两种简便测定尿肌酐排出量的方法

采用实验评定法,对同一天的尿液分别测定两个时段的尿肌酐量、晨尿肌酐量及全日尿肌酐量,并对两种简便测定尿肌酐的方法进行分析比较。结果表明,两段尿测定法与一段尿法均能比较客观代表全日尿肌酐量。     

白散泥稻田肥料效应试验研究

肥料是作物增产的重要因素。在农田施肥实践过程中,氮、磷、钾肥及配比用量因土壤不同而不同。笔者进行了白散泥稻田氮磷钾肥料效应的试验,采用3个因子、4个不同施肥用量的水平试验,推荐了最佳施肥用量。     

无机洗涤助剂的进展

介绍了国内外洗涤助剂的发展状况，传统洗涤助剂磷酸盐被限制，沸石类助剂有局限，层状硅酸钠以优良的洗涤性能，环保无污染的特点，成为洗涤工业的新宠。     

Preparation and characterization of metakaolin-phosphate cement

We prepared cold-setting cement with metakaolin from kaolin dehydrated at 800 ℃ and phosphate, and studied the phase composition, microstructure and setting reaction mechanism of the cementing material by means of infrared spectroscopy, thermogravimetry, X-ray diffraction, and scanning electron microscopy. The metakaolin-phosphate cement is predominantly amorphous, where the phases responsible for chemical setting are mainly amorphous aluminophosphate hydrates. The reactivity of metakaolin depends on the particle size. Metakaolin particles of 1.75 μm in D50 have an acid dissolution index up to 18.45%, and the reaction with phosphate at room temperature to form metakaolin-phosphate cement takes only 6 h. The so obtained cement shows a compressive strength of 92.5 MPa after 7 d and keeps its amorphous phase at 1 000 ℃, demonstrating better bonding and mechanical properties and higher stability at a medium or high temperature.     

含DMPP硫硝铵不同基追肥比例对小青菜硝酸盐累积及品质的影响

采用土培试验对含硝化抑制剂DMPP(3，4-二甲基吡唑磷酸盐)硫硝铵(ASN)氮肥(简称ASN DMPP)不同基追肥比例对小青菜硝酸盐累积及营养品质的影响进行了探讨．结果表明，等氮量(每千克土用0．5g氮)施用条件下基肥75％、追肥25％的基追肥比例不仅可提高蔬菜产量、降低硝酸盐含量，还可提高Vc、氨基酸、Zn、N、K含量，改善了蔬菜品质。     

Influence of casein phosphopeptide-amorphous calcium phosphate application,smear layer removal,and storage time on resin-dentin bonding

The aim of this study is to evaluate the influence of Tooth Mousse (TM) application, smear layer removal, and storage time on resin-dentin microtensile bond strength (μTBS). Dentin specimens were divided into two groups: (1) smear layer covered; (2) smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive (Clearfil SE Bond (CSE); Kuraray Medical, Tokyo, Japan), an all-in-one adhesive (G-Bond (GB); GC Corp, Tokyo, Japan), and a total-etch adhesive (Adper Single Bond 2 (SB); 3M ESPE, St. Paul, MN, USA), the specimens were stored for 3 d or 6 months in deionized water at 37 °C, and μTBS was tested and analyzed. With the exception of SB (no TM application) and GB, the μTBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage (P≤0.001). Bond strength of GB decreased significantly when using EDTA (3 d storage, P<0.05). TM application only increased the μTBS of GB (no EDTA) and SB (with EDTA) after 3 d (P≤0.02). Comparing the adhesives after 3 d of storage, CSE exhibited the greatest μTBS values followed by GB and SB (P≤0.02). The factors of adhesive, EDTA, and TM did not show any significant impact on μTBS when specimens were stored for 6 months (P>0.05). The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on μTBS of dentin bonds after a period of 6 months.     

Delivering MC3T3-E1 cells into injectable calcium phosphate cement through alginate-chitosan microcapsules for bone tissue engineering

研究目的：本研究应用海藻酸钠-壳聚糖微囊保护成骨细胞,接种到β-磷酸三钙/磷酸钙骨水泥（β-TCP/CPC）浆料中,使β-TCP/CPC骨修复材料具有一定的细胞活性,同时提高固化后材料的孔隙率和孔径,以最终实现提高β-TCP/CPC骨水泥的降解速度,加快成骨和骨修复。创新要点：本研究首次应用海藻酸钠-壳聚糖微胶囊包封成骨细胞与CPC浆料复合,复合后实现自动细胞释放,释放出的细胞具有良好的生物学活性。研究方法：（1）高压静电成囊法制备载小鼠成骨前体细胞（MC3T3-E1）的海藻酸钙和海藻酸钠-壳聚糖微胶囊;（2）微囊化MC3T3-E1细胞,进行体外培养,使用细胞计数试剂盒（CCK-8）检测细胞活性,并用钙黄绿素-AM（Calcein-AM）和碘化丙啶（PI）进行活死细胞双重染色;（3）微囊化MC3T3-E1细胞与β-TCP/CPC浆料复合培养后,激光共聚焦扫描显微镜和环境扫描电子显微镜观测细胞在材料上的释放、粘附,CCK-8法检测材料上细胞的活力,碱性磷酸酶（ALP）检测观察细胞的分化状况,茜素红染色观察释放细胞的矿化能力。重要结论：海藻酸钠-壳聚糖微胶囊可作为可注射磷酸钙骨水泥内部接种成骨细胞并实现细胞释放的良好载体,释放出的成骨细胞具有良好的生物学活性。     

A facile approach to construct hybrid multi-shell calcium phosphate gene particles

The calcium phosphate (CaP) particles have attracted much attention in gene therapy. How to construct stable gene particles was the determining factor. In this study,hybrid multi-shell CaP gene particles were successfully constructed. First,CaP nanoparticles served as a core and were coated with DNA for colloidal stabilization. The ξ-potential of DNA-coated CaP nanoparticles was -15 mV. Then polyethylenimine (PEI) was added and adsorbed outside of the DNA layer due to the electrostatic attraction. The ξ-pot...     

三丙酮胺对离体大鼠心肌缺血的保护作用

离体大鼠心脏灌流实验表明,三丙酮胺(TAA)能改善缺血心肌的收缩功能,降低缺血心叽中过氧化产物丙二醛(MDA)含量,保护超氧化物歧化酶(SOD)的活性,提高胞浆肌酸磷酸激酶(CPK)含量,并有效地抑制CaCl_2诱导的血小板聚集作用.     

利用荷移光谱法测定可待因片剂的含量

本文研究了可待因与 7,7,8,8-四氰基对二次甲基苯醌 (TCNQ)的荷移反应 ,对反应条件进行了优化 .在丙酮介质中 ,二者在室温 (30℃ )中 30min即可形成 1:1荷移络合物 .分别在74 3和 84 0nm处有较强光吸收 .可待因浓度在 0 .6～ 7(g·mL-1范围内符合比尔定律 ,其表观摩尔吸光系数在 2 .3× 10 4～ 5 .1× 10 4;方法的相对标准偏差为 1.8%～ 2 .4 % (n =9) .