRCl-subunit ring-finger protein BMI1, AtBMIIa, AtBMIlb and AtBMIlc, can bind with AtRINGla or AtRINGIb, and in addition, AtBMIlc can bind with LHP1. The Atbmila Atbmilb double mutant shows derepression of embryonic traits similar to that of the Atringla Atringlb double mutant. Interestingly, expression levels of AtBMIla, AtBMIlb and AtBMIlc are elevated in the Atringla Atringlb mutant and those of AtBMIlc, AtRINGla and AtRINGlb are elevated in the Atbmila Atbmilb mu- tant, suggesting a self-regulatory feedback mechanism. Taken together, our results illuminate crucial functions of the PRCl-like ring-finger components in stable repression of embryonic traits and regulatory genes for proper somatic growth.

Preparation and Properties of Polyacrylamide/Sodium Alginate Hydrogel and the Effect of Fe^(3+)Adsorption on Its Mechanical Performance

The preparation and application of functional hydrogels based on natural polysaccharides have always been a hot research topic.In this study,using acrylamide(AM)monomer,N,N'-methylene bisacrylamide(MBA)as crosslinking agent,potassium persulfate(K2S2O8)as initiator,in the presence of natural polysaccharide sodium alginate(SA),the PAM/SA hydrogel was prepared by free radical polymerization.Fourier transform infrared spectroscopy(FT-IR),swelling performance tests,scanning electron microscope(SEM),thermogravimetric analysis(TGA),UV-visible spectrophotometer,mechanical property measurements were carried out to analyze the composition,morphology,and performance of the hydrogels.The swelling behavior,dye adsorption performance,and the mechanical properties of PAM/SA hydrogels before and after Fe^(3+)adsorption were studied.The experimental results showed that the introduction of SA with 4.7%,7.8%,and 10.3%effectively improved the mechanical and dye adsorption properties of PAM composite hydrogels.The adsorption capacity of PAM/4.7%SA and PAM/10.3%SA hydrogels at equilibrium can reach 40.01 and 44.02 mg/g for methylene blue,which is higher than the value 13.58 mg/g of pure PAM hydrogel.The compressive strength of pure PAM hydrogel is 0.124 MPa.When the SA content is 4.7%,7.8%,and 10.3%,the compressive strength of the PAM/SA hydrogel was corresponding to 0.130 MPa,0.134 MPa,and 0.152 MPa,respectively.Fe^(3+)was introduced into the PAM/SA hydrogels,and PAM/SA/Fe^(3+)double-network hydrogels with excellent mechanical properties could be prepared by adjusting the SA content(4.7%,7.8%,and 10.3%),soaking time(1 h,2 h,3 h,4 h,5 h,6 h),and Fe^(3+)concentration(4.76%,7.41%,9.09%,and 13.04%).Under the same Fe^(3+)concentration of 9.09%and adsorption time of 4 h,the compressive strengths of the PAM/4.7%SA,PAM/7.8%SA,and PAM/10.3%SA hydrogels could reach 0.354 MPa,0.767 MPa,and 0.778 MPa,respectively.

Extraction Technology of Total Flavonoids from Pueraria lobata (Willd.) Ohwi and Content Determination of Pueraria lobata (Willd.) Ohwi at Different Altitudes

[Objectives]To optimize the extraction technology of total flavonoids from Pueraria lobata( Willd.) Ohwi. [Methods]The ultraviolet-visible spectrophotometry was used to determine the content of total flavonoids in Pueraria lobata( Willd.) Ohwi. With the puerarin as index,the reflux extraction and single factor test were employed to investigate the effects of temperature,time,ethanol concentration and solid-liquid ratio on the content of total flavonoids in Pueraria lobata( Willd.) Ohwi,respectively. Under the optimal extraction technology,the content of total flavonoids in Pueraria lobata( Willd.) Ohwi at different altitudes was determined.[Results] The optimum extraction process was as follows: 70%ethanol; solid-liquid ratio of 1∶ 30; 1 h reflux extraction. Under these conditions,the extraction rate of flavonoids in Pueraria lobata( Willd.) Ohwi was 11. 48%,the total flavonoids content of different kudzu parts was in the order of roots > stems > leaves,and the total flavonoids content of the sample at about an altitude of 1000 m was significantly higher than at the altitudes of 1400 m and 1700 m.[Conclusions]It was suggested that the Pueraria lobata( Willd.) Ohwi should not be cultivated as medicinal plant in too high mountains,and the stems and leaves of Pueraria lobata( Willd.) Ohwi could be used as raw materials for extracting total flavonoids.

Determination of Inorganic Elements in Roots, Stems and Leaves of Arctium lappa L. by ICP-OES

[Objectives] To determine the content of 20 inorganic elements in 18 samples of roots, stems and leaves from of Arctium lappa L. produced in different areas. [Methods] The wet digestion and technique of inductively coupled plasma emission spectrometry(ICP-OES) were used. [Results] 20 kinds of inorganic elements in the samples of A. lappa L. roots contained rich elements essential for human beings such as K, Ca, Na, P and trace elements Cu, Fe, Zn; heavy metals Pb, As, Cu, Cd in A. lappa L. samples did not exceed the limit, and Hg was not detected in all 12 samples; heavy metals in A. lappa L. roots harvested in 12 months did not exceed the limit. [Conclusions] Compared with the roots of A. lappa L., the inorganic elements in the stems and leaves of A. lappa L. were relatively less. The samples collected from Shuimo Town in Wenchuan County of Aba Prefecture with an altitude of 920 m showed little difference from samples collected from Qiongxi Town in Hongyuan County of Aba Prefecture with an altitude of 3 505 m in 20 kinds of inorganic elements.

Extraction Process of Green Pigment from Leaves of Arctium lappa L. by Ultrasound Assisted Method and Its Stability Study

[Objectives] The research aimed to extract green pigment from leaves of Arctium lappa L. and inspect its stability. [Methods] Ultrasound assisted method was used. [Results] Water bath temperature had little impact on green pigment, and Al^(3+), Cu^(2+), Mg^(2+) and Zn^(2+) in metal ions greatly affected green pigment, while Fe^(3+) had very little impact on the stability of green pigment. pH did not basically affect green pigment of A. lappa L. [Conclusions] The extraction rate and stability of green pigment from leaves of A. lappa L. were higher, and it was one of materials suitable for extracting green pigment.

Rheological Investigation with Palierne’s Model on a Polystyrene/Nylon 6 Blending Melt Compatibilized by a Polystyrene Grafted Maleic Anhydride

The dynamic rheological behaviors are measured by small amplitude oscillatory shear on a rotational rheometer for a polystyrene (PS)/nylon 6 (PA6) blend compatibilized by a polystyrene grafted maleic anhydride (PS-g-MAH). The storage moduli versus angular frequency (G’-ω) data of the blends are fitted by Palierne model. The Palierne model fits the data basically well for the PA6-rich blends and the 70/6/30 (PS/PS-g-MAH/PA6) blend. The fitting results show that the PS-g-MAH has a fine compatibilizing effect on the PS/PA6 blends.

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and orthogonal design were adopted to study the extraction technology for total phenols of leaves in Acanthopanax giraldii Harms. [Results]The optimum extraction conditions were determined as follows: extraction solvent( 70% methanol),solid-liquid ratio( 1∶ 35),and reflux extraction time( 60 min). Under these conditions,the yield of crude extract from total phenols of leaves in Acanthopanax giraldii Harms was 38. 67 mg/g.[Conclusions] The technology was simple,and of low cost and high extraction rate,suitable for the extraction of total phenols of leaves in Acanthopanax giraldii Harms.

银扇草再生体系的建立

为建立银扇草(Lunaria annua)体外再生体系,以其真叶为外植体,探讨消毒条件、植物生长调节剂组合及浓度对愈伤组织诱导、不定芽和不定根分化的影响;进一步分析了生根方式对成苗和幼苗生长的影响。结果表明,用75%乙醇消毒45秒配合0.1%升汞溶液消毒6分钟为银扇草叶片外植体最佳消毒处理;真叶愈伤组织诱导及不定芽分化的最适培养基为MS+0.5 mg·L^(-1)6-BA+2.0 mg·L^(-1)2,4-D,愈伤组织诱导率达93.37%,不定芽分化率达84.08%;最佳生根培养基为MS+0.1 mg·L^(-1)NAA,从接种叶片外植体到获得再生植株约90天。该研究建立了银扇草稳定的再生体系,为开发利用银扇草资源及挖掘功能基因奠定了基础。

利用室内质控与能力验证数据评定HBV DNA和HCV RNA测量不确定度

目的根据ISO15189《医学实验室—质量和能力的要求》,评估实时荧光定量PCR检测HBV DNA和HCV RNA引入测量不确定度的应用。方法采用室内质控数据计算HBV DNA和HCV RNA测量复现性引入的不确定度,采用国家卫生健康委员会临床检验中心能力验证结果计算HBV DNA和HCV RNA偏倚引入的不确定度,将二者合成计算出合成标准不确定度和扩展不确定度。结果HBV DNA测定低浓度相对合成标准不确定度为5.21%,高浓度为3.47%;低浓度相对扩展不确定度为10.42%,高浓度为6.94%(k=2)。HCV RNA测定低浓度相对合成标准不确定度为6.43%,高浓度为5.18%;低浓度相对扩展不确定度为12.86%,高浓度为10.36%(k=2)。HBV DNA低浓度(=3.45)扩展不确定度为0.36,小于目标不确定度(0.40),但高浓度(=6.38)扩展不确定度为0.44,高于目标不确定度(0.40);HCV RNA低浓度(=3.23)和高浓度(=5.24)扩展不确定度分别为0.42和0.54,均高于目标不确定度(0.40)。结论实时荧光定量PCR测定HBV DNA和HCV RNA引入不确定度使结果具有可比性,有助于检验报告的结果解释,并可作为检验质量持续改进的依据。

A review of covalent organic frameworks for metal ion fluorescence sensing

The concentration of metallic elements is closely associated with overall health.However,the discharge of untreated industrial wastewater can lead to metal-containing pollutants entering the human body through the food chain,disrupting the organism’s homeostasis and posing a risk to human health.Co-valent organic framework materials(COFs)have emerged as a novel porous material for detecting or adsorbing metal ions due to their unique pore structure,topological structure and flexible design.This paper summarizes the role,toxicity,and sources of metal ions related to human health,as well as the design,synthesis and performance of COFs fluorescent materials for detecting these elements.The inter-action mechanism of different fluorescent COFs and metal ions are discussed.Additionally,the remaining challenges and prospects of COFs fluorescence sensors are provided.We believe this review will be useful in directing the development of fluorescent COFs towards metal ions.

Stretchable and environment-resistant doubly crosslinked hydrogel for all-in-one supercapacitor and strain sensors

Despite their importance as components for flexible electronics,most stretchable hydrogels suffer from incomplete recovery after deformation,are prone to failure upon long-term repeated stretching,and cannot be exploited at subzero temperatures because of the freezing of their constituent water.Conse-quently,strategies for circumventing these drawbacks are highly sought after.This study describes the synthesis of a doubly(chemically and physically)crosslinked hydrogel from gelatin and methacrylic acid and demonstrates the suitability of this material for the fabrication of high-performance stretchable and environment-resistant supercapacitors and strain sensors.The performance of this supercapacitor(areal capacitance=1,210.2 mF/cm^(2) at a current density of 1 mA/cm^(2),maximum energy density=158.8μW.h/cm^(-1),maximum power density=659.5μW/cm^(2))was superior to that of most of integrated super-capacitors reported to date and was hardly affected by stretchable,low temperatures,bending,ice-cold water and strong acid/alkali solutions or long-term storage.Additionally,a strain sensor based on the above hydrogel was capable of accurately capturing human body motions when affixed to skin and recognising mouse movement(even in humid environments)after implantation into mouse legs.Our work may pave the way to high-performance stretchable and environment-resistant wearable electronics.

Multifunctional electroactive bio-adhesive for robustly-integrated wound therapy and postoperative wound-status warning and assessment

Wound abnormalities such as secondary wound laceration and inflammation are common postoperative health hazards during clinical procedures.The continuous treatment,healing induction,and real-time visualization of wound status and complications,including wound re-tearing,inflammation,and morphology,are key focal points for comprehensive healthcare.Herein,an on-demand quadruple energy dissipative strategy was proposed for the nanoengineering of a physically and chemically synergistic double-layer gelatin-based bio-adhesive(DLGel)by combining a multi-network adhesive layer and a versatile electroactive energy dissipative layer based on contrivable interlocking micro-pillar arrays and crosslinked polymer chains.The subtly multiple energy dissipation designs enable DLGel with robust adhesive strength to omnipotently wet and dynamic tissue,providing a basis for reliable wound closure.DLGel achieves comprehensive wound-healing induction through electrical stimulation and possesses reversible underwater light/thermal adhesion,excellent hemostatic performance,outstanding antimicrobial properties,and self-repair capability.Furthermore,a novel deep-learning strategy is creatively established to respond to mechanical deformation due to wound anomalies.This strategy translates biological information into visual graphics,providing real-time early warning and assessment of postoperative wound-abnormality/-morphology,such as laceration,inflammation,and necrosis.Therefore,DLGel and its associated signal collection and processing protocol enable the integration of reliable wound closure,wound healing,and real-time postoperative wound-status warning and assessment within the unobservable and undetectable“black box”regions in a context of non-clinical comprehensive therapy.

Ultrasound-driven BaTiO_(3) nanorobots patching immunologic barrier to cure chronic rheumatoid arthritis

The disruption and reconstruction of the TREM2^(+) tissue resident macrophage(TRM)barrier on the surface of synovial lining play a key role in the activation and"remission"of rheumatoid arthritis(RA),which engender the prediction of this immunologic barrier as a potential driver for the achievement of"cure"in RA.However,strategies to promote the reconstruction of this barrier have not been reported,and the effect of patching this barrier remains unidentified.On the other hand,appropriate piezoelectric stimulation can reprogram macrophages,which has never been exerted on this barrier TRM yet.Herein,we design piezoelectric tetragonal BaTiO_(3)(BTO)ultrasound-driven nanorobots(USNRs)by the solvothermal synthesis method,which demonstrates satisfactory electro-mechanical conversion effects,paving the way to generate controllable electrical stimulation under ultrasound to reprogram the barrier TRM by minimally invasive injection into joint cavity.It is demonstrated that the immunologic barrier could be patched by this USNR effectively,thereby eliminating the hyperplasia of vessels and nerves(HVN)and synovitis.Additionally,TREM2 deficiency serum-transfected arthritis(STA)mice models are applied and proved the indispensable role of TREM2 in RA curing mediated by USNR.In all,our work is an interesting and important exploration to expand the classical tetragonal BTO nanoparticles in the treatment of autoimmune diseases,providing a new idea and direction for the biomedical application of piezoelectric ceramics.

Preparation and properties of a double quaternary ammonium copolymer used in acid fracturing

Triethylamine(TEA),1,4-dibromobutane(C4H8Br2)and N,N-dimethylaminopropyl acrylamide(DMAPAA)were selected to synthesize a double quaternary ammonium cationic monomer(TDD).TDD,acrylamide(AM),2-acrylamido-2-methylpropane sulfonic acid(AMPS)and acrylic acid(AA)were used to create a quadripolymer(PAAT)that was characterized by FT-IR and ^(1)H NMR.Following that,the basic performance of thickened acid was assessed.The results revealed that PAAT outperformed PAA(copolymerized by AM,AMPS and AA)in terms of acid solubility,thickening performance,temperature resistance and shear resistance.Furthermore,this crosslinked acid containing PAAT was subjected to a series of performance evaluations.The viscosity of the crosslinked acid could be kept at 67 mPa$s at 160C after 90 min and the weight loss rate of crosslinked acid in acid-rock reaction at 60 min was 23%,indicating the temperature resistance and retarder performance of the crosslinked acid solution was significantly better than that of the thickening acid and the blank acid.A scanning electron microscopy experiment revealed that crosslinked acid has good corrosion ability and low damage to the reservoir.The above experimental results indicated that the thickener PAAT has a promising future application in acid fracturing of high-temperature and high-mineralization carbonate reservoirs.